W11.3_Antimicrobial Resistance

Question 1

Define antibiotics and antimicrobial resistance. What is ‘One Health’? Debunk some of the misconceptions of antibiotics regarding pharmaceuticals and agriculture.

Answer 1

• Antibiotics: medicines that inhibit the growth/destroy microorganisms
• Antimicrobial resistance: bacteria/fungi develop ability to defeat the drugs recognised to kill them
• “One Health”: antibiotic resistance can circulate among humans/livestocks/environment…
• *Pharmaceutical companies don’t prioritise development of new antibiotics for monetary gain
• *More antibiotics are used in healthcare than agriculture in UK

Question 2

How does antimicrobial resistance develop?

Answer 2

• Selection pressure of antibiotics (Darwinism)
• Transfer of resistance genes
• Transduction: bacteriophages mediate transfer of DNA between bacteria
• Conjugation: sex pilus (small tube) forms between two bacterial cells, where gene transfer occurs through transferring plasmid
• Transformation: take up free DNA from environment, incorporate into their chromosomes
• Rapid cell division

Question 3

Contrast intrinsic/innate and acquired resistance. Give some examples of common resistant bacteria.

Answer 3

• Intrinsic/innate resistance
• Lack of target structure
• Impermeable to antibiotics
• Acquired resistance
• Enzymatic inactivation of antibiotics
• Modification of target
• Efflux mechanism (pumps out antibiotics)
• Common resistant bacteria: E. Coli, K. Pneumoniae, E. Faecium, P. Aeruginosa, MRSA

Question 4

Explain how misuse of antibiotics is caused.

Answer 4

• Prescribed unnecessarily/delayed in critically ill patients
• Broad-spectrum ones are used too generously/narrow-spectrum ones are used incorrectly
• Inappropriate dose/duration
• Treatment not streamlined according to microbiological culture data results

Question 5

Describe the role of antimicrobial stewardship in pharmacists.

Answer 5

• Ensure rational use/health promotion to public/prescriber education
• Promotion of empiric guideline choice/review management of individual patients
• Restrict reserved antibiotics/selective reporting of sensitivities to first line choices