Screening and evaluation of antiviral compounds against Equid alpha-herpesviruses using an impedance-based cellular assay

Equid alpha-herpesviruses (EHV) are responsible for different diseases in equine population. EHV-1 causes respiratory diseases, abortions and nervous disorders, EHV-4 causes respiratory diseases and sporadic abortion, while EHV-3 is responsible of equine coital exanthema. In view of the lack of efficacy of vaccines against EHV-1 and EHV-4 and in the absence of vaccines against EHV-3, the use of antiviral treatment is of great interest. In this study, we documented the interest of the Real-Time Cell Analysis (RTCA) technology to monitor the cytopathic effects induced by these viruses on equine dermal cells, and established the efficacy of this method to evaluate the antiviral effect of aciclovir (ACV) and ganciclovir (GCV). In addition, the RTCA technology has also been found appropriate for the high-throughput screening of small molecules against EHV, allowing the identification of spironolactone as a novel antiviral against EHV. •RTCA system is effective to monitor ECP formation induced by equid alphaherpesviruses on equine dermal cells.•Ganciclovir is ten-fold more effective than aciclovir against EHV-1, EHV-4 and EHV-3 on equine dermal cells.•RTCA system is suitable for high-throughput screening of small antiviral molecules against EHVs.•Spironolactone is identified as a new potential antiviral compound against EHV-1.