The relationship between the Cbm and Cnm genes in Streptococcus mutans isolated from arches and brackets of patients and antibiotic resistance profiles.

PURPOSE: Human dental caries is a troublesome disorder of the teeth, and the bacterium mostly responsible is Streptococcus mutans. The Cbm and Cnm genes, which encode the Cbm and Cnm proteins respectively, are two of the virulence factors associated with Streptococcus mutans strains. Oral appliances such as dental arches and brackets accelerate streptococcal colonization and caries formation. The aim of this study was to determine the gene frequency of Cnm and Cbm in Streptococcus mutans strains isolated from oral arches and brackets in orthodontics patients and their relationship to antibiotic resistance.

METHODS: Four hundred seventy-three orthodontics patients were included in this study and 384 Streptococcus mutans strains were isolated from the arches and brackets of these patients. The strains were identified and verified using a Vitek-2 compact system and their antibiotic susceptibility was determined by the disc diffusion method. The presence of the Cbm and Cnm genes was confirmed by the PCR method.

RESULTS: It was found that 2.08% of the strains the Cbm gene and 16.14% the Cnm gene. The rate of co-existence of these two genes was 0.78%.

CONCLUSION: Strains those harbored the Cbm and Cnm genes are more resistant to antibiotics and more likely to be major risk factors for caries in orthodontic patients.