RESUMO
In Thailand, no reports are available on Escherichia coli serotype O157:H7, a causative agent of severe bloody diarrhoea, sometimes associated with haemolytic-uraemic syndrome and thrombotic thrombocytopenic purpura. The reason for the non-identification of infection due to E. coli O157 in this country and in other developing countries has not been rigorously discussed. The aim of this study was to determine the humoral response against the infectious organism. The IgM and IgG antibody responses against E. coli O157 lipopolysaccharide were studied using indirect enzyme-linked immunosorbent assay. Three hundred and thirty-two serum samples obtained from healthy blood donors and patients with diseases unrelated to diarrhoea were investigated. With a cut-off value of mean +2 SDs for each age-group, the frequency of the IgM and IgG responses to O157 lipopolysaccharide was 11.74% (39 of 332 samples) and 22.59% (75 of 332 samples) respectively. Furthermore, agglutination test of 173 subjects revealed titres ranging from 10 to 40 in all the samples. The results suggest possible exposure of the Thai population to cross-reacting antigens from other intestinal organisms in addition to infection due to E. coli O157:H7.
Assuntos
Adolescente , Adulto , Testes de Aglutinação/métodos , Anticorpos Antibacterianos/sangue , Criança , Pré-Escolar , Países em Desenvolvimento , Ensaio de Imunoadsorção Enzimática/métodos , Escherichia coli O157/imunologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Lactente , Japão , Lipopolissacarídeos/imunologia , Pessoa de Meia-Idade , Valores de Referência , TailândiaRESUMO
We describe the isolation of one strain of Shiga toxin-producing Escherichia coli 091: H21 from a child with diarrhea in the city of Porto Alegre, RS, Brazil. Considering the pathogenic potential of STEC, these organisms should be looked for more carefully among our population.
Assuntos
Criança , Diarreia Infantil/diagnóstico , Escherichia coli , Técnicas In Vitro , Infecções Bacterianas/diagnóstico , Infecções por Escherichia coli/diagnóstico , Diagnóstico ClínicoRESUMO
O fator hemaglutinante (HAF) foi extraido e purificado a partir de amostra de Escherichia coli de aderencia difusa (DAEC), pertencente ao sorogrupo 0128 de E. coli enteropatogenica classica (EPEC). O peso molecular do HAF foi estimado em 18.000 Da usando SDS-PAGE de 66.000 Da empregando Sephadex G 100, o que sugere a estrutura do HAF consistir de 3 a 4 subunidades. O emprego da tecnica "gold immunolabeling" com antissoro especifico anti-HAF revelou que este valor nao e uma estrutura do tipo fimbria na superficie da bacteria...