Dissertations / Theses: 'Theileria parva'

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Heussler, Volker Theo. ""Theileria parva" and "Theileria annulata" : parasite survival strategies and host cell transformation /." Bern : [s.n.], 2001. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.

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Watt, Darren Milton. "Studies on Theileria parva in Rhipicephalus appendiculatus." Thesis, University of Edinburgh, 2000. http://hdl.handle.net/1842/30040.

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Aspects of the association between the haemoprotozoan parasite Theileria parva and it's tick vector Rhipicephalus appendiculatus were investigated. Examination of dissected and stained tick salivary glands by light microscopy is the traditional technique for assessing tick infections. Field collected ticks are often alcohol preserved, or die before they are returned to the laboratory which precludes dissection. A PCR was developed which detected the parasite within alcohol preserved ticks. Parasite detection by this method was highly correlated with that of microscopy. The technique was then used on cattle and tick samples collected from three field sites in Kenya to assess T. parva prevalence. One field site (Limuru) had been vaccinated with a live 'infection and treatment' vaccine, while the other two areas (Kakamega and Kitale) were unvaccinated at that time. Limuru showed lower T. parva prevalence than may have been expected if a carrier state had been created as a result of vaccination. All the cattle sampled in Kakamega and Kitale were infected with an unidentified Theileria species and tick infections ranged from 1.5% to 20% respectively. The results from the three areas were discussed in relation to the effect of the vaccine in Limuru and the implications of vaccine introduction into Kitale and Kakamega. T. parva infection levels in tick salivary glands can the characteristically represented by a negative binomial distribution. The dynamics of infection needs to be better understood for a number of reasons. Ticks are used as the raw material for the 'infection and treatment vaccine' and the production process could be greatly improved by reliably obtaining a greater abundance of less aggregated tick infections. Another reason is that mathematical models for disease prediction and control would greatly benefit by increased knowledge of parasite dynamics through the tick T. appendiculatus infected with T. parva and control, uninfected ticks (for comparison) were dissected at regular times throughout their moult, fixed and embedded in plastic.

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Hemmink, Johanneke Dinie. "Antigenic diversity in Theileria parva in vaccine stabilate and African buffalo." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/9622.

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Theileria parva is a tick-borne intracellular protozoan parasite which infects cattle and African buffalo in Eastern and Southern Africa. Cattle may be immunised against T. parva by the infection and treatment method (ITM), which involves inoculation with live sporozoites and simultaneous treatment with oxytetracycline. One such ITM vaccine is the Muguga Cocktail, which is composed of a mixture of three parasite stocks: Muguga, Serengeti-transformed and Kiambu 5. Although the vaccine has been used with success in the field in several areas in Eastern Africa, there is evidence that vaccination using cattle-derived parasites does not always provide adequate protection against buffalo-derived T. parva. A number of T. parva antigens recognised by CD8+ T cells from cattle immunised by ITM have been identified in previous studies. A proportion of these antigens show a high degree of sequence polymorphism and allelic diversity is believed to be much greater in buffalo-derived T. parva than in cattle-derived parasites. The present study focussed on the development and application of a deep sequencing technique for characterising genotypically heterogeneous T. parva DNA samples. A panel of genes encoding CD8+ T cell antigens was used as the basis of a multi-locus sequence typing system (MLST) built upon Roche 454 amplicon sequencing technology. This system was validated using parasite stocks of known composition and then utilised to investigate genetic and antigenic diversity in vaccine stabilates and samples derived from African buffalo. The MLST profile obtained for the Muguga Cocktail stocks was compared to those of African buffalo in two geographically separated sites and was also compared with micro/mini-satellite DNA profiles of Muguga Cocktail stocks. The three components of the T. parva Muguga Cocktail vaccine were found to have limited genotypic and antigenic diversity using both methods. The composition of vaccine batches produced in a single production run (ILRI0801-ILRI0804) was shown to be relatively consistent. In contrast, the composition of the component stocks was shown to alter following passage through cattle and ticks. The deep multi-locus sequence profile and satellite DNA profile established in this study may be used as a reference for comparison with future vaccine batches. It is suggested that formulation of a new cocktail vaccine containing three parasite clones selected on the basis of genotypic and antigenic divergence may well provide protection comparable to that obtained with the Muguga Cocktail. The components of such a vaccine could readily be distinguished and the composition of vaccine batches monitored, thus allowing improved quality control and greater consistency of the vaccine. Genetic and antigenic diversity was found to be very high in parasite populations from African buffalo from the Kruger National Park, South Africa and the Ol Pejeta conservancy, Kenya. The estimated average genetic ‘distance’ between any two alleles in the Kruger National Park and within the Ol Pejeta conservancy was very similar for all six genes investigated. Many of the identified alleles were ‘private’ to either the buffalo from Ol Pejeta or the Kruger National Park and many of these alleles were present in several individuals in one location. Principal co-ordinate analysis and phylogenetic investigation of several antigen-encoding loci indicated that extant buffalo parasite populations are geographically sub-structured although some of the underlying diversity may reflect ‘ancient’ polymorphism in an ancestral population. A subset of the CD8+ T cell antigens examined exhibited extensive antigenic polymorphism while others were highly conserved at the amino acid level. These conserved genes may represent good candidates for the development of next generation vaccines, as strain specificity may be overcome if protective CD8+ T cell responses could be generated against these conserved antigens. This would enable the use of sub-unit vaccines in areas where cattle co-graze with buffalo. Theileria sp (buffalo) was identified in cell lines isolated from cattle, indicating that this parasite can transform bovine lymphocytes and may therefore be implicated in pathology in cattle. Phylogenetic analysis of T. parva and T. sp (buffalo) clones using the 5S subunit ribosomal RNA gene, Tp6, Tp7 and Tp8 showed a clear distinction between the two parasite species. These genes could thus be considered as candidates for an improved diagnostic test for T. parva in South Africa.

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Mining, Simeon Kipkoech. "Theileria parva : the investigation of maternally derived immunity in calves." Thesis, University of Liverpool, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317186.

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Malu, Muia Ndavi. "Production and role of #gamma#-interferon during Theileria parva infections." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259628.

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6

Ochanda, Horace. "Factors affecting the population dynamics of Theileria parva in rhipicephalid ticks." Thesis, University of Warwick, 1994. http://wrap.warwick.ac.uk/3979/.

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A series of experiments were carried out to investigate some of the poorly understood aspects of the life cycle of Theilefid parva in its rhipicephalid tick vectors. The first series of experiments established that nymphae infected as larvae develop lower levels of infection compared to adults infected as nymphae, while female ticks develop higher infections than males. It was shown that the period of development of sporoblasts into mature sporozoites took on average four days in the nyrnphal ticks compared to five days in the adult ticks. Infection levels developing in different tick instars or sexes appeared to be related to the number and position of type III salivary gland acini. The second series of experiments established that there were considerable differences in the vector competence of different stocks of Rhipicephalus appendiculatus and R. zambeziensis for the transmission of Muguga and Boleni stocks of Yheileria parva. Finally the study established that survival of infected R. appendiculatus and the T parva they harboured was longer under quasi-natural climatic conditions compared to all the laboratory conditions examined. Basically, infection levels in the ticks did not affect the duration of survival of the ticks, however, survival of the parasite appeared to be influenced by the intensity of infection in the tick as the parasites diminished more rapidly in ticks having high infections than in those having low infections. Nymphae and the parasites they harboured survived for shorter periods compared to the adult ticks and their infections. Data generated from these series of experiments will be used to develop quantitative models of T parva dynamics in the tick vectors. The relative importance of the factors influencing the levels of infection developing in the tick vector were analysed statistically by the logistic and Poisson regression. Factors found to play a significant role included tick instar or gender, tick stock, parasite stock, the ambient climatic conditions in which infected ticks survived and the day of tick repletion after infection of the bovine host. Individually, the bovine host or its piroplasm parasitaernia were found to be poor predictors of infection levels developing in the salivary glands of the tick vector. However, when piroplasm parasitaernia was included in a model lacking the days post-repletion variable, the bovine host factor became significant.

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Li, Xiaoying. "T cell receptor repertoires of immunodominant CD8 T cell responses to Theileria parva." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/19552.

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Previous research has provided evidence that CD8 T cells mediate immunity against infection with Theileria parva. However, the immunity induced by one parasite strain doesn‟t give complete protection against other strains and this is associated with parasite strain specificity of the CD8 T cell responses. There is evidence that such strain specificity is a consequence of the CD8 T cell responses of individual animals being focused on a limited number of immunodominant polymorphic peptide-MHC determinants. Dominant responses to the Tp2 antigen have been demonstrated in animals homozygous for the A10 MHC haplotype. Three Tp2 epitopes recognised by A10+ animals (Tp249-59, Tp250-59 and Tp298-106) have been defined. This project set out to investigate the dominance of these epitopes and to examine the T cell receptor (TCR) repertoires of the responding T cells. The specific objectives were to: (i) Determine the dominance hierarchies of the three defined Tp2 epitopes in both A10-homozygous and -heterozygous cattle. (ii) Examine the clonal repertoires of epitope-specific responses by analysis of TCR gene expression. (iii) Isolate full-length cDNAs encoding TCR α and β chain pairs from T cell clones of defined epitope specificity and use them to generate cells expressing the functional TCRs. Using MHC class I tetramers the relative dominance of CD8 T cell responses were found to differ between A10-homozygous and heterozygous cattle. All A10-homozygous cattle examined had detectable responses to all 3 Tp2 epitopes, the Tp249-59 epitope consistently being the most dominant. By contrast, only some A10-heterozygous cattle had detectable responses to Tp2 and when present the response was specific only for the Tp298-106 epitope. Analyses of the sequences of expressed TCR β chains showed that the responses in individual animals were clonotypically diverse, but often contained a few large expanded clonotypes. The TCRs of Tp298-106–specific T cells showed preferential usage of the Vβ13.5 gene and the frequent presence of a “LGG” motif within the CDR3 of the B chain. A conserved (public) TCRβ clonotype shared by the Tp250-59-specific CD8 T cells from all A10-homozygous cattle was identified. The TCRα chains co-expressed with this public TCRβ clonotype were identified for a number of T cell clones. Lentivirus transduction of Jurkat cells with three full-length TCR α and β chain pairs resulted in successful expression of one of the α/β chain pairs as a functional TCR, thus providing the basis for future work to generate bovine T cells expressing defined TCRs in vitro.

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Chaisi, Mamohale E. "Diversity of Theileria parasites in African buffalo (Syncerus caffer) and the challenge of differential diagnosis." Thesis, University of Pretoria, 2012. http://hdl.handle.net/2263/31238.

