Avian influenza viruses(AIVs)represent an ongoing threat to global health due to their capacity for genetic evolution,zoonotic transmission,and pandemic emergence.This review highlights recent progress in understandin...Avian influenza viruses(AIVs)represent an ongoing threat to global health due to their capacity for genetic evolution,zoonotic transmission,and pandemic emergence.This review highlights recent progress in understanding the molecular mechanisms underlying AIV infection,including viral immune evasion strategies and host-virus interactions.It discusses recent outbreaks involving reassortant strains such as H5N1 and H9N2,and examines their public health co-nsequences.Advancements in antiviral therapy,including resistance patterns,and the development of next-generation vaccines such as messenger RNA and universal influenza vaccines are reviewed.The integration of genomic surveillance,artificial intelligence-driven prediction,and One Health approaches is emphasized as essential for pandemic preparedness.This comprehensive overview aims to provide researchers and policymakers with actionable insights for controlling the evolving threat of avian influenza.展开更多
The H4 subtype of avian influenza virus(AIV)is prevalent worldwide,but only receives little attention due to its low pathogenicity in poultry.Consequently,it remains largely unclear whether H4 AIVs pose a potential th...The H4 subtype of avian influenza virus(AIV)is prevalent worldwide,but only receives little attention due to its low pathogenicity in poultry.Consequently,it remains largely unclear whether H4 AIVs pose a potential threat to the poultry industry and public health.During the period from 2011 to 2022,we conducted an active surveillance programm.A total of 154,762 swab samples were collected across various provinces,and 427 H4 viruses were detected,resulting in a positivity rate of 0.28%.All H4 viruses were isolated from poultry,primarily from ducks in live poultry markets.We further investigated the genetic evolutionary characteristics and pathogenicity of 20 H4Nx viruses isolated in our program.Phylogenetic analysis revealed that the 20 H4Nx viruses belonged to the Eurasian lineage and exhibited significant genetic diversity,with 19 distinct genotypes identified.Molecular characterization indicated that these viruses were low-pathogenicity AIVs with limited binding affinity to human receptors,yet they contained mutations associated with enhanced viral replication and pathogenicity in mammals.Pathogenicity tests conducted in ducks demonstrated that H4 viruses were weakly pathogenic,exhibiting limited replication and transmission capabilities.However,some viruses were able to replicate effectively in mice and induce weight loss.For instance,DK/AH/AG61/11(H4N6)can replicate efficiently in MDCK cells,indicating a potential threat to mammals.These findings underscore the importance of ongoing surveillance of H4 AIVs to better understand their evolution and transmission dynamics and to prevent potential public health risks.展开更多
On January 30,2024,China announced the first human case of H10N5 influenza infection.Prior to this,human cases of H10N7 and H10N8 had been reported.It is now appropriate to re-examine the evolution and future epidemio...On January 30,2024,China announced the first human case of H10N5 influenza infection.Prior to this,human cases of H10N7 and H10N8 had been reported.It is now appropriate to re-examine the evolution and future epidemiological trends of the H10 and N5 subtypes of avian influenza viruses(AIVs).In this study,we analyzed the reassortment characteristics of the first human-derived H10N5 AIV(A/Zhejiang/ZJU01/2023),as well as the evolutionary dynamics of the wild bird-derived H10 and N5 subtypes of AIVs over the past decade.Our findings indicate that the human-derived H10N5 AIV exhibited low pathogenicity.A/bean_goose/Korea/KNU-10/2022(H10N7)and A/mallard/Novosibirsk_region/962k/2018(H12N5)were identified as the potential reassortment parents.The virus has existed since 2022 and several isolations have been reported in Bangladesh.Phylogenetic analysis showed that H10Ny and HxN5 AIVs in China are clustered differently based on the East Asian-Australian(eastern)and Central Asian-Indian(western)migratory flyways.The H10Ny and HxN5 AIV reassortant strains may cause human infections through accidental spillover.It is possible that another center of AIV evolution,mutation,and reassortment may be developing along the migratory flyways in northeastern Asia,distinct from Europe,the Americas,and China's Yangtze River Delta and Pearl River Delta,which should be closely monitored to ensure the safety of the public.展开更多
Five monoclonal antibodies（Mabs） to nuclear protein of avain influenza virus（AIV） were developed by syncretizing SP 2/0 and the spleen cells from BALB of mice immuized with H9 subtype AIV. Specificity of these Mab...Five monoclonal antibodies（Mabs） to nuclear protein of avain influenza virus（AIV） were developed by syncretizing SP 2/0 and the spleen cells from BALB of mice immuized with H9 subtype AIV. Specificity of these Mabs were identified by immunofluorescent assay（IFA） and enzyme linked immunosorbent assay （ELISA）. These five Mabs which were named as AIV-NP-2C3, AIV-NP-6A5, AIV-NP-3 H9, AIV-NP-7B4, AIV-NP-2H4 could react with all viruses of AIV-H9 strains in tests. The result of Western blotting showed that only the 60 ku protein antigen of AIV-H9 could be recognized by the Mabs but never recognized by New castle disease virus, REV and infectious bursa disease virus. The result of preliminary application showed that avian influenza viruses could be deetected bv Mabs in IFA and ELISA. All these Mabs will probably play important roles in preventing and monitoring avian influenza viruses.展开更多
