Identification of Key Bacteria Involved in the Induction of Incident Bacterial Vaginosis: A Prospective Study.

Background: The sequence of events preceding incident bacterial vaginosis (iBV) is unclear. Methods: African American women who have sex with women, who had no Amsel criteria and Nugent scores of 0-3, were followed for 90 days to detect iBV (defined as a Nugent score of 7-10 on at least 2-3 consecutive days), using self-collected vaginal swab specimens. For women with iBV (cases) and women maintaining normal vaginal flora (healthy women), 16S ribosomal RNA gene sequencing targeting V4 was performed. Longitudinal vaginal microbiome data were analyzed. Results: Of 204 women screened, 42 enrolled; of these, 45% developed iBV. Sequencing was performed on 448 specimens from 14 cases and 8 healthy women. Among healthy women, Lactobacillus crispatus dominated the vaginal microbiota in 75%. In contrast, prior to iBV, the vaginal microbiota in 79% of cases was dominated by Lactobacillus iners and/or Lactobacillus jensenii/Lactobacillus gasseri. The mean relative abundance of Prevotella bivia, Gardnerella vaginalis, Atopobium vaginae, and Megasphaera type I became significantly higher in cases 4 days before (P. bivia), 3 days before (G. vaginalis), and on the day of (A. vaginae and Megasphaera type I) iBV onset. The mean relative abundance of Sneathia sanguinegens, Finegoldia magna, BV-associated bacteria 1-3, and L. iners was not significantly different between groups before onset of iBV. Conclusion: G. vaginalis, P. bivia, A. vaginae, and Megasphaera type I may play significant roles in iBV.

Basic vaginal pH, bacterial vaginosis and aerobic vaginitis: prevalence in early pregnancy and risk of spontaneous preterm delivery, a prospective study in a low socioeconomic and multiethnic South American population.

BACKGROUND: Bacterial vaginosis (BV) increases the risk of spontaneous preterm deliveries (PD) in developed countries. Its prevalence varies with ethnicity, socioeconomic conditions and gestational age. Aerobic vaginitis (AV) has also been implicated with spontaneous PD. The present study aimed to estimate the prevalence of asymptomatic BV, the accuracy of vaginal pH level to predict BV and to estimate the risk of spontaneous PD <34 and <37 weeks' gestation of BV and AV. METHODS: Women attending prenatal public services in Rio de Janeiro were screened to select asymptomatic pregnant women, < 20 weeks' gestation, with no indication for elective PD and without risk factors of spontaneous PD. Vaginal smears of women with vaginal pH > = 4.5 were collected to determine the Nugent score; a sample of those smears was also classified according to a modified Donders' score. Primary outcomes were spontaneous PD < 34 and <37 weeks' gestation and abortion. RESULTS: Prevalence of asymptomatic BV was estimated in 28.1% (n = 1699); 42.4% of the smears were collected before 14 weeks' gestation. After an 8-week follow up, nearly 40% of the initially BV positive women became BV negative. The prevalence of BV among white and black women was 28.1% (95% CI: 24.6%-32.0%) and 32.5% (95% CI: 28.2%-37.2%), respectively. The sensitivity of vaginal pH= > 4.5 and = > 5.0 to predict BV status was 100% and 82%, correspondingly; the 5.0 cutoff value doubled the specificity, from 41% to 84%. The incidence of < 37 weeks' spontaneous PDs among BV pregnant women with a pH= > 4.5 was 3.8%. The RR of spontaneous PD < 34 and <37 weeks among BV women with pH > =4.5, as compared with those with intermediate state, were 1.24 and 1.86, respectively (Fisher's exact test, p value = 1; 0.52, respectively, both ns). No spontaneous case of PD or abortion was associated with severe or moderate AV. CONCLUSIONS: A high prevalence of asymptomatic BV was observed without statistically significant difference between black and white women. The RRs of spontaneous PD < 34 and <37 weeks among women with BV, as compared with those with intermediate state were not statistically significant but were consistent with those found in the literature.

