[Enteroadherent Escherichia coli exhibiting localized pattern of adherence among infants with diarrhoea in Brazil--incidence and prevalence of serotypes]

Abstract

The incidence of enteroadherent Escheridhia coli exhibiting localized adherence to HeLa cells was investigated using the EAF probe (Nataro et al., J. Infect. Dis., 152:560-563, 1985) among 126 infants below 3 years of age along with 126 age-matched healthy controls in Brazil. The EAF probe proved to be sensitive and specific in detection of enteroadherent E. coli. EAF-probe positive E. coli was isolated from 23.0% of the infants with acute diarrhoea while the corresponding rate of isolation from healthy controls was 11.9%. EAF-probe positive E. coli strains belonging to the classical enteropathogenic E. coli (EPEC) serogroups were more often associated with diarrheal cases (18.3%) than with strains isolated from control healthy infants (5.6%). The predominant EAF-probe positive E. coli serotypes were O55:H-, O111:H2 and O119:H6. These serotypes, especially O111:H2, were mainly isolated from cases with diarrhoea suggesting a strong causal association. Among the EAF positive non-EPEC serotypes, the most prevalent serotype was O88:H25 and this represents a, hitherto, unrecognized diarrheagenic E. coli serotype.