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In South Africa, the diagnosis of Theileria parva in cattle and buffalo has been complicated by the presence of mildly pathogenic and non-pathogenic Theileria spp. This can lead to inaccurate diagnostic results and confuse the epidemiology of theileriosis. The aims of this study were to identify and characterize the 18S rRNA genes of novel Theileria spp. of the African buffalo, as well as to test new gene targets that will allow for the development of more accurate diagnostic tests for the identification of T. parvainfections in cattle and buffalo. Buffalo blood samples originating from different geographical regions in South Africa and from Mozambique were screened for the presence of Theileria spp. by the reverse line blot (RLB) hybridization assay. A total of six Theileria spp., namely T. parva, Theileria sp. (buffalo), Theileria mutans, Theileria velifera and Theileria buffeli, were identified from the buffalo samples. These occurred mainly as mixed infections. Some of the samples hybridized only with the Theileria/Babesia genus specific probe that is used in the RLB assay, and not with any of the species-specific probes used, suggesting the presence of novel genotypes or species. The full-length 18S rRNA genes of parasites from selected samples were characterized by cloning and sequencing. In addition to the identification of 18S rRNA gene sequences that were similar to published Theileria spp. of cattle and buffalo, we identified Theileria sp. (bougasvlei), and novel 18S rRNA gene variants of T. mutans, T. velifera, T. bufJeli. This variation explained why the RLB hybridization assay failed to detect these species in some of the analysed samples. As extensive variation was observed within the T. mutan group, specific RLB oligonucleotide probes were designed from the V 4 hypervariable region of the T. mutans-like 1 and 2/3 18S rRNA gene sequences. Unfortunately these cross-hybridized with T. mutans target DNA and could not be used to screen buffalo samples to determine the occurrence of these genotypes in buffalo in South Africa. This problem could be solved by designing probes from a more variable area of the 18S rRNA gene of the T. mutans groups. Alternatively, a quantitative real-time PCR (qPCR) assay could be used for differentiation of these genotypes as it is more sensitive than the RLB assay. Despite the variation observed in the full-length T parva 18S rRNA gene sequences, the area in the V 4 hypervariable region where the T parva RLB and real-time PCR hybridization probes were developed was relatively conserved between sequences obtained in this study. The existing T parva-specific qPCR assay was able to successfully detect all T parva variants identified in this study and, although amplicons were obtained from Theileria sp. (buffalo) and Theileria sp. (bougasvlei) DNA, these species were not detected by the T parva-specific hybridization probes. The sequences of the other Theileria spp. and the novel genotypes identified in this study under the probes were also different from that of T parva and therefore these species do not compromise the specificity of the T parva 18S qPCR assay. In order to determine the sequence variation and phylogenetic positions of T buffeli spp. of the African buffalo, we cloned and sequenced their 18S rRNA gene and complete internal transcribed spacer (ITS). We identified novel T buffeli-like and T sinensis-like 18S rRNA and ITS genotypes from buffalo originating from two different geographical regions in South Africa. There was extensive sequence variation between these novel South African genotypes and known T buffeli-like and T sinensis-like genotypes. The presence of organisms with T buffeli-like and T. sinensis-like genotypes in the African buffalo is of significant importance, particularly to the cattle industry in South Africa as these animals might act as sources of infections to naIve cattle. Recently, a qPCR assay based on the cox III gene was developed for the diagnosis of Theileria spp. in cattle. This test detects and differentiates six Theileria spp. in cattle. We evaluated the use of this assay for the detection of Theileria spp. in buffalo. The results of the cox III qPCR were compared to those of the RLB and 18S qPCR for the simultaneous detection and differentiation of Theileria spp. of the African buffalo, and for the specific detection of T parva, respectively. The cox III genes from selected samples with non-specific melting peaks were characterized by cloning and sequencing. Extensive sequence variation in the cox III gene was observed between and within species. The T mutans group was the most variable. The qPCR assay could be further improved by designing new primers and probes using all known cox III gene sequences of Theileria spp. Of buffalo and cattle. This study highlights the complexity of the diagnosis of T parva in cattle and buffalo in South Africa. It provides invaluable information towards the development of an improved molecular diagnostic assay for T parva and co-infecting species in cattle and buffalo in South Africa which will assist the veterinary regulatory authorities in the control of Corridor disease in South Africa.
Thesis (PhD)--University of Pretoria, 2011.
Veterinary Tropical Diseases
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Tosas, Auguet Olga. "Interactions amongst the community of endemic pathogens of African cattle : a longitudinal study in south east Uganda." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/1517.

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The work presented in this thesis is focused upon the community of endemic pathogens of African cattle in Sub-Saharan Africa, which has long constrained livestock production in these areas. The first aim of this work is to investigate whether the pathogen community as a whole shapes the ensuant epidemiology and morbidity which are currently attributed to any of its individual pathogens. The second aim is to determine if a greater understanding of the interactions present amongst genetically distinct parasites of the same species can be used to better explain epidemiological features that are at present poorly understood. Emphasis is placed on examining spatial variation in the epidemiology of Theileria parva, a tick-transmitted protozoan that causes East Coast Fever. To achieve these aims, this work examines field data collected from a large and comprehensive study conducted in south east Uganda. Through application of apposite statistical techniques and mathematical modelling, aspects of the complex relations amongst the pathogen community and their environment are explored. Evidence is presented that demonstrates the paramount role of the pathogen community as a whole in shaping the infection dynamics and pathogenicity of any of its individual components. By focusing on a single member of this pathogen community (Theileria parva), some of the influences of host, vector, geographical location, temporal dynamics and intra-species pathogen interactions are elucidated. Application of a polymorphic molecular marker to Theileria parva infected blood samples and the use of Cox proportional hazard analysis, show variability in the survival of infections in cattle in high and low tick challenge areas. Moreover infection survival, which plays a pivotal role in parasite transmission, is shown to be a function of the interactions established amongst genetically distinct co-infective parasites. In consequence, vector intensity alone is insufficient to develop reliable transmission models which can accurately predict the epidemiology of the parasite inside and outside enzootic belts. Finally, a theoretical model is developed which, based upon the field evidence obtained throughout this work, provides a possible explanation for the mechanics of T. parva survival in cattle. In summary, this thesis makes a case that consideration of both inter- and intra-species pathogen interactions, can greatly augment understanding of the epidemiology of these pathogen communities. An integrated approach to pathogen dynamics can better equip an integrated approach to control of important diseases of African cattle.

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Guergnon, Julien. "Etude des voies de signalisation participant à la survie des lymphocytes B et T transformées par les parasites Theileria parva et Theileria annulata." Paris 7, 2005. http://www.theses.fr/2005PA077026.

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Sibeko, K. P. (Kgomotso Penelope). "Improved molecular diagnostics and characterization of Theileria parva isolates from cattle and buffalo in South Africa." Thesis, University of Pretoria, 2010. http://hdl.handle.net/2263/24872.

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The aim of this study was to improve the official diagnostic test package in South Africa for detection of Theileria parva infections in cattle and Cape buffalo (Syncerus caffer) and to investigate the presence of cattle-type T. parva parasites in buffalo and cattle in South Africa. To improve diagnosis of T. parva infections, a T. parva-specific real-time polymerase chain reaction (PCR) assay based on hybridization probe technology was developed. Oligonucleotide primers and hybridization probes used in the assay were designed based on the 18S ribosomal RNA (rRNA) gene. The primers amplify T. parva and Theileria sp. (buffalo) DNA but the hybridization probes specifically detect T. parva amplicons. Because of the high sequence similarity between the T. parva and Theileria sp. (buffalo) 18S rRNA genes, amplification of Theileria sp. (buffalo) DNA could not be avoided; no other bovine blood pathogens tested were amplified by these primers. The real-time PCR assay demonstrated superior sensitivity compared to other molecular tests used in detection of T. parva infections, reliably detecting the parasite in carrier animals with a piroplasm parasitaemia as low as 8.79x10-4% with minute template DNA input. The assay requires less time to perform with a low risk of contamination because of the closed-tube system that does not require handling of amplicons for post-PCR analysis. The presence of cattle-typeT. parva parasites in buffalo and cattle was investigated using restriction fragment length polymorphism (RFLP) profiles of PCR products and sequences of the parasite genes which code for the antigenic proteins p67, p104, and the polymorphic immunodominant molecule (PIM). Cattle-type p67, p104 and PIM alleles were identified from three T. parva samples obtained from cattle from a farm near Ladysmith in the KwaZulu-Natal Province. These cattle-type alleles were identical to those previously identified from a cattle-derived T. parva stock, T. parva Muguga, a parasite stock that causes East Coast fever (ECF) in Kenya; however, ECF was not diagnosed in animals in this farm. Cattle-type alleles identical to those previously reported were not identified from T. parva buffalo samples, but variants of p67 allele 1 as well as p104 allele 1, both previously obtained from T. parva Muguga, were identified. It is not known if parasites that possess these variants can cause disease, and the risk of their adapting to cattle as in the case of ECF and January disease needs to be evaluated. Furthermore, these findings suggest that cattle-like alleles may not be exclusively associated with cattle-derived T. parva parasites. Most of the p67, p104 and PIM gene sequences obtained in this study were not identical to known sequences; furthermore, novel alleles were identified, demonstrating extensive genetic diversity in the South African T. parva parasite population in buffalo. The significance of the parasites that possess ‘novel’ alleles in the epidemiology of theileriosis in South Africa still needs to be determined. The identification of variants and novel alleles reveals that p67, p104 and PIM gene PCR-RFLP profiles are more complex than previously thought and the classification of buffalo- and cattle-derived T. parva parasites in South Africa based on p67, p104 and PIM gene profiles would not be possible. Identification of more reliable markers that can be directly associated with the theilerial disease syndromes remains a challenge.
Thesis (PhD)--University of Pretoria, 2009.
Veterinary Tropical Diseases
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Borchers, Lauren-Leigh. "Genotyping a novel Theileria parva candidate vaccine antigen in cattle- and buffalo-derived parasites." Diss., University of Pretoria, 2020. http://hdl.handle.net/2263/77442.

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Theileriosis is a lymphoproliferative tick-borne disease of cattle and other wild ruminants, caused by infection with a protozoan, Theileria parva. The disease is prevalent in cattle throughout Central, East and southern Africa, where it threatens 50% of the cattle population. There are various control and treatments methods used against theileriosis; however, they all have limitations. The available live immunisation method, the Muguga cocktail, does not confer protection against all field strains, particularly buffalo-derived T. parva. Attempts to develop a subunit vaccine have been promising but these have shown limited efficacy due to antigenic and genetic diversity of T. parva strains in the field. Thus, there is a need to search for additional vaccine candidates. A related study has identified potential vaccine candidates using a genome-wide in silico approach. Consequently, the aim of this study was to genotype one of the identified antigens. TP04_0028 was selected for genotyping among candidate genes with high expression levels in the schizont stage of both cattle- and buffalo-derived T. parva isolates. Specific primers were designed and optimised for PCR amplification and sequencing. The comprehensive analysis of sequences from 17 cattle- and 17 buffalo-derived T. parva, from East and southern Africa, showed conservation in 12 (60%) of the 20 TP04_0028 predicted epitopes, in both parasite types, irrespective of geographical origin. Eighteen of the 20 predicted epitopes are conserved amongst different BoLA alleles and an area of 7 overlapping epitopes could be the starting point for initial experimental evaluation of the immunogenic properties of TP04_0028. Once the immunogenicity of these epitopes have been tested and the extent to provide protection from cattle- and buffalo-derived infections have been verified, they may be considered for vaccine development.
Dissertation (MSc (Veterinary Science))--University of Pretoria, 2019.
Veterinary Tropical Diseases
MSc (Veterinary Science)
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Thompson, Bronwen Eleanor. "Occurrence of Theileria parva infection in cattle on a farm in KwaZulu-Natal, South Africa." Diss., Electronic thesis, 2007. http://upetd.up.ac.za/thesis/available/etd-11012007-133653/.

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Mwamuye, Micky Mwananje [Verfasser]. "Delimiting Theileria parva strain diversity towards targeted and unified approaches in the control of T. parva cattle infections / Micky Mwananje Mwamuye." Berlin : Freie Universität Berlin, 2021. http://d-nb.info/1241540713/34.

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Jennings, Amy Elizabeth. "Epidemiology and clinical outcomes associated with Theileria parva in a cohort of East African short horn zebu calves." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/12226.

