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Updated: May 20, 2026
Plaque Assay for Murine Norovirus
Published on: August 22, 2012
Comparison of ELISA attachment and infectivity assays for murine norovirus
Kirsten A Hirneisen1, Kalmia E Kniel
1Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716, USA.
Abstract:
Human noroviruses cause approximately 58% of foodborne illnesses in the USA. Recent studies have shown norovirus attachment to the carbohydrates moieties of host cellular receptors. Using murine norovirus (MNV) as a surrogate, an ELISA method was utilized to assess attachment through binding to host cell receptors; MNV attachment was correlated to infectivity determined by plaque assay. ELISA plates were coated with porcine gastric mucin and untreated, heat-, high pressure-, ozone- and UV-treated MNV was added followed by monoclonal anti-MNV IgG antibody. The average OD(405) of MNV-containing wells were divided by negative control wells and expressed as the 'P/N ratio'; values ≥2 were considered positive. Infectivity of MNV following heat and HPP treatments was determined using the plaque assay. Heat-treated MNV attachment decreased significantly with decreasing viral infectivity whereby the P/N ratio was <2 after treatment at 80 and 100°C for 5 min which correlated with a non-intact capsid as shown by RNase treatment. No significant difference in attachment was observed for pressure-, ozone- and UV-treated MNV. These findings suggest potentially different effects on the viral capsid due to different food processing methods.
Insights
Murine norovirus (MNV) attachment to host cells decreased with heat treatment, impacting infectivity. Other methods like HPP, ozone, and UV did not significantly alter MNV attachment, suggesting varied effects of food processing on viral capsids.
Area of Science:
- Foodborne illness
- Virology
- Food safety
Background:
- Human noroviruses are a leading cause of foodborne illness in the USA.
- Norovirus attachment to host cells involves carbohydrate moieties on cellular receptors.
- Murine norovirus (MNV) serves as a surrogate for studying norovirus attachment and infectivity.
Purpose of the Study:
- To assess the effect of different food processing methods on MNV attachment to host cell receptors.
- To correlate MNV attachment with viral infectivity after various treatments.
- To investigate the impact of heat, high-pressure processing (HPP), ozone, and UV treatment on MNV capsid integrity.
Main Methods:
- An ELISA method was used to measure MNV attachment to porcine gastric mucin.
- MNV infectivity was determined by plaque assay.
- Viral capsid integrity was assessed using RNase treatment after heat application.
Main Results:
- Heat treatment significantly reduced MNV attachment and infectivity, with P/N ratios <2 at 80°C and 100°C for 5 min, correlating with capsid damage.
- HPP, ozone, and UV treatments did not show significant differences in MNV attachment compared to untreated MNV.
- RNase treatment indicated a non-intact capsid in heat-treated MNV.
Conclusions:
- Heat treatment effectively reduces MNV attachment and infectivity, likely due to capsid damage.
- HPP, ozone, and UV treatments appear to preserve MNV attachment and capsid integrity.
- Different food processing methods may have distinct effects on norovirus capsid stability and infectivity.
