Anaerobic and aerobic urethral flora in healthy females

Abstract

We characterized the aerobic and anaerobic urethral flora of five healthy females by performing urethral and midstream urine cultures once weekly for 8 weeks. Aerobic cultures were performed monthly for an additional 3 months. Lactobacillus spp. were isolated from 52 of 57 samples, Staphylococcus epidermidis from 42 of 57, Corynebacterium spp. from 26 of 57, and alpha-hemolytic streptococci from 14 of 57. Two subjects had E. coli serogroup O6 and group B streptococci isolated on five occasions, respectively. Anaerobes were isolated from 32 of 35 urethral urines (91%). Bacteroides melaninogenicus accounted for 46% of these isolates. The anaerobic urethral flora varied slightly from week to week, and a similar anaerobic flora was isolated from the introitus, fourchette, and cutaneous perineum. In addition, anaerobes were isolated from 16 of 18 healthy females who had a urethral urine sample cultured once only, and B. melaninogenicus was the most frequent isolate. Of the 21 B. melaninogenicus isolates identified to subspecies, 14 were subsp. intermedius.