Academic literature on the topic 'Schistosoma spp'
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Journal articles on the topic "Schistosoma spp"
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Crego-Vicente, Beatriz, Pedro Fernández-Soto, Begoña Febrer-Sendra, Juan García-Bernalt Diego, Jérôme Boissier, Etienne K. Angora, Ana Oleaga, and Antonio Muro. "Application of a Genus-Specific LAMP Assay for Schistosome Species to Detect Schistosoma haematobium x Schistosoma bovis Hybrids." Journal of Clinical Medicine 10, no. 6 (March 22, 2021): 1308. http://dx.doi.org/10.3390/jcm10061308.
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Schistosomiasis is a disease of great medical and veterinary importance in tropical and subtropical regions caused by different species of parasitic flatworms of the genus Schistosoma. The emergence of natural hybrids of schistosomes indicate the risk of possible infection to humans and their zoonotic potential, specifically for Schistosoma haematobium and S. bovis. Hybrid schistosomes have the potential to replace existing species, generate new resistances, pathologies and extending host ranges. Hybrids may also confuse the serological, molecular and parasitological diagnosis. Currently, LAMP technology based on detection of nucleic acids is used for detection of many agents, including schistosomes. Here, we evaluate our previously developed species-specific LAMP assays for S. haematobium, S. mansoni, S. bovis and also the genus-specific LAMP for the simultaneous detection of several Schistosoma species against both DNA from pure and, for the first time, S. haematobium x S. bovis hybrids. Proper operation was evaluated with DNA from hybrid schistosomes and with human urine samples artificially contaminated with parasites’ DNA. LAMP was performed with and without prior DNA extraction. The genus-specific LAMP properly amplified pure Schistosoma species and different S. haematobium-S. bovis hybrids with different sensitivity. The Schistosoma spp.-LAMP method is potentially adaptable for field diagnosis and disease surveillance in schistosomiasis endemic areas where human infections by schistosome hybrids are increasingly common.
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MANNECK, THERESIA, JENNIFER KEISER, and JOACHIM MÜLLER. "Mefloquine interferes with glycolysis in schistosomula of Schistosoma mansoni via inhibition of enolase." Parasitology 139, no. 4 (February 6, 2012): 497–505. http://dx.doi.org/10.1017/s0031182011002204.
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SUMMARYThe antimalarial drug mefloquine has promising antischistosomal properties killing haematophagous adult schistosomes as well as schistosomula. The mode of action and involved drug targets of mefloquine in Schistosoma mansoni schistosomula are unknown. In order to identify mefloquine-binding proteins and thus potential drug targets, mefloquine affinity chromatography with S. mansoni schistosomula crude extracts was performed. We found one specific mefloquine-binding protein that was identified by mass spectrometry as the glycolytic enzyme enolase (Q27877). Enolase activity assays were performed on schistosomula crude extracts and on the recombinant enolase Q27877 expressed in Escherichia coli. In schistosomula crude extracts enolase activity was inhibited by mefloquine and by the enolase inhibitor sodium fluoride, while activity of the recombinant enolase was not affected. In contrast to enolase from crude extracts, recombinant Q27877 did not bind to mefloquine-agarose. Using isothermal microcalorimetry, we next investigated the metabolic inhibition of mefloquine and 3 known glycolytic inhibitors in Schistosoma spp., namely sodium fluoride, 3-bromopyruvate and menadione on schistosomula in the presence or absence of glucose. We found that in the presence of glucose, schistosomula were less affected by mefloquine, sodium fluoride and 3-bromopyruvate, whereas glucose had no protective effect when schistosomula had been exposed to menadione. These results suggest a potential role of mefloquine as an inhibitor of glycolysis, at least in stages where other targets like haem degradation are not relevant.
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Tuffour, Isaac, Irene Ayi, Theresa Manful Gwira, Edward Dumashie, Yvonne Ashong, and Regina Appiah-Opong. "Schistosoma Egg Antigen Induces Oncogenic Alterations in Human Prostate Cells." Analytical Cellular Pathology 2018 (December 9, 2018): 1–10. http://dx.doi.org/10.1155/2018/4675380.
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Schistosomiasis is a neglected tropical disease that affects 200 million people and accounts for 100,000 deaths annually. In endemic geographical areas, schistosomiasis has been implicated as an etiological agent in the pathogenesis of bladder, colorectal, and renal carcinoma largely due to Schistosoma eggs in tissues that comes with chronic infection. Several studies have also reported cases of association between Schistosoma infection and prostate cancer. The possible causal association is however poorly understood. We hypothesized in this study that infection of the prostate cells with Schistosoma spp promotes cancer. Urine samples from individuals living in Galilea, a schistosomiasis endemic community in the Ga South District of Ghana, were collected and screened for Schistosoma infection via microscopy and multiplex PCR. Soluble egg antigens (SEA) were prepared from Schistosoma egg-positive urine samples and assessed for the ability to induce cancer-like phenotypes including excessive proliferation, oxidative stress (reduced glutathione (GSH) depletion), and diminished apoptosis in cultured human prostate (PNT2) cells. Molecular analysis revealed infecting schistosome species to be S. haematobium and S. mansoni. Prostate cell proliferation was significantly induced by 12.5 μg/ml SEA (p=0.029). Also, SEA dose-dependently depleted cellular GSH. Flow cytometric analysis and fluorescence staining revealed that SEA dose-dependently diminished apoptosis, significantly, in prostate cells. Findings of this study suggest that schistosome infection may play a role in the pathogenesis of prostate cancer. In vivo studies are however needed to confirm this association.
