Molecular Assessment of Bacterial Vaginosis by Lactobacillus Abundance and Species Diversity

Background To date, women are most often diagnosed with bacterial vaginosis (BV) using microscopy based Nugent scoring or Amsel criteria. However, the accuracy is less than optimal. The aim of the present study was to confirm the identity of known BV-associated composition profiles and evaluate indicators for BV using three molecular methods. Methods Evaluation of indicators for BV was carried out by 16S rRNA amplicon sequencing of the V5-V7 region, a tailor-made 16S rRNA oligonucleotide-based microarray, and a PCR-based profiling technique termed IS-profiling, which is based on fragment variability of the 16S-23S rRNA intergenic spacer region. An inventory of vaginal bacterial species was obtained from 40 females attending a Dutch sexually transmitted infection outpatient clinic, of which 20 diagnosed with BV (Nugent score 7–10), and 20 BV negative (Nugent score 0–3). Results Analysis of the bacterial communities by 16S rRNA amplicon sequencing revealed two clusters in the BV negative women, dominated by either Lactobacillus iners or Lactobacillus crispatus and three distinct clusters in the BV positive women. In the former, there was a virtually complete, negative correlation between L. crispatus and L. iners. BV positive subjects showed cluster profiles that were relatively high in bacterial species diversity and dominated by anaerobic species, including Gardnerella vaginalis, and those belonging to the Families of Lachnospiraceae and Leptotrichiaceae. Accordingly, the Gini-Simpson index of species diversity, and the relative abundance Lactobacillus species appeared consistent indicators for BV. Under the conditions used, only the 16S rRNA amplicon sequencing method was suitable to assess species diversity, while all three molecular composition profiling methods were able to indicate Lactobacillus abundance in the vaginal microbiota. Conclusion An affordable and simple molecular test showing a depletion of the genus Lactobacillus in combination with an increased species diversity of vaginal microbiota could serve as an alternative and practical diagnostic method for the assessment of BV

Distinct Neisseria gonorrhoeae Transmission Networks Among Men Who Have Sex With Men in Amsterdam, the Netherlands

Background. Molecular typing was used to elucidate Neisseria gonorrhoeae transmission networks among men who have sex with men (MSM) in Amsterdam, the Netherlands. We determined whether clusters of patients infected with specific N. gonorrhoeae genotypes were related to various epidemiological characteristics. Methods. MSM (age >= 18 years) visiting the sexually transmitted infections (STI) clinic between July 2008 and August 2009 were eligible. After STI screening, participants completed a behavioral questionnaire concerning the previous 6 months. N. gonorrhoeae cultures were genotyped using multiple-locus variable-number tandem repeat analysis typing. Results. We obtained 278 N. gonorrhoeae-positive isolates from 240 MSM. Five large clusters (>= 10 isolates), a unique sixth cluster (n = 9), and 8 smaller clusters (5- 9 isolates) were identified. Prevalence of human immunodeficiency virus differed between clusters I and VI (P = .003), ranging from 27.8% to 100%. Receptive unprotected anal intercourse was frequently reported by MSM (51.8%) but did not differ significantly among clusters. Significant differences were identified concerning the participant's history of syphilis (P = .030), having met partners at a popular sex venue in Amsterdam (P = .048), and meeting partners outside Amsterdam (P = .036). Conclusions. Distinct N. gonorrhoeae transmission networks were present in a mixed high-risk MSM population; concordance between clusters and epidemiological characteristics was present but not marke