MICROBIAL QUALITY OF RAW AND ROASTED BEEF

Abstract

Foodborne pathogens initiate infections that can affect consumers when contaminated food is ingested. Bacteria (Escherichia coli and Salmonella spp) are among the food industry's major foodborne pathogens that require control for consumer safety. The research investigated the prevalence of Escherichia coli and Salmonella spp in raw and roasted beef (Kebab) to ensure consumer safety. In addition, nine antibiotics were assessed for antibiotic response in Escherichia coli and Salmonella spp isolates. Forty-five (45) samples comprising 15 raw beef samples, 15 roasted beef samples from retailing points (zero storage) and 15 roasted beef samples from retailing points (stored for 1 h 30 min) were analysed. Escherichia coli and Salmonella spp were isolated and identified using colony characteristics of selective agar like LEMB agar and XLD (Xylose Lysine Desoxycholate) agar, respectively. From the results, Salmonella spp was only present in the raw samples (6 cfu/ml) but absent in the roasted samples, while Escherichia coli was present in both raw (14 cfu/ml) and roasted (1 cfu/ml) samples. The overall prevalence of Escherichia coli and Salmonella spp in the samples was 93.33% and 40.00%, respectively. For antibiotic resistance in Escherichia coli isolates, all antibiotics were non-reactive except for Teicoplanin (70.59%), Gentamicin (5.88%), and Suphamethoxazole (5.88%), which were reactive with an overall prevalence of 9.15%. The isolates were sensitive to all antibiotics and ranged from 100% to 23.53%, with the highest overall prevalence of 87.58%. Similarly, for antibiotic resistance, Salmonella spp isolates were non-reactive with Chloramphenicol, Ciprofloxacin, Ceftriaxone, Gentamicin, and Tetracycline, while the four remaining antibiotics had a percentage of 16.67% each. The overall prevalence of antibiotic resistance was 7.41%. Salmonella spp isolates were also sensitive to all antibiotics and ranged from 100% - 50%, with an overall prevalence of 83.33%. The presence of foodborne pathogens is a consumer risk that requires attention to ensure food safety and security. Excessive antibiotic use can increase resistant bacteria, making the antibiotics less effective for both animals and humans. The presence of antibiotic residues in food (roasted beef) can be associated with many health problems and allergies. It could negatively affect the health of consumers' liver, kidneys, reproductive system, and immune system.