Antibiotic resistance

Question 1

organism is considered resistant when

Answer 1

it is unlikely to respond to attainable levels of that drug in tissues

Question 2

types of resistance

Answer 2

inherent/intrinsic, acquired

Question 3

what type of bacteria is always resistant to aminoglycosides

Answer 3

streptococci

Question 4

what type of bacteria is always resistant to vancomycin

Answer 4

gram negative

Question 5

acquired resistance

Answer 5

may be present in some strains but not others, lab sensitivity testing is required to establish this

Question 6

ways of resistance being acquired

Answer 6

spontaneous mutation, spread of resistance by plasmids or transposons

Question 7

beta lactase production

Answer 7

bacterial enzymes that cleave the beta lactic ring of the antibiotic (penicillin) and render it inactive. staphylococcus aureus produce beta lactamase

Question 8

ways to combat b lactamase

Answer 8

combine two drugs eg co-amoxiclav, introduce a second component to antibiotic as an inhibitor of beta lactamase eg fluclocacillin

Question 9

extended spectrum b lactamases

Answer 9

enzymes that mediate resistance to extended spectrum cephalosporins

Question 10

alteration of PBP target site

Answer 10

mutations in PBP genes result in a modified target site to which B lactates will no longer bind. example- MRSA

Question 11

PBP target site alteration can be treated with

Answer 11

vancomycin, linezolid, flucloxacilin (not for MRSA)

Question 12

recent resistance problems

Answer 12

vancomycin restart enterococci have emerged. peptidoglycan precursor to which vancomycin normally binds has an altered site