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James, Stephanie L. "Schistosoma spp.: Progress toward a defined vaccine." Experimental Parasitology 63, no. 3 (June 1987): 247–52. http://dx.doi.org/10.1016/0014-4894(87)90170-6.
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Castillo, Jesus Rico, Diana Alame, Madalina Tuluc, Michelle Nagurney, and Noha Ghusson. "Acute Appendicitis Associated With Schistosoma Species." American Journal of Clinical Pathology 152, Supplement_1 (September 11, 2019): S60—S61. http://dx.doi.org/10.1093/ajcp/aqz113.058.
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Abstract Objectives Schistosomiasis is a public health problem in tropical regions of the world, highly endemic in sub-Saharan Africa but uncommon in the United States. It is considered second only to malaria as the most devastating human parasitic diseases, and it is mainly classified as urinary or intestinal. Here we report a rare case of acute appendicitis associated with Schistosoma spp. Case Presentation A 28-year-old male presented to our institution in October 2018 with a 2-day history of periumbilical and right lower quadrant abdominal pain associated with nausea, vomiting, fever, and chills. CT scan of the abdomen in the emergency department showed hyperenhancement of the appendix, with an increased diameter of 10 mm and infiltration of the adjacent fat, compatible with appendicitis. The patient was administered intravenous piperacillin-tazobactam and underwent an uncomplicated laparoscopic appendectomy. Histopathological examination of the appendectomy specimen reveals neutrophilic infiltrate of the wall consistent with acute appendicitis, with granulomatous inflammation surrounding parasitic eggs measuring 60 by 37 μm morphologically consistent with Schistosoma spp. within the wall. Additionally, Ziehl-Neelsen stained negative. Significant travel history included a trip to Lake Malawi approximately 9 years prior to this presentation where he frequently swam in freshwater lakes. He does not recall developing an acute illness associated with this travel. Discussion Chronic schistosomiasis is the result of host immune responses to schistosome eggs that become lodged in the capillaries or organs and cause granulomatous reactions. Chronic inflammation can lead to bowel wall ulceration, hyperplasia, and polyposis and, with massive infection, to periportal liver fibrosis, dysuria, and hematuria. Small bowel involvement is very unusual and only rare cases of appendicitis have been reported worldwide. Additionally, Ziehl-Neelsen stained negative favoring other Schistosoma species instead of S mansoni, S intercalatum, or S japonicum. Fortunately, the patient underwent surgery, received praziquantel, and achieved full recovery.
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Härter, Georg, Hagen Frickmann, Sebastian Zenk, Dominic Wichmann, Bettina Ammann, Peter Kern, Bernhard Fleischer, Egbert Tannich, and Sven Poppert. "Diagnosis of neuroschistosomiasis by antibody specificity index and semi-quantitative real-time PCR from cerebrospinal fluid and serum." Journal of Medical Microbiology 63, no. 2 (February 1, 2014): 309–12. http://dx.doi.org/10.1099/jmm.0.066142-0.
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We describe the case of a 16-year-old German male expatriate from Ghana who presented with obstipation, dysuria, dysaesthesia of the gluteal region and the lower limbs, bilateral plantar hypaesthesia and paraesthesia without pareses. A serum–cerebrospinal fluid (CSF) Schistosoma spp. specific antibody specificity index of 3.1 was considered highly suggestive of intrathecal synthesis of anti-Schistosoma spp. specific antibodies, although standardization of this procedure has not previously been described. Diagnosis was confirmed by detection of Schistosoma DNA in CSF by semi-quantitative real-time PCR at 100-fold concentration compared with serum. Accordingly the two diagnostic procedures, which have not previously been applied for routine diagnosis, appear to be useful for the diagnosis of neuroschistosomiasis. Clinical symptoms resolved following anthelmintic and anti-inflammatory therapy.
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Pereira, Tiago Campos, Cláudia Carolina Silva Evangelista, Gustavo Borges, Eliana Maria Zanotti-Magalhães, Luiz Augusto Magalhães, and Iscia Lopes-Cendes. "Applications of RNA Interference in Schistosomiasis: Gene Function Identification and Development of New Therapies." ISRN Parasitology 2013 (December 31, 2013): 1–10. http://dx.doi.org/10.5402/2013/247036.
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The study of Schistosoma species has undergone a dramatic change in recent years mainly due to transcriptome, proteome, and genome analyses. In order to better understand the biology of the parasite and to develop new and more efficient/specific drugs, scientists have now the task to translate genetic information into functional data. The present paper aims to review the use of RNA interference (RNAi), a versatile technique used in gene silencing, for the dissection of the cellular/molecular biology of Schistosoma spp. In addition, we will review information on the recent development of a new generation of RNA-based drugs. Examples of specific experimental approaches will be presented and discussed, such as identification of gene function, development of therapies by targeting eggs, miracidia (as a strategy for environmental use), sporocysts (for infestation control in the intermediate host), and schistosomula/adult worms (as a treatment strategy). Furthermore, some of the main advantages, drawbacks, and future directions of these new applications and techniques will also be discussed.
