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Sample records for adult schistosoma mansoni

  1. Schistosoma mansoni

    DEFF Research Database (Denmark)

    Friis, Henrik; Byskov, Jens

    1987-01-01

    Recent surveys in Ngamiland, Botswana, indicate increasing prevalence of Schistosoma mansoni infections. With the introduction of a schistosomiasis control programme, 354 of 373 schoolchildren were examined quantitatively for eggs of S. mansoni, and 317 were examined clinically for hepato...

  2. Serological screening of the Schistosoma mansoni adult worm proteome.

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    Fernanda Ludolf

    2014-03-01

    Full Text Available BACKGROUND: New interventions tools are a priority for schistosomiasis control and elimination, as the disease is still highly prevalent. The identification of proteins associated with active infection and protective immune response may constitute the basis for the development of a successful vaccine and could also indicate new diagnostic candidates. In this context, post-genomic technologies have been progressing, resulting in a more rational discovery of new biomarkers of resistance and antigens for diagnosis. METHODOLOGY/PRINCIPAL FINDINGS: Two-dimensional electrophoresed Schistosoma mansoni adult worm protein extracts were probed with pooled sera of infected and non-infected (naturally resistant individuals from a S. mansoni endemic area. A total of 47 different immunoreactive proteins were identified by mass spectrometry. Although the different pooled sera shared most of the immunoreactive protein spots, nine protein spots reacted exclusively with the serum pool of infected individuals, which correspond to annexin, major egg antigen, troponin T, filamin, disulphide-isomerase ER-60 precursor, actin and reticulocalbin. One protein spot, corresponding to eukaryotic translation elongation factor, reacted exclusively with the pooled sera of non-infected individuals living in the endemic area. Western blotting of two selected recombinant proteins, major egg antigen and hemoglobinase, showed a similar recognition pattern of that of the native protein. CONCLUDING/SIGNIFICANCE: Using a serological proteome analysis, a group of antigens related to the different infection status of the endemic area residents was identified and may be related to susceptibility or resistance to infection.

  3. Isoforms of Hsp70-binding human LDL in adult Schistosoma mansoni worms.

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    Pereira, Adriana S A; Cavalcanti, Marília G S; Zingali, Russolina B; Lima-Filho, José L; Chaves, Maria E C

    2015-03-01

    Schistosoma mansoni is one of the most common parasites infecting humans. They are well adapted to the host, and this parasite's longevity is a consequence of effective escape from the host immune system. In the blood circulation, lipoproteins not only help to conceal the worm from attack by host antibodies but also act as a source of lipids for S. mansoni. Previous SEM studies showed that the low-density lipoprotein (LDL) particles present on the surface of adult S. mansoni worms decreased in size when the incubation time increased. In this study, immunocytochemical and proteomic analyses were used to locate and identify S. mansoni binding proteins to human plasma LDL. Ultrathin sections of adult worms were cut transversely from the anterior, medial and posterior regions of the parasite. Immunocytochemical experiments revealed particles of gold in the tegument, muscle region and spine in male worms and around vitelline cells in females. Immunoblotting and 2D-electrophoresis using incubations with human serum, anti-LDL antibodies and anti-chicken IgG peroxidase conjugate were performed to identify LDL-binding proteins in S. mansoni. Analysis of the binding proteins using LC-MS identified two isoforms of the Hsp70 chaperone in S. mansoni. Hsp70 is involved in the interaction with apoB in the cytoplasm and its transport to the endoplasmic reticulum. However, further studies are needed to clarify the functional role of Hsp70 in S. mansoni, mainly related to the interaction with human LDL.

  4. Caracterização de cepas de Schistosoma mansoni por morfometria de vermes adultos provenientes de infecção unissexual Characterization of Schistosoma mansoni strains by morphometry of adult worms derived from single-sex infection

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    José Roberto Machado-Silva

    2003-12-01

    Full Text Available Camundongos foram infectados com cercárias, de um único sexo, de cepas simpátricas do Schistosoma mansoni. Nos vermes adultos, foram encontradas diferenças significativas (pMice were infected with only one sex cercaria derived from sympatric strains of Schistosoma mansoni. Adult worms presented significative differences (p<0.05 regarding suckers, testicular lobes, ovary and thickness of the tegument. Data show that morphometric study of unisexual infection worms can be also used for characterization of Schistosoma mansoni strains.

  5. Ultrastructural analysis of miltefosine-induced surface membrane damage in adult Schistosoma mansoni BH strain worms.

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    Bertão, Humberto Gonçalves; da Silva, Renata Alexandre Ramos; Padilha, Rafael José R; de Azevedo Albuquerque, Mônica Camelo Pessôa; Rádis-Baptista, Gandhi

    2012-06-01

    Schistosomiasis is an infectious parasitic disease caused by helminths from the genus Schistosoma; it affects over 200 million people globally and is endemic in 70 countries. In Brazil, 6 million individuals are infected with Schistosoma mansoni. Furthermore, as the prevalence of S. mansoni infections is increasing, approximately 26 million citizens in 19 Brazilian states are at risk for infection. Schistosomiasis disease control involves predominately the administration of a single drug, praziquantel. Although praziquantel exhibits chemotherapeutic efficacy and safety, its massive use in endemic zones, the possibility of the emergence of drug-resistant Schistosoma parasites, and the lack of another efficacious antischistosomal drug demand the discovery of new schistosomicidal compounds. First developed as anti-tumor drug, miltefosine is an alkylphospholipid derivative that exhibits bioactivity against Leishmania and Trypanosoma parasites, free-living protozoa, bacteria, and fungi. With its anti-parasite activity, miltefosine was the first orally administered drug against visceral and cutaneous leishmaniasis approved. Previously, by means of the MTT cytotoxic assay and a DNA fragmentation test, we verified that, at doses of 100 and 200 μM (40 and 80 μg/mL), miltefosine exhibited in vitro schistosomicidal activity against adult S. mansoni worms. Here, we present ultrastructural evidence of rapid, severe miltefosine-induced surface membrane damage in S. mansoni following drug treatment. The number of dead parasites was concentration- and time-dependent following miltefosine treatment. At a miltefosine concentration of 200 μM (∼80 μg/mL), in vitro parasite killing was initiated as early as 3 h post-incubation, and it was maximal after 24 h of treatment. The parasite death was preceded by progressive surface membrane damage, characterized by tegument peeling, spine reduction and erosion, blister formation and rupture, and the emergence of holes. According to our

  6. Curcumin Generates Oxidative Stress and Induces Apoptosis in Adult Schistosoma mansoni Worms

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    de Paula Aguiar, Daniela; Brunetto Moreira Moscardini, Mayara; Rezende Morais, Enyara; Graciano de Paula, Renato; Ferreira, Pedro Manuel; Afonso, Ana; Belo, Silvana; Tomie Ouchida, Amanda; Curti, Carlos; Cunha, Wilson Roberto; Rodrigues, Vanderlei

    2016-01-01

    Inducing apoptosis is an interesting therapeutic approach to develop drugs that act against helminthic parasites. Researchers have investigated how curcumin (CUR), a biologically active compound extracted from rhizomes of Curcuma longa, affects Schistosoma mansoni and several cancer cell lines. This study evaluates how CUR influences the induction of apoptosis and oxidative stress in couples of adult S. mansoni worms. CUR decreased the viability of adult worms and killed them. The tegument of the parasite suffered morphological changes, the mitochondria underwent alterations, and chromatin condensed. Different apoptotic parameters were determined in an attempt to understand how CUR affected adult S. mansoni worms. CUR induced DNA damage and fragmentation and increased the expression of SmCASP3/7 transcripts and the activity of Caspase 3 in female and male worms. However, CUR did not intensify the activity of Caspase 8 in female or male worms. Evaluation of the superoxide anion and different antioxidant enzymes helped to explore the mechanism of parasite death further. The level of superoxide anion and the activity of Superoxide Dismutase (SOD) increased, whereas the activity of Glutathione-S-Transferase (GST), Glutathione reductase (GR), and Glutathione peroxidase (GPX) decreased, which culminated in the oxidation of proteins in adult female and male worms incubated with CUR. In conclusion, CUR generated oxidative stress followed by apoptotic-like-events in both adult female and male S. mansoni worms, ultimately killing them. PMID:27875592

  7. Phenotypic characterization of Schistosoma mansoni adult wormsrecovered from undernourished mice: a morphometric study focusing on the reproductive system

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    Neves Renata Heisler

    2002-01-01

    Full Text Available A morphometric study focusing on some features of the reproductive system of Schistosoma mansoni adult worms was performed, aiming to complete previously reported data concerning the effects of undernourishment of the host on the parasites. Male worms were significantly affected (p<0.05 regarding the testicular lobes.

  8. Functional visualization of the excretory system of adult Schistosoma mansoni by the fluorescent marker resorufin.

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    Sato, H; Kusel, J R; Thornhill, J

    2002-12-01

    Excretion of metabolic wastes as well as xenobiotics is a major concern of all living organisms, and the Platyhelminthes including Schistosoma mansoni possess the protonephridial excretory system for their survival. Except for some ultra-structural and biochemical information, little is known about the protonephridium of platyhelminths due to a lack of established techniques for exploring the excretory activity. This study describes a new technique to assess the excretory activity of S. mansoni by use of the fluorescent marker resorufin, which is a potential substrate of the drug efflux pump, P-glycoprotein. After simple diffusion into the schistosome body, fluorescent resorufin was concentrated in the excretory tubules by an energy-dependent mechanism and excreted via the nephridiopore. The present technique of labelling functionally the excretory system was applicable to adult worms, but not schistosomula or cercariae. A variety of modulators known to interfere with mammalian P-glycoprotein function perturbed resorufin excretion from male adult schistosomes, including cyclosporin A, Ro11-2933, verapamil, or nifedipine. This technique of labelling the excretory system with fluorescent resorufin has enabled us to study aspects of the physiological function, hitherto unknown, of the protonephridial system of S. mansoni.

  9. In vitro and in vivo effects of hesperidin treatment on adult worms of Schistosoma mansoni.

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    Allam, G; Abuelsaad, A S A

    2014-09-01

    Hesperidin has been reported to exert a wide range of pharmacological effects, including antifungal, antiviral, antioxidant, anti-inflammatory and anticarcinogenic activities. Herein, the schistosomicidal activity of this compound was evaluated in vitro and in vivo. Using an in vitro assay, a concentration of 200 μg/ml of hesperidin resulted in the mortality of 100% adult worms of Schistosoma (S.) mansoni within 72 h and a partial tegumental alteration in 10% of worms. However, after 144 h incubation, 50 and 100 μg/ml concentrations showed 0% and 10% mortality in adult worms, respectively, without any changes to the tegument. Sublethal doses did not influence egg output nor the development of eggs deposited by pairs of adult worms. In an in vivo study, mice infected with S. mansoni and treated with 600 mg hesperidin/kg body weight showed a respective reduction of 50, 45.2, 50 and 47.5% of males, females, worm pairs and total worm burden. In addition, a respective reduction, based on the number of eggs/g tissue, of 41.5, 63.7 and 58.6% was observed in the liver, intestine and liver/intestinal tissue combined. Furthermore, S. mansoni-specific IgG level significantly increased with hesperidin treatment, whereas IgA and IgE levels were not significantly changed. IgM levels decreased in response to cercarial antigen preparation but were not altered in response to soluble worm or soluble egg antigen. As in hesperidin-treated mice, praziquantel-treated mice showed a similar pattern of specific antibody response to S. mansoni antigens. The present study represents the first report on the effects of the schistosomicidal activity of hesperidin.

  10. Morphometric study of Schistosoma mansoni adult worms recovered from undernourished infected mice

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    Sheilla A Oliveira

    2003-07-01

    Full Text Available Some unfavourable effects of malnutrition of the host on Schistosoma mansoni worm biology and structure have been reported based upon brigthfield microscopy. This paper aims to study by morphometric techniques, some morphological parameters in male and female adult worms recovered from undernourished albino mice in comparison with parasites recovered from well-fed infected mice. Undernourished animals were fed a multideficient and essentially low protein diet (RBD diet and compared to well-fed control mice fed with the commercial diet NUVILAB. Seventy-five days post-infection with 80 cercarie (BL strain animals were sacrificed. All adult worms were fixed in 10% formalin and stained with carmine chloride. One hundred male and 60 female specimens from each group (undernourished and control were examined using an image system analysis Leica Quantimet 500C and the Sigma Scan Measurement System. The following morphometrical parameters were studied: body length and width, oral and ventral suckers, number and area of testicular lobes, length and width of ovary and uterine egg. For statistical analysis, the Student's t test for unpaired samples was applied. Significant differences (p < 0.05 were detected in body length and width, in parameters of suckers, uterine egg width, ovary length and area of testicular lobes, with lower values for specimens from undernourished mice. The nutritional status of the host has negative influence on S. mansoni adult worms, probably through unavailability of essential nutrients to the parasites.

  11. Synergy of Omeprazole and Praziquantel In Vitro Treatment against Schistosoma mansoni Adult Worms

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    Anderson, Leticia; Venancio, Thiago M.; Nakaya, Helder I.; Miyasato, Patrícia A.; Rofatto, Henrique K.; Zerlotini, Adhemar; Nakano, Eliana; Oliveira, Guilherme; Verjovski-Almeida, Sergio

    2015-01-01

    Background Treatment and morbidity control of schistosomiasis relies on a single drug, praziquantel (PZQ), and the selection of resistant worms under repeated treatment is a concern. Therefore, there is a pressing need to understand the molecular effects of PZQ on schistosomes and to investigate alternative or synergistic drugs against schistosomiasis. Methodology We used a custom-designed Schistosoma mansoni expression microarray to explore the effects of sublethal doses of PZQ on large-scale gene expression of adult paired males and females and unpaired mature females. We also assessed the efficacy of PZQ, omeprazole (OMP) or their combination against S. mansoni adult worms with a survival in vitro assay. Principal Findings We identified sets of genes that were affected by PZQ in paired and unpaired mature females, however with opposite gene expression patterns (up-regulated in paired and down-regulated in unpaired mature females), indicating that PZQ effects are heavily influenced by the mating status. We also identified genes that were similarly affected by PZQ in males and females. Functional analyses of gene interaction networks were performed with parasite genes that were differentially expressed upon PZQ treatment, searching for proteins encoded by these genes whose human homologs are targets of different drugs used for other diseases. Based on these results, OMP, a widely prescribed proton pump inhibitor known to target the ATP1A2 gene product, was chosen and tested. Sublethal doses of PZQ combined with OMP significantly increased worm mortality in vitro when compared with PZQ or OMP alone, thus evidencing a synergistic effect. Conclusions Functional analysis of gene interaction networks is an important approach that can point to possible novel synergistic drug candidates. We demonstrated the potential of this strategy by showing that PZQ in combination with OMP displayed increased efficiency against S. mansoni adult worms in vitro when compared with

  12. Schistosoma mansoni Sambon, 1907: morphometric differences between adult worms from sympatric rodent and human isolates

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    Neves Renata Heisler

    1998-01-01

    Full Text Available A computer software for image analysis (IMAGE PRO PLUS, MEDIA CYBERNETICS was utilized in male and females adult worms, aiming the morphological characterization of Schistosoma mansoni samples isolated from a slyvatic rodent, Nectomys squamipes, and humans in Sumidouro, Rio de Janeiro, Brazil and recovered from Mus musculus C3H/He. The following characters for males's testicular lobes were analyzed: number, area, density, larger and smaller diameter, longer and shorter axis and perimeter and extension; for females: area, longer and shorter axis, larger and smaller diameter and perimeter of the eggs and spine; oral and ventral suckers area and distance between them in both sex were determined. By the analysis of variance (one way ANOVA significant differences (p<0.05 were observed in all studied characters, except for the density of testicular lobes. Significant differences (p<0.05 were detected for all characters in the female worms. Data ratify that sympatric isolates present phenotypic differences and the adult female characters are useful for the proper identification of S. mansoni isolates.

  13. Schistosomicidal Activity of the Essential Oil of Ageratum conyzoides L. (Asteraceae against Adult Schistosoma mansoni Worms

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    Wilson R. Cunha

    2011-01-01

    Full Text Available The in vitro schistosomicidal effects of the essential oil of Ageratum conyzoides L. (Ac-EO against adult worms of Schistosoma mansoni is reported in this paper. Concerning this activity, Ac-EO was considered to be active, but less effective than the positive control (praziquantel, PZQ in terms of separation of coupled pairs, mortality, decrease in motor activity, and tegumental alterations. However, Ac-EO caused an interesting dose-dependent reduction in the number of eggs of S. mansoni. Precocene I (74.30% and (E-caryophyllene (14.23% were identified as the two major constituents of Ac-EO. These compounds were tested individually and were found to be much less effective than Ac-EO and PZQ. A mixture of the two major compounds in a ratio similar to that found in the Ac-EO was also less effective than Ac-EO, thus revealing that there are no synergistic effects between these components. These results suggest that the essential oil of A. conyzoides is very promising for the development of new schistosomicidal agents.

  14. Tegumental Ca-stimulated adenosine triphosphatase activity in adult Schistosoma mansoni worms Atividade da adenosina trifosfatase estimulada pelo Ca no tegumento de vermes adultos de Schistosoma mansoni

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    Italo M. Cesari

    1989-09-01

    Full Text Available A Ca-stimulated ATPase activity (pH 9.5 associated with the tegumental membrane enriched (TME fraction of Schistosoma mansoni adults was partially inhibited by NAP-taurine or by increasing concentrations of chlorpromazine; endogenous calmodulin was found associated with the TME fraction. A similar activity (pH 8.6 was histochemically visualized whithin the tegument of fixed worms on the cytoplasmic leaflet of both the doubel surface membrane and the basement membrane; this reaction was inhibited by 1 µM chloropromazine and it was also observed on the inner side of double membrane vesicles present in the TME fraction. No ATPase activity could be seen at alkaline pH with added Mg or Na/K ions. Without ATP, the addition of external Ca to the fixed worms induced the appearance of lead precipitates on the tegumental discoid bodies; this reaction was inhibited by molybdate and not by chlorpromazine. The intrategumentary regulation of calcium by the systems described and the possible use of phenothiazines against schistosimes are discussed.A atividade ATPse (pH 9.5 estimulada por ions de Ca associados a uma fração enriquecida de membranas do tegumento (fração EMT de vermes adultos de Schistosoma mansoni, foi inibida pro NAP-taurina ou por concentrações crescentes de clorpromacina. Foi encontrada calmodulina enfogena associada principlamente a esta fração. Em vermes adultos fixados com glutaraldeido se detectou histoquimicamente uma atividade ATPase similar (pH 8.6 na face citoplasmática da dupla membrana de superfície e da membrana por 1 µM de clorpromacina e foi também observada na face interna de vesículas de dupla membrana presentes na fração EMT. Não se pôde detectar atividade ATpase em pH alcalino na presença de ions de Mg ou Na/K. A adição externa de Ca, sem ATP, aos vermes fixados induz ao aparecimento de precipitados nos corpos discóides do tegumento; esta reação foi inibida. Os resultados são discutidos em relação a

  15. Antischistosomal activity of a calcium channel antagonist on schistosomula and adult Schistosoma mansoni worms

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    Vanessa Silva-Moraes

    2013-08-01

    Full Text Available Current schistosomiasis control strategies are largely based on chemotherapeutic agents and a limited number of drugs are available today. Praziquantel (PZQ is the only drug currently used in schistosomiasis control programs. Unfortunately, this drug shows poor efficacy in patients during the earliest infection phases. The effects of PZQ appear to operate on the voltage-operated Ca2+channels, which are located on the external Schistosoma mansoni membrane. Because some Ca2+channels have dihydropyridine drug class (a class that includes nifedipine sensitivity, an in vitro analysis using a calcium channel antagonist (clinically used for cardiovascular hypertension was performed to determine the antischistosomal effects of nifedipine on schistosomula and adult worm cultures. Nifedipine demonstrated antischistosomal activity against schistosomula and significantly reduced viability at all of the concentrations used alone or in combination with PZQ. In contrast, PZQ did not show significant efficacy when used alone. Adult worms were also affected by nifedipine after a 24 h incubation and exhibited impaired motility, several lesions on the tegument and intense contractility. These data support the idea of Ca2+channels subunits as drug targets and favour alternative therapeutic schemes when drug resistance has been reported. In this paper, strong arguments encouraging drug research are presented, with a focus on exploring schistosomal Ca2+channels.

  16. Morphological Study of Adult Male Worms of Schistosoma mansoni Sambon, 1907 by Scanning Electron Microscopy

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    José Roberto Machado-Silva

    1997-09-01

    Full Text Available Tubercles, spines and sensory receptors are the most studied structures of adult male worms of Schistosoma mansoni isolated in other countries. The purpose of this investigation was to properly define these structures in Brazilian worms. Specimens 7-8 weeks after infection were recovered from albino SW mice and from a wild rodent (Nectomys squamipes and processed for scanning electron microscopy studies. Photomicrographs of the anterior region with the aspects related to the outer and inner regions of both suckers were considered. The ventral portion of the middle region was represented by the anterior of gynaecophoric canal while the dorsal surface was studied in its ventral and dorsal regions mainly focusing the aspect of the tubercles, spines and sensorial papillae. The outer surface of the oral sucker is spiny and spines are bigger, sharp with sensory receptors in their posterior edge. Tubercles with spines or receptors are more concentrated in the middle region and in one of the margins of the gynaecophoric canal. An excretory pore-like structure in the posterior portion was observed. The gynaecophoric canal has few sensory structures, spines broadned in their mid-region and are sharp pointed at the distal end. It was concluded that the presently studied characters are similar to those previously reported

  17. Anthelmintic activity in vivo of epiisopiloturine against juvenile and adult worms of Schistosoma mansoni.

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    Guimarães, Maria A; de Oliveira, Rosimeire N; Véras, Leiz M C; Lima, David F; Campelo, Yuri D M; Campos, Stefano Augusto; Kuckelhaus, Selma A S; Pinto, Pedro L S; Eaton, Peter; Mafud, Ana C; Mascarenhas, Yvonne P; Allegretti, Silmara M; de Moraes, Josué; Lolić, Aleksandar; Verbić, Tatjana; Leite, José Roberto S A

    2015-03-01

    Schistosomiasis is a serious disease currently estimated to affect more that 207 million people worldwide. Due to the intensive use of praziquantel, there is increasing concern about the development of drug-resistant strains. Therefore, it is necessary to search for and investigate new potential schistosomicidal compounds. This work reports the in vivo effect of the alkaloid epiisopiloturine (EPI) against adults and juvenile worms of Schistosoma mansoni. EPI was first purified its thermal behavior and theoretical solubility parameters charaterised. In the experiment, mice were treated with EPI over the 21 days post-infection with the doses of 40 and 200 mg/kg, and 45 days post-infection with single doses of 40, 100 and 300 mg/kg. The treatment with EPI at 40 mg/kg was more effective in adult worms when compared with doses of 100 and 300 mg/kg. The treatment with 40 mg/kg in adult worms reduced parasite burden significantly, lead to reduction in hepatosplenomegaly, reduced the egg burden in faeces, and decreased granuloma diameter. Scanning electron microscopy revealed morphological changes to the parasite tegument after treatment, including the loss of important features. Additionally, the in vivo treatment against juvenile with 40 mg/kg showed a reduction of the total worm burden of 50.2%. Histopathological studies were performed on liver, spleen, lung, kidney and brain and EPI was shown to have a DL50 of 8000 mg/kg. Therefore EPI shows potential to be used in schistosomiasis treatment. This is the first time that schistosomicidal in vivo activity of EPI has been reported.

  18. Anthelmintic activity in vivo of epiisopiloturine against juvenile and adult worms of Schistosoma mansoni.

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    Maria A Guimarães

    2015-03-01

    Full Text Available Schistosomiasis is a serious disease currently estimated to affect more that 207 million people worldwide. Due to the intensive use of praziquantel, there is increasing concern about the development of drug-resistant strains. Therefore, it is necessary to search for and investigate new potential schistosomicidal compounds. This work reports the in vivo effect of the alkaloid epiisopiloturine (EPI against adults and juvenile worms of Schistosoma mansoni. EPI was first purified its thermal behavior and theoretical solubility parameters charaterised. In the experiment, mice were treated with EPI over the 21 days post-infection with the doses of 40 and 200 mg/kg, and 45 days post-infection with single doses of 40, 100 and 300 mg/kg. The treatment with EPI at 40 mg/kg was more effective in adult worms when compared with doses of 100 and 300 mg/kg. The treatment with 40 mg/kg in adult worms reduced parasite burden significantly, lead to reduction in hepatosplenomegaly, reduced the egg burden in faeces, and decreased granuloma diameter. Scanning electron microscopy revealed morphological changes to the parasite tegument after treatment, including the loss of important features. Additionally, the in vivo treatment against juvenile with 40 mg/kg showed a reduction of the total worm burden of 50.2%. Histopathological studies were performed on liver, spleen, lung, kidney and brain and EPI was shown to have a DL50 of 8000 mg/kg. Therefore EPI shows potential to be used in schistosomiasis treatment. This is the first time that schistosomicidal in vivo activity of EPI has been reported.

  19. Anthelmintic Activity In Vivo of Epiisopiloturine against Juvenile and Adult Worms of Schistosoma mansoni

    Science.gov (United States)

    Guimarães, Maria A.; de Oliveira, Rosimeire N.; Véras, Leiz M. C.; Lima, David F.; Campelo, Yuri D. M.; Campos, Stefano Augusto; Kuckelhaus, Selma A. S.; Pinto, Pedro L. S.; Eaton, Peter; Mafud, Ana C.; Mascarenhas, Yvonne P.; Allegretti, Silmara M.; de Moraes, Josué; Lolić, Aleksandar; Verbić, Tatjana; Leite, José Roberto S. A.

    2015-01-01

    Schistosomiasis is a serious disease currently estimated to affect more that 207 million people worldwide. Due to the intensive use of praziquantel, there is increasing concern about the development of drug-resistant strains. Therefore, it is necessary to search for and investigate new potential schistosomicidal compounds. This work reports the in vivo effect of the alkaloid epiisopiloturine (EPI) against adults and juvenile worms of Schistosoma mansoni. EPI was first purified its thermal behavior and theoretical solubility parameters charaterised. In the experiment, mice were treated with EPI over the 21 days post-infection with the doses of 40 and 200 mg/kg, and 45 days post-infection with single doses of 40, 100 and 300 mg/kg. The treatment with EPI at 40 mg/kg was more effective in adult worms when compared with doses of 100 and 300 mg/kg. The treatment with 40 mg/kg in adult worms reduced parasite burden significantly, lead to reduction in hepatosplenomegaly, reduced the egg burden in faeces, and decreased granuloma diameter. Scanning electron microscopy revealed morphological changes to the parasite tegument after treatment, including the loss of important features. Additionally, the in vivo treatment against juvenile with 40 mg/kg showed a reduction of the total worm burden of 50.2%. Histopathological studies were performed on liver, spleen, lung, kidney and brain and EPI was shown to have a DL50 of 8000 mg/kg. Therefore EPI shows potential to be used in schistosomiasis treatment. This is the first time that schistosomicidal in vivo activity of EPI has been reported. PMID:25816129

  20. Differential anti-glycan antibody responses in Schistosoma mansoni-infected children and adults studied by shotgun glycan microarray.

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    Angela van Diepen

    Full Text Available BACKGROUND: Schistosomiasis (bilharzia is a chronic and potentially deadly parasitic disease that affects millions of people in (subtropical areas. An important partial immunity to Schistosoma infections does develop in disease endemic areas, but this takes many years of exposure and maturation of the immune system. Therefore, children are far more susceptible to re-infection after treatment than older children and adults. This age-dependent immunity or susceptibility to re-infection has been shown to be associated with specific antibody and T cell responses. Many antibodies generated during Schistosoma infection are directed against the numerous glycans expressed by Schistosoma. The nature of glycan epitopes recognized by antibodies in natural schistosomiasis infection serum is largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: The binding of serum antibodies to glycans can be analyzed efficiently and quantitatively using glycan microarray approaches. Very small amounts of a large number of glycans are presented on a solid surface allowing binding properties of various glycan binding proteins to be tested. We have generated a so-called shotgun glycan microarray containing natural N-glycan and lipid-glycan fractions derived from 4 different life stages of S. mansoni and applied this array to the analysis of IgG and IgM antibodies in sera from children and adults living in an endemic area. This resulted in the identification of differential glycan recognition profiles characteristic for the two different age groups, possibly reflecting differences in age or differences in length of exposure or infection. CONCLUSIONS/SIGNIFICANCE: Using the shotgun glycan microarray approach to study antibody response profiles against schistosome-derived glycan elements, we have defined groups of infected individuals as well as glycan element clusters to which antibody responses are directed in S. mansoni infections. These findings are significant for further

  1. Imatinib treatment causes substantial transcriptional changes in adult Schistosoma mansoni in vitro exhibiting pleiotropic effects.

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    Christin Buro

    2014-06-01

    Full Text Available BACKGROUND: Schistosome parasites cause schistosomiasis, one of the most important infectious diseases worldwide. For decades Praziquantel (PZQ is the only drug widely used for controlling schistosomiasis. The absence of a vaccine and fear of PZQ resistance have motivated the search for alternatives. Studies on protein kinases (PKs demonstrated their importance for diverse physiological processes in schistosomes. Among others two Abl tyrosine kinases, SmAbl1 and SmAbl2, were identified in Schistosoma mansoni and shown to be transcribed in the gonads and the gastrodermis. SmAbl1 activity was blocked by Imatinib, a known Abl-TK inhibitor used in human cancer therapy (Gleevec/Glivec. Imatinib exhibited dramatic effects on the morphology and physiology of adult schistosomes in vitro causing the death of the parasites. METHODOLOGY/PRINCIPAL FINDINGS: Here we show modeling data supporting the targeting of SmAbl1/2 by Imatinib. A biochemical assay confirmed that SmAbl2 activity is also inhibited by Imatinib. Microarray analyses and qRT-PCR experiments were done to unravel transcriptional processes influenced by Imatinib in adult schistosomes in vitro demonstrating a wide influence on worm physiology. Surface-, muscle-, gut and gonad-associated processes were affected as evidenced by the differential transcription of e.g. the gynecophoral canal protein gene GCP, paramyosin, titin, hemoglobinase, and cathepsins. Furthermore, transcript levels of VAL-7 and egg formation-associated genes such as tyrosinase 1, p14, and fs800-like were affected as well as those of signaling genes including a ribosomal protein S6 kinase and a glutamate receptor. Finally, a comparative in silico analysis of the obtained microarray data sets and previous data analyzing the effect of a TGFβR1 inhibitor on transcription provided first evidence for an association of TGFβ and Abl kinase signaling. Among others GCP and egg formation-associated genes were identified as common

  2. Morphological study of adult male worms of Schistosoma mansoni Sambon, 1907 by confocal laser scanning microscopy

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    Machado-Silva José Roberto

    1998-01-01

    Full Text Available Aiming to detail data obtained through brightfield microscopy (BM on reproductive, excretory and digestive system, specimens of Schistosoma mansoni eight weeks old, were recovered from SW mice, stained with Langeron's carmine and analyzed under a confocal laser scanning microscope CLSM 410 (Carl Zeiss. The reproductive system presented a single and lobate testis, with intercommunications between the lobes without efferent duct. Supernumerary testicular lobe was amorphous and isolated from the normal ones. Collecting tubules (excretory ducts, followed by the excretory bladder, opening to the external media through the excretory pore, were observed at the posterior extremity of the body. In the digestive tract, a cecal swelling was noted at the junction that originates the single cecum. It was concluded that through confocal laser scanning microscopy, new interpretations of morphological structures of S. mansoni worms could be achieved, modifying adopted and current descriptions. The gonad consists of a single lobed testis, similar to that observed in some trematode species. Moreover, the same specimens can be observed either by BM or CLSM, considering that the latter causes only focal and limited damage in tissue structures.

  3. The lethality of Euphorbia conspicua to adults of Biomphalaria glabrata, cercaria of Schistosoma mansoni and larvae of Artemia salina.

    Science.gov (United States)

    dos Santos, Aldenir F; de Azevedo, Denise P L; dos Santos Mata, Rosalina da C; de Mendonça, Dina I M Dinis; Sant'Ana, Antônio E Goulart

    2007-01-01

    Leaf extracts of Euphorbia conspicua (Euphorbiaceae), together with the latex and fractions derived therefrom, were evaluated for their molluscicidal and cercaricidal activities and their toxicities to brine shrimps. Whilst the leaf extracts were inactive against Biomphalaria glabrata, the latex, its triterpenic fraction and irritant fractions I and II exhibited high activities against adult snails with LC90 values of 4.87, 10.55, 0.64 and 0.10 microg/mL, respectively. The latex and its derived fractions were considered lethal to the cercaria of Schistosoma mansoni at concentrations of 100 microg/mL. The toxicities of the latex and the irritant fractions, but not of the triterpenic fraction, against Artemia salina were high with LC50 values < 10 microg/mL. The possible application of the latex of E. conspicua as an alternative natural molluscicide is considered.

  4. Anthelmintic Activity of Crude Extract and Essential Oil of Tanacetum vulgare (Asteraceae against Adult Worms of Schistosoma mansoni

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    Loyana Silva Godinho

    2014-01-01

    Full Text Available Schistosomiasis, a parasitic disease caused by trematode flatworms of the genus Schistosoma, affects more than 200 million people worldwide, and its control is dependent on a single drug, praziquantel. Tanacetum vulgare (Asteraceae is used in folk medicine as a vermifuge. This study aimed to investigate the in vitro schistosomicidal activity of the crude extract (TV and the essential oil (TV-EO from the aerial parts of T. vulgare. TV-EO was obtained by hydrodistillation and analyzed by GC/MS, which allowed the identification of β-thujone (84.13% as the major constituent. TV and TV-EO, at 200 μg/mL, decreased motor activity and caused 100% mortality of all adult worms. At 100 and 50 μg/mL, only TV caused death of all adult worms, while TV-EO was inactive. TV (200 μg/mL was also able to reduce viability and decrease production of developed eggs. Confocal laser scanning microscopy showed morphological alterations in the tegument of the S. mansoni surface after incubation with TV (50 and 100 μg/mL. Quantitative analysis on the schistosomes tegument showed that TV caused changes in the numbers of tubercles of S. mansoni male worms in a dose-dependent manner. The findings suggest that T. vulgare is a potential source of schistosomicidal compounds.

  5. Schistosoma mansoni Egg, Adult Male and Female Comparative Gene Expression Analysis and Identification of Novel Genes by RNA-Seq

    Science.gov (United States)

    Anderson, Letícia; Amaral, Murilo S.; Beckedorff, Felipe; Silva, Lucas F.; Dazzani, Bianca; Oliveira, Katia C.; Almeida, Giulliana T.; Gomes, Monete R.; Pires, David S.; Setubal, João C.; DeMarco, Ricardo; Verjovski-Almeida, Sergio

    2015-01-01

    Background Schistosomiasis is one of the most prevalent parasitic diseases worldwide and is a public health problem. Schistosoma mansoni is the most widespread species responsible for schistosomiasis in the Americas, Middle East and Africa. Adult female worms (mated to males) release eggs in the hepatic portal vasculature and are the principal cause of morbidity. Comparative separate transcriptomes of female and male adult worms were previously assessed with using microarrays and Serial Analysis of Gene Expression (SAGE), thus limiting the possibility of finding novel genes. Moreover, the egg transcriptome was analyzed only once with limited bacterially cloned cDNA libraries. Methodology/Principal findings To compare the gene expression of S. mansoni eggs, females, and males, we performed RNA-Seq on these three parasite forms using 454/Roche technology and reconstructed the transcriptome using Trinity de novo assembly. The resulting contigs were mapped to the genome and were cross-referenced with predicted Smp genes and H3K4me3 ChIP-Seq public data. For the first time, we obtained separate, unbiased gene expression profiles for S. mansoni eggs and female and male adult worms, identifying enriched biological processes and specific enriched functions for each of the three parasite forms. Transcripts with no match to predicted genes were analyzed for their protein-coding potential and the presence of an encoded conserved protein domain. A set of 232 novel protein-coding genes with putative functions related to reproduction, metabolism, and cell biogenesis was detected, which contributes to the understanding of parasite biology. Conclusions/Significance Large-scale RNA-Seq analysis using de novo assembly associated with genome-wide information for histone marks in the vicinity of gene models constitutes a new approach to transcriptome analysis that has not yet been explored in schistosomes. Importantly, all data have been consolidated into a UCSC Genome Browser search

  6. Phenotypic plasticity in adult worms of Schistosoma mansoni (Trematoda:Schistosomatidae evidenced by brightfield and confocal laser scanning microscopies

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    Renata Heisler Neves

    2004-03-01

    Full Text Available A comparative morphometric study was performed to identify host-induced morphological alterations in Schistosoma mansoni adult worms. A wild parasite population was obtained from a naturally infected rodent (Nectomys squamipesand then recovered from laboratory infected C3H/He mice. Furthermore, allopatric worm populations maintained for long-term under laboratory conditions in Swiss Webster mice were passed on to N. squamipes. Suckers and genital system (testicular lobes, uterine egg, and egg spine were analyzed by a digital system for image analysis. Confocal laser scanning microscopy (CLSM showed details of the genital system (testicular lobes, vitelline glands, and ovary and the tegument just below the ventral sucker. Significant morphological changes (p < 0.05 were detected in male worms in all experimental conditions, with no significant variability as assessed by CLSM. Significant changes (p < 0.05 were evident in females from the wild population related to their ovaries and vitelline glands, whereas allopatric females presented differences only in this last character. We conclude that S. mansoni worms present the phenotypic plasticity induced by modifications in the parasite's microenvironment, mainly during the first passage under laboratory conditions.

  7. Anthelmintic activity in vitro and in vivo of Baccharis trimera (Less) DC against immature and adult worms of Schistosoma mansoni.

    Science.gov (United States)

    de Oliveira, Rosimeire Nunes; Rehder, Vera Lúcia Garcia; Oliveira, Adriana Silva Santos; Jeraldo, Veronica de Lourdes Sierpe; Linhares, Arício Xavier; Allegretti, Silmara Marques

    2014-04-01

    Although its efficiency against all Schistosoma species, praziquantel (PZQ) shows low efficacy against schistosomula and juvenile stages. The potential for development of resistance to PZQ has justified the search for new alternative chemotherapies. In this scenario, studies to new formulations, more comprehensive and without adverse effects, are being conducted. One viable and promising treatment is the study of medicinal plants as a new approach to the experimental treatment for Schistosomiasis. Amongst all the variety of the medicinal species studied, we can highlight Baccharis trimera (Less) DC, known as "Carqueja-amarga". This paper not only describes the effect of crude dichloromethane extract (DE) and aqueous fraction (AF) obtained from B. trimera, in vitro but also is the first one that investigates the in vivo efficacy of B. trimera against schistosomula, juvenile and adult worms of Schistosoma mansoni BH strain. In the experiment, mice were treated with DE, AF and PZQ (40 and 200mg/kg) over the period of larval development (3 and 30 post-infection; pi), and adult worms (60days post-infection; pi). The in vitro results show that the DE and AF effects are dose-dependents, being the 130μg/mL the most effective one in a shorter period of incubation. The exposure of the in vitro samples over adult parasites were able to inhibit 100% of the oviposition in females. Likewise caused the mortality of the parasites with morphological alterations on the tegument, on the suckers, oral and acetabulum, in both males and females after 6-72h of exposure. Additionally, the in vivo treatments against juvenile and adult infection were more effective compared to the control group untreated. Administrations of AF and DE in day 30pi (juvenile worms) show female worm total burden reductions of 75% and 68% respectively. At the same period of infection reductions of respectively 98% and 97% egg/g in the faeces were seen. In relation to the different egg developmental stages

  8. Ultrastructural analysis of β-lapachone-induced surface membrane damage in male adult Schistosoma mansoni BH strain worms.

    Science.gov (United States)

    Aires, André de Lima; Ximenes, Eulália Camelo Pessoa Azevedo; Silva, Renata Alexandre Ramos; Barbosa, Vanessa Xavier; Góes, Alexandre José da Silva; Peixoto, Christina Alves; Souza, Valdênia Maria Oliveira; Albuquerque, Mônica Camelo Pessôa de Azevedo

    2014-07-01

    The present study provides, for the first time, conclusions on the in vitro schistosomicidal properties of β-lap. Adult male Schistosoma mansoni worms of the BH strain were used for the study. Motility, mortality, cell viability and alterations in the tegument were employed as schistosomicidal parameters. Alterations in motility were observed 6h after incubation in concentrations of 50 and 100 μM. β-lap decreased significantly the worm viability, reducing the formation of formazan in 17.7%, 27.4% and 54.8% at concentrations of 25, 50 and 100 μM, respectively. Mortality in concentrations of 50 and 100 μM was of 67% and 100%, respectively, after 24h. The death of the parasite was preceded by progressive surface membrane damage, characterized by tegument peeling, spine reduction and erosion, blister formation and rupture, and the emergence of holes. In addition to this, in the anterior portion, intense general edema, areas of cracking with a wrinkled surface, furrows and a fibrous appearance were also observed. The results of the present study thus provide a sound basis for further in-depth studies of the schistosomicidal properties of β-lap, both in the laboratory and in the field.

  9. Comparative evaluation of Schistosoma mansoni, Schistosoma intercalatum, and Schistosoma haematobium alkaline phosphatase antigenicity by the alkaline phosphatase immunoassay (APIA).

    Science.gov (United States)

    Cesari, I M; Ballén, D E; Mendoza, L; Ferrer, A; Pointier, J-P; Kombila, M; Richard-Lenoble, D; Théron, A

    2014-04-01

    To know if alkaline phosphatase (AP) from schistosomes other than Schistosoma mansoni can be used as diagnostic marker for schistosomiasis in alkaline phosphatase immunocapture assay (APIA), we comparatively tested n-butanol extracts of adult worm membranes from a Venezuelan (JL) strain of S. mansoni (Ven/AWBE/Sm); a Cameroonian (EDEN) strain of Schistosoma intercalatum (Cam/AWBE/Si) and a Yemeni strain of Schistosoma haematobium (Yem/AWBE/Sh). APIA was evaluated with sera of patients from Venezuela, Senegal, and Gabon infected with S. mansoni, from Gabon infected with S. intercalatum or S. haematobium, from Chine infected with Schistosoma japonicum and from Cambodian patients infected with Schistosoma mekongi. Results indicate that 92.5% (37/40) of Venezuela sera, 75% (15/20) of Senegal sera, 39.5% (17/43) of S. haematobium sera, and 19.2% (5/26) S. intercalatum sera were APIA-positive with the Ven/AWBE/Sm preparation. APIA with the Cam/AWBE/Si preparation showed that 53.8% of S. intercalatum-positive sera had anti-AP antibodies, and 51.2% S. haematobium-positive sera cross-immunocapturing the S. intercalatum AP. APIA performed with Yem/AWBE/Sh showed that 55.8% S. haematobium sera were positive. Only two out of nine S. japonicum sera were APIA-positive with the Ven/AWBE/Sm and Cam/AWBE/Si, and no reaction was observed with Cambodian S. mekongi-positive sera. AP activity was shown to be present in all the schistosome species/strains studied. The use of APIA as a tool to explore the APs antigenicity and the presence of Schistosoma sp. infections through the detection of anti-Schistosoma sp. AP antibodies in a host, allowed us to demonstrate the antigenicity of APs of S. mansoni, S. intercalatum, and S. haematobium.

  10. Résistance a la dessiccation de Biomphalaria glabrata adultes infestés par plusieurs miracidiums de Schistosoma mansoni

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    F. Lancastre

    1989-06-01

    Full Text Available Les auteurs ont soumis à 6 semaines d'anhydrobiose 1200 Biomphalaria adultes, saines, ou parasitées par 8 ± 2 miracidiums de Schistosoma mansoni depois 3 ou 12 jours, ou émettant des cercaires. Les planorbes étaient placées individuellement sur, ou dans de la terre humide, dans des boîtes closes ou aérées. La survie a été nulle chez les planorbes saines, infestées, ou déjà positives, placées dans les boîtes closes. Chez les mollusques placés dans les boîtes aérées, elle a été de 44% chez les témoins sains, et de 40,6% pour l'emsemble des infestées depuis 3 et 12 jours, avec chez ces derniers une meilleure survie lorsqu'ils étaient en surface. N n'est pas apparu de différence entre les infestations de 3 jours et de 12 jours. La mortalité et la production cercarienne sont infériéures à celles de planorbes infestées et gardées en eau. L'analyse des émissions montre une production des cercaires mâles siginificativement inférieure à celle des cercaires femelles ou mâles et femelles. Chez toutes les B. glabrata positives, les auteurs ont observé des variations périodiques dans la production des cercaires, quel que soit le sexe de celles-ci. De plus, chez les mollusques préalablement soumis à dessiccation, il existe de nombreus arrêts ou pauses dans l'émission des larves.

  11. The cercarial glycocalyx of Schistosoma mansoni

    OpenAIRE

    1985-01-01

    Cercariae, the freshwater stage of Schistosoma mansoni infectious to man, are covered by a single unit membrane and an immunogenic glycocalyx. When cercariae penetrate the host skin, they transform to schistosomula by shedding tails, secreting mucous and enzymes, and forming microvilli over their surface. Here the loss of the glycocalyx from cercariae transforming in vitro was studied morphologically and biochemically. By scanning electron microscopy, the glycocalyx was a dense mesh composed ...

  12. In vitro effects of amodiaquine on paired Schistosoma mansoni adult worms at concentrations of less than 5 µg/mL

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    Kentaro Kato

    2013-04-01

    Full Text Available In this study, the in vitro effects of amodiaquine (AQ monotherapy on the egg output of paired adult Schistosoma mansoni worms and their survival during in vitro culture were assessed. In addition, the gross morphological alterations of male and female worms caused by AQ were visually observed under a dissecting microscope. AQ significantly reduced the daily egg output of paired adult S. mansoni worms following incubation for 14 days at 1-5 µg/mL, but not at 0.5 µg/mL, compared with the control group. AQ also reduced the survival of male and female worms at concentrations of 2 and 5 µg/mL, respectively. Moreover, exposure to 5 µg/mL AQ caused severe swelling and/or localisation of black content in the body of all male and female worms within one or two days of incubation; subsequently, shrinkage in the male worms and elongation in the female worms were observed. The initial morphological alterations caused by AQ occurred along the intestinal tract of the male and female worms. To our knowledge, this is the first study to report not only the efficacy of AQ at concentrations lower than 5 µg/mL on paired adult S. mansoni worms, but also the effects of AQ on the intestinal tracts of worms in in vitro culture.

  13. THE SUSCEPTIBILITY OF RECENT ISOLATES OF Schistosoma mansoni TO PRAZIQUANTEL

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    Adriana Maria B. MENDONÇA

    2016-01-01

    Full Text Available Introduction: Schistosomiasis is a chronic disease caused by trematode flatworms of the genus Schistosoma and its control is dependent on a single drug, praziquantel (PZQ, but concerns over PZQ resistance have renewed interest in evaluating the in vitro susceptibility of recent isolates of Schistosoma mansoni to PZQ in comparison with well-established strains in the laboratory. Material and methods: The in vitro activity of PZQ (6.5-0.003 µg/mL was evaluated in terms of mortality, reduced motor activity and ultrastructural alterations against S. mansoni. Results: After 3 h of incubation, PZQ, at 6.5 µg/mL, caused 100% mortality of all adult worms in the three types of recent isolates, while PZQ was inactive at concentrations of 0.08-0.003 µg/mL after 3 h of incubation. The results show that the SLM and Sotave isolates basically presented the same pattern of susceptibility, differing only in the concentration of 6.5 µg/mL, where deaths occurred from the range of 1.5 h in Sotave and just in the 3 h range of SLM. Additionally, this article presents ultrastructural evidence of rapid severe PZQ-induced surface membrane damage in S. mansoni after treatment with the drug, such as disintegration, sloughing, and erosion of the surface. Conclusion: According to these results, PZQ is very effective to induce tegument destruction of recent isolates of S. mansoni.

  14. Immunization with PIII, a fraction of Schistosoma mansoni soluble adult worm antigenic preparation, affects nitric oxide production by murine spleen cells

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    Diana Magalhães de Oliveira

    1998-01-01

    Full Text Available Nitric oxide (NO is an important effector molecule involved in immune regulation and defense. NO produced by cytokine-activated macrophages was reported to be cytotoxic against the helminth Schistosoma mansoni. Identification and characterization of S. mansoni antigens that can provide protective immunity is crucial for understanding the complex immunoregulatory events that modulate the immune response in schistosomiasis. It is, then, essential to have available defined, purified parasite antigens. Previous work by our laboratory identified a fraction of S. mansoni soluble adult worm antigenic preparation (SWAP, named PIII, able to elicit significant in vitro cell proliferation and at the same time lower in vitro and in vivo granuloma formation when compared either to SEA (soluble egg antigen or to SWAP. In the present work we report the effect of different in vivo trials with mice on their spleen cells ability to produce NO. We demonstrate that PIII-immunization is able to significantly increase NO production by spleen cells after in vitro stimulation with LPS. These data suggest a possible role for NO on the protective immunity induced by PIII.

  15. Morphological aspects of Schistosoma mansoni adult worms isolated from nourished and undernourished mice: a comparative analysis by confocal laser scanning microscopy

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    Neves Renata Heisler

    2001-01-01

    Full Text Available Malnutrition hampers the course of schistosomiasis mansoni infection just as normal growth of adult worms. A comparative morphometric study on adult specimens (male and female recovered from undernourished (fed with a low protein diet - regional basic diet and nourished (rodent commercial laboratory food, NUVILAB white mice was performed. Tomographic images and morphometric analysis of the oral and ventral suckers, reproductive system and tegument were obtained by means of confocal laser scanning microscopy. Undernourished male specimens presented smaller morphometric values (length and width of the reproductive system (first, third and last testicular lobes and thickness of the tegument than controls. Besides that, it was demonstrated that the dorsal surface of the male worms bears large tubercles unevenly distributed, but kept grouped and flat. At the subtegumental region, vacuolated areas were detected. It was concluded that the inadequate nutritional status of the vertebrate host has a negative influence mainly in the reproductive system and topographical somatic development of male adult Schistosoma mansoni, inducing some alterations on the structure of the parasite.

  16. Uncovering Notch pathway in the parasitic flatworm Schistosoma mansoni.

    Science.gov (United States)

    Magalhães, Lizandra G; Morais, Enyara R; Machado, Carla B; Gomes, Matheus S; Cabral, Fernanda J; Souza, Julia M; Soares, Cláudia S; Sá, Renata G; Castro-Borges, William; Rodrigues, Vanderlei

    2016-10-01

    Several signaling molecules that govern development in higher animals have been identified in the parasite Schistosoma mansoni, including the transforming growth factor β, protein tyrosine kinases, nuclear hormone receptors, among others. The Notch pathway is a highly conserved signaling mechanism which is involved in a wide variety of developmental processes including embryogenesis and oogenesis in worms and flies. Here we aimed to provide the molecular reconstitution of the Notch pathway in S. mansoni using the available transcriptome and genome databases. Our results also revealed the presence of the transcripts coded for SmNotch, SmSu(H), SmHes, and the gamma-secretase complex (SmNicastrin, SmAph-1, and SmPen-2), throughout all the life stages analyzed. Besides, it was observed that the viability and separation of adult worm pairs were not affected by treatment with N-[N(3,5)-difluorophenacetyl)-L-Alanyl]-S-phenylglycine t-butyl ester (DAPT), a Notch pathway inhibitor. Moreover, DAPT treatment decreased the production of phenotypically normal eggs and arrested their development in culture. Our results also showed a significant decrease in SmHes transcript levels in both adult worms and eggs treated with DAPT. These results provide, for the first time, functional validation of the Notch pathway in S. mansoni and suggest its involvement in parasite oogenesis and embryogenesis. Given the complexity of the Notch pathway, further experiments shall highlight the full repertoire of Notch-mediated cellular processes throughout the S. mansoni life cycle.

  17. Purification of a chymotrypsin-like enzyme present on adult Schistosoma mansoni worms from infected mice and its characterization as a host carboxylesterase.

    Science.gov (United States)

    Igetei, Joseph E; Liddell, Susan; El-Faham, Marwa; Doenhoff, Michael J

    2016-04-01

    A serine protease-like enzyme found in detergent extracts of Schistosoma mansoni adult worms perfused from infected mice has been purified from mouse blood and further characterized. The enzyme is approximately 85 kDa and hydrolyses N-acetyl-DL-phenylalanine β-naphthyl-ester, a chromogenic substrate for chymotrypsin-like enzymes. The enzyme from S. mansoni worms appears to be antigenically and enzymatically similar to a molecule that is present in normal mouse blood and so is seemingly host-derived. The enzyme was partially purified by depleting normal mouse serum of albumin using sodium chloride and cold ethanol, followed by repeated rounds of purification by one-dimensional sodium dodecyl sulphate polyacrylamide gel electrophoresis. The purified material was subjected to tandem mass spectrometry and its derived peptides found to belong to mouse carboxylesterase 1C. Its ability to hydrolyse α- or β-naphthyl acetates, which are general esterase substrates, has been confirmed. A similar carboxylesterase was purified and characterized from rat blood. Additional evidence to support identification of the enzyme as a carboxylesterase has been provided. Possible roles of the enzyme in the mouse host-parasite relationship could be to ease the passage of worms through the host's blood vessels and/or in immune evasion.

  18. In vitro and in vivo anthelmintic activity of (-)-6,6'-dinitrohinokinin against schistosomula and juvenile and adult worms of Schistosoma mansoni.

    Science.gov (United States)

    Pereira, Ana C; Silva, Márcio L A E; Souza, Julia Medeiros; Laurentiz, Rosangela S de; Rodrigues, Vanderlei; Januário, Ana H; Pauletti, Patrícia M; Tavares, Denise C; Filho, Ademar A Da Silva; Cunha, Wilson R; Bastos, Jairo K; Magalhães, Lizandra G

    2015-09-01

    The chemotherapy of schistosomiasis relies on the use of praziquantel. However, concerns over drug resistance have encouraged the search for new drug leads. This paper is the first report on the in vitro and in vivo activity of (-)-6,6'-dinitrohinokinin (DNK) against Schistosoma mansoni. In vitro, the lethal concentrations for 50% of parasites (LC50) of DNK against adult worms were 103.9±3.6 and 102.5±4.8μM at 24 and 72h, respectively. Scanning electron microscopy images showed extensive tegumental alterations such as peeling and smaller numbers of tubercles in the spine of adult worms. DNK also elicited high mortality of schistosomula, with LC50 values of 57.4±2.3, 32.5±0.9, and 20.4±1.2μM at 24, 48, and 72h, respectively. DNK displayed moderate activity against the juvenile liver parasite, with an LC50 value of 179.5±2.3 μM at 72h. This compound reduced the total number of eggs by over 83%, and it affected the development of eggs produced by adult worms. The selectivity index showed that at 24h, DNK was 8.5 and 15.4 times more toxic to the adult worms and schistosomula than to Chinese hamster lung fibroblast cells, respectively. Treatment of infected mice with DNK moderately decreased worm burden (33.8-52.3%), egg production (40.7-60.0%), and spleen and liver weights. Together, our results indicated that DNK presents moderate in vitro and in vivo activities against S. mansoni, and it might therefore be interesting to explore the structure-activity relationship of the antischistosomal activity of this compound.

  19. Partial molecular characterization of Sm8, a tegumental antigen of Schistosoma mansoni

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    Frederico GC Abath

    2002-10-01

    Full Text Available Sm8 is a major tegumental antigen of Schistosoma mansoni. The partial cDNA was isolated and analyzed. Sequence analysis revealed transmembrane compatible hydrophobic domains and a putative leucine zipper pattern. The mRNA and the protein are predominantly expressed in adult worms.

  20. Glycogen metabolism in Schistosoma mansoni worms after their isolation from the host

    NARCIS (Netherlands)

    Tiolens, A.G.M.; Bergh, S.G. van den

    1987-01-01

    Adult Schistosoma mansoni worms rapidly degrade their endogenous glycogen stores immediately after isolation from the host. In NCTC 109 or in a diphasic culture medium the glycogen levels slowly recovered again after the initial decrease. The rapid degradation of glycogen could be prevented, even in

  1. Preliminary analysis of miRNA pathway in Schistosoma mansoni.

    Science.gov (United States)

    Gomes, Matheus S; Cabral, Fernanda J; Jannotti-Passos, Liana K; Carvalho, Omar; Rodrigues, Vanderlei; Baba, Elio H; Sá, Renata G

    2009-03-01

    RNA silencing refers to a series of nuclear and cytoplasmatic processes involved in the post-transcriptional regulation of gene expression or post-transcriptional gene silencing (PTGS), either by sequence-specific mRNA degradation or by translational arrest. The best characterized small RNAs are microRNAs (miRNAs), which predominantly perform gene silencing through post-transcriptional mechanisms. In this work we used bioinformatic approaches to identify the parasitic trematode Schistosoma mansoni sequences that are similar to enzymes involved in the post-transcriptional gene silencing mediated by miRNA pathway. We used amino acid sequences of well-known proteins involved in the miRNA pathway against S. mansoni genome and transcriptome databases identifying a total of 13 putative proteins in the parasite. In addition, the transcript levels of SmDicer1 and SmAgo2/3/4 were identified by qRT-PCR using cercariae, adult worms, eggs and in vitro cultivated schistosomula. Our results showed that the SmDicer1 and SmAgo2/3/4 are differentially expressed during schistosomula development, suggesting that the miRNA pathway is regulated at the transcript level and therefore may control gene expression during the life cycle of S. mansoni.

  2. Structural studies of Schistosoma mansoni adenylate kinases

    Energy Technology Data Exchange (ETDEWEB)

    Marques, I.A. [Universidade Federal de Goias (UFG), Goiania, GO (Brazil); Pereira, H.M.; Garrat, R.C. [Universidade de Sao Paulo (USP-SC), Sao Carlos, SP (Brazil)

    2012-07-01

    Full text: Parasitic diseases are a major cause of death in developing countries, however receive little or no attention from pharmaceutical companies for the development of novel therapies. In this respect, the Center for Structural Molecular Biology (CBME) of the Institute of Physics of Sao Carlos (IFSC / USP) has developed expertise in all stages of the development of active compounds against target enzymes from parasitic diseases. The present work focuses on the adenylate kinase enzymes (ADK's) from Schistosoma mansoni. These enzymes are widely distributed and catalyze the reaction of phosphoryl exchange between nucleotides in the reaction 2ADP to ATP + AMP, which is critical for the cells life cycle. Due to the particular property of the reaction catalyzed, the ADK's are recognized as reporters of the cells energetic state, translating small changes in the balance between ATP and ADP into a large change in concentration of AMP. The genome of S. mansoni was recently sequenced by the Sanger Center in England. On performing searches for genes encoding adenylate kinases we found two such genes. The corresponding gene products were named ADK1 (197 residues) and ADK2 (239 residues), and the two sequences share only 28 percent identity. Both have been cloned into the pET-28a(+)vector, expressed in E. coli and purified. Preliminary tests of activity have been performed only for ADK1 showing it to be catalytically active. Crystallization trials were performed for both proteins and thus far, crystals of ADK1 have been obtained which diffract to 2.05 at the LNLS beamline MX2 and the structure solved by molecular replacement. Understanding, at the atomic level, the function of these enzymes may help in the development of specific inhibitors and may provide tools for developing diagnostic tests for schistosomiasis. (author)

  3. Reproductive system abnormalities in Schistosoma mansoni adult worms isolated from Nectomys squamipes (Muridae: Sigmodontinae: brightfield and confocal laser scanning microscopy analysis

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    Neves Renata Heisler

    2003-01-01

    Full Text Available Schistosoma mansoni adult worms with genital anomalies isolated from Nectomys squamipes (Muridae: Sigmodontinae were studied by confocal laser scanning microscopy under the reflected mode. One male without testicular lobes (testicular agenesia/anorchism and two females, one with an atrophied ovary and another with 17 uterine eggs, were identified. The absence of testicular lobes occurred in a worm presenting otherwise normal male adult characteristics: tegument, tubercles and a gynaecophoric canal with spines. In both female specimens the digestive tube showed a vacuolated appearance, and the specimen with supernumerary uterine eggs exhibited a developing miracidium and an egg with a formed shell. The area of the ventral sucker was similar in both specimens however the tegument thickness, ovary and vitelline glands of the specimen with the atrophied ovary were smaller than those of the one with supernumerary eggs. These reported anomalies in the reproductive system call attention to the need to improve our understanding of genetic regulation and the possible role of environmental influences upon trematode development.

  4. Inheritance of Schistosoma mansoni infection incompatibility in Biomphalaria alexandrina snails

    OpenAIRE

    Iman F Abou El Naga; Eissa, Maha M.; Shereen F Mossallam; Safaa I Abd El-Halim

    2010-01-01

    In this study, we looked at the inheritance of susceptibility and resistance to Schistosoma mansoni infection in the first generation of crossbred Biomphalaria alexandrina snails. Our ultimate goal is to use such information to develop a biological method of controlling schistosomiasis. We infected laboratory-bred snails with S. mansoni miracidia and examined cercarial shedding to determine susceptibility and resistance. Five parental groups were used: Group I contained 30 susceptible snails,...

  5. Evidentiation of Paramyosin (Sm-97 as a Modulating Antigen on Granulomatous Hypersensitivity to Schistosoma mansoni Eggs

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    Hirsch Cristine

    1997-01-01

    Full Text Available A Schistosoma mansoni adult worm anionic fraction (PIII has previously been shown to protect mice against challenge infection and to reduce pulmonary and hepatic granulomatous hypersensitivity. Serum from PIII-immunized rabbit was used to screen a lgt11 cDNA library from S. mansoni adult worm in order to identify antigens capable of modulating granulomatous hypersensitivity. We obtained four clones with 400 (Sm-III.11, 900 (Sm-III.16, 1100 (Sm-III.10 and 1300 (Sm-III.12 bp of length. All clone-specific antibodies were able to recognize most of the PIII components. The sequence analysis showed that these clones presented high homology with S. mansoni paramyosin (Sm-97. These findings ascribe a new function to this antigen with an important role in modulation of granulomatous hypersensitivity to S. mansoni eggs

  6. Schistosoma mansoni antigenic extracts obtained by different extraction procedures

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    Miriam Tendler

    1981-06-01

    Full Text Available Solubilization of Schistosoma mansoni antigens was obtained by agitation of adult worms in a 3M KCl solution. The protein contents of the KCl extrats varied from 0.35 to 0.96 mg/ml. Sera from 97 patients with hepatointestinal shistosomiasis and viable eggs in stools from a Brazilian endemic area were studied by immunoelectroomophoresis and Ouchterlony immunodiffusion methods with the KCl extract and with another antigen, obtained by homogenization of adult schistosomes in saline. The rate of positiveness of immunoprecipitation deterctions by immunoelectroomophoresis with the KCl extract was 53.5%. A correlation was verified between methods of detection and extration procedures, resulting in a better association of the extract obtained by agitation in 3M KCl and immunoelectroomophoresis.Foi obtida a solubilização de antígenos do Schistosoma mansoni por agitação de vermes adultos em solução de KCl 3M. O teor protéico dos extratos de KCl variou de 0,35 a 0,96mg/ ml. Foram testados pelos métodos de imunoeletroosmoforese (IEOP e dupla imunodifusão (Ouchterlony, 97 soros de doentes de area endêmica brasileira de esquistossomose, forma clínica hepatointestinal e com exames coprológicos positivos para S. mansoni, com o extrato de KCl e outro antígeno obtido pela homogenização de vermes adultos em salina. A taxa de positividade das reações de imunoprecipitação por IEOP com o antígeno extraído pela ação do KCl 3M foi 53,5%. Foi verificada a correlação entre os métodos de detecção e de extração resultando numa melhor associação entre o extrato obtido por agitação no KCl 3M e a IEOP.

  7. Schistosome syntenin partially protects vaccinated mice against Schistosoma mansoni infection.

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    Barbara C Figueiredo

    2014-08-01

    Full Text Available Schistosomiasis is a neglected tropical disease caused by several species of trematode of the genus Schistosoma. The disease affects more than 200 million people in the world and causes up to 280,000 deaths per year, besides having high morbidity due to chronic illness that damages internal organs. Current schistosomiasis control strategies are mainly based on chemotherapy, but many researchers believe that the best long-term strategy to control disease is a combination of drug treatment and immunization with an anti-schistosome vaccine. Among the most promising molecules as vaccine candidates are the proteins present in the tegument and digestive tract of the parasite.In this study, we describe for the first time Schistosoma mansoni syntenin (SmSynt and we evaluate its potential as a recombinant vaccine. We demonstrate by real-time PCR that syntenin is mainly expressed in intravascular life stages (schistosomula and adult worms of the parasite life cycle and, by confocal microscopy, we localize it in digestive epithelia in adult worms and schistosomula. Administration of siRNAs targeting SmSynt leads to the knock-down of syntenin gene and protein levels, but this has no demonstrable impact on parasite morphology or viability, suggesting that high SmSynt gene expression is not essential for the parasites in vitro. Mice immunization with rSmSynt, formulated with Freund's adjuvant, induces a Th1-type response, as suggested by the production of IFN-γ and TNF-α by rSmSynt-stimulated cultured splenocytes. The protective effect conferred by vaccination with rSmSynt was demonstrated by 30-37% reduction of worm burden, 38-43% reduction in the number, and 35-37% reduction in the area, of liver granulomas.Our report is the first characterization of syntenin in Schistosoma mansoni and our data suggest that this protein is a potential candidate for the development of a multi-antigen vaccine to control schistosomiasis.

  8. Bioactivity of miltefosine against aquatic stages of Schistosoma mansoni, Schistosoma haematobium and their snail hosts, supported by scanning electron microscopy

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    El Bardicy Samia

    2011-05-01

    Full Text Available Abstract Background Miltefosine, which is the first oral drug licensed for the treatment of leishmaniasis, was recently reported to be a promising lead compound for the synthesis of novel antischistosomal derivatives with potent activity in vivo against different developmental stages of Schistosoma mansoni. In this paper an in vitro study was carried out to investigate whether it has a biocidal activity against the aquatic stages of Schistosoma mansoni and its snail intermediate host, Biomphalaria alexandrina , thus being also a molluscicide. Additionally, to see whether miltefosine can have a broad spectrum antischistosomal activity, a similar in vitro study was carried out on the adult stage of Schistosoma haematobium, the second major human species, its larval stages and snail intermediate host, Bulinus truncutes. This was checked by scanning electron microscopy. Results Miltefosine proved to have in vitro ovicidal, schistolarvicidal and lethal activity on adult worms of both Schistosoma species and has considerable molluscicidal activity on their snail hosts. Scanning electron microscopy revealed several morphological changes on the different stages of the parasite and on the soft body of the snail, which further strengthens the current evidence of miltefosine's activity. This is the first report of mollusicidal activity of miltefosine and its in vitro schistosomicidal activity against S.haematobium. Conclusions This study highlights miltefosine not only as a potential promising lead compound for the synthesis of novel broad spectrum schistosomicidal derivatives, but also for molluscicidals.

  9. Schistosoma mansoni and Host-Parasite Interactions

    NARCIS (Netherlands)

    S.M-C.A. de Walick (Saskia)

    2015-01-01

    markdownabstract__Abstract__ Blood-dwelling parasitic trematodes (flatworms) of the genus Schistosoma cause the disease schistosomiasis or Bilharzia. There are 5 different Schistosoma species that infect humans and many other infecting different mammals. Over 200 million people worldwide are infect

  10. Susceptibility of Iraqi fresh water snails to infection with Schistosoma haematobium and Schistosoma mansoni Egyptian strains.

    Science.gov (United States)

    Wajdi, N A; Hussain, W I; El-Hawary, M F

    1979-01-01

    A great number of Egyptian workers and farmers are seeking settlement in Iraq and some of them proved to have either Schistosoma Haematobium (S.h.) or Schistosoma mansoni (S.m) or even mixed infection. Besides, there is the possibility that some of the Iraqi fresh water snails may prove to be susceptible to infection by one or both of the Schistosoma Egyptian strains. The present study deals with investigations on the susceptibility of Iraqi B. truncatus, Gyranaulus ehrenbergi, Physa c.f. fontinalis, Lymnea lagetis, Melanoides tuberculata and Melanopsis nodes by these parasites. Egyptian S. haematobium but not Egyptian S. mansoni infect Iraqi B. truncatus and both proved to be unable to infect any of the other snails included in the study. Yet, the number of cercariae shedded by B. truncatus snails infected with the Egyptian S. haematobium strain, was much less that the number of cercariae shedded by these snails when infected with the Iraqi S. Haematobium strain.

  11. Metabonomic investigation of human Schistosoma mansoni infection

    DEFF Research Database (Denmark)

    Balog, Crina I.A.; Meissner, Axel; Göraler, Sibel;

    2011-01-01

    . Investigation of the host-parasite interaction at the molecular level and identification of biomarkers of infection and infection-related morbidity would be of value for improved strategies for treatment and morbidity control. To this end, we conducted a nuclear magnetic resonance (NMR) based metabonomics study...... in their urinary profiles. The potential molecular markers of S. mansoni infection were found to be primarily linked to changes in gut microflora, energy metabolism and liver function. These findings are in agreement with data from earlier studies on S. mansoni infection in experimental animals and thus provide...

  12. Influence of Schistosoma mansoni and Hookworm Infection Intensities on Anaemia in Ugandan Villages

    Science.gov (United States)

    Chami, Goylette F.; Fenwick, Alan; Bulte, Erwin; Kontoleon, Andreas A.; Kabatereine, Narcis B.; Tukahebwa, Edridah M.; Dunne, David W.

    2015-01-01

    Background The association of anaemia with intestinal schistosomiasis and hookworm infections are poorly explored in populations that are not limited to children or pregnant women. Methods We sampled 1,832 individuals aged 5–90 years from 30 communities in Mayuge District, Uganda. Demographic, village, and parasitological data were collected. Infection risk factors were compared in ordinal logistic regressions. Anaemia and infection intensities were analyzed in multilevel models, and population attributable fractions were estimated. Findings Household and village-level predictors of Schistosoma mansoni and hookworm were opposite in direction or significant for single infections. S. mansoni was found primarily in children, whereas hookworm was prevalent amongst the elderly. Anaemia was more prevalent in individuals with S. mansoni and increased by 2.86 fold (p-value<0.001) with heavy S. mansoni infection intensity. Individuals with heavy hookworm were 1.65 times (p-value = 0.008) more likely to have anaemia than uninfected participants. Amongst individuals with heavy S. mansoni infection intensity, 32.0% (p-value<0.001) of anaemia could be attributed to S. mansoni. For people with heavy hookworm infections, 23.7% (p-value = 0.002) of anaemia could be attributed to hookworm. A greater fraction of anaemia (24.9%, p-value = 0.002) was attributable to heavy hookworm infections in adults (excluding pregnant women) as opposed to heavy hookworm infections in school-aged children and pregnant women (20.2%, p-value = 0.001). Conclusion Community-based surveys captured anaemia in children and adults affected by S. mansoni and hookworm infections. For areas endemic with schistosomiasis or hookworm infections, WHO guidelines should include adults for treatment in helminth control programmes. PMID:26513151

  13. Influence of Schistosoma mansoni and Hookworm Infection Intensities on Anaemia in Ugandan Villages.

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    Goylette F Chami

    Full Text Available The association of anaemia with intestinal schistosomiasis and hookworm infections are poorly explored in populations that are not limited to children or pregnant women.We sampled 1,832 individuals aged 5-90 years from 30 communities in Mayuge District, Uganda. Demographic, village, and parasitological data were collected. Infection risk factors were compared in ordinal logistic regressions. Anaemia and infection intensities were analyzed in multilevel models, and population attributable fractions were estimated.Household and village-level predictors of Schistosoma mansoni and hookworm were opposite in direction or significant for single infections. S. mansoni was found primarily in children, whereas hookworm was prevalent amongst the elderly. Anaemia was more prevalent in individuals with S. mansoni and increased by 2.86 fold (p-value<0.001 with heavy S. mansoni infection intensity. Individuals with heavy hookworm were 1.65 times (p-value = 0.008 more likely to have anaemia than uninfected participants. Amongst individuals with heavy S. mansoni infection intensity, 32.0% (p-value<0.001 of anaemia could be attributed to S. mansoni. For people with heavy hookworm infections, 23.7% (p-value = 0.002 of anaemia could be attributed to hookworm. A greater fraction of anaemia (24.9%, p-value = 0.002 was attributable to heavy hookworm infections in adults (excluding pregnant women as opposed to heavy hookworm infections in school-aged children and pregnant women (20.2%, p-value = 0.001.Community-based surveys captured anaemia in children and adults affected by S. mansoni and hookworm infections. For areas endemic with schistosomiasis or hookworm infections, WHO guidelines should include adults for treatment in helminth control programmes.

  14. Comparative Evaluation of Anthelmintic Activity of Edible and Ornamental Pomegranate Ethanolic Extracts against Schistosoma mansoni

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    Doaa A. Yones

    2016-01-01

    Full Text Available Due to the development of praziquantel (PZQ schistosomes resistant strains, the discovery of new antischistosomal agents is of high priority in research. This work reported the in vitro and in vivo effects of the edible and ornamental pomegranate extracts against Schistosoma mansoni. Leaves and stem bark ethanolic extracts of both dried pomegranates were prepared at 100, 300, and 500 μg/mL for in vitro and 600 and 800 mg/kg for in vivo. Adult worms Schistosoma mansoni in RPMI-1640 medium for in vitro and S. mansoni infected mice for in vivo tests were obtained from Theodor Bilharz Research Institute, Cairo, Egypt. In vitro activity was manifested by significant coupled worms separation, reduction of motor activity, lethality, and ultrastructural tegumental alterations in adult worms. In vivo activity was manifested revealed by significant reduction of hepatic granulomas number and diameter, decreased number of bilharzial eggs in liver tissues, lowered liver inflammatory infiltration, decreased hepatic fibrosis, and inducible nitric oxide synthase (iNOS expression. Ethanolic stem bark extract of edible pomegranate exhibited highest antischistosomal activities both in vitro and in vivo. Therefore, pomegranate showed a good potential to be used as a promising new candidate for the development of new schistosomicidal agents.

  15. A potential vector of Schistosoma mansoni in Uruguay Um vetor potencial do Schistosoma mansoni no Uruguai

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    W. Lobato Paraense

    1989-09-01

    Full Text Available Susceptibily experiments were carried out with a Biomphalaria straminea-like planorbid snail (Biomphalaria aff. straminea, species inquirenda from Espinillar, near Salto (Uruguay, in the area of the Salto Grande reservoir, exposed individually to 5 miracidia of Schistosoma mansoni (SJ2 and BH2 strains. Of 130 snails exposed to the SJ2 strain, originally infective to Biomphalaria tenagophila, 30 became infected (23%. The prepatent (precercaria period ranged from 35 to 65 days. The cercarial output was irregular, following no definite pattern, varying from 138 to 76,075 per snail (daily average 4.3 to 447.5 and ending up with death. Three specimens that died, without having shed cercarie, on days 69 (2 and 80 after exposure to miracidia, had developing secondary sporocysts in their tissues, justifying the prospect of a longer precercarial period in these cases. In a control group of 120 B. teangophila, exposed to the SJ2 strain, 40 became infected, showing an infection rate (33.3% not significantly different from that of the Espinillar snail (X [raised to the power of] 2 = 3.26. No cercarie were produced by any of the Espinilar snails exposed to miracidia of the BH2 strain, originally infective to Biomphalaria glabrata. Four specimens showed each a primary sporocyst in one tentacle, which disappeared between 15 and 25 days post-exposure, and two others died with immature, very slender sporocysts in their tissues on days 36 and 54. In a control group of 100 B. glabrata exposed to BH2 miracidia, 94 shed cercariae (94% and 6 remained negative. Calculation of Frandsen's (1979a, b TCP/100 index shows that "Espinillar Biomphalaria-SJ2 S. mansoni" is a vector-parasite "compatible" combination. Seeing that tenagophila-borne schistosomiasis is prevalent in Rio de Janeiro and São Paulo states and has recently spread sothwards to Santa Catarina state, and the range of B. tenagophila overlaps taht of the Espinillar Biomphalaria, the possibility of

  16. Chromatographic Fingerprint Analysis and Effects of the Medicinal Plant Species Mitracarpus frigidus on Adult Schistosoma mansoni Worms

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    Rodrigo Luiz Fabri

    2014-01-01

    Full Text Available The aims of this work were to evaluate the in vitro and in vivo schistosomicidal properties of the methanolic extract of the aerial parts of Mitracarpus frigidus (MFM and to determine its HPLC profile. For the in vitro experiment, four pairs of adult worms, obtained from infected mice, were exposed to different concentrations of MFM (100 to 400 μg/mL for 24 and 48 h and analyzed under an inverted microscope. For the in vivo experiment, mice were inoculated with cercariae and, 20 days after infection, MFM (100 and 300 mg/kg was administered orally for the following 25 days. Mice were euthanized after 60 days. MFM showed in vitro schistosomicidal activity, exhibiting the opening of the gynaecophoral canal of some male schistosomes, the presence of contorted muscles, vesicles, and the darkening of the paired worms skin. In vivo experiments showed that MFM treatments significantly reduced total worm count, as praziquantel, showing a decrease in liver and spleen weight. Also, a significant reduction in granuloma density was observed. MFM treatment did not cause alterations in the liver function of either infected or noninfected mice. The HPLC chromatogram profile showed the presence of kaempferol-O-rutinoside, rutin, kaempferol, psychorubrin, and ursolic acid.

  17. Anthelmintic effects of the essential oil of fennel (Foeniculum vulgare Mill., Apiaceae) against Schistosoma mansoni.

    Science.gov (United States)

    Wakabayashi, Kamila A L; de Melo, Nathalya I; Aguiar, Daniela P; de Oliveira, Pollyanna F; Groppo, Milton; da Silva Filho, Ademar A; Rodrigues, Vanderlei; Cunha, Wilson R; Tavares, Denise C; Magalhães, Lizandra G; Crotti, Antônio E M

    2015-07-01

    Foeniculum vulgare Mill. (Apiaceae), known as fennel, is a widespread aromatic herbaceous plant, and its essential oil is used as additive in the food, pharmaceutical, cosmetic, and perfume industries. The in vitro antischistosomal activity and cytotoxic effects against V79 cells of the essential oil of F. vulgare cultivated in southeastern Brazil (FV-EO) was investigated. The FV-EO was obtained by hydrodistillation and characterized by GC-FID and GC/MS analyses. (E)-Anethole (69.8%) and limonene (22.5%) were identified as the major constituents. Its anthelmintic activity against Schistosoma mansoni was evaluated at concentrations of 10, 50, and 100 μg/ml, and it was found to be active against adult S. mansoni worms, although it was less effective than the positive control praziquantel (PZQ) in terms of separation of the coupled pairs, mortality, and decreased motor activity. However, FV-EO elicited an interesting dose-dependent reduction in the number of S. mansoni eggs. On their own, (E)-anethole and the limonene enantiomers were much less effective than FV-EO and PZQ. An XTT-cytotoxicity-based assay evidenced no FV-EO cytotoxicity against V79 cells. In summary, FV-EO displayed moderate in vitro schistosomicidal activity against adult S. mansoni worms, exerted remarkable inhibitory effects on the egg development, and was of low toxicity.

