engleski

On the antibacterial activity of metal-exchanged zeolites

The antibacterial activity of metal-exchanged clinoptilolite (M-Z ; M - Cu, Zn, Ni, Ag) and zeolite A (M-A) toward Gram- positive (Staphylococcus aureus) and Gram-negative (Acinetobacter baumannii and Escherichia coli) bacteria was investigated in different water media. The cations released from the zeolites are mainly found to be responsible for the antibacterial action. According to the results, the antibacterial action of the examined zeolites decreases in the following order: Ag-Z, Ag-A > Cu-Z, Cu-A > Zn-Z, Zn-A > Ni-Z, Ni-A toward all examined bacterial types. Mechanism of the bactericidal activity of silver ions toward pathogenic multidrug resistant Gram-negative Acinetobacter baumannii has been proposed on a molecular level using the X-ray near-edge structure (XANES) spectroscopy. Silver ions bind prevalently the amine (˃NH) and hydroxyl (-OH) groups belonging to DNA inside bacterial cells and to the sites in the outer cell membrane of A. baumannii. Considering the bactericidal activity of Ag-Z a novel antibacterial polymer composite, based on Ag-Z and poly(vinyl chloride) was prepared.

zeolites, metal, antibacterial activity, multidrug resistant, mechanism of antibacterial activity

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