841: Select microbes present in early 2nd trimester in the cervicovaginal space are associated with subsequent Group B Strep colonization

Abstract

Microbial communities at different sites influence both health and disease. The cervicovaginal (CV) microbiota have documented associations with sexually transmitted infection acquisition and spontaneous preterm birth. While colonization with Group B Streptococcus (GBS) is prevalent, it remains a significant risk factor for neonatal morbidity. There are no data on how CV microbial communities might influence colonization with GBS. Therefore, the objective of this study was to determine if the CV microbiota is associated with GBS colonization (GBS-C) in pregnant women. A 3 year prospective cohort study of women with singleton pregnancies was utilized (“M&M,” n=1,943). We performed a nested case-control study of 394 GBS- and 158 GBS+ women with 16s rRNA gene analysis of CV specimens collected at 16-20 weeks. Women were considered GBS-C if they were treated with antibiotics for GBS+ in labor. Nine bacteria were selected for analysis based on prior associations with adverse pregnancy outcomes. Odds of GBS colonization (GBS-C) by quartile of relative abundance was estimated with logistic regression adjusting for race and intercourse ≤ 24hrs of visit. The overall rate of GBS+ was 27.3%. GBS+ women were more likely to have had intercourse within 24 hours of the biospecimen collection but otherwise the cases and controls were similar (Table 1). At 16-20 weeks, increasing levels of Sneathia sanguinegens were associated with an increasing rate of GBS+ (0= 14.6%, Q1= 27.1%, Q2= 28.2%, Q3=34.7%, Q4=34.2%), which remained significant after adjustment with odds ranging from Q1 aOR: 2.49 (95% CI 1.16-5.37) up to Q4 aOR: 3.50 (95% CI 1.62-7.54). GBS+ rates also increased with Gardnerella vaginalis levels from 20.3% at Q1 to 31.9% at Q4, which was significant after adjustment: Q2: aOR 1.78 [1.01-3.13], Q3: aOR 1.82 [1.01-3.27], Q4: aOR 1.96 [1.10-3.48]. Certain bacteria present early in the 2nd trimester in the CV space are associated with increased rates of GBS colonization. Microbial communities at various biological sites can be modified without the use of antibiotics. As such, future research should investigate if GBS colonization may be prevented by modifying the CV microbiota, thus limiting, if not preventing, the use of antibiotics during labor without compromising neonatal risk. (NRO14784 ME)