Enterohemorrhagic and other Shigatoxin-producing Escherichia coli - Escherichia coli: Pathotypes and Principles of Pathogenesis - page 122

TABLE 5.2 STEC adherence factors

Potential adhesins Function

EspA Filamentous appendage that promotes type III effector

delivery and mediates interaction between host cells
and AE pathogens ( Ebel et al., 1998 ; Knutton et al.,
1998 ; Daniell et al., 2001 ).

Long polar fimbriae
(LPF)

Required for adherence and microcolony formation in
eukaryotic cells ( Torres et al., 2002 ; Torres et al., 2004 ).
Has a role in pig, sheep ( Jordan et al., 2004 ) and infant
rabbit colonization ( Lloyd et al., 2012 ) and influencing
intestinal tissue tropism ( Fitzhenry et al., 2006 ). Binds to
ECM proteins ( Farfan et al., 2011 ).

F9 Fimbriae (Type I pilus
homolog)

Potential role in colonization in young calves and in
adherence to cells in culture ( Low et al., 2006 ).

Curli fimbriae Associated with increased virulence of EHEC in mice

( Uhlich et al., 2002 ). Promotes attachment of EHEC
(O111:H-7-57C+, O157:H7 5-11C+ and O103:H2
7-52C+) to certain abiotic surfaces ( Cookson et al., 2002 ;
Pawar et al., 2005 ).

OmpA Promotes adherence to HeLa and polarized Caco-2 cells

( Torres and Kaper, 2003 ; Torres et al., 2006 ).

IrgA homolog adhesion
(Iha)

Confers the adherence phenotype on laboratory
E. coli ; possess siderophore-receptor activity
( Tarr et al., 2000 ; Rashid et al., 2006 ).

EHEC factor for
adherence (Efa)

Important for adhesion of non-O157 EHEC to CHO
cells in vitro, hemagglutination, autoaggregation and
colonization of bovine intestines ( Nicholls et al., 2000 ;
Stevens et al., 2002 ; Deacon et al., 2010 ).

Calcium binding
Antigen 43 homolog (Cah)

Binds to calcium and promotes autoaggregation and
biofilm formation ( Torres et al., 2002 ).

Hemorrhagic coli pilus
(HCP) (Type IV pili)

Binds to laminin and fibronectin, promotes twitching
motility, biofilm formation and hemagglutination
( Xicohtencatl-Cortes et al., 2007 , 2009 ). Activates
release of pro- and anti-inflammatory cytokines
from polarized, cultured intestinal cells ( Ledesma
et al., 2010 ).

Escherichia coli common
pilus (ECP)

Important for adherence to cultured epithelial cells and
virulence of E. coli O157 in humans ( Rendon et al., 2007 ).

ToxB Homolog of Efa1, encoded on plasmid pO157 and

promotes adherence to cultured epithelial cells ( Tatsuno
et al., 2001 ). Affects production and secretion of some
virulence factors required for the development of A/E
lesions ( Stevens et al., 2004 ).