Zoonotic bacteria Flashcards
Who are at high risk of developing zoonotic infections?
Vets, farmers, ranchers, lab workers etc
True or false: in general, humans are only incidental hosts for zoonotic illnesses?
True
Why are there not many vaccine for zoonotic infections?
Not feasible d/t low incidence
What is the gram stain, morphology, of bacillus anthrax? Spores? Aerobic?
Gram positive rod
Aerobic
Spore forming
How does bacillus anthracis appear in a stain?
Long chains or single with squared ends
Where are spores of anthrax found? How long are they viable for?
Soil, viable for decades
Squared ended gram positive bacilli = ?
Bacillus anthracis
How do you diagnose bacillus anthracis?
Culture is very easy
What is the main virulence factor for bacillus anthracis?
Protein capsule
Poly D-glutamic acid
What are the three toxins that bacillus anthracis produces?
Lethal toxin
Edema toxin
Protective antigen
What is the pathogenesis of the lethal toxin that anthrax produces?
Disrupts normal cellular signaling events, leading to cell death
What is the pathogenesis of the edema toxin produced by anthrax?
Increase adenylate cyclase upregulation = water efflux
What is the general way that we become infected with bacillus anthracis?
Inhaled or inoculated spores
What is the pathophysiology of the protective antigen that bacillus anthracis produces?
Binds to cellular receptors. Activated by cleavage by host cell enzymes. Allows edema/lethal factor to enter
What is the reservoir of anthrax? Where in the world?
Cattle, sheep, goats, horses
Everywhere
How do animals become infected with bacillus anthracis?
Grazing pastures
What are the two primary ways that anthrax can be transmitted?
Cutaneous Inoculation
inhalation
What is wool-sorters disease?
Bacillus anthracis poisoning
Who is usually infected via the inoculation route of anthrax?
Butchers
Can anthrax be ingested?
yes, but more rare
The majority of human cases of anthrax poisoning are of what type?
Cutaneous
What are the initial symptoms of cutaneous bacillus anthracis poisoning?
Small, red, painless papule, that turns to vesicle to necrotic ulcer (eschar)
Lymph node swelling
Eschar = what bacterial disease?
Anthrax
What is the treatment for cutaneous bacillus anthracis poisoning?
topical abx
What is the fatality rate of cutaneous anthrax poisoning with and without treatment?
with = <1% w/o = 5-20%
What are the presenting symptoms for inhalation bacillus anthracis poisoning?
Non-productive cough, SOB, malaise, nonspecific
What are the second stage symptoms of anthrax?
Fever, diaphoresis, extreme SOB, cyanosis,
Meningitis
What is the mortality rate of inhalation anthrax?
100% w/o treatment
75% with
What are the findings on a CXR for anthrax?
Enlarged hilar lymph
What is the incubation period of ingested anthrax?
1-7 days
What are the symptoms of ingested anthrax?
abdominal pain, oral lesions, bloody diarrhea,
What is the case fatality of ingested anthrax?
100%
What is the treatment for cutaneous anthrax?
Amox
What is the treatment for inhalation anthrax?
doxy/cipro with two additional abx
Is there a vaccination for anthrax?
Yes
What are the three species of brucella that infect humans?
B. Abortis (cattle)
B. Suis (piggies)
B. melitensis (goats)
What is the gram stain and morphology of brucella? how fast do they grow?
Small, slow growing gram negative coccobacilli
In what cells does brucella survive in?
Phagosomes of macrophages/monocytes
How is brucella transmitted?
Aerosol or ingestion of contaminated foods
Is human to human transmission of brucella possible?
Yes, but rare
What is the presentation for brucellosis? (4)
Acute, undulating fever, arthralgias, myalgias, and diaphoresis (with characteristic Hay-like scent)
Pregnancy and brucellosis can lead to what?
Premie or miscarriage
What is the usual food product associated with brucella?
Unpasteurized Milk
How do you diagnose brucellosis? (3)
Blood culture, serology, PCR
What is the treatment for brucellosis?
6 weeks of tetracycline and rifampin
How do you prevent Brucellosis?
Quarantine and vaccination of cattle.
Pasteurize dairy products
What is the gram stain and morphology of pasteurellosis? Aerobic?
Gram negative, coccobacilli, facultative anaerobe
What are the virulence factors of pasteurella multocida?
