Medline ® Abstracts for References 12,24,25

BACKGROUND: Bacterial vaginosis affects millions of women and is associated with several serious health conditions. The cause of bacterial vaginosis remains poorly understood despite numerous studies based on cultures. Bacteria in microbial communities can be identified without cultivation by characterizing their ribosomal DNA (rDNA) sequences.

METHODS: We identified bacteria in samples of vaginal fluid with a combination of broad-range polymerase-chain-reaction (PCR) amplification of 16S rDNA with clone analysis, bacterium-specific PCR assay of 16S rDNA, and fluorescence in situ hybridization (FISH) performed directly on vaginal fluid from 27 subjects with bacterial vaginosis and 46 without the condition. Twenty-one subjects were studied with the use of broad-range PCR of 16S rDNA, and 73 subjects were studied with the use of bacterium-specific PCR.

RESULTS: Women without bacterial vaginosis had 1 to 6 vaginal bacterial species (phylotypes) in each sample (mean, 3.3), as detected by broad-range PCR of 16S rDNA, and lactobacillus species were the predominant bacteria noted (83 to 100 percent of clones). Women with bacterial vaginosis had greater bacterial diversity (P<0.001), with 9 to 17 phylotypes (mean, 12.6) detected per sample and newly recognized species present in 32 to 89 percent of clones per sample library (mean, 58 percent). Thirty-five unique bacterial species were detected in the women with bacterial vaginosis, including several species with no close cultivated relatives. Bacterium-specific PCR assays showed that several bacteria that had not been previously described were highly prevalent in subjects with bacterial vaginosis but rare in healthy controls. FISH confirmed that newly recognized bacteria detected by PCR corresponded to specific bacterial morphotypes visible in vaginal fluid.

CONCLUSIONS: Women with bacterial vaginosis have complex vaginal infections with many newly recognized species, including three bacteria in the Clostridiales order that were highly specific for bacterial vaginosis.

OBJECTIVE: Risk factors for bacterial vaginosis (BV) include douching and sexual activity, although the exact cause of BV is unknown.

GOAL: The goal of this study was to determine the relative significance of douching as a risk factor for BV.

STUDY DESIGN: Two hundred fifty adolescent women who regularly douched were enrolled into a randomized douching intervention trial. Behavioral questionnaires and testing for sexually transmitted diseases and BV were performed. Associations between baseline characteristics and behaviors were compared for teens who were BV-positive and BV-negative at baseline.

RESULTS: Positive correlates of BV included multiple partners, recent sexual intercourse, douching after menses, recent douching, and gonorrhea. Of these, douching after menses showed the strongest association (odds ratio, 5.11; 95% confidence interval, 1.99-13.15) in a multivariate analysis.

CONCLUSIONS: Douching after menses was strongly correlated with BV; however, difficulty remains in trying to evaluate douching and sexual behavior independently.

OBJECTIVES: To examine variability in bacterial vaginosis (BV) over 6- to 12-month intervals.

STUDY DESIGN: One thousand one hundred ninety-three women were followed for a median of 3 years with serial vaginal swab Gram stains for BV. Discrete time hazard models were fit to identify independent risk factors for BV.

RESULTS: Women with BV at study entry were categorized as having normal flora at the next visit 20% of the time, and women with normal flora at study entry were categorized as having BV at the next visit 20% of the time. Among women with initially normal flora, factors associated with BV were black race, lower education, a history of BV, a history of chlamydial/gonococcal cervicitis, and lack of monogamy.

CONCLUSION: About one fifth of women with normal flora develop BV over a given 6- to 12-month interval, and the modifiable risk factors of cervicitis and lack of monogamy contribute to the development of BV.