The foodproof norovirus detection kit (GI, GII, GIV) is designed for quality laboratories of food manufactures, analytical service providers and government laboratories.
Simultaneous, qualitative detection and differentiation of noroviruses from genogroups I, II and IV is possible using a one-step real-time reverse transcriptase PCR, said the firm.
Different genotypes for norovirus exist such as three human pathogenic ones: GI, GII and GIV.
BIOTECON Diagnostics said detection takes about two and a half hours from PCR setup to result, after sample preparation and limit of detection (LOD) was set at 10 virus copies per reaction for GI- and GII-RNA.
Norovirus detection
Olaf Degen, head of product management, said challenges for detecting norovirus involved needing an appropriate “Virus Sample Preparation Kit” - sensitive at low RNA concentrations in food.
“The first step includes always a concentration step - for berries, fruits, water or seafood including oysters. PCR reaction is for the benefit of norovirus RNA transcription," he told FoodQualityNews.
“The current methods on the markets did not fulfil the full range of detection and differentiation of genotypes with a full range of controls in a multiplex reaction.
“However, if you have a positive signal for genotypes GI or GII, the process control signal may be suppressed, this is a normal reaction.
“For time and cost-saving the modern labs prefer one-step methods and not parallel runs of different systems.
“Most of the systems present in the market are for stool control (in clinics) but not for food matrices. There is a lack of focused food systems.”
Current market state
Norovirus can be found contaminating all food prepared under poor hygienic conditions which was not sufficiently cooked. Severe outbreaks have been reportedly caused by contaminated salads, berries, raw vegetables, raw meat and shellfish.
Based on primers and probes of the ISO/TS 15216 method and §64 German Food and Feed Code (LFGB), the detection kit contains an additional phage process control.
It was verified for performance with a foods including berries, fruits, water or seafood such as oysters.
This verification was made in conjunction with the foodproof Virus Sample Preparation Kit to extract highly purified norovirus RNA from food.
Applicability of the system has been shown on all open real-time PCR platforms with appropriate technology for monitoring labeled, 5’ nuclease probes.
Development time for the test was 12 months, said Degen.
“Our method was tested in different labs taking part in a European ring trial (CEFAS Ring trial): The European Union Reference Laboratory (EURL) - Proficiency Testing Scheme - Noroviruses and hepatitis A virus in bivalve molluscan shellfish. The test kit showed 100% accuracy," he said.
“Single PCR systems exist on the market. Genotypes (GI, GII, GIV) could not be differentiated in a multiplex in one system to-date. The new system allows a one-step approach for food matrices.
“A process control is mandatory but not found in other systems. We introduce a phage process control for the first time.”