动物疾病(英文)最新文献

Infectious pandemics result in hundreds and millions of deaths, notable examples of the Spanish Flu, the Black Death and smallpox. The current pandemic, caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), is unprecedented even in the historical term of pandemics. The unprecedentedness is featured by multiple surges, rapid identification of therapeutic options and accelerated development of vaccines. Remdesivir, originally developed for Ebola viral disease, is the first treatment of COVID-19 (Coronavirus disease 2019) approved by the United States Food and Drug Administration. As demonstrated by in vitro and preclinical studies, this therapeutic agent is highly potent with a broad spectrum activity against viruses from as many as seven families even cross species. However, randomized controlled trials have failed to confirm the efficacy and safety. Remdesivir improves some clinical signs but not critical parameters such as mortality. This antiviral agent is an ester/phosphorylation prodrug and excessive hydrolysis which increases cellular toxicity. Remdesivir is given intravenously, leading to concentration spikes and likely increasing the potential of hydrolysis-based toxicity. This review has proposed a conceptual framework for improving its efficacy and minimizing toxicity not only for the COVID-19 pandemic but also for future ones caused by remdesivir-sensitive viruses.

Canine coronavirus (CCoV), a member of the genus Alphacoronavirus, is an enveloped, single-stranded positive-sense RNA virus that responsible for gastroenteritis in dogs. In this study, two CCoV isolates were successfully propagated from 53 CCoV-positive clinical specimens by serial passaging in A-72 cells. These two strains, CCoV JS1706 and CCoV JS1712, caused cytopathic effects in A-72 cells. The sizes of virus plaque formed by them differed in early passages. Electron microscopy revealed a large quantity of typical coronavirus particles with 80-120 nm in diameter in cell culture media and cytoplasm of infected cells, in which they appeared as inclusion bodies. RT-PCR analysis of S gene indicated that these two isolates were belonged to CCoV IIa subtype. Homology of RdRp, S, M and N proteins between the two strains were 100, 99.6, 99.2 and 100.0%, respectively, whereas they were 99.4-100%, 83.1-95.2%, 88.5-99.2% and 91.9-99.7% identity compared to CCoV II reference strains. Phylogenetic analysis of RdRp, S, M and N protein showed that they were closely related to CCoV II strains. These two subtype IIa isolates will be useful for evaluating the pathogenesis and evolution of CCoV and for developing diagnostic reagents and vaccines.

Coronaviruses (CoVs) are a group of related enveloped RNA viruses that have severe consequences in a wide variety of animals by causing respiratory, enteric or systemic diseases. Porcine epidemic diarrhea virus (PEDV) is an economically important CoV distributed worldwide that causes diarrhea in pigs. nsp14 is a nonstructural protein of PEDV that is involved in regulation of innate immunity and viral replication. However, the function and mechanism by which nsp14 modulates and manipulates host immune responses remain largely unknown. Here, we report that PEDV nsp14 is an NF-κB pathway antagonist. Overexpression PEDV nsp14 protein remarkably decreases SeV-, poly (I:C)- and TNF-α-induced NF-κB activation. Meanwhile, expression of proinflammatory cytokines is suppressed by nsp14. nsp14 inhibits the phosphorylation of IKKs by interacting with IKKs and p65. Furthermore, nsp14 suppresses TNF-α-induced phosphorylation and nuclear import of p65. Overexpression nsp14 considerably increases PEDV replication. These results suggest a novel mechanism employed by PEDV to suppress the host antiviral response, providing insights that can guide the development of antivirals against CoVs.

Porcine epidemic diarrhea virus (PEDV), as the main causative pathogen of viral diarrhea in pigs, has been reported to result in high morbidity and mortality in neonatal piglets and cause significant economic losses to the swine industry. Rapid diagnosis methods are essential for preventing outbreaks and transmission of this disease. In this study, a paper-based lateral flow immunoassay for the rapid diagnosis of PEDV in swine fecal samples was developed using stable color-rich latex beads as the label. Under optimal conditions, the newly developed latex bead-based lateral flow immunoassay (LBs-LFIA) attained a limit of detection (LOD) as low as 10^3.60 TCID₅₀/mL and no cross-reactivity with other related swine viruses. To solve swine feces impurity interference, by adding a filtration unit design of LFIA without an additional pretreatment procedure, the LBs-LFIA gave good agreement (92.59%) with RT-PCR results in the analysis of clinical swine fecal samples (n = 108), which was more accurate than previously reported colloidal gold LFIA (74.07%) and fluorescent LFIA (86.67%). Moreover, LBs-LFIA showed sufficient accuracy (coefficient of variance [CV] < 15%) and stable (room temperature storage life > 56 days) performance for PEDV detection, which is promising for on-site analysis and user-driven testing in pig production system.

Supplementary information: The online version contains supplementary material available at 10.1186/s44149-021-00029-1.