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This thesis takes data from the Infectious Diseases of East African Livestock (IDEAL) project. The project was a longitudinal calf cohort study based in Western Kenya. Indigenous short horn zebu calves were recruited at birth and then visited every 5 weeks through their first year of life. The aim of this thesis was to improve understanding of the epidemiology of Theileria parva, with a particular focus on variation in host response. 362 of the 548 calves in the study cohort were classified as having seroconverted to T. parva, and 381 to T. mutans before 1 year old. The diagnostic tools used to identify exposure in the calf were compared, and environmental and calf level risk factors associated with the age at seroconversion were sought. Decreased elevation of the homestead and increased size of the herd were found to be significantly associated with an increased hazard of seroconversion to T. parva. There was little variation in hazard of T. mutans captured across the study site. The outcome ‘clinical episode’ was used to classify whether the calf was ill at each routine visit. A large number of calves passed through their first year of life without clinical disease being observed, and a minority of calves experienced the majority of clinical episodes. Multiple clinical episodes were apparently related in time, suggesting that they were due either to the same or connected pathogenic processes. A low birth weight, larger herds, and older farmers were all risk factors for being a sick calf. Both high helminth burden and T. parva were found to be significantly associated with clinical disease at a population level. A lot of variation was seen in the clinical presentation of disease. The clinical signs associated with fatal East Coast Fever (ECF), the clinical disease associated with T. parva infection, were found to be very variable. Although this may have been partly due to the varying times in the disease process that calves were observed prior to death, the complication of the clinical picture was also suggested to be due to co-infections. 71% of the cohort was infected with T. parva in their first year of life, but only a fraction (8.7%) went on to die from that infection. Unmatched and matched nested case control study formats were used to investigate the risk factors associated with death following T. parva infection (ECF death) in these calves. It was found that being infected young was a risk factor for death. Calves owned by older farmers were also at higher risk of death following infection. Going out grazing was found to be protective, and equivocal evidence was found for an association between prior T. mutans exposure and reduced odds of ECF death. If these initial findings from this work are correct, it is likely that T. mutans is influencing the clinical presentation of T. parva in endemic regions.

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Taracha, Evans Lumbasi Nabwera. "Investigation of cytotoxic T-lymphocyte responses of cattle to Theileria parva by limiting dilution analyses." Thesis, Brunel University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293004.

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Geysen, Dirk. "The application of molecular biology techniques to analyse diversity in Theileria parva populations in Zambia." Thesis, Brunel University, 2000. http://bura.brunel.ac.uk/handle/2438/5303.

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Theileria parva is a complex protozoan parasite causing East Coast fever in Eastern and Central Africa. Vaccination using live parasites is an effective control measure and has been used in Zambia based on locally isolated and introduced T. parva stocks. Diversity among T. parva populations was investigated in parasites from two Zambian provinces with different disease epidemiologies and control histories. Isolates from the pre-vaccination era, local and exotic stocks used for vaccination, and one recent field isolate were cloned and passaged in vitro to study genomic stability over time. The results of the data from three genome-wide probes indicate a marked homogeneity and stability among the Zambian isolates in contrast to East African isolates. Results from Southern blot profiles and the polymorphic immunodominant molecule (PIM) sequence analysis suggest a common origin for the Zambian isolates from the pre-vaccination era, except for one isolate (Zam5) from Southern Province. This isolate showed characteristics suggesting a buffalo origin. Assays for genotype characterisation were developed using five allelic markers. Multilocus characterisation revealed identical profiles in a recent Zambian isolate from Southern Province and two components of an exotic cocktail vaccine, indicating the escape of one of the vaccine stocks in the field. Characterisation of T. parva field populations by RFLP-PCR assays after immunisation revealed the presence of dominant genotypes from those that had been used for vaccination. Circumstantial evidence for the involvement of one of the exotic vaccine parasites in epidemics in Southern Province is presented and a hypothesis formulated for the rapid spread of this genotype. Analysis of the characterisation data suggested the existence of two groups of T. parva parasites of different origin. The classic T. parva group, characterised by a dimorphism of the p150, p104 and p32 loci and the absence of a p67 insert and a buffalo-derived group which showed a polymorphism of p150, p104 and p32 and the presence of a p67 insert. There is evidence that recombination occurs, resulting in parasites that have characteristics of both groups. The relevance of these recombinant parasites in the epidemiology of the disease seems low. Characterisation of larger samples from areas of regular buffalo-cattle contact is necessary to clarify this. Sequence analysis of the most discriminative locus (PIM) was undertaken and gene conversion could be the main mechanism generating diversity. A more appropriate nomenclature for T. parva is proposed based on the growing evidence of molecular differences among isolates and stocks.

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Ehrfeld, Angelika Y. B. [Verfasser]. "Isolierung und Charakterisierung des Aktin- Gens des intrazellulaeren Parasiten Theileria Parva / Angelika Y. B. Ehrfeld." Karlsruhe : KIT-Bibliothek, 1989. http://d-nb.info/1165143038/34.

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Musembi, Susan Mbithe. "Immunological assays relevant to definition of bovine theileria parva-specific cytotoxic CD8+ T cell responses." Thesis, Brunel University, 2012. http://bura.brunel.ac.uk/handle/2438/7171.

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A major objective in Theileria parva subunit vaccine development is to induce a vaccine antigen specific response mediated by cytotoxic CD8+ T cells (CTL). Therefore it is essential to be able to measure the frequency of the responding CD8+ T cells after vaccination and correlate it with a clinical outcome on challenge. Recently concluded immunogenicity and efficacy studies of T. parva specific CTL antigens showed successful induction of CTL responses in some animals, which correlated with reduced disease severity after challenge. To provide correlates of immunity antigen-specific CD8+ T cell mediated IFN-γ responses and CTL lytic responses were measured over the course of the experiments. Several challenges presented in these trials aimed at optimising vaccine efficacy. While the IFN-γ ELISPOT is a sensitive and reliable assay widely used in vaccine research, the use of chromium/indium release assay remains to be the only assay in use that measures T. parva-specific CTL activity. Hence the overall goal of the study was to develop novel reagents and novel assays to identify parasite-specific CD8+ T lymphocytes with lytic potential. To address this objective, bovine perforin, granzymes A and B, as specific effector proteins expressed in activated CTL were cloned and expressed using a baculovirus expression system. Sequence analysis of the cloned cDNAs showed the isolated cDNA belonged to the perforin and granzyme sub-families respectively. Perforin cDNA demonstrated 85% homology to human perforin with presence of conserved regions resembling calcium binding motif, membrane attack complex component as well complement protein. The sequences encoded by the cloned granzyme A and B cDNAs have the features of a trypsin like serine protease and demonstrates over 70% homology to the human cDNA over the active enzyme region as well catalytic residues characteristic of serine proteases. The expressed polypeptides of all three proteins were used to produce specific antibodies for use as reagents in immunoassays including ELISpot and intracellular staining for flow cytometric analysis. While the antibodies showed reactivity to the recombinant proteins, these reagents displayed different functionality in the recognition of the native protein. Peptide-major histocompatibility complexes (MHC) class I tetrameric complexes (tetramers) are proving invaluable as fluorescent reagents for enumeration, characterisation and isolation of peptide-specific CD8+ T cells and have afforded advantages to phenotype antigen-specific T cells with minimal in vitro manipulation. Fluorescent bovine tetramers were shown to specifically stain antigen-specific CTL by directly binding the T cell receptor (TCR). Analyses of CD8 T-cell responses in live-vaccine immunised cattle also showed that this method is robust and demonstrates changes in the kinetics and specificity of the CD8+ T cell response in primary and secondary infections with T. parva. On average, results of functional assays and tetramer staining followed parallel trends, measured roughly the same populations and allowed for surface and intracellular staining for CD8 T cell marker and perforin, respectively, demonstrating a method that reliably quantifies the frequency, phenotype and function of specific CD8+ T cells. The technical simplicity, rapidity and ability of the flow cytometric technique described in this thesis to measure low frequency antigen-specific responses suggests that tetramer staining, combined with functional assays could be broadly applicable to the valuation of vaccination efficacy to determine which protocols are most successful in inducing CTL responses.

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20

Mahlobo, Bongiwe Priscah. "Functional annotation of selected Theileria parva hypothetical proteins without known sequence descriptions and pathway associations." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/62576.

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Cattle theileriosis is infamous for hampering the economic development of south, central and east African countries due to the exorbitant numbers of cattle mortalities. The disease is caused by Theileria parva, a tick-transmitted hemoprotozoan parasite belonging to the phylum Apicomplexa. Infection of cattle with the cattle-derived T. parva isolates is responsible for the East Coast fever while infections by buffalo-derived isolates result in the Corridor disease. A transcriptome study comparing two T. parva isolates, representing cattle- and buffalo-derived parasites, identified several differentially expressed transcripts, of which 54.4% encode hypothetical proteins (HPs). These proteins are believed to be crucial in understanding the disease syndromes caused by T. parva infections; hence, the purpose of this study was to annotate their function. The 309 proteins analysed in this study exclude HPs that were assigned sequence descriptions and had pathway associations with initial screenings using Blast2GO and KEGG pathway analyses. For function prediction, an integrated bioinformatics approach was employed which facilitated sequence comparison, protein family classification, domains discovery, sub-cellular localisation, protein-protein interactions and identification of virulence factors. Overall, 277 (90%) HPs were successfully annotated for function with 224 of these being possible virulent proteins. Enzymes, membrane-associated proteins, transcription factors and secreted proteins, were some of the protein families detected among the HPs. Secretome analysis revealed 57 HPs containing signal peptides, suggesting possible interactions with the host. Thus, among the HPs investigated, there are proteins that could have various functions significant to the pathogenesis of cattle theileriosis including attachment of the pathogen to the host surfaces, disruption of host signal pathways, colonisation of the host cell, immunosuppression, host cell phenotype modulation and proliferation. Sub-cellular localisation revealed three HPs that did not have homologs to any of the vertebrate host proteins, which can be investigated as possible therapeutic targets. The findings of this study will facilitate a better understanding of the mechanism of pathogenesis associated with cattle theileriosis and identification of novel targets to improve disease control strategies. Thus, HPs with predicted biological roles of interest should be further explored experimentally to confirm their roles in cattle theileriosis.
Dissertation (MSc)--University of Pretoria, 2017.
Veterinary Tropical Diseases
MSc
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21

Kariuki, Dadson P. "Studies on the carrier state of East Coast fever (Theileria parva parva) in relation to the epidemiology and control of the disease." Thesis, University of Salford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303071.

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22

Odongo, David Onyango. "Molecular analysis of the Theileria parva carrier state and genetic diversity of the parasite in cattle." Thesis, Brunel University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412431.

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23

Gerhards, Joachim [Verfasser]. "Theileria parva (Apicomplexa, Theileriidae): Isolierung, Klonierung, Charakterisierung und Expression von Transkripten des intralymphozytaeren Stadiums / J. Gerhards." Karlsruhe : KIT-Bibliothek, 1990. http://d-nb.info/1161801669/34.

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24

Kamwendo, Soviet Pair. "Theileria parva and Rhipicephalus appendiculatus : a study of the parasite-tick relationship with reference to Malawi." Thesis, University of Liverpool, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333682.

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25

Connelley, Timothy. "Immunodominance, clonal composition and TCRβ repertoire of the bovine CD8+ T-cell response to Theileria parva." Thesis, University of Edinburgh, 2007. http://hdl.handle.net/1842/29708.

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Results from previous studies have inferred that the CD8⁺ T-cell response to T. parva is focused on a limited number of immunodominant antigens that exhibit polymorphism between different parasite strains. This could pose a major challenge to the design of a broadly effective subunit vaccine. The object of this study was to quantitatively assess immunodominance in the CD8⁺T-cell response to T. parva and to characterise the clonal composition and TCRβ repertoires of the epitope-specific T-cell populations. The results from four animals presented in this study have demonstrated that the CD8⁺ T-cell response restricted by two MHC class I haplotypes is reproducibly dominated by single polymorphic epitopes. The T-cell populations specific for both these epitopes were polyclonal but dominated by a limited number of large clonal expansions and the TCRβ repertoires expressed by these populations were diverse. During the course of this work several novel bovine TCRβ genes were identified. Further examination of TCRβ cDNA transcripts and the bovine genome assembly substantially expanded the known bovine TCRβ repertoire, which is now the largest characterised for any species. Notably several Vβ subfamilies, especially Vβ1 and 13 have undergone extensive duplication and contain large numbers of genes. By annotating the available genomic data it has been shown that the bovine TCRβ locus has a highly conserved synteny with the human TCRβ locus. Furthermore this annotation has demonstrated that prodigious duplication of a cassette containing a Vβ1 and Vβ13 gene has contributed to the large membership of these two subfamilies and that there are three D-J-Cβ clusters in the bovine TCRB locus rather than in the two seen in the other mammalian TCRβ loci described.

