ELISA and Copan Based Evaluation and Analysis of Antibiotic Residues in Cattle Milk in Qazvin, Iran

Aims: Daily consumption of milk containing antibiotic residues has become a great public health concern. This study aimed to evaluate the antibiotic residues in cattle raw milk using Copan milk test and specific enzyme-linked immunosorbent (ELISA) kits. Materials & Methods: In this study, ۹۲ milk samples were collected from Qazvin province, Iran in two seasons during ۲۰۱۹. All the samples were analyzed by the Copan milk test and competitive ELISA kits to evaluate gentamicin, tetracycline, tylosin, chloramphenicol, penicillin, and sulfonamide residues in milk. Findings: The results showed that ۴۵ milk samples (۴۸.۹۱%) were positive for the presence of antibiotic residues. Samples collected in summer were significantly (p<.۰۵) more contaminated with antibiotic residues (۳۰.۴۳%) than those collected in winter (۱۸.۴۷%). The highest mean contamination was related to sulfonamide (۱۳.۷۲±۱.۲۱ ng/mL), followed by gentamicin (۱۳.۲۴±۲.۸۱ ng/mL) and tylosin (۱۳.۱۵±۱.۳۷ ng/mL) residues, and the lowest mean contamination was related to penicillin residues (۰.۰۰۷±۰.۰۰۲ ng/mL). The limit of detection (LOD) was ۲, ۲.۵, ۰.۰۲, ۸, ۰.۴, ۰.۰۸, and ۱۳ ng/mL for gentamicin, tylosin, chloramphenicol, sulfamethazine, tetracycline, penicillin, and flumequine, respectively. Chloramphenicol residues were above the maximum residue limit (MRL) according to the Codex and European Commission (EC) (۰ ng/mL) in all the samples. Sulfonamides residues were above the Codex MRL (۲۵ ng/mL) in ۳۳.۳۳% of the samples. Conclusion: The results shows that monitoring of antibiotic residues in milk and dairy products is necessary. Indeed, examining the amount of antibiotic residues in dairy products could be an important aspect of their monitoring.

Keywords:

Antibiotic , Residues , Milk , Copan , ELISA