Treatment of Bacterial Vaginosis: A Comparison of Metronidazole and Clindamycin on Human Anaerobic Bacteria and Lactobacilli

Background: Bacterial vaginosis (BV) is a disturbance of vaginal microflora that affects up to one-third of women of reproductive age. To compare the frequencies, clinical characteristics, and antimicrobial susceptibilities of vaginal microbes before and after metronidazole and clindamycin therapy. Results: A total of 140 premenopausal women with BV and 10 healthy women who underwent routine gynecological examination and were examined by the Vaginal Microecology Evaluation System at Beijing Obstetrics and Gynecology Hospital between October 2018 and February 2019 were recruited for this study. Gardnerella (G.) vaginalis and Lactobacillus isolates were isolated and cultured. Clinical isolates were then evaluated for antimicrobial susceptibilities in vitro to metronidazole and clindamycin. Nested PCR and denaturing gradient gel electrophoresis were used to characterize the quantitative structure of bacterial signatures. Facultatively anaerobic bacteria including G. vaginalis (40.31 %), Prevotella isolates (14.89 %) and Atopobium (A.) vaginae (4.65 %) were among the most frequently isolated species among the 129 samples. The clinical isolates had a significantly higher susceptibility rate to clindamycin than to metronidazole (80.00% vs 32.14%; P = 0.002) in vitro. Conclusions: Given metronidazole sparing Lactobacillus, metronidazole has better vaginal acidification than clindamycin in vivo. The CDC-recommended regimens for BV management with metronidazole and clindamycin were demonstrated to have roughly equivalent clinical efficacy. We recommend administering Lactobacillus probiotics 5 to 7 days after the last antibiotic dose when choosing clindamycin therapy.