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26

Eichhorn, Margarete [Verfasser]. "IL-2 Rezeptor und MHC-Klasse II Antigene: Elemente der Wachstumskontrolle Theileria parva-infizierter Lymphozyten / Margarete Eichhorn." Karlsruhe : KIT-Bibliothek, 1992. http://d-nb.info/1150302054/34.

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27

Mukolwe, Donald Lubembe. "Population genetic structure, genotypic and antigenic diversity of Theileria parva field strains from eastern and southern Africa." Thesis, University of Pretoria, 2019. http://hdl.handle.net/2263/76736.

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Theileria parva utilizes genetic diversity as a survival strategy in evasion of the host’s immune system. Hence, effective control of T. parva infections is highly reliant on understanding the extent of genotypic and antigenic diversity of T. parva in cattle-derived and buffalo-derived isolates. Thus, the aim of this study was to identify differences between cattle- and buffalo-derived T. parva field parasites from eastern and southern Africa based on antigenic and genotypic diversity, and define the population genetic structure of T. parva parasites from the two regions. Sequence analysis of the central variable region of the sporozoite antigen gene, p67, revealed two subtypes of p67 allele type 1, an allele type previously exclusively associated with East Coast fever. Each subtype was unique to parasites from eastern and southern Africa, thus differentiating the p67 allele type 1 population responsible for Corridor disease in South Africa from that which occurs in East Africa. The other three p67 allele types (2, 3 and 4) were detected only from buffalo-derived T. parva parasites from buffalo and Corridor disease cases. Sequences of regions containing CD8+ T-cell epitopes in ten schizont antigens, designated Tp1 to Tp10, showed epitope variants in Tp1, Tp2, Tp4, Tp5 and Tp9, where Tp2 and Tp5 had the most and least variants respectively. Tp1, Tp2 and Tp9 had variants that were common in cattle- and buffalo-derived parasites from the two regions investigated. Variants on the immunodominant Tp249-59 and Tp250-59 epitopes were only identified in buffalo-derived parasites from South Africa, while one variant of Tp1214-224 was common in parasites from the two regions. The significance of Tp4 and Tp5 in immunity is not known and the effects of natural variants of Tp9 epitope on CTL recognition have not been reported. MS19 and ms5 loci were the most and least diverse respectively, and buffalo-derived T. parva parasites showed high levels of genetic diversity. Parasites associated with Corridor disease in South Africa and East Coast fever in eastern Africa had distinguishing allelic profiles on three loci (MS8, MS19 and MS33). Individual populations from the two regions were in linkage equilibrium (VDThesis (PhD)--University of Pretoria, 2019.
Veterinary Tropical Diseases
PhD
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28

Choopa, Chimvwele Namantala. "Diagnosis of tick-borne diseases in cattle in Bushbuckridge Mpumalanga South Africa and identification of Theileria parva carriers." Diss., University of Pretoria, 2015. http://hdl.handle.net/2263/53321.

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The Mnisi community is in the north-eastern corner of the Bushbuckridge Municipal Area, Mpumalanga Province, South Africa. This community is located at the livestock/wildlife interface sharing borders with several game reserves, and livestock are likely to be exposed to diseases with a wildlife reservoir, such as Corridor disease. Known tick vectors of important diseases such as Corridor disease, redwater, heartwater and anaplasmosis are present in the area. Although the farmers frequently dip their cattle in acaricide-filled dip tanks to control the tick burden, tick-borne diseases (TBDs) are still a major problem. This study was undertaken to determine if the symptoms of cattle in poor health in the Mnisi community could be attributed to TBDs. Corridor disease has previously been identified in cattle in the Mnisi community. Recent experimental studies have shown that T. parva DNA can be detected in infected cattle that survive the disease in the field. An additional aim of the study was therefore to identify T. parva carrier cattle in the area, and to search for evidence of selection of cattle-adapted T. parva parasites in carrier cattle. The study was conducted from July 2012 to June 2013. During the study period, samples from clinically sick cattle suspected of TBDs were collected to determine the cause of their symptoms. Blood smears from the clinically sick cattle were analysed using light microscopy while some cases were subjected to histopathology and T. parva-specific quantitative real-time polymerase chain reaction (qPCR). DNA extracted from blood samples and in some cases tissue samples collected from clinically sick cattle (n=137) was tested for the presence of haemoparasite DNA using the reverse line blot (RLB) hybridization assay. To identify T. parva carrier cattle, records from Hluvukani Animal Clinic and Bushbuckridge State Veterinary office were scrutinized to identify herds that may have been exposed to T. parva infection. Blood samples (n=670) were collected from herds that had recorded Corridor disease cases in the past three years, as well as herds that may have shared grazing with buffalo from the Kruger National Park and surrounding private game reserves. The indirect fluorescent antibody test (IFAT) was used to check for T. parva antibodies. Seropositive herds were revisited, as well as herds that had confirmed Corridor disease cases during the study period, and blood samples were collected (n=432). DNA extracted from these samples was screened for the presence of T. parva DNA using the T. parva-specific qPCR. In an attempt to find evidence of selection of cattle-adapted T. parva, the p67, p104 and PIM parasite genes were amplified from qPCR positive samples, and the amplicons were cloned and sequenced. Out of the 137 clinical disease cases examined from the study area, 24 cases of TBDs were diagnosed, of which 19 were Theileria related. The RLB hybridization assay confirmed the presence of tick-borne haemoparasites in the Mnisi community: 89 of the 137 clinical disease cases (65.0%) were found positive for one or more haemoparasite (Theileria, Babesia, Anaplasma and/or Ehrlichia species) while 48 (35.0%) were negative or below the detectable limit of the test. IFAT results indicated that there is a high seroprevalence of theileriosis (63.6%) in the Mnisi community area, but this may be due to cross reactions with other Theileria parasites known to be present (e.g. T. taurotragi). Fewer cattle (13.4%) were seropositive at the highest titre tested (160), and these are most likely to be associated with T. parva. In DNA extracted from blood samples from these seropositive herds, the T. parva-specific qPCR detected T. parva in eleven samples (2.6%). Eight of the eleven cattle were re-sampled six months later, but only one was still qPCR positive. All of the p104 and PIM sequences and two of the three p67 sequences were characteristic of buffalo-type T. parva alleles previously identified, implying that the T. parva infections in the cattle were transmitted directly from buffalo to cattle, and providing no evidence of selection of cattle-type alleles in the carrier animals. The study revealed that TBDs are a problem in the Mnisi community and surrounding area. Most important of the TBDs identified was Corridor disease, a notifiable disease in South Africa, which was the cause of most deaths among the cattle that were sampled. There was no evidence for the selection of cattle-derived T. parva alleles in any of the samples from T. parva carrier cattle, but a p67 sequence obtained from a clinical case was closely related to previously-identified alleles from cattle-derived isolates. Theileria parva DNA could only be detected in carrier cattle for a limited time post-exposure, suggesting that the infection will be cleared in infected animals before larvae or nymphs are available to pick up infections the following season. However, one bovine was still qPCR positive six months post-exposure, albeit with a very high Cp value (indicating a very low parasitaemia). The selection of T. parva parasites in cattle from the diverse T. parva population in African buffalo, therefore, remains a concern in the Mnisi community area, and at other livestock/wildlife interfaces in South Africa, but the risk is probably very low.
Dissertation (MSc)--University of Pretoria, 2015.
tm2016
Veterinary Tropical Diseases
MSc

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29

Stoltsz, Wilhelm Heinrich. "Aspects of the epidemiology of Theileria parva infections in cattle and African buffalo (Syncerus caffer) in South Africa revealed by tick transmission and sub-inoculation of blood." Diss., University of Pretoria, 2011. http://hdl.handle.net/2263/24952.

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The aim of this study was to investigate three key epidemiological aspects of Theileria parva infections in cattle and African buffalo (Syncerus caffer) in South Africa. The first of these was the possible behavioural change (i.e. transformation) of buffalo-derived T. parva (causing classical Corridor disease in cattle) to what might be considered cattle-derived T. parva (causing classical East Coast fever in cattle) after repeated tick-passage in cattle. For the first time a South African isolate of buffalo-derived T. parva was successfully transmitted using Rhipicephalus zambeziensis for eight passages in non-splenectomised cattle. This was achieved despite most animals developing fatal infections with extremely low piroplasm parasitaemias, and without chemotherapeutic intervention. This finding indicates that, contrary to earlier belief, Corridor disease is not a self-limiting disease in cattle, and given the opportunity, could well become established in a cattle population in the absence of buffalo. Despite repeated tick transmission in cattle of the South African buffalo isolate of T. parva used in this study, it did not exhibit the behavioural changes associated with “transformation” to typical cattle-derived T. parva. Secondly, the potential role of the common waterbuck (Kobus ellipsiprymnus) in the selection of cattle-adapted subpopulations of parasites from buffalo-derived T. parva was investigated. Waterbuck captured in Kruger National Park (KNP) were screened by conventional and molecular diagnostic techniques for Theileria spp. infections. Laboratory-reared R. zambeziensis were fed on captive buffalo confirmed to be naturally infected with T. parva. The ensuing adult ticks were fed on captive waterbuck and cattle. All the waterbuck were found to carry microscopically detectable Theileria sp. piroplasm infections, found by polymerase chain reaction (PCR) diagnosis to belong to a hitherto uncharacterised Theileria species. R. zambeziensis adults which fed as nymphs on the buffalo transmitted fatal T. parva infections to cattle. However, no transmission of T. parva to the waterbuck could be demonstrated clinically or by PCR diagnosis. Also, R. zambeziensis nymphs that were subsequently fed on the waterbuck failed to transmit T. parva to cattle in the ensuing adult stage, confirming the absence of T. parva-group infections in the waterbuck. The results suggest that buffalo in KNP probably do not carry T. parva-group parasites which are readily transmissible to common waterbuck and waterbuck are therefore unlikely to play an important role in the epidemiology of T. parva-group infections in cattle in South Africa. Thirdly, to investigate the carrier state of buffalo-derived T. parva infections in cattle, blood from infected non-splenectomised and splenectomised carrier cattle was subinoculated to splenectomised cattle. T. parva infections were successfully transmitted by subinoculation of 1000 ml of blood at various intervals after infection to splenectomised recipient cattle. Donor animals comprised of recovered intact cattle, reacting intact cattle or splenectomised recovered cattle. Microscopically detectable piroplasm parasitaemias were detected in all recipients after inoculation. One splenectomised recipient developed a moderate clinical reaction, accompanied by a moderate schizont parasitosis, but recovered spontaneously, confirming persistence of schizonts in some T. parva carrier animals. By contrast, a T. parva piroplasm infection, persisting in a treated recovered splenectomised bovine, in the apparent absence of circulating schizonts, was serially (consecutively) passaged in splenectomised cattle. Seroconversion occurred in all recipient cattle. With the exception of the recipient which developed a clinical reaction and circulating schizonts, none of the recipients showed any clinical signs of T. parva infection. Upon homologous sporozoite challenge with T. parva, two out of three recipient animals with only microscopically detectable piroplasm parasitaemias developed fatal T. parva infections and one recovered after exhibiting severe clinical signs. These findings confirm the stage-specific immunity in T. parva and, contrary to popular belief, the possibility of long-term maintenance of piroplasm parasitaemias in the absence of schizonts in carrier cattle. The technique of subinoculating and establishing virulent T. parva carrier infections in splenectomised cattle also provides a method whereby buffalo-derived parasite stocks may be isolated and maintained for characterisation and the preparation of sporozoite stabilates for inclusion in T. parva vaccines. Copyright
Dissertation (MSc)--University of Pretoria, 2011.
Veterinary Tropical Diseases
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30

Lessard, Pierre. "The application of computerized geographic information systems to epidemiological surveillance of cattle diseases caused by Theileria Parva." Diss., This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-08032007-102231/.

