PRELIMINARY GROUPING OF MUTACINS

All the mutacins described so far have been shown to be different subs tances. To classify 86 mutacinogenic strains, we determined their acti vity spectra towards 12 standard oral streptococci and towards themsel ves, using a deferred antagonism test. The mutacinogenic strains could be grouped into 15 mutacinotypes according to their activity spectra against the 12 standard oral streptococci. By combining the results of their activity spectra and their sensitivity patterns amongst themsel ves, we defined 24 mutacin groups. Using the 24 type strains correspon ding to these groups as producers and as indicators, it will be easier to classify new mutacin-producing isolates.