Detection of antibiotic residues in cow’s milk using microbiological screening test in Souk Ahras, Algeria

Abstract

The aim of the present study was to investigate antibiotic residues in raw and fermented cow’s milk in Souk Ahras region, Algeria. A total of 78 cow’s milk samples were collected, including 46 samples of raw milk from various farms and 32 samples of fermented cow’s milk purchased from various points of sale. Samples were examined using a microbiological test (the European four-plate test). Results indicate that only 35 (17/46 raw milk and 18/32 fermented milk) samples were free from antibiotic residues. A high prevalence of antibiotic residues was observed in both raw and fermented milk (63,04%) and (43,75%), respectively. β-lactams and/or tetracyclines were the most detected in both raw and fermented milk, with (47,83%) and (43,75%), respectively. A rate of 30.43% for aminoglycosides, 15.22% for β-lactams and/or macrolides, and 13.04% for sulfonamides were detected in raw cow’s milk. However, a rate of 18.75% for macrolides and/or β-lactams, 12,50% for aminoglycosides, and 3.12% for sulfonamides were detected in fermented milk. A rate of 62.07% of raw milk was contaminated with one family of antibiotics. Werehase (64.28%) of fermented milk was positive for two families of antibiotics. This preliminary study allowed us to outline the presence of antibiotic residues in raw and fermented cow’s milk in Souk-Ahras region. Failure to adhere to good antibiotic usage practices, particularly regarding the withdrawal periods after treatment, can lead to the presence of residues in animal products, thereby exposing consumers to health risks.