Characterization of Reproductive Microbiota of Primiparous Cows During Early Postpartum Periods in the Presence and Absence of Endometritis

Abstract

Endometritis has a major impact on fertility in postpartum dairy cows. Since previous studies showed an association between reproductive microbiota and perinatal disease, we monitored both bovine uterine and vaginal microbiota in primiparous cows to elucidate the effect of early postpartum microbiota on endometritis. Uterine and vaginal samples were collected at time points from pre-calving to 35 days postpartum (DPP), and analyzed by 16S rRNA sequencing, combined with ancillary bacterial culture. A total of seven healthy cows and seven cows diagnosed with endometritis on 35 DPP were used in the current study. The uterine and vaginal microbiota showed a maximum of 20.1% shared amplicon sequence variants (ASVs) at linked time points. 16S rRNA based analysis and traditional culture methods revealed that Trueperella showed a higher abundance in both uterus and vagina of the endometritis group compared to the healthy group on 21 DPP (U-test p < 0.05). Differential abundance analysis of the uterine microbiota showed that Enterococcus and six bacterial genera including Bifidobacterium were unique to the healthy group on the day of calving (0 DPP) and 28 DPP, respectively. In contrast, Histophilus and Mogibacteriaceae were characteristic bacteria in the vagina pre-calving in cows that later developed endometritis, suggesting that these bacteria could be valuable to predict clinical outcomes. Comparing the abundances of bacterial genera in the uterine microbiota, a negative correlation was observed between Trueperella and several bacteria including Lactobacillus. These results suggest that building an environment where there is an increase in bacteria that are generally recognized as beneficial, such as Lactobacillus, may be one possible solution to reduce the abundance of Trueperella and control endometritis.

Fecal and vaginal microbiota of vaccinated and non-vaccinated pregnant elk challenged with Brucella abortus

“…We observed that OTUs 3 and 5 (classified by BLAST as Porphyromonas ) as well as OTU 9 ( Trueperella ) increased in relative abundance from Precalve to Postcalve in agreement with the literature. Their parent genera increased over this interval as well ( 84 , 85 , 110 , 118 ). As discussed previously, Porphyromonas can colonize and invade ruminant uterine tissues and is associated with a number of reproductive tract diseases.…”

“…It is well-established in the literature that parturition induces a significant, discrete shift in microbial community structure and composition in the mammalian reproductive tract ( 76 , 84 , 107–110 ). In particular, Bicalho et al and Kudo et al also observed a trend of decrease in alpha diversity in cattle vaginal microbiota following parturition ( 84 , 110 ). The mammalian reproductive tract alpha diversity is also known to shift longitudinally during pregnancy but prior to parturition, corroborating the additional differences between VT combinations of different timepoints as well as the PCoA plots ( 72 , 111–114 ).…”

Temporal changes in ewe vaginal microbiota throughout gestation

“…There is limited information about the impact of Bacteroides, Prevotella, or Porphyromonas colonization of the vaginal tract in sheep on reproductive performance. However, all three genera have all been associated with cattle experiencing reproductive maladies such as metritis, endometritis, or vaginitis ( Elad et al, 2004 ; Bicalho et al, 2017 ; Cunha et al, 2018 ; Kudo et al, 2021 ).…”

Vaginal Microbiome Dynamics of Cows in Different Parities

“…Changes in the vaginal microbiome can affect the reproductive health of cows [ 26 ]. Some harmful strains of bacteria, such as Streptococcus , E. coli , and P. pyogenea , can affect the uterus and ovaries through infection, leading to inflammation and the development of infection.…”