TABLE 2.

Characteristics of bacterial strains used in this study^a

Bacterial strain	Serotype	stx1/stx2b	eaec	EHECd
EHEC
N-9	O157:H7	+/+	+	+
N-5	O157:H7	+/+	+	+
N-10	O157:H7	+/−	+	+
N-20	O157:H−	+/−	+	+
OK-7	O157:H7	−/+	+	+
OK-12	O157:H7	−/+	+	+
Controls
E. coli NP-4 (isolated from a healthy adult)		−/−	−	−
S. soerenga O301		−/−	−	−

^aDNA hybridization using a probe specific for enteroaggregative E. coli indicated that none of the strains were enteroaggregative. 

^bBy PCR using specific primers for stx₁ and stx₂. 

^cBy DNA hybridization using a probe specific for eae. 

^dBy DNA hybridization using a probe specific for the EHEC 60-MDa plasmid.