Comparative analysis of a novel N-butanol-prepared antigen vs thermo-resistant and sonicated antigens for human leptospirosis detection.

The diagnosis of human leptospirosis is mainly based on serological assays. Since the extraction by N-butanol has only been studied as an antigen for the diagnosis of cattle leptospirosis, this study aimed to investigate the feasibility of the N-butanol preparation for the diagnosis of human leptospirosis and compare it with sonicated and thermo-resistant antigens in IgM dot-blot test. Paired serum samples from 147 laboratory-confirmed leptospirosis cases were tested. The control group consisted of 148 serum samples from healthy individuals and nonleptospirosis cases. N-butanol antigens from serovar Copenhageni (ButC3) and serovar Patoc (ButP3) showed reactivity with antileptospiral antibodies from patients with confirmed leptospirosis. In the acute phase, sensitivities of IgM dot-blot assay with ButC3 and ButP3 antigens were 47.6% and 51.0%, respectively. In the convalescent phase, sensitivities were 95.9% (ButC3) and 93.2% (ButP3), and no significant differences were observed among the IgM dot-blot tests with other antigens. The specificity of the IgM dot-blot test with ButC3 antigen was good (92.6%), but with ButP3 (83.1%), it was significantly lower than with the other tests. The IgM dot-blot test described in this study is simple to perform and presents reliable visual results. Antigens prepared by N-butanol proved to be valuable diagnostic markers of leptospirosis.

Multiparametric assay of screening for the diagnosis of mycoses of interest in Public Health: standardization of methodology / Ensaio multiparamétrico de triagem para diagnóstico de micoses de interesse em Saúde Pública: padronização da metodologia

The standardization and validation of a multiplex assay requires the combination of important parameters such as sensitivity and specificity, acceptable levels of performance, robustness, and reproducibility. We standardized a multiparametric Dot-blot aimed at the serological screening of paracoccidioidomycosis, histoplasmosis, and aspergillosis. A total of 148 serum were evaluated: 10 from healthy subjects, 36 from patients with paracoccidioidomycosis, 62 from patients with histoplasmosis, and 40 from patients with aspergillosis. It was found that the multiparametric Dot-blot showed a high percentage of cross-reactivity. However, when evaluated individually, in the serological screening of histoplasmosis, a good performance was observed when compared to the double immunodiffusion assay, considered the gold standard test, with 100% co-positivity and 83.3% co-negativity. The performance of serological screening for aspergillosis was not satisfactory when compared to double immunodiffusion, showing 71.4% co-positivity and 100% co-negativity. The evaluation of the stability of nitrocellulose membranes showed that membranes sensitized with H. capsulatum antigen remained stable for 90 days and those sensitized with A. fumigatus antigen for 30 days. We conclude that the use of crude antigens was not suitable for the standardization of the multiparametric Dot-blot assay, due to the high cross-reactivity, and that further tests should be performed with purified proteins (AU).

A padronização e validação de um ensaio multiplex requer a combinação de parâmetros importantes, como sensibilidade e especificidade, níveis aceitáveis de desempenho, robustez e reprodutibilidade. Este trabalho padronizou um Dot-blot multiparamétrico visando a triagem sorológica da paracoccidioidomicose, histoplasmose e aspergilose. Foram avaliadas 148 amostras de soro: 10 de indivíduos saudáveis, 36 de pacientes com paracoccidioidomicose, 62 de pacientes com histoplasmose e 40 de pacientes com aspergilose. Verificou-se que o Dot-blot multiparamétrico apresentou elevado percentual de reatividade cruzada. Entretanto, quando avaliado individualmente, na triagem sorológica da histoplasmose observou-se bom desempenho quando comparado ao ensaio de imunodifusão dupla, considerado o teste padrão ouro, com 100% de co-positividade e 83,3% de co-negatividade. O desempenho da triagem sorológica da aspergilose não foi satisfatório quando comparado a imunodifusão dupla, apresentando 71,4% de co-positividade e 100% de co-negatividade. A avaliação da estabilidade das membranas de nitrocelulose mostrou que membranas sensibilizadas com antígeno de H. capsulatum permaneceram estáveis por 90 dias e as sensibilizadas com antígeno de A. fumigatus, por 30 dias. Concluímos que o uso de antígenos brutos não foi adequado para a padronização do ensaio de Dot-blot multiparamétrico, devido ao alto índice de reatividade cruzada, e que novos testes devem ser realizados com proteínas purificadas (AU).

