TABLE 1.
Replication of M2KO virus in micea
| Virus | PFU of virus inoculated per mouse | Days postinfection | Virus titer (mean ± SD log10 [PFU/g]) from indicated sourceb
|
|
|---|---|---|---|---|
| Lungs | Nasal turbinates | |||
| PR8 | 1 × 103 | 3 | 8.5 ± 0.1 | 6.0, 5.8 |
| 1 × 103 | 6 | 7.0 ± 0.1 | 6.4 ± 0.2 | |
| M2KO | 3 × 106 | 3 | 5.7 ± 0.3 | ND |
| 3 × 106 | 6 | 5.5 ± 0.3 | ND | |
| 3 × 105 | 3 | 4.1 ± 0.2 | ND | |
| 3 × 105 | 6 | 5.3, 4.2 | ND | |
| 3 × 104 | 3 | 5.2 | ND | |
| 3 × 104 | 6 | ND | ND | |
a
Three BALB/c mice per group were intranasally infected with the indicated amounts of virus (50 μl per mouse) and sacrificed on days 3 and 6 postinfection for virus titration. When virus was not recovered from all three mice, individual titers were recorded. On day 3 postinfection, virus was not recovered from organs of mice infected with either 3 × 102 or 3 × 103 PFU of M2KO virus (data not shown).
b
ND, not detected (detection limit, 10 PFU/ml/lung).