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31

Tsotetsi, Teboho Nicholus. "Validation of expression profiles of differentially expressed transcripts identified in cattle-derived and buffalo-derived Theileria parva isolates by RNA sequencing." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/62570.

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The intracellular apicomplexan protozoan parasite Theileria parva is a causative agent of cattle theileriosis which manifests in two disease syndromes, namely East Coast fever (ECF) and Corridor disease. Although ECF was eradicated from South Africa, cattle theileriosis still persists in the form of Corridor disease. Moreover, it is not known if the T. parva parasites present in buffalo in South Africa could cause ECF if they were to become established in cattle. This has made it essential to identify genetic differences that would allow successful discrimination of cattle-derived (causative agents of ECF) and buffalo-derived (causative agents of Corridor disease) T. parva parasites. Consequently, Next Generation Sequencing (NGS) was utilized to analyse T. parva transcriptomes from two isolates representing cattle-derived and buffalo-derived parasites, in order to identify gene expression profiles that may characterize cattle-derived and buffalo-derived T. parva isolates. However, RNA-sequencing (RNA-seq) experiments can be influenced by variability caused by technical effects including multiple template preparation stages, diverse sequencing chemistries and complex data processing of NGS experiments; it is thus crucial that data from these experiments is validated using other technologies. Thus, the aim of this study was to use quantitative real-time polymerase chain reaction (qPCR) for validation of differentially expressed genes (DEGs) identified from the RNA-seq study using NGS. Three groups of genes representing different expression profiles, including: 1. constitutively expressed genes; 2. up- and down-regulated genes and 3. genes exclusively expressed in one isolate or the other, were selected for validation. Prior to validation of expression profiles for the selected set of genes using qPCR, endogenous control genes had to be selected in order to normalize qPCR gene expression data. Since there is no information available on the evaluation of the expression stability of these genes in T. parva isolates, the expression stability of five candidate reference genes, β-actin, glyceraldehyde-3-phosphate dehydrogenase, 28S rRNA, cytochrome b and fructose bisphosphatase aldolase (F6P), was evaluated for identification of reliable reference genes. The outcome of the stability rankings for each gene varied according to the program showing that the criteria for stability ranking differ from program to program. It is for this reason that the RefFinder tool, used in this study, integrates the different programs and gives a recommended comprehensive ranking. Therefore, based on this comprehensive analysis between the two T. parva isolates investigated, 28S rRNA and β-actin genes were selected as most suitable reference genes for this study. Intra- and inter-assay variation analysis of the selected reference genes showed that there was no significant variation in the expression of these genes between the two T. parva isolates with the p values being less than 0.05 and the coefficient of variation percentage being low (<2) for all the genes tested. Thus, we propose that genes coding for 28S rRNA and β-actin proteins be employed as endogenous control genes in studies that involve gene expression analysis of T. parva. Validation of expression profiles from RNA-seq data obtained using NGS was performed using qPCR. In this study, the comparative CT method for qPCR data analysis was employed to analyse the expression profiles of selected genes. The use of this method requires initial validation by ensuring that the target genes have approximately the same amplification efficiency as the endogenous control genes. Therefore, the amplification efficiencies of target genes and endogenous control genes were evaluated by constructing validation plots from standard curves generated from selected constitutively expressed and differentially expressed genes, in comparison to the standard curves of the two endogenous control genes. Initially, cDNA was prepared from total RNA isolated from bovine and buffalo lymphoblastoid cell cultures infected with Theileria parva (Muguga) and Theileria parva (7014), respectively, previously used for RNA-seq by NGS. The quantity of the parasite cDNA from the two isolates was interpolated from the standard curve and standardized to a concentration of 36.03 ng/μl, to eliminate concentration bias in downstream gene expression analysis. This study passed the comparative CT method validation experiment since the absolute slopes of ΔCT vs. Log input cDNA for the selected target genes were all less than 0.1 as required. Twenty DEGs, constituting up- and down-regulated genes and genes exclusively expressed in one isolate or the other, and 10 stably expressed (constitutive) genes were selected for validation of expression profiles from RNA-seq data obtained using NGS. Discrepancies between RNA-seq and qPCR analyses were observed from all three groups of target genes but mostly in the constitutively expressed group of genes; in this group only 40% of the qPCR results corroborated with RNA-seq findings while 60% demonstrated variations in expression with four genes down-regulated and one up-regulated in T. parva 7014 relative to T. parva Muguga. Since most of the disagreements in the two datasets were down-regulated expression, this finding suggests that RNA-seq was more sensitive in detecting low abundant RNA transcripts.
Dissertation (MSc)--University of Pretoria, 2017.
Veterinary Tropical Diseases
MSc
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32

Baumann, Ina [Verfasser]. "Theileria parva-induzierte Transformation von Rinderlymphozyten: Das raf-Gen als DNA-Sonde zum Nachweis von Veraenderungen im Methylierungsmuster des Rindergenoms / Ina Baumann." Karlsruhe : KIT-Bibliothek, 1991. http://d-nb.info/1161801596/34.

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33

Eygelaar, Dewald. "Tick-borne haemoparasite prevalence and Theileria parva strain diversity in African buffalo (Syncerus caffer) from northern Botswana and Gonarezhou National Park, Zimbabwe." Diss., University of Pretoria, 2015. http://hdl.handle.net/2263/53295.

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The African buffalo (Syncerus caffer) is host for many pathogens known to cause economically important diseases and is often considered an important reservoir for livestock diseases. Theileriosis, heartwater, babesiosis and anaplasmosis are considered the most important tick-borne diseases of livestock in sub-Saharan Africa, resulting in extensive economic losses to livestock farmers in endemic areas. In this study a variety of tick-borne haemoparasites (Theileria, Babesia, Anaplasma and Ehrlichia species) were identified either as mixed or single infections using the reverse line blot (RLB) hybridization assay from buffalo blood samples in the Chobe National Park (CNP) and Okavango Delta (OD), Botswana and in the Gonarezhou National Park (GNP), Zimbabwe. Also, a quantitative real-time PCR (qPCR) assay was used to identify Theileria parva more specifically in both these countries while the indirect fluorescent antibody test (IFAT) was used to identify Theileria parva more specifically in Botswana only. An attempt was made to characterize T. parva through the size differentiation of p67 genotypes and characterization of the variable regions of T. parva antigen genes, p104 and PIM, by using semi-nested PCR-RFLP profiles. This is the first report of tick-borne haemoparasites in northern Botswana and one of only a few from Zimbabwe. This study identified the following tick-borne haemoparasites: Theileria spp. present, T. parva (60%) and T. mutans (37%) were the most prevalent in the two wildlife areas from Botswana, while Theileria sp. (sable) (50%), T. parva (48%) and T. mutans (38%) were most prevalent in GNP, Zimbabwe. Other species of interest were Anaplasma marginale subsp. centrale (30%), A. marginale (20%), Babesia occultans (23%) and Ehrlichia ruminantium (6%) in Botswana and Anaplasma marginale subsp. centrale (25%) and Babesia occultans (15%) in Zimbabwe. Generally speaking, the buffalo population in the OD sample had lower levels of haemoparasite infection than the buffalo in the CNP and GNP, with the exception of Theileria sp. (buffalo) and to a lesser extent Anaplasma sp. Omatjenne and B. bovis (in the two later cases, where very few positives were detected). Interesting findings included: Anaplasma sp. Omatjenne identified in this study, another research group identified 16.5% to be positive in their samples, but the parasite was found in very low concentrations (3.1%) in our study. B. occultans causes a benign form of cattle babesiosis and was also reported in South Africa by by this research group for the first time. Our study identified 21.1% samples to be positive compared to the study in Hluhluwe-iMfolozi Park, South Africa (50.0%). This study serves as another report of the presence of these two parasites in buffalo. As in Uganda, the pathogenic B. bovis has previously been reported to be absent from buffalo in Botswana but were identified at a low concentration in OD. Similarly, E. ruminantium could be identified in a few CNP and OD buffalo tested. The significance of buffalo as possible reservoir host of some of these economically important haemoparasites (i.e. A. marginale, E. ruminantium) remains unknown. Theileria sp. (sable), which is fatal to sable (Hippotragus niger) and roan antelope (Hippotragus equinus), but non-pathogenic to buffalo was identified in some of the Botswana and Zimbabwe buffalo but positive RLB signals might be due to cross reactions of the Theileria sp. (sable) probe with T. velifera. Theileriosis is recognized as a major threat to the livestock industry as some members of the genus may cause severe disease and mortality, whereas others may only cause mild or subclinical infections. In this study the efficiency of IFAT, qPCR and RLB in identifying T. parva were compared to each other. qPCR was the most effective (81%) followed by IFAT (74%) and then RLB (60%) in Botswana. In Zimbabwe, qPCR (70%) identified more samples to be positive than RLB (48%). The level of agreement between the tests for detection of T. parva positive animals was higher between qPCR and IFAT (kappa=0.56), than between qPCR and RLB (kappa=0.26) or the latter and IFAT (kappa=0.15) in Botswana. The kappa agreement between qPCR and RLB in Zimbabwe was 0.27. The RLB, IFAT and qPCR tests all indicated a high prevalence of T. parva in the study areas. This indicates a high risk of spreading Corridor disease caused by T. parva from buffalo to cattle by the vector ticks at the wildlife-livestock interface. Several T. parva antigen genes have been identified as good candidates for differentiation between buffalo-derived and cattle-derived T. parva isolates. Some of these genes include: p67, p104 and the polymorphic immunodominant molecule (PIM). These genes were amplified in an attempt to differentiate between buffalo-derived and cattle-derived profiles. Amplification of p67 in this study led to the identification of three of the four known p67 alleles. Cluster analysis for p104 showed that samples from Botswana and Zimbabwe clustered together in clade B with themselves and with samples from Hluhluwe while all samples from the Kruger National Park clustered in clade A with samples from Ladysmith. The cluster analysis of PIM revealed that samples from this project (Botswana and Zimbabwe) cluster in four clades, distinct from all samples from South Africa, which, except for one sample from Hluhluwe, clustered in a single clade. In conclusion, this study highlights the diversity of haemoparasites present in African buffalo from northern Botswana and Zimbabwe and also the role of African buffalo as a sentinel species for livestock tick-borne pathogens. Important tick-borne haemoparasites identified in this study included: T. parva, A. marginale, B. bovis and E. ruminantium. This study reconfirmed that p67 profiles are too complex and could not be used to distinguish between cattle- and buffalo-derived T. parva isolates. Mixed infections of p104 and PIM profiles generated by PCR-RFLP analysis were too complex to successfully differentiate between known profiles. Further cloning and sequencing of single infections are needed.
Dissertation (MSc)--University of Pretoria, 2015.
tm2016
Veterinary Tropical Diseases
MSc

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BAUMGARTNER, MARTIN. "Activation constitutive et parasite dependante de la pi3-k : les fonctions regulatrices de la pi3-k dans des cellules b transformees par theileria parva." Paris 6, 2001. http://www.theses.fr/2001PA066266.

