Chlorine dioxide inhibits the replication of porcine reproductive and respiratory syndrome virus by blocking viral attachment

Porcine reproductive and respiratory syndrome virus (PRRSV) causes a great economic loss to the swine industry globally. Current prevention and treatment measures are not effective to control the outbreak and spread of porcine reproductive and respiratory syndrome (PARS). In other words, new antiviral strategies are urgently needed. Chlorine dioxide (ClO2) is regarded as a broad-spectrum disinfectant with strong inhibitory effects on microbes and parasites. The purpose of this study was to evaluate the inhibitory effects and underlying molecular mechanisms of ClO2 against PRRSV infection in vitro. Here, we identified ClO2 (the purity is 99%) could inhibit the infection and replication of PRRSV in both Marc-145 cells and porcine alveolar macrophages (PAMs). ClO2 could block PRRSV binding to cells rather than internalization and release, suggesting that ClO2 blocks the first stage of the virus life cycle. We also demonstrated that the inhibition exerted by ClO2 was attributed to the degradation of PRRSV genome and proteins. Moreover, we confirmed that ClO2 could decrease the expression of inflammatory cytokines induced by PRRSV. In summary, ClO2 is an efficient agent and potently suppressed PRRSV infection in vitro.