Urban parks can be considered critical environments for investigating antimicrobial resistance, as they can act as resistomes. These conditions can directly contribute to the proliferation and dissemination of resistant bacteria and resistance genes, causing significant impacts on One Health. Therefore, the objective of this study was to investigate the potential of two urban parks in the metropolitan region of Curitiba, Paraná, as possible resistome environments.

Water samples were collected from lagoons in two locations: 1) Parque das Águas (Pinhais - PR) and 2) Parque de São José dos Pinhais (PR). Sampling was performed at three points in each park, with 2 km between them. Water was collected in sterile tubes. In the laboratory, 200 µL of water was plated on selective ESBL medium to detect bacteria resistant to beta-lactams. Quantification of antimicrobials belonging to the tetracycline and beta-lactam classes was performed using the TwinSensor test. After colony growth on the ESBL medium, the isolated bacteria were plated on Mueller-Hinton medium to evaluate susceptibility to ciprofloxacin (CIP), tetracycline (TET), amoxicillin + clavulanate (AMC), azithromycin (AZI), and penicillin (PEN).

Beta-lactam–resistant strains were identified at all points in both parks. In Parque das Águas, strains of Pseudomonas spp. and Escherichia coli resistant to PEN and AMC and Klebsiella pneumoniae resistant to AMC and PEN were detected. In Parque de São José dos Pinhais, in addition to Pseudomonas spp. and E. coli resistant to PEN and AMC, strains of Proteus spp. resistant to PEN, AMC, and AZI and K. pneumoniae resistant to PEN were also found. The concentrations of antimicrobials detected included tetracycline (80 µg/L), oxytetracycline (50 µg/L), amoxicillin (2 µg/L), and penicillin (3 µg/L). These results indicate that both parks act as resistomes, possibly influenced by adjacent water bodies previously identified as contaminated by antimicrobials, such as the Iguaçu and Iraí rivers.

The evaluated urban parks may act as resistomes. Despite their ecological and social importance, human influence in these environments represents a potential risk to One Health, highlighting the need for monitoring and strategies to mitigate the spread of antimicrobial resistance.