Effect of smoking on colonization by Bacteroides forsythus in patients with chronic periodontitis

Bacteroides forsythus is the least investigated species of the "red complex" of bacteria responsible for periodontitis. This is due, at least in part, to the difficulty in identifying these bacteria by classic techniques requiring in vitro cultures. Thus, the aim of the current study was to design a fast and robust technique for the detection of B. forsythus. For this purpose, DNA was isolated by magnetic microbeads from dental plaque and gingival crevical fluid, and the presence of the gene coding for 16S rRNA of B. forsythus was detected by conventional of quantitative real-time PCR. The study enrolled patients affected by periodontitis and healthy subjects, and both groups were comprised of heavy and mild smokers. The assays revealed that bot gingival fluid and dental plaque served well as the material for test samples. The periodontitis group had a markedly higher rate of infection by B. forsythus than healthy subjects. The infection rate was also higher in the group of smokers but did not depend on whether the patients were heavy or mild smokers. In conclusion, the novel methodology may become a powerful tool in the hands of clinicians, allowing them to obtain a faster and more accurate diagnosis of B. forsythus in periodontal infections.