Diagnosis of human strongyloidiasis: Application in clinical practice.

This review considers the advantages and disadvantages of parasitological techniques, methods of detecting antibodies and antigens, as well as molecular biology techniques in the diagnosis of human strongyloidiasis. In addition, it elucidates the potential of different techniques for rapid and effective detection of clinical cases, thus enabling early treatment and preventing fatal consequences of this helminthiasis.

Seroepidemiological evidence for Taenia solium taeniasis/cysticercosis in three Venezuelan rural communities.

Taenia solium is the most common parasite infection of the brain, causing neurocysticercosis and typically found in rural communities with free-ranging pigs. Identification of transmission in rural areas is essential for its control. Risk factors and transmission of the parasite were evaluated in three rural Venezuelan communities (Valle del Rio and Potrero Largo, Cojedes state; and Palmarito, Portuguesa state) by a questionnaire (112 households) and coprological (492 samples) and serological (433 human and 230 porcine sera) analysis, respectively. Typical risk factors were found in all three communities: free-foraging pig husbandry, deficient sanitary conditions, high open defecation and ignorance of the parasite life cycle. Coprological examinations revealed a high level of soil-transmitted parasites. Importantly, two T. solium adult worm carriers were identified in each of the three communities. Anti-metacestode antibodies and the HP10 secreted metacestode glycoprotein were detected at significant levels in human and porcine sera in Valle del Rio, Potrero Largo and Palmarito. In conclusion, these communities may be considered to be endemic for taeniasis/cysticercosis, and the instigation of an appropriate control programme is recommended.

Diagnostic value of glycoprotein band patterns of three serologic enzyme-linked immunoelectrotransfer blot assays for neurocysticercosis.

The enzyme-linked immunoelectrotransfer blot (EITB) assay to detect antibodies in serum is a complementary tool for the diagnosis of neurocysticercosis (NCC). Presence of at least one glycoprotein band corresponding to a Taenia solium (T. solium) antigen indicates a positive result; however, EITB assays have multiple glycoprotein bands, and previous work has suggested that band patterns may have additional diagnostic value. We included 58 participants with a definitive diagnosis of NCC who received care at the Instituto Nacional de Neurología y Neurocirugía in Mexico City. Three different EITB tests were applied to participants' serum samples (LDBio, France; US Centers for Disease Control and Prevention [CDC]; and Instituto de Diagnóstico y Referencia Epidemiológicos [InDRE]). There was substantial variability in specific glycoprotein band patterns among the three assays. However, in age- and sex-adjusted logistic regression models, the number of glycoprotein bands was positively associated with the presence of vesicular extraparenchymal cysts (InDRE adjusted odds ratio [aOR] 1.60 p < 0.001; CDC aOR 6.31 p < 0.001; LDBio aOR 2.45 p < 0.001) and negatively associated with the presence of calcified parenchymal cysts (InDRE aOR 0.63 p < 0.001; CDC aOR 0.25 p < 0.001; LDBio aOR 0.44 p < 0.001). In a sensitivity analysis also adjusting for cyst count, results were similar. In all three EITB serum antibody tests, the number of glycoprotein bands consistently predicted cyst stage and location, although magnitude of effect differed.

Diagnosis of Taeniosis in rural Venezuelan communities: Preliminary characterization of a Taenia solium specific monoclonal (VP-1) Coproantigen ELISA.

