Microbiology 2 (antibiotic resistance and stewardship)

Question 1

What is the 3rd independent party that needs to be considered when using antibiotics?

Answer 1

The microbial ecosystem

Question 2

What is resistance in general? (lab)

Answer 2

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)

Question 3

What does susceptible mean?

Answer 3

Implied that an antimicrobial will inhibit bacterial growth at clinically achievable concentrations

Question 4

What is Multi-drug resistance?

What is the lay mans term for this?

Answer 4

Non-susceptibilty to at least 1 agent in 3 or more antimicrobial categories
Superbugs

Question 5

What is extensive drug resistance?

Answer 5

Non-susceptibilty to all but 2 or fewer antimicrobial categories (i.e. bacterial isolates remain susceptible to only 1 or 2 categories)

Question 6

What is pan drug resistance?

Answer 6

Non-susceptibilty to all agents in all antimicrobial categories (i.e.e no agents tested as susceptible for that organism)

Question 7

What is antibiotic resistance?

Answer 7

When microbes are resistant to one or more antimicrobial agents, used to treat infection or as an antiseptic

Question 8

What are the 6 mechanisms by which a bacteria can become resistant to an antibiotic?

Answer 8

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

Question 9

What are the possible parts of a bacteria that antibiotics work on? (4)

Answer 9

Cell wall
Cell membrane
DNA inhibitor
Cytoplasm

Question 10

What are the 2 basic ways by which antibiotic resistance can be acquired? + definition

Answer 10

Vertical transmission (bacterium accumulates mutations and passes these to subsequent generations)
Horizontal transmission(resistant genes are passed from one bacteria to another)

Question 11

What are the 3 mechanisms of horizontal transmission?

Answer 11

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)

Question 12

What is the name of the process by which widespread antibiotic use has caused more bacteria to become resistant?

Answer 12

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)

Question 13

What are the 3 main reasons why we are seeing more resistance?

Answer 13

Increasing resistance in community
Complacency regarding antibiotics
Increased use of (empiric) broad-spectrum antibiotics

Question 14

What are the 4 main ways by which we can fight back against antibiotic resistance?

Answer 14

Preventing infections, preventing the spread of disease
Tracking
Improving antibiotic presecribing and use AKA “stewardship”
Developing new drugs

Question 15

For an individual patient with a UTI prescribed an antibiotic within the last 2 months, what is the increased level of risk of resistance?

Answer 15

2.5 fold (risk will last for up to 12 months)

Question 16

What is antimicrobial stewardship?

Answer 16

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

Question 17

For surgical prophylaxis antibiotic treatment, how many doses should be given?

Answer 17

One dose within 60 minutes before knife to skin

Question 18

Does hand hygiene contribute to the spread of antibiotic resistance?

Answer 18

Yes, it is one of the key ways by which it is spread

Question 19

Does the route of therapy make any difference towards the development of antimicrobial resistance?

Answer 19

No

Question 20

What are the 6 main drivers for antibiotic resistance?

Answer 20

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

Question 21

What are the 2 steps that prevent infections and therefore reduce antimicrobial resistance?

Answer 21

Vaccinate

Take catheters out

Question 22

What are the 2 steps in terms of diagnosing and treating effectively that reduces antimicrobial resistance?

Answer 22

Target the pathogen

Access the experts

Question 23

What are the 5 steps in terms of using antimicrobials wisely that reduces the amount of antibiotic resistance experienced?

Answer 23

Practice antimicrobial control
Use local data
Tract infection, not contaminisation or colonisation
Know when to say "no" to vance
Stop treatment when cured

Question 24

What are the 2 steps in terms of preventing transmission that prevents antimicrobial resistance?

Answer 24

Isolate the pathogen

Break the chain