TABLE 1.

Strains used in this study

Strain	Relevant information	Reference or Source
14028s		ATCC
14028s phoP		14
14028s hilA		2
14028s invA		15
VT4Tx	Vermont DT104 bovine isolate	USDA, Athens, Ga.
3016	Georgia DT104 poultry isolate	USDA, Athens, Ga.
2745	Washington DT104 human isolate	J. Gay, Washington State University
4157	Washington DT104 bovine isolate	J. Gay, Washington State University