Rapid identification of colonization factor antigens I & II of enterotoxigenic Escherichia coli by coagglutination test

Specific antisera for colonization factor antigens (CFA/I and CFA/II) were adsorbed to Staphylococcus aureus Cowan I strain, ATCC 12598 to make coagglutination (CoA) reagents for detection of CFAs in enterotoxigenic Esch. coli (ETEC) isolates. Among 1782 strains of Esch. coli isolated from patients with acute diarrhoea, 238 (13.4%) strains exhibited CFA expression. Most prevalent CFA/I positive serogroups were 015, 0148, 0153, 020, 0128, 0114 and 078. CFA/II was detected among isolates of serogroup 080, 085, 06 and 08. Ten ETEC isolates each of serogroups 04, 07, 061, 068, 0117 and 0158 did not show presence of CFA/I or CFA/II. CoA technique proved an appropriate, rapid diagnostic tool which can be used for screening large number of Esch. coli isolates in epidemiological studies.