Gardnerella vaginalis population dynamics in bacterial vaginosis

Eur J Clin Microbiol Infect Dis. 2017 Jul;36(7):1269-1278. doi: 10.1007/s10096-017-2933-8. Epub 2017 Feb 14.

Abstract

Bacterial vaginosis (BV) is the leading cause of vaginal discharge and is associated with the facultative Gram-variable bacterium Gardnerella vaginalis, whose population structure consists of four clades. Our goal was to determine if these clades differ with regard to abundance during BV. We performed a short-term longitudinal study of BV. Patients were evaluated according to the Amsel criteria and Nugent scoring at initial diagnosis, immediately after treatment and at a 40- to 45-day follow-up visit. G. vaginalis clade abundance was determined by quantitative real-time polymerase chain reactions (qPCRs). Among all specimens, the abundance of clades 1 and 4 were higher than that of clades 2 and 3 (P < 0.001). In general, the abundance of each clade increased with the degree of vaginal dysbiosis, as determined by the Nugent score and was greater in women with Amsel 4 compared with those with Amsel 0. Only clade 1 abundance was greater when Amsel 0 or 1 specimens were compared with Amsel 2 or 3 specimens (P < 0.01). Following antimicrobial treatment, abundance of clades 1 (P < 0.001) and 4 (P < 0.05) decreased regardless of the clinical and microbiological outcome, whereas clade 2 only decreased in women who had a sustained treatment response for 40-45 days (P < 0.01). Recurrent BV was characterized by post-treatment increases of clade 1 and 2 (P < 0.01). Clades 1 and 4 predominate in vaginal specimens. Clade abundance differs with regard to the Nugent score, the Amsel criteria, and response to therapy and BV recurrence.

MeSH terms

  • Adolescent
  • Adult
  • Bacterial Load
  • Female
  • Gardnerella vaginalis / classification
  • Gardnerella vaginalis / genetics
  • Gardnerella vaginalis / growth & development*
  • Genotype
  • Humans
  • Longitudinal Studies
  • Middle Aged
  • Population Dynamics*
  • Real-Time Polymerase Chain Reaction
  • Vaginosis, Bacterial / microbiology*
  • Young Adult