EPITHELIAL-CELL INVASIVENESS OF NON-ENTEROPATHOGENIC SEROTYPES OF ESCHERICHIA-COLI

Current evidence suggests that enteropathogenic Escherichia coli (EPEC ) of traditional serotypes possess a three-stage pathogenesis: localis ed adherence (LA) to, attachment-effacement (AE) of, and penetration o f, enterocytes, all of which can be rr-produced in tissue culture mode ls in vitro. Three E coli isolates of non-traditional serotypes (02:H2 , 02:H25 and 015:H2) isolated from children with diarrhoea were previo usly shown to be positive for LA and AE activities in laboratory model s. In the present study, they were, in addition, shown to be positive for invasion of a HEp-2 cell monolayer. These findings further establi sh the pathogenicity of non-traditional serotypes of E. coli and their role in the causation of diarrhoea.