IA. General Microbiology | 16. Non-toxic virulence factors of bacteria. Flashcards
What are Non-toxic virulence factors?
substances on the surface and extracellular enzymes
I. Surface structures
1. What are the surface structures acting asNon-toxic virulence factors?
- Capsule
- Pili, fimbriae (e.g. E. coli)
- Adhesins (e.g. B. pertussis)
- F protein (fibronectin binding, S. pyogenes)
- Protein A (IgG binding, S. aureus)
- Lipoteichoic acid (S. pyogenes)
- Invasins (provoked phagocytosis, e.g. Listeria)
I. Surface structures
2. What is the role of surface structures?
help in adhesion, mimicri, and avoid phagocytosis
I. Surface structures
3A. What are the features of capsule as non-toxic virulence factor?
Capsule → provides physical protection
- Helpful in avoiding phagocytosis, mechanical
defense, attachment to surfaces
- Made of polysaccharides, except in B. anthracis (poly-D-glutamic acid) and S.pyogenes (hyaluronic acid)
- Seen in: H. influenzae, Streptococcus pneumonia, Str. agalactiae, Neisseria meningitidis, E.coli, Bacillus anthracis
I. Surface structures
3B. What is the capsule made of?
Made of polusaccharides, except in B. anthracis (poly-D-glutamic acid) and S.pyogenes (hyaluronic acid)
I. Surface structures
3C. Where can you see capsule?
Seen in: H. influenzae, Streptococcus pneumonia, Str. agalactiae, Neisseria meningitidis, E.coli, Bacillus anthracis
I. Surface structures
4. Give example(s) of bacteria that have Pili, fimbriae
E. coli
I. Surface structures
5. Give example(s) of bacteria that have Adhesins
B. pertussis
I. Surface structures
6. Give example(s) of bacteria that have F protein
fibronectin binding, S. pyogenes
I. Surface structures
7. Give example(s) of bacteria that have Protein A
IgG binding, S. aureus
I. Surface structures
8. Give example(s) of bacteria that have Lipoteichoic acid
S. pyogenes
I. Surface structures
9. Give example(s) of bacteria that have Invasins
provoked phagocytosis, e.g. Listeria
II. Enzymes
1. What is the role of enzymes as non-toxic virulence factor?
- For invasion and degradation
- To avoid host defense (antiphagocytic)
II. Enzymes
2. What are the enzymes participating in invasion and degradation?
- Hyaluronidase, collagenase (penetrate deeper into skin), elastase, phospholipase, fibrinolysin
- Proteases, DNAse, RNAse, streptodornase, lecithinase, hemolysins
II. Enzymes
3. What are the enzymes participating in avoiding host defense (antiphagocytic)?
- Coagulase, IgA protease, leukocidin (can lyse leukocytes)