TABLE 1.
Infectious titers and viral particle count of CA/09-X179A and wt CA/09 stocks
| Virus | Titera |
Virus countb (no. of viral particles/ml) | |
|---|---|---|---|
| MLD50/ml | EID50/ml | ||
| CA/09-X179A | 1.85 × 105 | 3.2 × 108 | (7.1 ± 1.8) × 108 |
| wt CA/09 | 3.3 × 107 | 5.9 × 108 | (9.8 ± 2.9) × 108 |
a
MLD50 were measured in DBA/2 mice. Viral titers were determined in mice and eggs rather than MDCK cells because the CA/09-X179A virus induced opaque, small plaques in MDCK cells that were difficult to count accurately.
b
The number of viral particles was counted with a Virus Counter 2100 system (ViroCyt, Boulder, CO). Shown are the averages of three counts that used 1:5, 1:10, and 1:20 dilutions of each viral stock.