A sensitive reverse transcription loop-mediated isothermal amplification （RT-LAMP） assay was developed for rapid visual detection of Murray valley encephalitis virus （MVEV） infection. The reaction was performed in...A sensitive reverse transcription loop-mediated isothermal amplification （RT-LAMP） assay was developed for rapid visual detection of Murray valley encephalitis virus （MVEV） infection. The reaction was performed in one step in a single tube at 63 ~C for 60 min with the addition of the hydroxynaphthol blue （HNB） dye prior to amplification. The detection limit of the RT-LAMP assay was 100 copies per reaction based on 10-fold dilutions of in vitro transcribed RNA derived from a synthetic MVEV DNA template. No cross-reaction was observed with other encephalitis-associated viruses. The assay was further evaluated using spiked cerebrospinal fluid sample with pseudotype virus containing the NS5 gene of MVEV.展开更多
During the two-year pandemic of coronavirus disease 2019(COVID-19), its causative agent, severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), has been evolving. SARS-CoV-2 Delta, a variant of concern, has beco...During the two-year pandemic of coronavirus disease 2019(COVID-19), its causative agent, severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), has been evolving. SARS-CoV-2 Delta, a variant of concern, has become the dominant circulating strain worldwide within just a few months. Here, we performed a comprehensive analysis of a new B.1.617.2 Delta strain(Delta630) compared with the early WIV04 strain(WIV04) in vitro and in vivo, in terms of replication, infectivity, pathogenicity, and transmission in hamsters. When inoculated intranasally, Delta630 led to more pronounced weight loss and more severe disease in hamsters. Moreover, 40%mortality occurred about one week after infection with 10^(4)PFU of Delta630, whereas no deaths occurred even after infection with 10^(5)PFU of WIV04 or other strains belonging to the Delta variant. Moreover, Delta630outgrew over WIV04 in the competitive aerosol transmission experiment. Taken together, the Delta630 strain showed increased replication ability, pathogenicity, and transmissibility over WIV04 in hamsters. To our knowledge, this is the first SARS-CoV-2 strain that causes death in a hamster model, which could be an asset for the efficacy evaluation of vaccines and antivirals against infections of SARS-CoV-2 Delta strains. The underlying molecular mechanisms of increased virulence and transmission await further analysis.展开更多
基金supported by the Scientific Research Project of General Administration of Quality Supervision,Inspection and Quarantine of P.R.C(2011IK132)the China Mega-Project for Infectious Disease(2013ZX10004-001)
文摘A sensitive reverse transcription loop-mediated isothermal amplification （RT-LAMP） assay was developed for rapid visual detection of Murray valley encephalitis virus （MVEV） infection. The reaction was performed in one step in a single tube at 63 ~C for 60 min with the addition of the hydroxynaphthol blue （HNB） dye prior to amplification. The detection limit of the RT-LAMP assay was 100 copies per reaction based on 10-fold dilutions of in vitro transcribed RNA derived from a synthetic MVEV DNA template. No cross-reaction was observed with other encephalitis-associated viruses. The assay was further evaluated using spiked cerebrospinal fluid sample with pseudotype virus containing the NS5 gene of MVEV.
基金supported by China Natural Science Foundation (82150201)
文摘During the two-year pandemic of coronavirus disease 2019(COVID-19), its causative agent, severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), has been evolving. SARS-CoV-2 Delta, a variant of concern, has become the dominant circulating strain worldwide within just a few months. Here, we performed a comprehensive analysis of a new B.1.617.2 Delta strain(Delta630) compared with the early WIV04 strain(WIV04) in vitro and in vivo, in terms of replication, infectivity, pathogenicity, and transmission in hamsters. When inoculated intranasally, Delta630 led to more pronounced weight loss and more severe disease in hamsters. Moreover, 40%mortality occurred about one week after infection with 10^(4)PFU of Delta630, whereas no deaths occurred even after infection with 10^(5)PFU of WIV04 or other strains belonging to the Delta variant. Moreover, Delta630outgrew over WIV04 in the competitive aerosol transmission experiment. Taken together, the Delta630 strain showed increased replication ability, pathogenicity, and transmissibility over WIV04 in hamsters. To our knowledge, this is the first SARS-CoV-2 strain that causes death in a hamster model, which could be an asset for the efficacy evaluation of vaccines and antivirals against infections of SARS-CoV-2 Delta strains. The underlying molecular mechanisms of increased virulence and transmission await further analysis.
