Listeria Monocytogenes Flashcards
1
Q
What is listeria?
A
Gram +ve rods, is a major food borne pathogen, endemic in animals so doesn’t cause epidemic
2
Q
Where is listeria found?
A
In soil most places, only causes infection under certain circumstances
3
Q
Why is it a good model intracellular parasite?
A
- invasive
- targets many host cells such as macrophages and non-professional phagocytes
- carries out cytosolic replication
4
Q
How do outbreaks occur?
A
Food associated with infection is spread across the country by food industry
Usually soft cheeses, salmon, sandwiches
5
Q
Pathogenesis of listeria?
A
- Forces entry and penetrates non-phagocytic cells
- consequence of phagocytosis is formation of a phagosome - usually undergo maturation and fuse with lysosomes and contents get destroyed
- listeria escapes from phagocytic vacuole and carries out cutosolic replication
6
Q
How are listeriopods formed?
A
After cytosolic replication, F-actin rearranges to form tails with a bacterium at the tip
7
Q
How does actin allow motility?
A
ActA is a surface protein of L.monocytogenes, and is a molecular mimic of the eukaryotic actin nucleation promoting factor WASP
Activates the actin polymerising function of the Arp2/3 complex
