Isolation, characterization, and antimicrobial susceptibility pattern of Escherichia coli O157:H7 from foods of bovine origin in Mekelle, Tigray, Ethiopia

Abstract

Escherichia coli O157:H7 is an emerging and major zoonotic foodborne pathogen. It has an increasing concern about the spread of antimicrobial-resistant strains. This study aimed to isolate and characterize Shiga toxin-producing E. coli O157:H7 from raw milk, yogurt, and meat of bovine origin and determine their antimicrobial susceptibility pattern. A cross-sectional study was conducted from December 2014 to June 2015, and a total of 284 milk and meat samples were collected from different sources in Mekelle. The collected samples were analyzed for the presence of E. coli and Shiga toxin-producing E. coli O157:H7 and the determination of their antimicrobial susceptibility pattern following the standard bacteriological and molecular techniques and procedures and antimicrobial sensitivity test. Out of the total 284 samples, 70 (24.6%) were bacteriologically positive for E. coli and 14.3% were found to be Shiga toxin-producing E. coli O157:H7. Of note, 100% of E. coli isolates carried the pal gene and 41.7% eaeA gene (EHEC). Of these EHEC isolates, 40% and 60% were positive for stx1 and stx2, respectively. E. coli isolates showed the highest level of susceptibility to gentamycin (91.7%) but the highest level of resistance to amoxicillin (95.8%). Of the tested isolates, 18 (75%) of E. coli showed multidrug-resistant. This study revealed the occurrence of Shiga toxin-producing E. coli O157:H7 in foods of bovine origin in the study area. In conclusion, a nationwide phenotypic and molecular characterization, in-depth typing, and drug-resistant gene identification of E. coli O157:H7 should be undertaken.

Occurrence of Escherichia coli, Salmonella spp. and Staphylococcus aureus and Antimicrobial Susceptibility Profile in Locally and Commercially Produced Yogurt Sold in Addis Ababa, Ethiopia

“…are frequently detected in yogurt, are sometimes present in concentrations above the normative levels, and consequently may have adverse effects on consumer health[6,7].The result of tetracycline resistance was more frequently observed compared with the other antibiotics of E. coli isolates in this study, in agreement with the reports of Tadesse et al,. 2021 [28] (27.7%) and lower than the ndings of Gugsa et al,2022[9] (41.7%),Messele et al,2017 [29] (47.6%), Ahmed and Shimamoto,2015[30] (80.6%),Disassa et al,2017 [31] (81.8%),Ababu et al,2020 [32] (63.63%), and Hailu,2020[33] (60.61%) but was higher than the ndings ofBekele et al,2014…”

“…Studies and observations conducted elsewhere in Ethiopia have also indicated that the increase in the proportion of antimicrobial-resistant strains could be due to the irrational use of antimicrobials and the inappropriateness of the prescription and dispensing methods in both the public veterinary and private health setups of the country [12,43]. The scienti c literature indicates that the presence of multidrugresistant bacterial pathogens in ruminants, and consequently in dairy products, may cause drug-resistant infections in humans [14,15,8,9,10,11,12,16].…”

“…Essentially, even a little contamination may deteriorate the quality of yogurt, which may have negative effects on consumer health [6,7]. A previous study conducted in Ethiopia has also indicated that yogurt is a potential reservoir for different pathogenic microorganisms of public health concern [8, 9,10,11,12], and fermentation of yogurt does not control this pathogen [13]; therefore, yogurt can be a potential health hazard if it is prepared from milk contaminated with this pathogen and does not show any off odor [13]. Thus, it is di cult to depend on sensory evaluation as a sign of safety [13].…”

“…Studies and observations have indicated that in recent years, widespread overuse and misuse of antimicrobial agents in food animal production have contributed to the development of numerous bacteria with multiple drug resistance patterns that have emerged in Ethiopia [14,15,8,9,10,11,12,16].…”

“…Abebe et al, 2023 [8] analyzed 35 yogurt samples from Dessie and Kombolcha towns, Ethiopia, and detected E. coli in 5 (13.9%) samples. Gugsa et al, 2022[9] studied 48 yogurt samples from Mekelle, Tigray, Ethiopia, and reported a prevalence of 11 (22.9%) andBedasa et al, 2018 [10] reported a prevalence of 9/35 (25.71%) E. coli after analyzing 35 yogurt samples in and around Bishoftu, Central Ethiopia. Additionally,Muluken et al, 2016 …”