engleski

Determination of neomycin residues in meat by a validated ELISA method

Neomycin, an aminoglycoside produced by Streptomyces fradiae, is used as a broad-spectrum antibiotic due to its growth inhibition of Gram- positive (Staphylococcus aureus, Mycobacterium tuberculosis) and Gram-negative bacteria (E. coli, Enterobacter aerogenes, Klebsiella pneumonia, Proteus vulgaris). It is used orally to treat bacterial gastrointestinal infections of domestic animals and to treat mastitis by intramammary administration. Consequently, its use may result in the presence of drug residues in meat and other foods of animal origin. Residues of aminoglycoside antibiotics in food have been found to cause kidney damage and damage to cranial nerves resulting in hearing loss. In order to protect consumer health, the European Union (EU) established an maximum residue limits (MRL) for neomycin in foods of animal origin, at 500 μg kg-1 for muscle. The enzyme-linked immunosorbent assay (ELISA) method, validated according to Commission Decision 2002/657/EC, was used for the detection of neomycin residues in muscle tissue. The microtiter plates for ELISA were precoated with sheep antibodies to mouse IgG. Muscle samples were analysed following trichloroacetic acid extraction. The following validation parameters were determined for the method: LOD, limit of detection 11.1 g kg-1 ; LOQ, limit of quantification 25.9 g kg-1 ; CCβ, capability of detection 155.7 g kg-1 ; precision with CV ranging up to 24.9% ; linearity with R2 > 0.98 in the area from 6.25–200 μg kg-1 ; recovery 73% to 123% ; within-laboratory reproducibility < 30%. The validation method proved to meet the set criteria for the detection of neomycin in the muscle matrix. A total of 250 muscle samples, 150 beef and 100 pork, were tested for neomycin residues using ELISA during 2013. Concentrations of neomycin were measured in the ranges with mean values (μg kg-1): beef 0.3–21.5 and 4.3 ; pork 1.1–58.0 and 12.2. Results obtained in all muscle samples were lower than establish MRL value. The results indicate that meat in Croatia contains very low levels of neomycin residues and is therefore safe for human consumption.

aminoglycosides; ELISA; beef meat; pork meat; neomycin; residues; validation

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