14. Listeria Flashcards
(25 cards)
How do G+ pathogens infect cells?
Use surface proteins to invade+control cells
Most common cause of listeriosis (bacteria)?
Listeria monocytogenes infection
Transmission of L. monocytogenes?
Contaminated food
General symptoms of listeriosis?
Nausea, diarrhea, muscle aches, fever
What body system can listeriosis spread to?
Nervous system
Infective dose of listeria?
100-1000 organisms
Listeria onset of symptoms?
30 days after exposure
Listeria is a gram-_______, _____cellular pathogen
gram-positive
intracellular
What are internalins?
Surface proteins on Listeria that help internalize them
The effectors on Listeria are called what?
Internalins
Receptor for internalin A in humans?
E-cadherin
Function if internalin A?
Bacterial entry into non-phagocytic cells
Amino acid length of internalin A and B?
Internalin A = 800 aa
Internalin B = 630 aa
Receptor for internalin B?
HGF-R (hepatocyte growth factor receptor)
Protein that helps Listeria break membranes once internalized?
Listeriolysin O (LLO)
Effector that Listeria uses to recruit actin?
ActA
What is Met?
Another name for HGF-R
How does Listeria invade cells using internalin B and receptor Met?
Hijacks endocytic machinery and uses clathrin-mediated endocytosis (recruits clathrin to sites of contact)
Where is E-cadherin found?
At adherin junctions
What is cell extrusion?
Cells at the top of a villus gets removed
How is E-cadherin exposed?
Cell extrusion of a villus (top of a villus as cells get removed)
What does ActA mimic? What is it?
N-WASp
Regulator of actin dynamics
In which organs do Listeria replicate like crazy?
Liver and spleen
What happens if internalin A is mutated?
Listeria unable to get into villus
