Academic literature on the topic 'Parasites'
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Journal articles on the topic "Parasites"
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WOOD, CHELSEA L., and KEVIN D. LAFFERTY. "How have fisheries affected parasite communities?" Parasitology 142, no. 1 (March 3, 2014): 134–44. http://dx.doi.org/10.1017/s003118201400002x.
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SUMMARYTo understand how fisheries affect parasites, we conducted a meta-analysis of studies that contrasted parasite assemblages in fished and unfished areas. Parasite diversity was lower in hosts from fished areas. Larger hosts had a greater abundance of parasites, suggesting that fishing might reduce the abundance of parasites by selectively removing the largest, most heavily parasitized individuals. After controlling for size, the effect of fishing on parasite abundance varied according to whether the host was fished and the parasite's life cycle. Parasites of unfished hosts were more likely to increase in abundance in response to fishing than were parasites of fished hosts, possibly due to compensatory increases in the abundance of unfished hosts. While complex life cycle parasites tended to decline in abundance in response to fishing, directly transmitted parasites tended to increase. Among complex life cycle parasites, those with fished hosts tended to decline in abundance in response to fishing, while those with unfished hosts tended to increase. However, among directly transmitted parasites, responses did not differ between parasites with and without fished hosts. This work suggests that parasite assemblages are likely to change substantially in composition in increasingly fished ecosystems, and that parasite life history and fishing status of the host are important in predicting the response of individual parasite species or groups to fishing.
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Farahani, Sajad. "Success of Infection by Parasites." Journal of Biomedical Research & Environmental Sciences 4, no. 7 (July 2023): 1153–55. http://dx.doi.org/10.37871/jbres1780.
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The success of infection by parasites during the host-parasite coevolution is related to increasing a parasite’s ability to alter intermediate host behaviour, resulting in higher fitness of parasites. The “increased host abilities’ hypothesis” posits that parasites manipulate the behavior of their intermediate hosts or improves its chances of intermediate host survival in order to enhance their transmission to the next host. Research shows that the transmission of the parasites to their definitive host is facilitated by non-host predator avoidance by the intermediate host, which would otherwise prevent completion of the parasite’s life cycle.
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Hart, B. L. "Behavioural defense against parasites: interaction with parasite invasiveness." Parasitology 109, S1 (1994): S139—S151. http://dx.doi.org/10.1017/s0031182000085140.
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SUMMARYBehavioural patterns involved in avoiding, repelling, or removing parasites allow mammalian hosts to defend themselves from an array of parasites that threaten the host's fitness in the natural world. Some examples of behavioural defenses and the presumed target parasites are: grooming to remove ticks, grouping to reduce attack rate of biting flies, fly repelling movements to reduce parasitic flies, and selective grazing to reduce intake of faecal-borne parasites. These behavioural defenses are discussed with regard to effectiveness in controlling the target parasites. Parasites have sometimes evolved behavioural strategies of evading, penetrating or disabling these behavioural defenses. These parasite behavioural strategies, though less studied, are discussed. Also discussed is the possibility that host behavioural patterns that may defend against one parasite may be exploited by a different type of parasite to facilitate its own transmission. The interplay between host defensive strategies, the cost versus the effectiveness of such strategies, and a parasite's evasion or exploitation of such strategies, may be useful in understanding some aspects of host-parasite dynamics in nature.
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Severins, Maite, Don Klinkenberg, and Hans Heesterbeek. "How selection forces dictate the variant surface antigens used by malaria parasites." Journal of The Royal Society Interface 9, no. 67 (July 6, 2011): 246–60. http://dx.doi.org/10.1098/rsif.2011.0239.
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Red blood cells infected by the malaria parasite Plasmodium falciparum express variant surface antigens (VSAs) that evade host immunity and allow the parasites to persist in the human population. There exist many different VSAs and the differential expression of these VSAs is associated with the virulence (damage to the host) of the parasites. The aim of this study is to unravel the differences in the effect key selection forces have on parasites expressing different VSAs such that we can better understand how VSAs enable the parasites to adapt to changes in their environment (like control measures) and how this may impact the virulence of the circulating parasites. To this end, we have built an individual-based model that captures the main selective forces on malaria parasites, namely parasite competition, host immunity, host death and mosquito abundance at both the within- and between-host levels. VSAs are defined by the net growth rates they infer to the parasites and the model keeps track of the expression of, and antibody build-up against, each VSA in all hosts. Our results show an ordered acquisition of VSA-specific antibodies with host age, which causes a dichotomy between the more virulent VSAs that reach high parasitaemias but are restricted to young relatively non-immune hosts, and less virulent VSAs that do not reach such high parasitaemias but can infect a wider range of hosts. The outcome of a change in the parasite's environment in terms of parasite virulence depends on the exact balance between the selection forces, which sets the limiting factor for parasite survival. Parasites will evolve towards expressing more virulent VSAs when the limiting factor for parasite survival is the within-host parasite growth and the parasites are able to minimize this limitation by expressing more virulent VSAs.
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Forbes, Mark R., André Morrill, and Jennifer Schellinck. "Host species exploitation and discrimination by animal parasites." Philosophical Transactions of the Royal Society B: Biological Sciences 372, no. 1719 (March 13, 2017): 20160090. http://dx.doi.org/10.1098/rstb.2016.0090.
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Parasite species often show differential fitness on different host species. We developed an equation-based model to explore conditions favouring host species exploitation and discrimination. In our model, diploid infective stages randomly encountered hosts of two species; the parasite's relative fitness in exploiting each host species, and its ability to discriminate between them, was determined by the parasite's genotype at two independent diallelic loci. Relative host species frequency determined allele frequencies at the exploitation locus, whereas differential fitness and combined host density determined frequency of discrimination alleles. The model predicts instances where populations contain mixes of discriminatory and non-discriminatory infective stages. Also, non-discriminatory parasites should evolve when differential fitness is low to moderate and when combined host densities are low, but not so low as to cause parasite extinction. A corollary is that parasite discrimination (and host-specificity) increases with higher combined host densities. Instances in nature where parasites fail to discriminate when differential fitness is extreme could be explained by one host species evolving resistance, following from earlier selection for parasite non-discrimination. Similar results overall were obtained for haploid extensions of the model. Our model emulates multi-host associations and has implications for understanding broadening of host species ranges by parasites. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’.
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Mathieu-Bégné, Eglantine, Simon Blanchet, Guillaume Mitta, Clément Le Potier, Géraldine Loot, and Olivier Rey. "Transcriptomic Adjustments in a Freshwater Ectoparasite Reveal the Role of Molecular Plasticity for Parasite Host Shift." Genes 13, no. 3 (March 16, 2022): 525. http://dx.doi.org/10.3390/genes13030525.
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A parasite’s lifestyle is characterized by a critical dependency on its host for feeding, shelter and/or reproduction. The ability of parasites to exploit new host species can reduce the risk associated with host dependency. The number of host species that can be infected by parasites strongly affects their ecological and evolutionary dynamics along with their pathogenic effects on host communities. However, little is known about the processes and the pathways permitting parasites to successfully infect alternative host species, a process known as host shift. Here, we tested whether molecular plasticity changes in gene expression and in molecular pathways could favor host shift in parasites. Focusing on an invasive parasite, Tracheliastes polycolpus, infecting freshwater fish, we conducted a transcriptomic study to compare gene expression in parasites infecting their main host species and two alternative host species. We found 120 significant differentially expressed genes (DEGs) between parasites infecting the different host species. A total of 90% of the DEGs were identified between parasites using the main host species and those using the two alternative host species. Only a few significant DEGs (seven) were identified when comparing parasites from the two alternative host species. Molecular pathways enriched in DEGs and associated with the use of alternative host species were related to cellular machinery, energetic metabolism, muscle activity and oxidative stress. This study strongly suggests that molecular plasticity is an important mechanism sustaining the parasite’s ability to infect alternative hosts.
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Duneau, David, and Dieter Ebert. "The role of moulting in parasite defence." Proceedings of the Royal Society B: Biological Sciences 279, no. 1740 (April 11, 2012): 3049–54. http://dx.doi.org/10.1098/rspb.2012.0407.
