Helicobacter pylori and Streptococcus pyogenes in Dental Plaque of Children

Helicobacter pylori infection and beta-hemolytic streptococcal pharyngitis are common bacterial infection in children. These pathogens are found in dental plaque. However, the identification of them in rampant caries children has not been reported. Objective: to assess the prevalence of Helicobacter pylori and Streptococcus pyogenes in dental plaque of children with rampant caries compared with caries-free children. Methods: 67 healthy children, aged 31-140 months [rampant caries group(n=37) and caries-free group(n=30)] participated in this study. Their parents were interviewed for children's demographic information and the subjects' oral health was examined including DT(dt), DS(ds), and debris index. A sterile spoon excavator size 1.5 mm was used to scrape 2 mg of supragingival plaque from molars and then transferred into tubes containing reducing transport fluid(RTF). The quantity of microorganisms was examined by culturing in their selective media; for H. pylori contained nalixidic acid, vancomycin, trimethoprim, amphotercin and 5% sheep blood where as trimethoprim and sulfamethoxazole for S. pyogenes. In addition, the PCR assay was used for the detection of H. pylori. The prevalence of both organisms between rampant and caries-free children were compared by chi-square test at 0.05 significant level. Results: The prevalence of H. pylori by culturing method in rampant caries and caries free group was 0.03% and 0%, whereas by PCR technique was 86.5% and 90.0%, respectively. S. pyogenes of the rampant caries and the caries-free groups were 10.0% and 10.8%, respectively. There were no significant difference in the prevalence of H. pylori and S. pyogenes in dental plaque between both groups. Conclusions: (i)There was no significant difference in the prevalence of Helicobacter pylori between the rampant caries and caries-free groups. (ii)The detection rate of S. pyogenes in dental plaque was rather low and there was no significant difference between both groups. This study was supported by Thai Health Promotion Foundation.