TABLE 3.

Lung infection at early time points in mice immunized orally with 10¹¹ CFU of strain WR201 bacteria and challenged i.n. 8 weeks later with strain 16M bacteria^a

Expt and time pointb	Infection (Log CFU [mean ± SD]) in mice immunized with:
	Saline	WR201
I
Day 1	3.31 ± 0.21	2.62 ± 0.32c
Wk 1	2.9 ± 0.37	1.49 ± 0.22c
Wk 2	2.46 ± 0.88	0.71 ± 1.02c
II
Day 1	3.34 ± 0.55	2.76 ± 0.59
Wk 1	2.37 ± 0.42	2.74 ± 0.41
III
Day 1	3.35 ± 0.26	2.76 ± 0.24c
Wk 1	2.33 ± 0.65	2.33 ± 0.17
Wk 2	1.72 ± 1.24	1.65 ± 0.67
IV
Day 1	3.15 ± 0.49	2.86 ± 0.37
Wk 1	2.67 ± 0.72	1.79 ± 1.00
V
Day 1	2.86 ± 0.29	2.33 ± 0.48
VI
Day 1	3.51 ± 0.54	3.49 ± 0.23
VII
Day 1	3.4 ± 0.11	2.71 ± 0.57c
Wk 1	2.34 ± 0.33	1.35 ± 0.83c
Alle
Day 1	3.27 ± 0.21	2.79 ± 0.35c
Wk 1	2.52 ± 0.25	1.94 ± 0.58d

^aMice were immunized with 10¹¹ CFU of WR201 or sham-immunized with saline. Eight weeks later, all were challenged i.n. with 10⁴ CFU of 16M. Animal were euthanized at the times indicated after challenge and the number of bacterial CFU in the lungs was determined by serial dilution and plating on Brucella agar. Data for experiments I to VII are expressed as mean ± SD log CFU for groups of 5 mice.

^bExperiment numbers are the same throughout the text.

^cSignificantly different from saline group (P < 0.05).

^dP < 0.08 versus saline group by Student's t test; P < 0.05 by Mann-Whitney U test).

^eResults represent means ± SD of all seven experiments (day 1) or five experiments (Week 1).