TABLE 4.

Summary of potential virulence factors contained within CRD_I in E. coli O157:H7 strains

CRDI	Genetic environment	Potential virulence factor(s) identified within LSPA-6 genotype 111111 CR
14	Rhs elements	None identified
16	Sp1 prophage	None identified
69a	Sp5 prophage	ECs1170, gene for putative protein with DksA/TraR C4-type zinc finger domain (42)
69b	Sp5 prophage	None identified
69c	Sp5 prophage, transposon	ECs1236, gene for putative outer membrane precursor protein with Ail/Lom protein domain (3, 35); ECs1250, gene for putative protein with DksA/TraR C4 type zinc finger domain (42)
72	SpLE1 prophage-like element, transposon	ECs1382, similar to hemolysin-activating protein hecB gene of Neisseria meningitidis (57); ECs1386, similar to immunoglobulin-binding regulator ibrA gene of E. coli ECOR-9 (50); ECs1387, similar to immunoglobulin-binding regulator ibrB gene of E. coli ECOR-9 (50); ECs1388, similar to plasmid-encoded regulator perC gene of EPEC (11); ECs1391, similar to bundle-forming pilus bfpM gene of EPEC EAF plasmid (55)
78	Sp7 prophage	ECs1588, similar to plasmid-encoded regulator perC gene of EPEC (11)
82/83	Transposon	ECs1693, homologue of prrA of a proposed iron transport system in E. coli CFT073 (15); ECs1694, homologue of the modD of a proposed iron transport system in E. coli CFT073 (15); ECs1695, homologue of yc73 of proposed iron transport system in E. coli CFT073 (15); ECs1696, homologue of yc73 of proposed iron transport system in E. coli CFT073 (15); ECs1697, homologue of fepC of proposed iron transport system in E. coli CFT073 (15); ECs1698, homologue of iron transport permease FecD of E. coli CFT073 (60); ECs1699, homologue of putative ATP-binding protein of ABC transporter in Shigella flexneri 2a strain 301 (18)
91/92/93	Sp10 prophage, transposon	None identified
153	Sp15 prophage	None identified
286	SpLE5 prophage-like element, transposon	ECs5250, required for colonization of calves (9); ECs5252, similar to BamHI control element in Bacillus amyloliquefaciens (6)
pO157-RTa	pO157 plasmid	None identified

^aRT, putative reverse transcriptase.