Brucella Flashcards
What is the Gram stain reaction of Brucella?
Gram-negative.
Is Brucella motile?
Non-motile.
What are the oxygen requirements of Brucella?
Aerobic and carboxyphilic
Which enzymes are produced by Brucella?
Catalase and urease.
Does Brucella ferment carbohydrates in peptone media?
No.
What type of pathogen is Brucella? (parasite)
Facultative intracellular parasite.
Which Brucella species affects goats?
B. melitensis
Which Brucella species affects cattle?
B. abortus
Which Brucella species affects swine?
B. suis
Which Brucella species affects sheep?
B. ovis
Which Brucella species affects dogs?
B. canis
Which Brucella species is found in rodents?
B. neotomae
Which Brucella species infects marine mammals?
B. maris
What type of bacteria is Brucella morphologically?
coccobacilli
Name four Brucella species that infect humans.
B. abortus, B. suis, B. melitensis, B. canis.
What is the most common route of Brucella infection?
Mucous membranes (digestive tract, genital tract, skin).
How does Brucella survive inside neutrophils?
Inhibits degranulation and myeloperoxidase activity.
What substance stimulates Brucella growth in ungulate placenta and testes?
Erythritol.
What B. abortus Strain does not respond to erythritol?
B. abortus Strain 19.
What type of immune response is critical for Brucella immunity?
Cell-mediated (CD4+ and CD8+ T-cells).
Which complement pathway is activated by B. abortus LPS?
Classical pathway (via IgM/IgG).
What type of lesions are seen in chronic brucellosis?
Granulomatous lesions.
Which cytokine enhances granuloma formation in brucellosis?
TNF (Tumor Necrosis Factor).
What are the two major surface antigens of smooth Brucella strains?
A and M antigens.
Which Brucella species are naturally rough (lack A/M antigens)?
B. canis and B. ovis.
What is the vaccine strain
B. abortus 19?
What strain? A smooth, low-virulence mutant that elicits agglutinins.
B. abortus 19
A rough strain that does not trigger standard serological tests.
B. abortus RB51
Which bacteria cross-react with B. abortus in serological tests?
Yersinia enterocolitica
Brucella is a spore-forming bacterium. (True/False)
False.
One of the most important diseases caused by brucella abortus?
Brucellosis in cattle
How is B. abortus primarily transmitted?
Ingestion of contaminated uterine discharges, urine, feces, or milk
Bulls transmit B. abortus through ?
mating via infected semen
What is the incubation period for B. abortus?
30-60 days
Where does B. abortus localize in pregnant cows?
Placenta of gravid uterus
Where does B. abortus localize in non-pregnant cows?
Udder (interstitial mastitis) and lymph nodes
What lesions form in internal organs?
Granulomatous foci in liver, lungs, lymph nodes, spleen
How long can cows remain infected?
For years
Where does B. abortus localize in bulls?
Testicles (epididymis) and seminal vesicles
When do abortions typically occur?
6 months or later in gestation
What reproductive problems occur in males?
Sterility/infertility and abscessation
What is the rapid field screening test B. abortus?
Card test (stained antigen)
What are the laboratory diagnostic methods?
Agglutination test, ELISA, CFT
What detects milk contamination of B. abortus?
Brucellosis ring test
What vaccination is used for calves for B. abortus?
Strain 19 (B. abortus biotype 1)
What is the rough attenuated vaccine strain of B. abortus?
RB51
How do nursing pigs get infected by Brucella suis?
Through Brucella suis-contaminated milk
Which animals are susceptible to Brucella suis infection?
Swine of all ages (including feral swine) can be infected by Brucella suis
What are the main transmission routes for Brucella suis?
Brucella suis spreads through contaminated food, water, soil, and coitus with infected boars
What reproductive effects does Brucella suis cause in sows?
Brucella suis causes abortion, stillbirths, and weak piglets (typically only one abortion per sow)
What musculoskeletal problems does Brucella suis cause?
Brucella suis leads to spondylitis and lameness in infected pigs
How does Brucella suis infection differ from cattle brucellosis?
Brucella suis causes more generalized infection in pigs and may be cleared but allows reinfection
Where does Brucella suis localize in infected pigs?
Brucella suis localizes in lymph nodes, spleen, liver, kidneys, reproductive organs, and bones
How long can Brucella suis persist in the uterus?
Brucella suis can persist in uterine discharges for up to 30 months
Why is the agglutination test unreliable for Brucella suis diagnosis?
Swine don’t produce reliable agglutinating antibodies against Brucella suis
What diagnostic test is more accurate than agglutination for Brucella suis?
The card test is more accurate than agglutination for Brucella suis detection
