Abstract: In this study, a rapid high-throughput screening kit for the detection of mono- and multi-residues of common antibiotics in animal-derived foods was developed based on the microbial chromogenic assay. Bacillus sterothermophilus (CICC 10392) was used as the indicator strain. Its cells were immobilized under optimized conditions and seeded into the wells of a 96-well microplate to detect four types of common antibiotic residues in livestock and poultry meat. As a result, the problem of time-consuming cultivation and the difficulty of transporting liquid bacterial culture could be overcome. The results showed that use of 0.1 g/mL polyvinyl alcohol as the carrier, boric acid-phosphate solution (pH 6.0) as the crosslinking agent, and an initial bacterial suspension concentration (A600 nm) of 0.8 were the best immobilization conditions in terms of the mechanical stability and microbial activity. The detection limits for tetracyclines, aminoglycosides, macrolides, β-lactams separately, and aminoglycosides in combination with tetracyclines or β-lactams were 40–60, 60–120, 60–100, 20–40, 20–40, and 10 μg/kg, respectively, conforming to the requirements for antibiotic residue limits. The same results were obtained on 70 animal-derived food samples using the kit and chromatography. The results indicated that the kit could be used to reliably detect antibiotic residues in animal-derived food samples.

Key words: high-throughput, antibiotic residues, immobilization, animal-derived food