Antimicrobial Drugs & Drug Resistance

Question 1

What are antimicrobial drugs?

Answer 1

Compounds that kill or control the growth of microorganisms in the host

Question 2

What kind of toxicity do antimicrobial drugs have?

Answer 2

Selective

Question 3

What are the 2 broad categories of antimicrobial drugs?

Answer 3

Synthetic & natural

Question 4

What is meant when drugs are described as “synergistic”?

Answer 4

One drug is good, but two drugs are better

Question 5

What type of drugs disrupt eukaryotic cells more and why?

Answer 5

Drugs that disrupt plasma membranes because eukaryotic cells do not have a cell wall

Question 6

Which type of antimicrobial drugs are for external use only?

Answer 6

Ones that target cytoplasmic membrane structure and function

Question 7

What do antimicrobial drugs that target RNA elongation do?

Answer 7

Interfere with translation

Question 8

What is the difference between growth factors & growth factor analogs?

Answer 8

• Structurally similar

- Growth factors function in the cell, while growth factor analogs do not

Question 9

What do sulfa drugs do?

Answer 9

Inhibit growth of bacteria by inhibiting folic acid synthesis, thus inhibiting nucleic acid synthesis

Question 10

What do quinolones do?

Answer 10

Inhibit DNA gyrase, which prevents DNA supercoiling

Question 11

What type(s) of bacteria are quinolones active against?

Answer 11

Gram negatives & Gram positives

Question 12

What organisms produce antibiotics naturally?

Answer 12

Bacteria & fungi

Question 13

Less than 1% of known antibiotics are _______

Answer 13

Clinically useful

Question 14

What are semi-synthetic antibiotics?

Answer 14

Artificially modified natural antibiotics

Question 15

With respect to antibiotics, how do microbes differ?

Answer 15

The susceptibility of microbes to different antibiotics varies greatly

Question 16

What are the 2 types of antibiotics?

Answer 16

Broad-spectrum & narrow-spectrum

Question 17

What do broad-spectrum antibiotics do?

Answer 17

Target most of bacteria that it sees (no preference)

Question 18

When are broad-spectrum antibiotics given?

Answer 18

When a patient has an infection but the cause is unknown

Question 19

What is the disadvantage to broad-spectrum antibiotics?

Answer 19

Kill normal flora

Question 20

When are narrow-spectrum drugs given?

Answer 20

When the cause of the infection is known

Question 21

What is the advantage to narrow-spectrum drugs?

Answer 21

Preserve normal flora

Question 22

Define bacteriostatic

Answer 22

Interfere with growth of bacteria which keeps the number constant so immune system can kill the bacteria

Question 23

Define bacteriocidal

Answer 23

Destroys bacteria and eliminates threat entirely

Question 24

What are beta-lactam antibiotics?

Answer 24

Cell wall synthesis inhibitors

Question 25

What are 2 examples of beta-lactam antibiotics and what are their similarities & differences?

Answer 25

- Penicillins & cephalosporins - Similar mode of action (target cell wall) - Cephalosporins have a more broad spectrum than penicillins

Question 26

What is penicillin effective against?

Answer 26

Gram positive bacteria

Question 27

Who discovered penicillin?

Answer 27

Alexander Fleming

Question 28

What are cephalosporins resistant to?

Answer 28

Beta-lactamases

Question 29

What are cephalosporins commonly used to treat?

Answer 29

Gonorrhea

Question 30

What are aminoglycosides?

Answer 30

Amino sugars bonded by glycosidic linkages

Question 31

What do aminoglycosides target?

Answer 31

30S subunit of a ribosome

Question 32

What are examples of aminoglycosides?

Answer 32

Streptomycin, kanamycin, neomycin, & gentamicin

Question 33

What type of bacteria do aminoglycosides target?

Answer 33

Gram negatives

Question 34

Which antibiotics are considered "last resort antibiotics"?

Answer 34

Aminoglycosides

Question 35

What are macrolides & are they broad- or narrow-spectrum?

Answer 35

- Lactone rings bonded to sugars | - Broad-spectrum

Question 36

What do macrolides target and what does this lead to?

Answer 36

- 50S subunit of a ribosome | - Leads to partial inhibition of protein synthesis

Question 37

How are tetracyclines produced?

Answer 37

- Naturally by several species of Streptomyces | - Semi-synthetically

Question 38

Are tetracyclines broad- or narrow-spectrum?

Answer 38

Broad

Question 39

What do tetracyclines inhibit?

Answer 39

30S subunit of ribosome

Question 40

What are the 2 most widely used antibiotics?

Answer 40

Penicillins & tetracyclines

Question 41

What are 2 examples of novel antibiotics?

Answer 41

Daptomycin & platensimycin

Question 42

What is daptomycin?

Answer 42

Cyclic lipopeptide active against Gram positives

Question 43

What does daptomycin do?

Answer 43

Forms pore in cell membrane, which causes depolarization

Question 44

How is daptomycin produced?

Answer 44

By Streptomyces

Question 45

What is platensimycin?

Answer 45

Fatty acid biosynthesis inhibitor

Question 46

Is platensimycin broad- or narrow-spectrum?

Answer 46

Broad

Question 47

What is antimicrobial drug resistance?

Answer 47

Ability of a microorganism to resist the effects of an antimicrobial agent to which it is normally sensitive

Question 48

What are the 2 types of antimicrobial drug resistance?

Answer 48

Chromosomal & plasmid-encoded

Question 49

What are 5 mechanisms of antimicrobial drug resistance?

Answer 49

1) Reduced permeability 2) Inactivation of antibiotic 3) Alternation of target 4) Development of resistant biochemical pathway 5) Efflux

Question 50

How is reduced permeability used for antimicrobial drug resistance and what is an example of a drug that uses this?

Answer 50

- Keeps drug to exterior of bacterial cell | - Penicillin

Question 51

How is inactivation of the antibiotic used for antimicrobial drug resistance and what are examples of drugs that uses this?

Answer 51

- Enzyme cuts at vital area to reduce antimicrobial properties - Penicillins, chloramphenicol, aminoglycosides

Question 52

What are examples of drugs that uses alternation of target for antimicrobial drug resistance?

Answer 52

Erthromycin, streptomycin, norfloxacin

Question 53

What is an example of a drug that uses development of resistant biochemical pathways for antimicrobial drug resistance?

Answer 53

Sulfonamides

Question 54

How is efflux used for antimicrobial drug resistance and what is an example of a drug that uses this?

Answer 54

- Bacteria let drug inside, but pumps it to the exterior once it realizes that it is causing harm - Tetracyclines, chloramphenicol, fluoroquinolones

Question 55

What are 80% of antibiotics produced for?

Answer 55

Use in agricultural practices

Question 56

What does MRSA stand for?

Answer 56

Methicillin-resistant Staphylococcus aureus

Question 57

What does VRE stand for?

Answer 57

Vancomycin-resistant enterococci

Question 58

What are 4 methods for preventing antimicrobial resistance?

Answer 58

1) Prevention of infections 2) Rapid, conclusive diagnosis 3) Prudent use of antimicrobials 4) Prevention of transmission