IRON(III)-CHELATING RESINS .9. ANTIBACTERIAL ACTIVITY OF A WATER-INSOLUBLE IRON(III)-CHELATING RESIN

Antibacterial activity of a water-insoluble iron(III)-chelating resin with covalently bonded 3-hydroxy-2-methyl-4(1H)-pyridinone (HMP) group s was evaluated in a brain heart infusion (BHI) medium. The activity o f the resin against Escherichia coli was lower than that of soluble HM P iron(III) chelators, whereas against Listeria inocua, an activity ap proximately equal to those of the soluble chelators was found. It was observed that the growth of E. coli and L. inocua was reduced by incre asing the amounts of the resin from 2 to 40 mg of resin/mL of medium. Inhibition of bacterial growth in the presence of the resin (10 mg/mL) was abolished by addition of ferric ion to the medium, indicating tha t the growth of E. coli and L. inocua was dependent on the available i ron in the medium. Reducing the iron concentration in the medium from 14.2 to 0.16 mu M (by action of the resin) resulted in a decrease in t he growth response from 100% to 19% for E. coli and from 100% to 10% f or L. inocua. In addition, the influence of citrate was studied, but o nly small effects of citrate supplementation on the growth of bacteria and on the antibacterial activity of the resin were observed.