Table 2. Replication and virulence of the H5N1 viruses in mice.
| Virus replication in organs, log10eID50/ml*
|
||||||||
|---|---|---|---|---|---|---|---|---|
| Viruses | Lung | Spleen | Kidney | Brain | Seroconversion† | MLD50, log10 eID50 | Pathotype‡ | Genotype§ |
| GSGD/1/96 | - | - | - | - | No | >6.5 | Non | A |
| DKGX/07/99 | - | - | - | - | No | >6.5 | Non | B |
| DKFJ/19/00 | - | - | - | - | No | >6.5 | Non | C |
| DKGD/12/00 | - | - | - | - | No | >6.5 | Non | A |
| DKZJ/11/00 | - | - | - | - | No | >6.5 | Non | A |
| DKZJ/52/00 | - | - | - | - | No | >6.5 | Non | D |
| DKGX/22/01 | - | - | - | - | Yes | >6.5 | Non | D |
| DKGD/07/00 | 3.7 ± 0.1 | - | - | - | Yes | >6.5 | Low | A |
| DKGD/1/01 | 1.8 ± 0.7 | - | - | - | Yes | >6.5 | Low | D |
| DKFJ/17/01 | 1.4 ± 0.4 | - | - | - | Yes | >6.5 | Low | D |
| DKGX/53/02 | 3.2 ± 0.5 | - | - | - | Yes | >6.5 | Low | I |
| DKGD/40/00 | 3.9 ± 0.5 | + | - | - | Yes | 6.4 | Middle | E |
| DKGX/50/01 | 4.0 ± 0.7 | + | - | - | Yes | 6.4 | Middle | G |
| DKSH/13/01 | 2.7 ± 1.4 | - | - | - | Yes | 5.0 | Middle | D |
| DKSH/38/01 | 3.4 ± 1.2 | 1.8 ± 0.7 | - | - | Yes | 5.8 | Middle | F |
| DKSH/8/01 | 5.9 ± 0.4 | 1.7 ± 1.2 | + | + | ND | 4.7 | Middle | A |
| DKGD/22/02 | 3.2 ± 1.0 | - | - | - | ND | 4.8 | Middle | D |
| DKSH/37/02 | 4.8 ± 0.6 | + | - | - | ND | 5.3 | Middle | H |
| DKGX/35/01 | 5.1 ± 2.2 | 1.3 ± 0.8 | + | + | ND | 1.5 | High | D |
| DKSH/35/02 | 5.6 ± 0.1 | + | + | + | ND | 2.3 | High | F |
| DKFJ01/02 | 6.5 ± 0.3 | 2.0 ± 0.6 | + | 1.6 ± 0.5 | ND | <0.5 | High | I |
| DKFJ/13/02 | 6.6 ± 0.2 | 1.2 ± 0.2 | 1.4 ± 0.1 | + | ND | <0.5 | High | H |
Six-week-old BALB/c mice were infected i.n. with 106 eID50 of each virus in a 50-μl volume. Organs were collected on day 3 postinoculation, and clarified homogenates were titrated for virus infectivity in eggs at initial dilutions of 1:10 (lung), 1:2 (other tissues), or undiluted if negative at the lowest dilution. + and -, virus was detected or not detected, respectively, in the undiluted samples.
Sera were collected on day 14 postinoculation, and seroconversion was tested by agar gel precipitation and HI tests. ND, all mice in the indicated group died before day 14.
Pathotypes were determined on the basis of replication and lethality in mice, as described in Materials and Methods. Non, nonpathogenic; Low, low pathogenicity; Middle, medium pathogenicity; High, high pathogenicity.
Genotypes were determined on the basis of the diversity of the PBI, PA, NP, M, and NS nucleotide sequences, as described in Fig. 3.