Evaluation of the Analytical Performance of the Fully Automated Gene Analyzer µTASWako g1 for the Detection of SARS-CoV-2.

BACKGROUND: The worldwide spread of coronavirus disease 2019 (COVID-19) has led to an urgent need for nucleic acid amplification test (NAAT) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Because NAAT has many manual processes, results may vary depending on the operator. Therefore, it has been required to develop a fully automated testing device and reagent that detects genetic material from SARS-CoV-2. The µTASWako g1 system (FUJIFILM Wako Pure Chemical Corporation, Osaka, Japan), a genetic analyzer, provides results in 75 minutes by performing a fully automated PCR process. METHODS: We evaluated the analytical and clinical performance of the µTASWako g1 system for the detection of SARS-CoV-2 RNA. RESULTS: The µTASWako g1 system had the limit of detection at 2,000 copies/mL using a known concentration of RNA. In clinical samples, the µTASWako g1 system had a sensitivity of 88.0% and 100% specificity compared to conventional RT-PCR. The µTAS Wako g1 system could detect three variants of concern carrying spike mutations including N501Y, E484K, and L452R. CONCLUSIONS: As the assay on the µTASWako g1 system is highly accurate for the detection of SARS-CoV-2 regardless of the experience of operator, it can be widely applicable in clinical laboratories.

Enhanced enteric neurogenesis by Schwann cell precursors in mouse models of Hirschsprung disease.

Hirschsprung disease (HSCR) is characterized by congenital absence of enteric neurons in distal portions of the gut. Although recent studies identified Schwann cell precursors (SCPs) as a novel cellular source of enteric neurons, it is unknown how SCPs contribute to the disease phenotype of HSCR. Using Schwann cell-specific genetic labeling, we investigated SCP-derived neurogenesis in two mouse models of HSCR; Sox10 haploinsufficient mice exhibiting distal colonic aganglionosis and Ednrb knockout mice showing small intestinal aganglionosis. We also examined Ret dependency in SCP-derived neurogenesis using mice displaying intestinal aganglionosis in which Ret expression was conditionally removed in the Schwann cell lineage. SCP-derived neurons were abundant in the transition zone lying between the ganglionated and aganglionic segments, although SCP-derived neurogenesis was scarce in the aganglionic region. In the transition zone, SCPs mainly gave rise to nitrergic neurons that are rarely observed in the SCP-derived neurons under the normal condition. Enhanced SCP-derived neurogenesis was also detected in the transition zone of mice lacking RET expression in the Schwann cell lineage. Increased SCP-derived neurogenesis in the transition zone suggests that reduction in the vagal neural crest-derived enteric neurons promotes SCP-derived neurogenesis. SCPs may adopt a neuronal subtype by responding to changes in the gut environment. Robust SCP-derived neurogenesis can occur in a Ret-independent manner, which suggests that SCPs are a cellular source to compensate for missing enteric neurons in HSCR.