[Objective] The study aims to determine the optimal concentration of trypsin for the proliferation of avian influenza virus （AIV） H9N2 subtype in Madin- Darby canine kidney （MDCK） cells. [Method] Three AIV H9 subt...[Objective] The study aims to determine the optimal concentration of trypsin for the proliferation of avian influenza virus （AIV） H9N2 subtype in Madin- Darby canine kidney （MDCK） cells. [Method] Three AIV H9 subtype isolates were inoculated on MDCK cells respectively. Then, DMEM containing different concentrations of trypsin as maintenance media were added to MDCK monolayer cells. The cytopathic effect （CPE） was observed once every 24 h, and the HA titer of the supematant was measured by HA assay. [Result] When the trypsin concentration was 10 -20 μg/ml in DMEM, the HA titer of virus culture reached 7 log2 （1：128）. Almost all cells were cytopathic after 96 h post inoculation with 1：1 000 or 1：10 000 dilution of AIV culture, and the virus titer reached a peak after 72 -96 h. [ Conclusion] The optimal concentration of trypsin is 10 -20 pg/ml for proliferation of AIV H9N2 subtype in MDCK cells.展开更多
Canine health is consistently affected by the circulation of the H3N2 strain of canine influenza virus(CIV).Prior research has indicated that the isolation rate of H3N2 CIVs in dogs has gradually increased in China,an...Canine health is consistently affected by the circulation of the H3N2 strain of canine influenza virus(CIV).Prior research has indicated that the isolation rate of H3N2 CIVs in dogs has gradually increased in China,and these viruses have progressively adapted to humans over the course of their evolution within canine hosts,posing a significant public health threat.However,the key factors influencing the spread of CIVs remain elusive.From January 2020 to December 2022,during the COVID-19 pandemic,strict epidemic prevention policies were implemented in China.Thus,this measure provides an ideal model for studying factors influencing the prevalence of CIVs.In this study,we continuously monitored the prevalence of CIVs in China before and after the COVID-19 pandemic.We found that the pathogen detection rate and seropositivity rate of domestic CIVs significantly declined after the implementa-tion of epidemic control measures.However,after restrictions on human movement were lifted in 2023,the circula-tion of CIVs gradually increased.Our results demonstrate that restricting human activity directly impacts the epi-demic caused by CIVs and provide a theoretical basis for the implementation of control measures during outbreaks of zoonotic diseases in human companion animals.展开更多
Avian-origin H3N2 canine influenza virus(CIV)is one of the most prevalent influenza virus subtypes in dogs world-wide.Previous studies have shown that during the evolution of H3N2 CIV in dogs,its adaptability in mamma...Avian-origin H3N2 canine influenza virus(CIV)is one of the most prevalent influenza virus subtypes in dogs world-wide.Previous studies have shown that during the evolution of H3N2 CIV in dogs,its adaptability in mammals increased gradually,suggesting that dogs can serve as a potential intermediate host for cross-species transmission of the avian influenza virus.In this study,we report results from the surveillance and characterization of H3N2 CIVs iso-lated from animal hospitals and kennels in 2021 in China.We characterized the CIVs’genetic and antigenic variation,receptor-binding specificity,and virulence in mice.The hemagglutinin(HA)phylogenetic result showed that these H3N2 CIVs belonged to Clade 5.1,a clade formed after 2019.Compared to the 2016-2019 strains in China,the 2021 H3N2 CIVs had similar antigenicity and receptor-binding specificity.The pathogenicity in mice was significantly reduced after infection with two 2021 strains,but the replication capacity was similar,suggesting that a virus-host balance might have been established.This report emphasizes the importance of close surveillance and monitoring of H3N2 CIVs in dogs to prevent the emergence of novel influenza viruses with public health threats.展开更多
