Pasteurella species and Mannheimia haemolytica
- 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
- Common commensal of the upper respiratory tract and gastrointestinal tract mucosa of animals
- Usually opportunistic organisms, causing disease during times of stress, low resistance or concurrent infection
- Resist phagocytosis by their capsule
- Not part of the human bacterial flora
Pasteurella Properties
- Short Gram-negative bacilli or coccobacilli
- Oxidase-positive
- May show bipolar staining
- Catarrhal odour
- Produce endotoxins which cause host damage and death
Pasteurella multocida
- Large grey colonies on blood agar
- Not haemolytic
- Do not grow on MacConkey
- Four capsular serotypes, A,B,D,E and recently F
- Primary and secondary pathogen
- Responsible for secondary infections following primary viral and mycoplasmal infections, especially in the lungs, for example during pig enzootic pneumonia
- Typa A
- Commensal in upper respiratory tract of animals in UK
- Primary pathogen in fowl cholera - a septicaemia in chickens and turkeys
- Secondary pathogen commomly repsonsible for dog and cat bite wound infections in humans and animals
- Some strains involved in Atrophic rhinitis of pigs, and produce osteolytic toxin
- Involved in 'Snuffles' in rabbits (Pateurellosis)
- Type B
- Causes Haemorrhagic Septicaemia of cattle in Southern Europe and Asia
- Type D
- Primary and secondary pathogen
- Causes Atropic Rhinitis along with Bordetella bronchiseptica in pigs
- Produces an osteolytic toxin, which stimulates osteoclasts, inducing bone resorption
- Type E
- Causes African Bovine Haemorrhagic Septicaemia
Pasteurella pneumotropica
- Carried in nasopharynx of many small rodents
- Causes pneumonia in rodents as a secondary disease
Mannheimia
Mannheimia haemolytica
- Cause of epizootic pneumonia in cattle known as Shipping Fever, Transit Fever or pneumonic pasteurellosis
- Usually secondary to viral infections such as parainfluenza - 3 or IBR, or to mycoplasma
- Causes pasteurellosis in sheep
- Beta-haemolytic on blood agar
- Grow weakly on MacConkey agar
- All are Manheimia A biotypes
- Strains often produce a cytotoxin, known as leukotoxin, which kills leukocytes of ruminants
- Leukotoxin is a member of the RTX group toxins, and is probably largely responsible for the pathogenicity of the bacteria in septicaemia and pneumonia
Mannheimia glucosida
- Previously biotype A11
Mannheimia trehalosi
- T biotypes - trehalose fermenters