Relationship between Candida albicans and Streptococcus mutans in early childhood caries, evaluated by quantitative PCR.

Background: The aim of this study was to analyze the synergistic relationship between Candida albicans and Streptococcus mutans in children with early childhood caries (ECC) experience. Methods: Dental plaque and unstimulated saliva samples were taken from 30 subjects aged 3-5 years old, half with (n=15, dmft > 4) and half without (n=15) ECC. The abundance of C. albicans and S. mutans and relative to total bacteria load were quantify by real-time PCR (qPCR). This method was also employed to investigate the mRNA expression of glycosyltransferase ( gtfB ) gene in dental plaque. Student's t-test and Pearson's correlation were used to perform statistical analysis. Results: Within the ECC group, the quantity of both microorganisms were higher in the saliva than in dental plaque. The ratio of C. albicans to total bacteria was higher in saliva than in plaque samples (p < 0.05). We observed the opposite for S. mutans (p < 0.05). The different value of C. albicans and S. mutans in saliva was positively correlated, and negatively correlated in dental plaque. Transcription level of S. mutans gtfB showed a positive correlation with C. albicans concentration in dental plaque.  Conclusion: C. albicans has a positive correlation with cariogenic traits of S. mutans in ECC-related biofilm of young children.