Listeria Monocytogenes

Question 1

Overview

Answer 1

• g +
• coccobacilli
• faculatative anerobe
• motile
• non-spore forming
• can grow 4-45oC & high salt
• intracellular growth

Question 2

Encounter

Answer 2

• Fresh water or soil resorvoir

Question 3

Entry

Answer 3

Ingestion of contam. food

Question 4

Spread

Answer 4

• Point source spred (contam. food)
• NO person —> person

Question 5

Multiplication

Answer 5

• Colonizes intestinal epithelial cells, M-cells, macrophages, and neutrophils
• Escapes phagosome & replicates in the cytoplasm

Question 6

Damage

Answer 6

• Healthy: Flu Like w/ or w/out GItis, self-limiting
• Others: bacteremia or meningits

Question 7

DX

Answer 7

• g stain of CSF
• culture of CFS, blood, & occas. stool

Question 8

TX

Answer 8

• Antibiotics: penicillins, gentamicin, erythromycin

Question 9

PV

Answer 9

• Impossible
• moniter food processing plants

Question 10

Growth & Uptake

Answer 10

forces intestinal cells to become phagocytic using zipper method (Internalin, Inl)

Inl A intrx w/ host E-cadherin & InlB w/ host Met causing cytoskelton reagrangment & uptake of L.mon

Question 11

Virulence Factor:
Listeriolysin O

Answer 11

• froms pore in phagosome —> release L.mon into cell cytoplasm
• not phagosome membrane specific

Question 12

Virulence Factor:
ActA

Answer 12

• Bacteria secretes ActA which anchors in the outer membrane.
• ActA activates host Arp2/3 complex, whcihduces formation of branched actin filaments.
• allows bacteria to move cell —> w/out re-entering intestine
• literally pushed cell to cell
• avoids AB response