CHARACTERIZATION OF VAGINAL AND ENDOMETRIAL MICROBIOME IN PATIENTS WITH
CHRONIC ENDOMETRITIS: A PILOT STUDY.
Abstract
Comparative study of CD138 immunostain and microbiome of the female
reproductive tract (vaginal and endometrial) in the diagnosis of chronic
endometritis. A pilot study from May 2017 to May 2019. Instituto
Bernabeu fertility clinic. Cohort study with sixty patients undergoing
assisted reproductive treatment. The vaginal and endometrial microbiome
was analyzed by mass sequencing of the V3V4 region of 16S rRNA.
Bioinformatics analysis was performed using QIIME2 and MicrobiomeAnalyst
packages. Alpha, beta diversity and taxonomic characterization were
compared with positive and negative CD138 groups for chronic
endometritis. Different bacterial communities were detected when vaginal
and endometrial samples were analyzed in patients with and without
endometritis diagnosed with CD138 immunohistochemistry. In patients with
endometritis, a higher alpha diversity index tendency was found in
vaginal samples (p=0.15) and significant differences in endometrial
samples (p=0.01). In the beta diversity analysis, no significant
differences were observed between the groups established as per the
diagnosis of endometritis. Vaginal and endometrial samples from women
with endometritis showed a microbiome pattern not dominated by
Lactobacillus spp. Relative abundance analysis identified genera
Ralstonia and Gardnerella in endometrial sample, and genera
Streptoccoccus and Ureaplasma in vaginal sample of CE patients diagnosed
with CD138. Our results demonstrate the existence of a characteristic
vaginal and endometrial microbiota in endometritis patients. Different
genera and species have been identified in patients with and without
endometritis depending on whether the sample is endometrial or vaginal.
There is a relationship between vaginal microbiome alteration and
chronic endometritis.