What are Koch’s postulates?
- associated with the disease and characteristics
- isolate from diseased host and grown in culture
- reproduced with pure culture of organism and introduced into new healthy host
- same organism must be re-isolated from infected host
Steps for Gram stain
- heat dry sample on slide
- 1 min of crystal violet
- rinse gently with h2o
- 1 min iodine
- rinse gently with h2o
- add decolorizer quickly
- rinse with h2o
- add safranin for no more than 10 secs
- rinse with h2o and blot dry
How would your treat toxins from bacterial infections?
with anti-toxins
Exotoxins are?
cytolytic enzymes, receptor binding proteins
What do exotoxins do?
They alter cell functions or kill the cell
What are the three ways exotoxins affect the cell?
- hemolysis
- pore forming
- alpha toxin
The three membrane damaging toxins are?
- proteases
- phospholipases
- detergent like action
What symptoms do AB subunit toxins do to infected patients?
Diarrhea, loss of neural function, and possible death
How do AB toxins work?
The B promotes entry into the cell and A inhibits vital function of the cell.
What are the biochemical targets for AB toxins?
Ribosomes and transport cell signaling
Corynebacterium diphtheriae (C.diphtheriae) uses what kind of toxin?
AB toxin which
- inactivates elongation factor
- Prevents protein synth. by ribosome
- Cell death
C. diphtheriae inhibits what function in the cell?
protein synthesis
What are the 3 results due to AB toxin?
- Inhibition of protein
- Hyperactivation
- Effects on nerve-muscle transmission
Vibrio cholerae (V. cholerae) uses AB toxins. (Cholera toxin) How does the toxin affect the cell?
- increases adenylate cyclase activity
- increase in cAMP
- loss of cell nutrients
- diarrhea
Clostridium tetani ( C. tetani) produces the tetanus toxin. How does it affect the cell?
- Produces tetanospasmin
- tetanospasmin causes inhibitory transmitter release blocked
- continuous stimulation by excitatory transmitter
Clostridium botulinum ( C. botulinum) produces the botulism toxin. How does that toxin affect the cell?
- toxin blocks release of ACH from vesicles
2. stimulation blocked
