Microbial risk assessment with special focus on antibiotic residues in mastitic buffalo milk

Abstract

Fifty buffaloes(healthy and mastitic udders) were milked aseptically from separate regions of Kaliobia governorate .California mastitis test (CMT) and bacteriological examination were achieved .Upon susceptibility testing (12) antibiotics were used to explain different susceptibility patterns of the isolated bacteria The objective of this study was the detection of oxytetracycline, sulphadimidine, penicillin G and ampicillin residues in raw buffalo's milk. 45 samples of raw milk (13 for oxytetracycline ,11 for sulphadimidine , 11 for penicillin G and 10 for ampicillin) were collected from private farms in Banha at Kaliobia Governorate. The period of exiperiment was January-March 2015 and the sample was analyzed with high performance liquid chromatography (HPLC) method. Out of the samples examined for oxytetracycline 30.76% (4 /13) were found to contain oxytetracycline residues and 54.5% (6/11) were found to contain sulfonamide residue. The amount of oxytetracycline in positive milk samples were found 452 ng/ml, 560 ng/ml, 1475 ng/ml and 2833 ng/ml which are much higher than WHO and FD recommended level. While, sulphadimidine residue was detected in the range of 3-22 ng/ml in 2 samples and 28-44 ng/ml in 4 samples which were lower than WHO and FD recommended level. Penicillin G and ampicillin residues did not found in the examined milk samples. This study indicates the presence of oxytetracycline residues more than allowed amount. Regulatory authorities should ensure proper withdrawal period before milking the animals and definite supervisions are necessary on application of these drugs.