Serodiagnosis of infection with Verocytotoxin-producing Escherichia coli

Human sera (167) were screened for antibodies to lipopolysaccharide (LPS) p repared from strains of Verocytotoxin-producing Escherichia coli (VTEC) bel onging to a range of serogroups, secreted proteins expressed by attaching a nd effacing VTEC, enterohaemolysin and H = 7 flagellar proteins. Twelve ser a (about 7%) contained antibodies to the LPS of E, coli 05 (one), 026 (two) , 0145(one), 0145 (one), 0163 (one) and 0165 (five). Sera containing antibo dies to the LPS off. roll O26 and O145 also contained antibodies to secrete d proteins of 100 and 40 kDa. An additional 34 sera, known to contain antib odies to the lipopolysaccharide of E. roll O157, were examined for antibodi es to enterohaemolysin, H = 7 flagellar antigens and bacterial cell surface -associated proteins of 5, 6 and 22 kDa. Three sera contained antibodies to enterohaemolysin and one serum contained antibodies to flagellar proteins. Antibodies to membrane-associated proteins were not detected. It was concl uded that enterohaemolysin, H = 7 flagellar proteins and the cell surface-a ssociated proteins were unsuitable for use in immunoassays for providing ev idence of infection with VTEC.