Metabolomics and Machine Learning Approaches Combined in Pursuit for More Accurate Paracoccidioidomycosis Diagnoses.

Brazil and many other Latin American countries are areas of endemicity for different neglected diseases, and the fungal infection paracoccidioidomycosis (PCM) is one of them. Among the clinical manifestations, pneumopathy associated with skin and mucosal lesions is the most frequent. PCM definitive diagnosis depends on yeast microscopic visualization and immunological tests, but both present ambiguous results and difficulty in differentiating PCM from other fungal infections. This research has employed metabolomics analysis through high-resolution mass spectrometry to identify PCM biomarkers in serum samples in order to improve diagnosis for this debilitating disease. To upgrade the biomarker selection, machine learning approaches, using Random Forest classifiers, were combined with metabolomics data analysis. The proposed combination of these two analytical methods resulted in the identification of a set of 19 PCM biomarkers that show accuracy of 97.1%, specificity of 100%, and sensitivity of 94.1%. The obtained results are promising and present great potential to improve PCM definitive diagnosis and adequate pharmacological treatment, reducing the incidence of PCM sequelae and resulting in a better quality of life.IMPORTANCE Paracoccidioidomycosis (PCM) is a fungal infection typically found in Latin American countries, especially in Brazil. The identification of this disease is based on techniques that may fail sometimes. Intending to improve PCM detection in patient samples, this study used the combination of two of the newest technologies, artificial intelligence and metabolomics. This combination allowed PCM detection, independently of disease form, through identification of a set of molecules present in patients' blood. The great difference in this research was the ability to detect disease with better confidence than the routine methods employed today. Another important point is that among the molecules, it was possible to identify some indicators of contamination and other infection that might worsen patients' condition. Thus, the present work shows a great potential to improve PCM diagnosis and even disease management, considering the possibility to identify concomitant harmful factors.

Perfil sorológico dos pacientes com suspeita clínica de paracoccidiodomicose avaliados pelo Instituto Adolfo Lutz no ano de 2016 / Serological profile of patients with clinical suspicion of paracoccidiodomycosis evaluated by Instituto Adolfo Lutz in 2016

Oitenta porcento dos casos de paracoccidioidomicose (PMC) ocorrem no Brasil. As regiões brasileiras com maior número de casos são: sul, sudeste e centro-oeste, sendo emergente no norte e nordeste. A imunodifusão dupla em gel de agarose assume grande importância no diagnóstico, por permitir o monitoramento da doença e por oferecer subsídios para levantamentos soroepidemiológicos. O objetivo deste trabalho foi de avaliar e caracterizar os pacientes atendidos no Laboratório de Imunodiagnóstico das Micoses do Instituto Adolfo Lutz de São Paulo, em 2016. Trata-se de um estudo retrospectivo realizado utilizando-se dados secundários e avaliando-se as seguintes informações: idade, sexo, procedência do pedido médico, resultado e histórico sorológico dos pacientes. Dos 1.408 pacientes, 12,8% apresentaram reatividade sorológica para Paracoccidioides brasiliensis. Destes, 42,5% não possuiam histórico sorológico, sendo considerados como casos novos da doença. A classificação dos pacientes reagentes por gênero demonstrou que 83,4% eram do sexo masculino, com razão de masculinidade de 5:1. A faixa etária variou de um (1) a 92 anos, e aproximadamente 40% dos pacientes eram da faixa etária de 41 a 60 anos. Este estudo demonstra e reforça a importância da implementação dos estudos soroepidemiológicos como ferramenta auxiliar para nortear as ações de vigilância e políticas em saúde na PCM. (AU)