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Parasitic infections consist of a succession of steps during which hosts and parasites interact in specific manners. At each step, hosts can use diverse defence mechanisms to counteract the parasite's attempts to invade and exploit them. Of these steps, the penetration of parasites into the host is a key step for a successful infection and the epithelium is the first line of host defence. The shedding of this protective layer (moulting) is a crucial feature in the life cycle of several invertebrate and vertebrate taxa, and is generally considered to make hosts vulnerable to parasites and predators. Here, we used the crustacean Daphnia magna to test whether moulting influences the likelihood of infection by the castrating bacterium Pasteuria ramosa . This parasite is known to attach to the host cuticula before penetrating into its body. We found that the likelihood of successful parasite infection is greatly reduced if the host moults within 12 h after parasite exposure. Thus, moulting is beneficial for the host being exposed to this parasite. We further show that exposure to the parasite does not induce hosts to moult earlier. We discuss the implications of our findings for host and parasite evolution and epidemiology.
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Kelsen, Anne, Robyn S. Kent, Anne K. Snyder, Eddie Wehri, Stephen J. Bishop, Rachel V. Stadler, Cameron Powell, et al. "MyosinA is a druggable target in the widespread protozoan parasite Toxoplasma gondii." PLOS Biology 21, no. 5 (May 8, 2023): e3002110. http://dx.doi.org/10.1371/journal.pbio.3002110.
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Toxoplasma gondii is a widespread apicomplexan parasite that can cause severe disease in its human hosts. The ability of T. gondii and other apicomplexan parasites to invade into, egress from, and move between cells of the hosts they infect is critical to parasite virulence and disease progression. An unusual and highly conserved parasite myosin motor (TgMyoA) plays a central role in T. gondii motility. The goal of this work was to determine whether the parasite’s motility and lytic cycle can be disrupted through pharmacological inhibition of TgMyoA, as an approach to altering disease progression in vivo. To this end, we first sought to identify inhibitors of TgMyoA by screening a collection of 50,000 structurally diverse small molecules for inhibitors of the recombinant motor’s actin-activated ATPase activity. The top hit to emerge from the screen, KNX-002, inhibited TgMyoA with little to no effect on any of the vertebrate myosins tested. KNX-002 was also active against parasites, inhibiting parasite motility and growth in culture in a dose-dependent manner. We used chemical mutagenesis, selection in KNX-002, and targeted sequencing to identify a mutation in TgMyoA (T130A) that renders the recombinant motor less sensitive to compound. Compared to wild-type parasites, parasites expressing the T130A mutation showed reduced sensitivity to KNX-002 in motility and growth assays, confirming TgMyoA as a biologically relevant target of KNX-002. Finally, we present evidence that KNX-002 can slow disease progression in mice infected with wild-type parasites, but not parasites expressing the resistance-conferring TgMyoA T130A mutation. Taken together, these data demonstrate the specificity of KNX-002 for TgMyoA, both in vitro and in vivo, and validate TgMyoA as a druggable target in infections with T. gondii. Since TgMyoA is essential for virulence, conserved in apicomplexan parasites, and distinctly different from the myosins found in humans, pharmacological inhibition of MyoA offers a promising new approach to treating the devastating diseases caused by T. gondii and other apicomplexan parasites.
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Jürgens, Anna-Sophie, and Alexander G. Maier. "From circus acts to violent clowns: The parasite as performer." Journal of Science & Popular Culture 3, no. 1 (March 1, 2020): 39–56. http://dx.doi.org/10.1386/jspc_00011_1.
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Abstract With the growing awareness of the contribution of parasites to life, their influences on humans also become clearer. The parasite's footprints can be seen everywhere, in genetics, epidemiology, medicine, history and, as this article clarifies, parasites play a vivid part in our cultural imagination surrounding popular entertainment. Drawing and expanding on Michel Serres' and Enid Welsford's discussions of the parasite as a cultural force, this article explores the line of filiation and interplay between biological parasites, circus arts and their comic emblem, the clown, in different narratives and media. It documents not only fantasies of a collaborative relationship between flea performers and their 'masters', and of the relationship between clowns and parasites, both of which are mischievous 'characters', but also circus-related imaginaries of parasitic remote control.
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Coppens, Isabelle. "Metamorphoses of malaria: the role of autophagy in parasite differentiation." Essays in Biochemistry 51 (October 24, 2011): 127–36. http://dx.doi.org/10.1042/bse0510127.
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Several protozoan parasites undergo a complex life cycle that alternates between an invertebrate vector and a vertebrate host. Adaptations to these different environments by the parasites are achieved by drastic changes in their morphology and metabolism. The malaria parasites must be transmitted to a mammal from a mosquito as part of their life cycle. Upon entering the mammalian host, extracellular malaria sporozoites reach the liver and invade hepatocytes, wherein they meet the challenge of becoming replication-competent schizonts. During the process of conversion, the sporozoite selectively discards organelles that are unnecessary for the parasite growth in liver cells. Among the organelles that are cleared from the sporozoite are the micronemes, abundant secretory vesicles that facilitate the adhesion of the parasite to hepatocytes. Organelles specialized in sporozoite motility and structure, such as the inner membrane complex (a major component of the motile parasite's cytoskeleton), are also eliminated from converting parasites. The high degree of sophistication of the metamorphosis that occurs at the onset of the liver-form development cascade suggests that the observed changes must be multifactorial. Among the mechanisms implicated in the elimination of sporozoite organelles, the degradative process called autophagy contributes to the remodelling of the parasite interior and the production of replicative liver forms. In a broader context, the importance of the role played by autophagy during the differentiation of protozoan parasites that cycle between insects and vertebrates is nowadays clearly emerging. An exciting prospect derived from these observations is that the parasite proteins involved in the autophagic process may represent new targets for drug development.
Dissertations / Theses on the topic "Parasites"
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Grenier, Simon. "Biologie et physiologie des relations hôtes-parasitoïdes chez 3 tachinaires (Diptera, Tachinidae) d'intérêt agronomique : développement en milieux artificiels : lutte biologique." Lyon 1, 1986. http://www.theses.fr/1986LYO10004.
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Ferté, Hubert. "Les nématodes parasites du tube digestif du chevreuil (Capreolus capreolus L. 1758) : à propos d'une enquête réalisée dans le nord-est de la France." Tours, 1987. http://www.theses.fr/1987TOUR3805.
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Braga, Marta Isabel Fragoso Lampreia. "Prevalência e sazonalidade de parasitoses gastrointestinais, cardiovasculares e hemáticas em cães do distrito de Beja, Portugal." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2017. http://hdl.handle.net/10400.5/13687.
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Dissertação de Mestrado Integrado em Medicina VeterináriaOs cães têm um importante papel na sociedade actual, contribuindo frequentemente para o desenvolvimento físico, social e emocional de crianças e para o bem-estar dos seus donos; contudo, podem ser portadores de muitas parasitoses, algumas com importância na saúde animal e potencial zoonótico. Este trabalho surge devido à escassez de dados epidemiológicos em cães na região Sul de Portugal, pretendendo estudar a prevalência e a sazonalidade de parasitoses gastrointestinais, cardiovasculares e hemáticas em cães de três canis do distrito de Beja: Canil Intermunicipal (CI), Canil Municipal de Ferreira do Alentejo (CF) e Associação Cantinho dos Animais de Beja (CA). Assim, de Março de 2015 a Fevereiro de 2016 foram colhidas 122 amostras fecais (AF) e 266 amostras sanguíneas (AS). As AF foram analisadas pelas técnicas de Flutuação de Willis, Sedimentação Natural, esfregaço fecal corado pelo método de Ziehl-Neelsen e contagem de ovos em câmara de McMaster. Nas AS realizaram-se as técnicas de Knott e de esfregaços corados pelo método de Giemsa e das Fosfatases Ácidas. Das AF 63% exibiam pelo menos um agente. Observou-se uma prevalência de 33% para Giardia spp., 25% para Ancylostomatidae, 12% para Cryptosporidium spp., 8% para Cystoisospora spp., 6% para Toxascaris leonina, 4% para Toxocara canis, 2,5% para Taeniidae, 2% para Trichuris vulpis. Das AS 74,3% apresentavam pelo menos um agente, registando-se 68% de amostras positivas para micoplasmas hemotrópicos (Mycoplasma spp.), 9% para Babesia spp., 5% para Dirofilaria immitis e 3% para Acantocheilonema spp. O canil com maior prevalência de parasitas gastrointestinais e amostras de sangue infectadas foi o CI, com prevalências de 87% e 86%, respectivamente. A estação do ano com maior prevalência de infecções foi o Inverno, com 81% das amostras fecais e 87% das amostras sanguíneas infectadas com pelo menos um agente. Este estudo mostra um elevado grau e diversidade de parasitismo na população de canídeos de Beja. De ressalvar que ambientes de canil conjugam características ideais para a infecção continuada por parasitas com ciclo de vida directo, alguns dos quais com potencial zoonótico. Torna-se por isso fundamental adoptar uma profilaxia dirigida e regular no controlo destas parasitoses, a fim de melhorar a saúde dos animais e diminuir os riscos para a Saúde Pública, e sensibilizar funcionários, voluntários e visitantes para a adopção de medidas que permitam quebrar o ciclo e evitar a transmissão destes agentes.