The objective of this study was to identify and treat carriers of adult Taenia solium present in two rural Venezuelan communities through examination of faecal samples by coproscopical analysis, and by the application of a polyclonal and a monoclonal (VP-1) coproantigen ELISA. Both the polyclonal and monoclonal ELISA's were negative when tested with soluble extracts of adults of Ascaris lumbricoides, Hymenolepis nana and Trichuris trichura. The polyclonal ELISA was positive for soluble extracts adults of T. solium and T. saginata, whereas the monoclonal ELISA, which recognizes a glycoprotein, was restricted to T. solium, and was also negative with faecal samples from five cases of T. saginata adult infections. In the first community studied, Potrero Largo (Total population: 300), of 248 faecal samples examined, 2 individuals were positive for Taenia spp eggs by coproscopical analysis and the VP-1 ELISA, and yielded T. solium adults upon purging. In contrast, when the polyclonal coproAg ELISA was applied to the same 248 faecal samples, there were a considerable number of positives. Indeed, seven patients highly positive in the polyclonal ELISA did not yield a Taenia spp upon purging and were negative in the VP-1 ELISA. In the second community studied La Yuca (Total population 560), none of the 333 individuals who donated faeces was positive for Taenia spp eggs. Many, however, were infected with a range of intestinal helminth and protozoan parasites. A total of 76 faecal samples with representative intestinal parasite were then tested in the polyclonal and VP-1 assays. Of these, many gave an unacceptable number of significant optical densities in the polyclonal coproAg ELISA. In contrast, all were negative in the VP-1 ELISA, thus providing evidence for the species specificity of the VP-1 ELISA in faecal samples. These results with the VP-1 coproAg ELISA, although preliminary, justify further validation through the testing of more faecal samples from T. solium and T. saginata adult infected individuals.

Distribution of Taenia solium Diagnostic Glycoproteins in the Different Developmental Stages of the Parasite.

Taenia solium is a helminth parasite that causes 2 diseases in humans: cysticercosis and taeniasis. The establishment of T. solium metacestodes in the central nervous system causes neurocysticercosis, while development of the adult tapeworm in the small intestine causes taeniasis. Serological diagnosis of neurocysticercosis is performed by Western blot with an enriched fraction of glycoproteins that has been extensively used for clinical diagnosis and epidemiological surveys. The lectin-bound fraction that is used for this assay contains 7 antigenic glycoproteins. These antigenic proteins are considered to be highly specific for cysticercosis when tested with heterologous parasitic diseases. However, recent studies show that people with taeniasis have cross-reactive antibodies against the neurocysticercosis diagnostic glycoproteins and vice versa. Nevertheless, it is not known if these diagnostic proteins are expressed in the adult stage of the parasite. In this paper, we describe the location of 3 of these glycoproteins in T. solium adults and cysticerci using polyclonal antibodies raised against a synthetic peptide based on the amino acid sequence of TS14, a recombinant protein T24H, and the native GP50. The glycoproteins' distribution was different in invaginated and evaginated cysticerci as well as in adult tapeworms. Specifically, the 3 glycoproteins studied were differentially expressed during embryogenesis. Our findings indicate that expression of the diagnostic glycoproteins is developmentally regulated; this is noteworthy since these glycoproteins are considered specific for the diagnosis of neurocysticercosis but nevertheless are present in different structures throughout the development of T. solium. Here we describe the glycoprotein expression and localization, which can be important in understanding their biological functions. In addition, our results help clarify the cross-reaction observed between people with neurocysticercosis and taeniasis to TS14, T24H, and GP50, which are used as diagnostic antigens for neurocysticercosis.

The Advances in Molecular and New Point-of-Care (POC) Diagnosis of Schistosomiasis Pre- and Post-praziquantel Use: In the Pursuit of More Reliable Approaches for Low Endemic and Non-endemic Areas.

Like soil-transmitted helminth infections, schistosomiasis is an important neglected tropical disease (NTD) related to poverty with a major impact on public health in developing countries. Diagnosis of active infection is crucial for surveillance of controlled or post-elimination schistosomiasis areas. In addition, the use of conventional diagnostic tools in non-exposed populations (such as travelers) results in misdiagnoses in the prepatent period of infection. Also, the accuracy of standard tests applied in low-endemicity areas (LEAs) decreases after several rounds of treatment. We aimed to determine whether it would be necessary to replace schistosomiasis conventional diagnostic tests such as parasitological methods in LEAs. Also, we evaluate the use of new tools in non-endemic areas. Reliable, cheap and easy-to-use diagnostic tools are needed to respond to the demands of a new era of elimination and eradication of schistosomiasis. To this end, molecular diagnosis-including nucleic acid-based assays (loop-mediated isothermal amplification, polymerase chain reaction) and circulating cathodic and anodic antigen detection tests have become promising strategies. In this review, we attempt to address the use of alternative diagnostic tests for active infection detection and drug-monitoring after specific schistosomiasis treatment.

