Antimicrobial resistance associated with the treatment of bacterial vaginosis.

Author(s): Beigi RH, Austin MN, Meyn LA, Krohn MA, Hillier SL

Affiliation(s): MetroHealth Medical Center and Dept. of Obstetrics and Gynecology, Case Western Reserve University, 2500 MetroHealth Drive, Cleveland, OH 44109-1998, USA. rbeigi@metrohealth.org

Publication date & source: 2004-10, Am J Obstet Gynecol., 191(4):1124-9.

Publication type: Clinical Trial; Randomized Controlled Trial

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.