  18. Host-induced morphological changes of Schistosoma mansoni Sambon, 1907 male worms

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    José Roberto Machado-Silva

    1994-09-01

    Full Text Available In order to evaluate the permissiveness of Nectomys squamipes to Schistosoma mansoni and the influence of the albino mice on the morphological aspects of adult worms derived from a population isolated from N. squamipes, the morphology of adult S. mansoni Sambon, 1907 male worms was studied using a digital image analyser (MOP VIDEOPLAN and light microscopy. Their sources were as follows: (1 recovered from the wild rodent N. squamipes Brants naturally infected from Sumidouro, RJ, Brazil; (2 recovered from albino mice experimentally infected with the strain derived from N. squamipes; (3 recovered after the isolation of a strain derived from aboriginal human infections in Sumidouro. Worms recovered from N. squamipes (group 1 showed body lenght and distance between suckers significantly bigger than those of the specimens maintained in mice (groups 2 and 3. The number of tests in group 1 was statistically less than of groups 2 and 3. Group 2 strains which were maintained in mice, presented the lenght of the worms as the only significant different character. Data show that: (1 N. squamipes is a more suitable host for the development of S. mansoni when compared to the albino mice; (2 a strain of S. mansoni isolated from a natural host undergoes morphological changes after its passage in the white mouse.

  19. Specific immunoglobulin measurements related to exposure and resistance to Schistosoma mansoni infection in Sudanese canal cleaners

    DEFF Research Database (Denmark)

    Satti, M.Z.; Lind, Peter; Vennervald, B.J.;

    1996-01-01

    The present work comprises a longitudinal study of Schistosoma mansoni infection in occupationally hyper-exposed canal cleaners in the Sudan and the influence of chemotherapy on humoral immune parameters. The study groups included chronically infected canal cleaners (n = 19), newly recruited canal...... was used to detect specific IgE and IgG subclasses in response to whole worm antigen (WWH) and soluble egg antigen (SEA) before and 3 months after praziquantel treatment in the groups of canal cleaners and before and 1 year after treatment in normally exposed adults. When intensity of infection...

  20. Schistosoma mansoni Sambon, 1907: comparative morphologica studies of some Brazilian strains Schistosoma mansoni Sambon, 1907: estudos comparativos da morfologia de algumas cepas brasileiras

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    José Roberto Machado-Silva

    1995-10-01

    Full Text Available The morphology of Schistosoma mansoni adult male worms from three strains which have been maintained in albino mice for several generations, was compared to a strain that has been isolated from the natural host Nectomys squamipes (Rodentia: Muridae captured in Sumidouro (Rio de Janeiro State and have been maintained in the same sylvatic rodent under laboratory conditions. Total length of specimens, distance between suckers, the number of testes and extention of testes grouping were the taxonomic characters analysed. The worms recovered from N. squamipes showed expressive differences (pA morfologia de vermes adultos machos de tres cepas de Schistosoma mansoni, mantidas por várias gerações em camundongos albinos, foi comparada com uma cepa isolada do hospedeiro natural Nectomys squamipes (Rodentia: Muridae e mantida, em laboratório, neste mesmo roedor silvestre. Como caracteres taxonômicos foram analisados o comprimento total, o numero de testículos, a distância entre as ventosas e a distância ocupada pelos testículos nos espécimes. Os vermes recuperados de N. squamipes apresentaram diferenças significativas (p<0,01 em relação às outras cepas para quaisquer caracteres morfológicos estudados. As cepas mantidas em camundongos apresentaram diferença estatística em vários caracteres (p<0,01. Alguns vermes adultos além da disposição normal dos testículos, apresentavam também uma localização atípica destas glândulas sexuais. Conclui-se que a morfologia dos vermes adultos pode ser utilizada para caracterizar cepas de S. mansoni e que as passagens sucessivas de uma cepa em camundongos não induzem a alterações morfológicas nos vermes adultos.

  1. Characterization of human heterophil hemolysins induced by Schistosoma mansoni infection

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    Munir Chamone

    1983-09-01

    Full Text Available Heterophil antibodies could be detected in sera from normal or from patient with chronic schistosomiasis. Their hemolytic activities depend on the integrity of the complement classic pathway. The heterophil antibodies from patient sera presented a higher specificity for Schistosoma mansoni antigen preparations than those detected in normal sera. Most of the hemolytic activity observed in normal sera can be destroyed at 56ºC for 4 min. On the other hand, about 80% of the sera from infected patients are partially or totally resistant to this heat-treatment. The hemolytic activities of sera were eluted from a gel filtration column in different fractions of the first peak.Anticorpos heterófilos foram detectados nos soros de pacientes normais ou com esquistossomose mansoni crônica. Suas atividades hemolíticas dependem da integridade da via clássica do sistema do complemento. Os anticorpos heterófilos dos pacientes esquistossomóticos apresentaram maior especificidade para antígenos de Schistosoma mansoni do que aqueles anticorpos detectados nos soros de pacientes normais. A atividade hemolítica do anticorpo nos soros normais podia ser destruída pelo aquecimento destes soros a 56ºC durante 4 minutos. Por outro lado, cerca de 80% dos soros de pacientes esquistossomóticos eram parcial ou totalmente resistentes ao mesmo tratamento. As atividades dos anticorpos heterófilos foram eluídas através da filtração em gel, em diferentes frações no primeiro pico.

  2. In vitro evaluation of schistosomicidal activity of essential oil of Mentha x villosa and some of its chemical constituents in adult worms of Schistosoma mansoni.

    Science.gov (United States)

    Matos-Rocha, Thiago José; dos Santos Cavalcanti, Marília Gabriela; Barbosa-Filho, José Maria; Lúcio, Ana Silvia Suassuna Carneiro; Veras, Dyana Leal; Feitosa, Ana Paula Sampaio; de Siqueira Júnior, José Pinto; de Almeida, Reinaldo Nóbrega; Marques, Márcia Ortiz Mayo; Alves, Luiz Carlos; Brayner, Fábio André

    2013-09-01

    This study aimed to determine the composition of the essential oil of Mentha x villosa and to evaluate its biological effects in vitro on adult worms of S. mansoni. Rotundifolone (70.96 %), limonene (8.75 %), trans-caryophyllene (1.46 %), and β-pinene (0.81 %) were shown to be the major constituents of this oil. Adult worms of S. mansoni were incubated with different concentrations of the essential oil (1, 10, 100, 250, 500, and 1000 µg/mL) and of its constituents rotundifolone (0.7, 3.54, 7.09, 70.96, 177.4, 354.8, and 700.96 µg/mL), limonene (43.75 µg/mL), trans-caryophyllene (7.3 µg/mL), and β-pinene (4.03 µg/mL). No schistosomicidal activity was identified at the trans-caryophyllene and β-pinene concentrations studied. However, use of the essential oil (10 µg/mL), rotundifolone (7.09 µg/mL), and limonene (43.75 µg/mL) resulted in decreased worm motility continuing until 96 hours of observation. At higher concentrations (100 and 70.96 µg/mL, respectively), both the essential oil and rotundifolone caused mortality among adult worms of S. mansoni. The positive control praziquantel caused the death of all parasites after 24 h of evaluation. The results from this study suggest that the essential oil of Mentha x villosa presents schistosomicidal efficacy.

  3. Flavonoids and Sesquiterpene Lactones from Artemisia absinthium and Tanacetum parthenium against Schistosoma mansoni Worms

    Directory of Open Access Journals (Sweden)

    Luísa Maria Silveira de Almeida

    2016-01-01

    Full Text Available Human schistosomiasis, caused by trematode worms of the genus Schistosoma, is one of the most significant neglected tropical diseases, affecting more than 200 million individuals worldwide and praziquantel is the only available drug to treat this disease. Artemisia absinthium L. and Tanacetum parthenium L. are species popularly used as anthelmintics. We investigated the in vitro schistosomicidal activity of crude extracts of A. absinthium (AA and T. parthenium (TP and their isolated compounds. AA and TP, at 200 μg/mL, were active, causing 100% mortality of all adult worms. Chromatographic fractionation of AA leads to isolation of artemetin and hydroxypelenolide, while santin, apigenin, and parthenolide were isolated from TP. Artemetin, hydroxypelenolide, santin, and apigenin, at 100 μM, were inactive against adult worms. Parthenolide (12.5 to 100 μM caused 100% mortality, tegumental alterations, and reduction of motor activity of all adult worms of S. mansoni, without affecting mammalian cells. Confocal laser scanning microscopy showed tegumental morphological alterations and changes on the numbers of tubercles of S. mansoni worms. This report provides the first evidence for the in vitro activity of parthenolide against adult worms of S. mansoni, opening the route to further schistosomicidal studies with this compound.

  4. Praziquantel treatment decreases Schistosoma mansoni genetic diversity in experimental infections.

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    Regina Coeli

    Full Text Available BACKGROUND: Schistosomiasis has a considerable impact on public health in many tropical and subtropical areas. In the new world, schistosomiasis is caused by the digenetic trematode Schistosoma mansoni. Chemotherapy is the main measure for controlling schistosomiasis, and the current drug of choice for treatment is praziquantel (PZQ. Although PZQ is efficient and safe, its repetitive large-scale use in endemic areas may lead to the selection of resistant strains. Isolates less susceptible to PZQ have been found in the field and selected for in the laboratory. The impact of selecting strains with a decreased susceptibility phenotype on disease dynamics and parasite population genetics is not fully understood. This study addresses the impact of PZQ pressure on the genetics of a laboratory population by analyzing frequency variations of polymorphic genetic markers. METHODOLOGY: Infected mice were treated with increasing PZQ doses until the highest dose of 3 × 300 mg/Kg was reached. The effect of PZQ treatment on the parasite population was assessed using five polymorphic microsatellite markers. Parasitological and genetic data were compared with those of the untreated control. After six parasite generations submitted to treatment, it was possible to obtain a S. mansoni population with decreased susceptibility to PZQ. In our experiments we also observed that female worms were more susceptible to PZQ than male worms. CONCLUSIONS: The selective pressure exerted by PZQ led to decreased genetic variability in S. mansoni and increased endogamy. The understanding of how S. mansoni populations respond to successive drug pressure has important implications on the appearance and maintenance of a PZQ resistance phenotype in endemic regions.

  5. Prolonged somatostatin therapy may cause down–regulation of SSTR–like GPCRs on Schistosoma mansoni

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    Eric Van Marck

    2007-09-01

    Full Text Available Background & objectives: Chemotherapy with praziquantel remains the only control measure to Schistosoma mansoni infections to date. The neuropeptide hormone somatostatin gives relief from gastrointestinal disturbances, liverpathology, and reduces egg production in S. mansoni infected mice, suggesting an interaction of somatostatin with the parasite rather than with the host alone. Using antibodies directed to epitopes of the seven somatostatin transmembrane receptors (SSTRs, the presence of SSTRs (or proteins that contain these epitopes was shown on both worm– and eggstages of S. mansoni. The present study was undertaken to investigate whether SSTRs on S. mansoni displayed homo/heterodimerisation properties as well as agonist induced down–regulation. Results: Somatostatin therapy was effective after two days of treatment with no further reduction in pathology after five days of therapy. Immunohistochemistry performed on parasite sections showed reactivity of the anti–SSTR antibodies to the tegument and internal parts of adult S. mansoni worms. SDS–PAGE–Western blotting identified protein bands of 70–100 and 200–250 kDa molecular weight. Upon carboxymethylation of the sulfhydryl groups of proteins in the worm lysate, a reduction in density of the protein band at 200–250 kDa and an increase in density of the protein band at 70–100 kDa were noted. This suggested that a substantial amount of the proteins detected on the blot are present as a homo/heterodimer. A protein microarray was used to investigate whether somatostatin therapy induced receptor down– or up–regulation on the adult worm of S. mansoni. Slides spotted with primary anti–SSTR antibody were exposed to lysates of worms collected from infected C3H mice that received none, two days or five days somatostatin treatment, followed by a secondary anti– SSTR antibody coupled to a fluorophore. Comparison of the different samples in terms of parasite dilution till when

  6. Whole genome resequencing of the human parasite Schistosoma mansoni reveals population history and effects of selection

    Science.gov (United States)

    Crellen, Thomas; Allan, Fiona; David, Sophia; Durrant, Caroline; Huckvale, Thomas; Holroyd, Nancy; Emery, Aidan M.; Rollinson, David; Aanensen, David M.; Berriman, Matthew; Webster, Joanne P.; Cotton, James A.

    2016-01-01

    Schistosoma mansoni is a parasitic fluke that infects millions of people in the developing world. This study presents the first application of population genomics to S. mansoni based on high-coverage resequencing data from 10 global isolates and an isolate of the closely-related Schistosoma rodhaini, which infects rodents. Using population genetic tests, we document genes under directional and balancing selection in S. mansoni that may facilitate adaptation to the human host. Coalescence modeling reveals the speciation of S. mansoni and S. rodhaini as 107.5–147.6KYA, a period which overlaps with the earliest archaeological evidence for fishing in Africa. Our results indicate that S. mansoni originated in East Africa and experienced a decline in effective population size 20–90KYA, before dispersing across the continent during the Holocene. In addition, we find strong evidence that S. mansoni migrated to the New World with the 16–19th Century Atlantic Slave Trade. PMID:26879532

  7. Update of the Gene Discovery Program in Schistosoma mansoni with the Expressed Sequence Tag Approach

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    Élida ML Rabelo

    1997-09-01

    Full Text Available Continuing the Schistosoma mansoni Genome Project 363 new templates were sequenced generating 205 more ESTs corresponding to 91 genes. Seventy four of these genes (81% had not previously been described in S. mansoni. Among the newly discovered genes there are several of significant biological interest such as synaptophysin, NIFs-like and rho-GDP dissociation inhibitor

  8. Binding of von Willebrand factor and plasma proteins to the eggshell of Schistosoma mansoni

    NARCIS (Netherlands)

    Dewalick, Saskia; Hensbergen, Paul J; Bexkens, Michiel L; Grosserichter-Wagener, Christina; Hokke, Cornelis H; Deelder, André M; de Groot, Philip G; Tielens, Aloysius G M; van Hellemond, Jaap J

    2014-01-01

    Schistosoma mansoni eggs have to cross the endothelium and intestinal wall to leave the host and continue the life cycle. Mechanisms involved in this essential step are largely unknown. Here we describe direct binding to the S. mansoni eggshell of von Willebrand factor and other plasma proteins invo

  9. Schistosoma mansoni proteins attenuate gastrointestinal motility disturbances during experimental colitis in mice

    Institute of Scientific and Technical Information of China (English)

    Nathalie; E; Ruyssers; Benedicte; Y; De; Winter; Joris; G; De; Man; Natacha; D; Ruyssers; Ann; J; Van; Gils; Alex; Loukas; Mark; S; Pearson; Joel; V; Weinstock; Paul; A; Pelckmans; Tom; G; Moreels

    2010-01-01

    AIM:To investigate the therapeutic effect of Schistosoma mansoni(S.mansoni) soluble worm proteins on gastrointestinal motility disturbances during experimental colitis in mice. METHODS:Colitis was induced by intrarectal injection of trinitrobenzene sulphate(TNBS) and 6 h later,mice were treated ip with S.mansoni proteins.Experiments were performed 5 d after TNBS injection.Inflammationwas quantified using validated inflammation parameters. Gastric emptying and geometric center were measured to assess in vivo...

  10. Ultrastructural and biochemical detection of biotin and biotinylated polypeptides in Schistosoma mansoni

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    Santos P.R.P.

    1997-01-01

    Full Text Available Biotinylation is proposed for the identification of surface proteins in Schistosoma mansoni using the streptavidin-HRP conjugate for the detection of labeled polypeptides. However, control samples also showed several endogenous biotinylated polypeptides. In an attempt to determine the possibility of nonspecific binding between the streptavidin-HRP conjugate and polypeptides from S. mansoni, the conjugate was blocked with biotinamidecaproate-N-hydroxysuccinimide ester (BcapNHS before biotin-streptavidin blotting. No bands were detected on the nitrocellulose sheet, demonstrating the specific recognition of biotin by the streptavidin present in the conjugate. Whole cercariae and cercarial bodies and tails showed several endogenous biotinylated polypeptides. The biotin concentration was 13 µg/190,000 cercariae. Adult worms presented less endogenous biotinylated polypeptides than cercariae. These results may be due to changes in the environment from aerobic to anaerobic conditions when cercarial bodies (schistosomula are transformed into adult worms and a decrease in CO2 production may occur. Cercariae, cercarial bodies and adult male worms were examined by transmission electron microscopy employing an avidin-colloidal gold conjugate for the detection of endogenous biotin. Gold particles were distributed mainly on the muscle fibers, but dispersed granules were observed in the tegument, mitochondria and cytosol. The discovery of endogenous biotin in S. mansoni should be investigated in order to clarify the function of this vitamin in the parasite

  11. The effect of Zymomonas mobilis culture on experimental Schistosoma mansoni infection O efeito da cultura de Zymomonas mobilis na infecção experimental por Schistosoma mansoni

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    Juliana de Fátima Macedo Santos

    2004-12-01

    Full Text Available C57Bl/10 male mice infected with Schistosoma mansoni were distributed into mixed, prophylactic and curative groups. A culture of Zymomonas mobilis was orally administered to mice. A 61% protection from the infection was observed in the curative group (p Camundongos C57Bl/10 do sexo masculino, infectados com Schistosoma mansoni foram distribuídos nos grupos misto, profilático e curativo. Cultura de Zymomonas mobilis foi administrada oralmente aos camundongos. Uma proteção de 61% foi observada no grupo curativo (p<0,05. Os estudos histopatológicos dos fígados e intestinos mostraram resultados similares.

  12. Schistosoma mansoni cercariae exploit an elastohydrodynamic coupling to swim efficiently

    CERN Document Server

    Krishnamurthy, Deepak; Bhargava, Arjun; Prakash, Manu

    2016-01-01

    The motility of many parasites is critical for the infection process of their host, as exemplified by the transmission cycle of the blood fluke Schistosoma mansoni. In their human infectious stage, immature, submillimetre-scale forms of the parasite known as cercariae swim in freshwater and infect humans by penetrating through the skin. This infection causes Schistosomiasis, a parasitic disease that is comparable to malaria in its global socio-economic impact. Given that cercariae do not feed and hence have a finite lifetime of around 12 hours, efficient motility is crucial for the parasite's survival and transmission of Schistosomiasis. However, a first-principles understanding of how cercariae swim is lacking. Via a combined experimental, theoretical and robotics based approach, we demonstrate that cercariae propel themselves against gravity by exploiting a unique elastohydrodynamic coupling. We show that cercariae beat their tail in a periodic fashion while maintaining a fixed flexibility near their poster...

  13. Estudios inmunologicos en hamsters (Cricetus auratus infectados con Schistosoma mansoni

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    Eduardo Monge

    1986-08-01

    Full Text Available Los resultados de este trabajo muestran que el hamster (Cricetus auratus puede ser utilizado como un modelo experimental para estudios inmunológicos en la infección por Schistosoma mansoni. Los datos obtenidos, relativos a inmunidad concomitante, producción de anticuerpo letal e inmunosupresión se asemejan a los conseguidos en otros modelos experimentales ya establecidos. Estas observaciones indican que el hámster, además de ser un hospedero satisfactorio para el mantenimiento del parásito en el laboratorio, puede ser considerado como un modelo experimental alterno cuyo crecimiento y mantenimiento son relativamente simples y además es un animal de fácil manejo.

  14. Towards an understanding of the function of the phytochelatin synthase of Schistosoma mansoni.

    Science.gov (United States)

    Rigouin, Coraline; Nylin, Elyse; Cogswell, Alexis A; Schaumlöffel, Dirk; Dobritzsch, Dirk; Williams, David L

    2013-01-01

    Phytochelatin synthase (PCS) is a protease-like enzyme that catalyzes the production of metal chelating peptides, the phytochelatins, from glutathione (GSH). In plants, algae, and fungi phytochelatin production is important for metal tolerance and detoxification. PCS proteins also function in xenobiotic metabolism by processing GSH S-conjugates. The aim of the present study is to elucidate the role of PCS in the parasitic worm Schistosoma mansoni. Recombinant S. mansoni PCS proteins expressed in bacteria could both synthesize phytochelatins and hydrolyze various GSH S-conjugates. We found that both the N-truncated protein and the N- and C-terminal truncated form of the enzyme (corresponding to only the catalytic domain) work through a thiol-dependant and, notably, metal-independent mechanism for both transpeptidase (phytochelatin synthesis) and peptidase (hydrolysis of GSH S-conjugates) activities. PCS transcript abundance was increased by metals and xenobiotics in cultured adult worms. In addition, these treatments were found to increase transcript abundance of other enzymes involved in GSH metabolism. Highest levels of PCS transcripts were identified in the esophageal gland of adult worms. Taken together, these results suggest that S. mansoni PCS participates in both metal homoeostasis and xenobiotic metabolism rather than metal detoxification as previously suggested and that the enzyme may be part of a global stress response in the worm. Because humans do not have PCS, this enzyme is of particular interest as a drug target for schistosomiasis.

  15. Towards an Understanding of the Function of the Phytochelatin Synthase of Schistosoma mansoni

    Science.gov (United States)

    Rigouin, Coraline; Nylin, Elyse; Cogswell, Alexis A.; Schaumlöffel, Dirk; Dobritzsch, Dirk; Williams, David L.

    2013-01-01

    Phytochelatin synthase (PCS) is a protease-like enzyme that catalyzes the production of metal chelating peptides, the phytochelatins, from glutathione (GSH). In plants, algae, and fungi phytochelatin production is important for metal tolerance and detoxification. PCS proteins also function in xenobiotic metabolism by processing GSH S-conjugates. The aim of the present study is to elucidate the role of PCS in the parasitic worm Schistosoma mansoni. Recombinant S. mansoni PCS proteins expressed in bacteria could both synthesize phytochelatins and hydrolyze various GSH S-conjugates. We found that both the N-truncated protein and the N- and C-terminal truncated form of the enzyme (corresponding to only the catalytic domain) work through a thiol-dependant and, notably, metal-independent mechanism for both transpeptidase (phytochelatin synthesis) and peptidase (hydrolysis of GSH S-conjugates) activities. PCS transcript abundance was increased by metals and xenobiotics in cultured adult worms. In addition, these treatments were found to increase transcript abundance of other enzymes involved in GSH metabolism. Highest levels of PCS transcripts were identified in the esophageal gland of adult worms. Taken together, these results suggest that S. mansoni PCS participates in both metal homoeostasis and xenobiotic metabolism rather than metal detoxification as previously suggested and that the enzyme may be part of a global stress response in the worm. Because humans do not have PCS, this enzyme is of particular interest as a drug target for schistosomiasis. PMID:23383357

  16. Towards an understanding of the function of the phytochelatin synthase of Schistosoma mansoni.

    Directory of Open Access Journals (Sweden)

    Coraline Rigouin

    Full Text Available Phytochelatin synthase (PCS is a protease-like enzyme that catalyzes the production of metal chelating peptides, the phytochelatins, from glutathione (GSH. In plants, algae, and fungi phytochelatin production is important for metal tolerance and detoxification. PCS proteins also function in xenobiotic metabolism by processing GSH S-conjugates. The aim of the present study is to elucidate the role of PCS in the parasitic worm Schistosoma mansoni. Recombinant S. mansoni PCS proteins expressed in bacteria could both synthesize phytochelatins and hydrolyze various GSH S-conjugates. We found that both the N-truncated protein and the N- and C-terminal truncated form of the enzyme (corresponding to only the catalytic domain work through a thiol-dependant and, notably, metal-independent mechanism for both transpeptidase (phytochelatin synthesis and peptidase (hydrolysis of GSH S-conjugates activities. PCS transcript abundance was increased by metals and xenobiotics in cultured adult worms. In addition, these treatments were found to increase transcript abundance of other enzymes involved in GSH metabolism. Highest levels of PCS transcripts were identified in the esophageal gland of adult worms. Taken together, these results suggest that S. mansoni PCS participates in both metal homoeostasis and xenobiotic metabolism rather than metal detoxification as previously suggested and that the enzyme may be part of a global stress response in the worm. Because humans do not have PCS, this enzyme is of particular interest as a drug target for schistosomiasis.

  17. Compatibility of Schistosoma mansoni Cameroon and Biomphalaria pfeifferi Senegal.

    Science.gov (United States)

    Southgate, V R; Tchuenté, L A; Théron, A; Jourdane, J; Ly, A; Moncrieff, C B; Gryseels, B

    2000-11-01

    The vectorial capacity of Biomphalaria pfeifferi from Ndiangue, Senegal, was investigated with an allopatric isolate of Schistosoma mansoni from Nkolbisson, Cameroon. The snail infection rate after exposure to a single miracidium per snail (MD1) was 56. 3 %, and 91.6%, for snails exposed to 5 miracidia per snail (MD5). The minimum pre-patent period was 21 days. The mean total cercarial production for the MDI group was 18,511 cercariae per snail, and 9757 cercariae for the MD5 group. The maximum production of cercariae for 1 day was 4892 observed in a snail from the MDI group at day 43 post-infection. The mean longevity of snails was higher in group MD1 (88 days p.i.) than in group MD5 (65 days p.i.). The chronobiological emergence pattern revealed a circadian rhythm with one shedding peak at mid-day. Comparisons are made with the vectorial capacity of the sympatric combination of B. pfeifferi Senegal/S. mansoni Senegal.

  18. Identification of Schistosoma mansoni candidate antigens for diagnosis of schistosomiasis

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    Gardenia Braz Figueiredo Carvalho

    2011-11-01

    Full Text Available The development of a more sensitive diagnostic test for schistosomiasis is needed to overcome the limitations of the use of stool examination in low endemic areas. Using parasite antigens in enzyme linked immunosorbent assay is a promising strategy, however a more rational selection of parasite antigens is necessary. In this study we performed in silico analysis of the Schistosoma mansoni genome, using SchistoDB database and bioinformatic tools for screening immunogenic antigens. Based on evidence of expression in all parasite life stage within the definitive host, extracellular or plasmatic membrane localization, low similarity to human and other helminthic proteins and presence of predicted B cell epitopes, six candidates were selected: a glycosylphosphatidylinositol-anchored 200 kDa protein, two putative cytochrome oxidase subunits, two expressed proteins and one hypothetical protein. The recognition in unidimensional and bidimensional Western blot of protein with similar molecular weight and isoelectric point to the selected antigens by sera from S. mansoni infected mice indicate a good correlation between these two approaches in selecting immunogenic proteins.

  19. Inheritance of Schistosoma mansoni infection incompatibility in Biomphalaria alexandrina snails

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    Iman F Abou El Naga

    2010-03-01

    Full Text Available In this study, we looked at the inheritance of susceptibility and resistance to Schistosoma mansoni infection in the first generation of crossbred Biomphalaria alexandrina snails. Our ultimate goal is to use such information to develop a biological method of controlling schistosomiasis. We infected laboratory-bred snails with S. mansoni miracidia and examined cercarial shedding to determine susceptibility and resistance. Five parental groups were used: Group I contained 30 susceptible snails, Group II contained 30 resistant snails, Group III contained 15 susceptible and 15 resistant snails, Group IV contained 27 susceptible and three resistant snails and Group V contained three susceptible and 27 resistant snails. The percentage of resistant snails in the resulting progeny varied according to the ratio of susceptible and resistant parents per group; they are 7%, 100%, 68%, 45% and 97% from Groups I, II, III, IV and V, respectively. On increasing the percentage of resistant parent snails, the percentage of resistant progeny increased, while cercarial production in their susceptible progeny decreased.

  20. ULTRASTRUCTURAL CHANGES IN Schistosoma mansoni MALE WORMS AFTER in vitro INCUBATION WITH THE ESSENTIAL OIL OF Mentha x villosa Huds

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    Thiago José MATOS-ROCHA

    2016-01-01

    Full Text Available Introduction: The essential oil Mentha x villosa (MVEO has a wide range of actions, including antibacterial, antifungal, antiprotozoal and schistosomicidal actions. The present study aimed to investigate the ultrastructural changes of MVEO on the tegument of adult Schistosoma mansoni. Materials and Methods: Different concentrations of MVEO were tested on S. mansoni adult worms in vitro. Ultrastructural changes on the tegument of these adult worms were evaluated using scanning electron microscopy (SEM and transmission electron microscopy (TEM. Results: The MVEO caused the death of all worms at 500 μg mL-1 after 24 h. After 24h of 500 μg mL-1 MVEO treatment, bubble lesions were observed over the entire body of worms and they presented loss of tubercles in some regions of the ventral portion. In the evaluation by TEM, S. mansoni adult worms treated with MVEO, 500 μg mL-1, presented changes in the tegument and vacuoles in the syncytial matrix region. Glycogen granules close to the muscle fibers were visible. Conclusion: The ability of MVEO to cause extensive ultrastructural damage to S. mansoni adult worms correlates with its schistosomicidal effects and confirms earlier findings with S. mansoni.

  1. Genetic knockdown and pharmacological inhibition of parasite multidrug resistance transporters disrupts egg production in Schistosoma mansoni.

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    Ravi S Kasinathan

    2011-12-01

    Full Text Available P-glycoprotein (Pgp and multidrug resistance-associated proteins (MRPs are ATP-dependent transporters involved in efflux of toxins and xenobiotics from cells. When overexpressed, these transporters can mediate multidrug resistance (MDR in mammalian cells, and changes in Pgp expression and sequence are associated with drug resistance in helminths. In addition to the role they play in drug efflux, MDR transporters are essential components of normal cellular physiology, and targeting them may prove a useful strategy for development of new therapeutics or of compounds that enhance the efficacy of current anthelmintics. We previously showed that expression of Schistosoma mansoni MDR transporters increases in response to praziquantel (PZQ, the current drug of choice against schistosomiasis, and that reduced PZQ sensitivity correlates with higher levels of these parasite transporters. We have also shown that PZQ inhibits transport by SMDR2, a Pgp orthologue from S. mansoni, and that PZQ is a likely substrate of SMDR2. Here, we examine the physiological roles of SMDR2 and SmMRP1 (the S. mansoni orthologue of MRP1 in S. mansoni adults, using RNAi to knock down expression, and pharmacological agents to inhibit transporter function. We find that both types of treatments disrupt parasite egg deposition by worms in culture. Furthermore, administration of different MDR inhibitors to S. mansoni-infected mice results in a reduction in egg burden in host liver. These schistosome MDR transporters therefore appear to play essential roles in parasite egg production, and can be targeted genetically and pharmacologically. Since eggs are responsible for the major pathophysiological consequences of schistosomiasis, and since they are also the agents for transmission of the disease, these results suggest a potential strategy for reducing disease pathology and spread.

  2. Mefloquine interferes with glycolysis in schistosomula of Schistosoma mansoni via inhibition of enolase.

    Science.gov (United States)

    Manneck, Theresia; Keiser, Jennifer; Müller, Joachim

    2012-04-01

    The 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.

  3. Characterization of export receptor exportins (XPOs) in the parasite Schistosoma mansoni.

    Science.gov (United States)

    Abreu, Fabiano C P; Pereira, Roberta V; Oliveira, Victor F; Gomes, Matheus de S; Jannotti-Passos, Liana K; Borges, William C; Guerra-Sá, Renata

    2013-12-01

    Several proteins and different species of RNA that are produced in the nucleus are exported through the nuclear pore complexes, which require a family of conserved nuclear export receptors called exportins (XPOs). It has been reported that the XPOs (XPO1, XPO5, and XPOT) are directly involved in the transport processes of noncoding RNAs from the nucleus to the cytoplasm and/or from cytoplasm to the nucleus. All three genes are present in fungi, plants, and deuterostome metazoans. However, protostome metazoan species lack one of the three genes across evolution. In this report, we have demonstrated that all three XPO proteins are present in the parasite protostome Schistosoma mansoni. As this parasite has a complex life cycle presenting several stages in different hosts and environments, implying a differential gene regulation, we proposed a genomic analysis of XPOs to validate their annotation. The results showed the conservation of exportin family members and gene duplication events in S. mansoni. We performed quantitative RT-PCR, which revealed an upregulation of SmXPO1 in 24 h schistosomula (sixfold when compared with cercariae), and similar transcription levels were observed for SmXPO5 and SmXPOT in all the analyzed stages. These three XPO proteins have been identified for the first time in the protostome clade, which suggests a higher complexity in RNA transport in the parasite S. mansoni. Taken together, these results suggest that RNA transport by exportins might control cellular processes during cercariae, schistosomula, and adult worm development.

  4. Ultrastructural study on the morphological changes to male worms of Schistosoma mansoni after in vitro exposure to allicin Estudo ultraestrutural das alterações morfológicas de vermes machos de Schistosoma mansoni após exposição in vitro à alicina

    OpenAIRE

    Caliandra Maria Bezerra Luna Lima; Francisca Inês de Sousa Freitas; Liana Clébia Soares Lima de Morais; Marília Gabriela dos Santos Cavalcanti; Lânia Ferreira da Silva; Rafael José Ribeiro Padilha; Constância Gayoso Simões Barbosa; Fábio André Brayner dos Santos; Luiz Carlos Alves; Margareth de Fátima Formiga Melo Diniz

    2011-01-01

    INTRODUCTION: Garlic has a wide range of actions, including antibacterial, antiviral, antifungal, antiprotozoal and anthelmintic actions. This antiparasitic activity has been attributed to allicin, which is the main constituent of garlic. The present study aimed to investigate the in vitro activity of allicin on the tegument of adult Schistosoma mansoni worms using scanning electron microscopy. METHODS: Swiss Webster mice were infected with S. mansoni cercariae (100 per mouse) and sacrificed ...

  5. Characterization of the phytochelatin synthase of Schistosoma mansoni.

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    Debalina Ray

    2011-05-01

    Full Text Available Treatment for schistosomiasis, which is responsible for more than 280,000 deaths annually, depends exclusively on the use of praziquantel. Millions of people are treated annually with praziquantel and drug resistant parasites are likely to evolve. In order to identify novel drug targets the Schistosoma mansoni sequence databases were queried for proteins involved in glutathione metabolism. One potential target identified was phytochelatin synthase (PCS. Phytochelatins are oligopeptides synthesized enzymatically from glutathione by PCS that sequester toxic heavy metals in many organisms. However, humans do not have a PCS gene and do not synthesize phytochelatins. In this study we have characterized the PCS of S. mansoni (SmPCS. The conserved catalytic triad of cysteine-histidine-aspartate found in PCS proteins and cysteine proteases is also found in SmPCS, as are several cysteine residues thought to be involved in heavy metal binding and enzyme activation. The SmPCS open reading frame is considerably extended at both the N- and C-termini compared to PCS from other organisms. Multiple PCS transcripts are produced from the single encoded gene by alternative splicing, resulting in both mitochondrial and cytoplasmic protein variants. Expression of SmPCS in yeast increased cadmium tolerance from less than 50 µM to more than 1,000 µM. We confirmed the function of SmPCS by identifying PCs in yeast cell extracts using HPLC-mass spectrometry. SmPCS was found to be expressed in all mammalian stages of worm development investigated. Increases in SmPCS expression were seen in ex vivo worms cultured in the presence of iron, copper, cadmium, or zinc. Collectively, these results indicate that SmPCS plays an important role in schistosome response to heavy metals and that PCS is a potential drug target for schistosomiasis treatment. This is the first characterization of a PCS from a parasitic organism.

  6. Immunization against Egyptian Schistosoma mansoni infection by multivalent DNA vaccine

    Institute of Scientific and Technical Information of China (English)

    Mahmoud H Romeih; Hanem M Hassan; Tarek S Abou Shousha; Mohamed A Saber

    2008-01-01

    The development of multivalent vaccines consisting of several antigens is a novel approach to creating broad-range protection against different parasite strains and parasite life cycle stages. We have previously confirmed that the schistosome Sm21.7 and SmFimbrin (SmFim) proteins could induce protection in mice. Therefore, this study aimed to construct the multivalent DNA vaccine Sm21.7-SmFim/pBudCE4.1 and evaluate its immune efficacy. The open reading frames of two Schistosoma mansoni genes, Sm21.7 and SmFim, were inserted into the eukaryotic expression plasmid pBudCE4.1 designed for the independent expression of two genes in mammalian cells. To evaluate the in vitro expression of the multivalent Sm21.7-SmFim/pBudCE4.1 DNA vaccine and its immunological effect in mice, the recombinant plasmid Sm21.7-SmFim/pBudCE4.1 was used to transfect 293T cells, and the expression of mRNA and proteins was examined using reverse transcription-polymerase chain reaction and Western blot analysis. Then the ability of Sm21.7.SmFim/pBudCE4.1 to protect against S. mansoni challenge infections was analyzed according to worm burden and egg reduction rates after vaccination of mice. Vaccinated mice showed a significant level of protection (56%), and a decrease in the number and size, and change in the cellular profile, of granulomas. Egg reduction in liver and intestine was 41.53% and 55.63%,respectively, as determined relative to mice that received the empty vector only. In addition to reductions in worm viability,worm fecundity and egg hatching ability were observed following challenge infection in the immunized group.Results showed that Sm21.7-SmFim/pBudCE4.1 could express Sm 21.7 and SmFim mRN A and proteins. Enzyme-linked immunosorbent assay and Western blot analysis indicated that immunized mice generated specific immunoglobulin G against Sm21.7-SmFim/pBudCE4.1. These results suggest that vaccination with multivalent S. mansoni DNA vaccine (SmFim-Sm21.7/pBudCE4.1) not only induces a

  7. Detection of Schistosoma mansoni and Schistosoma haematobium by Real-Time PCR with High Resolution Melting Analysis.

    Science.gov (United States)

    Sady, Hany; Al-Mekhlafi, Hesham M; Ngui, Romano; Atroosh, Wahib M; Al-Delaimy, Ahmed K; Nasr, Nabil A; Dawaki, Salwa; Abdulsalam, Awatif M; Ithoi, Init; Lim, Yvonne A L; Chua, Kek Heng; Surin, Johari

    2015-07-16

    The present study describes a real-time PCR approach with high resolution melting-curve (HRM) assay developed for the detection and differentiation of Schistosoma mansoni and S. haematobium in fecal and urine samples collected from rural Yemen. The samples were screened by microscopy and PCR for the Schistosoma species infection. A pair of degenerate primers were designed targeting partial regions in the cytochrome oxidase subunit I (cox1) gene of S. mansoni and S. haematobium using real-time PCR-HRM assay. The overall prevalence of schistosomiasis was 31.8%; 23.8% of the participants were infected with S. haematobium and 9.3% were infected with S. mansoni. With regards to the intensity of infections, 22.1% and 77.9% of S. haematobium infections were of heavy and light intensities, respectively. Likewise, 8.1%, 40.5% and 51.4% of S. mansoni infections were of heavy, moderate and light intensities, respectively. The melting points were distinctive for S. mansoni and S. haematobium, categorized by peaks of 76.49 ± 0.25 °C and 75.43 ± 0.26 °C, respectively. HRM analysis showed high detection capability through the amplification of Schistosoma DNA with as low as 0.0001 ng/µL. Significant negative correlations were reported between the real-time PCR-HRM cycle threshold (Ct) values and microscopic egg counts for both S. mansoni in stool and S. haematobium in urine (p < 0.01). In conclusion, this closed-tube HRM protocol provides a potentially powerful screening molecular tool for the detection of S. mansoni and S. haematobium. It is a simple, rapid, accurate, and cost-effective method. Hence, this method is a good alternative approach to probe-based PCR assays.

  8. Detection of Schistosoma mansoni and Schistosoma haematobium by Real-Time PCR with High Resolution Melting Analysis

    Directory of Open Access Journals (Sweden)

    Hany Sady

    2015-07-01

    Full Text Available The present study describes a real-time PCR approach with high resolution melting-curve (HRM assay developed for the detection and differentiation of Schistosoma mansoni and S. haematobium in fecal and urine samples collected from rural Yemen. The samples were screened by microscopy and PCR for the Schistosoma species infection. A pair of degenerate primers were designed targeting partial regions in the cytochrome oxidase subunit I (cox1 gene of S. mansoni and S. haematobium using real-time PCR-HRM assay. The overall prevalence of schistosomiasis was 31.8%; 23.8% of the participants were infected with S. haematobium and 9.3% were infected with S. mansoni. With regards to the intensity of infections, 22.1% and 77.9% of S. haematobium infections were of heavy and light intensities, respectively. Likewise, 8.1%, 40.5% and 51.4% of S. mansoni infections were of heavy, moderate and light intensities, respectively. The melting points were distinctive for S. mansoni and S. haematobium, categorized by peaks of 76.49 ± 0.25 °C and 75.43 ± 0.26 °C, respectively. HRM analysis showed high detection capability through the amplification of Schistosoma DNA with as low as 0.0001 ng/µL. Significant negative correlations were reported between the real-time PCR-HRM cycle threshold (Ct values and microscopic egg counts for both S. mansoni in stool and S. haematobium in urine (p < 0.01. In conclusion, this closed-tube HRM protocol provides a potentially powerful screening molecular tool for the detection of S. mansoni and S. haematobium. It is a simple, rapid, accurate, and cost-effective method. Hence, this method is a good alternative approach to probe-based PCR assays.

  9. The genome of the blood fluke Schistosoma mansoni

    Science.gov (United States)

    Berriman, Matthew; Haas, Brian J.; LoVerde, Philip T.; Wilson, R. Alan; Dillon, Gary P.; Cerqueira, Gustavo C.; Mashiyama, Susan T.; Al-Lazikani, Bissan; Andrade, Luiza F.; Ashton, Peter D.; Aslett, Martin A.; Bartholomeu, Daniella C.; Blandin, Gaelle; Caffrey, Conor R.; Coghlan, Avril; Coulson, Richard; Day, Tim A.; Delcher, Art; DeMarco, Ricardo; Djikeng, Appoliniare; Eyre, Tina; Gamble, John A.; Ghedin, Elodie; Gu, Yong; Hertz-Fowler, Christiane; Hirai, Hirohisha; Hirai, Yuriko; Houston, Robin; Ivens, Alasdair; Johnston, David A.; Lacerda, Daniela; Macedo, Camila D.; McVeigh, Paul; Ning, Zemin; Oliveira, Guilherme; Overington, John P.; Parkhill, Julian; Pertea, Mihaela; Pierce, Raymond J.; Protasio, Anna V.; Quail, Michael A.; Rajandream, Marie-Adèle; Rogers, Jane; Sajid, Mohammed; Salzberg, Steven L.; Stanke, Mario; Tivey, Adrian R.; White, Owen; Williams, David L.; Wortman, Jennifer; Wu, Wenjie; Zamanian, Mostafa; Zerlotini, Adhemar; Fraser-Liggett, Claire M.; Barrell, Barclay G.; El-Sayed, Najib M.

    2009-01-01

    Schistosoma mansoni is responsible for the neglected tropical disease schistosomiasis that affects 210 million people in 76 countries. We report here analysis of the 363 megabase nuclear genome of the blood fluke. It encodes at least 11,809 genes, with an unusual intron size distribution, and novel families of micro-exon genes that undergo frequent alternate splicing. As the first sequenced flatworm, and a representative of the lophotrochozoa, it offers insights into early events in the evolution of the animals, including the development of a body pattern with bilateral symmetry, and the development of tissues into organs. Our analysis has been informed by the need to find new drug targets. The deficits in lipid metabolism that make schistosomes dependent on the host are revealed, while the identification of membrane receptors, ion channels and more than 300 proteases, provide new insights into the biology of the life cycle and novel targets. Bioinformatics approaches have identified metabolic chokepoints while a chemogenomic screen has pinpointed schistosome proteins for which existing drugs may be active. The information generated provides an invaluable resource for the research community to develop much needed new control tools for the treatment and eradication of this important and neglected disease. PMID:19606141

  10. UVB-induced immune suppression and infection with Schistosoma mansoni

    Energy Technology Data Exchange (ETDEWEB)

    Noonan, F.P.; Lewis, F.A. [George Washington Univ., Washington, DC (United States). School of Medicine]|[Biomedical Research Inst., Rockville, MD (United States)

    1995-01-01

    Irradiation with ultraviolet B (UVB, 290-320 nm) causes a systematic immunosuppression of cell-mediated immunity. The question of whether UV immunosuppression modulates the course of infectious diseases is important because UVB levels in sunlight are sufficient to predict significant UV-induced immunosuppression at most latitudes. We have investigated the effect of immunosuppressive doses of UVB on the disease caused by the helminth parasite Schistosoma mansoni. C57BL/6 mice were irradiated once or three times weekly over 60-80 days with UV from a bank of FS40 sunlamps. Each UV treatment consisted of an immunosuppressive UV dose, as determined by suppression of contact hypersensitivity to trinitrochlorobenzene, corresponding to about 15-30 min of noonday tropical sunlight exposure under ideal clear sky conditions. Cumulative UV doses were between 80 and 170 kJ/m{sup 2}. Worm and egg burdens, liver granuloma diameters and liver fibrosis showed minimal changes (< 20%) compared with parameters in unirradiated animals. Ultraviolet irradiation (a total of 55 kJ/m{sup 2} administered in six treatments) did not impair the resistance to rechallenge conferred by vaccination with {sup 60}Co-irradiated cercariae. We have observed a dichotomy between UV immnosuppression and both disease and vaccination in this helminth infection, in contrast to the effects of UVB shown in other infectious diseases. (author).

  11. Immunolocalization of Schistosoma mansoni and Schistosoma haematobium antigens reacting with their Egyptian snail vectors.

    Science.gov (United States)

    El-Dafrawy, Shadia M; Mohamed, Amira H; Hammam, Olfat A; Rabia, Ibrahim

    2007-12-01

    The reaction of the haemolymph and the tissue of infected intermediate hosts, Biomphalaria alexandrina and Bulinus truncatus to Schistosoma mansoni and S. haematobium antigens were investigated using the indirect immunoperoxidase technique. A new technique, Agarose cell block was used in collection of haemolymph which helped in collecting plenty of well formed cells in comparison to the ordinary one using the cytospin. Collected haemolymph and prepared tissues of uninfected and infected B. alexandria and B. truncatus were fixed and then reacted with anti-S. mansoni and anti-S. haematobium IgG polyclonal antibodies. The haemolymph and tissue of infected B. alexandrina and B. truncatus gave a positive peroxidase reaction represented by a brown colour. In haemolymph, the positive peroxidase reaction was detected mainly in the cytoplasm of the amoebocytes. In the tissue, it was detected in epithelial cells lining the tubules, male cells in the lumen of the tubules and in female oogonia cells along the periphery of the tubules. The similarity in the strength and distribution of positive reaction in B. alexandrina and B. truncates was observed as compared to control. Thus, the immunoperoxidase technique proved to be an effective indicator for the schistosome-antigen in the snails.

  12. Papain-Based Vaccination Modulates Schistosoma mansoni Infection-Induced Cytokine Signals.

    Science.gov (United States)

    Abdel Aziz, N; Tallima, H; Hafez, E A; El Ridi, R

    2016-02-01

    We have previously shown that immunization of outbred rodents with cysteine peptidases-based vaccine elicited type 2-biased immune responses associated with consistent and reproducible protection against challenge Schistosoma mansoni. We herein start to elucidate the molecular basis of C57BL/6 mouse resistance to S. mansoni following treatment with the cysteine peptidase, papain. We evaluated the early cytokine signals delivered by epidermal, dermal, and draining lymph node cells of naïve, and S. mansoni -infected mice treated 1 day earlier with 0 or 50 μg papain, or immunized twice with papain only (10 μg/mouse), papain-free recombinant S. mansoni glyceraldehyde 3-phosphate dehydrogenase and 2-Cys peroxiredoxin peptide (10 and 15 μg/mouse, respectively = antigen Mix), or papain-adjuvanted antigen Mix. Schistosoma mansoni infection induced epidermal and lymph node cells to release type 1, type 2 and type 17 cytokines, known to counteract each other. Expectedly, humoral immune responses were negligible until patency. Papain pretreatment or papain-based vaccination diminished or shut off S. mansoni infection early induction of type 1, type 17 and type 2 cytokines except for thymic stromal lymphopoietin and programmed the immune system towards a polarized type 2 immune milieu, associated with highly significant (P < 0.005 - <0.0001) resistance to S. mansoni infection.

  13. Efeitos de imunopotenciadores não específicos na infecção experimental pelo Schistosoma mansoni: I. levamisole Effects of non-specific immunopotentiators in experimental Schistosoma mansoni infection: I. levamisole

    Directory of Open Access Journals (Sweden)

    Silvia M. L. Montenegro

    1991-02-01

    Full Text Available Os efeitos do levamisole nas alterações histopatológicas, resistência do hospedeiro e quimiotaxia "in vivo" foram estudados na infecção experimental pelo Schistosoma mansoni em camundongos da linhagem C57B1/10. O tratamento profilático resultou em um aumento no número de vermes adultos obtidos pela perfusão e também em uma taxa de mortalidade maior (p The effects of levamisole on the histopathological changes, host's resistance and "in vivo" chemotaxis in Schistosoma mansoni experimental infection of C57B1/10 inbred mice were studied. Prophylatic treatment resulted in an increase in the number of adult worms obtained by perfusion and also increased the mortality rate (p < 0.05. The histopathological changes (liver and intestines were similar in all the groups. A significant reduction of "in vivo" chemotaxis occurred in infected control mice as well as in those submitted to prophylatic treatment with levamisole. Chemotatic activity reached the same levels of normal control mice (non-infected and non-treated with levamisole, when the curative scheme was used. Levamisole seems to increase the susceptibility of inbred C57B1/10 mice to the infection with S. mansoni when administered prior to the infection and increase the chemotatic activity to normal levels when given after infection.

  14. Effect of maternal Schistosoma mansoni infection and praziquantel treatment during pregnancy on Schistosoma mansoni infection and immune responsiveness among offspring at age five years.

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    Robert Tweyongyere

    Full Text Available Offspring of Schistosoma mansoni-infected women in schistosomiasis-endemic areas may be sensitised in-utero. This may influence their immune responsiveness to schistosome infection and schistosomiasis-associated morbidity. Effects of praziquantel treatment of S. mansoni during pregnancy on risk of S. mansoni infection among offspring, and on their immune responsiveness when they become exposed to S. mansoni, are unknown. Here we examined effects of praziquantel treatment of S. mansoni during pregnancy on prevalence of S. mansoni and immune responsiveness among offspring at age five years.In a trial in Uganda (ISRCTN32849447, http://www.controlled-trials.com/ISRCTN32849447/elliott, offspring of women treated with praziquantel or placebo during pregnancy were examined for S. mansoni infection and for cytokine and antibody responses to SWA and SEA, as well as for T cell expression of FoxP3, at age five years.Of the 1343 children examined, 32 (2.4% had S. mansoni infection at age five years based on a single stool sample. Infection prevalence did not differ between children of treated or untreated mothers. Cytokine (IFNγ, IL-5, IL-10 and IL-13 and antibody (IgG1, Ig4 and IgE responses to SWA and SEA, and FoxP3 expression, were higher among infected than uninfected children. Praziquantel treatment of S. mansoni during pregnancy had no effect on immune responses, with the exception of IL-10 responses to SWA, which was higher in offspring of women that received praziquantel during pregnancy than those who did not.We found no evidence that maternal S. mansoni infection and its treatment during pregnancy influence prevalence and intensity of S. mansoni infection or effector immune response to S. mansoni infection among offspring at age five years, but the observed effects on IL-10 responses to SWA suggest that maternal S. mansoni and its treatment during pregnancy may affect immunoregulatory responsiveness in childhood schistosomiasis. This might have

  15. Experimental Evaluation of the Pathogenicity of Different Strains of Schistosoma mansoni

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    Antônio Aurélio Euzébio

    2012-01-01

    Full Text Available The pathogenesis of three different Schistosoma mansoni strains from the Brazilian states of Minas Gerais (BH strain and São Paulo (SJ and SD strains was evaluated in experimentally infected mice. Observations of the most severe clinical cases among local patients treated (SD strain in the city of Campinas (São Paulo, Brazil formed the basis of this study. Mice were used as definitive hosts and were infected with cercariae from Biomphalaria tenagophila (SJ and SD strains and Biomphalaria glabrata (BH strains. The parameters analyzed were as follows: number of S. mansoni eggs in mice feces; number of granulomas per tissue area in liver, spleen, lungs, pancreas, and ascending colon; measurements of hepatic and intestinal granulomas; number of adult worms; and measurements of trematode eggs. The comparison among the three strains indicated that the SD strain, isolated in Campinas, presented a higher worm recovery relative to the number of penetrating cercariae. In addition, when compared to the SJ and BH strains, the SD strain demonstrated similar pathogenicity to the BH strain, with a greater quantity of granulomas in the viscera, as well as larger granulomas and eggs. Furthermore, a greater quantity of trematode eggs was also shed in the feces.

  16. Experimental Evaluation of the Pathogenicity of Different Strains of Schistosoma mansoni.

    Science.gov (United States)

    Euzébio, Antônio Aurélio; Zuim, Nádia Regina Borim; Linhares, Arício Xavier; Magalhães, Luiz Augusto; Zanotti-Magalhães, Eliana Maria

    2012-01-01

    The pathogenesis of three different Schistosoma mansoni strains from the Brazilian states of Minas Gerais (BH strain) and São Paulo (SJ and SD strains) was evaluated in experimentally infected mice. Observations of the most severe clinical cases among local patients treated (SD strain) in the city of Campinas (São Paulo, Brazil) formed the basis of this study. Mice were used as definitive hosts and were infected with cercariae from Biomphalaria tenagophila (SJ and SD strains) and Biomphalaria glabrata (BH strains). The parameters analyzed were as follows: number of S. mansoni eggs in mice feces; number of granulomas per tissue area in liver, spleen, lungs, pancreas, and ascending colon; measurements of hepatic and intestinal granulomas; number of adult worms; and measurements of trematode eggs. The comparison among the three strains indicated that the SD strain, isolated in Campinas, presented a higher worm recovery relative to the number of penetrating cercariae. In addition, when compared to the SJ and BH strains, the SD strain demonstrated similar pathogenicity to the BH strain, with a greater quantity of granulomas in the viscera, as well as larger granulomas and eggs. Furthermore, a greater quantity of trematode eggs was also shed in the feces.

  17. Vaccination with Enzymatically Cleaved GPI-Anchored Proteins from Schistosoma mansoni Induces Protection against Challenge Infection

    Directory of Open Access Journals (Sweden)

    Vicente P. Martins

    2012-01-01

    Full Text Available The flatworm Schistosoma mansoni is a blood fluke parasite that causes schistosomiasis, a debilitating disease that occurs throughout the developing world. Current schistosomiasis control strategies are mainly based on chemotherapy, but many researchers believe that the best long-term strategy to control schistosomiasis is through immunization with an antischistosomiasis vaccine combined with drug treatment. In the search for potential vaccine candidates, numerous tegument antigens have been assessed. As the major interface between parasite and mammalian host, the tegument plays crucial roles in the establishment and further course of schistosomiasis. Herein, we evaluated the potential of a GPI fraction, containing representative molecules located on the outer surface of adult worms, as vaccine candidate. Immunization of mice with GPI-anchored proteins induced a mixed Th1/Th2 type of immune response with production of IFN-γ and TNF-α, and low levels of IL-5 into the supernatant of splenocyte cultures. The protection engendered by this vaccination protocol was confirmed by 42% reduction in worm burden, 45% reduction in eggs per gram of hepatic tissue, 29% reduction in the number of granulomas per area, and 53% reduction in the granuloma fibrosis. Taken together, the data herein support the potential of surface-exposed GPI-anchored antigens from the S. mansoni tegument as vaccine candidate.

  18. Structural parameters, molecular properties, and biological evaluation of some terpenes targeting Schistosoma mansoni parasite.

    Science.gov (United States)

    Mafud, Ana C; Silva, Marcos P N; Monteiro, Daniela C; Oliveira, Maria F; Resende, João G; Coelho, Mayara L; de Sousa, Damião P; Mendonça, Ronaldo Z; Pinto, Pedro L S; Freitas, Rivelilson M; Mascarenhas, Yvonne P; de Moraes, Josué

    2016-01-25

    The use of natural products has a long tradition in medicine, and they have proven to be an important source of lead compounds in the development of new drugs. Among the natural compounds, terpenoids present broad-spectrum activity against infective agents such as viruses, bacteria, fungi, protozoan and helminth parasites. In this study, we report a biological screening of 38 chemically characterized terpenes from different classes, which have a hydroxyl group connected by hydrophobic chain or an acceptor site, against the blood fluke Schistosoma mansoni, the parasite responsible for schistosomiasis mansoni. In vitro bioassays revealed that 3,7-dimethyl-1-octanol (dihydrocitronellol) (10) was the most active terpene (IC50 values of 13-52 μM) and, thus, we investigated its antischistosomal activity in greater detail. Confocal laser scanning microscopy revealed that compound 10 induced severe tegumental damage in adult schistosomes and a correlation between viability and tegumental changes was observed. Furthermore, we compared all the inactive compounds with dihydrocitronellol structurally by using shape and charge modeling. Lipophilicity (miLogP) and other molecular properties (e.g. molecular polar surface area, molecular electrostatic potential) were also calculated. From the 38 terpenes studied, compound 10 is the one with the greatest flexibility, with a sufficient apolar region by which it may interact in a hydrophobic active site. In conclusion, the integration of biological and chemical analysis indicates the potential of the terpene dihydrocitronellol as an antiparasitic agent.

  19. Schistosoma mansoni antigens alter activation markers and cytokine profile in lymphocytes of patients with asthma.

    Science.gov (United States)

    de Almeida, Tarcísio Vila Verde Santana; Fernandes, Jamille Souza; Lopes, Diego Mota; Andrade, Lorena Santana; Oliveira, Sérgio Costa; Carvalho, Edgar M; Araujo, Maria Ilma; Cruz, Álvaro A; Cardoso, Luciana Santos

    2017-02-01

    Asthma is a chronic disease characterized by airway inflammation, obstruction and hyperresponsiveness. Severe asthma affects a small proportion of subjects but results in most of the morbidity, costs and mortality associated with the disease. Studies have suggested that Schistosoma mansoni infection reduces the severity of asthma and prevent atopy.

  20. The effect of praziquantel against Schistosoma mansoni-infections in Botswana

    DEFF Research Database (Denmark)

    Friis, H; Byskov, Jens

    1989-01-01

    Chemotherapy of all infected individuals, using praziquantel 40 mg/kg in a single dose, was the initial component of the recently introduced control programme against Schistosoma mansoni-infections in Ngamiland, Botswana. To evaluate the effect of praziquantel in Ngamiland, 81 children were...

  1. C-type lectin interactions with Schistosoma mansoni SEA : Molecular basis and function

    NARCIS (Netherlands)

    Liempt, van P.A.G.

    2007-01-01

    Outline of this thesis The studies described in this thesis have been performed to gain more insight in the recognition of Schistosoma mansoni glycans by C-type lectins and the consequences for dendritic cell mediated immune responses. As a first approach to understand the molecular interactions o

  2. An atlas for Schistosoma mansoni organs and life-cycle stages using cell type-specific markers and confocal microscopy.

    Directory of Open Access Journals (Sweden)

    James J Collins

    Full Text Available Schistosomiasis (bilharzia is a tropical disease caused by trematode parasites (Schistosoma that affects hundreds of millions of people in the developing world. Currently only a single drug (praziquantel is available to treat this disease, highlighting the importance of developing new techniques to study Schistosoma. While molecular advances, including RNA interference and the availability of complete genome sequences for two Schistosoma species, will help to revolutionize studies of these animals, an array of tools for visualizing the consequences of experimental perturbations on tissue integrity and development needs to be made widely available. To this end, we screened a battery of commercially available stains, antibodies and fluorescently labeled lectins, many of which have not been described previously for analyzing schistosomes, for their ability to label various cell and tissue types in the cercarial stage of S. mansoni. This analysis uncovered more than 20 new markers that label most cercarial tissues, including the tegument, the musculature, the protonephridia, the secretory system and the nervous system. Using these markers we present a high-resolution visual depiction of cercarial anatomy. Examining the effectiveness of a subset of these markers in S. mansoni adults and miracidia, we demonstrate the value of these tools for labeling tissues in a variety of life-cycle stages. The methodologies described here will facilitate functional analyses aimed at understanding fundamental biological processes in these parasites.

  3. Evolution of sarcoma 180 (ascitic tumor in mice infected with Schistosoma mansoni

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    Fausto Edmundo Lima Pereira

    1986-03-01

    Full Text Available Mice infected with 60 cercariae of Schistosoma mansoni were more resistant to the sarcoma 180 ascites tumor. Tumor inoculation was performed 50 days after schistosoma infection and the animals were observed and weighed at 48 hours intervals for development and progression of malignancy. In infected mice the weight gain (ascites formation started later and was shorter than in uninfected Controls. Also, the number of tumor cells into the peritoneal cavity 72h after tumor implantation was shorter in infected group than incontrols. This in creased resistance against a transplantable tumor probably is related to the effect of endotoxin on tumoricidal activity of macrophages activated by the infection. The immunodepression induced by Schistosoma mansoni infection enhances the proliferation of endogenous bacteria increasing the amount of endotoxin absorbed from the gut.

  4. Anthelmintic Effects of Alkylated Diamines and Amino Alcohols against Schistosoma mansoni

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    Fábio de Souza Fernandes

    2013-01-01

    Full Text Available Polyamines are substances involved in many aspects of cell growth, division, and differentiation. Because of the metabolic differences between host cells and parasite cells, polyamine metabolism has been considered as a potential target for the chemotherapy of parasitic diseases. The aim of this work was to evaluate the schistosomicidal activity of different N-alkylated diamines (3a–3h, amino alcohols (4a–4d, and glycosylated amino alcohols (10a–10d. Compounds were prepared by synthetic methods and submitted to in vitro evaluation against adult worms of Schistosoma mansoni. At 100 μM, 3b, 3e, and 3h as well as 4a, 4b, 4d, 10a, 10b, and 10d resulted in 100% mortality of adult schistosomes. Compound 3d (12.5 to 100 μM caused the death of 100% of both male and female adult schistosomes, while 3f (12.5 to 100 μM resulted in 100% mortality of only male adult worms, whereas no mortality in female worms was observed. Compounds 3d and 3f were also able to reduce viability and decrease production of developed eggs in comparison with the negative control group. Diamines 3d and 3f may represent useful lead compounds for further optimization in order to develop new schistosomicidal agents.

  5. Analysis of regulatory protease sequences identified through bioinformatic data mining of the Schistosoma mansoni genome

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    Minchella Dennis J

    2009-10-01

    Full Text Available Abstract Background New chemotherapeutic agents against Schistosoma mansoni, an etiological agent of human schistosomiasis, are a priority due to the emerging drug resistance and the inability of current drug treatments to prevent reinfection. Proteases have been under scrutiny as targets of immunological or chemotherapeutic anti-Schistosoma agents because of their vital role in many stages of the parasitic life cycle. Function has been established for only a handful of identified S. mansoni proteases, and the vast majority of these are the digestive proteases; very few of the conserved classes of regulatory proteases have been identified from Schistosoma species, despite their vital role in numerous cellular processes. To that end, we identified protease protein coding genes from the S. mansoni genome project and EST library. Results We identified 255 protease sequences from five catalytic classes using predicted proteins of the S. mansoni genome. The vast majority of these show significant similarity to proteins in KEGG and the Conserved Domain Database. Proteases include calpains, caspases, cytosolic and mitochondrial signal peptidases, proteases that interact with ubiquitin and ubiquitin-like molecules, and proteases that perform regulated intramembrane proteolysis. Comparative analysis of classes of important regulatory proteases find conserved active site domains, and where appropriate, signal peptides and transmembrane helices. Phylogenetic analysis provides support for inferring functional divergence among regulatory aspartic, cysteine, and serine proteases. Conclusion Numerous proteases are identified for the first time in S. mansoni. We characterized important regulatory proteases and focus analysis on these proteases to complement the growing knowledge base of digestive proteases. This work provides a foundation for expanding knowledge of proteases in Schistosoma species and examining their diverse function and potential as targets

  6. Protein kinase C and extracellular signal-regulated kinase regulate movement, attachment, pairing and egg release in Schistosoma mansoni.

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    Margarida Ressurreição

    2014-06-01

    Full Text Available Protein kinases C (PKCs and extracellular signal-regulated kinases (ERKs are evolutionary conserved cell signalling enzymes that coordinate cell function. Here we have employed biochemical approaches using 'smart' antibodies and functional screening to unravel the importance of these enzymes to Schistosoma mansoni physiology. Various PKC and ERK isotypes were detected, and were differentially phosphorylated (activated throughout the various S. mansoni life stages, suggesting isotype-specific roles and differences in signalling complexity during parasite development. Functional kinase mapping in adult worms revealed that activated PKC and ERK were particularly associated with the adult male tegument, musculature and oesophagus and occasionally with the oesophageal gland; other structures possessing detectable activated PKC and/or ERK included the Mehlis' gland, ootype, lumen of the vitellaria, seminal receptacle and excretory ducts. Pharmacological modulation of PKC and ERK activity in adult worms using GF109203X, U0126, or PMA, resulted in significant physiological disturbance commensurate with these proteins occupying a central position in signalling pathways associated with schistosome muscular activity, neuromuscular coordination, reproductive function, attachment and pairing. Increased activation of ERK and PKC was also detected in worms following praziquantel treatment, with increased signalling associated with the tegument and excretory system and activated ERK localizing to previously unseen structures, including the cephalic ganglia. These findings support roles for PKC and ERK in S. mansoni homeostasis, and identify these kinase groups as potential targets for chemotherapeutic treatments against human schistosomiasis, a neglected tropical disease of enormous public health significance.

  7. Synthesis and activity of new triphenylphosphonium derivatives of betulin and betulinic acid against Schistosoma mansoni in vitro and in vivo.

    Science.gov (United States)

    Spivak, Anna Yu; Keiser, Jennifer; Vargas, Mireille; Gubaidullin, Rinat R; Nedopekina, Darya A; Shakurova, Elvira R; Khalitova, Rezeda R; Odinokov, Victor N

    2014-11-01

    We studied the antischistosomal activity of betulin, betulinic acid and its 9 triphenylphosphonium derivatives characterized by a covalently linkage of the hydrophobic fragment of triterpenoid at C(2)- or C(30)-position with the triphenylphosphonium moiety via a hydrocarbon bridge. The triphenylphosphonium salts showed in vitro antischistosomal activity against newly transformed schistosomula (NTS) and adult worms of Schistosoma mansoni at low micromolar concentrations. In contrast betulin and betulinic acid were inactive against NTS and adult S. mansoni. Of the 9 triphenylphosphonium derivatives tested, the allyl salts 10 (IC50 of 0.76 μg/mL) and 11 (IC50 of 0.64 μg/mL) demonstrated the highest antischistosomal activity against adult S. mansoni. Low worm burden reductions of 22% were observed in vivo for these two compounds. In conclusion, triphenylphosphonium derivatives were obtained from available natural betulin by simple transformations, rendering it practical and useful for large scale application. However, further structural modifications are necessary to translate the promising antischistosomal in vitro activities into in vivo.

  8. Identification of schistosoma mansoni antigens recognised by spleen cells of C57B1/6 mice immunized with ultraviolet-irradiated cercariae

    Energy Technology Data Exchange (ETDEWEB)

    Osman, A.; El Ridi, R. (Cairo Univ. (Egypt)); Guirguis, N. (VACSERA, El Agouza Cairo (Egypt). Biomedical Research Dept.); Dean, D.A. (U.S. Naval Medical Research Unit No. 3, Cairo (Egypt))

    1994-11-01

    Spleen cells of C57B1/6 mice immunized twice with Schistosoma mansoni cercariae attenuated by ultraviolet irradiation proliferated and produced interleukin-(I1)-2 and/or I1-4 in response to both soluble schistosomular and adult worm antigens of 72-68, 60-62, 50, 45, 29.5 and 28 kDa. All of these bands, except the 45 kDa, were also recognized by serum antibodies in Western blotting. (author).

  9. Vaccination with antioxidant enzymes confers protective immunity against challenge infection with Schistosoma mansoni

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    Philip T LoVerde

    2004-08-01

    Full Text Available Schistosoma mansoni, an intravascular parasite, lives in a hostile environment in close contact with host humoral and cellular cytotoxic factors. To establish itself in the host, the parasite has evolved a number of immune evasion mechanisms, such as antioxidant enzymes. Our laboratory has demonstrated that the expression of antioxidant enzymes is developmentally regulated, with the highest levels present in the adult worm, the stage least susceptible to immune elimination, and the lowest levels in the larval stages, the most susceptible to immune elimination. Vaccination of mice with naked DNA constructs containing Cu/Zn cytosolic superoxide dismutase (CT-SOD, signal-peptide containing SOD or glutathione peroxidase (GPX showed significant levels of protection compared to a control group. We have further shown that vaccination with SmCT-SOD but not SmGPX results in elimination of adult worms. Anti-oxidant enzyme vaccine candidates offer an advance over existing vaccine strategies that all seem to target the larval developmental stages in that they target adult worms and thus may have therapeutic as well as prophylactic value. To eliminate the potential for cross-reactivity of SmCT-SOD with human superoxide dismutase, we identified parasite-specific epitope-containing peptides. Our results serve as a basis for developing a subunit vaccine against schistosomiasis.

  10. Schistosoma mansoni polypeptides immunogenic in mice vaccinated with radiation-attenuated cercariae

    Energy Technology Data Exchange (ETDEWEB)

    Dalton, J.P.; Strand, M.

    1987-10-01

    We compared the humoral immune response of mice protected against Schistosoma mansoni by vaccination with radiation-attenuated cercariae to that of patently infected mice, and we identified antigens that elicit a greater, or unique, immune response in the vaccinated mice. These comparisons were based upon radioimmunoprecipitations and immunodepletion of (/sup 35/S)methionine-labeled schistosomular and adult worm polypeptides, followed by one- and two-dimensional polyacrylamide gel analyses. The humoral responses of patently infected mice and of mice vaccinated once were remarkably similar and were directed against schistosome glycoproteins ranging in molecular size from greater than 300 to less than 10 kDa. Exposing mice to a second vaccination resulted in a marked change in the immune response, to one predominantly directed toward high molecular size glycoproteins. Sequential immunodepletion techniques identified five schistosomular and seven adult worm antigens that showed a greater or unique immunogenicity in vaccinated mice as compared with patently infected mice. These adult worm antigens were purified by preparative sequential immunoaffinity chromatography and used to prepare a polyclonal antiserum, anti-irradiated vaccine. This antiserum bound to the surface of live newly transformed and lung-stage schistosomula, as assessed by immunofluorescence assays, and was reactive with a number of /sup 125/I-labeled schistosomular surface polypeptides, including a doublet of 150 kDa that was also recognized by sera of vaccinated mice but not by sera of patently infected mice.

  11. Choline incorporation by Schistosoma mansoni: distribution of choline metabolites during development and after sexual differentiation

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    Ancelin, M.L.; Torpier, G.; Vial, H.J.; Capron, A.

    1987-06-01

    Choline metabolism was investigated in Schistosoma mansoni during the main phases of its development, namely, schistosomula, 11- and 15-day-old worms, and adults. At the physiological choline concentration used in the assay (20 microM), betaine was, along with phosphatidylcholine, one of the most abundant choline metabolites, revealing considerable choline oxidation activity. Very little radioactivity was associated with CDP-choline, whereas a sustained incorporation into phosphocholine occurred. These results provide good evidence that CTP:phosphocholine cytidylyltransferase plays a regulatory role in the de novo pathway of phosphatidylcholine biosynthesis. During development, the incorporation of choline into its various metabolites was maximal in 11-day-old worms. At this stage, the oxidative pathway predominated over the Kennedy pathway, whereas at all other stages the de novo phosphatidylcholine biosynthesis was predominant. Furthermore, choline incorporation into betaine was much more important in the adult female worm than in the male, indicating a major difference in choline incorporation and distribution between the 2 sexes of the adult worms.

  12. Homology-based annotation of non-coding RNAs in the genomes of Schistosoma mansoni and Schistosoma japonicum

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    Santana Clara

    2009-10-01

    Full Text Available Abstract Background Schistosomes are trematode parasites of the phylum Platyhelminthes. They are considered the most important of the human helminth parasites in terms of morbidity and mortality. Draft genome sequences are now available for Schistosoma mansoni and Schistosoma japonicum. Non-coding RNA (ncRNA plays a crucial role in gene expression regulation, cellular function and defense, homeostasis, and pathogenesis. The genome-wide annotation of ncRNAs is a non-trivial task unless well-annotated genomes of closely related species are already available. Results A homology search for structured ncRNA in the genome of S. mansoni resulted in 23 types of ncRNAs with conserved primary and secondary structure. Among these, we identified rRNA, snRNA, SL RNA, SRP, tRNAs and RNase P, and also possibly MRP and 7SK RNAs. In addition, we confirmed five miRNAs that have recently been reported in S. japonicum and found two additional homologs of known miRNAs. The tRNA complement of S. mansoni is comparable to that of the free-living planarian Schmidtea mediterranea, although for some amino acids differences of more than a factor of two are observed: Leu, Ser, and His are overrepresented, while Cys, Meth, and Ile are underrepresented in S. mansoni. On the other hand, the number of tRNAs in the genome of S. japonicum is reduced by more than a factor of four. Both schistosomes have a complete set of minor spliceosomal snRNAs. Several ncRNAs that are expected to exist in the S. mansoni genome were not found, among them the telomerase RNA, vault RNAs, and Y RNAs. Conclusion The ncRNA sequences and structures presented here represent the most complete dataset of ncRNA from any lophotrochozoan reported so far. This data set provides an important reference for further analysis of the genomes of schistosomes and indeed eukaryotic genomes at large.

  13. Sequential histological changes in Biomphalaria glabrata during the course of Schistosoma mansoni infection

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    Queli Teixeira Lemos

    2001-07-01

    Full Text Available Biomphalaria glabrata, highly susceptible to Schistosoma mansoni, were seen to shed less and less cercariae along the time of infection. Histological examination kept a close correlation with this changing pattern of cercarial shedding, turning an initial picture of no-reaction (tolerance gradually into one of hemocyte proliferation with formation of focal encapsulating lesions around disintegrating sporocysts and cercariae, a change that became disseminated toward the 142nd day post miracidial exposure. Findings were suggestive of a gradual installation of acquired immunity in snails infected with S. mansoni.

  14. Anti-schistosomal IgE and its relation to gastrointestinal allergy in breast-fed infants of Schistosoma mansoni infected mothers.

    Science.gov (United States)

    Noureldin, M S; Shaltout, A A

    1998-08-01

    To study the relationship between presence of gastrointestinal allergic manifestations in breast-fed infants and presence of IgE against Schistosoma mansoni antigens, sixty breast-fed infants of S. mansoni infected mothers were selected. Of them, thirty infants were suffering from manifestations of gastrointestinal allergy (patients) and the other thirty were not suffering from such manifestations (controls). Levels of IgE against S. mansoni adult worm antigen (AWA), soluble egg antigen (SEA) and cercarial antigen (CA) were determined, by ELISA, in sera of these infants. There was significant association between presence of allergic manifestations and presence of IgE against AWA (P = 0.018), SEA (P < 0.001) and CA (P = 0.002). Also, concentration of IgE against AWA was significantly higher in patients group than the control group (P = 0.024). IgE against AWA showed significant negative correlation with haemoglobin concentration (P = 0.009) and serum albumin level (P = 021) and significant positive correlation with absolute eosinophilic count (P = 0.005). Also, IgE against CA showed significant negative correlation with haemoglobin concentration (p = 0.047) and serum albumin level (0 = 0.036). It was concluded that gastrointestinal allergy in breast-fed infants of S. mansoni infected mothers may be due to hypersensitivity of Schistosoma mansoni antigens present in mothers' milk. Schistosoma mansoni should be investigated and treated in mothers from endemic localities when their breast-fed infants are suffering from manifestations suggestive of gastrointestinal allergy.

  15. Effects of garlic on Schistosoma mansoni harbored in albino mice: molecular characterization of the host and parasite.

    Science.gov (United States)

    Riad, Nahed H A; Taha, Hoda A; Mahmoud, Yomna I

    2013-04-15

    Garlic has been used for its health benefits for thousands of years. Modern research confirmed many of the healing properties of garlic, including its antiparasitic activity. This study was designed to evaluate the antischistosomal action of garlic through detecting the changes in DNA profile of Schistosoma mansoni worms and the infected mouse. Forty mice were subcutaneously infected with ~200 Schistosoma mansoni cercariae/mouse. Infected mice were divided into four equal groups: non-treated, prophylactic, therapeutic, and continuously-treated. Non-infected control and garlic-treated groups were assigned for the sake of comparison. Garlic extract (50mg/kg bw/mouse) was given orally, day after day, at a fixed daytime. Seven weeks post-infection, adult schistosomes were recovered by perfusion and the livers of the mice were excised out and were processed for DNA extraction and Random Amplification of Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR). The results showed that garlic exerted no major changes in the genome of schistosomes. Nevertheless, that schistosomal infection induced genetic alterations in the DNA of mice, and garlic was able to ameliorate such alterations to a great extent.

  16. Developmental expression analysis and immunolocalization of a biogenic amine receptor in Schistosoma mansoni

    OpenAIRE

    El-Shehabi, Fouad; Vermeire, Jon J.; Yoshino, Timothy P.; Ribeiro, Paula

    2009-01-01

    A Schistosoma mansoni G-protein coupled receptor (SmGPCR) was previously cloned and shown to be activated by the biogenic amine, histamine. Here we report a first investigation of the receptor’s subunit organization, tissue distribution and expression levels in different stages of the parasite. A polyclonal antibody was produced in rabbits against the recombinant third intracellular loop (il3) of SmGPCR. Western blot studies of the native receptor and recombinant protein expressed in HEK293 c...

  17. SmCL3, a gastrodermal cysteine protease of the human blood fluke Schistosoma mansoni.

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    Jan Dvorák

    Full Text Available Blood flukes of the genus Schistosoma are platyhelminth parasites that infect 200 million people worldwide. Digestion of nutrients from the host bloodstream is essential for parasite development and reproduction. A network of proteolytic enzymes (proteases facilitates hydrolysis of host hemoglobin and serum proteins.We identified a new cathepsin L termed SmCL3 using PCR strategies based on S. mansoni EST sequence data. An ortholog is present in Schistosoma japonicum. SmCL3 was heterologously expressed as an active enzyme in the yeast, Pichia pastoris. Recombinant SmCL3 has a broad pH activity range against peptidyl substrates and is inhibited by Clan CA protease inhibitors. Consistent with a function in degrading host proteins, SmCL3 hydrolyzes serum albumin and hemoglobin, is localized to the adult gastrodermis, and is expressed mainly in those life stages infecting the mammalian host. The predominant form of SmCL3 in the parasite exists as a zymogen, which is unusual for proteases. This zymogen includes an unusually long prodomain with alpha helical secondary structure motifs. The striking specificity of SmCL3 for amino acids with large aromatic side chains (Trp and Tyr at the P2 substrate position, as determined with positional scanning-synthetic combinatorial library, is consistent with a molecular model that shows a large and deep S2 pocket. A sequence similarity network (SSN view clusters SmCL3 and other cathepsins L in accordance with previous large-scale phylogenetic analyses that identify six super kingdoms.SmCL3 is a gut-associated cathepsin L that may contribute to the network of proteases involved in degrading host blood proteins as nutrients. Furthermore, this enzyme exhibits some unusual sequence and biophysical features that may result in additional functions. The visualization of network inter-relationships among cathepsins L suggests that these enzymes are suitable 'marker sequences' for inclusion in future phylogenetic analyses.

