Prevalence of multi drug antimicrobial resistance in Mannheimia haemolytico isolated from high-risk Stocker cattle at arrival and two weeks after processing

Abstract

Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in North American beef cattle. Mannheimia haemolytica (Mh) is the bacterial pathogen most frequently isolated from cattle with BRD and the prevalence of antimicrobial resistance in this pathogen has been increasing. Administration of antimicrobials to prevent BRD is commonplace in stocker cattle. Our objectives were to determine the prevalence of Mh isolated from the nasopharynx of high-risk stocker cattle at arrival and at resampling 10 to 14 days later, and second, to determine the prevalence of antimicrobial resistant Mh at these same time points.