Identification of genes transcribed by Pasteurella multocida in rabbit livers through the selective capture of transcribed sequences.

Pasteurella multocida, a Gram-negative nonmotile coccobacillus, is the causative agent of fowl cholera in poultry, hemorrhagic septicemia in cattle, atropic rhinitis in swine, and snuffles in rabbits. The differentially expressed gene profile of P. multocida in infected rabbit livers was identified and compared with that from in vitro culture by selective capture of transcribed sequences. A total of 31 genes were identified, of which 28 encoded enzymes for amino acid biosynthesis and metabolism, intermediary metabolism, and energy metabolism, or proteins for regulatory adaptive responses, general microbial stress response, transport proteins, and secreted proteinases. Three were unknown, novel genes. Five genes representing different categories were chosen randomly and verified by real-time reverse transcriptase-polymerase chain reaction analysis. All were upregulated by P. multocida in infected rabbit livers, with changes ranging from 1.61- to 13.55-fold when compared with in vitro cultures. This study has identified genes of P. multocida that are upregulated during infection of rabbit livers when compared with in vitro growth conditions. The genes will provide a molecular basis for further study of the pathogenesis of P. multocida.