RESUMO
OBJECTIVE: To assess the clinical manifestations and incidence of infection associated with Shiga-like toxin-producing Escherichia coli (SLTEC). STUDY DESIGN: Children with diarrhea within a defined geographic area during a 12-month period were examined for the presence of SLTEC in their stools by polymerase chain reaction with the use of primers that were complementary to sequences of Shiga-like toxins types I and II and to other virulence factors. RESULTS: There were 13 SLTEC infections among 468 children with diarrhea. Besides Shiga-like toxin sequences, the virulence genes eae and EHEC-hly were found in 10 isolates; these isolates were categorized as enterohemorrhagic E. coli (EHEC). Only 2 of 13 isolates were of the O157 strain. All reported cases occurred in summer (June through September) with the exception of one case in April. The infections were sporadic, and the infected children lived in rural and urban areas. Three infections in children with disabilities were hospital acquired. The majority of children had watery diarrhea, two had bloody diarrhea, and one had mild hemolytic-uremic syndrome. The overall incidence of SLTEC infection was 12.5 hospitalized children per 100,000 children less than 16 years of age. CONCLUSIONS: The most frequent clinical manifestation of SLTEC infection was watery diarrhea indistinguishable from other forms of infectious diarrhea. The shift from the O157 strain toward non-O157 SLTEC strains associated with diarrhea, also observed in German patients with hemolytic-uremic syndrome, points to a change in the epidemiologic features of SLTEC-associated disease. Testing for non-O157 SLTEC should be considered in children with diarrhea without a recognized cause.
Assuntos
Toxinas Bacterianas/metabolismo , Diarreia/microbiologia , Enterotoxinas/metabolismo , Infecções por Escherichia coli/microbiologia , Escherichia coli/isolamento & purificação , Pré-Escolar , Diarreia/epidemiologia , Escherichia coli/classificação , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Feminino , Genes Bacterianos , Alemanha/epidemiologia , Síndrome Hemolítico-Urêmica/epidemiologia , Síndrome Hemolítico-Urêmica/microbiologia , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Estudos Prospectivos , Estações do Ano , Estudos Soroepidemiológicos , Sorotipagem , Toxina Shiga IRESUMO
Twenty-three snakes of nine different species were investigated. Of these, 21 were carriers of a total of 22 different Salmonella serovars (subspecies I 14 types, subspecies IIIb 6 types, subspecies IV 2 types). A triphasic variant of S. IIIb 48:i:z:Rz72 was identified for the first time. Numerous serovars of subspecies I strains have previously been demonstrated in humans and animals in large areas of South America. It is concluded that these snakes may constitute a potential reservoir for human infections. Biochemically variant strains occurred as a lactose-positive variant of S. michigan, an indole-positive isolate of S. IIIb 61:r:z53 as well as a dulcitol-positive strain of S. IIIb 48:i:z:Rz72. The method of preparation of the specific diagnostic Rz72 factor serum for determination of this antigen is described.