Adhesion to cells in culture and plasmid profiles of enteropathogenic Escherichia coli isolated from outbreaks and sporadic cases of infant diarrhoea.

Enteropathogenic strains of Escherichia coli (EPEC) that caused 10 outbreaks of infant diarrhoea in the U.K. between 1968 and 1986 were studied. All gave localised adherence (LA) to HEp-2 cells, HeLa cells and Intestine 407 cells in culture. All hybridised with the EPEC adherence factor (EAF) probe. The hybridising sequences were carried on plasmids ranging in size from 26 to 76 MDa. EPEC from sporadic cases of infant diarrhoea occurring between 1979 and 1986 that belonged to the same serotypes as the outbreak strains were also studied. All strains of serotypes O111ab.H2, O114.H2, O119.H6, O127.H6 and O142.H6 gave LA and were EAF-positive. In other serotypes, non-adhering strains or strains giving diffuse adherence were found also. In addition, strains of serotype O128.H2 which gave LA but did not hybridise with the EAF probe were identified. The strains isolated from sporadic cases of diarrhoea in the U.K. were similar, with respect to adhesion and hybridisation, to those isolated from sporadic cases of diarrhoea in developing countries.