Influence of agents on Streptococcus mutans cell wall and cell membrane hydrophobicity, fatty acid composition, and structure

• Grant number: 22/10992-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2022
• End date: February 29, 2024
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Marlise Inêz Klein Furlan
• Grantee: Rebeca Correa Saes
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil
• Associated research grant: 21/06801-1 - Extracellular matrix: from biology to strategies for controlling cariogenic biofilms, AP.JP2

Abstract

It is unknown how changes in cellular hydrophobicity, the fatty acid composition of the cell membrane, and cell wall and cell membrane structure, triggered by agents used for controlling S. mutans biofilm formation, contribute to the alteration of biofilm formation. The cell wall provides sites for extracellular matrix components bridging the cells within the biofilm, while cell wall and cell membrane modifications can affect cell survival. Therefore, the aim is to evaluate the changes in cell hydrophobicity, the fatty acid composition of the cell membrane, and cell wall and cell membrane structure triggered using agents that target the cell wall and the cell membrane. Hence, bacterial cells will be grown in distinct growth phases and treated with different agents with known targets in the cell: tt-farnesol (cell membrane), compound 1771 (lipoteichoic acid synthesis, found in the cell wall), sodium fluoride (agent used in oral care formulations to promote remineralization of teeth; enolase from the glycolytic pathway in the bacterial cell), or no agent (vehicle control). The treated cells will be assessed using methodologies to determine the hydrophobicity (phase separation method; hydrophilic cells in the aqueous phase and hydrophobic cells in the oil phase), the composition of cell membrane fatty acid (Membrane Fatty Acid Analysis - FAME), and structure (ultrastructure via transmission electron microscopy, cell morphology via scanning electron microscopy). The images will be described qualitatively. The quantitative data will be analyzed using descriptive and inferential statistics (±=0.05). The changes in the parameters evaluated may explain how they contribute to the prevention of biofilm construction by the agents tested.(AU)