Study Of Dominant Bacterial Species In Vaginal And Uterine Mucosal Microbiocenosis In Clinically Healthy Cows In The Natal And Postpartum Period

Abstract

Dysbiotic conditions most often precede clinical occurrences of pathological processes. Lactobacilli are components of the microflora, which usually affect and cause a local immune response. The presence of a sufficient number of lactobacilli on a detected membrane is a crucial factor that ensures an adequate level of local immunity. Knowledge of the microbiota in the genital tract and its variation is essential for understanding the characteristics of different infectious pathologies. It allows us to develop appropriate treatment and preventive measures and thus reduce the occurrence of obstetric and gynecologic pathologies in cows. This study focuses on dominant bacterial species in vaginal and uterine microbiocoenosis in postpartum cows, in relation to morphological and immunological parameters in cow's blood. Studies of vaginal swabs were carried out on 30 Holstein-Friesian cows from 1 to 45 days after calving using microbiological techniques. Species identification of isolated microorganisms was performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Morphological and immunological parameters of blood were studied on days 1, 14, and 28 after calving, using commonly accepted methods and a hematology analyzer.

It has been established that the species-specific composition of microflora varies and is represented by families such as Enterobacteriaceae, Streptococcaceae, Staphylococcus, Pseudomonas, Enterococcus, and Bacillus. Members of the genera Moraxella and Pasteurella were isolated from individual animals, as well as other species. The symbiotic microflora also includes Lactobacillus, Bacillus, and Pediococcus, which were isolated from cows.

When acute postpartum endometritis occurs in cows, only pathogenic microflora is isolated. Lactobacilli are not isolated from vaginal swabs. It has been established that changes in cell immunity factors, including phagocytic indicators such as phagocytosis, phagocyte numbers, and phago index and capacity, are recorded when cows are sick with acute post-partum endometritis. The number of T cells in cows with endo metritis is significantly higher than in clinically healthy cows by 23.5% on day 14 after calving, while all cows with acute endometritis also have an increase in the number of B cells compared to animals without signs of disease. Lysozyme activity in blood serum is 1.7 times lower on the first day after calving than normal values but by the end of postpartum period, it exceeds reference levels by a factor of one. The insemination index was 1.71, and the service period for cows was 115 days. This indicates a relationship between local immune mechanisms in cow's reproductive systems and overall immunity factors during the postpartum period, as well as their effect on the occurrence of postpartum pathology. Thus, when endometritis occurs, the normal microbiota is replaced by pathogenic bacteria, and cellular and humoral immunity factors are activated at the same time.