Development of a Gaussia luciferase immunoprecipitation assay for detecting Schistosoma japonicum infection.

Timely and accurate diagnosis of Schistosoma infection is important to adopt effective strategies for schistosomiasis control. Previously, we demonstrated that Schistosoma japonicum can secret extracellular vesicles and their cargos may serve as a novel type of biomarkers for diagnosing schistosomiasis. Here, we developed a Gaussia luciferase immunoprecipitation assay combined with S. japonicum extracellular vesicle (SjEV) protein to evaluate its potential for diagnosing schistosomiasis. A saposin-like protein (SjSLP) identified from SjEVs was fused to the Gaussia luciferase as the diagnostic antigen. The developed method showed good capability for detecting S. japonicum infection in mice and human patients. We also observed that the method could detect Schistosoma infection in mice as early as 7 days of post-infection, which showed better sensitivity than that of indirect ELISA method. Overall, the developed method showed a good potential for detecting Schistosoma infection particularly for early stage, which may provide an alternative strategy for identify Schistosoma infection for disease control.

Fluorescent quantum dot-based nanotool for targeted identification and evaluation of the schistosomiasis circulating cathodic antigen in tissue samples.

Schistosomiasis represents a serious public health problem, a disease for which the circulating cathodic antigen (CCA) is a relevant biomarker. Quantum dots (QDs) are advantageous fluorescent nanoparticles that can be used as specific nanoprobes. In this study, a nanotool based on QDs and anti-CCA antibodies was developed, which, in association with fluorescence microscopy, was applied to trace and evaluate the CCA profile in schistosomiasis-infected tissue samples. Kidney and liver tissues from mice at different disease phases were used as models. QDs and the conjugates were characterized by absorption and emission spectroscopies. Microscopy analyses were used to map and assess CCA accumulation in infected tissue slices in respect to non-infected control samples. The fluorescent microplate assay (FMA) and Zeta potential (ζ) analyses indicated an effective conjugation, which was corroborated by the absence of labeling in non-infected tissue slices (which lack CCA) after incubation with the nanoprobe. Infected liver and kidney tissues exhibited notable staining by the QDs-anti-CCA conjugate. The CCA accumulation increased as follows: 30 < 60 = 120 days post-infection, with 30, 60, and 120 days corresponding to the pre-patent, acute, and beginning of chronic disease phases, respectively. Therefore, this innovative approach, combining imaging acquisition with the sensitivity and specificity of the QDs-anti-CCA conjugate, demonstrated efficiency in locating and comparatively evaluating CCA deposition in biological samples, thereby opening new possibilities for schistosomiasis research.

Retrospective analysis of canine fecal flotation and coproantigen immunoassay hookworm positive results in Greyhounds and other dog breeds.

Recent studies demonstrated that Greyhounds are commonly infected with Ancylostoma caninum and these infections have been shown to be resistant to anthelmintics. This study evaluated samples submitted to a commercial reference laboratory (IDEXX Laboratories) for canine fecal flotation zinc sulfate centrifugation and coproantigen immunoassay between January 1, 2019, and July 30, 2023 for evidence that Greyhounds were more often positive for Ancylostoma spp. (hookworms) compared to other breeds. The purpose of the study was to determine if Greyhounds were more likely to be hookworm-positive compared to other breeds, if Greyhounds on preventives with efficacy against hookworm infections are more likely to test positive than other breeds, if their infections take longer to resolve, to estimate how long this takes and to assess whether the proportion of hookworm positive tests for all breeds is increasing over time. Records of 25,440,055 fecal results were obtained representing 17,671,724 unique dogs. Of these, 49,795 (∼0.3%) were Greyhounds. The overall odds ratio (OR) of 15.3 (p < 0.001) suggests that Greyhounds are at significantly higher risk than other breeds for hookworm positive float findings, and the OR of 14.3 (p < 0.001) suggests significantly higher risk for hookworm antigen positive results. The median time to negative testing event from the Turnbull distribution estimate was in the interval of 1-2 days for other breeds and 71-72 days for Greyhounds. These results provide evidence that anthelmintic resistant A. caninum strains may be having population-level impacts on the frequency and duration of infections in Greyhounds. The findings have broader health implications beyond Greyhounds as MADR A. caninum strains could spread to other breeds and even pet owners.

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.

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.

