Antibiotic resistance

Question 1

define multi-drug resistant

Answer 1

MDR: non-susceptibility to at least 1 agent in 3 or more antimicrobial categories

Question 2

define extensive drug resistance - XDR

Answer 2

XDR: non-susceptibility to at least 1 agent in all but 2 or fewer antimicrobial categories (ie, bacterial isolates remain susceptible to only 1 or 2 categories)

Question 3

define pandrug resistant

Answer 3

PDR: non-susceptibility to all agents in all antimicrobial categories
(ie, no agents tested as susceptible for that organism)

Question 4

what are the 6 main resistance mechanisms?

Answer 4

1. inactivation
2. impermeability
3. efflux
4. altered target
5. PBPS
6. By-pass

Question 5

what do Penicillin binding proteins normally do?

Answer 5

they are involved in the synthesis of peptidoglycan for the bacterial cell wall

Question 6

what happens when peniciilin binds to the PBPs ?

Answer 6

the synthesis cannot occur

Question 7

how is PBPs a mechanism of resistance?

Answer 7

the PBPs are changing structure so there is no longer a perfect fit with the penicillin so the synthesis of peptidoglycan is not inhibited

Question 8

Antimicrobials: site of action

1. Cell____
2. Cell _____
3. ____ inhibitor
4. _____-

Answer 8

1. cell wall
2. cell membrane
3. DNA inhibitor
4. cytoplasm

Question 9

which antimicrobials work on the cell wall?

Answer 9

beta-lactams and glycopeptides

Question 10

where do the majority of antimicrobials work?

Answer 10

on the ribosomes

Question 11

how do beta-lactams work?

Answer 11

they bind to the PBPs and prevent cell wall synthesis

Question 12

where is the source of most genetic transfer in our bodies

Answer 12

the bowel - think of all the coliforms

Question 13

E.coli will not only transfer genetic material to ___ but also to other ___ e.g. klebsiella

Answer 13

E.coli, bacteria

Question 14

what are the three mechanisms of genetic transmission through horizontal transmission (note vertical transmission is when the bacterium accumulates mutations through genome replication)

Answer 14

transformation, transduction and conjugation

Question 15

what is transformation

Answer 15

when bacteria scavenge resistance genes from dead bacterial cells and integrate them into their own genomes

Question 16

what is transduction?

Answer 16

when resistance genes are transferred by bacteriophages (viruses that infect bacteria);

Question 17

what is conjugation?

Answer 17

when genes are transferred between bacterial cells through tubes called pilli.

Question 18

how do we fight against bacterial resistance? 4 mechanisms

Answer 18

1. preventing infections, preventing the spread of disease
2. tracking
3. improving prescribing and use
4. developing new drugs

Question 19

what are the 4 Ds of antimicrobial stewardship?

Answer 19

1. dose
2. duration.
3. drug
4. de-escalation

Question 20

antimicrobials can also cause ___

Answer 20

toxicity

Question 21

there should be ___ ___ ____ for surgery

Answer 21

single dose prophylaxis

Question 22

The drivers for resistance:
A. ___ _____ ANTBIOTIC THERAPY

B. ____ DURATION OF THERAPY

C. ___ OR ______ DOSE OF ANTIBIOTIC

D.____ OF THERAPY MAKES NO DIFFERENCE

E. TOTAL __ OF ANTIBIOTIC USE

F. GIVING ANTIBIOTIC IN THE ABSENCE OF I_______

G. GIVING ANTIBIOTIC IN THE PRESENCE OF ___ FOR ___ PERIODS

Answer 22

A. BROAD SPECTRUM ANTBIOTIC THERAPY

B. LONG DURATION OF THERAPY

C. LOW OR SUBOPTIMAL DOSE OF ANTIBIOTIC

D. ROUTE OF THERAPY MAKES NO DIFFERENCE

E. TOTAL AMOUNT OF ANTIBIOTIC USE

F. GIVING ANTIBIOTIC IN THE ABSENCE OF INFECTION

G. GIVING ANTIBIOTIC IN THE PRESENCE OF PUS FOR LONG PERIODS

Question 23

___ doses drive resistance

Answer 23

small

Question 24

how to prevent resistance?

1. ___ infections
2. ___ and ___ effectively
3. use _____ wisely
4. prevent ______

Answer 24

1. prevent infections
2. diagnose and treat effectively
3. use antimicrobials wisely
4. prevent transmission - break the chain