Structural and Serological Characterization of Yet Another New O Antigen, O86, in Clinical Strains.

Bacteria from the genus are facultative human pathogens, primarily attacking the urinary tract and wounds. A total of 85 O serogroups have been identified so far among these bacilli. Bprz 86 was isolated from the fistula of a patient in Łódź, Poland. Enzyme-Linked Immunosorbent Assay (ELISA) and Western blotting studies involving the Bprz 86 lipopolysaccharide (LPS) and the strain-specific rabbit antiserum indicated that the strain, which does not belong to any of the O1-O85 serogroups, shares a common epitope with O17 antigens and is identical to another clinical strain, Sm 120, isolated from the urine of a patient in the area. The O-specific polysaccharide (O antigen) was obtained from Bprz 86 LPS through mild acid degradation, and the six-constituent structure of its repeating unit was determined using chemical analyses and 1D and 2D H and C Nuclear Magnetic Resonance (NMR) spectroscopy. It includes ()-3-hydroxybutanoyl, which, along with fucosamine and glucose residues, forms a fragment also present in the O17 antigens. Based on the obtained serological and chemical data, the two studied isolates were proposed as candidates for a new successive O serogroup in the genus , O86.