Bacteriology - Antibiotics

Question 1

Name the drug(s) whose mechanism of action is described below:

Binds penicillin-binding proteins →inhibits transpeptidase → blocks cell wall synthesis; also releases autolytic enzymes (bactericidal)

Answer 1

β-Lactam antibiotics (penicillin, cephalosporins, cephalomycins, carbapenems, and monobactams)

Question 2

Name the drug(s) whose mechanism of action is described below:

Forms reactive cytotoxic metabolites inside cell

Answer 2

Metronidazole

Question 3

Name the drug(s) whose mechanism of action is described below:

Binds and inactivate β-lactamase → protects antibiotic

Answer 3

β-Lactamase inhibitors

Question 4

Name the drug(s) whose mechanism of action is described below:

Inhibits 50S peptidyl transferase

Answer 4

Chloramphenicol

Question 5

Name the drug(s) whose mechanism of action is described below:

Blocks entry of aa-tRNA to 305 ribosomal complex

Answer 5

Tetracyclines

Question 6

Name the drug(s) whose mechanism of action is described below:

Blocks transpeptidation of D-ala Inhibits dihydrof olate reductase

Answer 6

Vancomycin

Question 7

Name the drug(s) whose mechanism of action is described below:

Inhibits dihydrofolate reductase

Answer 7

Trimethoprim (TMP)

Question 8

Name the drug(s) whose mechanism of action is described below:

Para-aminobenzoic acid (PABA) antimetabolites →↓ dihydropteroate synthase

Answer 8

Sulfonamides

Question 9

Name the drug(s) whose mechanism of action is described below:

Binds to 30S subunit → block formation of 70S initiation complex → misreading of mRNA

Answer 9

Aminoglycosides

Question 10

Name the drug(s) whose mechanism of action is described below:

Binds to 50S subunit → inhibit translocase

Answer 10

Macrolides (erythromycin and azithromycin)

Question 11

Name the drug(s) whose mechanism of action is described below:

Blocks DNA topoisomerase (gyrase)

Answer 11

Quinolones (ciprofloxacin and levofloxacin)

Question 12

Name the drug(s) whose mechanism of action is described below:

Blocks 50S peptide bond formation

Answer 12

Clindamycin

Question 13

Name the drug(s) whose mechanism of action is described below:

Inhibits DNA-dependent RNA polymerase

Answer 13

Rifampin

Question 14

Name the drug(s) whose mechanism of action is described below:

Interferes with mycolic acid synthesis

Answer 14

INH

Question 15

Name the drug(s) whose mechanism of action is described below:

Bind to bacterial/fungal cell membranes → disrupt osmotic properties

Answer 15

Polymyxins

Question 16

Name the drug(s) whose mechanism of action is described below:

PABA antagonist → blocks purine synthesis

Answer 16

Sulfones (dapsone and sulfoxone)

Question 17

Name the antibacterial drug(s) associated with each of the following unique toxicities:

Kernicterus in infants

Answer 17

Sulfonamides and ceftriaxone

Question 18

Name the antibacterial drug(s) associated with each of the following unique toxicities:

Interstitial nephritis

Answer 18

Penicillins

Question 19

Name the antibacterial drug(s) associated with each of the following unique toxicities:

Disulfiram-like reactions

Answer 19

Metronidazole, second-generation cephalosporins

Question 20

Name the antibacterial drug(s) associated with each of the following unique toxicities:

Photosensitivity rash

Answer 20

Doxycycline

Question 21

Name the antibacterial drug(s) associated with each of the following unique toxicities:

Gray baby syndrome

Answer 21

Chloramphenicol

Question 22

Name the antibacterial drug(s) associated with each of the following unique toxicities:

Megaloblastic anemia

Answer 22

IMP

Question 23

Name the antibacterial drug(s) associated with each of the following unique toxicities:

Hemolytic anemia in G6PD-def icient patient

Answer 23

Sulfonamides, chloramphenicol, nitrofurantoin, and INH

Question 24

Name the antibacterial drug(s) associated with each of the following unique toxicities:

Hepatotoxicity, vitamin B6 deficiency, lupuslike syndrome

Answer 24

INH (Note: ↑ t1/2 in slow acetylators)

Question 25

Name the antibacterial drug(s) associated with each of the following unique toxicities: Pseudomembranous colitis

Answer 25

Clindamycin (most common)

Question 26

Name the antibacterial drug(s) associated with each of the following unique toxicities: Fanconi syndrome

Answer 26

Tetracycline (ingestion of expired drug)

Question 27

Name the antibacterial drug(s) associated with each of the following unique toxicities: Ototoxicity and nephrotoxicity

Answer 27

Aminoglycosides

Question 28

Name the antibacterial drug(s) associated with each of the following unique toxicities: Red, pruritic rash on torso with rapid IV infusion (red man syndrome)

Answer 28

Vancomycin

Question 29

Name the antibacterial drug(s) associated with each of the following unique toxicities: Reversible cholestatic hepatitis; ↑ GI motility

Answer 29

Erythromycin

Question 30

Name the antibacterial drug(s) associated with each of the following unique toxicities: Achilles tendonitis; cartilage damage in laboratory animals

Answer 30

Fluoroquinolones

Question 31

Name the antibacterial drug(s) associated with each of the following unique toxicities: Red-orange discoloration of bodily secretions

Answer 31

Rifampin

Question 32

Name the antibacterial drug(s) associated with each of the following unique toxicities: Discolors teeth; suppresses bone growth in kids

Answer 32

Tetracycline

Question 33

Name the antibacterial drug(s) associated with each of the following unique toxicities: Aplastic anemia (dose independent)

Answer 33

Chloramphenicol

Question 34

Name the antibacterial drug(s) associated with each of the following unique toxicities: Neurotoxicity and nephrotoxicity

Answer 34

Polymyxins

Question 35

Name six uses for metronidazole:

Answer 35

1. Giardia 2. Entamoeba 3. Trichomonas 4. Gardnerella vaginalis 5. Anaerobes (C. difficile, bacteroides) 6. Helicobacter pylori (part of triple therapy)

Question 36

Which drug is used as solo prophylaxis for TB?

Answer 36

INH

Question 37

How do organisms develop resistance against vancomycin?

Answer 37

D-lac (or D-ser) replaces terminal D-ala in cell wall → ↓ affinity of vancomycin for cell wall

Question 38

Name the drug(s) whose mechanism of action is described below: Binds penicillin-binding proteins →inhibits transpeptidase → blocks cell wall synthesis; also releases autolytic enzymes (bactericidal)

Answer 38

β-Lactam antibiotics (penicillin, cephalosporins, cephalomycins, carbapenems, and monobactams)