TABLE 4.
Microscopic lesion scores from pigs inoculated with either PRRSV, M. hyopneumoniae, or both
Group | Score for pneumonia induced by PRRSVa or M. hyopneumoniaeb at the following necropsy date:
|
|||||
---|---|---|---|---|---|---|
Day 3
|
Day 10
|
Day 28
|
||||
PRRSV | M. hyopneumoniae | PRRSV | M. hyopneumoniae | PRRSV | M. hyopneumoniae | |
A | 1.2 ± 1.1 Bc | 0 | 4.0 ± 0.9 A | 1.7 ± 1.0 A | 4.8 ± 0.7 A | 3.9 ± 0.4 A |
B | 1.0 ± 0 B | 0.3 ± 0.5 | 3.3 ± 1.5 A | 0.8 ± 0.4 B | 1.3 ± 0.5 B | 1.6 ± 1.1 C |
Cd | 3.3 ± 0.5 A | 0 | 3.3 ± 0.5 A | 1.8 ± 1.0 A | 4.3 ± 1.2 A | 3.8 ± 0.5 A |
D | 0 C | 0.2 ± 0.4 | 0 B | 0.5 ± 0.6 B,C | 0.1 ± 0.4 C | 1.0 ± 0 C |
E | 0.2 ± 0.4 C | 0 | 0 B | 0.5 ± 0.6 B,C | 0 C | 2.5 ± 0.8 B |
F | 1.5 ± 0.8 B | 0.3 ± 0.5 | 3.7 ± 0.8 A | 0 C | 1.4 ± 0.5 B | 1.1 ± 0.6 C |
G | 0.2 ± 0.4 C | 0 | 0 B | 0.8 ± 0.4 B,C | 0 C | 0.3 ± 0.5 D |
PRRSV scores are based on the severity of interstitial pneumonia. 0, no microscopic lesions; 1, mild multifocal pneumonia; 2, mild diffuse pneumonia; 3, moderate multifocal pneumonia; 4, moderate diffuse pneumonia; 5, severe multifocal pneumonia; 6, severe diffuse pneumonia.
M. hyopneumoniae scores are based on the severity of peribronchiolar and perivascular cuffing and lymphoid nodule formation, as follows: 1, mild; 2, moderate; 3, severe; 4, very severe. 0, no microscopic lesions.
Within each column, values followed by different letters (A, B, C, or D) are significantly different from each other (P < 0.001).
Group C received PRRSV on day −10 and M. hyopneumoniae on day 0 and so is not matched with the other groups with respect to the number of days after inoculation with PRRSV.