Pathogenic Bacteria Contamination along the Beef line at Asella Municipal Abattoir, Arsi Zone Oromia Regional State, Ethiopia

Abstract

Abstract Background: Foodborne bacterial pathogens and spoilage microbes leads to economic loss as a result of foods deterioration and public health risk. In areas where there is habit of raw meat consumption, various bacteria may result in acquire food-borne diseases and intoxication.Methods: A cross-sectional study was conducted to assess microbial contamination along Asella Municipal Beef Abattoir line. A total of 470 samples consisting of 400 beef carcasses swab and 70 environmental samples (apron, carcass splitting axil, personnel hand, hooks, knife, meat wrapping plastics, cleaning water) were collected and examined for presences of microbial. One colony type was characterized per positive samples, with no mixed microbial contamination report in this work. The isolation and identification of bacterial contaminates was performed according to the standard microbiological procedures. For E. coli, the hemolytic nature and appearance of metallic sheen on eosin methylene blue agar were used to define the pathogenicity. Additionally, rabbit plasma-based coagulase test was used to differentiate coagulase positive Staphylococcus (CPS) and coagulase negative Staphylococcus (CNS) as indication of pathogenicity.Results: Out of the total samples examined, 99.1% (95% CI= 97.8-99.8) were contaminated with bacteria. The observed proportion of beef abattoir line contamination was; Staphylococcus aureus (36.4%), CNS (16.2%), other grams positive isolates (14.0%), Staphylococcus hyicus (13.8%), and E. coli (10.9%), and Staphylococcus intermedius (7.9%). The total proportion of samples positive for coagulase positive (pathogenic) Staphylococcus species were 58.1% (95% CI= 53.5-62.6), with a 61.4% and 57.5% occurrence in abattoir environment and carcass samples, respectively. All sampling locations were found contaminated with S. aureus (34.3-60.0%) and E. coli (10.0-30.0%). All locations were contaminated with CNS (10.0-20.0%), except for carcass splitting axil. S. hyicus contaminated all location at rate of 10.0-30.0%, except the hooks and cleaning water. S. intermedius was observed only at carcass splitting axil (10.0%), cleaning water (10.0%) and carcass (8.0%). Other grams positive isolates were observed at 10.0-30.0%, but not on carcass splitting axil and hooks. The observed isolation rate of CPS (40-90%), S. aureus (30-60%), S. hyicus (0-30%), S. intermedius (0-10%), E. coli (10-30), and CNS (0-20) in different abattoir environment was higher than the isolation rate from carcass samples at proportion of 57.5%, 34.3%, 14.5%, 8.8%, 10.5, and 16.8%, respectively. Based on chi-square analysis S. aureus was significantly (p<0.05) higher in environmental (48.6%) than in meat (43.3%) samples. But the proportion of distribution with other isolates was insignificant (p>0.05) between environmental (2.9-12.9%) and meat (8.0-16.8%) samples.Conclusion: The finding indicates the presence of one or more zoonotic and spoilage bacterial pathogens in the beef abattoir which might lead to mixed foodborne infection and intoxication. Therefore, hygienic operations in the beef line; proper handling of working equipment’s and carcass; as well as the application of modern working facilities could reduce the risk of such microbial hazards associated with beef production in the abattoirs.