  18. Effect of praziquantel treatment of Schistosoma mansoni during pregnancy on intensity of infection and antibody responses to schistosome antigens

    DEFF Research Database (Denmark)

    Tweyongyere, Robert; Mawa, Patrice A.; Emojong, Nicholas O.;

    2009-01-01

    Schistosoma mansoni during pregnancy, compared with treatment after delivery. Methods A nested cohort of 387 Schistosoma mansoni infected women was recruited within a larger trial of de-worming during pregnancy. Women were randomised to receive praziquantel or placebo during pregnancy. All women were treated...... after delivery. Infection intensity after treatment was assessed by a single Kato-Katz examination of stool samples with duplicate slides and categorised as undetected, light (1-99 eggs per gram (epg)), moderate (100-399 epg) or heavy (=400 epg). Antibodies against S. mansoni worm and egg antigens were...... infection (median (IQR) epg: 749 (521, 1169)) with S. mansoni. At six weeks after praziquantel treatment during pregnancy S. mansoni infection was not detectable in 81.9% of the women and prevalence and intensity had decreased to 11.8% light, 4.7% moderate and 1.6% heavy a similar reduction when compared...

  19. Genetic Variation between Biomphalaria alexandrina Snails Susceptible and Resistant to Schistosoma mansoni Infection

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    Suzanne M. F. El-Nassery

    2013-01-01

    Full Text Available Much effort has been made to control schistosomiasis infection in Egypt. However, enduring effects from such strategies have not yet been achieved. In this study, we sought to determine the genetic variability related to the interaction between Biomphalaria alexandrina snails and Schistosoma mansoni. Using RAPD-PCR with eight (10 mers random primers, we were able to determine the polymorphic markers that differed between snails susceptible and resistant to Schistosoma mansoni infection using five primers out of the eight. Our results suggest that the RAPD-PCR technique is an efficient means by which to compare genomes and to detect genetic variations between schistosomiasis intermediate hosts. The RAPD technique with the above-noted primers can identify genomic markers that are specifically related to the Biomphalaria alexandrina/Schistosoma mansoni relationship in the absence of specific nucleotide sequence information. This approach could be used in epidemiologic surveys to investigate genetic diversity among Biomphalaria alexandrina snails. The ability to determine resistant markers in Biomphalaria alexandrina snails could potentially lead to further studies that use refractory snails as agents to control the spread of schistosomiasis.

  20. Genetic variation between Biomphalaria alexandrina snails susceptible and resistant to Schistosoma mansoni infection.

    Science.gov (United States)

    El-Nassery, Suzanne M F; Abou-El-Naga, Iman F; Allam, Sonia R; Shaat, Eman A; Mady, Rasha F M

    2013-01-01

    Much effort has been made to control schistosomiasis infection in Egypt. However, enduring effects from such strategies have not yet been achieved. In this study, we sought to determine the genetic variability related to the interaction between Biomphalaria alexandrina snails and Schistosoma mansoni. Using RAPD-PCR with eight (10 mers) random primers, we were able to determine the polymorphic markers that differed between snails susceptible and resistant to Schistosoma mansoni infection using five primers out of the eight. Our results suggest that the RAPD-PCR technique is an efficient means by which to compare genomes and to detect genetic variations between schistosomiasis intermediate hosts. The RAPD technique with the above-noted primers can identify genomic markers that are specifically related to the Biomphalaria alexandrina/Schistosoma mansoni relationship in the absence of specific nucleotide sequence information. This approach could be used in epidemiologic surveys to investigate genetic diversity among Biomphalaria alexandrina snails. The ability to determine resistant markers in Biomphalaria alexandrina snails could potentially lead to further studies that use refractory snails as agents to control the spread of schistosomiasis.

  1. Compatibility of Ugandan Schistosoma mansoni isolates with Biomphalaria snail species from Lake Albert and Lake Victoria

    DEFF Research Database (Denmark)

    Adriko, Moses; Standley, Claire J.; Tinkitina, Benjamin

    2013-01-01

    In order to investigate the capacity of being intermediate host for Schistosoma mansoni, the Ugandan F1 generation of Biomphalaria snail species that were laboratory-bred from parent populations originally collected from either Lake Victoria or Lake Albert was challenged with sympatric and non......-sympatric S. mansoni isolates. After a prepatent period of 20 days, a daily 10-hourly snail shedding for cercariae was done to determine the infection rate, cercarial production per hour and survival period of infected snails. The study suggests that when parasite strains from a different geographical origin...... is used for infection, survival of infected snails increase, leading to an increased transmission potential. Although earlier literature had indicated that the Lake Victoria Biomphalaria sudanica is refractory to S. mansoni, we showed that all Ugandan Biomphalaria spp., including B. sudanica from all...

  2. Immunoelectron microscopical localization of a circulating antigen in the excretory system of Schistosoma mansoni. Ultrastructural localization studies of the excretory system of S. mansoni.

    Science.gov (United States)

    Bogers, J J; Nibbeling, H A; Van Marck, E A; Deelder, A M

    1995-01-01

    In this study the excretory system of Schistosoma mansoni was ultrastructurally examined with a recently described monoclonal antibody (mAb) against a circulating antigen. In previous studies this mAb was found to have affinity for the excretory system. Strong immunoreactivity was found on the flagella of the flame cells and of the collecting ducts throughout the worm. The eggshell and the space between the miracidium and the eggshell showed strong reactivity with a declining gradient towards the exterior, suggesting a secretion process. In cercariae, immunoreactivity was restricted to the tegument, whereas in schistosomula the labeling pattern resembled that of the adult worm, demonstrating positive reactivity of the flame cells and no immunostaining of the tegument. This stage-dependent differential expression of different antigens in the excretory system and in the tegument could suggest a maturation process of the excretory system.

  3. Development of Schistosoma mansoni worms in mice analyzed by bright field and confocal microscopy

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    Carla de Lamare Biolchini

    2006-10-01

    Full Text Available The blood flukes of mammals (Digenea: Schistosomatidae are among trematodes unique whose adult worms have separeted sexes which are dissimilar in appearance. The developmental features, growth and organogenesis of Schistosoma mansoni were studied in Swiss Webster mice by a digital system for image analysis and confocal microscopy. Data so far obtained showed two phases with significative morphological changes at 3-4 weeks post-infection, and a gradual similar development onwards in the reproductive system and tegument. Our male-dependent phase demonstrated that mating occurs before sexual maturing. At week three, the majority of male worms (59% had formed the gynaecophoric canal although testicular lobes and tegumental tubercles were absent. By this time, 33% females had an incipient ovary (without cellular differentiation. At week four, 77.2% males presented testicular lobes with few germinative cells while 26% had developing tegumental tubercles. The immature ovary was observed in 69% females. Suckers followed different pattern of growth between male and females. The size of oral and ventral suckers from six-week-old male worms grew abruptly (3.0 fold more than that of three-week-old. In female worms, maximum growth was attained at week four, reducing in size thereafter. From sixth week onwards, all specimens showed the fully developed reproductive system. Probably, these features are morphological traits which schistosome has experienced from hermaphrodite to dioecy.

  4. Factors Involved in Schistosoma mansoni Infection, in Rural Areas of Northeast Brazil

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    Coutinho Eridan M

    1997-01-01

    Full Text Available Two contiguous villages in Tracunhaém county (State of Pernambuco, endemic for schistosomiasis, were studied: Itapinassu (138 inhabitants and São Joaquim (91 inhabitants. Agriculture predominates in the former region while ceramics is the main activity in the latter. Although no statistical difference was found regarding prevalence, severe infection (>400 epg predominated in Itapinassu, probably related to the kind of occupation. No association was found between parasite burden and severity of disease, in spite of the high infection rates for Schistosoma mansoni in both communities (approx. 60%. Typical epidemiological features of schistosomiasis such as age-related prevalences and intensities of infection (high in children, low in adults were also mutual characteristics. Nutritional status determined through anthropometric evaluation was carried out by measuring specific anthropometric indicators. A deficit of energy intake, as well as vitamin A and riboflavin deficiencies were detected. The prevalence of moderate or severe undernutrition in patients under 18 years old was 21.9% in Itapinassu and 24.1% in São Joaquim. In this group an association was found between prevalence of schistosomiasis and chronic undernutrition. Similarly, for patients over 18 year old the prevalence of undernutrition was higher than 20%. However, in this case no association between nutritional status and either prevalence of schistosomiasis or parasite burden could be detected. The two communities had not been treated for eight years.

  5. A new rapid diagnostic test for detection of anti-Schistosoma mansoni and anti-Schistosoma haematobium antibodies

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    Coulibaly Jean T

    2013-01-01

    Full Text Available Abstract Background Parasitological methods are widely used for the diagnosis of schistosomiasis. However, they are insensitive, particularly in areas of low endemicity, and labour-intensive. Immunoassays based on detection of anti-schistosome antibodies have the merit of high sensitivity and recently a rapid diagnostic test (RDT, incorporating Schistosoma mansoni cercarial transformation fluid (SmCTF for detection of anti-schistosome antibodies in blood has been developed. Here, we assessed the diagnostic performance of the SmCTF-RDT for S. mansoni and S. haematobium infections by comparing it with microscopy for egg detection. Methods A cross-sectional survey was carried out in Azaguié, south Côte d’Ivoire. 118 pre-school-aged children submitted two stool and two urine samples, which were subjected to the Kato-Katz and urine filtration methods for the detection of S. mansoni and S. haematobium eggs, respectively. Urine was also subjected to a commercially available cassette test for S. mansoni, which detects circulating cathodic antigen. A finger-prick blood sample was used for the SmCTF-RDT for detection of anti-S. mansoni and anti-S. haematobium antibodies. Results The prevalence of both anti-S. mansoni and anti-S. haematobium antibodies was more than three times higher than the prevalence of infection estimated by egg detection under a microscope. Using quadruplicate Kato-Katz as the reference standard for the diagnosis of S. mansoni infection, the sensitivity, negative predictive value (NPV, and positive predictive value (PPV of the SmCTF-RDT was 75.0%, 84.2% and 22.5%, respectively. When two urine filtrations were considered as the reference standard for the diagnosis of S. haematobium infection, the sensitivity, NPV and PPV of SmCTF-RDT was 66.7%, 94.9% and 5.1%, respectively. The specificity of SmCTF-RDT, when using egg-detection as the reference standard, was estimated to be 34.4%. This low specificity may be a reflection of the

  6. Serotonin signaling in Schistosoma mansoni: a serotonin-activated G protein-coupled receptor controls parasite movement.

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    Nicholas Patocka

    2014-01-01

    Full Text Available Serotonin is an important neuroactive substance in all the parasitic helminths. In Schistosoma mansoni, serotonin is strongly myoexcitatory; it potentiates contraction of the body wall muscles and stimulates motor activity. This is considered to be a critical mechanism of motor control in the parasite, but the mode of action of serotonin is poorly understood. Here we provide the first molecular evidence of a functional serotonin receptor (Sm5HTR in S. mansoni. The schistosome receptor belongs to the G protein-coupled receptor (GPCR superfamily and is distantly related to serotonergic type 7 (5HT7 receptors from other species. Functional expression studies in transfected HEK 293 cells showed that Sm5HTR is a specific serotonin receptor and it signals through an increase in intracellular cAMP, consistent with a 5HT7 signaling mechanism. Immunolocalization studies with a specific anti-Sm5HTR antibody revealed that the receptor is abundantly distributed in the worm's nervous system, including the cerebral ganglia and main nerve cords of the central nervous system and the peripheral innervation of the body wall muscles and tegument. RNA interference (RNAi was performed both in schistosomulae and adult worms to test whether the receptor is required for parasite motility. The RNAi-suppressed adults and larvae were markedly hypoactive compared to the corresponding controls and they were also resistant to exogenous serotonin treatment. These results show that Sm5HTR is at least one of the receptors responsible for the motor effects of serotonin in S. mansoni. The fact that Sm5HTR is expressed in nerve tissue further suggests that serotonin stimulates movement via this receptor by modulating neuronal output to the musculature. Together, the evidence identifies Sm5HTR as an important neuronal protein and a key component of the motor control apparatus in S. mansoni.

  7. Assessment of toxicity of Moringa oleifera flower extract to Biomphalaria glabrata, Schistosoma mansoni and Artemia salina.

    Science.gov (United States)

    Rocha-Filho, Cláudio A A; Albuquerque, Lidiane P; Silva, Luanna R S; Silva, Patrícia C B; Coelho, Luana C B B; Navarro, Daniela M A F; Albuquerque, Monica C P A; Melo, Ana Maria M A; Napoleão, Thiago H; Pontual, Emmanuel V; Paiva, Patrícia M G

    2015-08-01

    This study reports the effect of an aqueous extract from Moringa oleifera Lam. flowers on Biomphalaria glabrata embryos and adults and on Schistosoma mansoni adult worms. The extract contains tannins, saponins, flavones, flavonols, xanthones, and trypsin inhibitor activity. The toxicity of the extract on Artemia salina larvae was also investigated to determine the safety of its use for schistosomiasis control. After incubation for 24h, the flower extract significantly (p<0.05) delayed the development of B. glabrata embryos and promoted mortality of adult snails (LC50: 2.37±0.5mgmL(-1)). Furthermore, treatment with the extract disrupted the development of embryos generated by snails, with most of them remaining in the blastula stage while control embryos were already in the gastrula stage. Flower extract killed A. salina larvae with a LC50 value (0.2±0.015mgmL(-1)) lower than that determined for snails. A small reduction (17%) in molluscicidal activity was detected when flower extract (2.37mgmL(-1)) was exposed to tropical environmental conditions (UVI index ranging from 1 to 14, temperature from 25 to 30°C, and 65% relative humidity). Toxicity to A. salina was also reduced (LC50 value of 0.28±0.01mgmL(-1)). In conclusion, M. oleifera flower extract had deleterious effects on B. glabrata adults and embryos. However, unrestricted use to control schistosomiasis should be avoided due to the toxicity of this extract on A. salina.

  8. Therapy with bone marrow cells reduces liver alterations in mice chronically infected by Schistosoma mansoni

    Institute of Scientific and Technical Information of China (English)

    Sheilla Andrade Oliveira; Bruno Solano Freitas Souza; Cada Adriana Guimar(a)es-Ferreira; Elton Sá Barreto; Siane Campos Souza; Luiz Antonio Rodrigues Freitas; Ricardo Ribeiro-dos-Santos; Milena Botelho Pereira Soares

    2008-01-01

    AIM: To investigate the potential of bone marrow mononuclear cells (BM-MCs) in the regeneration of hepatic lesions induced by Schistosoma mansoni (S.mansoni) chronic infection.METHODS: Female mice chronically infected with S.mansoni were treated with BM-MCs obtained from male green fluorescent protein (GFP) transgenic mice by intravenous or intralobular injections. Control mice received injections of saline in similar conditions. Enzyme-linked immunosorbent assay (ELISA) assay for transforming growth factor-beta (TGF-β), polymerase chain reaction (PCR) for GFP DNA, immunofluorescence and morphometric studies were performed.RESULTS: Transplanted GFP+ cells migrated to granuloma areas and reduced the percentage of liver fibrosis. The presence of donor-derived cells was confirmed by Fluorescence in situ hybridization (FISH) analysis for detection of cells bearing Y chromosome and by PCR analysis for detection of GFP DNA. The levels of TGF-β, a cytokine associated with fibrosis deposition, in liver fragments of mice submitted to therapy were reduced. The number of oval cells in liver sections of S.rnansoni-infected mice increased 3-4 fold after transplantation. A partial recovery in albumin expression, which is decreased upon infection with S.mansoni, was found in livers of infected mice after cellular therapy.CONCLUSION: In conclusion, transplanted BMCs migrate to and reduce the damage of chronic fibrotic liver lesions caused by S.mansoni.

  9. Schistosoma mansoni infection modulates the immune response against allergic and auto-immune diseases

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    Maria Ilma Araújo

    2004-08-01

    Full Text Available Chronic Schistosoma mansoni infection leads to a type 2-immune response with increased production of interleukin (IL-10. Evidence indicates chronic exposure to S. mansoni down regulates the type 1 immune response and prevents the onset of Th1-mediated diseases such as multiple sclerosis, diabetes mellitus and Cronh's disease. Furthermore, our own studies have revealed that chronic exposure to S. mansoni also down regulates atopic disease, Th2-mediated diseases. Our studies show an inverse association between the skin prick test reactivity and infection with S. mansoni and show the severity of asthma is reduced in subjects living in an endemic area of S. mansoni. Moreover, we hypothesize the mechanisms involved in the modulation of inflammatory response in atopic individuals, is likely dependent on IL-10 production, an anti-inflammatory cytokine elevated during helminth infections. Patients with asthma and helminth infections produced less IL-5 than patients with asthma without helminth infections, and this down regulation could, in part, be mediated by IL-10. In conclusion, helminthic infections, through induction of regulatory mechanisms, such as IL-10 production, are able to modulate the inflammatory immune response involved in the pathology of auto-immune and allergic disease.

  10. Evidence for Novel Pharmacological Sensitivities of Transient Receptor Potential (TRP Channels in Schistosoma mansoni.

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    Swarna Bais

    2015-12-01

    Full Text Available Schistosomiasis, caused by parasitic flatworms of the genus Schistosoma, is a neglected tropical disease affecting hundreds of millions globally. Praziquantel (PZQ, the only drug currently available for treatment and control, is largely ineffective against juvenile worms, and reports of PZQ resistance lend added urgency to the need for development of new therapeutics. Ion channels, which underlie electrical excitability in cells, are validated targets for many current anthelmintics. Transient receptor potential (TRP channels are a large family of non-selective cation channels. TRP channels play key roles in sensory transduction and other critical functions, yet the properties of these channels have remained essentially unexplored in parasitic helminths. TRP channels fall into several (7-8 subfamilies, including TRPA and TRPV. Though schistosomes contain genes predicted to encode representatives of most of the TRP channel subfamilies, they do not appear to have genes for any TRPV channels. Nonetheless, we find that the TRPV1-selective activators capsaicin and resiniferatoxin (RTX induce dramatic hyperactivity in adult worms; capsaicin also increases motility in schistosomula. SB 366719, a highly-selective TRPV1 antagonist, blocks the capsaicin-induced hyperactivity in adults. Mammalian TRPA1 is not activated by capsaicin, yet knockdown of the single predicted TRPA1-like gene (SmTRPA in S. mansoni effectively abolishes capsaicin-induced responses in adult worms, suggesting that SmTRPA is required for capsaicin sensitivity in these parasites. Based on these results, we hypothesize that some schistosome TRP channels have novel pharmacological sensitivities that can be targeted to disrupt normal parasite neuromuscular function. These results also have implications for understanding the phylogeny of metazoan TRP channels and may help identify novel targets for new or repurposed therapeutics.

  11. Infestazione intestinale da Schistosoma mansoni: un caso emblematico di importazione

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    Maria Chiara Medori

    2005-12-01

    Full Text Available Viene descritto, sia dal punto di vista clinico che parassitologico, un caso di importazione di schistosomiasi intestinale da S. mansoni contratta durante un soggiorno in Tanzania. Dopo circa 50 giorni da un contatto casuale ma ripetuto con le acque del Lago Vittoria, al soggetto, giovane adulto in missione umanitaria, compare febbre elevata, accompagnata da astenia (presente da più giorni cui segue un episodio di diarrea acuta. La comparsa anche di una ipereosinofilia, dapprima assente, spinge il curante ad eseguire immediatamente un esame coproparassitologico standard (in precedenza sempre negativo che risulta positivo per uova di S. mansoni. La terapia condotta con praziquantel risolve il caso e porta a guarigione il soggetto, cui inizialmente era stata esclusa la malaria, allorché dopo circa 1 mese dal rientro aveva presentato rialzo termico con disturbi respiratori.

  12. Massa tumoral secundária a infecção por Schistosoma mansoni simulando neoplasia de pulmão: relato de caso Tumoral pulmonary mass secondary to Schistosoma mansoni infection resembling neoplasia: case report

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    Cláudio Dornas de Oliveira

    2009-12-01

    Full Text Available Indivíduos infectados com Schistosoma mansoni na fase crônica da doença podem apresentar comprometimento pulmonar com sintomatologia e alterações radiológicas variáveis. Os pulmões podem ser acometidos pela migração anômala de ovos do sistema porta para o sistema arterial pulmonar (através de anastomoses porto-sistêmicas e menos comumente por migrações ectópicas de vermes adultos. Há casos com extenso comprometimento parenquimatoso e outros com predomínio de arterites, com hipertensão pulmonar e cor pulmonale. Paciente jovem, residente em área endêmica de esquistossomose, com massa pulmonar sugestiva de neoplasia foi submetida a toracotomia exploradora sem possibilidade de ressecção da massa. Exame histopatológico mostrou vários granulomas esquistossomóticos e hiperplasia do tecido conjuntivo, sem sinais de neoplasia. Evoluiu com insuficiência respiratória e instabilidade hemodinâmica no pós-operatório imediato. Recebeu tratamento específico (praziquantel associado a prednisona. A paciente cursou com infecção pulmonar e choque séptico. Recebeu antibioticoterapia, aminas vasoativas, suporte ventilatório e tratamento hemodiálitico sem melhora. Evoluiu para óbito 28 dias após cirurgia.Patients with chronic Schistosoma mansoni infection may feature a range of pulmonary symptoms and radiological findings. Eggs, and rarely adult worms, may passively enter the pulmonary circulation, usually via the portal system, where they may cause pulmonary inflammation, fibrosis, hypertension and cor pulmonale. A 25-year-old patient who lived in a schistosomiasis endemic area with a pulmonary mass suggestive of malignancy underwent exploratory thoracotomy. The mass was adherent, with no resection possibility. The lung-biopsy specimen evaluation showed several granulomas with Schistosoma mansoni eggs and hyperplasic connective tissue with no sign of malignancy. The patient had respiratory failure and hypotension immediately

  13. Two sequential PCR amplifications for detection of Schistosoma mansoni in stool samples with low parasite load

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    Maria Cristina Carvalho do Espírito-Santo

    2012-10-01

    Full Text Available Schistosomiasis constitutes a major public health problem, with an estimated 200 million individuals infected worldwide and 700 million people living in risk areas. In Brazil there are areas of high, medium and low endemicity. Studies have shown that in endemic areas with a low prevalence of Schistosoma infection the sensitivity of parasitological methods is clearly reduced. Consequently diagnosis is often impeded due to the presence of false-negative results. The aim of this study is to present the PCR reamplification (Re-PCR protocol for the detection of Schistosoma mansoni in samples with low parasite load (with less than 100 eggs per gram (epg of feces. Three methods were used for the lysis of the envelopes of the S. mansoni eggs and two techniques of DNA extraction were carried out. Extracted DNA was quantified, and the results suggested that the extraction technique, which mixed glass beads with a guanidine isothiocyanate/phenol/chloroform (GT solution, produced good results. PCR reamplification was conducted and detection sensitivity was found to be five eggs per 500 mg of artificially marked feces. The results achieved using these methods suggest that they are potentially viable for the detection of Schistosoma infection with low parasite load.

  14. Toxicity of lapachol and isolapachol and their potassium salts against Biomphalaria glabrata, Schistosoma mansoni cercariae, Artemia salina and Tilapia nilotica.

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    Lima, Nadja Maria Fernandes; dos Santos, Aldenir Feitosa; Porfírio, Zenaldo; Goulart, Marília O F; Sant'Ana, Antônio Euzébio G

    2002-07-01

    The toxicity of soluble derivatives (potassium salt) of lapachol and isolapachol in different stages of the life cycle of Schistosoma mansoni is evaluated. The potassium salts of isolapachol and lapachol showed significant molluscicidal activity against the adult snail (LC90Artemia salina Leach) indicated very high toxicity for the potassium salt of isolapachol (LC90=1.54 ppm), differently from the potassium salt of lapachol that can be considered non toxic (LC90=176.3 ppm). The same tendency is observed with piscicidal activity, for which the isolapachol salt has showed higher toxicity. The obtained selectivity ratios concerning LC50 and LC90 for lapachol, in relation to Tilapia nilotica lethality assay are 2.33 and 1.26, respectively. Despite the piscicidal toxicity, the use of the salt of lapachol can be recommended for field tests in Schistosomiasis, with caution.

  15. Cloning and characterization of SmZF1, a gene encoding a Schistosoma mansoni zinc finger protein

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    Souza Paulo R Eleutério de

    2001-01-01

    Full Text Available The zinc finger motifs (Cys2His2 are found in several proteins playing a role in the regulation of transcripton. SmZF1, a Schistosoma mansoni gene encoding a zinc finger protein was initially isolated from an adult worm cDNA library, as a partial cDNA. The full sequence of the gene was obtained by subcloning and sequencing cDNA and genomic fragments. The collated gene sequence is 2181 nt and the complete cDNA sequence is 705 bp containing the full open reading frame of the gene. Analysis of the genome sequence revealed the presence of three introns interrupting the coding region. The open reading frame theoretically encodes a protein of 164 amino acids, with a calculated molecular mass of 18,667Da. The predicted protein contains three zinc finger motifs, usually present in transcription regulatory proteins. PCR amplification with specific primers for the gene allowed for the detection of the target in egg, cercariae, schistosomulum and adult worm cDNA libraries indicating the expression of the mRNA in these life cycle stages of S. mansoni. This pattern of expression suggests the gene plays a role in vital functions of different life cycle stages of the parasite. Future research will be directed to elucidate the functional role of SmZF1.

  16. SmShb, the SH2-Containing Adaptor Protein B of Schistosoma mansoni Regulates Venus Kinase Receptor Signaling Pathways

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    Morel, Marion; Vanderstraete, Mathieu; Cailliau, Katia; Hahnel, Steffen; Grevelding, Christoph G.; Dissous, Colette

    2016-01-01

    Venus kinase receptors (VKRs) are invertebrate receptor tyrosine kinases (RTKs) formed by an extracellular Venus Fly Trap (VFT) ligand binding domain associated via a transmembrane domain with an intracellular tyrosine kinase (TK) domain. Schistosoma mansoni VKRs, SmVKR1 and SmVKR2, are both implicated in reproductive activities of the parasite. In this work, we show that the SH2 domain-containing protein SmShb is a partner of the phosphorylated form of SmVKR1. Expression of these proteins in Xenopus oocytes allowed us to demonstrate that the SH2 domain of SmShb interacts with the phosphotyrosine residue (pY979) located in the juxtamembrane region of SmVKR1. This interaction leads to phosphorylation of SmShb on tyrosines and promotes SmVKR1 signaling towards the JNK pathway. SmShb transcripts are expressed in all parasite stages and they were found in ovary and testes of adult worms, suggesting a possible colocalization of SmShb and SmVKR1 proteins. Silencing of SmShb in adult S. mansoni resulted in an accumulation of mature sperm in testes, indicating a possible role of SmShb in gametogenesis. PMID:27636711

  17. Cloning and Molecular Characterization of the Schistosoma mansoni Genes RbAp48 and Histone H4

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    Patrícia P Souza

    2002-10-01

    Full Text Available The human nuclear protein RbAp48 is a member of the tryptophan/aspartate (WD repeat family, which binds to the retinoblastoma (Rb protein. It also corresponds to the smallest subunit of the chromatin assembly factor and is able to bind to the helix 1 of histone H4, taking it to the DNA in replication. A cDNA homologous to the human gene RbAp48 was isolated from a Schistosoma mansoni adult worm library and named SmRbAp48. The full length sequence of SmRbAp48 cDNA is 1036 bp long, encoding a protein of 308 amino acids. The transcript of SmRbAp48 was detected in egg, cercariae and schistosomulum stages. The protein shows 84% similarity with the human RbAp48, possessing four WD repeats on its C-terminus. A hypothetical tridimensional structure for the SmRbAp48 C-terminal domain was constructed by computational molecular modeling using the b-subunit of the G protein as a model. To further verify a possible interaction between SmRbAp48 and S. mansoni histone H4, the histone H4 gene was amplified from adult worm genomic DNA using degenerated primers. The gene fragment of SmH4 is 294 bp long, encoding a protein of 98 amino acids which is 100% identical to histone H4 from Drosophila melanogaster.

  18. SmShb, the SH2-Containing Adaptor Protein B of Schistosoma mansoni Regulates Venus Kinase Receptor Signaling Pathways.

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    Morel, Marion; Vanderstraete, Mathieu; Cailliau, Katia; Hahnel, Steffen; Grevelding, Christoph G; Dissous, Colette

    2016-01-01

    Venus kinase receptors (VKRs) are invertebrate receptor tyrosine kinases (RTKs) formed by an extracellular Venus Fly Trap (VFT) ligand binding domain associated via a transmembrane domain with an intracellular tyrosine kinase (TK) domain. Schistosoma mansoni VKRs, SmVKR1 and SmVKR2, are both implicated in reproductive activities of the parasite. In this work, we show that the SH2 domain-containing protein SmShb is a partner of the phosphorylated form of SmVKR1. Expression of these proteins in Xenopus oocytes allowed us to demonstrate that the SH2 domain of SmShb interacts with the phosphotyrosine residue (pY979) located in the juxtamembrane region of SmVKR1. This interaction leads to phosphorylation of SmShb on tyrosines and promotes SmVKR1 signaling towards the JNK pathway. SmShb transcripts are expressed in all parasite stages and they were found in ovary and testes of adult worms, suggesting a possible colocalization of SmShb and SmVKR1 proteins. Silencing of SmShb in adult S. mansoni resulted in an accumulation of mature sperm in testes, indicating a possible role of SmShb in gametogenesis.

  19. Use of geospatial modeling to predict Schistosoma mansoni prevalence in Nyanza Province, Kenya.

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    Dana M Woodhall

    Full Text Available BACKGROUND: Schistosomiasis, a parasitic disease that affects over 200 million people, can lead to significant morbidity and mortality; distribution of single dose preventative chemotherapy significantly reduces disease burden. Implementation of control programs is dictated by disease prevalence rates, which are determined by costly and labor intensive screening of stool samples. Because ecological and human factors are known to contribute to the focal distribution of schistosomiasis, we sought to determine if specific environmental and geographic factors could be used to accurately predict Schistosoma mansoni prevalence in Nyanza Province, Kenya. METHODOLOGY/PRINCIPAL FINDINGS: A spatial mixed model was fit to assess associations with S. mansoni prevalence in schools. Data on S. mansoni prevalence and GPS location of the school were obtained from 457 primary schools. Environmental and geographic data layers were obtained from publicly available sources. Spatial models were constructed using ArcGIS 10 and R 2.13.0. Lower S.mansoni prevalence was associated with further distance (km to Lake Victoria, higher day land surface temperature (LST, and higher monthly rainfall totals. Altitude, night LST, human influence index, normalized difference vegetation index, soil pH, soil texture, soil bulk density, soil water capacity, population, and land use variables were not significantly associated with S. mansoni prevalence. CONCLUSIONS: Our model suggests that there are specific environmental and geographic factors that influence S. mansoni prevalence rates in Nyanza Province, Kenya. Validation and use of schistosomiasis prevalence maps will allow control programs to plan and prioritize efficient control campaigns to decrease schistosomiasis burden.

  20. Immunostimulatory effects of extract of Pulicaria crispa before and after Schistosoma mansoni infection.

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    Maghraby, Amany S; Shalaby, Nagwa; Abd-Alla, Howida I; Ahmed, Samia A; Khaled, Hussein M; Bahgat, Mahmoud M

    2010-01-01

    The immunostimulatory effects of methanolic extract from Pulicaria crispa were investigated in mice before and after infection with Schistosoma mansoni. Mice were subjected for daily intra-peritoneal injection by the extract (33 ng/mouse) for 10 successive days followed by infecting every mouse with 100 S. mansoni cercariae. Treatment with the extract induced significant increase (p < 0.05) in sera-IL-2 before and after infection. Upon using soluble worm antigen preparation or cancer bladder homogenates as antigens in ELISA, the detected levels of IgG were significantly (p < 0.05) higher in sera from treated-infected mice than untreated P. crispa infected mice. Using crude Escherichia coli lysate as an antigen in ELISA, it was detected a significant (p < 0.05) increase in IgG levels in sera from the extract-treated mice before and after infection.

  1. Construction and characterization of a Schistosoma mansoni bacterial artificial chromosome library.

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    Le Paslier, M C; Pierce, R J; Merlin, F; Hirai, H; Wu, W; Williams, D L; Johnston, D; LoVerde, P T; Le Paslier, D

    2000-04-15

    A bacterial artificial chromosome (BAC) library has been established from genomic DNA isolated from the trematode parasite of human, Schistosoma mansoni. This library consists of more than 21,000 recombinant clones carrying inserts in the pBeloBAC11 vector. The mean insert size was 100 kb, representing an approximate 7.95-fold genome coverage. Library screening with eight chromosome-specific or single-copy gene probes yielded between 1 and 9 positive clones, and none of those tested was absent from the library. End sequences were obtained for 93 randomly selected clones, and 37 showed sequence identity to S. mansoni sequences (ESTs, genes, or repetitive sequences). A preliminary analysis by fluorescence in situ hybridization localized 8 clones on schistosome chromosomes 1 (2 clones), 2, 3, 5, Z, and W (3 clones). This library provides a new resource for the physical mapping and sequencing of the genome of this important human pathogen.

  2. The growth and development of Schistosoma mansoni in mice exposed to sublethal doses of radiation

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    Aitken, R.; Wilson, R.A. (Univ. of York, Heslington (England))

    1989-12-01

    The maturation of Schistosoma mansoni was studied in mice exposed to various sublethal doses of radiation. Although the treatment of mice with 500 rads of radiation prior to infection did not alter parasite maturation, doses in excess of 500 rads led to a reduction in worm burden. This could not be attributed to a delay in the arrival of parasites in the hepatic portal system. Worms developing in mice treated with 800 rads commenced egg-laying about 1 wk later than worms in intact mice, and the rate of egg deposition appeared to be lower in irradiated hosts. The data demonstrate that exposure of C57BL/6 mice to doses of radiation in excess of 500 rads impairs their ability to carry infections of S. mansoni. The findings do not support the hypothesis that primary worm burdens in the mouse are controlled by a host immune response.

  3. Polymyxin B as inhibitor of LPS contamination of Schistosoma mansoni recombinant proteins in human cytokine analysis

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    Pacífico Lucila G

    2007-01-01

    Full Text Available Abstract Background Recombinant proteins expressed in Escherichia coli vectors are generally contaminated with endotoxin. In this study, we evaluated the ability of Polymyxin B to neutralize the effect of LPS present as contaminant on Schistosoma mansoni recombinant proteins produced in E. coli in inducing TNF-α and IL-10. Peripheral blood mononuclear cells from individuals chronically infected with S. mansoni were stimulated in vitro with recombinant Sm22.6, Sm14 and P24 antigens (10 μg/mL in the presence of Polymyxin B (10 μg/mL. Results The levels of cytokines were measured using ELISA. There was greater than 90 % reduction (p S. mansoni recombinant proteins in the presence of Polymyxin B, a reduction in the levels of TNF-α and IL-10 was also observed. However, the percentage of reduction was lower when compared to the cultures stimulated with LPS, probably because these proteins are able to induce the production of these cytokines by themselves. Conclusion This study showed that Polymyxin B was able to neutralize the effect of endotoxin, as contaminant in S. mansoni recombinant antigens produced in E. coli, in inducing TNF-α and IL-10 production.

  4. The genomic proliferation of transposable elements in colonizing populations: Schistosoma mansoni in the new world.

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    Wijayawardena, Bhagya K; DeWoody, J Andrew; Minchella, Dennis J

    2015-06-01

    Transposable elements (TEs) are mobile genes with an inherent ability to move within and among genomes. Theory predicts that TEs proliferate extensively during physiological stress due to the breakdown of TE repression systems. We tested this hypothesis in Schistosoma mansoni, a widespread trematode parasite that causes the human disease schistosomiasis. According to phylogenetic analysis, S. mansoni invaded the new world during the last 500 years. We hypothesized that new world strains of S. mansoni would have more copies of TEs than old world strains due to the physiological stress associated with invasion of the new world. We quantified the copy number of six TEs (Saci-1, Saci-2 and Saci-3, Perere-1, Merlin-sm1, and SmTRC1) in the genome and the transcriptome of old world and new world strains of S. mansoni, using qPCR relative quantification. As predicted, the genomes of new world parasites contain significantly more copies of class I and class II TEs in both laboratory and field strains. However, such differences are not observed in the transcriptome suggesting that either TE silencing mechanisms have reactivated to control the expression of these elements or the presence of inactive truncated copies of TEs.

  5. Hybridism between Biomphalaria cousini and Biomphalaria amazonica and its susceptibility to Schistosoma mansoni

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    Tatiana Maria Teodoro

    2011-11-01

    Full Text Available Molecular techniques can aid in the classification of Biomphalaria species because morphological differentiation between these species is difficult. Previous studies using phylogeny, morphological and molecular taxonomy showed that some populations studied were Biomphalaria cousini instead of Biomphalaria amazonica. Three different molecular profiles were observed that enabled the separation of B. amazonica from B. cousini. The third profile showed an association between the two and suggested the possibility of hybrids between them. Therefore, the aim of this work was to investigate the hybridism between B. cousini and B. amazonica and to verify if the hybrids are susceptible to Schistosoma mansoni. Crosses using the albinism factor as a genetic marker were performed, with pigmented B. cousini and albino B. amazonica snails identified by polymerase chain reaction-restriction fragment length polymorphism. This procedure was conducted using B. cousini and B. amazonica of the type locality accordingly to Paraense, 1966. In addition, susceptibility studies were performed using snails obtained from the crosses (hybrids and three S. mansoni strains (LE, SJ, AL. The crosses between B. amazonica and B. cousini confirmed the occurrence of hybrids. Moreover, hybrids can be considered potential hosts of S. mansoni because they are susceptible to LE, SJ and AL strains (4.4%, 5.6% and 2.2%, respectively. These results indicate that there is a risk of introducing schistosomiasis mansoni into new areas.

  6. Spatial distribution of Biomphalaria spp., the intermediate host snails of Schistosoma mansoni, in Brazil.

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    Scholte, Ronaldo G C; Carvalho, Omar S; Malone, John B; Utzinger, Jürg; Vounatsou, Penelope

    2012-09-01

    Schistosomiasis mansoni remains an important parasitic disease of man, endemic in large parts of sub-Saharan Africa, the Middle East, South America and the Caribbean. The aetiological agent is the trematode Schistosoma mansoni, whereas aquatic snails of the genus Biomphalaria act as intermediate hosts in the parasite life cycle. In Brazil, the distribution of Biomphalaria spp. is closely associated with the occurrence of schistosomiasis. The purpose of this study was to map and predict the spatial distribution of the intermediate host snails of S. mansoni across Brazil. We assembled snail "presenceonly" data and used a maximum entropy approach, along with climatic and environmental variables to produce predictive risk maps. We identified a series of risk factors that govern the distribution of Biomphalaria snails. We find that high-risk areas for B. glabrata are concentrated in the regions of Northeast and Southeast and the northern part of the South region. B. straminea are found in the Northeast and Southeast regions, and B. tenagophila are concentrated in the Southeast and South regions. Our findings confirm that the presence of the intermediate host snails is correlated with the occurrence of schistosomiasis mansoni. The generated risk maps of intermediate host snails might assist the national control programme for spatial targeting of control interventions and to ultimately move towards schistosomiasis elimination in Brazil.

  7. Development of a real time polymerase chain reaction for quantitation of Schistosoma mansoni DNA

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    Ana Lisa do Vale Gomes

    2006-10-01

    Full Text Available This report describes the development of a SYBR Green I based real time polymerase chain reaction (PCR protocol for detection on the ABI Prism 7000 instrument. Primers targeting the gene encoding the SSU rRNA were designed to amplify with high specificity DNA from Schistosoma mansoni, in a real time quantitative PCR system. The limit of detection of parasite DNA for the system was 10 fg of purified genomic DNA, that means less than the equivalent to one parasite cell (genome ~580 fg DNA. The efficiency was 0.99 and the correlation coefficient (R² was 0.97. When different copy numbers of the target amplicon were used as standards, the assay could detect at least 10 copies of the specific target. The primers used were designed to amplify a 106 bp DNA fragment (Tm 83ºC. The assay was highly specific for S. mansoni, and did not recognize DNA from closely related non-schistosome trematodes. The real time PCR allowed for accurate quantification of S. mansoni DNA and no time-consuming post-PCR detection of amplification products by gel electrophoresis was required. The assay is potentially able to quantify S. mansoni DNA (and indirectly parasite burden in a number of samples, such as snail tissue, serum and feces from patients, and cercaria infested water. Thus, these PCR protocols have potential to be used as tools for monitoring of schistosome transmission and quantitative diagnosis of human infection.

  8. RNA interference in Schistosoma mansoni schistosomula: selectivity, sensitivity and operation for larger-scale screening.

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    Saša Stefanić

    Full Text Available BACKGROUND: The possible emergence of resistance to the only available drug for schistosomiasis spurs drug discovery that has been recently incentivized by the availability of improved transcriptome and genome sequence information. Transient RNAi has emerged as a straightforward and important technique to interrogate that information through decreased or loss of gene function and identify potential drug targets. To date, RNAi studies in schistosome stages infecting humans have focused on single (or up to 3 genes of interest. Therefore, in the context of standardizing larger RNAi screens, data are limited on the extent of possible off-targeting effects, gene-to-gene variability in RNAi efficiency and the operational capabilities and limits of RNAi. METHODOLOGY/PRINCIPAL FINDINGS: We investigated in vitro the sensitivity and selectivity of RNAi using double-stranded (dsRNA (approximately 500 bp designed to target 11 Schistosoma mansoni genes that are expressed in different tissues; the gut, tegument and otherwise. Among the genes investigated were 5 that had been previously predicted to be essential for parasite survival. We employed mechanically transformed schistosomula that are relevant to parasitism in humans, amenable to screen automation and easier to obtain in greater numbers than adult parasites. The operational parameters investigated included defined culture media for optimal parasite maintenance, transfection strategy, time- and dose-dependency of RNAi, and dosing limits. Of 7 defined culture media tested, Basch Medium 169 was optimal for parasite maintenance. RNAi was best achieved by co-incubating parasites and dsRNA (standardized to 30 µg/ml for 6 days; electroporation provided no added benefit. RNAi, including interference of more than one transcript, was selective to the gene target(s within the pools of transcripts representative of each tissue. Concentrations of dsRNA above 90 µg/ml were directly toxic. RNAi efficiency was

  9. Schistosoma mansoni: effects of anesthetics and antimonial drugs on worm shift in the mouse

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    José Renan da Cunha-Melo

    1986-08-01

    Full Text Available Mice experimentally infected with Schistosoma mansoni were injected with sodium thiopental or sodium antimonyl gluconate (Triostib R, or submitted to halothane inhalation, with or without a previous injection of thiopental. Data obtained showed that halothane and thiopental induce worm shift to the liver (99 and 76%, respectively. Sodium gluconate and antimonium (Triostib R shifted 52% of worms towards the liver. These results seem to indicate that the use of antimonium would be unnecessary, when surgical removal of schistosomules is carried out through the extracorporeal filtration technique, in patients with portal hypertension.

  10. Characterization of the cGMP-dependent protein kinase SmcGK1 of Schistosoma mansoni

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    Silke Leutner

    2011-06-01

    Full Text Available Schistosomes are trematode parasites and of worldwide medical importance for humans and animals. Growth and development of these parasites require a specific host environment, but also permanent communication processes between the two genders. Accumulating molecular evidence indicates that the responsible interactions are mediated by signal transduction processes. Conserved signaling molecules were identified, and first approaches made for their characterization. However, no representative of the conserved family of cGMP-dependent protein kinases (cGKs has been described in this parasite yet. Within the Schistosoma mansoni genome data-set we identified cGK homologs, of which one was investigated in more detail in this study. We present the cloning of SmcGK1, whose sequence shows homology to cGKs of higher eukaryotes. SmcGK1 was found to be gender-independently transcribed in adult schistosomes. The occurrence of SmcGK1 sense and antisense transcripts suggests that the expression of this gene is controlled at the post-transcriptional level. In situ hybridization experiments demonstrated a gonad-preferential expression profile in both genders indicating a role of SmcGK1, at least during sexual development of schistosomes. Using a cGK-specific inhibitor to treat adult schistosomes in vitro finally resulted in a multifaceted phenotype including slow motion, oocyte congestion, and reduced egg production.Esquistossomos são parasitas trematodos de importância médica em todo o mundo para o homem e os animais. O crescimento e o desenvolvimento destes parasitas requerem um ambiente específico do hospedeiro, mas também um processo de comunicação permanente entre parasitas dos dois sexos. Evidência molecular tem se acumulado e indica que as interações são mediadas por processos de transdução de sinal. Moléculas sinalizadoras conservadas foram identificadas, e as primeiras abordagens têm sido feitas para sua caracterização. Contudo, não foi

  11. Additional Evaluation of the Point-of-Contact Circulating Cathodic Antigen Assay for Schistosoma mansoni Infection.

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    Mwinzi, Pauline N M; Kittur, Nupur; Ochola, Elizabeth; Cooper, Philip J; Campbell, Carl H; King, Charles H; Colley, Daniel G

    2015-01-01

    Studies of the urine-based point-of-contact cathodic circulating antigen test (POC-CCA) in Schistosoma mansoni-endemic settings in Africa indicate it has good sensitivity in detecting infections, but in areas of low prevalence, the POC-CCA can be positive for persons who are egg-negative by Kato-Katz stool assays. We examined the POC-CCA assay for: (a) batch-to-batch stability; (b) intra-reader and inter-reader variability; (c) day-to-day variability compared to Kato-Katz stool assays, and (d) to see if praziquantel (PZQ) treatment converted Kato-Katz-negative/POC-CCA positive individuals to POC-CCA negativity. We found essentially no batch-to-batch variation, negligible intra-reader variability (2%), and substantial agreement for inter-reader reliability. Some day-to-day variation was observed over 5 days of urine collection, but less than the variation in Kato-Katz stool assays over 3 days. To evaluate the effect of treatment on Kato-Katz(-)/POC-CCA(+) children, 149 children in an area of 10-15% prevalence who were Kato-Katz(-) based on 3 stool samples but POC-CCA(+) were enrolled. Seven days after treatment (PZQ 40 mg/kg) samples were again collected and tested. Almost half (47%) POC-CCA positive children turned negative. Those still POC-CCA positive received a second treatment, and 34% of them turned POC-CCA negative upon this second treatment. Most who remained POC-CCA positive shifted each time to a "lesser" POC-CCA "level of positivity." The data suggest that most Kato-Katz-negative/POC-CCA positive individuals harbor low-intensity infections, and each treatment kills all or some of their adult worms. The data also suggest that when evaluated by a more sensitive assay, the effective cure rates for PZQ are significantly less than those inferred from fecal testing. These findings have public health significance for the mapping and monitoring of Schistosoma infections and in planning the transition from schistosomiasis morbidity control to elimination of

  12. Toxicity of cadmium to Schistosoma mansoni cercariae: effects on vitality and developmental ability in white mice

    Energy Technology Data Exchange (ETDEWEB)

    Holliman, R.B. (Virginia Polytechnic Inst. and State Univ., Blacksburg); Esham, L.P.

    1977-09-29

    Time-until-death studies were run on cercariae of Schistosoma mansoni in 8 concentrations of cadmium (from cadmium sulfate) ranging from 100 ppM to 0.0001 ppM. All concentrations used were found to be toxic, and at 10 ppM all cercariae were dead within 4 hours, which coincides with their period of maximum infectability following emergence from the snail host. At 2 ppM, all cercariae died within 8 hours, and at 1 ppM all died within 16 hours. In addition, groups of cercariae were exposed to cadmium concentrations of 10, 1, and 0.1 ppM for periods of 30, 20, and 10 minutes. Thereafter, cercariae from these groups were allowed to penetrate the tails of white mice or were injected subcutaneously into mice. After 8 weeks, these mice were autopsied and the adult worms collected by perfusion. Maturation of cercariae from both methods of invasion was seriously impaired. Statistical analysis using a 3 x 4 x 2 factoral design for analysis of variance showed both time of exposure and concentration of cadmium ion to be significant factors in determining number of worms developing at p = 0.01. A significant interaction between time of exposure and concentration was found to exist. The two methods of infection did not have a significant effect on the number of worms recovered. Therefore, it appears that those toxicant-exposed cercariae capable of maturing do not need assistance in transversing the skin barrier but can penetrate and migrate to reach the mesenteric venules for maturation.

  13. Congenital and nursing effects on the evolution of Schistosoma mansoni infection in mice

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    J. A. Lenzi

    1987-01-01

    Full Text Available Modification of the immune response to schistosomal infection in children or offspring born to mother R infected with Schistosoma mansoni has been demonstrated in human and in experimental schistosomiasis. One of the hypothesis to explain this fact could be the transfer of circulating antigens and antibodies from mother to foetus through the placenta or from mother to child by milk. The results of this spontaneous transference are controversial in the literature. In an attempt to investigate these questions, we studied one hundred and twenty offspring (Swiss mice, sixty born to infected-mothers (group A and sixty born to non-infected mothers (group B. These were percutaneously infected with 50 cercariae/mouse, and divided in six sub-groups (20 mice/sub-group, according to the following schedule: after birth (sub-groups A.I and B.I, 10 days old (sub-groups A.II and B.II and 21 days old (sub-groups A.III and B.III. After the exposure period, the young mice returned to their own mothers for nursing. Six weeks later, the mice were killed. We obtained the following results: 1 There is transference of antibody to cercariae (CAP, adult worms (SWAP and egg antigens (SEA from the infected mothers to the offspring, probably through placenta and milk; 2 Offspring born to infected mothers exhibit much less coagulative hepatic necrosis and show a lower number of eggs in the small intestine and a less intense and predominant exsudative stage of the hepatic granulomas when compared with the exsudative-productive stage of the control groups. The findings suggest that congenital and nursing factors can interfere on the development of the schistosomiasis infection, causing an hyporesponse to the eggs.

  14. Molecular cloning of Schistosoma mansoni calcineurin subunits and immunolocalization to the excretory system.

    Science.gov (United States)

    Mecozzi, B; Rossi, A; Lazzaretti, P; Kady, M; Kaiser, S; Valle, C; Cioli, D; Klinkert, M Q

    2000-10-01

    In order to explain the schistosomicidal effect of cyclosporin A, the hypothesis was advanced that the drug, complexed with cyclophilin, inhibits the phosphatase activity of parasite calcineurin (CN), with mechanisms similar to those operating in its immunosuppressive action. As a preparatory step to the testing of this hypothesis, we report the molecular cloning of both CN subunits in Schistosoma mansoni. The catalytic (A) subunit has a predicted sequence of 607 amino acids and shows substantial similarity to other cloned CNs, except for the carboxy-terminal end that is highly divergent. The regulatory (B) subunit consists of 169 amino acids that are 86% identical to those of the human counterpart and, from its anomalous electrophoretic mobility, it appears to be myristoylated. The results of Southern blotting experiments are compatible with the existence of multiple genes for CNA and a single gene for CNB. Western blots showed that both subunits are present at all stages of the parasite life cycle and can be detected both in the soluble and in the membrane fraction. Immunofluorescence confocal microscopy revealed a striking concentration of the anti-CNA reactivity in 6-8 discrete spots in the schistosomula and in distinct spots along the body of the adult parasite, corresponding to the expected localization of flame cells. Both patterns were confirmed by a perfect co-localization of the anti-CNA signal with that of a previously characterized anti-flame cell monoclonal antibody. The preferential confinement of schistosome CN to the protonephridial system suggests that the enzyme in the parasite may fulfil similar functions to those performed in mammalian kidneys.

  15. Immunological system and Schistosoma mansoni: co-evolutionary immunobiology. What is the eosinophil role in parasite-host relationship?

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    Henrique L Lenzi

    1997-12-01

    Full Text Available Schistosomes, ancestors and recent species, have pervaded many hosts and several phylogenetic levels of immunity, causing an evolutionary pressure to eosinophil lineage expression and response. Schistosoma mansoni adult worms have capitalized on the apparent adversity of living within the mesenteric veins, using the dispersion of eggs and antigens to other tissues besides intestines to set a systemic activation of several haematopoietic lineages, specially eosinophils and monocytes/macrophages. This activation occurs in bone marrow, spleen, liver, lymph nodes, omental and mesenteric milky spots (activation of the old or primordial and recent or new lymphomyeloid tissue, increasing and making easy the migration of eosinophils, monocytes and other cells to the intestinal periovular granulomas. The exudative perigranulomatous stage of the periovular reaction, which present hystolitic characteristics, is then exploited by the parasites, to release the eggs into the intestinal lumen. The authors hypothesize here that eosinophils, which have a long phylogenic story, could participate in the parasite - host co-evolution, specially with S. mansoni, operating together with monocytes/ macrophages, upon parasite transmission.

  16. Simple school questionnaires can map both Schistosoma mansoni and Schistosoma haematobium in the Democratic Republic of Congo.

    Science.gov (United States)

    Lengeler, C; Makwala, J; Ngimbi, D; Utzinger, J

    2000-01-05

    The use of self-administered questionnaires has been shown in different African countries to be inexpensive and reliable for the rapid identification of communities at highest risk of urinary schistosomiasis. For intestinal schistosomiasis due to Schistosoma mansoni there is a clear need for a similar approach. We report the results from a large-scale study undertaken in the western part of the Democratic Republic of Congo (DRC, formerly Zaire). Within 4 weeks questionnaires were correctly completed in 136 out of 160 schools (85%). In 57 of these schools children were screened for infections with schistosomes and geohelminths. The prevalence of 'schistosomiasis' as reported in the questionnaires showed the best correlation with the prevalence of S. mansoni infections (r = 0.77, P schools with a high risk of intestinal schistosomiasis gave positive predictive values of 87 and 62%, and negative predictive values of 74 and 87% for moderate and high infection thresholds, respectively. Reported 'blood in stool' was another useful indicator for intestinal schistosomiasis. Reported 'blood in urine' showed the best correlation with urinary schistosomiasis (r = 0.75, P school children in DRC have a distinct perception of intestinal and urinary schistosomiasis and that questionnaires could be useful to identify high-risk schools for both parasites.

  17. The feasibility of MS and advanced data processing for monitoring Schistosoma mansoni infection

    DEFF Research Database (Denmark)

    Balog, Crina I.A.; Alexandrov, Theodore; Derks, Rico J.

    2010-01-01

    Sensitive diagnosis, monitoring of disease progression and the evaluation of chemotherapeutic interventions are of prime importance for the improvement of control and prevention strategies for Schistosomiasis. The aim of the present study was to identify novel markers of Schistosoma mansoni infec...

  18. Suppression of basophil histamine release and other IgE-dependent responses in childhood Schistosoma mansoni/hookworm coinfection

    DEFF Research Database (Denmark)

    Pinot de Moira, Angela; Fitzsimmons, Colin M; Jones, Frances M;

    2014-01-01

    in Ugandan schoolchildren coinfected with Schistosoma mansoni and hookworm. METHODS: Skin prick test (SPT) sensitivity to house dust mite allergen (HDM) and current wheeze were assessed pre-anthelmintic treatment. Nonspecific (anti-IgE), helminth-specific, and HDM-allergen-specific basophil histamine release...

  19. Reconstructing Colonization Dynamics of the Human Parasite Schistosoma mansoni following Anthropogenic Environmental Changes in Northwest Senegal.

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    Frederik Van den Broeck

    2015-08-01

    Full Text Available Anthropogenic environmental changes may lead to ecosystem destabilization and the unintentional colonization of new habitats by parasite populations. A remarkable example is the outbreak of intestinal schistosomiasis in Northwest Senegal following the construction of two dams in the '80s. While many studies have investigated the epidemiological, immunological and geographical patterns of Schistosoma mansoni infections in this region, little is known about its colonization history.Parasites were collected at several time points after the disease outbreak and genotyped using a 420 bp fragment of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1 and nine nuclear DNA microsatellite markers. Phylogeographic and population genetic analyses revealed the presence of (i many genetically different haplotypes at the non-recombining mitochondrial marker and (ii one homogenous S. mansoni genetic group at the recombining microsatellite markers. These results suggest that the S. mansoni population in Northwest Senegal was triggered by intraspecific hybridization (i.e. admixture between parasites that were introduced from different regions. This would comply with the extensive immigration of infected seasonal agricultural workers from neighboring regions in Senegal, Mauritania and Mali. The spatial and temporal stability of the established S. mansoni population suggests a swift local adaptation of the parasite to the local intermediate snail host Biomphalaria pfeifferi at the onset of the epidemic.Our results show that S. mansoni parasites are very successful in colonizing new areas without significant loss of genetic diversity. Maintaining high levels of diversity guarantees the adaptive potential of these parasites to cope with selective pressures such as drug treatment, which might complicate efforts to control the disease.

  20. Crystal Structure of Schistosoma mansoni Adenosine Phosphorylase/5’-Methylthioadenosine Phosphorylase and Its Importance on Adenosine Salvage Pathway

    Science.gov (United States)

    Torini, Juliana Roberta; Brandão-Neto, José; DeMarco, Ricardo; Pereira, Humberto D'Muniz

    2016-01-01

    Schistosoma mansoni do not have de novo purine pathways and rely on purine salvage for their purine supply. It has been demonstrated that, unlike humans, the S. mansoni is able to produce adenine directly from adenosine, although the enzyme responsible for this activity was unknown. In the present work we show that S. mansoni 5´-deoxy-5´-methylthioadenosine phosphorylase (MTAP, E.C. 2.4.2.28) is capable of use adenosine as a substrate to the production of adenine. Through kinetics assays, we show that the Schistosoma mansoni MTAP (SmMTAP), unlike the mammalian MTAP, uses adenosine substrate with the same efficiency as MTA phosphorolysis, which suggests that this enzyme is part of the purine pathway salvage in S. mansoni and could be a promising target for anti-schistosoma therapies. Here, we present 13 SmMTAP structures from the wild type (WT), including three single and one double mutant, and generate a solid structural framework for structure description. These crystal structures of SmMTAP reveal that the active site contains three substitutions within and near the active site when compared to it mammalian counterpart, thus opening up the possibility of developing specific inhibitors to the parasite MTAP. The structural and kinetic data for 5 substrates reveal the structural basis for this interaction, providing substract for inteligent design of new compounds for block this enzyme activity. PMID:27935959

  1. Three monoclonal antibodies with specific binding activity to the excretory system of Schistosoma mansoni: an immunoelectron microscopic study using the gold labeling technique.

    Science.gov (United States)

    de Water, R; Fransen, J A; Schut, D W; Deelder, A M

    1987-09-01

    This study describes three monoclonal antibodies against the excretory system of Schistosoma mansoni. Immunofluorescence revealed antigens forming part of the excretory system of cercariae, adult worms, and miracidia, which were located on the luminal membranes of flame and first tubule cells by immunoelectron microscopy. These antigens are either structural components of the membranes or they derive from excretory fluid and are absorbed during transport and ultrafiltration. Binding specificity of the monoclonal antibodies was tested by immunoelectrophoresis and competitive immunofluorescence; one or two antigens were recognized by each. Reactivity of the antigens after treatment with 7.5% trichloroacetic acid or Rossman's fixative demonstrates at least partial polysaccharide content.

  2. The Schistosoma mansoni Cytochrome P450 (CYP3050A1 Is Essential for Worm Survival and Egg Development.

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    Peter D Ziniel

    2015-12-01

    Full Text Available Schistosomiasis affects millions of people in developing countries and is responsible for more than 200,000 deaths annually. Because of toxicity and limited spectrum of activity of alternatives, there is effectively only one drug, praziquantel, available for its treatment. Recent data suggest that drug resistance could soon be a problem. There is therefore the need to identify new drug targets and develop drugs for the treatment of schistosomiasis. Analysis of the Schistosoma mansoni genome sequence for proteins involved in detoxification processes found that it encodes a single cytochrome P450 (CYP450 gene. Here we report that the 1452 bp open reading frame has a characteristic heme-binding region in its catalytic domain with a conserved heme ligating cysteine, a hydrophobic leader sequence present as the membrane interacting region, and overall structural conservation. The highest sequence identity to human CYP450s is 22%. Double stranded RNA (dsRNA silencing of S. mansoni (SmCYP450 in schistosomula results in worm death. Treating larval or adult worms with antifungal azole CYP450 inhibitors results in worm death at low micromolar concentrations. In addition, combinations of SmCYP450-specific dsRNA and miconazole show additive schistosomicidal effects supporting the hypothesis that SmCYP450 is the target of miconazole. Treatment of developing S. mansoni eggs with miconazole results in a dose dependent arrest in embryonic development. Our results indicate that SmCYP450 is essential for worm survival and egg development and validates it as a novel drug target. Preliminary structure-activity relationship suggests that the 1-(2,4-dichlorophenyl-2-(1H-imidazol-1-ylethan-1-ol moiety of miconazole is necessary for activity and that miconazole activity and selectivity could be improved by rational drug design.

  3. Serodiagnosis of Schistosoma mansoni infections in an endemic area of Burkina Faso: performance of several immunological tests with different parasite antigens.

    Science.gov (United States)

    Sorgho, Hermann; Bahgat, Mahmoud; Poda, Jean-Noel; Song, Wenjian; Kirsten, Christa; Doenhoff, Michael J; Zongo, Issaka; Ouédraogo, Jean-Bosco; Ruppel, Andreas

    2005-02-01

    The performance of indirect haemagglutination assays (IHA), enzyme-linked immunosorbent assays (ELISA) and indirect immunofluorescent antibody tests (IFAT) were compared with 450 sera from a Schistosoma mansoni-endemic area in Burkina Faso. All participants in this survey provided at least one sample each of stool, urine and serum. From those with an egg-negative Kato-Katz thick smear, a second stool sample was examined. IHA was based on either extracts of adult S. mansoni worms (SmIHA) or S. japonicum egg antigen (SjIHA). For ELISA, three antigen preparations were used, namely: (i) soluble S. mansoni adult worm antigens (SWAP); (ii) soluble S. mansoni egg antigens (SEA); and (iii) a cationic exchange fraction of S. mansoni eggs (CEF6). IFAT was performed with S. mansoni male worm sections. Among the egg-excretors, the sensitivity of ELISA was high and egg antigens performed slightly better (SEA, 96%; CEF6, 97%) than worm antigen (94%). Sensitivity of IHA was satisfactory with homologous (Sm, >85%), but not heterologous (Sj, 56%) parasite antigen. In IFAT, the parenchyma-associated fluorescence showed high sensitivity (95%), but gut-associated fluorescence, which is known to be a sensitive diagnostic marker for schistosome-infected European travelers, was observed only in 76% of a sub-sample of 100 of the endemic sera. Among sera from egg-negative individuals, many gave positive reactions in several or all of the tests employed. These reactions (formally "false positive") are considered to represent true infections, since chemotherapy had not yet been delivered to this population. For the purpose of further surveys in Burkina Faso or other resource-poor settings, we suggest IHA as an accurate diagnostic test and propose to further improve its performance by including egg rather than worm antigens.

  4. Evolution of sarcoma 180 (ascitic tumor in mice infected with Schistosoma mansoni

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    Fausto Edmundo Lima Pereira

    1986-03-01

    Full Text Available Mice infected with 60 cercariae of Schistosoma mansoni were more resistant to the sarcoma 180 ascites tumor. Tumor inoculation was performed 50 days after schistosoma infection and the animals were observed and weighed at 48 hours intervals for development and progression of malignancy. In infected mice the weight gain (ascites formation started later and was shorter than in uninfected Controls. Also, the number of tumor cells into the peritoneal cavity 72h after tumor implantation was shorter in infected group than incontrols. This in creased resistance against a transplantable tumor probably is related to the effect of endotoxin on tumoricidal activity of macrophages activated by the infection. The immunodepression induced by Schistosoma mansoni infection enhances the proliferation of endogenous bacteria increasing the amount of endotoxin absorbed from the gut.Camundongos infectados com 60 cercárias de Schistosoma mansoni tomaram-se mais resistentes ao sarcoma 180 na forma de tumor ascítico. A inoculação das células tumorais foi feita no 50º dia de infecção e a evolução do tumor foi acompanhada através dapesagem dos animais com intervalos de 48 horas. Nos camundongos infectados o ganho de peso (formação da ascite começou mais tarde e foi menor do que nos controles não infectados. Também o número de células tumorais na cavidade peritoneal 72 horas após a implantação do tumor foi menor no grupo infectado. Este aumento de resistência a um tumor transplantávelpossivelmente está relacionado ao efeito de endotoxinas sobre a atividade tumoricida dos macrofagos ativados pela infecção. A imunossupressão induzida pela infecção favorece a proliferação de bactérias da flora endógena aumentando a quantidade de endotoxinas absorvidas pelo intestino.

  5. Use of monoclonal antibodies prepared against Schistosoma mansoni hatching fluid antigens for demonstration of Schistosoma haematobium circulating egg antigens in urine.

    Science.gov (United States)

    Nibbeling, H A; Kahama, A I; Van Zeyl, R J; Deelder, A M

    1998-05-01

    A panel of 17 monoclonal antibodies (MAbs) against Schistosoma soluble egg antigens (SEAs) was produced from BALB/c mice immunized with antigens secreted/excreted by Schistosoma mansoni eggs. In this study, we demonstrate that 16 MAbs were reactive with S. haematobium SEA in addition to S. mansoni SEA. The MAbs were tested as potential immunodiagnostic reagents in a homologous sandwich ELISA format to detect circulating soluble egg antigens (CSEAs) in serum and urine samples of S. mansoni- or S. haematobium-infected individuals. When samples of S. mansoni-infected individuals were tested, none of these MAbs performed as good as the previously described S. mansoni-specific 114-5B1-A and 114-4D12-A MAbs. However, 11 MAbs (of the IgM isotype) detected CSEA in urine samples of S. haematobium-infected individuals. Three MAbs, 290-2E6-A, 291-3D5-A, and 291-5D5-A, were selected for a pilot study with 47 urine samples of S. haematobium-infected individuals from Kenya. The CSEA levels detected with each of these ELISAs showed a significant correlation with urinary egg counts (Spearman rho > 0.37, P 0.74, P < 0.001). Based on the 92% specificity and 90% sensitivity of the assay, the ELISA using MAb 290-2E6-A was found to be the most promising assay for immunodiagnosis of S. haematobium infections.

  6. The changing pattern of pathology due to Schistosoma mansoni infection

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    Zilton A. Andrade

    1985-09-01

    Full Text Available A survey of the autopsy data on hepatosplenic schistosomiasis during periods, before and after the advent of new chemotherapeutic drugs, revealed that: a the pathological presentation was the same for the two periods; b the number of cases in the last five years is progressively decreasing; c hepatosplenic disease due to schistosomiasis is becoming rare in young people. These data represent a change in the pattern of pathology in schistosomiasis, probably related to new chemotherapy.Uma revisão dos dados de necrópsias realizadas em portadores da forma hépato-esplênica da esquistossomose, feita em dois períodos, antes e após a introdução das novas e efetivas drogas contra o S. mansoni, revelou que: a as lesões encontradas foram qualitativamente as mesmas nos dois períodos; b a percentagem dos casos hépato-esplênicos mostra decréscimo progressivo nos últimos cinco anos do estudo; c os casos de esquistossomose hépato-esplênica estão se tornando raros em jovens. Tais elementos constituem uma mudança no padrão de apresentação da doença, possivelmente relacionada com a introdução da nova quimioterapia curativa.

  7. Changes on Schistosoma mansoni (Digenea: Schistosomatidae worm load in Nectomys squamipes (Rodentia: Sigmodontinae concurrently infected with Echinostoma paraensei (Digenea: Echinostomatidae

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    Arnaldo Maldonado Júnior

    2001-09-01

    Full Text Available The water rat, Nectomys squamipes, closely involved in schistosomiasis transmission in Brazil, has been found naturally infected simultaneously by Schistosoma mansoni and Echinostoma paraensei. Laboratory experiments were conducted to verify parasitic interaction in concurrent infection. It was replicated four times with a total of 42 water rats and essayed two times with 90 mice pre-infected with E. paraensei. Rodents were divided into three groups in each replication. A wild strain recently isolated from Sumidouro, RJ, and a laboratory strain of S. mansoni from Belo Horizonte (BH was used. Rats infected with E. paraensei were challenged 4 weeks later with S. mansoni and mice 2 or 6 weeks after the infection with S. mansoni. Necropsy took place 8 weeks following S. mansoni infection. The N. squamipes treatment groups challenged with S. mansoni RJ strain showed a significant decrease (80 and 65% in the S. mansoni parasite load when compared with their respective control groups. There was a significant change or no change in the hosts challenged with the BH strain. The persistence time of E. paraensei within host was extended in relation to control groups, with a consequent enhancement of the number of recovered worm. An E. paraensei strain-specific influence on S. mansoni parasitism is reported. This paper presents some experimental data about this interaction in N. squamipes and Mus musculus.

  8. Anti-Inflammatory Properties of Menthol and Menthone in Schistosoma mansoni Infection

    Science.gov (United States)

    Zaia, Mauricio G.; Cagnazzo, Túlio di Orlando; Feitosa, Karina A.; Soares, Edson G.; Faccioli, Lúcia H.; Allegretti, Silmara M.; Afonso, Ana; Anibal, Fernanda de Freitas

    2016-01-01

    Schistosomiasis is a parasitic disease caused by several species of trematode worms and it is believed that more than 261 million people are affected worldwide. New drug development has become essential because there is a risk of the parasite becoming resistant to Praziquantel, the only drug available for this infection. This study evaluated parasitological, immunological and histological parameters in mice infected with Schistosoma mansoni and treated with an herbal commercial medicine. This drug consists of menthol (30–55%) and menthone (14–32%). A 60 day treatment regimen with the herbal medicine decreased the number of S. mansoni eggs in the feces, liver, and intestine and reduced the number of hepatic granulomas. We observed a reduction of 84% in blood eosinophilia and a decrease in the IL-4 and IL-10 blood levels after treatment. Therefore, we propose that schistosomiasis treatment with this herbal medicine for 60 days has an immunomodulatory and anti-inflammatory action in this animal model for schistosomiasis thus contributing to the decrease in physio pathological effects caused by S. mansoni infection. PMID:27378927

  9. Comparison of Schistosoma mansoni soluble cercarial antigens and soluble egg antigens for serodiagnosing schistosome infections.

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    Huw Smith

    Full Text Available A Schistosoma mansoni cercarial antigen preparation (cercarial transformation fluid--SmCTF was evaluated for detection of anti-schistosome antibodies in human sera in 4 collaborating laboratories. The performance of SmCTF was compared with that of S. mansoni egg antigens (SmSEA in an indirect enzyme-immunoassay (ELISA antigen assay, the latter being used routinely in 3 of the 4 participating laboratories to diagnose S. mansoni and S. haematobium infections. In the fourth laboratory the performance of SmCTF was compared with that of S. japonicum egg antigens (SjSEA in ELISA for detection of anti-S. japonicum antibodies. In all 4 laboratories the results given by SmCTF in ELISA were very similar to those given by the antigen preparation routinely used in the respective laboratory to detect anti-schistosome antibodies in human infection sera. In so far as the ELISA results from SmCTF are thus so little different from those given by schistosome egg antigens and also cheaper to produce, the former is a potentially useful new diagnostic aid for schistosomiasis.

  10. Predicting the spatial distribution of Biomphalaria straminea, a potential intermediate host for Schistosoma mansoni, in China

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    Mohamed R. Habib

    2016-11-01

    Full Text Available Schistosomiasis is one of the most prevalent parasitic diseases impacting human health in the tropics and sub-tropics. The geographic distribution of Schistosoma mansoni, the most widespread species, includes areas in Africa, the Middle East, South America and the Caribbean. Snails of the genus Biomphalaria act as intermediate host for S. mansoni. Biomphalaria straminea is not indigenous in China but was accidentally introduced to Hong Kong from South America and has spread to other habitats in the southern parts of the country. This species is known for its great dispersal capacity that highlights the importance of the snail as a potential host for S. mansoni in China. In this connection, although no such infection has been recorded in the field so far, the continuous expansion of China’s projects in endemic areas of Africa and import of the infection via returning workers or visitors deserve attention. The purpose of this study was to map and predict the spatial distribution of B. straminea in China. Snail occurrence data were assembled and investigated using MaxEnt software, along with climatic and environmental variables to produce a predictive risk map. Of the environmental variables tested, the precipitation of warmest quarter was the most contribution factor for snail’s spatial distribution. Risk areas were found in southeastern China and it is expected that they will guide policies and control programmes to potential areas area of snail abundance and used for spatial targeting of control interventions for this invasive species.

  11. Therapeutic Effects of Allium sativum and Allium cepa in Schistosoma mansoni experimental infection

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    Mona Mohamed Mantawy

    2011-06-01

    Full Text Available The effects of both garlic (Allium sativum and onion (Allium cepa on some biochemical parameters in Schistosoma mansoni infected mice individually and mixed either with or without the currently used drug, praziquantel (PZQ were investigated. These involved some immunological parameters, namely IgM, IgG, interleukins 2 and 6 (IL-2 and 6 and tumor necrosis factor (TNF-α, some antioxidant enzymes [catalase, superoxide dismutase (SOD and glutathione peroxidase (GPX]. In addition, parasitological and histopathological investigations were performed. No changes were observed in the normal control mice treated with dry extract of onion or garlic, individually or mixed, with or without PZQ, compared to the normal healthy control group. Infection with S. mansoni showed an increase in IgG, IgM, IL-2, IL-6, TNF-α and catalase enzyme, accompanied with a decrease in GPX and SOD antioxidant enzyme activities. Remarkable amelioration was noticed in the levels of all the measured parameters in S. mansoni infected mice after administration of the studied extracts. Moreover a significant reduction in worm burden, hepatic and intestinal eggs and oogram count was noticed which was reflected in normalization of liver architecture.

  12. Anti-Inflammatory Properties of Menthol and Menthone in Schistosoma mansoni Infection.

    Science.gov (United States)

    Zaia, Mauricio G; Cagnazzo, Túlio di Orlando; Feitosa, Karina A; Soares, Edson G; Faccioli, Lúcia H; Allegretti, Silmara M; Afonso, Ana; Anibal, Fernanda de Freitas

    2016-01-01

    Schistosomiasis is a parasitic disease caused by several species of trematode worms and it is believed that more than 261 million people are affected worldwide. New drug development has become essential because there is a risk of the parasite becoming resistant to Praziquantel, the only drug available for this infection. This study evaluated parasitological, immunological and histological parameters in mice infected with Schistosoma mansoni and treated with an herbal commercial medicine. This drug consists of menthol (30-55%) and menthone (14-32%). A 60 day treatment regimen with the herbal medicine decreased the number of S. mansoni eggs in the feces, liver, and intestine and reduced the number of hepatic granulomas. We observed a reduction of 84% in blood eosinophilia and a decrease in the IL-4 and IL-10 blood levels after treatment. Therefore, we propose that schistosomiasis treatment with this herbal medicine for 60 days has an immunomodulatory and anti-inflammatory action in this animal model for schistosomiasis thus contributing to the decrease in physio pathological effects caused by S. mansoni infection.

  13. Development of Schistosoma mansoni in Biomphalaria tenagophila, Biomphalaria straminea and Biomphalaria glabrata Desenvolvimento do Schistosoma mansoni em Biomphalaria tenagophila, Biomphalaria straminea e Biomphalaria glabrata

    Directory of Open Access Journals (Sweden)

    Cecilia Pereira de Souza

    1995-06-01

    Full Text Available A comparative study of the development of Schistosoma mansoni during the intra-molluscan phase was made by means of histological sections of Biomphalaria tenagophila, B. straminea and B. glabrata from Brazil. Two hundred snails of each species were individually exposed to 50 miracidia of the S. mansoni, AL line. No larvae were observed in the snails fixed 72 h after exposure. In specimens shedding cercariae, 31 days after exposure tissue reactions encapsulating the larvae were seen in B. tenagophila and B. straminea, in the head-foot, mantle collar and renal ducts. No tissue reactions occurred in the digestive glands of these two species. In B. glabrata the presence of numerous sporocysts and cercariae without tissue reactions was observed in the digestive gland, and other organs. The levels of infection of the snails and the average numbers of cercariae shed per day were 32.6% and 79±90 respectively for B. tenagophila, 11.3% and 112±100 for B. straminea and 75.3% and 432±436 for B. glabrata. The lower levels of infection and average numbers of cercariae shed by B. tenagophila and B. straminea are thus related to their more potent internal defense systems.Foi feito estudo comparativo do desenvolvimento do Schistosoma mansoni na fase intra-molusco, através de cortes histológicos, em Biomphalaria tenagophila, B. straminea e B. glabrata. Duzentos moluscos de cada espécie foram expostos individualmente a 50 miracídios de S. mansoni da linhagem AL. Nenhuma larva foi observada nos exemplares fixados 72 horas após a exposição. Nos exemplares eliminando cercárías, 31 dias após a exposição, foram observadas reações teciduais de encapsulamento de larvas em B. tenagophila e B. straminea, na região cefalopodal, colar do manto e dutos renais. Nas glândulas digestivas das duas espécies não foram observadas reações. Em B. glabrata foi registrada a presença de numerosos esporocistos e cercárias sem reação tecidual na gl

  14. Susceptibility of Argentinean Biomphalaria tenagophila and Biomphalaria straminea to infection by Schistosoma mansoni and the possibility of geographic expansion of mansoni schistosomiasis

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    Luciana Franceschi Simoes

    2013-10-01

    Full Text Available Introduction Human migration and the presence of natural vectors (mollusks of Schistosoma mansoni are the primary causes of the expansion of mansoni schistosomiasis into southern areas of South America. Water conditions are favorable for the expansion of this disease because of the extensive hydrographic network, which includes the basins of the Paraná and Uruguay rivers and favors mollusk reproduction. These rivers also aid agriculture and tourism in the area. Despite these favorable conditions, natural infection by S. mansoni has not yet been reported in Argentina, Uruguay, or Paraguay. Methods Two species of planorbid from Argentina, Biomphalaria straminea and B. tenagophila, were exposed to the miracidia of five Brazilian strains of S. mansoni. Results Biomphalaria tenagophila (Atalaya, Buenos Aires province was infected with the SJS strain (infection rate 3.3%, confirming the experimental susceptibility of this Argentinian species. Biomphalaria straminea (Rio Santa Lucía, Corrientes province was susceptible to two Brazilian strains: SJS (infection rate 6.7% and Sergipe (infection rate 6.7%. Conclusions These results demonstrate that species from Argentina have the potential to be natural hosts of S. mansoni and that the appearance of foci of mansoni schistosomiasis in Argentina is possible.

