Lecture 14 Flashcards
1
Q
Barriers to Infection
A
- Physical Barriers
- Chemical Barriers
2
Q
Physical Barriers
A
Epithelial Layers:
1. Skin
2. Mucosa
3. Glands
3
Q
Chemical Barriers
A
- Acidic pH
- Antimicrobial Agents
4
Q
Additional Barriers
A
- Glycocalyx
- Mucus
5
Q
Epidermis
A
- Stratified epithelium
- Keratinized Layer
6
Q
Mucosa
A
- Epithelial cells make mucus
- Phage bind to sugars in the mucus
- Protective layer is established
- Phage can infect and destroy/ susceptible bacteria
7
Q
A. Phage
A
Consistently found in mucus across species
8
Q
B. Phage
A
Display a modest binding affinity for mucus glycoproteins
9
Q
Epithelial Secretions
A
Controlling surface microbe populations
10
Q
Proteolytic Enzymes
A
Lysozyme
11
Q
Lysozyme
A
- Secreted into tears, saliva, milk, respiratory tract
- Cleaves peptidoglycan molecules in bacterial cell walls
12
Q
Gram Negative Bacteria: Less sensitive
A
E. coli
1. Cell wall organization
2. LPS
3. Outer membrane
4. Peptidoglycan
5. Inner membrane
13
Q
Gram Positive Bacteria: More sensitive
A
S. areus
1. Glycolipids
2. Glycoproteins
3. Peptidoglycan
4. Membrane
14
Q
Lysozome Effects on Bacteria
A
- Loss of structural support of the plasma membrane
- More susceptible to osmotic stresses
- Loss of physical barrier
15
Q
Metal Ion Chelators
A
- Lactoferrin (Fe3+)
- Calprotectin (Ca2+)
- Psoriasin (Ca2+)
