International Journal of Morphology
versión On-line ISSN 0717-9502
SALAZAR, Luis A et al. Molecular Detection of Cariogenic Streptococci in Saliva. Int. J. Morphol. [online]. 2008, vol.26, n.4, pp. 951-958. ISSN 0717-9502. doi: 10.4067/S0717-95022008000400027.
Streptococcus mutans and Streptococcus sobrinus are the main causative organisms of dental caries. Nevertheless, the microbiological and biochemical methods, available at the moment in Chile, do not allow to the fast detection and identification of these bacteria. The aim of this investigation is implement the polymerase chain reaction (PCR) technique to detect the presence of S. mutans and S. sobrinus in saliva. A total of 51 schoolchildren (5 to 17 years oíd) from five different schools from Temuco city (Chile) participated in this study. The presence of salivary mutans streptococci was determined by microbiological method, and the species differentiation was assessed using PCR technique. The sensitivity for the PCR technique was 1000 cfu/mL of saliva, ten times superior to the sensitivity of the microbiological method used (10,000 cfu/mL). In addition, the analysis of the specificity of the amplification, evaluated by enzymatic restriction, confirmed the presence of the investigated bacteria. The prevalence of S. mutans was of 88.2% and for 5. sobrinus was 11.8%. The combined presence of both bacteria was observedin 7.8% of the individuáis. In conclusión, theobtained results indícate that the implemented methodology is useful for the rapid detection of S. mutans and S. sobrinus in saliva.
Palabras clave : Caries; Streptococcus mutans; PCR.