| Title | Isolation and Characterization of the Mutans Streptococci from the Dental Plaques in Koreans |
|---|---|
| Author | So Young Yoo1,2, Seon Joo Park3, Dong Ki Jeong3, Kwang-Won Kim3, Sung-Hoon Lim2,3, Sang-Ho Lee2,4, Son-Jin Choe5, Young-Hyo Chang6, Insoon Park6, and Joong-Ki Kook1,2* |
| Address | 1Department of Oral Biochemistry, College of Dentistry, Chosun University, Gwang-ju 501-759, Republic of Korea, 2The Second Stage of BK21 High-tech Dental Care and Human Resource Training Center, Chosun University, Gwang-ju 501-759, Republic of Korea, 3Department of Orthodontics, College of Dentistry, Chosun University, Gwang-ju 501-759, Republic of Korea, 4Department of Pediatric Dentistry, College of Dentistry, Chosun University, Gwang-ju 501-759, Republic of Korea, 5Professor Emeritus, College of Dentistry, Seoul National University, Seoul 110-749, Republic of Korea, 6Korean Collection for Type Cultures, Biological Resources Center, Korea Research Institute of Bioscience and Biotechnology, Daejon 305-333, Republic of Korea |
| Bibliography | Journal of Microbiology, 45(3),246-255, 2007, |
| DOI | |
| Key Words | biotype, dex gene, mutans streptococci, 16S rDNA |
| Abstract | Mutans streptococci have been implicated as cariogenic bacteria in dental caries because they can produce high levels of dental caries-causing lactic acid and extracellular polysaccharide. The aim of this study was to isolate and characterize the mutans streptococci from the dental plaque obtained from Koreans. The dental plaque samples were collected from the anterior and molar teeth of both jaws in 155 subjects (aged 2 to 33.2 years, average age 13.7±4.7 years). The samples were diluted by 100-fold in 1x PBS and plated on mitis-salivarius bacitracin (MSB) agar plates. The mutans streptococci grown on MSB plates were screened by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) targeting dextranase gene (dex). The mutans streptococci were identified at the species level using a 16S rDNA sequencing comparison method. The biochemical tests were carried out to biotype the mutans streptococci. Ninety-five strains of the mutans streptococci out of 358 colonies, which were derived from 141 subjects, were isolated. Of them, 77 strains and 18 strains were Streptococcus mutans and Streptococcus sobrinus, respectively. The biotyping data showed that 62, 1, 20, 10, and 2 strains were biotypes I, II, IV, V and variant, respectively. Of the two strains of variant biotype, one strains was similar to biotype IV except that it was positive to the arginine hydrolysis test. We considered this one strain a new biotype, and classified it as biotype VII. In conclusion, S. mutans and its biotype I was most frequently isolated in Korean dental plaque. The mutans streptococci strains isolated in this study might be useful for the study of the pathogenesis and the prevention of dental caries. |
| Download PDF | 45(3)-10.pdf |