TABLE 4.
Pathogenesis of WD534tc/C in gnotobiotic calves coinfected with either virulent IND/A or attenuated NCDV/A bovine rotaviruses or virulent Cowden/C porcine rotaviruses
| Group, viruses, and calf no. | Age (days) at inoculation | Clinical signa | Diarrheab or virus sheddingc at PID:
|
Seroconversiond | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | ||||
| Group 5, WD534tc/C + IND/A | ||||||||||
| 11 | 6 | Diarrhea | − | − | + | + | EUT | ND | ||
| gpA shedding | +/+/+ | +/+/+ | +/+/+ | +/+/+ | ||||||
| gpC shedding | −/−/− | +/+/+ | +/+/+ | +/+/− | ||||||
| 12 | 24 | Diarrhea | + | + | EUT | ND | ||||
| gpA shedding | +/+/+ | +/+/+ | ||||||||
| gpC shedding | +/+/− | +/+/+ | ||||||||
| Group 6, Cowden/C + IND/A | ||||||||||
| 13 | 6 | Diarrhea | − | + | + | + | + | + | +e | + |
| gpA shedding | +/+/+ | +/+/+ | +/+/+ | +/+/+ | +/+/+ | +/+/+ | +/+/+ | |||
| gpC shedding | +/+/+ | +/+/− | +/+/− | +/−/− | +/−/− | +/−/− | −/−/− | |||
| Group 7, WD534tc/C + NCDV/A | ||||||||||
| 14f | 5 | Diarrhea | + | + | EUT | ND | ||||
| gpA shedding | −/−/− | −/−/− | ||||||||
| gpC shedding | −/−/− | −/−/− | ||||||||
| 15f | 6 | Diarrhea | − | + | + | + | + | + | +g | + |
| gpA shedding | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | |||
| gpC shedding | +/−/− | +/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | |||
| 16h | 6 | Diarrhea | − | + | − | + | + | + | − | + |
| gpA shedding | +/+/− | +/+/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | |||
| gpC shedding | +/−/− | +/−/− | −/−/− | −/−/− | −/−/− | −/−/− | −/−/− | |||
gpA shedding, group A rotavirus shedding; gpC shedding, group C rotavirus 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 of group A and group C rotavirus were 105 to 106 FFU/ml and about 102 FFU/ml, respectively.
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.
Diarrhea lasted until PID 9.
Challenge dose of NCDV/A was 105 FFU.
Diarrhea lasted until PID 7.
Challenge dose of NCDV/A was 107 FFU.