SERUM ANTIBODIES TO SECRETED PROTEINS IN PATIENTS INFECTED WITH ESCHERICHIA-COLI O157 AND OTHER VTEC

Certain strains of verotoxigenic Escherichia coli (VTEC), and in parti cular those belonging to serogroup O157, cause attaching and effacing (AE) lesions of the host gut mucosa during pathogenesis. The mechanism s involved with bacterial attachment and the destruction of microvilli are determined by a cluster of genes within the LEE region, which als o encode five secreted proteins. Sera from patients with antibodies to the lipopolysaccharide (LPS) of E. coli O157 and other VTEC were test ed for antibodies to these secreted proteins. Twenty-one of 34 (62 %) sera with antibodies to the lipopolysaccharide (LPS) of E. coil O157 a lso contained antibodies to one or more of the secreted proteins. Five of 12 sera containing antibodies to the LPS of a range of other VTEC serogroups also contained antibodies to 1 or more of the 5 secreted pr oteins, as did 16 of 70 (23 %) sera from patients with haemolytic urae mic syndrome (HUS), haemorrhagic colitis (HC) or diarrhoea, but withou t bacteriological evidence of infection with VTEC and which did not co ntain antibodies to VTEC serogroups O5, O115, O145, O153 or O157. The detection of serum antibodies to secreted proteins may provide additio nal information for interpreting the results of established lipopolysa ccharide-based VTEC serology.