TABLE 3.
Pathogenesis of virulent IND/A, attenuated NCDV/A, and WD534tc/C bovine rotaviruses and Cowden/C porcine rotavirus in gnotobiotic calves
| Group, virus, and calf no. | Age (days) at inoculation | Clinical sign | Diarrheaa or virus sheddingb at PID:
|
Seroconversionc | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | ||||
| Group 1, IND/A | ||||||||||
| 1 | 5 | Diarrhea | − | + | + | EUT | ND | |||
| Virus shedding | −/−/− | +/+/+ | +/+/+ | |||||||
| 2 | 4 | Diarrhea | − | + | + | + | EUT | ND | ||
| Virus shedding | −/−/− | +/+/+ | +/+/+ | +/+/+ | ||||||
| Group 2,d NCDV/A | ||||||||||
| 3 | 5 | Diarrhea | + | + | EUT | ND | ||||
| Virus shedding | −/−/− | −/−/− | ||||||||
| 4e | 6 | Diarrhea | +/− | +/− | +/− | +/− | +/− | +/− | +/− | + |
| Virus shedding | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | |||
| 5e | 6 | Diarrhea | +/− | +/− | +/− | +/− | +/− | +/− | +/− | + |
| Virus shedding | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | |||
| Group 3, WD534tc/C | ||||||||||
| 6 | 6 | Diarrhea | + | + | + | + | + | + | +f | + |
| Virus shedding | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | |||
| 7 | 21 | Diarrhea | + | + | + | + | + | + | +f | + |
| Virus shedding | +/−/− | +/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | |||
| 8 | 2 | Diarrhea | − | − | + | + | + | + | +f | + |
| Virus shedding | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | |||
| 9 | 6 | Diarrhea | − | − | + | EUT | ND | |||
| Virus shedding | +/+/− | −/−/− | −/−/− | |||||||
| Group 4, Cowden/C | ||||||||||
| 10 | 8 | Diarrhea | − | − | − | − | − | − | − | + |
| Virus shedding | −/+/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | |||
+, fecal consistency of ≥2; +/−, questionable or mild diarrhea (fecal consistency of 1); −, no diarrhea (normal feces). EUT, euthanized for histopathology.
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 105 to 106 FFU/ml.
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.
All calves in this group were inoculated with 105 FFU.
Calf had mild diarrhea before challenge.
Diarrhea persisted from PID 8 to 11.