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Navarro, Rohani C., Aleyla E. de Cadiz, Jordan M. Fronda, Lynnell Alexie D. Ong, and Vicente Y. Belizario Jr. "Prevalence of Schistosoma japonicum infection in water buffaloes in selected areas in Davao del Norte and Davao de Oro, the Philippines." January-July 7, no. 1 (February 16, 2021): 12–18. http://dx.doi.org/10.14202/ijoh.2021.12-18.
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Background and Aim: Schistosomiasis (SCH) japonica is a zoonotic disease that can infect several mammalian hosts. Bovines, particularly water buffaloes, are considered the most important reservoir hosts due to the high levels of schistosome eggs, they excrete into the environment. In the Philippines, the previous studies have revealed a high prevalence of SCH in bovines in selected provinces in Luzon, Visayas, and Mindanao. However, there is a lack of studies on SCH in the Davao Region, Mindanao, where the infection remains a public health concern. This study aimed to determine the prevalence of SCH in water buffaloes in four barangays (villages) each in Braulio Dujali, Davao del Norte and Maragusan, Davao de Oro, Southeastern Mindanao, the Philippines. Materials and Methods: Fecal samples from 91 water buffaloes were collected intrarectally, processed using the formalin-ethyl acetate sedimentation technique, and examined microscopically to determine the prevalence of SCH. Results: A total of three water buffaloes (8.6%) in Maragusan were determined to be positive for Schistosoma japonicum, while none in Braulio Dujali. The prevalence of other parasites (Fasciola spp. [53.8%], Paramphistome spp. [20.9%], Amphistome spp. [16.5%], Strongyle spp. [11.0%], Balantidium spp. [9.9%], Eurytrema spp. [2.2%], and Gongylonema pulchrum [1.1%]) was also observed. Conclusion: The results of the study provide baseline data on the presence of S. japonicum in water buffaloes in the Davao Region, Mindanao. Strategies for controlling and eliminating SCH in animal reservoir hosts, especially in water buffaloes, are necessary for the long-term control and elimination of SCH in humans.
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Jones, Isabel J., Susanne H. Sokolow, Andrew J. Chamberlin, Andrea J. Lund, Nicolas Jouanard, Lydie Bandagny, Raphaël Ndione, et al. "Schistosome infection in Senegal is associated with different spatial extents of risk and ecological drivers for Schistosoma haematobium and S. mansoni." PLOS Neglected Tropical Diseases 15, no. 9 (September 27, 2021): e0009712. http://dx.doi.org/10.1371/journal.pntd.0009712.
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Schistosome parasites infect more than 200 million people annually, mostly in sub-Saharan Africa, where people may be co-infected with more than one species of the parasite. Infection risk for any single species is determined, in part, by the distribution of its obligate intermediate host snail. As the World Health Organization reprioritizes snail control to reduce the global burden of schistosomiasis, there is renewed importance in knowing when and where to target those efforts, which could vary by schistosome species. This study estimates factors associated with schistosomiasis risk in 16 villages located in the Senegal River Basin, a region hyperendemic for Schistosoma haematobium and S. mansoni. We first analyzed the spatial distributions of the two schistosomes’ intermediate host snails (Bulinus spp. and Biomphalaria pfeifferi, respectively) at village water access sites. Then, we separately evaluated the relationships between human S. haematobium and S. mansoni infections and (i) the area of remotely-sensed snail habitat across spatial extents ranging from 1 to 120 m from shorelines, and (ii) water access site size and shape characteristics. We compared the influence of snail habitat across spatial extents because, while snail sampling is traditionally done near shorelines, we hypothesized that snails further from shore also contribute to infection risk. We found that, controlling for demographic variables, human risk for S. haematobium infection was positively correlated with snail habitat when snail habitat was measured over a much greater radius from shore (45 m to 120 m) than usual. S. haematobium risk was also associated with large, open water access sites. However, S. mansoni infection risk was associated with small, sheltered water access sites, and was not positively correlated with snail habitat at any spatial sampling radius. Our findings highlight the need to consider different ecological and environmental factors driving the transmission of each schistosome species in co-endemic landscapes.
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Boes, J., A. L. Willingham, Shi Fuhui, Hu Xuguang, L. Eriksen, P. Nansen, and T. B. Stewart. "Prevalence and distribution of pig helminths in the Dongting Lake Region (Hunan Province) of the People's Republic of China." Journal of Helminthology 74, no. 1 (March 2000): 45–52. http://dx.doi.org/10.1017/s0022149x00000068.
