Unit 5abx

Question 1

chemically modified antibiotics, and chemically synthesized chemotherapeutic agents which inhibit or kill microorganisms

Answer 1

what is antimicrobial

Question 2

chemotherapeutic agents that either kill or inhibit the growth of microorganisms. naturally synthesized

Answer 2

what is antibiotic

Question 3

drugs used to treat infections, cancers and other diseases and conditions

Answer 3

what is chemotherapeutic

Question 4

define empirical treatment

Answer 4

assumed drug would work w/o actually testing to prove that it would

Question 5

list modes of action of antimicrobials used for bacterial infection

Answer 5

• cell wall synthesis inhibition
• inhibition of protein synthesis at the ribosomal level
• inhibition of DNA, RNA
• folate pathway competitive inhibition
• active against cell membrane

Question 6

list the characteristics of an ideal antimicrobial agent (“Magimycin”)

Answer 6

• bactericidal
• narrow-spectrum
• inexpensive
• non toxic, non irritating, non staining
• no sensitization
• high concentration of active form available in tissue
• taken orally but absorbed proximally
• no resistance

Question 7

features of beta-lactams

Answer 7

beta-lactam ring, bind to PBP in cell wall. bactericidal against gram POS

Question 8

penicillin features

Answer 8

beta-lactam. narrow spectrum (gram POS), cheap, effective. vulnerable to beta-lactamase

Question 9

beta-lactam. extended spectrum some gram POS. vulnerable to beta-lactamase

Answer 9

ampicillin

Question 10

beta-lactam.replace penicillin, inhibits beta-lactmase binding

Answer 10

oxacillin

Question 11

beta lactam: cephems (cephalosporins)

Answer 11

cefazolin, ceftazidime, cefoxitin, ceftaroline

Question 12

target binding site is d-ala d-ala in peptidoglycan

Answer 12

vancomycin

Question 13

narrow gram POS. toxic use topically. interferes with sterol synthesis

Answer 13

bacitracin

Question 14

modification of cephalosporins (cephems)

Answer 14

diff 2nd ring structure (6-membered dihydrothiazine) and 2 side chains

Question 15

how do generations relate to spectrum and resistance to beta-lactamases

Answer 15

gram POS coverage is lost and gram NEG gained. resistance to b-lactamases increases w/generation

Question 16

why is vancomycin effective against gram POS that have altered PBPs

Answer 16

no beta-lactam ring therefore not affected by b-lactamases and doesn’t bind to PBPs

Question 17

drugs for above the diaphragm anerobic infections

Answer 17

Class: lincosamide such as clindamycin

Question 18

drug for BELOW the diaphragm anerobic infections

Answer 18

metronidazole aka flagyl

Question 19

class of drugs unsuitable for anerobic infections and why

Answer 19

aminoglyside b/c cellular uptake is aerobic

Question 20

rationale for combo therapy amp and gentamicin

Answer 20

treat severe systemic infections, β-lactam

drug weakens cell wall allows greater uptake of the aminoglycoside

Question 21

rationale for combo therapy trimethoprim and sulphamethoxazole TMP-SMX

Answer 21

less adverse effects than sulphas. useful in UTI and respiratory

Question 22

specific drugs in MLS group- Macrolides

Answer 22

erythomycin, claithomycin, azithromycin, dirithromycin, c

Question 23

specific drugs in the MLS group Lincosamides

Answer 23

clindamycin

Question 24

specific drugs in the MLS group Streptogramin

Answer 24

Quinupristin - dalfopristin (Synercid)

Question 25

why nitrofurantoin is useful for bladder infections but not kidney infections

Answer 25

high bactericidal levels are

achieved in urine but may be undetectable in other sites

Question 26

why bacitracin and polymyxin B and E (colisitin) are used topically

Answer 26

nephrotoxic meaning interferes with sterol synthesis

Question 27

why polymyxins: considered drugs of “last resort”

Answer 27

disrupt our phospholipid acts like detergent

Question 28

why polymyxin E useful for ID as part of antibiogram

Answer 28

intrinsic resistance in the

Enterobacteriaceae family is rare and predictable as an identification aid