title: Real-time PCR for quantification of Streptococcus mutans.
abstract: A real-time polymerase chain reaction (PCR) assay was developed for the quantification of Streptococcus mutans. Primers targeting gtf genes of S. mutans were designed and tested for their specificity using 28 oral streptococcal strains, three other bacterial strains, and human DNA. The primers could amplify specifically the target DNA fragment from a mixture of oral streptococcus genomic DNA containing about 10 fg to 10 ng of S. mutans genome DNA. The real-time PCR produced a linear quantitative detection range over concentrations spanning seven exponential values, with a detection limit of a few copies of S. mutans' genomic DNA per reaction tube. The results of the real-time PCR assay corresponded well to those of conventional culture assays for S. mutans in saliva samples. A real-time PCR assay for Streptococcus sobrinus and Streptococcus downei was also established and produced results that corresponded well to those from conventional culture assays for S. sobrinus in saliva samples. These assays will be useful as a new means to assess one of the important risk factors for caries.
authors.affiliation: Department of Oral Health, National Institute of Public Health, 1-23-1 Toyama, Shinjuku-ku, 162-8640, Tokyo, Japan. akiray@nih.go.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Yano
authors.forename: Noboru
authors.initials: N
authors.lastname: Kaneko
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Ida
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Hanada
mesh_terms: D015373:Bacterial Typing Techniques; D002648:Child; D017931:DNA Primers / Q000032:analysis; D005964:Glucosyltransferases / Q000235:genetics; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D012463:Saliva / Q000382:microbiology; D012680:Sensitivity and Specificity; D013290:Streptococcal Infections / Q000175:diagnosis*; D013295:Streptococcus mutans / Q000235:genetics / Q000302:isolation & purification*; D016986:Streptococcus sobrinus / Q000235:genetics / Q000302:isolation & purification
chemical_list: D017931:DNA Primers; D005964:Glucosyltransferases; C110463:glucosyltransferase C