Antibiotics

Question 1

Antimicrobials can be…

Answer 1

• Narrow spectrum (NS): Affect only a certain type of microbe
• Broad spectrum (BS): Affect a broad range of microbes

Question 2

Antimicrobials can act by…(5)

Answer 2

1. Inhibiting cell wall synthesis
2. Inhibiting protein synthesis
3. Inhibiting nucleic acid replication and transcription
4. Injuring the plasma membrane
5. Inhibiting synthesis of essential metabolites

Question 3

Antimicrobial that disrupts cell wall synthesis

Answer 3

Penicillin (beta-lactam ring core): Prevents cross-linking of peptidoglycan

Question 4

Antimicrobials that inhibit protein synthesis (3)

Answer 4

Erythromycin, Azithromycin, Tetracyclines

Question 5

Antimicrobials that inhibit nucleic acid replication and transcription (2)

Answer 5

Quinolones, Ciprofloxacin

Question 6

Antibiotic Resistance Mechanisms (4)

Answer 6

1. Blocks entry to cell
2. Inactivating enzymes (e.g. beta-lactamases)
3. Alteration of target molecule (no binding)
4. Efflux (removal) of antibiotic

Question 7

Factors Contributing to Antibiotic Resistance

Answer 7

1. Mutation
2. Resistance genes transferred on plasmids or transposons
3. Misuse of antibiotics