[A study on the bactericidal activity of povidone-iodine in the synthetic mediums]

To evaluate the bactericidal activity of povidone-iodine (PVI), synthetic mediums without the protein components were prepared. The stability of the available iodine in the synthetic mediums was compared with that in heart infusion broth (HIB; natural broth). The available iodine was remarkably decreased soon after addition of PVI in the HIB, but it was stable for 24 hr in the synthetic mediums. The growth of Escherichia coli and Salmonella enteritidis were found to be normal in the synthetic mediums. Minimal inhibitory concentrations (MICs) of PVI in the synthetic mediums were about one thousandth of that in HIB, and the phenol coefficients (PCs) of PVI in the synthetic mediums were about 30 times lower than that in the HIB.