Vaginal microbial composition is associated with differential risk of urogenital infection. Although Lactobacillus spp. are thought to confer protection against infection, the lack of in vivo models resembling the human vaginal microbiota remains a prominent barrier to mechanistic discovery. Using 16S rRNA amplicon sequencing of C57BL/6J female mice, we found that vaginal microbial composition varies within and between colonies across three vivaria. Noting vaginal microbial plasticity in conventional mice, we assessed the vaginal microbiome of humanized microbiota mice (^HMbmice). Like the community structure in conventional mice, ^HMbmice vaginal microbiota clustered into community state types but, uniquely, ^HMbmice communities were frequently dominated by Lactobacillus or Enterobacteriaceae. Compared to conventional mice, ^HMbmice were less susceptible to uterine ascension by urogenital pathobionts group B Streptococcus (GBS) and Prevotella bivia. Although Escherichia and Lactobacillus both correlated with the absence of uterine GBS, vaginal pre-inoculation with exogenous ^HMbmouse-derived E. coli, but not Ligilactobacillus murinus, reduced vaginal GBS burden. Overall, ^HMbmice serve as a useful model to elucidate the role of endogenous microbes in conferring protection against urogenital pathogens.

阴道微生物组成与泌尿生殖道感染的不同风险相关。虽然乳酸菌属。被认为可以提供针对感染的保护，但缺乏类似于人类阴道微生物群的体内模型仍然是机械发现的一个突出障碍。通过对 C57BL/6J 雌性小鼠进行 16S rRNA 扩增子测序，我们发现三个小鼠的阴道微生物组成在菌落内部和菌落之间存在差异。注意到传统小鼠的阴道微生物可塑性，我们评估了人源化微生物群小鼠（^HMb小鼠）的阴道微生物组。与传统小鼠的群落结构一样，^HMb小鼠阴道微生物群聚集成群落状态类型，但独特的是，^{HMb小鼠群落经常以}乳杆菌或肠杆菌科为主。与传统小鼠相比，^{HMb小鼠对泌尿生殖道致病菌 B 组}链球菌(GBS) 和普雷沃氏菌 (Prevotella bivia)引起的子宫上升不太敏感。尽管大肠杆菌和乳酸杆菌均与子宫 GBS 的缺乏相关，但阴道预接种外源^HMb小鼠来源的大肠杆菌（而非鼠Ligilactobacillus murinus）可减少阴道 GBS 负担。总体而言，^HMb小鼠是阐明内源性微生物在提供针对泌尿生殖病原体的保护方面的作用的有用模型。