Profiles of Sensitivity to Antibiotics and Heavy Metals in Strains of Pseudomonas mendocina Isolates from Leachate Pond

<b>Background/Objetives</b>: Antimicrobial Resistance (AMR) is a multifaceted issue that the World Health Organization (WHO) identifies as one of the primary threats to global health for humans, animals, and the environment. In Colombia, AMR has been extensively studied at the hospital level; however, there are limited environmental studies, particularly concerning leachates from landfills. The objective of this study was to identify and determine the genetic relationships, as well as the sensitivity profiles to antibiotics and heavy metals, of ten <i>Pseudomonas mendocina</i> isolates from a leachate pond. <b>Methods</b>: Identification was conducted using MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight), while genotyping was performed via rep-PCR. Antibiotic susceptibility to β-lactams, aminoglycosides, and quinolones was assessed using the Kirby-Bauer method. Additionally, sensitivity profile to heavy metals was evaluated using the broth microdilution technique. <b>Results</b>: Rep-PCR analysis indicated that 60% (<i>n</i> = 6/10) of the isolates exhibited a clonal relationship. Sensitivity testing revealed that 30% (<i>n</i> = 3/10) of the isolates displayed reduced sensitivity to aminoglycosides and β-lactams. Finally, the broth microdilution showed that 90% (<i>n</i> = 9/10) of the isolates were tolerant to copper sulfate. <b>Conclusions</b>: These results provide evidence that landfill leachates may serve as a potential reservoir for bacteria harboring antimicrobial resistance determinants.