Session 4- Introduction to Antibiotics and Resistance Flashcards
bactericidal
kill the bacteria
bacteriostatic
stop the bacteria from reproducing
how to choose an antibiotic
is it active against target organism does it reach site of infection is it available in the right formulation what is the half life does it interact with other drugs are there toxicity issues does it require therapeutic drug monitoring does your patient have an allergy to any antibiotic class
what are the different ways to measure antibiotic resistance
Disc sensitivity/Diffusion testing- putting the organism on the agar plate and putting paper discs containing antobiotics and reading the zone of clearance
Minimum inhibitory clearance- the first concentration of antobiotic that inhibits the growth of bacteria,
what is intrinsic antibiotic resistance
a bacterial species is naturally resistant to a certain antibiotic or family of antibiotics, without the need for mutation or gain of further genes. The antibiotic does not that target the specific characteristics of the bacteria, therefore, unable to gain access to bacteria- this is usually a permanent ‘resistance’.
what is acquired antibiotic resistance
occurs when a particular microorganism obtains the ability to resist the activity of a particular antimicrobial agent to which it was previously susceptible
usually permanent and via chromosomal gene mutation/horizontal gene transfer
mechanisms for acquired antibiotic resistance
- enzymatic modification or destruction of antibiotics
- enzymatic alteration of antibiotic targets or mutation of bacterial target sites
- overexpression of efflux pumps
adapted antibiotic resistance
This only causes a mild stress response to the bacteria- hence it will respond by becoming resistant to the antibiotic
antifungals
azoles
polyenes
antivirals
aciclovir
oseltamivir
metronidazone
anti bacterial and anti protozoal
beta-lactam antibiotics
prevent cell wall synthesis pennicilin, carbapenem, cephalosporin
what is antimocrobial stewardship
coordinated interventions designed to improve and measure the appropriate use of antimicrobials by promoting the selection of teh optimal antimicrobial drug regimen, dose, duration of therapy, and route of administration.
Antimicrobial stewards seek to achieve optimal clinical outcomes related to antimicrobial use, minimize toxicity and other adverse events, reduce the costs of health care infections, and limit the selection for antimicrobial resistant strains
MDR
multi drug resistant- non-susceptibility to at least one agent in three or more antimicrobial categories
XDR
extensively drug resistant- non-susceptibility to at least one agent in all but two or fewer antimicrobial categories