Longitudinal Study of the Dynamics of Vaginal Microflora during Two Consecutive Menstrual Cycles

Abstract

BackgroundAlthough the vaginal microflora (VMF) has been well studied, information on the fluctuation of the different bacterial species throughout the menstrual cycle and the information on events preceding the presence of disturbed VMF is still very limited. Documenting the dynamics of the VMF during the menstrual cycle might provide better insights. In this study, we assessed the presence of different Lactobacillus species in relation to the BV associated species during the menstrual cycle, assessed the influence of the menstrual cycle on the different categories of vaginal microflora and assessed possible causes, such as menstruation and sexual intercourse, of VMF disturbance. To our knowledge, this is the first longitudinal study in which swabs and Gram stains were available for each day of two consecutive menstrual cycles, whereby 8 grades of VMF were distinguished by Gram stain analysis, and whereby the swabs were cultured every 7th day and identification of the bacterial isolates was carried out with a molecular technique.MethodsSelf-collected vaginal swabs were obtained daily from 17 non pregnant, menarchal volunteers, and used for daily Gram staining and weekly culture. Bacterial isolates were identified with tDNA-PCR and 16 S rRNA gene sequencing.ResultsNine women presented with predominantly normal VMF and the 8 others had predominantly disturbed VMF. The overall VMF of each volunteer was characteristic and rather stable. Menses and antimicrobials were the major disturbing factors of the VMF. Disturbances were always accompanied by a rise in Gram positive cocci, which also appeared to be a significant group within the VMF in general.ConclusionsWe observed a huge interindividual variability of predominantly stable VMF types. The importance of Gram positive cocci in VMF is underestimated. L. crispatus was the species that was most negatively affected by the menses, whereas the presence of the other lactobacilli was less variable.

The Vaginal Microbiota: What Have We Learned after a Decade of Molecular Characterization?

“…Similarly, several longitudinal VMB studies showed that a majority of women have a stable VMB microbiome [23], [26], [54], [59], [62]. A study in post-menopausal women showed that the VMB is usually stable in that group as well [49].…”

“…Studies also consistently suggest that menses is the largest disturbing factor during the menstrual cycle, with sometimes large reductions in lactobacilli [38], [59], [62], [63], shifts from L. crispatus to L. iners [38], [70], or the appearance of BV-associated bacteria, streptococci or other Gram-positive cocci [54], [70]. Pregnancy, which is also accompanied by high estradiol levels, is associated with high levels of lactobacilli, particularly L. crispatus , and low bacterial diversity [55], [68].…”

“…Two important areas of consensus emerged. First, almost all women carry vaginal lactobacilli regardless of their BV status by Nugent or Amsel criteria [19], [20], [22], [23], [25], [26], [33], [37]–[42], [45], [47], [48], [54], [59], [60], [62], [63], [73], [76], [80] but L. crispatus is predominantly found in BV-negative women [20], [22], [23], [25], [32], [33], [37], [38], [40], [42], [48], [50], [54], [59], [60], [62], [63], [65], [73], [75], [76], [80] whereas L. iners (and to a lesser extent L. gasseri ) is also found in women with intermediate microbiota or BV [21], [23], [25], [33], [37], [38], [40]–[42], [47], [50], [54], [59], [60], [62], [63], [65], [73], [76], …”

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

“…The present study builds upon previous work of our group, where we reported the results of Gram stain and culture for 17 menarchal women, who self-swabbed the vagina daily during two MCs [10]. Here, we add concentrations obtained by quantative PCR for five vaginal key species, i.e.…”

Actinomyces and Related Organisms in Human Infections

“…Fecal samples were shown to harbor only a few clones identified as Actinomyces, with "A. viscosus" and A. odontolyticus being represented (42). Actinomyces species found in the human (female) urogenital tract in the absence of actinomycetal infection include A. meyeri, A. neuii, A. radingae, A. turicensis, and A. urogenitalis (43)(44)(45)(46)(47). After the detection of Actinobaculum schaalii (currently Actinotignum schaalii), a taxon closely related to the members of the genus Actinomyces, in urine, groin swabs, and vaginal swabs (18), it was recently suggested that this organism might be a relatively frequent commensal residing on the skin and mucosae of urogenital sites, but not in the colon, since no detection from feces was made (48).…”