Table 2.

Colonization in target tissues obtained at necropsy after experimental challenge at midgestation with 10⁷ CFU of B. abortus strain 2308

Vaccination strategy	Log CFU/g (no. culture positive/total)a in:
	Parotid lymph node	Prescapular lymph node	Suprammamary lymph node	Placentome
Hand RB51b	0.8 ± 0.4 b (3/6)*	0 ± 0 b (0/6)*	0.7 ± 0.5 ab (2/6)	4.0 ± 1.8 ab (3/6)*
Dart RB51c	1.2 ± 0.5 b (4/7)	0.3 ± 0.3 b (1/7)*	0.9 ± 0.4 ab (4/7)	4.5 ± 1.6 ab (4/7)
Booster RB51d	0.8 ± 0.6 b (2/5)*	0 ± 0 b (0/5)*	0 ± 0 b (0/5)*	1.7 ± 1.1 b (2/5)*
Control	2.7 ± 0.3 a (6/6)	1.7 ± 0.4 a (5/6)	1.9 ± 0.5 a (5/6)	7.6 ± 0.3 a (6/6)

^aData are means ± standard errors of the means. Colonization means with different letters are significantly different (P < 0.05). *, vaccination treatment group in which the incidence of infection in a tissue is significantly different (P < 0.05) from the incidence of infection in the control treatment group.

^bThe vaccination dose was 1.1 × 10¹⁰ CFU.

^cThe vaccination dose was 2.2 × 10¹⁰ CFU.

^dThe initial vaccination dose was 1.1 × 10¹⁰ CFU, and the booster vaccination dose was 2.2 × 10¹⁰ CFU.