Brucella genus

Question 1

Brucella Genus species

Answer 1

10 species, 4 cause human disease:
- B. Abortus (cattle)
- B. Melitensis (goat/sheep)
- B. Suis (swine)
- B.Canis (dog)
= Brucellosis or Undulant fever

Question 2

Brucella info

Answer 2

• Zoonotic
• Direct contact with animals
• Indirectly by ingesting unpasteurized milk, dairy, raw meat
• Inhalation (category B bioterrorist weapon)
  = incubation of 1-3 weeks

Question 3

Brucella Morphology

Answer 3

• Gram Negative
• Coccobacilli
• Facultative I.C

Question 4

Brucella Cultivation

Answer 4

• Facultative Aerobe (since i.c)
• Slow growth on blood agar
• Fastidious
• Brucella Agar

Question 5

Brucella Virulence factors

Answer 5

• Endotoxin (LPS)
• no exotoxins

Question 6

Brucella Diseases

Answer 6

• Brucellosis (Malta fever): Undulant fever, Anorexia, Myalgia, Orchitis, can cause Chronic symptoms if untreated 3-6 months
• Inhibit Phagosome-Lysosome fusion so can cause Bacteremia to Liver/Spleen

Question 7

Brucella Disease by Species

Answer 7

• B. Abortus, Canis: Mild disease & rare complication
• B. Suis: Destructive lesions
• B. Melitensis: Severe disease & severe complications

Question 8

Brucella Diagnosis

Answer 8

• Serology (AB detection, Wright reaction of tube agglutination)
• Cultivation (but not safe)

Question 9

Brucella Treatment

Answer 9

• Doxycycline
• Rifampicin
  (TMP-SMX in pregnant/child)