Serological evidence for the role of Bacteroides fragilis and enterobacteriaceae in the pathogenesis of acute pelvic inflammatory disease.

Pelvic inflammatory disease (PID) is classically divided into gonococcal and non-gonococcal forms depending on whether or not gonococcus is isolated from the lower genital tract. Chlamydia trachomatis seems to be another major pathogen in PID. In an attempt to determine the role of facultative enteric bacteria and anaerobic Bacteroides fragilis in the pathogenesis of PID antibodies to the enterobacterial common antigen (ECA) and B. fragilis capsular polysaccharide were measured in paired sera of 101 consecutive patients with PID. Significant ECA and B. fragilis antibody tires were each found in about a third of the patients whether or not the lower-genital-tract culture yielded gonococci or C. trachomatis. These results support the concept that PID is a polymicrobial infection in which both anaerobes and aerobic enteric bacteria, as well as gonococci and C. trachomatis, have an important role.