Bassis, C. | Search bioRxiv

bioRxiv2019

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

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.

microbiology↗

bioRxiv2019

Evaluation of Bacteria Detected in Both Urine and Open Wounds in Nursing Facility Residents

Nursing home residents are at a greater risk of developing pressure injuries that develop into an open wound. Open wounds can be colonized with bacteria from multiple sources. Emerging evidence suggests the specific composition of the open wound microbial community can result in delayed wound healing and increased infection risk. Understanding the factors that influence microbial colonization of open wounds, can lead to the prevention of infections. The relationship between bacteria found in urine and that of open wounds, is currently unknown. Recent studies have shown that nursing home residents can harbor a urinary microbiota independent of symptoms and frequently experience urinary incontinence. To determine if the colonization of open wounds mirrors urinary colonization, we conducted a pilot study with nursing home residents, comparing bacteria present in open pressure injuries below the umbilicus and urine. To identify microbial species that were present in both urine and open wound at one timepoint, standard bacteriologic culture techniques followed by MALDI-TOF was used as well as16S rRNA-encoding gene amplicon sequencing. In this study we found that some bacteria detected in urine were also detected in open wounds in one individual at one timepoint, using both culture dependent and independent techniques. Bacterial species that were more often detected at both sites included Enterococcus faecalis, Proteus mirabilis, Escherichia coli, and Providencia stuartii. This pilot study provides evidence that urinary colonization can mirror open wound colonization. Further studies are needed to investigate if parallel colonization of these anatomical sites affect infection outcomes.

microbiology↗