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L'objective de ce travail etait l'identification des mecanismes moleculaires qui controlent la proliferation et la survie des cellules infectees par le parasite protozoaire theileria. Nous nous sommes focalises sur la phosphoinositde 3-kinase (pi3-k) et la famille des src kinases, deux regulateurs majeurs des voies de signalisation des cellules eucaryotes. Nous avons pu demontrer que la pi3-k est activee de facon constitutive dans des cellules b infectees par t. Parva. L'activation de la pi3-k est strictement dependante de la presence intracytoplasmique du parasite et engendre la proliferation des cellules infectees par theileria en controlant la transition g1-s et g2/m. Contrairement a son role cle dans la proliferation, la pi3-k ne contribue pas a la protection antiapoptotic des cellules infectees. Conforme a cette notion, nous avons pu demontrer que la proteine kinase b (pkb), un mediateur majeur dans la voie antiapoptotic induit par la pi3-k, n'est pas activee dans des cellules b infectees. En outre, nous avons pu demontrer que l'activation de la pi3-k est a l'origine de l'expression et de la secretion de gm-csf. Le facteur gm-csf contribue a la proliferation de maniere autocrine et, de plus, regule l'etat d'activation de hck, une kinase de la famille src. L'inhibition pharmacologique des src kinases provoque un arret de proliferation, suggerant que des kinases de la famille src et la pi3-k soient requises pour la transformation des lymphocytes par theileria. Conformement, l'activation du facteur de transcription ap-1 depend de l'action combinee de hck et pi3-k. Contrairement a la pi3-k, l'activite et l'etat de phosphorylation de hck augmentent suite a l'elimination du parasite suggerant que l'activite finale de hck resulte de la combinaison des signaux positifs et negatifs, tous deux controles par le parasite. Nous proposons que hck ait regule par un mecanisme base sur l'exclusion de csk de la fraction membranaire enrichi en glycosphingolipides et par un mecanisme inconnu qui depend de la pi3-k. Le fait que l'activation de hck est controlee de facon negative par la pi3-k indique que la transformation dependante de theileria et donc la dissemination du parasite est determinee par la regulation positive et negative des voies de signalisation de la cellule hote.

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Obara, Isaiah Otieno [Verfasser]. "Sizing up the host and parasite genotype considerations relevant to the choice of candidate subunit vaccine antigens intended to render cattle immune to Theileria parva / Isaiah Otieno Obara." Berlin : Freie Universität Berlin, 2017. http://d-nb.info/1133074693/34.

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Spooner, P. R. "Oxytetracycline and Theileria parva : The effects of the drug and its mechanisms of action with respect to the 'infection and treatment' method of immunizing cattle against East Coast Fever." Thesis, Brunel University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234076.

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Santos, Marcos André Ferreira. "Desenvolvimento de métodos moleculares para detecção de Theileria annulata." Master's thesis, Faculdade de Ciências e Tecnologia, 2011. http://hdl.handle.net/10362/6271.

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Dissertação para a obtenção do Grau de Mestre em Genética Molecular e Biomedicina
A theileriose tropical (ou mediterrânica) é uma doença transmitida por carraças e que afecta bovinos, resultando em elevadas perdas económicas na produção e comércio internacional destes animais. O agente da doença é o hemoparasita Theileria annulata e a sua detecção em animais infectados é habitualmente realizada através de exame microscópico de esfregaços de sangue, que apresenta baixa sensibilidade na identificação de animais portadores, onde apenas um número diminuto de eritrócitos se mantém infectado. O objectivo deste estudo foi desenvolver métodos melhorados de detecção de T. annulata em amostras de sangue de bovino, baseados nas tecnologias de PCR em tempo real e de amplificação isotérmica de ácidos nucleicos (LAMP). Foram desenhados oligonucleótidos iniciadores com alvos complementares no gene Tams1, específico de T. annulata,para o método de LAMP. O DNA foi extraído a partir de amostras de sangue de bovino, usando métodos comerciais robotizados e kits de extracção, e foi usado como molde nas reacções de PCR em tempo real (com o corante intercalante EvaGreen®) e LAMP. Estas amostras de DNA encontravam-se testadas para a presença de parasitas dos géneros Theileria e Babesia, usando um método de hibridação reversa em membrana (Reverse Line Blotting – RLB). A detecção de T. annulata por PCR em tempo real nestas amostras revelou uma especificidade e sensibilidade de 100% e 80%,respectivamente, usando o teste de RLB como referência. A técnica de LAMP, por sua vez, conseguiu detectar uma amostra com baixa parasitémia correspondente a 0,03%. Ambas as técnicas usadas neste trabalho demonstraram ser eficientes na detecção de T. annulata, constituindo a técnica de PCR em tempo real um bom método de detecção em laboratórios bem equipados e a técnica de LAMP uma promissora ferramenta em laboratórios de diagnóstico com menores recursos.
Apoiado pelo Deputado Europeu Rui Tavares através do financiamento de uma bolsa de estudo

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VAJANA, ELIA. "Studio della storia evoluzionistica e conservazione delle specie zootecniche attraverso analisi di genomica del paesaggio e modelli di nicchia ecologica." Doctoral thesis, Università Cattolica del Sacro Cuore, 2017. http://hdl.handle.net/10280/19085.

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Attività antropiche e pressioni di mercato stanno rapidamente riducendo la biodiversità. Per questa ragione, conservare il patrimonio ecosistemico, tassonomico e genetico risulta fondamentale al fine di garantire potenziale adattativo alle specie, e, in ultima analisi, un futuro sostenibile per il pianeta. Al fine di minimizzare la perdita di biodiversità, numerosi metodi sono stati proposti per priorizzare ecosistemi, specie e popolazioni. Il presente lavoro di tesi fornisce in primo luogo una revisione di tali approcci, proponendo un albero decisionale volto a favorirne un corretto utilizzo. Secondariamente, la variabilità genomica neutrale del bufalo d’acqua (Bubalus bubalis L.) è investigata per mezzo di un pannello di marcatori SNP a media densità, rivelando due centri di domesticazione (India Nord-occidentale, Cina-Indocina) e possibili rotte di migrazione per gli ecotipi ‘river’ e ‘swamp’. L’adattamento locale ad East Coast Fever, patologia endemica delle popolazioni bovine in Africa Sub-sahariana, è stato inoltre studiato in bovini autoctoni Ugandesi (Bos taurus L.) combinando tecniche di modellizzazione delle nicchie ecologiche e di genomica del paesaggio. L’approccio ha portato ad indentificare PRKG1 e SLA2 come possibili geni di adattamento. I risultati sono discussi alla luce delle possibili implicazioni nella conservazione del bufalo e nella gestione delle risorse genetiche animali Ugandesi.
Biodiversity is quickly disappearing due to human impact on the biosphere, and to market pressure. Consequently, the protection of both wild and domestic species needs to become a priority in order to preserve their evolutionary potential and, ultimately, guarantee a sustainable future for coming human generations. To date, tens of methods have been proposed to prioritize biodiversity for conservation purposes. Here, an ontology for priority setting in conservation biology is provided with the aim of supporting the selection of the most opportune methodologies given specific conservation goals. Further, two case studies are presented characterizing neutral and adaptive genomic diversity in water buffalo (Bubalus bubalis L.) and indigenous Ugandan cattle (Bos taurus L.), respectively. In particular, two independent domestication centres (North-western India and Indochina) and separate migration routes are suggested for the ‘river’ and ‘swamp’ water buffalo types. In the case of indigenous Ugandan cattle, the integration of species distribution modelling and landscape genomics techniques allowed the identification of PRKG1 and SLA2 as candidate genes for local adaptation to East Coast Fever, a vector-borne disease affecting bovine populations of Sub-Saharan Africa. Results are discussed for their implications in water buffalo conservation and Ugandan cattle adaptive management.

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39

VAJANA, ELIA. "Studio della storia evoluzionistica e conservazione delle specie zootecniche attraverso analisi di genomica del paesaggio e modelli di nicchia ecologica." Doctoral thesis, Università Cattolica del Sacro Cuore, 2017. http://hdl.handle.net/10280/19085.

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Attività antropiche e pressioni di mercato stanno rapidamente riducendo la biodiversità. Per questa ragione, conservare il patrimonio ecosistemico, tassonomico e genetico risulta fondamentale al fine di garantire potenziale adattativo alle specie, e, in ultima analisi, un futuro sostenibile per il pianeta. Al fine di minimizzare la perdita di biodiversità, numerosi metodi sono stati proposti per priorizzare ecosistemi, specie e popolazioni. Il presente lavoro di tesi fornisce in primo luogo una revisione di tali approcci, proponendo un albero decisionale volto a favorirne un corretto utilizzo. Secondariamente, la variabilità genomica neutrale del bufalo d’acqua (Bubalus bubalis L.) è investigata per mezzo di un pannello di marcatori SNP a media densità, rivelando due centri di domesticazione (India Nord-occidentale, Cina-Indocina) e possibili rotte di migrazione per gli ecotipi ‘river’ e ‘swamp’. L’adattamento locale ad East Coast Fever, patologia endemica delle popolazioni bovine in Africa Sub-sahariana, è stato inoltre studiato in bovini autoctoni Ugandesi (Bos taurus L.) combinando tecniche di modellizzazione delle nicchie ecologiche e di genomica del paesaggio. L’approccio ha portato ad indentificare PRKG1 e SLA2 come possibili geni di adattamento. I risultati sono discussi alla luce delle possibili implicazioni nella conservazione del bufalo e nella gestione delle risorse genetiche animali Ugandesi.
Biodiversity is quickly disappearing due to human impact on the biosphere, and to market pressure. Consequently, the protection of both wild and domestic species needs to become a priority in order to preserve their evolutionary potential and, ultimately, guarantee a sustainable future for coming human generations. To date, tens of methods have been proposed to prioritize biodiversity for conservation purposes. Here, an ontology for priority setting in conservation biology is provided with the aim of supporting the selection of the most opportune methodologies given specific conservation goals. Further, two case studies are presented characterizing neutral and adaptive genomic diversity in water buffalo (Bubalus bubalis L.) and indigenous Ugandan cattle (Bos taurus L.), respectively. In particular, two independent domestication centres (North-western India and Indochina) and separate migration routes are suggested for the ‘river’ and ‘swamp’ water buffalo types. In the case of indigenous Ugandan cattle, the integration of species distribution modelling and landscape genomics techniques allowed the identification of PRKG1 and SLA2 as candidate genes for local adaptation to East Coast Fever, a vector-borne disease affecting bovine populations of Sub-Saharan Africa. Results are discussed for their implications in water buffalo conservation and Ugandan cattle adaptive management.

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Shukla, Girish C. "Role of the 7.1 kb extrachromosomal genetic element of Theileria parava in parasite biology." Thesis, Brunel University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337464.

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Velloso, Álvaro Jorge. "Estudo da infecção pelo TMEV em culturas de células BHK-21 para avaliar a atividade terapêutica do IFN-Β humano na esclerose múltipla." Instituto de Tecnologia em Imunobiológicos, 2009. https://www.arca.fiocruz.br/handle/icict/5827.

