Antibiotic resistance Flashcards
define multi-drug resistant
MDR: non-susceptibility to at least 1 agent in 3 or more antimicrobial categories
define extensive drug resistance - XDR
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)
define pandrug resistant
PDR: non-susceptibility to all agents in all antimicrobial categories
(ie, no agents tested as susceptible for that organism)
what are the 6 main resistance mechanisms?
- inactivation
- impermeability
- efflux
- altered target
- PBPS
- By-pass
what do Penicillin binding proteins normally do?
they are involved in the synthesis of peptidoglycan for the bacterial cell wall
what happens when peniciilin binds to the PBPs ?
the synthesis cannot occur
how is PBPs a mechanism of resistance?
the PBPs are changing structure so there is no longer a perfect fit with the penicillin so the synthesis of peptidoglycan is not inhibited
Antimicrobials: site of action
- Cell____
- Cell _____
- ____ inhibitor
- _____-
- cell wall
- cell membrane
- DNA inhibitor
- cytoplasm
which antimicrobials work on the cell wall?
beta-lactams and glycopeptides
where do the majority of antimicrobials work?
on the ribosomes
how do beta-lactams work?
they bind to the PBPs and prevent cell wall synthesis
where is the source of most genetic transfer in our bodies
the bowel - think of all the coliforms
E.coli will not only transfer genetic material to ___ but also to other ___ e.g. klebsiella
E.coli, bacteria
what are the three mechanisms of genetic transmission through horizontal transmission (note vertical transmission is when the bacterium accumulates mutations through genome replication)
transformation, transduction and conjugation
what is transformation
when bacteria scavenge resistance genes from dead bacterial cells and integrate them into their own genomes
what is transduction?
when resistance genes are transferred by bacteriophages (viruses that infect bacteria);
what is conjugation?
when genes are transferred between bacterial cells through tubes called pilli.
how do we fight against bacterial resistance? 4 mechanisms
- preventing infections, preventing the spread of disease
- tracking
- improving prescribing and use
- developing new drugs
what are the 4 Ds of antimicrobial stewardship?
- dose
- duration.
- drug
- de-escalation
antimicrobials can also cause ___
toxicity
there should be ___ ___ ____ for surgery
single dose prophylaxis
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
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
___ doses drive resistance
small
how to prevent resistance?
- ___ infections
- ___ and ___ effectively
- use _____ wisely
- prevent ______
- prevent infections
- diagnose and treat effectively
- use antimicrobials wisely
- prevent transmission - break the chain
