Antibiotic resistance

Question 1

what are the causes of antibiotic resistance

Answer 1

sensitive ones die but resistant ones dominant colonisation - subsequent endogenous infection more likely to be resistant

Question 2

what are the two types of resistance mechanisms

Answer 2

innate fundamental properties such as cell walls etc

and acquired - new gene or mutations horizontal transfer

Question 3

what antibiotic are these types of organisms resistant to
gram neg
gram pos
anaerobes and streptococci

Answer 3

neg - glycopeptides and daptomycin

pos - aztreonam and colistin

AS - ahminoglycosides

Question 4

what are the 5 specific types of antimicrobial resistance

Answer 4

absent target 
decreased permeability 
target modification 
enzymatic depredation 
drug efflux

Question 5

what is an examples of absent target in antibiotics

Answer 5

using an antibacterial against a fungus

Question 6

give two examples of deceased permeability in resistance

Answer 6

gram neg bacilli have outer cell membrane resistant to vancomycin

gentamicin won’t work on anaerobic organisms as require o2 transport mechanism

Question 7

give examples of target modification in antibiotic resistance

Answer 7

MRSA altered binding so B lactam wont bind such as flucoxacillin

VRE - altered peptide sequence means resistant to vancomycin

Question 8

give examples of enzymatic degradation of antibiotic resistance

Answer 8

staphylococcal penicillinase inactivates penicillin or cephalosporins

aminoglycoside modifying enzymes inhibit gentamicin

CAT inactivates chloramphenicol

Question 9

give examples of drug efflux in antibiotic resistance

Answer 9

gram neg pump drugs back out such as anti fungal triazoles and candida spp

Question 10

what are resistance genes encoded by

Answer 10

plasmids

Question 11

how are plasmids transferred in antibiotic resistance

Answer 11

horizontal - from plasmids to genome via intergrins - usually have multiple resistance genes

vertically - transferred to daughter cells in cell division

Question 12

define antibiotic era

Answer 12

era since the widespread availability of antibiotics to treat infection

Question 13

define post antibiotic era

Answer 13

after widespread antibiotic resistance which has reduced antibiotic availability

Question 14

what is empirical therapy

Answer 14

treating with best guess while cultures are tested - risk of under treatment and excessive broad spectrum = resistance risk

Question 15

what are the three issues with targeted therapy

Answer 15

expensive
toxic
last line

Question 16

when would you use sensitivity testing

Answer 16

to inform antibiotic therapy
first line choice if does not require immediate treatment
second line choice after empire therapy or after failure of initial therapy

provide epidemiological data - early warnings to public health