LPS
Capsule
Where is pasteurella multocida found? what about geographically?
Nasopharynx of dogs or cats
Worldwide
How is pasteurella multocida transmitted?
bite or scratch of a dog or cat
What are the symptoms of pasteurella multocida?
Rapid cellulitis
Lymphangitis
How do you diagnose pasteurellosis?
Signs
h/o exposure
Culture
What is the treatment for pasteurellosis?
PCN
What is the gram stain and morphology of leptospira interrogans?
Thin, gram negative spiral shaped bacteria with termianal hooks
What specialization does leptospira interrogans have?
Terminal hooks
Does leptospira interrogans stain or grow well?
No
What is the pathogenesis of leptospira interrogans?
Invade abraded skin, and intact mucus membranes to cause bacteremia
How do you see leptospira interrogans?
Darkfield
Where is leptospirosis usually found?
Worldwide, but tropics usually
How is leptospira interrogans transmitted?
Contaminated animal urine or water
Usually swimming
What are the reservoirs of leptospira interrogans?
over 200 domestic and wild animals have this thing
What is the phase 1 of leptospirosis?
Non-specific symptoms then resolution
What is phase 2 of leptospirosis?
Meningitis, jaundice, renal failure, petechial rash
What is the mortality rate of leptospira interrogans?
5-40%
How do you diagnose leptospira interrogans?
Culture (hard)
Serology
What is the treatment for leptospira interrogans?
PCN and ampicillin
How do you prevent leptospirosis?
Limit exposure to animal urine
What is the gram stain and morphology of francisella tularensis? Aerobic?
Small, slow growing aerobic, gram negative coccobacilli
Is francisella tularensis hard to grow in culture?
Yes
What cells does francisella tularensis infect?
monocytes/macrophages
What are the virulence factors of francisella tularensis?
Capsule
LPS
Where is tularemia found geographically?
Northern hemisphere
What is the reservoir for francisella tularensis?
wild mammals
How is francisella tularensis transmitted?
Hard-shelled Ticks or through contact with animal blood
What are the symptoms of a skin infection with francisella tularensis? (3)
Red, painful, swollen papule that becomes purulent and ulcerates
May lead to bacteremia
What are the symptoms of oculoglandular tularemia?
Painful conjunctivitis with swollen cervical lymph nodes
What are the symptoms of pneumonic tularemia?
Pneumonitis eventual sepsis
How do you diagnose francisella tularensis?
culture, serology
What is the treatment for francisella tularensis?
Gentamycin
What is the gram stain and morphology of yersinia pestis?
Non-motile gram negative rod
What is the family of bacteria for yersinia pestis?
Enterobacteriaceae
What is the virulence factors for Yersinia pestis?
Protein capsule
LPS
Plasmids x3
What is the stain that is utilized for yersinia? What does this detect?
Giemsa–detects the protein capsule
What color do all bacteria show up on a Giemsa stain?
Purple
What do Yersinia pestis bacteria look like under the microscope?
Closed safety pin
Closed safety pin bacteria = ?
Yersinia Pestis
What are the three plasmids that Yersinia has, and what do they do?
- Biofilm formation
- Enhanced resistance to macrophage killing
- Complement resistance
Why is it significant that Yersinia forms a biofilm?
Can be regurgitated by fleas
What are the resrvoirs of Yersinia?
mammals and rats
Where in the world is Yersinia found?
Worldwide
What are the most important vectors in the US for Yersinia?
Coyotes
How is Yersinia transmitted?
Rodent to fleas, humans as accidental host
Is human to human transmission possible with Yersinia pestis?
Yes
What are the symptoms of the black plague?
Painful lymphadenopathy –buboes
What are the two fatal consequences of untreated buboes from Yersinia pestis?
Gangrene
Bacteremia
What are the symptoms of pneumonic plague?
Nonspecific LRI, then more severe with hemoptysis, circulatory collapse
How do you diagnose pneumonic plague?
Sputum samples
What is the mortality rate of untreated bubonic plague? Pneumonic? What about treated?
Bubonic = 50% Pneumonic = 100%
Treated = 15% for both
What is the treatment for Yersinia pestis?
Streptomycin
What are the three forms of tularemia?
- Ulceroglandular
- Oculoglandular
- Pneumonic