Synthetic peptides as an antigenic base in an ELISA for laboratory diagnosis of schistosomiasis mansoni.

A pool of five synthetic peptides was used as an antigenic base in an ELISA (ELISA-Pp) for laboratory diagnosis of Schistosoma mansoni. Serum samples were obtained from individuals with acute (n=23) and chronic (n=30) schistosomiasis, with other parasitoses (n=39) or without parasitic infections (n=100). ELISA-Pp was compared with other immunoenzymatic methods for detection of IgM (IgM-ELISA) or IgG (IgG-ELISA) as well as an immunofluorescence test for detection of IgM antibodies (IgM-IFT). The sensitivity and specificity of ELISA-Pp was 86.8% and 94.2% when tested on the schistosomiasis group and the non-schistosomiasis group, respectively. Comparison of ELISA-Pp with other serological methods resulted in kappa concordance indices varying from 0.59 to 0.75. Evaluation of anti-peptide IgG antibodies showed higher levels in patients with acute compared with chronic schistosomiasis (P=0.001). ELISA-Pp showed satisfactory sensitivity and high specificity and may constitute a potentially useful method for laboratory diagnosis of schistosomiasis mansoni.

Genotypic identification of Cryptosporidium spp. isolated from HIV-infected patients and immunocompetent children of São Paulo, Brazil.

Cryptosporidium isolates identified in fourteen stool samples, collected from five HIV-infected patients and nine immunocompetent children, living in the State of São Paulo, Brazil, were submitted to a molecular analysis using a nested PCR followed of restriction fragment length polymorphism (RFLP), for genetic characterization. The analysis was based on digestion with RsaI restriction enzyme of a DNA fragment amplified from the Cryptosporidium oocyst wall protein (COWP) gene. Based on this analysis, four samples were identified as Cryptosporidium parvum, eight as Cryptosporidium hominis and two presented a profile that corresponded to Cryptosporidium meleagridis when compared to the standards used in the analysis. The use of molecular methods can be helpful to identify source of infections and risk factors related to Cryptosporidium infection in our communities.

[Serology as a diagnostic tool for surveillance and control of schistosomiasis in Holambra, São Paulo State, Brazil]. / Utilização de método sorológico como ferramenta diagnóstica para implementação da vigilância e controle da esquistossomose no Município de Holambra, São Paulo, Brasil.

The present study aimed to evaluate the incorporation of the immunofluorescence test (IFT) with adult parasite paraffin sections as antigen substrate for the detection of IgM antibodies (IgM-IFT), as a diagnostic method in the schistosomiasis control program in the county (municipality) of Holambra, São Paulo State, Brazil. This city was selected for this study based on its low endemicity for schistosomiasis, the first cases having been reported in 1993, and because of the need to implement a control program with more sensitive diagnostic techniques. 202 individuals underwent IgM-IFT, with 48 serologically positive cases; of these, 28 were tested with the Kato-Katz technique, using three stool samples. Schistosoma mansoni eggs were found in 14 individuals, with egg counts varying from 2.7 to 224 per gram of stool. The results indicate the potential usefulness of IgM-IFT as a screening test, subject to subsequent confirmation using a parasitological method, in low-endemic areas for schistosomiasis.

Seroepidemiological aspects of human infection by Strongyloides stercoralis in Alfenas, southern Minas Gerais, Brazil.

INTRODUCTION: In most Strongyloides stercoralis infected individuals, nematoidosis occurs asymptomatically, but in immunocompromised patients, it can cause hyperinfection. Serological techniques seem to be a good alternative for detecting this parasite. METHODS: The frequency of seropositivity for strongyloidiasis in Alfenas, MG, was estimated using the enzyme linked immunosorbent assay on blood samples, between May and August of 2015. RESULTS: Out of 258 samples tested, 53.9% were positive, and the frequency of seropositive individuals was higher in the peripheral districts of the municipality. CONCLUSIONS: The results indicate high seropositivity rates for strongyloidiasis among the residents of Alfenas city.

