TABLE 5.
Pathogenesis of WD534tc/C in gnotobiotic piglets compared to that of virulent or attenuated Cowden/C porcine strains
| Virus and pig no. | Age (days) at inoculation | Clinical sign | Diarrheaa or virus sheddingb at PID:
|
Seroconversionc | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | ||||
| WD534tc/C | ||||||||||
| 1 | 4 | Diarrhea | − | − | + | + | + | + | +d | + |
| Virus shedding | −/−/− | +/+/− | +/+/+ | +/+/− | +/+/− | +/+/− | +/−/− | |||
| 2 | 4 | Diarrhea | − | − | + | + | EUT | ND | ||
| Virus shedding | −/−/− | +/+/+ | +/+/+ | +/+/+ | ||||||
| 3 | 4 | Diarrhea | − | − | + | EUT | ND | |||
| Virus shedding | −/−/− | +/+/+ | +/+/+ | |||||||
| Virulent Cowden/C | ||||||||||
| 4 | 4 | Diarrhea | − | − | + | + | EUT | ND | ||
| Virus shedding | +/+/− | +/+/+ | +/+/+ | +/+/+ | ||||||
| Attenuated Cowden/C | ||||||||||
| 5 | 26 | Diarrhea | − | − | − | − | − | − | − | + |
| Virus shedding | +/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | |||
| 6 | 4 | Diarrhea | − | − | − | − | − | − | − | + |
| Virus shedding | −/−/− | −/−/− | +/−/− | +/−/− | +/−/− | −/−/− | −/−/− | |||
a
+, fecal consistency of ≥2; +/−, questionable or mild diarrhea (fecal consistency of 1); −, no diarrhea (normal feces). EUT, euthanized for histopathology.
b
Virus shedding determined by three assays. Virus detected (+) or not detected (−) by RT-PCR, IEM, and CCIF assays (results shown in this order separated by slashes in table). The CCIF titers were about 104 FFU/ml.
c
Seroconversion to NCDV/A, WD534tc/C, or Cowden/C rotavirus after PID 21 determined by FFN test (antibody titers of ≥50 compared to <50 for acute sera). +, seroconversion detected; ND, not done.
d
Diarrhea lasted until PID 7.