Bacterial vaginosis-associated bacteria in cisgender men who have sex with women: prevalence, association with non-gonococcal urethritis and natural history

Fannyhessea vaginae and Clearance of Lactobacillus iners Are Associated With Incident Nonchlamydial Non- Mycoplasma genitalium Urethritis in Men Who Have Sex With Women

BACKGROUND

The etiology of nongonococcal urethritis (NGU) is incompletely understood. We sought to determine if genitourinary bacterial diversity or specific taxa were associated with incident NGU.

METHODS

From August 2014 to July 2018, men who have sex with women attending a sexual health clinic were clinically evaluated, including Mycoplasma genitalium (MG) and Chlamydia trachomatis (CT) testing, at enrollment and 6 monthly visits. New cases of NGU (≥5 polymorphonuclear leukocytes per high-power field in urethral exudates plus either symptoms or visible discharge) and their visit preceding NGU diagnosis were matched 1:1 to 2 sequential visits without NGU (controls). We determined associations with incident NGU and applied broad-range 16S rRNA gene polymerase chain reaction and sequencing to urine samples from each visit. We used conditional logistic regression to evaluate the association of Shannon Diversity Index, species richness, Haemophilus influenzae , Fannyhessea vaginae, Lactobacillus iners, and Streptococcus mitis group with incident non-CT-non-MG-NGU (NCNM-NGU).

RESULTS

Of 62 matched case-control pairs, median age was 32 years. Higher Shannon Diversity Index the previous month was associated with higher odds of incident NCNM-NGU (adjusted odds ratio [aOR], 2.8 per unit increase; 95% confidence interval [CI], 1.03-7.47), as was F. vaginae at NGU diagnosis (aOR, 5.1; 95% CI, 1.28-20.15), F. vaginae acquisition (aOR, 13.8; 95% CI, 1.96-97.33), and consistent carriage of F. vaginae (aOR, 16.1; 95% CI, 1.66-156.29). Odds of NCNM-NGU were higher when L. iners cleared between visits (aOR, 18.0; 95% CI, 1.08-299.24). Neither the H. influenzae nor S. mitis group was associated with incident NCNM-NGU.

CONCLUSIONS

F. vaginae acquisition/detection and L. iners clearance were associated with urethritis. This merits investigation in larger longitudinal studies using species-specific detection methods.

Deciphering the role of female reproductive tract microbiome in reproductive health: a review

Relevant studies increasingly indicate that female reproductive health is confronted with substantial challenges. Emerging research has revealed that the microbiome interacts with the anatomy, histology, and immunity of the female reproductive tract, which are the cornerstone of maintaining female reproductive health and preventing adverse pregnancy outcomes. Currently, the precise mechanisms underlying their interaction and impact on physiological functions of the reproductive tract remain elusive, constituting a prominent area of investigation within the field of female reproductive tract microecology. From this new perspective, we explore the mechanisms of interactions between the microbiome and the anatomy, histology, and immunity of the female reproductive tract, factors that affect the composition of the microbiome in the female reproductive tract, as well as personalized medicine approaches in managing female reproductive tract health based on the microbiome. This study highlights the pivotal role of the female reproductive tract microbiome in maintaining reproductive health and influencing the occurrence of reproductive tract diseases. These findings support the exploration of innovative approaches for the prevention, monitoring and treatment of female reproductive tract diseases based on the microbiome.

Amygdalobacter indicium gen. nov., sp. nov., and Amygdalobacter nucleatus sp. nov., gen. nov.: novel bacteria from the family Oscillospiraceae isolated from the female genital tract

Four obligately anaerobic Gram-positive bacteria representing one novel genus and two novel species were isolated from the female genital tract. Both novel species, designated UPII 610-JT and KA00274T, and an additional isolate of each species were characterized utilizing biochemical, genotypic and phylogenetic analyses. All strains were non-motile and non-spore forming, asaccharolytic, non-cellulolytic and indole-negative coccobacilli. Fatty acid methyl ester analysis for UPII 610-JT and KA00274T and additional isolates revealed C16 : 0, C18 : 0, C18:1ω9c and C18:2ω6,9c to be the major fatty acids for both species. UPII 610-JT had a 16S rRNA gene sequence similarity of 99.4 % to an uncultured clone sequence (AY724740) designated as Bacterial Vaginosis Associated Bacterium 2 (BVAB2). KA00274T had a 16S rRNA gene sequence similarity of 96.5 % to UPII 610-JT. Whole genomic DNA mol% G+C content was 42.2 and 39.3 % for UPII 610-JT and KA00274T, respectively. Phylogenetic analyses indicate these isolates represent a novel genus and two novel species within the Oscillospiraceae family. We propose the names Amygdalobacter indicium gen. nov., sp. nov., for UPII 610-JT representing the type strain of this species (=DSM 112989T, =ATCC TSD-274T) and Amygdalobacter nucleatus gen. nov., sp. nov., for KA00274T representing the type strain of this species (=DSM 112988T, =ATCC TSD-275T).