Bacteria Chapter 1: Intro

Question 1

What is pathogenicity?

Answer 1

ability of bacterium to cause disease

qualitative concept

Question 2

What is a pathogen?

Answer 2

bacterium that is capable of harming a normal host – does not always cause harm

ie. Mycobacterium tuberculosis

Question 3

What is an opportunistic pathogen?

Answer 3

bacterium that harms a compromised host

ie. Pseudomonas aeruginosa

Question 4

What is virulence?

Answer 4

measure of the pathogenicity of a microorganism

quantitative concept

Question 5

How is virulence expressed?

Answer 5

cell number that will elicit pathogenic response in the host within a given time period

ie. need less of highly virulent organism, and more of less virulent organism, to cause the same response

Question 6

What is a primary infection?

Answer 6

initial, acute infection

Question 7

What is a secondary infection?

Answer 7

later (or second) infection caused by an opportunistic organism after a primary infection has weakened the host defences

Question 8

What is a subclinical infection?

Answer 8

host has no apparent symptoms

Question 9

What is a nosocomial infection?

Answer 9

acquired at a hospital

Question 10

What organisms cause local infection

Answer 10

non-invasive organism

Question 11

What organisms cause systemic infection?

Answer 11

invasive organisms