Table 1.
Virus infectivity and distribution of virus M antigen in tissues from chickens inoculated with DkYK10, DkYK10-B5, or DkYK10-B10
| Virus | Infectivitya,b (log10 EID50/g) |
M antigena,c |
||||
|---|---|---|---|---|---|---|
| Lung | Spleen | Brain | Lung | Spleen | Brain | |
| DkYK10 | 6.8 ± 0.6 | 5.9 ± 0.6 | 7.6 ± 0.5 | +, +, +, + | −, −, −, + | +++, +++, +++, +++ |
| DkYK10-B5 | 7.8 ± 0.3 | 7.1 ± 0.3 | 7.9 ± 0.5 | +++, +++, +++, +++ | +++, ++, +, ++ | ++, ++, +++, +++ |
| DkYK10-B10 | 7.3 ± 0.3 | 6.9 ± 0.4 | 7.5 ± 0 | +++, +++, ++, +++ | +++, +, ++, ++ | ++, ++, +++, +++ |
a
Four chickens per group were inoculated intranasally with 106.0 EID50 of DkYK10, DkYK10-B5, or DkYK10-B10 and sacrificed just before natural death. Tissues were obtained for virus infectivity and M antigen distribution analysis.
b
Titers of individual lungs, spleens, and brains were determined with embryonated chicken eggs; the mean virus titers ± standard deviations of four chickens are shown.
c
Grading of M antigen is as follows: −, none; +, mild; ++, moderate; +++, severe.