Biochemical and serological patterns of Escherichia coli O2 strains isolated from patients with urinary tract infections.

We examined the results of two biochemical test systems for their ability to discriminate a series of 58 Escherichia coli O2 strains collected from patients with urinary tract infections. The O:K:H serotypes and O antigen factors of the strains were also determined. The strains could be assigned to 13 distinct serological patterns by means of O2 antigen factors as well as K and H antigens. The combination of O:K:H-serotyping with biotyping enabled very fine strain discrimination. These data indicate that the biotyping system of Achtman (BTA) is more precise than the Enterobacteriaceae-code-system described by Reiske (ECR) and that the determination of BTA types supports the identification of bacterial clones.