Detection of Streptococcus mutans and Streptococcus sobrinus and Their Association with Oral Microbiome Stressors in 6–18-month-old Infants

AIM: To determine the presence of Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus) and their association with extrinsic and intrinsic variables in 6–18-month-old infants. METHODS: This was an analytical, cross-sectional study of 65 6–18-month-old infants who visited the Centers for Early Childhood in Buenos Aires City. Three groups were established according to the presence of teeth—group I (GI)—edentulous infants, group II (GII)—infants with 1–8 teeth, and group III (GIII)—infants with 9–16 teeth. Data on the variables, diet, use of artificial teats, and oral hygiene were gathered using a self-administered questionnaire. An oral examination was performed according to the International Caries Detection and Assessment System (ICDAS II) criterion. A saliva sample was taken by aspiration with a sterile plastic syringe. Cariogenic Streptococci (CS) were counted using the adherence test in modified gold broth (AT-MGB). Molecular detection and quantification were performed by quantitative polymerase chain reaction (qPCR) (gtfB, gtfT, and tuf). RESULTS: A total of 12% of infants received oral hygiene, 38% used bottles, 30% used pacifiers, and 55% had sugar intake. S. sobrinus and S. mutans were detected in 57.1 and 28.6% of the children with caries, respectively. Groups I, II, and III had CS counts of log 2, 3.4, and 3.7, respectively. S. sobrinus was detected in 26.7% of GI, 52.9% of GII, and 85.7% of GIII, while S. mutans was detected in 13.3%, 35.3%, and 57.7%, respectively. CONCLUSION: The prevalence of S. sobrinus was higher than S. mutans in all groups. The presence of CS was significantly associated with sugar intake. No association was found between S. mutans and S. sobrinus and the presence of caries, hygiene habits, or use of artificial teats. CLINICAL SIGNIFICANCE: This study supports the role of diet in developing a cariogenic biofilm in children under 2 years of age. HOW TO CITE THIS ARTICLE: Cornejo CF, Soken LJ, Salgado PA, et al. Detection of Streptococcus mutans and Streptococcus sobrinus and Their Association with Oral Microbiome Stressors in 6–18-month-old Infants. Int J Clin Pediatr Dent 2023;16(1):68-73.