Monoclonal Antibodies to Lipopolysaccharide O Antigens of Enterohemorrhagic Escherichia coli Strains in Serogroups O26, O45, O103, O111, O121, and O145.

Non-O157 enterohemorrhagic Escherichia coli in priority serogroups O26, O45, O103, O111, O121, and O145 are increasingly recognized as important human pathogens. In the present study, a panel of monoclonal antibodies (MAbs) to the lipopolysaccharide O antigens of E. coli in serogroups O26, O45, O103, O111, O121, and O145 was produced. The specificity was evaluated by examining the reactivity of the MAbs with 50 E. coli strains and 42 non–E. coli bacteria, and several MAbs highly specific for E. coli strains in each of the six non-O157 priority serogroups were identified. The use of these highly specific MAbs may be of considerable value for determining whether an E. coli isolate belongs to one of the six priority non-O157 serogroups, for developing specific detection assays for these organisms, and for characterizing the lipopolysaccharide O antigens of isolates in these serogroups.