Overview and mechanisms of classes of antimicrobial agents

Question 1

Which antibiotics act on cell wall synthesis

Answer 1

Beta lactams (e.g. pellicilins, cephalosporins, carbapenems)

Glycopeptide antibiotics e.g. Vancomycin

Question 2

Which antibiotics act on cell membrane

Answer 2

Polymyxins

Question 3

Which antibiotics act on the 30s subunit

Answer 3

Tetracyclines

Aminoglycosides

Question 4

Which antibiotics acts on 50s subunit

Answer 4

Macrolides

Clindomycin

Question 5

Which antibiotics acts on nucleic acid synthesis

Answer 5

Quinolose (act on DNA gyrase)

Rifampin- act on RNA polymerase

Question 6

Which antibiotics act on folate synthesis

Answer 6

Sulfonamides

trimethoprim

Question 7

What is the mode of action of beta lactams

Answer 7

Bind to and inhibit penicillin binding proteins

PBPs have a role in cross linking the peptidoglycan layer of cell wall

Inhibition of this process leads to weakening and rupture of the cell wall

Question 8

What do beta lactase inhibitors do

Answer 8

Given in conjunction with beta lactam antibiotics. Some bacteria produce b lactase which destroys beta lactam ring. beta lactamase inhibitors protect beta lactam from destruction

Question 9

What are protein synthesis inhibitors

Answer 9

MAcrolides e.g. erythromycin

Tetracyclines e.g. doxycycline

Aminoglycosides e.g. Gentamicin