BioProject

Mannheimia haemolytica are bacteria that typically reside in cattle as commensal members of their upper respiratory tract. More...

Mannheimia haemolytica are bacteria that typically reside in cattle as commensal members of their upper respiratory tract. However, when cattle are immunocompromised, M. haemolytica can invade their lungs and cause respiratory disease and/or death. It has been known for some time that not all strains of M. haemolytica associate equally with bovine respiratory disease. This has been shown by both serotype and pulsed-field gel electrophoresis (PFGE) typing methods. In this study, the genomes of 1,133 M. haemolytica isolates were sequenced, including isolates from the lungs of cattle with respiratory disease and from the nasopharynx of cattle without signs of respiratory disease. A new classification system for M. haemolytica of North American cattle was developed from analyses of the sequences and identification of nucleotide polymorphism genotypes. Additionally, associations of select genetic types of M. haemolytica with the lungs of cattle with respiratory disease, a distinct integrative and conjugative element (ICE), and antibiotic resistance genes were identified. Less...