The global epidemiology of bacterial vaginosis: a systematic review.

Bacterial vaginosis (BV) enhances the acquisition and transmission of a range of sexually transmitted infections including human immunodeficiency virus. This has made it more important to uncover the reasons why some populations have very high BV prevalences and others not. This systematic review describes the global epidemiology of BV. It summarizes data from peer-reviewed publications detailing the population prevalence of BV as diagnosed by a standardized and reproducible methodology-Nugent scoring system. BV variations between countries, and between ethnic groups within countries, are described. We evaluated 1692 English- and non-English-language articles describing the prevalence of BV using MEDLINE and the Web of Science databases. A total of 86 articles met our inclusion criteria. BV prevalences were found to vary considerably between ethnic groups in North America, South America, Europe, the Middle East, and Asia. Although BV prevalence is, in general, highest in parts of Africa and lowest in much of Asia and Europe, some populations in Africa have very low BV prevalences and some in Asia and Europe have high rates.

Gardnerella, Trichomonas and Candida in cervical smears of 58,904 immigrants participating in the Dutch national cervical screening program.

OBJECTIVE: To report the prevalence of Gardnerella, Trichomonas and Candida in the cervical smears of 9 immigrant groups participating in the Dutch national cervical screening program. STUDY DESIGN: Cervical smears were taken from 58,904 immigrant participants and 498,405 Dutch participants. As part of the routine screening process, all smears were screened for the overgrowth of Gardnerella (i.e. smears with an abundance of clue cells) and for the presence of Trichomonas and Candida. The smears were screened by 6 laboratories, all of which use the Dutch KOPAC coding system. The odds ratio and confidence interval were calculated for the 9 immigrant groups and compared to Dutch participants. RESULTS: Immigrants from Suriname, Turkey and the Dutch Antilles have a 2-5 times higher prevalence of Gardnerella and Trichomonas when compared to native Dutch women. Interestingly, the prevalence of Trichomonas in cervical smears of Moroccan immigrants is twice as high, yet the prevalence of Gardnerella is 3 times lower than in native Dutch women. CONCLUSIONS: Immigrants with a high prevalence of Gardnerella also have a high prevalence of Trichomonas. In the context of the increased risk of squamous abnormalities in smears with Gardnerella, such slides should be screened with extra care.

Pregnancy-specific association of vitamin D deficiency and bacterial vaginosis.

OBJECTIVE: Recent data suggest vitamin D deficiency (VDD) is associated with bacterial vaginosis (BV) during pregnancy. We hypothesized that VDD is a risk factor for BV in nonpregnant women. STUDY DESIGN: Using National Health and Nutrition Examination Survey data, we conducted multivariable logistic regression analyses stratified by pregnancy. RESULTS: VDD was associated with BV only in pregnant women (adjusted odds ratio [AOR], 2.87; 95% confidence interval [CI], 1.13-7.28). Among nonpregnant women, douching (AOR, 1.72; 95% CI, 1.25-2.37), smoking (AOR, 1.66; 95% CI, 1.23-2.24), and black race (AOR, 2.41; 95% CI, 1.67-3.47) were associated with BV; oral contraceptive use was inversely associated with BV (AOR, 0.60; 95% CI, 0.40-0.90). VDD moderated the association between smoking and BV in nonpregnant women. CONCLUSION: Risk factors for BV differ by pregnancy status. VDD was a modifiable risk factor for BV among pregnant women; evaluation of vitamin D supplementation for prevention or adjunct therapy of BV in pregnancy is warranted.

Race of male sex partners and occurrence of bacterial vaginosis.