ABSTRACT - Prevalence and seasonal variation of gastrointestinal, cardiovascular and hematic parasites in dogs from Beja district, Portugal - Dogs have an important role in our society, contributing to the physical, social and emotional development of children and to the well-being of their owners; however, they may be carriers of many parasitic diseases, some of them with importance in Animal Health and with zoonotic potential. This study aimed to fulfil the lack of epidemiological data concerning dog parasites in the southern region of Portugal, namely on the prevalence and seasonal variation of gastrointestinal, cardiovascular and hematic parasites in dogs of three kennels from Beja district: Intermunicipal Kennel (CI), Municipal Kennel of Ferreira do Alentejo (CF) and Association Cantinho dos Animais from Beja (CA). Thus, from March 2015 to February 2016, 122 faecal samples (FS) and 266 blood samples (BS) were collected. FS were analyzed by Willis Flotation, Natural Sedimentation, Fecal Smear stained with Ziehl-Neelsen method and egg counting in McMaster's chamber. In BS Knott test and Smear stained with Giemsa and acid phosphatase histochemical stain were performed. Overall, 63% of the FS showed at least one agent. It was detected a prevalence of 33% for Giardia spp., 25% for Ancylostomatidae, 12% for Cryptosporidium spp., 8% for Cystoisospora spp., 6% for Toxascaris leonina, 4% for Toxocara canis, 2,5% for Taeniidae , 2% for Trichuris vulpis. In total, 74,3% of the BS were positive for at least one agent. It was observed a prevalence of 68% for hemotropic mycoplasmas (Mycoplasma spp.), 9% for Babesia spp., 5% for Dirofilaria immitis and 3% for Acantocheilonema spp. CI was the kennel with the highest prevalence of gastrointestinal parasites and positive blood samples, with prevalence of 87% and 86%, respectively. The season with the highest prevalence was the winter, with 81% of FS and 87% of BS positive for at least one agent. This study showed a high level and diversity of parasitism in dog’s population of Beja. It should be noted that kennel environment combine the ideal characteristics for the continuous infection by parasites with direct life cycle, some of them with zoonotic potential. It is, therefore, crucial to adopt a targeted and regular prophylaxis in the control of these parasites, in order to improve animal health and reduce the risk to Public Health, and also alert officials, volunteers and visitors of these kennels about measures to break the cycle and avoid the transmission of these agents.
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Schneider, Maria Victoria. "Modes de reproduction chez le parasitoi͏̈de solitaire Venturia canesces." Lyon 1, 2003. http://www.theses.fr/2003LYO10071.
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Venturia canescens, un parasitoi͏̈de ichneumonidé de chenilles de piralidés, a deux modes de reproduction : arrhénotoque, (mâles haploi͏̈des et femelles diploi͏̈des)) et thélytoque (des femelles vierges engendrent des filles diploi͏̈des). Cette thélytoquie n'est pas l'effet de bactéries symbiotiques. Dans le Sud de la France, les deux modes de reproduction coexistent en sympatrie. La thèse traite des questions soulevées par cette coexistence. Une étude de la distribution géographique et une analyse moléculaire des populations, ont montré l'existence d'un clone thélytoque très répandu. Cependant quelques individus thélytoques sont génétiquement très proches des individus arrhénotoques. Une importante partie de la variabilité chez les thélytoques est due à un flux génique à partir de mâles arrhénotoques. Pour mieux comprendre la coexistence des deux modes de reproduction, différents traits d'histoire de vie et compromis génétiques reflétants des différentes pressions de sélection ont été étudiés.
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Bell, Andrew Stuart. "Studies on the biosystematics and biology of strigeids (Digenea) parasitic in freshwater fish." Thesis, University of Stirling, 1995. http://hdl.handle.net/1893/3383.
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This study is concerned with two strigeid genera which utilise fish as their second intermediate host and piscivorous birds as a definitive host, i.e. Apatemon (Apatemon) Sudarikov, 1959 and Ichthyocotylurus Odening, 1969. Although the lifecycle has been ascertained for most Ichthyocotylurus spp., confusion and disagreement still exist as to the constituent species, while all of the life-stages have been described for only a single member of the subgenus Apatemon (Apatemon). In order to clarify species membership to these taxa and indeed the taxonomic position of the subgenus Apatemon (Apatemon) further information was required on the life-cycles and life-stages of these strigeids. Although, metacercariae from this family have been recorded from a variety of British fishes, confirmed records, i.e. those supported with life-cycle data, are limited to a single species. It was this lack of confidence in identifying metacercariae recovered from fishes and the lack of known good criteria for distinguishing the adults that prompted the present study. Collections of metacercariae from a variety of hosts and locations were made, from which all subsequent life-cycle stages were obtained. The project aims were to establish the identity of the forms occurring in British fishes, by applying discriminatory techniques to the experimentally reared life-stages. In addition to traditional methods, techniques with little previous application to these genera were used and included, scanning electron microscopy (SEM), chaetotaxy, principal components analysis (PCA), and karyology. Furthermore, behavioural aspects such as the release patterns of cercariae from their molluscan hosts were studied to investigate whether they would prove to be of diagnostic value. Metacercariae obtained from the sampling survey were tentatively identified, using all currently employed methods for their determination, i.e. morphology, nature of cyst, host and site specificities, as Ichthyocotylurus erraticus (Rudolphi, 1809), I. variegatus (Creplin, 1825), Apatemon gracilis (Rudolphi, 1819) and A. annuligerum (Nordmann, 1832). Material collected from Finland was considered to contain both Ichthyocotylurus spp. recovered in the U.K., as well as I. platycephalus (Creplin, 1825) and I. pileatus (Rudolphi, 1802). The Ichthyocotylurus spp. were found to be more host specific than A. gracilis, although A. annuligerum was considered oioxenic to perch Perea fluiatilis L. Records of I. erraticus from gwyniad Coregonus lavaretus (L.) and grayling Thymallus thymallus (L.), and A. gracilis from arctic charr Salvelinus alpinus (L.) constitute first listings from Britain. The large number of sensilla present on the body surface of these metacercariae, observed by SEM and chaetotaxy, precluded their diagnostic use. PCA was, however, found to be of value for distinguishing between species and determining morphological variation within a species. I. erraticus, I. variegatus and A. gracilis adults were successfully reared in experimental hosts using metacercariae from a variety of fish hosts, sites within a single fish host and geographical sites. The adults obtained enabled clarification of the identities assigned to the metacercariae. Those metacercariae believed to represent I. pileatus and A. annuligerum failed to establish in experimental hosts. Herring gulls and lesser black-backed gulls proved to be extremely good experimental hosts for both Ichthyocotylurus spp., with the vast majority of infections establishing and providing high yields of eggs and adults. These infections yielded information on the establishment, development, fecundity, site specificity, longevity and morphological variability of the adults. Aspects of the morphology and biology of I. variegatus adults recorded were found to support its validity as a species discrete from I. platycephalus which was in some doubt. The experimental hosts used for A. gracilis infections, domestic and mallard ducklings, were found to be less satisfactory. Challenges were performed with A. gracilis metacercariae from three sources, rainbow trout, salmon parr and stone loach. The latter source was the only one to result in egg producing adults, with specimens exhibiting normal morphology and demonstrating an increased longevity over adults raised from salmonid metacercariae. These findings suggest that the metacercarial host may affect the successful completion of the life-cycle. Eggs of known origin were collected for all three cultured strigeid species, enabling