Preferential Induction of Rough Variants in Streptococcus mutans by Ethidium Bromide

Abstract
Different colonial variants of Streptococcus mutans were studied. Rough variants were induced frequently from an original mucoid-type strain in cultures to which ethidium bromide was added. Rough variants had less insoluble dextran like polysaccharides than the original mucoid strain. Mitomycin C caused cell lysis in mucoid cells but not in rough cells.