TABLE 4.

Recovery of E. coli O157:H7 strains ATCC 43895 and FRIK 816-3 from feces following oral administration to ICR mice^a

E. coli dose (CFU)	No. of mice with ≥1 fecal sample positive for E. coli O157:H7/5 mice examined in trial (no. of mice with ≥1 fecal sample positive for E. coli O157:H7/15 mice examined in 3 trials)
	Trial with 10% sucrose			Trial with 0.05 M PB–10% sucrose
	I	II	III	I	II	III
Control	0	0	0 (0)	0	0	0 (0)
Strain 43895
101	0	0	0 (0)	ND	ND	ND ND
102	0	3	2 (5)	ND	ND	ND ND
103	5	4	3 (12)	ND	ND	ND ND
Strain 816-3
102	0	0	0 (0)b	0	0	0 0
103	1	0	1 (2)c	2	2	1 (5)
104	1	2	1 (4)d	3	4	3 (10)

^aCell pellets (strain ATCC 43895 or FRIK 816-3) were suspended and diluted to the appropriate concentration in 10% sucrose or 0.05 M phosphate buffer (PB) in 10% sucrose. Each mouse was administered 0.5 ml of the sucrose-cell suspension or sucrose-phosphate-cell suspension. Control mice were fed 0.5 ml of 10% sucrose or 0.05 M phosphate buffer containing 10% sucrose with no E. coli O157:H7. Results are from fecal samples collected 24 h after administration. ND, not determined. 

^bSignificantly different (P < 0.05) from results obtained with the parent strain (ATCC 43895) inoculated at a dose of 10² CFU. 

^cSignificantly different (P < 0.001) from results obtained with the parent strain (ATCC 43895) inoculated at a dose of 10³ CFU. 

^dSignificantly different (P < 0.05) from results obtained with strain 816-3 inoculated at a dose of 10⁴ CFU in phosphate buffer.