title: Inactivation of RNA Viruses by Gamma Irradiation: A Study on Mitigating Factors.
abstract: Effective inactivation of biosafety level 4 (BSL-4) pathogens is vital in order to study these agents safely. Gamma irradiation is a commonly used method for the inactivation of BSL-4 viruses, which among other advantages, facilitates the study of inactivated yet morphologically intact virions. The reported values for susceptibility of viruses to inactivation by gamma irradiation are sometimes inconsistent, likely due to differences in experimental protocols. We analyzed the effects of common sample attributes on the inactivation of a recombinant vesicular stomatitis virus expressing the Zaire ebolavirus glycoprotein and green fluorescent protein. Using this surrogate virus, we found that sample volume and protein content of the sample modulated viral inactivation by gamma irradiation but that air volume within the sample container and the addition of external disinfectant surrounding the sample did not. These data identify several factors which alter viral susceptibility to inactivation and highlight the usefulness of lower biosafety level surrogate viruses for such studies. Our results underscore the need to validate inactivation protocols of BSL-4 pathogens using "worst-case scenario" procedures to ensure complete sample inactivation.
authors.affiliation: Department of Microbiology, School of Medicine, Boston University, 620 Albany Street, Boston, MA 02118, USA. hume@bu.edu.|National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, 620 Albany Street, Boston, MA 02118, USA. hume@bu.edu.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Hume
authors.affiliation: National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, 620 Albany Street, Boston, MA 02118, USA. james218@bu.edu.
authors.forename: Joshua
authors.initials: J
authors.lastname: Ames
authors.affiliation: Department of Microbiology, School of Medicine, Boston University, 620 Albany Street, Boston, MA 02118, USA. rennick@bu.edu.|National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, 620 Albany Street, Boston, MA 02118, USA. rennick@bu.edu.
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Rennick
authors.affiliation: Department of Microbiology, School of Medicine, Boston University, 620 Albany Street, Boston, MA 02118, USA. pduprex@bu.edu.|National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, 620 Albany Street, Boston, MA 02118, USA. pduprex@bu.edu.
authors.forename: W Paul
authors.initials: WP
authors.lastname: Duprex
authors.affiliation: Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South 4th St, Hamilton, MT 59840, USA. marzia@niaid.nih.gov.
authors.forename: Andrea
authors.initials: A
authors.lastname: Marzi
authors.affiliation: National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, 620 Albany Street, Boston, MA 02118, USA. John.Tonkiss@tufts.edu.
authors.forename: John
authors.initials: J
authors.lastname: Tonkiss
authors.affiliation: Department of Microbiology, School of Medicine, Boston University, 620 Albany Street, Boston, MA 02118, USA. muehlber@bu.edu.|National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, 620 Albany Street, Boston, MA 02118, USA. muehlber@bu.edu.
authors.forename: Elke
authors.initials: E
authors.lastname: Mühlberger
mesh_terms: D005720:Gamma Rays; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics; D018116:Vesiculovirus / Q000235:genetics / Q000528:radiation effects*; D014759:Viral Envelope Proteins / Q000235:genetics; D038301:Virus Inactivation
chemical_list: D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; C113189:envelope glycoprotein, Ebola virus; D049452:Green Fluorescent Proteins
keywords: BSL-4; Ebola virus; La Crosse virus; biosafety; gamma irradiation; measles virus; vesicular stomatitis virus; virus inactivation