  15. "In vivo" leukocyte chemotaxis in experimental mice Schistosoma mansoni infection Quimiotaxia de leucócitos "in vivo" na infecção experimental por Schistosoma mansoni

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    Kirte Maria Teixeira

    1994-06-01

    Full Text Available The "in vivo" chemotaxis was studied in C57B1/10 mice 10, 30, 50 and 60 days after a Schistosoma mansoni infection in comparison to a control group (uninfected mice. Staphylococcal protein A was injected into a connective tissue air pouch of control and experimental mice and the leukocyte chemotaxis was counted. A decrease in polymorphonuclear (PMN leukocyte response was found in infected mice in comparison to the control group (pA quimiotaxia de leucócitos "in vivo" foi avaliada em camundongos da linhagem C57B1/10 e estudada 10, 30, 50 e 60 dias após a infecção por Schistosoma mansoni. A proteína A foi utilizada como quimiotático e injetada no tecido conjuntivo no dorso dos camundongos dos grupos experimentais e controle. Nos grupos experimentais foi observado uma diminuição na resposta dos leucócitos polimorfonucleares (PMN em comparação com o grupo controle (p<0.05. Os camundongos estudados 10 dias após a infecção, mostraram uma diminuição na resposta quimiotática de leucócitos PMN, comparando com o grupo controle (p<0.05 e este dado tornou-se mais evidente nos grupos experimentais estudados 30 e 50 dias após a infecção. Apesar da resposta quimiotática dos leucócitos PMN nos camundongos estudados 60 dias após a infecção aumentarem em comparação aos animais analisados 50 dias após a infecção, este aumento foi bem menor em relação ao grupo controle. A resposta quimiotática dos mononucleares não apresentou diferença significativa entre camundongos experimentais e controles

  16. Oogram studies in mice infected with Schistosoma mansoni and treated with dexamethasone Oograma em camundongos infectados com Schistosoma mansoni e tratados com dexametasona

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    Marco Victor Hermeto

    1994-04-01

    Full Text Available Mice infected with about 90 cercariae of Schistosoma mansoni (LE strain were treated during five consecutive days with dexamethasone (50 mg/Kg, subcutaneously, starting on the 42th day of infection. Groups of five mice were then daily sacrificed from the first day after onset of treatment until the first day after. The perfusion of the portal system was performed and a piece of the intestine was processed for qualitative and quantitative oograms. This treatment carries to larger numbers of eggs in the tissues of treated mice, when compared with untreated groups. No changes were observed in the kinetics of oviposition, as all stages of viable eggs were observed in the tissues of treated and control mice. These data reinforce the hypothesis of a partial blockade of the egg excretion in immunossupressed mice.Camundongos infectados com cerca de 90 cercárias da cepa LE de Schistosoma mansoni foram tratados durante 5 dias consecutivos com dexametasona (50mg/ Kg, subcutaneamente a partir do 42º dia de infecção. Grupos de cinco camundongos foram sacrificados diariamente após o primeiro dia do início do tratamento até o primeiro dia após o término. A perfusão do sistema porta foi feita e fragmentos do intestino foram processados para a realização de oogramas qualitativos e quantitativos. O tratamento leva a um maior número de ovos nos tecidos dos camundongos tratados, se comparado com os grupos não tratados. Nenhuma mudança foi observada na cinética de oviposição, e ovos viáveis em todos os estádios evolutivos foram observados nos tecidos de camundongos tratados e controles. Estes dados reforçam a hipótese de um bloqueio parcial na saída de ovos dos tecidos do intestino para o lúmem intestinal em camundongos imunossuprimidos.

  17. Excretion of fluorescent substrates of mammalian multidrug resistance-associated protein (MRP) in the Schistosoma mansoni excretory system.

    Science.gov (United States)

    Sato, H; Kusel, J R; Thornhill, J

    2004-01-01

    The protonephridium of platyhelminths including Schistosoma mansoni plays a pivotal role in their survival by excretion of metabolic wastes as well as xenobiotics, and can be revealed in the living adult parasite by certain fluorescent compounds which are concentrated in excretory tubules and collecting ducts. To determine the presence of the multidrug resistance-associated protein (MRP) as a possible transporter in protonephridial epithelium, adult schistosomes were exposed to a fluorescent Ca2+ indicator, fluo-3 acetyloxymethyl ester, which is a potential substrate of mammalian MRP. Specific fluorescence related to fluo-3/Ca2+ chelate delineated the whole length of the protonephridial system. Simultaneously, a fluorescent substance was accumulated in the posterior part of collecting ducts and the excretory bladder. Similarly, when other fluorogenic substrates for mammalian MRP such as monoclorobimane, fluorescein diacetate, and 5(6)-carboxyfluorescein diacetate were applied to adult schistosomes, these fluorescent markers were observed in the excretory tubules through to the excretory bladder. The excretory system of mechanically-transformed schistosomula was not labelled with any of these 4 fluorescent markers. These findings suggest that the protonephridial epithelium of adult schistosomes, but not schistosomula, might express the homologue of the mammalian MRP transporting organic anionic conjugates with glutathione, glucuronate or sulphate as well as unconjugated amphiphilic organic anions.

  18. Disposition of mefloquine and enpiroline is highly influenced by a chronic Schistosoma mansoni infection.

    Science.gov (United States)

    Ingram, Katrin; Duthaler, Urs; Vargas, Mireille; Ellis, William; Keiser, Jennifer

    2013-09-01

    Chronic Schistosoma mansoni infections lead to severe tissue destruction of the gut wall and liver and can influence drug disposition. This study aimed to investigate the impact of a chronic S. mansoni infection on the pharmacokinetic (PK) parameters of two promising antischistosomal lead candidates (mefloquine and enpiroline) in mice. Studies were conducted in two different mouse cohorts (S. mansoni-infected and uninfected mice) for both drugs. Plasma samples were collected at various time points after oral treatment (200 mg/kg of body weight) with study drugs. A high-performance liquid chromatography (HPLC) method was validated to analyze enpiroline and mefloquine in plasma. Livers and intestines were collected from infected animals to determine the onset of action, hepatic shift, and worm burden reduction. Following mefloquine administration, hepatic shifting and significant worm burden reductions (79.2%) were observed after 72 h. At 1 week posttreatment with enpiroline, the majority of worms had migrated to the liver and significant worm burden reductions were observed (93.1%). The HPLC method was selective, accurate (87.8 to 111.4%), and precise (mefloquine, with a 5-fold increase of t1/2 (182.7 h versus 33.6 h) and 2-fold increase of AUC (1,116,517.8 ng · h/ml versus 522,409.1 ng · h/ml). S. mansoni infections in mice influence the PK profiles of enpiroline and mefloquine, leading to delayed clearance. Our data confirm that drug disposition should be carefully studied in schistosomiasis patients.

  19. The dendritic cell-specific C-type lectin DC-SIGN is a receptor for Schistosoma mansoni egg antigens and recognizes the glycan antigen Lewis x.

    NARCIS (Netherlands)

    Die, van I.M.; Vliet, van SJ; Nyame, AK; Cummings, RD; Bank, CM; Appelmelk, B.J.; Geijtenbeek, T.B.H.; Kooijk, van Y.

    2003-01-01

    Schistosoma mansoni soluble egg antigens (SEAs) are crucially involved in modulating the host immune response to infection by S. mansoni. We report that human dendritic cells bind SEAs through the C-type lectin dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN). Monoclonal antibodies agai

  20. Long-term effect of mass chemotherapy, transmission and risk factors for Schistosoma mansoni infection in very low endemic communities of Venezuela

    NARCIS (Netherlands)

    Hofstede, Stefanie N.; Tami, Adriana; van Liere, Genevieve A. F. S.; Ballen, Diana; Incani, Renzo N.

    2014-01-01

    The prevalence of Schistosoma mansoni infection in Venezuela has changed from high to low due mostly to successful control activities, including mass chemotherapy and molluscicide applications. This study examined the impact of mass chemotherapy on S. mansoni transmission and risk factors for infect

  1. Biodistribution study of the anesthetic sodium phenobarbital labelled with technetium-99 in swiss mice infected with Schistosoma mansoni Sambon, 1907

    Energy Technology Data Exchange (ETDEWEB)

    Simoes, Susana Balmant Emerique; Machado Silva, Jose Roberto [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Faculdade de Ciencias Medicas. Dept. de Patologia e Laboratorios; Gutfilen, Bianca; Oliveira, Marcia Betania; Bernardo Filho, Mario [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia. Dept. de Biofisica e Biometria; Presgrave, Otavio Augusto Franca [Fundacao Inst. Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Inst. Nacional de de Controle de Qaulidade em Saude. Dept. de Farmacologia e Toxicologia

    1997-09-01

    Technetium-99 m ({sup 99m} Tc) is a radionuclide that has negligible environmental impact, is easily available, inexpensive and can be used as a radioactive tracer in biological experiences. In order to know the mode of action of sodium phenobarbital in moving adult Schistosoma mansoni worms from mesenteric veins to the liver, we labelled sodium phenobarbital (PBBT) with {sup 99m} Tc and a biodistribution study in infected and non-infected Swiss mice was performed. The PBBT was incubated with stannous chloride used as reducing agent and with {sup 99m} Tc, as sodium pertechnetate. The radioactivity labelling(%) was determined by paper ascending chromatography performed with acetone (solvent). The{sup 99m} Tc-PBBT was administered by intraperitoneal route to Swiss mice infected eight weeks before. The animals were perfused after different periods of time (0,1,2,3,4 hr) when blood, spleen, liver, portal vein, mesenteric veins, stomach, kidneys and adult worms were isolated. The radioactivity present in these samples was counted in a well counter and the percentage was determined. THe radioactivity was mainly taken up by the blood, kidney, liver and spleen. No radioactivity was found on the adult worms. We concluded that the worm shift was due to an action on the host of the sodium phenobarbital. (author) 24 refs., 3 tabs.

  2. Schistogram changes after administration of antischistosomal drugs in mice at the early phase of Schistosoma mansoni infection

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    Andrea Cassia Simoes Vimieiro

    2013-11-01

    Full Text Available Mice infected with Schistosoma mansoni were treated with oxamniquine, praziquantel, artesunate at the pre-patent phase, aiming at observing schistogram alterations. Half of the animals were perfused five days post-treatment for counting and classification of immature worms, based on pre-established morphological criteria (schistogram; the remaining animals were evaluated 42 or 100 days after infection and perfusion of the portal-system was performed for collection and counting of adult worms and oogram. It was observed that oxamniquine and artesunate treatment administered at the pre-postural phase causes significant reduction in the number of immature and adult worms. However, there was little reduction with praziquantel when used at the dose of 400 mg/kg for treatments administered 14, 15, 21 or 23 days post-infection. Artesunate was responsible for significant alterations in development of young worms, as well as for a higher number of worms presenting intestinal damages. Immature adult worms were detected in mice treated with artesunate or oxamniquine at the pre-patent phase of infection and recovered by perfusion 100 days after infection. Schistogram proved to be a very useful tool for experimental evaluation of the activity of antischistosomal drugs and a good model to identify the most sensitive stages to drugs.

  3. Cloning of a cDNA encoding a surface antigen of Schistosoma mansoni schistosomula recognized by sera of vassinated mice

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    Dalton, J.P.; Tom, T.D.; Strand, M.

    1987-06-01

    Spleen cells of mice vaccinated with radiation-attenuated Schistosoma mansoni cercariae were used to produce monoclonal antibodies directed against newly transformed schistosomular surface antigens. One of these monoclonal antibodies recognized a polypeptide of 18 kDa. Binding was measured by radioimmunoassay. This glycoprotein was purified by monoclonal antibody immunoaffinity chromatography and a polyclonal antiserum was prepared against it. Immunofluorescence assays showed that the polyclonal antiserum bound to the surface of newly transformed schistosomula and lung-stage organisms but not to the surface of liver-stage and adult worms. Using this polyclonal antiserum we isolated recombinant clones from an adult worm cDNA expression library constructed in lambdagt11. Clone 654.2 contained an insert of 0.52 kilobase and hybridized to a 1.2-kilobase mRNA species from adult worms. Most importantly, clone 654.2 produced a fusion protein of 125 kDa that was reactive with sera of vaccinated mice that are capable of transferring resistance. This result encourages future vaccination trials with the fusion protein.

  4. Additional Evaluation of the Point-of-Contact Circulating Cathodic Antigen Assay for Schistosoma mansoni Infection

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    Pauline N.M. Mwinzi

    2015-03-01

    Full Text Available Studies of the urine-based point-of-contact Cathodic Circulating Antigen test (POC-CCA in S. mansoni-endemic settings in Africa indicate it has good sensitivity in detecting infections, but in areas of low prevalence, the POC-CCA can be positive for persons who are egg-negative by Kato-Katz stool assays. We examined the POC-CCA assay for: a batch- to-batch stability; b intra-reader and inter-reader variability; c day-to-day variability compared to Kato-Katz stool assays, and d to see if praziquantel (PZQ treatment converted Kato-Katz-negative/POC-CCA positive individuals to POC-CCA negativity. We found essentially no batch-to-batch variation, negligible intra-reader variability (2% and substantial agreement for inter-reader reliability. Some day-to-day variation was observed over 5 days of urine collection, but less than the variation in Kato-Katz stool assays over 3 days. To evaluate the effect of treatment on Kato-Katz(- /POC-CCA(+ children, 149 children in an area of 10-15% prevalence who were Kato-Katz(- based on 3 stool samples but POC-CCA(+ were enrolled. Seven days after treatment (PZQ 40mg/kg samples were again collected and tested. Almost half (47% POC-CCA positive children turned negative. Those still POC-CCA positive received a second treatment, and 34% of them turned POC-CCA negative upon this second treatment. Most who remained POC-CCA positive shifted each time to a lesser POC-CCA level of positivity. The data suggest that most Kato-Katz-negative/POC-CCA positive individuals harbor low intensity infections, and each treatment kills all or some of their adult worms. The data also suggest that when evaluated by a more sensitive assay, the effective cure rates for PZQ are significantly less than those inferred from fecal testing. These findings have public health significance for the mapping and monitoring of Schistosoma infections and in planning the transition from schistosomiasis morbidity control to elimination of transmission.

  5. Characterization of SR3 reveals abundance of non-LTR retrotransposons of the RTE clade in the genome of the human blood fluke, Schistosoma mansoni

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    Brindley Paul J

    2005-11-01

    Full Text Available Abstract Background It is becoming apparent that perhaps as much as half of the genome of the human blood fluke Schistosoma mansoni is constituted of mobile genetic element-related sequences. Non-long terminal repeat (LTR retrotransposons, related to the LINE elements of mammals, comprise much of this repetitive component of the schistosome genome. Of more than 12 recognized clades of non-LTR retrotransposons, only members of the CR1, RTE, and R2 clades have been reported from the schistosome genome. Results Inspection of the nucleotide sequence of bacterial artificial chromosome number 49_J_14 from chromosome 1 of the genome of Schistosoma mansoni (GenBank AC093105 revealed the likely presence of several RTE-like retrotransposons. Among these, a new non-LTR retrotransposon designated SR3 was identified and is characterized here. Analysis of gene structure and phylogenetic analysis of both the reverse transcriptase and endonuclease domains of the mobile element indicated that SR3 represented a new family of RTE-like non-LTR retrotransposons. Remarkably, two full-length copies of SR3-like elements were present in BAC 49-J-14, and one of 3,211 bp in length appeared to be intact, indicating SR3 to be an active non-LTR retrotransposon. Both were flanked by target site duplications of 10–12 bp. Southern hybridization and bioinformatics analyses indicated the presence of numerous copies (probably >1,000 of SR3 interspersed throughout the genome of S. mansoni. Bioinformatics analyses also revealed SR3 to be transcribed in both larval and adult developmental stages of S. mansoni and to be also present in the genomes of the other major schistosome parasites of humans, Schistosoma haematobium and S. japonicum. Conclusion Numerous copies of SR3, a novel non-LTR retrotransposon of the RTE clade are present in the genome of S. mansoni. Non-LTR retrotransposons of the RTE clade including SR3 appear to have been remarkably successful in colonizing, and

  6. Micro-geographical heterogeneity in Schistosoma mansoni and S. haematobium infection and morbidity in a co-endemic community in northern Senegal.

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    Lynn Meurs

    Full Text Available BACKGROUND: Schistosoma mansoni and S. haematobium are co-endemic in many areas in Africa. Yet, little is known about the micro-geographical distribution of these two infections or associated disease within such foci. Such knowledge could give important insights into the drivers of infection and disease and as such better tailor schistosomiasis control and elimination efforts. METHODOLOGY: In a co-endemic farming community in northern Senegal (346 children (0-19 y and 253 adults (20-85 y; n = 599 in total, we studied the spatial distribution of S. mansoni and S. haematobium single and mixed infections (by microscopy, S. mansoni-specific hepatic fibrosis, S. haematobium-specific urinary tract morbidity (by ultrasound and water contact behavior (by questionnaire. The Kulldorff's scan statistic was used to detect spatial clusters of infection and morbidity, adjusted for the spatial distribution of gender and age. PRINCIPAL FINDINGS: Schistosoma mansoni and S. haematobium infection densities clustered in different sections of the community (p = 0.002 and p = 0.023, respectively, possibly related to heterogeneities in the use of different water contact sites. While the distribution of urinary tract morbidity was homogeneous, a strong geospatial cluster was found for severe hepatic fibrosis (p = 0.001. Particularly those people living adjacent to the most frequently used water contact site were more at risk for more advanced morbidity (RR = 6.3; p = 0.043. CONCLUSIONS/SIGNIFICANCE: Schistosoma infection and associated disease showed important micro-geographical heterogeneities with divergent patterns for S. mansoni and S. haematobium in this Senegalese community. Further in depth investigations are needed to confirm and explain our observations. The present study indicates that local geospatial patterns should be taken into account in both research and control of schistosomiasis. The observed extreme focality of schistosomiasis even at community level

  7. Sequencing and identification of expressed Schistosoma mansoni genes by random selection of cDNA clones from a directional library

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    Glória R. Franco

    1995-04-01

    Full Text Available We have initiated a gene discovery program in Schistosoma mansoni based on the technique of Expressed Sequence Tags (ESTs, i.e. partial sequences of cDNAs obtained from single passes in automatic DNA sequencers. ESTs can be used to identify genese onf the basis of their homology whith sequences from other species deposited in DNA or protein databases. Trasncripts with sequences without matches in teh databases may represent novel parasite-specific genes. This approach has shown to be very efficient and in less than two years a broad range of novel genes has already been ascertained, more than doubling the number of known S. mansoni genes.

  8. Susceptibility of Biomphalaria tenagophila and Biomphalaria straminea to Schistosoma mansoni infection detected by low stringency polymerase chain reaction

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    JANNOTTI-PASSOS Liana Konovaloff

    2000-01-01

    Full Text Available In order to determine Schistosoma mansoni infection rates in Biomphalaria tenagophila and B. straminea, low stringency polymerase chain reaction (LS-PCR technique was used as a complementary method to light exposure technique. LS-PCR has already been standardized in our laboratory to detect the trematode DNA in B. glabrata. Higher S. mansoni infection rates were detected using conventional method and LS-PCR. The parasite DNA profile was detected in both species after 7-day exposure to miracidia, using LS-PCR. This technique enables early detection of schistosomiasis transmission focuses, in endemic areas, before the beginning of cercariae shedding.

  9. [Hypocomplementary membrano-proliferative glomerulonephritis in a Malagasy patient with schistosomiasis mansoni (detection of bilharzial antigen on glomerular basement membrane using monoclonal antibodies)].

    Science.gov (United States)

    Rajaonarivelo, P; Rajaona, H R; Alix, J L; Couderc, P; Daveau, C; Santoro, F; Nogueira-Quetroz, J A; Lovens, M; Capron, A; Cordonnier, D

    1986-01-01

    Schistosomiasis due to Schistosoma mansoni affects more than 40 millions people all over the world. Renal involvement is observed mainly in endemic areas. We report a case of hypocomplementemic membrano-proliferative glomerulonephritis in a malagasy man who suffered also from hepatosplenic bilharziosis. The relation between Schistosoma mansoni and the nephropathy was proved by indirect immunofluorescence test using a monoclonal antibody directed against the caecum of adult Schistosoma mansoni.

  10. Purification and characterization of an elastinolytic proteinase secreted by cercariae of Schistosoma mansoni.

    Science.gov (United States)

    McKerrow, J H; Pino-Heiss, S; Lindquist, R; Werb, Z

    1985-03-25

    An elastinolytic proteinase secreted by tissue-invasive larvae of Schistosoma mansoni has been purified to homogeneity. Size-exclusion chromatography and chromatofocusing were used to purify the enzyme 18-fold from crude larval secretions. The native enzyme has a molecular weight of 30,000, a pI of 8, a pH optimum of 9, and a calcium dependence of 2 mM. A second Mr 17,000 form of the enzyme was present in crude secretions and appears to be an autoproteolysis product. The enzyme is a serine proteinase that preferentially binds tetrapeptide inhibitors or substrates with an aromatic or hydrophobic residue at the P-1 site. In addition to being active against elastin, the enzyme degrades Azocoll, gelatin, laminin, fibronectin, keratin, and type IV collagen.

  11. Garlic attenuates histological and histochemical alterations in livers of Schistosoma mansoni infected mice.

    Science.gov (United States)

    Mahmoud, Y I; Riad, N H; Taha, H

    2016-08-01

    Interest in screening for new anti-schistosomal agents is growing because of increased concerns about resistance to and safety of praziquantel. We investigated the anti-schistosomal action of prophylactic and therapeutic doses of garlic on the histological and histochemical alterations caused by Schistosoma mansoni infection. Livers of infected mice were characterized by granulomas, periportal inflammation and fibrosis, hepatocyte vacuolation, fatty degeneration and necrosis, and hypertrophy and pigmentation of Kupffer cells. Significant depletion of carbohydrates and increased lipid vacuoles also were observed. All garlic regimens caused suppression of granuloma formation and amelioration of histological and histochemical changes; the continuous treatment protocol produced the best results. Garlic appears to be a safe and economical anti-schistosomal adjuvant for attenuating the pathogenicity of schistosomiasis.

  12. Morfologia e desenvolvimento de Schistosoma mansoni Sambon, 1907 em infecções unissexuais experimentalmente produzidas no camundongo Morphology and development of Schistosoma mansoni Sambon, 1907 in unisexual infections produced experimentally in mice

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    Eliana Maria Zanotti

    1982-04-01

    Full Text Available Estudou-se o desenvolvimento de Schistosoma mansoni em infecções unissexuais no camundongo. Os esquistossomos fêmeos apresentaram-se menos desenvolvidos do que os machos. Houve correlação entre o comprimento dos machos e o número de testículos. Verificou-se que o isolamento sexual é prejudicial aos dois sexos, principalmente à fêmea.The Schistosoma mansoni development in mice submitted to unisexual infections was studied. The single female worms developed less than the single males. There was correlation between the male's length and the number of his tests. It was verified that sexual isolation of the schistosomes is prejudicial to both sexes, mainly for the female.

  13. A directed approach for the identification of transcripts harbouring the spliced leader sequence and the effect of trans-splicing knockdown in Schistosoma mansoni

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    Marina de Moraes Mourao

    2013-09-01

    Full Text Available Schistosomiasis is a major neglected tropical disease caused by trematodes from the genus Schistosoma. Because schistosomes exhibit a complex life cycle and numerous mechanisms for regulating gene expression, it is believed that spliced leader (SL trans-splicing could play an important role in the biology of these parasites. The purpose of this study was to investigate the function of trans-splicing in Schistosoma mansoni through analysis of genes that may be regulated by this mechanism and via silencing SL-containing transcripts through RNA interference. Here, we report our analysis of SL transcript-enriched cDNA libraries from different S. mansoni life stages. Our results show that the trans-splicing mechanism is apparently not associated with specific genes, subcellular localisations or life stages. In cross-species comparisons, even though the sets of genes that are subject to SL trans-splicing regulation appear to differ between organisms, several commonly shared orthologues were observed. Knockdown of trans-spliced transcripts in sporocysts resulted in a systemic reduction of the expression levels of all tested trans-spliced transcripts; however, the only phenotypic effect observed was diminished larval size. Further studies involving the findings from this work will provide new insights into the role of trans-splicing in the biology of S. mansoni and other organisms. All Expressed Sequence Tags generated in this study were submitted to dbEST as five different libraries. The accessions for each library and for the individual sequences are as follows: (i adult worms of mixed sexes (LIBEST_027999: JZ139310 - JZ139779, (ii female adult worms (LIBEST_028000: JZ139780 - JZ140379, (iii male adult worms (LIBEST_028001: JZ140380 - JZ141002, (iv eggs (LIBEST_028002: JZ141003 - JZ141497 and (v schistosomula (LIBEST_028003: JZ141498 - JZ141974.

  14. The diterpenoid 7-keto-sempervirol, derived from Lycium chinense, displays anthelmintic activity against both Schistosoma mansoni and Fasciola hepatica.

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    Jennifer Edwards

    2015-03-01

    Full Text Available BACKGROUND: Two platyhelminths of biomedical and commercial significance are Schistosoma mansoni (blood fluke and Fasciola hepatica (liver fluke. These related trematodes are responsible for the chronic neglected tropical diseases schistosomiasis and fascioliasis, respectively. As no vaccine is currently available for anti-flukicidal immunoprophylaxis, current treatment is mediated by mono-chemical chemotherapy in the form of mass drug administration (MDA (praziquantel for schistosomiasis or drenching (triclabendazole for fascioliasis programmes. This overreliance on single chemotherapeutic classes has dramatically limited the number of novel chemical entities entering anthelmintic drug discovery pipelines, raising significant concerns for the future of sustainable blood and liver fluke control. METHODOLOGY/ PRINCIPLE FINDINGS: Here we demonstrate that 7-keto-sempervirol, a diterpenoid isolated from Lycium chinense, has dual anthelmintic activity against related S. mansoni and F. hepatica trematodes. Using a microtiter plate-based helminth fluorescent bioassay (HFB, this activity is specific (Therapeutic index = 4.2, when compared to HepG2 cell lines and moderately potent (LD50 = 19.1 μM against S. mansoni schistosomula cultured in vitro. This anti-schistosomula effect translates into activity against both adult male and female schistosomes cultured in vitro where 7-keto-sempervirol negatively affects motility/behaviour, surface architecture (inducing tegumental holes, tubercle swelling and spine loss/shortening, oviposition rates and egg morphology. As assessed by the HFB and microscopic phenotypic scoring matrices, 7-keto-sempervirol also effectively kills in vitro cultured F. hepatica newly excysted juveniles (NEJs, LD50 = 17.7 μM. Scanning electron microscopy (SEM evaluation of adult F. hepatica liver flukes co-cultured in vitro with 7-keto-sempervirol additionally demonstrates phenotypic abnormalities including breaches in tegumental

  15. The Schistosoma mansoni phylome: using evolutionary genomics to gain insight into a parasite’s biology

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    Silva Larissa

    2012-11-01

    Full Text Available Abstract Background Schistosoma mansoni is one of the causative agents of schistosomiasis, a neglected tropical disease that affects about 237 million people worldwide. Despite recent efforts, we still lack a general understanding of the relevant host-parasite interactions, and the possible treatments are limited by the emergence of resistant strains and the absence of a vaccine. The S. mansoni genome was completely sequenced and still under continuous annotation. Nevertheless, more than 45% of the encoded proteins remain without experimental characterization or even functional prediction. To improve our knowledge regarding the biology of this parasite, we conducted a proteome-wide evolutionary analysis to provide a broad view of the S. mansoni’s proteome evolution and to improve its functional annotation. Results Using a phylogenomic approach, we reconstructed the S. mansoni phylome, which comprises the evolutionary histories of all parasite proteins and their homologs across 12 other organisms. The analysis of a total of 7,964 phylogenies allowed a deeper understanding of genomic complexity and evolutionary adaptations to a parasitic lifestyle. In particular, the identification of lineage-specific gene duplications pointed to the diversification of several protein families that are relevant for host-parasite interaction, including proteases, tetraspanins, fucosyltransferases, venom allergen-like proteins, and tegumental-allergen-like proteins. In addition to the evolutionary knowledge, the phylome data enabled us to automatically re-annotate 3,451 proteins through a phylogenetic-based approach rather than solely sequence similarity searches. To allow further exploitation of this valuable data, all information has been made available at PhylomeDB (http://www.phylomedb.org. Conclusions In this study, we used an evolutionary approach to assess S. mansoni parasite biology, improve genome/proteome functional annotation, and provide insights into

  16. Extra-cellular matrix changes in Schistosoma mansoni-infected Biomphalaria glabrata

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    Borges Claudia Maria da Cunha

    2003-01-01

    Full Text Available Reactivity of snails against parasites exhibits a primitive focal reaction, with encapsulation, phagocytosis and destruction of parasite larvae by macrophage-like cells - the hemocytes. This reaction mimics granulomatous inflammation seen in higher animals. However, different from the latter, little is known about the participation of extra-cellular matrix in such snail defense reactions. Normal and Schistosoma mansoni-infected Biomphalaria glabrata of different strains were submitted to cytological, histological, ultrastructural and biochemical methods in order to investigate the behavior of extra-cellular tissues at the site of anti-parasite reactions. In spite of the presence of two cell-types in peripheral hemolymph, only one cell-type was present at the sites of tissue reactions. Although pre-existent collagen and elastic fibers and microfibrils sometimes appeared slightly compressed around focal reactions, no evidences of duplication, synthesis or deposition of connective-tissue extra-cellular components were observed within or around the zones of reactive cell accumulations. Thus, tissue reactions against S. mansoni in the snail B. glabrata appeared exclusively dependent on one specific population of hemocytes.

  17. Polymerase Chain Reaction: A Better Method for Diagnosing Chronic Schistosoma mansoni Infections.

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    Abdel-Hafeez, Ekhlas Hamed; Mohamed, Rabie M; Belal, Usama S; Abdel-Raheem, Ehab M; Naoi, Koji; Norose, Kazumi

    2015-12-01

    For more effective diagnosis of the acute and chronic stages of Schistosoma mansoni infection in humans, the polymerase chain reaction (PCR) technique was compared with the Kato-Katz method. A total of 150 stool samples were collected from inpatient and outpatient clinics at the Department of Tropical Medicine, Minia University Hospital, Egypt. Three groups of patients, 50 with acute intestinal schistosomiasis, 70 with chronic intestinal schistosomiasis and 30 normal healthy controls were studied. Stool samples were analyzed by PCR and the Kato-Katz method. The mean number of eggs per gram of feces was 4.6 when estimated by the Kato-Katz method in positive stool samples from acute schistosomiasis cases but only 1.7 in chronic cases. In acute intestinal schistosomiasis, 15 and 45 out of 50 cases were positive by Kato-Katz and PCR, respectively. In the chronic intestinal schistosomiasis cases, 6 and 68 out of 70 cases were positive by the Kato-Katz and PCR methods, respectively. We conclude that PCR appears to be an effective diagnostic technique for S. mansoni infection, especially where a low worm burden exists, such as in chronic cases.

  18. Efficacy of Citrus reticulata and Mirazid in treatment of Schistosoma mansoni

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    Manal A Hamed

    2005-11-01

    Full Text Available This work has been carried out to investigate the effect of Schistosoma mansoni infection on mice livers after treatment with the ethanolic extract of Citrus reticulata root or the oleo-resin extract from Myrrh of Commiphora molmol tree (Mirazid, as a new antishistosomal drug. Marker enzymes for different cell organelles were measured; succinate dehydrogenase (SDH; lactate dehydrogenase (LDH and its isoenzymes; glucose-6-phosphatase (G-6-Pase; acid phosphatase (AP and 5'- nucleotidase. Liver function enzymes; aspartate aminotransferase (AST; alanine aminotransferase (ALT, and alkaline phosphatase (ALP were also estimated. Parasitological studies through ova count and worm burden will also be taken into consideration. The results showed a marked reduction in SDH, LDH, AST, and ALT enzyme activities and a significant increase in G-6-Pase, AP, 5'- nucleotidase, and ALP after S. mansoni infection. A noticeable alteration in LDH subunits were also noticed. Treatment with C. reticulata or Mirazid improved all the previous enzyme activities with a noticeable reduction in ova count and worm burden.

  19. Radiation-resistant acquired immunity of vaccinated mice to Schistosoma mansoni

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    Aitken, R.; Coulson, P.S.; Dixon, B.; Wilson, R.A.

    1987-11-01

    Vaccination of mice with attenuated cercariae of Schistosoma mansoni induces specific acquired resistance to challenge infection. This resistance is immunologically-mediated, possibly via a delayed-type hypersensitivity. Studies of parasite migration have shown that the protective mechanism operates most effectively in the lungs of vaccinated mice. We have probed the mechanism by exposing mice to 500 rads of gamma radiation before challenge infection. Our results show that the effector mechanism operative against challenge larvae is resistant to radiation. In contrast, classical immune responses are markedly suppressed by the same treatment. While leukocyte populations in the blood fall dramatically after irradiation, numbers of cells recoverable by bronchoalveolar lavage are unaffected. We suggest that vaccination with attenuated cercariae establishes populations of sensitized cells in the lungs which trigger the mechanism of resistance when challenge schistosomula migrate through pulmonary capillary beds. Although the cells may be partially disabled by irradiation, they remain responsive to worm antigens and thereby capable of initiating the elimination mechanism. This hypothesis would explain the radiation resistance of vaccine-induced immunity to S. mansoni.

  20. Antigenic community between Schistosoma mansoni and Biomphalaria glabrata: on the search of candidate antigens for vaccines

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    N Chacón

    2002-10-01

    Full Text Available We have previously confirmed the presence of common antigens between Schistosoma mansoni and its vector, Biomphalaria glabrata. Cross-reactive antigens may be important as possible candidates for vaccine and diagnosis of schistosomiasis. Sera from outbred mice immunized with a soluble Biomphalaria glabrata antigen (SBgA of non-infected B. glabrata snails recognized molecules of SBgA itself and S. mansoni AWA by Western blot. Recognition of several molecules of the SBgA were inhibited by pre-incubation with AWA (16, 30, 36, 60 and 155 kDa. The only specific molecule of AWA, inhibited by SBgA, was a 120 kDa protein. In order to determine which epitopes of SBgA were glycoproteins, the antigen was treated with sodium metaperiodate and compared with non-treated antigen. Molecules of 140, 60 and 24 kDa in the SBgA appear to be glycoproteins. Possible protective effects of the SBgA were evaluated immunizing outbred mice in two different experiments using Freund's Adjuvant. In the first one (12 mice/group, we obtained a significant level of protection (46% in the total worm load, with a high variability in worm recovery. In the second experiment (22 mice/group, no significant protection was observed, neither in worm load nor in egg production per female. Our results suggest that SBgA constitutes a rich source of candidate antigens for diagnosis and prophylactic studies.

  1. Confocal laser scanning microscopy for detection of Schistosoma mansoni eggs in the gut of mice.

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    Martha Charlotte Holtfreter

    Full Text Available BACKGROUND: The gold standard for diagnosing Schistosoma mansoni infections is the detection of eggs from stool or biopsy specimens. The viability of collected eggs can be tested by the miracidium hatching procedure. Direct detection methods are often limited in patients with light or early infections, whereas serological tests and PCR methods fail to differentiate between an inactive and persistent infection and between schistosomal species. Recently, confocal laser scanning microscopy (CLSM has been introduced as a diagnostic tool in several fields of medicine. In this study we evaluated CLSM for the detection of viable eggs of S. mansoni directly within the gut of infected mice. METHODOLOGY/PRINCIPAL FINDINGS: The confocal laser scanning microscope used in this study is based on the Heidelberg Retina Tomograph II scanning laser system in combination with the Rostock Cornea Module (image modality 1 or a rigid endoscope (image modality 2. Colon sections of five infected mice were examined with image modalities 1 and 2 for schistosomal eggs. Afterwards a biopsy specimen was taken from each colon section and examined by bright-field microscopy. Visualised eggs were counted and classified in terms of viability status. CONCLUSIONS/SIGNIFICANCE: We were able to show that CLSM visualises eggs directly within the gut and permits discrimination of schistosomal species and determination of egg viability. Thus, CLSM may be a suitable non-invasive tool for the diagnosis of schistosomiasis in humans.

  2. Potency of Allium sativum and Allium cepa Oils against Schistosoma mansoni Infection in Mice

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    Nadia S. Metwally

    2006-06-01

    Full Text Available Introduction: It has been reported that garlic (Allium sativum and onion (Allium cepa are used all over the world in different diseases, such as infections, injuries, gastrointestinal dysfunctions and cardiovascular diseases. Therefore, our aim in this work was to study the ability of garlic and onion oils to offset the infectivity as well as the metabolic disturbances induced by Schistosoma mansoni parasitism. Methods: The two current drugs were given in a dosage of 5ml / kg body weight/ day. Three aspects of drug action were investigated, the effect on S. mansoni infection, the effect on liver functions, and on liver metabolism. The parasitological investigation included worm burden and ova count. Results: Serum biochemical analysis of infected mice revealed a significant increase in the levels of aspartate aminotransferase (AST, alanine aminotransferase (ALT , ­ glutamyltransferase (GGT , alkaline phosphatase ( ALP, acid phosphatase (AP, while a decrease in glucose, total lipids total cholesterol, high - and low- density lipoproteins cholesterol (HDL and LDL, triglycerides, total proteins and albumin was observed. Liver tissue analysis of infected animals showed a marked increase in L- hydroxyproline (HP concentration and xanthine oxidase (XO activity accompanied with a reduction in total adenosinetriphosphatase (ATPase and phosphofructokinase (PFK enzymatic activities. Treatment with either garlic or onion oils greatly normalized liver function enzymes and variably improved the other parameters with a noticeable reduction in worm burden and ova count. Conclusions: It could be concluded that garlic or onion may play a role against the metabolic disturbances caused by S. mansoni infection, owing to an effect which may be induced by improving the immunological host system and their antioxidant activities

  3. Soil transmitted helminths and schistosoma mansoni infections among school children in zarima town, northwest Ethiopia

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    Birhan Wubet

    2011-07-01

    Full Text Available Abstract Background In Ethiopia, because of low quality drinking water supply and latrine coverage, helminths infections are the second most predominant causes of outpatient morbidity. Indeed, there is a scarcity of information on the prevalence of soil transmitted helminths and Schistosomiasis in Ethiopia, special in study area. Therefore, the aim of this study was to determine the prevalence and associated risk factors of soil transmitted helminths and intestinal Schistosomiasis. Methods Cross-sectional study was conducted among 319 school children of Zarima town from April 1 to May 25, 2009. A pre-tested structured questionnaire was used to collect socio-demographic data and possible risk factors exposure. Early morning stool samples were collected and a Kato Katz semi concentration technique was used to examine and count parasitic load by compound light microscope. Data entry and analysis was done using SPSS-15 version and p-value Results Out of 319 study subjects, 263 (82.4% of the study participants infected with one or more parasites. From soil transmitted helminths, Ascaris lumbricoides was the predominant isolate (22% followed by Hookworms (19% and Trichuris trichiura (2.5%. Schistosoma mansoni was also isolated in 37.9% of the study participants. Hookworm and S. mansoni infections showed statistically significant associations with shoe wearing and swimming habit of school children, respectively. Conclusion Prevalence of soil transmitted helminths (STH and S.mansoni was high and the diseases were still major health problem in the study area which alerts public health intervention as soon as possible.

  4. Molecular approach for detecting early prepatent Schistosoma mansoni infection in Biomphalaria alexandrina snail host.

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    Farghaly, Adel; Saleh, Ayman A; Mahdy, Soad; Abd El-Khalik, Dalia; Abd El-Aal, Naglaa F; Abdel-Rahman, Sara A; Salama, Marwa A

    2016-09-01

    The present study aimed to evaluate a polymerase chain reaction (PCR) assay used for detection of Schistosoma mansoni infection in Biomphalaria alexandrina snails in early prepatent period and to compare between it and the ordinary detection methods (shedding and crushing). Biomphalaria alexandrina snails are best known for their role as intermediate hosts of S. mansoni. DNA was extracted from infected snails in addition to non-infected "negative control" (to optimized the efficiency of PCR reaction) and subjected to PCR using primers specific to a partial sequence of S. mansoni fructose-1,6-bus phosphate aldolase (SMALDO). SMALDO gene was detected in the infected laboratory snails with 70, 85, and 100 % positivity at the 1st, 3rd, and 7th day of infection, respectively. In contrast, the ordinary method was not sensitive enough in detection of early prepatent infection even after 7 days of infection which showed only 25 % positivity. By comparing the sensitivity of the three methods, it was found that the average sensitivity of shedding method compared to PCR was 23.8 % and the average sensitivity of crushing method compared to PCR was 46.4 % while the sensitivity of PCR was 100 %. We conclude that PCR is superior to the conventional methods and can detect positive cases that were negative when examined by shedding or crushing methods. This can help in detection of the areas and times of high transmission which in turn will be very beneficial in planning of the exact timing of the proper control strategy.

  5. Thyroid hormone receptor orthologues from invertebrate species with emphasis on Schistosoma mansoni

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    Niles Edward G

    2007-08-01

    Full Text Available Abstract Background: Thyroid hormone receptors (TRs function as molecular switches in response to thyroid hormone to regulate gene transcription. TRs were previously believed to be present only in chordates. Results: We isolated two TR genes from the Schistosoma mansoni and identified TR orthologues from other invertebrates: the platyhelminths, S. japonium and Schmidtea mediterranea, the mollusc, Lottia gigantean and the arthropod Daphnia pulex. Phylogenetic analysis of the DNA binding domain and/or ligand binding domain shows that invertebrate and vertebrate TRs cluster together, TRs from the vertebrates and from the jawless vertebrate (lamprey clustered within separate subgroups, Platyhelminth TRs cluster outside of the vertebrate TR subgroups and that the schistosome TRs and S. mediterranea TRs clustered within separate subgroups. Alignment of the C-terminus of the A/B domain revealed a conserved TR-specific motif, termed TR 'N-terminus signature sequence', with a consensus sequence of (G/PYIPSY(M/LXXXGPE(D/EX. Heterodimer formation between S. mansoni TRs and SmRXR1 suggests that the invertebrate TR protein gained the ability to form a heterodimer with RXR. ESMA analysis showed that SmTRα could bind to a conserved DNA core motif as a monomer or homodimer. Conclusion: Vertebrate TR genes originated from a common ancestor of the Bilateria. TR genes underwent duplication independently in the Protostomia and Deuterostomia. The duplication of TRs in deuterostomes occurred after the split of jawless and jawed vertebrates. In protostomes, TR genes underwent duplication in Platyhelminths, occurring independently in trematode and turbellarian lineages. Using S. mansoni TRs as an example, invertebrate TRs exhibited the ability to form a dimer with RXR prior to the emergence of the vertebrate TRs and were able to bind to vertebrate TR core DNA elements as a monomer or homodimer.

  6. Localização de Schistosoma mansoni no plexo porta de Mus musculus experimentalmente infectados por um só sexo do trematódeo Localization of Schistosoma mansoni in the portal system of Mus musculus infected experimentally by a single sex of the trematode

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    Eliana Maria Zanotti

    1982-08-01

    Full Text Available Foi estudado o hábito migratório de Schistosoma mansoni em infecções bissexuais e nas produzidas por um só sexo do trematódeo, tendo sido evidenciada a influência do sexo no deslocamento dos esquistossomos. Nas infecções bissexuais parece que o deslocamento dos vermes para os vasos mesentéricos visa o acasalamento e a oviposição.S. mansoni migration in mice infected by unisexual or bisexual modes was studied. The research shows the influence of the adult worms. It seems that in the bisexual infections the schistosome migration to the mesenteric vessels takes place with a view to copulation and oviposition.

  7. Suppression of Basophil Histamine Release and Other IgE-dependent Responses in Childhood Schistosoma mansoni/hookworm Coinfection

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    Pinot de Moira, Angela; Fitzsimmons, Colin M.; Jones, Frances M.; Wilson, Shona; Cahen, Pierre; Tukahebwa, Edridah; Mpairwe, Harriet; Mwatha, Joseph K.; Bethony, Jeffrey M.; Skov, Per S.; Kabatereine, Narcis B.; Dunne, David W.

    2014-01-01

    Background. The poor correlation between allergen-specific immunoglobulin E (asIgE) and clinical signs of allergy in helminth infected populations suggests that helminth infections could protect against allergy by uncoupling asIgE from its effector mechanisms. We investigated this hypothesis in Ugandan schoolchildren coinfected with Schistosoma mansoni and hookworm. Methods. Skin prick test (SPT) sensitivity to house dust mite allergen (HDM) and current wheeze were assessed pre-anthelmintic treatment. Nonspecific (anti-IgE), helminth-specific, and HDM-allergen-specific basophil histamine release (HR), plus helminth- and HDM-specific IgE and IgG4 responses were measured pre- and post-treatment. Results. Nonspecific- and helminth-specific-HR, and associations between helminth-specific IgE and helminth-specific HR increased post-treatment. Hookworm infection appeared to modify the relationship between circulating levels of HDM-IgE and HR: a significant positive association was observed among children without detectable hookworm infection, but no association was observed among infected children. In addition, hookworm infection was associated with a significantly reduced risk of wheeze, and IgG4 to somatic adult hookworm antigen with a reduced risk of HDM-SPT sensitivity. There was no evidence for S. mansoni infection having a similar suppressive effect on HDM-HR or symptoms of allergy. Conclusions. Basophil responsiveness appears suppressed during chronic helminth infection; at least in hookworm infection, this suppression may protect against allergy. PMID:24782451

  8. Evaluation of the CCA Immuno-Chromatographic Test to Diagnose Schistosoma mansoni in Minas Gerais State, Brazil.

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    Alda Maria Soares Silveira

    2016-01-01

    Full Text Available The Kato-Katz (KK stool smear is the standard test for the diagnosis of Schistosoma mansoni infection, but suffers from low sensitivity when infections intensities are moderate to low. Thus, misdiagnosed individuals remain untreated and contribute to the disease transmission, thereby forestalling public health efforts to move from a modality of disease control to one of elimination. As an alternative, the urine-based diagnosis of schistosomiasis mansoni via the circulating cathodic antigen immuno-chromatographic test (CCA-ICT has been extensively evaluated in Africa with the conclusion that it may replace the KK test in areas where prevalences are moderate or high.The objective was to measure the performance of the CCA-ICT in a sample study population composed of residents from non-endemic and endemic areas for schistosomiasis mansoni in two municipalities of Minas Gerais state, Brazil. Volunteers (130 were classified into three infection status groups based on duplicate Kato-Katz thick smears from one stool sample (2KK test: 41 negative individuals from non-endemic areas, 41 negative individuals from endemic areas and 48 infected individuals from endemic areas. Infection status was also determined by the CCA-ICT and infection exposure by antibody ELISA (enzyme-linked immunosorbent assay to S. mansoni soluble egg antigen (SEA and soluble (adult worm antigen preparation (SWAP. Sensitivity and specificity were influenced by whether the trace score visually adjudicated in the CCA-ICT was characterized as positive or negative for S. mansoni infection. An analysis of a two-graph receiver operating characteristic was performed to change the cutoff point. When the trace score was interpreted as a positive rather than as a negative result, the specificity decreased from 97.6% to 78.0% whereas sensitivity increased from 68.7% to 85.4%. A significantly positive correlation between the CCA-ICT scores and egg counts was identified (r = 0.6252, p = 0

  9. Molecular Characterization of the Schistosoma mansoni Zinc Finger Protein SmZF1 as a Transcription Factor

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    D'Astolfo, Diego S.; Cardoso, Fernanda C.; Rajão, Matheus A.; Mourão, Marina M.; Gava, Elisandra; Oliveira, Sérgio C.; Macedo, Andréa M.; Machado, Carlos R.; Pena, Sérgio D. J.; Kitten, Gregory T.; Franco, Glória R.

    2009-01-01

    Background During its development, the parasite Schistosoma mansoni is exposed to different environments and undergoes many morphological and physiological transformations as a result of profound changes in gene expression. Characterization of proteins involved in the regulation of these processes is of importance for the understanding of schistosome biology. Proteins containing zinc finger motifs usually participate in regulatory processes and are considered the major class of transcription factors in eukaryotes. It has already been shown, by EMSA (Eletrophoretic Mobility Shift Assay), that SmZF1, a S. mansoni zinc finger (ZF) protein, specifically binds both DNA and RNA oligonucleotides. This suggests that this protein might act as a transcription factor in the parasite. Methodology/Principal Findings In this study we extended the characterization of SmZF1 by determining its subcellular localization and by verifying its ability to regulate gene transcription. We performed immunohistochemistry assays using adult male and female worms, cercariae and schistosomula to analyze the distribution pattern of SmZF1 and verified that the protein is mainly detected in the cells nuclei of all tested life cycle stages except for adult female worms. Also, SmZF1 was heterologously expressed in mammalian COS-7 cells to produce the recombinant protein YFP-SmZF1, which was mainly detected in the nucleus of the cells by confocal microscopy and Western blot assays. To evaluate the ability of this protein to regulate gene transcription, cells expressing YFP-SmZF1 were tested in a luciferase reporter system. In this system, the luciferase gene is downstream of a minimal promoter, upstream of which a DNA region containing four copies of the SmZF1 putative best binding site (D1-3DNA) was inserted. SmZF1 increased the reporter gene transcription by two fold (p≤0.003) only when its specific binding site was present. Conclusion Taken together, these results strongly support the hypothesis

  10. Suppression of Basophil Histamine Release and Other IgE-dependent Responses in Childhood Schistosoma mansoni/hookworm Coinfection

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    Pinot de Moira, Angela; Fitzsimmons, Colin M.; Frances M Jones; Wilson, Shona; Cahen, Pierre; Tukahebwa, Edridah; Mpairwe, Harriet; Mwatha, Joseph K; Bethony, Jeffrey M.; Skov, Per S.; Kabatereine, Narcis B.; Dunne, David W.

    2014-01-01

    Background.  The poor correlation between allergen-specific immunoglobulin E (asIgE) and clinical signs of allergy in helminth infected populations suggests that helminth infections could protect against allergy by uncoupling asIgE from its effector mechanisms. We investigated this hypothesis in Ugandan schoolchildren coinfected with Schistosoma mansoni and hookworm. Methods.  Skin prick test (SPT) sensitivity to house dust mite allergen (HDM) and current wheeze were assessed pre-anthelmintic...

  11. Formol-ether concentration method in the diagnosis of active schistosoma mansoni in patients with detectable IHA

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    Al Mofarreh Mohammad

    2000-01-01

    Full Text Available Schistosomiasis is a world wide human infection. In Saudi Arabia there are multiple endemic foci. Various methods have been used to diagnose Schistosoma mansoni. We studied 1410 patients coming from S. mansoni endemic areas with detectable antibodies by indirect hemagglutination (IHA. Stool specimens were tested for S. mansoni ova by direct smear and formol-ether concentration (FEC methods. The objective of the study was to identify patients with active schistosomiasis using FEC method and a single direct smear. Twenty percent of IHA positive patients had active infection detected by FEC, while a single direct stool smear diagnosed only 2.4% (P< 0.0001. The percentage of positive FEC was significantly increasing in linear trend with IHA level. This trend wasn′t observed with direct smear examination. The current data suggest that FEC is helpful to diagnose active schistosomiasis, therefore it is recommended in IRA positive individuals.

  12. Portal Doppler ultrasound evaluation in myelitis by Schistosoma mansoni Avaliação pela ultrassonografia com Doppler portal na mielite pelo Schistosoma mansoni

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    Claudio Henrique Fernandes Vidal

    2010-02-01

    Full Text Available The mechanism for development of schistosomal myelitis has not yet been completely understood. Few publications have tried to establish a link between the general clinical presentation of the illness and its neurological manifestations. Objective: To evaluated the portal blood flow in patients with schistosomal myelitis and controls. Method: Forty-three individuals were evaluated using portal Doppler ultrasound. Group I consisted of 13 patients with the spinal form of schistosomiasis. Group II included 10 patients with intestinal and hepatointestinal forms of schistosomiasis, but no neurological symptoms; while group III involved 20 healthy controls. Results: Portal venous speed and portal venous flow were significantly elevated in group I (pA fisiopatogênese da mielopatia esquistossomótica não é completamente entendida, sendo escassas as publicações que tentam inferir a relação entre a forma clínica da esquistossomose e suas manifestações neurológicas. Objetivo: Avaliar o fluxo sanguíneo do sistema porta em pacientes com mielite esquistossomótica, contribuindo no entendimento dos mecanismos que favorecem a chegada dos parasitas e/ou seus derivados ao sistema nervoso. Método: Foram avaliados 43 indivíduos pela Dopplerfluxometria portal. O grupo I constou de 13 pacientes com esquistossomose medular, sendo o grupo II composto por 10 portadores de formas intestinal e hepatointestinal (sem doença neurológica, e o grupo III, por 20 controles sadios. Resultados: A velocidade venosa portal e o fluxo venoso portal foram significativamente elevados (p-valor<0,001 no grupo I. Conclusão: A Dopplerfluxometria demonstrou a presença de estados hiperdinâmicos do leito vascular porta em pacientes com mielite pelo Schistosoma mansoni.

  13. Soil-Transmitted Helminths and Schistosoma mansoni Infections in Ethiopian Orthodox Church Students around Lake Tana, Northwest Ethiopia

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    Afework Bitew, Aschalew; Abera, Bayeh; Seyoum, Walle; Endale, Befekadu; Kiber, Tibebu; Goshu, Girma; Admass, Addiss

    2016-01-01

    Background Soil-transmitted helminths (STH) and Schistosoma mansoni infections are the major neglected tropical diseases that result in serious consequences on health, education and nutrition in children in developing countries. The Ethiopian Orthodox church students, who are called Yekolotemari in Amharic, live in areas with poor sanitation and hygiene. Moreover, they are not included in the national STH control programs. Thus, STH and S. mansoni infections prevalence is unknown. Methods A cross-sectional study was conducted on 384 students in June 2014 to determine STH and S. mansoni infections prevalence. Moreover, the knowledge of students about STH and S. mansoni was assessed. Data on knowledge and clinical symptoms were collected using structured questionnaires via face to face interview. Stool specimens were examined by formol-ether concentration method. Results The overall prevalence of intestinal helminths infections was 85.9% (95% confidence interval (CI): 82.1–89%). STHs infections prevalence was 65.6% (95% CI: 60.7–70.2%). The prevalence of hookworm, Ascaris lumbricoides and Trichuris trichiura were 31.8% (95% CI: 27.3–36.6%), 29.4% (25–31%) and 3.1% (1.8–5.4%), respectively. On the other hand, S. mansoni prevalence was 14.3% (95% CI: 11.1–18.1%). Majority of students infected with S. mansoni had bloody stool with crud odds-ratio of 2.9 (95% CI: 1.5–5.5). Knowledge assessment showed that 50 (13%) and 18 (4.9%) of the respondents knew about transmission of STH and S. mansoni, respectively. Conclusions The prevalence of STH and S. mansoni infections were high thus de-worming program should include the students of Ethiopian Orthodox churches. Furthermore, provision and use of sanitary facilities, health education for students to create awareness of parasitic infections and improved personal hygiene should be in place. PMID:27203749

  14. Soil-Transmitted Helminths and Schistosoma mansoni Infections in Ethiopian Orthodox Church Students around Lake Tana, Northwest Ethiopia.

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    Aschalew Afework Bitew

    Full Text Available Soil-transmitted helminths (STH and Schistosoma mansoni infections are the major neglected tropical diseases that result in serious consequences on health, education and nutrition in children in developing countries. The Ethiopian Orthodox church students, who are called Yekolotemari in Amharic, live in areas with poor sanitation and hygiene. Moreover, they are not included in the national STH control programs. Thus, STH and S. mansoni infections prevalence is unknown.A cross-sectional study was conducted on 384 students in June 2014 to determine STH and S. mansoni infections prevalence. Moreover, the knowledge of students about STH and S. mansoni was assessed. Data on knowledge and clinical symptoms were collected using structured questionnaires via face to face interview. Stool specimens were examined by formol-ether concentration method.The overall prevalence of intestinal helminths infections was 85.9% (95% confidence interval (CI: 82.1-89%. STHs infections prevalence was 65.6% (95% CI: 60.7-70.2%. The prevalence of hookworm, Ascaris lumbricoides and Trichuris trichiura were 31.8% (95% CI: 27.3-36.6%, 29.4% (25-31% and 3.1% (1.8-5.4%, respectively. On the other hand, S. mansoni prevalence was 14.3% (95% CI: 11.1-18.1%. Majority of students infected with S. mansoni had bloody stool with crud odds-ratio of 2.9 (95% CI: 1.5-5.5. Knowledge assessment showed that 50 (13% and 18 (4.9% of the respondents knew about transmission of STH and S. mansoni, respectively.The prevalence of STH and S. mansoni infections were high thus de-worming program should include the students of Ethiopian Orthodox churches. Furthermore, provision and use of sanitary facilities, health education for students to create awareness of parasitic infections and improved personal hygiene should be in place.

  15. Monoclonal antibody-based dipstick assay: a reliable field applicable technique for diagnosis of Schistosoma mansoni infection using human serum and urine samples.

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    Demerdash, Zeinab; Mohamed, Salwa; Hendawy, Mohamed; Rabia, Ibrahim; Attia, Mohy; Shaker, Zeinab; Diab, Tarek M

    2013-02-01

    A field applicable diagnostic technique, the dipstick assay, was evaluated for its sensitivity and specificity in diagnosing human Schistosoma mansoni infection. A monoclonal antibody (mAb) against S. mansoni adult worm tegumental antigen (AWTA) was employed in dipstick and sandwich ELISA for detection of circulating schistosome antigen (CSA) in both serum and urine samples. Based on clinical and parasitological examinations, 60 S. mansoni-infected patients, 30 patients infected with parasites other than schistosomiasis, and 30 uninfected healthy individuals were selected. The sensitivity and specificity of dipstick assay in urine samples were 86.7% and 90.0%, respectively, compared to 90.0% sensitivity and 91.7% specificity of sandwich ELISA. In serum samples, the sensitivity and specificity were 88.3% and 91.7% for dipstick assay vs. 91.7% and 95.0% for sandwich ELISA, respectively. The diagnostic efficacy of dipstick assay in urine and serum samples was 88.3% and 90.0%, while it was 90.8% and 93.3% for sandwich ELISA, respectively. The diagnostic indices of dipstick assay and ELISA either in serum or in urine were statistically comparable (P>0.05). In conclusion, the dipstick assay offers an alternative simple, rapid, non-invasive technique in detecting CSA or complement to stool examinations especially in field studies.

  16. Functional expression and characterization of Schistosoma mansoni cathepsin B and its trans-activation by an endogenous asparaginyl endopeptidase.

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    Sajid, Mohammed; McKerrow, James H; Hansell, Elizabeth; Mathieu, Mary A; Lucas, Kimberley D; Hsieh, Ivy; Greenbaum, Doron; Bogyo, Matthew; Salter, Jason P; Lim, Kee C; Franklin, Christopher; Kim, Jea-Hyoun; Caffrey, Conor R

    2003-09-01

    Peptidases are essential for the establishment and survival of the medically important parasite, Schistosoma mansoni. This helminth expresses a number of gut-associated peptidases that degrade host blood proteins, including hemoglobin, as a means of nutrition. Using irreversible affinity probes, we demonstrate that S. mansoni cathepsin B-like endopeptidase 1 (SmCB1) is the most abundant papain family cysteine peptidase in both the parasite gut and somatic extracts. SmCB1 zymogen (SmCB1pm) was functionally expressed in Pichia pastoris (4-11mgl(-1)). Monospecific and immunoselected antibodies raised against SmCB1pm localized the enzyme exclusively to the gut lumen and surrounding gastrodermis of adult worms. Recombinant SmCB1pm was unable to catalyze its activation, even at low pH. However, recombinant S. mansoni asparaginyl endopeptidase (SmAE), another gut-associated cysteine peptidase, processed and activated SmCB1pm in trans. Consistent with the known specificity of AEs, processing occurred on the carboxyl side of an asparagine residue, two residues upstream of the start of the mature SmCB1 sequence. The remaining pro-region dipeptide was removed by rat cathepsin C (dipeptidyl-peptidase I)-an action conceivably performed by an endogenous cathepsin C in vivo. The activated recombinant SmCB1 is biochemically identical to the native enzyme with respect to dipeptidyl substrate kinetics and pH profiles. Also, the serum proteins, hemoglobin, serum albumin, IgG, and alpha-2 macroglobulin were efficiently degraded. Further, a novel application of an assay to measure the peptidyl carboxypeptidase activity of SmCB1 and other cathepsins B was developed using the synthetic substrate benzoyl-glycinyl-histidinyl-leucine (Bz-Gly-His-Leu). This study characterizes the major digestive cysteine peptidase in schistosomes and defines novel trans-processing events required to activate the SmCB1 zymogen in vitro which may facilitate the digestive process in vivo.

  17. The Schistosoma mansoni tegumental-allergen-like (TAL protein family: influence of developmental expression on human IgE responses.

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    Colin M Fitzsimmons

    Full Text Available BACKGROUND: A human IgE response to Sm22.6 (a dominant IgE target in Schistosoma mansoni is associated with the development of partial immunity. Located inside the tegument, the molecule belongs to a family of proteins from parasitic platyhelminths, the Tegument-Allergen-Like proteins (TALs. In addition to containing dynein-light-chain domains, these TALs also contain EF-hand domains similar to those found in numerous EF-hand allergens. METHODOLOGY/PRINCIPAL FINDINGS: S. mansoni genome searches revealed 13 members (SmTAL1-13 within the species. Recent microarray data demonstrated they have a wide range of life-cycle transcriptional profiles. We expressed SmTAL1 (Sm22.6, SmTAL2, 3, 4, 5 and 13 as recombinant proteins and measured IgE and IgG4 in 200 infected males (7-60 years from a schistosomiasis endemic region in Uganda. For SmTAL1 and 3 (transcribed in schistosomula through adult-worms and adult-worms, respectively and SmTAL5 (transcribed in cercariae through adult-worms, detectable IgE responses were rare in 7-9 year olds, but increased with age. At all ages, IgE to SmTAL2 (expressed constitutively, was rare while anti-SmTAL2 IgG4 was common. Levels of IgE and IgG4 to SmTAL4 and 13 (transcribed predominantly in the cercariae/skin stage were all low. CONCLUSIONS: We have not measured SmTAL protein abundance or exposure in live parasites, but the antibody data suggests to us that, in endemic areas, there is priming and boosting of IgE to adult-worm SmTALs by occasional death of long-lived worms, desensitization to egg SmTALs through continuous exposure to dying eggs and low immunogenicity of larval SmTALs due to immunosuppression in the skin by the parasite. Of these, it is the gradual increase in IgE to the worm antigens that parallels age-dependent immunity seen in endemic areas.

  18. Aspectos imunológicos e parasitológicos em Biomphalaria tenagophila infectadas por Schistosoma mansoni e outros Digenea Immunological and parasitological aspects of Biomphalaria tenagophila infected by Schistosoma mansoni and other Digenea

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    Doralice de Souza Luro Balan

    1993-12-01

    Full Text Available Estudou-se o comportamento de amebócitos de Biomphalaria tenagophila infectadas por Schistosoma mansoni, por outros Digenea e a resistência à superinfecção, presente em infecções mistas. Foi verificada a atividade fagocitária dos amebócitos, o número destas células circulantes, a reação amebocitária nos tecidos, o perfil eletroforético da hemolinfa, além da reação de imunodifusão. Concluiu-se que moluscos infectados por outros Digenea apresentam resistência à superinfecção por S. mansoni, sendo que os amebócitos parecem não ter participação direta na destruição dos esporocistos de S. mansoni nesta eventualidade. Nos moluscos infectados observou-se maior número de amebócitos circulantes e aumento de capacidade fagocitária destas células.The behavior of Biomphalaria tenagophila amoebocytes was studied in infections produced by Schistosoma mansoni and other Digenea, The resistance to superinfection was also verified in mixed infections. Data on amoebocyte phagocytic activity, on the number of amoebocytes in hemolymph, and on amoebocyte tissue ractions were obtained and eletrophoretic and imunodiffusion examinations of the hemolymph were carried out. It was concluded that the snails infected with Digenea show resistance to superinfection with S. mansoni. Apparently sporocysts are not destroyed by the action of amoebocytes. An increase in amoebocyte phagocytic activity was discovered in infected snails. Immunoeletrophoresis shows quantitative and qualitative differences in the hemolymph of the infected snails.

  19. Susceptibility of Some Wild Rodents Widely Distributed in Egyptian Foci to Schistosoma mansoni Infection under Laboratory Conditions

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    Ismail M. Al-Sharkawi

    2011-01-01

    Full Text Available The most important definitive host of Schistosoma mansoni is the human, however, numerous other mammalian species were found to be infected with this parasite. Among these species, the wild rodents are the most common. In this study, the susceptibility of some wild rodents widely distributed in Egypt to S. mansoni infection was evaluated. Five wild species were tested for the susceptibility of S. mansoni infection in vitro; including Mus musculus (black mice, Acomys cahirinus (Cairo spiny mice, Rattus rattus (house rats, Rattus norvegilcus (Norway rats, Rattus norvegicus (albino rats and Arvicanthis niloticus (Nile rats. Laboratory mice were used as a positive control. Rodents were infected individually with 150 S. mansoni cercariae by tail immersion and housed for 8 week post-infection. The results reported that the Nile rats showed the highest number of worm burden (90 worms, while the Norway rats and the laboratory rats showed the lowest numbers among the tested species. This study also showed that the Nile rats, the house rats and the Norway rats yielded high number of eggs in the liver tissues. In contrast, the Cairo spiny mice, the black mice and albino rats yielded low number of eggs in the liver tissue. As compared to the permissive host albino mice, the Nile rats, the black mice, the Cairo spiny mice and the house rats showed comparable granuloma size. In contrast, albino rats and Norway rats showed a small granuloma size. Alltogether, these data showed that S. mansoni infection to these wild rodents was species dependant.

  20. Reduced Efficacy of Praziquantel Against Schistosoma mansoni Is Associated With Multiple Rounds of Mass Drug Administration

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    Crellen, Thomas; Walker, Martin; Lamberton, Poppy H. L.; Kabatereine, Narcis B.; Tukahebwa, Edridah M.; Cotton, James A.; Webster, Joanne P.

    2016-01-01

    Background. Mass drug administration (MDA) with praziquantel is the cornerstone of schistosomiasis control in sub-Saharan Africa. The effectiveness of this strategy is dependent on the continued high efficacy of praziquantel; however, drug efficacy is rarely monitored using appropriate statistical approaches that can detect early signs of wane. Methods. We conducted a repeated cross-sectional study, examining children infected with Schistosoma mansoni from 6 schools in Uganda that had previously received between 1 and 9 rounds of MDA with praziquantel. We collected up to 12 S. mansoni egg counts from 414 children aged 6–12 years before and 25–27 days after treatment with praziquantel. We estimated individual patient egg reduction rates (ERRs) using a statistical model to explore the influence of covariates, including the number of prior MDA rounds. Results. The average ERR among children within schools that had received 8 or 9 previous rounds of MDA (95% Bayesian credible interval [BCI], 88.23%–93.64%) was statistically significantly lower than the average in schools that had received 5 rounds (95% BCI, 96.13%–99.08%) or 1 round (95% BCI, 95.51%–98.96%) of MDA. We estimate that 5.11%, 4.55%, and 16.42% of children from schools that had received 1, 5, and 8–9 rounds of MDA, respectively, had ERRs below the 90% threshold of optimal praziquantel efficacy set by the World Health Organization. Conclusions. The reduced efficacy of praziquantel in schools with a higher exposure to MDA may pose a threat to the effectiveness of schistosomiasis control programs. We call for the efficacy of anthelmintic drugs used in MDA to be closely monitored. PMID:27470241

  1. Germline transgenesis and insertional mutagenesis in Schistosoma mansoni mediated by murine leukemia virus.

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    Gabriel Rinaldi

    Full Text Available Functional studies will facilitate characterization of role and essentiality of newly available genome sequences of the human schistosomes, Schistosoma mansoni, S. japonicum and S. haematobium. To develop transgenesis as a functional approach for these pathogens, we previously demonstrated that pseudotyped murine leukemia virus (MLV can transduce schistosomes leading to chromosomal integration of reporter transgenes and short hairpin RNA cassettes. Here we investigated vertical transmission of transgenes through the developmental cycle of S. mansoni after introducing transgenes into eggs. Although MLV infection of schistosome eggs from mouse livers was efficient in terms of snail infectivity, >10-fold higher transgene copy numbers were detected in cercariae derived from in vitro laid eggs (IVLE. After infecting snails with miracidia from eggs transduced by MLV, sequencing of genomic DNA from cercariae released from the snails also revealed the presence of transgenes, demonstrating that transgenes had been transmitted through the asexual developmental cycle, and thereby confirming germline transgenesis. High-throughput sequencing of genomic DNA from schistosome populations exposed to MLV mapped widespread and random insertion of transgenes throughout the genome, along each of the autosomes and sex chromosomes, validating the utility of this approach for insertional mutagenesis. In addition, the germline-transmitted transgene encoding neomycin phosphotransferase rescued cultured schistosomules from toxicity of the antibiotic G418, and PCR analysis of eggs resulting from sexual reproduction of the transgenic worms in mice confirmed that retroviral transgenes were transmitted to the next (F1 generation. These findings provide the first description of wide-scale, random insertional mutagenesis of chromosomes and of germline transmission of a transgene in schistosomes. Transgenic lines of schistosomes expressing antibiotic resistance could advance

  2. Evaluation of urine CCA assays for detection of Schistosoma mansoni infection in Western Kenya.

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    Hillary L Shane

    Full Text Available Although accurate assessment of the prevalence of Schistosoma mansoni is important for the design and evaluation of control programs, the most widely used tools for diagnosis are limited by suboptimal sensitivity, slow turn-around-time, or inability to distinguish current from former infections. Recently, two tests that detect circulating cathodic antigen (CCA in urine of patients with schistosomiasis became commercially available. As part of a larger study on schistosomiasis prevalence in young children, we evaluated the performance and diagnostic accuracy of these tests--the carbon test strip designed for use in the laboratory and the cassette format test intended for field use. In comparison to 6 Kato-Katz exams, the carbon and cassette CCA tests had sensitivities of 88.4% and 94.2% and specificities of 70.9% and 59.4%, respectively. However, because of the known limitations of the Kato-Katz assay, we also utilized latent class analysis (LCA incorporating the CCA, Kato-Katz, and schistosome-specific antibody results to determine their sensitivities and specificities. The laboratory-based CCA test had a sensitivity of 91.7% and a specificity of 89.4% by LCA while the cassette test had a sensitivity of 96.3% and a specificity of 74.7%. The intensity of the reaction in both urine CCA tests reflected stool egg burden and their performance was not affected by the presence of soil transmitted helminth infections. Our results suggest that urine-based assays for CCA may be valuable in screening for S. mansoni infections.

  3. Small gene family encoding an eggshell (chorion) protein of the human parasite Schistosoma mansoni

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    Bobek, L.A.; Rekosh, D.M.; Lo Verde, P.T.

    1988-08-01

    The authors isolated six independent genomic clones encoding schistosome chorion or eggshell proteins from a Schistosoma mansoni genomic library. A linkage map of five of the clones spanning 35 kilobase pairs (kbp) of the S. mansoni genome was constructed. The region contained two eggshell protein genes closely linked, separated by 7.5 kbp of intergenic DNA. The two genes of the cluster were arranged in the same orientation, that is, they were transcribed from the same strand. The sixth clone probably represents a third copy of the eggshell gene that is not contained within the 35-kbp region. The 5- end of the mRNA transcribed from these genes was defined by primer extension directly off the RNA. The ATCAT cap site sequence was homologous to a silkmoth chorion PuTCATT cap site sequence, where Pu indicates any purine. DNA sequence analysis showed that there were no introns in these genes. The DNA sequences of the three genes were very homologous to each other and to a cDNA clone, pSMf61-46, differing only in three or four nucleotices. A multiple TATA box was located at positions -23 to -31, and a CAAAT sequence was located at -52 upstream of the eggshell transcription unit. Comparison of sequences in regions further upstream with silkmoth and Drosophila sequences revealed very short elements that were shared. One such element, TCACGT, recently shown to be an essential cis-regulatory element for silkmoth chorion gene promoter function, was found at a similar position in all three organisms.

  4. Condiloma acuminado anal com ovos de Schistosoma mansoni em paciente HIV-positivo Condilomata acuminata with Schistosoma eggs in HIV-positive patient

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    Fabiana Pirani Carneiro

    2007-06-01

    Full Text Available Condiloma acuminado e ovos de Schistosoma são freqüentemente encontrados na região anal, mas não há nenhum caso descrito de associação dessas doenças nessa região. No colo uterino a associação de infecção por HPV (vírus do papiloma humano e ovos de Schistosoma em paciente HIV (vírus da imunodeficiência humana-positivo já foi relatada e há evidências de que essa associação possa alterar a história natural dessas doenças. Assim como no colo uterino, é possível que essa interação também ocorra na região anal. Nosso objetivo, portanto, é relatar um caso de condiloma anal em paciente HIV-positivo, que foi submetido a ressecção cirúrgica e que apresentou no exame histopatológico numerosos ovos de Schistosoma mansoni.Condilomata acuminata and Schistosoma eggs are frequently found in the anal region, but there is no report about the association of these diseases in this region. The association of HPV infection and Schistosoma eggs in an HIV-positive patient was found in uterine cervix and there is evidence suggesting that this association can alters the natural history of these diseases. Like in the cervix, it is possible that this interaction also occurs in the anal region. So, we report a case of anal Condilomata acuminata, in an HIV-positive patient, that was ressected and contained on histopathologic examination, multiple Schistosoma eggs.

  5. Venus kinase receptors control reproduction in the platyhelminth parasite Schistosoma mansoni.

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    Mathieu Vanderstraete

    2014-05-01

    Full Text Available The Venus kinase receptor (VKR is a single transmembrane molecule composed of an intracellular tyrosine kinase domain close to that of insulin receptor and an extracellular Venus Flytrap (VFT structure similar to the ligand binding domain of many class C G protein coupled receptors. This receptor tyrosine kinase (RTK was first discovered in the platyhelminth parasite Schistosoma mansoni, then in a large variety of invertebrates. A single vkr gene is found in most genomes, except in S. mansoni in which two genes Smvkr1 and Smvkr2 exist. VKRs form a unique family of RTKs present only in invertebrates and their biological functions are still to be discovered. In this work, we show that SmVKRs are expressed in the reproductive organs of S. mansoni, particularly in the ovaries of female worms. By transcriptional analyses evidence was obtained that both SmVKRs fulfill different roles during oocyte maturation. Suppression of Smvkr expression by RNA interference induced spectacular morphological changes in female worms with a strong disorganization of the ovary, which was dominated by the presence of primary oocytes, and a defect of egg formation. Following expression in Xenopus oocytes, SmVKR1 and SmVKR2 receptors were shown to be activated by distinct ligands which are L-Arginine and calcium ions, respectively. Signalling analysis in Xenopus oocytes revealed the capacity of SmVKRs to activate the PI3K/Akt/p70S6K and Erk MAPK pathways involved in cellular growth and proliferation. Additionally, SmVKR1 induced phosphorylation of JNK (c-Jun N-terminal kinase. Activation of JNK by SmVKR1 was supported by the results of yeast two-hybrid experiments identifying several components of the JNK pathway as specific interacting partners of SmVKR1. In conclusion, these results demonstrate the functions of SmVKR in gametogenesis, and particularly in oogenesis and egg formation. By eliciting signalling pathways potentially involved in oocyte proliferation, growth

  6. Venus kinase receptors control reproduction in the platyhelminth parasite Schistosoma mansoni.

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    Vanderstraete, Mathieu; Gouignard, Nadège; Cailliau, Katia; Morel, Marion; Hahnel, Steffen; Leutner, Silke; Beckmann, Svenja; Grevelding, Christoph G; Dissous, Colette

    2014-05-01

    The Venus kinase receptor (VKR) is a single transmembrane molecule composed of an intracellular tyrosine kinase domain close to that of insulin receptor and an extracellular Venus Flytrap (VFT) structure similar to the ligand binding domain of many class C G protein coupled receptors. This receptor tyrosine kinase (RTK) was first discovered in the platyhelminth parasite Schistosoma mansoni, then in a large variety of invertebrates. A single vkr gene is found in most genomes, except in S. mansoni in which two genes Smvkr1 and Smvkr2 exist. VKRs form a unique family of RTKs present only in invertebrates and their biological functions are still to be discovered. In this work, we show that SmVKRs are expressed in the reproductive organs of S. mansoni, particularly in the ovaries of female worms. By transcriptional analyses evidence was obtained that both SmVKRs fulfill different roles during oocyte maturation. Suppression of Smvkr expression by RNA interference induced spectacular morphological changes in female worms with a strong disorganization of the ovary, which was dominated by the presence of primary oocytes, and a defect of egg formation. Following expression in Xenopus oocytes, SmVKR1 and SmVKR2 receptors were shown to be activated by distinct ligands which are L-Arginine and calcium ions, respectively. Signalling analysis in Xenopus oocytes revealed the capacity of SmVKRs to activate the PI3K/Akt/p70S6K and Erk MAPK pathways involved in cellular growth and proliferation. Additionally, SmVKR1 induced phosphorylation of JNK (c-Jun N-terminal kinase). Activation of JNK by SmVKR1 was supported by the results of yeast two-hybrid experiments identifying several components of the JNK pathway as specific interacting partners of SmVKR1. In conclusion, these results demonstrate the functions of SmVKR in gametogenesis, and particularly in oogenesis and egg formation. By eliciting signalling pathways potentially involved in oocyte proliferation, growth and migration

  7. Molecular cloning and characterization of novel glutamate-gated chloride channel subunits from Schistosoma mansoni.

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    Vanessa Dufour

    Full Text Available Cys-loop ligand-gated ion channels (LGICs mediate fast ionotropic neurotransmission. They are proven drug targets in nematodes and arthropods, but are poorly characterized in flatworms. In this study, we characterized the anion-selective, non-acetylcholine-gated Cys-loop LGICs from Schistosoma mansoni. Full-length cDNAs were obtained for SmGluCl-1 (Smp_096480, SmGluCl-2 (Smp_015630 and SmGluCl-3 (Smp_104890. A partial cDNA was retrieved for SmGluCl-4 (Smp_099500/Smp_176730. Phylogenetic analyses suggest that SmGluCl-1, SmGluCl-2, SmGluCl-3 and SmGluCl-4 belong to a novel clade of flatworm glutamate-gated chloride channels (GluCl that includes putative genes from trematodes and cestodes. The flatworm GluCl clade was distinct from the nematode-arthropod and mollusc GluCl clades, and from all GABA receptors. We found no evidence of GABA receptors in S. mansoni. SmGluCl-1, SmGluCl-2 and SmGluCl-3 subunits were characterized by two-electrode voltage clamp (TEVC in Xenopus oocytes, and shown to encode Cl⁻-permeable channels gated by glutamate. SmGluCl-2 and SmGluCl-3 produced functional homomers, while SmGluCl-1 formed heteromers with SmGluCl-2. Concentration-response relationships revealed that the sensitivity of SmGluCl receptors to L-glutamate is among the highest reported for GluCl receptors, with EC₅₀ values of 7-26 µM. Chloride selectivity was confirmed by current-voltage (I/V relationships. SmGluCl receptors are insensitive to 1 µM ivermectin (IVM, indicating that they do not belong to the highly IVM-sensitive GluClα subtype group. SmGluCl receptors are also insensitive to 10 µM meclonazepam, a schistosomicidal benzodiazepine. These results provide the first molecular evidence showing the contribution of GluCl receptors to L-glutamate signaling in S. mansoni, an unprecedented finding in parasitic flatworms. Further work is needed to elucidate the roles of GluCl receptors in schistosomes and to explore their potential as drug targets.

  8. Accuracy of urine circulating cathodic antigen (CCA test for Schistosoma mansoni diagnosis in different settings of Cote d'Ivoire.