BACKGROUND: Whether bacterial vaginosis (BV) is sexually transmitted is uncertain. Also it is unknown why BV is approximately twice as prevalent among black as among white women. An association of BV with a characteristic of the male sex partner, such as race, might support sexual transmission as well as account for the observed ethnic disparity in BV. METHODS: Three thousand six hundred twenty nonpregnant women 15 to 44 years of age were followed quarterly for 1 year. At each visit, extensive questionnaire data and vaginal swabs for Gram's staining were obtained. The outcome was transition from BV-negative to positive (Nugent's score > or =7) in an interval of 2 consecutive visits. RESULTS: BV occurred in 12.8% of 906 sexually active intervals to white women-24.8% of intervals when the woman reported a black partner and 10.7% when all partners were white. Among white women, there was a 2-fold increased risk for BV incidence with a black, compared with a white partner (risk ratio [RR] 2.3, 95% confidence interval 1.6-3.4; adjusted RR 2.2, 95% confidence interval 1.5-3.4), but differed according to condom use. In the presence of consistent condom use, the adjusted RR was 0.7 (0.3-2.4); it was 2.4 (1.0-6.2) in the presence of inconsistent use; and 2.7 (1.7-4.2) in the absence of condom use. Black women could not be studied, as there were insufficient numbers who reported only white male sex partners. CONCLUSION: The association of BV occurrence with partner's race, and its blunting by condom use, suggests that BV may have a core group component and may be sexually transmitted.

Concordance of rectal and cervical Chlamydia trachomatis OmpA genotypes infecting women in Birmingham, Alabama.

We evaluated cervical and rectal Chlamydia trachomatis OmpA genotypes isolated from 22 women in Birmingham, AL, who were infected at both sites. Two women had mixed infection at one site. Of 20 women infected with a single OmpA genotype at each site, four (20%) had discordant genotypes at these sites.

Predicting risk of bacterial vaginosis: the role of race, smoking and corticotropin-releasing hormone-related genes.

Bacterial vaginosis (BV) is one of the most prevalent vaginal disorders in adult women and is associated with adverse pregnancy outcomes such as pre-term birth. Genetic factors, particularly in genes involved in inflammation and infection, are associated with this condition. Additionally, environmental risk factors including stress and smoking are associated with BV. The purpose of this study was to identify genetic variants in stress-related genes such as corticotropin-releasing hormone (CRH), receptor 1, receptor 2 and binding protein (CRH-BP) that associate with BV. Also gene-environment effects with smoking are determined. BV was quantified using the Nugent score in 82 white and 65 black women in the first trimester of pregnancy. Associations between Nugent score, genotype and smoking were analyzed using Kruskal-Wallis and Wilcoxon rank sum non-parametric tests. In white women, non-smokers with the CT genotype at CRH-BP + 17487 have lower Nugent scores (median: 0, range: 0-0) than non-smokers with the TT genotype (median: 2, range: 0-8) (P = 0.002); whereas smokers with the CT genotype have higher Nugent scores (median: 6, range: 0-10) than smokers with the TT genotype (median: 1, range: 0-10) (P = 0.021). In black women, the AG genotype at CRH + 3362 or CRH - 1667 is associated with lower Nugent scores (median for both: 3, range: 0-10) compared with the homozygous genotypes (median for each homozygous genotype: 8, range: 0-10). Also, in black women, models remain significant after adjusting for smoking (P = 0.04 for both). These data indicate that susceptibility to BV is affected by patterns of genetic variation in stress-related genes and smoking plays an important role.

Relationship between vitamin D status and the vaginal microbiome during pregnancy.

OBJECTIVE: Evidence supports an inverse association between vitamin D and bacterial vaginosis (BV) during pregnancy. Furthermore, both the vaginal microbiome and vitamin D status correlate with pregnancy outcome. Women of African ancestry are more likely to experience BV, to be vitamin D deficient, and to have certain pregnancy complications. We investigated the association between vitamin D status and the vaginal microbiome. STUDY DESIGN: Subjects were assigned to a treatment (4400 IU) or a control group (400 IU vitamin D daily), sampled three times during pregnancy, and vaginal 16S rRNA gene taxonomic profiles and plasma 25-hydroxyvitamin D [25(OH)D] concentrations were examined. RESULT: Gestational age and ethnicity were significantly associated with the microbiome. Megasphaera correlated negatively (p = 0.0187) with 25(OH)D among women of African ancestry. Among controls, women of European ancestry exhibited a positive correlation between plasma 25(OH)D and L. crispatus abundance. CONCLUSION: Certain vaginal bacteria are associated with plasma 25(OH)D concentration.

