A rapid microbial inhibition-based screening strategy for fluoroquinolone and quinolone residues in foods of animal origin

Helen Ashwin, Sara Stead, Marianne Caldow, Matthew Sharman, Jacques Stark, Angelique de Rijk, Brendan J. Keely

Research output: Contribution to journalArticlepeer-review


A rapid, high-throughput antimicrobial screening assay for the detection of fluoroquinolone and 4-quinolone residues in foods of animal origin has been developed in ampoule format. The assay employs a single Escherichia coli species sensitive to those Gram-negative inhibitiory antimicrobial compounds and is presented in a comparable format to the existing commercially available Premi (R) Test and Delvotest (R) ampoule-based microbial inhibition tests (DSM, Delft, The Netherlands). In the novel E. coli assay the microorganism, in vegetative state, is inoculated into a nutrient agar pellet containing a pH sensitive acid-base indicator dye. A simple extraction protocol that is selective for fluoroquinolone and quinolone compounds was developed to recover, cleanup and concentrate the target analyte(s) from a variety of tissue types and matrices prior to screening analysis. The method detected 16 target compounds at concentrations equal to or below the maximum residue limits (where applicable). The method has been validated using the prototype assay in accordance with the 2002/657/EC guidelines for the validation of qualitative screening assays. False positive and false negative responses rates for the procedure have been determined as less than 5%. The stability of a selection of representative target analytes has been demonstrated for a 20-week period under a variety of storage conditions both in tissue and in extract. Crown Copyright (C) 2008 Published by Elsevier B.V All rights reserved.

Original languageEnglish
Pages (from-to)241-246
Number of pages6
Issue number1-2
Publication statusPublished - 1 Apr 2009


  • Fluoroquinolone
  • 4-Quinolone
  • Antimicrobial inhibition
  • Screening and food safety

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