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    Jean T Coulibaly

    2011-11-01

    Full Text Available BACKGROUND: Promising results have been reported for a urine circulating cathodic antigen (CCA test for the diagnosis of Schistosoma mansoni. We assessed the accuracy of a commercially available CCA cassette test (designated CCA-A and an experimental formulation (CCA-B for S. mansoni diagnosis. METHODOLOGY: We conducted a cross-sectional survey in three settings of Côte d'Ivoire: settings A and B are endemic for S. mansoni, whereas S. haematobium co-exists in setting C. Overall, 446 children, aged 8-12 years, submitted multiple stool and urine samples. For S. mansoni diagnosis, stool samples were examined with triplicate Kato-Katz, whereas urine samples were tested with CCA-A. The first stool and urine samples were additionally subjected to an ether-concentration technique and CCA-B, respectively. Urine samples were examined for S. haematobium using a filtration method, and for microhematuria using Hemastix dipsticks. PRINCIPAL FINDINGS: Considering nine Kato-Katz as diagnostic 'gold' standard, the prevalence of S. mansoni in setting A, B and C was 32.9%, 53.1% and 91.8%, respectively. The sensitivity of triplicate Kato-Katz from the first stool and a single CCA-A test was 47.9% and 56.3% (setting A, 73.9% and 69.6% (setting B, and 94.2% and 89.6% (setting C. The respective sensitivity of a single CCA-B was 10.4%, 29.9% and 75.0%. The ether-concentration technique showed a low sensitivity for S. mansoni diagnosis (8.3-41.0%. The specificity of CCA-A was moderate (76.9-84.2%; CCA-B was high (96.7-100%. The likelihood of a CCA-A color reaction increased with higher S. mansoni fecal egg counts (odds ratio: 1.07, p<0.001. A concurrent S. haematobium infection or the presence of microhematuria did not influence the CCA-A test results for S. mansoni diagnosis. CONCLUSION/SIGNIFICANCE: CCA-A showed similar sensitivity than triplicate Kato-Katz for S. mansoni diagnosis with no cross-reactivity to S. haematobium and microhematuria. The low sensitivity

  9. Pulmonary leukocytic responses are linked to the acquired immunity of mice vaccinated with irradiated cercariae of Schistosoma mansoni

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    Aitken, R.; Coulson, P.S.; Wilson, R.A.

    1988-05-15

    Pulmonary cellular responses in C57BL/6 mice exposed to Schistosoma mansoni have been investigated by sampling cells from the respiratory airways with bronchoalveolar lavage. Mice exposed to cercariae attenuated with 20 krad gamma-radiation developed stronger and more persistent pulmonary leukocytic responses than animals exposed to equal numbers of normal parasites. Although vaccination with irradiated cercariae also stimulated T cell responses of greater magnitude and duration than normal infection, the lymphocytic infiltrate elicited by each regimen did not differ substantially in its composition, 5 wk after exposure. Studies with cercariae attenuated by different treatments established that a link exists between the recruitment of leukocytes to the lungs of vaccinated mice and resistance to reinfection. There was a strong association between pulmonary leukocytic responses and the elimination of challenge infections by vaccinated mice. Animals exposed to irradiated cercariae of S. mansoni were resistant to homologous challenge infection but were not protected against Schistosoma margrebowiei. Homologous challenge of vaccinated mice stimulated anamnestic leukocytic and T lymphocytic responses in the lungs, 2 wk postinfection, but exposure of immunized animals to the heterologous species failed to trigger an expansion in these populations of cells. Our studies indicate that pulmonary leukocytes and T lymphocytes are intimately involved in the mechanism of vaccine-induced resistance to S. mansoni. It remains unclear whether these populations of cells initiate protective inflammatory reactions against challenge parasites in the lungs, or accumulate in response to the activation of the protective mechanism by other means.

  10. Parasitological characteristics of Schistosoma mansoni infection in swiss mice with underlying malnutrition

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    Simões Carla

    2002-01-01

    Full Text Available The effects of a protein-restricted diet (8% protein, 81% carbohydrate and 11% lipids on Schistosoma mansoni infectivity, fecal egg excretion and intestinal egg distribution in Swiss (SW mice were studied. Pregnant mice received a deficient diet from the middle of gestation until delivery. Seven-days-old mice were exposed to 50 cercariae (BH strain, Brazil. Offspring mice had a free access to the deficient diet since lactation until adulthood. The controls were fed with a commercial mice diet. A parasitological examination was performed between six and eight weeks post-infection while both groups were necropsied one week later. Mice on the experimental diet showed a significant loss in body weight. There was no significant difference (p > 0.05 in pre-patent period, kinetics of egg excretion and worm recovery from mice on either diet. Significant differences (p < 0.05 were found concerning to the percentage of deposited eggs in the distal segment of the small intestine from hosts on the experimental diet.Our data suggest that experimental malnutrition induced for a long term has no detrimental effect on the acute schistosomiais infection in SW mice.

  11. Circulating anodic antigen for detection of Schistosoma mansoni infection in Egyptian patients.

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    El-Morshedy, H; Kinosien, B; Barakat, R; Omer, E; Khamis, N; Deelder, A M; Phillips, M

    1996-02-01

    We evaluated the ability of circulating anodic antigen (CAA) to identify infection with Schistosoma mansoni in a prospective cohort study of 257 Egyptian men, 147 with infection diagnosed by repeated Kato thick smears, and 110 without detectable infection. The CAA levels were obtained and the stool examinations were performed two weeks and one, two, four, and six months after praziquantel therapy for infected men. A CAA enzyme-linked immunosorbent assay was repeated twice on subjects who were otherwise negative for schistosomiasis. Circulating anodic antigen was detected in 117 cases, with an overall test sensitivity before treatment of 0.8. Sensitivity was related to the intensity of infection, ranging from 1.00 with > 400 eggs per gram (epg) of feces to 0.60 for those with or = 4. We conclude that CAA has moderate sensitivity and excellent specificity when used to identify infection with schistosomiasis, as well as to monitor the results of therapy after at least one month after treatment.

  12. The extracellular release of Schistosoma mansoni HMGB1 nuclear protein is mediated by acetylation

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    Coutinho Carneiro, Vitor; Moraes Maciel, Renata de; Caetano de Abreu da Silva, Isabel; Furtado Madeira da Costa, Rodrigo [Instituto de Bioquimica Medica, Programa de Biotecnologia e Biologia Molecular, Universidade Federal do Rio de Janeiro, CCS, Ilha do Fundao, Rio de Janeiro 21941-590 (Brazil); Neto Paiva, Claudia; Torres Bozza, Marcelo [Departamento de Imunologia, Instituto de Microbiologia Professor Paulo de Goes, Universidade Federal do Rio de Janeiro, CCS, Ilha do Fundao, Rio de Janeiro 21941-590 (Brazil); Rosado Fantappie, Marcelo, E-mail: fantappie@bioqmed.ufrj.br [Instituto de Bioquimica Medica, Programa de Biotecnologia e Biologia Molecular, Universidade Federal do Rio de Janeiro, CCS, Ilha do Fundao, Rio de Janeiro 21941-590 (Brazil)

    2009-12-25

    Schistosoma mansoni HMGB1 (SmHMGB1) was revealed to be a substrate for the parasite histone acetyltransferases SmGCN5 and SmCBP1. We found that full-length SmHMGB1, as well as its HMG-box B (but not HMG-box A) were acetylated in vitro by SmGCN5 and SmCBP1. However, SmCBP1 was able to acetylate both substrates more efficiently than SmGCN5. Interestingly, the removal of the C-terminal acidic tail of SmHMGB1 (SmHMGB1{Delta}C) resulted in increased acetylation of the protein. We showed by mammalian cell transfection assays that SmHMGB1 and SmHMGB1{Delta}C were transported from the nucleus to the cytoplasm after sodium butyrate (NaB) treatment. Importantly, after NaB treatment, SmHMGB1 was also present outside the cell. Together, our data suggest that acetylation of SmHMGB1 plays a role in cellular trafficking, culminating with its secretion to the extracellular milieu. The possible role of SmHMGB1 acetylation in the pathogenesis of schistosomiasis is discussed.

  13. Indirect Effects of Oral Tolerance Inhibit Pulmonary Granulomas to Schistosoma mansoni Eggs

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    Geraldo Magela Azevedo

    2012-01-01

    Full Text Available Parenteral injection of tolerated proteins into orally tolerant mice inhibits the initiation of immunological responses to unrelated proteins and blocks severe chronic inflammatory reactions of immunological origin, such as autoimmune reactions. This inhibitory effect which we have called “indirect effects of oral tolerance” is also known as “bystander suppression.” Herein, we show that i.p. injection of OVA + Al(OH3 minutes before i.v. injection of Schistosoma mansoni eggs into OVA tolerant mice blocked the increase of pulmonary granulomas. In addition, the expression of ICAM-1 in lung parenchyma in areas outside the granulomas of OVA-orally tolerant mice was significantly reduced. However, at day 18 after granuloma induction there was no difference in immunofluorescency intensity to CD3, CD4, F4/80, andα-SMA per granuloma area of tolerant and control groups. Reduction of granulomas by reexposure to orally tolerated proteins was not correlated with a shift in Th-1/Th-2 cytokines in serum or lung tissue extract.

  14. La queratotaxia cercariana en la diferenciacion de sexos de schistosoma mansoni

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    Luz Arelis Pino

    1988-09-01

    Full Text Available El número de papilas argirófilas superficiales y su modelo de disposición en el tegumento de las cercarias (quetotaxia de Schistosoma mansoni nos permitió diferenciar los sexos a nivel del mencionado estadío larvario, mediante los siguientes critérios: - Mayor homogeneidad en las cercarias machos, en cuanto al número total de papilas ventrales y dorsales a nivel de cuerpo y cola cercarianos (C.V. = 4,1%, que en las cercarias hembras (C. V. = 18,3% (P < 0,001. - Presencia en el 80% de las cercarias machos de cuatro papilas en los cuadrantes "C" ó "D" inferior-izquierdo e inferior-derecho, respectivamente ventrales, mientras que dicho caracter sólo está presente en el 40% de las cercarias hembras (P < 0,001. - Diferencia estadísticamente significativa (P < 0,001 entre el número total promedio de papilas corporales centrales de las cercarias hembras (X = 11,9 ± 0,2 y el de las cercarias machos (X = 11,1 ± 0,3. - Diferencia estadísticamente significativa (P < 0,05 para la mayor distancia promedio entre las papilas AIL y AIIL, de cada cercaria, en relación con el sexo (femenino = 25,5 µm ± 0,33; masculino = 27,3 µm ± 0,26.

  15. Mechanisms of evasion of Schistosoma mansoni schistosomula to the lethal activity of complement

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    F. Juarez Ramalho-Pinto

    1992-01-01

    Full Text Available Schistosomula of Schistosoma mansoni became resistant to antibody-dependent complement damage in vitro after pre-incubation with normal human erythrocytes (NHuE whatever the ABO or Rh blood group. Resistant parasites were shown to acquire host decay accelerating factor (DAF , a 70 kDa glycoprotein attached to the membrane of NHue by a GPI anchor. IgG2a mAb anti-human DAF (IA10 immunoprecipitated a 70 kDa molecule from 125I-labeled schistosomula pre-incubated with NHuE and inhibited their resistance to complement-dependent killing in vtro. Incubationof schistosomula with erytrocytes from patients with paroxsimal nocturnal hemoglobinuria (PNHE or SRBC, wich are DAF-deficient, did not protect the parasites from complement lesion. Supernatant of 100,000 x g collected from NHuE incubated for 24 h in defined medium was shown to contain a soluble form of DAF and to protect schistosomula from complement killing. Schistosomula treated with trypsin before incubation with NHuE ghosts did not become resistant to complement damage. On the other hand, pre-treatment with chymotrypsin did not interfere with the acquisition of resistance by the schistosomula. These results indicate that, in vitro, NHuE DAF can be transferred to schistosomula in a soluble form and that the binding of this molecule to the parasite surface is dependent upon trypsin-sensitive chymotrypsin-insensitive polipeptide(s present on the surface of the worm.

  16. A bacterial artificial chromosome library for Biomphalaria glabrata, intermediate snail host of Schistosoma mansoni

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    Coen M Adema

    2006-10-01

    Full Text Available To provide a novel resource for analysis of the genome of Biomphalaria glabrata, members of the international Biomphalaria glabrata Genome Initiative (biology.unm.edu/biomphalaria-genome.html, working with the Arizona Genomics Institute (AGI and supported by the National Human Genome Research Institute (NHGRI, produced a high quality bacterial artificial chromosome (BAC library. The BB02 strain B. glabrata, a field isolate (Belo Horizonte, Minas Gerais, Brasil that is susceptible to several strains of Schistosoma mansoni, was selfed for two generations to reduce haplotype diversity in the offspring. High molecular weight DNA was isolated from ovotestes of 40 snails, partially digested with HindIII, and ligated into pAGIBAC1 vector. The resulting B. glabrata BAC library (BG_BBa consists of 61824 clones (136.3 kb average insert size and provides 9.05 × coverage of the 931 Mb genome. Probing with single/low copy number genes from B. glabrata and fingerprinting of selected BAC clones indicated that the BAC library sufficiently represents the gene complement. BAC end sequence data (514 reads, 299860 nt indicated that the genome of B. glabrata contains ~ 63% AT, and disclosed several novel genes, transposable elements, and groups of high frequency sequence elements. This BG_BBa BAC library, available from AGI at cost to the research community, gains in relevance because BB02 strain B. glabrata is targeted whole genome sequencing by NHGRI.

  17. Schistosoma mansoni: quantification of skin penetration and early migration by differential external radioassay and autoradiography

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    Georgi, J.R. (New York State College of Veterinary Medicine, Ithaca (USA))

    1982-04-01

    Eleven gamma-emitting radionuclides (/sup 49/Sc, /sup 54/Mn, /sup 59/Fe, /sup 60/Co, /sup 65/Zn, /sup 75/Se (as selenomethionine, selenocystine, selenite and selenate), /sup 109/Cd, /sup 125/Sb, /sup 133/Ba, /sup 137/Cs and /sup 203/Hg) were screened as labelling agents for Schistosoma mansoni cercariae by incubation of infected Biomphalaria glabrata snails in radioactive solution. Only (/sup 75/Se)methionine yielded satisfactorily labelled cercariae. Differential external radioassay, a new technique employing partial body shielding within a total body counter, permitted separate estimation of tail and body radioactivity of conscious mice previously exposed by tail immersion to /sup 75/Se-labelled cercariae, with measurements repeated as often as desired. Approximately 39% of the /sup 75/Se present in emergent cercariae was retained by schistosomula transformed in vitro but this was subject to considerable variation, especially in schistosomula transformed in vivo. Secreted or catabolized label from penetrant cercariae and schistosomula was rapidly removed from the skin by the bloodstream. Numbers of schistosomula in tail skin were directly proportional to the number of reduced silver foci counted on tail autoradiograms; only a very small fraction of tail radioactivity represented unbound ('spurious') label. Migration of schistosomula away from skin was 50% complete at 3.8-4.3 days, as determined by probit analysis of autoradiographic data.

  18. Comparison between morphological and staining characteristics of live and dead eggs of Schistosoma mansoni

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    AK Sarvel

    2006-10-01

    Full Text Available Schistosoma mansoni eggs are classified, according to morphological characteristics, as follows: viable mature and immature eggs; dead mature and immature eggs, shells and granulomas. The scope of this study was to compare the staining characteristics of different morphological types of eggs in the presence of fluorescent labels and vital dyes, aiming at differentiating live and dead eggs. The eggs were obtained from the intestines of infected mice, and put into saline 0.85%. The fluorescent labels were Hoechst 33258 and Acridine Orange + Ethidium Bromide and vital dyes (Trypan Blue 0.4% and Neutral Red 1%. When labelled with the probe Hoechst 33258, some immature eggs, morphologically considered viable, presented fluorescence (a staining characteristic detected only in dead eggs; mature eggs did not present fluorescence, and the other types of dead eggs, morphologically defined, showed fluorescence. As far as Acridine Orange + Ethidium Bromide are concerned, either the eggs considered to be live, or the dead ones, presented staining with green color, and only the hatched and motionless miracidium was stained with an orange color. Trypan Blue was not able to stain the eggs, considered to be dead but only dead miracidia which had emerged out of the shell. Neutral Red stained both live and dead eggs. Only the fluorescent Hoechst 33258 can be considered a useful tool for differentiation between dead and live eggs.

  19. Exposure to Hycanthone alters chromatin structure around specific gene functions and specific repeats in Schistosoma mansoni

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    David eRoquis

    2014-07-01

    Full Text Available Schistosoma mansoni is a parasitic plathyhelminth responsible for intestinal schistosomiasis (or bilharziasis, a disease affecting 67 million people worldwide and causing an important economic burden. The schistosomicides hycanthone, and its later proxy oxamniquine, were widely used for treatments in endemic areas during the 20th century. Recently, the mechanism of action, as well as the genetic origin of a stably and Mendelian inherited resistance for both drugs was elucidated in two strains. However, several observations suggested early on that alternative mechanisms might exist, by which resistance could be induced for these two drugs in sensitive lines of schistosomes. This induced resistance appeared rapidly, within the first generation, but was metastable (not stably inherited. Epigenetic inheritance could explain such a phenomenon and we therefore re-analyzed the historical data with our current knowledge of epigenetics. In addition, we performed new experiments such as ChIP-seq on hycanthone treated worms. We found distinct chromatin structure changes between sensitive worms and induced resistant worms from the same strain. No specific pathway was discovered, but genes in which chromatin structure modification were observed are mostly associated with transport and catabolism, which makes sense in the context of the elimination of the drug. Specific differences were observed in the repetitive compartment of the genome. We finally describe what types of experiments are needed to understand the complexity of heritability that can be based on genetic and/or epigenetic mechanisms for drug resistance in schistosomes.

  20. Immunity to Schistosoma mansoni in congenitally athymic, irradiated and mast cell-depleted rats

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    Ford, M.J.; Bickle, Q.D.; Taylor, M.G.

    1987-04-01

    Immunity to Schistosoma mansoni was investigated in congenitally athymic (Nu/Nu) rats, irradiated rats and in mast cell-depleted rats. Nu/Nu rats failed to develop significant resistance following vaccination with irradiated cercariae, although Nu/Nu recipients of serum from vaccinated Fischer rats (VRS) manifested resistance comparable to heterozygous controls, suggesting that T-cells were required in the induction of resistance but were not involved in the efferent arm of antibody-dependent elimination. Radiosensitive cells (including eosinophils, basophils, neutrophils, lymphocytes and mast cells) were apparently not essential for the antibody-dependent elimination of lung or post-lung stages since irradiated (700-750 rad.) recipients of VRS manifested comparable degrees of resistance to unirradiated controls in spite of a greater than 85% reduction in total blood leucocyte counts after irradiation. Depletion of 99% of tissue mast cells by treatment of rats with Compound 48/80 had no significant effect on the attrition of a challenge infection in rats rendered immune by vaccination with irradiated cercariae or by transfer of VRS. However, there was a significant increase in worm recovery in unimmunized and mast cell-depleted or irradiated rats, indicating that mast cells and perhaps other radio-isotope sensitive cells may be involved in innate resistance.

  1. Circulating Antigens Levels in Different Clinical Forms of the Schistosoma mansoni Infection

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    Yerkes Pereira e Silva

    1999-01-01

    Full Text Available With the aim to evaluate the circulating cathodic antigen (CCA levels in relation to the different clinical phases of Schistosoma sp. infection a sandwich ELISA using monoclonal antibody 5H11 was performed. The sera of three groups of 25 Brazilian patients with acute, intestinal and hepatosplenic forms of S. mansoni infection were tested and compared to a non-infected control group. Patients and control groups were matched for age and sex and the number of eggs per gram of feces was equally distributed among the three patient groups. Sensitivity of 100%, 72%, 52% of the assay was observed for the intestinal, hepatosplenic and acute toxemic groups respectively. The specificity was 100%. Intestinal and hepatosplenic groups presented CCA levels significantly higher in comparison to those observed for acute patients (F-ratio = 2,524; p = 0.000 and F-ratio = 6,314; p = 0.015 respectively. There was no significant difference of CCA serum levels between hepatosplenic and intestinal groups (F-ratio = 1,026; p = 0.316.

  2. A salting out and resin procedure for extracting Schistosoma mansoni DNA from human urine samples

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    Rodrigues Nilton B

    2010-04-01

    Full Text Available Abstract Background In this paper a simple and cheap salting out and resin (InstaGene matrix® resin - BioRad DNA extraction method from urine for PCR assays is introduced. The DNA of the fluke Schistosoma mansoni was chosen as the target since schistosomiasis lacks a suitable diagnostic tool which is sensitive enough to detect low worm burden. It is well known that the PCR technique provides high sensitivity and specificity in detecting parasite DNA. Therefore it is of paramount importance to take advantage of its excellent performance by providing a simple to handle and reliable DNA extraction procedure, which permits the diagnosis of the disease in easily obtainable urine samples. Findings The description of the extraction procedure is given. This extraction procedure was tested for reproducibility and efficiency in artificially contaminated human urine samples. The reproducibility reached 100%, showing positive results in 5 assay repetitions of 5 tested samples each containing 20 ng DNA/5 ml. The efficiency of the extraction procedure was also evaluated in a serial dilution of the original 20 ng DNA/5 ml sample. Detectable DNA was extracted when it was at a concentration of 1.28 pg DNA/mL, revealing the high efficiency of this procedure. Conclusions This methodology represents a promising tool for schistosomiasis diagnosis utilizing a bio-molecular technique in urine samples which is now ready to be tested under field conditions and may be applicable to the diagnosis of other parasitic diseases.

  3. Genetic variability and identification of the intermediate snail hosts of Schistosoma mansoni

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    Teofânia HDA Vidigal

    1998-01-01

    Full Text Available Studies based on shell or reproductive organ morphology and genetic considerations suggest extensive intraspecific variation in Biomphalaria snails. The high variability at the morphological and genetic levels, as well as the small size of some specimens and similarities between species complicate the correct identification of these snails. Here we review our work using methods based on polymerase chain reaction (PCR amplification for analysis of genetic variation and identification of Biomphalaria snails from Brazil, Argentina, Uruguay and Paraguay. Arbitrarily primed-PCR revealed that the genome of B. glabrata exihibits a remarkable degree of intraespecific polymorphism. Low stringency-PCR using primers for 18S rRNA permited the identification of B. glabrata, B. tenagophila and B. occidentalis. The study of individuals obtained from geographically distinct populations exhibits significant intraspecific DNA polymorphism, however specimens from the same species, exhibit some species specific LSPs. We also showed that PCR-restriction fragment of length polymorphism of the internal transcribed spacer region of Biomphalaria rDNA, using DdeI permits the differentiation of the three intermediate hosts of Schistosoma mansoni. The molecular biological techniques used in our studies are very useful for the generation of new knowledge concerning the systematics and population genetics of Biomphalaria snails.

  4. Polyethyleneimine (PEI mediated siRNA gene silencing in the Schistosoma mansoni snail host, Biomphalaria glabrata.

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    Matty Knight

    2011-07-01

    Full Text Available An in vivo, non-invasive technique for gene silencing by RNA interference (RNAi in the snail, Biomphalaria glabrata, has been developed using cationic polymer polyethyleneimine (PEI mediated delivery of long double-stranded (ds and small interfering (si RNA. Cellular delivery was evaluated and optimized by using a 'mock' fluorescent siRNA. Subsequently, we used the method to suppress expression of Cathepsin B (CathB with either the corresponding siRNA or dsRNA of this transcript. In addition, the knockdown of peroxiredoxin (Prx at both RNA and protein levels was achieved with the PEI-mediated soaking method. B. glabrata is an important snail host for the transmission of the parasitic digenean platyhelminth, Schistosoma mansoni that causes schistosomiasis in the neotropics. Progress is being made to realize the genome sequence of the snail and to uncover gene expression profiles and cellular pathways that enable the snail to either prevent or sustain an infection. Using PEI complexes, a convenient soaking method has been developed, enabling functional gene knockdown studies with either dsRNA or siRNA. The protocol developed offers a first whole organism method for host-parasite gene function studies needed to identify key mechanisms required for parasite development in the snail host, which ultimately are needed as points for disrupting this parasite mediated disease.

  5. Strukturelle Charakterisierung hämolymphproteingebundener N-Glykane und immunhistochemische Lokalisierung antigener Strukturen von Biomphalaria glabrata, die mit Glykokonjugaten des Humanparasiten Schistosoma mansoni kreuzreagieren

    OpenAIRE

    Lehr, Tobias

    2007-01-01

    In der vorliegenden Arbeit wurden N-Glykane der Zwischenwirtsschnecke Biomphala¬ria glabrata, die mit Glykokonjugaten des Humanparasiten Schistosoma mansoni serolo¬gisch kreuzreagieren, strukturell charakterisiert. Dazu waren die N-Glykane aus Hämolymphproteinen nicht-infizierter Schnecken nach proteolytischem Verdau enzyma¬tisch freigesetzt, durch Immunaffinitätschromatographie unter Verwendung von immobilisierten Antikörpern gegen lösliche Eiantigene von S. mansoni (anti-SEA) angereichert, ...

  6. A COMPARATIVE EPIDEMIOLOGIC STUDY OF SPECIFIC ANTIBODIES (IgM AND IgA AND PARASITOLOGICAL FINDINGS IN AN ENDEMIC AREA OF LOW TRANSMISSION OF Schistosoma mansoni

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    KANAMURA Herminia Yohko

    1998-01-01

    Full Text Available The diagnostic potential of circulating IgM and IgA antibodies against Schistosoma mansoni gut-associated antigens detected by the immunofluorescence test (IFT on adult worm paraffin sections was evaluated comparatively to the fecal parasitological method, for epidemiological purposes in low endemic areas for schistosomiasis. Blood samples were collected on filter paper from two groups of schoolchildren living in two different localities of the municipality of Itariri (São Paulo, Brazil with different histories and prevalences of schistosomiasis. The parasitological and serological data were compared to those obtained for another group of schoolchildren from a non-endemic area for schistosomiasis. The results showed poor sensitivity of the parasitological method in detecting individuals with low worm burden and indicate the potential of the serological method as an important tool to be incorporated into schistosomiasis control and vigilance programs for determining the real situation of schistosomiasis in low endemic areas.

  7. Prevalência da infecção pelo Schistosoma mansoni em dois municípios do Estado de Alagoas Prevalence of Schistosoma mansoni infection in two municipalities of the State of Alagoas, Brazil

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    Danylo César Correia Palmeira

    2010-06-01

    Full Text Available INTRODUÇÃO: Estudos preliminares indicam uma provável expansão da esquistossomose em Alagoas. Este trabalho analisa a ocorrência do Schistosoma mansoni em escolares de dois municípios, localizados nas bacias hidrográficas dos rios Mundaú e Paraíba. MÉTODOS: O grupo de estudo foi constituído por 690 escolares da zona urbana, com idade entre sete e 15 anos. Foram aplicados interrogatórios socioeconômicos e foram usados exames parasitológicos para diagnostico da esquistossomose (métodos de Kato e de Lutz. Foram tratados os casos positivos e foram ministradas palestras para alunos e familiares sobre educação sanitária. RESULTADOS: A prevalência de Schistosoma mansoni foi de 24,9%. A associação entre esquistossomose e outras parasitoses foi significativa em relação à tricuríase (pINTRODUCTION: Preliminary studies indicate a probable schistosomiasis expansion in Alagoas. This work analyzes the occurrence of Schistosoma mansoni in students from two municipalities, located in the Mundaú and Paraíba rivers basins. METHODS: The study group consisted of 690 students in the urban area, aged between seven and 15 years. A standardized socio-economic questionnaire was filled out and parasitological tests were used to diagnosis schistosomiasis (Lutz and Kato methods. Positive cases were treated and students and their families were lectured about health education. RESULTS: The Schistosoma mansoni prevalence was 24.9%. The association between schistosomiasis and other parasitic diseases was significant in relation to trichuriasis (p <0.05. Only 50% of infected children lived in brick homes with sanitation and public water supply. Among them, 48.1% used to go usually to the water collections and 55.8% of them knew rivers snails. The concordance analysis between the Lutz and Kato methods showed disagreement in 54.2%, with greater sensitivity for the Lutz technique (76.4%. CONCLUSIONS: The indices obtained characterize the municipalities

  8. Structure-Bioactivity Relationship for Benzimidazole Thiophene Inhibitors of Polo-Like Kinase 1 (PLK1, a Potential Drug Target in Schistosoma mansoni.

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    Thavy Long

    2016-01-01

    Full Text Available Schistosoma flatworm parasites cause schistosomiasis, a chronic and debilitating disease of poverty in developing countries. Praziquantel is employed for treatment and disease control. However, its efficacy spectrum is incomplete (less active or inactive against immature stages of the parasite and there is a concern of drug resistance. Thus, there is a need to identify new drugs and drug targets.We show that RNA interference (RNAi of the Schistosoma mansoni ortholog of human polo-like kinase (huPLK1 elicits a deleterious phenotypic alteration in post-infective larvae (schistosomula or somules. Phenotypic screening and analysis of schistosomula and adult S. mansoni with small molecule inhibitors of huPLK1 identified a number of potent anti-schistosomals. Among these was a GlaxoSmithKline (GSK benzimidazole thiophene inhibitor that has completed Phase I clinical trials for treatment of solid tumor malignancies. We then obtained GSKs Published Kinase Inhibitor Sets (PKIS 1 and 2, and phenotypically screened an expanded series of 38 benzimidazole thiophene PLK1 inhibitors. Computational analysis of controls and PLK1 inhibitor-treated populations of somules demonstrated a distinctive phenotype distribution. Using principal component analysis (PCA, the phenotypes exhibited by these populations were mapped, visualized and analyzed through projection to a low-dimensional space. The phenotype distribution was found to have a distinct shape and topology, which could be elicited using cluster analysis. A structure-activity relationship (SAR was identified for the benzimidazole thiophenes that held for both somules and adult parasites. The most potent inhibitors produced marked phenotypic alterations at 1-2 μM within 1 h. Among these were compounds previously characterized as potent inhibitors of huPLK1 in cell assays.The reverse genetic and chemical SAR data support a continued investigation of SmPLK1 as a possible drug target and/or the prosecution of

  9. Schistosoma mansoni Infections, Undernutrition and Anaemia among Primary Schoolchildren in Two Onshore Villages in Rorya District, North-Western Tanzania

    Science.gov (United States)

    2016-01-01

    Background Undernutrition and anaemia remains to be a major public health problem in many developing countries, where they mostly affect children. Intestinal parasitic infections are known to affect both growth and haemoglobin levels. Much has been reported on the impact of geohelminths on anaemia and undernutrition, leaving that of Schistosoma mansoni not well studied. Therefore this study intended to determine the association between S.mansoni infections, anaemia and undernutrition among schoolchildren in Rorya district, Northwestern Tanzania. Methodology A cross-sectional study was carried among schoolchildren in two onshore villages namely Busanga and Kibuyi in Rorya district. Single stool specimens were collected from 513 randomly selected schoolchildren and processed for microscopic examination using the Kato-Katz method. Nutritional status was determined by anthropometry. Blood samples were also collected and examined for malaria parasites and haemoglobin levels using the Giemsa stain and HaemoCue methods, respectively. A pretested questionnaire was used to collect socio-demographic data and associated factors. Results The prevalence of S. mansoni infection and malaria was 84.02% and 9.16%, respectively. Other parasites found were Ascaris lumbricoides (1.36%) and Hookworm (1.36%). The prevalence of stunting and wasting was 38.21% and 14.42%, respectively. The prevalence of anaemia was 29.43%, whereby 0.58% had severe anaemia. S. mansoni infection was not found to be associated with undernutrition or anaemia (p>0.05). The risk of stunting and wasting increased with increasing age (p<0.001). Anaemia was associated with age, sex and village of residence (p<0.05). Conclusions S.mansoni, undernutrition and anaemia are highly prevalent in the study area. The observed rates of undernutrition and anaemia were seen not to be associated with S.mansoni infection suggesting possibly being a result of poor dietary nutrients. This study suggests that policy makers should

  10. Green tea (Camellia sinesis) ameliorates female Schistosoma mansoni-induced changes in the liver of Balb/C mice.

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    Bin Dajem, Saad M; Shati, Ali A; Adly, Mohamed A; Ahmed, Osama M; Ibrahim, Essam H; Mostafa, Osama M S

    2011-10-01

    This study was designed to assess the effect of green tea, an aqueous extract of Camellia sinensis, on the oxidative stress, antioxidant defense system and liver pathology of Schistosoma mansoni-infected mice. Green tea at concentration of 3% (w/v) was given orally to treated mice as sole source of drinking water from the end of the 4th week to the end of 10th week post-infection; untreated mice were allowed to drink normal water. The data of the studied S. mansoni-infected mice exhibited a suppression of hepatic total antioxidant capacity, superoxide dismutase (SOD), catalase (CAT) activity and glutathione content. The liver lipid peroxidation was deleteriously elevated in S. mansoni-infected mice. The hepatic total protein content, AST and ALT activities were profoundly decreased in the S. mansoni-infected mice. Most hepatocytes were damaged and showed abnormal microscopic appearance with aggressive necrosis. Both total protein and glycogen levels have been greatly reduced as indicated by histochemical examination. The treatment of S. mansoni-infected mice with green tea succeeded to suppress oxidative stress by decreasing the lipid peroxides but failed to significantly enhance the antioxidant defense system and deteriorated changes owing to liver damage and necrosis. In consistence with biochemical data, histopathological and histochemical data indicated that treatment of S. mansoni-infected mice with green tea could ameliorate hepatocytes thus reduce cellular necrosis and partially restore both total protein and glycogen levels. Thus, the study concluded that the green tea suppresses the oxidative stress through its constituent with free radicals scavenging properties rather than through the endogenous antioxidant defense system.

  11. Detection of Schistosoma mansoni Antibodies in a Low-Endemicity Area Using Indirect Immunofluorescence and Circumoval Precipitin Test

    Science.gov (United States)

    Carvalho do Espírito-Santo, Maria Cristina; Pinto, Pedro Luiz; Gargioni, Cybele; Viviana Alvarado-Mora, Monica; Pagliusi Castilho, Vera Lúcia; Pinho, João Ranato Rebello; de Albuquerque Luna, Expedito José; Borges Gryschek, Ronaldo Cesar

    2014-01-01

    Parasitological diagnostic methods for schistosomiasis lack sensitivity, especially in regions of low endemicity. The objective of this study was to determine the prevalence of Schistosoma mansoni infections by antibody detection using the indirect immunofluorescence assay (IFA-IgM) and circumoval precipitin test (COPT). Serum samples of 572 individuals were randomly selected. The IFA-IgM and COPT were used to detect anti-S. mansoni antibodies. Of the patients studied, 15.9% (N = 91) were IFA-IgM positive and 5.1% (N = 29) had COPT reactions (P < 0.001 by McNemar's test). Immunodiagnostic techniques showed higher infection prevalence than had been previously estimated. This study suggests that combined use of these diagnostic tools could be useful for the diagnosis of schistosomiasis in epidemiological studies in areas of low endemicity. PMID:24639303

  12. Health implications of chronic hepatosplenomegaly in Kenyan school-aged children chronically exposed to malarial infections and Schistosoma mansoni

    DEFF Research Database (Denmark)

    Wilson, Shona; Vennervald, Birgitte J; Kadzo, Hilda;

    2010-01-01

    with hepatosplenomegaly. Children who presented with hepatosplenomegaly had the lowest height-for-age Z-scores. This study shows that hepatosplenomegaly associated with chronic exposure to malaria and schistosomiasis is not a benign symptom amongst school-aged children but has potential long-term health consequences.......Hepatosplenomegaly among school-aged children in sub-Saharan Africa is highly prevalent. Two of the more common aetiological agents of hepatosplenomegaly, namely chronic exposure to malaria and Schistosoma mansoni infection, can result in similar clinical presentation, with the liver and spleen...... investigated in a study area where children were chronically exposed to malaria throughout while S. mansoni transmission was geographically restricted. Hepatosplenomegaly was associated with increased portal vein diameters, with enlargement of the spleen rather than the liver being more closely associated...

  13. Hox genes in the parasitic platyhelminthes Mesocestoides corti, Echinococcus multilocularis, and Schistosoma mansoni: evidence for a reduced Hox complement.

    Science.gov (United States)

    Koziol, Uriel; Lalanne, Ana I; Castillo, Estela

    2009-02-01

    Little is known about the Hox gene complement in parasitic platyhelminthes (Neodermata). With the aim of identifying Hox genes in this group we performed two independent strategies: we performed a PCR survey with degenerate primers directed to the Hox homeobox in the cestode Mesocestoides corti, and we searched genomic assemblies of Echinococcus multilocularis and Schistosoma mansoni. We identified two Hox genes in M. corti, seven in E. multilocularis, and nine in S. mansoni (including five previously reported). The affinities of these sequences, and other previously reported Hox sequences from flatworms, were determined according to phylogenetic analysis, presence of characteristic parapeptide sequences, and unusual intron positions. Our results suggest that the last common ancestor of triclads and neodermatans had a Hox gene complement of at least seven genes, and that this was probably derived by gene loss from a larger ancestral Hox complement in lophotrochozoans.

  14. The role of antibody affinity and titre in immunity to Schistosoma mansoni following vaccination with highly irradiated cercariae

    Energy Technology Data Exchange (ETDEWEB)

    Vignali, D.A.A.; Devey, M.E.; Bickle, Q.D.; Taylor, M.G. (London School of Hygiene and Tropical Medicine (UK))

    1990-02-01

    Sera from rabbits and rats vaccinated with highly irradiated cercariae of Schistosoma mansoni (VRabS, VRatS) were found to be of substantially higher affinity than sera from CBA mice vaccinated four times (4 x CVMS), single sex sera (SSS) or chronic infection sera (CIS). In contrast, immunoprecipitation studies demonstrated that sera from vaccinated LA mice (LVMS) recognized {sup 125}I-labelled schistosomular surface antigens more intensely than sera from vaccinated HA mice (HVMS). However, peritoneal macrophages from HA and LA mice in the presence of HVMS, LVMS or 4 x CVMS, and naive macrophages activated in vitro with interferon-gamma (IFN-{gamma})/lipopolysaccharide (LPS) mediated comparable levels of schistosomula killing in vitro. The experiments described here provide evidence that the titre of antibody rather than its affinity may be a more critical factor in the development of optimal immunity to S. mansoni. (author).

  15. A cyclohexanecarboxamide derivative with inhibitory effects on Schistosoma mansoni cercarial serine protease and penetration of mice skin by the parasite.

    Science.gov (United States)

    Bahgat, Mahmoud; Aboul-Enein, Mohamed N; El Azzouny, Aida A; Maghraby, Amany; Ruppel, Andreas; Soliman, Wael M

    2009-01-01

    A cyclohexanecarboxamide derivative, N-phenyl-N-[1-(piperidine-1-carbonyl)cyclohexyl] benzamide (MNRC-5), was evaluated for its inhibitory effects on Schistosoma mansoni cercarial serine protease activity and cercarial penetration. MNRC-5 exerted an inhibitory effect on S. mansoni cercarial serine protease at serial concentrations of the specific chromogenic substrate Boc-Val-Leu-Gly-Arg-PNA for such enzyme family and the inhibitory coefficient (Ki) value was deduced. Moreover, topical treatment of mice tails with the most potent inhibitory concentration of MNRC-5 formulated in jojoba oil successfully blocked cercarial penetration as demonstrated by a significant reduction (75%; p jojoba oil base containing no MNRC-5. In addition, the IgM and IgG reactivities to crude S. mansoni cercarial, worm and egg antigens were generally lower in sera from treated infected mice than untreated infected mice. In conclusion, we report on a new serine protease inhibitor capable for blocking penetration of host skin by S. mansoni cercariae as measured by lowering worm burden and decrease in the levels of both IgM and IgG towards different bilharzial antigens upon topical treatment.

  16. Genome-wide identification of novel microRNAs and their target genes in the human parasite Schistosoma mansoni.

    Science.gov (United States)

    de Souza Gomes, Matheus; Muniyappa, Mohan Kumar; Carvalho, Sávio Gonçalves; Guerra-Sá, Renata; Spillane, Charles

    2011-08-01

    Mature microRNAs (miRNAs) are small, non-coding regulatory RNAs which can elicit post-transcriptional repression of mRNA levels of target genes. Here, we report the identification of 67 mature and 42 precursor miRNAs in the Schistosoma mansoni parasite. The evolutionarily conserved S. mansoni miRNAs consisted of 26 precursor miRNAs and 35 mature miRNAs, while we identified 16 precursor miRNAs and 32 mature miRNAs that displayed no conservation. These S. mansoni miRNAs are located on seven autosomal chromosomes and a sex (W) chromosome. miRNA expansion through gene duplication was suggested for at least two miRNA families miR-71 and mir-2. miRNA target finding analysis identified 389 predicted mRNA targets for the identified miRNAs and suggests that the sma-mir-71 may be involved in female sexual maturation. Given the important roles of miRNAs in animals, the identification and characterization of miRNAs in S. mansoni will facilitate novel approaches towards prevention and treatment of Schistosomiasis.

  17. Risk factors and spatial distribution of Schistosoma mansoni infection among primary school children in Mbita District, Western Kenya.

    Directory of Open Access Journals (Sweden)

    Sachiyo Nagi

    2014-07-01

    Full Text Available An increasing risk of Schistosoma mansoni infection has been observed around Lake Victoria, western Kenya since the 1970s. Understanding local transmission dynamics of schistosomiasis is crucial in curtailing increased risk of infection.We carried out a cross sectional study on a population of 310 children from eight primary schools. Overall, a total of 238 (76.8% children were infected with S. mansoni, while seven (2.3% had S. haematobium. The prevalence of hookworm, Trichuris trichiura and Ascaris lumbricoides were 6.1%, 5.2% and 2.3%, respectively. Plasmodium falciparum was the only malaria parasite detected (12.0%. High local population density within a 1 km radius around houses was identified as a major independent risk factor of S. mansoni infection. A spatial cluster of high infection risk was detected around the Mbita causeway following adjustment for population density and other potential risk factors.Population density was shown to be a major factor fuelling schistosome infection while individual socio-economic factors appeared not to affect the infection risk. The high-risk cluster around the Mbita causeway may be explained by the construction of an artificial pathway that may cause increased numbers of S. mansoni host snails through obstruction of the waterway. This construction may have, therefore, a significant negative impact on the health of the local population, especially school-aged children who frequently come in contact with lake water.

  18. Adenina fosforibosiltransferase de Schistosoma mansoni: proposta de detalhamento do mecanismo catalítico por dinâmica molecular

    OpenAIRE

    Victor Emanoel Armini Caldas

    2011-01-01

    A Adenina Fosforibosiltransferase (APRT E.C. 2.4.2.7) pertence à família de enzimas Fosforibosil Transferases (PRTase) do Tipo I , que catalisa a conversão reversível de Adenina e 5-fosfo-α-D-ribose-1-difosfato (PRPP) em difosfato e adenosina monofosfato, um importante precursor energético da célula. A APRT integra a via de salvação de purinas, única forma de suprir o balanço de purinas em Schistosoma mansoni. Este trabalho apresenta o isolamento, clonagem, expressão heteróloga e purif...

  19. Further evaluation of an updated PCR assay for the detection of Schistosoma mansoni DNA in human stool samples

    Directory of Open Access Journals (Sweden)

    Luciana I Gomes

    2009-12-01

    Full Text Available A previously reported sensitive PCR assay for the detection of Schistosoma mansoni DNA was updated and evaluated. Changes in the DNA extraction method, including the use of a worldwide available commercial kit and the inclusion of additional quality control measures, increased the robustness of the test, as confirmed by the analysis of 67 faecal samples from an endemic area in Brazil. The PCR assay is at hand as a proven, reliable diagnostic test for the control of schistosomiasis in specific settings.

  20. Avaliação in vitro do efeito imunomodulador do leite materno de camundongos infectados pelo Schistosoma mansoni

    OpenAIRE

    Sales,Iana Rafaela Fernandes

    2015-01-01

    A alta prevalência de esquistossomose crônica em gestantes, bem como em mulheres em idade fértil, tem sido amplamente relatada. Esta condição materna é capaz de alterar a resposta imune do descendente em longo prazo. O presente estudo teve o objetivo de avaliar o efeito in vitro do leite materno de mães infectadas pelo Schistosoma mansoni em esplenócitos e caracterizar os peptídeos encontrados nesse leite. Para isso, camundongos fêmeas infectadas ou não, tiveram seu leite coletado no 12º dia ...

  1. Modeling the distribution of Schistosoma mansoni and host snails in Uganda using satellite sensor data and Geographical Information Systems

    DEFF Research Database (Denmark)

    Stensgaard, Anna-Sofie; Jørgensen, A; Kabatereine, N B

    2005-01-01

    The potential value of MODIS satellite sensor data on Normalized Difference Vegetation Index (NDVI) and land surface temperatures (LST) for describing the distribution of the Schistosoma mansoni-"Biomphalaria pfeifferi"/Biomphalaria sudanica parasite-snail system in inland Uganda, were tested....... The parasite, however, appears to be restricted in its distribution in both the north-eastern and the south-western regions of Uganda. The absence of disease in the south-west can not be attributed to the absence of snail hosts. Results suggest a combination of satellite sensor data on temperature and standard...

  2. Trace elements in the human scalp hair and finger nails as affected by infection with Schistosoma mansoni

    Energy Technology Data Exchange (ETDEWEB)

    El-Khatib, A.M. (Alexandria Univ. (Egypt). Dept. of Physics); Bahnassy, A.A. (King Abdulaziz Univ., Jeddah (Saudi Arabia). Faculty of Medicine); Denton, M. (California Univ., Berkeley, CA (United States). Dept. of Nuclear Engineering)

    1995-01-01

    The concentration of 13 elements has been determined in finger nail and scalp hair of 4 groups representing normal and infected Schistosoma mansoni subjects. Samples were irradiated by thermal neutrons from a Triga Mark III Reactor, for 10 min. Measurements were made using a HPGe detector coupled with ADC and PDP 11/34 data processing equipment. The results showed significant increases of Al, Cl, I and Br in both finger nails and scalp hair of bilharzial patients above those of normal subjects while Mg, Ca, V, Mn, Cu, Sr, K, S and Na showed significant decreases. Most of the elements showed a higher concentration in finger nails than in hair. (author).

  3. Artesunate Effect on Schistosome Thioredoxin Glutathione Reductase and Cytochrome c Peroxidase as New Molecular Targets in Schistosoma mansoni-infected Mice

    Institute of Scientific and Technical Information of China (English)

    Amany A.Abdin; Dalia S.Ashour; Zeinab S.Shoheib

    2013-01-01

    Objective To investigate the possible effect of artesunate (ART) on schistosome thioredoxin glutathione reductase (TGR) and cytochrome c peroxidase (CcP) in Schistosoma mansoni-infected mice. Methods A total of 200 laboratory bred male Swiss albino mice were divided into 4 groups (50 mice in each group). Group I:infected untreated group (Control group) received a vehicle of 1%sodium carbonyl methylcellulose (CMC-Na); Group II: infected then treated with artesunate; Group III: infected then treated with praziquantel, and group IV:infected then treated with artesunate then praziquantel. Adult S. mansoni worms were collected by Animal Perfusion Method, tissue egg counted, TGR, and CcP mRNA Expression were estimated of in S. mansoni adult worms by semi-quantitative rt-PCR. Results Semi-quantitative rt-PCR values revealed that treatment with artesunate caused significant decrease in expression of schistosome TGR and CcP in comparison to the untreated group. In contrast, the treatment with praziquantel did not cause significant change in expression of these genes. The results showed more reduction in total worm and female worm count in combined ART-PZQ treated group than in monotherapy treated groups by either ART or PZQ. Moreover, complete disappearance (100%) of tissue eggs was recorded in ART-PZQ treated group with a respective reduction rate of 95.9%and 68.4%in ART-and PZQ-treated groups. Conclusion The current study elucidated for the first time that anti-schistosomal mechanisms of artesunate is mediated via reduction in expression of schistosome TGR and CcP. Linking these findings, addition of artesunate to praziquantel could achieve complete cure outcome in treatment of schistosomiasis.

  4. Schistosoma mansoni: ação da lovastatina no modelo murino

    Directory of Open Access Journals (Sweden)

    Araújo Neusa

    2002-01-01

    Full Text Available Com o objetivo de avaliar a ação da lovastatina na postura do Schistosoma mansoni foram usados camundongos infectados com 100 ±10 cercárias da cepa LE. Trinta dias após a infecção, os animais foram tratados com 100, 200 e 400mg/kg de lovastatina, via oral, durante cinco dias consecutivos e sacrificados 7,15,30 ou 60 dias após o tratamento. Foram analisados: distribuição de vermes no mesentério e fígado, mortalidade de vermes no fígado, alteração do oograma, contagem de ovos no jejuno e fígado, presença de ovos intra-uterino e morfologia dos vermes dos grupos tratados e controle (animais infectados e não tratados. Diferenças estatisticamente significativas foram encontradas, na dose de 400mg/kg, entre grupos tratados e controles quando se considerou a presença de ovos no útero, a alteração do oograma, ovos nos diferentes estágios de desenvolvimento no jejuno e fígado e no comprimento do corpo dos vermes machos e fêmeas. O estudo morfológico dos vermes mostrou alterações degenerativas sendo as principais no aparelho reprodutor, com redução e alteração dos folículos vitelínicos e do ovário das fêmeas e modificações nos testículos dos machos. Os resultados apresentados levam à conclusão que a droga em estudo reduz, consideravelmente, a oviposição das fêmeas do S. mansoni, aumenta o tamanho dos vermes, provoca alterações no sistema reprodutivo de machos e fêmeas e pode ocasionar morte de parte significativa da população de vermes na dose de 400mg/kg.

  5. A Novel Toll-Like Receptor (TLR Influences Compatibility between the Gastropod Biomphalaria glabrata, and the Digenean Trematode Schistosoma mansoni.

    Directory of Open Access Journals (Sweden)

    Emmanuel A Pila

    2016-03-01

    Full Text Available Schistosomiasis, a devastating disease caused by parasitic flatworms of the genus Schistosoma, affects over 260 million people worldwide especially in tropical and sub-tropical regions. Schistosomes must undergo their larval development within specific species of snail intermediate hosts, a trait that is shared among almost all digenean trematodes. This unique and long-standing host-parasite relationship presents an opportunity to study both the importance of conserved immunological features in novel immunological roles, as well as new immunological adaptations that have arisen to combat a very specific type of immunological challenge. While it is well supported that the snail immune response is important for protecting against schistosome infection, very few specific snail immune factors have been identified and even fewer have been functionally characterized. Here, we provide the first functional report of a snail Toll-like receptor, which we demonstrate as playing an important role in the cellular immune response of the snail Biomphalaria glabrata following challenge with Schistosoma mansoni. This TLR (BgTLR was identified as part of a peptide screen of snail immune cell surface proteins that differed in abundance between B. glabrata snails that differ in their compatibility phenotype to challenge by S. mansoni. The S. mansoni-resistant strain of B. glabrata (BS-90 displayed higher levels of BgTLR compared to the susceptible (M-line strain. Transcript expression of BgTLR was found to be very responsive in BS-90 snails when challenged with S. mansoni, increasing 27 fold relative to β-actin (non-immune control gene; whereas expression in susceptible M-line snails was not significantly increased. Knockdown of BgTLR in BS-90 snails via targeted siRNA oligonucleotides was confirmed using a specific anti-BgTLR antibody and resulted in a significant alteration of the resistant phenotype, yielding patent infections in 43% of the normally resistant

  6. Antischistosomal activity of acridanone- hydrazones in Cebus monkeys experimentally infected with the SJ strain of Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Paulo Marcos Zech Coelho

    1995-09-01

    Full Text Available In this study, four compounds were utilized at the dose of 12.5mg/kg body weight, p.o., to treat Cebus monkeys experimentally infected with about 200 cercariae of Schistosoma mansoni (SJ strain, via transcutaneous route. The oograms performed with rectal snips, as well as stool examinations carried out periodically, showed no viable eggs of the parasite, from day 29 to 226post-treatment. The perfusion undertaken after killing the animals showed absence of worms in the treated monkeys, whereas 83 worms were recovered from the control, thus corroborating the results obtained by means of oograms and coproscopy. These results confirm the efficacy of 9-acridanone- hydrazones previously tested against the LE strain of S. mansoni. The low curative dose and apparent absence of toxicity render these dmgs an important therapeutic reserve, taking into consideration the reports on the resistance of S. mansoni to the modern drugs oxamniquine and praziquantel.No presente trabalho, quatro compostos foram utilizados na dose de 12,5mg/kg de peso, por via oral, em macacos infectados transcutaneamente com cerca de 200 cercárias de Schistosoma mansoni. Os oogramas realizados com fragmentos de mucosa retal e os exames de fezes realizados, periodicamente, demonstraram a ausência de ovos viáveis do parasito a partir do 29- até o 226a dia pós-tratamento. A perfusão, apôs sacrifício dos animais tratados, não detectou vermes, enquanto que do macaco cotztrole 83 vermes foram recuperados, confirmando assim os resultados dos oogramas e da coproscopia. Estes resultados confirmam a eficácia das 9-acridanonas- hydrazonas já observada anteriormente contra a cepa LE de S. mansoni. A baixa dosagem curativa e aparente ausência de toxicidade colocam estas drogas como uma reserva terapêutica importante, tendo em vista o relato de resistência do S. mansoni às drogas modernas oxamniquína e praziquantel.

  7. Estudo quantitativo de metais presentes na hemolinfa de Biomphalaria glabrata (Gastropoda, infectadas e não infectadas com Schistosoma mansoni Quantitative study of metal present in the hemolymph of Biomphalaria glabrata (Gastropoda, infected and uninfected with Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Marco Antonio Vasconcelos Santos

    2005-04-01

    Full Text Available Inicialmente, desenvolveu-se um estudo para quantificar e comparar as concentrações de alguns metais presentes em duas amostras de hemolinfa do caramujo Biomphalaria glabrata (infectados e não-infectados com Schistosoma mansoni. A espectrometria de emissão óptica com fonte de plasma induzido (ICP-OES, foi utilizada para analisar os metais nas duas amostras. Os metais estudados foram: alumínio, cálcio, cádmio, cobalto, cromo, cobre, ferro, potássio, magnésio, manganês, chumbo e zinco. Os resultados mostram que, a princípio, os metais não são fatores determinantes no processo de defesa desses organismos contra este parasita, quando presente nos seus tecidos.We conducted a preliminary study to quantify and compare two concentrations of the same metals present in the hemolymph of snail Biomphalaria glabrata. In this context, we used Induction Coupled Plasma Optical Emission Spectroscopy technique (ICP-OES, to analyze the metals in the two samples (snails infected and not infected with Schistosoma mansoni. The metals studied were: aluminum, calcium, cadmium, cobalt, chromium, copper, iron, potassium, magnesium, manganese, lead and zinc. Preliminary results showed that such metals are not involved in the defense of these organisms against the parasite, when present in their tissues.

  8. Antigens of worms and eggs showed a differentiated detection of specific IgG according to the time of Schistosoma mansoni infection in mice

    Directory of Open Access Journals (Sweden)

    Rafaella Fortini Queiroz Grenfell

    2012-08-01

    Full Text Available INTRODUCTION: The correlation between the immunological assay and the antibody titer can offer a tool for the experimental analysis of different phases of the disease. METHODS: Two simple immunological assays for Schistosoma mansoni in mice sera samples based on specific IgG detection for worms soluble antigens and eggs soluble antigens were standardized and evaluated in our laboratory. Fifty mice were used in negative and positive groups and the results obtained by enzyme-linked immunosorbent assays (ELISA assays were compared with the number of worms counted and the IgG titers at different times of infection. RESULTS: Data showed that ELISA using adult worm antigens (ELISA-SWAP presented a satisfactory correlation between the absorbance value of IgG titers and the individual number of worms counted after perfusion technique (R²=0.62. In addition, ELISA-SWAP differentially detected positive samples with 30 and 60 days post infection (p=0.011 and 0.003, respectively, whereas ELISA using egg antigens (ELISA-SEA detected samples after 140 days (p=0.03. CONCLUSIONS: These data show that the use of different antigens in immunological methods can be used as potential tools for the analysis of the chronological evolution of S. mansoni infection in murine schistosomiasis. Correlations with human schistosomiasis are discussed.

  9. Schistosoma mansoni polo-like kinases and their function in control of mitosis and parasite reproduction

    Directory of Open Access Journals (Sweden)

    Colette Dissous

    2011-06-01

    Full Text Available Polo-like kinases are important regulators of cell cycle progression and mitosis. They constitute a family of conserved serine/threonine kinases which are highly related in their catalytic domains and contain polo boxes involved in protein-protein interactions and subcellular localization. In mammals, five Plks (Plk 1-5 encompass diverse roles in centrosome dynamics, spindle formation, intra S-phase and G2/M checkpoints and DNA damage response. Plk1 is a key positive regulator of mitosis and is overexpressed in various types of cancers. Plk4 is a divergent member of the Plk family, with essential functions in centriole duplication. Homozygous disruption of Plk1 or Plk4 in mice is lethal in embryos. Two Plk members SmPlk1 and SmSak, homologous to Plk1 and Plk4 respectively, are present in the parasitic platyhelminth Schistosoma mansoni. Structural and functional analyses of SmPlk1 have demonstrated its conserved function in the regulation of cell cycle G2/M transition in Xenopus oocytes. The anti-cancer drug BI 2536 (the most potent and selective Plk1 inhibitor inhibits specifically the catalytic activity of SmPlk1 and induced profound alterations in schistosome gonads, indicating a role of SmPlk1 in parasite gametogenesis and its potential as a novel chemotherapeutic target against schistosomiasis. Functions of SmSak in cell cycle regulation and schistosome gonad development are currently investigatedQuinases do tipo Polo ("polo-like" são importantes reguladores da progressão do ciclo celular e da mitose. Elas constituem uma família de serina/treonina quinases que são altamente relacionadas entre si no seu domínio catalítico e contêm blocos "polo" envolvidos com interações proteína-proteína e com localização subcelular. Em mamíferos, cinco Plks (Plk 1-5 englobam diversos papéis na dinâmica do centrossomo, formação do fuso, "checkpoints" dentro da fase S e da transição G2/M, e na resposta aos danos do DNA. Plk1 é um regulador

  10. Decay of antibody isotypes against early developmental stages of Schistosoma mansoni after treatment of schistosomiasis patients

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    Herminia Yohko KANAMURA

    1997-09-01

    Full Text Available Antibodies to a number of parasite antigens are found in schistosomiasis patients, and antibodies to early developmental stages were demonstrated to be efficient immunologic markers for the diagnosis of schistosomiasis. In the present study, decay patterns of IgM and IgG antibodies against cercariae and schistosomula were investigated, in comparison to antibodies against worms and eggs in schistosomiasis patients after chemotherapy, for an investigation of seroepidemiologic aspects. Data obtained in the study of 359 serum samples from patients with Schistosoma mansoni infection, noninfected individuals, and patients followed-up for a period of 12 to 15 months after treatment provided the basis to postulate a general pattern for the kinetics of antibody decay. Before treatment, the antibody pattern was represented by a unimodal curve, which shifted to a bimodal curve after treatment, and ended with a unimodal curve similar to that for the noninfected group. Different types of antibodies were classified into four categories according to their decay features, and anti-schistosomulum IgM was classified into the moderate-decay caterogy, whereas other antibodies to early parasite stages were classified into the slow-decay category. The present methodology permits the identification of the most suitable antibodies to be detected in field control programs for schistosomiasis or other parasitosesEm pacientes com esquistossomose, são encontrados anticorpos contra grande número de antígenos parasitários, e aqueles contra formas evolutivas jovens do parasita demonstraram que eram eficientes marcadores imunológicos para o diagnóstico da esquistossomose. Padrões de queda de anticorpos IgM e IgG contra cercária e esquistossômulo foram aqui estudados, comparativamente aos dos anticorpos contra verme e ovo, em pacientes esquistossomóticos após quimioterapia, abordando aspectos soroepidemiológicos. Dados obtidos no estudo de 359 amostras de soros

  11. Antischistosomal activity of ginger (Zingiber officinale) against Schistosoma mansoni harbored in C57 mice.

    Science.gov (United States)

    Mostafa, Osama M S; Eid, Refaat A; Adly, Mohamed A

    2011-08-01

    The repeated chemotherapy of schistosomiasis has resulted in the emergence of drug-resistant schistosome strains. The development of such resistance has drawn the attention of many authors to alternative drugs. Many medicinal plants were studied to investigate their antischistosomal potency. The present work aimed to evaluate antischistosomal activity of crude aqueous extract of ginger against Schistosoma mansoni. Sixteen mice of C57 strain were exposed to 100 ± 10 cercariae per mouse by the tail immersion method; the mice were divided into two groups: untreated group and ginger-treated one. All mice were sacrificed at the end of 10th week post-infection. Worm recovery and egg counting in the hepatic tissues and faeces were determined. Surface topography of the recovered worms was studied by scanning electron microscopy. Histopathological examination of liver and intestine was done using routine histological procedures. The worm burden and the egg density in liver and faeces of mice treated with ginger were fewer than in non-treated ones. Scanning electron microscopical examination revealed that male worms recovered from mice treated with ginger lost their normal surface architecture, since its surface showed partial loss of tubercles' spines, extensive erosion in inter-tubercle tegumental regions and numerous small blebs around tubercles. Histopathological data indicated a reduction in the number and size of granulomatous inflammatory infiltrations in the liver and intestine of treated mice compared to non-treated mice. The results of the present work suggested that ginger has antischistosomal activities and provided a basis for subsequent experimental and clinical trials.

  12. Suscetibilidade de biomphalaria glabrata, B. straminea e B. tenagophila a diferentes cepas de schistosoma mansoni

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    Luiz Candido de Souza Dias

    1987-08-01

    Full Text Available Em condições experimentais foi estudada a suscetibilidade de Biomphalaria glabrata, B. straminea e B. tenagophila a quatro linhagens humanas (MAP, PTH, UPH, e OuH e duas de roedores silvestres (PTR e VPR do Schistosoma mansoni. Grupos de 50 moluscos foram expostos individualmente a 10 miracídios e observados durante 70 dias. Avaliou-se a suscetibilidade dos moluscos ao parasito por meio da % de animais com esporocistos, % de moluscos que eliminavam cercárias e mortalidade conjunta dos animais expostos e infectados. Exemplares de B. glabrata mineira infectaram-se com cepa simpátrica (MAP e com 5 alopátricas do Estado de São Paulo (PTH, VPH, OuH, PTR e VPR. B. glabrata paulista mostrou altas taxas de infecção com as cepas MAP, VPR e OuH do trematódeo. Quatro % dos exemplares B. straminea de São Paulo eliminavam cercárias de cepas simpátricas; com cepa mineira apenas 4% apresentaram esporocistos na vigência de 20 miracídios por molusco; as menores taxas de mortalidade foram registradas com essa espécie de molusco, não sendo maior do que 20%. B. tenagophila paulista foi suscetível apenas às linhagens simpáticas sendo 6% a maior taxa de moluscos que eliminaram cercárias. Os resultados indicam que os movimentos populacionais humanos dentro do território paulista e para fora dele são importantes na disseminação da esquistossomose mansônica.

  13. The use of microencapsulated hepatocytes transplantation reduces mortality and liver alterations in Schistosoma mansoni infected hamsters.

    Science.gov (United States)

    Sherif, Soad A; Moharib, Mona N; El-Lakkany, Naglaa M; Hammam, Olfat A; Salman, Fatma H; El-Naggar, Mohamed M

    2014-04-01

    Hepatocyte transplantation is an attractive therapeutic modality for liver disease as an alternative for orthotropic liver transplantation. The goal of this work was to study the adequacy of intrasplenic hepatocyte transplantation (HCTx) in fresh and microencapsulated forms, in a hamster model of liver fibrosis by Schistosoma mansoni infected hamsters were divided into 6 groups; untreated for 11 weeks (GI) and for 15 weeks (GII), treated with praziquantel (PZQ) 7 weeks PI, and killed 4 weeks (GIII) and 8 weeks (GIV) post-treatment. Treated with PZQ 7 weeks PI, and then treated orally with immunosuppressive drug "cyclosporine (4 weeks post PZQ treatment), 24 hr. before interasplenic injection with fresh hepatocytes (V). Treated with PZQ 7 weeks PI, and then injected interasplenically (4 weeks post-treatment) with microencapsulated hepatocytes (GVI). GI & GIII were killed 11 weeks PI for assessment the anti-schistosomal efficacy of PZQ. The other four groups were killed 15 weeks PI for investigation of liver and spleen histology, serum liver enzymes and hepatic oxidative markers before and after HCTx. Freshly isolated hepatocytes with a mean viability 92.97 +/- 1.2% were used for microencapsulation and transplantation. Histological study showed the presence of transplanted hepatocytes in spleen of recipient. PZQ accelerated healing of hepatic granulomatous lesions as evidenced parasitologically by the increase in the percentage of dead eggs and histologically showing more granuloma circumscription with more ova degeneration and less inflammatory cells. The 25-day survival rates in GII, GIV, GV& GVI were 5/15 (33.3%), 8/15 (53.3%), 10/15 (66.7%) and 9/15 (60%) respectively. In addition, there were significantly better outcomes in serum biochemical indexes such as ALT, AST, gamma-GT, ALP, and hepatic SOD and MDA in the fresh and microencapsulated groups than in PZQ-treated group, without great differences between the microencapsulated and the fresh transplanted groups

  14. Septins of Platyhelminths: identification, phylogeny, expression and localization among developmental stages of Schistosoma mansoni.

    Science.gov (United States)

    Zeraik, Ana E; Rinaldi, Gabriel; Mann, Victoria H; Popratiloff, Anastas; Araujo, Ana P U; Demarco, Ricardo; Brindley, Paul J

    2013-01-01

    Septins are a family of eukaryotic GTP binding proteins conserved from yeasts to humans. Originally identified in mutants of budding yeast, septins participate in diverse cellular functions including cytokinesis, organization of actin networks, cell polarity, vesicle trafficking and many others. Septins assemble into heteroligomers to form filaments and rings. Here, four septins of Schistosoma mansoni are described, which appear to be conserved within the phylum Platyhelminthes. These orthologues were related to the SEPT5, SEPT10 and SEPT7 septins of humans, and hence we have termed the schistosome septins SmSEPT5, SmSEPT10, SmSEPT7.1 and SmSEPT7.2. Septin transcripts were detected throughout the developmental cycle of the schistosome and a similar expression profile was observed for septins in the stages examined, consistent with concerted production of these proteins to form heterocomplexes. Immunolocalization analyses undertaken with antibodies specific for SmSEPT5 and SmSEPT10 revealed a broad tissue distribution of septins in the schistosomulum and colocalization of septin and actin in the longitudinal and circular muscles of the sporocyst. Ciliated epidermal plates of the miracidium were rich in septins. Expression levels for these septins were elevated in germ cells in the miracidium and sporocyst. Intriguingly, septins colocalize with the protonephridial system of the cercaria, which extends laterally along the length of this larval stage. Together, the findings revealed that schistosomes expressed several septins which likely form filaments within the cells, as in other eukaryotes. Identification and localization demonstrating a broad distribution of septins across organs and tissues of schistosome contributes towards the understanding of septins in schistosomes and other flatworms.

  15. Septins of Platyhelminths: identification, phylogeny, expression and localization among developmental stages of Schistosoma mansoni.

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    Ana E Zeraik

    Full Text Available Septins are a family of eukaryotic GTP binding proteins conserved from yeasts to humans. Originally identified in mutants of budding yeast, septins participate in diverse cellular functions including cytokinesis, organization of actin networks, cell polarity, vesicle trafficking and many others. Septins assemble into heteroligomers to form filaments and rings. Here, four septins of Schistosoma mansoni are described, which appear to be conserved within the phylum Platyhelminthes. These orthologues were related to the SEPT5, SEPT10 and SEPT7 septins of humans, and hence we have termed the schistosome septins SmSEPT5, SmSEPT10, SmSEPT7.1 and SmSEPT7.2. Septin transcripts were detected throughout the developmental cycle of the schistosome and a similar expression profile was observed for septins in the stages examined, consistent with concerted production of these proteins to form heterocomplexes. Immunolocalization analyses undertaken with antibodies specific for SmSEPT5 and SmSEPT10 revealed a broad tissue distribution of septins in the schistosomulum and colocalization of septin and actin in the longitudinal and circular muscles of the sporocyst. Ciliated epidermal plates of the miracidium were rich in septins. Expression levels for these septins were elevated in germ cells in the miracidium and sporocyst. Intriguingly, septins colocalize with the protonephridial system of the cercaria, which extends laterally along the length of this larval stage. Together, the findings revealed that schistosomes expressed several septins which likely form filaments within the cells, as in other eukaryotes. Identification and localization demonstrating a broad distribution of septins across organs and tissues of schistosome contributes towards the understanding of septins in schistosomes and other flatworms.

  16. Septins of Platyhelminths: Identification, Phylogeny, Expression and Localization among Developmental Stages of Schistosoma mansoni

    Science.gov (United States)

    Zeraik, Ana E.; Rinaldi, Gabriel; Mann, Victoria H.; Popratiloff, Anastas; Araujo, Ana P. U.; DeMarco, Ricardo; Brindley, Paul J.

    2013-01-01

    Septins are a family of eukaryotic GTP binding proteins conserved from yeasts to humans. Originally identified in mutants of budding yeast, septins participate in diverse cellular functions including cytokinesis, organization of actin networks, cell polarity, vesicle trafficking and many others. Septins assemble into heteroligomers to form filaments and rings. Here, four septins of Schistosoma mansoni are described, which appear to be conserved within the phylum Platyhelminthes. These orthologues were related to the SEPT5, SEPT10 and SEPT7 septins of humans, and hence we have termed the schistosome septins SmSEPT5, SmSEPT10, SmSEPT7.1 and SmSEPT7.2. Septin transcripts were detected throughout the developmental cycle of the schistosome and a similar expression profile was observed for septins in the stages examined, consistent with concerted production of these proteins to form heterocomplexes. Immunolocalization analyses undertaken with antibodies specific for SmSEPT5 and SmSEPT10 revealed a broad tissue distribution of septins in the schistosomulum and colocalization of septin and actin in the longitudinal and circular muscles of the sporocyst. Ciliated epidermal plates of the miracidium were rich in septins. Expression levels for these septins were elevated in germ cells in the miracidium and sporocyst. Intriguingly, septins colocalize with the protonephridial system of the cercaria, which extends laterally along the length of this larval stage. Together, the findings revealed that schistosomes expressed several septins which likely form filaments within the cells, as in other eukaryotes. Identification and localization demonstrating a broad distribution of septins across organs and tissues of schistosome contributes towards the understanding of septins in schistosomes and other flatworms. PMID:24367716

  17. Schistosomal myeloradiculopathy due to Schistosoma mansoni: Report on 17 cases from an endemic area

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    Badr Hatem

    2011-01-01

    Full Text Available Background: After malaria, schistosomiasis is the second most prevalent tropical disease. The prevalence of oviposition in CNS of infected persons varies from 0.3 to 30%. The conus medullaris is a primary site of schistosomiasis, either granulomatous or acute necrotizing myelitis. Objective: To report the clinical, radiological, and laboratory results of spinal cord schistosomiasis (SCS and to design proper therapeutic regimens. Materials and Methods: Seventeen patients (13 males and four females with SCS were enrolled between 1994 and 2009 at Mansoura University Hospitals. Their median age at diagnosis was 19 years (13-30 years. Independent neurological, radiological, and laboratory assessments were performed for both groups, excluding pathological confirmation that was done earlier in eight patients (Group 1. In the group 2 (nine patients, indirect hemagglutination (IHA test for bilharziasis in blood and cerebrospinal fluid (CSF was performed. Higher positive titer in CSF than serum indicated SCS plus induction of antibilharzial and corticosteroid protocols for 12 months with a three-year follow-up. Results: Rate of neurological symptoms of granulomatous intramedullary cord lesion was assessed independently in 16 cases and acute paraparesis in one case. All patients in group 2 had positive IHA against Schistosoma mansoni with median CSF and serum ranges 1/640 and 1/320, respectively. Seven patients (41.18% had complete recovery, eight patients (47.06% showed partial recovery, and no response was reported in two patients (11.76% (P = 0.005. There was no recorded mortality in the current registry. Conclusions: Rapid diagnosis of SCS with early medical therapies for 12 months is a crucial tool to complete recovery.

  18. Characteristics of the human host have little influence on which local Schistosoma mansoni populations are acquired.

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    Lúcio M Barbosa

    Full Text Available BACKGROUND: Brazil remains the country in the Americas with the highest prevalence of schistosomiasis. A combination of control efforts and development, however, has sharply reduced its intensity and distribution. The acquisition of specific schistosome populations may be dependent on host characteristics such as sex, age, geography, work, habits and culture. How these and other host characteristics align with parasite subpopulations may guide approaches to improve control. METHODOLOGY: A cohort of more than 90% of the residents in two rural communities in Brazil participated in an epidemiologic survey of demographic, socio-economic and behavioral characteristics. The variables sex, age, intensity of infection, socio-economic index, % lifetime spent on site, previous infection, and trips outside the district were used to group parasites infecting individuals. Schistosoma mansoni infection status was determined by examination of stools submitted on 3 different days. The aggregate of eggs collected from the whole stool was used to determine degree of population differentiation from allele frequencies for 15 microsatellites. CONCLUSIONS/SIGNIFICANCE: Infection prevalence was 41% for these communities, and the epidemiologic characteristics were similar to many of the endemic areas of Brazil and the world. Parasite population structuring was observed between the two communities (Jost's D 0.046, CI95% 0.042-0.051, although separated by only 8 km and connected by a highway. No structuring was observed when infected individuals were stratified by host's biologic, demographic or epidemiologic characteristics. Those most heavily infected best reflected the communities' overall parasite diversity. The lack of differentiation within villages suggests that individuals are likely to get infected at the same sites or that the same parasite multilocus genotypes can be found at most sites. The geographic structuring between villages and the lack of structuring

  19. Schistosoma mansoni: parasitology and immunology of baboons vaccinated with irradiated cryopreserved schistosomula

    Energy Technology Data Exchange (ETDEWEB)

    Damian, R.T.; Powell, M.R.; Roberts, M.L. (Georgia Univ., Athens (USA). Dept. of Zoology); Clark, J.D. (Georgia Univ., Athens (USA). Lab. Animal Medicine); Stirewalt, M.A.; Lewis, F.A. (Biomedical Research Inst., Rockville, MD (USA))

    1985-06-01

    Young baboons (Papio cynocephalus) were vaccinated with ..gamma..-irradiated (500 Gy) cryopreserved Puerto Rican strain schistosomula of S. mansoni. Protection against heterologous, normal Kenyan Strain S. mansoni challenge infection was erratic and partial; and two putative correlates of immunity, reduced worm fecundity and change in worm location (anterior shift) were not observed. However, immunization of baboons with this vaccine resulted in a stimulated immune system. Both cellular and humoral anamnesis were demonstrable in vaccinated-challenged baboons. Schistosome infection-associated IgM hypergammaglobulinemia was also greatly reduced in vaccinated-challenged baboons. However IgG antibodies to adult, egg, and cercarial antigens were increased after challenge infection in preimmunized baboons. Vaccination appears to have resulted in a redirection of the immune system into anti-parasite channels, but this more specific immune response was insufficient to confer good protection against challenge infection in this experiment. The dampening effect of the vaccine on the hypergammaglobulinemia of schistosomiasis is another candidate for a possible ''anti-pathogenesis'' effect of irradiated schistosome larval vaccines.

  20. Schistosoma mansoni: continuous variation in susceptibility of the vector snail of schistosomiasis, Biomphalaria tenagophila I. Self-fertilization-lineage.

    Science.gov (United States)

    Mascara, D; Kawano, T; Magnanelli, A C; Silva, R P; Sant' Anna, O A; Morgante, J S

    1999-11-01

    Mascara, D., Kawano, T., Magnanelli, A. C., Silva, R. P. S., Sant' Anna, O. A., and Morgante, J. S. 1999. Schistosoma mansoni: continuous variation in susceptibility of the vector snail of schistosomiasis, Biomphalaria tenagophila I. Self-Fertilization-Lineage. Experimental Parasitology 93, 133-141. Artificial selection of Biomphalaria tenagophila snails for susceptibility to infection by Schistosoma mansoni (Brazilian SJ strain) was carried out from natural populations. After five self-fertilization generations, two lineages were isolated and were designated as SUSC (highly susceptible 93-100%) and RES (nonsusceptible 5-0%). Length of the prepatent period, cercarial production, and mortality of the hosts in postexposure were determined in all generations (F(1)-F(8)) and were analyzed as quantitative traits related to host susceptibility. Distribution patterns of frequencies were observed within snail families (samples derived from one F(0) snail), these traits showing a significant influence by selection applied to susceptibility. The multiple quantitative classes were described in terms of continuous variation. During the selection of SUSC lineage, classes with higher values of prepatent length and lower cercarial production were eliminated, and the heritability calculated for these two traits was 0.811 and 0.709, respectively. Experimental results were correlated with an increase in the level of susceptibility in the generations selected and are discussed in relation to inheritance patterns as well as the quantitative variation of susceptibility.

  1. A loop-mediated isothermal amplification (LAMP assay for early detection of Schistosoma mansoni in stool samples: a diagnostic approach in a murine model.

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    Pedro Fernández-Soto

    2014-09-01

    Full Text Available Human schistosomiasis, mainly due to Schistosoma mansoni species, is one of the most prevalent parasitic diseases worldwide. To overcome the drawbacks of classical parasitological and serological methods in detecting S. mansoni infections, especially in acute stage of the disease, development of cost-effective, simple and rapid molecular methods is still needed for the diagnosis of schistosomiasis. A promising approach is the loop-mediated isothermal amplification (LAMP technology. Compared to PCR-based assays, LAMP has the advantages of reaction simplicity, rapidity, specificity, cost-effectiveness and higher amplification efficiency. Additionally, as results can be inspected by the naked eye, the technique has great potential for use in low-income countries.A sequence corresponding to a mitochondrial S. mansoni minisatellite DNA region was selected as a target for designing a LAMP-based method to detect S. mansoni DNA in stool samples. We used a S. mansoni murine model to obtain well defined stool and sera samples from infected mice with S. mansoni cercariae. Samples were taken weekly from week 0 to 8 post-infection and the Kato-Katz and ELISA techniques were used for monitoring the infection. Primer set designed were tested using a commercial reaction mixture for LAMP assay and an in house mixture to compare results. Specificity of LAMP was tested using 16 DNA samples from different parasites, including several Schistosoma species, and no cross-reactions were found. The detection limit of our LAMP assay (SmMIT-LAMP was 1 fg of S. mansoni DNA. When testing stool samples from infected mice the SmMIT-LAMP detected S. mansoni DNA as soon as 1 week post-infection.We have developed, for the first time, a cost-effective, easy to perform, specific and sensitive LAMP assay for early detection of S. mansoni in stool samples. The method is potentially and readily adaptable for field diagnosis and disease surveillance in schistosomiasis-endemic areas.

