Table 1.
Development of macroscopically visible pulmonary lesions and cytological changes within bronchoalveolar lavage fluid (BALF) of pigs following intra-tracheal inoculation of either porcine respiratory coronavirus (PRCV) only, lipoteichoic acid (LTA) only or a combination of PRCV followed 24 h later by LTA (PRCV-LTA).
| Parameter | Inoculation group | Hours after PRCV/LTA inoculation |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| 27/3 | 28/4 | 29/5 | 32/8 | 36/12 | 42/18 | 48/24 | 72/48 | ||
| Macroscopically visible lung lesions a (%) |
PRCV only | 0 | 0.1 | 1.3 | 0.6 | 0.3 | 9.5 | 6.0 | 5.0 |
| LTA only | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| PRCV-LTA | 2.0 | 2.3 | 0 b | 1.0 | 0 b | 4.0 | 2.6 | 8.5 | |
|
| |||||||||
| Total BALF cells (x 106) |
PRCV only | 144 | 173 | 122 | 142 | 181 | 305 | 152 | 138 |
| LTA only | 430 | 550 | 760 | 371 | 260 | 83 | 136 | 235 | |
| PRCV-LTA | 172 | 294 | 105 | 331 | 243 | 223 | 134 | 163 | |
|
| |||||||||
| Neutrophils in BALF (%) |
PRCV only | 2.3 | 1.9 | 3.9 | 6.3 | 5.1 | 4.7 | 3.3 | 3.4 |
| LTA only | 70.8 | 59.0 | 80.6 | 56.7 | 39.3 | 3.6 | 1.6 | 21.0 | |
| PRCV-LTA | 10.9 | 31.2 | 4.7 | 45.4 | 16.6 | 11.4 | 6.2 | 4.2 | |
a
Macroscopically visible lesions were calculated as the mean of the percentage of affected dorsal and ventral lung surfaces.
b
Minimal lesions representing <0.05 % of the total lung surface.