Continuity of carbapenem resistance determinants in carioca river and Rodrigo de Freitas Lagoon, Rio de Janeiro, Brazil, after decade.

Antimicrobial resistance is a major global issue in the 21st century, extending beyond hospitals to various ecosystems and organisms, including animals, soil, and bodies of water, thus becoming a One Health concern. This study investigates resistant Gram-negative bacteria and their antimicrobial resistance genes in water samples from the Carioca River (CR) and Rodrigo de Freitas Lagoon (RFL) in Rio de Janeiro, Brazil. The samples were collected from different locations, and bacteria were identified using Matrix-Assisted Laser Desorption/Ionization Time of Flight technology. Antimicrobial susceptibility was evaluated using the agar disk diffusion method and minimum inhibitory concentration testing. The presence of resistance determinants was investigated through conventional Polymerase Chain Reaction. Among the 101 Gram-negative isolates, 45% (46/101) were non-susceptible to carbapenems, with resistance genes found, including blaKPC (41%; 19/46), blaGES (26%; 12/46), blaNDM (6%; 3/46), blaCTX−M (6%; 3/46) and blaVIM (2%; 1/46). The intl1 was detected in 32% (15/46) of the bacterial isolates. When comparing the current study to a 2013 investigation, the consistent presence of blaKPC was observed at CR collection points. Additionally, blaKPC was detected in RFL. This highlights the persistent presence of blaKPC in the investigated environments, posing a threat to human, animal and environmental health.