Mechanisms of antimicrobial resistance

Question 1

B-lactams

Answer 1

hydrolysis

mutant PBP

Question 2

Tetracycline

Answer 2

Active efflux from the cell

Question 3

Aminoglycosides

Answer 3

Inactivation by enzymes

Question 4

Sulfonamides

Answer 4

Overproduction of target

Question 5

Fluoroquinolones

Answer 5

Mutant DNA gyrase

Question 6

Chloramphenicol

Answer 6

Reduced uptake into cell

Question 7

Vancomycin

Answer 7

reporgramming of D-ala-D-ala

Question 8

Quinupristin/dalfopristin

Answer 8

ribosomal methylation

Question 9

Macrolides erythromycin

Answer 9

RNA methylation

drug efflux

Question 10

When combined with the beta-lactamase inhibitor tazobactam, this penicillin possesses the broades antibacterial spectrum among its kind

Answer 10

Piperacillin

Question 11

A 28 year old Caucasian male with cystic fibrosis developed Pseudomonas aeruginosa pneumonia. Sensitivity studies showed resistance to levofloxacin. Which of the following drug resistance mechanisms is responsible for this ?

Answer 11

alterations in the target enzymes (DNA gyrase and topoisomerase IV) and of changes in drug entry and efflux

Question 12

Tetracycline resistance in gram + and gram - bacteria

Answer 12

active efflux of antimicrobial agent

Question 13

Fluconaole resistance in candida spp

Answer 13

active efflux of antimicrobial agent

Question 14

Resistance to multiple antibiotic classes in Pseudomonas aeuruginosa

Answer 14

Impermeability

Question 15

Glycopeptide resistance in S. aureus

Answer 15

Impermeability

Question 16

Aminoglycoside resistance in strict anaerobes

Answer 16

Impermeability - uptake requires O2 dependent transportern system

Question 17

Aminoglycoside resistance in streptococci

Answer 17

Impermeability

Question 18

meticillin/flucloxacillin, resistance in MRSA

Answer 18

Altered penicillin -binding protein

Question 19

S. pneumoniae and Neisseria meningitidis resistance in penicillin

Answer 19

Altered penicillin -binding protein

Question 20

glyopeptide resistant Enterococci

Answer 20

Altered peptidolgycan

Question 21

Rifampicin resistance in Mycobacterium tuberculosis

Answer 21

RNA polymerase mutation

Question 22

Ciprofloxacin resistance in enterobacteriacea

Answer 22

DNA gyrase mutation

Question 23

Resistance to protein synthesis inhibitors (macrolides, lincosamides, aminoglycosides, rifampicin, linezolid)

Answer 23

ribosomal protein gene mutations

Question 24

trimethoprim resistance is due to

Answer 24

dihydrofolate reducatase mutations

Question 25

Echinocandin resistance in cryptococcus spp.

Answer 25

Absence of antimicrobial target

Question 26

trimethoprim resistance is due to

Answer 26

Overproducion of dihydrofolate reductase

Question 27

resistance of Staph aureus to penicilllin

Answer 27

penicillinase - degradation of antimicrobial agent

Question 28

Enterobacteriaceae

Answer 28

enzymatic degradation of antimicrobial agent extended spectrum beta lactamase producing enterobacteriaceae AmpC Beta lactamases (cephalsporinases) enterobacteriaceae