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Inhibition of capsular protein synthesis of Pasteurella multocida strain P-1059

Nattawooti Sthitmatee1, Yasushi Kataoka, Takuo Sawada

  • 1Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Muang, Chiang Mai 50100, Thailand. drneaw@gmail.com

The Journal of Veterinary Medical Science
|July 13, 2011
PubMed

Insights

A new Pasteurella multocida mutant, PBA322, lacking the OmpH capsular protein, was developed. This mutant strain shows significantly reduced pathogenicity in chickens, indicating potential for vaccine development.

Area of Science:

  • Veterinary Microbiology
  • Bacterial Pathogenesis

Background:

  • Pasteurella multocida is a significant pathogen in poultry and livestock.
  • The OmpH capsular protein plays a role in P. multocida virulence.

Purpose of the Study:

  • To construct and characterize a P. multocida mutant deficient in OmpH expression.
  • To evaluate the pathogenicity of the OmpH-deficient mutant in animal models.

Main Methods:

  • Construction of a mutant strain (PBA322) using antisense RNA targeting the ompH gene via electroporation.
  • Phenotypic characterization of colonies (color, capsule thickness) using microscopy.
  • Analysis of OmpH protein levels using SDS-PAGE.
  • Pathogenicity assessment in mice and chickens.

Main Results:

  • Mutant PBA322 exhibited grayish colonies, indicating loss of capsule synthesis, unlike the iridescent parental strain.
  • SDS-PAGE revealed significantly lower OmpH levels in PBA322 compared to the parent strain.
  • Electron microscopy showed a thinner capsule in PBA322.
  • The mutant strain PBA322 was completely attenuated in chickens.

Conclusions:

  • The ompH gene is crucial for capsule synthesis and virulence in P. multocida.
  • Strain PBA322 is a viable candidate for further investigation as a live attenuated vaccine against P. multocida infections in chickens.

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