Pathogenicity and Comparative Genomics Analysis: Pasteurella multocida Serogroups A and F Isolated from Domestic Rabbits in China

Pasteurella multocida is a zoonotic pathogen that causes severe respiratory infections in domestic rabbits. Serogroup F strains have been increasingly reported but remain poorly characterized. Two strains, PS-JQ08 (serogroup A) and PS-JQ09 (serogroup F), were isolated from deceased rabbits in China. Pathogenicity was assessed in mouse and rabbit models, and whole-genome sequencing was performed for comparative genomic analysis. Both strains were highly pathogenic but induced distinct pathological profiles: PS-JQ08 caused hepatocellular vacuolar degeneration, whereas PS-JQ09 induced hemorrhage and edema. Genomic analysis revealed that both strains harbored core virulence genes involved in adhesion, iron acquisition, and antiphagocytosis; however, the serogroup F strain harbored unique iron transport genes and arsenic resistance systems. Phylogenetic analysis revealed that PS-JQ08 clustered with avian serogroup A strains, whereas PS-JQ09 clustered with porcine- and rabbit-derived serogroup F strains. These findings provide clues for exploring the genetic mechanism underlying pathogenic differentiation of Pasteurella multocida between serogroups A and F, and provide valuable genomic information to support vaccine development and disease control in rabbits.