Cumulative acquisition of pathogenicity islands has shaped virulence potential and contributed to the emergence of LEE-negative Shiga toxin-producing Escherichia coli strains
JournalEmerging Microbes and Infections
PublisherTaylor and Francis Ltd.
MetadataShow full item record
AbstractShiga toxin-producing Escherichia coli (STEC) are foodborne pathogens causing severe gastroenteritis, which may lead to hemolytic uremic syndrome. The Locus of Enterocyte Effacement (LEE), a Pathogenicity Island (PAI), is a major determinant of intestinal epithelium attachment of a group of STEC strains; however, the virulence repertoire of STEC strains lacking LEE, has not been fully characterized. The incidence of LEE-negative STEC strains has increased in several countries, highlighting the relevance of their study. In order to gain insights into the basis for the emergence of LEE-negative STEC strains, we performed a large-scale genomic analysis of 367 strains isolated worldwide from humans, animals, food and the environment. We identified uncharacterized genomic islands, including two PAIs and one Integrative Conjugative Element. Additionally, the Locus of Adhesion and Autoaggregation (LAA) was the most prevalent PAI among LEE-negative strains and we found that it contributes to colonization of the mice intestine. Our comprehensive and rigorous comparative genomic and phylogenetic analyses suggest that the accumulative acquisition of PAIs has played an important, but currently unappreciated role, in the evolution of virulence in these strains. This study provides new knowledge on the pathogenicity of LEE-negative STEC strains and identifies molecular markers for their epidemiological surveillance. Copyright 2019, Copyright 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of Shanghai Shangyixun Cultural Communication Co., Ltd.
Integrative Conjugative Element
Locus of Adhesion and Autoaggregation
Identifier to cite or link to this itemhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85064118989&doi=10.1080%2f22221751.2019.1595985&partnerID=40&md5=7dbf75def8cb0b7b44f589d8c7409752; http://hdl.handle.net/10713/10594