Eighty percent of paracoccidioidomycosis (PMC) cases occur in Brazil. The highest numbers occur in south, southeast and center-west region, being emergent in the north and northeast areas. The double immunodiffusion in agarose gel is valuable for its diagnosis, as it allows the monitoring of the disease and offers subsidies for the seroepidemiological surveys. This study evaluated and characterized the patients attended in 2016 at the Mycoses Immunodiagnosis Laboratory of Adolfo Lutz Institute of São Paulo. This retrospective study, based on the secondary data, evaluated the information: age, sex, medical request origin, result and serological history of the patients. Of 1,408 patients, 12.8% presented positive serological reactivity for Paracoccidioides brasiliensis. Of them, 42.5% had no serological history and they were considered as new cases. The classification of reactive patients by gender showed that 83.4% were males, being the masculinity ratio of 5:1. The age range was one (1) to 92 years old, and ±40% of the patients were of age ranging from 41-60 years old. This study reinforces the importance of the implementation of the seroepidemiological studies as to guide the surveillance actions and the public health politics in PCM. (AU)

Perfil sorológico dos pacientes com suspeita clínica de paracoccidiodomicose avaliados pelo Instituto Adolfo Lutz no ano de 2016 / Serological profile of patients with clinical suspicion of paracoccidiodomycosis evaluated by Instituto Adolfo Lutz in 2016

Oitenta porcento dos casos de paracoccidioidomicose (PMC) ocorrem no Brasil. As regiões brasileiras com maior número de casos são: sul, sudeste e centro-oeste, sendo emergente no norte e nordeste. A imunodifusão dupla em gel de agarose assume grande importância no diagnóstico, por permitir o monitoramento da doença e por oferecer subsídios para levantamentos soroepidemiológicos. O objetivo deste trabalho foi de avaliar e caracterizar os pacientes atendidos no Laboratório de Imunodiagnóstico das Micoses do Instituto Adolfo Lutz de São Paulo, em 2016. Trata-se de um estudo retrospectivo realizado utilizando-se dados secundários e avaliando-se as seguintes informações: idade, sexo, procedência do pedido médico, resultado e histórico sorológico dos pacientes. Dos 1.408 pacientes, 12,8% apresentaram reatividade sorológica para Paracoccidioides brasiliensis. Destes, 42,5% não possuiam histórico sorológico, sendo considerados como casos novos da doença. A classificação dos pacientes reagentes por gênero demonstrou que 83,4% eram do sexo masculino, com razão de masculinidade de 5:1. A faixa etária variou de um (1) a 92 anos, e aproximadamente 40% dos pacientes eram da faixa etária de 41 a 60 anos. Este estudo demonstra e reforça a importância da implementação dos estudos soroepidemiológicos como ferramenta auxiliar para nortear as ações de vigilância e políticas em saúde na PCM.

Eighty percent of paracoccidioidomycosis (PMC) cases occur in Brazil. The highest numbers occur in south, southeast and center-west region, being emergent in the north and northeast areas. The double immunodiffusion in agarose gel is valuable for its diagnosis, as it allows the monitoring of the disease and offers subsidies for the seroepidemiological surveys. This study evaluated and characterized the patients attended in 2016 at the Mycoses Immunodiagnosis Laboratory of Adolfo Lutz Institute of São Paulo. This retrospective study, based on the secondary data, evaluated the information: age, sex, medical request origin, result and serological history of the patients. Of 1,408 patients, 12.8% presented positive serological reactivity for Paracoccidioides brasiliensis. Of them, 42.5% had no serological history and they were considered as new cases. The classification of reactive patients by gender showed that 83.4% were males, being the masculinity ratio of 5:1. The age range was one (1) to 92 years old, and ±40% of the patients were of age ranging from 41-60 years old. This study reinforces the importance of the implementation of the seroepidemiological studies as to guide the surveillance actions and the public health politics in PCM.

