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Vacuolating cytotoxic activity of Pasteurella multocida causing haemorrhagic septicaemia in buffalo and cattle

N H Shah1, J Biewenga, N H Shah

  • 1Center of Animal Biotechnology, Veterinary Research Institute, Peshawar, Pakistan.

FEMS Microbiology Letters
|September 15, 1996
PubMed

Insights

Pasteurella multocida strains causing haemorrhagic septicaemia (HS) induce macrophage damage. This study identifies a vacuolating cytotoxic activity in HS-associated strains, crucial for understanding disease pathogenesis.

Area of Science:

  • Veterinary Microbiology
  • Pathogen Toxinology

Background:

  • Haemorrhagic septicaemia (HS) is a severe disease in livestock, primarily affecting buffalo and cattle.
  • Pasteurella multocida is the causative agent of HS, with specific serotypes implicated in outbreaks.

Purpose of the Study:

  • To investigate the toxic mechanisms of Pasteurella multocida strains responsible for HS.
  • To identify virulence factors associated with HS-causing strains using a mouse model.

Main Methods:

  • In vivo study using a mouse model injected with Pasteurella multocida serotype B:2,5.
  • Electron microscopy of peritoneal macrophages to assess cellular damage.
  • In vitro assays with RAW 264 macrophage cell line and bacterial cultures/supernatants.
  • Neutralization assay using specific antiserum.

Main Results:

  • Intraperitoneal injection of P. multocida induced significant cytoplasmic vacuolation, lysis, and death in mouse macrophages.
  • In vitro, HS-associated P. multocida strains and their culture supernatants caused macrophage vacuolation.
  • This vacuolating activity was neutralized by antiserum from infected buffalo, indicating a specific cytotoxic factor.

Conclusions:

  • HS-associated Pasteurella multocida strains possess a vacuolating cytotoxic activity.
  • This activity contributes to the pathogenesis of haemorrhagic septicaemia by damaging host macrophages.
  • Further characterization of this toxin may lead to novel therapeutic strategies.

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