title: Development of a novel genetically modified bioluminescent-bacteria-based assay for detection of fluoroquinolones in animal-derived foods.
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.
authors.affiliation: MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Guyue
authors.initials: G
authors.lastname: Cheng
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Dong
authors.forename: Yulian
authors.initials: Y
authors.lastname: Wang
authors.forename: Dapeng
authors.initials: D
authors.lastname: Peng
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
authors.forename: Haihong
authors.initials: H
authors.lastname: Hao
authors.forename: Shuyu
authors.initials: S
authors.lastname: Xie
authors.forename: Wei
authors.initials: W
authors.lastname: Qu
authors.forename: Zhenli
authors.initials: Z
authors.lastname: Liu
authors.forename: Zonghui
authors.initials: Z
authors.lastname: Yuan
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D015374:Biosensing Techniques / Q000379:methods; D002417:Cattle; D002645:Chickens; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics; D024841:Fluoroquinolones / Q000032:analysis*; D005504:Food Analysis / Q000379:methods*; D017930:Genes, Reporter; D005818:Genetic Engineering / Q000379:methods; D057230:Limit of Detection; D008156:Luciferases / Q000235:genetics; D008163:Luminescent Measurements / Q000379:methods*; D008460:Meat / Q000032:analysis; D008892:Milk / Q000737:chemistry; D011401:Promoter Regions, Genetic; D011938:Rec A Recombinases / Q000235:genetics; D013552:Swine
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D024841:Fluoroquinolones; D008156:Luciferases; D011938:Rec A Recombinases