Bacteriological quality of raw meat and dairy products and antibiogram profile of bacterial pathogens in Jimma town, southwest Ethiopia

Abstract

Abstract Background:Although consumers and venders have been benefiting from foods of animal origin, such foods are also perceived to be a major public health concern due to contamination, as they are ideal media for diverse microbes. Therefore, evaluation of bacteriological quality and safety of animal origin foods such as raw meat and dairy products and investigation of antibiogram profiles of selected pathogenic bacteria are important to ensure the safety of consumers. Methods: A total of 120 food samples, 30 from raw meat, raw milk, cottage cheese, and cream cake, were collected from three local markets at the Agip, Kochi and Merkato sites in Jimma town from August 2020 to March 2021. The samples were transported to Jimma University Postgraduate Laboratory and analyzed following standard microbiological methods,including isolation, enumeration, and characterization of food pathogens. Results:The highest mean microbial counts (colony forming units per gram or per milliliter) of aerobic mesophilic bacteria (7.37±0.68), aerobic spore-forming bacteria (5.91±0.56), staphylococci (5.59±0.74), Enterobacteriaceae (4.14±0.74) and coliforms (3.95±0.66) were recorded from raw meat. There was a statistically significant difference (p<0.005) with regard to microbial counts in all food samples. In all the food samples, Staphylococcus spp. was dominant (34.74%), followed by Bacillus spp. (25.93%) and Enterobacteriaceae (13.51%). Among the pathogens, Staphylococcus aureus in raw meat (43.33%), Bacillus spp. (20%) in milk, and Escherichia coli spp. (16.67%) in meat samples were dominant. Moreover, Salmonella spp. and Pseudomonas spp. from raw milk were highly resistant to nalidixic acid. Overall, Pseudomonas spp. (28.57%) and Escherichia coli spp. (8.33%) were resistant to a maximum of five antibiotics. Discussion and conclusions: Food contamination problems in the present study could be due to poor personal hygiene and cross-contamination from farm to table. From the current study, the raw meat and dairy products in Jimma town were poor in terms of both microbial quality and safety. Regular inspection foods and training to all involved with the food at any stage are necessary to minimize the observed microbiological safety and quality problems. Moreover, the antibiotic resistance patterns of the isolated pathogens alarm the need for regular surveillance and monitoring of foods that are of animal origins and processing to design appropriate strategies for minimizing the possible risks caused by such pathogens.