Cervical and Vaginal Flora Specimens Are Highly Concordant with Respect to Bacterial Vaginosis-Associated Organisms and Commensal Lactobacillus Species in Women of Reproductive Age

Abstract

Matched vaginal and cervical specimens from 96 subjects were analyzed by quantitative PCR for the presence and concentration of bacterial vaginosis-associated microbes and commensal Lactobacillus spp. Detection of these microbes was 92% concordant, indicating that microbial floras at these body sites are generally similar. The vaginal microbiome plays an important role in female reproductive tract health. The vaginal microbiome of healthy women generally falls into one of five categories, four of which are dominated by a single lactobacillus species (Lactobacillus crispatus, L. gasseri, L. iners, or L. jensenii) and the fifth of which is characterized by diverse anaerobic and facultative species (1). This final group has traditionally been associated with bacterial vaginosis (BV), a disease characterized by vaginal discharge and odor (2), as well as human immunodeficiency virus (HIV) transmission (3), Trichomonas vaginalis infection (4), and preterm labor (5). Although less well studied, the cervical microbiome may arguably be of greater relevance, as the cervix is the site of infection by numerous pathogens, such as HIV, human papillomavirus (HPV), Chlamydia trachomatis, and Neisseria gonorrhoeae. A recent study found that a lactobacillus-dominated cervical microbiome is inversely associated with the prevalence of HIV, herpes simplex virus type 2, and high-risk human papillomavirus (6). Studies evaluating the cervicovaginal flora have variously sampled the cervix, the vagina, or both sites simultaneously. Therefore, it is of general interest to comparatively analyze the flora at these sites to determine if results generated from sampling the vagina can be generalized to the cervix and vice versa. For example, the cervical transformation zone is enriched in T cells and antigen-presenting cells compared to the vagina (7), and thus, differential immune responses at these sites could impact the composition of their respective microbiomes. To our knowledge, only two prior studies have addressed this issue (8, 9), and although informative, these studies analyzed small subject cohorts and utilized semiquantitative methodology. Our goal in this study was to quantitatively analyze the cervical and vaginal floras with respect to lactobacillus species as well as microbes associated with abnormal floras, such as BV, from a substantial subject cohort.We performed a cross-sectional study from a prospective cohort, enrolling subjects who were receiving ambulatory gynecologic care at either the Care Center for Women at University of Florida Health (a teaching hospital with related ambulatory clinics) or the University of Florida Southside Women's Health Specialists (a freestanding ambulatory care center). The study took place from May 2006 to June 2009. Written informed consent was obtained from all subjects, and the study was carried out with the approval of Western Institutional Review Board. The purpose of the study was to evaluate the microbiology and immunology of BV. Therefore, subjects were recruited who were either c...

Development and Validation of a Highly Accurate Quantitative Real-Time PCR Assay for Diagnosis of Bacterial Vaginosis

“…qPCR assays used to quantify BV-associated microbes and Lactobacillus spp. have been previously described (19,25). The Megasphaera spp.…”

Epidemiology and resistance trends of Staphylococcus aureus isolated from vaginal samples: a 10-year retrospective study in Hungary

“…There is no generally accepted clinical strategy for therapy for AV; however, several proposals have been published. The distinction between AV and BV is crucial for the choice of appropriate therapy (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). Metronidazole has no effect on AV, unlike in BV and Trichomonas vaginalis infections, for which this drug is routinely used (6)(7)(8)(9).…”

“…Following puberty, the thicker stratified epithelium and higher levels of glycogen in the reproductive tract of females also favor Lactobacillus colonization (2)(3)(4). In addition to lactobacilli, other microorganisms commonly identified as commensals in the female genital tract include Staphylococcus aureus, Streptococcus agalactiae (group B Streptococcus), Enterococcus faecalis, Escherichia coli, and Candida albicans (7)(8)(9). After menopause, estrogen levels drop in the female body, dramatically affecting the vaginal microbiota; the pH rises to 6.0 to 8.0, corresponding to the reduction or elimination of lactobacilli and the increased colonization of the vaginal tract by members of the Enterobacteriaceae family, Gram-positive cocci, and Bacteroides and Prevotella species (fecal flora) (2-6).…”

The genital tract and rectal microbiomes: their role in HIV susceptibility and prevention in women

“…bacteria – Chlamydia trachomatis and Neisseria gonorrhoeae ; protozoa – Trichomonas vaginalis ; viruses – Human papillomaviruses and Herpes simplex viruses; and fungi – Candida spp.). Studies examining whether there are differences between the cervical and vaginal microbiomes have revealed a high level of concordance in microbial diversity between the cervix and vagina. The composition of the female genital tract microbiome is unique to each woman and is probably established early on in life through exposure to key maternal microorganisms during birth .…”