further life-cycle studies, these were incubated and miracidia successfully raised. Developmental periods were found to be temperature dependent and differed for the three species at 20°C: A. gracilis < I. erraticus < I. variegatus. Light microscopy revealed the morphology of all three species to be identical, as were the epidermal plate formulae and chaetotaxy, indicated by silver-staining. The nomenclature for the distribution of miracidial sensilla derived by Dimitrov et al. (1989) was amended to enable a full description of these species. Osmotic shock resulted in an improved deciliation of the miracidia compared to sonication and subsequent SEM observation confirmed the arrangement of body surface structures, while revealing sensilla forms. Behavioural aspects of I. variegatus miracidia were examined, with a maximum longevity (< 11 hours) recorded at the lowest temperature studied (l0 degrees C), and host finding demonstrated to occur by an increased turning response in the presence of substances emitted from the susceptible snail host, following an initial unresponsive dispersal phase. Ichthyocotylurus cercariae were found in naturally infected Valvata piscinalis which constitutes the first record in Britain of cercariae of this genus. Cercariae of I. erraticus and I. variegatus were successfully raised experimentally from miracidia of known identity and origin within naive, experimentally raised V. piscinalis hosts, while A. gracilis cercariae were obtained from laboratory reared Lymnaea peregra. Cercarial developmental periods within the molluscan host were found to be temperature dependent and markedly different for the strigeid genera investigated, as were their behaviour and morphology. The Ichthyocotylurus spp. exhibit a distinct diurnal emergence rhythm from their molluscan host, being shed during the hours of daylight, while A. gracilis cercariae demonstrate a reciprocal pattern, emerging during the hours of darkness. Behavioural contrasts were also observed in longevities, emergence strategies (route of exit) and swimming behaviour. The two Ichthyocotylurus spp. were extremely similar, the only cercarial features found to be of diagnostic use were: the presence or absence of eye-spots; their differing developmental periods from miracidium to cercaria; the number and distribution of sensilla when compared by PCA; and their differing longevities at 20 degrees C. Characters considered to be of value in differentiating between strigeid cercariae at the species level, including the armature, chaetotaxy pattern and resting posture, did not differ between these two species. SEM observations enabled descriptions of the variety and structure of sensilla present on different life-stages, while transmission electron microscopy revealed the internal structure of cercarial sensory structures. Experimentally raised cercariae were found to be infective and the life-cycle was completed for the three strigeid species. Host specificities were observed for I. erraticus and A. gracilis, being particularly stringent for the latter species, while site specificities recorded were as observed in natural infections. Metacercarial maturation periods (for encystment) were highly temperature dependent, being comparable for the two Ichthyocotylurus spp. and more rapid than for A. gracilis specimens.
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Mintsa, Nguema Rodrigue. "Interactions hôte-parasite dans le modèle Biomphalaria pfeifferi-Schistosoma mansoni du Dhofar (Oman) : génétique des populations de l’hôte, traits d’histoire de vie et conséquences sur la transmission du parasite." Perpignan, 2010. http://www.theses.fr/2010PERP0995.
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Cette thèse a été réalisée dans le contexte de la réémergence de la schistosomose à Schistosoma mansoni (plathelminthe trématode) dans le Dhofar en Oman. Le travail est centré sur les interactions hôte-parasite et sur leurs conséquences sur la transmission du schistosome. Une première partie est consacrée à l’étude spatio-temporelle de la structure génétique des populations de Biomphalaria pfeifferi (mollusque gastéropode d’eau douce). Elle a été réalisée à l’aide de neuf marqueurs microsatellites sur 18 populations de mollusques. Les populations de B. Pfeifferi étudiées sont caractérisées par une très faible variabilité génétique intra populationnelle. Par contre, elles sont fortement différenciées génétiquement. Une différenciation temporelle a également été enregistrée dans certaines populations. Une seconde partie est consacrée à l’étude des traits d’histoire de vie et des relations hôte-parasite. Elle a été réalisée à l’aide de huit combinaisons hôte-parasite qui diffèrent soit par la population de parasite (origine humaine ou origine murine), soit par la catégorie du site (naturel ou aménagé), soit par le morphe du mollusque (pigmenté ou albinos). Les traits d’histoire de vie suivants ont été analysés : croissance, fécondité et survie de B. Pfeifferi et taux d’infestation, période prépatente et production cercarienne de S. Mansoni. Les résultats montrent que la population de S. Mansoni et le morphe de B. Pfeifferi jouent un rôle majeur dans la transmission de la schistosomose dans le Dhofar. Les résultats sont discutés en termes de compatibilité hôte-parasiteThis thesis has been conducted in the context of the reemergence of schistosomiasis caused by Schistosoma mansoni (flatworm trematode) in Dhofar (Oman). The work focuses on the host-parasite interactions and their implications on schistosome transmission. The first part is devoted to a spatiotemporal study of the population genetics of Biomphalaria pfeifferi (freshwater gastropod snail). Nine microsatellite markers were used for characterization of 18 populations of B. Pfeifferi. The results showed that intrapopulations genetic variability was very low. However, the populations were highly differentiated. Temporal differentiation was also recorded in some populations. A second part concerns to the study of the life-history traits and host-parasite relationships. It was conducted using eight host-parasite combinations that differ either by the parasite population (human versus murine), by the waterbody category (natural versus man-made) or by the morph of the snail (pigmented versus albino). The following life-history traits were analyzed: growth, fecundity and survival of B. Pfeifferi and rate of infection, prepatent period and cercarial production of S. Mansoni. The results show that both the origin of S. Mansoni and the pigmentation of B. Pfeifferi play a major role in transmission of schistosomiasis in Dhofar. The results are discussed in terms of host-parasite compatibility
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Owen, Sinclair Patrick. "The first epidemiological study on the prevalence of cardiopulmonary and gastrointestinal parasites in cats and dogs from the Algarve region of Portugal using the FLOTAC technique." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2017. http://hdl.handle.net/10400.5/14521.
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Dissertação de Mestrado Integrado em Medicina VeterináriaAlthough over the past decades various parasitologal surveys have been conducted in Portugal, at present scant information is available on the prevalence of clinically-relevant gastrointestinal and cardiopulmonary parasites in the Algarve. This study performed between February and April 2016 using the FLOTAC technique was undertaken to address this. Faecal samples were collected from 66 dogs and 76 cats > 6 months old from shelters in the region. Faecal forms of six different groups of endoparasites were detected, four of which with zoonotic potential. The overall prevalence in both species was 31%, with 21.2% of the dog samples positive and 39.5% of the cat samples positive for at least one parasite. Concurrent infections with two parasites were detected in 2.6% of the dog samples and 9.2% of the cats. Toxocara spp. was the most common parasite found in 13.6% (EPG: 61.3 ± 74.65) of the dogs samples and 31.6% (EPG 523.92 ± 688.75) of the cats. Other parasites found in dogs were Ancylostomatidae (3%), Taeniidae (6%) and Trichuris spp. (2%) and in cats Ancylostomatidae (5.3%), Aelurostrongylus abstrusus (4%), Cystoisospora spp. (6.6%) and Taeniidae (1.3%) were found. The presence of zoonotic parasites in the population studied as well as the elevated prevalence of Toxocara spp. overall are concerning and highlight the need for regular prophylaxis, hygiene and sanitary control measures in pets as well as shelter animals.
