RESUMEN
Polyclonal antibodies against the coccidiostat maduramicin were produced by the immunization of rabbits with a conjugate between maduramicin and human serum albumin. The antibodies exhibited minimal cross-reactivity with structurally similar ionophoric coccidiostats (monensin, salinomycin, narasin and laslocid). An enzyme-linked immunosorbent assay (ELISA) was developed for maduramicin in poultry tissue using these antibodies. The ELISA had a limit of detection of approximately 0.02 ng/g in tissue (ng/ml in serum) and a limit of determination of 1.0 ng/g in tissue (ng/ml in serum). The half-life of maduramicin was measured in broiler chickens that had been treated with a therapeutic dose of maduramicin for 14 days. Following withdrawal of the medicated feed, the mean half-lives of maduramicin were 20, 39 and 13 h in liver, muscle and serum, respectively. At the recommended withdrawal period (5 days) the mean residual maduramicin concentration in liver was 1.6 ng/g, in muscle was 1.5 ng/g and in serum was 0.05 ng/ml.
Asunto(s)
Antibacterianos/análisis , Pollos/metabolismo , Residuos de Medicamentos/análisis , Contaminación de Alimentos/análisis , Animales , Antibacterianos/sangre , Antibacterianos/farmacocinética , Residuos de Medicamentos/farmacocinética , Ensayo de Inmunoadsorción Enzimática , Semivida , Humanos , Lactonas/análisis , Lactonas/sangre , Lactonas/farmacocinética , Hígado/química , Hígado/metabolismo , Músculo Esquelético/química , Músculo Esquelético/metabolismoRESUMEN
Salinomycin is widely used as a feed additive to control coccidiosis in the broiler industry world-wide. EC legislation on veterinary drug residues will soon be extended to cover poultry. This will require the development of rapid assays to screen for the presence of residual concentrations of this and other drugs in poultry meat. This study describes the development of an enzyme-linked immunosorbent assay for salinomycin that has a limit of detection of approximately 0.2 ng/g. The antibody cross-reacts with narasin, but is not subject to interference from lasalocid, maduramicin or monensin. Residual concentrations of salinomycin were measured in the tissues of broilers following feeding of medicated feed containing 60 mg/kg salinomycin. Salinomycin residues were present only at very low concentrations in liver and muscle, and fell below the limit of decision of the assay within 2 days of withdrawal of the medicated feed.
Asunto(s)
Antibacterianos/análisis , Ensayo de Inmunoadsorción Enzimática , Contaminación de Alimentos , Inspección de Alimentos/métodos , Aves de Corral , Piranos/análisis , Animales , Antibacterianos/sangre , Antibacterianos/farmacocinética , Residuos de Medicamentos , Análisis de los Alimentos , Semivida , Hígado/química , Músculos/química , Piranos/sangre , Piranos/farmacocinética , Sensibilidad y EspecificidadRESUMEN
Polyclonal antibodies against the coccidiostat, lasalocid, were raised in sheep. The antisera were applied in an enzyme-linked immunosorbent assay (ELISA) for lasalocid, which was validated for chicken serum, liver and muscle. Bridge homology in the ELISA was overcome by absorbing unspecific antisera onto a conjugate between salinomycin and chicken serum albumin, which was immobilized onto Biosilon beads. The described assay is highly specific for lasalocid, and is capable of detecting lasalocid at concentrations of less than 0.15 ng/g, depending on the tissue. Residual concentrations of lasalocid in broilers fed medicated feed containing 90 mg/kg lasalocid were measured during a 7 day withdrawal period. The half-life of lasalocid was 11, 36 and 41 h in serum, liver and muscle, respectively. Lasalocid concentrations in liver were approximately 10 ng/g 7 days withdrawal of the medicated feed.