Figure 1.

Subgingival biofilm samples from pathological periodontal pockets cultivated on blood agar plates for 48 h at 37 °C in an anaerobic atmosphere. (A) Sample obtained from a periodontal pocket of a middle-aged patient diagnosed with generalized chronic periodontitis. The macroscopical observation of the plated sample showed occurrence of a variety of colonies corresponding to different bacterial species. (B) Sample obtained from a periodontal pocket of a 25-year-old patient diagnosed with localized aggressive periodontitis. The macroscopical observation of the plated sample showed predominantly the occurrence a single colony type. (C) Microscopical (50× magnification) examination indicated that all colonies belonged to the A. actinomycetemcomitans species, which was confirmed in assays based on genetic characterization.