Pulmonary Toxocariasis Mimicking Invasive Aspergillosis in a Patient with Ulcerative Colitis

A 45-year-old-male who had underlying ulcerative colitis and presented with fever and dry cough. Initially, the patient was considered to have invasive aspergillosis due to a positive galactomannan assay. He was treated with amphotericin B followed by voriconazole. Nevertheless, the patient deteriorated clinically and radiographically. The lung biopsy revealed eosinophilic pneumonia, and ELISA for Toxocara antigen was positive, leading to a diagnosis of pulmonary toxocariasis. After a 10-day treatment course with albendazole and adjunctive steroids, the patient recovered completely without any sequelae. Pulmonary toxocariasis may be considered in patients with subacute or chronic pneumonia unresponsive to antibiotic agents, particularly in cases with eosinophilia.

An Outbreak of Trichinosis with Molecular Identification of Trichinella sp. in Vietnam

The 5th outbreak of trichinosis occurred in a mountainous area of North Vietnam in 2012, involving 24 patients among 27 people who consumed raw pork together. Six of these patients visited several hospitals in Hanoi for treatment. Similar clinical symptoms appeared in these patients within 5-8 days after eating infected raw pork, which consisted of fever, muscle pain, difficult moving, edema, difficult swallowing, and difficult breathing. ELISA revealed all (6/6) positive reactions against Trichinella spiralis antigen and all cases showed positive biopsy results for Trichinella sp. larvae in the muscle. The larvae detected in the patients were identified as T. spiralis (Vietnamese strain) by the molecular analysis of the mitochondrial cytochrome c oxidase subunit III (cox3) gene.

Estandarización de la técnica de Western blot para el diagnóstico de la fasciolosis humana utilizando antígenos de excreción-secreción de Fasciola hepática / Western blot technique standardization of the diagnosis of human fasciolosis using Fasciola hepatica excreted-secreted antigens

Objetivos. Evaluar la eficacia de la técnica de electroinmunotransferencia (EITB) o Western blot utilizando antígenos de excreción-secreción de las formas adultas de Fasciola hepatica (Fh E/S Ag) para el diagnóstico de la fasciolosis humana. Materiales y métodos. Los antígenos fueron obtenidos a las 18 horas de incubación en medio Minimum Essential Eagle y preparados a la concentración proteica de 0,15 ug/uL; los cuales, al ser enfrentados con un pool de sueros de pacientes con fasciolosis confirmada por el hallazgo de huevos del parásito en las heces, se detectaron los antígenos de 10, 12, 17, 23, 27, 30, 36, 43, 66 y 136 KDa, con los cuales se desarrolló la técnica de Western blot. La sensibilidad se evaluó empleando sueros de 67 pacientes con fasciolosis, y la especificidad con sueros de 57 pacientes con otras parasitosis y diez sueros de personas no parasitadas. Resultados. De los 67 sueros, 64 reaccionaron con la banda de 23 KDa y 61 con la banda de 17KDa. Estas dos bandas no fueron detectadas por ninguno de los sueros de pacientes con otras parasitosis, ni de personas no parasitadas, siendo por ello consideradas como específicas y diagnósticas. Conclusiones. La sensibilidad de la prueba, utilizando las bandas de 17 y 23 KDa, fue de 95,5 por ciento cuando se presenta reacción positiva en una o en las dos bandas, siendo la especificidad para estos dos antígenos de 100 por ciento con un valor predictivo positivo de 100 por ciento y un valor predictivo negativo de 95,71 por ciento.

Objectives. To evaluate the performance of the enzyme-linked immunoelectrotransfer blot assay (EITB, Western blot) using excretory/secretory antigens from adult forms of Fasciola hepatica (Fh E/S Ag) for the diagnosis of human fasciolosis. Materials and methods. Antigens were obtained after 18 hours of incubation in culture medium Minimum Essential Eagle, prepared at a protein concentration of 0.15 ug/uL and run against a pool of sera of patients with proven fasciolosis (confirmed by the finding of parasite eggs in the stool microscopy). Antigens of 10, 12, 17, 23, 27, 30, 36, 43, 66 and 136 kDa were detected and used to develop the Western blot technique. The sensitivity was evaluated using sera from 67 fasciolosis patients, and the specificity using sera from 57 patients with other parasitic diseases, and 10 from healthy individuals. Results. Out of the 67 sera, 64 reacted with the 23 kDa band and 61 with the one of 17 kDa. These two bands were not detected in sera from patients with other parasitic diseases or in those from healthy volunteers and thus could be considered specific and diagnostic. Conclusions. The sensitivity of the test, using the bands of 17 and 23 kDa, was 95.5 percent for positive reactions to at least one of these two bands, being its specificity 100 percent with a positive predictive value of 100 percent and negative predictive value of 95.71 percent.

