Short Communication — Stability of “Free” Norovirus RNA on Fresh Produce

Abstract

AbstractThe accuracy and dependability of results generated through molecular detection of specific target sequences of RNA, commonly used for detecting viruses in food, have been extensively debated within the scientific community. Such concerns have been raised by researchers, clients, and regulators alike, highlighting the need for further investigation and clarification. In particular, there has been debate about the possibility of molecular methods to detect enteric viruses, such as norovirus, in foods, producing false positive RT-PCR results due to the presence of “free” target RNA sequences in the food supply chain environment. This study aimed to investigate this issue by evaluating the recovery of “free” norovirus RNA from lettuce leaves. The “free” RNA was produced using heat treatment and chemical extraction methods. The study findings indicate that recovery of heat-extracted RNA from the lettuce leaves decreased markedly within 24 h, while recovery of chemically extracted RNA remained stable and even increased over time. The results of this study suggest that positive molecular detection of viruses in food is more likely to be associated with intact and potentially infectious virus particles, rather than “free” unprotected RNA. These findings have significant implications for the food industry and regulatory bodies in terms of the interpretation, accuracy and reliability of molecular detection methods for virus detection in food.