Concordance of the point-of-care circulating cathodic antigen test for the diagnosis of intestinal schistosomiasis in a low endemicity area.

BACKGROUND: The Kato-Katz technique is recommended worldwide for the diagnosis of intestinal schistosomiasis, detecting parasite eggs in feces of infected people. However, new tests have been developed in order to facilitate diagnosis, e.g. by detection of specific antigens secreted by schistosomes, such as the circulating cathodic antigen (CCA). The aim of this study was to evaluate the performance of the point-of-care circulating cathodic antigen test (POC-CCA) compared to the Kato-Katz technique in a low prevalence area in the Amazon Region, located in the municipality of Primavera, State of Pará, Brazil. METHODS: Positivity rates of the POC-CCA test and the Kato-Katz technique were calculated. The sensitivity, specificity, accuracy and kappa coefficient were determined by comparing both methods. The reference standard was established using 16 Kato-Katz slides, 12 of the first fecal sample, two of the second and two of the third one. The study also included the concordance between POC-CCA results and different numbers and combinations of Kato-Katz slides. RESULTS: The prevalence of schistosomiasis according to the reference standard or POC-CCA test reached a rate of 9.4% or 23.9%, respectively, among a total of 372 participants. The positivity rates by the Kato-Katz technique increased from 2.4 to 9.4%, according to the increase in the number of slides examined and fecal samples collected. A sensitivity of 55.6%, specificity 76.9%, accuracy 76% and κ coefficient of 0.06 was observed by comparing one slide of the first sample and POC-CCA. Comparing 6 slides from three different samples, two slides of each, with POC-CCA resulted in a sensitivity of 58.3%, specificity 78.4%, accuracy 77% and κ coefficient of 0.16. Finally, the comparison of 16 slides from three different samples with POC-CCA revealed a sensitivity of 65.7%, specificity 80.4%, accuracy 79%, and κ coefficient of 0.27. CONCLUSIONS: The immunochromatographic test has the potential to be an important tool to combat schistosomiasis because of its practicality and applicability but should be applied with caution in low prevalence areas and in programs that aim to eliminate this disease. TRIAL REGISTRATION: CAAE#21824513.9.0000.5091 . January 31st, 2014.

Diagnosis of Schistosoma mansoni infections: what are the choices in Brazilian low-endemic areas?

The population of Brazil is currently characterised by many individuals harbouring low-intensity Schistosoma mansoni infections. The Kato-Katz technique is the diagnostic method recommended by the World Health Organization (WHO) to assess these infections, but this method is not sensitive enough in the context of low egg excretion. In this regard, potential alternatives are being employed to overcome the limits of the Kato-Katz technique. In the present review, we evaluated the performance of parasitological and immunological approaches adopted in Brazilian areas. Currently, the diagnostic choices involve a combination of strategies, including the utilisation of antibody methods to screen individuals and then subsequent confirmation of positive cases by intensive parasitological investigations.

Development and Validation of a Copro-Enzyme-Linked Immunosorbent Assay Sandwich for Detection of Echinococcus granulosus-Soluble Membrane Antigens in Dogs.

