Bacterial viruses (bacteriophages) play a significant role in microbial community dynamics. Within the human gastrointestinal tract, for instance, associations among bacteriophages (phages), microbiota stability, and human health have been discovered. In contrast to the gastrointestinal tract, the phages associated with the urinary microbiota are largely unknown. Preliminary metagenomic surveys of the urinary virome indicate a rich diversity of novel lytic phage sequences at an abundance far outnumbering that of eukaryotic viruses. These surveys, however, exclude the lysogenic phages residing within the bacteria of the bladder. To characterize this phage population, we examined 181 genomes representative of the phylogenetic diversity of bacterial species within the female urinary microbiota and found 457 phage sequences, 226 of which were predicted with high confidence. Phages were prevalent within the bladder bacteria: 86% of the genomes examined contained at least one phage sequence. Most of these phages are novel, exhibiting no discernible sequence homology to sequences in public data repositories. The presence of phages with substantial sequence similarity within the microbiota of different women supports the existence of a core community of phages within the bladder. Furthermore, the observed variation between the phage populations of women with and without overactive bladder symptoms suggests that phages may contribute to urinary health. To complement our bioinformatic analyses, viable phages were cultivated from the bacterial isolates for characterization; a novel coliphage was isolated, which is obligately lytic in the laboratory strain C. Sequencing of bacterial genomes facilitates a comprehensive cataloguing of the urinary virome and reveals phage-host interactions. Bacteriophages are abundant within the human body. However, while some niches have been well surveyed, the phage population within the urinary microbiome is largely unknown. Our study is the first survey of the lysogenic phage population within the urinary microbiota. Most notably, the abundance of prophage exceeds that of the bacteria. Furthermore, many of the prophage sequences identified exhibited no recognizable sequence homology to sequences in data repositories. This suggests a rich diversity of uncharacterized phage species present in the bladder. Additionally, we observed a variation in the abundances of phages between bacteria isolated from asymptomatic "healthy" individuals and those with urinary symptoms, thus suggesting that, like phages within the gut, phages within the bladder may contribute to urinary health.

Urinary tract infections (UTIs) are one of the most common human bacterial infections. While UTIs are commonly associated with colonization by Escherichia coli , members of this species also have been found within the bladder of individuals with no lower urinary tract symptoms (no LUTS), also known as asymptomatic bacteriuria. Prior studies have found that both uropathogenic E. coli (UPEC) strains and E. coli isolates that are not associated with UTIs encode for virulence factors. Thus, the reason(s) why E. coli sometimes causes UTI-like symptoms remain(s) elusive. In this study, the genomes of 66 E. coli isolates from adult female bladders were sequenced. These isolates were collected from four cohorts, including women: (1) without lower urinary tract symptoms, (2) overactive bladder symptoms, (3) urgency urinary incontinence, and (4) a clinical diagnosis of UTI. Comparative genomic analyses were conducted, including core and accessory genome analyses, virulence and motility gene analyses, and antibiotic resistance prediction and testing. We found that the genomic content of these 66 E. coli isolates does not correspond with the participant’s symptom status. We thus looked beyond the E. coli genomes to the composition of the entire urobiome and found that the presence of E. coli alone was not sufficient to distinguish between the urobiomes of individuals with UTI and those with no LUTS. Because E. coli presence, abundance, and genomic content appear to be weak predictors of UTI status, we hypothesize that UTI symptoms associated with detection of E. coli are more likely the result of urobiome composition.

The discovery of bacteria in the female urinary bladder has fundamentally changed current dogma regarding the urinary tract and related urinary disorders. While prior research has characterized many of the bacterial components of the female urinary tract, the viral fraction of this community is largely unknown. Viruses within the human microbiota far outnumber bacterial cells, with the most abundant viruses being those that infect bacteria (bacteriophages). Similar to observations within the microbial communities (microbiota) of the gut and oral cavity, preliminary surveys of the urinary tract and bladder microbiota indicate a rich diversity of uncharacterized bacteriophage (phage) species. Phages are vital members of microbiota, playing critical roles in shaping bacterial metabolism and community structure. Here, we review the current knowledge of phages within the urinary tract and their possible contribution to urinary tract health. Furthermore, as the natural predators of bacteria, phages have garnered renewed interest in their use as antimicrobial agents. Both historical and recent applications of phage therapy for lower urinary tract infections and other disorders are discussed.

Viruses are the most abundant component of the human microbiota. Recent evidence has uncovered a rich diversity of viruses within the female bladder, including both bacteriophages and eukaryotic viruses. We conducted whole-genome sequencing of the bladder microbiome of 30 women: 10 asymptomatic 'healthy' women and 20 women with an overactive bladder. These metagenomes include sequences representative of human, bacterial and viral DNA. This analysis, however, focused specifically on viral sequences. Using the bioinformatic tool virMine, we discovered sequence fragments, as well as complete genomes, of bacteriophages and the eukaryotic virus JC polyomavirus. The method employed here is a critical proof of concept: the genomes of viral populations within the low-biomass bladder microbiota can be reconstructed through whole-genome sequencing of the entire microbial community.

Recent research has debunked the myth that urine is sterile, having uncovered bacteria within the bladders of healthy individuals. However, the identity, diversity, and putative roles of bacteriophages in the bladder are unknown. We report the draft genome sequences of seven bacteriophages isolated from microbial communities from adult female bladders.