title: A rapid microbial inhibition-based screening strategy for fluoroquinolone and quinolone residues in foods of animal origin.
abstract: 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 Test and Delvotest 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.
authors.affiliation: Central Science Laboratory, Sand Hutton, York YO41 1LZ, UK.
authors.forename: Helen
authors.initials: H
authors.lastname: Ashwin
authors.forename: Sara
authors.initials: S
authors.lastname: Stead
authors.forename: Marianne
authors.initials: M
authors.lastname: Caldow
authors.forename: Matthew
authors.initials: M
authors.lastname: Sharman
authors.forename: Jacques
authors.initials: J
authors.lastname: Stark
authors.forename: Angelique
authors.initials: A
authors.lastname: de Rijk
authors.forename: Brendan J
authors.initials: BJ
authors.lastname: Keely
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000302:isolation & purification; D004350:Drug Residues / Q000032:analysis* / Q000302:isolation & purification; D024841:Fluoroquinolones / Q000032:analysis* / Q000302:isolation & purification; D005504:Food Analysis / Q000379:methods*; D008826:Microbial Sensitivity Tests / Q000379:methods*; D011804:Quinolines / Q000032:analysis* / Q000302:isolation & purification; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D014020:Tissue Extracts / Q000032:analysis
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D011804:Quinolines; D011933:Reagent Kits, Diagnostic; D014020:Tissue Extracts