TABLE 3.

Pathological and microbiological parameters of protection against experimental infection with M. bovis

Group	No. of animals with lung lesions/ total no.	No. of animals with lymph node lesions/ total no.	Mean lung scorea	Mean lymph node scoreb	Mean no. of lymph nodes with lesions per animal	No. of M. bovis culture-positive animals/ total no.	No. of retropharyn- geal and thoracic lymph nodes M. bovis positive/ total no.	Mean log10 CFU of M. bovis for retropharyngeal and thoracic lymph nodes
Nonvaccinated	9/12	12/12	2.67 ± 0.56	3.75 ± 0.33	2.42 ± 0.42	12/12	32/72	1.89 ± 0.43
DNA	8/12	12/12	2.92 ± 0.67	4.00 ± 0.33	2.58 ± 0.29	12/12	35/72	2.03 ± 0.44
DNA/BCG	3/12c	5/12d	0.42 ± 0.26d	1.08 ± 0.43e	1.08 ± 0.49c	9/12	22/72	1.36 ± 0.34d
BCG	5/12	7/12c	1.33 ± 0.54	1.92 ± 0.56d	1.33 ± 0.41	10/12	21/72	1.51 ± 0.42

^aLung lesion scores: 0, no lesions; 1, 1 to 9 lesions; 2, 10 to 29 lesions; 3, 30 to 99 lesions; 4, 100 to 199 lesions; 5, ≥200 lesions.

^bLymph node lesion score of the most severely affected node for each animal based on the following scale: 0, no lesions; 1, 1 to 5 small lesions (diameter, 1 to 4 mm); 2, 5 to 19 small lesions; 3, ≥20 small lesions; 4, medium-size lesion (diameter, 5 to 9 mm); 5, large lesion (diameter, ≥10 mm).

^cSignificantly different from the value for the nonvaccinated group (P < 0.05).

^dSignificantly different from the value for the nonvaccinated group (P < 0.01).

^eSignificantly different from the value for the nonvaccinated group (P < 0.001).