14. Listeria

Question 1

How do G+ pathogens infect cells?

Answer 1

Use surface proteins to invade+control cells

Question 2

Most common cause of listeriosis (bacteria)?

Answer 2

Listeria monocytogenes infection

Question 3

Transmission of L. monocytogenes?

Answer 3

Contaminated food

Question 4

General symptoms of listeriosis?

Answer 4

Nausea, diarrhea, muscle aches, fever

Question 5

What body system can listeriosis spread to?

Answer 5

Nervous system

Question 6

Infective dose of listeria?

Answer 6

100-1000 organisms

Question 7

Listeria onset of symptoms?

Answer 7

30 days after exposure

Question 8

Listeria is a gram-_______, _____cellular pathogen

Answer 8

gram-positive

intracellular

Question 9

What are internalins?

Answer 9

Surface proteins on Listeria that help internalize them

Question 10

The effectors on Listeria are called what?

Answer 10

Internalins

Question 11

Receptor for internalin A in humans?

Answer 11

E-cadherin

Question 12

Function if internalin A?

Answer 12

Bacterial entry into non-phagocytic cells

Question 13

Amino acid length of internalin A and B?

Answer 13

Internalin A = 800 aa

Internalin B = 630 aa

Question 14

Receptor for internalin B?

Answer 14

HGF-R (hepatocyte growth factor receptor)

Question 15

Protein that helps Listeria break membranes once internalized?

Answer 15

Listeriolysin O (LLO)

Question 16

Effector that Listeria uses to recruit actin?

Answer 16

ActA

Question 17

What is Met?

Answer 17

Another name for HGF-R

Question 18

How does Listeria invade cells using internalin B and receptor Met?

Answer 18

Hijacks endocytic machinery and uses clathrin-mediated endocytosis (recruits clathrin to sites of contact)

Question 19

Where is E-cadherin found?

Answer 19

At adherin junctions

Question 20

What is cell extrusion?

Answer 20

Cells at the top of a villus gets removed

Question 21

How is E-cadherin exposed?

Answer 21

Cell extrusion of a villus (top of a villus as cells get removed)

Question 22

What does ActA mimic? What is it?

Answer 22

N-WASp

Regulator of actin dynamics

Question 23

In which organs do Listeria replicate like crazy?

Answer 23

Liver and spleen

Question 24

What happens if internalin A is mutated?

Answer 24

Listeria unable to get into villus

Question 25

Difference between internalin A and B strategy?

Answer 25

Internalin A enters through cell extrusions of villi

Internalin B binds to receptor Met to get internalized => clathrin-mediated endocytosis