General Microbiology Flashcards
Normal flora of gingival crevices
Anaerobes: bacteroides, Prevetella, Fusobacterium, Strep & Actinomyyes
Adherence mechanisms contributing to pathogenicity
- Pili/fimbrae (most Gram -)
- Teichoic Acids (Gram +)
- Adhesins (pertussis toxin, hemagglutinin)
- IgA Proteases
Exotoxin
Gram + & Gram -
Can be modified to produce toxoid that is still immunogenic–>can be used for vaccine
A-B component
- B component Binds cell recepter—> internalization of A
- A component is Active (toxic)
Normal flora of the vagina
Lactobacillus
Endotoxins
Gram -
LPS=Lipopolysaccharide
Toxic portion is Lipid A
Heat stable, not immunogenic, cannot be converted to a toxoid=no vaccine
MOA: overactivated the immune system
- activated Macrophages–> TNF-a, IL-1 (fever), IL-6
- bradykinin induced vasodilation
Normal Flora of Skin
Staph. epidermidis
Normal Flora of colon (babies & adult)
Babies that are breast fed: Bifidobacterium
Adults: Bacteroides/Provetella, E. coli, Bifidobacterium
What nutritional function does your normal floral have?
Synthesizing K & B Vitamins
Normal flora of your nose
Staph aureus
Normal flora of your orppharynx
Viridians strep (including Strep Mutans)
Strep mutans secretes a biofil that glues it and other oral flora to teeth–>dental plaque
Mechanisms for avoiding host cell destruction
Antiphagocytic surface components
- S. pyogenes- M Protein
- N. gonorrhea- Pili
- S. aureus- A Protein
IgA protease- Nesseria, Haemophilus, S. pneumo
Types of Exotoxins
- Inhibitors of protein synthesis ( inactivation of eEF2 or interference w/ ribosomes): diptheria, exotoxin A (P. aeruginosa), shiga toxin, verotoxin
- Neurotoxins: tetanus toxin, botulinum toxin
- Super-antigens: TSST-1, Exotoxin A ( S. pyogens)
- cAMP inducers (activated AC or ADP ribosylates): heat labile toxin, cholera toxin, antrax toxin, pertussis toxin
- Cytolysins (lyse cells from outside): C. perfringens Alpha toxin, S. aureus Alpha toxin
