E. coli O157:H7 and Salmonella Species: Public Health Importance and Microbial Safety in Beef at Selected Slaughter Houses and Retail Shops in Eastern Ethiopia

Abstract

A cross-sectional study was conducted from March 2014 to January 2015 in Dire Dawa city and Haramaya University slaughterhouses and retail shops to identify major foodborne pathogens, assess the beef microbial safety and potential contamination risk factors. 320 beef and environmental pooled samples were examined for the presence of E. coli, E. coli O157:H7 and Salmonella in accordance with international standard guidelines. On each visit of the slaughter house a total of four pooled swab samples were taken each from cleaned, disinfected and dry surfaces, other from hooks, knives and aprons, the third from personnel’s hands who works on flaying, evisceration and carcass cutting before the beginning of operation. For isolation and identification of pathogens from meat, 25 gram of sample was weighed, cut in to small piece with different sterile scalpel blade and placed into sterile stomacher bags. The questionnaire survey data and laboratory results of the collected samples were entered into databases using Micro-Soft Excel computer program and analyze using SPSS version-19.0. Of 290 total beef samples collected, E. coli was isolated from 36(12.41%) and of which 6(2.06%) were confirmed on Sorbitol MacConkey agar to be E. coli O157 H7. On the other hand 8(2.75%) Salmonella spp. was identified using culture and biochemical tests. The present study indicated significantly higher fecal coliforms counts in beef samples from HU slaughterhouse (7.50 log10 cfug-1) than in carcass sample from Haramaya retail shop (4.80 log10 cfug-1). Out of 30 environmental pooled samples, E. coli, E. coli O157:H7 and Salmonella were investigated in 7(23.33%), 2(6.66%) and 2(6.66%), respectively. From the visual observations: slaughterhouse, hygienic practice employed, personnel habit were found below the minimum standards. Therefore, good management and hygienic practices should be introduced in order to enhance the overall safety and hygienic quality of beef for the safeguard of consumers.