Oral active microbiota of dental caries

Identifying the microbial species in caries lesions is instrumental to determine the etiology of dental caries. However, a significant proportion of bacteria in carious lesions have not been cultured, and the use of molecular methods has been limited to DNA-based approaches, which detect both active and inactive or dead microorganisms. To identify the RNA-based, metabolically active bacterial composition of caries lesions at different stages of disease progression in order to provide a list of potential etiological agents of tooth decay. Non-cavitated enamel caries lesions (n=15) and dentin caries lesions samples (n=12) were collected from 13 individuals. RNA was extracted and cDNA constructed, which was used to amplify the 16S rRNA gene. The resulting 780 bp PCR products were pyrosequenced using Titanium-plus chemistry and the sequences obtained were used to determine the bacterial composition.