Medline ® Abstract for Reference 100

OBJECTIVE: This study was undertaken to evaluate antimicrobial susceptibility of vaginal anaerobic bacteria before and after treatment of bacterial vaginosis.

STUDY DESIGN: A randomized clinical trial of 119 nonpregnant women with bacterial vaginosis receiving either intravaginal metronidazole for 5 days or clindamycin for 3 days was performed. Women had 1 baseline and 3 follow-up visits at which quantitative vaginal cultures were performed. Anaerobic isolates underwent antimicrobial susceptibility testing.

RESULTS: Complete susceptibility data was available on 95 women (47 metronidazole and 48 clindamycin). Of 1059 anaerobic bacterial isolates, less than 1% demonstrated resistance to metronidazole. In contrast, 17% demonstrated baseline clindamycin resistance, and 53% demonstrated resistance to clindamycin after therapy. Women exposed to clindamycin (but not metronidazole) had high frequencies (80%) of clindamycin-resistant anaerobic bacteria that persisted for 90 days after treatment.

CONCLUSION: Treatment of bacterial vaginosis with clindamycin is associated with marked evidence of antimicrobial resistance among vaginal anaerobic bacteria. This may increase the vaginal reservoir of macrolide-resistant bacteria.