AUTHOR=Freire Claudia A. , Rodrigues Beatriz O. , Elias Waldir P. , Abe Cecilia M. 

TITLE=Adhesin related genes as potential markers for the enteroaggregative Escherichia coli category

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.997208

DOI=10.3389/fcimb.2022.997208

ISSN=2235-2988

ABSTRACT=<p>Enteroaggregative <italic>Escherichia coli</italic> (EAEC) is an important cause of diarrhea in children and adults worldwide. This pathotype is phenotypically characterized by the aggregative-adherence (AA) pattern in HEp-2 cells and genetically associated to the presence of the <italic>aatA</italic> gene. EAEC pathogenesis relies in different virulence factors. At least, three types of adhesins have been specifically associated with EAEC strains: the five variants of the aggregative adherence fimbriae (AAF), the aggregative forming pilus (AFP) and more recently, a fibrilar adhesin named CS22. Our study aimed to evaluate the presence of AAF, AFP and CS22-related genes among 110 EAEC strains collected from feces of children with diarrhea. The presence of <italic>aggR</italic> (EAEC virulence regulator) and genes related to AAFs (<italic>aggA, aafA</italic>, <italic>agg3A</italic>, <italic>agg4A</italic>, <italic>agg5A</italic> and <italic>agg3/4C</italic>), AFP (<italic>afpA1</italic> and <italic>afpR</italic>) and CS22 (<italic>cseA</italic>) was detected by PCR, and the adherence patterns were evaluated on HeLa cells. a<italic>ggR</italic>-positive strains comprised 83.6% of the collection; among them, 80.4% carried at least one AAF-related gene and presented the AA pattern. <italic>aggA</italic> was the most frequent AAF-related gene (28.4% of <italic>aggR</italic>+ strains). <italic>cseA</italic> was detected among <italic>aggR</italic>+ (16.3%) and <italic>aggR</italic>- strains (22.2%); non-adherent strains or strains presenting AA pattern were observed in both groups. <italic>afpR</italic> and <italic>afpA1</italic> were exclusively detected among <italic>aggR</italic>- strains (77.8%), most of which (71.4%) also presented AA pattern. Our results indicate that AAF- and AFP-related genes may contribute to identify EAEC strains, while the presence of <italic>cseA</italic> and its importance as an EAEC virulence factor and genotypic marker needs to be further evaluated.</p>