Anthrax and Plague

Question 1

Describe the structure of bacillus anthracis (known as anthrax from now on). Does it have a capsule???

Answer 1

Large Gm (+) rods in boxcar chains

Yes, encapsulated (made of protein poly-D-glutamate, NOT polysaccharides)

Question 2

Does anthrax like oxygen? Does it form spores?

Answer 2

Yes, it is an obligate aerobe

Yes, it forms spores

Question 3

Where does anthrax exist on this vast Earth? How do we get it?

Answer 3

Place on Earth: soil

How we get it:

1) Cutaneous
2) Inhalation
3) GIT (infected meat ew)

Question 4

Exotoxins of anthrax?

Answer 4

1) Lethal factor (LF)+PA: Zinc-metaloprotease that cleaves MAP kinase (controls cells growth) → tissue necrosis (black eschar)
2) Edema factor (EF)+PA: acts like adenylate cyclase that inc cAMP → fluid buildup in extracellular space → edema → prevents phagocytosis and host defenses. Calmodulin dependent.

Question 5

What’s that PA shit you put on that last flashcard?

Answer 5

PA: protective antigen = B subunit that is the cell binding component for each of the above toxins. Anti-PA antibodies neutralize the toxin

Question 6

So one of anthrax’s toxins is good enough to infect, right???

Answer 6

WRONG

Ya need 2 to tango (aka you must have both toxins)

Question 7

So what’s so concerning about anthrax? What do you get in terms of disease of the LUNG?

Answer 7

Lungs: wool sorter’s disease from spores present in the wool (anthrax found naturally in soil). Sx: dry cough (cold sx → rapidly progresses to pulmonary hemorrhage→ spread to mediastinal lymph nodes → hemorrhagic mediastinitis (widened mediastinum on CXR w/ pleural effusions. No infiltrates) → 100% death

GI (rare): n/v, fever, ulcers at site of invasion (mouth, esophagus, intestine etc

Question 8

Is your beautiful porcelin skin safe from anthrax?

Answer 8

NO IT’S NOT SAFE AT ALL

Skin (95%): papule → black eschar (painless), spread to lymph nodes

Question 9

That piece of cake you just ate? Gonna stay down if you’ve ingested some anthrax?

Answer 9

NO IT’S NOT GONNA STAY DOWN.

GI sx (rare): nausea, VOMITING (there goes the cake), fever, ulcers at site of invasion (mouth, esophagus, intestine etc)

Question 10

HOW DO WE GET RID OF THE BLACK ESCHAR/ anthrax in general

Answer 10

1) fluoroquinolones

2) tetracyclines (2’)

Question 11

Vaccine for anthrax so we never ever ever get back together?

Answer 11

Biothrax:

inactivated vaccine made mostly of PA, traces of EF and LF

Question 12

What does yersinia pestis look like?

Answer 12

Gm (-) rod

Safety pin appearance

Question 13

What about some staining for yersinia?

Answer 13

1) Grows on McConkey agar

2) Wayson staining shows light blue bacilli with dark blue polar bodies

Question 14

Vector for yersinia? General transmission?

Answer 14

Vector: FLEES
Transmission: occurs naturally in SW US. Cycles through rodents (mainly prairie dogs in US). Epizootics common in cool summers following wet winters. Cat transmission to humans>dogs

Question 15

Describe to me, if you please, the pathogenesis of a yersinia pestis infection? Thank you, good friend.

Answer 15

Flee bites and regurgitates bacteria→ vesicular lesion→ phagocytosis by PMNs→ killed in PMNs or released→ can now resist further phagocytosis→ travel to lymphatics and localized to a lymph node→ bubo → stops here or disseminates leading to pneumonia, septic shock or meningitis.

Question 16

What’s the most terrible, worstest ever disease that yersinia pestis causes?

Answer 16

THE BUBONIC PLAGUE

Question 17

Virulence factors for yersinia?

Answer 17

Yops (yersinia-associated outer proteins) secreted by Type 3 secretion system: inhibit cytokine produce and phagocytosis

Question 18

Treatment for yersinia pestis?

Answer 18

Aminoglycosides (streptomycin) + Tetracycline

Question 19

Vaccine for yersinia so we don’t all go and get the bubonic plague the next time we see a prairie dog?

Answer 19

Killed vaccine

Huuuuuuuuuh

Question 20

They didn’t actually talk about Francisella tularensis in lecture but it was highlighted in green and nothing else was SO YOU GONNA GET FLASHCARDS ON IT NOW

Answer 20

Carry on

Question 21

Structure for Francisella tularensis

Answer 21

Gm (-) coccibacilli, facultative intracellular

Question 22

Where does Francisella tularensis come from?

Answer 22

Dermacentor ticks, rabbits are main reservoir. Can be aerosolized (terrorism!)

Question 23

What does Francisella tularensis cause

Answer 23

Painful ulcer at site of infection→ regional lymphadenopathy (granulomas with caseating necrosis reticuloendothelial organs like lymph nodes)

Question 24

Treatment for Francisella tularensis

Answer 24

Aminoglycosides