Investigation of Streptococcus mutans isolated from dental caries patients

Introduction: The clinical specimens (100) were collected from patients suffering from dental plague infectious during the period from October ( 2012 to March 2013) inNajaf City . Methodology: Streptococcus mutans isolates were detected by cultural and biochemical tests as well as API 20strep , then confirm the GTFB gene by PCR technique . Result: Streptococcus mutans were recorded (40%) among Mutans Streptococcus from total isolates . The virulence factors of bacteria were detected and the results showed that all isolates were produced glucan,biofilm and Dextranase 40(100%) and varied produce heamolysin 30(75%) . Also, 20-25(50-62.5%) of Streptococcus mutans has the colonization factor antigen III, ,I respectively and 15 (37.5%) of isolates are mutacin production.Finally, Molecular study by PCR technique was used for detection gtfB gene, it was found the gtfB gene predominance in 22 (55%) of clinical isolates .Conclusion: The study showed that Streptococcus mutans have gtfB gene which responsible for the pathogenicity of Streptococcus mutans .