Relação da ordem de parição no isolamento bacteriano no fundo vaginal durante o pós-parto imediato de vacas leiteiras mestiças

Abstract

The secretions present in the vaginal fornix during the first days postpartum can reflect the uterine environment. The temporary loss of physical barriers during calving allows the ascension of microorganisms that negatively impact the fertility of dairy cows. Factors such as parity order can alter this microbial flow due to differences in inflammatory responses, involution time, and reproductive anatomy of primiparous and multiparous cows. Therefore, this study analyzed the effect of parity order on bacterial isolation in the vaginal fornix in the immediate postpartum period of dairy cows, aiming to determine the characteristic bacterial profile of each category. Between March 2025 and January 2026, 100 cows from a commercial dairy farm in the region of Uberlândia, MG, were evaluated. Vaginal discharge samples were collected from the vaginal fornix region between 0 and 3 days postpartum using the Metricheck device. The samples, individually packaged in sterile tubes, were transported to the laboratory of INATA Ltda. For sample culturing, with the aid of a swab, a smear of the collected content was performed on one-third of the plates and then streaked with a bacteriological loop. The media used were Blood agar, a non-selective medium indicated for the cultivation of bacteria in general, and MacConkey agar, a selective differential medium for the growth and identification of enterobacteria. Furthermore, one of the Blood agar plates was incubated in an anaerobiosis jar for the growth of strict anaerobic bacteria, and another Blood agar plate was incubated in aerobiosis along with the MacConkey agar plate, all in an incubator at 37°C for 48 hours. After the initial inoculum, suspected colonies were isolated and subcultured onto the following culture media: Blood agar, MacConkey agar, and Chromogenic agar, and incubated in an atmosphere according to suspicion, in an incubator at 37°C for 48 hours. Bacterial species were characterized by the MALDI-TOF MS method. It was observed that bacterial isolation rates in material collected from the vaginal fornix, as well as the distribution of samples according to the number of bacterial species isolated from bovine females, increased with parity order. Therefore, the number of previous calvings of the bovine female exerts an influence on the bacterial diversity present in the uterus and the vaginal fornix during the immediate postpartum period.