Dental caries is a multifactorial biofilm-related disease in which mutans and non-mutans Streptococcus species harboring glucosyltransferase (gtf) genes play significant roles. This cross-sectional analytical study aimed to investigate the prevalence, bacterial load, and molecular distribution of Streptococcus species and gtf genes among Turkish mother-child pairs. A total of 72 mother-child pairs (144 saliva samples) were analyzed by culture, quantitative CFU counting, PCR, and RFLP. Microbial load was expressed as colony-forming units per milliliter (CFU/mL), and correlations between bacterial density and DMFT indices were statistically analyzed. Dental examinations were carried out by two calibrated pediatric dentists (Cohen’s κ = 0.85) according to WHO criteria. Sociodemographic and behavioral data were recorded through structured questionnaires. Exclusion criteria included antibiotic use within the past 14 days, supported by published data showing that the oral microbiota re-equilibrates within 2 weeks after exposure. Statistical analyses were performed using chi-square and correlation tests, and effect sizes and 95% confidence intervals were calculated. S. mutans, S. sanguinis, and S. oralis were the predominant species. Quantitative analysis expressed as CFU/mL revealed a mean S. mutans load of 5.43 ± 0.52 log₁₀ CFU/mL in mothers and 5.09 ± 0.60 log₁₀ CFU/mL in children (p = 0.013). Six gtf genes (gtfD, gtfT, gtfK, gtfP, gtfR, and gtfG) were variably detected across isolates, with maternal enrichment of S. oralis gtfR (p = 0.042, OR = 2.84, 95% CI = 1.02–7.95). Spearman’s and Pearson’s analyses revealed significant correlations between brushing frequency and DMFT scores (r =-0.46 in mothers; r =-0.52 in children), maternal education and S. mutans prevalence (r = 0.39), sugar intake and DMFT (r = 0.47), and maternal–child DMFT values (r = 0.42, p < 0.01). Effect sizes and 95% confidence intervals were calculated for all key associations, providing greater statistical transparency and methodological rigor. By incorporating CFU/mL quantification and expanded gtf gene profiling, this study delivers a more comprehensive evaluation of microbial-behavioral interactions. Multispecies gtf gene carriage was demonstrated for the first time in a Turkish population, highlighting vertical microbial transmission and interspecies glucan-synthesis pathways relevant to pediatric dentistry. The consistent detection of gtf-positive streptococci, including non-mutans species, underscores the clinical importance of maternal microbial screening. Routine CFU-based and genotypic monitoring could improve individualized caries-risk assessment and guide family-centered preventive strategies in pediatric dentistry.
Şeker et al. (Wed,) studied this question.