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...

Evaluación del efecto protector de 2 inmunógenos de Trchinella spiralis en ratas Long Evans con modificación nutricional e infectado con Trichinella spiralis / Evaluation of the protective effect of 2 inmunogenos of Trchinella spiralis in rats Long Evans with nutritional modification and infected with Trichinella spiralis

La Trichinellosis es una zoonosis endémica, cosmopolita, sus huéspedes son, ratas, cerdo y otros mamíferos entre ellos el hombre, la presencia de Trichinellosis se debe a la ingestión de carne de cerdo insuficientemente cocinada, afecta a países con bajos recursos económicos. Se han caracterizado Inmunógenos, siendo el inmunodominante el de 45 kDa, efectivo contra T. spiralis, desafortunadamente no ha cristalizado en una vacuna. Se han descrito efectos de desnutrición (DN) sobre órganos linfáticos. Los mecanismos de defensa del huésped son alterados con DN proteico-calórico (DPC). Evaluar el efecto protector de 2 inmunógenos de T. spiralis en ratas Long Evans con modificación Nutricional e infectado con T. spiralis. 80 ratas Long Evans de 30 días de edad, divididas en 2 grupos: 40 Nut con 24 de proteína y 40 DN con 12 de proteína de los cuales se subdividieron en 8 sub grupos con tratamiento: a) 10 animales control b)10 animales infectados con T. spiralis, c) 10 animales inmunizados con antígeno soluble total (AST), d) 10 animales inmunizados con inmunógeno de 45 kDa de T. spiralis (esquema de inmunización una aplicación cada semana por 4 ocasiones), retados a la 1era semana de la culminación de inmunización, sacrificadas a la 6 sexta semana post-infección. Parámetros a evaluar: Determinación de la carga parasitaria mediante la Digestión Artificial (D/A), Determinación de las características morfológicas de la célula nodriza por la técnica de compresión de tejidos, detección de la respuesta inmune por WB. Con la técnica de D/A, se obtuvieron en los diferentes tratamientos, de las ratas Nut, DN, Inmunizadas e Infectadas. Mostró diferencia significativa en la cantidad de Ll que se presentaron en 30gr de músculos estriado, los grupos controles de ratas Nut y DN sin infección, ausencia de Ll, y en los grupos de ratas Nut infectadas, se recolectaron 200 µl de Ll, para el grupo de DN infectado se recolecto 400 µl de Ll, en el grupo de Nut inmunizadas con AST.

Influence of the cerebrospinal fluid laboratory parameters in the ELISA test for neurocysticercosis using a total cysticerci antigen

Avaliar se os parâmetros do líquido cefalorraquidiano (LCR) podem influenciar na reatividade da resposta imune específica do LCR na neurocisticercose (NC). Amostras de LCR de 109 pacientes foram analisadas e classificadas em três grupos, de acordo com as manifestações neurológicas e reatividade do teste de Ab-ELISA para NC no LCR. Grupo A, 18 pacientes com enfermidades neurológicas compatíveis com NC e reatividade do teste Ab-ELISA para NC no LCR; grupo B, 50 pacientes com enfermidades neurológicas não compatíveis com NC e reatividade do teste Ab-ELISA para NC no LCR; grupo C, 41 pacientes com enfermidades neurológicas não compatíveis com NC e na ausência de reatividade do teste de Ab-ELISA para NC no LCR. A análise do LCR do grupo A foi compatível com NC. O grupo B apresentou maior freqüência e intensidade da pleocitose, da presença de hemácias no LCR, hiperproteinorraquia, reatividade imune para outros agentes etiológicos em comparação aos grupos A e C (p<0.05). Os dados indicam que o processo inflamatório e os elevados níveis de concentração da proteína no LCR podem influenciar na ocorrência de reações falso positivas de Ab-ELISA para NC. Destacamos a importância da correlação clínico-laboratorial para o diagnóstico de neurocisticercose e o uso de testes laboratoriais confirmatórios.