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AbstractThe prevalence of helminths in pigs was investigated in five rural communities situated on the embankment of Dongting Lake in Zhiyang County, Hunan Province, People's Republic of China, in an area known to be endemic for Schistosoma japonicum. The helminth prevalences identified on the basis of faecal egg count analysis were: Oesophagostomum spp. (86.7%), Ascaris suum (36.7%), Metastrongylus spp. (25.8%), Strongyloides spp. (25.8%), Trichuris suis (15.8%), Globocephalus spp. (6.7%), Gnathostoma spp. (4.2%), Schistosoma japonicum (5.0%) and Fasciola spp. (1.3%). Post mortem examinations of a small number of pigs depositing eggs of different helminth species revealed the presence of Oesophagostomum dentatum, O. quadrispinulatum, A. suum, Metastrongylus apri, M. pudendotectus, T. suis, G. hispidum and Ascarops dentata. Prevalences of all helminths, with the exception of Oesophagostomum spp., were higher in young pigs (< 8 months old) compared with adult pigs. Prevalences of trematodes were very low, especially for S. japonicum which had decreased dramatically compared with previous reports from this area of P.R. China, whereas prevalences of nematodes were generally in agreement with those reported from other Yangtze River Provinces. Results from helminth prevalence studies in pigs, conducted in other provinces of P.R. China between 1987 and 1997, are presented and discussed. It was concluded that a government helminth control programme, implemented in 1995 to control S. japonicum infection in pigs in Hunan Province, may have resulted in a greatly reduced prevalence of S. japonicum in pigs in this region.
Dissertations / Theses on the topic "Schistosoma spp"
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Lima, Luciane Mota. "Efeito dos antígenos de schistosoma spp. sobre a resposta imune em indivíduos infectados pelo htlv-1." IInstituto de Ciências da Saúde, 2014. http://repositorio.ufba.br/ri/handle/ri/17516.
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Introdução- O HTLV-1 é o virus causador da leucemia/linfoma de células T em adultos (ATLL) e da mielopatia associada ao HTLV-1/Paraparesia Espástica Tropical (HAM/TSP). Enquanto a resposta imune desencadeada na infecção pelo HTLV-1 é polarizada para o tipo Th1, tem sido mostrado que nas helmintiases cronicas, a exemplo da esquistossomose, existe um desvio para a resposta imune do tipo Th2 e regulatoria, que modula a resposta Th1 envolvidas em algumas doenças autoimunes. A hipotese dese estudo é que os antígenos do Schistosoma spp. modulam “in vitro” a resposta imune exacerbada na infecção pelo HTLV-1. Metodos- Os antígenos do Schistosoma rSm29, rShTSP2 e PIII foram adicionados às culturas de CMSP de indivíduos infectados pelo HTLV-1 e os níveis de citocinas e quimiocinas do sobrenadante foram medidos usando a técnica de ELISA sandwich. As frequências das células TCD4+ e TCD8+ expressando CD25, CTLA-4, Foxp3 e de linfócitos T monócitos e linfócitos B expressando IL-10 foram medidas usando a citometria de fluxo. Resultados- Comparando os níveis de citocinas nas culturas de CMSP não estimuladas verificou-se que os níveis de IFN- e TNF-α foram reduzidos com a presença do rSm29 em 50 e 53% dos pacientes (média de redução de 59 e 43%, respectivamente), em 59 e 29% deles na presença do rShTsp2 (47 e 45%, respectivamente) e em 50 e 41% após a adição do PIII (35 e 45%, respectivamente). Por outro lado, os níveis de IL-10 aumentaram após a adição destes antígenos em 74, 22 e 44% dos indivíduos, média de redução 327, 573 e 35%, respectivamente. A frequência das células TCD4+CD25High aumentaram na presença dos referidos antígenos (sem estímulo (se) = 0,6 ± 2%, estimulados com rSm29 = 1,2 ± 1%, rShTsp2 = 0,9 ± 0,5 e PIII = 0,9 ± 0,6%, respectivamente). A frequência das células TCD4+CD25HighFoxp3+ e TCD8+CD25HighFoxp3+ também aumentaram após a adição dos antígenos. Entretanto, a frequência das células TCD4+CD25HighCTLA-4+ foi significativamente mais alta nas culturas estimuladas com rSm29 (se = 21 ± 10%, rSm29 = 25 ± 12%; p<0,05) e a frequência de TCD8+CD25High também aumentou na presença de rSm29 e rShTsp-2 nas culturas (0,7 ± 0,4%, 0,8 ± 0,5%; p<0.05 respectivamente; se = 0,5 ± 0,3%). A frequência das células TCD4+ expressando IL-10 aumentou na presença de rSm29 e rShTSP (7,3%, p=0,034; 7,5%, p=0,023; respectivamente; se=5,4%). A frequência das células TCD8+ expressando IL-10 aumentou após a adição de rShTSP-2 e PIII (13,1%, p=0,034; 10,9%, p=0,034, respectivamente, se=9.5%). A presença do rSm29 aumentou a frequência de monócitos expressando IL-10 (20,1%, p=0,05; se=19,8%). Por outro lado, a adição do rSm29 e rShTSP-2 resultou na diminuição da produção de CXCL9 nas culturas de CMSP (18,17 ± 9,73 pg/ml, p=0,044 e 16,146 ± 9,23, p=0,031, respectivamente; se=19,75 ± 9,73). Conclusão- Nós concluímos que os antígenos de Schistosoma spp. foram capazes de modular negativamente in vitro a resposta imune inflamatória nos indivíduos infectados pelo HTLV-1.
