Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/647545

The rodent vaginal microbiome across the estrous cycle and the effect of genital nerve electrical stimulation

Levy, M.·Bassis, C.·Kennedy, E.·Yoest, K. E.·Becker, J. B.·Bell, J.·Berger, M. B.·Bruns, T. M.
View original source ↗Export metadata ↓

Abstract

Treatment options are limited for the approximately 40% of postmenopausal women worldwide who suffer from female sexual dysfunction (FSD). Neural stimulation has shown potential as a treatment for genital arousal FSD, however the mechanisms for its improvement are unknown. One potential cause of some cases of genital arousal FSD are changes to the composition of the vaginal microbiota, which is associated with vulvovaginal atrophy. The primary hypothesis of this study was that neural stimulation may induce healthy changes in the vaginal microbiome, thereby improving genital arousal FSD symptoms. In this study we used healthy rats, which are a common animal model for sexual function, however the rat vaginal microbiome is understudied. Thus this study also sought to examine the composition of the rat vaginal microbiota. Treatment rats (n=5) received 30 minutes of cutaneous electrical stimulation targeting the genital branch of the pudendal nerve, and Control animals (n=4) had 30-minute sessions without stimulation. Vaginal lavage samples were taken during a 14-day baseline period including multiple estrous periods and after twice-weekly 30-minute sessions across a six-week trial period. Analysis of 16S rRNA gene sequences was used to characterize the rat vaginal microbiota in baseline samples and determine the effect of stimulation. We found that the rat vaginal microbiota is dominated by Proteobacteria, Firmicutes, and Actinobacteria, which changed in relative abundance during the estrous cycle and in relationship to each other. While the overall stimulation effects were unclear in these healthy rats, some Treatment animals had less alteration in microbiota composition between sequential samples than Control animals, suggesting that stimulation may help stabilize the vaginal microbiome. Future studies may consider additional physiological parameters, in addition to the microbiome composition, to further examine vaginal health and the effects of stimulation.

Source connections

Explore related subjects

microbiologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Levy, M., Bassis, C., Kennedy, E., Yoest, K. E., Becker, J. B., Bell, J., Berger, M. B., Bruns, T. M.. 2019-05-31. The rodent vaginal microbiome across the estrous cycle and the effect of genital nerve electrical stimulation. https://doi.org/10.1101/647545

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Genomic analysis of the Streptococcus anginosus group; taxonomic implications, evolutionary insights and clinical considerations

Background: The Streptococcus anginosus group (SAG) (S. anginosus, S. intermedius, and S. constellatus) causes serious, potentially life-threatening, invasive infections, often in otherwise healthy individuals. However, the group's diversity is still poorly understood, and with it, the ability to identify prognostic markers of severe disease. Methods: Long-read sequencing produced closed genomes for 29 isolates from 25 patients hospitalised primarily for invasive SAG infections, and 21 isolates from 20 non-hospitalised controls. Genomes were classified with GTDB-Tk and combined with 211 reference genomes. After dereplication, 207 SAG genomes (38 isolate, 169 reference) representing 206 strains were analysed using: GTDB classification, average nucleotide identity, multi-marker and core-genome SNP phylogenies, recombination-aware analyses, mobilome, CAZyme and gapseq metabolic profiling, and lineage-aware genome-wide association testing for invasive phenotype. Results: Agreement between GTDB-Tk and MALDI-TOF taxonomic classifications was low (42.8%), including two S. massiliensis cases mis-identified by MALDI-TOF as SAG. S. anginosus resolved into four taxa (S. anginosus, S. hominis, S. whileyi and S. vaginalis). Phylogenies based on core genome single-nucleotide polymorphisms resolved these species into distinct clades, whereas 16S rRNA gene and multilocus sequence analysis phylogenies did not. The four ex-S. anginosus taxa showed a gradient of genomic cohesion, with S. vaginalis being near-clonal, in contrast to S. anginosus, which shared high levels of sequence ancestry with other neighbouring taxa. Carbohydrate utilisation was strongly lineage-associated, as was propensity for invasive disease. A ~15Kbp glycosaminoglycan utilisation locus was found in the three taxa of highest disease severity propensity (S. intermedius, S. constellatus, S. whileyi) which predicts a direct host glycosaminoglycan feeding mechanism that may contribute to invasive disease. No single functional feature, gene or core-genome SNP was associated with invasiveness however after lineage-adjustment. Combined feature analysis suggests S. vaginalis has undergone a niche restriction and has evolved for a primary existence in the female urogenital tract. Conclusions: Under-reported species may be mis-diagnosed as SAG invasive infections. SAG is more diverse than its current three-species definition, with the conventional S. anginosus species proposed to be classed into a complex of four distinct taxa. Invasive capacity appears to be an emergent system-level property rather than from individual features.

microbiology↗
bioRxiv2026

Cell-scale confinement reorders bacterial speed rankings

Which bacterium swims fastest depends on where the race is run. Speeds are usually measured in open liquid, yet many bacteria live in pores, mucus and host passages no wider than a cell. Using a microfluidic device with eight channel widths (0.80-3.00 m) in one field of view, we tracked unlabeled cells of eight species spanning five motility systems. Chamber height, a polymer additive and channel width each reordered the ranking. Vibrio alginolyticus, the fastest in open liquid, slowed to ~4 m/s in 1.25-m channels, whereas Campylobacter jejuni and Bacillus subtilis kept 33-46 m/s. Open liquid speed did not predict robustness to confinement. In two unrelated lineages, host symbionts that pass through narrow passages during colonization, Caballeronia insecticola and Vibrio fischeri, outran their non-symbiotic relatives in the channels, and crossed them with flagella wrapped around the cell body at nearly the speed of unwrapped cells. Where space is tight, the ability to keep moving, not top speed, sets the ranking.

microbiology↗
bioRxiv2026

The biochemical composition of coronavirus Nucleocapsid proteins drives the bicistronic properties of their sub-genomic mRNAs

The nucleocapsid (N) gene of coronaviruses (CoVs) encodes a structural RNA-binding protein required for viral assembly. In SARS- and MERS-CoV viruses, reading frame 2 of N contains an overlapping open reading frame (ORF) encoding an innate immune antagonist accessory protein. However, the extent of this dual coding capacity across the CoV family, and the genetic features driving overlapping ORF formation, remain unexamined. Here, we developed an in-silico tool (ORFan) to screen structural gene sub-genomic mRNA sequences from 152 species of coronavirus for the presence of overlapping accessory gene candidates. We found that frame 2 of the N gene in Alpha-, Beta- and Delta-CoVs frequently contains a potential accessory ORF (AcORF), conserved at the subgenus level, unlike the spike, envelope and membrane genes. We also show that CoV nucleotide biases in conjunction with codon biases integral to N protein function drive the relatively high abundances of start codons in frame two and stop codons in frame three, explaining the tendency towards frame 2 AcORFs. We further suggest that viral nucleotide biases and the codon composition required for RNA-binding function facilitate overlapping ORF formation in other virus families

microbiology↗