Methods: 33 patients with clinical and radiological proof of aggressive periodontitis and 20 healthy subjects were enrolled in this study. API, GI, BOP, CAL and PD were recorded in a six-point-measurement per tooth. Samples of the subgingival biofilm were taken with paper points from 4 teeth of each individual. The paper points were immersed in thioglycolate broth. 10-2 – 10-5 broth dilutions were cultured on sheep blood agar at 37°C in aerobic atmosphere. Alpha- or non-hemolytic, small and catalase negative colonies were biochemical identified with the rapid ID 32 STREP system (bioMerieux, Lyon, France) and MALDI-TOF-MS. All mass spectra were acquired using an Autoflex (Bruker Daltonics, Bremen, Germany) operated under the Flexcontrol software ver.2.4 (Bruker Daltonics). Automated peak extraction was done with Flexanalysis ver.2,4 (Bruker Daltonics). For spectra identification was used MatLab 7.3 (The Mathworks Inc., USA) and a database with 20 species of oral streptococci identified by PCR and 16S rDNA sequencing. Chi-square and Mann-Whitney-U-test were used for statistical analysis.
Results: We identified a total of 134 strains of oral streptococci (11 species), the most prevalent ones being S.oralis 36 (67,9%),S.sanguinis 33 (62,3%), S.mitis 17 (32,1%), S.gordonii 8 (15,1%) S.constellatus 8 (15,1%). S.sanguinis was significantly more often found in healthy subjects (p=0,001). Mann-Whitney U-test showed that the absence of S.sanguinis is significant associated with high values of API, GI, BOP, CAL and PD (p=0.001-0.002).
Conclusions: The association with health instead of aggressive periodontitis confirms that S.sanguinis could be considered as one of the “protective bacteria” from subgingival biofilm. Otherwise, there were no significant differences in distribution of oral streptococci species in patients and healthy subjects.