Identification of Antibiotic Residues in Raw Milk Samples Coming from the Metropolitan Area of Bucharest

Abstract

The study aimed at evaluating antibiotic residues in raw milk coming from two categories of providers: dairy farmers and processed milk producers. The analyses were carried out in a private laboratory at the request of the providers. 210 samples, collected monthly during 2012 (January to December) were analyzed (n = 210). Of the 210 samples of raw milk, 45.71% (n = 96) came from dairy farmers and 54.29% (n = 114) came from processed milk producers. The milk samples were tested using the Beta Star Combo method based on chemical reactions with reagents attached to gold particles. All milk samples had a pH ranging between 6.6-6.9. The presence of tetracycline and beta-lactam antibiotic was analyzed as these are the most used antibiotics in the treatment of mammary glands diseases in dairy cows. Of all the 210 samples, antibiotic residues were detected in 66 samples of which 42 contaminated samples came from dairy farmers. Beta-lactam antibiotics residues have been detected in 12 samples and tetracycline in 30 samples. In the contaminated samples coming from the processed milk producers, only traces of tetracycline were found. These results are a warning signal showing antibiotics entering the human food chain in this way, this being even more alarming if we take into consideration the fact that milk, in general, is a product mainly consumed by children and the elderly.