Detection of traces of tetracyclines from fish with a bioluminescent sensor strain incorporating bacterial luciferase reporter genes.
Bioluminescent Escherichia coli K-12 strain for the specific detection of the tetracycline family of antimicrobial agents was optimized to work with fish samples. The biosensing strain contains a plasmid incorporating the bacterial luciferase operon of Photorhabdus luminescens under the control of the tetracycline responsive element from transposon Tn10 (Korpela et al. Anal. Chem. 1998, 70, 4457-4462). The extraction procedure of oxytetracycline from rainbow trout (Oncorhynchus mykiss) tissue was optimized. There was neither need for centrifugation of homogenized tissue nor use of organic solvents. The lowest levels of detection of tetracycline and oxytetracycline from spiked fish tissue were 20 and 50 microg/kg, respectively, in a 2-h assay. The optimized assay protocol was tested with fish that were given a single oral dose of high and low concentrations of oxytetracycline. The assay was able to detect oxytetracycline residues below the European Union maximum residue limits, and the results correlated well with those obtained by conventional HPLC (R = 0.81).
Pellinen
Teijo
T
Department of Biotechnology, University of Turku, Tykistökatu 6A, FIN-20520 Turku, Finland.
Bylund
Göran
G
Virta
Marko
M
Niemi
Anneli
A
Karp
Matti
M
D000818:Animals; D015374:Biosensing Techniques; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005506:Food Contamination; D008156:Luciferases / Q000235:genetics*; D008163:Luminescent Measurements; D017686:Oncorhynchus mykiss; D009876:Operon; D010118:Oxytetracycline / Q000032:analysis; D020637:Photorhabdus / Q000201:enzymology / Q000235:genetics; D011994:Recombinant Proteins; D013754:Tetracyclines / Q000032:analysis*
D011994:Recombinant Proteins; D013754:Tetracyclines; D008156:Luciferases; D010118:Oxytetracycline