46I-12 |
Detection of streptomycin and dihydrostreptomycin residues in milk, honey and meat samples using the BiacoreQ biosensor |
J. Ferguson1, A. Baxter1, and L. WAHLSTROM2. (1) XenoSense Ltd, Queen's University, Belfast, 10 Malone Road, BELFAST, BT9 5BN, United Kingdom, (2) Biacore AB, Rapsgatan 7, Uppsala, S-754 50, Sweden These aminoglycoside antibiotics find licensed use for bacterial infections in cattle, sheep, pigs and poultry, honeybee diseases such as European Foulbrood and the control of fireblight, which affects fruit trees during blossom. Residues of these antibiotics may present a potential hazard to the consumer in terms of toxicity, allergic reaction and the development of bacterial resistance. European and U.S. permitted residue limits for streptomycin and dihydrostreptomycin have been set at 0.2ppm in milk, 0.5ppm in muscle and 1ppm in kidney. Currently none exist for honey. The BIACORE®Q system is an automated and robust biosensor that performs reliable and sensitive analyses in real time. An inhibition assay was developed on a sensor chip coated with a streptomycin derivative and using a polyclonal antibody as a detecting molecule. The assay was applied to the detection of streptomycin and dihydrostreptomycin residues in bovine milk, honey, porcine muscle and kidney. The antibody showed high cross-reactivity with dihydrostreptomycin (101%) and no significant cross-reaction with other aminoglycosides or commonly used antibiotics. The Limit of Detection (LOD) for each assay was calculated as: milk (0.03ppm), honey (0.015ppm), kidney (0.05ppm) and muscle (0.07ppm). Repeatability (coefficient of variation, %CV) between runs (n=3) were determined as 4.3% (0.2ppm) and 2.8% (0.1ppm) in milk, 13.3% (0.04ppm) and 9.5% (0.02ppm) in honey, 7.1% (1ppm) and 7.6% (0.5ppm) in kidney and 7.1% (0.5ppm) and 11% (0.25ppm) in muscle. Sample preparation was minimal. Whole milk was analyzed directly; honey samples were diluted with buffer; kidney and muscle samples were homogenized with extraction buffer, then centrifuged. A rapid and reliable method for the detection of streptomycin and dihydrostreptomycin in milk, honey, porcine muscle and kidney using the BIACORE®Q is reported.
Handout (.ppt format, 296.5 kb)
Session 46I, Toxicology & Safety Evaluation
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