Mechanisms of viral inactivation methods against hepatitis C virus

S Pfaender, J Brinkmann, D Todt, N Riebesehl, J Steinmann, J Steinmann, T Pietschmann, E Steinmann

Appl. Environ. Microbiol. AEM.03580-14; Accepted manuscript posted online 19 December 2014

Virus inactivation by chemical disinfectants is an important instrument for infection control in medical settings, but the mechanisms involved are poorly understood. In this study, we systematically investigated the effects of several antiviral treatments on hepatitis C virus (HCV) particles as model for enveloped viruses. Studies were performed with authentic cell culture derived viruses and influence of chemical disinfectants, heat and UV treatment on HCV was analyzed by determination of infectious particles in a limiting dilution assay, quantitative RT-PCR, core ELISA and proteolytic protection assay. All different inactivation methods resulted in a loss of HCV infectivity by targeting different parts of the virus particle. Alcohols like ethanol and 2-propanol did not affect the viral RNA genome integrity, but disrupted the viral envelope membrane in a capsid protection assay. Heat and UV treatment of HCV particles resulted in direct damage of the viral genome as transfection of viral particle associated RNA into permissive cells did not initiate RNA replication. Additionally, heat incubation at 80°C disrupted the HCV envelope rendering the viral capsid susceptible to proteolytic digest. This study demonstrated the molecular processes of viral inactivation of an enveloped virus and should facilitate the development of effective disinfection strategies in infection control not only against HCV but also against other enveloped viruses.