Cystic echinococcosis (CE) is a parasitic zoonosis caused by the larval stage of the tapeworm Echinococcus granulosus. Detection of the adult stage in the canine definitive host is essential for estimating infection rates, surveillance and monitoring of CE control programs. This study sought to develop and validate a coproantigen sandwich enzyme-linked immunosorbent assay (copro-ELISA), based on antibodies against E. granulosus-soluble membrane antigens (EGMA), that is capable of distinguishing infected and noninfected dogs. Anti-E. granulosus polyclonal immunoglobulin G antibodies were obtained from rabbit antiserum against EGMA. Optimization of the test was performed with 51 positive and 56 negative stool samples of canine echinococcosis. Specificity, sensitivity, cross-reactivity, intra- and inter-assay precision, and over time detection were evaluated. According to the receiver operating characteristic analysis, the diagnostic sensitivity and specificity were 96.1% (CI: 85.9-99.6) and 98.2% (CI: 89.5-100), respectively. Negative and positive predictive values were 96.5% (CI: 91.7-100) and 98% (CI: 94.1-100), respectively. No cross-reactivity with Taenia hydatigena, Dipylidium caninum, or Toxocara canis was observed. Intra- and inter-assay repeatability showed values of less than 15% of the variation coefficient. The over time detection was from 20 to 27 days postinfection with E. granulosus. The copro-ELISA based on EGMA detection offers a simplified in-house development of diagnostic testing. This assay showed high specificity and sensitivity and had no cross-reactivity with other parasites. Further studies and development of this test in a kit format may be useful for the detection of active infection in dogs living in CE endemic regions.

Evaluating a point-of-care circulating cathodic antigen test (POC-CCA) to detect Schistosoma mansoni infections in a low endemic area in north-eastern Brazil.

Schistosomiasis is still a public health problem in Brazil. The Kato-Katz test is the most frequently used diagnostic method for Schistosoma mansoni infection. However, it lacks sensitivity in areas of low prevalence. We have assessed the positivity rate of S. mansoni infection in Bananeiras, a village on Capistrano, Ceara, Brazil by performing a point-of-care test in urine to determine the circulating cathodic antigens (POC-CCA), and we compared the findings with those of the Kato-Katz technique for egg detection in stool and an enzyme-linked immunosorbent assay for specific antibodies against adult worms (SWAP-ELISA) in serum before treatment (baseline). Additionally, the POC-CCA and Kato-Katz test results were compared at one and two years post-treatment, and only POC-CCA strips were utilised for follow-up testing on urine samples at 3-6 weeks. Only one sample of stool and urine was collected per event. Overall, 258 individuals were investigated at the baseline. The POC-CCA test detected 10 (3.9%) positive cases; however, this amount increased to 30 (11.6%) when considering trace readings as positive (t + ), whereas the Kato-Katz method found only 4 (1.6%) positive cases and the SWAP-ELISA detected 105 (40.7%) positive cases. The consistency observed between a single POC-CCA (t + ) or (t-) and the Kato-Katz (three slides) was poor (Kappa indexes <0.20). The highest positivity rate as determined by CCA and Kato-Katz was found in adults. At the baseline, a praziquantel treatment was administered to all individuals regardless of their infection status. According to the POC-CCA test, 93% of the previous positive cases became negative by the third week after the treatment; this rate reached 100% at the sixth week assessment. The follow-up showed that of the 175 individuals evaluated at one year post-treatment, only one (0.6%) showed 'trace' results, and all the individuals were negative for eggs in the stool. At two years, all 185 examined individuals were negative by the Kato-Katz method, and 11 (5.9%) presented traces by POC-CCA. Our results indicate that a single POC-CCA test reveals a significantly higher number of positive cases than the Kato-Katz technique for diagnosing S. mansoni in a low endemic setting, when trace results are considered as positive cases. Nevertheless, the true significance of the trace is not clear. These findings reinforce the need to associate different tools for improved schistosomiasis diagnosis in individuals with low parasite burdens.

The use of circulating cathodic antigen rapid test and serology for diagnosis of active Schistosoma mansoni infection in migrants in Italy, a non-endemic country: a cross sectional study.

Diagnosis of schistosomiasis in migrants coming from endemic areas can be difficult, especially in asymptomatic subjects. Light-intensity disease, in fact, may be missed due to the low sensitivity of the stool microscopy and serologic testing cannot distinguish between a resolved infection and an active infection in patients who have been infected and treated in the past, because specific antibodies can persist despite cure. We describe a cross-sectional study conducted on 82 migrants tested for Schistosoma mansoni on single blood (anti-schistosome antibodies, total IgE) and urine [point-of-care (POC) circulating-cathodic-antigen (CCA) test] samples. A positive POC-CCA test (active infection) resulted in two untreated patients with a positive serology while all patients (n = 66) with a past infection showed a negative POC-CCA test. POC-CCA urine test in combination with serology may be helpful in rapidly differentiate active from past S. mansoni infection in migrants coming from endemic areas.

