title: Longitudinal qPCR study of the dynamics of L. crispatus, L. iners, A. vaginae, (sialidase positive) G. vaginalis, and P. bivia in the vagina.
abstract: BACKGROUND
  To obtain more detailed understanding of the causes of disturbance of the vaginal microflora (VMF), a longitudinal study was carried out for 17 women during two menstrual cycles.
  
  
  METHODS
  Vaginal swabs were obtained daily from 17 non-pregnant, menarchal volunteers. For each woman, Gram stains were scored, the quantitative changes of 5 key vaginal species, i.e. Atopobium vaginae, Lactobacillus crispatus, L. iners, (sialidase positive) Gardnerella vaginalis and Prevotella bivia were quantified with qPCR and hydrogen-peroxide production was assessed on TMB+ agar.
  
  
  RESULTS
  Women could be divided in 9 subjects with predominantly normal VMF (grades Ia, Ib and Iab, group N) and 8 with predominantly disturbed VMF (grades I-like, II, III and IV, group D). VMF was variable between women, but overall stable for most of the women. Menses were the strongest disturbing factor of the VMF. L. crispatus was present at log7-9 cells/ml in grade Ia, Iab and II VMF, but concentrations declined 100-fold during menses. L. crispatus below log7 cells/ml corresponded with poor H(2)O(2)-production. L. iners was present at log 10 cells/ml in grade Ib, II and III VMF. Sialidase negative G. vaginalis strains (average log5 cells/ml) were detected in grade I, I-like and IV VMF. In grade II VMF, predominantly a mixture of both sialidase negative and positive G. vaginalis strains (average log9 cells/ml) were present, and predominantly sialidase positive strains in grade III VMF. The presence of A. vaginae (average log9 cells/ml) coincided with grade II and III VMF. P. bivia (log4-8 cells/ml) was mostly present in grade III vaginal microflora. L. iners, G. vaginalis, A. vaginae and P. bivia all increased around menses for group N women, and as such L. iners was considered a member of disturbed VMF.
  
  
  CONCLUSIONS
  This qPCR-based study confirms largely the results of previous culture-based, microscopy-based and pyrosequencing-based studies.
authors.affiliation: Laboratory for Bacteriology Research, Department of Clinical Chemistry, Microbiology, and Immunology, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium. Guido.LopesdosSantosSantiago@ugent.be
authors.forename: Guido Lopes dos Santos
authors.initials: GL
authors.lastname: Santiago
authors.forename: Inge
authors.initials: I
authors.lastname: Tency
authors.forename: Hans
authors.initials: H
authors.lastname: Verstraelen
authors.forename: Rita
authors.initials: R
authors.lastname: Verhelst
authors.forename: Marijke
authors.initials: M
authors.lastname: Trog
authors.forename: Marleen
authors.initials: M
authors.lastname: Temmerman
authors.forename: Leen
authors.initials: L
authors.lastname: Vancoillie
authors.forename: Ellen
authors.initials: E
authors.lastname: Decat
authors.forename: Piet
authors.initials: P
authors.lastname: Cools
authors.forename: Mario
authors.initials: M
authors.lastname: Vaneechoutte
mesh_terms: D039903:Actinobacteria / Q000235:genetics / Q000254:growth & development*; D000293:Adolescent; D000328:Adult; D058491:Bacterial Load; D005260:Female; D006194:Gardnerella vaginalis / Q000235:genetics / Q000254:growth & development*; D005840:Gentian Violet; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007778:Lactobacillus / Q000235:genetics / Q000254:growth & development*; D008137:Longitudinal Studies; D008597:Menstrual Cycle; D008598:Menstruation; D059013:Microbial Consortia / Q000235:genetics*; D009439:Neuraminidase / Q000378:metabolism; D010619:Phenazines; D018720:Prevotella / Q000235:genetics / Q000254:growth & development*; D060888:Real-Time Polymerase Chain Reaction; D014621:Vagina / Q000382:microbiology*
chemical_list: C035863:Gram's stain; D010619:Phenazines; D006861:Hydrogen Peroxide; D009439:Neuraminidase; D005840:Gentian Violet