Antibiotics resistance

Question 1

What is the result of antibiotic resistance?

Answer 1

• Increases mortality
• Challenges control of infectious diseases
• Threatens a return to pre-antibiotic era
• Increases costs of health care
• Jeopardizes health-care gains to society

Question 2

What are the 4 areas of resistance?

Answer 2

Question 3

What are the different ways of antibiotic resistance?

Answer 3

Question 4

What are the different mechanisms of resistance?

Answer 4

1. Natural resistance

• Must reach the target but there are natural barriers, porins and export pump
• Eg. A single mutation in a porin gene can give you multiple resistance

2. Genetic mechanisms - acquired

• Chromosome-mediated - due to spontaneous mutation
  
  • In the target molecules or drug uptake system
  • Mutants are selected, they are not induced
• Plasmid-mediated
  
  • Common in gram-negative bacteria
  • Transferring through gene exchange drug resistance via conjugation
  • Multi-drug resistance

3. Non-genetic mechanisms - tolerance (reversible, makes infections more hard to treat)

• Inaccessibility to drugs (abscesses and lesions where the drug can’t get to the site)
• Stationary phase - they’re not growing anymore but still causing signs and symptoms

Question 5

How does gene transfer happen in bacteria?

Answer 5

• Mechanism for genetic heterogeneity and evolution
• Rapid, cross-species
• Can be either virulence, drug resistance or antigens

Question 6

How can bacteria become resistance to beta-lactam?

Answer 6

Question 7

What does clauvulanic acid do?

Answer 7

Clavulanic acid binds to beta-lactamase enzyme of the bacteria to block it, allowing the amoxicillin to inhibit protein synthesis and give you a broad spectrum activity

• Useful drug combination to address organisms that are resistant because of the acquisition of beta-lactamase enzymes

Question 8

What is the resistance mechanism in gram negative bacteria?

Answer 8

Question 9

In summary, what are the different ways bacteria can become resistant to penicillin?

Answer 9

Question 10

How can you prevent or overcome antibiotic resistance?

Answer 10

• Control use - complete the course, appropriate prescribing
• New or modified drugs
• Combination therapy - different targets
• Infection control