Characterization of a clone from an adult worm cDNA library selected with anti-Schistosoma mansoni human antibodies dissociated from immune complexes: a preliminary report.

Considering the scarcity of defined antigens, actually useful and reliable for use in the field studies, we propose an alternative method for selection of cDNA clones with potential use in the diagnosis of schistosomiasis. Human antibodies specific to a protein fraction of 31/32 kDa (Sm31/32), dissociated from immune complexes, are used for screening of clones from an adult worm cDNA library. Partial sequencing of five clones, selected through this strategy, showed to be related to Schistosoma mansoni: two were identified as homologous to heat shock protein 70, one to glutathione S-transferase, one to homeodomain protein, and one to a previously described EST (expressed sequence tag) of S. mansoni. This last clone was the most consistently reactive during the screening process with the anti-Sm31/32 antibodies dissociated from the immune complexes. The complete sequence of this clone was obtained and the translation data yielded only one ORF (open reading frame) that code for a protein with 57 amino acids. Based on this amino acid sequence two peptides were chemically synthesized and evaluated separately against a pool of serum samples from schistosomiasis patients and non-schistosomiasis individuals. Both peptides showed strong reactivity only against the positive pool, suggesting that these peptides may be useful as antigens for the diagnosis of schistosomiasis mansoni.

Leishmania infantum INFECTION IN DOGS FROM THE SOUTHERN REGION OF MINAS GERAIS STATE, BRAZIL.

Visceral leishmaniasis is a systemic and chronic disease and dogs are the main reservoir of the etiologic agent, Leishmania infantum (syn L. chagasi). A serological and molecular investigation of canine visceral leishmaniasis (CVL) was performed in the municipality of Alfenas, located in the southern region of Minas Gerais, where the disease is not endemic. Samples from 87 dogs were submitted to serological tests including the Dual Path Platform (DPP (r) ) CVL Bio-Manguinhos rapid test, an in-house enzyme-linked immunosorbent assay (ELISA) and an immunofluorescence antibody test (IFAT), as well as molecular techniques such as a conventional polymerase chain reaction (PCR) with the RV1/RV2 primers and a quantitative PCR (qPCR) with the LinJ31, Ldon and DNApol primers. Of the 87 serum samples, eight (9.2%) were positive for Leishmania using the DPP rapid test, but only four (4.6%) were confirmed by ELISA and two (2.3%) by IFAT. In these two serologically confirmed cases, spleen and liver samples were positive by all the employed molecular and parasitological procedures performed on spleen samples. When whole blood samples were used in the molecular assays, two samples (2.3%) were positive only by qPCR. DNA extracted and amplified from the spleens of seropositive dogs was sequenced, showing 100% of similarity with the Leishmania infantum (syn L. chagasi) sequence. Thus, the first cases of CVL have been confirmed in the Alfenas region, suggesting the importance of canine surveys in non-endemic municipalities for CVL to monitor disease progression and to prevent outbreaks.

Seroepidemiological aspects of human infection by Strongyloides stercoralis in Alfenas, southern Minas Gerais, Brazil

Abstract INTRODUCTION: In most Strongyloides stercoralis infected individuals, nematoidosis occurs asymptomatically, but in immunocompromised patients, it can cause hyperinfection. Serological techniques seem to be a good alternative for detecting this parasite. METHODS The frequency of seropositivity for strongyloidiasis in Alfenas, MG, was estimated using the enzyme linked immunosorbent assay on blood samples, between May and August of 2015. RESULTS: Out of 258 samples tested, 53.9% were positive, and the frequency of seropositive individuals was higher in the peripheral districts of the municipality. CONCLUSIONS: The results indicate high seropositivity rates for strongyloidiasis among the residents of Alfenas city.

