Bacterial Path and Host Defense Mechs Flashcards Preview

(Week 3) Foundations of Medicine > Bacterial Path and Host Defense Mechs > Flashcards

Flashcards in Bacterial Path and Host Defense Mechs Deck (10)
Loading flashcards...
1
Q

What the three mechanisms of disease for bacteria?

A

Toxicity, Host Immune Response, and Colonation and Proliferation.

2
Q

What is LPS and where is it found?

A

LPS is an endotoxin and found on gram (-) bacteria.

3
Q

Name some virulence factors found in salmonella.

A
  • Toxins (enterotoxin, endotoxin, and cytotoxin).
  • Iron-chelating siderophores.
  • Cell surface polysaccharide O antigen, flagellar H antigen, and fimbriae all enhance adherence.
  • Capsular Vi polysaccharide inhibits complement binding and antibody-mediated killing.
  • Salmonella contains at least two pathogenicity islands known as Salmonella pathogenicity island 1 and 2 (SPI1 and SPI2). Responsible for invasion, systemic disease, and host-immune evasion.
  • Salmonella plasmids contain drug resistance genes.
4
Q

What does O antigen do?

A

Inhibits phagocytic killing of bacteria.

5
Q

Name the three types organisms that have Hemolysins and an example of each.

A

Alpha: Will damage but not kill RBC, strep-virdans (mouth)
Beta: Completely destroys RBC, strep-pyrogenase
Gamma: No hemolysin, staph-epidermis

6
Q

With AB toxins, the B portion binds to a receptor protein while the A portion shuts down protein synthesis in the cell. (T/F)

A

T

7
Q

How does the botulinum toxin affect muscle?

A

It blocks the release of Acetylcholine and therefore muscles can’t contract.

8
Q

How does the tetanus toxin affect muscle?

A

It binds to inhibitory interneurons and prevents the release of glycine, thus, preventing the relaxation of muscle.

9
Q

What causes random T Cells and MHC molecules to bind incorrectly, thus increasing inflammation?

A

Superantigens (an exotoxin)

10
Q

What is the difference between type 2 and type 3 hypersensitivity?

A

Type 2: Ab are made, but also binds to self