A new approach for detection of antimicrobial drugs in food: Premi ®Test coupled to scanner technology

Abstract

A rapid, high-throughput antimicrobial screening assay has been developed that combines either a physical fluid extraction or a solvent extraction technique with the commercially available Premi ®Test. In order to remove the subjectivity of the visual end-point measurement associated with this microbial inhibition assay, work has been conducted to couple the Premi ®Test to scanner technology. The use of the solvent extraction provides an enhanced detection capability for a wide range of drugs at or below one-half the maximum residue limit (MRL) concentrations in a variety of matrices, as demonstrated by dose response curve data. Secondary class-specific assays, for the identification of β-lactams and sulphonamides following the primary screen have been previously developed and recently validated using the scanner technology. Method validation using both fortified and incurred tissues has been undertaken to establish the ruggedness of the technique. The false-positive and -negative rates have been established at less than 5% for a range of drug/matrix combinations. The CCβ values determined for this qualitative screening assay are at concentrations less than the MRL. This integrated screening strategy provides a reliable tool for antimicrobial residue monitoring in surveillance programmes.