Case report: Misleading serological diagnosis of paracoccidioidomycosis in a young patient with the cute form disease: Paracoccidioides brasiliensis or paracoccidioides lutzii?

Negative results in serological routine screening of patients with microbiologically proven aracoccidioidomycosis (PCM) are occasionally reported. Failure in detecting anti-Paracoccidioides antibodies has been ascribed to factors either related to serological techniques or to the status of the host immune reactivity. Recently, this issue has been renewed by the recognition that the Paracoccidioides genera comprises two species, lutzii and brasiliensis, which have distinct antigenic profiles and, therefore, may elicit different host antibody responses. We describe a patient with the acute form PCM due to Paracoccidioides brasiliensis with negative results on two reference centers' routine screening for P. brasiliensis antibodies, but positive results with Paracoccidioides lutzii antigens. The present case report suggests that antibodies elicited during P. brasiliensis infection recognize antigenic fractions shared by both species, highlighting the difficulties in distinguishing the two infections by means of the currently available routine serological assays

Case Report: Misleading Serological Diagnosis of Paracoccidioidomycosis in a Young Patient with the Acute Form Disease: Paracoccidioides brasiliensis or Paracoccidioides lutzii?

Negative results in serological routine screening of patients with microbiologically proven Paracoccidioidomycosis (PCM) are occasionally reported. Failure in detecting anti-Paracoccidioides antibodies has been ascribed to factors either related to serological techniques or to the status of the host immune reactivity. Recently, this issue has been renewed by the recognition that the Paracoccidioides genera comprises two species, lutzii and brasiliensis, which have distinct antigenic profiles and, therefore, may elicit different host antibody responses. We describe a patient with the acute form PCM due to Paracoccidioides brasiliensis with negative results on two reference centers' routine screening for P. brasiliensis antibodies, but positive results with Paracoccidioides lutzii antigens. The present case report suggests that antibodies elicited during P. brasiliensis infection recognize antigenic fractions shared by both species, highlighting the difficulties in distinguishing the two infections by means of the currently available routine serological assays.

Fast protocol for the production of Histoplasma capsulatum antigens for antibody detection in the immunodiagnosis of histoplasmosis.

BACKGROUND: Current methods for the production of Histoplasma capsulatum antigens are problematic in terms of standardization, specificity, stability, repeatability and reproducibility. AIMS: In this study, we sought to optimize the methodology for producing H. capsulatum antigens, and to evaluate its applicability. METHODS: Antigenic preparations obtained from 12 H. capsulatum isolates were evaluated by double immunodiffusion and immunoblotting assays against homologous and heterologous sera. RESULTS: The evaluated and optimized protocol allowed a more stable production, as well as repeatable, reproducible, with shorter culture time and less costly. By double immunodiffusion and immunoblotting assays, the best pattern of reactivity was observed for antigens obtained with 33 days of culture from the isolates 200 and 406 against the M antigen and for the isolate 200 with 15 days against H antigen. The SDS-PAGE presented antigenic components of molecular masses between 17 and 119kDa. The immunoblotting sensitivity was 95.5% and 100% with histoplasmosis sera from ill patients and sera from H. capsulatum infected but otherwise healthy patients, respectively, to the antigen derived from isolates 200 and 406. CONCLUSIONS: We suggest the employment of the antigen from isolate 200, with 15 or 30 days of culture, in the double immunodiffusion and immunoblotting assays due to its good ability to discriminate both sera from patients with histoplasmosis illness and histoplasmosis infection, in addition to its high specificity against heterologous sera.

Standardization and validation of Dot-ELISA assay for Paracoccidioides brasiliensis antibody detection.

