This study investigated the contribution of phages, outer membrane vesicles (OMVs), and contaminating DNA to the presence of antibiotic resistance genes (ARGs) in food viromes. Viral fractions from chicken, fish, and mussels were analyzed. After purification using CsCl density gradient centrifugation and DNase treatment, the presence of ARGs within phage particles was confirmed. Proteomic analysis revealed a predominance of phage proteins (71.8% in fish, 52.9% in mussels, 78.7% in chicken sample 1, and 64.1% in chicken sample 2), while membrane proteins (3.8–21.4%) were less abundant, indicating minimal OMV contamination. Electron microscopy confirmed the presence of Myoviridae and Siphoviridae phages. The results support the reliability of methods used to detect ARG-carrying phage particles and highlight their significance in food viromes.

Pedro Blanco-Picazo, Sara Morales-Cortes, María Dolores Ramos-Barbero, Cristina García-Aljaro, Lorena Rodríguez-Rubio, Maite Muniesa