Microarray Analysis of the Microbiota of Young Children

Objectives: This study aimed to improve characterization of the oral microbiota of early childhood caries using rapid molecular methods.

Methods: This case-control study compared socio-demographic, dietary, clinical, and microbiological factors among children with and without dental caries. Ninety children, 46 with dental caries, were sampled in a community dental clinic. Supragingival samples were collected from anterior and posterior teeth and analyzed by PCR for Streptococcus mutans. Posterior samples from age and gender matched children with (n=5) and without (n=5) caries were analyzed using the Human Oral Microbe Identification Microarray (HOMIM). The caries-free samples were also analyzed using 16S rRNA clonal analysis.

Results: 58% of the children were male, mean age 5.57 (±0.17). 58% were Caucasian, 30% African-American, 12% Asian, and 49% Hispanic. 24% of parents had not completed high-school and 54% earned <$20,000/year. Dental caries was associated with daily soda consumption (p=0.02), plaque (p=0.001), gingivitis (p=0.03), and S. mutans detection by PCR in posterior teeth (p=0.001, 35/53 S. mutans positive had caries). S. mutans in posterior teeth was associated with plaque (p=0.001), gingivitis (p=0.05), household earning >$20,000 (p=0.006), and soda consumption (p=0.03). 57 named species and 10 phylotypes were identified by HOMIM. Caries and caries-free children shared a high prevalence of Streptococcus species. Rothia dentocariosa/mucilaginosa was detected more frequently in caries and S. sobrinus was detected only in caries. Comparison of HOMIM and clonal analyses showed 10 species detected by both methods (including S. mitis, S. oralis and Gemella morbillorum), 41 species and 8 phylotypes detected only by HOMIM, and 12 species and 2 phylotypes detected only by clonal analysis.

Conclusion: A wide range of species, in addition to S. mutans and S. sobrinus, were identified in young children. HOMIM provided a rapid identification of multiple oral species in early childhood caries.

Supported by NIH/NIDCR DE14264, DE11443, T32 DE007151, DE007327-07