[Direct effect of nitroxoline in the inhibition of bacterial adherence to urinary catheters]

Nitroxolin or 5-nitro-8-hydroxyquinoline, used in the treatment of acute or recurrent uncomplicated urinary tract infection, has been investigated to demonstrate direct inhibitory effect on Escherichia coli adherence to solid surfaces. First of all, influence of growth medium on bacterial adherence was studied. No relation occurs between growth media enhancing production of adhesins and the ability to adhere to solid surfaces. While bacteria are grown on minimal medium, nitroxolin (MIC/16 to MIC/4) can significantly reduce bacterial adherence to urinary catheter of uropathogenic strains of Escherichia coli AL52 and 382. Increasing the concentration of nitroxolin does not proportionally modify this decrease. When growth is realised on LB broth or agar, nitroxolin does not affect bacterial adherence of strain AL52 and higher doses (8 to 32 mg.l-1) are necessary to obtain the same inhibition of adherence of strain 382. Nitroxolin, in certain conditions, can, directly and rapidly, reduce bacterial adherence to solid surfaces.