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Huot, Camille. "Caractérisation et rôle dans l'interaction tripartite du microbiote d'hôtes intermédiaires Planorbidae des parasites trématodes Schistosoma spp. agent responsable de la bilharziose." Thesis, Perpignan, 2019. https://theses-public.univ-perp.fr/2019PERP0041.pdf.
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Tout organisme vivant est confronté à des microorganismes, qu'ils s'agissent de bactéries, de virus, de champignons ou de protistes, à un moment ou un autre de sa vie. Le microbiote largo sensu représente l'ensemble de ces microorganismes, présents dans un hôte à un temps T. Il est, depuis plusieurs années, considéré comme un compartiment à part entière de son hôte. Il peut avoir un impact sur différentes fonctions biologiques de l'hôte, telles que la nutrition, le développement ou encore l'immunité. Il peut ainsi jouer un rôle clef dans les interactions entre organismes, notamment les interactions hôtes/parasites ou hôtes/pathogènes, en améliorant le système immunitaire de son hôte ou en impactant directement l'envahisseur. Le cas de Biomphalaria glabrata et autres Planorbidae, hôtes intermédiaires du parasite Schistosoma sp., agent responsable de la bilharziose, est un modèle parfait pour l'étude du rôle du microbiote dans les interactions hôtes/parasites. En effet, la compréhension de l'interaction du ver avec son hôte intermédiaire notamment pourrait ouvrir la voie vers de nouvelles mesures de lutte, comme le blocage de son cycle. La caractérisation du microbiote des mollusques et son rôle dans l'interaction est donc une piste intéressante à explorer. Au cours de cette thèse, j'ai (i) caractérisé le microbiote bactérien et protistes de différentes espèces de Planorbidae afin de le comparer en fonction de la phylogénie des mollusques ; (ii) étudié la dynamique des communautés bactériennes au cours d'une cinétique d'infestation chez différentes souches de B. glabrata et (iii) perturbé le microbiote bactérien et observé les conséquences sur la résistance des mollusques face aux parasites afin de mettre en avant un potentiel rôle de ces bactéries dans l'immunité de leur hôte. L'un des résultats principaux de cette thèse est la spécificité forte des communautés bactériennes à la phylogénie de leur hôte, qui va jusqu'à former un patron de phylosymbiose. De plus, une variation dans l'intensité ou dans la prévalence de l'infestation a été soulignée, selon la combinaison hôte/parasite, après une perturbation du microbiote, suggérant un lien entre ce dernier et l'immunité antiparasitaire des mollusques. Ce travail de thèse est donc un premier pas dans la compréhension de la relation tripartite entre un parasite, son hôte intermédiaire et le microbiote de ce dernier, pouvant, à terme, ouvrir de nouvelles perspectives dans la lutte contre l'agent responsable de la bilharzioseEvery living organism is faced, eventually, to microorganisms, whether they are bacteria, viruses, fungi or protists. Microbiota largo sensu represent all these microorganisms, living in a host a T time. It is considered, since years, as an integral compartment of its host. It can affect several host functions, like nutrition, development or immunity. Thus, it can play a key role in interactions between organisms, notably hosts/parasites and hosts/pathogens interactions, improving the immune system of its host or directly affecting the invader. The case of Biomphalaria glabrata and other Planorbidae, intermediate hosts of Schistosoma sp. parasites, responsible agent for bilharzia, is a perfect model to study the role of microbiota in host/parasite interactions. Indeed, understanding the interaction between the worm and its intermediate host could open the way for new measure to fight it, as blocking its lifecycle. The characterization of mollusks' microbiota and its role in the interaction is, thus, an interesting way to explore. During my PhD, I (i) characterized the bacterial and protist microbiota of several Planorbidae species in order to compare it according to host phylogeny; (ii) studied the dynamic of microbiota bacterial communities during an infection kinetic in different B. glabrata strains and; (iii) disturbed the bacterial microbiota and observed the consequences on the mollusks resistance to parasite, in order to highlight a potential role of these bacteria in their host immunity. One of the main results of this work is the high specificity of bacterial communities to their host phylogeny, displaying a phylosymbiosis pattern. Moreover, a variation in infection intensity or prevalence has been highlighted, depending on host/parasite combination, after a microbiota disturbance, suggesting a link between the latter and the antiparasitic immunity of mollusks. Thus, this PhD work is a first step in the understanding of the tripartite interaction between a parasite, its intermediate host and the microbiota of the latter, that could, in time, open new perspectives in the fight against the responsible agent of bilharzia
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Maurer, Rafael Lucyk. "Mecanismo de interação magnética dos ovos de Schistosoma spp. e características biológicas da cepa Esteio, Rio Grande do Sul." Pontifícia Universidade Católica do Rio Grande do Sul, 2012. http://hdl.handle.net/10923/5430.
