Related Experiment Video
Updated: Aug 17, 2026

Isolation of Epithelial Cells from Human Dental Follicle
Published on: November 5, 2021
First isolation of Streptococcus downei from human dental plaques
So Young Yoo1, Kwan-Joong Kim, Seong-Hoon Lim
1Department of Oral Biochemistry, College of Dentistry, Chosun University, 375 Seo-Suk Dong, Dong-Ku, Gwang-ju 501-759, Republic of Korea.
Abstract:
In this study, we isolated four bacterial strains grown on mitis-salivarius sucrose bacitracin agar. The strains had similar biochemical characteristics to biotypes I or II of mutans streptococci. The four isolates were identified as Streptococcus downei by 16S rDNA and dextranase gene (dex) sequencing as well as polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) targeting dex. To our knowledge, this is the first report of the isolation and identification of S. downei from dental plaque in humans. The results suggest that S. downei can inhabit the human oral cavity.
Related Concept Videos
Development of the Oral Microbiota
The Oral Microbiota
Streptococcal Pharyngitis
