Elena Emiko Sakata

Sorovares de Leptospira interrogans isolados de casos de leptospirose humana em São Paulo, Brasil

Eighteen strains of L. interrogans isolated from human cases were serotyped by the Agglutinin-absorption test at Instituto Adolfo Lutz in Sao Paulo, Brazil. Fourteen were identified as serovar copenhageni (Icterohaemorrhagiae serogroup), 2 as canicola (Canicola serogroup), 1 as castellonis (Ballum serogroup) and 1 as Pomona serogroup (serovar not yet defined). The frequency of serovar copenhageni in 100% of the isolates in Icterohaemorrhagiae serogroup is emphasized and more studies to verify the real serovars prevalence as subsidy to the epidemiology of this infection are suggested by the authors

Imunodiagnóstico da leptospirose humana através do teste ELISA-IgM, empregando-se diferentes preparações antigênicas a partir de sorotipos prevalentes de Leptospira interrogans

Realizou-se estudo comparativo de diferentes sorotipos de Leptospira interrogans utilizados na preparacao de antigenos empregados no teste ELISA, para a deteccao de anticorpos da classe IgM, em amostras de soro na fase precoce e tardia da leptospirose humana. Foram utilizados dez sorotipos, escolhidos entre os que apresentaram maior reatividade na soroaglutinacao microscopica (SAM), na cidade de Sao Paulo. Os cinco sorotipos que apresentaram melhores resultados individualmente no teste ELISA-IgM (canicola, hebdomadis, icterohaemorrhagiae, cynopteri e brasiliensis), foram tambem estudados em mistura antigenica. Os antigenos nao tratados apresentaram maior reatividade do que os antigenos tratados com Triton X - 100 (4%) a temperatura de 50oC, durante 4 horas. O teste ELISA-IgM empregando os sorotipos nao tratados, isoladamente, e em mistura antigenica, mostrou-se altamente sensivel, podendo ser empregado como teste de triagem para o diagnostico precoce da leptospirose humana. Outra aplicacao do teste e permitir a deteccao do inicio de situacoes epidemicas ou de surtos, possibilitando acionar medidas de vigilância epidemiologica.

Teste imunoenzimático (ELISA) para detecção de anticorpos circulantes da classe IgM na leptospirose humana

An Enzyme-linked immunosorbent assay ELISA was evaluated for the detection of IgA antibodies in the human leptospirosis. The assay proved to be sensitive and specific when compared with the ELISA-IgM, in the examinated serum samples. The results found suggest that IgA antibodies became positive later in leptospirosis, and will can be an evolutive indicator in the development of the diseaseFoi avaliado o teste imunoenzimatico (ELISA), para deteccao de anticorpos da classe IgM na leptospirose humana. Nas amostras de soros analisadas, o teste ELISA demonstrou ser mais sensivel, especifico e precoce, quando comparado ao teste de soroaglutinacao microscopica. A analise dos resultados obtidos nesta avaliacao demonstra que o teste ELISA permite detectar niveis baixos de anticorpos circulantes, e tambem anticorpos nao aglutinantes. nao detectaveis atraves do teste de soroaglutinacao microscopica.

Surto de leptospirose humana por atividade recreacional no município de José dos Campos, São Paulo: estudo soroepidemiológico

An outbreak of human leptospirosis due to recreational activities ocurred at Sao Jose dos Campos, Sao Paulo, Brazil in November 1987. It involved a group of persons who had participated in a gathering in a suburb club which had a swimming pool fed with natural water. Epidemiological investigation was carried out and laboratorial tests from the patients were done. It was observed that a high prevalence of the pomona serotype (91%) was found in the serological analyses, while the presence of the agent of the infection could not be found in the water club swimming pool.An outbreak of human leptospirosis due to recreational activities occurred at São José dos Campos, São Paulo, Brazil in November 1987. It involved a group of persons who had participated in a gathering in a suburb club which had a swimming pool fed with natural water. Epidemiological investigation was carried out and laboratory tests from the patients were done. It was observed that a high prevalence of the pomona serotype (91%) was found in the serological analyses, while the presence of the agent of the infection could not be found in the water club swimming pool.

Glicolipoproteína de Leptospira interrogans sorogrupo icterohaemorrhagiae: distribuição em fígado e rim de cobaias experimentalmente infectadas

Tissue damage in leptospirosis has been ascribed to direct effect of the microorganisms and/or their virulence, including products synthetised by leptospires or released during their lysis. This study aimed at chemical extraction of the glycolipoprotein (GLP) from virulent leptospires, production of a rabbit anti-GLP and analysis of its distribution in liver and kidney of inoculated guinea-pigs, sacrificed sequentially from the 1st to 6th day of infection, covering the whole, spectrum of acute leptospirosis. The comparison of GLP expression to local injuries aimed at new pathogenetic data. GLP was detected in liver and kidney in 2 out of 6 guinea-pigs on the 5th day and in all 6 animais on the 6th day of infection. Granular forms were seen in the cytoplasm of macrophages, free in interstitium or adhered to endothelial and parenchimal cell membranes, especially in the most damaged sites. These findings lead us to the hypothesis of GLP as a toxic factor resulting from leptospiral lysis by macrophages. Although it was not proved as a promoter of initial lesions, it seems to be related to the enhancement of tissue damage late in the course of the disease.

Avaliação da contraimunoeletroforese com antígenos dos sorovars icterohaemorrhagiae E patoc no diagnóstico sorológico da leptospirose humana

Counterimmunoelectrophoresis (CIE) was applied on paired sera from 135 pacients with leptospirosis and on 69 sera from a control group. The sera from pacients were subdivided in 4 groups according to the results obtained by the Microscopic Agglutination Test (MAT). The first samples sera from 58 pacientes were non reagent by MAT. Six monthly samples of sera were taken from 7 patients to follow-up and to determine the level of agglutinin and precipitin antibodies present using MAT and CIE. Serovars icterohaemorrhagie and patoc were used as antigens. Three types of antigens were compared, 1) Triton-X-100 extracted; 2) heat extacted and 3) a pool of them. The CIE using icterohaemorrhagiae derivated antigens types agreed with MAT in 92.64, 92.64 and 94.11% of the leptospirosis sera. The patoc antigens types reacted with the control group in 7.24, 86.95 and 84.05% of the samples, and consequently were eliminated from the present study. The icterohaemorrhagiae CIE reaction become positive earlier than MAT negative sera, and reverted to negative earlier in the follow-up samples from the pacients. The CIE was sensitive and specific, gave rapid results and was easy to perform.