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Previous issue date: 2012The autochthonous transmission of schistosomiasis in Rio Grande do Sul was confirmed for the first time in 1998, establishing the southernmost focus in Americas. Although no morphological differences were detected in a previous study, the investigation of biological characteristics of the parasite in the current study showed some peculiarities that may be relevant for a better understanding of transmission dynamics in the Esteio focus and adequacy of control measures. The epidemiological study of this focus led to the development of a diagnostic method, Helmintex, more sensitive than the traditional methods for detecting small number of eggs shed in the patients’ feces. In this method eggs are isolated through magnetic interaction with paramagnetic beads and this mechanism could be related to the presence of iron in the eggshell. Schistosoma mansoni worms ingest large amounts of blood and requires specialized metabolic pathway for iron elimination. When analyzed by energy dispersive spectroscopy iron and small crystal structures probably magnetite were identified in the eggshell.The presence of structures with potentially magnetizing properties led to the magnetic characterization of Schistosoma eggs and demonstration of ferromagnetic and paramagnetic behavior. Eggs were also analyzed to see if other helminth eggs compositional differences were related to different taxonomic groups and habitat types. These findings stimulate further research on the metabolic pathway involving iron, development of new treatment modalities and diagnostic tools.
A transmissão autóctone da esquistossomose no município de Esteio, Rio Grande do Sul foi confirmada pela primeira vez em 1998, constituindo o foco mais meridional das Américas. Embora não tenham sido detectadas diferenças morfológicas do parasito em estudo prévio, a abordagem das características biológicas neste trabalho evidenciou algumas peculiaridades, tais como a baixa infectividade do miracídios e a alta taxa de infecção unissexual por machos, que podem ter importância para uma melhor compreensão da dinâmica de transmissão no foco de Esteio e adequação das medidas de controle. O estudo epidemiológico do foco conduziu ao desenvolvimento de um método de diagnóstico, Helmintex, mais sensível que os métodos coprológicos clássicos para detectar o baixo número de ovos eliminados nas fezes dos pacientes. O método utiliza a interação magnética com microesferas paramagnéticas para o isolamento dos ovos. O mecanismo de interação dos ovos com o campo magnético poderia estar relacionado com a presença de ferro na casca do ovo. O Schistosoma mansoni ingere grande quantidade de sangue e necessita de rota metabólica especializada para eliminação do ferro. O objetivo do trabalho foi investigar a presença de ferro na casca do ovo por análise por espectroscopia por dispersão de energia.Os resultados possibilitaram a identificação do elemento químico ferro presente no ovo, além de pequenas estruturas cristalinas, provavelmente magnetita. A presença de estruturas com propriedades magnéticas suscetíveis de magnetização foram motivo para caracterização magnética dos ovos de Schistosoma com o encontro de comportamento ferromagnético e paramagnético. Também foram analisados ovos de outros helmintos para verificar se diferenças composicionais dos ovos estavam associadas a diferentes grupos taxonômicos e tipos de habitat. Os achados estimulam novas investigações sobre a rota metabólica envolvendo o ferro, desenvolvimento de novas modalidades de tratamento e recursos diagnósticos.
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Lima, Carlos Eduardo Pires Grault Vianna de. "Estudo de laboratório e de campo, sobre dinâmica populacional de Biomphalaria spp., hospedeiros intermediários do Schistosoma mansoni, no território brasileiro." reponame:Repositório Institucional da FIOCRUZ, 2013. https://www.arca.fiocruz.br/handle/icict/13182.
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Previous issue date: 2016-01-13Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil
A dinâmica de populações é centrada na observação da taxa de crescimento populacional. Essa análise, fundamentalmente, leva em conta a combinação de dois princípios básicos, taxa de reprodução e a taxa de mortalidade. Outros fatores extrínsecos, tais como migração, imigração, variações climáticas, competição por alimento ou nutrientes e doenças podem afetar a abundância de uma determinada espécie. Nessa tese, foram realizados quatro experimentos em laboratório e um estudo de campo de oito meses, no que se buscou analisar e comparar os parâmetros reprodutivos das três espécies hospedeiras de Schistosoma mansoni no território brasileiro, Biomphalaria glabrata, B. tenagophila e B. straminea. Os dois primeiros experimentos tiveram como objetivo analisar os parâmetros reprodutivos das três espécies, mais uma cepa de B. straminea refratária a infecção, quando expostas a infecção antes e após alcançarem a maturidade sexual, ou seja, quinze e quarenta e cinco dias após a eclosão dos moluscos. O terceiro experimento foi concebido para comparar o impacto provocado na capacidade reprodutiva das coortes estudadas frente à exposição ao parasito, quando realizada individualmente em cada molusco ou em massa. Nesse caso, a dependência da densidade do parasito dentro do hospedeiro poderia desempenhar papel crucial na dinâmica populacional No quarto experimento, teve como escopo amplificar o efeito da infecção, tal como proposto no experimento três, porém aumentando em ate quatro vezes o numero de miracídios por moluscos e a exposição foi realizada antes que os caramujos atingissem a maturidade sexual. O trabalho de campo foi conduzido em áreas onde ocorre a transmissão da esquistossomose, nos municípios de Barra Mansa e Sumidouro, estado do Rio de Janeiro. Os resultados obtidos em laboratório demonstraram que a cepa resistente de B. straminea apresentou sucesso reprodutivo significativamente superior em comparação as outras coortes estudadas. O efeito da infecção no sucesso reprodutivo foi menor em B. straminea do que nas outras duas espécies. A infecção imposta em indivíduos jovens de B. tenagophila e B. glabrata, ocasionou expressiva diminuição dos parâmetros reprodutivos em especial na ultima espécie. Quando a infecção foi imposta a caramujos sexualmente maduros que os valores observados para B. tenagophila foram significativamente superiores do que os verificados para B. glabrata As observações obtidas no estudo de campo foram semelhantes às 7 alcançadas nos experimentos realizados em laboratório. Os resultados deste estudo podem contribuir para melhor compreensão da abundancia e ampla distribuição geográfica de B. straminea e sua importância como hospedeiro intermediário
