Brucella

Question 1

What are the diseases the Brucella is known to cause?

Answer 1

Malta fever
Undulant fever
Bang’s disease
Brucellosis

Question 2

What are the general characteristics of Brucella?

Answer 2

Gram negative
Coccobacilli shape
Non-motile
Non-spore forming
Aerobic or microaerophilic

Question 3

What are the biochemical reactions of Brucella?

Answer 3

Catalase positive
Urease positive
Non-carbohydrate fermenting

Question 4

What is Brucellosis?

Answer 4

Chronic infection in animals that cause reproductive issues

Systemic febrile illness in humans

Question 5

Which Brucella species was used as a weapon by the US military?

Answer 5

Brucella suis

Question 6

Which Brucella species affects sheep and goats?

Answer 6

B. melitensis (sheep and goats)

B. ovis (sheep)

Question 7

Which Brucella species affects cattle?

Answer 7

B. abortus

Question 8

Which Brucella species affects dogs?

Answer 8

B. canis

Question 9

Which Brucella species affects pigs?

Answer 9

B. suis

Question 10

How does Brucella transfer?

Answer 10

Can penetrate mucous membranes

Spread by semen, milk, urine

Subclinical infection in dogs and pigs

Question 11

How does Brucella survive in the host?

Answer 11

Intracellular localization
Protection from drugs and antibodies

Question 12

Which Brucella species is the least pathogenic?

Answer 12

B. ovis

Question 13

What are the most to least severe Brucella species in humans?

Answer 13

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

Question 14

True or false.
Brucella infections are only severe in their natural hosts?

Answer 14

False.

Its rarely lethal and usually mild

Question 15

Where do you find Brucella normally?

Answer 15

Organs of the genital tract (native host)

Mammary glands and reticuloendothelial tissues (non-preferential hosts)

Question 16

What are the virulence factors of Brucella?

Answer 16

No obvious ones

LPS
Sulfhydryl protease
Urease
Catalase
Inhibition of phagosome-lysosome fusion
Erythritol

Question 17

What do Brucella species lack?

Answer 17

They lack the sequences that produce classic virulence factors

Question 18

In 2002, Brucella was found to do what?

Answer 18

Recruit actin and activate small GTPases to internalize it into cells

Question 19

What is a sulfhydryl protease?

Answer 19

It removes the Fc portion of IgG and can decrease phagocytosis and prevent destruction

Question 20

How does urease affect the host?

Answer 20

Generates ammonium ions to cause nervous system dysfunction

Question 21

How does catalase affect the host?

Answer 21

Protection from peroxide

Question 22

Why is erythritol important for Brucella?

Answer 22

Important for B. abortus, B. suis, and B. melitensis

It causes tissue tropism (increased localization where erythritol is at)

Question 23

How do you kill Brucella bacteria?

Answer 23

By pasteurization for 10-15 minutes

Heating at 60C for 10 mins

Direct sunlight

Acidic pH

Disinfectants

Question 24

True or False.
Immunity is obtained from recovering from an infection?

Answer 24

False. It is not always sufficient and antibodies and neutrophils can only kill organisms not inside phagosomes

Question 25

How is Brucella diagnosed?

Answer 25

Brucella milk ring test Rose Bengal plate test Complement fixation test ELISA Serum agglutination test Antiglobulin test Fluorescence polarization

Question 26

Where are Brucella samples collected from?

Answer 26

Blood, milk, serum, and vaginal exudates Aborted fetus and placenta

Question 27

How are Brucella species identified?

Answer 27

Direct examination of smears Stained with Gram, Koster's, Ziehl-Neelsen, Fluorescent Antibody

Question 28

What medium is used to isolate Brucella?

Answer 28

Tryptose agar

Question 29

What tests are used to diagnose bovine brucellosis?

Answer 29

Herd tests: milk ring test Brucella ring test Card test Rose bengal test

Question 30

What tests are used to diagnose canine brucellosis?

Answer 30

Agglutination: Rapid slide 2-mercapthoethanol tube Agar gel immunodiffusion

Question 31

How is Brucella prevented?

Answer 31

Vaccination for B. abortus and B. melitensis

Question 32

How is Brucella treated?

Answer 32

Livestock not attempted (high failure rate) Dihydrostreptomycin Tetracycline Minocycline