07_Antibiotics Chart_E18 and E19_Spencer - Sheet1

Question 1

Trimethoprim resistance

Answer 1

Plasmid-coded, trimethoprim-resistant dihydrofolate reductase.

Question 2

Penicillins resistance

Answer 2

Hydrolysis of ß-lactam ring by ß-lactamase enzyme; decreased Cephalosporins permeability of bacteria to the antibiotic; altered penicillin binding proteins.

Question 3

Methicillin resistance

Answer 3

Altered penicillin binding proteins (not in ß-lactamase). (a ß-lactamase-resistant penicillin).

Question 4

Aminoglycosides resistance

Answer 4

Enzymatic modification of drug by plasmid-coded enzyme; decreased permeability of bacteria to the antibiotic; mutation alters site to which antibiotic normally binds (e.g. S12 ribosomal protein for streptomycin).

Question 5

Tetracyclines resistance

Answer 5

Interference with transport of drug into cell.

Question 6

Chloramphenicol resistance

Answer 6

Detoxification of drug by acetylation of hydroxyl.

Question 7

Erythromycin resistance

Answer 7

Enzymatic methylation of 23S ribosomal RNA.

Question 8

Ciprofloxacin & Rifampin resistance

Answer 8

Altered target enzymes (gyrase, RNAP)

Question 9

Vancomycin resistance

Answer 9

Alteration of cell wall precursor target.

Question 11

Antimetabolites (sulfonamides, trimethoprim)

Answer 11

Inhibit synthesis of dihydrofolate, ultimately nucleic acid synthesis.

Question 12

Antimetabolite flucytosine

Answer 12

inhibits thmidylate synthetase and ultimately DNA synthesis

Question 13

Isoniazid

Answer 13

Inhibits synthesis of mycolic acid (specific for Mycobacteria)

Question 14

b-Lactams, penicillins, cephalosporins

Answer 14

Interfere with cell wall biosynthesis. Inhibition of transpeptidation weakens cell wall. Autolytic enzymes of bacteria then promote lysis.

Question 15

Cycloserine, bacitracin, glycopeptides, vancomycin, teichoplanin, caspofungin

Answer 15

Interfere with cell wall biosynthesis.

Question 16

Polymyxins, polyenes, nystatin, amphotericin B, daptomycin

Answer 16

Disrupt membrane integrity.

Question 17

Aminoglycosides (streptomycin)

Answer 17

Inhibit protein synthesis by binding to a specific protein of 30S ribosomal subunit.

Question 18

Aminoglycosides (gentamicin, kanamycin, neomycin, amikacin, tobramycin)

Answer 18

Bind to 30S ribosomal subunit at multiple sites. Inhibit protein synthesis.

Question 19

Tetracyclines

Answer 19

Block protein synthesis by inhibiting binding of amino-acyl t-RNA to 30S subunit.

Question 20

Erythromycin, azithromycin, clindamycin, chloramphenicol

Answer 20

Bind to 50S ribosomal subunit. Inhibit protein synthesis at chain elongation step.

Question 21

Oxazolidinones (linezolid)

Answer 21

Bind rRNA on both ribosomal subunits (new)

Question 22

Streptogramins (dalfopristin, quinupristin)

Answer 22

Bind to 50S ribosomal subunit (new)

Question 23

Mupirocin

Answer 23

Binds isoleucyl tRNA synthetase, preventing charging of Ile-tRNA and thus affecting protein synthesis.

Question 24

Fluoroquinolones (ciprofloxacin)

Answer 24

Inhibit bacterial DNA gyrase.

Question 25

Nitroimidazoles

Answer 25

Fragment DNA

Question 26

Rifampin

Answer 26

Binds to bacterial RNA polymerase and blocks transcription.

Question 27

Azoles (fluconazole, ketoconazole)

Answer 27

Inhibit ergosterol synthesis.

Question 28

Ethambutol

Answer 28

Unknown, anti-TB

Question 29

Pyrazinamide

Answer 29

Unknown, anti-TB