Prevalence and risk factors for intestinal parasitic infections in children attending daycare centers in Alfenas, southern Minas Gerais, Brazil

Intestinal parasitic infections are common among pre-school children in developing countries and they are often associated with gastrointestinal morbidity such as chronic diarrhea and malnutrition. Their circulation is mainly associated with lack of personal hygiene and environmental sanitation, as well as limited housing and food conditions. As the diagnosis of intestinal parasites is not a simple procedure, especially in population studies, due to difficulties encountered in strategies to obtain fecal samples, reliable prevalence data are scarce. Indeed, the epidemiological data on the prevalence of these parasites in different locations are important for the development of appropriate control measures. This study aimed to investigate the prevalence and risk factors associated with intestinal parasitic infection in children attending three public municipal daycare centers in Alfenas, MG. Three fecal samples from each child were collected on alternate days and processed by the spontaneous sedimentation technique and also through the commercially available centrifugal concentration technique, known as the TF-Test® (TFT). Information on the biological, social and physical environment, in which the children lived, were obtained through the application of a socio-epidemiological questionnaire to the parents or guardians and daycare staff. Giardia duodenalis was the parasite species most frequently detected among the children, with a positive rate of 27.8% (77/277). Entamoeba coli was detected in one of the daycare centers studied, with positivity rate of 43.7%, (7/16); and helminth infection in only two children. The present study showed that children of municipal daycare centers in Alfenas could be at risk of infection by intestinal parasites.

Aspectos epidemiológicos da esquistossomose em área do sudoeste de Minas Gerais, Brasil / Epidemiological aspects of schistosomiasis in area at the southwest of Minas Gerais, Brazil

This study was developed aiming at contributing to the schistosomiasis surveillance, within the scope of the Regional Health Superintendence of Alfenas, MG, in the South/Southwest mesoregion of the state, considered not endemic for schistosomiasis, unlike North and Northeast areas of the state. During the year of 2015, schoolchildren and migrants from two municipalities of this region, Arceburgo and Guaranésia, underwent parasitological and serological surveys. In the parasitological survey, no case of schistosomiasis was detected in Arceburgo. In Guaranésia, S. mansoni eggs were detected among the migrants, with a positivity rate of 13.6% (9/66), and in only one schoolchild. Seven members of his family, who were classified as residents of Guaranésia, but were determined as coming from Timbaúba, PE, when investigated by the epidemiological surveillance, they were also positive for S. mansoni. In the serological survey, the positivity for schistosomiasis was 18.5% among migrants from Guaranésia. Concerning the other intestinal parasites, the positivity rates ranged from 12.5% to 32.3%. The results suggest differences in the risk of exposure to S. mansoni and the importance of epidemiological surveillance, even in non-endemic areas, with a focus on migrants when they come from endemic regions for schistosomiasis.

Este estudo foi desenvolvido com o objetivo de contribuir com a vigilância da esquistossomose, no âmbito da Superintendência Regional de Saúde de Alfenas, MG, na mesorregião Sul/Sudoeste do estado, considerada não endêmica para a esquistossomose, ao contrário de outras áreas ao norte e nordeste do estado. Durante o ano de 2015, os escolares e migrantes de dois municípios dessa região, Arceburgo e Guaranésia, foram submetidos aos inquéritos parasitológico e sorológico. No inquérito parasitológico, nenhum caso de esquistossomose foi detectado em Arceburgo. Em Guaranésia, ovos de S. mansoni foram detectados entre os migrantes, com taxa e positividade de 13,6% (9/66), e em um único estudante. Sete membros da família, classificada como moradora de Guaranésia, mas determinada como oriunda de Timbaúba, PE quando investigada pela vigilância epidemiológica, foram também positivos para S. mansoni. No inquérito sorológico, a positividade para esquistossomose foi de 18,5% entre os migrantes de Guaranésia. Em relação às demais parasitoses, as taxas de positividade variaram de 12,5% a 32,3%. Os resultados sugerem diferenças em relação ao risco de exposição a S. mansonie a importância da vigilância epidemiológica, mesmo em áreas não endêmicas, com foco nos migrantes, quando estes são oriundos de regiões endêmicas para esquistossomose.

