Brucella Flashcards
What are the characteristics of Brucella?
- Gram negative
- Short rods (Coccobacilli)
- Aerobic (nonfermentative)
- Some carboxyphilic
- Facultatively intracellular pathogen
- Zoonotic
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What are the Brucell species?
- ANY species can infect any animal species
- B. abortus - cattle
- B. suis - Swine
- B. melitensis - Sheep, Goat, Humans
- B. ovis - Sheep
- B. canis - dogs
- B. neotomae - Desert wood rats (restricted host range and geographic distribution)
What is “Clasical Brucella”?
- B. abortus, B. suis, and B. melitensis
- Lited as protential bio-weapons by CDC
- Highly infectious
- Easily aerosolized
- Difficult to detect
What is the virulence of different Brucella species?
- B. abortus & B. melitensis Highly virulence
- B. ovis & B. canis Low virulence
- B. suis Intermediate virulence
How is Brucella transmitted?
- Primarily oral or venereal
- B. abortus & B. melitensis: More often oral
- B. ovis, B. suis, & B. canis More often venereal
Differentiation of Brucella Species
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What is Brucellosis?
- Infections of the reproductive organs
- Uterus, placenta
- Testicles, particularly epididymis
- Causes Abortions
- Zoonotic disease
What is Erythritol?
- Growth factor
- Present in placenta and testicle (not in humans)
- B. abortus, B. suis, & B. melitensis have preference
- B. canis does not require
What is Brucella abortus?
- Colonies exhibit Smooth to Rough dissociation
- Change in LPS structure
- R is avirulent
What is the Habitat for Brucella abortus?
- Obligate pathogen of animals
- Source of infection: infected or carrier animals
- Uterine discharges
- Milk and milk product
- feces
What is the geographic distribution of Brucella abortus?
- Worldwide
- Practically eradicated in the US
- All 50 state and Puerto Rico and Virgin islands are ‘Brucellosis class free’
- Still detected in states adjacent to Yellow Stone
What is the mode of infection of Brucella abortus?
- Ingstion
- Venereal transmission
- Milk from infected cows - for calves
How is Brucella abotus zoonotic?
- Occupational disease for Veterinarians and Slaughter house workers
- Vets:
- during vaccination
- Removal of retained placenta
What are the Virulence Factors of Brucella abortus?
- Endotoxin
- Abilit to survve in macrophages (Facultatively intracellular)
What diseases does Brucella abortus cause?
- Contagious abortion (Bang’s diesease)
- Abortion >5 mo, with retained placenta
- Infertility, mastitis
- Bull: orchitis and epididymitis
- Affects joints
What lesions are seen with Brucella abortus?
- Granulomatous and Suppurative
- Placentitis
- Endometritis
- Fetus:
- Edema and congestion of lungs
- hemorrhages of the epicardium and splenic capsule
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How is Brucella abortus Diagnosed?
- Difficut in bulls and non-pregnant females
- usually asymptomatic
- Abortion in cow
- particularly multiple in a herd
- Cattle with following signs should be tested:
- Abortion
- Increased frequency of retained placenta
- Testicular enlargement/abscesses
- Cultural examination:
- Sample: Fetal stomach contents, Placenta, Vaginal discharge, semen, Milk, Lymph nodes
- PCR assay for species confirmation
- Serology:
- Tube agglutination test
- Rapid plate agglutination test
- Milk Ring (ABRT) test
- Card test
- Vaccinated animals have IgM
- Infected animals have IgG
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How is the specificity of testing for Brucella abortus increased?
- Repeat test after several weeks
- Heating serum to 65C for 15 min
- Treatment ofserum with Rivanol or Mercaptoethanol (degrade IgM)
What other tests are there for Brucella abortus?
- Completement fixation test
- Particle concentration fluorescence immunoassay - Automated
- ELISA - very sensitive
What is treatment for Brucella abortus?
- Susceptible to aminoglycosides and tetracyclines
- NOT permitted in Food Animals
- Permitted in Dogs and humans
Is there a vaccine for Brucella abrotus?
- Strain 19 B.abortus biotype 1
- Live attenuated
- Only femle calves, 4-12 mo
- Males are not vaccinated - causes infertility
- RB51 strain (1996)
- Rough mutant o strain 2308
- Lacks O side chain in LPS
- Cell mediated immunity
- Used in adults also
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What is the National Brucellosis Eradication Program?
- Initiated in 1934, formally established in 1954
- Detection of infected animals
- Reactors are branded and slaughtered-Indemnity payment
- Herds with suspects are quarantined
- Vaccination of calves
How is Brucellosis Status designated? before 1998
- Class-free: No cattle or bison are infected for 12 consecutive months
- Class A: 2.5 herds/1,000 herds
- Class B: 15 herds/1,000 herds
- Class C: >15 herds/1,000 herds
What is the Brucellosis Surveillance Program?
