BEUCELLA

Question 1

• an important zoonotic disease worldwide caused by Brucella

Answer 1

Brucellosis

Question 2

*Four species associated with human illness:

1. = infects goats & sheep (most virulent & invasive)
2. = swines
3. = dogs
4. = abortion in cattle

Answer 2

Brucella melitensis

Brucella suis

Brucella canis

Brucella abortus

Question 3

“Bang’s bacillus, Bang’s disease”

Answer 3

B abortus

Question 4

& strong predilection to fetal bovine tissue called erythritol

Answer 4

B abortus

Question 5

Brucella

• Two rare species:

(sheep)
(wood rats)

Answer 5

B. ovis

B. neotomae

Question 6

Brucella

Only 1 species in the genus,________, with multiple biovars (based on DNA studies).

Answer 6

Brucella melitensis

Question 7

Brucella

CDC classifies them as category____ biological agents (easy to disseminate and cause moderate morbidity but low mortality*).

In humans:
(undulant fever by geographic locations - Malta, Crimean, Mediterranean fevers);

(veterinarians, animal handlers, lab workers)

Answer 7

B

Brucellosis

an occupational hazard

Question 8

Brucella

• MOT: (3)
• Clinical stages: Inc. period: 1-3 weeks

Answer 8

• Aerosolization/droplet infection
• percutaneous (contact with infected animal tissue)
• oral routes of exposure (unpasteurized milk & cheese)

Question 9

Brucella

Clinical stages: Inc. period: 1-3 weeks
-: fever, malaise, headache, anorexia, arthralgia, myalgia, back pain; also systemic, deep-seated disease, long-term sequelae - cardiac disease

-: - undulant fever, temperature rises in the afternoon and evening, and fall in the morning, also arthritis & epididymoorchitis

-: depression, arthritis, chronic fatigue syndrome.

Answer 9

Acute

Subchronic

Chronic form

Question 10

Brucella

Virulence factors
• Facultative_______organisms
- Inhibit fusion of phago-lysosome
- Replicate intracellularly

• _______in the cell wall
- Blood dissemination by monocytes to lymph nodes and reticuloendothelial system
- Granulomatous formation in lymphatic tissues (liver, spleen, bone marrow, & other RES)

Answer 10

intracellular

LPS endotoxin

Question 11

Brucella

Cell wall antigens - A & M

• high concentration of A antigens

• high concentration of M antigens

Answer 11

• B. abortus
• B. melitensis

Question 12

Brucella general characteristics

• more acute & severe disease

Answer 12

B. melitensis

Question 13

Brucella gc

• mild disease without suppurative complications & non-caseating granulomas of RES

Answer 13

• B. abortus

Question 14

Brucella gc

• chronic & suppurative lesions with caseating granulomas

Answer 14

• B. suis

Question 15

Brucella gc

• mild disease

Answer 15

• B. canis

Question 16

• Short GN coccobacillary forms
• Aerobic, nonmotile, unencapsulated
• Small, convex, smooth colonies (Enriched media: amino acids, vitamins, salts & glucose)

Answer 16

Brucella

Question 17

• Grows in ambient air except______
(5-10% CO2)

Answer 17

B. abortus

Question 18

Brucella: Laboratory Diagnosis
• Specimens:
• Culture: under biosafety level____
- grow on SBA, CHOC, MTM or Martin-Lewis media fror contaminated specimens, incubate until___ days

Answer 18

Blood culture, bone marrow, biopsy, serum for serological tests

3

4

Question 19

• Usually subtyped into biovars (____assay)

•________ medium
- A biphasic blood culture media incubate with 5-10% COz for 30 days

• Test for H2S, thionine and basic fuchsin dye inhibition, and agglutination by sera

• Serology:_____
- IgG titers above_________ suggestive brucellosis

Answer 19

PCR

Brucella agar or Castañeda medium

Brucella standard agglutination test

1:80 or 1:160

Question 20

Thionine
Fuchsin

B abortus

Answer 20

(+)
(-)

Question 21

Thionine
Fuchsin

B. suis
B. canis

Answer 21

-
+

Question 22

Prevention of brucellosis

Answer 22

Prevention:
- Pasteurization of milk, cook meat to safe temperatures
- Quarantine testing and vaccination of animals
- Careful handling of animals, wear appropriate safety gear
- use of biohazard hood

Question 23

Thionine
Fuchsin

B melatensis

Answer 23

(-)
(-)