WGS of Mannheimia haemolytica and Pasteurella multocida from dairy cattle with and without bovine respiratory disease

Mannheimia haemolytica and Pasteurella multocida are two of the main bacterial pathogens associated with Bovine Respiratory disease (BRD). BRD represents one of the most significant health challenges in the cattle industry, causing substantial economic losses through animal morbidity and mortality while raising serious welfare concerns. The objectives of this project were to: 1) characterize virulence factors (VF) and antimicrobial resistance (AMR) genes in Mannheimia haemolytica and Pasteurella multocida isolates from dairy cattle of different ages with and without BRD using whole-genome sequencing (WGS); 2) evaluate associations between microbial genetic elements and animal disease status; and 3) assess the accuracy of genome-based predictions for the antimicrobial resistance phenotype. Findings from this project demonstrate that identifying genomic markers based on gene presence/absence lacks discriminatory power within this population for identifying unique genotypes associated with disease status in these genomically diverse organisms.