为了建立一种便捷、灵敏的犬流感病毒(CIV)检测技术,本研究根据CIV相对保守的M片段设计3对特异性引物,建立CIV的RT-LAMP检测方法,对反应体系中的MgSO4、Betaine、Bst DNA PoLymerase、dNTP、引物浓度等分别进行了优化,并进行敏感性和特...为了建立一种便捷、灵敏的犬流感病毒(CIV)检测技术,本研究根据CIV相对保守的M片段设计3对特异性引物,建立CIV的RT-LAMP检测方法,对反应体系中的MgSO4、Betaine、Bst DNA PoLymerase、dNTP、引物浓度等分别进行了优化,并进行敏感性和特异性试验。结果表明:所建立的反应体系在恒温水浴锅中作用45min即可得到其特有的阶梯状条带,而且对犬细小病毒、犬瘟病毒和犬副流感病毒的扩增结果均为阴性。该方法对CIV RNA的最小检测限为0.1pg,灵敏性高于一步RT-PCR方法。RT-LAMP和普通RT-PCR方法检测临床样品的符合率为93.02%。该方法为犬流感病毒的临床检测提供了一种简便、实用的方法,为基层检疫提供了方便。展开更多
基金funded by the Beijing Academy of Agriculture and Forestry Sciences (2010A007)
文摘[Objective] The study aims to determine the optimal concentration of trypsin for the proliferation of avian influenza virus （AIV） H9N2 subtype in Madin- Darby canine kidney （MDCK） cells. [Method] Three AIV H9 subtype isolates were inoculated on MDCK cells respectively. Then, DMEM containing different concentrations of trypsin as maintenance media were added to MDCK monolayer cells. The cytopathic effect （CPE） was observed once every 24 h, and the HA titer of the supematant was measured by HA assay. [Result] When the trypsin concentration was 10 -20 μg/ml in DMEM, the HA titer of virus culture reached 7 log2 （1：128）. Almost all cells were cytopathic after 96 h post inoculation with 1：1 000 or 1：10 000 dilution of AIV culture, and the virus titer reached a peak after 72 -96 h. [ Conclusion] The optimal concentration of trypsin is 10 -20 pg/ml for proliferation of AIV H9N2 subtype in MDCK cells.
基金supported by the Major Project of Agricultural Biological Breeding(No.2023ZD0405304).
文摘Canine health is consistently affected by the circulation of the H3N2 strain of canine influenza virus(CIV).Prior research has indicated that the isolation rate of H3N2 CIVs in dogs has gradually increased in China,and these viruses have progressively adapted to humans over the course of their evolution within canine hosts,posing a significant public health threat.However,the key factors influencing the spread of CIVs remain elusive.From January 2020 to December 2022,during the COVID-19 pandemic,strict epidemic prevention policies were implemented in China.Thus,this measure provides an ideal model for studying factors influencing the prevalence of CIVs.In this study,we continuously monitored the prevalence of CIVs in China before and after the COVID-19 pandemic.We found that the pathogen detection rate and seropositivity rate of domestic CIVs significantly declined after the implementa-tion of epidemic control measures.However,after restrictions on human movement were lifted in 2023,the circula-tion of CIVs gradually increased.Our results demonstrate that restricting human activity directly impacts the epi-demic caused by CIVs and provide a theoretical basis for the implementation of control measures during outbreaks of zoonotic diseases in human companion animals.
基金supported by the Higher Education Discipline Innovation Project.
文摘Avian-origin H3N2 canine influenza virus(CIV)is one of the most prevalent influenza virus subtypes in dogs world-wide.Previous studies have shown that during the evolution of H3N2 CIV in dogs,its adaptability in mammals increased gradually,suggesting that dogs can serve as a potential intermediate host for cross-species transmission of the avian influenza virus.In this study,we report results from the surveillance and characterization of H3N2 CIVs iso-lated from animal hospitals and kennels in 2021 in China.We characterized the CIVs’genetic and antigenic variation,receptor-binding specificity,and virulence in mice.The hemagglutinin(HA)phylogenetic result showed that these H3N2 CIVs belonged to Clade 5.1,a clade formed after 2019.Compared to the 2016-2019 strains in China,the 2021 H3N2 CIVs had similar antigenicity and receptor-binding specificity.The pathogenicity in mice was significantly reduced after infection with two 2021 strains,but the replication capacity was similar,suggesting that a virus-host balance might have been established.This report emphasizes the importance of close surveillance and monitoring of H3N2 CIVs in dogs to prevent the emergence of novel influenza viruses with public health threats.
文摘为了建立一种便捷、灵敏的犬流感病毒(CIV)检测技术,本研究根据CIV相对保守的M片段设计3对特异性引物,建立CIV的RT-LAMP检测方法,对反应体系中的MgSO4、Betaine、Bst DNA PoLymerase、dNTP、引物浓度等分别进行了优化,并进行敏感性和特异性试验。结果表明:所建立的反应体系在恒温水浴锅中作用45min即可得到其特有的阶梯状条带,而且对犬细小病毒、犬瘟病毒和犬副流感病毒的扩增结果均为阴性。该方法对CIV RNA的最小检测限为0.1pg,灵敏性高于一步RT-PCR方法。RT-LAMP和普通RT-PCR方法检测临床样品的符合率为93.02%。该方法为犬流感病毒的临床检测提供了一种简便、实用的方法,为基层检疫提供了方便。
