Microbial Quality and Antibiotic Residues in Raw Beef from Selected Abattoirs in Accra, Ghana

Aims: To determine the microbial quality and the presence of antibiotic residues in raw beef from four major abattoirs in Accra, Ghana.
Study Design: Cross sectional.
Place and Duration of Study: Samples were obtained from the four major abattoirs namely; Madina, Tema (GIHOC), Accra, Amasaman and the University of Ghana (UG) Farms, transferred immediately to the Bacteriology Laboratory, Noguchi Memorial Institute for Medical Research, University of Ghana, for processing. The study was carried out between June 2013 and April, 2014.
Methodology: Raw beef samples were aseptically collected from 200 cattle slaughtered for consumption. Total plate count, presence of foodborne pathogens such as Listeria monocytogenes, Escherichia coli, E. coli 0157:H7, Staphylococcus aureus, Salmonella and Shigella species were determined after culture and incubation on standard microbiological media. Both liver and kidney samples were also collected from each of the 200 carcasses and tested for antibiotic residues using Premi® test kit (R-Biopharm AG, Germany).
Results: The total plate counts in all the samples from the abattoirs ranged between 8.3x103 – 5.5x105 cfu/g. A total of 43 pathogens were isolated. Of this number, 30 (69.76%) were E. coli, 8 (18.69%) S. aureus, 2 (4.65%) Salmonella Typhimurium, 2 (4.65%) L. monocytogenes and 1 (2.3%) Yersinia enterocolitica. Fifty-nine strains from other species were also isolated: Bacillus spp. (21), Enterobacter spp. (18), Pseudomonas aeruginosa (1), Aeromonas spp. (3), coliforms (12) and Klebsiella spp. (4). None of the E. coli isolated were positive for O157: H7. Overall, 18% of both the liver and kidney samples were positive for the presence of antibiotic residues but the kidneys recorded the highest (12%) percentage of positive whilst the liver recorded (6%).
Conclusion: Beef at the abattoirs were contaminated with foodborne pathogens and antibiotic residues, however, the total aerobic counts were within the acceptable range considered safe for human consumption. Detection of pathogens and antibiotic residues in beef is of public health concern.