Methicillin resistant Staphylococcus aureus: Influence of the use of subinhibitory concentrations on resistance to different antimicrobials and biofilm formation

• Grant number: 24/22619-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2025
• End date: December 31, 2025
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Nathalia Cristina Cirone Silva
• Grantee: Bruna Cavaccini Marretto
• Host Institution: Faculdade de Engenharia de Alimentos (FEA). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Methicillin-resistant Staphylococcus aureus are microorganisms commonly found in dairy products, cases of mastitis, and human infections. The increasing prevalence of resistant strains of this genus within the food chain has raised concerns regarding community transmission, underscoring the importance of One Health studies. This study aims to evaluate the inhibitory concentrations of cefoxitin and sanitizers (benzalkonium chloride and sodium hypochlorite) against MRSA and to investigate the potential effects of subinhibitory concentrations on sessile cells and the subsequent microbial resistance of the isolates, including within biofilms. Ten methicillin-resistant Staphylococcus aureus isolates will be utilized. These isolates will be exposed to subinhibitory concentrations of cefoxitin and sanitizers, followed by the assessment of biofilm formation, resistance, and minimum inhibitory concentrations (MIC) before and after exposure to subinhibitory conditions.