Classification of oral streptococci by two‐dimensional gel electrophoresis with direct activity stain for glycosyltransferases

Thirty eight strains of oral streptococci were divided into six types by two-dimensional gel electrophoresis (2-DE) followed by glycosyltransferase (GLT) activity stain: Type 1, Streptococcus mutans; Type 2, Streptococcus rattus; Type 3, Streptococcus sobrinus and Streptococcus downei; Type 4, Streptococcus cricetus; Type 5, Streptococcus salivarius; and Type 6, Streptococcus sanguis, Streptococcus oralis and Streptococcus gordonii. In Types 1, 2 and 5, two glucosyltransferases synthesizing water-insoluble (GTF-I) and water-soluble glucans (GTF-S) and a fructosyltransferase (FTF) were detected. In Types 3 and 4, GTF-I and two GTF-Ss were detected. Only one GTF-S was detected in Type 6. The 2-DE patterns for these six types were clearly distinguished from each other based on the kind, number and location of GLTs in gel.