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Final Multisystems Microbiology > Anthrax and Plague > Flashcards

Flashcards in Anthrax and Plague Deck (24)
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1

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

Large Gm (+) rods in boxcar chains

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

2

Does anthrax like oxygen? Does it form spores?

Yes, it is an obligate aerobe

Yes, it forms spores

3

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

Place on Earth: soil

How we get it:
1) Cutaneous
2) Inhalation
3) GIT (infected meat ew)

4

Exotoxins of anthrax?

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.

5

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

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

6

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

WRONG

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

7

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

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

8

Is your beautiful porcelin skin safe from anthrax?

NO IT'S NOT SAFE AT ALL

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

9

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

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)

10

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

1) fluoroquinolones
2) tetracyclines (2’)

11

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

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

12

What does yersinia pestis look like?

Gm (-) rod
Safety pin appearance

13

What about some staining for yersinia?

1) Grows on McConkey agar
2) Wayson staining shows light blue bacilli with dark blue polar bodies

14

Vector for yersinia? General transmission?

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

15

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

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.

16

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

THE BUBONIC PLAGUE

17

Virulence factors for yersinia?

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

18

Treatment for yersinia pestis?

Aminoglycosides (streptomycin) + Tetracycline

19

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

Killed vaccine

Huuuuuuuuuh

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

Carry on

21

Structure for Francisella tularensis

Gm (-) coccibacilli, facultative intracellular

22

Where does Francisella tularensis come from?

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

23

What does Francisella tularensis cause

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

24

Treatment for Francisella tularensis

Aminoglycosides