A Chinese rhesus macaque (Macaca mulatta) model for vaginal Lactobacillus colonization and live microbicide development

Abstract

We sought to establish a nonhuman primate model of vaginal Lactobacillus colonization suitable for evaluating live microbial microbicide candidates. Vaginal and rectal microflora in Chinese rhesus macaques (Macaca mulatta) were analyzed, with cultivable bacteria identified by 16S rRNA gene sequencing. Live lactobacilli were intravaginally administered to evaluate bacterial colonization. Chinese rhesus macaques harbored abundant vaginal Lactobacillus, with Lactobacillus johnsonii as the predominant species. Like humans, most examined macaques harbored only one vaginal Lactobacillus species. Vaginal and rectal Lactobacillus isolates from the same animal exhibited different genetic and biochemical profiles. Vaginal Lactobacillus was cleared by a vaginal suppository of azithromycin, and endogenous L. johnsonii was subsequently restored by intravaginal inoculation. Importantly, prolonged colonization of a human vaginal Lactobacillus jensenii was established in these animals. The Chinese rhesus macaque harbors vaginal Lactobacillus and is a potentially useful model to support the pre-clinical evaluation of Lactobacillus-based topical microbicides.