TABLE 3.
Occurrence and severity of gross and histopathological lesions at postmortema
| Lesionb | Lesionsc in treatment group:
|
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| i.m. (calf no. 1-4)d
|
i.n. (calf no. 1-4)
|
Control (calf no. 1-3)
|
|||||||||
| 1d | 2d | 3d | 4d | 1 | 2 | 3 | 4d | 1 | 2 | 3d | |
| Serosanguinous peritoneal fluid | − | − | − | − | − | − | + | − | + | + | − |
| Serosanguinous pericardial fluid | − | − | − | − | + | − | − | − | + | +/− | − |
| Serosanguinous pleural fluid | − | − | − | − | + | − | − | − | − | − | − |
| Enlarged prescapular lymph nodes | +/− | +/− | +/− | +/− | +/− | ++ | ++ | + | − | + | ++ |
| Grossly edematous/hemorrhagic lymph nodes/tissues | − | − | − | − | − | ++ | + | − | + | ++ | − |
| Enlarged liver | − | + | − | − | +++ | − | − | − | + | ++ | − |
| CNS perivascular hemorrhages | + | − | +/− | +/− | + | + | +/− | + | ++ | + | + |
| CNS serum leakage | − | − | − | − | − | − | + | + | − | + | − |
| Hemorrhage, prescapular LN | − | − | − | − | − | +++ | +++ | − | − | +++ | − |
| PMN infiltration, prescapular LN | +/− | +/− | + | +/− | +++ | +++ | +++ | + | +++ | ++ | + |
| Cell depletion, paracortex of prescapular LN | ++ | +++ | +++ | ++ | +/− | + | + | − | ++ | + | +++ |
a
Two groups of four calves each were vaccinated twice, at a 4-week interval, either i.m. or i.n., with the aroA mutant strain, and a group of three calves were left unvaccinated as controls. Two weeks after the second vaccination, the animals were challenged with the wild-type strain. Postmortem examination was done 7 days after challenge or earlier as dictated by clinical assessment.
b
LN, lymph node; PMN, polymorphonuclear leukocyte; CNS, central nervous system.
c
−, not present; +/−, slight; +, mild; ++, moderate; +++, severe.
d
Survived 7 days postchallenge.