Development of a novel genetically modified bioluminescent-bacteria-based assay for detection of fluoroquinolones in animal-derived foods

Anal Bioanal Chem. 2014 Dec;406(30):7899-910. doi: 10.1007/s00216-014-8228-3. Epub 2014 Oct 30.

Abstract

Fluoroquinolones (FQNs) are broad-spectrum antibacterial agents widely used in animal husbandry and aquaculture. The residues and antimicrobial resistance of such antibiotics are a major public health concern. To realize multianalyte detection of FQN residues, a genetically modified bacterium, Escherichia coli pK12 harboring plasmid pRecAlux3, was constructed in this study to develop a bioluminescent-bacteria-based assay for the detection of FQNs in animal-derived foods. This assay was based on the principle of induction of an SOS response by FQNs via inducing the recA-promoter-fused luciferase reporter gene existing on the plasmid pRecAlux3. E. coli pK12 was able to recognize 11 FQNs: difloxacin, enrofloxacin, ciprofloxacin, sarafloxacin, norfloxacin, danofloxacin, ofloxacin, pefloxacin, lomefloxacin, marbofloxacin, and orbifloxacin. This method could be applied to 11 edible tissues, including milk, fish muscle, and the muscles, livers, and kidneys of cattle, chickens, and pigs, with a very simple and rapid sample extraction procedure using only phosphate-buffered saline. The limits of detection of the FQNs were between 12.5 and 100 μg kg(-1), all of which were lower than the maximum residue limits. Most of the recoveries of the FQNs were in the range from 60 to 120 %, and the interassay coefficients of variation were less than 30 %. This method, confirmed by high-performance liquid chromatography, is reliable and can be used as both a screening test and a semiquantitative assay, when the identity of a single type of FQN is known.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Animals
  • Anti-Bacterial Agents / analysis*
  • Biosensing Techniques / methods
  • Cattle
  • Chickens
  • Escherichia coli / genetics*
  • Escherichia coli Proteins / genetics
  • Fluoroquinolones / analysis*
  • Food Analysis / methods*
  • Genes, Reporter
  • Genetic Engineering / methods
  • Limit of Detection
  • Luciferases / genetics
  • Luminescent Measurements / methods*
  • Meat / analysis
  • Milk / chemistry
  • Promoter Regions, Genetic
  • Rec A Recombinases / genetics
  • Swine

Substances

  • Anti-Bacterial Agents
  • Escherichia coli Proteins
  • Fluoroquinolones
  • Luciferases
  • Rec A Recombinases