Brucella

Question 1

What is the Gram stain reaction of Brucella?

Answer 1

Gram-negative.

Question 2

Is Brucella motile?

Answer 2

Non-motile.

Question 3

What are the oxygen requirements of Brucella?

Answer 3

Aerobic and carboxyphilic

Question 4

Which enzymes are produced by Brucella?

Answer 4

Catalase and urease.

Question 5

Does Brucella ferment carbohydrates in peptone media?

Answer 5

No.

Question 6

What type of pathogen is Brucella? (parasite)

Answer 6

Facultative intracellular parasite.

Question 7

Which Brucella species affects goats?

Answer 7

B. melitensis

Question 8

Which Brucella species affects cattle?

Answer 8

B. abortus

Question 9

Which Brucella species affects swine?

Answer 9

B. suis

Question 10

Which Brucella species affects sheep?

Answer 10

B. ovis

Question 11

Which Brucella species affects dogs?

Answer 11

B. canis

Question 12

Which Brucella species is found in rodents?

Answer 12

B. neotomae

Question 13

Which Brucella species infects marine mammals?

Answer 13

B. maris

Question 14

What type of bacteria is Brucella morphologically?

Answer 14

coccobacilli

Question 15

Name four Brucella species that infect humans.

Answer 15

B. abortus, B. suis, B. melitensis, B. canis.

Question 16

What is the most common route of Brucella infection?

Answer 16

Mucous membranes (digestive tract, genital tract, skin).

Question 17

How does Brucella survive inside neutrophils?

Answer 17

Inhibits degranulation and myeloperoxidase activity.

Question 18

What substance stimulates Brucella growth in ungulate placenta and testes?

Answer 18

Erythritol.

Question 19

What B. abortus Strain does not respond to erythritol?

Answer 19

B. abortus Strain 19.

Question 20

What type of immune response is critical for Brucella immunity?

Answer 20

Cell-mediated (CD4+ and CD8+ T-cells).

Question 21

Which complement pathway is activated by B. abortus LPS?

Answer 21

Classical pathway (via IgM/IgG).

Question 22

What type of lesions are seen in chronic brucellosis?

Answer 22

Granulomatous lesions.

Question 23

Which cytokine enhances granuloma formation in brucellosis?

Answer 23

TNF (Tumor Necrosis Factor).

Question 24

What are the two major surface antigens of smooth Brucella strains?

Answer 24

A and M antigens.

Question 25

Which Brucella species are naturally rough (lack A/M antigens)?

Answer 25

B. canis and B. ovis.

Question 26

What is the vaccine strain

Answer 26

B. abortus 19?

Question 27

What strain? A smooth, low-virulence mutant that elicits agglutinins.

Answer 27

B. abortus 19

Question 28

A rough strain that does not trigger standard serological tests.

Answer 28

B. abortus RB51

Question 29

Which bacteria cross-react with B. abortus in serological tests?

Answer 29

Yersinia enterocolitica

Question 30

Brucella is a spore-forming bacterium. (True/False)

Answer 30

False.

Question 31

One of the most important diseases caused by brucella abortus?

Answer 31

Brucellosis in cattle

Question 32

How is B. abortus primarily transmitted?

Answer 32

Ingestion of contaminated uterine discharges, urine, feces, or milk

Question 33

Bulls transmit B. abortus through ?

Answer 33

mating via infected semen

Question 34

What is the incubation period for B. abortus?

Answer 34

30-60 days

Question 35

Where does B. abortus localize in pregnant cows?

Answer 35

Placenta of gravid uterus

Question 36

Where does B. abortus localize in non-pregnant cows?

Answer 36

Udder (interstitial mastitis) and lymph nodes

Question 37

What lesions form in internal organs?

Answer 37

Granulomatous foci in liver, lungs, lymph nodes, spleen

Question 38

How long can cows remain infected?

Answer 38

For years

Question 39

Where does B. abortus localize in bulls?

Answer 39

Testicles (epididymis) and seminal vesicles

Question 40

When do abortions typically occur?

Answer 40

6 months or later in gestation

Question 41

What reproductive problems occur in males?

Answer 41

Sterility/infertility and abscessation

Question 42

What is the rapid field screening test B. abortus?

Answer 42

Card test (stained antigen)

Question 43

What are the laboratory diagnostic methods?

Answer 43

Agglutination test, ELISA, CFT

Question 44

What detects milk contamination of B. abortus?

Answer 44

Brucellosis ring test

Question 45

What vaccination is used for calves for B. abortus?

Answer 45

Strain 19 (B. abortus biotype 1)

Question 46

What is the rough attenuated vaccine strain of B. abortus?

Answer 46

RB51

Question 47

How do nursing pigs get infected by Brucella suis?

Answer 47

Through Brucella suis-contaminated milk

Question 48

Which animals are susceptible to Brucella suis infection?

Answer 48

Swine of all ages (including feral swine) can be infected by Brucella suis

Question 49

What are the main transmission routes for Brucella suis?

Answer 49

Brucella suis spreads through contaminated food, water, soil, and coitus with infected boars

Question 50

What reproductive effects does Brucella suis cause in sows?

Answer 50

Brucella suis causes abortion, stillbirths, and weak piglets (typically only one abortion per sow)

Question 51

What musculoskeletal problems does Brucella suis cause?

Answer 51

Brucella suis leads to spondylitis and lameness in infected pigs

Question 52

How does Brucella suis infection differ from cattle brucellosis?

Answer 52

Brucella suis causes more generalized infection in pigs and may be cleared but allows reinfection

Question 53

Where does Brucella suis localize in infected pigs?

Answer 53

Brucella suis localizes in lymph nodes, spleen, liver, kidneys, reproductive organs, and bones

Question 54

How long can Brucella suis persist in the uterus?

Answer 54

Brucella suis can persist in uterine discharges for up to 30 months

Question 55

Why is the agglutination test unreliable for Brucella suis diagnosis?

Answer 55

Swine don't produce reliable agglutinating antibodies against Brucella suis

Question 56

What diagnostic test is more accurate than agglutination for Brucella suis?

Answer 56

The card test is more accurate than agglutination for Brucella suis detection