Abstract

A study of 163 patients with ankylosing spondylitis seen on 433 occasions showed that active inflammatory disease was strongly associated with the presence of Klebsiella pneumoniae in the faeces (P less than 0.001). Sequential studies showed that in patients with inactive disease the presence of a positive culture for Klebsiella was associated with the subsequent development of active inflammatory disease (P less than 0.001). These findings support the hypothesis that Kl. pneumoniae may be an initiating agent in ankylosing spondylitis.