Effect of metronidazole on microbiomes associated with asymptomatic bacterial vaginosis

• Published in: Access microbiology 2019-03, Vol.1 (1A)
• Main Authors: Coudray, Makella, Ruiz-Perez, Daniel, Colbert, Brett, Krupp, Karl, Kumari, Hansi, Narasimhan, Giri, Mathee, Kalai, Madhivanan, Purnima
• Format: Article
• Language: English
• ISSN: 2516-8290; 2516-8290
• DOI: 10.1099/acmi.ac2019.po0531

Asymptomatic Bacterial Vaginosis (BV) damages vaginal epithelium increasing risk of sexually-transmitted infections. Gardnerella vaginalis , Atopobium vaginae , Prevotella amnii , P. bivia and Candida albicans are associated with BV. Presence of Lactobacillus spp. is indicative of a healthy microbiota. Symptomatic BV is treated with metronidazole. The role of microbiota and metronidazole treatment in the recurrence and persistence of asymptomatic BV remains to be elucidated. This study uses whole genome sequencing (WGS) to determine the microbiota changes with metronidazole treatment. DNA from 20 vaginal swabs was obtained at four time points over 12 months from five African American women and was subjected to WGS. The first time point is the untreated baseline. All subjects were tested every 4 months and received a course of metronidazole for each episode of BV during the 12 months period. Nugent scores were used to classify BV status. The microbial profiles were analyzed along with the sociodemographic metadata. Despite treatment, the participants did not recover from BV — two participants experienced persistent BV, and the rest had recurrent BV. WGS analyses show that G. vaginalis was the most abundant organism as compared to Lactobacillus species. The metronidazole treatment resulted in the loss of Lactobacillus and Prevotella species. One participant scored healthy based on Nugent score at one time point, during when Lactobacillus species dominated the microbiome. Based on this pilot longitudinal study, metronidazole may not be an effective treatment for asymptomatic BV. Studies with larger cohorts can lead to statistically significant conclusions to develop alternative interventions for asymptomatic BV.