Antígenos de larvas pulmonares de Ascaris suum reconocidos por anticuerpos producidos en Oryctolagus cuniculus / Ascaris suum lung larvae antigens recognized by antibodies produced in Oryctolagus cuniculus

El presente trabajo tuvo como objetivo determinar mediante la técnica de Western Blot los antígenos de larvas pulmonares de Ascaris suum que son detectados por anticuerpos producidos en Oryctolagus cuniculus inmunizado experimentalmente. Las larvas pulmonares (L3 y L4) fueron obtenidas en 120 ejemplares de Mus musculus cepa BALB/c ratón infectados experimentalmente por vía oral con huevos infectivos de A. suum. Parte de estas larvas fueron cultivadas en el medio Eagle (MEM) para la obtención de antígenos de excreción/secreción y la otra fue sonificada para la obtención de antígenos somáticos, los cuales sirvieron para inmunizar dos ejemplares de O. cuniculus, utilizando Adyuvante Completo e Incompleto de Freund. A las 5 semanas de inmunización se obtuvo sangre de los conejos por punción cardiaca a fin de recuperar el suero, parte del cual fue purificado parcialmente por precipitación salina y diálisis. Mediante la técnica de electroinmuno-transferencia (Western Blot) y usando sueros de los conejos inmunizados se detectaron en los antígenos de excreción/secreción de 20 horas de cultivo reducidos con dithiothreitol, 12 bandas antigénicas de 100, 72.4, 56.2, 42.7, 39.8, 34.6, 31.6, 30.2, 19.5, 16.9, 15.5 y 14.9 KDa, siendo las más reactivas las de 100, 72.4, 16.9, 15.5 y 14.9 KDa. En los antígenos somáticos bajo condiciones de reducción, se detectaron solamente seis bandas de 42.7, 39.8, 34.6, 30.2, 28 y 25.2 KDa de poca reactividad. Estos resultados permiten afirmar que los antígenos de excreción/secreción de A. suum de 20 horas de incubación en el medio MEM inducen la producción de un mayor número de anticuerpos de tipo IgG en conejos inmunizados experimen-talmente.

Excretory/secretory antigens (E/SAg) and somatic antigens (SAg) of Ascaris suum lung larvae that induce the immunoglobulin G antibodies production in Oryctolagus cuniculus experimentally immunized was determined. For this purposes, specimens of Mus musculus BALB/c were inoculated orally with infective eggs of A. suum obtained from pigs naturally parasitized in order to obtain the lung larvae. Part of these larvae was cultured in Minimum Essential Medium (MEM) to obtain E/SAg and another part was sonicated to obtain the SAg too. Both, E/SAg and SAg mixed with complete and incomplete Freund's adjuvant were used for rabbits immunization. Five weeks after the immunization, the rabbits were bled by cardiac puncture obtaining the immunosera by centrifugation, which was purified partially by saline precipitation and dialysis. By using an Western blot technique with purified immunoserum and E/SAg obtained to 20 hours and reduced with dithiothreitol, fourteen antigens bands of 100, 72.4, 56.2, 42.7, 39.8, 34.6, 31.6, 30.2, 19.5, 16.9, 15.5 y 14.9 KD, were detected. The bands of 100, 72.4, 16.9, 15.5 and 14.9 KDa were been the most reactives. Thereby the SAg, also reduced with dithiothreitol, seven bands of 42.7, 39.8, 34.6, 30.2, 28.0 and 25.2 KDa were detected. They were a bit clear. In conclusion, the E/SAg induce the highest production of immunoglobulin G antibodies in rabbits experimentally immunized.

Diagnóstico de las parasitosis intestinales mediante detección de coproantígenos / Diagnostic of intestinal parasitosis by coproantigen detection

Las parasitosis intestinales presentan una alta prevalencia en áreas tropicales y países en desarrollo, pero también son frecuentes en países industrializados. Tradicionalmente, su diagnóstico se ha realizado por el examen microscópico de las heces del paciente. Estas determinaciones muestran una sensibilidad pobre, exigen la toma de muestras seriadas, son muy laboriosas y requieren especialización técnica. En los últimos años, el avance en el estudio molecular de estos parásitos y la investigación de la respuesta inmune específica del paciente, junto con el empleo de las nuevas metodologías diagnósticas, han posibilitado el desarrollo de sistemas de detección más eficaces que apoyan al clínico, permiten el seguimiento de los tratamientos y facilitan los estudios epidemiológicos. Entre ellos, cabe destacar los métodos de detección de coproantígenos, que, en general, presentan buena especificidad y sensibilidad, y además se desarrollan en formatos sencillos, unas propiedades que los convierten en una herramienta útil en los laboratorios de microbiología

