Pathogens

Question 1

What is a pathogen

Answer 1

-carries and expresses virulence genes

Question 2

virulence is defined by 2 features

Answer 2

invasiveness

toxigenicity

Question 3

invasiveness

Answer 3

the ability of the microorganism to become established in the host, to overcome the host defenses and to spread in the tissues

Question 4

toxigenicity

Answer 4

the capacity of the microbe to produce substances known as toxins that damage specific tissues of the host

Question 5

examples of invasiveness

Answer 5

adhesins
capsules
enzymes
invasins
T3SS, T4SS

Question 6

Adhesins

Answer 6

-promote specific attachment to host cell surfaces
Afimbrial adhesins:glyco/lipid proteins
Fimbriae/pili: polymers

Question 7

capsule

Answer 7

• prevent destruction by immune cells

- not ONLY a virulence factor

Question 8

Lecithinase

Answer 8

degrades phosphatidylecholine and causes lysis of host cells

Question 9

gas gangrene: how does it function

Answer 9

uses lecithinase to lyse host cells

uses hyaluronidates and collagenase to destroy ECM

Question 10

T3SS fxns? and mechanism?

Answer 10

• forms a channel through all membranes and periplasmic space. Injects bacterial proteins into the host
  fxns:
  1. invasion of host cells
  2. control of host cells
  3. block phagosome maturation

Question 11

infectious diseases cause

Answer 11

pathogen growth

Question 12

intoxications cause

Answer 12

presence of a specific toxin

Question 13

exotoxin

Answer 13

secreted into the surrounding as the bacterial pathogen grows
-Leads to a cell-mediated response, activates antibodies

Question 14

endotoxins

Answer 14

part of the bacterial pathogen

Question 15

A subunit

Answer 15

(exotoxin)

modifies a target inside the host

Question 16

B subunit

Answer 16

binds to specific cell receptors providing tissue-cell type specificity

Question 17

botulinum

Answer 17

blocks acetylcholine release, flacid muscles

Question 18

tetnus

Answer 18

blocks glycine release, which usually inhibits acetylcholine release. Acetylcholine is released and muscles tense and spasm

Question 19

cholera

Answer 19

AB5 toxin
B binds to intestinal cells
A activates adenylyl cyclase
massive water movement into the colon

Question 20

Endotoxin

Answer 20

• produces inflammation

- can cause septic shock

Question 21

toxoid

Answer 21

inactivated toxin through heat or formaldehyde

Question 22

endotoxin examples

Answer 22

Lipid A of LPS