Table 3.
Clinical signs, fecal PEDV RNA shedding and serum PEDV antibody titers in conventional suckling pigs inoculated with P120, P160 or mock and challenged with highly virulent homologous US PC21A strain at 19–29 dpi.A
| Before PC21A challenge |
After PC21A challenge |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| P120-inoculated litter (n = 1) |
P160-inoculated litter (n = 1) |
Mock-inoculated litter (n = 1) |
P120-inoculated litter (n = 1) |
P160-inoculated litter (n = 1) |
Mock-inoculated litter (n = 1) |
|||||||
| Piglets (n = 8) |
Sow | Piglets (n = 7) |
Sow | Piglets (n = 7) |
Sow | Piglets (n = 6) |
Sow | Piglets (n = 7) |
Sow | Piglets (n = 5) |
Sow | |
| Morbidity (%) | 100 | no | 71 | no | 0 | no | 67 | no | 100 | yes | 100 | yes |
| Mortality (%) | 0 | no | 0 | no | 0 | no | 0 | no | 0 | no | 0 | no |
| Onset of diarrhea (dpi/dpc) | 2.75 ± 1.04 * | ND | 10.4 ± 5.27 | ND | ND | ND | 2.00 ± 0.00 | ND | 2.71 ± 0.76 | 3 | 1.80 ± 0.45 | 3 |
| Highest FC score | 3.00 ± 0.00 * | 0 | 1.71 ± 0.49 | 0 | 0.00 ± 0.00 | 0 | 2.17 ± 0.98 * | 0 | 3.00 ± 0.00 | 3 | 3.00 ± 0.00 | 3 |
| Duration of diarrhea (day) | 3.33 ± 1.21 * | ND | 0.86 ± 0.69 | 0 | 0.00 ± 0.00 | 0 | 0.67 ± 0.52 * | 0 | 2.71 ± 0.49 | 3 | 3.80 ± 0.84 | 4 |
| Onset of viral shedding (dpi/dpc) | 1.88 ± 0.35 * | 2 | 4.86 ± 0.69 | 6 | ND | ND | 1.00 ± 0.00 | 2 | 1.43 ± 0.53 | 1 | 1.60 ± 0.55 | 1 |
| Highest viral shedding titer (log10 GE/ml) | 11.24 ± 0.77 * | 7.1 | 8.90 ± 0.54 | 8.9 | ND | ND | 8.92 ± 1.67 * | 7.5 | 10.94 ±1.05 | 10.2 | 10.57 ± 0.81 | 10.44 |
| Weekly body weight gain (kg) | 1.45 ± 0.52 * | NT | 2.10 ± 0.28 | NT | NT | NT | 1.63 ± 1.30 * | NT | 0.17 ± 0.80 | NT | NT | NT |
| Serum IgG Ab titer (log2) B | 5.67 ± 2.34 * | 1 | 1.58 ± 1.11 | 1 | <2 | <2 | 8.50 ± 1.64 | 9 | 8.67 ± 0.98 | 10 | < 2 | < 2 |
| Serum IgA Ab titer (log2) B | 6.42 ± 1.59 * | 5 | <2 | <2 | <2 | <2 | 8.25 ± 0.27 * | 7 | 4.08 ± 1.04 | 4 | < 2 | < 2 |
| Serum VN Ab titer (log2) B | 3.33 ± 1.03 | 2 | 2.67 ± 1.40 | 3 | 2.57 ± 0.53 | 3 | 3.50 ± 1.52 | 4 | 4.00 ± 0.69 | 3 | 3.00 ± 0.00 | 3 |
ND, not detectable; NT, not tested; FC, fecal consistency, Ab, antibody; dpi, days post-inoculation; dpc, days post-challenge; GE, genomic equivalents; VN: viral neutralization.
*
Significant difference between P120- and P160-inoculated litters tested by t-test (P < 0.05).
A
One P3-inoculated litter serviced as positive control and had a mortality rate of >67% (8/12) and all piglets were euthanized by 9 dpi based on the early removal criteria in our animal experiment protocols.
B
Serum sample collected at 0 and 7 dpc, respectively.