TABLE 3.
Serological and clinical findings after inoculation of pigs with chimeric viruses derived from C1.1.1 and CoBrB 476S in animal experiment 2
| Groupa | Virus | Animal no. | Clinical findings
|
Serological findings (% inihibition) by E2 ELISAf on d.p.i.:
|
Viremiag on d.p.i.:
|
||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feverb | L/Tc | IFT (T K S I)d | Death (d.p.i.)e | 0 | 7 | 14 | 21 | 0 | 2 | 4 | 7 | 9 | 11 | 14 | 16 | 18 | 21 | 23 | |||
| A | CoBrB 476S | 5012c | 13 (5) | +/+ | ++++ | + (16) | 0 | 0 | 0 | − | − | − | + | + | + | + | + | ||||
| 5013 | 13 (2) | +/+ | ++++ | + (14) | 0 | 0 | 11 | − | − | + | + | + | + | + | |||||||
| 5014 | 13 (3) | +/+ | ++++ | + (14) | 0 | 0 | 43 | − | − | + | + | + | + | + | |||||||
| 5015 | 14 (2) | +/+ | ++++ | + (14) | 0 | 0 | 0 | − | − | + | + | + | + | + | |||||||
| B | CoBrB 476S/C1.1.1 (E2-p7-pNS2-3′) | 5016c | 10 (7) | +/+ | ++++ | + (16) | 0 | 0 | 0 | − | − | − | + | + | + | + | + | ||||
| 5017 | 10 (2) | +/+ | ++++ | + (11) | 0 | 0 | − | − | + | + | + | + | |||||||||
| 5018 | 6 (3) | +/+ | ++++ | + (9) | 0 | 0 | − | − | + | + | |||||||||||
| 5019 | 10 (3) | +/+ | +−++h | + (16) | 0 | 0 | 82 | − | − | + | + | − | + | − | − | ||||||
| C | C1.1.1/CoBrB | 5020c | 3 (11) | −/− | +−−−h | − | 0 | 0 | 0 | 97 | − | − | − | − | − | − | + | − | − | − | − |
| 5021 | − | +/− | −−−−i | − | 0 | 0 | 98 | 101 | − | − | − | + | − | − | − | − | − | − | − | ||
| 5022 | 1 (7) | +/− | −−−+hi | − | 0 | 0 | 100 | 100 | − | − | − | + | − | − | − | − | − | − | − | ||
| 5023 | − | −/+ | +−−−i | − | 0 | 0 | 98 | 101 | − | − | − | + | − | − | − | − | − | − | − | ||
| D | CoBrB/C1.1.1 (Npro′-C-Erns-E1) | 5024c | 7 (12) | +/+ | ++++ | + (18) | 0 | 0 | 0 | − | − | − | − | − | − | + | + | + | |||
| 5025 | 10 (5) | +/+ | ++++ | + (15) | 0 | 0 | 0 | − | − | + | + | + | + | + | |||||||
| 5026 | 7 (5) | +/+ | ++++ | + (11) | 0 | 0 | − | − | + | + | + | + | |||||||||
| 5027 | 9 (5) | +/+ | ++++ | + (18) | 0 | 0 | 0 | − | − | − | + | + | + | + | + | + | |||||
Three pigs in each group were inoculated intranasally once with 105 TCID50 of each virus. The sentinal (contact exposure) animals (c) were placed in each group 24 h after inoculation of the other animals.
Fever defined as a body temperature of ≥40°C. The number of days with fever is shown. The day the fever began is shown in parentheses. −, no fever.
Leukopenia (L) and thrombocytopenia (T) are defined as cell/platelet counts below 8 × 106 cells/ml and 200 × 106 cells/ml, respectively.
Immunofluorescence technique (IFT) for detection of viral antigen in cryostat sections from tonsils (T), kidney (K), spleen (S), and ileum (I) at death.
Pigs were either found dead or killed when moribund (+). The time of death (in days p.i. [d.p.i.]) is shown in parentheses. −, animal did not die.
The E2 ELISA specifically detects antibodies against CSFV.
Isolated leukocyte samples were incubated on SK6 cells for detection of virus by using an immunoperoxidase monolayer assay.
A few crypts in tonsils were found positive.
In some organ samples taken from the ileum, autolysis was found.