2 DD Host-Microbe Interactions Flashcards Preview

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Flashcards in 2 DD Host-Microbe Interactions Deck (23):
1

Definition: Infection

Process of establishing a relationship between microbe and host

- may/may not cause disease

2

Definition: Infectious disease
types?

Disease caused by an infection with a microbe

Communicable - transmitted patient to patient
Non-communicable - not transmitted

3

Definition: Pathogenicity
Frank vs opportunistic

Capacity to cause disease

Frank: microbes cause disease with normal hosts
Opportunistic: can't usually do in healthy people, need immunocompromised

4

Definition:Virulence
low vs high

Relative capacity to damage a host; measure of pathogenicity (ability to cause disease)

Few microbes needed for disease = high virulence
Many microbes needed for disease = low virulence

5

Koch's Postulates

1. Specific microbes are present regularly in characteristic lesions of the disease
2.The specific microbes can be isolated and grown in vitro.
3. Injection of the cultured microbes into animals reproduces the disease that you see in humans
4. The specific microbes can be re-isolated from lesions of the disease in animals.

- this shows that a microbe can be the cause of a specific disease

6

Stages of pathogenesis of ID

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

7

Typical stage in pathogenesis:
Encounter

1st stage

How the agent meets the host.

8

Give an example of microbial 'spreading factors' through tissues

during 3rd stage

Hyaluronidase, elastase, collagenase

9

how can coagulase inhibit spread of microbes.

coagulase: inhibits spread of microbes because it lays down fibrin to "wall off" and localize infection

10

Typical stage in pathogenesis:
damage

5th stage

how tissue damage is cause by the agent and/or the host response

are virulence factors present?

11

Typical stage in pathogenesis:
outcome

6th stage

does the microbial agent or the host win the battle, or do they learn to coexist?

12

Innate vs. Adaptive defense against infections

Innate: Immediate response
Adaptive: Defends against future recurrences

13

Things that affect composition of microbiome

1. Diet
2. Antibiotics
3. Anatomy
4. Genetics

14

Importance of microbiome

1. Effects on tissue/organ differentiation
2. Production of vitamins by flora
3. Biochemical conversions
4. Competition with pathogens for colonization of surfaces

15

If growth rate in vivo is slower than in vitro, what does that mean?

host defense is aiding to prevent infection

16

Skin normal flora

Staphylococci
Enteric bacilli
Corynebacteria
Propionobacterium acnes

17

Large intestine normal flora

Micrococcus streptococci (enterococcus)
Lactobacilli
Enteric bacilli
Clostridia
Pseudomonas

18

Vaginal normal flora

Streptococci
Lactobacilli
Bacteroides
Mycoplasma

19

What does the disease paradigm of pathogenesis mean?

Certain types of bacteria will result in very specific diseases

20

Using disease paradigm of pathogenesis, what causes Cholera?

A toxin-mediated disease

21

Using disease paradigm of pathogenesis, what causes Pneumococcal pneumonia

acute inflammation caused by invasive, extracellular bacteria

22

Using disease paradigm of pathogenesis, what causes Tuberculosis

infection by a facultative intracellular bacterium

23

What causes Rheumatic fever

pathology mediated by an immune response