Microbiology 2 (antibiotic resistance and stewardship) Flashcards
What is the 3rd independent party that needs to be considered when using antibiotics?
The microbial ecosystem
What is resistance in general? (lab)
A laboratory phenomena which implies that an antimicrobial will not inhibit bacterial growth at clinically achievable concentrations (not always translated into the clinical setting, however usually is)
What does susceptible mean?
Implied that an antimicrobial will inhibit bacterial growth at clinically achievable concentrations
What is Multi-drug resistance?
What is the lay mans term for this?
Non-susceptibilty to at least 1 agent in 3 or more antimicrobial categories
Superbugs
What is extensive drug resistance?
Non-susceptibilty to all but 2 or fewer antimicrobial categories (i.e. bacterial isolates remain susceptible to only 1 or 2 categories)
What is pan drug resistance?
Non-susceptibilty to all agents in all antimicrobial categories (i.e.e no agents tested as susceptible for that organism)
What is antibiotic resistance?
When microbes are resistant to one or more antimicrobial agents, used to treat infection or as an antiseptic
What are the 6 mechanisms by which a bacteria can become resistant to an antibiotic?
The drug can be inactivated
The drug can be impermeable
An efflux pump can form which pumps the drug straight back out
Penicillin binding proteins can form = higher affinity for the drug than the primary target
Mutations can alter the target so that it can’t bind
Mutations can change the designated target molecule so that the drug by-passes the original one
What are the possible parts of a bacteria that antibiotics work on? (4)
Cell wall
Cell membrane
DNA inhibitor
Cytoplasm
What are the 2 basic ways by which antibiotic resistance can be acquired? + definition
Vertical transmission (bacterium accumulates mutations and passes these to subsequent generations) Horizontal transmission(resistant genes are passed from one bacteria to another)
What are the 3 mechanisms of horizontal transmission?
Transformation (bacteria scavenge resistance genes from dead bacterial cells)
Transduction (resistance genes are transferred by bacteriophages - viruses that infect bacteria)
Conjugation (genes are transferred between bacterial cells through tubes called pilli)
What is the name of the process by which widespread antibiotic use has caused more bacteria to become resistant?
Evolutionary pressure (due to antibiotics becoming increasingly available, antibiotics being used when they are not indicated, antibiotics being used in livestock feed, releasing large quantities of antibiotics into the environment)
What are the 3 main reasons why we are seeing more resistance?
Increasing resistance in community
Complacency regarding antibiotics
Increased use of (empiric) broad-spectrum antibiotics
What are the 4 main ways by which we can fight back against antibiotic resistance?
Preventing infections, preventing the spread of disease
Tracking
Improving antibiotic presecribing and use AKA “stewardship”
Developing new drugs
For an individual patient with a UTI prescribed an antibiotic within the last 2 months, what is the increased level of risk of resistance?
2.5 fold (risk will last for up to 12 months)
What is antimicrobial stewardship?
The optimal selection, dosage and duration of antimicrobial treatment that results in the best clinical outcome for the treatment or prevention of infection, with minimal toxicity to the patient and minimal impact on subsequent resistance
For surgical prophylaxis antibiotic treatment, how many doses should be given?
One dose within 60 minutes before knife to skin
Does hand hygiene contribute to the spread of antibiotic resistance?
Yes, it is one of the key ways by which it is spread
Does the route of therapy make any difference towards the development of antimicrobial resistance?
No
What are the 6 main drivers for antibiotic resistance?
Broad spectrum antibiotic therapy
Long duration of therapy
Low or suboptimal dose of antibiotic
Total amount of antibiotic use
Giving antibiotic in the absence of infection
Giving antibiotic in the presence of pus or long period
What are the 2 steps that prevent infections and therefore reduce antimicrobial resistance?
Vaccinate
Take catheters out
What are the 2 steps in terms of diagnosing and treating effectively that reduces antimicrobial resistance?
Target the pathogen
Access the experts
What are the 5 steps in terms of using antimicrobials wisely that reduces the amount of antibiotic resistance experienced?
Practice antimicrobial control Use local data Tract infection, not contaminisation or colonisation Know when to say "no" to vance Stop treatment when cured
What are the 2 steps in terms of preventing transmission that prevents antimicrobial resistance?
Isolate the pathogen
Break the chain
