Host-Microbe Interactions

Question 1

Virulence

Answer 1

the degree of pathogenicity. Highly virulent microbes cause disease when it is introduced into a small number of cells.

Question 2

Pathogenicity

Answer 2

the ability to cause disease.

Frank pathogens cause disease in healthy hosts, while opportunistic hosts cause disease in compromised hosts

Question 3

Infectious disease

Answer 3

a disease caused by an infection w/ a microbe.

Question 4

Infection

Answer 4

the process whereby a microbe enters into a relationship with the host ;)

Question 5

Koch’s Postulates

Answer 5

Helps identify the cause of infection!

1. ) Specific microbes are present regularly in characteristic lesions of the disease.
2. ) Specific microbes can be isolated and grown in vitro.
3. ) Injection of the microbes into animal reproduces disease seen in humans.
4. ) Specific microbes can be re-isolated from lesion of disease in animals.

This obviously isn’t without fault.

Question 6

What are the stages of disease?

6 of them lol

Answer 6

1. ) Encounter
2. ) Entry
3. ) Spread
4. ) Multiplication
5. ) Damage
6. ) Outcome

Question 7

2.Describe “encounter” of the stages of disease

Answer 7

How the agent meets the host.
Endogenous encounter is from internal normal flora
Exogenous encounter is from the environment.

Question 8

2.Describe “entry” of the stages of disease

Answer 8

How the agent enters the host.
Colonization of body surfaces is first step in many microbial infections.
Includes adherence, binding or microbial surface proteins

Question 9

2.Describe “spread” of the stages of disease

Answer 9

How does the agent spread from site of entry?

Spreading factors: Hyaluronidase, elastase, and collagenase fascilitate the spread of microbes in tissue

COAGULASE INHIBITS SPREAD OF MICROBES!!! (walls off and localizes infection by promoting fibrin deposition)

Question 10

2.Describe “multiplication” of the stages of disease

Answer 10

How the agent multiplies in the host. Must exceed clearance and defense mechanisms of the host.

Question 11

2.Describe “damage” of the stages of disease

Answer 11

how tissue damage is caused.

1. ) Direct damage - microbial toxins/enzymes
2. ) Blocking or interfering w/ host defense mechanism (antiphagocytic capsules..)
3. ) Microbial products that cause direct damage can be used for development of vaccines!

Question 12

2.Describe “outcome” of the stages of disease

Answer 12

does one win? is there coexistance? is this the most pointless notecard yet? yes

Question 13

Cholera

Answer 13

toxin mediated disease.

Question 14

Pneumococcal pneumonia

Answer 14

acute inflammatory disease caused by bacterial pathogen. exudation of fluid. Antibody opsonizes bacteria…

Question 15

Tuberculosis

Answer 15

chronic disease caused by facultative intracellular bacterium and controlled by cell mediated immunity.

you’re infected forever lol sorry

Question 16

Rheumatic fever

Answer 16

follows strep infection - cross reaction, systemic activation of immune system