E2 Genus Brucella Flashcards
What organs do bacteria from the genus Brucella infect?
Reproductive organs
both male and female
What ages are affected by the genus Brucella?
Sexually mature animals
What species of Brucella is not zoonotic?
Brucella ovis
What is species in the most pathogenic in humans?
Brucella melitensis
What is the gram reaction and cultural characteristics of bacteria in the Brucella genus?
- Gram negative small rods
- Aerobic or microaerophilic
- Slow growth
What cells do bacteria in the Brucella genus infect?
- Macrophages
2. Endothelial cells
How does Brucella infect reproductive organs?
Infection of mucous membranes
Bacteremia spread to reproductive organs
How long is the incubation period for Brucella infection?
LONG
1-2 months before clinical signs
What disease do bacteria from the genus Brucella cause in humans?
Undulant fever
What is the disease caused by Brucella abortus in cattle?
Bang’s disease
What is the reservoir for Brucella abortus?
Wild ruminants
What is the prevalence of Brucella abortus in US cattle herds?
Nearly eradicated
What is the most frequent route of infection for Brucella abortus?
GI tract
but can occur through any mucus membrane
When does Brucella abortus cause abortions in cattle?
Late abortions
What effects if any does Brucella abortus have in male cattle?
- Orchitis
2. Epididymitis
How does Brucella abortus affect fertility in male cattle?
Can lead to sterility!
How does Brucella abortus cause abortions in cattle?
- Uldercation of endometrium
2. Destruction of placental villi in cotyledons
How long do infections with Brucella abortus last in cattle?
They are infected for life!
What other species besides cattle can be infected with Brucella abortus?
- Horses
- Sheep & goats
- Pigs
- HUMANS
What diseases can be caused by Brucella abortus in horses?
- Fistulous withers
2. Poll evil
Does Brucella abortus cause abortions in horses?
Rarely!
How does Brucella abortus typically infect humans?
Via cuts in the skin
How is Brucella abortus usually diagnosed?
- Clinical signs
- Direct smears from infected tissue
- ELISA (confirmatory test)
Is there a vaccine available for Brucella abortus?
Yes
DIVA vaccine
What animals are typically infected with Brucella suis?
Swine
more host specific
How is Brucella suis usually transmitted in pigs?
Venereal transmission
semen
Is there a vaccine for Brucella suis?
No
depopulation of herd
What are the clinical signs of Brucella suis in male pigs?
Orchitis
What animals can be infected by Brucella melitensis?
- Goats & sheep
- Cattle
- Humans
What is the disease called in humans infected by Brucella melitensis?
Malta fever
What animals are infected by Brucella ovis?
Only sheep!
highly host specific
Are abortions caused by Brucella ovis?
Rare
sometimes mummified fetuses
Is Brucella ovis pathogenic to humans?
No!
Are male or female sleep more affected by Brucella ovis?
Rams
can shed organism for 4 yrs
Can Brucella canis be transmitted from dogs to cattle?
No!
Can dogs be infected by Brucella species from livestock?
Yes
Both B. abortus and B. suis
What is special about infection with Brucella canis in dogs?
It is typically asymptomatic
unless pregnant
When does Brucella canis typically cause abortions?
Both
- Late embryonic death
- Late abortions
Are humans affected by Brucella canis?
Rarely
What is surprising about Brucella infections in humans? Why?
Rarely a cause of abortions!
Absence of erythritol in human placenta
Is there a risk from eating meat from an animal infected with Brucella?
No
cooking kills the bacteria
Is wildlife important for the continued presence of Brucella in the US?
Yes!
Is Brucella a reportable disease?
Yes!