Actions of Antibiotics

Question 1

Antimicrobial Agents can interfere with?

Answer 1

Cell wall synthesis, protein (ribosomes) synthesis, nucleic acid synthesis, plasma membrane integrity, folate synthesis and more

Question 2

Antibiotics of cell wall synthesis are

Answer 2

Beta Lactams, Vancomycin (glycopeptides) , Fosfomycin and Daptomycin

Question 3

What are the 4 classes of Beta Lactams?

Answer 3

Penicillin, Cephalosporin, Carbapenems, and Monobactams

Question 4

Antibiotics of cell membrane synthesis are

Answer 4

polymyxins, Bacitracin, Daptomycin, anti-fungals and Colistin (last resort antibiotic for gram negative organisms)

Question 5

Antibiotics of protein synthesis are

Answer 5

Tetracyclines, aminoglycosides, macrolides,lincosamides (clindamycin), linezolid, chloramphenicol, streptogramins

Question 6

Antibiotics of nucleic acid synthesis are

Answer 6

Quinolones and Metronidazole (DNA gyrase), and Rifampin and Bacitracin and Mupirocin (RNA polymerase)

Question 7

Antibiotics of Folate synthesis and that interfere with Metbolic pathways are

Answer 7

Sulfonamides, Trimethoprim; used in combination, Trimethoprim and Sulfomethoxazole (Bactrim)

Question 8

what do we know about beta lactam antibiotics

Answer 8

they are the most commonly prescribed drugs; all have the beta lactam ring. they are non-toxic and relatively cheap

Question 9

how many classes of penicillin are there?

Answer 9

Six classes of penicillin

Question 10

how many generations of cephalosporins?

Answer 10

4 generations of cephalosporin

Question 11

what are penicillin binding proteins?

Answer 11

PBPs are enzymes that catalyze the final cross linking reactions of peptidoglycan synthesis; used to identify MRSA

Question 12

how do the B-lactam antibiotics work?

Answer 12

antibiotics bind to the transpeptidase enzyme that cross links the peptidoglycan strands. irreversibly inhibits the transpeptidase enzyme bacterial cell wall synthesis is inhibited

Question 13

what do we know about the carbapenems?

Answer 13

these are beta-Lactam antibiotics which have a broad spectrum of action, they are a more advanced form of beta-Lactams and are highly resistant to enzymes

Question 14

how do glycopeptides work?

Answer 14

they will bind to the D-alanly-Dalanine residue, PBPs can no longer bind to these residues since it is blocked. Vancomycin is the main example, it is effective only against gram positive organisms

Question 15

what do we know about tetracylclines?

Answer 15

broad spectrum antibiotic, resistance to this antibiotic is common so use is limited

Question 16

how do we manage the patient when giving aminoglycoside drugs?

Answer 16

they are given aminoglycosides and have to be monitored, are renal and oto-toxic at high doses

Question 17

antibiotics of inhibition of membrane synthesis

Answer 17

polymyxin B, Colistin and Daptomycin

Question 18

antibiotics that inhibit the folate pathway

Answer 18

sulfonamides, Trimethoprim, Trimethoprim/Sulfamethoxazole, Dapsome (bactericidal)

Question 19

why does folate make a good selective target?

Answer 19

it does because folic acid is essential to synthesize adenine and thymine, and humans do not synthesize it.

Question 20

antibiotics of inhibition of nucleic acid synthesis

Answer 20

fluoroquinolones, rifampin and bacitracin

Question 21

empiric therapy

Answer 21

is useful for deciding what organism a person might be most susceptible to, and figuring out what antibiotic could handle that organisms