Escherichia coli O antigen typing using DNA microarrays.

DNA microarrays were developed for rapid identification of different serogroups of Escherichia coli in a single platform. Oligonucleotides, as well as PCR products from genes in the O antigen gene clusters of E. coli serogroups O7, O104, O111, and O157 were spotted onto glass slides. This was followed by hybridization with labeled long PCR products of the entire O antigen gene clusters of these serogroups. Results demonstrated that microarrays consisting of either oligonucleotides or PCR products generated specific signals for each serogroup. This is the first report describing the development of model DNA microarrays for determining the serogroup of E. coli strains.