Pasteurella species and Mannheimia haemolytica

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• Pasteurella multocida in Atrophic rhinitis of pigs and atrophic rhinitis
• Peritonitis in sheep
• Permeability types of pulmonary oedema.
• Can be secondary to IBR
• Causes 'Snuffles' in rabbits
• Manheimia haemolytica biotype A serotype 1 (90%) and Pasteurella multocida cause pneumonic pasteurellosis
• Pasteurellosis in pigs
• Can cause vascular fragility, leading to haemorrhagic disease.
• M. haemolytica and P. multocida may contribute to Enzootic pneumonia of calves
• Often follows parainfluenza - 3 infection of cattle
• P. haemolytica in enzootic pneumonia of lambs
• In pyothorax
• P. multocida in cellulitis in cats

Overview Pasteurella

• Found in the upper respiratory tract and gastrointestinal tract mucosa
• Usually opportunistic organisms, causing disease during times of stress, low resistance or concurrent infections
• Resist phagocytosis by their capsule
• Not part of the human bacterial flora

Bacteria Properties

• Short Gram-negative bacilli
• Oxidase-positive
• May show bipolar staining
• Catarrhal odour
• Produce endotoxins which cause host damage and death

Pasteurella multocida

• Typa A
  • Commensal in upper respiratory tract of animals in UK
  • Commomly repsonsible for dog and cat bite wound infections in humans and animals
  • Some strains involved in Atropic Rhinitis, and produce osteolytic toxin

• Type B
  • Causes Haemorrhagic Septicaemia of cattle in Southern Europe and Asia

• Type D
  • Causes Atropic Rhinitis along with Bordetella bronchiseptica
  • Produces an osteolytic toxin, which stimulates osteoclast, inducing bone resorption

• Type E
  • Causes Afican Bovine Haemorrhagic Septicaemia

Pasteurella pneumotropica

• Carried in nasopharynx of many small rodents
• Causes pneumonia in rodents as a secondary disease