Resistance to fluoroquinolones develops by:
|A||Altered metabolic pathway of bacteria|
|B||Alteration in the binding site of DNA gyrase|
|C||Decreased uptake of drug|
|D||Metabolism of drug by enzymatic modification|
a. Fluoroquinolones act intracellularly by inhibiting DNA gyrase. DNA gyrase is an essential bacterial enzyme that is a critical catalyst in the duplication, transcription, and repair of bacterial DNA.
b. Because of the unique mechanism of action plasmid mediated transferable resistance probably does not occur.
c. Resistance noted so far is due to chromosomal mutation producing a DNA gyrase with reduced affinity for fluoroquinolones, or due to reduced permeability of the bacterial membrane to these drugs.