The molecular physiological and genetic mechanisms underlying the superb efficacy of quinolones

The fluoroquinolones are the most widely used broad-spectrum antibiotics, accounting for 18% of global antibacterial market share.  They can kill bacteria rapidly with variety of derivatives available.    Different quinolones vary significantly in rate and spectrum of killing, oxygen requirement for metabolism and reliance upon protein synthesis.  Further understanding the sophisticated mechanisms of action of this important antibiotic family based on the molecular genetic response of bacteria can facilitate the discovery of better quinolone derivatives.  Factors such as SOS response, bacterial toxin-antitoxin system, programmed death, chromosome fragmentation and reactive oxygen have been implicated in the action to some extent.  “Two steps characteristic” of quinolones killing is also emphasized, which might inspire future better quinolones modification.