RESUMO - PRIMEIRO RASTREIO DE PARASITAS CARDIOPULMONARES E GASTROINTESTINAIS EM CÂES E GATOS DA REGIÂO DO ALGARVE UTILIZANDO A TÉCNICA DE FLOTAC - Apesar de nas últimas décadas terem surgido vários trabalhos de rastreio parasitológico em Portugal, atualmente continuam a existir poucos dados sobre a incidência de parasitas gastrointestinais e cardiopulmonares de carnívoros domésticos com relevância clinica no Algarve. Por esta razão foi realizado um estudo entre Fevereiro e Abril de 2016 utilizando a técnica do FLOTAC. No total foram colhidas 142 amostras de canis e gatis da região correspondendo a 66 cães e 76 gatos todos com > 6 meses de idade. Foram detetadas formas de eliminação fecal de seis grupos de endoparasitas, quatro dos quais com potencial zoonótico. A prevalência global no estudo foi de 31%, com 21.2% das amostras de canídeo positivas e 39.5% de felídeo positivos para pelo menos um parasita. Infeções mistas com dois parasitas foram observadas em 2.6% das amostras de cão e 9.2% das de gato. Toxocara sp. foi o parasita mais frequente em cães evidenciando-se em 13.6% (OPG: 61.3 ± 74.65) das amostras e em 31.6% (OPG 523.92 ± 688.75) das de gato. Nos cães também foram detetadas amostras positivas para Ancylostomatidae (3%), Taeniidae (6%) e Trichuris spp. (2%) e nos gatos Ancylostomatidae (5.3%), Aelurostrongylus abstrusus (4%), Cystoisospora spp. (6.6%) e Taeniidae (1.3%). A presença de parasitas com potencial zoonótico na população estudada bem como e elevada prevalência de Toxocara spp. é preocupante e alerta para a necessidade de desparasitação regular e medidas de controlo higio-sanitário adequadas, quer em animais com proprietário, quer em animais de abrigo.
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Isomursu, M. (Marja). "Host–parasite interactions of boreal forest grouse and their intestinal helminth parasites." Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526203645.
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Abstract Parasites are an inseparable part of the life of wild birds. They may cause morbidity, mortality or reduction in fecundity. Parasite distribution in hosts is typically not uniform and many host factors (e.g. age) may affect the pattern of distribution. Under certain conditions, parasites even have the potential to regulate the host population. The grouse species of Finnish forests — the capercaillie Tetrao urogallus , the black grouse Lyrurus tetrix and the hazel grouse Tetrastes bonasia — harbour several species of intestinal helminth parasites. The populations have fluctuated in cyclic manner but the mechanisms behind the cycles are largely unknown. I studied the interactions of forest grouse and their intestinal helminth parasites by using intestinal samples collected by hunters in five game management districts during eight years (1995–2002). The most common parasite species in the samples was the nematode Ascaridia compar. Also, three species of cestodes (Skrjabinia cesticillus, Paroniella urogalli and Hymenolepis sp.) were found. Large size, male gender and age over 1 year were connected with an increased probability and intensity of A. compar infection. Juvenile grouse were commonly infected with cestodes while in adults infections were quite rare. The influence of inbreeding on the susceptibility to parasite infections was studied in the capercaillie by analysing microsatellite heterozygosity. The less heterozygous birds were more likely to be infected with A. compar and were more intensely infected suggesting negative influence of inbreeding on parasite resistance. An indirect negative effect of parasites was found by comparing bags hunted with a trained dog or without a dog. Grouse infected by cestodes were significantly more common in the dog-assisted bag. Thus, cestode infection seemed to make grouse more vulnerable to canine predation. The interaction between grouse population dynamics and parasites was studied by analyzing the grouse densities obtained from annual wildlife counts and parasite indices. A. compar was most common and most abundant in the years of grouse population decline. The grouse population growth rate was negatively correlated with the annual mean abundance of A. compar. Relative survival but not breeding success decreased as the abundance of A. compar increased. The findings suggest that A. compar influences the dynamics of Finnish grouse even though regular cyclic dynamics are no longer evidentTiivistelmä Loiset kuuluvat erottamattomana osana luonnonvaraisten lintujen elämään. Ne voivat aiheuttaa sairautta, kuolleisuutta tai hedelmällisyyden alentumista. Tyypillisesti loiset ovat levinneet isäntäpopulaatioon epätasaisesti ja monet isännän ominaisuudet (esim. ikä) vaikuttavat levinneisyyteen. Tietyissä oloissa loiset voivat jopa säädellä isäntäpopulaatiotaan. Suomalaiset metsäkanalinnut — metso Tetrao urogallus, teeri Lyrurus tetrix ja pyy Tetrastes bonasia — ovat useiden suolistoloismatolajien isäntiä. Metsäkanapopulaatiot ovat vaihdelleet syklisesti, mutta syklejä aiheuttavat mekanismit ovat yhä tuntemattomia. Tutkin metsäkanalintujen ja niiden suolistoloisten välisiä vuorovaikutuksia käyttäen metsästäjien vuosina 1995–2002 viidestä eri riistanhoitopiiristä keräämiä suolistonäytteitä. Yleisin loislaji näytteissä oli kanalintusuolinkainen, Ascaridia compar. Myös kolme heisimatolajia (Skrjabinia cesticillus, Paroniella urogalli ja Hymenolepis sp.) todettiin. Suuri koko, koirassukupuoli ja yli yhden vuoden ikä olivat yhteydessä suurempaan kanalintusuolinkaistartunnan todennäköisyyteen ja voimakkuuteen. Nuorilla (alle 1 v.) linnuilla heisimadot olivat yleisiä, kun taas aikuisilla tartunnat olivat varsin harvinaisia. Sisäsiittoisuuden vaikutusta loistartuntaherkkyyteen tutkittiin metsolla mikrosatelliittiheterotsygotian perusteella. Vähemmän heterotsygoottiset metsot olivat todennäköisemmin ja voimakkaammin suolinkaisten infektoimia, mikä viittaa sisäsiittoisuuden negatiiviseen vaikutukseen loisten vastustuskykyyn. Loisten epäsuora haitallinen vaikutus havaittiin, kun verrattiin koiran kanssa ja ilman koiraa metsästettyä lintusaalista. Heisimadot olivat selvästi yleisempiä linnuilla, jotka oli metsästetty koiran kanssa kuin ilman koiraa metsästetyillä. Heisimatotartunta näytti siis altistavan metsäkanoja koiraeläinten saalistukselle. Metsäkanalintu- ja loispopulaatioiden välistä vuorovaikutusta tutkittiin analysoimalla vuosittaisia metsäkanatiheyksiä ja loisten runsautta. Kanalintusuolinkainen oli yleisimmillään ja runsaimmillaan metsäkanatiheyden laskuvuosina. Metsäkanapopulaation vuosittainen kasvuvauhti korreloi negatiivisesti kanalintusuolinkaisen vuosittaisen runsauden kanssa. Suhteellinen elossasäilyvyys laski kanalintusuolinkaisen runsauden lisääntyessä, mutta lisääntymistuloksen suhteen ei ollut samaa ilmiötä. Löydökset viittaavat siihen, että kanalintusuolinkaisella on vaikutusta suomalaisten metsäkanalintukantojen vaihteluihin, vaikka syklisiä kannanvaihteluja ei enää havaitakaan
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St, Vincent Chad Michael. "'Parasite single' women of Japan : 'parasites' or search for a new identity? /." Title page, contents and introduction only, 2002. http://web4.library.adelaide.edu.au/theses/09AR/09ars7749.pdf.
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Goodhead, Ian Barry. "Genomic approaches to understanding host resistance and parasite virulence in Trypanosoma parasites." Thesis, University of Liverpool, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.570185.
