Zoonotic Bacterial Diseases Flashcards
Zoonotic bacteria are typically asymptomatic in _____________.
animals
What does the word abattoir mean?
Slaughterhouse
What animal carries the plague?
Xenopsylla cheopis (the flea)
What are enzootic plagues?
A stable rodent/flea infection cycle that is maintained in a relatively resistant host population without excessive host mortality
What are epizootic plagues?
Similar to enzootic plagues but with higher mortality
Demic plagues are ___________.
human-to-human
Zootic plagues occur when _____________.
organisms get from animals to humans
What are the three types of plague?
- Bubonic: lymph infection
- Septicemic: infection of all organs (leads to DIC)
- Pneumonic: lung infection
Yersinia pestis has what unique staining pattern?
Bipolar staining (like the safety pin in the Sketchy video)
Note: Pasteurella also stains like this.
What rash is typical of Y. pestis infection?
Petechiae
Run through the Sketchy mnemonics for Yersinia.
- Gram-negative (like the red pet store walls)
- Treated with streptomycin (sai picking up poop) and tetracycline (like the hamster wheel)
- Resistant to cold (like the icicles on the awning outside)
- Pets can be given killed vaccines (like the sign saying “get your pets vaccinated before they’re killed”)
- Y. pestis is encapsulated (like the case on the rodent)
- Y. pestis has a T3SS (like the baster being used to fill the rodent’s water dish)
- Y. enterocolitca is transmitted by puppies and can mimic appendicitis (like the toddler next to the puppy being licked on his RLQ)
Plague is more common in what U.S. demographics?
Native Americans in the southwest
Francisella can be transmitted by ______________.
aerosolized rabbit poop/bodies in lawnmowers
The most common zoonotic infection is ____________.
Pasteurella multocida
In addition to rabbits, Francisella can also be transmitted by _____________.
house cats that have bitten rabbits or been bitten by ticks
What are the five routes of infection for F. tularensis?
- Glandular
- Ulceroglandular (most common; due to breach of skin)
- Oculoglandular
- Typhoidal (ingestional)
- Pulmonary (inhalational)
Tularemia is most common in _______________.
men in Kansas, Missouri, Louisiana, and Oklahoma (where rabbit hunting is common)
Go through the Sketchy scene for Francisella.
- Gram-negative coccobacillus (red radishes)
- Treated with Streptomycin (sai garden tools)
- Lymphadenopathy (mounds of dirt)
- Facultative intracellular (open cage)
Francisella is treated with ____________.
aminoglycosides, tetracycline, and fluoroquinolones
Why is plague generally more lethal/dangerous?
It can be transmitted human-to-human (though F. tularensis can be aerosolized).
Borrelia burgdorferi is carried by ___________.
the Ixodes scapularis tick
About 98% of Lyme disease cases are associated with _____________ ticks.
nymphal
The risk of human Lyme disease is greatest in ______________.
the late spring and summer
How can Borrelia be identified?
Darkfield microscopy or fluorescent antibodies to outer surface protein D
True or false: Borrelia secretes cariobacter toxin.
False. Borrelia burgdorferi does not have a toxin.
What rash is characteristic of B. burgdorferi?
Erythema migrans (bull’s eye rash)
What are the three stages of Lyme disease?
- Stage 1: erythema migrans
- Stage 2: cardiac block and myocarditis; bilateral Bell’s palsy
- Stage 3: migratory arthritis and encephalopathy
Why does Borrelia burgdorferi cause arthritis?
It has a glycosaminoglycan that binds to collagen.
In what case do recommendations say that you should give empiric antibiotics?
In a patient with erythema migrans
What treatments are recommended for Borrelia burgdorferi?
Doxycycline for early disease and ceftriaxone for late (neurologic disease)
(Think of the axes close to the third stage.)
How does the Y. pestis toxin work?
Secreted by a T3SS, YOPs is a tyrosine phosphatase that subverts the action of many phagocytic cells.
What does the word sylvatic mean?
Related to forests
Which kind of pet can spread plague?
Cats (remember this lecturer’s story about the cat who gave plague to the veterinarian)
What two antibiotics not featured in the Sketchy scene can kill Yersinia?
Chloramphenicol and fluoroquinolones –both capable of killing intracellular organisms
Which zoonotic bacteria is one of the most infectious bacterial agents known?
Francisella tularensis
An inoculum of less than 50 bacteria can infect unbroken skin and lead to tularemia.
Virulent strains of F. tularensis require _________ to grow.
cysteine
True or false: F. tularensis can spread by respiratory droplets.
False. It does not spread from person to person.
Borrelia burgdorferi can easily ____________.
cross intercellular junctions
What does recent research suggest about chronic Lyme disease?
That it doesn’t warrant treatment with antibiotics