  2. Evaluation of Circulating Cathodic Antigen (CCA) Urine-Tests for Diagnosis of Schistosoma mansoni Infection in Cameroon

    Science.gov (United States)

    Tchuem Tchuenté, Louis-Albert; Kueté Fouodo, Césaire Joris; Kamwa Ngassam, Romuald Isaka; Sumo, Laurentine; Dongmo Noumedem, Calvine; Kenfack, Christian Mérimé; Gipwe, Nestor Feussom; Nana, Esther Dankoni; Stothard, J. Russell; Rollinson, David

    2012-01-01

    Background The Kato-Katz is the most common diagnostic method for Schistosoma mansoni infection. However, the day-to-day variability in host egg-excretion and its low detection sensitivity are major limits for its use in low transmission zones and after widespread chemotherapy. We evaluated the accuracy of circulating cathodic antigen (CCA) urine-assay as a diagnostic tool of S. mansoni. In comparison, a low sensitive CCA test (CCA-L) was assessed. Methodology The study was conducted in three settings: two foci with single S. mansoni infections (settings A and B), and one mixed S. mansoni – S. haematobium focus (setting C). Stool and urine samples were collected from school-children on three consecutive days. Triplicate Kato-Katz readings were performed per stool sample. Each urine sample was tested with one CCA and only the first urine sample was subjected to CCA-L. Urine samples were also examined for S. haematobium eggs using the filtration method and for microhaematuria using urine reagent strips. Overall, 625 children provided three stool and three urine samples. Principal Findings Considering nine Kato-Katz thick smears as ‘reference’ diagnostic test, the prevalence of S. mansoni was 36.2%, 71.8% and 64.0% in settings A, B and C, respectively. The prevalence of S. haematobium in setting C was 12.0%. The sensitivities of single Kato-Katz, CCA and CCA-L from the first stool or urine samples were 58%, 82% and 46% in setting A, 56.8%, 82.4% and 68.8% in setting B, and 49.0%, 87.7% and 55.5% in setting C. The respective specificities were 100%, 64.7% and 100%; 100%, 62.3% and 91.3%; and 100%, 42.5% and 92.0%. Mixed infection with S. haematobium did not influence the CCA test results for S. mansoni diagnosis. Conclusions/Significance Urine CCA revealed higher sensitivity than CCA-L and triplicate Kato-Katz, and produced similar prevalence as nine Kato-Katz. It seems an attractive method for S. mansoni diagnosis. PMID:22860148

  3. Evaluation of circulating cathodic antigen (CCA urine-tests for diagnosis of Schistosoma mansoni infection in Cameroon.

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    Louis-Albert Tchuem Tchuenté

    Full Text Available BACKGROUND: The Kato-Katz is the most common diagnostic method for Schistosoma mansoni infection. However, the day-to-day variability in host egg-excretion and its low detection sensitivity are major limits for its use in low transmission zones and after widespread chemotherapy. We evaluated the accuracy of circulating cathodic antigen (CCA urine-assay as a diagnostic tool of S. mansoni. In comparison, a low sensitive CCA test (CCA-L was assessed. METHODOLOGY: THE STUDY WAS CONDUCTED IN THREE SETTINGS: two foci with single S. mansoni infections (settings A and B, and one mixed S. mansoni - S. haematobium focus (setting C. Stool and urine samples were collected from school-children on three consecutive days. Triplicate Kato-Katz readings were performed per stool sample. Each urine sample was tested with one CCA and only the first urine sample was subjected to CCA-L. Urine samples were also examined for S. haematobium eggs using the filtration method and for microhaematuria using urine reagent strips. Overall, 625 children provided three stool and three urine samples. PRINCIPAL FINDINGS: Considering nine Kato-Katz thick smears as 'reference' diagnostic test, the prevalence of S. mansoni was 36.2%, 71.8% and 64.0% in settings A, B and C, respectively. The prevalence of S. haematobium in setting C was 12.0%. The sensitivities of single Kato-Katz, CCA and CCA-L from the first stool or urine samples were 58%, 82% and 46% in setting A, 56.8%, 82.4% and 68.8% in setting B, and 49.0%, 87.7% and 55.5% in setting C. The respective specificities were 100%, 64.7% and 100%; 100%, 62.3% and 91.3%; and 100%, 42.5% and 92.0%. Mixed infection with S. haematobium did not influence the CCA test results for S. mansoni diagnosis. CONCLUSIONS/SIGNIFICANCE: Urine CCA revealed higher sensitivity than CCA-L and triplicate Kato-Katz, and produced similar prevalence as nine Kato-Katz. It seems an attractive method for S. mansoni diagnosis.

  4. Schistosoma mansoni infection prevalence and associated risk factors among schoolchildren in Demba Girara, Damot Woide District of Wolaita Zone, Southern Ethiopia

    Institute of Scientific and Technical Information of China (English)

    Bereket Alemayehu; Zewdneh Tomass

    2015-01-01

    Objective:To establish the prevalence and associated risk factors of Schistosoma mansoni (S. mansoni) infection among schoolchildren at a village in Wolaita Zone, Sothern Ethiopia. Methods:A cross-sectional study was carried out among primary schoolchildren. A total of 384 randomly selected study subjects provided stool samples for parasitological examination by Kato-Katz and Formalin-Ether concentration techniques. Secondary parasitological data were obtained from Health Center Laboratory to see the previous history of S. mansoni infection in the area. Statistical analysis was performed using SPSS software version 16. Results:From the total children examined, 85.4%were found positive for at least one helminth infection. S. mansoni infection (81.3%) was the most prevalent and the prevalence of STH was 32%. Moderate and heavy infection intensities were only observed in S. mansoni infections. The overall heavy intensity of infection was 56.4%. Contact to Bisare stream was the most important factor for S. mansoni infection (OR 3.9) followed by herding cattle near the stream (OR 2.527). Males were twice more likely to get the infection than females (OR 1.923). Analysis of secondary parasitological data showed that S. mansoni infection was a leading helminthic infection over the past years. Conclusions:The present study found a higher intensity and prevalence of S. mansoni infection in a rural village of Wolaita Zone. Therefore, appropriate integrated control and prevention measures need to be implemented in the study area.

  5. Aspectos imunológicos e parasitológicos em Biomphalaria tenagophila infectadas por Schistosoma mansoni e outros Digenea

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    Doralice de Souza Luro Balan

    1993-12-01

    Full Text Available Estudou-se o comportamento de amebócitos de Biomphalaria tenagophila infectadas por Schistosoma mansoni, por outros Digenea e a resistência à superinfecção, presente em infecções mistas. Foi verificada a atividade fagocitária dos amebócitos, o número destas células circulantes, a reação amebocitária nos tecidos, o perfil eletroforético da hemolinfa, além da reação de imunodifusão. Concluiu-se que moluscos infectados por outros Digenea apresentam resistência à superinfecção por S. mansoni, sendo que os amebócitos parecem não ter participação direta na destruição dos esporocistos de S. mansoni nesta eventualidade. Nos moluscos infectados observou-se maior número de amebócitos circulantes e aumento de capacidade fagocitária destas células.

  6. A multistrain approach to studying the mechanisms underlying compatibility in the interaction between Biomphalaria glabrata and Schistosoma mansoni.

    Science.gov (United States)

    Galinier, Richard; Roger, Emmanuel; Moné, Yves; Duval, David; Portet, Anaïs; Pinaud, Silvain; Chaparro, Cristian; Grunau, Christoph; Genthon, Clémence; Dubois, Emeric; Rognon, Anne; Arancibia, Nathalie; Dejean, Bernard; Théron, André; Gourbal, Benjamin; Mitta, Guillaume

    2017-03-01

    In recent decades, numerous studies have sought to better understand the mechanisms underlying the compatibility between Biomphalaria glabrata and Schistosoma mansoni. The developments of comparative transcriptomics, comparative genomics, interactomics and more targeted approaches have enabled researchers to identify a series of candidate genes. However, no molecular comparative work has yet been performed on multiple populations displaying different levels of compatibility. Here, we seek to fill this gap in the literature. We focused on B. glabrata FREPs and S. mansoni SmPoMucs, which were previously demonstrated to be involved in snail/schistosome compatibility. We studied the expression and polymorphisms of these factors in combinations of snail and schistosome isolates that display different levels of compatibility. We found that the polymorphism and expression levels of FREPs and SmPoMucs could be linked to the compatibility level of S. mansoni. These data and our complementary results obtained by RNA-seq of samples from various snail strains indicate that the mechanism of compatibility is much more complex than previously thought, and that it is likely to be highly variable within and between populations. This complexity must be taken into account if we hope to identify the molecular pathways that are most likely to be good targets for strategies aimed at blocking transmission of the parasite through the snail intermediate host.

  7. Biomphalaria tenagophila potencial vector of Schistosoma mansoni in the Paraná River basin (Argentina and Paraguay).

    Science.gov (United States)

    Borda, C Edgardo; Rea, María Josefa F

    2007-05-01

    Susceptibility and compatibility experiments were carried out with 700 Biomphalaria tenagophila from the Paraná River basin exposed to infection with Schistosoma mansoni. Individual infection was performed with 10 miracidia of SJ2 strain from the Paraiba valley (Brazil) originally infective to B. tenagophila. These snails were laboratory-breed progeny of B. tenagophila collected from six localities of Argentina and one from Paraguay. From Argentina: Rincón de Vences (7%) and Posadas (11%) became infected with S. mansoni and the calculation of Frandsen's index (TCP/100) shows that they were Class II poorly compatible. Those snails from Goya (22%), Maloyas (5%), and Berón de Astrada (3%) were Class III compatible to the S. mansoni. None of the 100 snails exposed from Caá-Catí became infected (Class 0 incompatible). Tested samples from Paraguay (Encarnación) were infected (20%) and compatible (Class III). It was also studied the persistence of the infection in 244 snails of the first generation (F1) of those that were susceptible from three places. It was demonstrated an increment of the susceptibility in the F1 from Maloyas (chi2 = 27.22; p = 0.0001) and Posadas (chi2 = 4.24; p = 0.04). The results point out the possibility that schistosomiasis might be able to spread into the Paraná River basin where B. tenagophila exists.

  8. Aspectos imunológicos e parasitológicos em Biomphalaria tenagophila infectadas por Schistosoma mansoni e outros Digenea

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    Balan Doralice de Souza Luro

    1993-01-01

    Full Text Available Estudou-se o comportamento de amebócitos de Biomphalaria tenagophila infectadas por Schistosoma mansoni, por outros Digenea e a resistência à superinfecção, presente em infecções mistas. Foi verificada a atividade fagocitária dos amebócitos, o número destas células circulantes, a reação amebocitária nos tecidos, o perfil eletroforético da hemolinfa, além da reação de imunodifusão. Concluiu-se que moluscos infectados por outros Digenea apresentam resistência à superinfecção por S. mansoni, sendo que os amebócitos parecem não ter participação direta na destruição dos esporocistos de S. mansoni nesta eventualidade. Nos moluscos infectados observou-se maior número de amebócitos circulantes e aumento de capacidade fagocitária destas células.

  9. Omental and pleural milky spots: different reactivity patterns in mice infected with Schistosoma mansoni reveals coelomic compartmentalisation

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    Mônica S Panasco

    2010-07-01

    Full Text Available In vertebrate animals, pleural and peritoneal cavities are repositories of milky spots (MS, which constitute an organised coelom-associated lymphomyeloid tissue that is intensively activated by Schistosoma mansoni infection. This study compared the reactive patterns of peritoneal MS to pleural MS and concluded from histological analysis that they represent independent responsive compartments. Whole omentum, lungs and the entire mediastinum of 54 S. mansoni-infected mice were studied morphologically. The omental MS of infected animals were highly activated, modulating from myeloid-lymphocytic (60 days of infection to lymphomyeloid (90 days of infection and lymphocytic or lymphoplasmacytic (160 days of infection types. The non-lymphoid component predominated in the acute phase of infection and was expressed by monocytopoietic, eosinopoietic and neutropoietic foci, with isolated megakaryocytes and small foci of late normoblasts and mast cells. Nevertheless, pleural or thoracic MS of infected mice were monotonous, consisting of small and medium lymphocytes with few mast and plasma cells and no myeloid component. Our data indicate that compartmentalisation of the MS response is dependent on the lymphatic vascularisation of each coelomic cavity, limiting the effects or consequences of any stimulating or aggressive agents, as is the case with S. mansoni infection.

  10. Schistosoma mansoni: the effect of dexamethasone on the cercaria-schistosomulum transformation, in vivo Schistosoma mansoni: o efeito da dexametasona na transformação da cercaria em esquistossômulo, in vivo

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    Alan Laue de Melo

    1994-02-01

    Full Text Available Treatment with dexamethasone (DMS in the early phases of the experimental Schistosoma mansoni infection causes an indirect effect on the cercaria-schistosomulum transformation process. This is observed when naive albino mice are treated with that drug (50 mg/Kg, subcutaneously and infected intraperitonealy 01 hour later with about 500 S. mansoni cercariae (LE strain. An inhibition in the host cell adhesion to the larvae, with a simultaneous delay in the cercaria-schistosomulum transformation, is observed. This effect is probably due to a blockade of the neutrophil migration to the peritoneal cavity of mice, by an impairment of the release of chemotactic substances. Such delay probably favors the killing of S. mansoni larvae, still in the transformation process, by the vertebrate host defenses, as the complement system.O tratamento com dexametasona (DMS nas fases iniciais da infecção experimental com S. mansoni leva a um efeito indireto sobre o processo de transformação da cercária em esquistossômulo, quando camundongos isentos de infecção são tratados com esta droga (50 mg/ kg, subcutâneamente e, 01 hora depois, são infectados intraperitonealmente com cerca de 500 cercárias de S. mansoni (cepa LE. Foi observada uma significativa redução na adesão de células do hospedeiro às larvas, com um atraso simultâneo no processo de transformação das cercárias em esquistossômulos. Este efeito é, provavelmente, devido a um bloqueio inespecifícico da migração neutrofilica para a cavidade peritoneal, através de um bloqueio da liberação de substâncias quimio-táticas. Tal atraso pode permitir a morte das larvas de S. mansoni (ainda em processo de transformação pelas defesas do hospedeiro vertebrado, como o sistema do complemento.

  11. Malacological assessment and natural infestation of Biomphalaria straminea (Dunker, 1848 by Schistosoma mansoni (Sambon, 1907 and Chaetogaster limnaei (K. von Baer, 1827 in an urban eutrophic watershed

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    M. Callisto

    Full Text Available The objective of this study was to perform a malacological assessment at the Ibirité reservoir watershed in the metropolitan region of Belo Horizonte (Minas Gerais and to evaluate the natural infestation rate of Biomphalaria straminea (Gastropoda: Planorbidaeby Schistosoma mansoni (Platyhelminthes: Trematoda and Chaetogaster limnaei (Oligochaeta: Naididae. The samples were collected from July to August 2002. The B. straminea individuals collected were kept in the laboratory; the natural infestation rate by S. mansoni and C. limnaei was assessed weekly. The malacological assessment identified fivemollusk species present in the Ibirité reservoir watershed: B. straminea, Physa marmorata, Lymnea sp., Melanoides tuberculatus,and Pomacea austrum. Laboratory observations showed that the B. straminea individuals were infected by C. limnaei rather than S. mansoni. Although there was no infection of B. straminea by S. mansoni,presence of B. straminea in itself merits close attention due to possible risk of human schistosomiasis by the local population.

  12. Estudo da potencialidade de populações de Biomphalaria straminea do Estado de Minas Gerais, como hospedeiras do Schistosoma mansoni Potentiality of the Biomphalaria straminea populations of the State of Minas Gerais, as hosts of Schistosoma mansoni

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    Cecília Pereira de Souza

    1983-09-01

    Full Text Available Caramujos de Biomphalaria straminea, descendentes de exemplares coletados em nove municípios do Estado de Minas Gerais, foram infectados experimentalmente com três cepas de Schistosoma mansoni: "LE", procedente de Belo Horizonte (MG; "SJ", procedente de São José dos Campos (SP e "AL" procedente do Nordeste (AL. As taxas de infeção variaram de 0,0 a 24,0% com a cepa "LE"; de 0,0 a 16% com a cepa "SJ" e de 2,0 a 9,0% com a cepa "AL". Os índices de infecção experimental obtidos foram semelhantes aos registrados por outros autores, para B. straminea dessa região. Comparou-se o número de cercárias de cepa "LE", eliminadas por oito exemplares de B. straminea de Baldim e oito Biomphalaria glabrata do controle, após 30 minutos de exposição à luz. O número de cercárias eliminadas por B. straminea foi de 4.550, aproximadamente cinco vezes menor que o de B. glabrata, 22.679. Discute-se a potencialidade desses moluscos como hospedeiros do S. mansoni nessa região.The decendents of Biomphalaria straminea snails collected in nine regions from the State of Minas Gerais were experimentally infected with three strains of Schistosoma mansoni: "LE", from Belo Horizonte, Minas Gerais; "SJ", from São José dos Campos, State of São Paulo and "AL", from State of Alagoas. The infection rates obtained were of 0 to 24% (LE strain, 0 to 16% (SJ strain and 2 to 9% (AL strain. These infection rates were similar to those obtained by other authors for B. straminea from this region. Comparation were made between the numbers of cercariae (LE strain shed by eight specimens of B. straminea from Baldim and eight B. glabrata of the control group, after 30 minutes of exposure to light. B. straminea shed 4,550 cercariae, about five times less than B. glabrata (22,679. The authors discuss the potentiality of theses molluscs as hosts of S. mansoni in this region.

  13. Simultaneous infection of Schistosoma mansoni and S. rodhaini in Biomphalaria glabrata: impact on chronobiology and cercarial behaviour

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    Richards Louisa

    2008-12-01

    Full Text Available Abstract Background The chances of a schistosome cercaria encountering a suitable definitive host may be enhanced by emergence from the molluscan intermediate host with maximal glycogen stores and by an appropriate chronobiological rhythm. This study aimed to identify and characterize the effects of potential competitive interactions in the snail host Biomphalaria glabrata, between the closely-related Schistosoma mansoni and S. rodhaini, on phenotypic behavioural traits. It was predicted that inter-specific competition would affect chronobiological emergence rhythms and reduce the activity of schistosome swimming behavioural traits. Biomphalaria glabrata snails (120 were exposed to either S. mansoni or S. rodhaini single infections, or a mixed infection of both species simultaneously and the resulting cercarial phenotypic traits were characterised. Cercariae were identified from co-exposed snails by amplification and sequencing of the mitochondrial cytochrome oxidase subunit 1 (CO1. Results S. mansoni and S. rodhaini largely maintained their distinct chronobiological rhythms after mixed exposures and infections. However, inter-specific competition appeared to result in a restriction of the shedding pattern of S. rodhaini and slight shift in the shedding pattern of S. mansoni. Inter-specific competition also significantly lowered hourly cercarial production for both parasite species in comparison to single exposures and infections and reduced cercarial swimming activity. Conclusion Inter-specific competition was shown to influence cercarial production, chronobiology and activity and should therefore be investigated further in field situations to determine the effects of these changes on parasite fitness (incorporating both host finding and infectivity where these two species overlap. Importantly this competition did not result in a large change in chronobiological emergence of cercariae for either species indicating that it would not have a large

  14. An in-depth analysis of a piece of shit: distribution of Schistosoma mansoni and hookworm eggs in human stool.

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    Stefanie J Krauth

    Full Text Available BACKGROUND: An accurate diagnosis of helminth infection is important to improve patient management. However, there is considerable intra- and inter-specimen variation of helminth egg counts in human feces. Homogenization of stool samples has been suggested to improve diagnostic accuracy, but there are no detailed investigations. Rapid disintegration of hookworm eggs constitutes another problem in epidemiological surveys. We studied the spatial distribution of Schistosoma mansoni and hookworm eggs in stool samples, the effect of homogenization, and determined egg counts over time in stool samples stored under different conditions. METHODOLOGY: Whole-stool samples were collected from 222 individuals in a rural part of south Côte d'Ivoire. Samples were cut into four pieces and helminth egg locations from the front to the back and from the center to the surface were analyzed. Some samples were homogenized and fecal egg counts (FECs compared before and after homogenization. The effect of stool storing methods on FECs was investigated over time, comparing stool storage on ice, covering stool samples with a water-soaked tissue, or keeping stool samples in the shade. PRINCIPAL FINDINGS: We found no clear spatial pattern of S. mansoni and hookworm eggs in fecal samples. Homogenization decreased S. mansoni FECs (p = 0.026, while no effect was observed for hookworm and other soil-transmitted helminths. Hookworm FECs decreased over time. Storing stool samples on ice or covered with a moist tissue slowed down hookworm egg decay (p<0.005. CONCLUSIONS/SIGNIFICANCE: Our findings have important implications for helminth diagnosis at the individual patient level and for epidemiological surveys, anthelmintic drug efficacy studies and monitoring of control programs. Specifically, homogenization of fecal samples is recommended for an accurate detection of S. mansoni eggs, while keeping collected stool samples cool and moist delayed the disintegration of

  15. New Insights into the Molecular Epidemiology and Population Genetics of Schistosoma mansoni in Ugandan Pre-school Children and Mothers

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    Betson, Martha; Sousa-Figueiredo, Jose C.; Kabatereine, Narcis B.; Stothard, J. Russell

    2013-01-01

    Significant numbers of pre-school children are infected with Schistosoma mansoni in sub-Saharan Africa and are likely to play a role in parasite transmission. However, they are currently excluded from control programmes. Molecular phylogenetic studies have provided insights into the evolutionary origins and transmission dynamics of S. mansoni, but there has been no research into schistosome molecular epidemiology in pre-school children. Here, we investigated the genetic diversity and population structure of S. mansoni in pre-school children and mothers living in lakeshore communities in Uganda and monitored for changes over time after praziquantel treatment. Parasites were sampled from children (<6 years) and mothers enrolled in the longitudinal Schistosomiasis Mothers and Infants Study at baseline and at 6-, 12- and 18-month follow-up surveys. 1347 parasites from 35 mothers and 45 children were genotyped by direct sequencing of the cytochrome c oxidase (cox1) gene. The cox1 region was highly diverse with over 230 unique sequences identified. Parasite populations were genetically differentiated between lakes and non-synonymous mutations were more diverse at Lake Victoria than Lake Albert. Surprisingly, parasite populations sampled from children showed a similar genetic diversity to those sampled from mothers, pointing towards a non-linear relationship between duration of exposure and accumulation of parasite diversity. The genetic diversity six months after praziquantel treatment was similar to pre-treatment diversity. Our results confirm the substantial genetic diversity of S. mansoni in East Africa and provide significant insights into transmission dynamics within young children and mothers, important information for schistosomiasis control programmes. PMID:24349589

  16. New insights into the molecular epidemiology and population genetics of Schistosoma mansoni in Ugandan pre-school children and mothers.

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    Martha Betson

    Full Text Available Significant numbers of pre-school children are infected with Schistosoma mansoni in sub-Saharan Africa and are likely to play a role in parasite transmission. However, they are currently excluded from control programmes. Molecular phylogenetic studies have provided insights into the evolutionary origins and transmission dynamics of S. mansoni, but there has been no research into schistosome molecular epidemiology in pre-school children. Here, we investigated the genetic diversity and population structure of S. mansoni in pre-school children and mothers living in lakeshore communities in Uganda and monitored for changes over time after praziquantel treatment. Parasites were sampled from children (<6 years and mothers enrolled in the longitudinal Schistosomiasis Mothers and Infants Study at baseline and at 6-, 12- and 18-month follow-up surveys. 1347 parasites from 35 mothers and 45 children were genotyped by direct sequencing of the cytochrome c oxidase (cox1 gene. The cox1 region was highly diverse with over 230 unique sequences identified. Parasite populations were genetically differentiated between lakes and non-synonymous mutations were more diverse at Lake Victoria than Lake Albert. Surprisingly, parasite populations sampled from children showed a similar genetic diversity to those sampled from mothers, pointing towards a non-linear relationship between duration of exposure and accumulation of parasite diversity. The genetic diversity six months after praziquantel treatment was similar to pre-treatment diversity. Our results confirm the substantial genetic diversity of S. mansoni in East Africa and provide significant insights into transmission dynamics within young children and mothers, important information for schistosomiasis control programmes.

  17. Schistosoma mansoni mucin gene (SmPoMuc expression: epigenetic control to shape adaptation to a new host.

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    Cecile Perrin

    Full Text Available The digenetic trematode Schistosoma mansoni is a human parasite that uses the mollusc Biomphalaria glabrata as intermediate host. Specific S. mansoni strains can infect efficiently only certain B. glabrata strains (compatible strain while others are incompatible. Strain-specific differences in transcription of a conserved family of polymorphic mucins (SmPoMucs in S. mansoni are the principle determinants for this compatibility. In the present study, we investigated the bases of the control of SmPoMuc expression that evolved to evade B. glabrata diversified antigen recognition molecules. We compared the DNA sequences and chromatin structure of SmPoMuc promoters of two S. mansoni strains that are either compatible (C or incompatible (IC with a reference snail host. We reveal that although sequence differences are observed between active promoter regions of SmPoMuc genes, the sequences of the promoters are not diverse and are conserved between IC and C strains, suggesting that genetics alone cannot explain the evolution of compatibility polymorphism. In contrast, promoters carry epigenetic marks that are significantly different between the C and IC strains. Moreover, we show that modifications of the structure of the chromatin of the parasite modify transcription of SmPoMuc in the IC strain compared to the C strain and correlate with the presence of additional combinations of SmPoMuc transcripts only observed in the IC phenotype. Our results indicate that transcription polymorphism of a gene family that is responsible for an important adaptive trait of the parasite is epigenetically encoded. These strain-specific epigenetic marks are heritable, but can change while the underlying genetic information remains stable. This suggests that epigenetic changes may be important for the early steps in the adaptation of pathogens to new hosts, and might be an initial step in adaptive evolution in general.

  18. Schistosoma mansoni in susceptible and resistant snail strains Biomphalaria tenagophila: in vivo tissue response and in vitro hemocyte interactions.

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    Rafael Nacif-Pimenta

    Full Text Available Schistosomiasis is a parasitic disease that is highly prevalent, especially in developing countries. Biomphalaria tenagophila is an important invertebrate host of Schistosoma mansoni in Brazil, with some strains (e.g. Cabo Frio being highly susceptible to the parasite, whereas others (e.g. Taim are completely resistant to infection. Therefore, B. tenagophila is an important research model for studying immune defense mechanisms against S. mansoni. The internal defense system (IDS of the snail comprises hemocytes and hemolymph factors acting together to recognize self from non-self molecular patterns to eliminate the threat of infection. We performed experiments to understand the cellular defenses related to the resistance and/or susceptibility of B. tenagophila to S. mansoni. During the early stages of infection, fibrous host cells of both snail strains were arranged as a thin layer surrounding the sporocysts. However, at later stages of infection, the cellular reactions in resistant snails were increasingly more intense, with thicker layers surrounding the parasites, in contrast to susceptible strains. All parasites were damaged or destroyed inside resistant snails after 10 h of infection. By contrast, parasites inside susceptible snails appeared to be morphologically healthy. We also performed experiments using isolated hemocytes from the two strains interacting with sporocysts. Hemocyte attachment started as early as 1 h after initial infection in both strains, but the killing of sporocysts was exclusive to hemocytes from the resistant strain and was time course dependent. The resistant strain was able to kill all sporocysts. In conclusion, our study revealed important aspects of the initial process of infection related to immune defense responses of strains of B. tenagophila that were resistant to S. mansoni compared with strains that were susceptible. Such information is relevant for the survival or death of the parasites and so is important

  19. Neuroschistosomiasis due to Schistosoma mansoni: a review of pathogenesis, clinical syndromes and diagnostic approaches Neuroesquistossomose devido a Schistosoma mansoni: revisão da patogênese, síndromes clínicas e manejo diagnóstico

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    Cristiana M. Nascimento-Carvalho

    2005-08-01

    Full Text Available Neuroschistosomiasis (NS is the second most common form of presentation of infection by the trematode, Schistosoma mansoni. Granulomatous inflammatory reaction occurs as a result of schistosome eggs being transmitted to spinal cord or brain via the vascular system, or by inadvertent adult worm migration to these organs. The two main clinical syndromes are spinal cord neuroschistosomiasis (acute or subacute myelopathy and localized cerebral or cerebellar neuroschistosomiasis (focal CNS impairment, seizures, increased intracranial pressure. Presumptive diagnosis of NS requires confirming the presence of S. mansoni infection by stool microscopy or rectal biopsy for trematode eggs, and serologic testing of blood and spinal fluid. The localized lesions are identified by signs and symptoms, and confirmed by imaging techniques (contrast myelography, CT and MRI. Algorithms are presented to allow a stepwise approach to diagnosis.Neuroesquistossomose (NS é a segunda forma mais freqüente de apresentação da infecção causada pelo trematódeo Schistosoma mansoni. A inflamação do tipo granulomatosa ocorre como resultado da presença de ovos do S. mansoni que atingiram a medula espinhal ou o encéfalo via o sistema vascular ou pela migração inadvertida de vermes adultos para estes órgãos. Duas síndromes clínicas principais podem ser identificadas: a mielopatia esquistossomótica (aguda ou subaguda e a neuroesquistossomose cerebral ou cerebelar localizada (comprometimento focal do Sistema Nervoso Central, convulsões, hipertensão intracraniana. O diagnóstico presumido da NS requer a confirmação da presença da infecção por exame microscópico de fezes ou pela biópsia retal em busca de ovos de trematódeo e testes sorológicos no sangue e no líquor. As lesões localizadas são identificadas por sinais e sintomas, e confirmadas por exames de imagem (mielografia contrastada, tomografia computadorizada e ressonância magnética. Algoritmos s

  20. Quantitative high-throughput screen identifies inhibitors of the Schistosoma mansoni redox cascade.

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    Anton Simeonov

    Full Text Available Schistosomiasis is a tropical disease associated with high morbidity and mortality, currently affecting over 200 million people worldwide. Praziquantel is the only drug used to treat the disease, and with its increased use the probability of developing drug resistance has grown significantly. The Schistosoma parasites can survive for up to decades in the human host due in part to a unique set of antioxidant enzymes that continuously degrade the reactive oxygen species produced by the host's innate immune response. Two principal components of this defense system have been recently identified in S. mansoni as thioredoxin/glutathione reductase (TGR and peroxiredoxin (Prx and as such these enzymes present attractive new targets for anti-schistosomiasis drug development. Inhibition of TGR/Prx activity was screened in a dual-enzyme format with reducing equivalents being transferred from NADPH to glutathione via a TGR-catalyzed reaction and then to hydrogen peroxide via a Prx-catalyzed step. A fully automated quantitative high-throughput (qHTS experiment was performed against a collection of 71,028 compounds tested as 7- to 15-point concentration series at 5 microL reaction volume in 1536-well plate format. In order to generate a robust data set and to minimize the effect of compound autofluorescence, apparent reaction rates derived from a kinetic read were utilized instead of end-point measurements. Actives identified from the screen, along with previously untested analogues, were subjected to confirmatory experiments using the screening assay and subsequently against the individual targets in secondary assays. Several novel active series were identified which inhibited TGR at a range of potencies, with IC(50s ranging from micromolar to the assay response limit ( approximately 25 nM. This is, to our knowledge, the first report of a large-scale HTS to identify lead compounds for a helminthic disease, and provides a paradigm that can be used to jump

  1. Atypical properties of a conventional calcium channel β subunit from the platyhelminth Schistosoma mansoni

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    Schneider Toni

    2008-03-01

    Full Text Available Abstract Background The function of voltage-gated calcium (Cav channels greatly depends on coupling to cytoplasmic accessory β subunits, which not only promote surface expression, but also modulate gating and kinetic properties of the α1 subunit. Schistosomes, parasitic platyhelminths that cause schistosomiasis, express two β subunit subtypes: a structurally conventional β subunit and a variant β subunit with unusual functional properties. We have previously characterized the functional properties of the variant Cavβ subunit. Here, we focus on the modulatory phenotype of the conventional Cavβ subunit (SmCavβ using the human Cav2.3 channel as the substrate for SmCavβ and the whole-cell patch-clamp technique. Results The conventional Schistosoma mansoni Cavβ subunit markedly increases Cav2.3 currents, slows macroscopic inactivation and shifts steady state inactivation in the hyperpolarizing direction. However, currents produced by Cav2.3 in the presence of SmCavβ run-down to approximately 75% of their initial amplitudes within two minutes of establishing the whole-cell configuration. This suppressive effect was independent of Ca2+, but dependent on intracellular Mg2+-ATP. Additional experiments revealed that SmCavβ lends the Cav2.3/SmCavβ complex sensitivity to Na+ ions. A mutant version of the Cavβ subunit lacking the first forty-six amino acids, including a string of twenty-two acidic residues, no longer conferred sensitivity to intracellular Mg2+-ATP and Na+ ions, while continuing to show wild type modulation of current amplitude and inactivation of Cav2.3. Conclusion The data presented in this article provide insights into novel mechanisms employed by platyhelminth Cavβ subunits to modulate voltage-gated Ca2+ currents that indicate interactions between the Ca2+ channel complex and chelated forms of ATP as well as Na+ ions. These results have potentially important implications for understanding previously unknown mechanisms by

  2. Effect of Schistosoma mansoni Infection on Innate and HIV-1-Specific T-Cell Immune Responses in HIV-1-Infected Ugandan Fisher Folk.

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    Obuku, Andrew Ekii; Asiki, Gershim; Abaasa, Andrew; Ssonko, Isaac; Harari, Alexandre; van Dam, Govert J; Corstjens, Paul L; Joloba, Moses; Ding, Song; Mpendo, Juliet; Nielsen, Leslie; Kamali, Anatoli; Elliott, Alison M; Pantaleo, Giuseppe; Kaleebu, Pontiano; Pala, Pietro

    2016-07-01

    In Uganda, fisher folk have HIV prevalence rates, about four times higher than the national average, and are often coinfected with Schistosoma mansoni. We hypothesized that innate immune responses and HIV-specific Th1 immune responses might be downmodulated in HIV/S. mansoni-coinfected individuals compared with HIV+/S. mansoni-negative individuals. We stimulated whole blood with innate receptor agonists and analyzed supernatant cytokines by Luminex. We evaluated HIV-specific responses by intracellular cytokine staining for IFN-γ, IL-2, and TNF-α. We found that the plasma viral load and CD4 count were similar between the HIV+SM+ and HIV+SM- individuals. In addition, the TNF-α response to the imidazoquinoline compound CL097 and β-1, 3-glucan (curdlan), was significantly higher in HIV/S. mansoni-coinfected individuals compared with HIV only-infected individuals. The frequency of HIV-specific IFN-γ+IL-2-TNF-α- CD8 T cells and IFN-γ+IL-2-TNF-α+ CD4 T cells was significantly higher in HIV/S. mansoni-coinfected individuals compared with HIV only-infected individuals. These findings do not support the hypothesis that S. mansoni downmodulates innate or HIV-specific Th1 responses in HIV/S. mansoni-coinfected individuals.

  3. Ultrastructural study on the morphological changes to male worms of Schistosoma mansoni after in vitro exposure to allicin Estudo ultraestrutural das alterações morfológicas de vermes machos de Schistosoma mansoni após exposição in vitro à alicina

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    Caliandra Maria Bezerra Luna Lima

    2011-06-01

    Full Text Available INTRODUCTION: Garlic has a wide range of actions, including antibacterial, antiviral, antifungal, antiprotozoal and anthelmintic actions. This antiparasitic activity has been attributed to allicin, which is the main constituent of garlic. The present study aimed to investigate the in vitro activity of allicin on the tegument of adult Schistosoma mansoni worms using scanning electron microscopy. METHODS: Swiss Webster mice were infected with S. mansoni cercariae (100 per mouse and sacrificed 50 days later to acquire the adult worms. These worms were collected by perfusion and placed in RPMI medium 1,640 at 37°C before transferring to RPMI media containing 0 (control, 5, 10, 15 and 20mg/mL of allicin, where they were incubated for 2h. The worms were fixed in 2.5% glutaraldehyde solution, washed twice, post-fixed in osmium tetroxide, washed twice and then dehydrated with ascending grades of ethanol. The samples were air-dried, mounted on stubs, gold coated in an ion sputtering unit and viewed using a scanning electron microscope. RESULTS: A concentration of 5mg/mL caused wrinkling in the tegument; a concentration of 10mg/mL resulted in changes to tubercles and loss or modification of spines. With 15 and 20mg/mL increasing damage to the tegument could be seen, such as vesicle formation and the presence of ulcers. CONCLUSIONS: These findings demonstrate the effect of allicin on adult S. mansoni worms and indicate that most of the changes occur at concentrations greater than that normally indicated for treatment.INTRODUÇÃO: O alho apresenta uma ampla gama de ações, incluindo antibacteriana, antiviral, antifúngico, antiprotozoário e anti-helmíntico. Esta atividade antiparasitária tem sido atribuída à alicina, que é o principal constituinte do alho. O presente estudo teve como objetivo investigar a ação in vitro da alicina no tegumento de vermes adultos de Schistosoma mansoni utilizando a microscopia eletrônica de varredura. M

  4. Biomphalaria straminea no Peru e sua suscetibilidade a cepas brasileiras de Schistosoma mansoni

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    C.A. Cuba Cuba

    1977-12-01

    Full Text Available Em Maio de 1973, um dos autores (C.A.C. coletou na localidade de Imacita, Província de Bagua, Departamento de Amazonas, vários espécimes de Biomphalaria straminea (Dunker, 1848, uma espécie que, até então, não havia sido assinalada no Peru. Descendentes destes indivíduos foram submetidos a provas de suscetibilidade às cepas BH e SJ de Schistosoma mansoni que, em condições naturais, evoluem em B. glabrata de Belo Horizonte e B. tenagophila de São José dos Campos, respectivamente. Oitenta espécimens foram expostos à cepa BH dos quais em 13 ou 16,2% a infecção evoluiu caracteristicamente até a formação de esporocistos secundários sem haver, contudo, eliminação de cercárias, mesmo no indivíduo que apresentou uma sobrevivência de 88 dias após a exposição. Não se verificou cura espontânea neste lote. Entre as 40 B. straminea expostas à cepa SJ 9 ou 22,5% infectaram-se, sendo que apenas duas eliminaram poucas cercárias aos 57 e 77 dias após a exposição, por dois dias consecutivos, tendo uma morrido e uma se curado espontaneamente. A cura espontânea do parasitismo foi notado em mais dois indivíduos, nos quais a infecção foi observada através da concha. Cortes histológicos seriados de 9 caramujos, expostos individualmente a 50 miracídios da cepa BH e fixados entre 6 e 120 horas após a exposição, mostraram esporocistos em desenvolvimento e esporocistos invadidos por amebócitos, sem formação de granulomas por parte do hospedeiro, fato assinalado em caramujos suscetíveis. A população estudada comportou-se experimentalmente de modo semelhante a outras populações de B. straminea testadas em laboratório, isto é, com baixa suscetibilidade, embora tal comportamento não afaste a possibilidade dela vir a manter o ciclo do parasita em sua área de distribuição.In May 1973 one of the Authors (C.A.C. collected specimens of Biomphalaria straminea (Dunker 1848 at imacita, Bagua Province, Amazonas, Pem. This

  5. Aspectos imunológicos do sistema enzimático fenoloxidase de Schistosoma mansoni Immunological aspects of the phenol oxidase enzymatic system of Schistosoma mansoni

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    João Tadeu Ribeiro-Paes

    1994-10-01

    Full Text Available O sistema enzimático fenoloxidase (EC 1.10.3.1, EC 1.10.3.2 está amplamente distribuido entre os seres vivos, tendo sido descrito em diferentes espécies do reino animal e vegetal. Apesar de desempenhar um papel fundamental na formação da cápsula ou parede dos ovos de trematódeos, o sistema enzimático fenoloxidase (PO tem sido pouco estudado nesses organismos. No presente trabalho são apresentados os resultados iniciais de imunizações de coelhos contra PO de fêmeas adultas de S. mansoni e tirosinase de cogumelo (Sigma. As análises imunológicas, realizadas através de imunodifusão dupla (teste de Ouchterlony e imunoeletroforese, revelaram identidade imunitária parcial entre a PO de machos e fêmeas. Não se observou reação cruzada entre os antissoros de coelhos imunizados contra PO e aqueles com tirosinase, indicando que, embora os sítios catalíticos de ambas as enzimas devam ser semelhantes, já que atuam sobre os mesmos substratos, os determinantes antigênicos devem ser diferentes. Os resultados descritos no presente trabalho representam um primeiro passo no sentido da purificação das isoenzimas da fenoloxidase e sua posterior utilização ao estudo dos mecanismos moleculares envolvidos na esclerotização da parede dos ovos de S. mansoni.The phenol oxidase enzymatic system (EC 1.10.3.1, EC 1.10.3.2 is widespread in different species of the animal and vegetal kingdom. Despite its importance in the eggshell formation of the trematodes phenol oxidase (PO has been little studied in these organisms, mainly in S. mansoni. This report presents the initial results concerning the immunization of rabbits with PO of S. mansoni and mushroom tyrosinase. The immunological analysis done by means of double immu-nodifusion (Ouchterlony and immunoelectrophoresis techniques revealed some immunological identity between the PO of males and females. It was not seen cross reaction between the antisera against PO and tyrosinase, what suggests

  6. Resistance of Biomphalaria occidentalis from Varzea das Flores dam, Minas Gerais, to Schistosoma mansoni infection detected by low stringency polymerase chain reaction

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    Cecilia Pereira de Souza

    2001-04-01

    Full Text Available Biomphalaria occidentalis Paraense, 1981 from Varzea das Flores dam, MG, Brazil, was exposed to infection with Schistosoma mansoni. Individual infection was performed with 140 B. occidentalis and 100 B. glabrata snails using LE and SJ strains. Two groups of B. occidentalis were killed after seven day-miracidia exposure to detect S. mansoni DNA, through the low stringency polymerase chain reaction (LS-PCR, and were negative. The infection rates were 69.2% (LE strain and 96.7% (SJ strain for B. glabrata and 0% for B. occidentalis. LS-PCR enabled early resistance diagnosis.

  7. 曼氏血吸虫Sm28GST疫苗研究进展%Advances in the Research of Sm28GST Vaccine of Schistosoma mansoni

    Institute of Scientific and Technical Information of China (English)

    李文桂; 陈雅棠

    2009-01-01

    曼氏血吸虫病(Schistosomiasis mansoni)是由曼氏血吸虫(Schistosoma mansoni,sm)引起的一种严重危害人类健康的人兽共患寄生虫病,主要流行于非洲、拉丁美洲和亚洲的53个国家和地区.本文综述了Sm28GST蛋白分子、DNA疫苗、rSt疫苗以及rBCG疫苗等方面的研究进展.

  8. Dominant character of the molecular marker of a Biomphalaria tenagophila strain (Mollusca: Planorbidae resistant to Schistosoma mansoni

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    Rosa Florence Mara

    2004-01-01

    Full Text Available Biomphalaria tenagophila population from Taim (state of Rio Grande do Sul, Brazil is totally resistant toSchistosoma mansoni, and presents a molecular marker of 350 bp by polymerase chain reaction and restriction fragment length polymorphism of the entire rDNA internal transcriber spacer. The scope of this work was to determine the heritage pattern of this marker. A series of cross-breedings between B. tenagophila from Taim (resistant and B. tenagophila from Joinville, state of Santa Catarina (susceptible was carried out, and their descendants F1 and F2 were submitted to this technique. It was possible to demonstrate that the specific fragment from Taim is endowed with dominant character, since the obtained segregation was typically mendelian.

  9. Liver cirrhosis and splenomegaly associated with Schistosoma mansoni in a Sudanese woman in Malaysia:A case report

    Institute of Scientific and Technical Information of China (English)

    Yamuna Rajoo; Romano Ngui; Rohela Mahmud; Ng Rong Xiang; Sharifah FS Omar; G Kumar; Yvonne AL Lim; Arine Fadzlun Ahmad; Amirah Amir; Zurainee Mohamed Nor

    2015-01-01

    We report a case of a patient with Schistosoma mansoni infection who presented with liver cirrhosis and splenomegaly. She was diagnosed by a serological test and Kato-Katz thick smear stool examination. The patient was a 52-year-old woman from Sudan who came to Malaysia for a week to visit her sons. The patient lives in the middle of Rabak region, Sudan, a highly endemic area for schistosomiasis where her daily routine includes rearing of cows and farming. The site of toilet and sources of drinking water are canals and wells; both infested with snails. Patient had a long history of exposure and coming into contact with water from these canals and wells.

  10. Schistosoma mansoni in mice: modulation of granulomatous response after reinfection and chemotherapeutic treatment Schistosoma mansoni em camundongos: modulação da resposta granulomatosa pós reinfecção e tratamento quimioterápico

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    Paulo Marcos Z. Coelho

    1994-09-01

    Full Text Available Mice previously infected with Schistosoma mansoni, and cured by specific treatment (400mg/kg oxamniquine, p. o. in the chronic phase of the disease, were reinfected 20 days after treatment to assess their capacityfor modulation ofthe granulomatous response. Histopathologic examination of the animals ' liver, at 60 days after reinfection, evidenced the presence of typical granulomas of the chronic phase in most animals. This infer that the capacity for modulation of the granulomatous response had been maintained, thus preventing a new acute phase of the disease. Conversely, a group of previously infected mice, untreated and submitted to reinfection, showed reactivation of the granulomatous response in 50% of the animals. The possible implications of these findings in human schistosomiasis mansoni are discussed.Para verificar a capacidade de modulação da resposta granulomatosa na esquistossomose murina, após cura quimioterápica, camundongos previamente infectadosforam curados com oxamniquina (400mg/kg, p. o. e reinfectados 20 dias após tratamento. O exame histopatológico do fígado dos animais, aos 60 dias após reinfecção, mostrou, na maioria deles, a presença de granulomas nafase produtiva, típicos da fase crônica da doença, pertnitindo a inferência de que a capacidade de modulação da resposta granulomatosa foi mantida, prevenindo assim uma outra fase aguda da doença. Por outro lado, um grupo de camundongos previamente infectados e submetidos a reinfecção mostrou a reagudização da resposta granulomatosa em 50% dos animais. As possíveis implicações destes achados na esquistossomose mansoni humana são discutidas.

  11. Estudo sobre o papel dos eosinofilos na destruição dos esquistossomulos do Schistosoma mansoni in vivo: (Nota prévia Role of eosinophils in destruction of schistosomula of Schistosoma mansoni in vivo (preliminary report

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    Zilton A. Andrade

    1984-09-01

    Full Text Available Esquistossômulos obtidos através de processo mecânico foram injetados na veia da cauda de camundongos Balb/c (2.000 esquist./0,15ml e as reações pulmonares foram estudadas histologicamente após 24, 48, 72 e 96 horas. Os animais estavam divididos em quatro grupos: 1 animais normais injetados com esquistossômulos vivos; 2 animais normais injetados com esquistossõmulos mortos; 3 animais infectados há dez semanas com 30 cercárias do Schistosoma mansoni e injetados com esquistossômulos vivos e 4 animais semelhantes aos do grupo acima, mas injetados com esquistossômulos mortos. As reações pulmonares bem desenvolvidas em torno dos esquistossômulos, só foram observadas nos animais injetados com esquistossômulos mortos e foram mais intensas e com maior quantidade de eosinófilos nos animais já infectados. estes resultados diferem daqueles observados in vitro, em que os esquistossômulos são destruídos por um sistema composto de anticorpos específicos, complemento e eosinófilos, estas últimas células destruindo as larvas por citoaderência, degranulação e citotoxidade. O presente trabalho indica que in vitro a infilstração de eosinófilos ocorre após a morte das larvas, no animal sensibilizado.Schistosoma mansoni cercariae mechanically transformed into schistosomula were injected, eitherdead or alive, into the tail vein (2.000 larvae/0,15ml of Balb/c mice which were either previously infected with S. mansoni (10 weeks/50 cercariae or non-infected. Histological examination of the lungs 24,48,72 and 96 hours after injection revealed that inflammatory reaction around schistosomula occurred only in the groups injected with dead schistosomula (killed by freezing and thawing. in non-infected animals the reaction was predominantly macrophagic while in those infected many eosinophis appeared around the dead larvae. These results are at variance with those obtained in vitro and suggest that in vitro the participation of eosinophils in

  12. Atual distribuição geográfica dos moluscos hospedeiros intermediários do Schistosoma mansoni em Belo Horizonte, MG, Brasil Current geographic distribution of intermediate hosts mollusca of Schistosoma mansoni in Belo Horizonte, MG, Brazil

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    Cecília Pereira de Souza

    1981-12-01

    Full Text Available Procedeu-se ao levantamento malacológico do município de Belo Horizonte, MG, com o objetivo de avaliar a distribuição, densidade e taxa de infecção dos moluscos hospedeiros intermediários do Schistosoma mansoni. Foram coletadas 3.261 Biomphalaria glabrata em 1979-81, das quais 100 (3,1% estavam infectadas com S. mansoni. Registrou-se a existência de 36 criadouros (35,0% de B. glabrata em 102 locais pesquisados, sendo 23 na bacia hidrográfica de Pampulha e 13 na do ribeirão do Arrudas. Foram encontrados 2 criadouros de B. tenagophila e 2 de B. straminea. Registrou-se também a presenca de exemplares de Pomacea haustrum, Physa sp e Drepanotrema cimex. Compararam-se os dados obtidos atualmente com os publicados em 1967. Houve reducao de mais de 50% no número de criadouros de B.glabrata, principalmente em decorrencias da expansão e progresso da cidade. Na zona periférica a esquistossomose continua endêmica, havendo necessidade de novas obras de saneamento básico para se conseguir o controle da doença.Malacological surveys were conducted in Belo Horizonte with a view to obtain new data on the distribution and density of schistosomose bearing snails and their natural rate of infection by Schistosoma mansoni. Of 3.261 Biomphalaria glabrata collected during 1979-81, 100 (3,1% were found naturally infected. One hundred and two water collections were surveyed and 36 (35% were found harboring the mentioned snail species (23 of them in the watershed of Pampulha, 13 in the tributaires of the Arrudas creek. The species B. tenagophila was found in two waterbodies, and B. straminea in two other. Other snail species collected were Pomacea haustrum, Physa sp and Drepanotrema cimex. Data of this survey were compared with data published in 1967 and 50% reduction in the snail breeding places was observed. This reduction was due mainly to public works and engineering activities accompanying the growth of city. Schistosomiasis is still present in the

  13. Influência da dieta hiperglicêmica e do diabetes aloxânico sobre a vitalidade do Schistosoma mansoni Sambon, 1907, em camundongos experimentalmente infectados The influence of hyperglicemic diet and aloxanic diabetes on the vitality of Schistosoma mansoni in experimentally infected mice

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    Luiz Augusto Magalhães

    1978-09-01

    Full Text Available Foram estudados alguns efeitos da dieta rica em açúcar e do diabetes aloxânico em Mus musculus albinos infectados com Schistosoma mansoni. Os resultados mostraram que: 1 o número de granulomas nos animais tratados pela aloxana foi significativamente menor do que nos animais não tratados por esta droga; 2 é possível que nos animais tratados pela aloxana exista algum fator que prejudique o desenvolvimento e a postura dos esquistossomos.Some effects of a sugar-rich diet and of the aloxanic diabetes in albino mice (Mus musculus infected with Schistosoma mansoni were considered. The results showed: 1. the number of granulomata for the aloxane treated animals was significantly lower than the number for untreated animals. 2. one may, then, surmise that the aloxane treatment generates conditions that inhibits the development and oviposition of S. mansoni.

  14. A esquistossomose mansoni no contexto da política de saúde brasileira Schistosoma mansoni in the context of the Brazilian health policy

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    Sandra Helena Cerrato Tibiriçá

    2011-01-01

    Full Text Available São muitos os fatores envolvidos na determinação da emergência e reemergência de doenças infecciosas. No caso da esquistossomose destacam-se os fatores biológicos como os relacionados ao habitat, às mutações e adaptações de microrganismos e hospedeiros, à resposta imunológica do hospedeiro e às adaptações bioecológicas de hospedeiros intermediários. Somam-se a esses, os não menos importantes fatores relacionados à gestão política, ocupação do ambiente e alocação de recursos financeiros. O Brasil reúne, hoje, importantes condições ecoepidemiológicas para a reemergência da esquistossomose e aumento da prevalência de algumas formas graves como mielorradiculopatia esquistossomótica, principalmente em áreas de baixa endemicidade. A expansão de suas fronteiras atinge os meios urbanos e rurais, destinados ao trabalho ou ao lazer, com comprometimento inclusive de setores de renda como o ecoturismo. Os avanços nas pesquisas acerca dos hospedeiros intermediário e definitivo do Schistosoma mansoni, para se transformarem em benefícios públicos, necessitam da sustentabilidade gerencial pública comprometida, interdisciplinar, fortalecida nas diferentes esferas de governo, vinculada ás sociedades civis tecnicamente capacitadas ao gerenciamento e comprometidas com as necessidades de saúde da população.There are many factors involved in the determination of the emergence and reemergence of infectious diseases. In the case of Schistosomiasis biological factors are highlighted as related to the habitat, to the microorganisms and hosts adaptations and mutations, to the immunologic reply of the host and to the bio-ecology adaptations of intermediate hosts. These are added to the not less important factors related to the management politics, occupation of the environment and allocation of financial resources. Brazil congregates, today, an important echo-epidemiologic conditions for the reemergence of Schistosomiasis. The

  15. Responses of the surface membrane and excretory system of Schistosoma mansoni to damage and to treatment with praziquantel and other biomolecules.

    Science.gov (United States)

    Oliveira, F A; Kusel, J R; Ribeiro, F; Coelho, P M Z

    2006-03-01

    Damage to the surface membrane of adult Schistosoma mansoni, and the activity of the excretory system, as shown by resorufin fluorescence, was observed following treatment with praziquantel and incubation with other molecules. Praziquantel treatment induced damage to the surface membrane as measured by the use of a variety of fluorescent compounds. The excretory system of the male worm was inhibited immediately after praziquantel treatment, but fully recovered after culture for 2 h following removal of praziquantel. The excretory system of the female, observed to be minimally active in untreated worm pairs, was often greatly activated in paired females, as shown by intense resorufin labelling, after praziquantel treatment, and this continued during recovery of the male excretory system. In experiments with normal worm pairs, the female could be activated by inhibiting the metabolic rate of the pair by a cooling procedure. The effects on the excretory system of changes in culture conditions (such as changes in pH, concentrations of bacterial lipopolysaccharide, cytokines, reactive oxygen species, compounds which remove cholesterol, such as beta-methyl cyclodextrin, and damaging basic poly-L-lysine) were also assessed. It is concluded that the extensive excretory system of the adult worm is responsive to drug treatment and to certain changes in environmental conditions. Its activity seems to be strongly linked to the integrity of the surface membrane.

  16. Confirmed local endemicity and putative high transmission of Schistosoma mansoni in the Sesse Islands, Lake Victoria, Uganda

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    Kabatereine Narcis B

    2011-03-01

    Full Text Available Abstract The Sesse Islands, in the Ugandan portion of Lake Victoria, have long been considered a low transmission zone for intestinal schistosomiasis. Based on observations of high prevalence of Schistosoma mansoni infection in the northern-most islands of this archipelago, a follow-up survey was conducted to ascertain whether transmission was endemic to this island group, combining parasitological and malacological surveys. Prevalence of intestinal schistosomiasis was again observed to be high, as was intensity of infections which, combined with low reported incidence of treatment, suggests that chemotherapy-based control initiatives are not being maximally effective in this region as high levels of population movement between islands and districts are confounding. The local disease transmission was confirmed by the observations of high abundance of Biomphalaria, as well as field-caught snails shedding S. mansoni cercariae. DNA sequencing of 12 cercariae revealed common mitochondrial cox1 haplotypes, as well as, novel ones, consistent with the high genetic diversity of this parasite in Lake Victoria. Intestinal schistosomiasis is firmly endemic in parts of the Sesse Islands and more broadly, this island group provides an insight into the future challenges to be faced by the Ugandan National Control Programme in regularly reaching these rather remote, inaccessible and largely itinerant communities.

  17. Biomphalysin, a new β pore-forming toxin involved in Biomphalaria glabrata immune defense against Schistosoma mansoni.

    Science.gov (United States)

    Galinier, Richard; Portela, Julien; Moné, Yves; Allienne, Jean François; Henri, Hélène; Delbecq, Stéphane; Mitta, Guillaume; Gourbal, Benjamin; Duval, David

    2013-03-01

    Aerolysins are virulence factors belonging to the β pore-forming toxin (β-PFT) superfamily that are abundantly distributed in bacteria. More rarely, β-PFTs have been described in eukaryotic organisms. Recently, we identified a putative cytolytic protein in the snail, Biomphalaria glabrata, whose primary structural features suggest that it could belong to this β-PFT superfamily. In the present paper, we report the molecular cloning and functional characterization of this protein, which we call Biomphalysin, and demonstrate that it is indeed a new eukaryotic β-PFT. We show that, despite weak sequence similarities with aerolysins, Biomphalysin shares a common architecture with proteins belonging to this superfamily. A phylogenetic approach revealed that the gene encoding Biomphalysin could have resulted from horizontal transfer. Its expression is restricted to immune-competent cells and is not induced by parasite challenge. Recombinant Biomphalysin showed hemolytic activity that was greatly enhanced by the plasma compartment of B. glabrata. We further demonstrated that Biomphalysin with plasma is highly toxic toward Schistosoma mansoni sporocysts. Using in vitro binding assays in conjunction with Western blot and immunocytochemistry analyses, we also showed that Biomphalysin binds to parasite membranes. Finally, we showed that, in contrast to what has been reported for most other members of the family, lytic activity of Biomphalysin is not dependent on proteolytic processing. These results provide the first functional description of a mollusk immune effector protein involved in killing S. mansoni.

  18. New Approaches with Different Types of Circulating Cathodic Antigen for the Diagnosis of Patients with Low Schistosoma mansoni Load

    Science.gov (United States)

    Grenfell, Rafaella; Harn, Donald A.; Tundup, Smanla; Da'dara, Akram; Siqueira, Liliane; Coelho, Paulo Marcos Zech

    2013-01-01

    Background Schistosomiasis mansoni is a debilitating and sometimes fatal disease. Accurate diagnosis plays a key role in patient management and infection control. However, currently available parasitological methods are laborious and lack sensitivity. The selection of target antigen candidates has turned out to be a promising tool for the development of more sensitive diagnostic methods. In our previous investigations, the use of crude antigens led to false-positive results. Recently, focus has been given to highly purified Schistosoma mansoni antigens, especially to circulating antigens. Method Thus, our main goal was to test different types of circulating cathodic antigen glycoprotein (CCA), as “crude antigen,” the protein chain of recombinant CCA and two individual peptides. These schistosome proteins/peptides were tested in a new diagnostic method employing immunomagnetic separation based on the improvement of antigen–antibody binding. Principal Findings Use of recombinant CCA as a diagnostic antigen allowed us to develop a diagnostic assay with high sensitivity and specificity with no false-negative results. Interestingly, the “crude antigen” worked as a good marker for control of cure after praziquantel treatment. Conclusions/Significance Our new diagnostic method was superior to enzyme-linked immunosorbent assay in diagnosing low endemicity patients. PMID:23469295

  19. New approaches with different types of circulating cathodic antigen for the diagnosis of patients with low Schistosoma mansoni load.

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    Rafaella Grenfell

    Full Text Available BACKGROUND: Schistosomiasis mansoni is a debilitating and sometimes fatal disease. Accurate diagnosis plays a key role in patient management and infection control. However, currently available parasitological methods are laborious and lack sensitivity. The selection of target antigen candidates has turned out to be a promising tool for the development of more sensitive diagnostic methods. In our previous investigations, the use of crude antigens led to false-positive results. Recently, focus has been given to highly purified Schistosoma mansoni antigens, especially to circulating antigens. METHOD: Thus, our main goal was to test different types of circulating cathodic antigen glycoprotein (CCA, as "crude antigen," the protein chain of recombinant CCA and two individual peptides. These schistosome proteins/peptides were tested in a new diagnostic method employing immunomagnetic separation based on the improvement of antigen-antibody binding. PRINCIPAL FINDINGS: Use of recombinant CCA as a diagnostic antigen allowed us to develop a diagnostic assay with high sensitivity and specificity with no false-negative results. Interestingly, the "crude antigen" worked as a good marker for control of cure after praziquantel treatment. CONCLUSIONS/SIGNIFICANCE: Our new diagnostic method was superior to enzyme-linked immunosorbent assay in diagnosing low endemicity patients.

  20. Differences in Brazilian strains of Schistosoma mansoni evaluated by means of morphometric analysis of cercariae of both sexes

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    Machado-Silva José Roberto

    2000-01-01

    Full Text Available Morphometrics of Brazilian strains (BH, SJ and CMO of Schistosoma mansoni cercariae were obtained with a computerized image analyzer (IMAGE PRO PLUS, MEDIA CYBERNETICS, considering the following characters: body area, tail, furcae, oral and ventral suckers and distance between them. For statistical analysis, the variance test (one-way Anova was applied and significant differences of p< 0.05 were considered. All morphometric values in the BH strain were significantly higher (p< 0.05 than in the others. Lower values were obtained in females of SJ strain for all characters, excepting the body area. Only this character showed to be significantly different in males and females of the three strains. Specimens of both sexes in the BH and SJ strains showed significant differences regarding all characters. It was observed that this morphometric analysis permits the characterization of strains and also the sex identification in S. mansoni cercariae. Due to its feasibility, this method can be applied as a tool in laboratories devoid of more complex equipment.

  1. Changes in the small intestine of Schistosoma mansoni-infected mice fed a high-fat diet.

    Science.gov (United States)

    Alencar, Alba Cristina Miranda de Barros; Neves, Renata Heisler; de Oliveira, Albanita Viana; Machado-Silva, José Roberto

    2012-05-01

    The consumption of a high-fat diet modifies both the morphology of the small intestine and experimentally tested effects of schistosomiasis mansoni. However, whether a schistosomiasis infection associated with a high-fat diet causes injury to the small intestine has never been investigated. Mice were fed either a high-fat or a standard-fat diet for 6 months and were then infected with Schistosoma mansoni cercariae. Physical characteristics of the intestinal tissue (mucosal thickness, small intestinal villi length and height, and abundance of goblet cells and enterocytes on the villous surface) and the distribution of granulomas along the intestinal segments and their developmental stage were measured at the time of sacrifice (9 or 17 weeks post-infection). The group fed a high-fat diet exhibited different granuloma stages, whereas the control group possessed only exudative granulomas. The chronically infected mice fed a high-fat diet exhibited higher granuloma and egg numbers than the acutely infected group. Exudative, exudative/exudative-productive and exudative-productive granulomas were present irrespective of diet. Computer-aided morphometric analysis confirmed that villus length, villus width, muscular height and submucosal height of the duodenal and jejunal segments were affected by diet and infection. In conclusion, a high-fat diet and infection had a significant impact on the small intestine morphology and morphometry among the animals tested.

  2. The use of protein hydrolysate improves the protein intestinal absorption in undernourished mice infected with Schistosoma mansoni

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    Coutinho Eridan M.

    2002-01-01

    Full Text Available Patients residing in endemic areas for schistosomiasis in Brazil are usually undernourished and when they develop the hepatosplenic clinical form of the disease should usually receive hospital care, many of them being in need of nutritional rehabilitation before specific treatment can be undertaken. In the mouse model, investigations carried out in our laboratory detected a reduced aminoacid uptake in undernourished animals which is aggravated by a superimposed infection with Schistosoma mansoni. However, in well-nourished infected mice no dysfunction occurs. In this study, we tried to improve the absorptive intestinal performance of undernourished mice infected with S. mansoni by feeding them with hydrolysed casein instead of whole casein. The values obtained for the coefficient of protein intestinal absorption (cpia among well-nourished mice were above 90% (either hydrolysed or whole protein. In undernourished infected mice, however, the cpia improved significantly after feeding them with hydrolysed casein, animals reaching values close to those obtained in well-nourished infected mice.

  3. Melatonin and schistosomal antigens ameliorate the anti-oxidative and biochemical response to Schistosoma mansoni infection in hamster

    Institute of Scientific and Technical Information of China (English)

    Nahla S.El-SHENAWY; Maha F.M.SOLIMAN; Shimaa E.Abel-RAHMAN

    2009-01-01

    The present study was designed to investigate the potential protective effect of melatonin as an antioxidant separately or in combination with antigens (cercarial; CAP or soluble worm; SWAP) against Schistosoma mansoni infection in hamsters. Each hamster was sensitized with an initial immunization of 0.6 ml of the extracted antigen (30 μg protein/mL). After four days, a second injection of 0.4 mL was given (20 μg protein/mL). Then, each hamster was exposed to 260±20 S.mansoni cercariae followed with melatonin treatment (3.5 mg/kg) for thirty days from the 1st day of post infection. Levels of lipid peroxidation (LPO) products, catalase (CAT) activity, hepatic glutathione (GSH) and biochemical changes in the liver and kidneys functions were investigated. The results revealed a high significant increasing of LPO and decreasing of CAT and GSH in liver of infected hamsters. Biochemical observations showed severe damage in the liver enzyme activities and increasing cholesterol level in infected animals. Melatonin co-treatment with antigen to the infected-hamster attenuated the increase of LPO and restored the activity of CAT and levels of hepatic GSH. Also, the biochemical damages in the liver and kidneys functions were reduced. The present study suggests that melatonin may be useful in combating free radical-induced damage due to infection toxicity. The immunization with previous antigens resulted in a remarkable improvement on the liver enzyme activities, which were increased after infection. Thus, vaccination of hamsters with antigens (both CAP and SWAP) and melatonin treatment has more potent effect on the enhancement of antioxidant and biochemical of S.mansoni infected-hamster than each treatment separately. Immunization of the hamster with SWAP followed by melatonin was the best way among the other regime treatments to improve the biochemical and antioxidant parameters of the infected-hamsters[Current Zoology 55(2):165-172,2009].

  4. Schistosoma mansoni: assessment of effects of oleic acid, cercarial age and water temperature on parasite-host attraction.

    Science.gov (United States)

    Lee, Vivien S T; Burgess, Jefferey L; Sterling, Charles R; Lutz, Eric A

    2013-09-01

    Although the lifecycle of Schistosoma spp. and pathophysiology of schistosomiasis have been established, the mechanism by which cercariae find their host is not well understood. Speculatively, host infection by random and accidental host contact is not as biologically plausible as a biochemical mechanism of mammalian attraction. A few studies have indicated that biochemical cues and temperature gradients may play a role in host identification, attraction and attachment triggers. This study aimed to elucidate these mechanisms more specifically through evaluation of biochemical, age and temperature influences leading to Schistosoma mansoni cercariae attraction and attachment behaviors. Oleic acid, a common unsaturated free fatty acid in the outer layer of human skin, was tested for cercariae attraction across biologically relevant concentrations. Influence of media type (beeswax, nail varnish and agar), age-dependent behavior variability and environmentally appropriate temperatures (22 and 30 °C) were also evaluated. Results indicated that oleic acid at concentrations of 0.3, 0.9 and 1.8 g/mL in beeswax significantly increased median attachment to media (median attachment of 7.50%, 4.20% and 3.71%, respectively, P0.05). Biochemical, age and environmental factors influencing cercarial host attraction and attachment behavior have been elucidated by this study. This information will inform further development of devices for environmental surveillance and potentially improve cercarial exposure prevention strategies.

  5. In silico repositioning-chemogenomics strategy identifies new drugs with potential activity against multiple life stages of Schistosoma mansoni.

    Science.gov (United States)

    Neves, Bruno J; Braga, Rodolpho C; Bezerra, José C B; Cravo, Pedro V L; Andrade, Carolina H

    2015-01-01

    Morbidity and mortality caused by schistosomiasis are serious public health problems in developing countries. Because praziquantel is the only drug in therapeutic use, the risk of drug resistance is a concern. In the search for new schistosomicidal drugs, we performed a target-based chemogenomics screen of a dataset of 2,114 proteins to identify drugs that are approved for clinical use in humans that may be active against multiple life stages of Schistosoma mansoni. Each of these proteins was treated as a potential drug target, and its amino acid sequence was used to interrogate three databases: Therapeutic Target Database (TTD), DrugBank and STITCH. Predicted drug-target interactions were refined using a combination of approaches, including pairwise alignment, conservation state of functional regions and chemical space analysis. To validate our strategy, several drugs previously shown to be active against Schistosoma species were correctly predicted, such as clonazepam, auranofin, nifedipine, and artesunate. We were also able to identify 115 drugs that have not yet been experimentally tested against schistosomes and that require further assessment. Some examples are aprindine, gentamicin, clotrimazole, tetrabenazine, griseofulvin, and cinnarizine. In conclusion, we have developed a systematic and focused computer-aided approach to propose approved drugs that may warrant testing and/or serve as lead compounds for the design of new drugs against schistosomes.

  6. Identification of the Schistosoma mansoni Molecular Target for the Antimalarial Drug Artemether

    KAUST Repository

    Lepore, Rosalba

    2011-11-28

    Plasmodium falciparum and Schistosoma mansonii are the parasites responsible for most of the malaria and schistosomiasis cases in the world. Notwithstanding their many differences, the two agents have striking similarities in that they both are blood feeders and are targets of an overlapping set of drugs, including the well-known artemether molecule. Here we explore the possibility of using the known information about the mode of action of artemether in Plasmodium to identify the molecular target of the drug in Schistosoma and provide evidence that artemether binds to SmSERCA, a putative Ca2+-ATPase of Schistosoma. We also predict the putative binding mode of the molecule for both its Plasmodium and Schistosoma targets. Our analysis of the mode of binding of artemether to Ca2+-ATPases also provides an explanation for the apparent paradox that, although the molecule has no side effect in humans, it has been shown to possess antitumoral activity. © 2011 American Chemical Society.

  7. The bladder carcinoma secondary to schistosoma mansoni infection: A case report with review of the literature

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    Murat Can Kiremit

    2015-01-01

    Conclusion: Regarding the increasing travels all around the world, clinicians should remember that Schistosoma infection is certainly a part of the differential diagnosis of bladder carcinoma, even if the patients are not from endemic regions.

  8. QUESTIONNAIRES IN THE SCREENING FOR Schistosoma mansoni INFECTION: A STUDY OF SOCIO DEMOGRAPHIC AND WATER CONTACT VARIABLES IN FOUR COMMUNITIES IN BRAZIL

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    Lima e Costa Maria Fernanda F.

    1998-01-01

    Full Text Available The use of questionnaires has been recommended for identifying, at a lower cost, individuals at risk for schistosomiasis. In this study, validity of information obtained by questionnaire in the screening for Schistosoma mansoni infection was assessed in four communities in the State of Minas Gerais, Brazil. Explanatory variables were water contact activities, sociodemographic characteristics and previous treatment for schistosomiasis. From 677, 1474, 766 and 3290 individuals eligible for stool examination in the communities, 89 to 97% participated in the study. The estimated probability of individuals to be infected, if they have all characteristics identified as independently associated with S.mansoni infection, varied from 15% in Canabrava, to 42% in Belo Horizonte, 48% in Comercinho and 80% in São José do Acácio. Our results do not support the hypothesis that a same questionnaire on risk factors could be used in screening for S.mansoni infection in different communities.

  9. The Epigenome of Schistosoma mansoni Provides Insight about How Cercariae Poise Transcription until Infection.

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    David Roquis

    Full Text Available Chromatin structure can control gene expression and can define specific transcription states. For example, bivalent methylation of histone H3K4 and H3K27 is linked to poised transcription in vertebrate embryonic stem cells (ESC. It allows them to rapidly engage specific developmental pathways. We reasoned that non-vertebrate metazoans that encounter a similar developmental constraint (i.e. to quickly start development into a new phenotype might use a similar system. Schistosomes are parasitic platyhelminthes that are characterized by passage through two hosts: a mollusk as intermediate host and humans or rodents as definitive host. During its development, the parasite undergoes drastic changes, most notable immediately after infection of the definitive host, i.e. during the transition from the free-swimming cercariae into adult worms.We used Chromatin Immunoprecipitation followed by massive parallel sequencing (ChIP-Seq to analyze genome-wide chromatin structure of S. mansoni on the level of histone modifications (H3K4me3, H3K27me3, H3K9me3, and H3K9ac in cercariae, schistosomula and adults (available at http://genome.univ-perp.fr. We saw striking differences in chromatin structure between the developmental stages, but most importantly we found that cercariae possess a specific combination of marks at the transcription start sites (TSS that has similarities to a structure found in ESC. We demonstrate that in cercariae no transcription occurs, and we provide evidences that cercariae do not possess large numbers of canonical stem cells.We describe here a broad view on the epigenome of a metazoan parasite. Most notably, we find bivalent histone H3 methylation in cercariae. Methylation of H3K27 is removed during transformation into schistosomula (and stays absent in adults and transcription is activated. In addition, shifts of H3K9 methylation and acetylation occur towards upstream and downstream of the transcriptional start site (TSS. We conclude

  10. A Very High Infection Intensity of Schistosoma mansoni in a Ugandan Lake Victoria Fishing Community Is Required for Association with Highly Prevalent Organ Related Morbidity

    Science.gov (United States)

    Tukahebwa, Edridah M.; Magnussen, Pascal; Madsen, Henry; Kabatereine, Narcis B.; Nuwaha, Fred; Wilson, Shona; Vennervald, Birgitte J.

    2013-01-01

    Background In schistosomiasis control programmes using mass chemotherapy, epidemiological and morbidity aspects of the disease need to be studied so as to monitor the impact of treatment, and make recommendations accordingly. These aspects were examined in the community of Musoli village along Lake Victoria in Mayuge district, highly endemic for Schistosoma mansoni infection. Methodology and Principal Findings A cross sectional descriptive study was undertaken in a randomly selected sample of 217 females and 229 males, with a mean age of 26 years (SD ±16, range 7–76 years). The prevalence of S. mansoni was 88.6% (95% CI: 85.6–91.5). The geometric mean intensity (GMI) of S. mansoni was 236.2 (95% CI: 198.5–460.9) eggs per gram (epg) faeces. Males had significantly higher GMI (370.2 epg) than females (132.6 epg) and age was also significantly associated with intensity of infection. Levels of water contact activities significantly influenced intensity of infection and the highest intensity of infection was found among people involved in fishing. However, organomegaly was not significantly associated with S. mansoni except for very heavy infection (>2000 epg). Liver image patterns C and D indicative of fibrosis were found in only 2.2% and 0.2%, respectively. S. mansoni intensity of infection was associated with portal vein dilation and abnormal spleen length. Anaemia was observed in 36.4% of the participants but it was not associated with S. mansoni infection intensity. Considering growth in children as one of the morbidity indicators of schistosomiasis, intensity of S. mansoni was significantly associated with stunting. Conclusion Although organ-related morbidity, with the exception of periportal fibrosis, and S. mansoni infections were highly prevalent, the two were only associated for individuals with very high infection intensities. These results contrast starkly with reports from Ugandan Lake Albert fishing communities in which periportal fibrosis is more

  11. A very high infection intensity of Schistosoma mansoni in a Ugandan Lake Victoria Fishing Community is required for association with highly prevalent organ related morbidity.

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    Edridah M Tukahebwa

    Full Text Available BACKGROUND: In schistosomiasis control programmes using mass chemotherapy, epidemiological and morbidity aspects of the disease need to be studied so as to monitor the impact of treatment, and make recommendations accordingly. These aspects were examined in the community of Musoli village along Lake Victoria in Mayuge district, highly endemic for Schistosoma mansoni infection. METHODOLOGY AND PRINCIPAL FINDINGS: A cross sectional descriptive study was undertaken in a randomly selected sample of 217 females and 229 males, with a mean age of 26 years (SD ± 16, range 7-76 years. The prevalence of S. mansoni was 88.6% (95% CI: 85.6-91.5. The geometric mean intensity (GMI of S. mansoni was 236.2 (95% CI: 198.5-460.9 eggs per gram (epg faeces. Males had significantly higher GMI (370.2 epg than females (132.6 epg and age was also significantly associated with intensity of infection. Levels of water contact activities significantly influenced intensity of infection and the highest intensity of infection was found among people involved in fishing. However, organomegaly was not significantly associated with S. mansoni except for very heavy infection (>2000 epg. Liver image patterns C and D indicative of fibrosis were found in only 2.2% and 0.2%, respectively. S. mansoni intensity of infection was associated with portal vein dilation and abnormal spleen length. Anaemia was observed in 36.4% of the participants but it was not associated with S. mansoni infection intensity. Considering growth in children as one of the morbidity indicators of schistosomiasis, intensity of S. mansoni was significantly associated with stunting. CONCLUSION: Although organ-related morbidity, with the exception of periportal fibrosis, and S. mansoni infections were highly prevalent, the two were only associated for individuals with very high infection intensities. These results contrast starkly with reports from Ugandan Lake Albert fishing communities in which periportal fibrosis

  12. Compounds Derived from the Bhutanese Daisy, Ajania nubigena, Demonstrate Dual Anthelmintic Activity against Schistosoma mansoni and Trichuris muris

    Science.gov (United States)

    Pearson, Mark S.; Giacomin, Paul R.; Becker, Luke; Sotillo, Javier; Pickering, Darren

    2016-01-01

    Background Whipworms and blood flukes combined infect almost one billion people in developing countries. Only a handful of anthelmintic drugs are currently available to treat these infections effectively; there is therefore an urgent need for new generations of anthelmintic compounds. Medicinal plants have presented as a viable source of new parasiticides. Ajania nubigena, the Bhutanese daisy, has been used in Bhutanese traditional medicine for treating various diseases and our previous studies revealed that small molecules from this plant have antimalarial properties. Encouraged by these findings, we screened four major compounds isolated from A. nubigena for their anthelmintic properties. Methodology/Principal Findings Here we studied four major compounds derived from A. nubigena for their anthelmintic properties against the nematode whipworm Trichuris muris and the platyhelminth blood fluke Schistosoma mansoni using the xWORM assay technique. Of four compounds tested, two compounds—luteolin (3) and (3R,6R)-linalool oxide acetate (1)—showed dual anthelmintic activity against S. mansoni (IC50 range = 5.8–36.9 μg/mL) and T. muris (IC50 range = 9.7–20.4 μg/mL). Using scanning electron microscopy, we determined luteolin as the most efficacious compound against both parasites and additionally was found effective against the schistosomula, the infective stage of S. mansoni (IC50 = 13.3 μg/mL). Luteolin induced tegumental damage to S. mansoni and affected the cuticle, bacillary bands and bacillary glands of T. muris. Our in vivo assessment of luteolin (3) against T. muris infection at a single oral dosing of 100 mg/kg, despite being significantly (27.6%) better than the untreated control group, was markedly weaker than mebendazole (93.1%) in reducing the worm burden in mice. Conclusions/Significance Among the four compounds tested, luteolin demonstrated the best broad-spectrum activity against two different helminths—T. muris and S. mansoni—and was

  13. Evaluation of point-of-contact circulating cathodic antigen assays for the detection of Schistosoma mansoni infection in low-, moderate-, and high-prevalence schools in western Kenya.

    Science.gov (United States)

    Foo, Karen T; Blackstock, Anna J; Ochola, Elizabeth A; Matete, Daniel O; Mwinzi, Pauline N M; Montgomery, Susan P; Karanja, Diana M S; Secor, W Evan

    2015-06-01

    We evaluated the performance of a point-of-contact circulating cathodic antigen assay (POC-CCA) to detect schistosome infections in primary school children (N = 1,801) living in areas with low, moderate, and high Schistosoma mansoni prevalence in western Kenya. The commercially available assay (CCA-1) and a second, experimental formulation (CCA-2) were compared against Kato-Katz stool examinations and an anti-schistosome enzyme-linked immunosorbent assay (ELISA). A latent class model based on the four tests was used to establish "true infection status" in three different zones based on their distance from Lake Victoria. As a screening tool for community treatment according to World Health Organization (WHO) guidelines, the Kato-Katz examination was in closest agreement with the latent class model, followed by the experimental CCA-2, soluble adult worm antigen preparation (SWAP) ELISA, and CCA-1, which had high sensitivity compared with the other tests but was consistently the least specific. Our experience suggests that POC-CCA tests offer a field-friendly alternative to Kato-Katz, but need further interpretation for appropriate field use.

