Rapid Time-Resolved Fluoroimmunoassay for the Screening of Narasin and Salinomycin Residues in Poultry and Eggs

Abstract

Anticoccidial drugs are extensively used in the poultry industry to control the infection of the single-cell protozoa of the genus Eimeria. The most commonly used coccidiostats in poultry are the polyether ionophores such as narasin and salinomycin. This paper presents a rapid and simple method for the screening of residues of these two coccidiostatic compounds in poultry and eggs. The method is based on time-resolved fluoroimmunoassay. Sample preparation of eggs consists only of one extraction and evaporation step, and a solid phase extraction step is needed only for the muscle sample preparation. Mean recoveries were 91.0% from muscle tissue and 81.1% from eggs for both narasin and salinomycin. The performance of the assay was evaluated only for narasin because salinomycin had a cross-reactivity of 100% in the assay, and the recoveries of the compounds were not significantly different (P >0.05). The limits of detection [mean + 3 x standard deviation (SD)] of narasin were 0.56 and 0.28 microg/kg, and the limits of quantification (mean + 9 x SD) were 1.80 and 0.57 microg/kg for muscle and eggs, respectively. The coefficients of variation (CV) of the interassay precision of the method, evaluated by five replicate analyses of muscle samples spiked with 2 microg/kg of narasin and egg samples spiked with 1 microg/kg of narasin, were 4.1 and 6.4%, respectively. The CVs of intra-assay precision tests, determined by 10 replicate analyses at the above-mentioned concentration levels, were 3.8 and 4.5%, respectively.

Fluorescence polarization immunoassay for salinomycin based on monoclonal antibodies

“…The sensitivity of FPIA developed could meet the requirement of SAL. Several ELISA for [10]. Since the mAb produced against SAL was primarily specific toward SAL, no significant cross-reactivity was observed with sulfamethazine, chloramphenicol, enrofloxacin, norfloxacin, and ciprofloxacin at 100 g/mL, but 67.6% cross-reactivities with narasin because of these two molecules possess the very similar chemical structure.…”

Stimulation of Eryptosis by Narasin

“…Exposure of human erythrocytes to narasin results in decrease of forward scatter reflecting cell shrinkage and to increase of annexin-V-binding reflecting cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. The concentrations required for the observed effect are within the range of plasma concentrations of treated poultry [56].…”

Cross-contamination of non-target feedingstuffs by narasin authorised for use as a feed additive - Scientific Opinion of the Panel on Contaminants in the Food Chain

“…A screening method based on rapid time-resolved fluoro-immunoassay (TR-FIA), was described by Peippo et al (2004) for the screening of the presence of narasin in animal products. The LODs were 0.56 and 0.28 µg/kg for muscle and eggs, respectively.…”