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Roughly one-third of cattle in sub-Saharan Africa are at risk of contracting "Nagana" - a disease caused by Trypanosoma parasites similar to those that cause human "Sleeping Sickness". Laboratory mice can also be infected by trypanosomes, and different mouse breeds show varying levels of susceptibility to infection, similar to what is seen between breeds of cattle. We have applied next-generation technologies to identify shared polymorphisms between susceptible mice, and annotated these for potential function alongside publicly available SNP data sets. By so doing, short lists of genes at the QTL have been created to aid functional testing in cattle. This includes two promising 'candidate genes': Pram1 and Cd244, which can now be tested to confirm their effect on response to trypanosome infection. The human-infective parasite Trypanosoma brucei rhodesiense generally causes an acute form of "sleeping sickness" across Eastern Africa, compared to the more chronic T b. gambiense infections found in Western Africa. The 1988-1993 Ugandan T b. rhodesiense outbreak constituted infections by parasites with differences in their clinical manifestation. Two such sub types, termed Busoga 17 (B 17) and Zambesi 310 (Z31O), caused more acute, and more chronic infections, respectively. In order to investigate whether the major QTL that regulates survival in T congolense infections (Tir 1) does so in a similar manner in T b. rhodesiense, mice congenic for the C5 7BL/ 6 allele (Tirl CC) at Tir 1 were infected with Z310 and B 1 7 zymodeme T b. rhodesiense parasites. Whilst Tir 1 was not found to have a significant effect on survival, all mice had a significantly shorter mean survival time when infected with B 17 (~1O. 7 days) than those infected with Z31 0 (~15.6 days), in line with previous observations of human infections. In order to identify genetic loci that might underlie differences in virulence between T b. rhodesiense zymodemes, cluster analysis was performed on the microsatellite genotypes of 31 T b. rhodesiense isolates that represented nine different zymodemes. Despite STRUCTURE identifying three population clusters, the Z310 and B 17 parasite populations could not be distinguished, suggesting that either multiple genes control virulence, that there is gene flow between similar parasite populations, or that the microsatellite genotyping is insufficient to distinguish between different parasite populations. Finally, we present the first whole-genome sequences of T b. rhodesiense field isolates, one each of Z310 and B 1 7. Genomic analysis of east African T b. rhodesiense and west African T b. gambiense has suggested that recombination may be occurring between them. SNP genotyping of 32 T b. rhodesiense isolates showed that differences in clinical phenotypes were associated with differences in alleles on chromosome 8. The genome sequence suggests that chromosome 8 is heterozygous for alleles of west African origin in the more virulent strain, suggesting that recombination may be associated with parasite virulence. This suggests that the human subspecies of T brucei are not genetically distinct, which has major implications for the control of the parasite, the spread of drug resistance and understanding the variation in virulence and the emergence of human infectivity. Further genetic analysis of T b. brucei populations from Western, central and Eastern Africa may be necessary to ascertain whether recombination is occurring directly between human-infective subspecies, or in the underlying animal-infective population.
Books on the topic "Parasites"
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Poulin, Robert. Evolutionary ecology of parasites. 2nd ed. Princeton, N.J: Princeton University Press, 2007.
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Frischknecht, Friedrich. Parasites. Wiesbaden: Springer Fachmedien Wiesbaden, 2024. http://dx.doi.org/10.1007/978-3-658-45403-6.
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Poulin, Robert. Evolutionary ecology of parasites: From individuals to communities. London: Chapman & Hall, 1998.
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M, Behnke Jerzy, ed. Parasites, immunity and pathology: The consequences of parasitic infection in mammals. London: Taylor & Francis, 1990.
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Sugoni͡aev, E. S. Host-parasite relations in insects: As they relate to eulecanium caraganae borchs, and its parasite Encyrtus infidus Rossi. Karachi, Pakistan: Published for the OICD, ARS, U.S. Dept. of Agriculture by G. Saad, 1989.
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Combes, Claude. Les associations du vivant: L'art d'être parasite. Paris: Flammarion, 2001.
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T, Englund Paul, Sher Alan, and Marine Biological Laboratory, eds. The Biology of parasitism: A molecular and immunological approach : based on the Biology of parasitism course held at the Marine Biological Laboratory in Woods Hole, Massachusetts. New York: Liss, 1988.
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Hawkins, Bradford A. Pattern and process in host-parasitoid interactions. Cambridge [England]: Cambridge University Press, 1994.
Find full textBook chapters on the topic "Parasites"
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Presterl, Elisabeth, Magda Diab-El Schahawi, Luigi Segagni Lusignani, Helga Paula, and Jacqui S. Reilly. "Parasites and Parasitic Diseases." In Basic Microbiology and Infection Control for Midwives, 161–70. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-02026-2_18.
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Williams, Andrew R. "Parasites and Parasitic Diagnostics." In Laboratory Animal Science and Medicine, 191–99. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-59103-7_11.
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Hinchliffe, Arnold P. "Parasites or Sub-Parasites." In Volpone, 33–38. London: Macmillan Education UK, 1985. http://dx.doi.org/10.1007/978-1-349-06536-3_5.
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Cerullo, Marcelo. "Parasites." In Encyclopedia of Ophthalmology, 1–3. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-35951-4_879-1.
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Suh, Kathryn N., and Jay S. Keystone. "Parasites." In Community-Acquired Pneumonia, 885–906. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/0-306-46834-4_59.
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Fowler, Murray E., and P. Walter Bravo. "Parasites." In Medicine and Surgery of Camelids, 231–69. Ames, Iowa USA: Blackwell Publishing, Inc., 2013. http://dx.doi.org/10.1002/9781118785706.ch8.
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Masterpol, Kasia Szyfelbein, Andrea Primiani, and Lyn McDivitt Duncan. "Parasites." In Atlas of Essential Dermatopathology, 10–11. London: Springer London, 2012. http://dx.doi.org/10.1007/978-1-4471-4471-7_4.
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Croese, John. "Parasites." In Textbook of Clinical Gastroenterology and Hepatology, 349–54. Oxford, UK: Wiley-Blackwell, 2012. http://dx.doi.org/10.1002/9781118321386.ch48.
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Primavera, Nicholas. "Parasites." In Encyclopedia of Evolutionary Psychological Science, 1–2. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-16999-6_2781-1.
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Hechinger, Ryan F., Kevin D. Lafferty, and Armand M. Kuris. "Parasites." In Metabolic Ecology, 234–47. Chichester, UK: John Wiley & Sons, Ltd, 2012. http://dx.doi.org/10.1002/9781119968535.ch19.
Full textConference papers on the topic "Parasites"
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K, Senthil, Yuktha Varshika J, Gopinath M, Pooja Sri V, Vishwa S, and Monikaa R. "Genomic Insights into the Classification and Identification of Plasmodium Parasites." In 2024 First International Conference on Innovations in Communications, Electrical and Computer Engineering (ICICEC), 1–6. IEEE, 2024. https://doi.org/10.1109/icicec62498.2024.10808865.
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Shesteperov, A. A., and E. S. Starostina. "PARASITOCENOTIC ASPECTS IN PHYTOPARASITOLOGY." In THEORY AND PRACTICE OF PARASITIC DISEASE CONTROL. VNIIP – FSC VIEV, 2024. http://dx.doi.org/10.31016/978-5-6050437-8-2.2024.25.462-468.
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The term "microparasitocenosis" proposed by A. P. Markevich, who combined parasitizing forms of resident microflora of the organism and parasites that entered from external environment. Viruses, viroids, bacteria, fungi, protozoa, phytohelminths, phytoparasitic mites and insects form the parasitocenosis in a macroorganism (plant) and represent a damaging complex that contributes to pathological changes in the macroorganism. The intention to simplify complex biological processes as much as possible has led to artificial isolation of any single pathogen. This turned out to be necessary and effective in studying causative agents of dangerous plant parasite infections. But it turned out to be inconsistent for associated infections and invasions since complex diseases develop when they are combined with other phytoparasites. Their synergism contributes to high harmfulness of complex diseases. Unfortunately, the problem of plant parasite infection and invasion has not been sufficiently studied in phytoparasitology. As defined, plant parasitism has boundaries from positive to neutral interactions of other types that are precisely outlined by pathogenicity. Harmfulness is exactly what can explain centuries-old hostility towards parasites. We considered the plant parasite cenosis of strawberries that included 27 plant parasites and 25 pathogens. The discovery of relationships between phytopathogens and phytoparasites has resulted in a qualitative change in cognitive tools and the interpretation of various pathogenic process phases. Based on systemic analysis, phytoparasites at different levels (plants, plant populations, biocenosis) are considered not as a mechanical population but as an integral system that functions under specific laws. Systemic quality of the plant parasitic cenosis appears in its interactions with other organisms.
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Abbas MARHOON, Ikhlas, and Marwa Sami ALWAN. "DETECTION OF PREVALENCE OF INTESTINAL PARASITES IN FRESHWATER FISH LIZA ABU FROM EUPHRATES RIVER, AL-DIWANIYAH CITY – IRAQ." In DETERMINATION OF THE ACTUAL INTENSITY BY CORRECTION OF THE EMISSION SPECTRUM LINES OF HEAVY METALS CONTAINED IN CRUDE OIL USING LASER INDUCED PLASMA –TECHNIQUE. Rimar Academy, 2022. http://dx.doi.org/10.47832/minarcongress4-8.
