Epidemiology of Shiga Toxin-Producing Escherichia coli O157 in the Province of Alberta, Canada, 2009–2016

Abstract

Shiga toxin-producing Escherichia coli (STEC) infections are the product of the interaction between bacteria, phages, animals, humans, and the environment. In the late 1980s, Alberta had one of the highest incidences of STEC infections in North America. Herein, we revisit and contextualize the epidemiology of STEC O157 human infections in Alberta for the period 2009–2016. STEC O157 infections were concentrated in large urban centers, but also in rural areas with high cattle density. Hospitalization was often required when the Shiga toxin genotype stx2a stx2c was involved, however, only those aged 60 years or older and infection during spring months (April to June) independently predicted that need. Since the late 1980s, the rate of STEC O157-associated hemolytic uremic syndrome (HUS) in Alberta has remained unchanged at 5.1%, despite a marked drop in the overall incidence of the infection. While Shiga toxin genotypes stx1a stx2c and stx2a stx2c seemed associated with HUS, only those aged under 10 years and infection during spring months were independently predictive of that complication. The complexity of the current epidemiology of STEC O157 in Alberta highlights the need for a One Health approach for further progress to be made in mitigating STEC morbidity.

Antimicrobial Usage Factors and Resistance Profiles of Shiga Toxin-Producing Escherichia coli in Backyard Production Systems From Central Chile

“…Serotypes reported by this study are commonly detected in animals or animal products ( 66 , 67 ), and linked to animal and human diarrhea ( 68 ) and HUS, under particular conditions ( 69 , 70 ). It is important to highlight that no O157 STEC strains were detected in this study, high morbidity, and mortality serotype linked to animal transmission ( 71 ). The stx subtype genes profile detected in this study, is consistent with that reported previously for most STEC isolates, both in animals from intensive farming systems and people ( 7 , 72 ).…”

Prevalence, O-genotype and Shiga toxin (Stx) 2 subtype of Stx-producing <i>Escherichia coli</i> strains isolated from Argentinean beef cattle

“…Stx2 is classified into at least 7 subtypes (Stx2a to Stx2g) based on their amino acid sequence diversity [ 34 ]. Among these subtypes, epidemiological data indicate that Stx2a and/or Stx2c producers were more frequently associated with HC and HUS cases [ 20 , 34 ]. Therefore, Stx2 subtyping is important since it may provide valuable information about the virulence of STEC strains.…”

Introduction to the Special Issue “Molecular Basis and the Pathogenesis of Enterohemorrhagic Escherichia coli Infections”

“…Future treatments for hemolytic uremic syndrome (HUS) would combat bacterial virulence factors instead of passively treating kidney failure, as discussed in a review of mechanisms of EHEC virulence [4]. The lack of progress in EHEC treatments was illustrated from work showing a decline in EHEC infections since the 1980s in the Province of Alberta, Canada, even though HUS still occurs in 5% of infections [5]. This lack of change in HUS incidence over time may also be influenced by changes in dominant EHEC strains.…”