[Occurrence of Cryptosporidium spp. in a dairy cattle herd from Caçapava Municipality, São Paulo State, Brazil]. / Ocorrência de Cryptosporidium spp. em um rebanho bovino leiteiro no Município de Caçapava, Estado de São Paulo, Brasil.

Occurrence of Cryptosporidium spp. was investigated in a Brazilian dairy farm over the course of 1 year. Cattle of different aged were employed and divided into seven groups: 0-2 months; 2-4 months; 4-6 months; 6- 10 months; 10-16 months; 16-24 months; > 24 months. Fecal samples were collected from a total of 849 animals in six times. These samples were evaluated by centrifugal flotation method using a sucrose solution. Herd occurrence for C. parvum was 0.6%, varied by month of sample collection from 0 to 1.4%. The highest frequency of C. parvum was found in animals 0-2 months old with oocysts in 3 of the 61 samples (4.9%). Herd occurrence for C. andersoni was 0.1%, varied by month of sample collection from 0 to 0.7%. Only one cow was found infected for C. andersoni.

Application of synthetic peptides in development of a serologic method for laboratory diagnosis of schistosomiasis mansoni.

The immunoreactivity of seven peptides synthesized from Schistosoma mansoni proteins, was evaluated by dot-blot and ELISA assays using two different sensitization methodologies. The best results were obtained on wells of the Costar 3590 microplates coated with peptides P1, P2, P3, P6, and P7 using conventional methodology. The signals increased considerably (p < 0.0003) on wells sensitized with P1 to P6 using alternative methodology. In contrast, the well coated with peptide P7 presented lower signal when compared with conventional methodology (p = 0.0019). These results, establish the basis for the application of synthetic peptides for laboratory diagnosis of schistosomiasis mansoni.

Efficacy of an enzyme-linked immunosorbent assay as a diagnostic tool for schistosomiasis mansoni in individuals with low worm burden.

IgM-ELISA is an immunoenzymatic method useful for detection of IgM antibodies against a fraction of Schistosoma mansoni adult worm antigen (AWA) that is soluble in trichloroacetic acid (AWA-TCA). This method was applied to three groups of individuals with different clinical and epidemiological characteristics, and the results compared with those obtained by other diagnostic methods: immunofluorescence test for detection of IgM antibodies (IgM-IFT) or IgG antibodies (IgG-IFT), ELISA for detection of IgG antibodies (IgG-ELISA), and two parasitological methods, Kato-Katz and miracidium hatching. The IgM-ELISA presented a sensitivity of 98%, when the parasitologic fecal examination was defined as reference diagnostic method, and a specificity of 98 and 97.3%, respectively for the group of clinically healthy individuals and other helminth carriers. A comparative analysis between the results of IgM-ELISA and those obtained by other serologic tests showed a good degree of agreement, with Kappa indices ranging from 0.95 to 0.98. The diagnostic efficacy of 97.8%, as determined with schistosomiasis patients with low parasitic burden, suggests the excellent performance of the IgM-ELISA and its usefulness for the diagnosis of schistosomiasis when applied in low endemic areas.

IgM-immunofluorescence test as a diagnostic tool for epidemiologic studies of Schistosomiasis in low endemic areas.

The high sensitivity and the ability to diagnose schistosomiasis in a very early phase after infection have indicated the detection of IgM antibodies to Schistosoma mansoni gut antigens by the immunofluorescence test (IgM-IFT) as a useful serological test for epidemiological studies in low endemic areas. When applied in a follow-up study for two years, higher rates of seroconversion from IFT negative to positive were observed during the summer months, suggesting seasonal transmission of schistosomiasis in the rural area of the municipality of Itariri (São Paulo, Brazil). In each survey, blood samples from about 600 schoolchildren were collected on filter paper and submitted to IgM-IFT. When the blood samples were classified for the IgM antibody levels, according to the intensity of fluorescent reaction observed at fluorescence microscopy, and correlated to the egg counts in the Kato-Katz positive patients, no association was observed. This observation might suggest that the intensity of fluorescence observed in the IgM-IFT, as an indicator of IgM antibody levels, could not be an useful seroepidemiological marker for classifying areas of low endemicity according to degrees of infection.

