Longitudinal qPCR Study of the Dynamics of <em>L. crispatus</em>, <em>L. iners</em>, <em>A. vaginae</em>, (Sialidase Positive) <em>G. vaginalis</em>, and <em>P. bivia</em> in the Vagina

<div><h3>Background</h3><p>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.</p> <h3>Methods</h3><p>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, <em>i.e. Atopobium vaginae</em>, <em>Lactobacillus crispatus</em>, <em>L. iners</em>, (sialidase positive) <em>Gardnerella vaginalis</em> and <em>Prevotella bivia</em> were quantified with qPCR and hydrogen-peroxide production was assessed on TMB+ agar.</p> <h3>Results</h3><p>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).</p> <p>VMF was variable between women, but overall stable for most of the women. Menses were the strongest disturbing factor of the VMF.</p> <p><em>L. crispatus</em> was present at log7–9 cells/ml in grade Ia, Iab and II VMF, but concentrations declined 100-fold during menses. <em>L. crispatus</em> below log7 cells/ml corresponded with poor H₂O₂-production. <em>L. iner</em>s was present at log 10 cells/ml in grade Ib, II and III VMF. Sialidase negative <em>G. vaginalis</em> 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 <em>G. vaginalis</em> strains (average log9 cells/ml) were present, and predominantly sialidase positive strains in grade III VMF. The presence of <em>A. vaginae</em> (average log9 cells/ml) coincided with grade II and III VMF. <em>P. bivia</em> (log4–8 cells/ml) was mostly present in grade III vaginal microflora.</p> <p><em>L. iners</em>, <em>G. vaginalis</em>, <em>A. vaginae</em> and <em>P. bivia</em> all increased around menses for group N women, and as such <em>L. iners</em> was considered a member of disturbed VMF.</p> <h3>Conclusions</h3><p>This qPCR-based study confirms largely the results of previous culture-based, microscopy-based and pyrosequencing-based studies.</p>