The role of Staphylococcus chromogenes in udder health

• Grant number: 24/02797-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: October 01, 2025
• End date: September 30, 2028
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
• Principal Investigator: Nathalia Cristina Cirone Silva
• Grantee: Bruna Lourenço Crippa
• Host Institution: Faculdade de Engenharia de Alimentos (FEA). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Mastitis is the most prevalent disease in dairy herds, impacting global production. Among the main causative agents is Staphylococcus aureus, and treating mastitis caused by this microorganism is difficult due to the multiple virulence and resistance factors that this species presents. Furthermore, Staphylococcus non-aureus (NAS) has been mentioned in studies as a causative agent of mastitis and as a prevention agent against other pathogens, mainly Staphylococcus chromogenes, the predominant species that stands out among the other NAS Therefore, this study aims to carry out complete genome sequencing and evaluate the competitive potential of S. chromogenes isolated from cow's milk concerning S. aureus that causes mastitis. There will be 70 isolates of S. chromogenes, 32 isolated from cows with subclinical mastitis, and 38 isolated from healthy cows. These strains will be evaluated for their antimicrobial activity against S. aureus previously isolated from mastitis, being susceptible (MSSA) and methicillin-resistant (MRSA) strains. Initially, screening will be carried out to determine whether S. chromogenes strains can inhibit the growth of S. aureus. Next, a survival curve will be carried out, and subsequently, the complete genome sequencing of the S. chromogenes strains will be performed to compare the genomes with the observed inhibitory activity