Pasteurella

Question 1

characterisitcs of pateurella

Answer 1

• Gram negative
  Coccobacilli/cocci
  Respiratory ± Reproductive infection
  Carriage (obligate)
  Commensals and opportunists
  “Stress” > disease
  Respiratory disease
  Occasionally septicaemias
• obligate parasites of vertebrates -> cats
• p. multocida is most significant

Question 2

what is P. multocida

Answer 2

• Short Gram negative rods
  with bipolar staining -> look like Safety pins
• Doesn’t grow on MCA
  Characteristic odour
  Most pathogenic strains possess a large capsule
  Five capsular serogroups
  16 “somatic” serogroups
• non-haemolytic

Question 3

what does P. multocida cause (5 main ones)

Answer 3

1. Septicaemia pasteurellosis:
   - “Haemorrhagic septicaemia” in cattle, buffalo etc
   - Acute septicaemia or chronic pleuropneumonia: “stress” of monsoon
   - Spreads from upper respiratory tract (URT) ± fatal
2. Fowl cholera **
   - acute septicaemia (esp. turkeys)
   - chronic URT signs
   - Stress ± introduction of virulent strain.
   - Vaccines used
3. Pneumonic pasteurellosis
   - Bronchopneumonia, often secondary to viral infections
4. Atrophic rhinitis (Pigs)
   With Bordetella bronchiseptica
   P. multocida type D > toxins
5. Cat and dog bites
   > abscesses + toxic signs -> ZOONOSIS

Question 4

how is P. multocida spread to humans

Answer 4

animal bites (cats and dogs)

Question 5

what is Mannheimia haemolytica

Answer 5

• causes “Shipping fever”
• Bovine respiratory disease complex
• Commensal of the nasopharynx
• Secondary pneumonia in feedlot cattle following primary viral infection
• Bovine herpes virus, BVD etc
• Stress-related following introduction to the feedlot
• Mixing in saleyards, transport, introduction
• weak growth on MCA

Question 6

how is Mannheimia haemolytica controlled and prevented

Answer 6

• bovolilis MH = Vaccine against
  Mannheimia haemolytica -> 3 weeks before shipment and on arrival
• Purchase stock direct from producer
  (avoid saleyards) From one with a quality assurance program in place (if possible)
• Purchase stock from nearby producers
• Reduce transit time (and therefore stress).