Differential effects of depot medroxyprogesterone acetate administration on vaginal microbiome in Hispanic White and Black women.

The use of depot medroxyprogesterone acetate (DMPA), a 3-monthly injectable hormonal contraceptive, is associated with an increased risk of HIV acquisition possibly through alteration of the vaginal microbiome. In this longitudinal interventional study, we investigated the impact of DMPA administration on the vaginal microbiome in Hispanic White and Black women at the baseline (visit 1), 1 month (visit 2), and 3 months (visit 3) following DMPA treatment by using 16S rRNA gene sequencing. No significant changes in the vaginal microbiome were observed after DMPA treatment when Hispanic White and Black women were analysed as a combined group. However, DMPA treatment enriched total vaginosis-associated bacteria (VNAB) and Prevotella at visit 2, and simplified the correlational network in the vaginal microbiome in Black women, while increasing the network size in Hispanic White women. The microbiome in Black women became more diversified and contained more VNAB than Hispanic White women after DMPA treatment. While the Firmicutes to Bacteroidetes (F/B) ratio and Lactobacillus to Prevotella (L/P) ratio were comparable between Black and Hispanic White women at visit 1, both ratios were lower in Black women than in Hispanic White women at visit 2. In conclusion, DMPA treatment altered the community network and enriched VNAB in Black women but not in Hispanic White women. The Lactobacillus deficiency and enrichment of VNAB may contribute to the increased risk of HIV acquisition in Black women. Future studies on the impact of racial differences on the risk of HIV acquisition will offer insights into developing effective strategies for HIV prevention. Abbreviations: DMPA: depot medroxyprogesterone acetate; PCR: polymerase chain reaction; OTU: operational taxonomic unit; STI: sexually transmitted infections; VNAB: vaginosis-associated bacteria.

Racial differences in cervical cytokine concentrations between pregnant women with and without bacterial vaginosis.

We have examined the association between cervical cytokine, chemokine and growth factor concentrations with bacterial vaginosis (BV) in pregnant white and black women. A nested case-control analysis was performed to examine 28 cervical cytokine, chemokine and growth factor concentrations in 83 white women (55 with normal flora and 28 with BV) and 81 black women (39 with normal flora and 42 with BV). White women with BV had significantly lower IP10 (P=0.001) and MCP1 (P=0.006) concentrations compared to women with normal flora. Black women with BV had higher IL-1alpha (P<0.001) concentrations than those with normal flora. In women with normal flora, whites had significantly higher levels of IL-1alpha (P=0.047), IL-6 (P=0.010), IL-10 (P=0.016) and PDGF-BB (P=0.010) than blacks. There were no significant concentration differences between white and black women with BV. These results demonstrate significant differences in cytokine and chemokine concentrations between women with and without BV. Ethnic differences in cytokine concentrations were also observed in women with normal flora, indicating that white and black women with normal flora have different cytokine levels, but respond to BV in a similar manner.

Viral sexually transmitted infections and bacterial vaginosis: 2001-2004 National Health and Nutrition Examination Survey data.

BACKGROUND: Bacterial vaginosis (BV) is a common condition believed to be associated with sexually transmitted infection (STI) susceptibility. Most studies of BV and STIs have come from treatment-seeking or high-risk populations. This study examines the association between 5 viral STIs, human papilloma virus (HPV), HIV, herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2), and Hepatitis C (HCV), and BV among women in the general US population. METHODS: Data from the 2001 and 2003-2004 National Health and Nutrition Examination Surveys were combined. Crude and adjusted relative risks and 95% confidence intervals were estimated from logistic regression analyses for rare outcomes (<10%) and from Poisson regression with robust error variance for common outcomes. Complex survey design was taken into consideration using the survey functions in Stata. RESULTS: Crude analyses found an association between BV and the prevalence of all 5 STIs. After adjustment for important confounders, only HSV-1 and HSV-2 were significantly associated with the presence of BV. Moreover, crude analyses stratified by race/ethnicity suggested that associations between BV and viral STIs may not be consistent across race/ethnicity subgroups. CONCLUSION: This population-based study found that BV was significantly associated with the prevalence of HSV-1 and HSV-2 and potentially associated with HIV and HPV. Given the frequency of BV in US women, small increases in STI susceptibility may have important impacts on STI transmission.

