Abstract

In this study 300 milk samples (200 cows, 50 camels and 50 goats) were collected randomly from farms, sale points and collection points in Khartoum State during winter and summer and investigated for antibiotics residues. Detection of antibiotic residues was performed using two methods: Trisensor antibiotic test and Modified One Plate Test. Also, isolation and identification of bacteria in antibiotic contaminated milk and their resistance to some antibacterial agents were performed. Eighty (40%) of the collected cow milk samples were positive to antibiotics residues, while all camel and goat milk samples were negative. Ten (12.5%) positive samples were found during winter and 23 (28.75%) were detected during summer from collection points. The positive samples from sale points (47, 58.75%) were 15 (18.75%) during winter and 32 (40%) during summer. The isolated Staphylococcus aureus (2; 0.49%) and S. auricularis (4; 0.98%) were sensitive to ampicillin, cephalaxin, cloxacillin and resistant to cefotaxime (75%). Bacillus cereus (18; 4.4%) showed resistance to ampicillin, cephalaxin and cloxacillin (100%). Bacillus coagulans (3; 0.7%) and B. pummilus (4; 0.9) were resistant to ampicillin and cloxacillin (100%). SimlarlyB. sphaericus (4; 0.9%) was resistant to cloxacillin (100%) and B. amyloliquefanciens (3; 0.7%) was resistant to ampicillin and cloxacillin (100%). Klebsiella spp. isolates showed resistant to cloxacillin (100%), ampicillin (66.7%) and cefotaxime (50%). All isolates of Moraxilla spp showed resistance to ampicillin, cloxacillin, cefotaxime and cephalaxin. Escherichia and Enterobacter isolates showed (100%) resistance to ampicillin, cloxacillin and cephalaxin. The present study concluded that the quality of milk obtained from cows was lower compared to that of goats and camels. Also, high antibiotic residues were found in the milk samples collected during summer. The study suggested that more efforts are needed to improve milk hygiene and quality.