Analysis of microbial communities associated with occult caries and periodontal pockets by denaturing gel gradient electrophoresis and 16s rDNA gene sequencing

• Grant number: 06/07120-8
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2007
• End date: April 30, 2009
• Field of knowledge: Health Sciences - Dentistry - Periodontology
• Principal Investigator: Reginaldo Bruno Gonçalves
• Grantee: Reginaldo Bruno Gonçalves
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

It is estimated that only 50% of oral bacteria can be cultivated and it is possible that pathogenic microorganisms are also found among non cultivated ones. The main model for studying microbial diversity is amplifying the 16S rDNA gene, cloning of the amplicons in Escherichia coli, and sequencing the cloned inserts. Besides, the technique of denaturating gradient gel electrophoresis (DGGE) has been demonstrating a great potential for qualitative studies of microbial constitution in the oral cavity. The present project aims to evaluate and compare, by DGGE technique, the genetic profile of microbial communities associated with healthy periodontal sites and sites showing periodontal pockets of 3 to 7 mm It also aims to evaluate the genetic profile of microbial communities associated with clinically detectable dentine caries lesions and occult caries lesions. Clinical samples of the referred sites will be collected, DNA will be extracted and a PCR will be performed for amplification of the 16S rDNA gene. The PCR products will run through a denaturating gradient gel (DGGE) and the bands obtained will be analyzed. After that, the dominant bands will be purified, cloned in E. coli cells and sequenced for identification of microorganisms present in the samples. (AU)