Genetic diversity and virulence potential of shiga toxin-producing Escherichia coli O113:H21 strains isolated from clinical, environmental, and food sources

Fil: Feng, Peter C H. Food and Drug Administration. Division of Microbiology; Estados Unidos.Fil: Delannoy, Sabine. French Agency for Food, Environmental, and Occupational Health and Safety. Laboratory for Food Safety; Francia.Fil: Lacher, David W. Food and Drug Administration. Division of Molecular Biology; Estados Unidos.Fil: Dos Santos, Luis Fernando. Universidade Federal de São Paulo. Department of Microbiology, Immunology and Parasitology; Brasil.Fil: Beutin, Lothar. Federal Institute for Risk Assessment. National Reference Laboratory for Escherichia coli; Alemania.Fil: Fach, Patrick. French Agency for Food, Environmental, and Occupational Health and Safety. Laboratory for Food Safety; Francia.Fil: Rivas, Marta. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Servicio Fisiopatogenia; Argentina.Fil: Hartland, Elizabeth L. University of Melbourne at the Peter Doherty Institute for Infection and Immunity. Department of Microbiology and Immunology; Australia.Fil: Paton, Adrienne W. University of Adelaide. School of Molecular and Biomedical Science. Research Centre for Infectious Diseases; Australia.Fil: Guth, Beatriz E C. Universidade Federal de São Paulo. Department of Microbiology, Immunology and Parasitology; Brasil.Shiga toxin-producing Escherichia coli strains of serotype O113:H21 have caused severe human diseases, but they are unusual in that they do not produce adherence factors coded by the locus of enterocyte effacement. Here, a PCR microarray was used to characterize 65 O113:H21 strains isolated from the environment, food, and clinical infections from various countries. In comparison to the pathogenic strains that were implicated in hemolytic-uremic syndrome in Australia, there were no clear differences between the pathogens and the environmental strains with respect to the 41 genetic markers tested. Furthermore, all of the strains carried only Shiga toxin subtypes associated with human infections, suggesting that the environmental strains have the potential to cause disease. Most of the O113:H21 strains were closely related and belonged in the same clonal group (ST-223), but CRISPR analysis showed a great degree of genetic diversity among the O113:H21 strains