The Tricycle Protocol was created by the World Health Organization in response to the increase in bacterial resistance to antimicrobials and the spread of their genetic determinants. The initiative aims at multisectoral monitoring and surveillance of Escherichia coli producing extended-spectrum beta-lactamases (ESBL-Ec) under the One Health approach, which, along with other species of Enterobacterales, is one of the critical priority pathogens for the production and development of new antimicrobials. Thus, the objective of this study was to evaluate the occurrence and profile of ESBL-Ec strains isolated from the waters of beaches in Niterói/RJ.

Water samples collected from Icaraí, Piratininga, and Jurujuba, presumptive for E. coli, were identified by mass spectrometry. The confirmed strains were subjected to selective pressure in CHROMagar ESBL and MacConkey agar with ceftriaxone at 4.0 µg/mL. The phenotypic susceptibility analysis was performed by disk diffusion against 22 antimicrobials. Genes for resistance to beta-lactams, quinolones, integrases, and virulence genes were investigated by polymerase chain reaction. Hemolysin production was analyzed phenotypically.

A total of 299 E. coli strains were isolated, of which 33 were potential ESBL producers. A high frequency of resistance to ampicillin and third-generation cephalosporins (> 80%) was observed. In 30 strains, ESBL genes (blaCTX-M-1,2, blaCTX-M-8, blaCTX-M-14, blaTEM, and blaSHV) were detected, with blaCTX-M-1,2 being the most prevalent, both in Icaraí and Jurujuba. Additionally, the qnrS, intl1, and intl2 genes were also detected. Furthermore, 18 ESBL-Ec strains were classified as multidrug-resistant (MDR). Among the ESBL-Ec strains, six carried the papC gene, which encodes fimbriae associated with adhesion and colonization in extraintestinal infections, as well as the hlyA gene for hemolysins; of these, five were MDR and two showed an alpha-hemolytic phenotype.

This is the first study describing MDR ESBL-Ec strains in beach waters of Niterói. This result highlights the importance of surveillance in natural ecosystems; however, the findings of this study, where MDR ESBL-Ec strains with resistance to quinolones, presence of integrase genes, and indication of extraintestinal virulence were detected, suggest the role of this ecosystem as a platform for persistence and dissemination of these anthropogenic-origin pathogens.