Enteroaggregative Escherichia coli - Escherichia coli: Pathotypes and Principles of Pathogenesis - page 245

TABLE 8.1 Putative EAEC virulence genes and factors

Unique
to EAEC

Factor Description

Master
regulator gene

AggR Master regulator of a package of EAEC plasmid

virulence genes, including aggregative adherence
factors, fimbriae AAF/I-AAF/IV, and a large cluster of
genes inserted on a pathogenicity island at the PheU
locus ( Bernier et al., 2002 )

Ye s

AggR regulated
genes

AatA Encodes ABC protein responsible for transporting the

dispersin protein out of the outer membrane of EAEC
( Nishi et al., 2003 )

ND

Aap Encodes a 10-kDa secreted protein named dispersin,

and is responsible for 'dispersing' EAEC across the
intestinal mucosa ( Sheikh et al., 2002 )

No

AggA Encodes AAF/I, mediates adherence to colonic

mucosa and hemagglutination of erythrocytes
( Nataro et al., 1992 )

Ye s

AafA Encodes AAF/II, mediates adherence to colonic

mucosa and hemagglutination of erythrocytes
( Czeczulin et al., 1997 )

Ye s

Agg3A Encodes AAF/III hemagglutination of erythrocytes

( Bernier et al., 2002 )

Ye s

Agg4A Encodes AAF/IV, mediates adherence to colonic

mucosa and hemagglutination of erythrocytes
( Boisen et al., 2008 )

Ye s

AaiC AaiC, secreted protein. Encoded on the chromosome.

Mode of action

ND

ORF3/4 a Co-regulated two-gene cluster with homology to

isoprenoid synthesis genes

ND

ORF61 a Expressed contact hemolysis of erythrocytes ND

CapU Hexosyltransferase homolog ( Czeczulin et al., 1999 ) ND

Toxin

Pet A 108-kDa autotransporter protein that functions as a

heat-labile enterotoxin and cytotoxin ( Navarro-Garcia
et al., 1998 )

Ye s

SigA IgA protease-like homolog ( Rajakumar et al., 1997 ) No