A cross sectional study of leptospirosis and fetal death in Yucatan, Mexico / Estudio transversal de leptospirosis y muerte fetal en Yucatán, México

Introduction: Leptospirosis is a zoonotic disease affecting mainly to low income human population. Acute leptospiral infection during pregnancy has been associated with spontaneous abortion and fetal death during the first trimester and the abortion may occur as consequence of systemic failure. Objective: To estimate the frequency of Leptospira interrogans infection in women with spontaneous abortion in the state of Yucatan, Mexico. Methods: A cross sectional study on women with spontaneous abortion was conducted. Serum samples were tested for Leptospirosis by the microaglutination test, to estimate the frequency of the infecting serovar. The indirect ELISA IgM was used to detect recent infection by L. interrogans. DNA was extracted from paraffin-embedded tissue of placenta for PCR detection of L. interrogans. Results: Overall frequency of infection with L. interrogans in the 81 women with abortion was 13.6%. Five of the 12 serovars evaluated were found and included. Two of the 11 women with abortion and positive to microaglutination test were also positive to the ELISA IgM test. None samples were positive for PCR Leptospira diagnosis. Conclusion: two women could be associated with spontaneous abortion due to leptospirosis, because they showed antibodies against L. interrogans in the microaglutination test and ELISA IgM assays. Differences between regions were found with respect to the prevalences of lesptospirosis.

Introducción: Leptospirosis es una enfermedad zoonótica que afecta principalmente la población humana de bajos recursos. Infección aguda por leptospirosis durante el embarazo se ha asociado con aborto espontáneo y muerte fetal durante el primer trimestre del embarazo. Objetivo: Estimar la frecuencia de infección por Leptospira interrogans en mujeres con aborto espontáneo en el estado de Yucatán, México. Métodos: Se efectuó un estudio trasversal en 81 mujeres con aborto espontáneo. La prueba de referencia para Leptospirosis, prueba de microaglutinación, se utilizó para estimar la frecuencia de la serovar infectante. El ELISA IgM indirecto se utilizó para detectar infección reciente por L. interrogans. Se extrajo ADN a partir de tejido embebido en parafina de placenta para la detección de L. interrogans por PCR. Resultados: La frecuencia global de la infección con L. interrogans en 81 mujeres con aborto, fue del 13.6%. Se encontró cinco de 12 serovares de Leptospira. Dos de las 11 mujeres con aborto espontáneo y positivo a microaglutinación también fueron positivas a la prueba ELISA IgM. Ninguna muestra fue positiva hacia el diagnóstico PCR de Leptospira. Conclusion: Dos mujeres podrían estar asociados con el aborto espontáneo debido a la leptospirosis, porque mostraron anticuerpos contra L. interrogans en la microaglutinación y ensayos de ELISA IgM. Diferencias entre regiones fueron encontradas con respecto a las prevalencias de leptospirosis.

Identificação de biofilme renal em ratos naturalmente infectados por Leptospira interrogans através de técnicas histoquímicas e de microscopia eletrônica de varredura, Brasil / Identification of renal biofilm in rats naturally infected with Leptospira interrogans using histochemical and scanning electron microscopy techniques, Brazil

INTRODUÇÃO: A leptospirose é um importante agravo de saúde pública e afeta ao menos um milhão de humanos por ano no mundo. Ratos de esgoto (Rattus norvegicus) são os principais reservatórios de leptospiras patogênicas nas áreas urbanas e excretam, através da urina, elevadas quantidades de bactérias diariamente. As leptospiras sobrevivem no ambiente e são transmitidas para novos hospedeiros através do contato com mucosas e pele. Leptospiras patogênicas formam densos biofilmes in vitro. A patogênese da leptospirose em reservatórios crônicos é pouco conhecida. OBJETIVO: Estudar a formação de biofilme por Leptospira interrogans em R. norvegicus capturados em uma área hiperendêmica de Salvador, Bahia, Brasil. MATERIAIS E MÉTODOS: Capturamos 86 ratos, dos quais 76 (88,4%) foram considerados portadores de L. interrogans através da avaliação por imunohistoquímica (IHQ) anti-L. interrogans e/ou Reação em Cadeia da Polimerase quantitativa em Tempo Real (RT-qPCR) utilizando iniciadores específicos para o gene lipL32. RESULTADOS: Ao exame de IHQ anti-L. interrogans, 69 ratos foram positivos. Destes, 24 (35%)...

INTRODUCTION: Leptospirosis is an important public health problem and affects at least one million people each year worldwide. Norway rats (Rattus norvegicus) are the main reservoir hosts of leptospires in urban environments. They excrete large amounts of bacteria daily. Leptospires survive in the environment and are transmitted to new hosts by contact with mucous membranes and skin. Pathogenic leptospires form dense biofilms in vitro. The pathogenesis of chronic leptospirosis in reservoirs is largely unknown. The aim of this work was to study biofilm formation by Leptospira interrogans in R. norvegicus caught in a hyperendemic area in Salvador, Bahia, Brazil. MATERIAL AND METHODS: We caught 86 rats, out of which 76 (88.4%) were carriers of L. interrogans according to immunohistochemistry (IHC) anti-L. interrogans and/or quantitative real time PCR (RT-qPCR) using LipL32 primers. RESULTS: From the 69 rats positive for IHC anti-L. interrogans, 24 (35%)...

Avanços no conhecimento da imunopatogênese da leptospirose e a aplicação do método do imprint como ferramenta qualitativa e quantitativa de leptospiras / Advances in understanding the immunopathogenesis of leptospirosis and application of the imprint method as a qualitative and quantitative tool leptospires

A leptospirose é uma zoonose causada por espiroquetas patogênicas pertencentes ao gênero Leptospira. O modelo da doença em camundongos tem vantagens devido à ampla gama de ferramentas genéticas e imunológicas disponíveis para pesquisas básicas. A maior limitação na conduta clínica e na pesquisa experimental da leptospirose é o fraco desempenho dos métodos disponíveis para detecção direta e para quantificação de leptospiras. Foi incluído nesta tese um conjunto de três manuscritos que visam investigar o desfecho da infecção pela cepa virulenta de Leptospira interrogans nas linhagens de camundongos selvagens (A, CBA, BALB/c e C57BL/6)...

Leptospirosis is a zoonosis caused by pathogenic spirochaetes belonging to the genus Leptospira. The mouse disease model is advantagous due to the broad array of immunological and genetic tools available for basic research. A major limitation in the clinical management and experimental research of leptospirosis is the poor performance of the available methods in the direct detection and quantification of leptospires. This thesis includes three manuscripts that investigate the outcome of infection by a virulent strain of Leptospira interrogans in wildtype mice strains: A, CBA, BALB/c and C57BL/6; in iNOS knockout (KO) mice, recombination activating gene 1 (RAG1) KO mice and CB17 severe combined immunodeficiency (SCID) mice. To investigate whether the imprint method (IM) of quantification was reliable we compared it with against real time PCR (qPCR) for the detection and quantification of leptospires in kidney samples from rats and hamsters. As expected, none of the wildtype mice were susceptible to lethal leptospirosis. The A and C57BL/6 strains exhibited high leptospiral loads in the kidney samples and the CBA and C57BL/6...