AUTHOR=Villhauer Alissa , Zhu Min , Shi Wei , Xie Xian Jin , Hughes Pamella , Lesch Amy , Weber-Gasparoni Karin , Kolker Justine , Drake David , Banas Jeffrey A. 

TITLE=Role of mutans streptococci, acid tolerant bacteria and oral Candida species in predicting the onset of early childhood caries

JOURNAL=Frontiers in Dental Medicine

VOLUME=Volume 4 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/dental-medicine/articles/10.3389/fdmed.2023.991746

DOI=10.3389/fdmed.2023.991746

ISSN=2673-4915

ABSTRACT=Aim:  Early childhood caries is the most common chronic infectious disease in children in the United States. This study, which is part of a larger, longitudinal study exploring oral microbiological components of caries development in children, reports on the impact of total mutans streptococci (MS), total acid-tolerant bacteria and Candida species on the development of dental caries in a subset of these children. Of particular interest was the relationship between caries development and co-colonization of mutans streptococci and Candida species.
Methods: Children between the ages of 12 and 47 months displaying no evidence of dental caries were recruited for a longitudinal study (n=130). Twelve age- and gender-matched pairs were selected. In each pair, one child developed caries during the study, and one did not. Whole mouth plaque samples were collected by swab at baseline and every 6 months thereafter for a duration of 18 months and spiral plated for microbial counts (CFU/ml). Cut-offs based on percent of total cultivable flora were designated for all microbial measures. A scoring system designated the Plaque Microbial Index (PMI) was developed for use in statistical analyses to assess potential predictive factors for caries risk assessment. 
Results:  Children who developed caries were significantly more likely to harbor higher percentages of acid tolerant bacteria (p=0.003), MS (p<0.001) and have Candida species present (p<0.001) at ≥1 visit leading up to caries onset. Mean PMI scores derived from the aforementioned microbial measures, were higher for caries active children than caries free children (p=0.000147). Co-colonization of MS and Candida species was significantly associated with caries development (p<0.001) and detection of both at the same visit had a 100% positive predictive value and 60% negative predictive value for caries development. 
Conclusion: In children who developed caries, there was a statistically significant association with the percent of total flora that was acid tolerant, the percent of MS, the presence of Candida and co-colonization of MS and Candida species. Combining these microbial measures into PMI scores further delineated children who developed caries from those who remained caries-free. These microbiological measures show potential as predictive factors and risk assessment tools for caries development.