BEUCELLA Flashcards
- an important zoonotic disease worldwide caused by Brucella
Brucellosis
*Four species associated with human illness:
- = infects goats & sheep (most virulent & invasive)
- = swines
- = dogs
- = abortion in cattle
Brucella melitensis
Brucella suis
Brucella canis
Brucella abortus
“Bang’s bacillus, Bang’s disease”
B abortus
& strong predilection to fetal bovine tissue called erythritol
B abortus
Brucella
• Two rare species:
(sheep)
(wood rats)
B. ovis
B. neotomae
Brucella
Only 1 species in the genus,________, with multiple biovars (based on DNA studies).
Brucella melitensis
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)
B
Brucellosis
an occupational hazard
Brucella
• MOT: (3)
• Clinical stages: Inc. period: 1-3 weeks
- Aerosolization/droplet infection
- percutaneous (contact with infected animal tissue)
- oral routes of exposure (unpasteurized milk & cheese)
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.
Acute
Subchronic
Chronic form
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)
intracellular
LPS endotoxin
Brucella
Cell wall antigens - A & M
• high concentration of A antigens
• high concentration of M antigens
- B. abortus
- B. melitensis
Brucella general characteristics
- more acute & severe disease
B. melitensis
Brucella gc
- mild disease without suppurative complications & non-caseating granulomas of RES
• B. abortus
Brucella gc
- chronic & suppurative lesions with caseating granulomas
• B. suis
Brucella gc
- mild disease
• B. canis
• Short GN coccobacillary forms
• Aerobic, nonmotile, unencapsulated
• Small, convex, smooth colonies (Enriched media: amino acids, vitamins, salts & glucose)
Brucella
• Grows in ambient air except______
(5-10% CO2)
B. abortus
Brucella: Laboratory Diagnosis
• Specimens:
• Culture: under biosafety level____
- grow on SBA, CHOC, MTM or Martin-Lewis media fror contaminated specimens, incubate until___ days
Blood culture, bone marrow, biopsy, serum for serological tests
3
4
• 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
PCR
Brucella agar or Castañeda medium
Brucella standard agglutination test
1:80 or 1:160
Thionine
Fuchsin
B abortus
(+)
(-)
Thionine
Fuchsin
B. suis
B. canis
-
+
Prevention of brucellosis
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
Thionine
Fuchsin
B melatensis
(-)
(-)
