Work

O1-S05.05 Association betweenTrichomonas vaginalisand vaginal bacterial community composition among asymptomatic reproductive-age women in the USA

Year: 2011

Type: article

Abstract: Background Vaginal bacterial communities are thought to prevent infection by sexually transmitted organisms. Prior work demonstrated that the vaginal microbiota of reproductive-age women in the US cluster into five groups of bacterial communities; four dominated byLactobacillus spp. (L iners, L crispatus, L gasseri, L jensenii), and one lacking significant numbers of lactobacilli and characterised by higher proportions of strictly anaerobic organisms (termed group IV). We sought to compare the vaginal microbiota ofT vaginalis-positive andT vaginalis-negative women using cultivation-independent methods. To our knowledge, this is the first analysis of the relationship betweenT vaginalisand vaginal bacterial communities characterised by molecular methodologies. Methods Self-collected vaginal swabs were obtained cross-sectionally from 396 asymptomatic US women equally representing four ethnic/racial groups. Screening for the presence ofT vaginaliswas performed using PCR targeting the 18S rRNA and ß-tubulin genes. Vaginal bacterial composition was characterised by pyrosequencing of barcoded 16S rRNA genes. The relationship between vaginal microbiota andT vaginaliswas evaluated by Fisher's exact testing and logistic regression. Results Of the 11T vaginalis-positive cases, 8 (72%) were classified to the low-Lactobacillus group IV, 2 (18%) and 1 (9%) with communities dominated byL inersandL crispatus, respectively (p value: 0.056). Group IV was associated with an eightfold increased odds of detectingT vaginaliscompared to women with communities dominated byL crispatus(OR: 8.26, 95% CI: 1.07% to 372.65%, p value: 0.04). Other than the major bacteria dominating each cluster, none of the other observed taxa showed significant association withT vaginalis-positivity although this may reflect few observed cases rather than lack of a true association. Ten (91%) of theT vaginaliscases self-reported Black ethnicity and 1 (9%) reported Asian, (p value: 0.00002). Conclusion Molecular analyses revealed that vaginal microbiota with low proportions of lactobacilli were significantly associated with presence ofT vaginalis. Longitudinal studies are needed to identify the causal nature of the relationship between vaginal bacterial communities and STI risk.

Source: Sexually Transmitted Infections

DOI: 10.1136/sextrans-2011-050109.29