Origin, Evolution, and Virulence of Porcine Deltacoronaviruses in the United States

Ma, Yuanmei; Zhang, Yu; Liang, Xueya; Lou, Fangfei; Oglesbee, Michael; Krakowka, Steven; Li, Jianrong

To further confirm that PdCV is an enteric pathogen of swine, three out of five Gn piglets in one isolator (animal experiment 2) were orally inoculated with 10 6 PFU of the PdCV MI strain, a swine testicular (ST) cell-adapted, plaque-purified virus. The other two Gn piglets in the same isolator received Dulbecco's modified Eagle's medium (DMEM). No obvious clinical signs were observed on days 1 and 2 p.i. in all three PdCV-inoculated Gn piglets. All three piglets developed diarrhea (score of 2) on day 3 p.i. and were subsequently terminated. Interestingly, the two other piglets in the same isolator, which did not receive virus inoculation, developed diarrhea (score of 2) on day 6 and were terminated on day 7. No or only mild vomiting was observed in piglets infected with the PdCV MI strain. Results establish the potential of PdCV to serve as a transmissible agent of clinically significant diarrheal disease.