OBJECTIVETo evaluate the feasibility of identifying oral streptococcus by comparing their metabolic profiling, and to find a convenient and rapid way to discriminate oral microorganisms.

METHODSThe pure cultivation of Streptococcus sanguis ATCC 10556 and Streptococcus sobrinus 6715 (reference strain) from solid culture were respectively inoculated in TPY liquid medium. Then the growth quantity was measured periodically by turbidimetry and the growth curves of the inoculated bacteria were completed. The culture solutions in the stationary phase of the two bacteria were centrifuged, and then tested with the 1H-nuclear magnetic resonance (1H-NMR) spectrometer respectively. The gained free induction decay (FID) data were all inputted into MestReC Soft and finally transformed into metabolic profiling. The metabolic profiles were integrated segmentingly and the results were inputted into SIMCA-P Soft for principal components analysis (PCA).

RESULTSThe PCA results showed the obvious clustering phenomena and the points of two group data differentially centralized in two clusters. Therefore, the NMR-based metabonomics profiles can discriminate the two different kinds of bacteria.

CONCLUSIONThe metabonomics can be expected to be a kind of promising useful method in quick discrimination of oral streptococcus.