Influence of agents and extracellular matrix in the generation of persisters cells in biofilms and characterization of the extracellular matrix produced by persisters cells

Abstract

Dental caries is a worldwide public health problem caused by the interaction between microorganisms in the biofilm and the diet. A diet rich in carbohydrates provides substrates for acid production and extracellular matrix build-up. This matrix is comprised mostly of exopolysaccharides and maintains the acids inside the biofilms and at the interface biofilm-teeth surfaces, hindering the neutralization by saliva and leading to teeth demineralization. Among the preventive approaches for dental caries is the use of bioactive agents that affect the virulence and/or the ability of pathogenic microorganisms to develop biofilms, especially matrix build-up. However, little is known about how the use of antimicrobial and antibiofilm agents in the oral cavity is involved in microbial tolerance and resistance. Specifically, it is unknown how the active principles of treatments act on the generation of persisters cells (i.e., microbial cells that exhibit tolerance to drugs). The matrix is a trait inherent to all biofilms; however, it is unknown the role of persisters cells in the matrix production and build-up (and vice-versa). Therefore, the proposal will investigate how agents and extracellular matrix influence the generation of persisters cells in biofilms and will characterize the matrix derived from persisters cells. Agents will be used to generate persisters cells that will be used to grow biofilms, which will be characterized via quantification of microbial population and matrix components, tridimensional structure, and gene expression. Next, a formulation will be developed with agents that yield fewer persisters cells and matrix with a lower amount of exopolysaccharides. The efficacy of this formulation will be determined via the evaluation of the microbiota and matrix of microcosmos biofilms (derived from saliva) and demineralization of the enamel surface. (AU)