Cloning and application of Vero cells for the sensitive replication of porcine epidemic diarrhea virus

To improve the sensibility of Vero cells to porcine epidemic diarrhea virus(PEDV),Vero cells were cloned by using the limiting dilution method and the susceptible cells to PEDV were selected by quantitative RT-PCR analysis.In result,one clone,Vero-S,which could reliably produce PEDV with high genomic copy numbers was selected from heterogeneous Vero parental cells.The viral genomic copy numbers could be as high as 2.1×109 copies/μL after the Vero-S cells inoculated with PEDV GZ strain for 3 days.The levels of viral genomic copy numbers in Vero-S cells were significantly higher than those in Vero parental cells(3.5×107 copies/μL).We isolated 3 PEDV strains from 3 pig farms by using the Vero-S cells.The results suggest that the constructed Vero-S cells line is more suitable to cultivate PEDV compared to Vero parental cells.