Lecture 19 - Resistance

Question 1

Whats the difference between intrinsic resistance and acquired resistance

Answer 1

intrinsic resistance - expressed in chromosomal genes
acquired resistance - mutations in chromosomes OR acquired via plasmids and transposons (emerge from previously sensitive strains)

Question 2

How do plasmids cause antibiotic resistance?

Answer 2

• extrachromosomial genetic elements that can replicate independently. can have up to 7 resistance genes on one plasmid.
• large plasmids can transfer via conjugation

Question 3

If a bacteria containing a resistant plasmid is exposed to high concentrations of an antibiotic what happenes

Answer 3

plasmid transferred cell to cell via conjugation so all cells possess plasmid, sensitive cells are killed. if no exposure then plasmid lost