Table 2.
RT-PCR and virus isolation from sera and tissues of seropositive, VI-negative PRRSV-infected pigs
| Pig no. | Grpa | dpfb | Antibodyc | RT-PCR (virus isolation)d |
||||
| Serume | Lung | TNSL | MDLN | MSLN | ||||
| 186 | 1 | 63 | 3.87 (16) | + (35) | − (−) | NDf (+) | + (−) | ND (−) |
| 189 | 2 | 75 | 2.09 (16) | − (20) | − (−) | ND (−) | + (−) | ND (+) |
| 62 | 2 | 75 | 4.22 (16) | − (28) | − (−) | + (+) | + (−) | ND (−) |
| 199 | 1 | 91 | 2.87 (64) | − (41) | − (−) | − (−) | + (−) | + (−) |
| 67 | 3 | 92 | 2.02 (16) | − (28) | − (−) | ND (+) | ND (+) | − (−) |
| 16 | 1 | 104 | 4.13 (32) | − (34) | − (−) | + (−) | + (−) | − (−) |
| 72 | 2 | 104 | 3.83 (256) | − (48) | − (−) | ND (+) | + (−) | + (−) |
| 69 | 2 | 132 | 2.31 (16) | − (34) | − (−) | + (+) | − (−) | − (−) |
| 71 | 2 | 132 | 1.57 (16) | − (34) | − (−) | + (−) | + (−) | − (−) |
a
Group designation based on virus and serology at the time of birth. Grp 1, virus-negative and seronegative; Grp 2, virus-positive and seronegative; Grp 3, virus-positive and seropositive.
b
Days post-farrowing on which the pig was sacrificed.
c
PRRSV antibody status, ELISA response and neutralizing titer (in parenthesis) at the time of sacrifice.
d
RT-PCR of ORF7 and virus isolation (in parenthesis) were performed on serum, lung, tonsil (TNSL), mandibular lymph node (MDLN) and mesenteric lymph node (MSLN).
e
The number in parentheses identifies the last day that a positive VI was obtained.
f
Not determined.