Paternal race and bacterial vaginosis during the first trimester of pregnancy.

OBJECTIVE: The purpose of this study was to determine the joint effects of maternal and paternal race on risk of bacterial vaginosis (BV) during the first trimester. STUDY DESIGN: In this cohort of black women and white women with singleton gestation at <13 weeks (n = 325), BV was diagnosed by vaginal pH and Gram stain. RESULTS: BV was less common among white women than black women. Paternal race modified the effect of maternal race on BV risk. BV risk was 2-fold greater among both white female-black male partners and black female-white male partners. BV risk was also 2-fold greater among black female-black male partners. Black race among both partners confers no additional risk than with 1 black partner. CONCLUSION: Paternal black race is an independent risk factor for BV during pregnancy and is as important a risk factor as maternal race. Studies of BV and adverse pregnancy outcomes should consider paternal race.

Racial disparity in bacterial vaginosis: the role of socioeconomic status, psychosocial stress, and neighborhood characteristics, and possible implications for preterm birth.

Racial disparity in preterm birth is one of the most salient, yet least well-understood health disparities in the United States. The preterm birth disparity may be due to differences in how women experience their racial identity in light of neighborhood factors, psychosocial stress, or the prevalence of or response to genital tract infections such as bacterial vaginosis (BV). The latest research emphasizes a need to explore all these factors simultaneously. This cross-sectional study of parous women in King County, Washington, USA investigated the effects of household income, psychosocial stress, and neighborhood socioeconomic characteristics on risk of BV after accounting for known individual-level risk factors. Relevant demographic, socioeconomic, and medical data were linked to U.S. census socioeconomic data by geocoding subjects' residential addresses. It was found that having a low income was significantly associated with an increased prevalence of BV among African American but not White American women. A higher number of stressful life events was significantly associated with higher BV prevalence among both African American and White American women. However, perceived stress was not related to BV risk among either group of women. Among White American women, neighborhood socioeconomic status (SES) was univariately associated with increased BV prevalence by principal components analysis, but was no longer significant after adjusting for individual-level risk factors. No neighborhood SES effects were observed for African American women. These results suggest that both the effects of individual- and neighborhood-level risk factors for BV may differ importantly by racial group, and stressful life events may have physiological effects independent of perceived stress.

Serum 25-Hydroxyvitamin D and Risk of Self-Reported Bacterial Vaginosis in a Prospective Cohort Study of Young African American Women.

BACKGROUND: Bacterial vaginosis (BV), the leading cause of vaginal discharge, is associated with multiple adverse health outcomes; however, its etiology is unknown. BV treatment is not very effective, thus prevention approaches are needed. Studies investigating the impact of vitamin D on the risk of BV have had mixed findings, including two studies reporting increased risk of recurrent BV for women with higher vitamin D. MATERIALS AND METHODS: Participants were nonpregnant women in a prospective fibroid study of African Americans (ages 23-34 years) from the Detroit area. The exposure was seasonally adjusted annual mean serum 25-hydroxyvitamin D [25(OH)D] at enrollment. The outcome was self-reported doctor-diagnosed BV over ∼20 months between baseline and follow-up. Multivariable-adjusted binomial regression models estimated the risk of BV for a doubling of 25(OH)D and sufficient (≥20 ng/mL) versus deficient (<20 ng/mL) 25(OH)D. RESULTS: In total, 1459 women were included. Median 25(OH)D was 15.2 ng/mL and 73% were deficient. Sixteen percent of participants reported BV diagnoses over follow-up, 78% of whom had recurrent BV. In multivariable-adjusted analyses, a doubling of 25(OH)D was associated with an increased, rather than the hypothesized decreased, risk of self-reported BV (risk ratio [RR] 1.22, 95% confidence interval 1.02-1.48). Sufficient women also had a significantly higher, rather than lower, risk of self-reported BV (RR 1.31). Results were robust to sensitivity analyses, and post hoc analyses showed no evidence of reverse causation. CONCLUSIONS: Overall, our findings do not support vitamin D deficiency as a risk factor for BV in these young, nonpregnant African American women.

