Multidrug-Resistant <i>Escherichia coli</i> Accumulated by Freshwater Bivalves: An Underestimated Risk for Public Health?
Joana C. L. Martins,
Ana Gonçalves,
Conceição Fernandes,
Edna Cabecinha,
Sandra Monteiro,
Hugo Guedes,
Gonçalo Almeida,
Juliana Garcia,
Gabriela J. da Silva,
Simone Varandas,
Maria J. Saavedra
Affiliations
Joana C. L. Martins
AB2Unit—Antimicrobials, Biocides & Biofilms Unit, Veterinary Sciences Department, University of Trás-os-Montes and Alto Douro (UTAD), 5001-801 Vila Real, Portugal
Ana Gonçalves
AB2Unit—Antimicrobials, Biocides & Biofilms Unit, Veterinary Sciences Department, University of Trás-os-Montes and Alto Douro (UTAD), 5001-801 Vila Real, Portugal
Conceição Fernandes
AB2Unit—Antimicrobials, Biocides & Biofilms Unit, Veterinary Sciences Department, University of Trás-os-Montes and Alto Douro (UTAD), 5001-801 Vila Real, Portugal
Edna Cabecinha
AB2Unit—Antimicrobials, Biocides & Biofilms Unit, Veterinary Sciences Department, University of Trás-os-Montes and Alto Douro (UTAD), 5001-801 Vila Real, Portugal
Sandra Monteiro
AB2Unit—Antimicrobials, Biocides & Biofilms Unit, Veterinary Sciences Department, University of Trás-os-Montes and Alto Douro (UTAD), 5001-801 Vila Real, Portugal
Hugo Guedes
National Institute for Agricultural and Veterinary Research I.P. (INIAV), Lugar da Madalena, 4485-655 Vila do Conde, Portugal
Gonçalo Almeida
National Institute for Agricultural and Veterinary Research I.P. (INIAV), Lugar da Madalena, 4485-655 Vila do Conde, Portugal
Juliana Garcia
CITAB—Centre for the Research and Technology of Agro-Environment and Biological Sciences, Institute for Innovation, Capacity Building and Sustainability of Agri-Food Production (Inov4Agro), University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal
Gabriela J. da Silva
Faculty of Pharmacy, Center for Neurosciences and Cell Biology, University of Coimbra, 3000-548 Coimbra, Portugal
Simone Varandas
AB2Unit—Antimicrobials, Biocides & Biofilms Unit, Veterinary Sciences Department, University of Trás-os-Montes and Alto Douro (UTAD), 5001-801 Vila Real, Portugal
Maria J. Saavedra
AB2Unit—Antimicrobials, Biocides & Biofilms Unit, Veterinary Sciences Department, University of Trás-os-Montes and Alto Douro (UTAD), 5001-801 Vila Real, Portugal
As bioindicators, freshwater bivalves are crucial for the assessment of the contamination impact on different levels of biological integration. Escherichia coli is used as a bioindicator of water fecal contamination, representing a critical global concern, especially with the rise of multidrug-resistant (MDR) strains. Phylogenetic diversity, pathotypic characterization, and antibiotic resistance profiles of E. coli isolated from freshwater bivalves (Anodonta anatina) were assessed. Samples were collected from the Tua River in Northern Portugal, from two different sites, Chelas and Barcel, representing different degrees of contamination. Antimicrobial susceptibility testing was performed by the disk diffusion method, and characterizations of the phylogenetic groups and pathotypes were assessed by PCR-multiplex and real-time PCR-multiplex, respectively. Results showed that 60% of isolates were characterized as MDR, including resistance to carbapenems, considered the last resort against multidrug-resistant bacteria. Within this study, it was also possible to verify the antimicrobial resistance (AMR) profile differences between the two sampling sites, with bivalve isolates from the Chelas site showing a higher percentage of antibiotic resistance. Among the E. coli isolates, the highest prevalence (55%) was observed in group B1, followed by group D or E (15%), group A (10%), and group E or Clade I (10%). None of the isolates were classified as diarrheagenic E. coli (DEC). This work highlights the potential transmission of antimicrobial-resistant bacteria through bivalves in the food chain. The ‘One Health’ approach is crucial for combating antimicrobial resistance, namely in edible freshwater species, emphasizing active surveillance to protect human, animal, and environmental health against the spread of antibiotic-resistant bacteria in aquatic environments.