Population dynamics is mainly concerned in establishing factors that affect the population growth rate, and is essentially based on two major elements, the reproducti ve and mortality rate s, for analysis. Other extrinsic factors, such as migration, climatic variations, food and nutrient competition, and diseases may affect the abundance of specific species. The aim of this study was to analyze and compare reproductive parameters among three Brazilian host species for Schistosoma mansoni , namely Biomphalaria g labrata, B. tenagophila and B. straminea , which were explored through four laboratory experiments and one eight - month field work. The first two experiments aimed in analyzing the reproductive parameters among these three species along with a refractory spe cies, B. Straminea , for infection, when exposed before and after reaching sexual maturity, in other words, fifteen to forty five days after the molluscs hatch. A third experiment was carried out to compare the impact on the reproductive capacity by the stu died cohorts when exposed to the parasite individually for each mollusc or in bulk. In this case, the reliance of the parasites density within the hosts could play a crucial role in the population dynamics. The fourth experiment was focused on amplifying t he effect of the infection, as was proposed by the third experiment, however increasing to up to four times the number of miracidia per snails and was performed prior to the mollusc’s sexual maturity. The field work was conducted in areas where schistosomi asis transmission occurs, in the counties of Barra Mansa and Sumidouro, in Rio de Janeiro state. The laboratory results demonstrated successful reproduction in the resistant specie for B. straminea , which was significantly higher among the other species st udied. The effect of infection on successful reproduction was lower in the B. straminea when compared to the other two species. The imposed infection on young snails from the B. tenagophila and B. g labrat a caused an expressive decrease in the reproductive parameters, especially the later specie. When infection occurred in sexually mature snails, the values observed for where significantly higher than those observed for B. g labrata The findings in the field work where similar to those observed in the lab experiments. These findings throw some light in the much wider geographical distribution of B. straminea and its importance on the epidemiology and transmission control of schistosomiasis, Especially in the north - eastern Brazil, where it is much more important than the other two species as a host of schistosomiasis.
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Maurer, Rafael Lucyk. "Mecanismo de intera??o magn?tica dos ovos de Schistosoma spp. e caracter?sticas biol?gicas da cepa Esteio, Rio Grande do Sul." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2012. http://tede2.pucrs.br/tede2/handle/tede/233.
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Previous issue date: 2012-03-16The autochthonous transmission of schistosomiasis in Rio Grande do Sul was confirmed for the first time in 1998, establishing the southernmost focus in Americas. Although no morphological differences were detected in a previous study, the investigation of biological characteristics of the parasite in the current study showed some peculiarities that may be relevant for a better understanding of transmission dynamics in the Esteio focus and adequacy of control measures. The epidemiological study of this focus led to the development of a diagnostic method, Helmintex, more sensitive than the traditional methods for detecting small number of eggs shed in the patients feces. In this method eggs are isolated through magnetic interaction with paramagnetic beads and this mechanism could be related to the presence of iron in the eggshell. Schistosoma mansoni worms ingest large amounts of blood and requires specialized metabolic pathway for iron elimination. When analyzed by energy dispersive spectroscopy iron and small crystal structures probably magnetite were identified in the eggshell. The presence of structures with potentially magnetizing properties led to the magnetic characterization of Schistosoma eggs and demonstration of ferromagnetic and paramagnetic behavior. Eggs were also analyzed to see if other helminth eggs compositional differences were related to different taxonomic groups and habitat types. These findings stimulate further research on the metabolic pathway involving iron, development of new treatment modalities and diagnostic tools.
A transmiss?o aut?ctone da esquistossomose no munic?pio de Esteio, Rio Grande do Sul foi confirmada pela primeira vez em 1998, constituindo o foco mais meridional das Am?ricas. Embora n?o tenham sido detectadas diferen?as morfol?gicas do parasito em estudo pr?vio, a abordagem das caracter?sticas biol?gicas neste trabalho evidenciou algumas peculiaridades, tais como a baixa infectividade do mirac?dios e a alta taxa de infec??o unissexual por machos, que podem ter import?ncia para uma melhor compreens?o da din?mica de transmiss?o no foco de Esteio e adequa??o das medidas de controle. O estudo epidemiol?gico do foco conduziu ao desenvolvimento de um m?todo de diagn?stico, Helmintex, mais sens?vel que os m?todos coprol?gicos cl?ssicos para detectar o baixo n?mero de ovos eliminados nas fezes dos pacientes. O m?todo utiliza a intera??o magn?tica com microesferas paramagn?ticas para o isolamento dos ovos. O mecanismo de intera??o dos ovos com o campo magn?tico poderia estar relacionado com a presen?a de ferro na casca do ovo. O Schistosoma mansoni ingere grande quantidade de sangue e necessita de rota metab?lica especializada para elimina??o do ferro. O objetivo do trabalho foi investigar a presen?a de ferro na casca do ovo por an?lise por espectroscopia por dispers?o de energia. Os resultados possibilitaram a identifica??o do elemento qu?mico ferro presente no ovo, al?m de pequenas estruturas cristalinas, provavelmente magnetita. A presen?a de estruturas com propriedades magn?ticas suscet?veis de magnetiza??o foram motivo para caracteriza??o magn?tica dos ovos de Schistosoma com o encontro de comportamento ferromagn?tico e paramagn?tico. Tamb?m foram analisados ovos de outros helmintos para verificar se diferen?as composicionais dos ovos estavam associadas a diferentes grupos taxon?micos e tipos de habitat. Os achados estimulam novas investiga??es sobre a rota metab?lica envolvendo o ferro, desenvolvimento de novas modalidades de tratamento e recursos diagn?sticos.
