Unveiling Antibiotic Resistance, Clonal Diversity, and Biofilm Formation in <i>E. coli</i> Isolated from Healthy Swine in Portugal
Adriana Silva,
Vanessa Silva,
Maria de Lurdes Enes Dapkevicius,
Mónica Azevedo,
Rui Cordeiro,
José Eduardo Pereira,
Patrícia Valentão,
Virgílio Falco,
Gilberto Igrejas,
Manuela Caniça,
Patrícia Poeta
Affiliations
Adriana Silva
Microbiology and Antibiotic Resistance Team (MicroART), Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
Vanessa Silva
Microbiology and Antibiotic Resistance Team (MicroART), Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
Maria de Lurdes Enes Dapkevicius
IITAA—Institute of Agricultural and Environmental Research and Technology, University of the Azores (UAc), 9700-042 Angra do Heroísmo, Portugal
Mónica Azevedo
Centre for the Studies of Animal Science, Institute of Agrarian and Agri-Food Sciences and Technologies, Oporto University, 4049-021 Porto, Portugal
Rui Cordeiro
Intergados, SA, Av. de Olivença, S/N, 2870-108 Montijo, Portugal
José Eduardo Pereira
CECAV—Veterinary and Animal Research Centre, University of Trás-os-Montes and Alto Douro, 5000-801 Vila Real, Portugal
Patrícia Valentão
Laboratory for Green Chemistry (LAQV) of the Network of Chemistry and Technology (REQUIMTE), Universidade do Porto, 2829-516 Caparica, Portugal
Virgílio Falco
Laboratory for Green Chemistry (LAQV) of the Network of Chemistry and Technology (REQUIMTE), Universidade do Porto, 2829-516 Caparica, Portugal
Gilberto Igrejas
LAQV-REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
Manuela Caniça
Centre for the Studies of Animal Science, Institute of Agrarian and Agri-Food Sciences and Technologies, Oporto University, 4049-021 Porto, Portugal
Patrícia Poeta
Microbiology and Antibiotic Resistance Team (MicroART), Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
Escherichia coli, a commensal microorganism found in the gastrointestinal tract of human and animal hosts, plays a central role in agriculture and public health. Global demand for animal products has promoted increased pig farming, leading to growing concerns about the prevalence of antibiotic-resistant E. coli strains in swine populations. It should be noted that a significant portion of antibiotics deployed in swine management belong to the critically important antibiotics (CIA) class, which should be reserved for human therapeutic applications. This study aimed to characterize the prevalence of antibiotic resistance, genetic diversity, virulence characteristics, and biofilm formation of E. coli strains in healthy pigs from various farms across central Portugal. Our study revealed high levels of antibiotic resistance, with resistance to tetracycline, ampicillin, tobramycin, and trimethoprim-sulfamethoxazole. Multidrug resistance is widespread, with some strains resistant to seven different antibiotics. The ampC gene, responsible for broad-spectrum resistance to cephalosporins and ampicillin, was widespread, as were genes associated with resistance to sulfonamide and beta-lactam antibiotics. The presence of high-risk clones, such as ST10, ST101, and ST48, are a concern due to their increased virulence and multidrug resistance profiles. Regarding biofilm formation, it was observed that biofilm-forming capacity varied significantly across different compartments within pig farming environments. In conclusion, our study highlights the urgent need for surveillance and implementation of antibiotic management measures in the swine sector. These measures are essential to protect public health, ensure animal welfare, and support the swine industry in the face of the growing global demand for animal products.
