Culturing of female bladder bacteria reveals an interconnected urogenital microbiota

Abstract

Metagenomic analyses have indicated that the female bladder harbors an indigenous microbiota. However, there are few cultured reference strains with sequenced genomes available for functional and experimental analyses. Here we isolate and genome-sequence 149 bacterial strains from catheterized urine of 77 women. This culture collection spans 78 species, representing approximately two thirds of the bacterial diversity within the sampled bladders, including Proteobacteria, Actinobacteria, and Firmicutes. Detailed genomic and functional comparison of the bladder microbiota to the gastrointestinal and vaginal microbiotas demonstrates similar vaginal and bladder microbiota, with functional capacities that are distinct from those observed in the gastrointestinal microbiota. Whole-genome phylogenetic analysis of bacterial strains isolated from the vagina and bladder in the same women identifies highly similar Escherichia coli, Streptococcus anginosus, Lactobacillus iners, and Lactobacillus crispatus, suggesting an interlinked female urogenital microbiota that is not only limited to pathogens but is also characteristic of health-associated commensals.

Fig. 1

Phylogenetic tree representing diversity of bacteria cultured from the female bladder. A representation of the full bacterial diversity (n = 149 isolates) that can be isolated using the expanded quantitative urine culture (EQUC) method from catheterized urine samples (n = 77 patients)

Fig. 2

Functional diversity between genomes of bacterial strains isolated from the bladder, vagina, and intestine. Discriminant analysis of principal components using conserved protein domains (CDD). Each color dot represents a strain from 3 different niches: blue (vagina; n = 92), red (bladder; n = 67), and green (gut; n = 152)

Fig. 3

Phylogenetic comparison of bladder and vaginal strains isolated from individual women using the 40 universal core genes. a Maximum likelihood tree constructed from E. coli strains isolated from the bladder (red) and vagina (blue) of individual patient (P1) and four reference strains. b Maximum likelihood tree constructed from S. anginosus strains isolated from the bladder (red) and vagina (blue) of individual patient (P2) and five reference strains. c Maximum likelihood tree constructed from L. iners strains isolated from the bladder (red) and vagina (blue) of individual patient (P3) and four reference strains. d Maximum likelihood tree constructed from L. crispatus strains isolated from the bladder (red) and vagina (blue) of individual patient (P4) and seven reference strains