TABLE 1.

Mortality of BALB/c mice challenged with ETEC strains H10407 and B7A^a

Strain and no. of organisms	No. of dead mice at day postchallenge:							Totalb
	1	2	3	4	5	6	7
H10407
0c	0	0	0	0	0	0	0	0/12 (0)
1 × 108	0	0	0	0	0	0	0	0/12 (0)
5 × 108	0	3	1	2	1	0	0	7/12 (58)
1 × 109	0	8	4					12/12 (100)
5 × 109	0	6						6/6 (100)
B7A
0c	0	0	0	0	0	0	0	0/12 (0)
1 × 108	0	0	0	0	0	0	0	0/12 (0)
5 × 108	0	0	2	1	0	0	0	3/12 (25)
1 × 109	0	0	5	4	0	0	1	10/12 (83)
5 × 109	0	1	5					6/6 (100)

^aMice were challenged i.n. with the bacterial dose in 50 μl of PBS diluent administered dropwise to the external nares of each mouse. The data recorded are a combination of two independent trials, except for the 5 × 10⁹ bacterial dose.

^bNumber of dead mice/total number of mice (percent mortality).

^cControl mice were administered 50 μl of PBS i.n.