Determination of Antibiotic Residues in Chicken Tissues ‎Using Four Plate Test Method

Antibiotics are widely used in poultry industry for prevention and therapy purposes. Due to non-compliance withdrawal times and improper use of antibiotics, it is a major public health and food security issue. The administration of antibiotics is one of the primary causes of antimicrobial resistance. It also may cause health problems such as genotoxic, carcinogenic, immunotoxic, or endocrine effects, allergic reactions, and changing natural micro flora of consumers. This study focuses on detection of antibiotic residues in the chicken tissue samples. 250 chicken liver, heart, muscle, gizzard, and skin samples were collected from Tabriz slaughterhouse. Four plate test as a microbiological method was used for detecting and analyzing antibiotic residues. This method is based on inhibition zone formation around the tissue samples in four culture media with different test bacteria and pH. To investigate the existence of enrofloxacin and ciprofloxacin residues, another extra plate containing Escherichia coli was added to the test. The sample analysis was done by using 1.5 g of each tissue. Among 250 samples including liver, muscle, gizzard, heart, and skin, 92% of liver samples, 12% of heart samples, 90% of skin samples, and 42% of muscle samples were contaminated by antibiotic residues. All the gizzard samples were free of antibiotics, while the most contaminated tissues were skin samples. Four plate test is an easy and appropriate method for applying in laboratories. The results focus on considering strict legislation for using veterinary drugs in poultry in Iran.