Phenotypic and genotypic characterization of multidrug-resistant enterobacteria isolated from surfaces in the Equine Medical and Surgical Clinic at HOVET-USP

• Grant number: 25/20734-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2025
• End date: November 30, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
• Principal Investigator: Marcos Bryan Heinemann
• Grantee: Giulia Haibara de Natal
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Monitoring multidrug-resistant bacteria on veterinary hospital surfaces helps in assessing biosafety, sanitary control, and identifying sources of contamination in equine clinical and surgical environments. Therefore, this study aims to evaluate biofilm formation capacity and susceptibility to antimicrobials, detect resistance genes to ¿-lactams, quinolones, and quaternary ammonium, and analyze the phylogenetic relationship of Enterobacterales isolated from surfaces in the equine clinical and surgical sector of HOVET-USP. Between September and October 2024, strains of Enterobacter hormaechei, Escherichia coli, and Klebsiella pneumoniae resistant to third-generation cephalosporins were isolated from surface swabs collected at the Equine Clinical and Surgical Service of HOVET-USP. The isolates will undergo phenotypic testing (disc diffusion and microdilution) to determine their antimicrobial susceptibility profile. DNA extraction and PCR will be performed to search for genes resistant to ¿-lactams, quinolones, and quaternary ammonium compounds. Biofilm tests and SE-AFLP typing for phylogenetic analysis will also be performed to assess clonal diversity and possible intra-hospital spread.