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Submitted by Priscila Nascimento (pnascimento@icict.fiocruz.br) on 2012-11-19T17:50:49Z No. of bitstreams: 1 alvaro-jorge-veloso.pdf: 4310180 bytes, checksum: 6e2b4b0375ed58ab1bdd5831f853ac9b (MD5)
Made available in DSpace on 2012-11-19T17:50:49Z (GMT). No. of bitstreams: 1 alvaro-jorge-veloso.pdf: 4310180 bytes, checksum: 6e2b4b0375ed58ab1bdd5831f853ac9b (MD5) Previous issue date: 2009
Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos. Rio de Janeiro, RJ, Brasil / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.
Para testar a atividade biológica do interferon beta (INF-β) no tratamento da esclerose múltipla (EM), é importante que se tenha um modelo animal. Como a infecção pelo vírus da encefalomielite murina de Theiler (do inglês TMEV – Theiler’s Murine Encephalomyelitis Vírus) é capaz de evoluir para uma lesão desmielinizantesimilar a da EM em humanos, este estudo se propõe a estabelecer os parâmetros para avaliar a infecção do TMEV em culturas de células de rim de hamster neonato (do inglês BHK-21– Baby hamster kidney cells). Para tanto foi necessário adaptar a amostra viral TMEV BeAn à cultura BHK-21, estabelecer um ensaio de RT-PCR e padronizar um PCR em tempo real.Também foi construido um vetor plasmidial contendo o gen L* do TMEV para expressãotransitoria em células HEK-293-T e esta construção plasmidial foi utilizada para obtenção de um soro policlonal anti-L* utilizando a metodologia de imunização genética. Como resultados foram obtidos estoques virais de células BHK-21 infectadas pelo TMEV e parte destes estoques foram avaliados quanto à presença de moléculas genômica TMEV, indicativa de replicação viral, por ensaios de RT-PCR e quantificação por PCR em tempo real. Asregiões do genoma do TMEV 3A3B e L* foram aquelas que forneceram melhores resultadosnesta avaliação genômica quantitativa, que deverá ser aplicada para todos os estoques TMEVBHK-21 que foram obtidos. O vetor plasmidial de expressão células HEK-293-T pcDNA4His/Max contendo o gene L* expressou com sucesso transitoriamente esta proteína heteróloga, porém não foi capaz de induzir a formação de anticorpos policlonais anti-L* em coelhos, através da técnica de imunização genética.
In order to evaluate the biologic activity of the therapeutic drug beta interferon to multiple sclerosis, an adequate animal model is necessary.inthis aspect the infection of murine encephalomyelitis virus can evolve to desmielinization that is very similar to human’s multiple sclerosis, the proposal of this study was the establishment of parameters to evaluate the TMEV infection in baby hamster kidney cells-BHK-21. Toward that objective was adapted the TMEV BeAn prototype sample to BHK-21 and also was established a RT-PCR and a real time PCR. Additionally, it was constructed a plasmid vector containing the L* gene of TMEV, for the expression in HEK-293-T cells. This plasmid vector was evaluated in the capacity to produce anti-L* antibodies by genetic immunization. It was possible to obtain stocks of BHK-21 TMEV infected and some of these contents were evaluated as of the quantity of genomic molecules of TMEV as an indicative of viral replication, by RT-PCR and real time PCR. The TMEV genomic regions 3A3B and L*provided best results in the quantitative evaluation. In thefuture, the real time PCR could be used to evaluate all the stocks that were produced. The plasmidial vector pcDNA4His/Max containing the L* gene was able to transiently express the L* protein, but unfortunately, it was not able to induce anti-L* in rabbits.

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NOVO, Maria Teresa Lourenço Marques. "Contributo para o estudo bioecológico de Culex (Culex) theileri Theobald, 1903 e Ochlerotatus (Ochlerotatus) caspis (Pallas, 1771) (Diptera: Culicidae) na áre da Comporta, Alcácer do Sal. Perspectivas para o seu controlo." Doctoral thesis, Instituto de Higiene e Medicina Tropical, 2008. http://hdl.handle.net/10362/62415.

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Culex theileri e Ochlerotatus caspius (Diptera: Culicidae) são duas espécies de mosquitos reconhecidamente abundantes em Portugal. Embora consideradas espécies zoofílicas, devido ao seu comportamento oportunista, mais marcado em Oc. caspius, representam fonte de incomodidade nas suas áreas de distribuição e durante os períodos de maiores densidades populacionais. Além disso são ainda vectores de agentes patogénicos com importância médica e/ou veterinária. Este estudo teve como objectivos o levantamento destas espécies a nível do território de Portugal continental e o estudo da sua bioecologia na área da Comporta, Alcácer do Sal, distrito de Setúbal, bem como das perspectivas para o seu controlo usando o bioinsecticida Bacillus thuringiensis var. israelensis (Bti). As prospecções efectuadas durante este estudo permitiram confirmar a maior densidade de Cx. theileri no centro-sul do País e a distribuição costeira de Oc. caspius, apresentando-se estas espécies como as mais abundantes a seguir a Cx. pipiens. Na área da Herdade da Comporta, Alcácer do Sal, pelo contrário, Cx. theileri e Oc. caspius são quase sempre, respectivamente, a primeira e segunda espécies mais abundantes. São ainda as que mais picam o Homem, respectivamente 300 e 200 picadas por hora e Homem. Apresentam ainda ciclos diários de actividade que se complementam, tendo Oc. caspius dois picos de actividade, nos crepúsculos matutino e vespertino, e Cx. theileri mantendo níveis elevados de actividade ao longo da noite. Observou-se que Cx. theileri e Oc. caspius são mais adequadamente amostradas com armadilhas CDC/CO2, apresentando picos de abundância, mais alargados para Cx. theileri, durante os meses de Abril a Outubro. Na região de estudo, larvas de Cx. theileri podem ser encontradas nos arrozais e ainda em algumas valas associadas a actividade agrícola. Ochlerotatus caspius utiliza como biótopos larvares não só as depressões existentes no sapal que apenas são alagadas pelas marés vivas e água das chuvas, mas também os arrozais da região após a sua segunda inundação. Culex theileri está presente nos arrozais em todas as localidades positivas para culicídeos, o mesmo não se podendo dizer de Oc. caspius que, para além do sapal, foi identificado nos arrozais do Cambado, Possanco e Torre, não se registando no Carvalhal, sempre no início da campanha de cultivo do arroz, após a primeira drenagem, com a segunda inundação. Quanto às outras espécies, pelo contrário, pareceexistir uma tendência para serem encontradas já na fase final do ciclo de produção dos arrozais, quando é mais marcada a eutrofização das águas. Durante este estudo, nem Cx. theileri nem Oc. caspius foram encontrados a colonizar tanques, recipientes de armazenamento de água e bebedouros de animais. Na caracterização fisico-química da água dos biótopos potenciais prospectados encontrou-se menor teor de oxigénio dissolvido nos biótopos positivos para culicídeos em relação aos negativos. Não se registaram diferenças nos parâmetros da água dos biótopos de Cx. theileri, apresentando os biótopos de Oc. caspius pH, condutância específica, total de sólidos dissolvidos, salinidade e oxigénio dissolvido superiores, e potencial redox inferior, em relação aos dos biótopos larvares onde não estava presente. De um modo geral, ambas as espécies se encontram simultaneamente nas formas imaturas e adultas em todos os locais amostrados. Apresentando estas espécies um comportamento exofílico, uma das abordagens mais adequada para o controlo das suas populações será constituída por técnicas de redução das densidades larvares. Assim, procedeu-se à realização de ensaios de campo em pequena escala com o larvicida Bti em suspensão aquosa, tendo-se obtido percentagens significativas de redução da densidade larvar total 24h após o tratamento, sempre superiores a 85%. As densidades larvares totais apresentaram contudo uma franca recuperação durante a semana seguinte ao tratamento, facto que pensamos dever--se à reduzida dimensão e não isolamento da área tratada. Foi também determinada a sensibilidade de Cx. theileri de insectário à mesma formulação de Bti aplicada nos ensaios de campo, tendo-se calculado os valores 154,0 μg/l e 332,5 μg/l para a LD50 e LD90, respectivamente. Foi ainda possível avaliar o impacte do larvicida na duração do desenvolvimento dos indivíduos sobreviventes à exposição ao Bti durante 24h. A aplicação de Bti na área de estudo, parece apresentar-se então como uma das medidas a adoptar no controlo da incomodidade causada por estas espécies.
Culex theileri and Ochlerotatus caspius (Diptera: Culicidae) are recognised as two of the most abundant species of mosquitoes in Portugal. These species are considered zoophilic. However, due to their markedly opportunistic biting behaviour, particularly evident in Oc. caspius, they are an important source of nuisance to humans along their distribution areas and during high density periods. In addition, both species are vectors of pathogens of both medical and veterinary importance. This study aimed at surveying these species in Portugal mainland, studying their bioecoly in the area of Comporta, Alcácer do Sal, district of Setúbal, as well as the perspectives for their control, using the bioinsecticide Bacillus thuringiensis var. israelensis (Bti). Country-wide surveys conducted in this study confirmed a higher density of Cx. theileri in the south-central region of Portugal and a coastal distribution for Oc. caspius. After Cx. pipiens, these were the most abundant mosquitoes in the country. However, in Herdade da Comporta, Alcácer do Sal, Cx. theileri and Oc. caspius were the first and the second most abundant species recorded. They were also the major human-biting mosquitoes with 300 and 200 bites per hour and per person, respectively. These species present complementary daily biting cycles, Oc. caspius has two biting peaks, in the morning and evening twilights, and Cx. theileri maintains high levels of activity through the night. We observed that Cx. theileri and Oc. caspius are more adequately sampled with CDC/CO2 traps, presenting peaks of abundance from April to October, wider for Cx. theileri. In the region studied, Cx. theileri larvae can be found in rice-fields and in ditches associated with agricultural activities. Ochlerotatus caspius explores small pools of brackish water in marshlands that are flooded by the large tides or by rainfall. Larvae of this species can also be found in rice fields particularly after their second flooding. Culex theileri is present in rice fields in all the localities positive for culicids, while Oc. caspius, was found in the marshland and was found in rice paddies of Cambado, Possanco and Torre, but not in Carvalhal, always at the beginning of the rice farming campaigns, after the first draining, with the second flooding. As for the other species, there is a tendency for their appearance towards the end of rice growing cycle, when the eutrophication of water is higher. During this study, neither Cx. theileri nor Oc. caspiuswere ever found in water tanks, water storage containers and animal drinking containers. In what concerns the physical and chemical characterization of the potencial biotopes water, a lesser amount of dissolved oxygen was found in the biotopes positive for culicids as opposed to the negative. No diferences were registered in the parameters of the biotopes positive for Cx. theileri, while the biotopes positive for Oc. caspius had higher pH, specific conductance, total dissolved solids, salinity and dissolved oxygen, and lower redox potential, in relation to the biotopes where this species was absent. Generally, both species were found simultaneously in the immature and adult forms in all the localities sampled. Since Cx. theileri and Oc. caspius are markedly exophilic, one of the most adequate approaches for control of their populations, should be aimed at larval reduction. Thus, small-scale field experiments with the larvicide Bti in aqueous suspension were carried out. Significant reductions, always above 85%, in total larval densities were obtained 24 h after treatment. However, larval densities increased to pre-treatment levels one week after Bti application. This could be explained by the relatively small area treated and by its lack of isolation from untreated areas. The susceptibility of Culex theileri from an insectary colony to the same formulation of Bti was determined in the laboratory with estimation of Lethal Dosages 50 and 90, as 154,0 μg/l and 332,5 μg/l for LD50 and LD90, respectively. The effect of the insecticide in the larval development of survivors that were exposed to Bti for 24h was also evaluated. In conclusion, the application of Bti can be considered as a measure to be adopted for the control of mosquito nuisance in the study area.

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Loss, Andrea Caetano Silva. "Avaliação do curso da infecção e da resposta humoral para Anaplasma marginale (Theiler, 1910) em bovinos submetidos ao processo de premunição." Universidade Federal de Minas Gerais, 1991. http://hdl.handle.net/1843/BUOS-8PKN7S.

