Table 1.
Growth potential in MDCK cells and pathogenicity for chicken of each virus
| Viruses | Plaque formation (log PFU/ml) | Pathogenicity (number of dead/sick/total ) | ||
|---|---|---|---|---|
| With trypsin | Without trypsin | 3-day-old chicks (air sac inoculation) | 4-week-old chickens (intravenous inoculation) | |
| rgY55 (H9N2) | 8.1 | -a | NTb | 0/0/8 |
| rgY55sub (H9N2) | 8.0 | - | 0/0/3 | 0/0/8 |
| rgY55sub-P5 (H9N2) | 7.6 | - | 0/0/4 | 0/0/8 |
| rgY55sub-P6 (H9N2) | 7.2 | 6.7 | 3/3/3 | 0/1/8 |
| rgY55sub-P7 (H9N2) | 7.8 | 7.5 | 3/3/3 | 0/5/8 |
| rgY55sub-P8 (H9N2) | 7.6 | 7.6 | 3/3/3 | 2/7/8 (4.0)c |
| rgY55sub-P9 (H9N2) | 7.2 | 6.9 | 3/3/3 | 1/8/8 (10.0) |
| rgY55sub-P10 (H9N2) | 6.5 | 6.1 | 3/3/3 | 6/8/8 (1.8) |
| rgVac1 (H5N1) | 7.6 | - | NT | 0/0/8 |
| rgVac1sub (H5N1) | 7.6 | 7.8 | 0/0/3 | 0/1/8 |
| rgVac1sub-P1 (H5N1) | 6.8 | 6.8 | 3/3/3 | 3/5/8 (5.3) |
| rgVac1sub-P2 (H5N1) | 6.4 | 6.5 | 6/6/6 | 8/8/8 (2.6) |
| rgVac1ins (H5N1) | 7.3 | - | 0/0/3 | 0/0/8 |
| rgVac1ins-P1 (H5N1) | 7.8 | 7.1 | 3/3/3 | 6/7/8 (6.8) |
| rgVac1ins-P2 (H5N1) | 7.1 | 7.1 | 4/4/4 | 6/8/8 (4.4) |
a A plaque was not observed.
b Not tested.
c Mean death days are shown in parentheses.