ARGs Detection in Listeria Monocytogenes Strains Isolated from the Atlantic Salmon ( Salmo salar ) Food Industry: A Retrospective Study

• Published in: Microorganisms
• Main Authors: Gianluigi Ferri, Carlotta Lauteri, Anna Rita Festino, Alberto Vergara
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2023
• Subjects: Listeria monocytogenes; salmon; antibiotic resistance; resistance genes; molecular biology; food safety; Biology (General); QH301-705.5; Atlantic salmon; Salmo salar
• Online Access: https://doi.org/10.3390/microorganisms11061509; https://doaj.org/article/fb24a1b9b49044ae8c7bbfc7d02519d2

Among bacterial foodborne pathogens, Listeria monocytogenes represents one of the most important public health concerns in seafood industries. This study was designed as a retrospective study which aimed to investigate the trend of antibiotic resistance genes (ARGs) circulation in L. monocytogenes isolates identified (in the last 15 years) from Atlantic salmon ( Salmo salar ) fresh and smoked fillets and environmental samples. For these purposes, biomolecular assays were performed on 120 L. monocytogenes strains collected in certain years and compared to the contemporary scientific literature. A total of 52.50% (95% CI: 43.57–61.43%) of these samples were resistant to at least one antibiotic class, and 20.83% (95% CI: 13.57–28.09%) were classified as multidrug resistant. Concerning ARGs circulation, tetracycline ( tet C, tet D, tet K, tet L, tet S), aminoglycoside ( aad A, str A, aac C2, aph A1, aph A2), macrolide ( cml A1, cat I, cat II), and oxazolidinone ( cfr , optr A, poxt A) gene determinants were majorly amplified. This study highlights the consistent ARGs circulation from fresh and processed finfish products and environmental samples, discovering resistance to the so-called critical important antimicrobials (CIA) since 2007. The obtained ARGs circulation data highlight the consistent increase in their diffusion when compared to similar contemporary investigations. This scenario emerges as the result of decades of improper antimicrobial administration in human and veterinary medicine.