First report of the distribution of Locus of Adhesion and Autoaggregation (LAA) pathogenicity island in LEE-negative Shiga toxin-producing Escherichia coli isolates from Argentina

COLELLO, ROCÍO; VÉLEZ, VICTORIA; GONZÁLEZ, JULIANA; MONTERO, DAVID; BUSTAMANTE, ANA; DEL CANTO, FELIPE; ETCHEVERRÍA, ANALÍA I.; VIDAL, ROBERTO; PADOLA, NORA LÍA

MICROBIAL PATHOGENESIS

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2018 vol. 123 p. 259 - 263

0882-4010

Shiga toxin-producing Escherichia coli (STEC) are important foodborne pathogens that can cause severe disease.The ability to adhere to epithelial cells is an important virulence trait and pathogenicity islands (PAIs) play animportant role. Recently, researchers identified a member of the Heat-resistant agglutinin family and characterizedthis antigen named Hemagglutinin from Shiga toxin-producing E. coli (Hes). More importantly, theyshowed that hes and other genes such as iha, pagC and agn43 were integrated in each of the four modules presentin the new PAI named Locus of Adhesion and Autoaggregation (LAA) whose presence is associated with severedisease linked to with LEE-negatives STEC.The distribution of LAA among STEC strains isolates from different origins between 2000 and 2015 fromcattle, the farm environment, and food and harboring diverse virulence was investigated. The STEC strains werecharacterized by PCR to detect three modules of LAA and agn43 (as marker of module IV), and phylogeneticgroups were determined. LAA was found in 46% of LEE-negative STEC corresponding to serogroups O91, O174,O113, O171, O178, O130 and others. The presence of this PAI is associated with strains harboring stx2 (56%)and belonging to phylogroup B1 (91%). LAA is a novel pathogenicity island associated with strains isolated fromHemolytic Uremic Syndrome cases. Therefore, the results of this study contribute to a better understandingregarding the pathogenicity of this emergent subset of STEC strains harboring LAA as a predictor of virulence ofLEE-negative STEC strains.