Antibiotic Resistance

• Resistance to a chemical poison is the ability of an organism to survive exposure to a dose of that poison which would normally be lethal to it
• Antibiotic resistant bacteria can evolve by the overuse of antibiotics such as:

  • Use of antibiotics in animal feed
  • Over-prescription by doctors
• Doctors are worried about resistance to antibiotics because some bacteria, e.g. coli are common in humans and can cause serious illness or even death
• How does a antibiotic resistance develop?

  1. Staphylococcus bacteria naturally include some strains that are resistant to some antibiotics
  2. Bacteria are exposed to multiple doses of antibiotics over a period of time
  3. Non-resistant bacteria are killed by the antibiotic
  4. Resistant strain reproduces and becomes more common than before
• MRSA (Methicillin resistant Staphylococcus aureus) has developed resistance to several antibiotics.
• Methods used in hospital to control MRSA are:

  • Hand washing
  • Thorough cleaning of hospital wards
  • Use of antibacterial gels
  • MRSA screening before surgery