The use of circulating cathodic antigen rapid test and serology for diagnosis of active Schistosoma mansoni infection in migrants in Italy, a non-endemic country: a cross sectional study

ABSTRACT Diagnosis of schistosomiasis in migrants coming from endemic areas can be difficult, especially in asymptomatic subjects. Light-intensity disease, in fact, may be missed due to the low sensitivity of the stool microscopy and serologic testing cannot distinguish between a resolved infection and an active infection in patients who have been infected and treated in the past, because specific antibodies can persist despite cure. We describe a cross-sectional study conducted on 82 migrants tested for Schistosoma mansoni on single blood (anti-schistosome antibodies, total IgE) and urine [point-of-care (POC) circulating-cathodic-antigen (CCA) test] samples. A positive POC-CCA test (active infection) resulted in two untreated patients with a positive serology while all patients (n = 66) with a past infection showed a negative POC-CCA test. POC-CCA urine test in combination with serology may be helpful in rapidly differentiate active from past S. mansoni infection in migrants coming from endemic areas.

[Detection of stool antigens of Echinococcus granulosus in dogs belonging to slaughterhouse workers and offal merchants in Metropolitan Lima]. / Detección de coproantígenos de Echinococcus granulosus en canes de trabajadores de camales y comercializadores de vísceras en Lima metropolitana.

OBJECTIVE: To demonstrate the presence of Echinoccocus granulosus in the definitive host in the city of Lima, Perú, by detecting parasite antigens in the stool of dogs belonging to offal handlers and merchants in authorized slaughterhouses in Metropolitan Lima. METHODS: Stool samples were collected from 58 dogs and examined using the coproELISA technique for the detection of secretory/excretory antigens of E. granulosus. A survey was conducted to obtain information on pet feeding and handling practices. RESULTS: Positivity to E. granulosus was detected in 13.8% (8/58) of the dogs. In 27.8% (5/18) of the homes, at least one animal showed positivity, and in families that had more than four dogs the chances of finding positivity in at least one dog were higher (P < 0.05). In all homes where at least one dog tested positive the pets were fed on offal. Of study participants, 94.4% (17) knew nothing about the routes of transmission of hydatid disease. CONCLUSIONS: Results show the presence of definitive hosts in the urban area of Lima and underscore the need to more widely disseminate practices for the prevention of parasite transmission.

Detección de coproantígenos de Echinococcus granulosus en canes de trabajadores de camales y comercializadores de vísceras en Lima metropolitana / Detection of stool antigens of Echinococcus granulosus in dogs belonging to slaughterhouse workers and offal merchants in Metropolitan Lima

RESUMEN Objetivo Demostrar la presencia de Echinoccocus granulosus en el hospedero definitivo en la ciudad de Lima, Perú, mediante la detección de antígenos del parásito en heces de canes pertenecientes a trabajadores y comercializadores de vísceras de centros de beneficio autorizados en Lima metropolitana. Métodos Se recolectaron muestras de heces de 58 canes, que fueron evaluadas utilizando la técnica coproELISA para detectar antígenos secretorio/excretorio de E. granulosus. Mediante una encuesta se obtuvo información sobre las prácticas de alimentación y el manejo de las mascotas. Resultados El 13,8% (8/58) de canes fue positivo a E. granulosus. En 27,8% (5/18) de los hogares se encontró al menos un animal positivo y se estimó que en las familias que tenían más de cuatro canes las posibilidades de encontrar al menos uno positivo eran mayores. En todos los hogares con al menos un can positivo sus mascotas se alimentaban con vísceras. El 94,4% (17) de los participantes no tenía conocimiento de las formas de contagio de la equinococosis. Conclusiones Los resultados muestran la presencia de hospederos definitivos en la zona urbana de Lima y subrayan la necesidad de aumentar la difusión de las prácticas para evitar la transmisión del parasito.