Prevalence of bacterial vaginosis: 2001-2004 National Health and Nutrition Examination Survey data.

OBJECTIVE: To estimate the prevalence and correlates of bacterial vaginosis among women between the ages of 14 and 49 years in the United States. METHODS: Data from the 2001-2001 and 2003-2004 National Health and Nutrition Examination Surveys were combined. Correlates of bacterial vaginosis evaluated included sociodemographic characteristics (age, race or ethnicity, education, poverty income ratio) and sexual history (age of first intercourse, number of sexual partners). Crude and adjusted odds ratios and 95% confidence intervals were estimated from logistic regression analyses. RESULTS: Almost one third of women (29%) were positive for bacterial vaginosis. Bacterial vaginosis prevalence varied with age, race or ethnicity, education, and poverty. Black, non-Hispanic (odds ratio [OR] 3.13, 95% confidence interval [CI] 2.58-3.80) and Mexican-American (OR 1.29, 95% CI 0.99-1.69) women had higher odds of bacterial vaginosis than white, non-Hispanic women after adjustment for other sociodemographic characteristics. Douching in the past 6 months was also an important predictor of bacterial vaginosis prevalence (OR 1.93, 95% CI 1.54-2.40). CONCLUSION: Bacterial vaginosis is a common condition among U.S. women, and the prevalence is similar to that in many treatment-seeking populations. Further studies are needed to disentangle the interactions between race or ethnicity and other sociodemographic characteristics. LEVEL OF EVIDENCE: III.

Mannose-binding lectin gene polymorphism, vulvovaginal candidiasis, and bacterial vaginosis.

OBJECTIVE: To evaluate associations between polymorphisms in the gene coding for mannose-binding lectin (MBL) and the diagnosis of acute or recurrent vulvovaginal candidiasis and bacterial vaginosis METHODS: Women at two outpatient clinics in Brazil filled out a questionnaire and were examined for the presence of vulvovaginal candidiasis or bacterial vaginosis. A buccal swab was blindly tested for codons 54 and 57 MBL2 gene polymorphisms by polymerase chain reaction and endonuclease digestion. RESULTS: A total of 177 women were enrolled. Vulvovaginal candidiasis was identified in 78 (44.1%) women, 33 (18.6%) had bacterial vaginosis, and 66 (37.3%) were normal controls. Recurrent vulvovaginal candidiasis was present in 50 (64.1%) of the women with vulvovaginal candidiasis; 20 (60.6%) of the bacterial vaginosis patients had recurrent disease. Vulvovaginal candidiasis was associated with white race (P=.007), bacterial vaginosis was associated with nonwhite race (P=.05), and both were associated with a history of allergy (P< or =.02) and having sexual intercourse at least three times a week (P<.001). Carriage of the variant MBL2 codon 54 allele B was more frequent in women with recurrent vulvovaginal candidiasis (25.0%) than in the women with acute vulvovaginal candidiasis (17.9%) or controls (10.6%) (P=.004). Allele B was also more prevalent in women with recurrent bacterial vaginosis (22.5%) than in those with acute bacterial vaginosis (0%) (P=.009). The MBL2 codon 57 polymorphism was infrequent and not associated with vulvovaginal candidiasis or bacterial vaginosis. CONCLUSION: The incidence of vulvovaginal candidiasis and bacterial vaginosis differs by ethnicity in Brazilian women. The MBL2 codon 54 gene polymorphism is associated with both recurrent vulvovaginal candidiasis and recurrent bacterial vaginosis.

