Biochemical mechanism of nitrofurantoin resistance in Vibrio el tor

Vibrio el tor cells contain a constitutive reductase enzyme which converts nitrofurantoin to an active principle that is responsible for the observed antibacterial activity of the drug. Acquisition of resistance of this strain towards nitrofurantoin is associated with the loss of this reductase. This enzyme is located in the periplasmic region of the nitrofurantoin-sensitive cells, and seems to play an important role in transporting the drug into the cells.