TABLE 1.

Cattle intestinal cell proliferation and persistence of E. coli O157:H7

Parameter	Duration culture positive for E. coli O157:H7d	Mean ± SE results in:
		Ileum	Cecum	Proximal colon	Central colon	Distal colon	All locations
Labeled cellsa (no. of cells/crypt)	Long-term	27.5 ± 3.7	3.1 ± 1.5e	7.8 ± 1.5	6.6 ± 2.2	8.8 ± 1.0e	10.8 ± 2.4
	Short-term	29.1 ± 3.0	10.9 ± 1.6e	11.3 ± 2.3	8.2 ± 1.8	11.4 ± 0.6e	14.2 ± 1.7
Crypt heightb (no. of cells/crypt column)	Long-term	68.7 ± 7.6	40.0 ± 2.3	47.6 ± 5.6	51.0 ± 2.5	61.1 ± 1.7	53.7 ± 3.2
	Short-term	65.1 ± 2.3	41.8 ± 1.6	51.1 ± 1.5	45.5 ± 4.2	61.8 ± 3.3	53.1 ± 2.2
Proliferation indexc (%)	Long-term	20.3 ± 2.9	3.9 ± 1.9e	8.0 ± 0.7	6.5 ± 2.2	7.3 ± 0.9	9.2 ± 1.0f
	Short-term	22.3 ± 2.0	13.2 ± 2.2e	11.0 ± 2.1	8.5 ± 1.2	9.4 ± 0.6	12.9 ± 1.2

^aLabeled cells are the number of PCNA-labeled cells per crypt. 

^bCrypt height is the total number of cells in each crypt column. 

^cThe proliferation index is the percentage of PCNA-labeled cells calculated as follows: [labeled cells/(2 × crypt height)]100. 

^dLong-term, animals that remained E. coli O157:H7 culture positive for 29 to 69 days (n = 3); short-term, animals that remained E. coli O157:H7 culture positive for 8 to 19 days (n = 5). 

^eLabeled cells were fewer in the long-term than in the short-term group in the cecum (P = 0.016) and distal colon (P = 0.027) (t test). 

^fSignificant effect of E. coli O157:H7 culture-positive duration over all locations (P = 0.043, split-plot ANOVA).