  14. The impact of zinc supplementation on Schistosoma mansoni reinfection rate and intensities

    DEFF Research Database (Denmark)

    Friis, Henrik; Ndhlovu, P; Mduluza, T

    1997-01-01

    OBJECTIVES: To assess the effect of zinc supplementation on susceptibility to S. mansoni reinfections among schoolchildren. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING AND SUBJECTS: 313 rural Zimbabwean schoolchildren (144 boys and 169 girls), 11-17 y). INTERVENTIONS......: Supplementation with zinc (30 or 50 mg) or placebo on schooldays for 12 months. Due to drought, a food programme was in operation during the last eight months of the study. OUTCOME MEASURES: S. mansoni and S. haematobium reinfection rates and intensities. RESULTS: There was no difference in reinfection rates...... rates or intensities were seen. CONCLUSIONS: Zinc supplementation reduced the intensity of S. mansoni reinfections. Although the intensities of reinfection were very low, the finding probably reflects a biological effect of zinc that could be of public health importance in settings with higher...

  15. Evaluation of anti-Schistosoma mansoni igG antibodies in patients with chronic schistosomiasis mansoni before and after specific treatment Avaliação da presença de anticorpos IgG anti-Schistosoma mansoni no soro de pacientes com esquistossomose mansônica crônica, antes e após tratamento específico

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    Célia Maria V. VENDRAME

    2001-06-01

    Full Text Available The circumoval precipitin test (COPT, enzyme-linked immunosorbent assay (ELISA and the immunoblotting anti-adult worm antigen (AWA and soluble egg antigen (SEA tests were applied to 17 chronically schistosome-infected patients for the detection of anti-Schistosoma mansoni antibodies before and on four occasions after oxamniquine administration over a period of six months. Compared to a control group, schistosomiasis patients showed high levels of IgG antibodies in AWA and SEA-ELISA. A decrease in IgG levels was observed six months after treatment, although negative reactions were not obtained. Significant decreases in IgG1, IgG3 and, mainly, IgG4, but not anti-SEA IgG2 levels were observed six months after treatment, again without negativity. Analysis of anti-AWA IgG antibodies by immunoblotting before treatment showed a 31 kDa strand in 14 patients (82% which disappeared in three cases up to six months after treatment; furthermore, anti-SEA IgG antibodies showed the same band in nine patients (53% before treatment, which disappeared in only four cases up to six months after treatment.Em 17 pacientes com infecção crônica por Schistosoma mansoni utilizaram-se os testes de reação periovular, imunoenzimático (ELISA e imunoblotting, empregando-se antígenos obtidos a partir de vermes adultos (AWA ou de ovos de S. mansoni (SEA, para detecção de anticorpos anti-S. mansoni, antes e em quatro ocasiões após tratamento com oxamniquine. Quando cotejados a grupo controle os pacientes esquistossomóticos revelaram altos níveis séricos de anticorpos IgG nos testes ELISA (anti-AWA e anti-SEA, não se observando, porém, negativação até seis meses após tratamento específico. Encontrou-se, entretanto, decréscimo significativo, sem negativação, dos níveis de IgG1, IgG3 e, principalmente, IgG4, quando se utilizou antígeno solúvel obtido a partir de ovos de S. mansoni (SEA, seis meses após administração de oxamniquine. O mesmo não foi

  16. Immunostimulatory property of a synthetic peptide belonging to the soluble ATP diphosphohydro-lase isoform (SmATPDase 2 and immunolocalisation of this protein in the Schistosoma mansoni egg

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    Rita Gabriela Pedrosa Ribeiro Mendes

    2011-11-01

    Full Text Available A peptide (SmB2LJ; r175-194 that belongs to a conserved domain from Schistosoma mansoni SmATPDase 2 and is shared with potato apyrase, as predicted by in silico analysis as antigenic, was synthesised and its immunostimulatory property was analysed. When inoculated in BALB/c mice, this peptide induced high levels of SmB2LJ-specific IgG1 and IgG2a subtypes, as detected by enzyme linked immunosorbent assay. In addition, dot blots were found to be positive for immune sera against potato apyrase and SmB2LJ. These results suggest that the conserved domain r175-194 from the S. mansoni SmATPDase 2 is antigenic. Western blots were performed and the anti-SmB2LJ antibody recognised in adult worm (soluble worm antigen preparation or soluble egg antigen antigenic preparations two bands of approximately 63 and 55 kDa, molecular masses similar to those predicted for adult worm SmATPDase 2. This finding strongly suggests the expression of this same isoform in S. mansoni eggs. To assess localisation of SmATPDase 2, confocal fluorescence microscopy was performed using cryostat sections of infected mouse liver and polyclonal antiserum against SmB2LJ. Positive reactions were identified on the external surface from the miracidium in von Lichtenberg's envelope and, in the outer side of the egg-shell, showing that this soluble isoform is secreted from the S. mansoni eggs.

  17. Ocorrência de linhagens humana e silvestre de Schistosoma mansoni, na pré-amazônia: I - estudo em moluscos Occurrence of wild and human strains of Schistosoma mansoni in lower Amazonia: I - study in moluscs

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    Othon de Carvalho Bastos

    1982-10-01

    Full Text Available Foram isoladas na região da Baixada Maranhense (Brasil, linhagens humana (H e silvestre(S de Schistosoma mansoni a partir de miracídios eclodidos de ovos encontrados em fezes de doentes humanos autóctones da Região e de fígados de roedores silvestres naturalmente infectados. Biomphalaria glabrata, descentes de caramujos coletados no campo, foram expostos, isoladamente, aos miracídios H e S, mantidos isolados em moluscário e observados durante 100 dias. Moluscos normais foram mantidos nas mesmas condições de ambiente em que foram submetidos os infectados e tomados como controle da experiência. Foram anotados os indices de infecção dos moluscos, as datas da eliminação de cercárias, quantidade de larvas eliminadas e mortalidade dos moluscos. Os dados sugeriram melhor adaptação do esquistossomo da linhagem H à B. glabrata. A linhagem S, por sua vez, foi três vezes mais virulenta do que a linhagem H. Estes dados foram comparados com os encontrados na literatura especializada e verificado diversidades nos comportamentos parasitológicos das linhagens em estudo, quando comparados com os encontrados nas linhagens H e S oriundas do Vale do Rio Paraíba do Sul, no Estado de São Paulo (Brasil.The wild (W and human (H strains of Schistosoma mansoni were isolated in the Lowland Region of the Maranhão State (Brazil. The snail progenies from Biomphalaria glabrata collected from that region were exposed to the W miracidia, obtained from livers of wild rodents, and H miracidia from eggs in human stools. A control gruop of normal snails was kept in the same conditions as the infected one. The date of the elimination of cercariae, the quantity of eliminated larvae, the infection index of the moluscs and the mortality rate of the snails were recorded. These data suggested better adaptation of the H strain to B. glabrata. The W strain presented three times more virulence to snails than the H strain. These results were compared with published

  18. Evolução das imunoglobunilas envolvidas na resposta imune de camundongos ao Schistosoma mansoni The evolution of immunoglobulins involved in the immune response to mice infected with Schistosoma mansoni

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    Othon de Carvalho Bastos

    1984-04-01

    Full Text Available Foi estudada a evolução das imunoglobulinas envolvidas na resposta imune de camundongos ao Schistosoma mansoni durante oito semanas de infecção, utilizando soros pluri-específicos como reativos biológicos e a técnica da imunoeletroforese bidimensional. Os resultados expressaram modulação da resposta imune humoral, tanto em soros de animais parasitados (I como nos normais, tomados como controle (C. Aumentos relativos dos níveis de imunoglobulinas entre estes dois grupos foram constatados pela relação I/C. Foi possível verificar o aparecimento de uma resposta primária, ocorrida entre o início da doença e a segunda semana de infecção, constituída de IgM e IgA, e uma secundária, iniciada na sexta semana de infecção, constituída pelas IgA; IgG1 e IgM, com aumentos relativos de 4.5; 3 e 2 vezes normal.The evolution of immunoglobulins involved in the immune response of mice infected with Schistosoma mansoni was studied by using plurispecific sera and the bi-dimensional immunoelectrophoresis technique. Determinations of the level of different immunoglobulins in infected animals and control groups which were mantained under similar conditions detected significant variations in both groups over the 8 weeks of observation. The study of the relationship (I/C between the level of immunoglobulins of the infected animals (I and that of corresponding control (C showed that the infected animals presented a primary response (1-2 weeks after infection date and a secondary response that was initiated in the 6th week of infection, with levels of IgA, IgG and IgM that were respectively 4.5, 3 and 2 times higher than those of corresponding control.

  19. Eficiência do diagnóstico coproscópico de Schistosoma mansoni em fezes prensadas The efficiency of the examination of compressed fecal samples for Schistosoma mansoni eggs

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    Horacio Manuel Santana Teles

    2003-07-01

    Full Text Available A eficácia do controle da esquistossomose depende em grande parte da sensibilidade da coproscopia. Passamos a utilizar, além da técnica de Kato-Katz, a de prensagem de fezes entre lâmina e lamínula de polipropileno, segundo Ferreira. De 1.282 amostras fecais colhidas entre 1998 e 2000 no Bairro da Palha, Município de Bananal, São Paulo, Brasil, 105 (8,2% resultaram positivas. A primeira técnica revelou 90 (7% e a segunda, 88 (6,9% amostras positivas. Os resultados concordaram, segundo a estatística kappa. Valores baixos de percentagens de positivos e de opg (ovos por grama de fezes, em Bananal, demandaram aumento do volume de material a examinar. Além de permitir a observação da viabilidade dos ovos de Schistosoma mansoni, a segunda técnica dispensa o uso de glicerina, de placa medidora e de tamisação; esta última, responsável por ulterior perda de precisão nas determinações de opg.The control of schistosomiasis depends mostly upon the sensitivity of stool examinations. We used both the Kato-Katz technique and the compression of samples between the slide and a polypropylene cover glass, according to Ferreira. Out of 1,282 samples collected between 1998 and 2000 in the Palha District, Municipality of Bananal, São Paulo State, Brazil, 105 (8.2 % were positive. The first and second methods revealed 90 (7% and 88 (6.9 % positive cases, respectively. According to the kappa statistic, both methods were in agreement. In Bananal, the proportion of positive cases and egg per gram (epg values are low, which calls for the examination of larger than usual volumes of feces. The viability of Schistosoma mansoni eggs can also be checked when using the second method, which dispenses with glycerin solution, measuring plates and sieves. The latter cause a further loss of precision in epg determinations.

  20. Utility of Schistosoma bovis Adult Worm Antigens for Diagnosis of Human Schistosomiasis by Enzyme-Linked Immunosorbent Assay and Electroimmunotransfer Blot Techniques

    Science.gov (United States)

    Pardo, J.; Carranza, C.; Turrientes, M. C.; Arellano, J. L. Pérez; Vélez, R. López; Ramajo, V.; Muro, A.

    2004-01-01

    Immunodiagnostic methods based on the detection of antibodies continue to be the most effective and practical methods for the diagnosis of imported schistosomiasis. Schistosoma bovis is a species whose final natural hosts are bovines, ovines, caprines, and small wild ruminants. Different studies have demonstrated the analogies existing between S. bovis and other Schistosoma species which affect humans. The objective of this work was to evaluate the utility of S. bovis adult worm antigens (AWA) for the diagnosis of imported human schistosomiasis by enzyme-linked immunosorbent assay (ELISA) and electroimmunotransfer blotting (EITB) techniques. By detecting eggs, the ELISA for S. bovis AWA was able to definitively detect imported cases with a sensitivity of 94%. The specificity of the ELISA for S. bovis AWA was 97%. There were no differences between the results of the S. bovis AWA ELISA for patients infected with Schistosoma mansoni and those infected with Schistosoma haematobium. The EITB technique showed bands of 85, 37, and 20 kDa, which are characteristic of infections with Schistosoma spp. Specific bands to indicate infection by different species of Schistosoma have not been detected. The combined use of the ELISA for S. bovis AWA and EITB increased the global sensitivity of the study to 97%. Our findings suggest that the ELISA for S. bovis AWA is a useful test for the immunodiagnosis of imported schistosomiasis and that EITB for detecting S. bovis AWA permits the confirmation of diagnosis when the ELISA for S. bovis AWA is positive. PMID:15539523

  1. The repertoire of G protein-coupled receptors in the human parasite Schistosoma mansoni and the model organism Schmidtea mediterranea

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    Zamanian Mostafa

    2011-12-01

    Full Text Available Abstract Background G protein-coupled receptors (GPCRs constitute one of the largest groupings of eukaryotic proteins, and represent a particularly lucrative set of pharmaceutical targets. They play an important role in eukaryotic signal transduction and physiology, mediating cellular responses to a diverse range of extracellular stimuli. The phylum Platyhelminthes is of considerable medical and biological importance, housing major pathogens as well as established model organisms. The recent availability of genomic data for the human blood fluke Schistosoma mansoni and the model planarian Schmidtea mediterranea paves the way for the first comprehensive effort to identify and analyze GPCRs in this important phylum. Results Application of a novel transmembrane-oriented approach to receptor mining led to the discovery of 117 S. mansoni GPCRs, representing all of the major families; 105 Rhodopsin, 2 Glutamate, 3 Adhesion, 2 Secretin and 5 Frizzled. Similarly, 418 Rhodopsin, 9 Glutamate, 21 Adhesion, 1 Secretin and 11 Frizzled S. mediterranea receptors were identified. Among these, we report the identification of novel receptor groupings, including a large and highly-diverged Platyhelminth-specific Rhodopsin subfamily, a planarian-specific Adhesion-like family, and atypical Glutamate-like receptors. Phylogenetic analysis was carried out following extensive gene curation. Support vector machines (SVMs were trained and used for ligand-based classification of full-length Rhodopsin GPCRs, complementing phylogenetic and homology-based classification. Conclusions Genome-wide investigation of GPCRs in two platyhelminth genomes reveals an extensive and complex receptor signaling repertoire with many unique features. This work provides important sequence and functional leads for understanding basic flatworm receptor biology, and sheds light on a lucrative set of anthelmintic drug targets.

  2. Combinatory microarray and SuperSAGE analyses identify pairing-dependently transcribed genes in Schistosoma mansoni males, including follistatin.

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    Silke Leutner

    2013-11-01

    Full Text Available BACKGROUND: Schistosomiasis is a disease of world-wide importance and is caused by parasitic flatworms of the genus Schistosoma. These parasites exhibit a unique reproduction biology as the female's sexual maturation depends on a constant pairing-contact to the male. Pairing leads to gonad differentiation in the female, and even gene expression of some gonad-associated genes is controlled by pairing. In contrast, no morphological changes have been observed in males, although first data indicated an effect of pairing also on gene transcription in males. METHODOLOGY/PRINCIPAL FINDINGS: To investigate the influence of pairing on males, we performed a combinatory approach applying SuperSAGE and microarray hybridization, generating the most comprehensive data-set on differential transcription available to date. Of 6,326 sense transcripts detected by both analyses, 29 were significantly differentially transcribed. Besides mutual confirmation, the two methods complemented each other as shown by data comparison and real-time PCR, which revealed a number of genes with consistent regulation across all methods. One of the candidate genes, follistatin of S. mansoni (SmFst was characterized in more detail by in situ hybridization and yeast two-hybrid (Y2H interaction analyses with potential binding partners. CONCLUSIONS/SIGNIFICANCE: Beyond confirming previously hypothesized differences in metabolic processes between pairing-experienced (EM and pairing-unexperienced males (UM, our data indicate that neuronal processes are involved in male-female interaction but also TGFβ-signaling. One candidate revealing significant down-regulation in EM was the TGFβ-pathway controlling molecule follistatin (SmFst. First functional analyses demonstrated SmFst interaction with the S. mansoni TGFβ-receptor agonists inhibin/activin (SmInAct and bone morphogenic protein (SmBMP, and all molecules colocalized in the testes. This indicates a yet unknown role of the TGF

  3. Comportamento da cepa LE de Schistosoma mansoni, após passagem em hospedeiro humano infectado acidentalmente

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    Neusa Araújo

    1986-12-01

    Full Text Available Uma auxiliar de laboratório infectou-se acidentalmente, com cercárias de Schistosoma mansoni, cepa LE, mantida rotineiramente em nossos laboratórios. Decorridos 5 meses, o exame parasitológico de fezes revelou 108 ovos/g . A pacientefoi tratada com oxamniquine, porém a infecção continuou ativa (6 ovos/g. Foi então obtido o isolado SSF mantido no modelo Biomphalaria glabrata - camundongo albino. Os resultados obtidos no estudo comparativo, entre o isolado SSF e a cepa LE, que lhe deu origem, mostraram que a duração do período pré-patente e o índice de infectividade em camundongos, bem como a resposta aos agentes esquistossomicidas (hycanthone, oxamniquine epraziquantel não apresentaram diferenças estatisticamente significativas. Por outro lado, o número de miracídios obtidos dos intestinos e fígados dos camundongos infectados foi o dobro com a cepa LE, quando comparados com aquele do isolado SSF. Também a variação do peso dos animais foi bastante diferente. Concluiu-se que apenas uma passagem pelo hospedeiro humano não mudou substancialmente as características da cepa estudada.A laboratory technician was accidentally infected with the LE strain of Schistosoma mansoni cercariae maintained in our laboratories. After 5 months infection parasitological examination revealed 108 eggs/g faeces. Althrough treated with oxamniquine, the infection still persisted (6 eggs/g of faeces. An isolate (SSF was obtained from that person and maintained in Biomphalaria glabrata - Swiss mouse by alternate passage. The experimental comparative results between the newly obtained SSF isolate and the original LE strain showed that the differences in pre-patent period, the mice infectivity level and the schistosomicidal response to hycanthone, oxamniquine and praziquantel was not statistically significant. On the other hand the number of miracidia recovered from intestines and livers of equally infected mice was twice as miich in the LE strain than

  4. Estudos sôbre a doença de Manson-Pirajá: (Esquistosomose pelo "Schistosoma Mansoni"

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    Octavio de Magalhães

    1947-03-01

    Full Text Available Os autores estudaram a doença produzida pelo «Schistosoma Mansoni» em Minas Gerais, Brasil. Fizeram um resumo histórico dos próprios trabalhos, iniciados no ano de 1933 em Belo Horizonte. Em 1937 um dos autores já havia mesmo, sentido a gravidade do problema sanitário, chamando a atenção para o Govêrno de Minas Gerais. Publicam os estudos que fizeram, inclu¬sive de lagos artificial da Pampulha, Belo Horizonte, e o parecer para ali combater a verminose. Dão os aspectos clínicos da doença, chamando a atenção para alguns dos mais importantes, clínicos e cirúrgicos da verminose. Referem às dificuldades do diagnostico, terapêutica e profilaxia, expondo a distribuição geográfica em Minas Gerais e publicando um mapa baseado nos estudos próprios e de outros colegas, feitos em 88 cidades mineiras. A média geral que os autores apuraram nas cidades infestadas foi de 13,70% para o trematódeo. Propõem, como já fizeram em 1941, a criação de um Serviço de combate à Esquistosomose no Brasil.(AUThe authours have studied the disease caused by the Schistosoma Mansoni in Minas Gerais, Brasil. They have made an historical summary of their own work, begun in 1933 in Belo Horizonte. In 1937 one of the authors, seeing the gravity of the sanitary problem, brought it to the notice of the government of Minas Gerais. They publish the studies they made, including that of the artificial lake of Pampulha, Belo Horizonte and their plan for fighting the verminosis. They give the clinical aspects of the disease, calling attention to the most important, clinical and surgical, of the verminosis. They refer to the difficulties of the diagnosis, therapeutics and prophylaxis, showing the geographical distribution in Minas Gerais and publish a map, based on their own studies and those of other colleagues, made in 88 cities of Minas Gerais. The average that the authors found in the infested cities, was 13.70 % for the trematodo. They suggest, as they had

  5. Schistosoma mansoni Infection in Ugandan Men Is Associated with Increased Abundance and Function of HIV Target Cells in Blood, but Not the Foreskin: A Cross-sectional Study.

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    Jessica L Prodger

    Full Text Available Schistosoma mansoni infection has been associated with an increased HIV prevalence in humans and SHIV incidence in primate models. We hypothesized that immune activation from this gastrointestinal mucosa infection would increase highly HIV-susceptible CD4 T cell subsets in the blood and the foreskin through common mucosal homing.Foreskin tissue and blood were obtained from 34 HIV- and malaria-uninfected Ugandan men who volunteered for elective circumcision, 12 of whom were definitively positive for S. mansoni eggs in stool and 12 definitively negative for both S. mansoni eggs and worm antigen. Tissue and blood T cell subsets were characterized by flow cytometry and immunohistochemistry (IHC. Th17 and Th1 cells from both the blood and foreskin expressed higher levels of CCR5 and were more activated than other CD4 T cell subsets. S. mansoni-infected men had a higher frequency of systemic Th1 cells (22.9 vs. 16.5% of blood CD4 T cells, p<0.05, Th17 cells (2.3 vs. 1.5%, p<0.05, and Th22 cells (0.5 vs. 0.3%, p<0.01 than uninfected men. Additionally, Th17 cells in the blood of S. mansoni-infected men demonstrated enhanced function (28.1 vs. 16.3% producing multiple cytokines, p = 0.046. However, these immune alterations were not observed in foreskin tissue.S. mansoni infection was associated with an increased frequency of highly HIV-susceptible Th1, Th17 and Th22 cell subsets in the blood, but these T cell immune differences did not extend to the foreskin. S. mansoni induced changes in T cell immunology mediated through the common mucosal immune system are not likely to increase HIV susceptibility in the foreskin.

  6. Contribuição ao levantamento da carta planorbídica do Estado de São Paulo: Pesquisa de focos com formas evolutivas do Schistosoma mansoni. II. Município de Peruibe (Litoral Sul do Estado de São Paulo Contribution to the survey of the planorbid chart of the State of São Paulo (Brazil: Investigation of foci with evolutive forms of Schistosoma mansoni. II. Peruibe county (Southern coast of the State of São Paulo

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    Mário Demar Perez

    1969-12-01

    Full Text Available Em levantamento realizado em Peruibe, em janeiro de 1966, foram identificados focos de Biomphalaria tenagophila infestados com formas evolutivas do Schistosoma mansoni.In this work the occurence of Biomphalaria tenagophila naturally parasited by evolutive forms of Schistosoma mansoni is registered in the city of Peruibe, situated in the Southern Littoral of the State of São Paulo (Brazil. Besides B. tenagophila, in the region it occurs also Drepanotrema cimex, a species not proved to be a host of Schistosoma mansoni and whose occurence had not yet been recorded in Peruibe.

  7. Accuracy of Urine Circulating Cathodic Antigen (CCA) Test for Schistosoma mansoni Diagnosis in Different Settings of Côte d'Ivoire

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    Coulibaly, Jean T.; Knopp, Stefanie; N'Guessan, Nicaise A.; Silué, Kigbafori D.; Fürst, Thomas; Lohourignon, Laurent K.; Brou, Jean K.; N'Gbesso, Yve K.; Vounatsou, Penelope; N'Goran, Eliézer K.; Utzinger, Jürg

    2011-01-01

    Background Promising results have been reported for a urine circulating cathodic antigen (CCA) test for the diagnosis of Schistosoma mansoni. We assessed the accuracy of a commercially available CCA cassette test (designated CCA-A) and an experimental formulation (CCA-B) for S. mansoni diagnosis. Methodology We conducted a cross-sectional survey in three settings of Côte d'Ivoire: settings A and B are endemic for S. mansoni, whereas S. haematobium co-exists in setting C. Overall, 446 children, aged 8–12 years, submitted multiple stool and urine samples. For S. mansoni diagnosis, stool samples were examined with triplicate Kato-Katz, whereas urine samples were tested with CCA-A. The first stool and urine samples were additionally subjected to an ether-concentration technique and CCA-B, respectively. Urine samples were examined for S. haematobium using a filtration method, and for microhematuria using Hemastix dipsticks. Principal Findings Considering nine Kato-Katz as diagnostic ‘gold’ standard, the prevalence of S. mansoni in setting A, B and C was 32.9%, 53.1% and 91.8%, respectively. The sensitivity of triplicate Kato-Katz from the first stool and a single CCA-A test was 47.9% and 56.3% (setting A), 73.9% and 69.6% (setting B), and 94.2% and 89.6% (setting C). The respective sensitivity of a single CCA-B was 10.4%, 29.9% and 75.0%. The ether-concentration technique showed a low sensitivity for S. mansoni diagnosis (8.3–41.0%). The specificity of CCA-A was moderate (76.9–84.2%); CCA-B was high (96.7–100%). The likelihood of a CCA-A color reaction increased with higher S. mansoni fecal egg counts (odds ratio: 1.07, p<0.001). A concurrent S. haematobium infection or the presence of microhematuria did not influence the CCA-A test results for S. mansoni diagnosis. Conclusion/Significance CCA-A showed similar sensitivity than triplicate Kato-Katz for S. mansoni diagnosis with no cross-reactivity to S. haematobium and microhematuria. The low sensitivity of

  8. Radicular dysfunction preponderance at early phase clinical evaluation in myelitis by Schistosoma mansoni

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    Claudio Henrique Fernandes Vidal

    2011-04-01

    Full Text Available In neuroschistosomiasis, the spinal cord is the most common place of the disease. In high prevalent areas for schistosomiasis mansoni, the clinical alertness is important for an early diagnostic, in order to decrease the final neurological damage. This study provides some useful neurologic information about a series of patients with schistosomal myelitis. METHOD: The sample consisted of 13 schistosomiasis mansoni carriers examined at the moment of the diagnosis of myelitis. RESULTS: The classical triad (lumbago, weakness at the lower limbs and urinary dysfunctions was documented in 11 (86.61% patients. The distribution of the clinical forms was: myeloradicular in six patients (46.15%, radicular in four (30.76% and myelitic in three (23.07%. CONCLUSION: The radicular dysfunction and their clinical associated forms were the most prominent pattern during the early phase of this disease.

  9. Impact of experimental duel infections with Schistosoma mansoni and Echinoccocus granulosus on hepatic histopathology.

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    Elwakil, Hala S; Ali, Nehad M; Talaat, Roba M; Osman, Wesam M

    2007-12-01

    Experimental duel infection with S. mansoni and E. granulosus was induced in mice to determine their effect on serum nitric oxide (NO) level and accordingly on the sequences of histopathological lesions affecting the liver. The results showed that serum NO level was significantly increased (pdeath of hydatid cyst in mice (GI) compared to E. granulosus (GV). So, the duel infection with the two parasites affected serum NO level and hepatic histopathology, by ameliorative or deteriorative effects, according to duration of infection with either.

  10. Efficiency of Immunization of Mice with Irradiated Antigen Against Schistosoma mansoni Infection in Comparison with Praziquantel

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    Mona A. El-Gawish, Manar N. Hafez, Fatma A. Eid* Maha G. Soliman*

    2006-01-01

    Introduction: The present study is an attempt to evaluate the protective effect of schistosomula antigen and the current antischistosomal drug praziquantel (PZQ) as a reference drug on mice infected with S. mansoni. Material and Methods: Mice were vaccinated by irradiated or non-irradiated schistosomula antigen, both at a dose of 100 ug protein/mice once weekly for 3 weeks, before infection with alive cercariae and compared with the treatment with i.m. injection of praziquantel at a dose of 4...

  11. Activation-induced apoptosis in peripheral blood mononuclear cells during hepatosplenic Schistosoma mansoni infections.

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    Ghoneim, H M; Demian, S R; Heshmat, M G; Ismail, N S; El-Sayed, Laila H

    2008-01-01

    It is well established that programmed cell death (apoptosis) is an important regulator of host responses during infection with a variety of intra- and extra-cellular pathogens. The present work aimed at assessment of in vitro spontaneous and phytohemagglutinin (PHA)-induced apoptosis in mononuclear cells isolated from patients with hepatosplenic form of S. mansoni infections. Cell death data were correlated to the degree of lymphoproliferative responses to PHA as well as to the serum anti-schistosomal antibody titers. A markedly significant increase in PHA-induced apoptosis in lymphocytes isolated from S. mansoni-infected patients was seen when compared to the corresponding healthy controls. However, a slight difference was recorded between the two studied groups regarding the spontaneous apoptosis. This was accompanied with a significant impairment of in vitro PHA-induced lymphoproliferation of T cells from S. mansoni patients. Data of the present study supports the hypothesis that activation-induced cell death (AICD) is a potentially contributing factor in T helper (Th) cell regulation during chronic stages of schistosomiasis, which represents a critically determinant factor in the host-parasite interaction and might influence the destiny of parasitic infections either towards establishment of chronic infection or towards host death.

  12. Envolvimento renal na associação salmonella-Schistosoma mansoni

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    José Roberto Lambertucci

    1987-06-01

    Full Text Available Vinte pacientes com a associação Salmonella-S. mansoni (Grupo 1 e 20 com esquistossomose mansoni hepatesplênica (Grupo 2 foram selecionados para o estudo. Submeteram-se os pacientes dos Grupos le 2 a exame clínico minucioso e a uma série de exames complementares, com destaque para as provas de função renal. Em 10 pacientes do Grupo 1 e 20 do Grupo 2, realizou-se, ainda, estudo histológico do rim à microscopia óptica, de fluorescência e eletrônica. As alterações renais foram mais freqüentes nos pacientes do Grupo 1. Após o tratamento dos pacientes do Grupo 1, com antibióticos e/ou esquistossomicidas, observou-se regressão das alterações renais sob o ponto de vista clínico, laboratorial e imunopatológico. Os autores concluem pela existência de duas nefropatias distintas: a nefropatia esquistossomótica e a encontrada em pacientes com a associação Salmonella-S. mansoni.

  13. Seleção genética de Biomphalaria glabrata e Biomphalaria tenagophila visando a alteração da suscetibilidade e resistência ao Schistosoma mansoni Genetic selection of Biomphalaria glabrata and Biomphalaria tenagophila seeking the alteration of the susceptibility and resistance to the Schistosoma mansoni

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    Nádia Regina Borim Zuim

    2005-10-01

    Full Text Available Gerações de Biomphalaria glabrata e Biomphalaria tenagophila selecionadas geneticamente para resistência e suscetibilidade ao Schistosoma mansoni das linhagens BH e SJ foram utilizadas no estudo da adaptação do trematódeo ao hospedeiro intermediário. As gerações dos planorbídeos foram obtidas por autofecundação dos moluscos que se apresentaram suscetíveis ou resistentes após a exposição aos miracídios de Schistosoma mansoni. Para Biomphalaria glabrata foram obtidas as gerações: Parental, F1S (Suscetível, F1R (Resistente, F2S e F2R. Para a Biomphalaria tenagophila foram estudadas as gerações: Parental, F1S, F1R e F50S. A comparação das taxas de infecção apresentadas pelas diferentes gerações mostrou que, em ambas as espécies, o aumento da suscetibilidade foi mais facilmente obtido do que o aumento da resistência. A dificuldade em aumentar a resistência do molusco ao S. mansoni tem fortes implicações epidemiológicas.Generations of Biomphalaria glabrata and Biomphalaria tenagophila selected genetically for resistance and susceptibility to Schistosoma mansoni of strains BH and SJ were used in a study of the trematode adaptation to the intermediate host. Descendants of the planorbids were obtained by self-fertilization of the mollusks that became susceptible or resistant after exposure to the miracidia of Schistosoma mansoni. For Biomphalaria glabrata they were obtained from the following generations: Parental, F1S (Susceptible, F1R (Resistant, F2S and F2R. For Biomphalaria tenagophila the studied generations were: Parental, F1S, F1R and F50S. The comparison of the infection rates presented by the different generations showed that the increase in susceptibility was more easily obtained in both species. The difficulty in increasing the resistance of the mollusks to Schistosoma mansoni has important epidemiologic implications.

  14. Comportamento da cepa LE de Schistosoma mansoni, após passagem em hospedeiro humano infectado acidentalmente

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    Neusa Araújo

    1986-12-01

    Full Text Available Uma auxiliar de laboratório infectou-se acidentalmente, com cercárias de Schistosoma mansoni, cepa LE, mantida rotineiramente em nossos laboratórios. Decorridos 5 meses, o exame parasitológico de fezes revelou 108 ovos/g . A pacientefoi tratada com oxamniquine, porém a infecção continuou ativa (6 ovos/g. Foi então obtido o isolado SSF mantido no modelo Biomphalaria glabrata - camundongo albino. Os resultados obtidos no estudo comparativo, entre o isolado SSF e a cepa LE, que lhe deu origem, mostraram que a duração do período pré-patente e o índice de infectividade em camundongos, bem como a resposta aos agentes esquistossomicidas (hycanthone, oxamniquine epraziquantel não apresentaram diferenças estatisticamente significativas. Por outro lado, o número de miracídios obtidos dos intestinos e fígados dos camundongos infectados foi o dobro com a cepa LE, quando comparados com aquele do isolado SSF. Também a variação do peso dos animais foi bastante diferente. Concluiu-se que apenas uma passagem pelo hospedeiro humano não mudou substancialmente as características da cepa estudada.

  15. Propiedad molusquicida de Euphorbia laurifolia A. Juss (Euphorbiaceae contra Biomphalaria glabrata Say hospedador intermediario de Schistosoma mansoni

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    José Ángel Mogollón-Morales

    2016-08-01

    Full Text Available En América Latina, los caracoles de Biomphalaria glabrata (Planorbidae son hospedadores intermediarios del parasito Schistosoma mansoni, agentes causantes de la schistosomiasis, una parasitosis que afecta a millones de personas en el mundo. El presente trabajo evalúa el papel de la especie Euphorbia laurifolia A. Juss (Euphorbiaceae contra B. glabrata. La actividad molusquicida se evaluó de acuerdo a los parámetros sugeridos por la Organización Mundial de la Salud. Se utilizaron caracoles de B. glabrata criados en el laboratorio. Se realizaron diferentes bioensayos utilizando extractos metanólico crudo, en n-hexano, en acetato de etilo y en metanol de las partes aéreas de E. laurifolia a diferentes concentraciones. Los resultados demostraron que esta especie posee una potente actividad letal con todos los extractos estudiados contra caracoles de B. glabrata, considerándose el mejor el extracto de acetato de etilo, el cual presentó una DL50 de 5,57 ppm.

  16. A 1,536-well-based kinetic HTS assay for inhibitors of Schistosoma mansoni thioredoxin glutathione reductase.

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    Lea, Wendy A; Jadhav, Ajit; Rai, Ganesha; Sayed, Ahmed A; Cass, Cynthia L; Inglese, James; Williams, David L; Austin, Christopher P; Simeonov, Anton

    2008-08-01

    Abstract: Schistosomiasis is a major neglected tropical disease that currently affects over 200 million people and leads to over 200,000 annual deaths. Schistosoma mansoni parasites survive in humans in part because of a set of antioxidant enzymes that continuously degrade reactive oxygen species produced by the host. A principal component of this defense system has been recently identified as thioredoxin glutathione reductase (TGR), a parasite-specific enzyme that combines the functions of two human counterparts, glutathione reductase and thioredoxin reductase, and as such this enzyme presents an attractive new target for anti-schistosomiasis drug development. Herein, we present the development of a highly miniaturized and robust screening assay for TGR. The 5-mul final volume assay is based on the Ellman reagent [5,5'-dithiobis(2-nitrobenzoic acid) (DTNB)] and utilizes a high-speed absorbance kinetic read to minimize the effect of dust, absorbance interference, and meniscus variation. This assay is further applicable to the testing of other redox enzymes that utilize DTNB as a model substrate.

  17. Biochemical changes after subchronic and chronic interaction of Schistosoma mansoni infection in Swiss albino mice with two specific compounds.

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    Hanna, Laila S; Medhat, Amina M; Abdel-Menem, Hanan A

    2003-04-01

    In Egypt, infection with Schistosoma mansoni (S.m.) and residues of pesticides have been considered as major environmental pollutants that adversely affect health. Effects of diazinon (DZN) and/or praziquantel (PZQ) on the levels of plasma triiodothyronine (T3), thyroxine (T4), activities of brain acetylcholinesterase (AchE) and liver alanine aminotransferase (ALT) in addition to blood reduced glutathione (GSH) in healthy and S.m. infected mice were investigated after 9 and 17 weeks of either infection or intoxication with DZN. Triiodothyronine showed significant differences among the different treatments. The group of mice treated with PZQ showed the highest levels of T3 at both time intervals. Thyroxine level showed significant differences between the two time intervals. The lowest levels of T4 were observed in the infected-PZQ group at week 17. The maximum inhibition of brain AchE activity was noticed in DZN-PZQ treated group after 9 and 17 weeks. The different treatments significantly reduced the activities of liver ALT. The highest decrease was recorded in the infected-DZN-PZQ group at week 9. All treatments significantly lowered the levels of blood GSH after 9 weeks.

  18. Efficient trans-cleavage by the Schistosoma mansoni SMalpha1 hammerhead ribozyme in the extreme thermophile Thermus thermophilus.

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    Vazquez-Tello, Alejandro; Castán, Pablo; Moreno, Renata; Smith, James M; Berenguer, José; Cedergren, Robert

    2002-04-01

    The catalytic hammerhead structure has been found in association with repetitive DNA from several animals, including salamanders, crickets and schistosomes, and functions to process in cis the long multimer transcripts into monomer RNA in vivo. The cellular role of these repetitive elements and their transcripts is unknown. Moreover, none of these natural hammerheads have been shown to trans-cleave a host mRNA in vivo. We analyzed the cis- and trans-cleavage properties of the hammerhead ribozyme associated with the SMalpha DNA family from the human parasite Schistosoma mansoni. The efficiency of trans-cleavage of a target RNA in vitro was affected mainly by both the temperature-dependent chemical step and the ribozyme-product dissociation step. The optimal temperature for trans-cleavage was 70 degrees C. This result was confirmed when both the SMalpha1 ribozyme and the target RNA were expressed in the extreme thermophile Thermus thermophilus. Moreover, SMalpha1 RNA showed a remarkable thermostability, equal or superior to that of the most stable RNAs in this species, suggesting that SMalpha1 RNA has been selected for stability. Computer analysis predicts that the monomer and multimer transcripts fold into highly compact secondary structures, which may explain their exceptional stability in vivo.

  19. Reductions in genetic diversity of Schistosoma mansoni populations under chemotherapeutic pressure: the effect of sampling approach and parasite population definition.

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    French, Michael D; Churcher, Thomas S; Basáñez, María-Gloria; Norton, Alice J; Lwambo, Nicholas J S; Webster, Joanne P

    2013-11-01

    Detecting potential changes in genetic diversity in schistosome populations following chemotherapy with praziquantel (PZQ) is crucial if we are to fully understand the impact of such chemotherapy with respect to the potential emergence of resistance and/or other evolutionary outcomes of interventions. Doing so by implementing effective, and cost-efficient sampling protocols will help to optimise time and financial resources, particularly relevant to a disease such as schistosomiasis currently reliant on a single available drug. Here we explore the effect on measures of parasite genetic diversity of applying various field sampling approaches, both in terms of the number of (human) hosts sampled and the number of transmission stages (miracidia) sampled per host for a Schistosoma mansoni population in Tanzania pre- and post-treatment with PZQ. In addition, we explore population structuring within and between hosts by comparing the estimates of genetic diversity obtained assuming a 'component population' approach with those using an 'infrapopulation' approach. We found that increasing the number of hosts sampled, rather than the number of miracidia per host, gives more robust estimates of genetic diversity. We also found statistically significant population structuring (using Wright's F-statistics) and significant differences in the measures of genetic diversity depending on the parasite population definition. The relative advantages, disadvantages and, hence, subsequent reliability of these metrics for parasites with complex life-cycles are discussed, both for the specific epidemiological and ecological scenario under study here and for their future application to other areas and schistosome species.

  20. Ionotropic Receptors Identified within the Tentacle of the Freshwater Snail Biomphalaria glabrata, an Intermediate Host of Schistosoma mansoni.

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    Di Liang

    Full Text Available Biomphalaria glabrata (B. glabrata is an air-breathing aquatic mollusc found in freshwater habitats across the Western Hemisphere. It is most well-known for its recognized capacity to act as a major intermediate host for Schistosoma mansoni, the human blood fluke parasite. Ionotropic receptors (IRs, a variant family of the ionotropic glutamate receptors (iGluR, have an evolutionary ancient function in detecting odors to initiate chemosensory signaling. In this study, we applied an array of methods towards the goal of identifying IR-like family members in B. glabrata, ultimately revealing two types, the iGluR and IR. Sequence alignment showed that three ligand-binding residues are conserved in most Biomphalaria iGluR sequences, while the IRs did exhibit a variable pattern, lacking some or all known glutamate-interactingresidues, supporting their distinct classification from the iGluRs. We show that B. glabrata contains 7 putative IRs, some of which are expressed within its chemosensory organs. To further investigate a role for the more ancient IR25a type in chemoreception, we tested its spatial distribution pattern within the snail cephalic tentacle by in situ hybridization. The presence of IR25a within presumptive sensory neurons supports a role for this receptor in olfactory processing, contributing to our understanding of the molecular pathways that are involved in Biomphalaria olfactory processing.

  1. Cercarial Chaetotaxy and Sex Differentiation of Schistosoma mansoni Deriving from Humans and Nectomys squamipes (Muridae: Sigmondontinae in Brazil

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    Nilcéa Freire

    2002-01-01

    Full Text Available A comparative study was made between sympatric isolates of Schistosoma mansoni: one from a wild rodent (R Nectomys squamipes and another one from humans (H isolated from a low endemic schistosomiasis transmission area in Brazil. Our purpose was to detect differences between them concerning chaetotaxy (number and pattern of distribution of the argentophilic papillae of the cercariae by means of silver impregnation. No significant difference (x > 0.05 between isolates was noted. Nevertheless, a significant difference (x < 0.05 was observed in the cercarial index (ratio of the distance between the first and the second preacetabular papillae and the distance between the first and the second dorsal preacetabular papillae of male and female cercariae in both isolates. Males presented a greater cercarial index than females. By means of multivariate analysis, male cercariae were distinguished from female cercariae through the following characteristics: average number of dorsal papillae on the right quadrant, average number of ventral middle papillae on the right quadrant (H isolate and average number of dorsal middle papillae on the left quadrant (R isolate. The results suggest that R and H isolates belong to the same population that could complete its life cycle in rodent-snail-rodent fashion.

  2. A comparative parasitologic study on Biomphalaria glabrata snail and C3H/He mice infected with human and murine isolates of Schistosoma mansoni derived from Sumidouro, Rio de Janeiro, Brazil

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    Nilcéa Freire

    2003-09-01

    Full Text Available Experiments were carried out to analyze the biological characteristics of two sympatric isolates of Schistosoma mansoni derived from humans and murines in a low endemic transmission area (Sumidouro county, state of Rio de Janeiro, Brazil. Sympatric reared-laboratory Biomphalaria glabrata and C3H/He mice were used as experimental hosts. Parameters assessed comprised: precercarial period, infectivity and mortality (snails, prepatent period, infectivity (percentage of cercariae maturation into adult worm and intestinal egg count (mice. The murine isolate showed a shorter precercarial period and higher infectivity than human isolate (p 0.05. These data suggest that both isolates are local sub-populations, providing support for the hypotheses that in a same biotope mixed populations or sub-populations circulate among their main host (human beings and/or rodent as an anfixenous infection.

  3. In Vitro Assessment of Anthelmintic Activities of Rauwolfia vomitoria (Apocynaceae Stem Bark and Roots against Parasitic Stages of Schistosoma mansoni and Cytotoxic Study

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    Emmanuel Mouafo Tekwu

    2017-01-01

    Full Text Available Schistosomiasis is a Neglected Tropical Diseases which can be prevented with mass deworming chemotherapy. The reliance on a single drug, praziquantel, is a motivation for the search of novel antischistosomal compounds. This study investigated the anthelmintic activity of the stem bark and roots of Rauwolfia vomitoria against two life stages of Schistosoma mansoni. Both plant parts were found to be active against cercariae and adult worms. Within 2 h of exposure all cercariae were killed at a concentration range of 62.5–1000 µg/mL and 250–1000 µg/mL of R. vomitoria stem bark and roots, respectively. The LC50 values determined for the stem bark after 1 and 2 h of exposure were 207.4 and 61.18 µg/mL, respectively. All adult worms exposed to the concentrations range of 250–1000 µg/mL for both plant parts died within 120 h of incubation. The cytotoxic effects against HepG2 and Chang liver cell assessed using MTT assay method indicated that both plant extracts which were inhibitory to the proliferation of cell lines with IC50 > 20 μg/mL appear to be safe. This report provides the first evidence of in vitro schistosomicidal potency of R. vomitoria with the stem bark being moderately, but relatively, more active and selective against schistosome parasites. This suggests the presence of promising medicinal constituent(s.

  4. Nitric oxide production by Biomphalaria glabrata haemocytes: effects of Schistosoma mansoni ESPs and regulation through the extracellular signal-regulated kinase pathway

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    Kirk Ruth S

    2009-04-01

    Full Text Available Abstract Background Schistosoma mansoni uses Biomphalaria glabrata as an intermediate host during its complex life cycle. In the snail, the parasite initially transforms from a miracidium into a mother sporocyst and during this process excretory-secretory products (ESPs are released. Nitric oxide (NO and its reactive intermediates play an important role in host defence responses against pathogens. This study therefore aimed to determine the effects of S. mansoni ESPs on NO production in defence cells (haemocytes from schistosome-susceptible and schistosome-resistant B. glabrata strains. As S. mansoni ESPs have previously been shown to inhibit extracellular signal-regulated kinase (ERK phosphorylation (activation in haemocytes from susceptible, but not resistant, B. glabrata the regulation of NO output by ERK in these cells was also investigated. Results Haemocytes from resistant snails challenged with S. mansoni ESPs (20 μg/ml over 5 h displayed an increase in NO production that was 3.3 times greater than that observed for unchallenged haemocytes; lower concentrations of ESPs (0.1–10 μg/ml did not significantly increase NO output. In contrast, haemocytes from susceptible snails showed no significant change in NO output following challenge with ESPs at any concentration used (0.1–20 μg/ml. Western blotting revealed that U0126 (1 μM or 10 μM blocked the phosphorylation (activation status of ERK in haemocytes from both snail strains. Inhibition of ERK signalling by U0126 attenuated considerably intracellular NO production in haemocytes from both susceptible and resistant B. glabrata strains, identifying ERK as a key regulator of NO output in these cells. Conclusion S. mansoni ESPs differentially influence intracellular NO levels in susceptible and resistant B. glabrata haemocytes, possibly through modulation of the ERK signalling pathway. Such effects might facilitate survival of S. mansoni in its intermediate host.

  5. Expression at a 20L scale and purification of the extracellular domain of the Schistosoma mansoni TSP-2 recombinant protein: a vaccine candidate for human intestinal schistosomiasis.

    Science.gov (United States)

    Curti, Elena; Kwityn, Clifford; Zhan, Bin; Gillespie, Portia; Brelsford, Jill; Deumic, Vehid; Plieskatt, Jordan; Rezende, Wanderson C; Tsao, Eric; Kalampanayil, Bose; Hotez, Peter J; Bottazzi, Maria Elena

    2013-11-01

    A novel recombinant protein vaccine for human schistosomiasis caused by Schistosoma mansoni is under development. The Sm-TSP-2 schistosomiasis vaccine is comprised of a 9 kDa recombinant protein corresponding to the extracellular domain of a unique S. mansoni tetraspanin. Here, we describe the cloning and the expression of the external loop of Sm-TSP-2 recombinant protein secreted by Pichia Pink the process development at 20L scale fermentation, and the two-steps purification, which resulted in a protein recovery yield of 31% and a protein purity of 97%. The developed processes are suitable for the production of purified protein for subsequent formulation and Phase 1 clinical studies.

  6. Comparison of purified 12 kDa and recombinant 15 kDa Fasciola hepatica antigens related to a Schistosoma mansoni fatty acid binding protein

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    George V. Hillyer

    1995-04-01

    Full Text Available Vaccines in schistosomiasis using homologous antigens have been studied extensively in experimentally infected mammalian hosts. Vaccines using heterologous antigens have received comparatively less attention. This review summarizes recent work on a heterologous 12 kDa Fasciola hepatica antigenic polypeptide which cross reacts with Schistosoma mansoni. A cDNA has been cloned and sequenced, and the predicted amino acid sequence of the recombinant protein has been shown to have significant (44 identity with a 14 kDa S. mansoni fatty acid binding protein. Thus in the parasitic trematodes fatty acid binding proteins may be potential vaccine candidates. The F. hepatica recombinant protein has been overexpressed and purified and denoted rFh15. Preliminary rFh15 migrates more slowly (i.e. may be slightly larger than nFh12 on SDS-PAGE and has a predicted pI of 6.01 vs. observed pI of 5.45. Mice infected with F. hepatica develop antibodies to nFh12 by 2 weeks of infection vs. 6 weeks of infection to rFh15; on the other hand, mice with schistosomiasis mansoni develop antibodies to both nFh12 and rFh15 by 6 weeks of infection. Both the F. hepatica and S. mansoni cross-reactive antigens may be cross-protective antigens with the protection inducing capability against both species.

  7. Envolvimento renal na associação salmonella-Schistosoma mansoni

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    José Roberto Lambertucci

    1987-06-01

    Full Text Available Vinte pacientes com a associação Salmonella-S. mansoni (Grupo 1 e 20 com esquistossomose mansoni hepatesplênica (Grupo 2 foram selecionados para o estudo. Submeteram-se os pacientes dos Grupos le 2 a exame clínico minucioso e a uma série de exames complementares, com destaque para as provas de função renal. Em 10 pacientes do Grupo 1 e 20 do Grupo 2, realizou-se, ainda, estudo histológico do rim à microscopia óptica, de fluorescência e eletrônica. As alterações renais foram mais freqüentes nos pacientes do Grupo 1. Após o tratamento dos pacientes do Grupo 1, com antibióticos e/ou esquistossomicidas, observou-se regressão das alterações renais sob o ponto de vista clínico, laboratorial e imunopatológico. Os autores concluem pela existência de duas nefropatias distintas: a nefropatia esquistossomótica e a encontrada em pacientes com a associação Salmonella-S. mansoni.The responses of Plasmodium falciparum to antimalarial drugs were evaluated through the in vitro test using blood sample collected from patients of 7 municipalities of the south of Pará State. Sixty nine microtests for chloroquine and mefloquine, 62 for amodiaquine and 61 for quinine were pet formed. The results showed a high resistancefor chloroquine (71%, a relatively low resistance level for amodiaquine (25.8% and little resistance to quinine (8.2%. For mefloquine 100% of sensitivity wasfound.

  8. Infection with Schistosoma mansoni has an Effect on Quality of Life, but not on Physical Fitness in Schoolchildren in Mwanza Region, North-Western Tanzania: A Cross-Sectional Study

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    Kinung’hi, Safari; Magnussen, Pascal; Kaatano, Godfrey; Olsen, Annette

    2016-01-01

    Background Infection with Schistosoma mansoni negatively impact children’s physical health and may influence their general well-being. The aim of this study was to investigate the effect of S. mansoni infections on a panel of morbidity indicators with emphasis on quality of life (PedsQL; measured in four different dimensions) and physical fitness (measured as VO2 max) among 572 schoolchildren aged 7–8 years. Methodology/Principal findings Prevalence of S. mansoni infections was 58.7%, with an...

  9. Efeito do praziquantel incorporado a lipossomas nos diferentes estágios de desenvolvimento dos ovos de Schistosoma mansoni

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    T. F. FREZZA

    2009-01-01

    Full Text Available

    A esquistossomose mansônica é causada pelo trematódeo digenético intravascular Schistosoma mansoni. Para o tratamento dessa enfermidade o praziquantel (PZQ e a oxamniquina (OXA são os fármacos escolhidos. No entanto, esses fármacos apresentam limitações quanto à ação e casos de resistência ou tolerância já foram relatados. Por esse motivo, são necessários os estudos de novas alternativas que visam melhorar os fármacos já existentes, como a incorporação desses em lipossomas. Este estudo verificou a ação do praziquantel incorporado a lipossomas (lip.PZQ sobre os ovos de S. mansoni, linhagem BH em camundongos Mus musculus (Swiss- SPF. Para tanto, foram testadas quatro doses de PZQ e lip.PZQ (47; 60; 250 e 300mg/kg sendo que parte dos camundongos foi tratada após 30 dias de infecção e outra após 45 dias. A análise do oograma mostrou que a dose lip.PZQ 300mg/kg administrada no 45º dia de infecção foi mais eficaz, pois reduziu a oviposição pelas fêmeas de S. mansoni. Palavras-chave: Schistosoma mansoni; praziquantel; lipossoma; oograma.

  10. Observações adicionais sobre o sexo do "Schistosoma mansoni" nas infestações por cercarias de um unico molusco Further observations on the sex of "Schistosoma mansoni" in the infestations produced by cercariae from a single snail

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    W. Lobato Paraense

    1949-12-01

    Full Text Available Em um córrego situado nos terrenos do Instituto Oswaldo Cruz, em Man¬guinhos, no qual existe uma população de Australorbis olivaceus, foi verificada a infestação natural dêste planorbídeo pelo Schistosoma mansoni, com o índice de 8.25% baseado na dissecção de 400 moluscos. As cercárias de 24 planorbídeos foram inoculadas em 24 cobaias, cada vertebrado recebendo as cercárias de um único molusco. Uma segunda série de inoculações em 6 cobaias foi feita com as cercárias de 6 planorbídeos sobreviventes, 10 dias apos a primeira série. As infestações resultantes foram tôdas unissexuais (13 vezes por machos, 11 vezes por fêmeas, observando-se entre os sexos a relação de 1 : 1. Em 6 casos infestados por fêmeas, cerca de 15% destas apresentaram no útero ou no ootipo formações ovulares (figs. 1 a 15, desprovidas de estruturas embrionárias, cujo número variou entre 1 e 6. Êstes ovos, quando depositados no fígado, davam origem a ligeiro infiltrado de células epitelióides e não apresentavam organização embrionária. Não foram vistos ovos nos cortes de intestino. Os órgãos sexuais das fêmeas achavam-se aparentemente bem desenvolvidos em grande número de exemplares. Os machos apresentaram testículos de aparência normal, em número variável de 4 a 9. Em 1% dos exemplares examinados foram encontrados testículos supranumerários. Em 2 casos foram encontrados machos secundàriamente hermafroditas (respectivamente 29% e 25%.The dissection of 400 Australorbis olivaceiis from a brook situated in the grounds of the Instituto Oswaldo Cruz (Manguinhos showed that 8.25 per cent of them were naturally infested with Schistosoma mansoni. The cercariae of 24 snails were inoculated into 24 guinea pigs, each of the latter receiving the cercariae from a single snail. A second series of inoculations with the cercariae of 6 surviving snails was made 10 days after the first series. All resulting infestations were unisexual (13 with

  11. Abundância e infecção do molusco Biomphalaria glabrata pelo Schistosoma mansoni no Estado do Rio de Janeiro, Brasil Abundance and Schistosoma mansoni infection of the snail Biomphalaria glabrata, Brazil

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    Alexandre Giovanelli

    2001-12-01

    Full Text Available OBJETIVOS: Investigar a distribuição espacial, a abundância e os índices de infecção natural de Biomphalaria glabrata, hospedeiro intermediário do Schistosoma mansoni, em localidade do Estado do Rio de Janeiro, RJ, Brasil. MÉTODOS: Na localidade de Pamparrão, município de Sumidouro, RJ, as coletas de moluscos foram realizadas bimestralmente no período de junho de 1991 a novembro de 1995. Foram estabelecidos 23 pontos de coleta ao longo do córrego Pamparrão e três de seus afluentes. Os moluscos capturados foram levados ao laboratório para diagnóstico da infecção. Para a análise dos dados, foram usados o coeficiente de Spearman (nível de 0,5% de significância e o teste de qui-quadrado. RESULTADOS: A abundância populacional de B. glabrata foi bastante variável ao longo do tempo e entre os ambientes amostrados. A maioria dos pontos de coleta apresentou correlação negativa com a pluviosidade. O afluente B destacou-se dos demais corpos d'água por apresentar taxas de infecção de B. glabrata elevadas (acima dos 25% em alguns pontos de coleta e persistentes. Foram encontrados mais moluscos infectados na estação seca do que na chuvosa (chi²=20,08; p=0,001. CONCLUSÕES: A população de moluscos foi influenciada negativamente pelo regime de chuvas, principalmente no córrego Pamparrão. A época de estiagem também parece ter favorecido a ocorrência de infecção, provavelmente devido ao menor volume de água dos córregos, o que aumentaria as chances de encontro do parasita com seu hospedeiro intermediário.OBJECTIVES: To investigate the spatial distribution, abundance and natural schistosomiasis infection levels in the snail Biomphalaria glabrata, the intermediate host of Schistosoma mansoni in an area of the State of Rio de Janeiro, Brazil. METHODS: In the Pamparrão area, Sumidouro county, RJ, Brazil, snail captures were carried out every other month from June 1991 to November 1995. There were 23 collecting sites along

  12. The contribution of water contact behavior to the high Schistosoma mansoni Infection rates observed in the Senegal River Basin

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    Stelma Foekje

    2011-07-01

    Full Text Available Abstract Background Schistosomiasis is one of the major parasitic diseases in the world in terms of people infected and those at risk. Infection occurs through contact with water contaminated with larval forms of the parasite, which are released by freshwater snails and then penetrate the skin of people. Schistosomiasis infection and human water contact are thus essentially linked, and more knowledge about their relationship will help us to develop appropriate control measures. So far, only few studies have related water contact patterns to infection levels. Methods We have conducted detailed direct water contact observations in a village in Northern Senegal during the first years of a massive Schistosoma mansoni outbreak to determine the role of human water contact in the extent of the epidemic. We quantified water contact activities in terms of frequency and duration, and described how these vary with age and sex. Moreover, we assessed the relationship between water contact- and infection intensity patterns to further elucidate the contribution of exposure to the transmission of schistosomiasis. Results This resulted in over 120,000 recorded water contacts for 1651 subjects over 175 observation days. Bathing was the main activity, followed by household activities. Frequency and duration of water contact depended on age and sex rather than season. Water contacts peaked in adolescents, women spent almost twice as much time in the water as men, and water contacts were more intense in the afternoon than in the morning, with sex-specific intensity peaks. The average number of water contacts per person per day in this population was 0.42; the average time spent in the water per person per day was 4.3 minutes. Conclusions The observed patterns of water contact behavior are not unusual and have been described before in various other settings in sub-Saharan Africa. Moreover, water contact levels were not exceptionally high and thus cannot explain the

  13. Evidence for Integrin – Venus Kinase Receptor 1 Alliance in the Ovary of Schistosoma mansoni Females Controlling Cell Survival

    Science.gov (United States)

    Gelmedin, Verena; Morel, Marion; Hahnel, Steffen; Cailliau, Katia; Dissous, Colette; Grevelding, Christoph G.

    2017-01-01

    In metazoan integrin signaling is an important process of mediating extracellular and intracellular communication processes. This can be achieved by cooperation of integrins with growth factor receptors (GFRs). Schistosoma mansoni is a helminth parasite inducing schistosomiasis, an infectious disease of worldwide significance for humans and animals. First studies on schistosome integrins revealed their role in reproductive processes, being involved in spermatogenesis and oogenesis. With respect to the roles of eggs for maintaining the parasite´s life cycle and for inducing the pathology of schistosomiasis, elucidating reproductive processes is of high importance. Here we studied the interaction of the integrin receptor Smβ-Int1 with the venus kinase receptor SmVKR1 in S. mansoni. To this end we cloned and characterized SmILK, SmPINCH, and SmNck2, three putative bridging molecules for their role in mediating Smβ-Int1/SmVKR1 cooperation. Phylogenetic analyses showed that these molecules form clusters that are specific for parasitic platyhelminths as it was shown for integrins before. Transcripts of all genes colocalized in the ovary. In Xenopus oocytes germinal vesicle breakdown (GVBD) was only induced if all members were simultaneously expressed. Coimmunoprecipitation results suggest that a Smβ-Int1-SmILK-SmPINCH-SmNck2-SmVKR1 complex can be formed leading to the phosphorylation and activation of SmVKR1. These results indicate that SmVKR1 can be activated in a ligand-independent manner by receptor-complex interaction. RNAi and inhibitor studies to knock-down SmILK as a representative complex member concurrently revealed effects on the extracellular matrix surrounding the ovary and oocyte localization within the ovary, oocyte survival, and egg production. By TUNEL assays, confocal laser scanning microscopy (CLSM), Caspase-3 assay, and transcript profiling of the pro-apoptotic BCL-2 family members BAK/BAX we obtained first evidence for roles of this signaling

  14. Prevalence of intestinal parasitic infections among children under five years of age with emphasis on Schistosoma mansoni in Wonji Shoa Sugar Estate, Ethiopia.

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    Yirgalem G/hiwot

    Full Text Available Intestinal parasite infections are major public health problems of children in developing countries causing undernutrition, anemia, intestinal obstruction and mental and physical growth retardation. This study was conducted to assess the prevalence of intestinal helminthic infections among children under five years of age with emphasis on Schistosoma mansoni in Wonji Shoa Sugar Estate, Ethiopia. A cross-sectional parasitological survey was conducted in under-five children living in Wonji Shoa Sugar Estate Ethiopia, April, 2013. Stool samples were collected and examined for intestinal parasites using single Kato-Katz and single Sodium acetate-acetic acid-formalin (SAF solution concentration methods. Out of 374 children examined using single Kato-Katz and single SAF-concentration methods, 24.3% were infected with at least one intestinal parasite species. About 10.4%, 8.8%, 4.6%, 2.9%, 1.6% and 0.8% of the children were infected with Hymenolepis nana, Schistosoma mansoni, Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis and hookworm, respectively. Prevalence of double, triple and quadruple intestinal helminthic infection was 6.4%, 0.54% and 1.1%, respectively. A significant increase in prevalence of S. mansoni (8.3% versus 3.2% and T. trichiura (2.7% versus 0.5% infection was observed when determined via the single Kato-Katz method compared to the prevalence of the parasites determined via the single SAF-concentration method. On the other hand, the single SAF-concentration method (9.1% revealed a significantly higher prevalence of H. nana infection than the single Kato-Katz (1.6% does. In conclusion, intestinal helminths infections particularly S. mansoni and H. nana were prevalent in under-five children of Wonji Shoa Sugar Estate. Including praziquantel treatment in the deworming program as per the World Health Organization guidelines would be vital to reduce the burden of these diseases in areas where S. mansoni and H. nana

  15. Schistosoma mansoni Tegument (Smteg) Induces IL-10 and Modulates Experimental Airway Inflammation

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    2016-01-01

    Background Previous studies have demonstrated that S. mansoni infection and inoculation of the parasite eggs and antigens are able to modulate airways inflammation induced by OVA in mice. This modulation was associated to an enhanced production of interleukin-10 and to an increased number of regulatory T cells. The S. mansoni schistosomulum is the first stage to come into contact with the host immune system and its tegument represents the host-parasite interface. The schistosomula tegument (Smteg) has never been studied in the context of modulation of inflammatory disorders, although immune evasion mechanisms take place in this phase of infection to guarantee the persistence of the parasite in the host. Methodology and Principal Findings The aim of this study was to evaluate the Smteg ability to modulate inflammation in an experimental airway inflammation model induced by OVA and to characterize the immune factors involved in this modulation. To achieve the objective, BALB/c mice were sensitized with ovalbumin (OVA) and then challenged with OVA aerosol after Smteg intraperitoneal inoculation. Protein extravasation and inflammatory cells were assessed in bronchoalveolar lavage and IgE levels were measured in serum. Additionally, lungs were excised for histopathological analyses, cytokine measurement and characterization of the cell populations. Inoculation with Smteg led to a reduction in the protein levels in bronchoalveolar lavage (BAL) and eosinophils in both BAL and lung tissue. In the lung tissue there was a reduction in inflammatory cells and collagen deposition as well as in IL-5, IL-13, IL-25 and CCL11 levels. Additionally, a decrease in specific anti-OVA IgE levels was observed. The reduction observed in these inflammatory parameters was associated with increased levels of IL-10 in lung tissues. Furthermore, Smteg/asthma mice showed high percentage of CD11b+F4/80+IL-10+ and CD11c+CD11b+IL-10+ cells in lungs. Conclusion Taken together, these findings

  16. SmTRC1, a novel Schistosoma mansoni DNA transposon, discloses new families of animal and fungi transposons belonging to the CACTA superfamily

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    Verjovski-Almeida Sergio

    2006-11-01

    Full Text Available Abstract Background The CACTA (also called En/Spm superfamily of DNA-only transposons contain the core sequence CACTA in their Terminal Inverted Repeats (TIRs and so far have only been described in plants. Large transcriptome and genome sequence data have recently become publicly available for Schistosoma mansoni, a digenetic blood fluke that is a major causative agent of schistosomiasis in humans, and have provided a comprehensive repository for the discovery of novel genes and repetitive elements. Despite the extensive description of retroelements in S. mansoni, just a single DNA-only transposon belonging to the Merlin family has so far been reported in this organism. Results We describe a novel S. mansoni transposon named SmTRC1, for S. mansoni Transposon Related to CACTA 1, an element that shares several characteristics with plant CACTA transposons. Southern blotting indicates approximately 30–300 copies of SmTRC1 in the S. mansoni genome. Using genomic PCR followed by cloning and sequencing, we amplified and characterized a full-length and a truncated copy of this element. RT-PCR using S. mansoni mRNA followed by cloning and sequencing revealed several alternatively spliced transcripts of this transposon, resulting in distinct ORFs coding for different proteins. Interestingly, a survey of complete genomes from animals and fungi revealed several other novel TRC elements, indicating new families of DNA transposons belonging to the CACTA superfamily that have not previously been reported in these kingdoms. The first three bases in the S. mansoni TIR are CCC and they are identical to those in the TIRs of the insects Aedes aegypti and Tribolium castaneum, suggesting that animal TRCs may display a CCC core sequence. Conclusion The DNA-only transposable element SmTRC1 from S. mansoni exhibits various characteristics, such as generation of multiple alternatively-spliced transcripts, the presence of terminal inverted repeats at the extremities of

  17. Accuracy of Urine Circulating Cathodic Antigen Test for the Diagnosis of Schistosoma mansoni in Preschool-Aged Children before and after Treatment

    Science.gov (United States)

    Coulibaly, Jean T.; N'Gbesso, Yves K.; Knopp, Stefanie; N'Guessan, Nicaise A.; Silué, Kigbafori D.; van Dam, Govert J.; N'Goran, Eliézer K.; Utzinger, Jürg

    2013-01-01

    Background The Kato-Katz technique is widely used for the diagnosis of Schistosoma mansoni, but shows low sensitivity in light-intensity infections. We assessed the accuracy of a commercially available point-of-care circulating cathodic antigen (POC-CCA) cassette test for the diagnosis of S. mansoni in preschool-aged children before and after praziquantel administration. Methodology A 3-week longitudinal survey with a treatment intervention was conducted in Azaguié, south Côte d'Ivoire. Overall, 242 preschoolers (age range: 2 months to 5.5 years) submitted two stool and two urine samples before praziquantel administration, and 86 individuals were followed-up posttreatment. Stool samples were examined with duplicate Kato-Katz thick smears for S. mansoni. Urine samples were subjected to POC-CCA cassette test for S. mansoni, and a filtration method for S. haematobium diagnosis. Principal Findings Before treatment, the prevalence of S. mansoni, as determined by quadruplicate Kato-Katz, single CCA considering ‘trace’ as negative (t−), and single CCA with ‘trace’ as positive (t+), was 23.1%, 34.3% and 64.5%, respectively. Using the combined results (i.e., four Kato-Katz and duplicate CCA(t−)) as diagnostic ‘gold’ standard, the sensitivity of a single Kato-Katz, a single CCA(t−) or CCA(t+) was 28.3%, 69.7% and 89.1%, respectively. Three weeks posttreatment, the sensitivity of a single Kato-Katz, single CCA(t−) and CCA(t+) was 4.0%, 80.0% and 84.0%, respectively. The intensity of the POC-CCA test band reaction was correlated with S. mansoni egg burden (odds ratio = 1.2, p = 0.04). Conclusions/Significance A single POC-CCA cassette test appears to be more sensitive than multiple Kato-Katz thick smears for the diagnosis of S. mansoni in preschool-aged children before and after praziquantel administration. The POC-CCA cassette test can be recommended for the rapid identification of S. mansoni infections before treatment. Additional studies are

  18. Accuracy of urine circulating cathodic antigen test for the diagnosis of Schistosoma mansoni in preschool-aged children before and after treatment.

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    Jean T Coulibaly

    Full Text Available BACKGROUND: The Kato-Katz technique is widely used for the diagnosis of Schistosoma mansoni, but shows low sensitivity in light-intensity infections. We assessed the accuracy of a commercially available point-of-care circulating cathodic antigen (POC-CCA cassette test for the diagnosis of S. mansoni in preschool-aged children before and after praziquantel administration. METHODOLOGY: A 3-week longitudinal survey with a treatment intervention was conducted in Azaguié, south Côte d'Ivoire. Overall, 242 preschoolers (age range: 2 months to 5.5 years submitted two stool and two urine samples before praziquantel administration, and 86 individuals were followed-up posttreatment. Stool samples were examined with duplicate Kato-Katz thick smears for S. mansoni. Urine samples were subjected to POC-CCA cassette test for S. mansoni, and a filtration method for S. haematobium diagnosis. PRINCIPAL FINDINGS: Before treatment, the prevalence of S. mansoni, as determined by quadruplicate Kato-Katz, single CCA considering 'trace' as negative (t-, and single CCA with 'trace' as positive (t+, was 23.1%, 34.3% and 64.5%, respectively. Using the combined results (i.e., four Kato-Katz and duplicate CCA(t- as diagnostic 'gold' standard, the sensitivity of a single Kato-Katz, a single CCA(t- or CCA(t+ was 28.3%, 69.7% and 89.1%, respectively. Three weeks posttreatment, the sensitivity of a single Kato-Katz, single CCA(t- and CCA(t+ was 4.0%, 80.0% and 84.0%, respectively. The intensity of the POC-CCA test band reaction was correlated with S. mansoni egg burden (odds ratio = 1.2, p = 0.04. CONCLUSIONS/SIGNIFICANCE: A single POC-CCA cassette test appears to be more sensitive than multiple Kato-Katz thick smears for the diagnosis of S. mansoni in preschool-aged children before and after praziquantel administration. The POC-CCA cassette test can be recommended for the rapid identification of S. mansoni infections before treatment. Additional studies are warranted

  19. Schistosoma mansoni in a low-prevalence area in Brazil: the importance of additional methods for the diagnosis of hard-to-detect individual carriers by low-cost immunological assays

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    Rafaella Fortini Queiroz Grenfell

    2013-05-01

    Full Text Available Schistosomiasis diagnosis is based on the detection of eggs in the faeces, which is laborious and lacks sensitivity, especially for patients with a low parasite burden. Immunological assays for specific antibody detection are available, but they usually demonstrate low sensitivity and/or specificity. In this study, two simple immunological assays were evaluated for the detection of soluble Schistosoma mansoni adult worm preparation (SWAP and egg-specific IgGs. These studies have not yet been evaluated for patients with low parasite burdens. Residents of an endemic area in Brazil donated sera and faecal samples for our study. The patients were initially diagnosed by a rigorous Kato-Katz analysis of 18 thick smears from four different stool samples. The ELISA-SWAP was successful for human diagnosis with 90% sensitivity and specificity, confirming the Kato-Katz diagnosis with nearly perfect agreement, as seen by the Kappa index (0.85. Although the ELISA-soluble S. mansoni egg antigen was 85% sensitive, it exhibited low specificity (80%; Kappa index: 0.75 and was more susceptible to cross-reactivity. We believe that immunological assays should be used in conjunction with Kato-Katz analysis as a supplementary tool for the diagnosis of schistosomiasis for patients with low infection burdens, which are usually hard to detect.

  20. Apoptose na modulação da resposta inflamatória aos ovos do Schistosoma mansoni

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    Tristão A.R.

    2000-01-01

    Full Text Available Foram estudadas 42 amostras de fígado de camundongos inoculados com cercárias do Schistosoma mansoni, obtidas 40, 60, 80 e 120 dias após a infecção e processadas rotineiramente. As lâminas obtidas foram coradas pela HE para análise qualitativa e morfométrica do número e área dos granulomas e pelo MGP para quantificação de células apoptóticas. Os animais com 40 dias de inoculação possuíam menos granulomas/lâmina ( ou = 11,78±4,01, com áreas pequenas ( ou = 52.713,88±5.244,34mm² e as menores médias de apoptose ( ou = 7,50±0.99. Os animais com 60 dias de inoculação tiveram os maiores granulomas ( ou = 114.851,20±5.517,20mim², em maior número ( ou = 92,88±10,62 e freqüente apoptose ( ou = 18,73±1,35. Os com 80 dias de inoculação apresentaram diminuição no tamanho dos granulomas ( ou = 89.305,57±6.162,79mim², mas grande quantidade deles ( ou = 131,09±15,60 e freqüência maior de apoptose ( ou = 19,93±1,49. Com 120 dias, a apoptose continuou freqüente ( ou = 19,84±1,88, os granulomas eram mais numerosos ( ou = 231,20±34,57, porém menores ( ou = 41.556,58±2.043,60mim². A ocorrência de apoptose ajuda a explicar a redução na celularidade e a conseqüente diminuição da área dos granulomas. A apoptose foi confirmada histologicamente pela técnica de "tunel". Assim, a apoptose participa da modulação do fenômeno inflamatório do tipo granulomatoso, reacional à embolização de ovos do parasito no fígado. Com a evolução da doença, desenvolve-se uma tolerância imunológica aos antígenos do ovo do Schistosoma mansoni, evidenciada morfologicamente pela diminuição da área média dos granulomas e pela maior freqüência de apoptose nas células componentes do granuloma.

  1. Optimal sample storage and extraction procotols for reliable multilocus genotyping of the human parasite Schistosoma mansoni.

    Science.gov (United States)

    Van den Broeck, F; Geldof, S; Polman, K; Volckaert, F A M; Huyse, T

    2011-08-01

    Genotyping individual larval stages and eggs of natural parasite populations is complicated by the difficulty of obtaining reliable genotypes from low quantity DNA template. A suitable storage and extraction protocol, together with a thorough quantification of genotyping errors are therefore crucial for molecular epidemiological studies. Here we test the robustness, handling time, ease of use, cost effectiveness and success rate of various fixation (Whatman FTA(®) Classic and Elute Cards, 70% EtOH and RNAlater(®)) and subsequent DNA extraction methods (commercial kits and proteinase K protocol). None of these methods require a cooling chain and are therefore suitable for field collection. Based on a multiplex microsatellite PCR with nine loci the success and reliability of each technique is evaluated by the proportion of samples with at least eight scored loci and the proportion of genotyping errors. If only the former is taken into account, FTA(®) Elute is recommended (83% success; 44% genotyping error; 0.2 €/sample; 1h 20 m handling time). However, when also considering the genotyping errors, handling time and ease of use, we opt for 70% EtOH with the 96-well plate technology followed by a simple proteinase K extraction (73% success; 0% genotyping error; 0.2 €/sample; 15m handling time). For eggs we suggest (1) to pool all eggs per person in 1.5 ml tubes filled with 70% EtOH for transport and (2) to identify each egg to species level prior to genotyping. To this end we extended the Rapid diagnostic PCR developed by Webster et al. (2010) with a S. mansoni-specific primer to discriminate between S. mansoni, S. haematobium and S. bovis in a single PCR reaction. The success rate of genotyping eggs was 75% (0% genotyping error). This is the first study to incorporate genotyping errors through re-amplification for the evaluation of schistosome sampling protocols and the identification of error-prone loci.

  2. Evaluation and optimization of the Circulating Cathodic Antigen (POC-CCA) cassette test for detecting Schistosoma mansoni infection by using image analysis in school children in Mwanza Region, Tanzania

    DEFF Research Database (Denmark)

    Partal, Miriam Casacuberta; Kinunghi, Safari; Vennervald, Birgitte J

    2016-01-01

    There is a need for diagnostic techniques which are sensitive, specific, rapid and easy to perform at the point-of-care. The aim of this study was to evaluate the diagnostic performance of the Circulating Cathodic Antigen (POC-CCA) assay for Schistosoma mansoni in four schools along the coast...

  3. Observed reductions in Schistosoma mansoni transmission from large-scale administration of praziquantel in Uganda: a mathematical modelling study.

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    Michael D French

    Full Text Available BACKGROUND: To date schistosomiasis control programmes based on chemotherapy have largely aimed at controlling morbidity in treated individuals rather than at suppressing transmission. In this study, a mathematical modelling approach was used to estimate reductions in the rate of Schistosoma mansoni reinfection following annual mass drug administration (MDA with praziquantel in Uganda over four years (2003-2006. In doing this we aim to elucidate the benefits of MDA in reducing community transmission. METHODS: Age-structured models were fitted to a longitudinal cohort followed up across successive rounds of annual treatment for four years (Baseline: 2003, TREATMENT: 2004-2006; n = 1,764. Instead of modelling contamination, infection and immunity processes separately, these functions were combined in order to estimate a composite force of infection (FOI, i.e., the rate of parasite acquisition by hosts. RESULTS: MDA achieved substantial and statistically significant reductions in the FOI following one round of treatment in areas of low baseline infection intensity, and following two rounds in areas with high and medium intensities. In all areas, the FOI remained suppressed following a third round of treatment. CONCLUSIONS/SIGNIFICANCE: This study represents one of the first attempts to monitor reductions in the FOI within a large-scale MDA schistosomiasis morbidity control programme in sub-Saharan Africa. The results indicate that the Schistosomiasis Control Initiative, as a model for other MDA programmes, is likely exerting a significant ancillary impact on reducing transmission within the community, and may provide health benefits to those who do not receive treatment. The results obtained will have implications for evaluating the cost-effectiveness of schistosomiasis control programmes and the design of monitoring and evaluation approaches in general.

  4. Effect of praziquantel administration on hepatic stereology of mice infected with Schistosoma mansoni and fed a low-protein diet

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    L.A. Barros

    2009-09-01

    Full Text Available A study was undertaken to investigate the effect of administering praziquantel (PZQ, focusing on the liver stereological findings of malnourished mice infected with Schistosoma mansoni. Thirty female Swiss Webster mice (age: 21 days; weight: 8-14 g were fed either a low-protein diet (8% or standard chow (22% protein for 15 days. Five mice in each group were infected with 50 cercariae each of the BH strain (Brazil. PZQ therapy (80 mg/kg body weight, per day was started on the 50th day of infection and consisted of daily administration for 5 days. Volume density (hepatocytes, sinusoids and hepatic fibrosis was determined by stereology using a light microscope. Body weight gain and total serum albumin levels were always lower in undernourished mice. Our stereological study demonstrated that treatment increased both volume density of hepatocytes in mice fed standard chow (47.56%, treated group and 12.06%, control and low-protein chow (30.98%, treated group and 21.44%, control, and hepatic sinusoids [standard chow (12.52%, treated group and 9.06%, control, low-protein chow (14.42%, treated group and 8.46%, control], while hepatic fibrosis was reduced [standard chow (39.92%, treated group and 78.88%, control and low-protein chow (54.60%, treated group and 70.10%, control]. On the other hand, mice fed low-protein chow decreased density volume of hepatocytes and hepatic fibrosis. In conclusion, our findings indicate that treatment with PZQ ameliorates hepatic schistosomiasis pathology even in mice fed a low-protein diet.

