Antimicrobials

Question 1

Antimicrobial drug class that inhibits folate synthesis

Answer 1

Sulfonamides

Question 2

What are 3 classes of DNA damaging drugs?

Answer 2

Nitroimidazole, Nitrofurans, Fluoroquinolones

Question 3

What is an example of a cell membrane disruptor?

Answer 3

Daptomycin

Question 4

What drug is associated with inhibiting the synthesis of mycolic acid?

Answer 4

Isoniazid

Question 5

What is an example of an RNA Polymerase Inhibitor?

Answer 5

Rifampin/Rifampicin

Question 6

What is an example of a 1st line (for prophylaxis and initial active infection) cell wall synthesis inhibitor, which inhibits arabinotransferases?

Answer 6

Ethambutol

Question 7

What are 5 classes of B-lactams?

Answer 7

Penicillins, Monobactams, Carbapenems, Cephalosporins, Clavams

Question 8

What drugs do you combine with Clavulanic Acid?

Answer 8

Monobactams and Carbapenems

Question 9

How do Nitroimidazole work?

Answer 9

They damage bacterial DNA by oxidative mechanisms

Question 10

How do fluoroquinolones affect bacteria?

Answer 10

They inhibit topoisomerase IV, preventing newly replicated chromosomes from separating into daughter cells AND they inhibit DNA gyrase (topoisomerase II) during DNA replication inducing damage

Question 11

Are quinolones/fluoroquinolones bacteriostatics or bactericidals? And are they better at working with gram positive or gram negative bacteria?

Answer 11

Bactericidal; Gram negative

Question 12

What type of drug is trimethoprim (tmp) combined with, what enzyme does these two combined medications act on, and what process does this enzyme inhibit?

Answer 12

Trimethoprim is combined with sulfamethoxazole (smx)/sulfonamides; they work on the DHFR; DHFR helps create folate which is used to make DNA

Question 13

Explain how resistance to sulfonamides develop?

Answer 13

Altered Drug Targets occur (spontaneous mutations in DHPS gene, horizontal acquisition of alternate DHPS); Swamp the system (increased production of folate precursor PABA; Altered drug exposure (decreased uptake)

Question 14

Are sulfonamides bacteriostatic or bacteriocidal? What types of bacteria do they work on?

Answer 14

Bacteriostatic; active against gram positive and gram negative and some protozoa

Question 15

What enzyme do sulfonamides work on while alone

Answer 15

7,8-DHPS

Question 16

How do lipopeptide drugs act?

Answer 16

They disrupt the cell membrane of gram positive bacteria by forming pores in the cytoplasmic membrane. They bind to phosphatidyl glycerol, which is abundant in prokaryotes and not that many eukaryotic cells?

Question 17

Where might you find eukaryotic phosphatidyl glycerol?

Answer 17

Found in the lung surfactant

Question 18

Give some examples of vancomycin resistance mechanisms

Answer 18

1. D-Ala-D-Ala target of glycoproteins is not encoded by a gene; 2. No known enzymes capable of inactivating glycopeptide antibiotics; 3. Vancomycin is primarily used to treat gram-positive infections; 4. Thus, the target is extracellular precluding altered drug uptate as a resistance mechanism

Question 19

What process do glycopeptides inhibit?

Answer 19

Transglycosylation of peptidoglycan; which links the sugar NAG and NAM residues together within the cell wall

Question 20

Give an example of glycopeptides

Answer 20

Vancomycin

Question 21

What are some examples of B-lactam drug resistances?

Answer 21

1. Alterations in porin preventing drugs from entering the cell; 2. Production of B-lactamases; 3. Alterations in PBPs

Question 22

How does Clavulanic acid work?

Answer 22

It inhibits the bacterial enzyme beta lactamase

Question 23

Give some examples of B-lactamases

Answer 23

1. Extended spectrum B-lactamases (ESBL)-Mostly derived from active site mutations in TEM/SHV and results in activity against extended-spectrum cephalosporins; 2. Metal-dependent (New Delhi Mettao-B-Lactamase)-NDM-1; there are more but these 2 are the highlighted ones

Question 24

How do B-lactamases work?

Answer 24

They cleave a bond in the B-lactam ring

Question 25

How do B-lactams work?

Answer 25

Overall, they inhibit transpeptidation of the dual D-alanine residues, which links the peptides to the NAMs in peptidoglycan. Beta-lactams are similar in structure to D-alanine and get inserted into the structure of peptidoglycan, therefore inhibiting cell wall peptidoglycan synthesis.

Question 26

What types of bacteria do B-lactams work on?

Answer 26

Gram positive mostly

Question 27

What are some classes of agents that interfere with the bacterial cell wall envelope?

Answer 27

1. B-lactams; 2. Glycopeptides; 3. Isoiazid; 4. Ethambutol; 5. Bacitracin; 6. Phospho(no)mycin; 7. Cycloserine; 8. Lipopeptides; 9. Polymyxins

Question 28

What drugs have minimal post-antibiotic effect?

Answer 28

Penicillins, cephalosporins, macrolides, clindamycin

Question 29

What drugs have longer post antibiotic effect?

Answer 29

Fluoroquinolones and Aminoglycosides

Question 30

What are some drugs with concentration dependent killing?

Answer 30

DNA inhibs: Fluoroquinolones; Protein inhibs: Aminoglycosides

Question 31

What are some drugs with time-dependent killing?

Answer 31

Wall inhibs: penicillins, cephalosporins; Protein inhibs: macrolides; clindamycin

Question 32

Drug class for penicillin?

Answer 32

B-lactams

Question 33

Drug class and subclass for azteronam?

Answer 33

B-lactams; monobactams

Question 34

Drug class and subclass for imipenem and meropenem?

Answer 34

B-lactams;carbapenems

Question 35

Drug class and sub class for nitrofuantoin?

Answer 35

DNA damaging drug; nitrofurans

Question 36

Drug class and subclass for ciprofloxacin, levofloxacin, moxifloxacin?

Answer 36

DNA damaging drugs; Fluoroquinolones

Question 37

Drug class and subclass for metronidazole?

Answer 37

DNA Damaging drugs; nitroimidazole