Introduction

Classification

Taxonomy

• Family: Pasteurellaceae.
• Genus: Pasteurella.
• Closely related to the genus Actinobacillus.
• Species: multocida.

Etymology

• Pasteurella - after Pasteur.
• Multocida: L: multus - many; cida - to kill; multocida - many-killing, ie pathogenic for many animals.

Active Forms

Clinical Effects

Epidemiology

Habitat

• Carried on the mucous membranes of susceptible host species. Widespread in carnivores.

Lifecycle

• Multiplies on mucous membranes of host.

Transmission

• Usually via the respiratory tract.

Pathological effects

• Antibodies are protective against hemorrhagic septicemia in cattle, but little is known about immunity in other species.

• All members of the genus are probably parasites.
• Stress, eg concurrent viral infection → becomes pathogenic.
• Endotoxins are important in septicemic diseases, eg bovine hemorrhagic septicemia.
• Thermolabile dermonecrotoxin is important in atrophic rhinitis of pigs.
• Animal to animal spread usually via the respiratory tract and virulence is enhanced by transmission.

Diseases caused

• Serogroup A:
  • Pneumonia or suppurative conditions, eg abscesses, mastitis in cattle, sheep, pigs, rabbits and other species.
  • Fowl cholera.
  • Also found as commensals.
• Serogroup B:
  • Epizootic hemorrhagic septicemia in ruminants.
  • Also found as commensals.
• Serogroup D:
  • Atrophic rhinitis in pigs (may be in association withBordetella bronchiseptica).
  • Pneumonia in pigs and other animals.
• Serogroup E:
  • Epizootic hemorrhagic septicemia in cattle and water buffalo in Africa.
• Serogroup F:
  • Found in turkeys - role unclear.

Other Host Effects

• Carried on mucous membranes, especially of carnivores.

Control

Control via chemotherapies

• Most strains of P. multocida are sensitive to penicillin, sulfonamides and tetracyclines.
• Plasmid-based resistance to many commonly used antibiotics is widely found.

Vaccination

• Killed vaccine available for cattle, poultry and pigs.
• Some attenuated, live vaccines used in poultry.

Diagnosis

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Mohan K, Sadza M, Madsen M et al (1994) Phenotypic characterization of Zimbabwean isolates of Pasteurella multocida. Vet Microbiol 38 (4), 351-357 PubMed.
• Bjurström L & Linde-Forsberg C (1992) Long-term study of aerobic bacteria of the genital tract in stud dogs. Am Vet Res 53 (5), 670-673 PubMed.
• Bjurström L & Linde-Forsberg C (1992) Long-term study of aerobic bacteria of the genital tract in breeding bitches. Am J Vet Res 53 (5), 665-669 PubMed.
• Collins F M (1977) Mechanisms of acquired resistance to Pasteurella multocida infection: a review. Cornell Veterinarian 67 (1), 103-138 PubMed.