Viral isolation in cell cultures has been regarded for decades as the“gold standard”for the laboratory diagnosis of influenza viral infections.Not all viral strains could be isolated from clinical samples.This study...Viral isolation in cell cultures has been regarded for decades as the“gold standard”for the laboratory diagnosis of influenza viral infections.Not all viral strains could be isolated from clinical samples.This study aimed to quantify the viral load in the samples before isolation to save working time and improve working efficiency.Four hundred samples from patients with influenza-like cases were confirmed pdmH1N1 positive(200 cases)and B Victoria(BV)positive(200 cases)by whole-genome sequencing and analyzed by ddPCR for viral load in samples before isolation,and isolation results were verified by hemagglutination(HA)assay and hemagglutination-inhibition(HI)tests.Probit regression analysis was used to calculate the isolation viral load limit with a 95%probability level by SPSS 19.0 software.The results showed that the isolation limit of viral load was 4.9×10^(4)(95%CI:2.5×10^(4)–9.0×10^(4))copies/mL for pdmH1N1 and 1.9×10^(4)(95%CI:7.8×103–3.6×10^(4))copies/mL for BV.The isolation rate of clinical samples is positively correlated with the viral load in clinical samples,which can be used for viral culture,providing important guidance for daily work.展开更多
Objective:To study hemagglutinin genetic evolution of some Middle East(ME) 2009 H1N1 pdm isolates and compared them with prototype vaccine strain[A/California/07/2009(H1N1)],which is used as a vaccine strain in the No...Objective:To study hemagglutinin genetic evolution of some Middle East(ME) 2009 H1N1 pdm isolates and compared them with prototype vaccine strain[A/California/07/2009(H1N1)],which is used as a vaccine strain in the Northern Hemisphere 2010-2011.Methods:Nucleotide and/ or amino acid sequences of HA gene of fifty-four ME 2009 H1N1 pdm isolates were retrieved from GenBank Database by using Basic BLAST engine.Phylogenetic trees were established for both nucleotide and amino acid sequences using the muscle algorithm of the computer program CLC free workbench 5.6.1 JRE software.Amino acids alignment was also done to compare sequences HA1 domains of HA genes of ME 2009 H1N1 pdm isolates(n=39) with amino acid sequence of prototype vaccine strain A/California/07/2009(H1N1).Results:Phylogenetic analysis of amino acids and nucleotides of the HA gene of the ME 2009 H1N1 pdm isolates confirmed their evolutionary position in cluster with prototype vaccine strain(A/California/07/2009(H1N1)) which is used as vaccine strain in the Northern Hemisphere 2010-2011.Antigenically,the ME 2009 H1N1 pdm isolates were homogeneous and closely related to prototype vaccine.Only a few amino acid substitutions in the HA among the ME 2009 H1N1 pdm isolates were analyzed.Conclusions: The current influenza vaccine is expected to provide a good protection against ME 2009 H1N1 pdm because it contains strains with H1HA[A/California/07/2009(H1N1)]-like strain.展开更多
Dear Editor,The avian influenza virus (AIV) H5N7 was first isolated from wild birds in North America in 2001 (Spackman et al.2007), and information on only 25 strains of this virus has been deposited in the Global Ini...Dear Editor,The avian influenza virus (AIV) H5N7 was first isolated from wild birds in North America in 2001 (Spackman et al.2007), and information on only 25 strains of this virus has been deposited in the Global Initiative on Sharing All Influenza Data (GISAID-http://platform.gisaid.org/epi3/frontend#493de3) database until October 30, 2018. Twenty viruses were identified in the United States from 2001 to2017.展开更多
基金Capital Health Development and Research of Special(2022‐1G‐3014)Beijing Science and Technology Planning Project of Beijing Science and Technology Commission(Z211100002521015 and Z211100002521019)+1 种基金National Key R&D Program of China(2021ZD0114100,2021ZD0114103)Cooperation Research Project(2020‐jk‐cd‐026).
文摘Viral isolation in cell cultures has been regarded for decades as the“gold standard”for the laboratory diagnosis of influenza viral infections.Not all viral strains could be isolated from clinical samples.This study aimed to quantify the viral load in the samples before isolation to save working time and improve working efficiency.Four hundred samples from patients with influenza-like cases were confirmed pdmH1N1 positive(200 cases)and B Victoria(BV)positive(200 cases)by whole-genome sequencing and analyzed by ddPCR for viral load in samples before isolation,and isolation results were verified by hemagglutination(HA)assay and hemagglutination-inhibition(HI)tests.Probit regression analysis was used to calculate the isolation viral load limit with a 95%probability level by SPSS 19.0 software.The results showed that the isolation limit of viral load was 4.9×10^(4)(95%CI:2.5×10^(4)–9.0×10^(4))copies/mL for pdmH1N1 and 1.9×10^(4)(95%CI:7.8×103–3.6×10^(4))copies/mL for BV.The isolation rate of clinical samples is positively correlated with the viral load in clinical samples,which can be used for viral culture,providing important guidance for daily work.
文摘Objective:To study hemagglutinin genetic evolution of some Middle East(ME) 2009 H1N1 pdm isolates and compared them with prototype vaccine strain[A/California/07/2009(H1N1)],which is used as a vaccine strain in the Northern Hemisphere 2010-2011.Methods:Nucleotide and/ or amino acid sequences of HA gene of fifty-four ME 2009 H1N1 pdm isolates were retrieved from GenBank Database by using Basic BLAST engine.Phylogenetic trees were established for both nucleotide and amino acid sequences using the muscle algorithm of the computer program CLC free workbench 5.6.1 JRE software.Amino acids alignment was also done to compare sequences HA1 domains of HA genes of ME 2009 H1N1 pdm isolates(n=39) with amino acid sequence of prototype vaccine strain A/California/07/2009(H1N1).Results:Phylogenetic analysis of amino acids and nucleotides of the HA gene of the ME 2009 H1N1 pdm isolates confirmed their evolutionary position in cluster with prototype vaccine strain(A/California/07/2009(H1N1)) which is used as vaccine strain in the Northern Hemisphere 2010-2011.Antigenically,the ME 2009 H1N1 pdm isolates were homogeneous and closely related to prototype vaccine.Only a few amino acid substitutions in the HA among the ME 2009 H1N1 pdm isolates were analyzed.Conclusions: The current influenza vaccine is expected to provide a good protection against ME 2009 H1N1 pdm because it contains strains with H1HA[A/California/07/2009(H1N1)]-like strain.
基金funded by the National Science and Technology Major Project (2018ZX10101004)the Open Research Fund Program of Wuhan National Bio-Safety Level 4 Lab of CAS (NBL2017003)+1 种基金China Ministry of Science and Technology (MOST) Key Research and Development Program (2016YFC1200800)the Shenzhen Science and Technology Research and Development Project (JCYJ20151029151932602)
文摘Dear Editor,The avian influenza virus (AIV) H5N7 was first isolated from wild birds in North America in 2001 (Spackman et al.2007), and information on only 25 strains of this virus has been deposited in the Global Initiative on Sharing All Influenza Data (GISAID-http://platform.gisaid.org/epi3/frontend#493de3) database until October 30, 2018. Twenty viruses were identified in the United States from 2001 to2017.
