Metagenomics of Cariogenic Microbiota in Primary Teeth with Deep Dentinal Caries: An Illumina-Based Sequencing Study

Abstract

Discrepancy in the dynamic metabolic progression of the dental biofilm leads to dental caries, which is a polymicrobial infection. The homeostasis of the biofilm is unaffected and is not apparent unless there is an imbalance in the mineralization pattern of the supragingival biofilm. Literature provides numerous facts on microorganisms related to dental caries. Pathologic colonizers in the early stages of tooth decay involve organisms like Streptococcus oralis, subsequent adherence of Streptococcus sobrinus, and Streptococcus mutans[1]. Reports suggest the association of highly complex, variable, and uncultivable microbial population with dental caries, even though prime organisms are commonly known to be allied with disease succession. Association of mutans group streptococci and lactobacilli with the initiation of caries and early caries development have been well documented [2]. Studies have shown transition of early caries causing gram-positive primary facultative bacteria to anaerobic gram-positive rods and cocci and gram-negative rods as the lesion progresses to deep carious lesion[3]. Mapping of bacterial taxa revealed up to 14 phyla along with 101 genera. This comprised around 706 diverse OTUs (Operational Taxonomic Units). Caries progression at various stages and bacterial profile of different species associated with several disease have been observed. Some of the observed species found abundantly in whitespot lesion and dentin lesion of both dentitions were S. Parasanguinis and S. salivarius[4]. Molecular methods for bacterial identification and enumeration are performed routinely to precisely study bacterial species associated with dental caries, including those that are not presently cultivable.