Table 3. Normal and super-shedder Escherichia coli O157:H7 strains used to inoculate the experimental steers.

Strain ID	Location (State) collected	Date collected	Type of shedding	Concentrations in feces (MPN/g)	Toxins
A9	TX	9/27/2011	Normal	43	Stx 2
W1	CA	9/13/2011	Normal	23	Stx 1/Stx 2
8055	CA	3/21/2012	Normal	2.42	Stx 2
14A	CA	1/18/2012	Super	2.1 × 104	Stx 1/Stx 2
Tx3800	TX	1/27/2012	Super	3.9 × 105	Stx 2
Tx1686	TX	1/27/2012	Super	4.7 × 104	Stx 2