Schistosomiasis mansoni: follow-up of control program based on parasitologic and serologic methods in a Brazilian community of low endemicity.

A field survey on schistosomiasis was carried out in 1998, in the municipality of Pedro de Toledo, a low endemic area in the state of São Paulo, Brazil. According to the parasitologic Kato-Katz method, the prevalence rate was 1.6%, with an infection intensity of 40.9 eggs per gram of stool. By the immunofluorescence test (IFT) for detection of IgG and IgM antibodies in the serum, IgG-IFT and IgM-IFT, respectively, prevalence indices of 33.2% and 33.5% were observed. To assess the impact of the schistosomiasis control program in the area, parasitologic and serologic data obtained in 1998, analyzed according to the age, sex, and residence zone, were compared to previous data obtained in a epidemiologic study carried out in 1980, when prevalence indices were of 22.8% and 55.5%, respectively by Kato-Katz and IgG-IFT. A significant fall of the prevalence was observed, indicating that the control measures were effective. Nonetheless, residual transmission was observed, demonstrating the need for a joint effort to include new approaches for better understanding the real situation and improving the control of the disease in low endemic areas.

Utilização de método sorológico como ferramenta diagnóstica para implementação da vigilância e controle da esquistossomose no Município de Holambra, São Paulo, Brasil / Serology as a diagnostic tool for surveillance and control of schistosomiasis in Holambra, São Paulo State, Brazil

O presente estudo teve como objetivo avaliar a incorporação da reação de imunofluorescência indireta para pesquisa de anticorpos IgM (RIF-IgM) como método diagnóstico no programa de controle da esquistossomose do Município de Holambra, Estado de São Paulo, Brasil. O município foi selecionado para este estudo considerando-se a notificação dos primeiros casos de esquistossomose a partir de 1993 e a necessidade do município de implementar o programa com técnicas diagnósticas mais sensíveis, tendo em vista ser caracteristicamente área de baixa endemicidade. Duzentos e dois indivíduos foram submetidos à RIF-IgM, dos quais 48 apresentaram-se positivos, sendo 28 destes submetidos à técnica de Kato-Katz, examinando-se três amostras de fezes. Ovos de Schistosoma mansoni foram encontrados em 14, com carga parasitária variando de 2,7 a 224,0 ovos por grama de fezes. Os resultados indicam a potencialidade da RIF-IgM como método de triagem, para posterior confirmação exaustiva por método parasitológico, em áreas de baixa endemicidade.

The present study aimed to evaluate the incorporation of the immunofluorescence test (IFT) with adult parasite paraffin sections as antigen substrate for the detection of IgM antibodies (IgM-IFT), as a diagnostic method in the schistosomiasis control program in the county (municipality) of Holambra, São Paulo State, Brazil. This city was selected for this study based on its low endemicity for schistosomiasis, the first cases having been reported in 1993, and because of the need to implement a control program with more sensitive diagnostic techniques. 202 individuals underwent IgM-IFT, with 48 serologically positive cases; of these, 28 were tested with the Kato-Katz technique, using three stool samples. Schistosoma mansoni eggs were found in 14 individuals, with egg counts varying from 2.7 to 224 per gram of stool. The results indicate the potential usefulness of IgM-IFT as a screening test, subject to subsequent confirmation using a parasitological method, in low-endemic areas for schistosomiasis.

