TABLE 2.

Prevalence^a of E. coli ONT:H25 in cattle from North America

Location	No. of cattle sampled	Total fecal samples	Culture-positive cattle (%)	No. of SMN PFGE isolates/total banked isolatesb	PFGE pattern
Northern Idaho (research barn)	23	46c	17.4-21.7	10/28	SH2
Eastern Washington (dairy)	40	320d	15.0-22.5	52/172	SH1
Central Washington (dairy)	27	27e	11.1	6/12	SH1
Southern Washington (dairy heifer raiser)	40	40e	15.0	12/37	SH1 (2)f
					SH3 (10)
Alberta, Canada (feedlot)	40	70g	7.5	7/9	SH2 (2)h
					SH3 (5)
Total	170	433	7.5-22.5	87/258

^aValues represent RAMS or fecal samples containing at least one ONT:H25 isolate.

^bThe number of SMN isolates tested by PFGE divided by the total number of SMN isolates banked.

^cRAMS samples were obtained from the same steers in a research herd on two occasions, 3 months apart.

^dRAMS samples were obtained from the same 40 heifers eight times, at 1-month intervals.

^eRAMS samples were obtained from 27 Holstein steers and 40 heifers once.

^fTwo isolates from one of six positive cattle showed the SH1 PFGE type.

^gA total of 40 feedlot cattle were sampled; 30 animals were sampled twice, 1 month apart, and 10 animals were sampled once.

^hTwo isolates from one of three positive cattle showed the SH2 PFGE type.