The role of non-human primates as reservoirs of multidrug-resistant Gram-Negative bacteria in Maranhão

• Grant number: 24/20698-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2025
• End date: January 31, 2026
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Preventive Veterinary Medicine
• Principal Investigator: Natália Carrillo Gaeta
• Grantee: Sabrina Pereira da Silva
• Host Institution: Universidade de Santo Amaro (UNISA). São Paulo , SP, Brazil

Abstract

Antimicrobial-resistant bacteria represents one of the most significant challenges in global public health, impacting both human and animal populations. Gram-negative bacteria are particularly notable due to their ability to inactivate antibiotics through enzymes such as extended-spectrum beta-lactamases (ESBLs) and carbapenemases. These enzymes neutralize widely used antimicrobials, compromising both medical and veterinary treatments and increasing the risk of untreatable infections. In pristine ecosystems, such as non-human primate habitats, antimicrobial resistance can persist even without direct antibiotic use, transmitted through indirect contact with contaminated soil and water. Primates, in this context, serve as bioindicators of resistance, providing a unique perspective for environmental monitoring and public health studies within the One Health approach. This study aims to investigate antimicrobial resistance in Gram-negative bacteria from the fecal microbiota of non-human primates in Maranhão, Brazil. The research includes the isolation and identification of bacterial species, resistance assessment through antimicrobial susceptibility testing, and the detection of resistance genes via PCR, focusing on genes associated with beta-lactamases and other clinically significant antimicrobials. Fecal samples will be collected from up to 30 primates, cultured on MacConkey agar to isolate Gram-negative bacteria, whose antimicrobial susceptibility will be evaluated by disk diffusion. Additionally, 22 clinically significant resistance genes will be assessed in the fecal samples using PCR (single or multiplex assays). The findings will contribute to the understanding of resistance reservoirs and the role of primates in the dissemination of resistance genes, reinforcing the need for continuous monitoring in veterinary health.