TABLE 1.

Escherichia coli isolates from cattle^b

Serogroupa	No. of strains isolated in yr:											Total
	2002	2003	2004	2005	2006	2007	2011	2013	2014	2015	2017
O103	0	0	0	0	0	0	0	40	86	25	6 (2)	157 (2)
O111	0	0	0	0	0	0	0	3	2	7	0	12
O121	0	0	0	0	0	0	0	41 (3)	33 (1)	28	1	103 (4)
O145	0	0	0	0	0	0	0	1	16 (1)	18	0	35 (1)
O157	14	28 (1)	10	9	6	57	67	11 (2)	19 (1)	12 (1)	6 (1)	239 (6)
O26	0	0	0	0	0	0	0	42 (1)	37 (6)	21 (3)	0	100 (10)
O45	0	0	0	0	0	0	0	34	40 (1)	28	2	104 (1)
Total	14	28 (1)	10	9	6	57	67	172 (6)	233 (10)	139 (4)	15 (3)	750 (24)

^aThe cattle E. coli isolates were recovered from feces or hides of cattle in feedlots and transportation trucks to slaughter plants (1–5; Reuter et al., unpublished data).

^bNumbers in parentheses indicate E. coli isolates with D_60°C values of >2 min.