Table 2.
Pathogenicity analysis of the PEDV strains 17GXCZ-1 ORF3d and 17GXCZ-1 ORF3c found in China, 2017 †.
| Groups | Inoculum Dose (2 mL) |
Mortality | Fecal Shedding, Log10 Copies/mL, by PIH, Mean |
Onset of Clinical Signs as Judged by PIH | Quantification of Viral Load, Log10 Copies/mL, Mean |
VH: CD, Mean | PEDV Antigen Detection in Frozen Tissues ‡ | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 24 | 48 | 72 | 96 | 120 | D | J | I | D | J | I | D | J | I | ||||
| Mock | Cell culture media | 0%, 4/4 | - | - | - | - | - | - | - | - | - | - | 3.32 | 2.44 | 2.86 | - | - | - |
| 17GXCZ-1 ORF3d | 6 log10 PFU/mL | 75%, 1/4 | - | 1.72 | 5.89 | 6.43 | 6.68 | 4.66 | 24-48 | 6.32 | 7.12 | 6.90 | 2.38 * | 1.94 * | 1.96 ** | ++ | +++ | + |
| 17GXCZ-1 ORF3c | 6 log10 PFU/mL | 50%, 2/4 | - | - | 4.94 | 5.76 | 6.43 | 3.46 | 36-48 | 6.18 | 6.42 | 6.87 | 2.32 * | 2.00 | 2.42 * | + | + | ++ |
† PEDV, porcine epidemic diarrhea virus; PIH, post inoculation hour; VH:CD, ratio of villous height to crypt depth; D-duodenum, J-jejunum, I-ileum; PFU, plaque formation unit; -, no result. ‡ PEDV antigen detection in frozen tissues. +, ++, and +++ denotes less than 30%, 30–60% and more than 60% of villous enterocytes showing a PEDV antigen positive signal, respectively. Viral load in the fecal wastes and in the tissues of the small intestine was detected by RT-quantitative PCR (RT-qPCR). * and ** represent significant differences when compared to the mock group, with p values of <0.05 and <0.01, respectively.