ABSTRACT Objective To demonstrate the presence of Echinoccocus granulosus in the definitive host in the city of Lima, Perú, by detecting parasite antigens in the stool of dogs belonging to offal handlers and merchants in authorized slaughterhouses in Metropolitan Lima. Methods Stool samples were collected from 58 dogs and examined using the coproELISA technique for the detection of secretory/excretory antigens of E. granulosus. A survey was conducted to obtain information on pet feeding and handling practices. Results Positivity to E. granulosus was detected in 13.8% (8/58) of the dogs. In 27.8% (5/18) of the homes, at least one animal showed positivity, and in families that had more than four dogs the chances of finding positivity in at least one dog were higher (P < 0.05). In all homes where at least one dog tested positive the pets were fed on offal. Of study participants, 94.4% (17) knew nothing about the routes of transmission of hydatid disease. Conclusions Results show the presence of definitive hosts in the urban area of Lima and underscore the need to more widely disseminate practices for the prevention of parasite transmission.

Anti-Taenia solium monoclonal antibodies for the detection of parasite antigens in body fluids from patients with neurocysticercosis.

Neurocysticercosis (NCC), an infection of the brain by Taenia solium (Ts) cysts, is the most common cause of adult-onset epilepsy in developing countries. Serological testing consists primarily of varying methods to detect antibodies in body fluids and more recently antigen (Ag) detection assays to identify individuals or animals with viable parasites. Antigen assays currently in use employ monoclonal antibodies (mAbs) raised against T. saginata, which have known cross reactivity to animal cestodes but are highly specific in human samples. We produced, characterized and tested 21 mAbs raised against T. solium whole cyst antigens, vesicular fluid or excretory secretory products. Reactivity of the TsmAbs against specific cyst structures was determined using immunofluorescence and immunohistochemistry on histological sections of Ts muscle cysts. Four TsmAbs reacted to vesicular space alone, 9 to the neck and cyst wall, one to the neck and vesicular space and 7 to the neck, cyst wall and vesicular space. An in-house ELISA assay to detect circulating Ts antigen, using the TsmAbs as capture antibodies and a rabbit polyclonal anti-Ts whole cyst antibody as a detector antibody demonstrated that eight of the 21 TsmAbs detected antigens in known NCC-positive human sera and three of these also in urine samples. Reactivity was expressed as normalized ratios of optical densities (OD positive control/OD negative control). Three TsmAbs had ratios >10 and five between 2 and 10. The TsmAbs have potential utility for the diagnosis and post-treatment monitoring of patients with viable NCC infections.

In Vitro Study of Taenia solium Postoncospheral Form.

BACKGROUND: The transitional period between the oncosphere and the cysticercus of Taenia solium is the postoncospheral (PO) form, which has not yet been completely characterized. The aim of this work was to standardize a method to obtain T. solium PO forms by in vitro cultivation. We studied the morphology of the PO form and compared the expression of antigenic proteins among the PO form, oncosphere, and cysticerci stages. METHODOLOGY/PRINCIPAL FINDINGS: T. solium activated oncospheres were co-cultured with ten cell lines to obtain PO forms, which we studied at three stages of development--days 15, 30, and 60. A high percentage (32%) of PO forms was obtained using HCT-8 cells in comparison to the other cell lines. The morphology was observed by bright field, scanning, and transmission electron microscopy. Morphology of the PO form changed over time, with the six hooks commonly seen in the oncosphere stage disappearing in the PO forms, and vesicles and microtriches observed in the tegument. The PO forms grew as they aged, reaching a diameter of 2.5 mm at 60 days of culture. 15-30 day PO forms developed into mature cysticerci when inoculated into rats. Antigenic proteins expressed in the PO forms are also expressed by the oncosphere and cysticerci stages, with more cysticerci antigenic proteins expressed as the PO forms ages. CONCLUSIONS/SIGNIFICANCE: This is the first report of an in vitro production method of T. solium PO forms. The changes observed in protein expression may be useful in identifying new targets for vaccine development. In vitro culture of PO form will aid in understanding the host-parasite relationship, since the structural changes of the developing PO forms may reflect the parasite's immunoprotective mechanisms. A wider application of this method could significantly reduce the use of animals, and thus the costs and time required for further experimental investigations.

