Difference between revisions of "Brucella species"
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Line 47: | Line 47: | ||
*Serological testing of milk (Milk Ring Test) and beef cattle (Rose Bengal Plate Test) | *Serological testing of milk (Milk Ring Test) and beef cattle (Rose Bengal Plate Test) | ||
*Serological tests detect anti-lipopolysaccharide antibodies | *Serological tests detect anti-lipopolysaccharide antibodies | ||
+ | *LPS antigen present in virulent as well as some vaccine strains therefore vaccination may confuse serological testing | ||
+ | *False positives due to cross-reaction with LPS in other bacteria | ||
+ | *Vaccination: | ||
+ | **Strain S19, a live vaccine, stimulating a cell-mediated immune response; vaccination of young animals; interferes with serological testing | ||
+ | **Newer RB51 vaccine has no LPS O-antigen therefore not detcted by serological tests | ||
+ | **Live attenuated ''Brucella melitensis'' vaccine to protect sheep and goats against ''B. melitensis'' | ||
+ | *Test and slaughter program has eradicated Brucellosis in the UK |
Revision as of 17:10, 17 May 2008
- B. abortus occasionally in arthritis of cattle
- Isolated from closed cases of Poll Evil and Fistulous Withers
Overview
- Important zoonoses worldwide
- Cause chronic granulomatous diseases
Characteristics
- Small, non-moltile, Gram negative coccobacilli
- Facultatice intracellular pathogens
- 6 species
Pathogenesis and pathogenicity
- Penetrate nasal, oral or pharyngeal mucosa
- Phagocytosed and carried to regional lymph nodes
- Survive and multiply in cells of the reticulo-endothelial system
- Inhibit lysosome-phagosome fusion
- Lymph nodes enlarge (lymphatic and lymphoreticular hyperplasia) and inflammation is induced
- Surviving organisms spread to other organs (liver, spleen, placenta) and cause granulomatous reactions
- Eythritol is a growth stimulant and attracts the bacteria to the bovine placenta
- Infection of foetus and abortion
Clinical disease
Diagnosis
Control
- Serological testing of milk (Milk Ring Test) and beef cattle (Rose Bengal Plate Test)
- Serological tests detect anti-lipopolysaccharide antibodies
- LPS antigen present in virulent as well as some vaccine strains therefore vaccination may confuse serological testing
- False positives due to cross-reaction with LPS in other bacteria
- Vaccination:
- Strain S19, a live vaccine, stimulating a cell-mediated immune response; vaccination of young animals; interferes with serological testing
- Newer RB51 vaccine has no LPS O-antigen therefore not detcted by serological tests
- Live attenuated Brucella melitensis vaccine to protect sheep and goats against B. melitensis
- Test and slaughter program has eradicated Brucellosis in the UK