Lecture 6 Microbial Control and Resistance

Question 1

What are mechanisms in which AMR occurs?

Answer 1

1. preventing access to the target of the antibiotic
2. degrading antibiotic
   3.altering antibiotic
3. rapid extruding of ab, efflux pump

Question 2

Why and how does Antimicrobial resistance occur?

Answer 2

by mutation from the spreading due to horizontal gene transfer

occurs due to misuse and overuse of antibiotics

Question 3

What antibiotics inhibit cell wall synthesis?

Answer 3

pennicilin

b-lactam ring
amino acid

inhibit cell wall synthesis by binding to

bacteriocidal

Question 4

Which AB inhibit protein synthesis?

Answer 4

Glycoaminosides
- amino
-sugar group

bind to 30 s sub unit and cause mRNA misreading, inhibiting protein synthesis

Tetraldehyde
-4 cyclic carbon rings

bind to 50S sub unit inhibiting protein syn

Question 5

Which AB inhibit metabolic pathways?

Answer 5

Sulfa drugs
imitate paba, fight for active site and inhibit folic acid synthesis. high selectivity, can create own folate and cannot obtain co factor from environment

trimethoprim
fight dhfa active site, looks like dha, also prevents folic acid production but at later step

these 2 ab can work together for synergistic drug interaction.

Question 6

Useful traits for AB

Answer 6

1. chemically stable
2. non allergenic
3. selective toxicity
4. water soluble
5. affordable
6. natural, semi, synthetic

Question 7

Ab therapeutic index

Answer 7

want the therapeutic index to be high. high toxicity dose, but low amount needed.

toxic dose/therapeutic dose

if it’s high it means it safe to use. if its low that means it has a narrow spectrum, meaning the therapeutic range is close to toxic.