Occurrence of Escherichia coli O157:H7 in retail raw meat products in Ethiopia

Abstract

Background: Escherichia coli O157:H7 (E. coli O157:H7) is now recognized as a major cause of diarrhoea, hemorrhagic colitis and hemolytic-uremic syndrome worldwide. Consumption of raw or undercooked meat of bovine origin has been the most common means of transmitting this organism. Methodology: Over a period of 7 months (October 2006 to April 2007), a total of 738 raw meat samples were collected from bovines (n= 250), sheep (n=243) and goat (n=245) and investigated for the presence of E. coli O157: H7. Antimicrobial susceptibility testing was performed using the disk diffusion method. Results: E. coli O157:H7 were isolated from 31 (4.2%) out of 738 meat samples examined. Among meat samples examined, the highest prevalence (8%) was recorded in beef, followed by lamb and mutton (2.5%) and goat meat (2%). The isolated strains were found to be susceptible (100%) to amikacin, chloramphenicol, gentamicin, kanamycin, nalidixic acid, norfloxacin, polymyxin B and trimethoprim-sulfamethoxazole. Multidrug resistance to three or more drugs was detected in 7/31 (22.6%) strains. Conclusions: The results of this study revealed the presence of E. coli O157:H7 in retail raw meats reaching consumers, indicating possible risks of infection to people through the consumption of raw/under-cooked meat or cross-contamination of other food products. Coordinated actions are needed to reduce or eliminate the risks posed by this organism at various stages in food chain. Multiple drug resistant isolates detected in the present study may pose a threat to humans and further limit therapeutic options.