Stability of hepatitis E virus at high hydrostatic pressure processing.

Area of Science:

• Food safety
• Virology
• Food processing technology

Background:

• Hepatitis E virus (HEV) causes acute and chronic hepatitis.
• Zoonotic HEV genotype 3 is prevalent in Europe, primarily transmitted through contaminated meat products.
• High hydrostatic pressure processing (HPP) is a nonthermal technology for pathogen inactivation in food.

Purpose of the Study:

• To evaluate the efficacy of HPP in inactivating HEV genotype 3.
• To determine the impact of pressure, temperature, and time on HEV infectivity reduction.
• To develop predictive models for HEV inactivation by HPP.

Main Methods:

• Cell culture-adapted HEV genotype 3 preparations were subjected to HPP at varying pressures (100-600 MPa) and temperatures (4°C and 20°C).
• Viral infectivity was quantified by counting fluorescent foci.
• Transmission electron microscopy was used to examine viral particle integrity post-treatment.
• Time-course experiments were conducted to assess inactivation kinetics.

Main Results:

• HPP application led to a gradual decrease in HEV infectivity with increasing pressure and duration.
• At 400 MPa for 2 minutes, infectivity reductions of 1 log10 (20°C) and 2 log10 (4°C) were observed.
• Near-complete inactivation (>3.5 log10 reduction) was achieved at 600 MPa, though low levels of infectious virus persisted in some replicates.
• HEV particles appeared disassembled and distorted at 600 MPa.
• Time-course experiments at 400 MPa showed a continuous decline in infectivity over 10 minutes.

Conclusions:

• HPP is effective in reducing HEV infectivity, with inactivation dependent on pressure intensity and treatment duration.
• HEV demonstrates relative stability against HPP compared to other viruses.
• Achieving significant HEV inactivation necessitates high pressure and/or extended processing times.