Bacteriology of the urethra in normal men and men with nongonococcal urethritis

Abstract

Sixty-nine Caucasian males without a previous history of urethritis and who developed nongonococcal urethritis (NGU) and 39 similar men without urethritis (NU) were cultured from the urethra for Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum, aerobes and anaerobes. C. trachomatis infection was proven by culture or serology in 26 (38%) of the NGU group and 1 (3%) of the NU group; the C. trachomatis-negative NGU group had significantly more U. urealyticum (81%) than the C. trachomatis-positive NGU group (42%) or the NU group (59%). Aerobes were isolated from all but 2 men with C. trachomatis-negative NGU. Anaerobes were isolated from significantly more NU men (91%) than from men with NGU (66%). The aerobic and anaerobic flora of the 2 NGU groups were similar. The NU group had significantly more aerobic lactobacilli, Haemophilus vaginalis, .alpha.-hemolytic streptococci (not Streptococcus faecalis) and anaerobes, predominantly Bacteroides spp. This study provided information about the prevalence and the variety of the aerobic and anerobic microbiological flora of the anterior urethra of sexually active males. It does not implicate any bacteria other than C. trachomatis and U. urealyticum as potential causes of NGU.