A novel TaqMan? MGB probe for specifically detecting Streptococcus mutans

To design a new TaqMan? MGB probe for improving the specificity of Streptococcus mutans's detection.We extracted six DNA samples from different streptococcal strains for PCR reaction. Conventional nested PCR and TaqMan? MGB real-time PCR were applied independently. The first round of nested PCR was carried out with the bacterial universal primers, while a second PCR was conducted by using primers specific for the 16S rRNA gene of Streptococcus mutans. The TaqMan? MGB probe for Streptococcus mutans was designed from sequence analyses, and the primers were the same as nested PCR. Streptococcus mutans DNA with 2.5 mg/L was sequentially diluted at 5-fold intervals to 0.16 μg/L. Standard DNA samples were used to generate standard curves by TaqMan? MGB real-time PCR.In the nested PCR, the primers specific for Streptococcus mutans also detected Streptococcus gordonii with visible band of 282 bp, giving false-positive results. In the TaqMan? MGB real-time PCR reaction, only Streptococcus mutans was detected. The detection limitation of TaqMan? MGB real-time PCR for Streptococcus mutans 16S rRNA gene was 20 μg/L.We designed a new TaqMan? MGB probe, and successfully set up a PCR based method for detecting oral Streptococcus mutans. TaqMan? MGB real-time PCR is a both specific and sensitive bacterial detection method.PubMed05782-64