BACKGROUND: Paracoccidioidomycosis (PCM) is a neglected systemic mycosis caused by a dimorphic fungus of the Paracoccidioides genus. The standard diagnosis is based on isolation of the fungi in culture, and by microscopic visualization of characteristic multiple budding yeast cells in biological samples. However, in some situations, access to the site of injury prevents the collection of biological material. A variety of immuno-serological techniques has proven useful for allowing inferring diagnosis with a certain degree of certainty, thus optimizing time. The aim of this study was to standardize and validate the Dot-ELISA (DE) assay, comparing it with the serological standard, double immunodiffusion (DI). METHODS: In order to standardize the DE assay, 143 serum samples were used. Out of those, 23 were from apparently healthy patients, 77 were from patients with confirmed PCM and 43 were from patients with other lung infections (tuberculosis, aspergillosis and histoplasmosis). To validate the DE technique, 300 serum samples from patients with PCM clinical suspicion (probable and possible cases) were employed, and these results were compared with those of DI. RESULTS: The DE assay showed sensitivity of 91%, specificity of 95.4%, positive predictive value of 96%, negative predictive value of 98.2%, accuracy of 93%, and great precision (k = 0.93). In addition, the nitrocellulose membranes have proved to be viable for using at least 90 days after P. brasiliensis B-339 antigen sensitization. CONCLUSION: Dot-ELISA method was found to be an extremely promising tool as serologic screening technique, because of its high sensitivity. Furthermore, Dot-ELISA shows the prospect of being transferred to laboratories of mycoserology including those with fewer resources or even to be used directly in the field. It has an excellent shelf life - membranes coated with antigen can be used for testing without changes in the pattern of reactivity among laboratories - and presents reliable values of sensitivity, specificity, predictive values, accuracy and a high correlation with the serological standard methodology. Based on the present findings, it possible to state that this technique constitutes a remarkable option to be used in routine diagnosis for public health centers.

Standardization and validation of Dot-ELISA assay for Paracoccidioides brasiliensis antibody detection

Abstract Background Paracoccidioidomycosis (PCM) is a neglected systemic mycosis caused by a dimorphic fungus of the Paracoccidioides genus. The standard diagnosis is based on isolation of the fungi in culture, and by microscopic visualization of characteristic multiple budding yeast cells in biological samples. However, in some situations, access to the site of injury prevents the collection of biological material. A variety of immuno-serological techniques has proven useful for allowing inferring diagnosis with a certain degree of certainty, thus optimizing time. The aim of this study was to standardize and validate the Dot-ELISA (DE) assay, comparing it with the serological standard, double immunodiffusion (DI). Methods In order to standardize the DE assay, 143 serum samples were used. Out of those, 23 were from apparently healthy patients, 77 were from patients with confirmed PCM and 43 were from patients with other lung infections (tuberculosis, aspergillosis and histoplasmosis). To validate the DE technique, 300 serum samples from patients with PCM clinical suspicion (probable and possible cases) were employed, and these results were compared with those of DI. Results The DE assay showed sensitivity of 91%, specificity of 95.4%, positive predictive value of 96%, negative predictive value of 98.2%, accuracy of 93%, and great precision (k = 0.93). In addition, the nitrocellulose membranes have proved to be viable for using at least 90 days after P. brasiliensis B-339 antigen sensitization. Conclusion Dot-ELISA method was found to be an extremely promising tool as serologic screening technique, because of its high sensitivity. Furthermore, Dot-ELISA shows the prospect of being transferred to laboratories of mycoserology including those with fewer resources or even to be used directly in the field. It has an excellent shelf life membranes coated with antigen can be used for testing without changes in the pattern of reactivity among laboratories and presents reliable values of sensitivity, specificity, predictive values, accuracy and a high correlation with the serological standard methodology. Based on the present findings, it possible to state that this technique constitutes a remarkable option to be used in routine diagnosis for public health centers.

