MICROBIOLOGICAL EFFECTS OF DIVALENT METAL -IONS INTERACTION WITH NITROXOLINE

The present work deals with the physico-chemical and microbiological i nvestigations made in order to explain the role of divalent cations in the mechanism of the action of nitroxoline (NIT), an antibiotic used in the treatment of uncomplicated urinary tract infections. Preliminar y studies reported that bacteriostatic and bactericidal activities of NIT on Escherichia coli strains are decreased in the presence of Mg2and Mn2+ but not with Ca2+. A spectrophotometric study, conducted in o rder to elucidate the interaction between metal ions and NIT, showed t he formation of drug-metal ion complexes. In addition, we examined the relationships between the metal ions-chelating property of NIT and it s effects on the decrease of the mannose sensitive hemagglutination ti ter and the production of siderophores from E. coli. The results sugge sted that these antimicrobial activities of NIT would also be due to t he complexation of metal ions by this molecule.