Table 1.

Characteristics of E. coli O157:H7 isolates used in this study

Strain(s)	Location of isolation	Presence of pO157_Sal	Source	Toxin(s)a	PFGE typeb	STc	Yr of isolation
Xuzhou-21	Xuzhou	+	Human	1 and 2	0001	96	1999
Xuzhou-65	Xuzhou	+	Human	1 and 2	0001	96	1999
Xuzhou-143	Xuzhou	+	Human	1 and 2	0001	96	1999
Xuzhou-223	Xuzhou	+	Human	1 and 2	0001	96	1999
Xuzhou-284	Xuzhou	+	Human	1 and 2	0001	96	1999
99A024	Xuzhou	+	Chicken	1 and 2	0001	96	1999
99A032	Xuzhou	+	Pig	1 and 2	0001	96	1999
99A038	Xuzhou	+	Chicken	1 and 2	0001	98	1999
2063	Xuzhou	+	Chicken	1 and 2	0175	NDe	1999
X114	Xuzhou	+	Chicken	1 and 2	0115	23	1999
X119	Xuzhou	+	Goat	1 and 2	0001	96	1999
X120	Xuzhou	+	Bovine	1 and 2	0001	96	1999
F828	Xuzhou	+	Pig	1 and 2	0173	ND	1999
F846	Xuzhou	+	Fly	1 and 2	0001	ND	1999
F971	Xuzhou	+	Goat	1 and 2	0001	ND	1999
EDL933	United States	−	Human	1 and 2	ND	23	1982
Sakai	Japan	−	Human	1 and 2	ND	23	1996
TW14359	United States	−	Human	2	ND	100	2006
Others (311 strains)d	I	−	II	1 and 2 or 2	III	IV	1988–2005

^a1 and 2 refer to stx₁ and stx₂, respectively.

^bPulsed-field gel electrophoresis (PFGE) XbaI pattern (see Fig. S2 in the supplemental material).

^cST, sequence type based on multilocus sequence typing of 15 housekeeping genes.

^dI, Jiangsu Province, Anhui Province, Shandong Province, Yunnan Province, Henan Province, and Tianjin City, China; II, human, bovine, goat, pig, chicken, and vegetable; III, 137 PFGE types in total; IV, 5 sequence types in total.

^eND, not determined.