Bacteriological Quality and Antibiotic Residues in Raw Cow Milk at Producer Level and Milk Products at Sale Points in the Northern Region of Ghana

Objective: To evaluate the bacteriological quality of raw cow milk and milk products produced and retailed in the Northern Region of Ghana based on total bacteria and coliform count, prevalence of bacteria pathogens and antibiotic residues.

Methodology: A cross sectional study was designed where raw milk (n=210) and milk products (n=60) comprising (local milk and millet beverage) (burkina), cottage cheese (wagashi) and yoghurt were sampled from cattle kraals and retailers respectively.

Total viable bacterial counts (TVBC) and total coliform counts (TCC) were determined for all samples followed by isolation and identification of common milk-borne bacteria pathogens using normal laboratory identification systems. Antimicrobial residue in raw milk was detected using the Charm ® Blue-Yellow II Test for Beta-lactams and Other Antimicrobial Drugs in Milk.

Results: Mean total viable bacteria and coliform counts were (2.40±7.44) x107 and (1.10 ±1.53) x104 cfu/ml for raw milk and (8.99±2.24) x 106 and (6.62±9.54) x103 cfu/mlfor milk products respectively. Escherichia coli (15.6%), Klebsiella pneumoniae (14.1%), Staphylococcus aureus (10.7%), Pseudomonas aeruginosa (4.8%), Mycobacterium species, (4.8%), Salmonella spp. (4.4%), Shigella spp. (2.6%), Escherichia. coli O157:H7 (1.9%) and Proteus spp. (1.5%) were isolated. Antibiotic residues above the EU maximum residue limit (MRL) were detected in 18.1% of raw milk samples.

Conclusion: The quality of raw milk sold in the northern region of Ghana is compromised by several bacteria pathogens and antibiotic residues at the farm level. This calls for continuous education on milk pasteurization, hygienic practices and proper antibiotic usage by herdsmen.