Prevalence of HEp-2 cell-adherent Escherichia coli and characterisation ofenteroaggregative E-coli and chain-like adherent E-coli isolated from children with and without diarrhoea, in Londrina, Brazil

A total of 919 Escherichia coli isolates from 125 children with diarrhoea ( cases) and 98 controls were assayed for adherence to HEp-2 cells. Localised adherence was found only in isolates from cases. Diffuse, aggregative (AA) , chain-like adherence (CLA) and variants of the AA pattern were found in b oth cases and controls. The AA isolates were tested for gene sequences asso ciated with enteroaggregative E. coli (EAEC). Only 25% of the isolates hybr idised with the EAEC probe, and the aafA, astA and pet gene sequences were found in 7.9%, 44.7% and 7.9% of the isolates, respectively. The aggA gene was not found, although 7.9% were positive for aggC. The CLA isolates react ed with the EAEC probe (55.6%),nd the aggC, astA and pet gene sequences wer e found in 66.7%, 33.3% and 11.1%, respectively. The aggR (55.6%), aspU (55 .6%), shf(33.3%) and she (22.2%) genes were also found in CLA isolates. (C) 2000 Federation of European Microbiological Societies. Published by Elsevi er Science B.V. All rights reserved.