Genome characterization of Pasteurella multocida subspecies septica and comparison with Pasteurella multocida subspecies multocida and gallicida.

Pasteurella multocida: subspecies multocida, gallicida, and septica are noted to have a contribution to fowl cholera, a life-threatening disease to both domestic and wild bird species. The genome sequences of avian P. multocida subspecies gallicida and multocida have been well analyzed and compared. However, the genome characterization of avian P. multocida subspecies septica is rarely discussed. In this study, we determined the draft genome sequence of a virulent P. multocida subspecies septica serogroup A strain HB02. The genome of P. multocida HB02 was composed of a single chromosome of 2,213,604 bp with a 40.27% G + C content, which showed a similar genome size and %GC content to the P. multocida subspecies multocida and gallicida genomes. The entire sequence specified 2002 putative coding DNA sequences plus 2 encoded rRNAs and 46 encoded tRNAs. In addition, the subspecies septica had a similar content of genes coding for metabolic traits that found in the subspecies gallicida and multocida. In addition, comparison of virulent versus avirulent avian P. multocida genomes identified 657 unique genes in either of the virulent strains HB02, P1059 and/or X73 compared to the avirulent strain Pm70. These genes should be the potential virulence-associated genes. Our work may add a novel genome sequence for the avian P. multocida genome database and shed a light on the pathogenesis of P. multocida.