Epidemiology of Non-O157 Shiga Toxin-Producing Escherichia coli in the Province of Alberta, Canada, from 2018 to 2021

Abstract

Non-O157 serogroups contribute significantly to the burden of disease caused by Shiga toxin-producing Escherichia coli (STEC) and have been underrecognized by traditional detection algorithms. We described the epidemiology of non-O157 STEC in Alberta, Canada for the period of 2018 to 2021. All non-O157 STEC isolated from clinical samples were submitted for serotyping and qPCR targeting the stx1 and stx2 genes. A total of 729 isolates were identified. Increased detection occurred over the summer months, peaking in July. Patients 18 years and younger made up 42.4% of cases, with 31.1% in those 0–9 years of age. There was a slight female predominance (399/729, 54.7%) A total of 50 different serogroups were detected; the most common were O26 (30.3%), O103 (15.9%), O111 (12.8%), O121 (11.0%), O118 (3.3%) and O71 (2.9%). These six serogroups made up 76.2% of all isolates. In total, 567 (77.8%) were positive for stx1, 114 (15.6%) were positive for stx2 and 48 (6.6%) were positive for both stx1 and stx2. A wide variety of non-O157 serogroups have been detected in Alberta, with the most frequent serogroups differing from other locations. These results highlight the need for further characterization of their virulence factors and clinical impact.

Isolation, Characterization, and Genome Analysis of a Novel Bacteriophage, Escherichia Phage vB_EcoM-4HA13, Representing a New Phage Genus in the Novel Phage Family Chaseviridae

“…However, non-O157 cases have been increasing, largely due to improved laboratory testing and reporting inclusion [10]. Non-O157 STEC cases are largely attributed to one of six serogroups-O26, O45, O103, O111, O121, and O145 [11,12]. As reported by Gould et al in 2013, the six serotypes combined had almost the same incidence rate as O157.…”

Detection and Characterization of Zoonotic Pathogens in Game Meat Hunted in Northwestern Italy

“…Shiga-toxin-producing E. coli (STEC) can cause serious diseases in humans (e.g., bloody diarrhea, haemolytic-uremic syndrome (HUS)) [12]. E. coli O157:H7 is the most frequently involved serotype in human diseases, but more than 400 O:H types of STEC (mainly O26, O45, O103, O104, O111, O121, and O145) have been associated with infection [13]. Transmission of STEC to humans can occur through the ingestion of contaminated meat or water, contact with animal feces, or person-to-person contact [8].…”

Pathogenomes and virulence profiles of representative big six non-O157 serogroup Shiga toxin-producing Escherichia coli

“…Serotype O157:H7 is the dominant causative agent of STEC disease in the U.S. ( Riley et al, 1983 ; Eppinger et al, 2011 , 2013 ; Sanjar et al, 2014 ; Rusconi et al, 2016 ). However, the incidence of non-O157 infections that feature different somatic antigens has been steadily increasing in recent years ( Gould et al, 2013 ; Vishram et al, 2021 ; Glassman et al, 2022 ; Tarr et al, 2023 ). Among these, emerging serogroups O26, O45, O103, O111, O121, and O145 account for the majority of clinical non-O157 STEC infections in the US and are colloquially referred to as the “Big Six” ( Eklund et al, 2001 ; Johnson et al, 2006 ; Bettelheim, 2007 ; Hadler et al, 2011 ; Hegde et al, 2012 ; Gould et al, 2013 ; Vishram et al, 2021 ).…”