Comparative genomics of Gardnerella vaginalis strains reveals substantial differences in metabolic and virulence potential.

TitleComparative genomics of Gardnerella vaginalis strains reveals substantial differences in metabolic and virulence potential.
Publication TypeJournal Article
Year of Publication2010
AuthorsYeoman, CJ, Yildirim, S, Thomas, SM, A Durkin, S, Torralba, M, Sutton, G, Buhay, CJ, Ding, Y, Dugan-Rocha, SP, Muzny, DM, Qin, X, Gibbs, RA, Leigh, SR, Stumpf, R, White, BA, Highlander, SK, Nelson, KE, Wilson, BA
JournalPLoS One
Volume5
Issue8
Paginatione12411
Date Published2010 Aug 26
ISSN1932-6203
KeywordsBacterial Proteins, Female, Gardnerella vaginalis, Genomics, Humans, Male, Molecular Sequence Data, Phylogeny, Vagina, Vaginosis, Bacterial, Virulence
Abstract

BACKGROUND: Gardnerella vaginalis is described as a common vaginal bacterial species whose presence correlates strongly with bacterial vaginosis (BV). Here we report the genome sequencing and comparative analyses of three strains of G. vaginalis. Strains 317 (ATCC 14019) and 594 (ATCC 14018) were isolated from the vaginal tracts of women with symptomatic BV, while Strain 409-05 was isolated from a healthy, asymptomatic individual with a Nugent score of 9.PRINCIPAL FINDINGS: Substantial genomic rearrangement and heterogeneity were observed that appeared to have resulted from both mobile elements and substantial lateral gene transfer. These genomic differences translated to differences in metabolic potential. All strains are equipped with significant virulence potential, including genes encoding the previously described vaginolysin, pili for cytoadhesion, EPS biosynthetic genes for biofilm formation, and antimicrobial resistance systems, We also observed systems promoting multi-drug and lantibiotic extrusion. All G. vaginalis strains possess a large number of genes that may enhance their ability to compete with and exclude other vaginal colonists. These include up to six toxin-antitoxin systems and up to nine additional antitoxins lacking cognate toxins, several of which are clustered within each genome. All strains encode bacteriocidal toxins, including two lysozyme-like toxins produced uniquely by strain 409-05. Interestingly, the BV isolates encode numerous proteins not found in strain 409-05 that likely increase their pathogenic potential. These include enzymes enabling mucin degradation, a trait previously described to strongly correlate with BV, although commonly attributed to non-G. vaginalis species.CONCLUSIONS: Collectively, our results indicate that all three strains are able to thrive in vaginal environments, and therein the BV isolates are capable of occupying a niche that is unique from 409-05. Each strain has significant virulence potential, although genomic and metabolic differences, such as the ability to degrade mucin, indicate that the detection of G. vaginalis in the vaginal tract provides only partial information on the physiological potential of the organism.

DOI10.1371/journal.pone.0012411
Alternate JournalPLoS ONE
PubMed ID20865041
PubMed Central IDPMC2928729
Grant ListU54-HG003273 / HG / NHGRI NIH HHS / United States
U54 HG004973 / HG / NHGRI NIH HHS / United States
U54 AI084844 / AI / NIAID NIH HHS / United States
U54 HG003273 / HG / NHGRI NIH HHS / United States
N01 AI 30071 / AI / NIAID NIH HHS / United States
U54-HG004973 / HG / NHGRI NIH HHS / United States
N01 AI030071 / AI / NIAID NIH HHS / United States