An ELISA for the detection of localized adherent classic enteropathogenic Escherichia coli serogroups

An ELISA for the detection of classic enteropathogenic Escherichia coli (EPEC) serogroups was developed. It detected EPEC positive for localized adherence (LA) by HeLa cell assay and EPEC positive for EPEC adherence factor (EAF) by DNA probe assay. A specific antiserum was raised with LA+ EPEC strain E2348/69 (serotype O127:H6) by immunizing rabbits and then absorbing the antiserum with its LA- derivative, MAR20. The absorbed antiserum reacted specifically with all 90 strains of E. coli belonging to eight different EPEC serogroups that were LA+ by HeLa cell assay and EAF+ by DNA probe assay. All E. coli strains including EPEC serogroups that were LA- by HeLa cell assay and EAF- by DNA probe assay were also negative by ELISA. Thus the ELISA is 100% sensitive and specific in detecting LA+ classic EPEC serogroups.