Gardnerella is a frequent member of the urogenital microbiota. Given the association between Gardnerella vaginalis and bacterial vaginosis (BV), significant efforts have been focused on characterizing this species in the vaginal microbiota. However, Gardnerella also is a frequent member of the urinary microbiota. In an effort to characterize the bacterial species of the urinary microbiota, we present here 10 genomes of urinary Gardnerella isolates from women with and without lower uri- nary tract symptoms. These genomes complement those of 22 urinary Gardnerella strains previously isolated and sequenced by our team. We included these genomes in a comparative genome analysis of all publicly available Gardnerella genomes, which include 33 urinary isolates, 78 vaginal isolates, and 2 other isolates. While once this genus was thought to consist of a single species, recent comparative ge- nome analyses have revealed 3 new species and an additional 9 groups within Gardnerella. Based upon our analysis, we suggest a new group for the species. We also find that distinction between these Gardnerella species/groups is possible only when considering the core or whole-genome sequence, as neither the sialidase nor vaginolysin genes are sufficient for distinguishing between species/groups despite their clinical importance. In contrast to the vaginal microbiota, we found that only five Gardnerella species/groups have been detected within the lower urinary tract. Although we found no association between a particular Gardnerella species/group(s) and urinary symptoms, further sequencing of urinary Gardnerella isolates is needed for both comprehensive taxonomic characterization and etiological classification of Gardnerella in the urinary tract. Importance Prior research into the bacterium Gardnerella vaginalis has largely focused on its association with bacterial vaginosis (BV). However, G. vaginalis is also frequently found within the urinary microbiota of women with and without lower urinary tract symptoms as well as individuals with chronic kidney disease, interstitial cystitis, and BV. This prompted our investigation into Gardnerella from the urinary microbiota and all publicly available Gardnerella genomes from the urogenital tract. Our work suggests that while some Gardnerella species can survive in both the urinary tract and vagina, others likely cannot. This study provides the foundation for future studies of Gardnerella within the urinary tract and its possible contribution to lower urinary tract symptoms.
Bibliographical noteFunding Information:
We acknowledge Trevor Lawley and his group at the Wellcome Trust Sanger Institute, in particular Nitin Kumar. We also thank Swarnali Banerjee for discussion on statistical analyses. We acknowledge funding from NIH (R01 DK104718 awarded to A.J.W.) and NSF (1661357 awarded to C.P.). E.C. is supported by the Mulcahy Research Fellowship (Loyola University Chicago). C. Putonti discloses research support from NSF. A. J. Wolfe discloses research support from NIH, the DOD, and the Kimberly Clark Corporation and membership on the scientific advisory boards of Pathnostics and Urobiome Therapeutics.
We acknowledge funding from NIH (R01 DK104718 awarded to A.J.W.) and NSF (1661357 awarded to C.P.). E.C. is supported by the Mulcahy Research Fellowship (Loyola University Chicago).
Copyright © 2021 Putonti et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.
- lower urinary tract symptoms
- urinary microbiome
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't
- Research Support, N.I.H., Extramural
- Research Support, U.S. Gov't, Non-P.H.S.