Table 2.

Virulence-associated genetic determinants of the main Escherichia coli pathotypes

Gene/genomic region/plasmid	Functional role	Comments
LEE PAI	Genomic island containing eae (encoding gene for an adhesin) as well as effectors and structural proteins associated with a type III secretion system	EPEC defining region
pINV	Encodes for a type III secretion system and for effectors allowing intracellular survival	EIEC/Shigella defining plasmid
est, elt	Heat-stable (ST) and heat-labile (LT) enterotoxins	ETEC defining genes
stx1, stx2	Shiga toxins (verotoxins) 1 and 2	EHEC defining genes
aggR, aatA, aaiC	Transcriptional regulator, transporter protein and secreted protein	Associated with EAEC phenotype

Adapted from Robins-Browne et al. [12]

LEE PAI, Locus of enterocyte effacement pathogenicity island; EPEC, enteropathogenic E. coli; EIEC, enteroinvasive E. coli; ETEC, enterotoxigenic E. coli; EHEC, enterohaemorrhagic E. coli; EAEC, enteroaggregative E. coli