- Market testing Program:
- Blood testing of cattle and bison sold or slaughtered
- Milk ring test of dairy herds
- New Strategy: (post 1998)
- Blood testing of cattle at slaughter
- Diagnostic laboratory-based abortion surveillance
What is the Brucellosis “Rapid Completion Plan?”
What was the Brucellosis Status Designation in 1998?
- Class free:
- No positive herd detected or one positive herd detected and her was depopulated and a thorough epidemiological investigation is completed
- Class A: Second positive herd detected within 24 months
What is Brucella suis?
- Can infect other animals
- 5 Biotypes:
- 1, 2, & 3 in pigs
- 4 & 5 in rodents and reindeer
- 2 in horses
What is the mode of infection of Brucella suis?
- Ingestion
- Nursing pigs from infected sows
- Venereal transmission
What does Brucellosis cause in Swine?
- Abortion (any time)
- Sterility
- Still births
- Spondylitis
- Abscesses in various organs
What are the control measures for Brucellosis in Swine?
- USDA National eradication programs is in place
- Elimination of the infected herd
- Infection occurs in wild and feral swine
- NO VACCINE
What is Brucella ovis?
- Least pathogenic species
- Venereal transmission
- Causes epididymitis in rams - often unilateral
- Causes abortion and infertillity in ewes
- B. abortus and B. melitensis are also involved
- B. abortus is more common than B. ovis
What is Brucella canis?
- Infects only dogs
- Highly conagious
- Mode of infection: Oral and venereal
What is the Pathogenesis of Brucella canis?
- Urine / Vaginal Secretions / Semen
- Makes contact with conjuctiva, Oral mucosa, Nasal mucosa
- Makes contact with genital mucosa
- B. canis is phagocytized
- Makes it into the lymph nodes
- Makes it into the blood
- Reaches the Reproductiv tract
- Female - goes to uterus / fetus
- Male - goes to epidiymis / prostate
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What symptoms does Canine Brucellosis cause in Females?
- Abortion (45 - 55 days)
- Aborted puppies show autolysi
- Edema and degenerative lesions
- Infertility
- Persistent vaginal discharge, which is loaded with B. canis
What symptoms does Canine Brucellosis cause in Males?
- Epididymitis
- Prostatitis
- Semen will have B. canis
- In chronic cases, testicular atrophy and sterility
What is Brucellosis in Dogs?
- Serious problem in breeding kennels
- Occationally B. abortus, suis or melitensis
- B canis infection in humans is mild
How is Canine Brucellosis Diagnosed?
- Cultural or PCR examination:
- Blood, vaginal discharde, aborted fetuses, semen
- Necropsy: lymph nodes and spleen
- Serology: Agglutination test
How is Canine Brucellosis Treated?
- Antibiotic:
-
Aminoglycosides and Tetracyclines
- Doxycycline and gentamicin combo
-
Aminoglycosides and Tetracyclines
- Long term treatment (3mo)
- Difficult to achieve complete cure
- Disease may relapse
- Not recommended for breeding dogs
How is Canine Brucellosis Prevented?
- No Vaccine
- Breeding Kennels:
- Periodic tsting and euthanizing all infected dogs
- Pet Dogs:
- Spay/Castration
- Treatment
- Consider Euthanasia
How is Brucellosis Controlled/Eradicated in Kennels?
- Quarantine
- Testing of all dogs
- Segregation of healthy dogs
- Euthanizing positive dogs
- Rigorous cleaningand disinfection
What is Brucellosis in Horses?
- B. abortus
- Abortion is rare
- Arthritis is common
-
B. abortus is associated with:
- Poll evil (Atlantal bursitis)
- Fistulous withers (Supraspinatus bursitis)
What is Brucellosis in Goats?
- B. melitensis most common
- Abortion
- Orchitis
What is Brucellosis in Humans?
-
B. abortus, suis, melitensis, rarely canis
- No B. ovis or neotomae
- B. melitensis causes the most serious infection
- “Malta fever” “Undulant Fever”
- Long incubation period
- ~100 cases per year in the US
- Source of Infection:
- direct contact
- Unpasteruized milk/cheese
- Occupational disease
- Most prevalent in: Farm workers, Slaughter house workers, Vets
- In the last decade, Brucellosis has changed to a foodborne disease
WWhat are the clinical signs of Brucellosis in Humans?
- Fever
- Chills
- Malaise
- Headache
- Joint Pains
- Fatigue
- ‘Chronic fatigue syndrom’
What does Brucellosis cause in general?
Infection of the reproductive organs