A citizen-science-enabled catalogue of the vaginal microbiome and associated factors.

Understanding the composition and function of the vaginal microbiome is crucial for reproductive and overall health. Here we established the Isala citizen-science project to analyse the vaginal microbiomes of 3,345 women in Belgium (18-98 years) through self-sampling, 16S amplicon sequencing and extensive questionnaires. The overall vaginal microbiome composition was strongly tied to age, childbirth and menstrual cycle phase. Lactobacillus species dominated 78% of the vaginal samples. Specific bacterial taxa also showed to co-occur in modules based on network correlation analysis. Notably, the module containing Lactobacillus crispatus, Lactobacillus jensenii and Limosilactobacillus taxa was positively linked to oestrogen levels and contraceptive use and negatively linked to childbirth and breastfeeding. Other modules, named after abundant taxa (Gardnerella, Prevotella and Bacteroides), correlated with multiple partners, menopause, menstrual hygiene and contraceptive use. With this resource-rich vaginal microbiome map and associated health, life-course, lifestyle and dietary factors, we provide unique data and insights for follow-up clinical and mechanistic research.

Construction and phenotypic characterization of M68, an RruI quorum sensing knockout mutant of the photosynthetic alphaproteobacterium Rhodospirillum rubrum.

Many bacterial species communicate using a complex system known as quorum sensing (QS) in which gene expression is controlled in response to cell density. In this study an N-acylhomoserine lactone (AHL) synthase (Rru_A3396) knockout mutant (M68) of Rhodospirillum rubrum S1H (WT) was constructed and characterized phenotypically under light anaerobic conditions. Results showed that R. rubrum WT produces unsubstituted, 3-OH and 3-oxo-substituted AHLs with acyl chains ranging from 4 to 14 carbons, with 3-OH-C8 being the most abundant. Growth, pigment content and swimming motility were found to be under the control of this LuxI-type QS system. In addition, cultivation in a low shear environment put forward the aggregative phenotype of M68 and linked biofilm formation to QS in R. rubrum S1H. Interestingly, QS-mutant M68 continued to produce decreased levels of 3-OH-C8-HSL, probably due to the presence of an extra HdtS-type AHL synthase.