Highly Regulated Bacteria - Brucella Flashcards
what are reportable diseases?
diseases of great public/animal health importance and have to be reported as soon as they’re detected
what is the benefit of reporting diseases?
collection of statistics
identify disease trends and track disease outbreaks
control future outbreaks
what are the reportable diseases that are select agents?
possible bio-weapons
Where and when was contagious equine metritis first described?
united kingdom in 1977
what is the causative agent of contagious equine metritis?
Taylorella equigenitalis
what gram is Taylorella equigenitalis and what media does it not grow on despite its gram stain result?
gram negative
No growth on MacConkey agar
what is the pathogenesis of contagious equine metritis?
contaminated semen and pre-ejaculatory fluids > intro into uterus > induce acute endometritis > mononuclear cells, plasma cells, and neutrophils into uterine lumen > profuse mucopurulent exudate
what are the clinical findings of contagious equine metritis?
mares - copious mucopurulet vaginal discharge > temporary infertility, vertical transmission
stallions - no clinical signs, asymptomatic carriers
How is contagious equine metritis transmitted?
venereal transmission
infected semen
contaminated instrument
How long can T. equigenitalis persist for in untreated stallions?
persist for months or years
How can foals become long-term asymptomatic carriers?
foals born to infected mares
How is contagious equine metritis diagnosed?
swabs from reproductive organs
no systemic antibiotics for at least 7 days or topical antibiotics for 21 days
sample transported on Amies medium
What medium is T. equigenitalis cultured on?
chocolate agar
timoney’s medium
How is contagious equine metritis treated?
-wash external genitalia with 2% chlorhexidine
-local antimicrobial treatments: nitrofurazone, silver sulfadiazine
-tx for 5 days
How is contagious equine metritis prevented?
strict/import/export testing
no vaccine available
What is the endemic area for Brucellosis?
yellowstone N.P.
what wild animals does brucellosis occur in?
wild bison and elk populations
what is brucellosis transmissible to?
cattle and humans
ZOONOTIC - select agent
what is the causative agent of brucellosis?
Brucella sp.
Define select agent
an infectious agent with potential for use in bioterrorism
what is the catalase, oxidase, and urease results for brucellosis?
all 3 positive
How long can Brucellosis survive in milk products, after birth, aborted fetuses, etc?
can survive for longer periods of time
what are the reservoirs of Brucellosis?
wild, feral and domestic animals
What is the use of vaccinating animals against Brucellosis?
immunization of animals
what groups are at the highest risk of brucellosis?
-people who consume unpasteurized milk products
-people in direct contact with infected animals
-lab techs and researchers
How is brucellosis transmitted?
ingestion of contaminated fetal tissues and fluids
What is the pathogenesis of brucellosis?
Brucella survives inside phagocytic cells > multiples in monocyte-macrophage cells > spread systemically, esp reproductive organs
what are the clinical findings of bovine brucellosis?
abortion/infertility - abortion storms
reduced milk yield
what are the clinical findings of canine brucellosis?
low virulence
abortions
very rarely zoonotic
what are the clinical findings of swine brucellosis?
abortion/infertility
what are the clinical findings of brucellosis in goat and sheep?
abortion, orchitis and arthritis
which brucellosis is the most dangerous zoonosis?
B. melitensis - goat and sheep
How is Brucellosis diagnosed?
culture - Columbia agar supplemented with 5% serum
serological or milk based tests - brucella milk ring test (MRT)
How is brucellosis treated in animals and prevented for vets?
no treatment
prevented for vets - safe handling, PPE
What is the causative agent of coxiellosis/Q fever?
Coxiella burnetii
How does Coxiella burnetii react to environmental stress?
resistant
Is Q fever transmissible to people?
yes - Coxiella burnetii is zoonotic
what are the two distinct cell types of coxiellosis? Describe each
small cell variant - metabolically inactive form and environmentally stable
large cell variant - metabolically active form
How many Coxiella burnetti bacteria does it take to infect humans?
a single bacterium
highly infectious
ID50 <= 10
What occupations if coxiellosis a hazard to?
farmers, veterinarians, zoo, and slaughterhouse workers
what animal populations is coxiellosis found in?
domestic ruminants - cattle, goats, sheep
where does Coxiella proliferate and what does this result in?
proliferates in uterus and mammary glands
results in late term abortion
How is Coxiellosis transmitted?
inhalation - usually from parturient sheep, goats, cattle, and rarely parturient cats/dogs
On a cellular level where does Coxiellosis multiply?
acidified phagolysosomes
Where is Coxiellosis localized to?
genital tract and mammary glands of animals
what clinical findings are associated with coxiellosis?
goats - abortions, infertility
ruminants - infertility in ruminants
How is coxiellosis diagnosed?
PCR - most sensitive and fast
How is coxiellosis prevented?
good husbandry practices - proper disposal of birth products
what are the agents we learned in this lecture that can be used as bioweapons?
select agents
Coxiella burnetti - Coxiellosis/Q fever
Brucella sp. - brucellosis
