Occurrence of mollicutes infection and molecular identification of ureaplasmas from the reproductive tract of dairy cattle kept under tropical conditions

Bacterial diseases associated with the Mollicutes class can lead to decreased milk production and reproductive disorders in cattle, causing significant economic losses and compromising animal welfare. This study aimed to investigate the presence of Mollicutes and Ureaplasma diversum in the reproductive tract of dairy cows and determine the associated risk factors, as well as identify circulating strains of Ureaplasma in herds. Vaginal swab samples from 392 lactating cows were subjected to generic polymerase chain reaction (PCR) for Mollicutes detection and specific PCR for U. diversum identification. An epidemiological questionnaire was used to analyze the risk factors. Positive samples for U. diversum were sequenced from the intergenic region 16-23 S rRNA and multiple alignments were performed to generate a phylogram. The geographical coordinates of the municipalities where the herds were located were used for the phylogeographic analysis. Mollicutes and U. diversum were detected in 45.4% (178/392) and 21.7% (85/392) of the samples, respectively, with a herd-level prevalence of 88.8%. Age group heifers (OR = 4.006; CI 1.283-12.510) and history of genital lesions (OR = 5.564; CI 3.011-10.284) were the biggest associated risk factors, in addition to other effects. The frequency of these agents was high and different strains of U. diversum were found to be spread throughout the studied states, likely due to the extensive animal movement network.