Evaluation of the “shelf life” of nitrocellulose membranes immobilized with Paracoccidioides brasiliensis antigen for performing the immunodiagnosis of paracoccidioidomycosis / Avaliação do “tempo de prateleira” de membranas de nitrocelulose imobilizadas com antígeno de Paracoccidioides brasiliensis para o imunodiagnóstico da paracoccidioidomicose

Considerando-se que o immunoblotting para o imunodiagnóstico da paracoccidioidomicose (PCM) é uma metodologia in house e laboriosa envolvendo duas etapas iniciais, SDS-PAGE e Western blot, neste estudo foi avaliado o tempo de prateleira das membranas de nitrocelulose sensibilizadas com antígeno de P. brasiliensis, armazenadas a -20 oC durante 7, 15, 30, 45, 60 e 90 dias. Vinte e oito amostras de soro foram analisadas em dois grupos de membranas de nitrocelulose (membranas previamente bloqueadas com PBS-leite 5 % e as não-bloqueadas). Não houve diferença no padrão de reatividade quando os soros foram avaliados frente a ambos os grupos, especialmente para membranas armazenadas por 7, 15, 30, 45 e 60 dias. A boa estabilidade do antígeno utilizado para sensibilizar as membranas fez com que estas pudessem ser armazenadas a -20 °C até 60 dias. Estas características contribuem para efetuar o diagnóstico rápido da PCM, bem como as perspectivas dessas membranas sensibilizadas serem encaminhadas para os laboratórios, que não possuam infraestrutura necessária para executar as etapas que antecedem a realização de immunoblotting, como a produção de antígeno, as técnicas de SDS PAGE e Western blot. Este procedimento contribui substancialmente para melhorar o diagnóstico sorológico da PCM, pois poderá fornecer resultados reprodutíveis nas unidades componentes da Rede de Laboratórios.

The immunoblotting reaction for performing the paracoccidioidomycosis (PCM) immunodiagnosis is an in-house methodology; and being a laborious task involving two previous steps, SDS-PAGE and Western blot, we evaluated the shelf life of nitrocellulose membranes containing the immobilized P. brasiliensis antigens, stored at -20 oC for 7, 15, 30, 45, 60 and 90 days. Twenty-eight serum samples were analyzed on two nitrocellulose membranes groups: (a) membranes previously blocked with PBS-5 % non-fat dry milk and (b) the priory non-blocked membranes. No difference was detected in the reactivity pattern in serum samples evaluated in the both membrane groups, especially for those stored for 7, 15, 30, 45 and 60 days. It might be emphasized that a good stability of P. brasiliensis antigens, immobilized on the nitrocellulose membranes, enable them to be stored up to 60 daysat -20 oC. This finding contributes to the rapid diagnosis of PCM, and for sending them to other laboratories without adequate infrastructure for carrying out the steps that precede the immunodetection as the antigen production, SDS-PAGE and Western blot techniques. This scheme contributes substantially to improve the quality of PCM serodiagnosis, as it provides reproducible results in the units of the Laboratory Network.

Standardization and validation of Dot-ELISA assay for Paracoccidioides brasiliensis antibody detection

Background Paracoccidioidomycosis (PCM) is a neglected systemic mycosis caused by a dimorphic fungus of the Paracoccidioides genus. The standard diagnosis is based on isolation of the fungi in culture, and by microscopic visualization of characteristic multiple budding yeast cells in biological samples. However, in some situations, access to the site of injury prevents the collection of biological material. A variety of immuno-serological techniques has proven useful for allowing inferring diagnosis with a certain degree of certainty, thus optimizing time. The aim of this study was to standardize and validate the Dot-ELISA (DE) assay, comparing it with the serological standard, double immunodiffusion (DI). Methods In order to standardize the DE assay, 143 serum samples were used. Out of those, 23 were from apparently healthy patients, 77 were from patients with confirmed PCM and 43 were from patients with other lung infections (tuberculosis, aspergillosis and histoplasmosis). To validate the DE technique, 300 serum samples from patients with PCM clinical suspicion (probable and possible cases) were employed, and these results were compared with those of DI. Results The DE assay showed sensitivity of 91%, specificity of 95.4%, positive predictive value of 96%, negative predictive value of 98.2%, accuracy of 93%, and great precision (k = 0.93). In addition, the nitrocellulose membranes have proved to be viable for using at least 90 days after P. brasiliensis B-339 antigen sensitization. Conclusion Dot-ELISA method was found to be an extremely promising tool as serologic screening technique, because of its high sensitivity. Furthermore, Dot-ELISA shows the prospect of being transferred to laboratories of mycoserology including those with fewer resources or even to be used directly in the field. It has an excellent shelf life - membranes coated with antigen can be used for testing without changes in the pattern of reactivity among laboratories - and presents reliable values of sensitivity, specificity, predictive values, accuracy and a high correlation with the serological standard methodology. Based on the present findings, it possible to state that this technique constitutes a remarkable option to be used in routine diagnosis for public health centers.(AU)