Books on the topic "Schistosoma spp"
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Lydyard, Peter, Michael Cole, John Holton, Will Irving, Nino Porakishvili, Pradhib Venkatesan, and Kate Ward. Case Studies in Infectious Disease: Schistosoma spp. Garland Science, 2009. http://dx.doi.org/10.4324/9780203854044.
Full textBook chapters on the topic "Schistosoma spp"
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Stöcker, W. "Schistosoma spp." In Lexikon der Medizinischen Laboratoriumsdiagnostik, 1–2. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-49054-9_3655-1.
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Stöcker, W. "Schistosoma spp." In Springer Reference Medizin, 2119–20. Berlin, Heidelberg: Springer Berlin Heidelberg, 2019. http://dx.doi.org/10.1007/978-3-662-48986-4_3655.
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Kašný, Martin, Libor Mikeš, Kateřina Dolečková, Vladimír Hampl, Jan Dvořák, Marian Novotný, and Petr Horák. "Cathepsins B1 and B2 of Trichobilharzia SPP., Bird Schistosomes Causing Cercarial Dermatitis." In Advances in Experimental Medicine and Biology, 136–54. Boston, MA: Springer US, 2011. http://dx.doi.org/10.1007/978-1-4419-8414-2_9.
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Boissier, Jerome, Gabriel Mouahid, and Hélène Moné. "Schistosoma spp." In Global Water Pathogen Project, edited by Lucy Robertson. Michigan State University, 2019. http://dx.doi.org/10.14321/waterpathogens.45.
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Lydyard, Peter M., Michael F. Cole, John Holton, William L. Irving, Nino Porakishvili, Pradhib Venkatesan, and Katherine N. Ward. "Schistosoma spp." In Case Studies in Infectious Disease, 393–402. Garland Science, 2021. http://dx.doi.org/10.4324/9780203856871-32.
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Dunne, D. W., and B. J. Vennervald. "Schistosomiasis." In Oxford Textbook of Medicine, 1202–12. Oxford University Press, 2010. http://dx.doi.org/10.1093/med/9780199204854.003.071101_update_001.
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Schistosomiasis is caused by trematode worms Schistosoma spp., whose life cycle requires a definitive vertebrate host and an intermediate freshwater snail host. Transmission to humans occurs through exposure to fresh water containing infectious larvae, which can penetrate intact skin before developing into blood-dwelling adult worms. The disease is patchily distributed in parts of South America, Africa, the Middle East, China, and South East Asia, with about 200 million people infected and 20 million suffering severe consequences of infection....
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Dunne, David, and Birgitte Vennervald. "Schistosomiasis." In Oxford Textbook of Medicine, edited by Christopher P. Conlon, 1540–51. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198746690.003.0182.
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Schistosomiasis is caused by trematode worms Schistosoma spp., whose life cycle requires a definitive vertebrate host and an intermediate freshwater snail host. Transmission to humans occurs through exposure to fresh water containing infectious larvae, which can penetrate intact skin before developing into blood-dwelling adult worms. The disease is patchily distributed in parts of South America, Africa, the Middle East, China, and Southeast Asia, with about 200 million people infected and 20 million suffering severe consequences of infection. Most infected people living in endemic areas have few (if any) overt symptoms, but clinical manifestations (when present) depend on the stage of infection. Praziquantel is the drug of choice, with corticosteroids added in cases of Katayama fever. Acute schistosomiasis responds well, but chronic disease less so, but rapid re-exposure and reinfection are common (particularly in young children) unless control measures are implemented at the community level.
Conference papers on the topic "Schistosoma spp"
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SEMYENOVA, S. K., and G. G. CHRISANFOVA. "THE LONG NONCODING REGION OF MITOCHONDRIAL DNA AS A POPULATION AND PHYLOGENETIC MARKER OF BIRD SCHISTOSOME TRICHOBILHARZIA SPP. (TREMATODA: SCHISTOSOMATIDAE)." In 5TH MOSCOW INTERNATIONAL CONFERENCE "MOLECULAR PHYLOGENETICSAND BIODIVERSITY BIOBANKING". TORUS PRESS, 2018. http://dx.doi.org/10.30826/molphy2018-36.
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