d) Mechanisms of resistance

State the mechanism of resistance that may develop with the drugs used. (4 marks)

I think that listing out general mechanisms of resistance would be fine.

General mechanisms of resistance (applies to antibiotics generally)

  • Mutation of the antibiotic target
  • Mutation of the bacterial enzyme required to activate the antibiotic
  • Enzymes which can breakdown the antibiotic
  • Efflux pumps which can pump the drug out of the bacterium.

Specific mechanisms of resistance:


  • Mutation of RNA polymerase causing reduced binding
  • Resistance occurs rapidly if used as monotherapy


  • Underexpression of enzyme required to convert drug into active metabolite


  • Increased production of arabinosyltransferase
  • Efflux pumps


  • Mutation of the enzyme required to convert pyrazinamide into active compound.



Mechanisms of pyrazinamide action and resistance

Complete and Continue