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A 176 samples of freshwater fish Liza abu were fishing from Euphrates river in the AlDiwaniyah city – Iraq , to investigate of some intestinal parasite , identify the rate of infection with this parasites and then determining the relationship between temperature and prevalence of parasitic infection rates , for the period between October 2020 and March 2021. All fish examined by using laboratory methods to detected intestinal parasitic infection. The results revealed that the total infection rate of prevalence of intestinal parasites in Liza abu was 75.56%, and the results recorded presence of five different species of parasites were isolated from freshwater fish which are as follows: Three species belonging to two classes of protozoan : Sporozoa (Cryptosporidium sp. and Eimeria sp.) and one species belonged to Ciliata which is Tetrahymena sp. with an infection rate 55.68% , 35.79% and 17.61% respectively. Two species belong to parasitic helminthes : Eustrongylides sp.(Nematodes) with an infection rate 22.73%, and the other species is related to Neoechinorhynchus sp. (Acanthocephalans) with an infection rate of 44.88%. Also results showed a significant difference in infection rates during the months of the study, the highest percentage of infection was appeared during March and February which reached 93.94% and 91.67% respectively, while the infection rate decreased in January (45.0%)
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Jitea (Sirbu), Beatrice Ana-Maria, Catalin Bogdan Sirbu, Tiana Florea, Ionela Hotea, and Gheorghe Darabus. "ENDOPARASITES FOUND IN LEPUS EUROPAEUS HUNTED IN WESTERN ROMANIA." In 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022v/6.2/s29.87.
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The European hare (Lepus europaeus) is widely spread throughout Europe, however, their numbers are declining in some countries, with parasites bearing some responsibility for this population decrease, due to their role as favouring factors. The aim of this study was to determine the gastrointestinal parasitic populations of hares (Lepus europaeus) from Romania. The study took place during the hunting seasons (November-February) of the years 2020-2022. Gastrointestinal tracts from 72 hares were subjected to a macro- and microscopic examination in order to determine the presence of endoparasites. Each intestinal segment was individualised and examined by standard methods. The faeces were subsequently examined using the flotation method (Willis) with suprasaturated NaCl solution. Fifty one (70.8%) animals were parasitized by one or several parasite species. The following helminths were found through necropsy: Trichostrongylus spp. (76.5 %), Passalurus ambiguus (15.7 %) in the digestive tract, Dicrocoelium dendriticum (9.8 in the liver and Cysticercus pisiformis (2 %) on the abdominal serosae. Additionally, Linguatula serrata nymphs were also found in 3.9 % animals. Coproscopy revealed a prevalence rate of 100% for Eimeria spp. Multiparasitism was more frequent than parasitism involving a single species. Although the identified parasites can play an important role in the health status of rabbits.
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Martins, Geovani L., Daniel S. Ferreira, Claudia M. Carneiro, and Andrea G. C. Bianchi. "Trypanosoma cruzi Detection using LSTM Convolutional Autoencoder." In Simpósio Brasileiro de Computação Aplicada à Saúde. Sociedade Brasileira de Computação - SBC, 2023. http://dx.doi.org/10.5753/sbcas.2023.230153.
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The presence of Trypanosoma cruzi (T. cruzi) parasites in blood samples is proof of the medical diagnosis of Chagas disease. Since the motion of these microorganisms is conspicuous in optical microscopy videos, we propose a spatio-temporal autoencoder for anomaly detection caused by parasite motility. This approach includes a spatial feature extractor and a temporal sequencer ConvLSTM for learning the temporal evolution of the spatial features. We trained the autoencoder with no parasites videos to learn the normal pattern and measured the regularity score in test videos with parasites. Our results showed that an LSTM-based autoencoder may identify T. cruzi anomalous motion, being a promising method for detecting parasites in microscopy videos.
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A. ALMASHAY, Ahmed. "ISOLATION AND IDENTIFICATION OF PARASITIC NEMATODES (CUCULLNUS LONGICOLLIS) THAT INFECTS (MULLUS SURMULETUS) FISH IN THE MARINE WATERS OF SIRTE-LIBYA." In IV.International Scientific Congress of Pure,Appliedand Technological Sciences. Rimar Academy, 2022. http://dx.doi.org/10.47832/minarcongress4-1.
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Due to the important geographical location that characterized the city of Sirte-Libya, and given the importance of fish wealth in this region and the negative impact that may occur as a result of infecting fish with parasites, and the lack of research studies on this subject in this region, so this research study was conducted to contribute to the to clarify this issue. A number of (70) fish specimens were collected from Sirte - Libyan coast facing Mediterranean Sea from January 2021 to March 2021 , and the measurements were made on them all marine fish examined externally in the laboratory, after that they were dissected by the scientific methods used and examined internally, as well as the digestive system was examined and conducted on parasites extracted by all the processes related to study. The discovered parasitic worms were carefully extracted, laboratory operations were conducted on them, and they were examined and photographed under a normal light microscope as well as an electron microscope. The results showed that (2) of these fish were infected with nematode worms of the species Cucullanus longicollis , which were extracted from the large intestines of these fish. This parasite was recorded for the first time in the marine waters of the city of Sirte-Libya.The general shape of the parasite has been described, supported by pictures. This research aims to identify the parasitic nematodes that infect Mullus surmuletus fish and to know the extent of environmental pollution in the study area and the rate of fish infestation, as well as to clarify and studying the general form of these parasitic worms under study
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A.ALMASHAY, Ahmed. "ISOLATION AND IDENTIFICATION OF PARASITIC NEMATODES (CUCULLNUS LONGICOLLIS) THAT INFECTS (MULLUS SURMULETUS) FISH IN THE MARINE WATERS OF SIRTE-LIBYA." In IV.International Scientific Congress of Pure,Appliedand Technological Sciences. Rimar Academy, 2022. http://dx.doi.org/10.47832/rimarcongress4-1.
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Due to the important geographical location that characterized the city of Sirte-Libya, and given the importance of fish wealth in this region and the negative impact that may occur as a result of infecting fish with parasites, and the lack of research studies on this subject in this region, so this research study was conducted to contribute to the to clarify this issue. A number of (70) fish specimens were collected from Sirte - Libyan coast facing Mediterranean Sea from January 2021 to March 2021 , and the measurements were made on them all marine fish examined externally in the laboratory, after that they were dissected by the scientific methods used and examined internally, as well as the digestive system was examined and conducted on parasites extracted by all the processes related to study. The discovered parasitic worms were carefully extracted, laboratory operations were conducted on them, and they were examined and photographed under a normal light microscope as well as an electron microscope. The results showed that (2) of these fish were infected with nematode worms of the species Cucullanus longicollis , which were extracted from the large intestines of these fish. This parasite was recorded for the first time in the marine waters of the city of Sirte-Libya.The general shape of the parasite has been described, supported by pictures. This research aims to identify the parasitic nematodes that infect Mullus surmuletus fish and to know the extent of environmental pollution in the study area and the rate of fish infestation, as well as to clarify and studying the general form of these parasitic worms under study. Key words: Mullus surmuletus, Cucullanus longicollis, Waters of Sırte
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Mirzaei, Yousef, Renas Abas, and Dunya Omar. "Soil Contamination with Intestinal Helminthic Parasites in Children’s Play Areas in Soran City, Kurdistan Region, Iraq." In 5th International Conference on Biomedical and Health Sciences, 328–30. Cihan University-Erbil, 2024. http://dx.doi.org/10.24086/biohs2024/paper.1205.
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Parasitic diseases caused by soil-transmitted helminths are significant diseases of humans and livestock, that only about the human population, affect about one third of the world’s people.These parasites passing some parts of their life cycle in the soil and then transfer from soil to new host. The primary goal of current study was to determine the rate of soil contamination by intestinal helminthic parasites in soil samples ghatered from children play areas in Soran city and suburbs. Sixty soil samples were collected randomly and examined by floatation technique. By applying NaNO3 solution, helminth forms were found in (40%) of urban samples while (33.3%) of them were positive by using sugar solution. Flotation by NaNO3 solution and sugar solution showed that (73.3%) and (53.3%) of rural samples were contaminated respectively. The predominant parasite species detected in the examined soil samples were Taenia spp. and Ascaris spp. This study demonstrated high level of soil contamination in both urban and rural play areas thus there is a serious threat and risk for acquiring helminth infection for children who use these areas.
