Protective potential of an attenuated Pasteurella multocida, whichexpresses only the N-terminal truncated fragment of P. multocida toxin

摘要

Pasteurella multocida serogroup D causes progressive atrophic rhinitis in pigs and produces a potent, intracellular, mitogenic toxinknown as P. multocida toxin (PMT), which is encoded by the toxA gene. Highly toxic to cells, PMT is a poor antigen and becomesmore immunogenic after its native structure has been destroyed. Previously, we found that the N-terminal fragment of PMT(N-PMT) can induce a strong immune response that is protective against wild-type challenge. Here, an attenuated P. multocidamutant expressing only N-PMT was developed and its protective effect was evaluated. The mutant provides protective immuneresponses against bacterial and toxin challenges, and so is a good live vaccine candidate.