Zoonotic Bacterial Diseases

Question 1

Zoonotic bacteria are typically asymptomatic in _____________.

Answer 1

animals

Question 2

What does the word abattoir mean?

Answer 2

Slaughterhouse

Question 3

What animal carries the plague?

Answer 3

Xenopsylla cheopis (the flea)

Question 4

What are enzootic plagues?

Answer 4

A stable rodent/flea infection cycle that is maintained in a relatively resistant host population without excessive host mortality

Question 5

What are epizootic plagues?

Answer 5

Similar to enzootic plagues but with higher mortality

Question 6

Demic plagues are ___________.

Answer 6

human-to-human

Question 7

Zootic plagues occur when _____________.

Answer 7

organisms get from animals to humans

Question 8

What are the three types of plague?

Answer 8

• Bubonic: lymph infection
• Septicemic: infection of all organs (leads to DIC)
• Pneumonic: lung infection

Question 9

Yersinia pestis has what unique staining pattern?

Answer 9

Bipolar staining (like the safety pin in the Sketchy video)

Note: Pasteurella also stains like this.

Question 10

What rash is typical of Y. pestis infection?

Answer 10

Petechiae

Question 11

Run through the Sketchy mnemonics for Yersinia.

Answer 11

• 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)

Question 12

Plague is more common in what U.S. demographics?

Answer 12

Native Americans in the southwest

Question 13

Francisella can be transmitted by ______________.

Answer 13

aerosolized rabbit poop/bodies in lawnmowers

Question 14

The most common zoonotic infection is ____________.

Answer 14

Pasteurella multocida

Question 15

In addition to rabbits, Francisella can also be transmitted by _____________.

Answer 15

house cats that have bitten rabbits or been bitten by ticks

Question 16

What are the five routes of infection for F. tularensis?

Answer 16

• Glandular
• Ulceroglandular (most common; due to breach of skin)
• Oculoglandular
• Typhoidal (ingestional)
• Pulmonary (inhalational)

Question 17

Tularemia is most common in _______________.

Answer 17

men in Kansas, Missouri, Louisiana, and Oklahoma (where rabbit hunting is common)

Question 18

Go through the Sketchy scene for Francisella.

Answer 18

• Gram-negative coccobacillus (red radishes)
• Treated with Streptomycin (sai garden tools)
• Lymphadenopathy (mounds of dirt)
• Facultative intracellular (open cage)

Question 19

Francisella is treated with ____________.

Answer 19

aminoglycosides, tetracycline, and fluoroquinolones

Question 20

Why is plague generally more lethal/dangerous?

Answer 20

It can be transmitted human-to-human (though F. tularensis can be aerosolized).

Question 21

Borrelia burgdorferi is carried by ___________.

Answer 21

the Ixodes scapularis tick

Question 22

About 98% of Lyme disease cases are associated with _____________ ticks.

Answer 22

nymphal

Question 23

The risk of human Lyme disease is greatest in ______________.

Answer 23

the late spring and summer

Question 24

How can Borrelia be identified?

Answer 24

Darkfield microscopy or fluorescent antibodies to outer surface protein D

Question 25

True or false: Borrelia secretes cariobacter toxin.

Answer 25

False. Borrelia burgdorferi does not have a toxin.

Question 26

What rash is characteristic of B. burgdorferi?

Answer 26

Erythema migrans (bull’s eye rash)

Question 27

What are the three stages of Lyme disease?

Answer 27

• Stage 1: erythema migrans
• Stage 2: cardiac block and myocarditis; bilateral Bell’s palsy
• Stage 3: migratory arthritis and encephalopathy

Question 28

Why does Borrelia burgdorferi cause arthritis?

Answer 28

It has a glycosaminoglycan that binds to collagen.

Question 29

In what case do recommendations say that you should give empiric antibiotics?

Answer 29

In a patient with erythema migrans

Question 30

What treatments are recommended for Borrelia burgdorferi?

Answer 30

Doxycycline for early disease and ceftriaxone for late (neurologic disease)

(Think of the axes close to the third stage.)

Question 31

How does the Y. pestis toxin work?

Answer 31

Secreted by a T3SS, YOPs is a tyrosine phosphatase that subverts the action of many phagocytic cells.

Question 32

What does the word sylvatic mean?

Answer 32

Related to forests

Question 33

Which kind of pet can spread plague?

Answer 33

Cats (remember this lecturer’s story about the cat who gave plague to the veterinarian)

Question 34

What two antibiotics not featured in the Sketchy scene can kill Yersinia?

Answer 34

Chloramphenicol and fluoroquinolones –both capable of killing intracellular organisms

Question 35

Which zoonotic bacteria is one of the most infectious bacterial agents known?

Answer 35

Francisella tularensis

An inoculum of less than 50 bacteria can infect unbroken skin and lead to tularemia.

Question 36

Virulent strains of F. tularensis require _________ to grow.

Answer 36

cysteine

Question 37

True or false: F. tularensis can spread by respiratory droplets.

Answer 37

False. It does not spread from person to person.

Question 38

Borrelia burgdorferi can easily ____________.

Answer 38

cross intercellular junctions

Question 39

What does recent research suggest about chronic Lyme disease?

Answer 39

That it doesn’t warrant treatment with antibiotics