Assay of Several Inactivation Steps on West Nile Virus and H7N1 Highly Pathogenic Avian Influenza Virus Suspensions

Xavier Abad

doi:10.4172/2167-0331.1000103

Abstract

Objectives: In any research laboratory, precautionary measures must be taken in order to reduce or eliminate the potential risk of accidental infection by biosafety level 3 (BSL3) pathogens, as Highly Pathogenic Avian Influenza Virus (HPAI) or West Nile Virus (WNV). Appropriate virus inactivation procedures have to be set up to allow necessary further processing of specimens outside BSL3 facilities. Methods: To study the elimination of WN and HPAI virus infectivity, the effect of different chemical and physical inactivation procedures on viral suspensions were investigated. A proper cell culture assay for each virus was performed to verify several treatments, which are commonly performed preceding transfer of materials outside of biocontainment, still allowing further investigations like sequencing or genome amplification. Results: Chemical inactivation with AVL buffer (Qiagen), Trizol® Reagent or Phenol chloroform: isoamylic alcohol treatment, as well as physical treatment (heat at two temperatures and three contact times) reduced viral infectivity in the viral suspension below the detection limit. Conclusion: Thermal treatments, but also Trizol® Reagent and AVL buffer (Qiagen), are suitable to produce noninfectious specimens for further use in molecular biology techniques

Highlights

Over the last few years, there has been an important increase in research on viral emerging diseases. This has led to rise in the numbers of biosafety level 3 (BSL3) facilities handling those emerging viruses (Avian Influenza Virus, SARS Coronavirus, and West Nile Virus)
With respect to thermal treatment, Reduction Factors (RF) up to 4.5 log10 was achieved in all cases, regardless of the virus type or the assayed temperature
As Phenol: chloroform: isoamylic alcohol, AVL or Trizol® resulted in higher toxicity for the aforementioned cell lines; the final reduction factor (RF) achieved was lower, between 2.5 and 4.5 log10

Summary

Introduction

Over the last few years, there has been an important increase in research on viral emerging diseases This has led to rise in the numbers of BSL3 facilities handling those emerging viruses (Avian Influenza Virus, SARS Coronavirus, and West Nile Virus). West Nile virus (WN virus), belonging to the genus Flavivirus in the Flaviviridae family, are spherical with a lipid envelope, 40-60 nm in diameter, enclosing a single linear positive sense RNA molecule [1]. This virus can cause human diseases as meningitis and encephalitis and for its handling and propagation, a BSL3 environment is mandatory

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Conclusion