Occurrence, molecular characteristics, and antimicrobial resistance of Escherichia coli O157 in cattle, beef and humans in Bishoftu Town, Central Ethiopia

Authors: GUTEMA, FANTA - Addis Ababa University; RASSCHAERT, GEERTRUI - Flanders Research Institute For Agriculture; Agga, Getahun; JUFARE, ALEMNESH - Alage Agricultural Technical Vocational Educational Training College; DUGUMA, ADDISU - Bishoftu Hospital; ABDI, RETA - Long Island University; DUCHATEAU, LUC - Ghent University; CROMBE, FLORENCE - Vrije Universiteit Brussel; GABRIEL, SARAH - Ghent University; DE ZEUTTER, LIEVEN - Ghent University

Submitted to: Foodborne Pathogens and Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/22/2020
Publication Date: 8/31/2020
Citation: Gutema, F.D., Rasschaert, G., Agga, G.E., Jufare, A., Duguma, A.B., Abdi, R.D., Duchateau, L., Crombe, F., Gabriel, S., De Zeutter, L. 2020. Occurrence, molecular characteristics, and antimicrobial resistance of Escherichia coli O157 in cattle, beef and humans in Bishoftu Town, Central Ethiopia. Foodborne Pathogens and Disease. 18(1);1-7. https://doi.org/10.1089/fpd.2020.2830.
DOI: https://doi.org/10.1089/fpd.2020.2830

Interpretive Summary: Most Escherichia coli bacteria are a normal flora of animals and humans without causing any harm. However, some strains such as E. coli O157 can cause self limiting bloody diarrhea in most human population. It causes severe bloody diarrhea in susceptible populations such as children, the elderly and the immune compromised individuals. It can also cause hemolytic uremic syndrome, a serious complication that can lead to kidney failure and death. Contaminated beef is a major source of infection and undercooked or raw beef consumption are the major routes of infection. In a study aimed to establish a relationship for its occurrence we observed E. coli O157 in cattle, retail beef and people with diarrhea. Fingerprinting showed that some isolates from the three sources share similarities indicating potential role f beef consumption for the occurrence of diarrhea in the human population. Hurdles of interventions during cattle production, processing and distribution, as well as public education are important prevention measures.

Technical Abstract: Escherichia coli O157 is a Shiga toxin-producing E. coli causing disease in humans. Cattle are the primary reservoir of the pathogen. Information regarding the contribution of cattle to diarrheal illnesses in humans through consumption of contaminated beef is scarce in Ethiopia. We collected samples from cattle, beef and diarrheic patients in Bishoftu town in Ethiopia to assess the occurrence and determine the virulence genes, genetic relatedness and antimicrobial resistance of E. coli O157. E. coli O157 was detected in 7% (n=240) of cattle fecal samples, in 6.3% (n=127) of the beef samples, and 2.8% (n=216) of the diarrheic patients’ stool samples. All isolates (n=31) were positive for intimin (eae), 24 (77%) of them were positive for Shiga toxin 2 (stx2) gene (21 stx2c and 3 stx2a), while Shiga toxin 1 (stx1) was not detected. The predominant (87.5%) subtype of stx2 was stx2c. The isolates were grouped into eight pulsed-field gel electrophoresis pulsotypes with three pulsotype groups containing isolates from the three sources, one pulsotype contained one isolate from human and beef and the remaining four groups contained isolates unique either to beef or humans. Except one multidrug resistant beef isolate, which was resistant to eight antimicrobial drugs, the remaining 30 isolates were susceptible to the 14 antimicrobials tested. In conclusion, the finding of genetically similar isolates among cattle, beef and humans may indicate a potential transmission of E. coli O157 to humans through beef. However, more robust studies are required to confirm the actual epidemiological link.