Investigating Resistance Mechanisms and the Influence of non-aureus Staphylococci Isolates from Teat Skin on the Adaptive Strategy of S. aureus

• Grant number: 24/05074-7
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Effective date (Start): August 01, 2024
• Effective date (End): February 28, 2025
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
• Principal Investigator: Marcos Veiga dos Santos
• Grantee: Erika Carolina Romão Bonsaglia
• Supervisor: Luciano Caixeta
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Research place: University of Minnesota, St. Paul (U of M), United States
• Associated to the scholarship: 22/13775-0 - Virulence factors and inflammatory response of S. aureus isolated from clinical and subclinical Mastitis and expression of cytokines in Bovine Mammary Epithelial Cells (BMEC), BP.PD

Abstract

The persistence of mastitis as a prominent challenge in the dairy industry continues to significantly impact both the quantity and quality of milk produced. Recent research highlights the crucial role of non-aureus Staphylococci (NAS) not only in the development but also in the prevention of mastitis, underscoring the urgent need for a deeper analysis of its interactions with conventional pathogens. The growing concern regarding antimicrobial resistance emphasizes the urgency of reducing antibiotic use in livestock, making it essential to explore alternatives for mastitis control. The inhibitory potential of NAS against Staphylococcus aureus presents a promising strategy for managing this condition, regardless of antibiotic use. The aim of this research project is to deepen the understanding of competitive dynamics between S. aureus and NAS, with the goal of identifying the genetic mechanisms underlying S. aureus resistance to NAS. To achieve this objective, strains of non-aureus Staphylococci isolated from the teat skin of organic dairy cows in lactation will be used, along with strains of S. aureus, to evaluate the inhibitory capacity of these strains. Additionally, experiments will be conducted to select resistant mutants of S. aureus that grow in the presence of NAS. These mutants will undergo whole-genome sequencing to identify the genetic variations associated with resistance to NAS. Bioinformatic analysis of the sequencing data will include identifying antimicrobial resistance genes, virulence factors, and gene clusters associated with the production of antimicrobial peptides.