Abstract

Streptococcus mutans is the primary etiological agent for dental caries, an oral disease considered to be a major public health problem worldwide. S. mutans exhibits extensive genotypic diversity, but the role of this variation is poorly understood. Different strains of S. mutans may display different virulence mechanisms as a function of the environment in which they grow, so the isolation of the differentially expressed proteins is very promising.For this study, we obtained the dental plaque from forty volunteer children, in order to isolate S. mutans. Four strains were isolated and genotyped by arbitrarily primed polymerase chain reaction (AP-PCR) using OPA3 primer, which identified three different genotypes. The strains of S. mutans which showed a similar genotype were analyzed by two-dimensional gel electrophoresis (2-D PAGE) to determine whether there were differentially expressed proteins among these strains, which were isolated from different oral conditions. Soluble cellular proteins were extracted from the steady-state planktonic cells of strains 4B and 17B and analyzed using 2-D PAGE. Analysis of the 2-D PAGE gelsrevealed a total of 20 proteins that were differentially expressed. It is of great interest to sequence these candidate proteins in order to predict which ones may participate in the process of adaptation and/or cariogenesis of S. mutans.

Key words: Arbitrarily primed polymerase chain reaction (AP-PCR), two-dimensional gel electrophoresis (2-D PAGE), Streptococcus mutans, genotypes, dental caries