Levels of antibiotic residues in cow's milk sold in commercial centers of Kampala city

Abstract

Veterinary drug residues in milk represent a health risk for the consumer especially young children. Prolonged exposure to antimicrobial residues in food and milk may lead to antimicrobial resistance and other health problems. The objective of this study was to evaluate the types of antibiotic residues and their levels in milk, and the health risks posed to milk consumers in Kampala City. A total of one hundred twenty five samples (25 processed and l 00 raw) were randomly obtained from different commercial points in Kampala. The milk was analyzed for quinolone, tetracycline, aminoglycoside, sulfonamide, amphenicol and 13-lactarn groups of antibiotics using liquid chromatography tandem mass spectrometry (LC/MS/MS). Residue levels of antibiotics in processed milk were in the range of; not detected to 0.0472 μg/l, not detected to 0.0056 μg/1, 1.2231 to 32.3927 μg/l, 1.8836 to 25.4283 μg/l, 0.0001 to 0.0006 μg/1, 0.0143 to 0.113 μg/l for quinolone, tetracycline, aminoglycoside, sulfonamide, amphenicol and 13-lactam, respectively. The corresponding levels in raw milk ranged from not detected to 0.0309 μg/1, not detected to 0.0309 μg/1, 1.1795 to 31.351 μg/l, 1.6698 to 38.2626 μg/l, not detected to 0.0004 μg/1 and not detected to 0.5109 μg/l. Levels of aminoglycoside were generally high compared to other groups of antibiotics in milk. However, drug residue levels were in all cases below the maximum residue limit (MRL) according to Food and Agriculture Organization (FAO) and United States Food and Drug Administration (USFDA). Based on the observed levels of antibiotics, processed and raw milk in Kampala is safe for human consumption. Nevertheless, regular monitoring of antibiotic residues in milk is recommended.