Although antimicrobials are valuable allies in animal production, their extended use has led to the emergence of antimicrobial resistance. Moreover, when withdrawal periods in food‑producing animals are not observed, antimicrobial residues can access the food chain, causing direct toxicity, allergies, and/or intestinal microbiota dysbiosis in consumers. Given that Spain and France are the largest meat producers in the EU and are among the top consumers, our study?s aim was to investigate the presence of antimicrobials in commercialized meat purchased in the Spain‑France cross-border area (POCTEFA region). 5,357 meat samples were collected from different animal species and a variety of different retailer types in Spain (Zaragoza, Bilbao, and Logroño) as well as in France (Toulouse and Perpignan). Meat samples were analysed by a screening method (Explorer®+QuinoScan®), yielding 194 positive samples, which were further evaluated by UPLC‑QTOF (Ultra Performance Liquid Chromatography‑Quadrupole Time of Flight) for confirmation. Chromatographic analyses found antimicrobial residues in 30 samples, although only 5 of them (0.093 % of initial samples) were non‑compliant according to the current legislation. Further studies suggested that this mismatch between screening and confirmatory analyses might be due to the presence of biologically active metabolites derived from antimicrobials unidentified by the targeted UPLC‑QTOF method, causing inhibition of the biological Explorer® test. Although chromatographic techniques detect the marker compounds determined by legislation and are the methods selected for official control of antimicrobials in food, metabolites might escape their monitoring. This thus suggests that biological tests are the most adequate ones in terms of ideal consumer health protection.

Serrano M.J., Elorduy J., Zabaleta I., Istamboulie G., González‑Fandos E., Bousquet‑Melou A., Mata L., Aymard C., Da Silva J., Lacroix M., Martínez‑Laorden A., García‑Gonzalo D., Condón S., Abilleira E., Pagán R. (en prensa). Presencia de residuos antibióticos en carnes comercializadas en el área transfronteriza España‑Francia: un enfoque novedoso en los métodos de vigilancia. ITEA‑Información Técnica Económica Agraria. Vol. xx: YY-YY. https://doi.org/10.12706/itea.2024.001