Validation of the Flow Cytometry Immunoassay, BEADYPLEXTM, for Multi-Class and Multi-Residue Screening for Antibiotics in Fish

Introduction:  Rapid and sensitive analytical methods for the detection of antibiotic residues in the food chain are essential to guaranteeing consumer protection and industrial transformation processes. Much of the effort in food analysis is focused on the development of multi-residue methods, which considerably shorten analysis time and reduce global costs. Flow Cytometric Immunoassays (FCIA) combine the detection of receptor-ligand interactions by immunoanalysis with the multi-parametric characterization of individually encoded beads. This feature provides great multiplexing capabilities, making FCIA especially suitable for the monitoring of multiple targets.

Purpose:  BEADYPLEX^TM is a competitive bead suspension FCIA for the multi-class and multi-residue screening of meat for antibiotics from 10 families, widely used in animal farming: tetracyclines, sulfonamides, β-lactams, aminoglycosides, macrolides, fluoroquinolones, lincosamides, phenicols, polymyxins, and pleuromutilins. The objective of this work was to expand the applicability of the method to fish.

Methods:  The simultaneous detection of up to 80 antimicrobial residues is possible, due to the combination in a single reaction of multiple bead-based immunoassays, which use generic receptors/antibodies. The rapid and solvent-free extraction method has been, previously, proven to be efficient for the application of BEADYPLEX^TM to muscle from different species (porcine, poultry, bovine). We conducted the validation of BEADYPLEX^TM in high and low-fat content fish, salmon and coley, respectively, following 2010 CRL Guidelines for the validation of screening methods for residues of veterinary medicines, supplementing European Decision 2002/657/EC.

Results:   The performance of the method in fish was found to be equivalent to that shown in meat, with detection capabilities, for most of the antibiotics within the scope, at or below European regulatory limits.

Significance:  BEADYPLEX^TM is a high-throughput, user-friendly screening method that provides sensitive and specific broad spectrum detection of antibiotics in multiple food matrices and the identification of the antimicrobial family in one test per sample.