HeLa cell-adherent enteropathogenic Escherichia coli in children under 1 year of age in Thailand

Enteropathogenic Escherichia coli (EPEC) was isolated from 11% of 148 Hmong children under 1 year old with diarrhea at a refugee camp in northern Thailand. Of 16 children with EPEC-associated diarrhea, 11 were infected with EPEC that adhered to HeLa cells in a diffuse pattern, 3 were infected with EPEC that adhered to HeLa cells in a localized adherence (LA) pattern, and 2 were infected with EPEC that were nonadherent. In Bangkok, EPEC was isolated from 6% of 64 children under 1 year old with diarrhea and 7% of 56 children of the same age without diarrhea. Of four children with diarrhea, two were infected with EPEC with an LA pattern, and two were infected with nonadherent EPEC. Of four children without diarrhea, one was infected with EPEC with an LA pattern, one was infected with EPEC that adhered in a diffuse pattern, and two were infected with nonadherent EPEC. The 21 EPEC isolates with an LA pattern hybridized with the EPEC adherence factor DNA probe. EPEC was the only enteric pathogen identified in 16 (80%) of 20 children with EPEC-associated diarrhea. EPEC was as frequently isolated from children under 1 year old as were other bacterial enteric pathogens. The problem of identifying EPEC with pools of polyvalent antisera are described, and the need to identify additional enteropathogenic determinants of EPEC is discussed.