Integrative and conjugative elements in Mycoplasmopsis bovis from Western Canadian feedlot cattle: characterization and conjugative transfer

Of these isolates, 33.1% harbored the array of MICE genes required for conjugation. <i>M. bovis</i> isolates conjugated at frequencies of 10-7-10-8 when cultured in SP4 broth under orbital agitation. Since MICE circularization is the initial step in conjugation, the presence of circular MICE (cMICE) was used as a proxy for conjugation capability (<i>n</i> = 451). Interestingly, 25.7% of the isolates were cMICE-positive, with a higher prevalence observed in <i>M. bovis</i> isolated from dairy as compared to beef feedlot cattle. Additionally, calves classified as high-risk for BRD were more likely to harbor cMICE-positive <i>M. bovis</i> in both cattle types. Backgrounded dairy cattle had a higher likelihood of carrying cMICE-positive <i>M. bovis</i> than those originating from ranches. These findings lay the groundwork for assessing cattle source as a determinant of cMICE-positive <i>M. bovis</i> and for developing targeted strategies to mitigate antimicrobial resistance.