Detection of Streptococcus mutans and Streptococcus sobrinus in Human Dental Plaque Samples by Using Semi-Quantitative Real-Time Polymerase Chain Reaction

Dental caries, a highly prevalent infectious disease in humans is caused by the bacterial plaque that coats the teeth surface and is a serious public health concern. Recently, the formation of dental plaque has been associated with the occurrence of various other systemic diseases, Alzheimer's disease, Cardiovascular diseases, Rheumatoid Arthritis, Respiratory diseases, Bacteremia and Cancer. Despite the fact that both Streptococcus mutans and Streptococcus sobrinus are the major etiologic agents of dental caries, S. mutans is more prevalent than S. sobrinus in dental plaque. Early detection of S. mutans and S. sobrinus was carried out from five caries affected dental plaque samples collected from Sri Ramakrishna Dental College and Hospital, Coimbatore, by using semi-quantitative real-time PCR. Specific primers for gtfB and gtfI genes of S. mutans and S. sobrinus respectively were used for the quantification of cariogenic bacteria in the given dental plaque samples. The Biopro Oral Microbiome transport media was prepared to carry dental plaque samples from the hospital to the laboratory. Genomic DNA extraction was done by employing magnetic beads and spin columns provided in the Biopro DNA isolation kit. Various biochemical tests were performed on the bacterial cultures isolated from dental plaque.