Anaerobes in genitourinary infections in men.

Urethral and sub-preputial swabs from 150 men were examined. There was a strong association between the isolation of anaerobic bacteria, particularly Bacteroides spp, and a clinical diagnosis of balanoposthitis, non-specific urethritis (NSU), or both. Aerobic bacteria formed the predominant flora in 28 healthy controls whereas anaerobes were predominant in specimens from 79 patients with balanoposthitis, from 24 with NSU, and from 19 with both. Bacteroides spp were the commonest isolates in all patient groups; B asaccharolyticus, B melaninogenicus ss intermedius, B ureolyticus, and B bivius were the most common species. The results obtained with the two swabs were identical except that Gardnerella vaginalis was isolated from the urethral swab only in five patients.