Padronização da metodologia de Dot-Blot para o diagnóstico rápido da paracoccidioidomicose / Metodology standartization of Dot-Blot for screening of paracoccidioidomycosis

A paracoccidioidomicose (PCM), micose profunda de natureza crônicagranulomatosa, apresenta maior incidência no Brasil. O diagnóstico de certezaderiva da visualização do agente etiológico, o fungo Paracoccidioides spp emamostras biológicas. No entanto, em algumas situações o acesso ao local dalesão impede a coleta do material biológico. Assim, as técnicas imunosorológicaspermitem inferir diagnóstico com certo grau de certeza, otimizandoo tempo utilizado para se obter resultados. A técnica sorológica amplamenteutilizada para o imunodiagnóstico da PCM é a imunodifusão dupla em gel deagarose (ID), com especificidade e sensibilidade variando de 65 a 100%; sendode fácil execução e não necessitando de automação. A técnica de Dot-Blot (DB) tem sido utilizada com sucesso no diagnóstico de inúmeras doençasparasitárias e infecciosas, como a toxoplasmose e a leishmaniose visceral. Nodiagnóstico da PCM, a metodologia mostrou-se promissora noacompanhamento de pacientes durante o tratamento anti-fúngico e eminquéritos soroepidemiológicos. Diante do exposto, o objetivo deste trabalho foipadronizar o ensaio de Dot-Blot visando o diagnóstico rápido da PCM,propondo que o mesmo seja uma ferramenta de triagem dos soros comsuspeita clínica para a doença. A padronização da técnica de Dot-Blot apresentou melhores resultados quando se utilizou antígeno obtido de filtradode cultura de P. brasiliensis do isolado B-339 para a sensibilização demembranas de nitrocelulose. As diluições de soro e conjugado foram de 1:40 e1:2000, respectivamente, incubando ambos em solução PBS-L 3%. Para apadronização do ensaio de Dot-Blot, 143 amostras de soro foram utilizadas echamadas de grupo controle. Destas, 23 amostras de soro foram de pacientesaparentemente sadios, 77 amostras de soro de pacientes com PCM confirmadae 43 amostras de soros com outras doenças (tuberculose, aspergilose ehistoplasmose)...

The paracoccidioidomycosis (PCM) is the greatest mycosis of chronicgranulomatous nature in Brazil. The definitive diagnosis derives from the view ofthe etiologic agent, Paracoccidioides spp in biological samples. However, insome situations, access to the site of injury prevents the collection of biologicalmaterial. Thus, immuno- serological techniques allow inferring diagnosis with adegree of certainty and optimizing time taken to get results. The serologicaltechnique widely used for immunodiagnosis of PCM is double immunodiffusionin agarose gel (DI), with a sensitivity and specificity ranging from 65 to 100%,being easy to perform and not requiring automation. The Dot-blot (DB)technique has been used successfully in the diagnosis of many infectious andparasitic diseases such as visceral leishmaniasis and toxoplasmosis. On thediagnosis of PCM, this methodology showed promise results in monitoringpatients during treatment with anti-fungal and seroepidemiological surveys.Given the above, the objective of this study was to standardize the Dot-blotassay targeting the rapid diagnosis of PCM, suggesting that it is a screeningtool for sera with clinical suspicion for the disease. The standardization of Dot-Blot showed better results when using antigen obtained from culture filtrate of P.brasiliensis isolated from B-339 to sensitize nitrocellulose membranes. Theserum and conjugated dilutions were...