Brucella Spp.

Question 1

characteristics

Answer 1

• Short Gram negative rods
• Non—motile, Slow growing
• Fastidious
• Need CO2 /serum
• Delicate
• Smooth and rough strains
• zoonotic
• repro diseases -> cause abortions

Question 2

Bovine brucellosis

Answer 2

• Brucella abortus
• Necrotic placentitis + abortion
• Males: Orchitis (inflammation of
  testicles) or epididymitis
• Chronic disease: small granulomas in lymph nodes, udders, joints etc > shedding in milk
• Reduced fertility and milk production
• Humans: “undulant fever

Question 3

Brucella abortus

Answer 3

• Bovine brucellosis
• placenta has many hemorrhhagic cotyledons
• No life cycle outside host
• Facultative intracellular pathogen
• Can cause chronic infection
• Highly infectious
• Ingestion, genital tract and skin
  (veterinarians)
• Aborted foetuses and foetal membranes
• Uterine discharges (large numbes of
  B. abortus are excreated for 2-4
  weeks)
• Treatment is ineffective - Test and
  slaughter
• eradicated from AUS

Question 4

B. suis in pigs

Answer 4

• Porcine brucellosis
• Feral pigs only
  **Notifiable disease
• Confined to QLD and North West NSW
• Feral pigs: 2% seropositive, Domestic pigs: 0%
• Sows: Abortion, stillbirth neonatal
  mortality and temporary sterility
• Boars: Excrete brucellae in semen
  testicular abnormality

Question 5

B. suis in dogs

Answer 5

• ** emerging disease of dogs in Australia
• Pig hunting dogs
• Dogs that have been fed raw, feral pig meat
• Dog-dog transmission
• Some dogs appear healthy
  **Notifiable disease

Question 6

Brucellosis in humans

Answer 6

• B. abortus, B. suis, B. melitensis
• *B. melitensis still the principal cause of infections
• Unpasteurised milk (India, West Africa, Iran)
• Hazard for veterinarians, meat workers and lab personnel
• Chronic relapsing fever/joint and muscle
  pain/chills/episodic weakness/headaches
  Complications may include suppurative
  arthritis/pericarditis/mental depression
• Mortality low