Somatic serogroups, capsular types, and species of fecal Klebsiella in patients with ankylosing spondylitis.

The purpose of the present study was to find out whether patients with ankylosing spondylitis (AS) carry fecal Klebsiella strains that belong to serotypes or species specific for AS. Somatic serotypes (O groups), capsular (K) serotypes, and biochemically identified species were determined for fecal klebsiellae isolated from 187 AS patients and 195 control patients. The controls were patients with fibromyalgia or rheumatoid arthritis.