Molecular study of new bacterial species and antimicrobial agents to control multispecies biofilms associated with early childhood caries

• Grant number: 14/13806-6
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: October 14, 2014
• End date: April 13, 2015
• Field of knowledge: Health Sciences - Dentistry - Pediatric Dentistry
• Principal Investigator: Cristiane Duque
• Grantee: Paula Fernanda Kreling Domingues
• Supervisor: Anne C. R. Tanner
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil
• Institution abroad: Forsyth Institute, United States
• Associated to the scholarship: 13/12285-0 - Evaluation of the antimicrobial activity and cytotoxicity of cationic peptide fragments isolated or in combination in the prevention of dental caries., BP.DR

Abstract

Early childhood caries (ECC) is a microbial infection that can severely compromise the dentition of young children. The etiology of ECC includes bacterial infection, dietary and host immunological factors. Recent studies in the US and UK suggest the importance of Bifidobacterium and Scardovia species in the etiology of early childhood caries, in addition to the traditional caries pathogens. Components of the innate immune system, such as antimicrobial cationic peptides (AMCP), are responsible for the maintenance of the ecological balance without development of opportunistic infections. Studies however, have demonstrated that children with ECC have low levels of some AMCP when compared to caries free children. The application of AMCP peptides or their fragments as antimicrobial agents could be an alternative to control biofilm of bacteria associated to ECC. The objectives of this study will be: 1) to detect new bacterial species, including Scardovia wiggsiae from caries free (CF), ECC and severe-ECC (S-ECC) children and; 2) to evaluate the inhibitory activity of AMCP fragments on mono and multispecies biofilms of cariogenic reference strains and clinical S. mutans isolates. In objective 1, saliva will be assayed from CF, ECC and S-ECC for putative cariogenic bacterial counts by Real Time-PCR, and selective isolation of S. mutans with PCR analysis. In objective 2, AMCP fragments will be tested against mono and multispecies biofilms containing cariogenic reference strains and S. mutans strains isolated from ECC children using qPCR and colorimetric assays and confocal microscopy. Data will be statistically analyzed considering p value less than 0.05. This study intends to contribute to study of new bacterial species associated to ECC and evaluate alternative antimicrobial agents to control multispecies biofilm. (AU)