13.2 Antimicrobial resistance and management

Question 1

How do cells acquire resistance to antibiotics?

Answer 1

• Transfer of resistance genes
• Mutation (e.g. of drug target)
• Selection due to antibiotic pressure
• Growth conditions e.g. biofilms

Question 2

Explain selection pressure (using antibiotics)

Answer 2

Question 3

Key multi-drug antibiotic resistance players and what type of bacteria they are

Answer 3

• Gram-positive cocci
  
  • ​**Staphylococcus aureus (MRSA**)
  • Pneumococci enterococci (VRE)
• Gram-negative cocci
  
  • Gonococci
• Gram-positive bacilli
  
  • ​Clostridium difficile
• Gram-negative bacilli
  
  • ​E.coli
  • Enterobacter
  • Helicobacter pylori

Gram-negative bacteria are more at risk of CRITICAL

Question 4

What has led to antibiotic resistance?

Answer 4

• Increased use of antibiotics
• Prescriptions taken incorrectly
• Antibiotics sold without medical supervision
• Prophylactic use before surgery
• Antibiotics used for viral infection
• Spread of resistant microbes in hospitals due to lack of hygiene
• Patients not completing course of antibiotics
• Antibiotics in animal feeds
• Worldwide communication and spread

Overall using less antibiotics has led to LESS resistance to antibiotics e.g. penicillin to S.Pneumoniae

Question 5

How to manage antimicrobial resistance?

Answer 5

1. INFECTION PREVENTION & CONTROL
   
   1. ​Minimising transmission of organisms
   2. Avoidance of infection and exposure to resisant organisms
2. ANTIMICROBIAL USAGE
   
   1. Decreasing antibiotic usage to decrease selection pressure effect
   2. ANY REDUCTION IN ANTIMICROBIAL USAGE WILL REDUCE RISK OF RESISTANCE
   3. _​_Doing the following things:
      
      1. DECREASE broad spectrum antibiotics
      2. REDUCE antibiotics when NO infection is present

Question 6

Explain antimicrobial stewardship

Answer 6

• Is a set of coordinated strategies to improve the use of antimicrobial medications with the goal of enhancing patient health outcomes, reducing antimicrobial resistance, and decreasing unnecessary costs

Question 7

What are positives and negatives of following antimicrobial stewardship (effectively delaying antibiotic treatment)?

Answer 7

• POSITIVES
  
  • ‘Equally effective’ - decreased antimicrobial usage, no harm evident
  • Providing good feedback to patient
  • Better professional acceptance
  • Good intervention of decreasing antimicrobial resistance
• NEGATIVES
  
  • ​Negative professional culture through breakdown in trust and communication
  • DELAY in administering 1st dose (of antibiotic)
  • MINIMAL evidence to demonstrate improved microbiological outcomes (decreases antibiotic resistance)

Question 8

Explain the process of using antibiotics in SEPSIS

Answer 8

1. Blood tests
2. Imaging
3. Culture using the antibiotic that will be given
   
   1. If no signs of bacterial infection STOP using antibiotics to minimise the harm of antimicrobials (1/5 patients on antimicrobials have so adverse side effects)
4. Clinical review & decision after 48-72 hours

Question 9

Explain the process of using antimicrobials when a patient has a UTI

Answer 9

1. Use an EMPIRIC TREATMENT
   
   1. 90-100%
      
      1. Respond to treatment –> Good clinical outcomes
      2. Decrease mortality
      3. Shortened length of stay
   2. 0-10%
      
      1. FAILURE of treatment (empiric)
         
         1. Poor patient outcomes
         2. Need ESCALATION of antimicrobials
         3. Antimicrobial team review
            
            1. MDT discussion

Clinical review and discussion after 48-72 hours

Question 10

What are the advantages of moving from intravenous (IV) to oral (PO) antimicrobial switch?

Answer 10

• Reduction in the likelihood of hospital acquired bacteraemia
• Patient is more likely to receive oral antibiotics at the correct time and miss fewer doses
• Potential reduction in the risk of adverse reactions; errors in preparation are significantly higher with parenteral drugs, compared to oral formulations.
• Reduces patient discomfort and enables improved mobility and the possibility of earlier discharge from the hospital.
• Saves medical and nursing time.
• A reduction in treatment costs IV antimicrobials costs account for 80% of antimicrobial budget

Question 11

What are the advantages and disadvantages of initial IV antimicrobials?

Answer 11

• ADVANTAGES
  
  • ​Quick onset of action
  • Patients can eat and drink if on PO antimicrobials
• DISADVANTAGES
  
  • ​Requires IV access
  • Costly
  • Takes time for nurses
  • High chance of adverse side effects

Question 12

What are the advantages and disadvantages of prolonged IV antimicrobials?

Answer 12

• ADVANTAGES
  
  • ​Useful for some
    
    • When deep-seated infection (general terms for infections of the entire skin layer including the subcutaneous and muscle tissue layers and their respective fascia structures) or when PO options unavailable
• DISADVANTAGES
  
  • ​RISK>BENEFIT for most patients
    
    • Increased line infeections
    • Increased drug costs
    • Higher risks of harm