Genotypic identification of Cryptosporidium spp. isolated from hiv-infected patients and immunocompetent children of São Paulo, Brazil / Identificação genotípica de Cryptosporidium spp. isolados a partir de pacientes com HIV e crianças imunocompetentes de São Paulo, Brasil

Cryptosporidium isolates identified in fourteen stool samples, collected from five HIV-infected patients and nine immunocompetent children, living in the Sate of São Paulo, Brazil, were submitted to a molecular analysis using a nested PCR followed of restriction fragment length polymorphism (RFLP), for genetic characterization. The analysis was based on digestion with RsaI restriction enzyme of a DNA fragment amplified from the Cryptosporidium oocyst wall protein (COWP) gene. Based on this analysis, four samples were identified as Cryptosporidium parvum, eight as Cryptosporidium hominis and two presented a profile that correspondedto Cryptosporidium meleagridis when compared to the standards used in the analysis. The use of molecular methods can be helpful to identify source of infections and risk factors related to Cryptosporidium infection in our communities.

Isolados de Cryptosporidium identificados em quatorze amostras de fezes, coletadas de cinco pacientes com infecção por HIV e de nove crianças imunocompetentes, residentes no estado de São Paulo, Brasil, foram submetidos a análise molecular por Nested-PCR, seguido da caracterização genética por polimorfismo do tamanho do fragmento de restrição (RFLP). A análise foi baseada na digestão, com a enzima de restrição RsaI, de um fragmento de DNA amplificado do gene que codifica a proteína de parede do oocisto de Cryptosporidium (COWP). Baseado nesta análise, quando comparadas aos padrões utilizados, quatro amostras foram identificadas como Cryptosporidium parvum, oito como Cryptosporidium hominis e duas apresentaram um perfil correspondente ao de Cryptosporidium meleagridis. O uso de métodos moleculares pode ser útil para identificar a fonte das infecções e os fatores de risco relacionados à infecção por Cryptosporidium em nossas comunidades.

Estudo de fatores socioambientais associados á ocorrência de leishmaniose tegumentar americana no município de Ubatuba, SP, Brasil / Study of social and environmental factors associatedn to the ocurrence of american tegumentary leishmaniasis in the municipality of Ubatuba, SP, Brazil

O objetivo deste estudo foi avaliar a influência de alguns fatores ambientais, como pluviometria e temperatura, na incidência de Leishmaniose Tegumentar Americana (LTA), no município de Ubatuba, Estado de São Paulo, Brasil, em 2003, e identificar condições socioeconômicas associadas à ocorrência da doença na região. O município de Ubatuba está situado no litoral norte do Estado de São Paulo, onde o clima é caracterizado como tropical úmido. Com uma extensa área de vegetação natural, Lutzomyia intermedia é a espécie predominante do flebotomíneo transmissor. Em 2003, foram notificados em Ubatuba 60 casos de LTA, o que caracterizou um pico epidêmico, quando comparado aos dados de anos anteriores. Através de visitas domiciliares e aplicação de um formulário, foram coletados de todos os 60 pacientes com LTA, notificados em 2003, dados sobre aspectos socioambientais, como: tipo, tamanho e local das residências, distância entre estas e a borda da mata, escolaridade, atividade ocupacional, renda per capita e grau de conhecimento sobre a doença. A ocorrência de LTA não foi associada à história de ocupação recente ou a grupo específico, seja quanto à faixa etária ou ao tipo de atividade laborativa, nem a variações anuais de temperatura e pluviometria. A ação antrópica ao meio ambiente apresentou-se como fator importante para aquisição da infecção, tendo sido identificada como um dos fatores de risco a pequena distância entre as moradias e a borda da mata, que era menor que 50 metros para a maioria (86,5%) dos doentes entrevistados.

