Calvo Fernández, CristinaDolcet Negre, Marta M.Martín-Maldonado Jiménez, BárbaraPulido Vadillo, MarioMontero, NataliaSuch, RogerGacía Vila, EncarnaciónDelgado Blas, Jose F.González Zorn, Bruno2025-09-292025-09-292025Calvo-Fernández, C., Dolcet-Negre, M. M., Martín-Maldonado, B., Pulido-Vadillo, M., Montero, N., Such, R., García-Vila, E., Delgado-Blas, J. F., & Gonzalez-Zorn, B. (2025). Human-wildlife ecological interactions shape Escherichia coli population and resistome in two sloth species from Costa Rica. Npj Antimicrobials and Resistance, 3(1), 62. https://doi.org/10.1038/s44259-025-00134-y2731-8745https://hdl.handle.net/11268/16249Antimicrobial resistance (AMR) is a global health concern, with natural ecosystems acting as reservoirs for resistant bacteria. We assessed AMR in Escherichia coli isolated from two wild sloth species in Costa Rica. E. coli from two-toed sloths (Choloepus hoffmanni), a species with greater mobility and a broader diet, showed resistance to sulfamethoxazole (25%), tetracycline (9.4%), chloramphenicol (6.3%), ampicillin (6.3%), trimethoprim (3.1%), and ciprofloxacin (3.1%), which correlated with the presence of resistance genes (tet(A), tet(B), blaTEM-1B, aph(3”)-Id, aph(6)-Id, sul2, qnrS1, floR and dfrA8). E. coli from three-toed sloths (Bradypus variegatus) showed 40% resistance to sulfamethoxazole despite no detected resistance genes, suggesting a regional effect. A significant negative correlation was found between AMR and distance to human-populated areas, highlighting anthropogenic impact on AMR spread. Notably, E. coli isolates from remote areas with no human impact indicate that some ecosystems remain unaffected. Preserving these areas is essential to protect environmental and public healthengAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/journal article10.1038/s44259-025-00134-yopen accessConservación de la fauna y flora silvestresCosta RicaEcologíaGoal 3: Ensure healthy lives and promote well-being for all at all agesGoal 4: Quality educationGoal 13: Take urgent action to combat climate change and its impacts