Intestinal parasites are highly prevalent in tropical areas and developing countries, but are also common in industrialised countries as well. Traditionally, their diagnosis has been made by microscopic examinations of the faeces of the patient. These have been shown to have poor sensitivity, require serial samples, are very time-consuming and require a specialised technique. In the last few years, advances in the molecular biology of these parasites and research into the specific immune response of the patient, has made it possible to develop more efficient detection systems that help the clinician, allow treatments to be followed up and make it easier to carry out epidemiological studies. Among these systems are the methods for detecting faecal antigens, which, in general, have good specificity and sensitivity; properties which make them a useful tool in microbiology laboratorios

Antigenic enzymes of Schistosoma mansoni: possible use for immunodiagnosis

Different enzymes of Schistosoma mansoni are recognized by IgG antibodies present in the sera of infected human patients. The antigenicity of these enzymes suggests their possible use in immunodiagnostic assays that would take advantage of their activities.

Pesquisa simultânea de antígeno, anticorpo e imunocomplexos específicos no soro de pacientes com esquistossomose crônica / Simultaneous determination of specific antigen, antibody and immune complexes in the serum of patients with chronic schistosomiasis

Säo descritas as principais etapas de uma técnica simples e sensível para a pesquisa, na mesma placa, do antígeno, do anticorpo e de imunocomplexos específicos baseada no "Enzyme-Linked Immunosorbent Assay" (ELISA). A técnica se mostrou de grande utilidade na pesquisa do antígeno, do anticorpo e de imunocomplexos específicos no soro de pacientes com esquistossomose hépato-intestinal crônica

Imunodiagnóstico da neurocisticercose: teste imunoenzimático com antígenos quimicamente ligados a suportes para pesquisa de anticorpos em soro e líquido cefalorraquiano / Neurocysticercosis immunodiagnosis: immunoenzimatic assay with antigens chemically bounded to supports to defect antibodies in CSF and sera

Foi padronizado o teste imunoenzimático, ELISA, utilizando-se componentes antigênicos de Cysticercus cellulosae quimicamente ligados a suportes sólidos constituídos de discos de tecido-resina (ELISA-d), para pesquisa de anticorpos em soro líquido cefalorraquiano (LCR), ensaiando-se uma única diluiçäo do espécime clínico. O suporte tecido-resina foi composto de tecido de poliéster impregnado com resina polimerizada de N-metilol-acrilamida, apresentando grupos N-metilol livres, capazes de reagir covalentemente com grupos funcionais de proteínas e polissacarídeos presentes no extrato antigênico salino total obtido de cisticercos. Foram ensaiados 38 soros e 74 LCR de pacientes com neurocisticercose comprovada e 50 soros e 107 LCR do grupo controle (pacientes com quadros clínicos neurológicos diversos e indivíduos supostamente normais). Obtivemos os seguintes índices de sensibilidade e especificidade: 94,7% e 92,0% para o teste realizado no soro e 98,6% e 100% para o teste realizado no LCR. O teste ELISA-d mostrou-se eficiente para o diagnóstico da neurocisticercose, principalmente quando realizado no LCR, com vantagens de estabilidade, facilidade de execuçäo e baixo custo

Detection of specific IgE antibodies in parasite diseases

Activation of Th1 or Th2 cells is associated with production of specific immunoglobulin isotypes, offering the opportunity to use antibody measurement for evaluation of T cell function. Schistosomiasis and visceral leishmaniasis are diseases associated with Th2 activation. However, an IgE response is not always detected in these patients. In the present study we evaluated specific IgE antibodies to S. mansoni and L. chagasi antigens by ELISA after depletion of serum IgG with protein G immobilized on Sepharose beads or RF-absorbent (purified sheep IgG antibodies anti-human IgG). In schistosomiasis patients, specific IgE to SWAP antigen was demonstrable in only 10 of 21 patients (48 percent) (mean absorbance + or - SD = 0.102 + or - 0.195) when unabsorbed serum was used. Depletion of IgG with protein G increased the number of specific IgE-positive tests to 13 (62 percent) and the use of RF-absorbent increased the number of positive results to 20 (95 percent) (mean absorbances + or - SD = 0.303 + or - 0.455 and 0.374 + or - 0.477, respectively). Specific IgE anti-L. chagasi antibodies were not detected in unabsorbed serum from visceral leishmaniasis patients. When IgG was depleted with protein G, IgE antibodies were detected in only 3 (11 percent) of 27 patients, and the use of RF-absorbent permitted the detection of this isotype in all 27 visceral leishmaniasis sera tested (mean absorbance + or - SD = 0.104 + or - 0.03). These data show that the presence of IgG antibodies may prevent the detection of a specific IgE response in these parasite diseases. RF-absorbent, a reagent that blocks IgG-binding sites and also removes rheumatoid factor, was more efficient than protein G for the demonstration of specific IgE antibodies

