Effect of Porcine Epidemic Diarrhea Virus Infectious Doses on Infection Outcomes in Naïve Conventional Neonatal and Weaned Pigs

Thomas, Joseph T.; Chen, Qi; Gauger, Phillip C.; Giménez-Lirola, Luis G.; Sinha, Avanti; Harmon, Karen M.; Madson, Darin M.; Burrough, Eric R.; Magstadt, Drew R.; Salzbrenner, Holly M.; Welch, Michael W.; Yoon, Kyoung-Jin; Zimmerman, Jeffrey J.; Zhang, Jianqiang

A U.S. PEDV prototype strain cell culture isolate USA/IN19338/2013 was isolated and propagated in Vero cells (ATCC CCL-81) in our lab as previously described [22] . A virus stock at the 7 th passage in cell culture was prepared and used in this study. The virus stock was 10-fold serially diluted in post-inoculation media (Minimum Essential Medium supplemented with 0.3% tryptose phosphate broth, 0.02% yeast extract, 5 μg/ml of trypsin 250, 10 unit/ml penicillin, 10 μg/ml streptomycin, 0.05 mg/ml gentamicin, and 0.25 μg/ml amphotericin B) to obtain 10 −1 to 10 −10 dilutions ( Table 1 ). The post-inoculation medium without virus was used as a negative control. Multiple aliquots of each dilution were prepared and stored at -80°C so that quantification of these virus dilutions and inoculation into pigs could be performed under the same number of freeze/thaw cycles.