Prevalence of Shiga-toxin producing Escherichia coli in Alberta beef cattle and characteristics of non-pathogenic microcin producing Escherichia coli champion battling bacterial virulence

Abstract

Zoonotic pathogens, like Shiga toxin-producing Escherichia coli (STEC) are a food safety and health risk. Among STEC, O157 is considered a major pathogen; however, globally the number of outbreaks with new emerging STEC strains is rising. Here, quantitative data on STEC O157 were gathered for western-Canada beef cattle and compared to emerging STEC. Quantitative data revealed; O178 is 4-times more numerous than O157 and high Shiga-toxin events are often not attributed to O157. Results suggest current surveillance likely misses emerging STEC due to restricted O-serogroup screening. Secondly, an alternate STEC mitigation strategy was investigated as an alternative approach to use of antibiotics which is controversial in human and animal therapeutics. Competition experiments identified a strong E. coli O103F which incapacitated STEC growth by producing a diffusible antimicrobial, most likely a microcin. The antimicrobial revealed tremendous potential for use along the farm-to-fork continuum or in human intervention to mitigate STEC.