Identification, Isolation, and Molecular Characterization of Betacoronavirus in Oryx leucoryx.

Coronaviruses (CoVs) are enveloped viruses with a large RNA genome (26 to 32 kb) and are classified into four genera: Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus. CoV infections cause respiratory, enteric, and neurologic disorders in mammalian and avian species. In 2019, Oryx leucoryx animals suffered from severe hemorrhagic diarrhea and high morbidity rates. Upon initial diagnosis, we found that the infected animals were positive for coronavirus by pancoronavirus reverse transcriptase RT-PCR. Next, we detected the presence of CoV particles in these samples by electron microscopy and immunohistochemistry. CoV was isolated and propagated on the HRT-18G cell line, and its full genome was sequenced. Full-genome characterization and amino acid comparisons of this viral agent demonstrated that this virus is an evolutionarily distinct Betacoronavirus belonging to the subgenus Embecovirus and the Betacoronavirus 1 species. Furthermore, we found that it is most similar to the subspecies dromedary camel coronavirus HKU23 by phylogenetic analysis. Here, we present the first report of isolation and characterization of Betacoronavirus associated with enteric disease in Oryx leucoryx. IMPORTANCE CoVs cause enteric and respiratory infections in humans and animal hosts. The ability of CoVs to cross interspecies barriers is well recognized, as emphasized by the ongoing pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The identification of novel CoV strains and surveillance of CoVs in both humans and animals are relevant and important to global health. In this study, we isolated and characterized a newly identified Betacoronavirus that causes enteric disease in a wild animal, Oryx leucoryx (the Arabian oryx). This work is the first report describing CoV infection in Oryx leucoryx and provides insights into its origin.

N-acetyl-ß-d-glucosaminidase activity assay for monitoring insulin-dependent diabetes using Ag-porous Si SERS platform.

Determination of urinary or serum N-acetyl-ß-d-glucosaminidase (NAG) activity as a tissue damage indicator is widely used in diagnosis of various pathologies, including diabetic nephropathy. Early and rapid biomarker detection is an important element of medical diagnosis, facilitating prompt therapeutic decisions and prognosis evaluation. Herein, we present a modified sensing approach for a rapid and reliable NAG activity determination in complex media using surface-enhanced Raman spectroscopy (SERS). Porous silicon (PSi) Fabry-Pérot interferometers were redesigned as sensitive SERS platforms utilizing the vast inherent surface area for silver (Ag) nanoparticles embedment. Interaction of the porous nanostructures with specific NAG-enzymatic products produces an indicative spectral fingerprint proportional in magnitude to its concentration. The sensitivity of Ag-PSi SERS substrates was evaluated in complex matrices presenting sufficient limits of detection compared with other advanced assays and techniques (0.07, 0.47 and 0.50 mU mL-1 for urine, milk and plasma, respectively). The augmented optical performance revealed recovery values of 96-109%, indicating successful and selective NAG recognition in biological fluids. Finally, the potential applicability of the suggested prototype for real-life scenarios was evaluated in vivo, in a model of insulin-dependent diabetes induced in sheep. Overall, the robust data confirm the application of SERS analysis for early diagnosis of pathology and for evaluation of clinical responses to pharmacological treatments.

High-dose vitamin B1 therapy prevents the development of experimental fatty liver driven by overnutrition.

Fatty liver is an abnormal metabolic condition of excess intrahepatic fat. This condition, referred to as hepatic steatosis, is tightly associated with chronic liver disease and systemic metabolic morbidity. The most prevalent form in humans, i.e. non-alcoholic fatty liver, generally develops due to overnutrition and sedentary lifestyle, and has as yet no approved drug therapy. Previously, we have developed a relevant large-animal model in which overnourished sheep raised on a high-calorie carbohydrate-rich diet develop hyperglycemia, hyperinsulinemia, insulin resistance, and hepatic steatosis. Here, we tested the hypothesis that treatment with thiamine (vitamin B1) can counter the development of hepatic steatosis driven by overnutrition. Remarkably, the thiamine-treated animals presented with completely normal levels of intrahepatic fat, despite consuming the same amount of liver-fattening diet. Thiamine treatment also decreased hyperglycemia and increased the glycogen content of the liver, but it did not improve insulin sensitivity, suggesting that steatosis can be addressed independently of targeting insulin resistance. Thiamine increased the catalytic capacity for hepatic oxidation of carbohydrates and fatty acids. However, at gene-expression levels, more-pronounced effects were observed on lipid-droplet formation and lipidation of very-low-density lipoprotein, suggesting that thiamine affects lipid metabolism not only through its known classic coenzyme roles. This discovery of the potent anti-steatotic effect of thiamine may prove clinically useful in managing fatty liver-related disorders.This article has an associated First Person interview with the joint first authors of the paper.