Evaluation of Bacterial Contamination From Raw and Cooked Fish, Mutton and Beef Sold by Local Vendors in Hyderabad, Pakistan

Abstract

Foodborne pathogens are spreading to humans through contamination of raw and cooked meat because of its inappropriate processing, handling and cooking. Therefore this research was performed for the evaluation of bacterial contamination from raw and cooked fish, mutton and beef sold by retailors in district Hyderabad. During present study, 150 total meat samples, 100 from raw meat (beef=40, mutton=40, fish=20) and 50 from cooked meat (beef=20, mutton=20, fish=10) were randomly collected from district Hyderabad and cultured on different media for isolation of bacterial species. The isolated species were identified by different biochemical tests. The results showed that the contamination of bacterial organisms in both raw and cooked meat was highest in beef followed by mutton and fish respectively (p < 0.05). In raw meat, bacterial species recorded were Escherichia coli (45%, 30% and 25%), Salmonella enteritidis (20%, 17.5% and 15%), Staphylococcus aureus (30%, 25% and 25%), Bacillus cereus (12.5%, 10% and 10%), Klebsiella pneumoniae (15%, 10% and 0%) and Shigella dysenteriae (10%, 12.5% and 5%) in beef, mutton and fish respectively. While from cooked beef, mutton and fish the prevalence of E. coli (25%, 25% and 20%), S. aureus (15%, 15% and 10%), S. enteritidis and B. cereus (10%, 10% and 10%) were observed. The highest (p < 0.05) bacterial load (g¹) was detected in raw (1.76×106) and cooked (6.1×104) beef than raw (1.55×106) and cooked (4.5×104) mutton respectively, while raw (1.25×106) and cooked (2.9×104) fish exhibited the least (p < 0.05) bacterial load than other raw and cooked meat (beef and mutton) respectively. Data regarding antimicrobial susceptibility exhibited that among eight antibiotics E. coli, S. enteritidis, S. aureus and B. cereus were observed sensitive to gentamycin, norfloxacin and ciprofloxacin. K. pneumoniae showed sensitivity against gentamycin, norfloxacin, ciprofloxacin, erythromycin, tetracycline and streptomycin; whereas S. dysenteriae was observed sensitive to gentamycin, norfloxacin, tetracycline and ampicillin. In conclusion, raw beef samples were found more contaminated than raw fish and mutton while cooked fish samples were observed less contaminated than cooked beef and mutton. Furthermore, all bacterial isolates (except K. pneumoniae) were found multidrug resistant.