Intracellular Bacterial Infection Flashcards Preview

MS2 - Infectious Disease > Intracellular Bacterial Infection > Flashcards

Flashcards in Intracellular Bacterial Infection Deck (24)
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1
Q

Listeria’s ability to enter cells allows it to infect _______________.

A

the CNS and the placenta (and subsequently fetuses)

2
Q

Listeria monocytogenes is __________-positive.

A

catalase (remember the cat –who kind of looks like Walter –playing with the Christmas tree ornaments beneath the table holding Santa’s cheese)

3
Q

Obligate intracellular pathogens often have mutations in _______________.

A

nutritional enzymes (indicating that they are entirely reliant on host enzymes)

4
Q

List the facultative intracellular bacteria.

A
Salmonella (birds walking in and out of cages) 
Shigella (gorilla being shot out of actin cannon) 
Listeria (rocket toys beneath the tree) 
Bartonella
Brucella 
Francisella
Legionella
Mycobacterium tuberculosis 
Nocardia
5
Q

List the obligate intracellular bacteria.

A
CREM E: 
Chlamydia
M. leprae
Coxiella
Rickettisa
Ehrlichia
6
Q

There are two kinds of Salmonella typhi: _________________.

A
  • Salmonella typhimurium (generalist)

- Salmonella typhi (human-specific)

7
Q

What are the two mechanisms by which bacteria can enter cells?

A
  • Zipper: close contact with host membrane

- Trigger: forced entry, usually by T3SS (such as that in Shigella or Salmonella)

8
Q

Intracellular infection allows for very fast _______________.

A

systemic infection; Salmonella can be found inside bloodstream macrophages only five minutes after inoculation in the stomach

9
Q

What makes Salmonella appear black on Hektoen agar?

A

Production of H2S

10
Q

NADPH oxidase produces ____________.

A

superoxide radicals (O2–•)

11
Q

How can pathogens deal with O2–•?

A

Superoxide dismutase, which produces H2O2

12
Q

Catalase breaks down __________.

A

H2O2 to water

13
Q

If a bacterium does not have enzymes to eliminate O2–• and H2O2, what other ways could it escape oxidative bursts?

A

By escaping the phagolysosome (such as Shigella and Listeria)

14
Q

What are some oxygen-independent mechanisms of killing intracellular pathogens?

A

Defensins
Phospholipase
Lysozyme

15
Q

What is the difference between a phagosome and phagolysosome?

A

Phagosomes are vacuoles that contain bacteria, while phagolysosomes are mature phagosomes that have created an acidic interior environment.

16
Q

How does Legionella escape phagocytic destruction inside cells?

A

It grows in the endoplasmic reticulum!

17
Q

How does Mycobacterium escape intracellular destruction?

A

It stays in early endosomes, which don’t acidify.

18
Q

Which bacterium escapes intracellular destruction by intercepting Golgi traffic?

A

Chlamydia

19
Q

Coxiella survives by _________________.

A

residing in phagolysosomes (the only organism to do so!); as such, it is said to be fusogenic

20
Q

Bartonella survives inside _______________.

A

erythrocytes; this is why it causes bacillary angiomatosis

21
Q

In general, the best antibiotic for intracellular bacteria is ______________.

A

tetracycline

22
Q

Which antibiotics reside in lysosomes?

A

Macrolides and aminoglycosides; this happens because these two are weak bases and get trapped in the acidic environment of the lysosome

23
Q

Which method of entry is also called macropinocytosis?

A

Trigger

24
Q

Which two human-cell-made products can inactivate aminoglycosides and beta-lactams?

A

Nitric oxide and IFN-gamma