Distribution of Locus of Adhesion and Autoaggregation and hes Gene in STEC Strains from Countries of Latin America

VÉLEZ, MARÍA VICTORIA; COLELLO, ROCÍO; ETCHEVERRÍA, ANALÍA INÉS; VIDAL, ROBERTO MAURICIO; MONTERO, DAVID ARTURO; ACUÑA, PATRICIA; GUILLÉN FRETES, ROSA MARÍA; TORO, MAGALY; PADOLA, NORA LÍA

CURRENT MICROBIOLOGY

SPRINGER

Lugar: Berlin; Año: 2020

0343-8651

Shiga toxin-producing Escherichia coli (STEC) are zoonotic food pathogens associated with foodborne diarrheal illness,hemorrhagic colitis, and complications such as hemolytic uremic syndrome (HUS). The ability to adhere to epithelial cellsis an important virulence trait, and pathogenicity islands (PAIs) play an important role on it. Some STEC carrying a PAInamed locus of enterocyte effacement (LEE-positive) have been frequently associated to HUS; however, STEC that do notcarry LEE (LEE-negative) have also been associated with this outcome. The burden of disease caused by LEE-negativeSTEC has increased recently in several countries like Argentina, Chile, and Paraguay. A new PAI ?the Locus of Adhesionand Autoagregation (LAA)?has been associated to severe disease in humans. In this study, we aimed to analyze the distributionof LAA and its possible predictor, the gene hes, in LEE-negative STEC strains isolated from Chile and Paraguay fromdifferent sources. The presence of the different LAA modules and hes were detected by PCR. LAA was found in 41.6% and41.0% of strains isolated from Chile and Paraguay, respectively. Strains were isolated from diverse origins and belonged toseveral serogroups including O91, O103, and O113. The hes gene was detected in 50% of the isolates from Paraguay andChile. Therefore, the detection of LAA and hes in STEC could complement current genetic evaluation schemes, allowingto classify LEE negative STEC strains as LAA-positive or LAA-negative STEC strains.