Characterization of a clone from an adult worm cDNA library selected with anti-Schistosoma mansoni human antibodies dissociated from immune complexes: a preliminary report

Considering the scarcity of defined antigens, actually useful and reliable for use in the field studies, we propose an alternative method for selection of cDNA clones with potential use in the diagnosis of schistosomiasis. Human antibodies specific to a protein fraction of 31/32 kDa (Sm31/32), dissociated from immune complexes, are used for screening of clones from an adult worm cDNA library. Partial sequencing of five clones, selected through this strategy, showed to be related to Schistosoma mansoni: two were identified as homologous to heat shock protein 70, one to glutathione S-transferase, one to homeodomain protein, and one to a previously described EST (expressed sequence tag) of S. mansoni. This last clone was the most consistently reactive during the screening process with the anti-Sm31/32 antibodies dissociated from the immune complexes. The complete sequence of this clone was obtained and the translation data yielded only one ORF (open reading frame) that code for a protein with 57 amino acids. Based on this amino acid sequence two peptides were chemically synthesized and evaluated separately against a pool of serum samples from schistosomiasis patients and non-schistosomiasis individuals. Both peptides showed strong reactivity only against the positive pool, suggesting that these peptides may be useful as antigens for the diagnosis of schistosomiasis mansoni.

Considerando a escassez de antígenos quimicamente definidos, realmente úteis e confiáveis para aplicação na soroepidemiologia da esquistossomose em larga escala, foi proposto, neste trabalho, um método alternativo para a seleção de clones de cDNA que expressam proteínas com putativo potencial diagnóstico na esquistossomose. Empregando anticorpos específicos contra uma fração proteica de 31/32 kDa (Sm31/32), purificados através da dissociação de imunocomplexos, foram selecionados cinco clones de cDNA a partir de genoteca de verme adulto de Schistosoma mansoni. O seqüenciamento parcial destes clones demonstrou que todos eram relacionados ao S. mansoni: dois apresentaram homologia com a proteína de choque térmico de 70 kDa e os demais com glutationa S-transferase, "homeodomain protein" e uma etiqueta de seqüência expressa (EST). Este último foi o clone que melhor reagiu, durante o processo de seleção, com os anticorpos anti-Sm31/32 dissociados de imunocomplexos. Baseado na seqüência de aminoácidos deste clone, dois peptídeos foram quimicamente sintetizados e analisados separadamente frente a misturas de soros de indivíduos normais e de pacientes com esquistossomose mansoni. Ambos os peptídeos demonstraram uma intensa reatividade somente contra a mistura de soros positivos, sugerindo que estes peptídeos podem ser úteis como antígenos para o diagnóstico da esquistossomose mansoni.

Detecção de Cryptosporidium meleagridis em amostras fecais de pacientes HIV positivos no Brasil / Detection of Cryptosporidium meleagridis in fecal samples of HIV-infected patients from Brazil

Amostras fecais de indivíduos portadores de HIV, e com Aids, foram submetidas ao diagnóstico laboratorial de criptosporidiose. Do total de 29 amostras, 15 apresentaram oocistos de Cryptosporidium sp no exame parasitológico, 13 foram reativas em ELISA para detecção de coproantígenos e em 16 foram obtidos produtos de amplificação por Nested-PCR. Foi realizada caracterização genotípica em cinco destes produtos amplificados, por meio de PCR-RFLP com a enzima de restrição AfaI (RsaI). Dois isolados foram identificados como Cryptosporidium hominis, um como Cryptosporidium parvum e dois apresentaram perfil eletroforético correspondente a Cryptosporidium meleagridis. Esses achados trazem evidências de que diferentes espécies de Cryptosporidium circulam no ambiente, traduzindo-se em risco tanto para humanos quanto para outros animais.

Application of synthetic peptides in development of a serologic method for laboratory diagnosis of schistosomiasis mansoni

The immunoreactivity of seven peptides synthesized from Schistosoma mansoni proteins, was evaluated by dot-blot and ELISA assays using two different sensitization methodologies. The best results were obtained on wells of the Costar 3590 microplates coated with peptides P1, P2, P3, P6, and P7 using conventional methodology. The signals increased considerably (p < 0.0003) on wells sensitized with P1 to P6 using alternative methodology. In contrast, the well coated with peptide P7 presented lower signal when compared with conventional methodology (p = 0.0019). These results, establish the basis for the application of synthetic peptides for laboratory diagnosis of schistosomiasis mansoni.