Serological, electrophoretic and biological properties of Fasciola hepatica antigens

Fasciola hepatica somatic antigen, its partially purified fractions and excretion-secretion products were investigated as to serological, electrophoretic and biological properties. In a Sephadex G-100 column (SG-100), Fasciola hepatica total antigen (FhTA) gave 5 fractions, and SDS-PAGE analysis showed they were glycoproteins ranging from 14 to 94 kDa molecular weight (MW). When these fractions were analyzed by enzyme-linked immunotransfer blot (EITB) and immunodiffusion in gel (ID) with serum from immunized rats with FhTA, the presence of different antigenic components was revealed. In the SDS-PAGE of excretor-secretor antigen (ESA), it was possible to observe peptides from 12 to 22 kDa, which were also present in FhTA. When the FhTA, its fractions and the ESA were analyzed by EITB with the immune rat serum (IRS), it was observed that only some fractions of the SG-100 shared antigens with the FhTA and ESA. Moreover, DTH and ITH responses were studied in FhTA immunized rats challenged with these different antigen components, revealing that the protein/carbohydrate ratio is important for inducing DTH response. The ESA was the most active component in the DTH and ITH response

Capillaria hepatica: a cause of septal fibrosis of the liver

Fine, long, fibrous septa were observed as a late change developing in the acinar zone III of the liver of rats experimentally infected with the helminth Capillaria hepatica. Hepatic septal fibrosis begun 30 days after inoculation of embryonated eggs into the stomach of rats and became clearly evident from the 40th day onwards. Experimental observation was undertaken for 170 days. Septal fibrosis increased progressively with time and was most marked when the parasitic nodules formed around larvae, disintegrating worms and eggs were involving. Septal fibrosis of the liver has not been previously recognized as a manifestation of hepatic capillariasis. The presence of sequestered parasite antigens, probably being slowly released within the liver, appears to be a major factor in the pathogenesis of hepatic septal fibrosis observed in rats with C. hepatica infection

Teniosis y detección de anticuerpos anticisticerco en personas de una comunidad rural del estado de Guerrero / Taeniosis and detection of antibodies against cysticerci among inhabitants of a rural community in Guerrero State, Mexico

OBJETIVO: Determinar la frecuencia de portadores de Taenia sp. y su relación con el diagnóstico de cisticercos en humanos en una comunidad rural del estado de Guerrero, México. MATERIAL Y MÉTODOS: Para detectar portadores de Taenia sp. se analizaron 403 muestras de heces de personas, por medio de ELISA para coproantígenos de Taenia sp., así como 92 muestras de suero para detectar anticuerpos anticisticerco mediante inmunoelectrotransferencia. El diseño del estudio fue transversal y se llevó a cabo durante 1998. Se hizo estadística descriptiva y se estimó razón de momios. RESULTADOS: De 403 muestras de heces evaluadas, cinco resultaron positivas (1.2 por ciento). Sólo en dos de las cinco personas positivas se obtuvo el cestodo adulto. En 3 (3.26 por ciento) de los 92 sueros se encontraron anticuerpos anticisticerco. Del total de sueros, 17 fueron de las personas con diagnóstico positivo a teniosis por coproantígenos o que cohabitaban con ellos (primer grupo), los restantes 75 provenían de personas en quienes no se detectaron casos en las viviendas (segundo grupo). En el primer grupo se detectaron 2 (11.8 por ciento) sueros positivos, mientras que en el segundo sólo 1 (1.3 por ciento) (RM= 9.87, I.C 0.64-295.56, p= 0.086). CONCLUSIONES: La dificultad para obtener el parásito adulto en las personas positivas a coproantígenos puede deberse a características propias de éste que dificultan su expulsión, a que la permanencia del cestodo en su huésped es menor a la esperada o a que el tratamiento fue insuficiente para obtener el parásito, o bien, a problemas de especificidad de la prueba. Es necesario realizar estudios tendientes a evaluar estas posibilidades, lo cual permitiría conocer mejor la dinámica de transmisión de esta parasitosis, con el fin de establecer medidas de prevención y control, además de poder comparar con mayor veracidad la eficacia de las pruebas diagnósticas en condiciones de campo