Real-time RT-PCR for norovirus screening in shellfish

Area of Science:

• Food safety
• Molecular biology
• Virology

Background:

• Norovirus is a leading cause of gastroenteritis, often transmitted through contaminated food and water.
• Accurate detection of norovirus in environmental and food samples is crucial for public health.
• Real-time reverse transcription polymerase chain reaction (RT-PCR) offers sensitive and rapid detection capabilities.

Purpose of the Study:

• To develop and validate a novel real-time RT-PCR assay for the simultaneous detection of norovirus genogroups I and II.
• To assess the assay's performance in detecting reference strains and naturally occurring norovirus in shellfish samples.

Main Methods:

• Development of a one-step real-time RT-PCR assay utilizing single primer sets and probes for norovirus genogroups I and II.
• Testing the assay with reference strains in artificially contaminated oysters.
• Validation using 150 archived naturally contaminated shellfish samples.

Main Results:

• The assay successfully detected reference strains of norovirus genogroups I and II in artificially contaminated oysters.
• The genogroup II primer set demonstrated broad utility, detecting diverse strains circulating in France since 1995 in naturally contaminated shellfish.
• Norovirus genogroup I strains were infrequently detected in the naturally contaminated shellfish samples.

Conclusions:

• The developed real-time RT-PCR assay is a valuable tool for norovirus detection in shellfish.
• The genogroup II assay is particularly effective for surveillance of prevalent strains in food sources.
• Further optimization may be needed for consistent detection of genogroup I strains in environmental samples.