Journal of Microbiology

Research Support, Non-U.S. Gov'ts

Immunological Roles of Pasteurella multocida Toxin (PMT) Using a PMT Mutant Strain: Tae Jung Kim , Nguyen Tat Toan , Eun Jin Jang , Bock Gie Jung , Jae Il Lee , Bong Joo Lee; J. Microbiol. 2007;45(4):364-366.; DOI: https://doi.org/2559 [pii]

Abstract: The immunological role of the Pasteurella multocida toxin (PMT) in mice was examined using a PMT mutant strain. After a nasal inoculation, the mutant strain failed to induce interstitial pneumonia. Moreover, PMT had no significant effect on the populations of CD4+, CD8+, CD3+, and CD19+ immunocytes in blood or on the populations of CD4+ and CD8+ splenocytes (P<0.01). However, there was a significant increase in the total number of cells in the BAL samples obtained from the wild-type P. multocida-inoculated mice. On the other hand, the level of IL-1 expression decreased when the macrophages from the bronchio-alveolar lavage were stimulated with PMT. Overall, PMT appears to play some role (stimulating and/or inhibiting) in the immunological responses but further studies will be required to confirm this.

Development of a toxA Gene Knock-out Mutant of Pasteurella multocida and Evaluation of its Protective Effects: Tae Jung Kim , Jae Il Lee , Bong Joo Lee; J. Microbiol. 2006;44(3):320-326.; DOI: https://doi.org/2380 [pii]

Abstract: Pasteurella multocida is an important veterinary and opportunistic human pathogen. In particular, strains of P. multocida serogroup D cause progressive atrophic rhinitis, and produce a potent, intracellular, mitogenic toxin known as P. multocida toxin (PMT), which is encoded by the toxA gene. To further investigate the toxigenic and pathogenic effects of PMT, a toxA-deleted mutant was developed by homologous gene recombination. When administrated to mice, the toxigenicity of the toxA mutant P. multocida was drastically reduced, suggesting that the PMT constributes the major part of the toxigenicity of P. multocida. Similar results were obtained in a subsequent experiment, while high mortalities were observed when toxA(+) P. multocida bacterial culture or culture lysate were administrated. Mice immunized with toxA(? P. multocida were not protected (none survived) following challenge with toxA(+) P. multocida or bacterial culture lysate (toxin). These results suggest that the toxigenicity of P. multocida is mainly derived from PMT.

Search