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Christenson, Mike. "Comprehensive Parasites." In CAADRIA 2014: Rethinking Comprehensive Design: Speculative Counterculture. CAADRIA, 2014. http://dx.doi.org/10.52842/conf.caadria.2014.771.
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Pennacchio, Francesco. "Honey bee-parasite immune suppression by parasites and pathogens." In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.92904.
Full textReports on the topic "Parasites"
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Leslie, Katie L., Rachel L. Welicky, Maureen A. Williams, and Chelsea L. Wood. Parasite Biodiversity. American Museum of Natural History, 2020. http://dx.doi.org/10.5531/cbc.ncep.0150.
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In this module, students have the opportunity to discover the hidden world of parasites: they will come face to face with living parasites, learn about what differentiates parasites from free-living species, observe some common adaptations to a parasitic lifestyle, explore the ecological role of parasites in food webs, and assess how parasite abundance might change in a changing world. To accomplish these goals, this module includes an introductory PowerPoint presentation (including a video of parasite ecologist Dr. Chelsea L. Wood delivering this introductory lecture) and two exercises. The first exercise is a wet lab that involves dissecting an easy (and disturbing) source of live parasite material: fresh fish from your local seafood market. The second exercise is a computer lab that will allow students to engage with real data to answer the question: how do human impacts on ecosystems change the abundance of parasites in wildlife? This module will introduce students to the basics of parasite ecology and provide an opportunity to practice their data analysis and interpretation skills.
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Jansen, Rob, Paul Syverson, and Nicholas J. Hopper. Throttling Tor Bandwidth Parasites. Fort Belvoir, VA: Defense Technical Information Center, September 2011. http://dx.doi.org/10.21236/ada559183.
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Rose, Andrew, and Mark Spiegel. Offshore Financial Centers: Parasites or Symbionts? Cambridge, MA: National Bureau of Economic Research, February 2006. http://dx.doi.org/10.3386/w12044.
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Ungar, Beth L. Diagnosis of AIDS-Related Intestinal Parasites. Fort Belvoir, VA: Defense Technical Information Center, January 1989. http://dx.doi.org/10.21236/ada231241.
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Ungar, Beth L. Diagnosis of AIDS-Related Intestinal Parasites. Fort Belvoir, VA: Defense Technical Information Center, June 1990. http://dx.doi.org/10.21236/ada231242.
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Erika M. Bueno, Erika M. Bueno. ZomBees: Are parasites controlling the minds of honey bees? Experiment, April 2014. http://dx.doi.org/10.18258/2332.
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Knowles, Donald, and Monica Leszkowicz Mazuz. Transfected Babesia bovis expressing the anti-tick Bm86 antigen as a vaccine to limit tick infestation and protect against virulent challenge. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7598160.bard.
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Bovine babesiosis, caused by the apicomplexan parasites Babesiabovisand B. bigemina, is a major tick borne disease of cattle with significant economic importance globally. The vectors of Babesia parasites are R. (Boophilus) annulatusand R. microplus. In Israel these parasites are transmitted manly by R. annulatus. The main goal of the proposal was developing and testing a novel B. bovisvaccine based on stably transfected attenuated B. bovisexpressing the anti-tick Bm86 antigen. This required generating a transfected- attenuated B. bovisparasite containing a bidirectional promoter expressing both, the gfp- bsd selectable marker and the tick vaccine antigen Bm86. The vaccine was tested for its ability to elicit protective immune responses against T. annulatusticks. Efficient control of babesiosis is based on a complex scheme of integrated management, including preventive immunization, anti-babesial chemotherapy and control of tick populations. Live vaccines based on attenuated parasites are the most effective measure to control babesiosis, and are currently used in several countries, including Israel. Live attenuated parasites lead to a chronic infection and development of strong and long term immunity in vaccinated cattle. Still, live vaccines have several limitations, including the difficulty to distinguish among vaccinated and naturally infected cattle and potential for sporadic outbreaks in vaccinated animals. Tick limitation is essential to control babesiosis but the main measure to reduce tick infestation is traditionally approached using acaricides, which is limited by environmental concerns and the development of resistance by the ticks. Alternative tick-control measures including the use of anti-tick vaccines are emerging, and at least partial protective immunity has been achieved against tick vectors by vaccination with recombinant protective tick antigens (ie: Bm86). In addition, the Babesia vaccine development toolbox has been recently expanded with the development of transfection technology in Babesia parasites. In this approved proposal we successfully developed a Babesia live attenuated transfected vaccine, which is able to express a B. bovisMSA-1 signal-Bm86 chimera and eGFP genes under the control of the B. bovisef- 1 and actin promoters respectively. Genetic analysis demonstrated specific stable integration of the transfected genes in the expected ef-1 locus, and immunofluorescence analysis confirmed expression of Bm86 in the surface of transfected parasites. When applied to splenectomized calves, the transfected parasites were able to cause persistent B. bovisinfection with production of antibodies reactive with Bm86 for at least six months. In addition, partial protection against ticks was also observed upon challenging the vaccinated animals with R. annulatuslarvae. However, when used on intact calves, the vaccine failed to elicit detectable immune responses against Bm86, and we are still in the process of interpreting the data and make necessary changes in our experimental approaches. Overall, the results obtained here represent a step forward towards the development of integrated vaccines against both ticks and tick –borne pathogens, using the Babesia attenuated parasites as a platform to the delivery of exogenous protective antigens
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Barlow, Reannan. Mechanisms of Escape from Host Immune Defenses by Apicomplexan Parasites. Ames (Iowa): Iowa State University, January 2020. http://dx.doi.org/10.31274/cc-20240624-997.
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Westwood, James H., Yaakov Tadmor, and Hanan Eizenberg. Identifying the genes involved in host root perception by root parasitic weeds: Genetic and transcriptomic analysis of Orobanche hybrids differing in signal response specificity. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7598145.bard.
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Seeds of the root parasitic plants of the genus Orobanchegerminate specifically in response to host-derived germination signals, which enables parasites to detect and attack preferred hosts. The best characterized class of germination stimulants is the strigolactones (SL), although some species respond to sesquiterpene lactones such as dehydrocostuslactone (DCL). Despite great progress in characterizing the SL signaling system in plants, the mechanism(s) by which parasite species detect specific compounds remains poorly understood. The goal of our project was to identify and characterize the genes responsible for stimulant specificity in O. cernuaand O. cumana. These two species are closely related, but differ in host range, with O. cernuaparasitizingSolanaceous crops such as tomato (and responding to SLs), and O. cumanaspecifically parasitizing sunflower (and responding to DCL). We used a genetic approach based on O. cernuax O. cumanahybrids to associate germination response with genes. We found that these parasite species each have multiple copies of KAI2d genes, which function in SL perception. In O. cernua, the OrceKAI2d2 responds to SL stimulants and is most consistently associated with hybrid lines that respond to SLs. For O. cumana, an apparently linked block of KAI2d genes was associated with response to DCL in hybrid lines, but we found no strong evidence that any of the OrcuKAI2d genes specifically recognize the DCL stimulant. Remarkably, one O. cumanagene, OrcuKAI2d5, responds to certain SLs in a genetic complementation assay, even though hybrid lines containing this gene show fidelity to DCL. In summary, we have identified the SL receptor in O. cernua, but the DCL receptor in O. cumanaremains unknown. Our data point to involvement of additional genes and yet greater levels of complexity regulating germination specificity in Orobanche. BARD Report - Project 4616 Page 2 of 8
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Cáceres, Agustin. Haiti: Neglected Infectious Diseases infographic. Inter-American Development Bank, August 2012. http://dx.doi.org/10.18235/0006211.
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In Haiti, the IDB and its partners integrate health, water and sanitation to fight intestinal parasites and other Neglected Infectious Diseases. This Infographic promotes the IDB's activities in Haiti and provides general information related to these diseases.