  5. Characterization of new Schistosoma mansoni microsatellite loci in sequences obtained from public DNA databases and microsatellite enriched genomic libraries

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    Rodrigues NB

    2002-01-01

    Full Text Available In the last decade microsatellites have become one of the most useful genetic markers used in a large number of organisms due to their abundance and high level of polymorphism. Microsatellites have been used for individual identification, paternity tests, forensic studies and population genetics. Data on microsatellite abundance comes preferentially from microsatellite enriched libraries and DNA sequence databases. We have conducted a search in GenBank of more than 16,000 Schistosoma mansoni ESTs and 42,000 BAC sequences. In addition, we obtained 300 sequences from CA and AT microsatellite enriched genomic libraries. The sequences were searched for simple repeats using the RepeatMasker software. Of 16,022 ESTs, we detected 481 (3% sequences that contained 622 microsatellites (434 perfect, 164 imperfect and 24 compounds. Of the 481 ESTs, 194 were grouped in 63 clusters containing 2 to 15 ESTs per cluster. Polymorphisms were observed in 16 clusters. The 287 remaining ESTs were orphan sequences. Of the 42,017 BAC end sequences, 1,598 (3.8% contained microsatellites (2,335 perfect, 287 imperfect and 79 compounds. The 1,598 BAC end sequences 80 were grouped into 17 clusters containing 3 to 17 BAC end sequences per cluster. Microsatellites were present in 67 out of 300 sequences from microsatellite enriched libraries (55 perfect, 38 imperfect and 15 compounds. From all of the observed loci 55 were selected for having the longest perfect repeats and flanking regions that allowed the design of primers for PCR amplification. Additionally we describe two new polymorphic microsatellite loci.

  6. Characterization of new Schistosoma mansoni microsatellite loci in sequences obtained from public DNA databases and microsatellite enriched genomic libraries.

    Science.gov (United States)

    Rodrigues, N B; Loverde, P T; Romanha, A J; Oliveira, G

    2002-01-01

    In the last decade microsatellites have become one of the most useful genetic markers used in a large number of organisms due to their abundance and high level of polymorphism. Microsatellites have been used for individual identification, paternity tests, forensic studies and population genetics. Data on microsatellite abundance comes preferentially from microsatellite enriched libraries and DNA sequence databases. We have conducted a search in GenBank of more than 16,000 Schistosoma mansoni ESTs and 42,000 BAC sequences. In addition, we obtained 300 sequences from CA and AT microsatellite enriched genomic libraries. The sequences were searched for simple repeats using the RepeatMasker software. Of 16,022 ESTs, we detected 481 (3%) sequences that contained 622 microsatellites (434 perfect, 164 imperfect and 24 compounds). Of the 481 ESTs, 194 were grouped in 63 clusters containing 2 to 15 ESTs per cluster. Polymorphisms were observed in 16 clusters. The 287 remaining ESTs were orphan sequences. Of the 42,017 BAC end sequences, 1,598 (3.8%) contained microsatellites (2,335 perfect, 287 imperfect and 79 compounds). The 1,598 BAC end sequences 80 were grouped into 17 clusters containing 3 to 17 BAC end sequences per cluster. Microsatellites were present in 67 out of 300 sequences from microsatellite enriched libraries (55 perfect, 38 imperfect and 15 compounds). From all of the observed loci 55 were selected for having the longest perfect repeats and flanking regions that allowed the design of primers for PCR amplification. Additionally we describe two new polymorphic microsatellite loci.

  7. Combining process-based and correlative models improves predictions of climate change effects on Schistosoma mansoni transmission in eastern Africa

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    Anna-Sofie Stensgaard

    2016-03-01

    Full Text Available Currently, two broad types of approach for predicting the impact of climate change on vector-borne diseases can be distinguished: i empirical-statistical (correlative approaches that use statistical models of relationships between vector and/or pathogen presence and environmental factors; and ii process-based (mechanistic approaches that seek to simulate detailed biological or epidemiological processes that explicitly describe system behavior. Both have advantages and disadvantages, but it is generally acknowledged that both approaches have value in assessing the response of species in general to climate change. Here, we combine a previously developed dynamic, agentbased model of the temperature-sensitive stages of the Schistosoma mansoni and intermediate host snail lifecycles, with a statistical model of snail habitat suitability for eastern Africa. Baseline model output compared to empirical prevalence data suggest that the combined model performs better than a temperature-driven model alone, and highlights the importance of including snail habitat suitability when modeling schistosomiasis risk. There was general agreement among models in predicting changes in risk, with 24-36% of the eastern Africa region predicted to experience an increase in risk of up-to 20% as a result of increasing temperatures over the next 50 years. Vice versa the models predicted a general decrease in risk in 30-37% of the study area. The snail habitat suitability models also suggest that anthropogenically altered habitat play a vital role for the current distribution of the intermediate snail host, and hence we stress the importance of accounting for land use changes in models of future changes in schistosomiasis risk.

  8. Use of humanised rat basophilic leukaemia cell line RS-ATL8 for the assessment of allergenicity of Schistosoma mansoni proteins.

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    Daniel Wan

    2014-09-01

    Full Text Available Parasite-specific IgE is thought to correlate with protection against Schistosoma mansoni infection or re-infection. Only a few molecular targets of the IgE response in S. mansoni infection have been characterised. A better insight into the basic mechanisms of anti-parasite immunity could be gained from a genome-wide characterisation of such S. mansoni allergens. This would have repercussions on our understanding of allergy and the development of safe and efficacious vaccinations against helminthic parasites.A complete medium- to high-throughput amenable workflow, including important quality controls, is described, which enables the rapid translation of S. mansoni proteins using wheat germ lysate and subsequent assessment of potential allergenicity with a humanised Rat Basophilic Leukemia (RBL reporter cell line. Cell-free translation is completed within 90 minutes, generating sufficient amounts of parasitic protein for rapid screening of allergenicity without any need for purification. Antigenic integrity is demonstrated using Western Blotting. After overnight incubation with infected individuals' serum, the RS-ATL8 reporter cell line is challenged with the complete wheat germ translation mixture and Luciferase activity measured, reporting cellular activation by the suspected allergen. The suitability of this system for characterization of novel S. mansoni allergens is demonstrated using well characterised plant and parasitic allergens such as Par j 2, SmTAL-1 and the IgE binding factor IPSE/alpha-1, expressed in wheat germ lysates and/or E. coli. SmTAL-1, but not SmTAL2 (used as a negative control, was able to activate the basophil reporter cell line.This method offers an accessible way for assessment of potential allergenicity of anti-helminthic vaccine candidates and is suitable for medium- to high-throughput studies using infected individual sera. It is also suitable for the study of the basis of allergenicity of helminthic proteins.

  9. Human IgG1 Responses to Surface Localised Schistosoma mansoni Ly6 Family Members Drop following Praziquantel Treatment

    Science.gov (United States)

    Chalmers, Iain W.; Fitzsimmons, Colin M.; Brown, Martha; Pierrot, Christine; Jones, Frances M.; Wawrzyniak, Jakub M.; Fernandez-Fuentes, Narcis; Tukahebwa, Edridah M.; Dunne, David W.; Khalife, Jamal; Hoffmann, Karl F.

    2015-01-01

    Background The heptalaminate-covered, syncytial tegument is an important anatomical adaptation that enables schistosome parasites to maintain long-term, intravascular residence in definitive hosts. Investigation of the proteins present in this surface layer and the immune responses elicited by them during infection is crucial to our understanding of host/parasite interactions. Recent studies have revealed a number of novel tegumental surface proteins including three (SmCD59a, SmCD59b and Sm29) containing uPAR/Ly6 domains (renamed SmLy6A SmLy6B and SmLy6D in this study). While vaccination with SmLy6A (SmCD59a) and SmLy6D (Sm29) induces protective immunity in experimental models, human immunoglobulin responses to representative SmLy6 family members have yet to be thoroughly explored. Methodology/Principal Findings Using a PSI-BLAST-based search, we present a comprehensive reanalysis of the Schistosoma mansoni Ly6 family (SmLy6A-K). Our examination extends the number of members to eleven (including three novel proteins) and provides strong evidence that the previously identified vaccine candidate Sm29 (renamed SmLy6D) is a unique double uPAR/Ly6 domain-containing representative. Presence of canonical cysteine residues, signal peptides and GPI-anchor sites strongly suggest that all SmLy6 proteins are cell surface-bound. To provide evidence that SmLy6 members are immunogenic in human populations, we report IgG1 (as well as IgG4 and IgE) responses against two surface-bound representatives (SmLy6A and SmLy6B) within a cohort of S. mansoni-infected Ugandan males before and after praziquantel treatment. While pre-treatment IgG1 prevalence for SmLy6A and SmLy6B differs amongst the studied population (7.4% and 25.3% of the cohort, respectively), these values are both higher than IgG1 prevalence (2.7%) for a sub-surface tegumental antigen, SmTAL1. Further, post-treatment IgG1 levels against surface-associated SmLy6A and SmLy6B significantly drop (p = 0.020 and p < 0

  10. Human IgG1 Responses to Surface Localised Schistosoma mansoni Ly6 Family Members Drop following Praziquantel Treatment.

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    Iain W Chalmers

    Full Text Available The heptalaminate-covered, syncytial tegument is an important anatomical adaptation that enables schistosome parasites to maintain long-term, intravascular residence in definitive hosts. Investigation of the proteins present in this surface layer and the immune responses elicited by them during infection is crucial to our understanding of host/parasite interactions. Recent studies have revealed a number of novel tegumental surface proteins including three (SmCD59a, SmCD59b and Sm29 containing uPAR/Ly6 domains (renamed SmLy6A SmLy6B and SmLy6D in this study. While vaccination with SmLy6A (SmCD59a and SmLy6D (Sm29 induces protective immunity in experimental models, human immunoglobulin responses to representative SmLy6 family members have yet to be thoroughly explored.Using a PSI-BLAST-based search, we present a comprehensive reanalysis of the Schistosoma mansoni Ly6 family (SmLy6A-K. Our examination extends the number of members to eleven (including three novel proteins and provides strong evidence that the previously identified vaccine candidate Sm29 (renamed SmLy6D is a unique double uPAR/Ly6 domain-containing representative. Presence of canonical cysteine residues, signal peptides and GPI-anchor sites strongly suggest that all SmLy6 proteins are cell surface-bound. To provide evidence that SmLy6 members are immunogenic in human populations, we report IgG1 (as well as IgG4 and IgE responses against two surface-bound representatives (SmLy6A and SmLy6B within a cohort of S. mansoni-infected Ugandan males before and after praziquantel treatment. While pre-treatment IgG1 prevalence for SmLy6A and SmLy6B differs amongst the studied population (7.4% and 25.3% of the cohort, respectively, these values are both higher than IgG1 prevalence (2.7% for a sub-surface tegumental antigen, SmTAL1. Further, post-treatment IgG1 levels against surface-associated SmLy6A and SmLy6B significantly drop (p = 0.020 and p < 0.001, respectively when compared to rising Ig

  11. 输入性曼氏血吸虫病临床分析%Clinical analysis of imported Schistosoma mansoni infections:a report of two cases and review of the literature

    Institute of Scientific and Technical Information of China (English)

    邹洋; 齐志群; 冯曼玲; 王非; 李威; 粟绍刚; 许炽熛; 谷俊朝

    2011-01-01

    Aim To analyze the clinical features of Schistosoma mansoni infections.Methods Two cases infected with Schistosoma mansoni were reported and the clinical features of schistosomiasis were discussed.Results Schistosoma mansoni infection mostly was a kind of imported schistosomiasis.The symptoms were severe,with different manifestations such as fever, gastro-intestinal symptoms.Final diagnosis was made by the presence of Schistosoma mansoni in stool samples or secretions from intestinal tract.Conclusion In patients with unexplained fever,gastro-intestinal symptoms or that do not respond to ordinary therapy, rare pathogens such as Schistosoma mansoni need to be considered.Praziquantel is currently the drug of choice for the treatment of schistosomiasis.%目的 提高对曼氏血吸虫病的临床诊断认识,减少误诊误治.方法 报道2例曼氏血吸虫感染,并结合国内外文献报道的临床资料进行分析.结果 曼氏血吸虫病是一种输入性血吸虫病,其可引起发热,胃肠道症状等急性血吸虫病的临床表现,确诊主要依据粪检或直肠黏膜活检找到曼氏血吸虫卵,吡喹酮等药驱虫治疗对大多数患者有效.结论 对不明原因的发热,胃肠道综合征等的患者,在治疗效果不佳,且以常见病难以解释时,要注意询问患者的流行病学史,减少误诊误治.

  12. Newly established monoclonal antibody diagnostic assays for Schistosoma mansoni direct detection in areas of low endemicity.

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    Rafaella Fortini Queiroz Grenfell

    Full Text Available BACKGROUND: Current available methods for diagnosis of schistosomiasis mansoni lack sufficient sensitivity, which results in underreporting of infectious in areas of low endemicity. METHODOLOGY/PRINCIPAL FINDINGS: We developed three novel diagnostic methodologies for the direct detection of schistosome infection in serum samples. These three new methods were evaluated with positive patients from a low endemicity area in southeast Brazil. The basis of the assay was the production of monoclonal antibodies against the protein backbone of heavily glycosylated Circulating Cathodic Antigen (CCA. The antibodies were also selected for having no specificity to repeating poly-Lewis x units. Assays based on the detection CCA-protein should not encounter a limitation in sensitivity due to a biological background of this particular epitope. Three diagnostic methodologies were developed and validated, (i Immunomagnetic Separation based on improved incubation steps of non-diluted serum, (ii Direct Enzyme-linked Immunosorbent Assay and (iii Fluorescent Microscopy Analysis as a qualitative assay. The two quantitative assays presented high sensitivity (94% and 92%, respectively and specificity (100%, equivalent to the analysis of 3 stool samples and 16 slides by Kato-Katz, showing promising results on the determination of cure. CONCLUSIONS/SIGNIFICANCE: The Immunomagnetic Separation technique showed excellent correlation with parasite burden by Cohen coefficient. The qualitative method detected 47 positive individuals out of 50 with the analysis of 3 slides. This easy-to-do method was capable of discriminating positive from negative cases, even for patients with low parasite burden.

  13. Countrywide Reassessment of Schistosoma mansoni Infection in Burundi Using a Urine-Circulating Cathodic Antigen Rapid Test: Informing the National Control Program.

    Science.gov (United States)

    Ortu, Giuseppina; Ndayishimiye, Onésime; Clements, Michelle; Kayugi, Donatien; Campbell, Carl H; Lamine, Mariama Sani; Zivieri, Antonio; Magalhaes, Ricardo Soares; Binder, Sue; King, Charles H; Fenwick, Alan; Colley, Daniel G; Jourdan, Peter Mark

    2017-01-23

    Following implementation of the national control program, a reassessment of Schistosoma mansoni prevalence was conducted in Burundi to determine the feasibility of moving toward elimination. A countrywide cluster-randomized cross-sectional study was performed in May 2014. At least 25 schools were sampled from each of five eco-epidemiological risk zones for schistosomiasis. Fifty randomly selected children 13-14 years of age per school were included for a single urine-circulating cathodic antigen (CCA) rapid test and, in a subset of schools, for duplicate Kato-Katz slides preparation from a single stool sample. A total of 17,331 children from 347 schools were tested using CCA. The overall prevalence of S. mansoni infection, when CCA trace results were considered negative, was 13.5% (zone range [zr] = 4.6-17.8%), and when CCA trace results were considered positive, it was 42.8% (zr = 34.3-49.9%). In 170 schools, prevalence of this infection determined using Kato-Katz method was 1.5% (zr ==0-2.7%). The overall mean intensity of S. mansoni infection determined using Kato-Katz was 0.85 eggs per gram (standard deviation = 10.86). A majority of schools (84%) were classified as non-endemic (prevalence = 0) using Kato-Katz; however, a similar proportion of schools were classified as endemic when CCA trace results were considered negative (85%) and nearly all (98%) were endemic when CCA trace results were considered positive. The findings of this nationwide reassessment using CCA rapid test indicate that Schistosoma infection is still widespread in Burundi, although its average intensity is probably low. Further evidence is now needed to determine the association between CCA rapid test positivity and low-intensity disease transmission.

  14. Diagnostic accuracy and applicability of a PCR system for the detection of Schistosoma mansoni DNA in human urine samples from an endemic area.

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    Martin Johannes Enk

    Full Text Available Schistosomiasis caused by Schistosoma mansoni, one of the most neglected human parasitoses in Latin America and Africa, is routinely confirmed by microscopic visualization of eggs in stool. The main limitation of this diagnostic approach is its lack of sensitivity in detecting individual low worm burdens and consequently data on infection rates in low transmission settings are little reliable. According to the scientific literature, PCR assays are characterized by high sensitivity and specificity in detecting parasite DNA in biological samples. A simple and cost effective extraction method for DNA of Schistosoma mansoni from urine samples in combination with a conventional PCR assay was developed and applied in an endemic area. This urine based PCR system was tested for diagnostic accuracy among a population of a small village in an endemic area, comparing it to a reference test composed of three different parasitological techniques. The diagnostic parameters revealed a sensitivity of 100%, a specificity of 91.20%, positive and negative predictive values of 86.25% and 100%, respectively, and a test accuracy of 94.33%. Further statistical analysis showed a k index of 0.8806, indicating an excellent agreement between the reference test and the PCR system. Data obtained from the mouse model indicate the infection can be detected one week after cercariae penetration, opening a new perspective for early detection and patient management during this stage of the disease. The data indicate that this innovative PCR system provides a simple to handle and robust diagnostic tool for the detection of S. mansoni DNA from urine samples and a promising approach to overcome the diagnostic obstacles in low transmission settings. Furthermore the principals of this molecular technique, based on the examination of human urine samples may be useful for the diagnosis of other neglected tropical diseases that can be detected by trans-renal DNA.

  15. Efficacy and safety of praziquantel in preschool-aged children in an area co-endemic for Schistosoma mansoni and S. haematobium.

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    Jean T Coulibaly

    Full Text Available BACKGROUND: In sub-Saharan Africa the recommended strategy to control schistosomiasis is preventive chemotherapy. Emphasis is placed on school-aged children, but in high endemicity areas, preschool-aged children are also at risk, and hence might need treatment with praziquantel. Since a pediatric formulation (e.g., syrup is not available outside of Egypt, crushed praziquantel tablets are used, but the efficacy and safety of this treatment regimen is insufficiently studied. METHODOLOGY: We assessed the efficacy and safety of crushed praziquantel tablets among preschool-aged children (<6 years in the Azaguié district, south Côte d'Ivoire, where Schistosoma mansoni and S. haematobium coexist. Using a cross-sectional design, children provided two stool and two urine samples before and 3 weeks after treatment. Crushed praziquantel tablets, mixed with water, were administered at a dose of 40 mg/kg. Adverse events were assessed and graded 4 and 24 hours posttreatment by interviewing mothers/guardians. PRINCIPAL FINDINGS: Overall, 160 preschool-aged children had at least one stool and one urine sample examined with duplicate Kato-Katz thick smears and a point-of-care circulating cathodic antigen (POC-CCA cassette for S. mansoni, and urine filtration for S. haematobium diagnosis before and 3 weeks after praziquantel administration. According to the Kato-Katz and urine filtration results, we found high efficacy against S. mansoni (cure rate (CR, 88.6%; egg reduction rate (ERR, 96.7% and S. haematobium (CR, 88.9%; ERR, 98.0%. POC-CCA revealed considerably lower efficacy against S. mansoni (CR, 53.8%. Treatment was generally well tolerated, but moderately severe adverse events (i.e., body and face inflammation, were observed in four Schistosoma egg-negative children. CONCLUSIONS/SIGNIFICANCE: Crushed praziquantel administered to preschool-aged children at a dose of 40 mg/kg is efficacious against S. mansoni and S. haematobium in a co-endemic setting of C

  16. Bayesian spatial risk prediction of Schistosoma mansoni infection in western Côte d'Ivoire using a remotely-sensed digital elevation model.

    Science.gov (United States)

    Beck-Wörner, Christian; Raso, Giovanna; Vounatsou, Penelope; N'Goran, Eliézer K; Rigo, Gergely; Parlow, Eberhard; Utzinger, Jürg

    2007-05-01

    An important epidemiologic feature of schistosomiasis is the focal distribution of the disease. Thus, the identification of high-risk communities is an essential first step for targeting interventions in an efficient and cost-effective manner. We used a remotely-sensed digital elevation model (DEM), derived hydrologic features (i.e., stream order, and catchment area), and fitted Bayesian geostatistical models to assess associations between environmental factors and infection with Schistosoma mansoni among more than 4,000 school children from the region of Man in western Côte d'Ivoire. At the unit of the school, we found significant correlations between the infection prevalence of S. mansoni and stream order of the nearest river, water catchment area, and altitude. In conclusion, the use of a freely available 90 m high-resolution DEM, geographic information system applications, and Bayesian spatial modeling facilitates risk prediction for S. mansoni, and is a powerful approach for risk profiling of other neglected tropical diseases that are pervasive in the developing world.

  17. Predicting frequency distribution and influence of sociodemographic and behavioral risk factors of Schistosoma mansoni infection and analysis of co-infection with intestinal parasites

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    Carla V.V. Rollemberg

    2015-05-01

    Full Text Available Geospatial analysis was used to study the epidemiology of Schistosoma mansoni, intestinal parasites and co-infections in an area (Ilha das Flores in Sergipe, Brazil. We collected individually georeferenced sociodemographic, behavioral and parasitological data from 500 subjects, analyzed them by conventional statistics, and produced risk maps by Kernel estimation. The prevalence rates found were: S. mansoni (24.0%, Trichuris trichiura (54.8%, Ascaris lumbricoides (49.2%, Hookworm (17.6% and Entamoeba histolytica (7.0%. Only 59/500 (11.8% individuals did not present any of these infections, whereas 279/500 (55.8% were simultaneously infected by three or more parasites. We observed associations between S. mansoni infection and various variables such as male gender, being rice farmer or fisherman, low educational level, low income, water contact and drinking untreated water. The Kernel estimator indicated that high-risk areas coincide with the poorest regions of the villages as well as with the part of the villages without an adequate sewage system. We also noted associations between both A. lumbricoides and hookworm infections with low education and low income. A. lumbricoides infection and T. trichiura infection were both associated with drinking untreated water and residential open-air sewage. These findings call for an integrated approach to effectively control multiple parasitic infections.

  18. Immunological and parasitological parameters in Schistosoma mansoni-infected mice treated with crude extract from the leaves of Mentha x piperita L.

    Science.gov (United States)

    Dejani, Naiara N; Souza, Laís C; Oliveira, Sandra R P; Neris, Débora M; Rodolpho, Joice M A; Correia, Ricardo O; Rodrigues, Vanderlei; Sacramento, Luis V S; Faccioli, Lúcia H; Afonso, Ana; Anibal, Fernanda F

    2014-08-01

    Schistosomiasis is a chronic disease caused by an intravascular trematode of the genus Schistosoma. Praziquantel is the drug used for treatment of schistosomiasis; nevertheless failure of treatment has been reported. Consequently, the identification of new effective schistosomicidal compounds is essential to ensure the effective control of schistosomiasis in the future. In this work we investigated the immunomodulatory and antiparasitic effects of the crude leaves extract of Mentha x piperita L. (peppermint) on murine Schistosomiasis mansoni. Female Balb/c mice were infected each with 50 S. mansoni cercariae and divided into three experimental groups: (I) untreated; (II) treated daily with M. x piperita L. (100mg/kg) and III) treated on 1/42/43 days post-infection with Praziquantel (500mg/kg). Another group with uninfected and untreated mice was used as a control. Subsequently, seven weeks post-infection, S. mansoni eggs were counted in the feces, liver and intestine. Worms were recovered by perfusion of the hepatic portal system and counted. Sera levels of IL-10, IL-5, IL-13, IFN-γ, IgG1, IgE and IgG2a were assayed by ELISA. Animals treated with a daily dose of M. x piperita L. showed increased sera levels of IL-10, IFN-γ, IgG2a and IgE. Besides, M. x piperita L. treatment promoted reduction in parasite burden by 35.2% and significant decrease in egg counts in the feces and intestine.

  19. Characterization of South American Snails of the Genus Biomphalaria (Basommatophora: Planorbidae) and Schistosoma mansoni (Platyhelminthes: Trematoda) in Molluscs by PCR-RFLP

    Science.gov (United States)

    Teodoro, Tatiana Maria; Jannotti-Passos, Liana Konovaloff; Lira-Moreira, Pollanah M.; Goveia, Christiane De Oliveira; Carvalho, Omar dos Santos

    2016-01-01

    The identification of snails of the genus Biomphalaria can be done using morphological characteristics which depends on the size of the snails and skill and knowledge of researcher. These methods sometimes are not adequate for identification of species. The PCR-RFLP, using the ITS region of the rDNA, has been used to identify Brazilian species of the genus Biomphalaria. Nevertheless, there is a lack of information about snails from other Latin American countries. In addition, some snails may be infected by Schistosoma mansoni and when submitted to PCR-RFLP they show molecular profiles different from those previously standardized for the other mollusc species. In this work the molecular profiles of 15 species and the subspecies were established by PCR-RFLP of ITS-rDNA with the enzyme DdeI. Moreover, the molecular profiles of host species, B. glabrata, B. straminea, B. tenagophila, and B. prona, infected by S. mansoni were also established. The molluscs were dissected to permit morphological identification. These results contribute to a correct identification of snails of the genus Biomphalaria and detection of these snails infected by S. mansoni. PMID:27981045

  20. Characterization of South American Snails of the Genus Biomphalaria (Basommatophora: Planorbidae and Schistosoma mansoni (Platyhelminthes: Trematoda in Molluscs by PCR-RFLP

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    Roberta Lima Caldeira

    2016-01-01

    Full Text Available The identification of snails of the genus Biomphalaria can be done using morphological characteristics which depends on the size of the snails and skill and knowledge of researcher. These methods sometimes are not adequate for identification of species. The PCR-RFLP, using the ITS region of the rDNA, has been used to identify Brazilian species of the genus Biomphalaria. Nevertheless, there is a lack of information about snails from other Latin American countries. In addition, some snails may be infected by Schistosoma mansoni and when submitted to PCR-RFLP they show molecular profiles different from those previously standardized for the other mollusc species. In this work the molecular profiles of 15 species and the subspecies were established by PCR-RFLP of ITS-rDNA with the enzyme DdeI. Moreover, the molecular profiles of host species, B. glabrata, B. straminea, B. tenagophila, and B. prona, infected by S. mansoni were also established. The molluscs were dissected to permit morphological identification. These results contribute to a correct identification of snails of the genus Biomphalaria and detection of these snails infected by S. mansoni.

  1. Development of a Schistosoma mansoni shotgun O-glycan microarray and application to the discovery of new antigenic schistosome glycan motifs.

    Science.gov (United States)

    van Diepen, Angela; van der Plas, Arend-Jan; Kozak, Radoslaw P; Royle, Louise; Dunne, David W; Hokke, Cornelis H

    2015-06-01

    Upon infection with Schistosoma, antibody responses are mounted that are largely directed against glycans. Over the last few years significant progress has been made in characterising the antigenic properties of N-glycans of Schistosoma mansoni. Despite also being abundantly expressed by schistosomes, much less is understood about O-glycans and antibody responses to these have not yet been systematically analysed. Antibody binding to schistosome glycans can be analysed efficiently and quantitatively using glycan microarrays, but O-glycan array construction and exploration is lagging behind because no universal O-glycanase is available, and release of O-glycans has been dependent on chemical methods. Recently, a modified hydrazinolysis method has been developed that allows the release of O-glycans with free reducing termini and limited degradation, and we applied this method to obtain O-glycans from different S. mansoni life stages. Two-dimensional HPLC separation of 2-aminobenzoic acid-labelled O-glycans generated 362 O-glycan-containing fractions that were printed on an epoxide-modified glass slide, thereby generating the first shotgun O-glycan microarray containing naturally occurring schistosome O-glycans. Monoclonal antibodies and mass spectrometry showed that the O-glycan microarray contains well-known antigenic glycan motifs as well as numerous other, potentially novel, antibody targets. Incubations of the microarrays with sera from Schistosoma-infected humans showed substantial antibody responses to O-glycans in addition to those observed to the previously investigated N- and glycosphingolipid glycans. This underlines the importance of the inclusion of these often schistosome-specific O-glycans in glycan antigen studies and indicates that O-glycans contain novel antigenic motifs that have potential for use in diagnostic methods and studies aiming at the discovery of vaccine targets.

  2. Role of Mannose-Binding Lectin Deficiency in HIV-1 and Schistosoma Infections in a Rural Adult Population in Zimbabwe

    DEFF Research Database (Denmark)

    Zinyama-Gutsire, Rutendo B L; Chasela, Charles; Madsen, Hans O

    2015-01-01

    BACKGROUND: Polymorphism in the MBL2 gene lead to MBL deficiency, which has been shown to increase susceptibility to various bacterial, viral and parasitic infections. We assessed role of MBL deficiency in HIV-1 and schistosoma infections in Zimbabwean adults enrolled in the Mupfure Schistosomiasis...... and HIV Cohort (MUSH Cohort). METHODS: HIV-1, S. haematobium and S. mansoni infections were determined at baseline. Plasma MBL concentration was measured by ELISA and MBL2 genotypes determined by PCR. We calculated and compared the proportions of plasma MBL deficiency, MBL2 structural variant alleles B...... (codon 54A>G), C (codon 57A>G), and D (codon 52T>C) as well as MBL2 promoter variants -550(H/L), -221(X/Y) and +4(P/Q) between HIV-1 and schistosoma co-infection and control groups using Chi Square test. RESULTS: We assessed 379 adults, 80% females, median age (IQR) 30 (17-41) years. HIV-1, S...

  3. Suscetibilidade aos agentes quimioterápicos de isolados de Schistosoma mansoni oriundos de pacientes tratados com oxamniquine e praziquantel e não curados

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    Neusa Araújo

    1996-10-01

    Full Text Available Foram estudados dez isolados de Schistosoma mansoni provenientes de pacientes residentes em Itaquara, Bahia, Brasil, tratados com oxamniquine eposteriormente com praziquantel, e ainda assim não curados. Caramujos (Biomphalaria glabrataj foram expostos a miracídios provenientes das fezes dos pacientes. Cercãrías eliminadas por estes caramujos e por moluscos coletados no peridomicílio dos pacientes foram utilizadas para infecção experimental de camundongos albinos. Os animais infectados foram tratados em dose única, via oral, com oxamniquine (25, 50 e 100 mg/kg ou praziquantel (100, 200 e 400mg/kg. Foram realizados estudos de análise e comparação de DNA de cercãrías de S. mansoni eliminadas pelos caramujos e de vermes adultos recolhidos de camundongos infectados experimentalmente com os isolados dos 10 pacientes e ainda de cercãrías de S. mansoni eliminadas por moluscos naturalmente infectados coletados em Itaquara. A cepa LE (mantida rotineiramente no laboratório foi usada como padrão de comparação da resposta aos agentes esquistossomicidas administrados. As respostas terapêuticas foram significativamente diferentes entre alguns dos isolados embora não fosse possível caracterizar nenhum como resistente. A análise dos perfis de amplificação de DNA nas cercãrías e nos vermes adultos dos isolados de S. mansoni demonstrou baixo grau de variabilidade indicando que estes são geneticamente próximos e revelando a ausência de rearranjos globais dentro dos genomas.

  4. Efficacy and Safety of Moxidectin, Synriam, Synriam-Praziquantel versus Praziquantel against Schistosoma haematobium and S. mansoni Infections: A Randomized, Exploratory Phase 2 Trial

    Science.gov (United States)

    Barda, Beatrice; Coulibaly, Jean T.; Puchkov, Maxim; Huwyler, Jörg; Hattendorf, Jan; Keiser, Jennifer

    2016-01-01

    Background Schistosomiasis affects millions of people, yet treatment options are limited. The antimalarial Synriam (piperaquine 150 mg/arterolane 750 mg) and the anthelminthic moxidectin revealed promising antischistosomal properties in preclinical or clinical studies. Methodology We conducted two single-blind, randomized exploratory Phase 2 trials in Schistosoma mansoni and S. haematobium-infected adolescents in northern and central Côte d’Ivoire. Our primary endpoints were cure rates (CRs) and egg reduction rates (ERRs) based on geometric mean and safety. Each subject was asked to provide two stool samples (S. mansoni trial) for Kato-Katz analysis or three urine samples (S. haematobium trial) for urine filtration and one finger prick for malaria screening at baseline and follow-up. Participants were randomly assigned to either moxidectin, Synriam, Synriam plus praziquantel or praziquantel. Principal Findings 128 adolescents (age: 12–17 years) were included in each study. Against S. haematobium moxidectin and Synriam revealed low efficacy. On the other hand, Synriam plus praziquantel and praziquantel yielded CRs of 60.0% and 38.5% and ERRs of 96.0% and 93.5%, respectively. CRs observed in the treatment of S. mansoni were 13.0%, 6.7%, 27.0%, and 27.6% for moxidectin, Synriam, Synriam plus praziquantel and praziquantel, respectively. ERRs ranged from 64.9% (Synriam) to 87.5% (praziquantel). Conclusion/Significance Synriam and moxidectin show low efficacy against S. haematobium, hence an ancillary benefit is not expected when these drugs are used for treating onchocerciasis and malaria in co-endemic settings. Further studies are needed to corroborate our findings that moxidectin and Synriam show moderate ERRs against S. mansoni. PMID:27636542

  5. Comparing diagnostic accuracy of Kato-Katz, Koga agar plate, ether-concentration, and FLOTAC for Schistosoma mansoni and soil-transmitted helminths.

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    Dominik Glinz

    Full Text Available BACKGROUND: Infections with schistosomes and soil-transmitted helminths exert a considerable yet underappreciated economic and public health burden on afflicted populations. Accurate diagnosis is crucial for patient management, drug efficacy evaluations, and monitoring of large-scale community-based control programs. METHODS/PRINCIPAL FINDINGS: The diagnostic accuracy of four copromicroscopic techniques (i.e., Kato-Katz, Koga agar plate, ether-concentration, and FLOTAC for the detection of Schistosoma mansoni and soil-transmitted helminth eggs was compared using stool samples from 112 school children in Côte d'Ivoire. Combined results of all four methods served as a diagnostic 'gold' standard and revealed prevalences of S. mansoni, hookworm, Trichuris trichiura, Strongyloides stercoralis and Ascaris lumbricoides of 83.0%, 55.4%, 40.2%, 33.9% and 28.6%, respectively. A single FLOTAC from stool samples preserved in sodium acetate-acetic acid-formalin for 30 or 83 days showed a higher sensitivity for S. mansoni diagnosis (91.4% than the ether-concentration method on stool samples preserved for 40 days (85.0% or triplicate Kato-Katz using fresh stool samples (77.4%. Moreover, a single FLOTAC detected hookworm, A. lumbricoides and T. trichiura infections with a higher sensitivity than any of the other methods used, but resulted in lower egg counts. The Koga agar plate method was the most accurate diagnostic assay for S. stercoralis. CONCLUSION/SIGNIFICANCE: We have shown that the FLOTAC method holds promise for the diagnosis of S. mansoni. Moreover, our study confirms that FLOTAC is a sensitive technique for detection of common soil-transmitted helminths. For the diagnosis of S. stercoralis, the Koga agar plate method remains the method of choice.

  6. The Sinbad retrotransposon from the genome of the human blood fluke, Schistosoma mansoni, and the distribution of related Pao-like elements

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    Morales Maria E

    2005-02-01

    Full Text Available Abstract Background Of the major families of long terminal repeat (LTR retrotransposons, the Pao/BEL family is probably the least well studied. It is becoming apparent that numerous LTR retrotransposons and other mobile genetic elements have colonized the genome of the human blood fluke, Schistosoma mansoni. Results A proviral form of Sinbad, a new LTR retrotransposon, was identified in the genome of S. mansoni. Phylogenetic analysis indicated that Sinbad belongs to one of five discreet subfamilies of Pao/BEL like elements. BLAST searches of whole genomes and EST databases indicated that members of this clade occurred in species of the Insecta, Nematoda, Echinodermata and Chordata, as well as Platyhelminthes, but were absent from all plants, fungi and lower eukaryotes examined. Among the deuterostomes examined, only aquatic species harbored these types of elements. All four species of nematode examined were positive for Sinbad sequences, although among insect and vertebrate genomes, some were positive and some negative. The full length, consensus Sinbad retrotransposon was 6,287 bp long and was flanked at its 5'- and 3'-ends by identical LTRs of 386 bp. Sinbad displayed a triple Cys-His RNA binding motif characteristic of Gag of Pao/BEL-like elements, followed by the enzymatic domains of protease, reverse transcriptase (RT, RNAseH, and integrase, in that order. A phylogenetic tree of deduced RT sequences from 26 elements revealed that Sinbad was most closely related to an unnamed element from the zebrafish Danio rerio and to Saci-1, also from S. mansoni. It was also closely related to Pao from Bombyx mori and to Ninja of Drosophila simulans. Sinbad was only distantly related to the other schistosome LTR retrotransposons Boudicca, Gulliver, Saci-2, Saci-3, and Fugitive, which are gypsy-like. Southern hybridization and bioinformatics analyses indicated that there were about 50 copies of Sinbad in the S. mansoni genome. The presence of ESTs

  7. Verificação da resposta de miracídios de Schistosoma mansoni a substâncias provenientes de moluscos planorbídeos: pesquisa de substâncias quimiotáxicas Response of Schistosoma mansoni miracidia to snail substance: research on chemiotaxic substances

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    Beatriz de Camargo Brasio

    1985-04-01

    Full Text Available Foi testada a atividade miraxonal da água de condicionamento (SCW e da hemolinfa de Biomphalaria glabrata e de B. tenagophila frente a miracídios de Schistosoma mansoni das linhagens BH e SJ. Foram pesquisados e isolados alguns componentes de SCW. Com os componentes isolados de SCW e com a hemolinfa foram preparados blocos de ágar. Esses blocos, assim preparados, foram colocados frente a miracídios de S. mansoni para avaliação da atividade miraxonal. Foram detectadas diferenças entre a ação miraxonal da hemolinfa e das substâncias isoladas de SCW. Observaram-se diferenças significativas entre os efeitos miraxonais das duas espécies de moluscos pesquisados frente a miracídios das linhagens BH e SJ.Several substances isolated from SCW (snail conditioned water and from snail hemolymph were tested for a possible chemiotaxic effect on Schistosoma mansoni miracidia. Two strains of miracidia were considered (SJ and BH. Agar plates prepared with one of the substances were exposed to sixty miracidia for five minutes. The number of contacts and contacts with return were counted. Ten replications were made. Eight types (and four sub types of agar plates were prepared: normal water (control, SCW (Biomphalaria glabrata and B. tenagophila, hemolymph (B. glabrata and B. tenagophila and amonia, calcium, magnesium, sodium and potassium. Log-linear models were fitted to the data to study the proportions of attraction to each substance and to compare them. Any possible differences in proportions of attraction between the two S. mansoni strains were tested.

  8. Espécimes de Schistosoma mansoni descritos por Pirajá da Silva no Brasil (1908 reexaminados pela técnica de microscopia de varredura a laser confocal Schistosoma mansoni specimens first described by Pirajá da Silva in Brazil (1908 re-examined by confocal laser scanning microscopy

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    José Roberto Machado-Silva

    2011-06-01

    Full Text Available INTRODUÇÃO: Pirajá da Silva fez contribuição magnífica à helmintologia ao descrever ovos de Schistosoma mansoni nas fezes de um paciente, no Estado da Bahia e a morfologia de vermes adultos. MÉTODOS: Neste estudo, apresentamos uma avaliação microscópica das lâminas montadas e depositadas na Coleção Helmintológica do Instituto Oswaldo Cruz. A técnica empregada nesta nova análise foi a microscopia de varredura a laser confocal. RESULTADOS: Na parte anterior dos vermes adultos machos, observamos ventosas com musculatura bem desenvolvida e células germinativas dentro dos lobos testiculares. Visualizamos, também, espinhos localizados na região mediana do canal ginecóforo. Na superfície dorsal, encontramos tubérculos e feixes musculares transversais e longitudinais. Em relação ao aparelho reprodutivo feminino, pudemos distinguir um ovo no interior do útero e o ovário alongado com células germinativas. As glândulas vitelínicas estavam restritas à parte posterior das fêmeas conectadas por um ducto vitelínico curto. CONCLUSÕES: As características morfológicas são similares as estudadas anteriormente por Pirajá da Silva com vermes frescos. Além disso, este estudo demonstra a importância de se depositar espécimes nas coleções helmintológicas abrindo possibilidade de novos estudos com estas lâminas.INTRODUCTION: Pirajá da Silva made a seminal contribution to helminthology by demonstrating both schistosome eggs in feces of patients from the State of Bahia and the morphology of Schistosoma mansoni adult worms. METHODS: In this study, a microscopic investigation of the whole-mounts deposited at the Helminthological Collection of the Oswaldo Cruz Institute is presented. Confocal laser scanning microscopy was used as the main investigation technique. RESULTS: At the anterior end of the adult male, suckers with well-developed musculature and germinative cells inside the testicular lobes were observed, as well as

  9. Infecção experimental de camundongos albinos com cercárias de Schistosoma mansoni Sambon, 1907, previamente submetidas a ação de termofosfato magnesiano

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    Roberto Milward-de-Andrade

    1989-04-01

    Full Text Available Foi realizada infecção experimental de camundongos albinos ("Swiss inbred" com cercárias de Schistosoma mansoni, cepa LE, submetidas à ação do adubo termofosfato magnesiano (Tfm, usualmente utilizado em latossolos tropicais e capaz, quando ingerido, de provocar o bloqueio da ovogênese de moluscos planorbídeos. Nas condições do experimento, observou-se a infecção dos roedores. Porém, o número de ovos eliminados pelo grupo controle, representado por cinco camundongos, foi sensivelmente maior que o do grupo Tfm, ainda que a recuperação de vermes, por perfusão, tenha sido bem menor. Do grupo Tfm, foram recuperados 163 (98,2% vermes adultos machos e apenas 3 (1,8% fêmeas, isoladas. Do grupo controle, a perfusão proporcionou 53 vermes adultos, sendo 13 machos, 18 fêmeas e 11 casais. Cada camundongo foi exposto a 150 cercárias.Experimental infection of white mice (Swiss inbred with LE strain Scistosoma mansoni cercariae submitted to the action of magnesium thermophosphate (Tfm, usually used in tropical latosoils, was performed. This product is able to block ovogenesis of planorbid molluscs. In these experimental conditions, rodents were infected. But, the number of eggs released by the control group (five mice was markedly greater than that of the Tfm group, although a short number of worms were recovered by perfusion. From the Tfm group, 163 adult worms (98,2% were recovered and only 3 females (1,8%. Of the control group, perfusion recovered 62 adult worms (22 male worms, 18 female and 11 couples. Each mice was exposed to 150 cercariae.

  10. Production of Shistosoma mansoni cercariae by Biomphalaria glabrata from a focus in Belo Horizonte, Minas Gerais Produção de cercárias de Schistosoma mansoni por Biomphalaria glabrata de foco em Belo Horizonte, Minas Gerais

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    Cecília Pereira de Souza

    1994-12-01

    Full Text Available The snail density, levels of infection and the monthly production of Schistosoma mansoni cercariae by Biomphalaria glabrata were determined in a focus of Barreiro de Baixo (Belo Horizonte, MG, Brazil. During a period of 38 months (1984 to 1987 5,366 snails were collected of which 324 (6.03% were infected with S. mansoni. The total number of cercariae shed was 5,667,312. Each snail shed an average of 17,422 cercariae during the time that it was under study in the laboratory. The greatest longevity of infected snails was 218 days. Natural cure was observed in 42 (12.9% of the infected specimens about 130 days after collection. The average snail density in the focus during the period of study was 16.3 snails per scoop. The shedding of cercariae by snails collected from the field was compared with laboratory bred specimens infected in mass with the LE strain of S. mansoni from Belo Horizonte. The laboratory infected snails shed an average of 6,061 cercariae each, a value 2.8 times less than the field specimens due to a shorter life span. The prevalence of schistosomiasis in the focus was 14.3%.A densidade planorbídica, as taxas de infecção e a produção mensal de cercárias de Schistosoma mansoni por Biomphalaria glabrata, foram determinadas em foco do Barreiro de Baixo (Belo Horizonte MG, Brasil. Durante 38 meses, de 1984 a 1987, foram capturados 5.366 moluscos dentre os quais 324 (6,03% estavam infectados com o S. mansoni. O total de cercárias eliminadas foi de 5.667.312. Cada molusco eliminou em média 17.422 cercárias durante sua permanência no laboratório. A maior longevidade dos moluscos infectados foi de 218 dias. Foi observada a cura natural de 42 (12,9% dos exemplares infectados, após cerca de 130 dias de captura. A densidade planorbídica média, no foco durante esse período foi de 16,3 moluscos por conchada. A eliminação de cercárias pelos moluscos do campo foi comparada com a de exemplares criados no laboratório, infectados

  11. Large-Scale Overproduction and Purification of Recombinant Histone Deacetylase 8 (HDAC8) from the Human-Pathogenic Flatworm Schistosoma mansoni.

    Science.gov (United States)

    Marek, Martin; Shaik, Tajith B; Duclaud, Sylvie; Pierce, Raymond J; Romier, Christophe

    2016-01-01

    Epigenetic mechanisms underlie the morphological transformations and shifts in virulence of eukaryotic pathogens. The targeting of epigenetics-driven cellular programs thus represents an Achilles' heel of human parasites. Today, zinc-dependent histone deacetylases (HDACs) belong to the most explored epigenetic drug targets in eukaryotic parasites. Here, we describe an optimized protocol for the large-scale overproduction and purification of recombinant smHDAC8, an emerging epigenetic drug target in the multicellular human-pathogenic flatworm Schistosoma mansoni. The strategy employs the robustness of recombinant expression in Escherichia coli together with initial purification through a poly-histidine affinity tag that can be removed by the thrombin protease. This protocol is divided into two steps: (1) large-scale production of smHDAC8 in E. coli, and (2) purification of the target smHDAC8 protein through multiple purification steps.

  12. Single versus double dose praziquantel comparison on efficacy and Schistosoma mansoni re-infection in preschool-age children in Uganda

    DEFF Research Database (Denmark)

    Nalugwa, Allen; Nuwaha, Fred; Tukahebwa, Edridah Muheki;

    2015-01-01

    , abdominal pain and bloody diarrhea. Overall re-infection rate 8 months post treatment was 44.5%. CONCLUSIONS: PZQ is efficacious and relatively safe to use in preschool-age children but there is still an unmet need to improve its formulation to suit small children. Two PZQ doses lead to significant......BACKGROUND: Schistosoma mansoni infection is proven to be a major health problem of preschool-age children in sub-Saharan Africa, yet this age category is not part of the schistosomiasis control program. The objective of this study was to compare the impact of single and double dose praziquantel...... (PZQ) treatment on cure rates (CRs), egg reduction rates (ERRs) and re-infection rates 8 months later, in children aged 1-5 years living along Lake Victoria, Uganda. METHODOLOGY/PRINCIPAL FINDINGS: Infected children (n= 1017) were randomized to receive either a single or double dose of PZQ. Initially...

  13. Anti-Arthritic Activity of Schistosoma mansoni and Trichinella spiralis Derived-Antigens in Adjuvant Arthritis in Rats: Role of FOXP3+ Treg Cells

    Science.gov (United States)

    Eissa, Maha M.; Ghazy, Amany A.; El azzouni, Mervat Z.; Boulos, Laila M.; Younis, Layla K.

    2016-01-01

    A growing body of evidence supports the concept of helminths therapy in a variety of autoimmune diseases. Here, we aimed to investigate the protective effects of autoclaved Schistosoma mansoni antigen (ASMA) and Trichinella spiralis antigen (ATSA) on the clinical and immunopathological features of rheumatoid arthritis (RA). Adjuvant arthritis was induced by subcutaneous and intradermal injections of complete Freund’s adjuvant into the plantar surface of the right hind paw and the root of the tail, respectively. Rats were randomly assigned to serve as normal control, untreated arthritis, ASMA or ATSA-treated arthritis groups. Antigens were given by intradermal injection in two doses, two weeks apart. The development, progression of arthritic features, and the impact on animals’ gait and body weight were followed up for 4 weeks. The associated changes in serum cytokines (IL-17, IFN-γ and IL-10), joints’ histopathology and immunohistochemistry of Foxp3+ T regulatory cells (Tregs) were evaluated at the end of the study. Treatment with either ASMA or ATSA attenuated the progression of clinical features of polyarthritis, improved gait and body weight gain, reduced the elevated serum IL-17 and further increased both IFN-γ and IL-10. Histopathologically, this was associated with a remarkable regression of paws’ inflammation that was limited only to the subcutaneous tissue, and a significant increase in the number of Foxp 3+ cells versus the untreated arthritis group. In conclusion, both Schistosoma mansoni and Trichinella spiralis derived antigens exerted protective effect against adjuvant arthritis with better effect achieved by ASMA treatment. This anti-arthritic activity is attributed to upregulation of the Foxp3+ Tregs, with subsequent favorable modulation of both pro- and anti-inflammatory cytokines. The use of autoclaved parasitic antigens excludes the deleterious effects of imposing helminthic infection by using live parasites, which may pave the way to a

  14. Liver and spleen magnetic resonance imaging evaluation in patients with chronic Schistosoma mansoni infection; Avaliacao hepatica e esplenica por ressonancia magnetica em pacientes portadores de esquitossomose mansonica cronica

    Energy Technology Data Exchange (ETDEWEB)

    Bezerra, Alexandre Sergio de Araujo; D' Ippolito, Giuseppe; Caldana, Rogerio Pedreschi; Cecin, Alexandre Oliveira; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Diagnostico por Imagem]. E-mail: alexandrebezerra@ig.com.br

    2004-10-01

    The objective was to qualitatively and quantitatively evaluate the morphological changes of the liver and spleen using magnetic resonance imaging (MRI) in patients with chronic infection by Schistosoma mansoni and the reproducibility of MRI findings in the hepatosplenic evaluation of these patients. We prospectively studied 28 schistosomiasis patients submitted to MRI of the upper abdomen. The scans were performed using a high field equipment (1.5 T), a body coil and a power injector for administration of intravenous contrast. The scans were interpreted by two independent examiners who evaluated the presence of morphological changes in the liver and spleen. Interobserver and intra observer agreement were measured using the kappa and intra class correlation tests. The results showed qualitative variables presenting good interobserver and intra observer agreement ({kappa} {>=} 0.65 and r {>=} 0.66, respectively). The best interobserver agreement was for the anteroposterior diameter of the spleen (r = 0.98). The observers identified reduction of the right hepatic lobe, enlargement of the left hepatic lobe and caudate lobes associated with splenomegaly in almost all patients, and also identified fissure widening, heterogeneity of hepatic parenchyma, irregularity of hepatic contours, presence of peripheral hepatic vessels and peri portal fibrosis in almost all patients. Hepatic morphological changes are characterized by reduction of the right lobe and enlargement of the caudate and left lobes, and morphological changes in the spleen are characterized by the presence of splenomegaly and siderotic nodules. MRI presents high reproducibility for the evaluation of these changes in patients with chronic infection by Schistosoma mansoni. (author)

  15. Sensitivity and Specificity of Multiple Kato-Katz Thick Smears and a Circulating Cathodic Antigen Test for Schistosoma mansoni Diagnosis Pre- and Post-repeated-Praziquantel Treatment

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    Lamberton, Poppy H. L.; Kabatereine, Narcis B.; Oguttu, David W.; Fenwick, Alan; Webster, Joanne P.

    2014-01-01

    Background Two Kato-Katz thick smears (Kato-Katzs) from a single stool are currently recommended for diagnosing Schistosoma mansoni infections to map areas for intervention. This ‘gold standard’ has low sensitivity at low infection intensities. The urine point-of-care circulating cathodic antigen test (POC-CCA) is potentially more sensitive but how accurately they detect S. mansoni after repeated praziquantel treatments, their suitability for measuring drug efficacy and their correlation with egg counts remain to be fully understood. We compared the accuracies of one to six Kato-Katzs and one POC-CCA for the diagnosis of S. mansoni in primary-school children who have received zero to ten praziquantel treatments. We determined the impact each diagnostic approach may have on monitoring and evaluation (M&E) and drug-efficacy findings. Method/Principle Findings In a high S. mansoni endemic area of Uganda, three days of consecutive stool samples were collected from primary school-aged children (six - 12 years) at five time-points in year one: baseline, one-week-post-, four-weeks-post-, six-months-post-, and six-months-one-week-post-praziquantel and three time-points in years two and three: pre-, one-week-post- and four-weeks-post-praziquantel-treatment/retreatment (n = 1065). Two Kato-Katzs were performed on each stool. In parallel, one urine sample was collected and a single POC-CCA evaluated per child at each time-point in year one (n = 367). At baseline, diagnosis by two Kato-Katzs (sensitivity = 98.6%) or one POC-CCA (sensitivity = 91.7%, specificity = 75.0%) accurately predicted S. mansoni infections. However, one year later, a minimum of three Kato-Katzs, and two years later, five Kato-Katzs were required for accurate diagnosis (sensitivity >90%) and drug-efficacy evaluation. The POC-CCA was as sensitive as six Kato-Katzs four-weeks-post and six-months-post-treatment, if trace readings were classified as positive. Conclusions

  16. Fecal Occult Blood and Fecal Calprotectin as Point-of-Care Markers of Intestinal Morbidity in Ugandan Children with Schistosoma mansoni Infection

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    Bustinduy, Amaya L.; Sousa-Figueiredo, José C.; Adriko, Moses; Betson, Martha; Fenwick, Alan; Kabatereine, Narcis; Stothard, J. Russell

    2013-01-01

    Background Calprotectin is a calcium-binding cytoplasmic protein found in neutrophils and increasingly used as a marker of bowel inflammation. Fecal occult blood (FOB) is also a dependable indicator of bowel morbidity. The objective of our study was to determine the applicability of these tests as surrogate markers of Schistosoma mansoni intestinal morbidity before and after treatment with praziquantel (PZQ). Methods 216 children (ages 3–9 years old) from Buliisa District in Lake Albert, Uganda were examined and treated with PZQ at baseline in October 2012 with 211 of them re-examined 24 days later for S. mansoni and other soil transmitted helminths (STH). POC calprotectin and FOB assays were performed at both time points on a subset of children. Associations between the test results and infection were analysed by logistic regression. Results Fecal calprotectin concentrations of 150–300 µg/g were associated with S. mansoni egg patent infection both at baseline and follow up (OR: 12.5 P = 0.05; OR: 6.8 P = 0.02). FOB had a very strong association with baseline anemia (OR: 9.2 P = 0.03) and medium and high egg intensity schistosomiasis at follow up (OR: 6.6 P = 0.03; OR: 51.3 P = 0.003). Both tests were strongly associated with heavy intensity S. mansoni infections. There was a significant decrease in FOB and calprotectin test positivity after PZQ treatment in those children who had egg patent schistosomiasis at baseline. Conclusions Both FOB and calprotectin rapid assays were found to correlate positively and strongly with egg patent S. mansoni infection with a positive ameloriation response after PZQ treatment indicative of short term reversion of morbidity. Both tests were appropriate for use in the field with excellent operational performance and reliability. Due to its lower-cost which makes its scale-up of use affordable, FOB could be immediately adopted as a monitoring tool for PC campaigns for efficacy evaluation before and after

  17. Fecal occult blood and fecal calprotectin as point-of-care markers of intestinal morbidity in Ugandan children with Schistosoma mansoni infection.

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    Amaya L Bustinduy

    2013-11-01

    Full Text Available BACKGROUND: Calprotectin is a calcium-binding cytoplasmic protein found in neutrophils and increasingly used as a marker of bowel inflammation. Fecal occult blood (FOB is also a dependable indicator of bowel morbidity. The objective of our study was to determine the applicability of these tests as surrogate markers of Schistosoma mansoni intestinal morbidity before and after treatment with praziquantel (PZQ. METHODS: 216 children (ages 3-9 years old from Buliisa District in Lake Albert, Uganda were examined and treated with PZQ at baseline in October 2012 with 211 of them re-examined 24 days later for S. mansoni and other soil transmitted helminths (STH. POC calprotectin and FOB assays were performed at both time points on a subset of children. Associations between the test results and infection were analysed by logistic regression. RESULTS: Fecal calprotectin concentrations of 150-300 µg/g were associated with S. mansoni egg patent infection both at baseline and follow up (OR: 12.5 P = 0.05; OR: 6.8 P = 0.02. FOB had a very strong association with baseline anemia (OR: 9.2 P = 0.03 and medium and high egg intensity schistosomiasis at follow up (OR: 6.6 P = 0.03; OR: 51.3 P = 0.003. Both tests were strongly associated with heavy intensity S. mansoni infections. There was a significant decrease in FOB and calprotectin test positivity after PZQ treatment in those children who had egg patent schistosomiasis at baseline. CONCLUSIONS: Both FOB and calprotectin rapid assays were found to correlate positively and strongly with egg patent S. mansoni infection with a positive ameloriation response after PZQ treatment indicative of short term reversion of morbidity. Both tests were appropriate for use in the field with excellent operational performance and reliability. Due to its lower-cost which makes its scale-up of use affordable, FOB could be immediately adopted as a monitoring tool for PC campaigns for efficacy evaluation before and after treatment.

  18. Sensitivity and specificity of multiple Kato-Katz thick smears and a circulating cathodic antigen test for Schistosoma mansoni diagnosis pre- and post-repeated-praziquantel treatment.

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    Poppy H L Lamberton

    2014-09-01

    Full Text Available Two Kato-Katz thick smears (Kato-Katzs from a single stool are currently recommended for diagnosing Schistosoma mansoni infections to map areas for intervention. This 'gold standard' has low sensitivity at low infection intensities. The urine point-of-care circulating cathodic antigen test (POC-CCA is potentially more sensitive but how accurately they detect S. mansoni after repeated praziquantel treatments, their suitability for measuring drug efficacy and their correlation with egg counts remain to be fully understood. We compared the accuracies of one to six Kato-Katzs and one POC-CCA for the diagnosis of S. mansoni in primary-school children who have received zero to ten praziquantel treatments. We determined the impact each diagnostic approach may have on monitoring and evaluation (M&E and drug-efficacy findings.In a high S. mansoni endemic area of Uganda, three days of consecutive stool samples were collected from primary school-aged children (six - 12 years at five time-points in year one: baseline, one-week-post-, four-weeks-post-, six-months-post-, and six-months-one-week-post-praziquantel and three time-points in years two and three: pre-, one-week-post- and four-weeks-post-praziquantel-treatment/retreatment (n = 1065. Two Kato-Katzs were performed on each stool. In parallel, one urine sample was collected and a single POC-CCA evaluated per child at each time-point in year one (n = 367. At baseline, diagnosis by two Kato-Katzs (sensitivity = 98.6% or one POC-CCA (sensitivity = 91.7%, specificity = 75.0% accurately predicted S. mansoni infections. However, one year later, a minimum of three Kato-Katzs, and two years later, five Kato-Katzs were required for accurate diagnosis (sensitivity >90% and drug-efficacy evaluation. The POC-CCA was as sensitive as six Kato-Katzs four-weeks-post and six-months-post-treatment, if trace readings were classified as positive.Six Kato-Katzs (two/stool from three stools and/or one POC-CCA are required

  19. Resistência de Biomphalaria peregrina de Santa Rita do Sapucaí, Minas Gerais, a infecção com três cepas de Schistosoma mansoni Resistance of Biomphalaria peregrina from Santa Rita do Sapucaí, State of Minas Gerais, Brazil, to infection with strain of Schistosoma mansoni

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    Cecília Pereira de Souza

    1988-12-01

    Full Text Available Descendentes do planorbídeo Biomphalaria peregrina, coletados em Santa Rita do Sapucaí, Minas Gerais, Brasil, foram expostos a miracídios de três cepas de Schistosoma mansoni: "LE" de Belo Horizonte, MG; "SJ" de São José dos Campos, SP e "AL" do Estado de Alagoas. Dentre 300 exemplares expostos, nenhum se infectou com as três cepas do trematódeo. Por outro lado, 300 exemplares de B. glabrata, dos grupos de controle, apresentaram taxas de infecção de 61,1 a 95,3% com as três cepas do trematódeo. As taxas de mortalidade de B. peregrina e de B. glabrata foram de 20,0 e de 28,0%, respectivamente.The descendants of the planorbid snail Biomphalaria peregrina, collected in the region of Santa rita do Sapucaí, Minas Gerais, Brazil, were exposed to miracidia of three strains of Schistosoma mansoni: "LE" strain from Belo Horizonte, State of Minas Gerais; "SJ", strain from São José dos Campos, State of São Paulo and "AL" strain from State of Alagoas. Of 300 snails exposed to miracidia of the three strains, none was infected. On the other hand, 300 Biomphalaria glabrata of the control groups showed infection rates of 61.1 to 95.3% with three strains. The mortality rates of B. peregrina and B. glabrata were 20% and 28%, respectively.

  20. Comportamento experimental de amostras de Schistosoma mansoni em relação às formas clínicas de esquistossomose: I. Estudo em camundongos Experimental behavior of samples of Schistosoma mansoni in relation to clinical forms of schistosomiasis: I. Study in mice

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    Mario José da Conceição

    1986-03-01

    ção da doença.Twenty isolates of Schistosoma mansoni were obtained from patients, all males 13 to 30 years old, autochtonous from the Village of Capitão Andrade, municipality of Itanhomi, state of Minas gerais, where an evolutive study of Manson's schistosomiasis is being performed since 1973. The isolates came from six patients with schistosome-infections (type I0, six with the hepato-instestinal form (type Ii, and eight with the hepaoesplenic form (type III. Each isolate was inoculated in mice divided in three groups of 16, exposed to 25, 50 and 100 cercariae, respectively. Controls were 12 uninfected mice. After 90 days adult worms were recovered from the portal by perfusion, from four mice of each experimental groups. Mice dying at various intervals and half of the rest f mice in each group sacrificed on the 90th and the 180th days were studied according to the following parameters: 1 weight of liver, spleen, lung and instestine; 2 egg count in the small intestine (proximal and medial and large intestine (distal. The average numbers of worms obtained by perfusion from groups I, II and III were 21.9%, 22% and 17.8% respectively. The average natural mortality rates of mice submitted to infection with 25,50 and 100 cercariae were, respectively, 12.4%, 23.2% and 40.2% for group I,4.7%, 19.5% and 22.2% for group II and 11.4%, 29.5% and 41.6% for group III, being therefore proportional to the inocula. The weight of the organs of the infected animals and the number of S. mansoni eggs was always proportional to the inoculum and the highest number of eggs were found in the median and proximal portion of the intestines in all three groups. The conclusion was the following: there was no correlation between the clinical forms of schistosomiasis and the behaviour of the isolates of S. mansoni in mice, the parasitological alternations being proportional to the inoculum used and the duration of the infection.

  1. A Crystallin Fold in the Interleukin-4-inducing Principle of Schistosoma mansoni Eggs (IPSE/α-1) Mediates IgE Binding for Antigen-independent Basophil Activation.

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    Meyer, N Helge; Mayerhofer, Hubert; Tripsianes, Konstantinos; Blindow, Silke; Barths, Daniela; Mewes, Astrid; Weimar, Thomas; Köhli, Thies; Bade, Steffen; Madl, Tobias; Frey, Andreas; Haas, Helmut; Mueller-Dieckmann, Jochen; Sattler, Michael; Schramm, Gabriele

    2015-09-04

    The IL-4-inducing principle from Schistosoma mansoni eggs (IPSE/α-1), the major secretory product of eggs from the parasitic worm S. mansoni, efficiently triggers basophils to release the immunomodulatory key cytokine interleukin-4. Activation by IPSE/α-1 requires the presence of IgE on the basophils, but the detailed molecular mechanism underlying activation is unknown. NMR and crystallographic analysis of IPSEΔNLS, a monomeric IPSE/α-1 mutant, revealed that IPSE/α-1 is a new member of the βγ-crystallin superfamily. We demonstrate that this molecule is a general immunoglobulin-binding factor with highest affinity for IgE. NMR binding studies of IPSEΔNLS with the 180-kDa molecule IgE identified a large positively charged binding surface that includes a flexible loop, which is unique to the IPSE/α-1 crystallin fold. Mutational analysis of amino acids in the binding interface showed that residues contributing to IgE binding are important for IgE-dependent activation of basophils. As IPSE/α-1 is unable to cross-link IgE, we propose that this molecule, by taking advantage of its unique IgE-binding crystallin fold, activates basophils by a novel, cross-linking-independent mechanism.

  2. Assessment of the impact of changes in temperature in Biomphalaria glabrata (Say, 1818 melanic and albino variants infected with Schistosoma mansoni (Sambon, 1907

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    E. A. F. Camargo

    Full Text Available Abstract Fluctuations in population density of planorbid hosts of S. mansoni are influenced by climatic factors. The knowledge about interference from changes in water temperature in these populations is an important aspect of the epidemiology of schistosomiasis. In this experiment, it is explored the influence of different temperatures on the development of Schistosoma mansoni in Biomphalaria glabrata melanic and albino variants. The results indicated an intrinsic relationship between temperature and development of the parasite in the intramollusc phase, independent of the pigmentation of the mantle of the molluscs. The higher the temperature, the shorter the period necessary for the development of the parasite was while the higher the mortality of infected mollusks. It is concluded that, in the presence of climate change, the increasement of temperature in cold and flooded regions may encourage the establishment of new foci of transmission of schistosomiasis by changing the geographic extent and extending the epidemiological transmission potential. In warm climates, higher temperatures, however, could compromise the transmission of the disease because of biological stress suffered by parasite and host. Under these conditions, it can result in the death of the parasite or a change in their ability to infect new host species of molluscs in new areas. Mantle pigmentation patterns in molluscs have not shown significant interference in the development of the parasite.

  3. A long-term intake of a protein hydrolysate seems to increase the risk of encephalopathy in mice infected with Schistosoma mansoni

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    Haroldo S Ferreira

    1998-01-01

    Full Text Available Previous investigations showed that Schistosoma mansoni infection aggravates protein malabsorption in undernourished mice and this can be reverted by administration of casein hydrolysate. The present study was undertaken to evaluate the effects of ingestion of casein hydrolysate for long periods. Albino Swiss mice were divided into eight groups. Diets contained 5% (undernourished or 20% (controls casein levels. For each group there were sub-groups ingesting whole or hydrolysed casein for 12 weeks. Infection with S. mansoni developed in half of the animals under each diet. All undernourished mice developed malabsorption. Low albuminemia was detected in infected animals independently of the protein level in the diet. However, albuminemia was lower in infected controls than in undernourished non-infected mice, suggesting a deficient liver protein synthesis. Infected mice fed on a 20% protein hydrolysed diet exhibited low weight gain and high mortality rates. On the other hand, non-infected mice ingesting the same diet had the highest body weights. We are investigating the hypothesis that infected mice, even when fed normal diets, are unable to metabolise large amounts of amino acids due to the liver lesions related to schistosomiasis and as a result die of hepatic coma. In some of them, the excessive accumulation of ammonia in the blood enhances the outcome of an encephalopathy.

  4. In vitro evaluation of permeation, toxicity and effect of praziquantel-loaded solid lipid nanoparticles against Schistosoma mansoni as a strategy to improve efficacy of the schistosomiasis treatment.

    Science.gov (United States)

    de Souza, Ana Luiza Ribeiro; Andreani, Tatiana; de Oliveira, Rosimeire Nunes; Kiill, Charlene Priscila; dos Santos, Fernanda Kolenyak; Allegretti, Silmara Marques; Chaud, Marco Vinícius; Souto, Eliana B; Silva, Amélia M; Gremião, Maria Palmira Daflon

    2014-03-10

    Solid lipid nanoparticles (SLN) are a promising drug delivery system for oral administration of poorly-water soluble drugs because of their capacity to increase the solubility of drug molecules when loaded in their lipid matrices, with the resulting improvement of the drug bioavailability. In the present work, we have developed praziquantel (PZQ)-loaded SLN and explored the biological applications of this system for intestinal permeation of PZQ. The effect in vitro on Schistosoma mansoni culture and the cytotoxicity in HepG2 line cell were also evaluated. The results showed a significant decrease in the intestinal absorption of PZQ loaded in SLN compared to free PZQ, suggesting that the SLN matrix could act as reservoir system. In culture of S. mansoni, we observed that PZQ-loaded SLN were more effective than free PZQ, leading the death of the parasites in less time. The result was proportional to doses of PZQ (25 and 50 μg mL⁻¹) and lipid concentration. Regarding cytotoxicity, the encapsulation of PZQ into SLN decreased the toxicity in HepG2 cells in comparison to the free PZQ. From the obtained results, PZQ-loaded SLN could be a new drug delivery system for the schistosomiasis treatment especially in marginalized communities, improving the therapeutic efficacy and reducing the toxic effects of PZQ.

  5. Validation of a Point-of-Care Circulating Cathodic Antigen Urine Cassette Test for Schistosoma mansoni Diagnosis in the Sahel, and Potential Cross-Reaction in Pregnancy.

    Science.gov (United States)

    Greter, Helena; Krauth, Stefanie J; Ngandolo, Bongo N R; Alfaroukh, Idriss O; Zinsstag, Jakob; Utzinger, Jürg

    2016-02-01

    On the shores of Lake Chad, schistosomiasis among mobile pastoralists was investigated in a field laboratory. Point-of-care circulating cathodic antigen (POC-CCA) cassette test, reagent strip, and filtration were conducted on urine samples. Fresh stool samples were subjected to the Kato-Katz technique, and fixed samples were examined with an ether-concentration method at a reference laboratory. POC-CCA urine cassette tests revealed a Schistosoma mansoni prevalence of 6.9%, compared with only 0.5% by stool microscopy. Three pregnant women with otherwise negative urine and stool testing had positive POC-CCA. This observation raises concern of cross-reactivity in pregnancy. Hence, two pregnant women in Switzerland with no history of schistosomiasis were subjected to POC-CCA and one tested positive. Our data suggest that POC-CCA can be performed under extreme Sahelian conditions (e.g., temperatures > 40°C), and it is more sensitive than stool microscopy for S. mansoni diagnosis. However, potential cross-reactivity in pregnancy needs further investigation.

  6. A Five-Country Evaluation of a Point-of-Care Circulating Cathodic Antigen Urine Assay for the Prevalence of Schistosoma mansoni

    Science.gov (United States)

    Colley, Daniel G.; Binder, Sue; Campbell, Carl; King, Charles H.; Tchuem Tchuenté, Louis-Albert; N'Goran, Eliézer K.; Erko, Berhanu; Karanja, Diana M. S.; Kabatereine, Narcis B.; van Lieshout, Lisette; Rathbun, Stephen

    2013-01-01

    We evaluated a commercial point-of-care circulating cathodic antigen (POC-CCA) test for assessing Schistosoma mansoni infection prevalence in areas at risk. Overall, 4,405 school-age children in Cameroon, Côte d'Ivoire, Ethiopia, Kenya, and Uganda provided urine for POC-CCA testing and stool for Kato-Katz assays. By latent class analysis, one POC-CCA test was more sensitive (86% versus 62%) but less specific (72% versus ∼100%) than multiple Kato-Katz smears from one stool. However, only 1% of POC-CCA tests in a non-endemic area were false positives, suggesting the latent class analysis underestimated the POC-CCA specificity. Multivariable modeling estimated POC-CCA as significantly more sensitive than Kato-Katz at low infection intensities (< 100 eggs/gram stool). By linear regression, 72% prevalence among 9–12 year olds by POC-CCA corresponded to 50% prevalence by Kato-Katz, whereas 46% POC-CCA prevalence corresponded to 10% Kato-Katz prevalence. We conclude that one urine POC-CCA test can replace Kato-Katz testing for community-level S. mansoni prevalence mapping. PMID:23339198

  7. Biomphalaria species distribution and its effect on human Schistosoma mansoni infection in an irrigated area used for rice cultivation in northeast Brazil

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    Delmany Moitinho Barboza

    2012-09-01

    Full Text Available The role of irrigated areas for the spread of schistosomiasis is of worldwide concern. The aim of the present study was to investigate the spatial distribution of the intermediate snail host Biomphalaria in an area highly endemic for schistosomiasis due to Schistosoma mansoni, evaluating the relationship between irrigation and types of natural water sources on one hand, and the influence of place and time of water exposure on the intensity of human infection on the other. A geographical information system (GIS was used to map the distribution of the intermediate snail hosts in Ilha das Flores, Sergipe, Brazil, combined with a clinical/epidemiological survey. We observed a direct correlation between the intensity of human infection with S. mansoni and irrigation projects. Malacological studies to identify snail species and infection rates showed that B. glabrata is the main species responsible for human schistosomiasis in the municipality, but that B. straminea also plays a role. Our results provide evidence for a competitive selection between the two snail species in rice fields with a predominance of B. glabrata in irrigation systems and B. straminea in natural water sources.

  8. Interaction between primary and secondary sporocysts of Schistosoma mansoni and the internal defence system of Biomphalaria resistant and susceptible to the parasite

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    Ana Carolina Alves de Mattos

    2011-06-01

    Full Text Available The outcome of the interaction between Biomphalaria and Schistosoma mansoni depends on the response of the host internal defence system (IDS and the escape mechanisms of the parasite. The aim of this study was to evaluate the responsiveness of the IDS (haemocytes and soluble haemolymph factors of resistant and susceptible Biomphalaria tenagophila lineages and Biomphalaria glabrata lineages in the presence of in vitro-transformed primary sporocysts and secondary sporocysts obtained from infected B. glabrata. To do this, we assayed the cellular adhesion index (CAI, analysed viability/mortality, used fluorescent markers to evaluate the tegumental damage and transplanted secondary sporocysts. B. tenagophila Taim was more effective against primary and secondary sporocystes than the susceptible lineage and B. glabrata. Compared with secondary sporocysts exposed to B. tenagophila, primary sporocysts showed a higher CAI, a greater percentage of dead sporocysts and were labelled by lectin from Glycine max and Alexa-Fluor 488 fluorescent probes at a higher rate than the secondary sporocysts. However, the two B. tenagophila lineages showed no cercarial shedding after inoculation with secondary sporocysts. Our hypothesis that secondary sporocysts can escape the B. tenagophila IDS cannot be confirmed by the transplantation experiments. These data suggest that there are additional mechanisms involved in the lower susceptibilty of B. tenagophila to S. mansoni infection.

  9. Analysis and comparison of immune reactivity in guinea-pigs immunized with equivalent numbers of normal or radiation-attenuated cercariae of Schistosoma mansoni

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    Rogers, M.V.; McLaren, D.J.

    1987-08-01

    Guinea-pigs immunized with equivalent numbers of normal or radiation-attenuated cercariae of Schistosoma mansoni develop close to complete resistance to reinfection at weeks 12 and 4.5 respectively. We here analyse and compare the immune responses induced by the two populations of cercariae. Both radiation-attenuated and normal parasites of S. mansoni elicited an extensive germinal centre response in guinea-pigs by week 4.5 post-immunization. The anti-parasite antibody titre and cytotoxic activity of serum from 4.5-week-vaccinated, or 4.5-week-infected guinea-pigs were approximately equal, but sera from 12-week-infected individuals had high titres of anti-parasite antibody, which promoted significant larvicidal activity in vitro. In all cases, larvicidal activity was mediated by the IgG/sub 2/ fraction of the immune serum. Lymphocyte transformation tests conducted on splenic lymphocytes from 4.5-week vaccinated guinea-pigs revealed maximal stimulation against cercarial, 2-week and 3-week worm antigens, whereas spleen cells from 4.5-week-infected guinea-pigs were maximally stimulated by cercarial and 6-week worm antigens. The splenic lymphocyte responses of 12-week infected animals were dramatic against antigens prepared from all life-stages of the parasite.

  10. The impact of iron supplementation on reinfection with intestinal helminths and Schistosoma mansoni in western Kenya

    DEFF Research Database (Denmark)

    Olsen, Annette; Nawiri, J; Friis, Henrik

    2001-01-01

    higher reinfection rate of hookworm at the 4-month examination (11.1% vs 0%, P = 0.009), but the difference was not significant at 8- and 12-month follow-up examinations. Iron supplementation had no effect on reinfection intensities in adults. Surprisingly, iron supplementation had no effect on either...... immune function or to unfavourable host gut conditions caused by an increased oxidative stress. In each case, the lack of effect in children remains to be explained. In contrast, iron supplementation apparently was short-lived in favour of hookworm infection, an effect that needs further clarification....... The findings suggest that iron supplementation has a role to play in helminth control programmes and that intraluminal factors may contribute to the regulation of some helminth infections....

  11. Humoral and cellular immune responses induced in mice by purified iridoid mixture that inhibits penetration of Schistosoma mansoni cercariae upon topical treatment of mice tails.

    Science.gov (United States)

    Bahgat, Mahmoud; Shalaby, Nagwa M M; Ruppel, Andreas; Maghraby, Amany S

    2005-08-01

    When tested for possible blocking effect on the cercarial, serine proteinase, elastase (CE) activity, an iridoid mixture extracted from leaves of Citharexylum quadrangular abolished 31% of the enzyme activity at final concentration 15 microg. When formulated in jojoba oil and applied to mice tails followed by infection with Schistosoma mansoni cercariae, the iridoid mixture blocked cercarial penetration and caused significant reducetion (94%; P < 0.05) in worm burden in treated mice in comparison to controls. Also, immunomodulatory effects of iridoid mixture, iridoid-treated S. mansoni worm homogenate on mice were studied by measuring IgG and IgM levels against E. coli lysates (ECL), solube S. mansoni worm antigenic preparation (SWAP) and cancer bladder homogenates (CBH) as antigens by ELISA. Cellular immune responses were studied by calculating mean percent of CD4+, CD8(+)-T, B-mesenteric lymph node cells (MLNC) and CD4+, CD8(+)-T thymocytes by direct immunofluorescence staining in treated mice as compared to untreated homogenate given mice or untreated mice. Injecting mice with serial dilutions of iridoid mixture resulted in fluctuation, peaks and troughs, in both IgG and IgM responses against the above mentioned antigens. 1st and 2nd immunizations with iridoid mixture treated homogenate resulted in significantly elevated (P < 0.05). IgM and IgG levels against the 3 used antigens in comparison with sera from control mice. Immunized mice with homogenate treated with iridoid mixture showed a significant increase (P < 0.05) in CD4+T thymocytes, a non significant increase in CD8+T thymocytes, a significant increase (P < 0.05) in CD4+T lymphocytes (MLNC) and a non significant increase in CD8+ T- and B-lymphocytes (MLNC) compared with mice immunized with untreated homogenate or non-injected normal mice.

  12. Study of the snail intermediate hosts for Schistosoma mansoni on Itamaracá Island in northeast Brazil: spatial displacement of Biomphalaria glabrata by Biomphalaria straminea

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    Constança S. Barbosa