Title: 1217 - Correlation of Mutans Streptococci Bacteriocin Genes to Children’s Caries Status


Ling Zhan (Presenter)
University of California, San Francisco

Iveta Markova-Mitev, University of California, San Francisco
charles Le, University of California, San Francisco
John Featherstone, University of California, San Francisco
Jing Cheng, University of California, San Francisco


Objectives: To assess prevalence of three novel antimicrobial peptide genes (NN2, PNS1, TKS1) of mutans Streptococci (MS) in 2-5 year old children with different caries status.

Methods: Eighty-two caries-free (CF) children and 36 children (age 2-5 years old) with severe early-childhood caries (S-ECC) were recruited. Oral MS levels were enumerated from oral swabs by selective culture. The presence of NN2, PNS1, TKS1 genes were identified by high-throughput illumina sequencing of MS isolates or by SYBR green qPCR assays. The prevalence of each single gene or gene combinations was compared by Chi Square test/Fisher’s exact test between CF and S-ECC groups and Odds Ratios were calculated. MS levels and decayed surfaces in subjects with or without a specific gene or combination of the genes were compared.

Results: Thirty-nine (47.6%) CF and 36 (97.3%) S-ECC subjects had MS infection. In MS infected children, PNS1 was the most commonly detected gene (38%) followed by NN2 (16%) and TKS1 (19%). TKS1 always co-exists with PNS1. Eight (21%) CF subjects vs 21 (58%) S-ECC subjects had at least one gene present (P<.05). By single gene, only PNS1 was significantly more prevalent in S-ECC than CF group (P<.05). When genes were combined, PNS1+NN2 and PNS1-TKS1 combinations were significantly more prevalent in the S-ECC than CF group (P<.05) with the highest odds ratio (9.17) in PNS1-TKS1 gene combination. There were no statistically significant differences in MS levels between subjects with and without any of the three genes (P>.05). However, subjects with PNS1 or PNS1+TKS1 had significantly more decayed surfaces (P<.05).

Conclusions: Combinations of PNS1, NN2 and TKS1 genes and their products may contribute to the subject’s caries risk. Future studies with larger sample-size and prospective longitudinal studies are needed to better understand the relationship of these genes with caries risk in children.

This abstract is based on research that was funded entirely or partially by an outside source:
The study is supported partially by NIH/NIDCR U54DE019285.

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: none