Controlling Microbial Growth in the Body: Antimicrobial Drugs

Question 1

Suffix common for the aminoglycosides class?

Answer 1

-mycin

Question 2

Define ESBL

Answer 2

Extended-spectrum beta-lactamases

Question 3

Define how inactivation of the drug works

Answer 3

microbe produces enzymes that break down drug i.e. beta-lactamase

Question 4

What are the key side effects of quinolones and fluoroquinolones?

Answer 4

photosensitivity, hallucinations, and suppresses cartilage development in children

Question 5

Give examples of beta-lactam drugs and beta-lactamase inhibitors.

Answer 5

beta-lactam drugs- penicillins, monobactams, cephalosporins, and carbapenems
inhibitors- sulbactam and clauvulanate

Question 6

Define MRSA

Answer 6

Methicillin-resistant staph aureus, must use vancomycin to treat

Question 7

inhibition of protein synthesis drugs

Answer 7

aminoglycosides and macrolides: end in -cin
tetracyclines: end in -line
streptogramins: synercid
other: chloramphenicol

Question 8

Which 2 types of microorganisms produce most antibiotics?

Answer 8

bacteria (streptomyces and cephalosporin) and fungi (penicillium and cephlosporins)

Question 9

How is E test different from Kirby-Bauer?

Answer 9

E test, a strip with varying levels of drug concentrations is placed on a lawn. Where the ellipse connects with the test strip concentration is the MIC.

Question 10

Which class of antimicrobial is doxycycline?

Answer 10

tertacyclines

Question 11

Why are sulfonamides not antibiotics?

Answer 11

they are synthetic

Question 12

Describe how increase in elimination of the drug works

Answer 12

mutations cause increase in efflux pumps which pump drug out i.e. quinolone resistance

Question 13

Describe 2 ways that you could obtain an MIC. What does MIC stand for?

Answer 13

E test and broth dilution
minimum inhibitory concentration

Question 14

What was the first antibiotic discovered? By whom? How?

Answer 14

Penicillin, Fleming, staph did not grow around penicillin in plate

Question 15

What are the key side effects of tetracyclines?

Answer 15

discolors teeth of children and fetus, affects long bone development, not indicated for pregnancy

Question 16

Describe how decrease in uptake of the drug works

Answer 16

Porins on gram-negative bacteria close

Question 17

injury to the plasma membrane drugs

Answer 17

polypeptide: bacitracin and polymixin B

Question 18

What type of enzyme destroys specifically the beta-lactam ring of cephalosporins?

Answer 18

cephalosporinase

Question 19

Define broad spectrum antibiotics

Answer 19

work against a large variety of bacteria

Question 20

Define how alteration of the target works

Answer 20

the cellular target of the drug is changed in some way. i.e. Penicillin binding proteins changing

Question 21

Define CRE

Answer 21

carbapenem resistant enterobacteriaceae

Question 22

inhibition of folic acid synthesis drugs

Answer 22

sulfonamides: begin with sulfa
trimethoprim

Question 23

What are three representative macrolides?

Answer 23

erythromycin
clarithromycin
azithromycin

Question 24

Define bactericidal

Answer 24

kills bacteria

Question 25

Suffix common for the macrolides class?

Answer 25

-mycin

Question 26

Why are clavulanate and sulbactam used in combination with some drugs? what do they inhibit?

Answer 26

They are beta-lactamase inhibitors

Question 27

inhibition of nucleic acid synthesis drugs

Answer 27

rifamycin: rifampin quinolones: end in acid or floxacin

Question 28

Define MIC and MBC.

Answer 28

MIC- minimum inhibitory concentration MBC- minimum bacteriocidal concentration

Question 29

Define VRE

Answer 29

vancomyocin resesitant enterococci

Question 30

Define MDR-TB

Answer 30

multidrug resistant TB

Question 31

What are the key side effects of rifampin?

Answer 31

reddish brown secretions

Question 32

Suffix common for the carbapenems class?

Answer 32

-penem

Question 33

Describe how the disk-diffusion method of antimicrobial susceptibility testing (Kirby-Bauer) is performed. What does the zone of inhibition indicate?

Answer 33

Smal disks of multiple drugs of a known amount are placed on the plate to test for susceptibility. Zone indicates how effective the drug is.

Question 34

Which class of antimicrobial is gentamicin?

Answer 34

aminoglycosides

Question 35

What are some advantages of the broth dilution method?

Answer 35

Both MIC and MBC can be directly observed in one set of dilutions. Can be miniaturized to test many drugs.

Question 36

Describe the modes of action of anti-viral drugs and be familiar with the examples given.

Answer 36

attachement antogonists: -arildones (pleconaril) and -neuraminidase inhibitors (tamiflu) inhibition of nucleic acid synthesis: acyclovir for herpes ribavirin for Hep C base analogs in AZT reverse transcriptase inhibitor

Question 37

Which four main classes of antimicrobics contain a Beta-lactam ring("garage")? Which type of enzyme, in general, destroys this ring?

Answer 37

penicillins, monobactams, cephalosporins, and carbapenems. beta-lactamase

Question 38

Define bacteriostatic

Answer 38

inhibits the growth of bacteria

Question 39

Suffix common for the penicillin class?

Answer 39

-cillin

Question 40

Which class of antimicrobial is vancomycin?

Answer 40

glycopeptide, inhibition of cell wall synthesis

Question 41

Suffix common for the quinolones and fluroquinolones class?

Answer 41

acid or -floxacin

Question 42

Define synergism and give an example.

Answer 42

two drugs that work together at a greater level. bactrim (sulfonamide and trimethoprim)

Question 43

Describe the modes of action of anti-fungal drugs and know examples given.

Answer 43

bind to ergosterol in cell membrane: polyenes, nyastatin and amphotericin B Inhibit synthesis of ergosterol: -azoles (clotrimazole and miconazaole) and allyamines (terbafine) interfere with mitosis (griseofulum) interfere with DNA synthesis (5-flucytosine)

Question 44

Why is it more difficult to develop antimicrobial agents that work against fungi, protozoa, and helminths (eukaryotic microbes)? and viruses? (obligate intracellular parasites).

Answer 44

More difficult because they are either similar to our own cells or rely on our cells

Question 45

inhibition of cell wall synthesis drugs

Answer 45

penicillins: end in -cilin cephalosporins: start with ce- monobactams: end in -nam carbapenems: end in -em polypeptides: bacitracin glycopeptide: vancomycin

Question 46

What are the key side effects of chloramphenicol?

Answer 46

suppresses RBC production, aplastic anemia

Question 47

Define VISA

Answer 47

vancomycin intermediate staph aureus