Risk factors for bacterial vaginosis during pregnancy among African American women.

OBJECTIVE: The objective of the study was to examine risk factors for bacterial vaginosis (BV) during pregnancy among African American women. STUDY DESIGN: As part of a study of preterm birth, African American women residing in Baltimore, MD, were recruited from prenatal care sites. Women enrolled prenatally (between 22 and 28 weeks' gestation) were asked to provide a vaginal smear specimen for ascertainment of BV. Log-binomial analysis was utilized. RESULTS: Approximately one quarter of the women were identified with BV (110 of 438). After adjusting for several confounders, vaginal douching during pregnancy remained significantly associated with an increased likelihood of BV. In addition, greater frequency of intercourse during the first trimester of pregnancy was significantly associated with an increased likelihood of BV. None of the social or psychosocial factors examined were associated with BV. CONCLUSION: Douching and sexual activity were associated with an increased risk of BV in the second trimester of pregnancy.

Vaginal Infections in Haitian Immigrant Women Living in Miami, Florida.

OBJECTIVE: To characterize vulvovaginal candidiasis (VC), trichomonas vaginalis (TV), and bacterial vaginosis (BV) among Haitian women living in Miami to identify contributing factors to cervical cancer disparity in this population. METHODS: Using a CBPR framework, 246 Haitian women (ages 21-65) were recruited. Self-collected cervical cytology specimens were analyzed for VC, TV, and BV. RESULTS: The proportion of participants with VC, TV, and BV, were 7.3%, 9.3%, and 19.9%, respectively. CONCLUSION: Haitian women may have a higher prevalence of TV than the general U.S. population, which may increase susceptibility to HPV, the primary cause of cervical cancer.

The influence of sexual activity on the vaginal microbiota and Gardnerella vaginalis clade diversity in young women.

OBJECTIVES: To examine the influence of sexual activity on the composition and consistency of the vaginal microbiota over time, and distribution of Gardnerella vaginalis clades in young women. METHODS: Fifty-two participants from a university cohort were selected. Vaginal swabs were self-collected every 3-months for up to 12 months with 184 specimens analysed. The vaginal microbiota was characterised using Roche 454 V3/4 region 16S rRNA sequencing, and G.vaginalis clade typing by qPCR. RESULTS: A Lactobacillus crispatus dominated vaginal microbiota was associated with Caucasian ethnicity (adjusted relative risk ratio[ARRR] = 7.28, 95%CI:1.37,38.57,p = 0.020). An L.iners (ARRR = 17.51, 95%CI:2.18,140.33,p = 0.007) or G.vaginalis (ARRR = 14.03, 95%CI:1.22,160.69, p = 0.034) dominated microbiota was associated with engaging in penile-vaginal sex. Microbiota dominated by L.crispatus, L.iners or other lactobacilli exhibited greater longitudinal consistency of the bacterial communities present compared to ones dominated by heterogeneous non-lactobacilli (p<0.030); sexual activity did not influence consistency. Women who developed BV were more likely to have clade GV4 compared to those reporting no sex/practiced non-coital activities (OR = 11.82, 95%CI:1.87,74.82,p = 0.009). Specimens were more likely to contain multiple G.vaginalis clades rather than a single clade if women engaged in penile-vaginal sex (RRR = 9.55, 95%CI:1.33,68.38,p = 0.025) or were diagnosed with BV (RRR = 31.5, 95%CI:1.69,586.87,p = 0.021). CONCLUSIONS: Sexual activity and ethnicity influenced the composition of the vaginal microbiota of these young, relatively sexually inexperienced women. Women had consistent vaginal microbiota over time if lactobacilli were the dominant spp. present. Penile-vaginal sex did not alter the consistency of microbial communities but increased G.vaginalis clade diversity in young women with and without BV, suggesting sexual transmission of commensal and potentially pathogenic clades.