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Objectives: Despite the benefits of antibiotics, their residues in foodstuffs prepared for human consumption could be cancerous and mutagenic and cause allergic reactions with toxic side effects, disorders in intestinal wall, adverse effects on microbial intestinal flora, and the emergence of resistant strains of bacteria. Therefore, the present study aimed to investigate the residual antibiotics in liver and muscle tissues of poultry samples using the four-plate test (FPT) method in Chaharmahal and Bakhtiari Province.
Materials & Methods: A total of 6406 samples were randomly collected from liver and muscle tissues of 3203 poultry samples from June 2016 to March 2017. Antibiotic residues were detected in liver and muscle samples using the four-plate test (FPT) method.
Findings: During a two-year study period, from a total of 6406 samples collected, 3203 (50%) samples were collected from liver tissues, and 3203 (50) samples were collected from muscle tissues of poultry samples, respectively. Among the liver and muscle samples, 12 (384/3203) and 6.4% (206/3203) were positive for the presence of antibiotic residues, respectively. According to the seasonal distribution of muscle samples, the highest rate of antibiotic residues was detected in the autumn with 3 % (95/3203), while the lowest rate was observed in the winter with 0.25% (8/3203) for both bacteria under study (Bacillus subtilis and Micrococcus luteus). According to the seasonal distribution of liver samples, the highest rate of antibiotic residues was detected in the autumn with 5% (159/3203), while the lowest rate was observed in the spring with 1.1% (35/3203).
Conclusion: In conclusion, a large number of liver tissues collected from poultry samples were contaminated with antibiotic residues, especially at pH=6 and in the autumn season. Therefore, it is recommended to implement appropriate strategies for managing and controlling the use of antibacterial agents in the veterinary industry. Also, it is necessary to monitor the withdrawal time of antibiotics and screen the maximum residue limits (MRLs) in poultry products including liver, egg, and meat.

 

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For the determination of antibiotic residues in industrial poultry carcasses in mazandaran province, 815 carcasses are sampled from three slaughterhouses      (Sari- Qaemshahr- Amol). For this purpose, the method of F.P.T (Four – Plate  – Test) was used. The principle of this method is formation of pellucid halo (inhibitory zone) around the extract in agar plate that was cultured with equal layer of bacteria. Altogether from 815 carcasses, were                examinated. 533 carcasses (%65.4) were called for antibiotic residues, at least in one organ (muscle- liver-kidney) or tow and or all three organs. Meanwhile, kidney with the most case positive (antibiotic residues) (%52.2) and then liver (%51) and muscle (%44.5) repose.

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Antibiotic residues in meat and other foods of animal origin have adverse effects on consumer health. In this study, first, penicillin residues of 45 samples (15 meat samples, 15 liver samples and 15 kidney samples) randomly collected from Tehran retailers were evaluated by ELISA method. Based on ELISA results, from total 45 samples, 43 cases were diagnosed as contaminated sample for antibiotic residues. The highest penicillin amount was observed for liver samples but there was no significant difference between kidney and liver samples (p=0.895). Subsequently, samples with equal amounts of penicillin were removed and other samples were analyzed by high performance liquid chromatography (HPLC) regarding penicillin G, ampicillin and amoxicillin. Penicillin G had the most value among other penicillin groups followed by ampicillin and amoxicillin, respectively. Liver samples showed higher levels of penicillin groups compared to meat and kidney samples, but no significant difference was found among them. Also, there was good correlation between ELISA and HPLC results and R² of all samples was greater than 0.99. Moreover, it was demonstrated that antibiotic residues of some samples were above the maximum residue limit (MRL) stated by world standards. Obtained results show the necessity of monitoring antibiotic residues in food of animal origin by related organizations especially the institute of standards & industrial research of Iran and veterinary organization.

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Excessive use of antibiotics in the animal husbandry causes the accumulation of their residual amounts in food of animal origin such as dairy products. Since the consumption of these foods has a negative effect on human health, authorized organizations such as the European :union: have set maximum residue limits (MRLs) for antibiotics in food of animal origin. This research aimed to present a magnetic ionic solvent based extraction procedure for preparation and preconcentration of tetracycline, oxytetracycline and enrofloxacin residues in cheese samples and their determination by high-performance liquid chromatography equipped with a diode array detector. For this, the effect of various parameters on the extraction efficiency was investigated and optimized. The results showed that the residual amounts of oxytetracycline and tetracycline in 4 and 5 samples of the tested cheeses, respectively, were determined above the permissible limits. Enrofloxacin residue was not found in any of the samples. From the advantages of the proposed extraction method, we can point out the high separation power and the possibility of highly sensitive analyzing of mixed analytes, so that under optimized conditions, the recovery percentage ranges were 80-91. The limits of detection and quantification were respectively less than 1.8 and 6 ng/g, which is much lower than the MRLs set for target antibiotics in cheese (100 ng/g).