Effect of different selenium sources and levels on porcine circovirus type 2 replication in vitro

Porcine circovirus type 2 (PCV2) has been linked to several disease syndromes during the last decade. A deficiency in selenium has also been associated with the increases of virulence of some viruses and severity of infectious disease. In order to evaluate the effect of different selenium sources and levels on PCV2 replication in PK-15 cells, three selenium sources, i.e. sodium selenite, kappa-selenocarrageenan and dl-selenomethionine at concentrations of 0, 2, 4, 8, and 16 μmol/L were used throughout this experiment. PCV2 loads in PK-15 cells were measured by a newly developed real-time quantitative PCR. A significantly inhibitive effect of dl-selenomethionine on PCV2 replication in vitro was demonstrated and the inhibition was concentration dependent within the range of 2–16 μmol/L. The inhibitive effect of dl-selenomethionine on PCV2 replication may be caused by enhanced activity of glutathione peroxidase. Our results may serve as a basis for further studies of the biological function of selenium and control of PCV2 infection.