5: Antimicrobial resistance and antimicrobial stewardship Flashcards
What percentage of antibiotic prescriptions are unneccessary?
Around 50%
What do antimicrobials act on?
All microorganisms
bacteria, fungi, viruses, protozoa
What do antibacterials act on?
Bacteria only
Antibiotics are mainly (antimicrobials / antibacterials).
antibacterials
What are antibiotics?
Produced naturally by microorganisms
Kill/inhibit growth of bacteria (mainly)
What is antibiotic resistance?
Ability of a bacteria to protect itself from the effects of an antibiotic
What is clinical resistant infection?
Bacteria which can survive in the antibiotic concentrations reached during therapy
Is resistance the same as immunity?
No
Bacteria are resistant to varying concentrations of antimicrobials, not totally immune
What is the susceptibility of a bacterium to an antibiotic?
Concentration of antibiotic at which it will start to be inhibited / die
MDR
PDR
XDR
Define these terms.
MDR - multi-drug resistant (susceptible to 3+ drugs)
XDR - extremely drug resistant (susceptible to 2 or less drugs)
PDR - pandrug resistant (susceptible to nothing)
Resistance is either ___ or ___.
innate , acquired
How is resistance transferred between bacteria?
Horizontal gene transfer via plasmids
Generally, by which two means to bacteria gain resistance?
Vertical transmission (accumulation of mutations through generations)
Horizontal transmission (swapping genes in the same generation)
Where are three means of horizontal gene transfer?
Transformation - resistance genes scavenged from dead bacterial cells
Transduction - resistance genes transferred from bacteriophage to bacteria
Conjugation - resistance genes transferred between living bacteria via pilli
How do healthy people pick up highly resistant strains of bacteria?
Foreign travel
What is an example of an enzyme, produced by resistant bacteria, which inactivates antibiotics?
Beta lactamase
Resistant bacterial membranes can be ___ to antibiotics.
impermeable
Which antibiotic is usually used to treat Staph. aureus infection?
Flucloxacillin
(Under/over)dosing of antibiotics can drive resistance.
Underdosing
The use of (narrow / broad) spectrum antibiotics drives resistance.
broad spectrum
e.g cephalosporins, quinolones
Antibiotic prescribing is ___ in some countries and this drives resistance.
unregulated
How do farmers increase the growth of their stock and prevent them from getting diseases?
Antibiotics in feed
The reasoning for prescribing antibiotics should be recorded in a patient’s ___.
notes
How long should surgical antibiotic prophylaxis be given for?
A day or so
any longer is excessive
