Prevalence and Implications of Shiga Toxin-Producing E. coli in Farm and Wild Ruminants

Abstract

Shiga-toxin-producing Escherichia coli (STEC) is a food-borne pathogen that causes human gastrointestinal infections across the globe, leading to kidney failure or even death in severe cases. E. coli are commensal members of humans and animals’ (cattle, bison, and pigs) guts, however, may acquire Shiga-toxin-encoded phages. This acquisition or colonization by STEC may lead to dysbiosis in the intestinal microbial community of the host. Wildlife and livestock animals can be asymptomatically colonized by STEC, leading to pathogen shedding and transmission. Furthermore, there has been a steady uptick in new STEC variants representing various serotypes. These, along with hybrids of other pathogenic E. coli (UPEC and ExPEC), are of serious concern, especially when they possess enhanced antimicrobial resistance, biofilm formation, etc. Recent studies have reported these in the livestock and food industry with minimal focus on wildlife. Disturbed natural habitats and changing climates are increasingly creating wildlife reservoirs of these pathogens, leading to a rise in zoonotic infections. Therefore, this review comprehensively surveyed studies on STEC prevalence in livestock and wildlife hosts. We further present important microbial and environmental factors contributing to STEC spread as well as infections. Finally, we delve into potential strategies for limiting STEC shedding and transmission.

Pathogenicity assessment of Shiga toxin-producing Escherichia coli strains isolated from wild birds in a major agricultural region in California

“…In recent years, non-O157:H7 STEC serotypes associated with foodborne outbreaks and human infections have increased ( Valilis et al, 2018 ), thus information about virulence and pathogenesis of STEC strains in diverse ecological niches is desired for the development of effective mitigation strategies. Wildlife has been recognized as a primary source of emerging infectious diseases, and these animal reservoirs can harbor uncommon or uncharacterized serotypes ( Kim et al, 2020 ; Ray and Singh, 2022 ). Although all STEC strains have the potential to pose health risks, acquisition of certain virulence traits would promote the emergence of strains with a high-risk to human health.…”

Exploring Long-Read Metagenomics for Full Characterization of Shiga Toxin-Producing Escherichia coli in Presence of Commensal E. coli

“…Under certain conditions, isolation-independent approaches are promising and could be applied in the case of ambiguous results that render decision making difficult, particularly when the STEC strain cannot be isolated. Many studies on STEC prevalence in cattle have been conducted but none on STEC prevalence compared to background E. coli [ 40 , 41 ]. Such studies would give insights into the application of long-read metagenomic approaches to characterize STEC among other E. coli.…”

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

“…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]. It has been observed that E. coli infections in animals can be asymptomatic; therefore, wildlife may be a natural reservoir of these pathogens, leading to an increased risk of zoonosis [14].…”