5.9 Antimicrobial Resistance

Question 1

why/ how does antimicrobial resistance develop?

Answer 1

genetic mutation

Question 2

What is the main route of administration of antibiotics to animals in Canada?

Answer 2

feed 84%
water 8%
injected 6%
other…

Question 3

are multidrug resistant pathogens more virulent than their susceptible counterparts? why?

Answer 3

NO

• Resistance genes are resistance genes, not virulence factors
• Outcome should be no worse if resistance is promptly detected
  and proper treatment is initiated

Question 4

Who directs antimicrobial use in animals?

Answer 4

• Veterinarians
  ▫ Prescription for individual animals
  ▫ Prescription for farm/group with valid relationship
  ▫ Prescription for mass (feed) medication
• Owners
  ▫ Deciding when to use antibiotics from a veterinarian

Question 5

Does restriction of antimicrobials in animals have an impact on resistance?

Answer 5

probably yes, resistance follows use

• But….
  ▫ Some conflicting data
  Between bacteria –
  Between drugs
  Between studies
  Focused on single bug/drug combinations
• Usually, the best way to reduce emergence and dissemination of antimicrobials is to reduce antimicrobial use

Question 6

• Antimicrobials should never be used to compensate for: (3)

Answer 6

▫ Poor management
▫ Poor practices
▫ Proper preventive medicine

Question 7

should we use antimicrobials ‘just in case’?

Answer 7

no

• “Let’s try an antibiotic first…” is not recommended in lieu of diagnostic testing
  ▫ Patient care
  ▫ Antimicrobial resistance