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This study was undertaken to evaluate the course of infection by Anaplasma marginale and the immune response in cattle associated with premunization against anaplasmosis. Thirty-nine Limousin cattle, about twenty-four months old, of both sexes, imported from the United States to Capitolio (MG) were used. Animals were alloted to five groups which were infected with Babesia spp and A. marginale. Infections with Babesfa spp were obtained using subcutaneous inoculation of 5x108 infected erythrocytes or by infestation with Boophilus microplus larvae originated from Babesia-infected female ticks. A. marginale infection was attained by subcutaneous inoculation of 5x108 infected erythrocytes simultaneously or seventeen days after animals had been inoculated with Babesia spp. Prepatent period and parasitemia were determinated by examining daily prepared blood smears; packed cell volume (PCV) was weekly determinated by the microhematocrit technique and retal temperature was daily measured twice a day. Treatment was established based on these parameters. Immune response for A. marginale was measured by the indirect fluorescent antibody technique. All animals were challenged with blood infected with A. marginale 56 (two groups) and 73 (three groups) days after inoculation. Although animals had been inoculated with Babesiaspp only data related to A. marginale are presented in this paper. Prepatent period ranged from 19.8 to 26.0 days; mean perasitemia at the beginning of treatment was 2.0% and mean number of treatment/animal varied from 3.2 to 4.4. Lower PCVvalues were found after the peak of parasitemia by A. marginale before and after challenge. Retal temperatures were higher in the afternoon during clinical anaplasmosis. Higher titers of anti-A. marginale antibodies (1:5120) were found 49 days after inoculation. An increase in titers were found up to 48 days after challenge, when the observations were finished.
Trinta e nove animais, de ambos os sexos, com idade aproximada de 24 meses, da raça Limousin, importados dos Estados Unidos, foram submetidos ao processo de premunição, no município de Capitólio (MG). Os animais foram divididos em 5 grupos e foram inoculados com Babesia spp. Através de sangue contendo 5x10 8 eritrócitos infectados, ou infestados com larvas de Boophilus microplus obtidas a partir de fêmeas ingurgitadas, provenientes de animais naturalmente infectados por Babesia spp, e receberam inoculação de 5x10 8 Anaplasma marginale simultaneamente ou 17 dias após a inoculação da Babesia. Esfregaços sanguíneos diários, determinação do volume globular semanal a da temperatura retal diariamente, no período da manhã e à tarde, foram realizados para a verificação do período prepatente, parasitemia e instituição dos tratamentos. Somente os dados para A. marginale foram considerados neste trabalho. O perfil sorológico dos animais, para A. marginale, foi observado através de exames semanais, pela reação de imunofluorescência indireta. Todos os animais foram desafiados em relação ao A. marginale 56 (grupos 3 e 5) e 73 (grupos 1, 2 e 4) dias após a inoculação. Para os diferentes grupos, o período prepatente médi0 variou de 19,8 a 26 dias, a parasitemia média no início do tratamento foi de 2,3% e o numero médio de tratamentos/animal foi de 3,2 a 4,4. O volume globular sofreu quedas após as fases de parasitemia de A. marginale, antes e após desafio. As temperaturas retais apresentaram elevações, maiores no período da tarde, na fase clínica da anaplasmose. À sorologia, títulos máximos (1:5120) de anticorpos anti-A. marginale foram obtidos 49 DAI. Após o desafio os títulos foram crescentes até o 48° dia.

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44

Collins, Nicola Elaine. "The relationship between theileria parva parva and t.p. lawrencei as shown by sporozoite antigen and ribosomal RNA gene sequences." Thesis, 1997. http://hdl.handle.net/10539/22930.

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A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Doctor of Philosophy.
The aim of this thesis was to develop DNA probes to distinguish between the protozoan parasites Theileria parva parva and T. p. lawrencei which cause East Coast fever (ECF) and Corridor disease respectively. ECF was eradicated from South Arrlca in 1954, and today Corridor disease has become the most important form of theileriosis. Although ECF has been eradicated, the vector ticks are still prevalent in South Africa and the cattle population would be highly susceptible to a recurrence of the disease, At present there is no reliable means of distinguishing between T.p. parva and T. p. lawrencei. Sequence differences between T. parva and other Theileria species have previously been found in the small subunit ribosomal RNA (rRNA) gene; probes designed to detect these sequence differences Can be used to distinguish between Theileria species. We therefore decided to search for differences in the rRNA genes of T. p. parva and T.p. lawrencei. To this end, the entire "RNA transcription unit was amplified from a cloned T. p, lawrence; parasite; the unit comprises the small subunit rRNA (SSUrRNA) gene, the internal transcribed spacer (ITS) and the large subunit rRNA (LSUrRNA) gene. The amplification products were cloned and sequenced, and the T.p, lawrencei rRNA sequence was compared to that of T. p, parva, While there was little variation in their SSUrRNA and LSUrRNA gene sequences, there was major sequence variation in the ITS The ITSs from twelve T. parva isolates were amplified, cloned and sequenced, and eleven characterisation oligonucleotide probes were identified. The T. p, parva isolates screened in this study hybridised with a limited subset of the probes, While the T. p. lawrencei isolates, hybridised with many more of the probes, indicating that the T. parva population in cattle is more homogenous than that in buffalo. There thus appears to have been a selection in cattle of a relatively homogenous subpopuiation of T. parva from a much larger, more diverse gene pool in buffalo. Although most T.p. parva isolates (93.5%) were detected by probe TPPI, and most T.p, lawrencei isolates (81.8%) were detected by
AC2017

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45

Mbizeni, Sikhumbuzo. "Investigations of the Theileria parva carrier-state in cattle at the livestock/wildlife interface of the uPhongolo-Mkuze area in KwaZulu Natal, South Africa." Diss., 2012. http://hdl.handle.net/2263/29676.

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Corridor disease (Theileria parva infection in cattle associated with carrier buffaloes) was not reported to cause serious outbreaks prior to 1994. From 2002-2004, outbreaks in cattle have increased in the areas where the disease is endemic in buffalo populations. In this study, the occurrence of Corridor disease outbreaks in the Zululand district municipality was closely monitored from 2004-2009. The observations included the number of cattle involved in the outbreaks, clinical signs, parasitological and post-mortem examinations while blood for serum and in EDTA were collected for serological (IFA test) and molecular (real-time PCR) tests specific for T. parva. Samples were collected from cattle involved in the outbreak, the sick and presumed recovered cattle. Recovered cattle from the farms were brought to the laboratory at the Onderstepoort Veterinary Institute for further investigations. This included tick pick-up and transmission attempts to demonstrate their carrier status as well as assessing their immunity to further experimental challenge using virulent T. parva stabilate. Results were obtained on Corridor disease outbreaks in the study area and ad hoc locations comprising a total of 15 commercial farms and community diptanks in the district from 2004 to 2009. A total of 31 outbreaks were recorded during the study period. The number of outbreaks per year was stable, being 3 or 4 from 2004 to 2007. A 100 percent increase was recorded in the subsequent years, 2008-2009. In one location, Morgenzon farm comprising a commercial and community farmers, had experienced regular outbreaks from 2004-2009. It is also noted that some farms experienced outbreaks for three consecutive years. Three other farms had experienced outbreaks for the first time in either 2008 or 2009. The most severe outbreak occurred in Nyalisa in 2009 where the disease was experienced for the first time in one herd in which 202 cattle were involved and 57 died within 30-40 days after the onset of the disease. Using all the tools mentioned above, the cause of death was confirmed to be due to T. parva infection. The Corridor disease outbreaks that were investigated, have mostly been reported during the months from March-May (88 %) but some (8 %) were encountered during the winter months (June-August). The distribution of outbreaks mainly coincided with the activity period of adult R. appendiculatus. During the investigation period, a total of 846 cattle were tested for Corridor disease and the prevalence was found to be 27 %. The percentage of cattle which were found positive by PCR was 16.5. Seven percent were found positive on both PCR and IFA tests, an indication of the development of a carrier state. However, 10 % of the cattle remained sero-positive with no indication of being parasite-carriers (real-time PCR negative). Five cattle which recovered from an apparent severe T. parva infection in the field and confirmed to be positive by PCR, all became negative before they were used in the transmission experiments. Ticks derived from these cattle were used to infect susceptible bovines but only T. taurotragi was transmitted. The xeno-diagnosis failed to demonstrate the carrier state in these field cattle. The five Corridor disease recovered cattle obtained from different study locations mentioned above, received lethal challenge using T. parva buffalo-derived stabilate. All challenged animals, including the susceptible control, showed schizont parasitosis as detected by the T. parvaDissertation (MSc)--University of Pretoria, 2012.
Veterinary Tropical Diseases
unrestricted

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46

Njuguna, James Thuo [Verfasser]. "Cloning and expression of deoxyhypusine synthase from Plasmodium vivax and Theileria parva as an approach for target evaluation in anti-parasitic chemotherapy / vorgelegt von James Thuo Njuguna." 2009. http://d-nb.info/996778136/34.

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47

Jackson, Angela M. "Development of a mass spectrometry based method for the identification of gp96-chaperoned peptides destined for presentation in MHC class I molecules." Thesis, 2006. http://hdl.handle.net/1828/2266.

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Theileria parva is an intracellular protozoan parasite and the causative agent of the lethal livestock disease East Coast fever (ECF). Research has shown that a protective cell-mediated immune response against parasite-infected lymphocytes is capable of clearing the host of T. parva (Pearson et al. 1979), leaving the host solidly immune to reinfection. The work presented in this thesis describes my attempts to develop a method for identification of major histocompatibility complex class I-associated T. parva peptides involved in eliciting this protective cell-mediated immune response. The soluble chaperone gp96 interacts with peptides destined for association with major histocompatibily complex class I molecules and is therefore a source of T. parva peptides that interact with extracellular immune effectors. Using sensitive mass spectrometry methods the gp96-chaperoned peptide proteome from model parasite infected T lymphocytes was compared to an uninfected T cell line. With our findings we have demonstrated proof of concept for a highly sensitive method for the elucidation of potentially immunogenic peptides capable of initiating a protective immune response against the intracellular parasite T parva.

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48

De, Castro Minique Hilda. "Sialotranscriptomics of the brown ear ticks, Rhipicephalus appendiculatus Neumann, 1901 and R. Zambeziensis Walker, Norval and Corwin, 1981, vectors of Corridor disease." Thesis, 2017. http://hdl.handle.net/10500/24735.

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Text in English
Corridor disease is an economically important tick-borne disease of cattle in southern Africa. The disease is caused by Theileria parva and transmitted by the vectors, Rhipicephalus appendiculatus and R. zambeziensis. There is currently no vaccine to protect cattle against T. parva that is permitted in South Africa. To develop recombinant anti-tick vaccines against Corridor disease, comprehensive databases of genes expressed in the tick’s salivary glands are required. Therefore, in Chapters 2 and 3, mRNA from the salivary glands of R. appendiculatus and R. zambeziensis was sequenced and assembled using next generation sequencing technologies. Respectively, 12 761 and 13 584 non-redundant protein sequences were predicted from the sialotranscriptomes of R. appendiculatus and R. zambeziensis and uploaded to public sequence domains. This greatly expanded the number of sequences available for the two vectors, which will be invaluable resources for the selection of vaccine candidates in future. Further, in Chapter 3, differential gene expression analysis in R. zambeziensis revealed dynamic expression of secretory protein transcripts during feeding, suggestive of stringent transcriptional regulation of these proteins. Knowledge of these intricate expression profiles will further assist vaccine development in future. In Chapter 4, comparative sialotranscriptomic analyses were performed between R. appendiculatus and R. zambeziensis. The ticks have previously shown varying vector competence for T. parva and this chapter presents the search for correlates of this variance. Phylogenetic analyses were performed using these and other publically available tick transcriptomes, which indicated that R. appendiculatus and R. zambeziensis are closely related but distinct species. However, significant expression differences were observed between the two ticks, specifically of genes involved in tick immunity or pathogen transmission, signifying potential bioinformatic signatures of vector competence. Furthermore, nearly four thousand putative long non-coding RNAs (lncRNAs) were predicted in each of the two ticks. A large number of these showed differential expression and suggested a potential transcriptional regulatory function of lncRNA in tick blood feeding. LncRNAs are completely unexplored in ticks. Finally, in Chapter 5, concluding remarks are given on the potential impact the R. appendiculatus and R. zambeziensis sialotranscriptomes may have on future vaccine developments and some future research endeavours are discussed.
Life and Consumer Sciences
Ph. D. (Life Sciences)

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