Molecular Characterization of Cariogenic and Non-cariogenic Streptoccoi Species in Dental Plaque Biofilm Using 16S-23S rRNA Gene Spacer Region Amplification

Interspecies competitive exclusion of microbial diversity explained using 16S-23S rRNA gene spacer region amplification. Virulent and non-virulent strains of streptococci strain were isolated from dental plaque biofilm for analysis. DNA isolation done from plaque strains from dental biofilms of caries-active and caries-free subjects, respectively. Two pairs of primers were designed from the 16S–23S rRNA gene spacer region to amplify the variable and species-specific non-coding regions. The results revealed that the ITS lengths (246 to 391 bp) and sequences were highly conserved among strains within a species. The precision of utilising intergenic spacer sequencing for recognisable proof of viridian group streptococci was checked by 16S rDNA sequencing for all strains apart from strains of Streptococcus oralis and Streptococcus mitis, which were hard to separate by their 16S rDNA arrangements. Comparative sequence analysis of the 16S-23S rRNA spacer region sequences revealed that not only Streptococcus mutans, but also Streptococcus salivarius, Streptococcus oralis and Streptococcus mitis play equal role in oral disesase progression as compare to Streptococcus mutans which is reported in previous studies.