Chapter 15: Bacterial Pathogenicity

Question 1

Stages of disease from host viewpoint

Answer 1

1. Infection (exposure); 2. Incubation (before you know that you are sick); 3. Initial symptoms (prodromal period); 4. Acute Symptoms; 5. Recovery (immune system kicks in and treatment is initiated)

Question 2

Stages of disease from Microbe’s point of view

Answer 2

1. Attachment and Entry; 2. multiplication; 3. evasion of defenses; 4. shedding (going back where they came from etc.)

Question 3

Major portals of entry

Answer 3

eyes, mouth, nose and throat, skin, large intestine, urinary and genital systems

Question 4

Major adherance factors

Answer 4

glycocalyx (s. mutans), fimbriae (e.coli), M protein (s. pyogenes), Opa protein (N. gonorrhoeae), host cytoskeleton as subway network

Question 5

Effect of coagulases

Answer 5

creates clots and prevents phagocytes from coming to get them

Question 6

effect of kinases

Answer 6

breaks things apart to mobilize nutrients (tissue breakdown)

Question 7

Effects of hyaluronidase

Answer 7

acid breakdown

Question 8

effect of collagenase

Answer 8

collagen breakdown. Hyaluronidase and collagenase both break down to get nutrients and further infection into host.

Question 9

IgA protease

Answer 9

Breaks down IgA (an antibody in mucosal system)

Question 10

Function of siderophores

Answer 10

sequester important nutrients. kind of like magnets that gather and store nutrients for metabolism later

Question 11

Difference between endotoxin and exotoxin and what bacteria produce them

Answer 11

Exotoxins are produced inside the cell, are released, and have a very broad effect on the body with lots of symptoms. Diptheria toxin, clostridum botulinum, clostridum tetani, vibrio cholerae;;;;;;;;;Endotoxins are part of the lipopolysaccharide layer and are specific in their targets. Lipid A is an endotoxin produced by gram negatives

Question 12

MOA of Type 1 A-B exotoxins ex. diptheria toxin

Answer 12

A does the action and B binds. inhibits protein synthesis

Question 13

MOA botulinum toxin

Answer 13

flaccid paralysis; excitatory ACh production is stopped by a microbe binding to the neuron

Question 14

MOA Colstridum Tetani

Answer 14

Causes rigid paralysis; microbe creates toxin which makes the neuron rapidly produce ACh.

Question 15

Cholerae Toxin

Answer 15

Forces the body to give up fluid and electrolytes until death ensues

Question 16

Type II: Membrane Disrupting Toxins

Answer 16

Hemolysin: lyse RBCs; Leukocidins: lyse WBCs

Question 17

Type III Superantigens

Answer 17

Antigens that elicit overproduction of cytokines by T cells (chemical messengers)

Question 18

Plasmids and lysogeny

Answer 18

Lysogeny is the cycle where a plasmid is altered and becomes dangerous

Question 19

How bacteria evade host defenses

Answer 19

capsules allow them to be virulent and grow in host cells