Lecture 32

Question 1

Name the 6 pathogens

Answer 1

virus - H1N1 influenza 
Fungi - Trichophyton spp.
Prions - kuru
Protozoa - plasmodium spp.
Helminths - ancylostoma dodenale 
Bacteria - Bacillus anthracic

Question 2

What are Koch’s Postulates

Answer 2

the guidelines to show that a specific pathogen causes specific disease symptoms

1. The pathogen must be present in every individual with the disease
2. A sample of the microorganism taken from the diseased host can be grown in pure culture
3. A sample of pure culture causes the same disease when injected in a healthy host
4. The microorganism can be recovered from the expirementally infected host

Question 3

What are the exceptions to Koch’s postulates

Answer 3

microbes can’t be cultured

pathogens that also can be found in healthy subjects

Question 4

What are the key stages of microbial pathogenesis

Answer 4

1. adherence to host cells
2. invasion of host tissues
3. Replication with host tissues
4. disease causing damage to host tissues

Question 5

What are exotoxins

Answer 5

can be fatal

produced in living bacteria, released into surrounding medium

Question 6

What are the three types of exotoxins

Answer 6

1. cytotoxins (streptolysis) - causes lysis of red blood cells
2. neurotoxins (Botulinum) - causes paralysis
3. Enterotoxins (Shiga toxin) - severe dysentery

Question 7

What are Endotoxins

Answer 7

cause inflammation
are lipopolysaccharides (LPS) components found in the outer membrane of Gram-negative bacteria
strong immune responses
-fever, inflammation, blood clotting, shock