Researchers at the National University of Singapore (NUS) specializing in food virology have achieved successful cultivation of the human norovirus using zebrafish embryos.
Assistant Professor Li Dan (right) and Dr Malcom Tan (left) from the NUS Department of Food Science and Technology microinjecting zebrafish embryos with the human norovirus under a microscope. Image Credit: National University of Singapore.
This breakthrough provides a valuable platform for evaluating the efficacy of virus inactivation methods relevant to water treatment and the food industry.
The human norovirus (HuNoV) currently stands as the primary culprit behind global acute gastroenteritis, contributing to an estimated 684 million cases of diarrhea and causing 212,000 annual fatalities. Over an extended period, the lack of an in vitro culture system has posed a significant obstacle in norovirus research.
The most recently optimized model for human intestinal enteroids, designed to support HuNoV replication, relies on human biopsy specimens acquired through surgical or endoscopic procedures, which are typically in short supply. Additionally, the maintenance of these cells proves to be both labor and resource-intensive.
Under the leadership of Assistant Professor Li Dan from the NUS Department of Food Science and Technology, and in collaboration with Professor Gong Zhiyuan from the NUS Department of Biological Sciences, a research team fortuitously uncovered the potential of zebrafish embryos as a host for cultivating the human norovirus (HuNoV).
The zebrafish embryo model, known for its ease of handling and robustness, demonstrated a remarkable ability to efficiently replicate HuNoVs. This study marks the inaugural demonstration of the highest fold-increase over the baseline, showcasing the unique effectiveness of this model.
Significantly, the model allows for the continuous passaging of HuNoV within a laboratory setting. This breakthrough capability enables researchers to propagate and maintain the presence of HuNoV over time, facilitating in-depth studies of its behavior, replication dynamics, and other essential properties.
The zebrafish embryo model represents an essential improvement in the HuNoV cultivation method. With its high efficiency and robustness, this tool is able to enhance both the breadth and depth of HuNoV-related research.”
Li Dan, Assistant Professor, National University of Singapore
Dan added, “It is expected that this tool will not only benefit the advancement of epidemiological research on HuNoV but will also be invaluable in establishing HuNoV inactivation parameters. These parameters are highly needed by the water treatment and food industries to develop more effective methods for preventing the spread of the virus.”
The study was published in Applied and Environmental Microbiology on March 21st, 2023.
The research team intends to employ the zebrafish embryo model to explore methods for inactivating human noroviruses (HuNoVs) in food products. The successful identification of infectious HuNoV in food products has proven to be a challenging objective thus far.
Although additional refinement and optimization efforts are necessary, the ongoing work of the research team shows considerable promise in addressing this formidable task.
Source:
Journal reference:
Tan, M. T. H., et al. (2023) Use of Zebrafish Embryos To Reproduce Human Norovirus and To Evaluate Human Norovirus Infectivity Decay after UV Treatment. Applied and Environmental Microbiology. doi.org/10.1128%2Faem.00115-23.
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