Profiling of dental plaque microflora on root caries lesions and the protein-denaturing activity of these bacteria

Kazuhiro Hashimoto, Takuichi Sato, Hidetoshi Shimauchi, Nandobuhiro Takahashi

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


Purpose: To profile plaque microflora on root-caries lesions, and to examine the protein-denaturing activity as a pilot study. Methods: Six subjects with root-caries were investigated. Plaque samples on root caries lesions (R), as well as from healthy supragingival sites (S) and periodontal pockets (≥5 mm) (P) were collected and cultured anaerobically on blood agar plates. The isolated bacteria were identified by 16S rRNA sequencing analysis, and examined for the protein-denaturing activity using the skim-milk plates and the SDS-PAGE, and for the acidogenicity using the FAB broth containing 1% glucose. Results: Propionibacterium, Actinomyces, Streptococcus, Lactobacillus and Bifidobacterium were predominant in R, while Actinomyces, Streptococcus, Veillonella and Capnocytophaga in S, and Actinomyces, Prevotella, Actinobaculum, Streptococcus, Olsenella and Eubacterium were predominant in P. Proteolytic bacteria comprised 40%, 26% and 57% of microflora in R, S and P, respectively. The skim-milk plates distinguished between protein-degrading and protein-coagulating bacteria, which comprised 7 and 33%, 0 and 26%, and 17 and 40% of microflora, in R, S and P, respectively. The SDS-PAGE analysis revealed that protein-degrading isolates were capable of degrading collagen molecules. Furthermore, the final culture pHs of protein-degrading and -coagulating bacteria were 5.0-5.4 and 3.8-3.9, respectively. The latter pH was low enough to denature proteins in skim milk. The microbial composition of R was distinct from those of S and P.

Original languageEnglish
Pages (from-to)295-299
Number of pages5
JournalAmerican Journal of Dentistry
Issue number5
Publication statusPublished - 2011 Oct 1

ASJC Scopus subject areas

  • Dentistry(all)


Dive into the research topics of 'Profiling of dental plaque microflora on root caries lesions and the protein-denaturing activity of these bacteria'. Together they form a unique fingerprint.

Cite this