Detection of Fluoroquinolone Residues by Microbiological Screening Method – Flumequine

Systematic control of antibiotic residues includes analysis and selection of large number of samples, and requires a wide range of screening methods. Screening tests should satisfy the following requirements: they must be capable to detect antibiotics of interest, detection limits must comply with the requirements (MRLmaximum residue limit), they must be easy to perform and cost effective, test results are to be obtained rapidly, and the tests must be standardized. The aim of this study was to examine the performance of screening test microbiological method with E. coli as test microorganism: capability to detect fluoroquinolone – flumequine at MRL levels in both fortified and incurred chicken and fish tissue samples. LOD (limit of detection) of microbiological method were determined in tissue samples fortified with flumequine. Incurred samples were obtained in experimental design where chickens were treated with therapeutical doses of flumequine. The presence of fluoroquinolones in muscle and liver was detected by microbiological and HPLC method. Examination results revealed detection limits of the microbiological method ranging from 300 ng/g to 400 ng/g for flumequine. Examination of treated animals using microbiological screening method gave positive results in all samples where the residues content was above MRL level. The results of examination of the flumequine residues in tissues of treated animals using screening microbiological method entirely fulfill the demands of a qualitative method.