Virulence Gene Characterization and Serotyping of Major Bacterial Pathogens Isolated from Bovine Respiratory Disease in Ethiopia

Bovine Respiratory Disease (BRD) causes a severe form of pneumonia in all age of cattle. This study was designed to investigate the distribution of capsular types, serotypes, and virulence-associated genes of the major bacterial pathogens from BRD outbreak samples in Ethiopia. In this study 166 samples were collected from clinically sick (n = 107) and pneumonic lung tissue (n = 59). Laboratory assay confirmed isolation of M. haemolytica 37 (22.29%), P. multocida 25 (15.06%), B. trehalosi 12 (7.23%), and H. somni 15 (9.04%). PCR assay of P. multocida capsular typing revealed 21 (84.0%) cap A (hyaD-hyaC) and 4 (16.0%) cap D (dcbF) strains. M. haemolytica serotypes belonged to A: 1, A: 2, and A: 6 from 26 (70.27%), 4 (10.81%), and 7 (18.92%) isolates, respectively. P. multocida biotyping showed isolation of A: 1, A: 2, and A: 3 from 3 (14.29%), 2 (9.52%),