E2 Genus Brucella

Question 1

What organs do bacteria from the genus Brucella infect?

Answer 1

Reproductive organs

both male and female

Question 2

What ages are affected by the genus Brucella?

Answer 2

Sexually mature animals

Question 3

What species of Brucella is not zoonotic?

Answer 3

Brucella ovis

Question 4

What is species in the most pathogenic in humans?

Answer 4

Brucella melitensis

Question 5

What is the gram reaction and cultural characteristics of bacteria in the Brucella genus?

Answer 5

1. Gram negative small rods
2. Aerobic or microaerophilic
3. Slow growth

Question 6

What cells do bacteria in the Brucella genus infect?

Answer 6

1. Macrophages

2. Endothelial cells

Question 7

How does Brucella infect reproductive organs?

Answer 7

Infection of mucous membranes

Bacteremia spread to reproductive organs

Question 8

How long is the incubation period for Brucella infection?

Answer 8

LONG

1-2 months before clinical signs

Question 9

What disease do bacteria from the genus Brucella cause in humans?

Answer 9

Undulant fever

Question 10

What is the disease caused by Brucella abortus in cattle?

Answer 10

Bang’s disease

Question 11

What is the reservoir for Brucella abortus?

Answer 11

Wild ruminants

Question 12

What is the prevalence of Brucella abortus in US cattle herds?

Answer 12

Nearly eradicated

Question 13

What is the most frequent route of infection for Brucella abortus?

Answer 13

GI tract

but can occur through any mucus membrane

Question 14

When does Brucella abortus cause abortions in cattle?

Answer 14

Late abortions

Question 15

What effects if any does Brucella abortus have in male cattle?

Answer 15

1. Orchitis

2. Epididymitis

Question 16

How does Brucella abortus affect fertility in male cattle?

Answer 16

Can lead to sterility!

Question 17

How does Brucella abortus cause abortions in cattle?

Answer 17

1. Uldercation of endometrium

2. Destruction of placental villi in cotyledons

Question 18

How long do infections with Brucella abortus last in cattle?

Answer 18

They are infected for life!

Question 19

What other species besides cattle can be infected with Brucella abortus?

Answer 19

1. Horses
2. Sheep & goats
3. Pigs
4. HUMANS

Question 20

What diseases can be caused by Brucella abortus in horses?

Answer 20

1. Fistulous withers

2. Poll evil

Question 21

Does Brucella abortus cause abortions in horses?

Answer 21

Rarely!

Question 22

How does Brucella abortus typically infect humans?

Answer 22

Via cuts in the skin

Question 23

How is Brucella abortus usually diagnosed?

Answer 23

1. Clinical signs
2. Direct smears from infected tissue
3. ELISA (confirmatory test)

Question 24

Is there a vaccine available for Brucella abortus?

Answer 24

Yes

DIVA vaccine

Question 25

What animals are typically infected with Brucella suis?

Answer 25

Swine | more host specific

Question 26

How is Brucella suis usually transmitted in pigs?

Answer 26

Venereal transmission | semen

Question 27

Is there a vaccine for Brucella suis?

Answer 27

No | depopulation of herd

Question 28

What are the clinical signs of Brucella suis in male pigs?

Answer 28

Orchitis

Question 29

What animals can be infected by Brucella melitensis?

Answer 29

1. Goats & sheep 2. Cattle 3. Humans

Question 30

What is the disease called in humans infected by Brucella melitensis?

Answer 30

Malta fever

Question 31

What animals are infected by Brucella ovis?

Answer 31

Only sheep! | highly host specific

Question 32

Are abortions caused by Brucella ovis?

Answer 32

Rare | sometimes mummified fetuses

Question 33

Is Brucella ovis pathogenic to humans?

Answer 33

No!

Question 34

Are male or female sleep more affected by Brucella ovis?

Answer 34

Rams | can shed organism for 4 yrs

Question 35

Can Brucella canis be transmitted from dogs to cattle?

Answer 35

No!

Question 36

Can dogs be infected by Brucella species from livestock?

Answer 36

Yes | Both B. abortus and B. suis

Question 37

What is special about infection with Brucella canis in dogs?

Answer 37

It is typically asymptomatic | unless pregnant

Question 38

When does Brucella canis typically cause abortions?

Answer 38

Both 1. Late embryonic death 2. Late abortions

Question 39

Are humans affected by Brucella canis?

Answer 39

Rarely

Question 40

What is surprising about Brucella infections in humans? Why?

Answer 40

Rarely a cause of abortions! | Absence of erythritol in human placenta

Question 41

Is there a risk from eating meat from an animal infected with Brucella?

Answer 41

No | cooking kills the bacteria

Question 42

Is wildlife important for the continued presence of Brucella in the US?

Answer 42

Yes!

Question 43

Is Brucella a reportable disease?

Answer 43

Yes!