Uncovering Antimicrobial Metabolites from Frog Skin Symbionts Inhabiting the Brazilian Atlantic Forest

• Grant number: 25/17394-9
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: February 10, 2026
• End date: February 09, 2027
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Nilton Erbet Lincopan Huenuman
• Grantee: Zuleyma Johana Becerra Tellez
• Supervisor: Christian Hertweck
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Leibniz Institute for Natural Product Research and Infection Biology, Germany
• Associated to the scholarship: 23/18292-0 - BiocinBR: Bacteriocin research platform to combat pathogens resistant to critical priority antimicrobials in Brazil, BP.DR

Abstract

The global dissemination of multidrug-resistant (MDR) pathogens listed by the World Health Organization (WHO) represents a public health challenge and highlights the urgent need for the discovery and development of novel antimicrobial agents. Microbial symbionts from amphibian skin could be a source of bioactive metabolites against pathogens such as Batrachochytrium dendrobatidis, a chytrid fungus responsible for the worldwide decline of amphibians. Our results suggest that these skin-associated bacteria might also possess inhibitory activity against WHO pathogens. We evaluated the antimicrobial potential of bacteria isolated from the skin of Phyllomedusa distincta (Anura: Hylidae), an endemic species found in conserved areas of the Brazilian Atlantic Forest, and Aquarana catesbeiana (Anura: Ranidae), an introduced species sampled from an anthropogenically disturbed environment in São Paulo State. Five bacterial strains exhibited inhibitory activity, with the highest effects against methicillin-resistant Staphylococci. These strains were identified as Enterobacter huaxiensis (n = 2), Pseudomonas protegens (n = 2), and P. berkeleyensis (n = 1). During the BEPE internship, under the supervision of Prof. Dr. Christian Hertweck, we will conduct an integrative approach combining genome mining, mass spectrometric imaging, and chemical analysis for the structural identification of the antimicrobial metabolites. This study provides the first genome reports of these bacterial species in South America and the first description of their inhibitory activity against MDR pathogens. These results will enable further biotechnological applications in clinical, veterinary, and agropecuaria settings, while also enhancing our understanding of amphibian skin microbiome diversity. Finally, it will contribute to the development of BiocinBR, Brazil's first database for natural products, hosted at http://onehealthbr.com.