Table 2.
Replication of parental and chimeric viruses in the brains of 1-day-old chicks
| Virus | Virus titer (log10 TCID50/g of brain)a |
|||
|---|---|---|---|---|
| Intracerebral infection |
Intranasal infection |
|||
| 2 dpi | 3 dpi | 3 dpi | 4 dpi | |
| rNDV | 6.12 | 5.83 | 5.21 | 5.8 |
| rAPMV-2 | N.D.b | N.D. | N.D. | N.D. |
| rNDV/2-F-HN | N.D. | N.D. | N.D. | N.D. |
| rAPMV-2/NDV-F-HN | 2.65 | 3.86 | 3.30 | 3.61 |
| rAPMV-2/NDV-F | N.D. | 1.81 | 1.86 | 1.92 |
a
One-day-old chicks in groups of 10 were infected with the indicated parental or chimeric virus (1 × 105 TCID50/bird) via the intracerebal or intranasal route, and two chicks per group were harvested on days 1 to 5 for virus titration. Brain tissue was collected and homogenized, and virus titers were determined by limiting dilution on DF1 cells with immunostaining using antibodies against the respective N protein.
b
N.D., not detected.