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Published on: November 16, 2017
Validation of Inactivation Methods for Arenaviruses
Silke Olschewski1, Anke Thielebein1, Chris Hoffmann1
1Department of Virology, Bernhard-Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany.
Abstract:
Several of the human-pathogenic arenaviruses cause hemorrhagic fever and have to be handled under biosafety level 4 conditions, including Lassa virus. Rapid and safe inactivation of specimens containing these viruses is fundamental to enable downstream processing for diagnostics or research under lower biosafety conditions. We established a protocol to test the efficacy of inactivation methods using the low-pathogenic Morogoro arenavirus as surrogate for the related highly pathogenic viruses. As the validation of chemical inactivation methods in cell culture systems is difficult due to cell toxicity of commonly used chemicals, we employed filter devices to remove the chemical and concentrate the virus after inactivation and before inoculation into cell culture. Viral replication in the cells was monitored over 4 weeks by using indirect immunofluorescence and immunofocus assay. The performance of the protocol was verified using published inactivation methods including chemicals and heat. Ten additional methods to inactivate virus in infected cells or cell culture supernatant were validated and shown to reduce virus titers to undetectable levels. In summary, we provide a robust protocol for the validation of chemical and physical inactivation of arenaviruses in cell culture, which can be readily adapted to different inactivation methods and specimen matrices.
Insights
A new protocol effectively validates methods for inactivating dangerous arenaviruses, like Lassa virus, ensuring safer research and diagnostics. This method uses a surrogate virus and filtration to assess inactivation efficacy in cell cultures.
Area of Science:
- Virology
- Biosafety
- Infectious Diseases
Background:
- Human-pathogenic arenaviruses, including Lassa virus, pose significant risks and require stringent biosafety level 4 containment.
- Effective inactivation of these viruses is crucial for safe downstream diagnostics and research.
- Current validation methods for chemical inactivation in cell culture are challenging due to chemical toxicity.
Purpose of the Study:
- To establish and validate a robust protocol for assessing the efficacy of virus inactivation methods for arenaviruses.
- To enable downstream processing of arenavirus samples under reduced biosafety conditions.
- To adapt the protocol for various inactivation techniques and sample types.
Main Methods:
- Utilized low-pathogenic Morogoro arenavirus as a surrogate for highly pathogenic arenaviruses.
- Employed filter devices to remove inactivating chemicals and concentrate viral particles before cell culture inoculation.
- Monitored viral replication over 4 weeks using indirect immunofluorescence and immunofocus assays.
- Validated the protocol using established chemical and heat inactivation methods.
Main Results:
- The developed protocol successfully validated ten additional inactivation methods.
- All validated methods reduced arenavirus titers to undetectable levels.
- The protocol demonstrated robustness and adaptability for different inactivation agents and sample matrices.
Conclusions:
- A reliable protocol for validating arenavirus inactivation in cell culture has been established.
- This method facilitates safer handling and research of dangerous arenaviruses.
- The protocol is adaptable for diverse inactivation strategies and sample types, enhancing biosafety in virology research.