[Study of infestation of dogs with Echinococcus granulosus in the province of La Rioja, Argentina]. / Estudio de infestación de caninos con Echinococcus granulosus en la provincia de La Rioja, Argentina.

This work was conducted in the province of La Rioja, located in northwestern Argentina. The aim of this study was to estimate the percentage of dog feces showing the presence of antigens of Echinococcus sp. in different regions of the province. A total of 269 samples of dried canine stool were taken, which were analyzed by the copro-ELISA technique. The most affected area was zone IV, which had 30.5% of positive samples. Zone I corresponding to the Capital Department of the province had 12% of positivity. In other areas, the percentages ranged between 11.4% and 14.8%. This is the first study in the province of La Rioja on the existence of this disease in dogs. The lack of control strategies has allowed the spread of echinococcosis.

Perfil proteico da hemolinfa de Biomphalaria glabrata e linhagens de B. straminea, frente à exposição ao Schistosoma mansoni / Protein profile of hemolymph of Biomphalaria glabrata and strains of B. straminea, against the exposure to the Schistosoma mansoni

O gênero Biomphalaria possui espécies de grande relevância médica uma vez que atuam como hospedeiros intermediários naturais do parasita Schistosoma mansoni, causador da esquistossomose. Dentro desse gênero de moluscos, três espécies são tidas como hospedeiros naturais do parasita, Biomphalaria glabrata, B. straminea e B. tenagophila. O perfil de suscetibilidade à infecção por S. mansoni dentro do gênero é muito variado e muitas pesquisas buscam elucidar a dinâmica da relação parasita-hospedeiro intermediário na finalidade de criar novas medidas de controle da doença. Por isso, esse estudo tem como objetivo determinar o perfil bidimensional de proteínas que podem estar envolvidas na resposta imune contra o S. mansoni comparando duas espécies com diferentes perfis de susceptibilidade B. glabrata, B. straminea além de uma refratária ao S. mansoni, a B. straminea R3. Para isso, os caramujos de cada espécie foram divididos em dois grupos: Infectado, expostos aos miracídios do S. mansoni; e Controle, submetidos ao estresse do processo de infecção livre de miracídios. A hemolinfa foi retirada 24 horas após a exposição. Foi feito o extrato proteico total e determinada a concentração das proteínas totais para cada grupo investigado. As proteínas foram separadas por eletroforese bidimensional onde foi obtido o ponto isoelétrico e peso molecular de todos os spots nos géis...

The Biomphalaria has species of great medical relevance since that act as natural intermediate hosts of the parasite Schistosoma mansoni, which causes schistosomiasis. Within this kind of mollusks, three species are considered natural hosts of the parasite, Biomphalaria glabrata, B. stramineaand B. tenagophila. The profile of usceptibility to S. mansoni infection within the genre is very varied and many studies seek to elucidate the dynamics of host-parasite relationship intermediary in order to create new disease control easures. Therefore, this study aims to determine the two-dimensional profile of proteins that may be involved in the immune response against S. mansonicomparing two species with different susceptibility profiles B. glabrata, B. straminea and a refractory to S. mansoni, B. straminea R3. For that, the snails of each species were divided into two groups: Infected exposed to iracidia of S. mansoni; and control, subjected to stress the miracidia free infection process. The hemolymph was removed 24 hours after exposure. It was made the total protein extract and determined the concentration of total protein for each group investigated. Proteins were separated by two-dimensional electrophoresis was obtained where the isoelectric point and molecular weight of all the spots in the gels...

Serological screening of the Schistosoma mansoni adult worm proteome.

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.