Genetic features of verotoxigenic Escherichia coli O157:H7 isolated from clinical cases of Argentina and Chile

[Shiga toxin producing Escherichia coli: the challenge of adherence to survive]

Shiga Toxin-producing Escherichia coli (STEC) is recognized as being responsible for a large number of foodborne illnesses around the world. The pathogenicity of STEC has been related to Stx toxins. However, the ability of STEC to colonize the host and other surfaces can be essential for developing its pathogenicity. Different virulence profiles detected in STEC could cause the emergence of strains carrying new genes codified in new pathogenicity islands linked to metabolism and adherence. Biofilm formation is a spontaneous mechanism whereby STEC strains resist in a hostile environment being able to survive and consequently infect the host through contaminated food and food contact surfaces. Biofilm formation shows intra-and inter-serotype variability, and its formation does not depend only on the microorganisms involved. Other factors related to the environment (such as pH, temperature) and the surface (stainless steel and polystyrene) influence biofilm expression. The «One Health» concept implies the interrelation between public, animal, and environmental health actors to ensure food safety, prevent cross-contamination and resistance to sanitizers, highlighting the need to identify emerging pathogens through new molecular markers of rapid detection that involve STEC strains carrying the Locus of Enterocyte Effacement or Locus of Adhesion and Autoaggregation.