Can Germ-lnhibitory Substances in Marketed Milk

The authors investigated germ-inhibitory substances in marketed milk taken from various suburban parts of Osaka from March to October, 1962, the test method for the substances was based on a modification of Resazurin test published by T. Matsui, as well as on a biochemical method. The results were summerized as follows; 1) Samples from 26 milk plants were subjected to Resazurin test, 8 among the samples were found positive to Resazurin test. 2) NFA was detected in the samples from 7 plants by the absorption spectral analysis as well as by the bioutographic analysis on their n-butanol extracts. 3) 72% of 25 strains isolated from the samples in which NFA was detected showed a resistance to NFA, 60% to Penicillin and O% to Streptomycin. Judging from the results of our investigations it seems to us that the strict inspection of milk is needed for public health.