[Objective] The research aimed to design primers that are suitable for detecting H5 and H7 subtypes of avian influenza virus （AIV） ; [Method] DNAStar was used to analyze the homology of the sequences of H5 and H7 su...[Objective] The research aimed to design primers that are suitable for detecting H5 and H7 subtypes of avian influenza virus （AIV） ; [Method] DNAStar was used to analyze the homology of the sequences of H5 and H7 subtypes of AIV accessed in GenBank, and design primers（ by Primer Premier 5.0） on high homologous region of these sequences, and then amplified by RT-PCR. [Result] The multiplex RT-PCR amplification, agarose gel electrophoresis and sequencing results showed that the self-designed primers are successful for detecting AIV. [Conclusion] It is feasible to rapidly diagnose AIV through this method.展开更多
[Objective] The study aimed to investigate the genetic variation characters of entire sequences between two H9N2 subtype avian influenza virus strains and other reference strains.[Method] The entire sequences of 8 gen...[Objective] The study aimed to investigate the genetic variation characters of entire sequences between two H9N2 subtype avian influenza virus strains and other reference strains.[Method] The entire sequences of 8 genes were obtained by using RT-PCR,and these sequences were analyzed with that of six H9N2 subtype avian influenza isolates in homology comparison and genetic evolution relation.[Result] The results showed that the nucleotide sequence of entire gene of the strain shared 91.1%-95.4% homology with other seven reference strains,and PG08 shared the highest homology 91.3% with C/BJ/1/94;ZD06 shared the highest homology 92.3% with D/HK/Y280/97.HA cleavage sites of two H9N2 subtype avian influenza virus isolated strains were PARSSR/GLF,typical of mildly pathogenic avian influenza virus.[Conclusion] Phylogenetic tree for entire gene of eight strains showed that the genetic relationship was the closest between ZD06 and C/Pak/2/99 strains,which belonged to the Eurasian lineage;PG08 shared the highest homology 91.3% with ZD06,it may be the product of gene rearrangements of other sub-lines.展开更多
Wild birds of the orders Anseriformes and Charadriiformes represent a natural reservoir of low pathogenic avian influenza(LPAI) viruses(family Orthomyxoviridae).Wild geese(order Anseriformes)relating to waterfowls und...Wild birds of the orders Anseriformes and Charadriiformes represent a natural reservoir of low pathogenic avian influenza(LPAI) viruses(family Orthomyxoviridae).Wild geese(order Anseriformes)relating to waterfowls undertake extensive migration flights reaching thousands of kilometers.Isolation of the avian influenza virus(AIV) from wild geese is quite low or absent.The aims of this study are to monitor the AIV in different wild goose species,nesting on Russian territory and the Tibet Plateau and to analyze the derived data for the purpose of determining the role of these wild bird species in spreading pathogens.In our study 3245 samples from nine wild goose species in nine regions of Russia and on the territory of the Tibet Plateau(the Xizang Autonomous Region) were tested and no AIV were detected.Our study shows the non-essential role of wild geese in the spread of the AIV over long distances and reaches theconclusion that geese are probably not natural reservoirs for the primary viruses.However,further inquiry of AIV in wild goose populations is required.Studies of wild geese and AIV ecology will allow us to obtainmore information about pathogen-host relationships and to make arrangements for the maintenance ofwild goose populations.展开更多
[Objective] The aim is to develop the piezoelectric immunosensor to detect H9-subtype avian influenza virus（AIV）.[Method] The immunosensor chip was constructed by self-assembling mercaptopmpionic acid（MPA） to be m...[Objective] The aim is to develop the piezoelectric immunosensor to detect H9-subtype avian influenza virus（AIV）.[Method] The immunosensor chip was constructed by self-assembling mercaptopmpionic acid（MPA） to be monolayer on the silver-coated electrode of quartz crystal and coupling the monoclonal antibody to H9 subtype AIV with N-ethy-N＇-（3-dimethyl aminopropyl）carbodiimide hydrochloride（EDC） and N-hydroxysuccinimide（NHS）.The immunosensor to detect H9 subtype AIV was established.[Result] The results showed that the immunosensor displayed better specificity to H9 AIV and had no response to H5AIV and NDV when it was used for detection.The sensitivity test indicated the detection sensitivity for the H9 subtype AIV could reach 20-100 EID50.[Conclusion] The research provided a foundation for further research on the immunosensor for detecting AIV and it could be a new approach to detect other related viruses.展开更多
This study investigated the humoral immunization of Astragalus polysaccharide （APS） against HgN2 avian influenza virus （H9N2 AIV） infection in chickens. The effects of APS treatment on H9N2 infection was evaluated...This study investigated the humoral immunization of Astragalus polysaccharide （APS） against HgN2 avian influenza virus （H9N2 AIV） infection in chickens. The effects of APS treatment on H9N2 infection was evaluated by an Mqq- [3（4, 5-dimethylthiazol-2-yl）-2, 3-diphenyl tetrazolium bromide] assay and analysis of MFIC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to H9N2 AIV wet enhanced in the first week after APS treatment. The results indicated that APS treatment reduces H9N2 AIV replication and promotes early humoral immune responses in young chickens.This study investigated the humoral immunization of Astragalus polysaccharide （APS） against HgN2 avian influenza virus （H9N2 AIV） infection in chickens. The effects of APS treatment on HgN2 infection was evaluated by an M]q- [3（4, 5-dimethylthiazol-2-yl）-2, 3-diphenyl tetrazolium bromide] assay and analysis of MHC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to PIgN2 AIV were enhanced in the first week after APS treatment. The results indicated that APS treatment reduces HgN2 AIV replication and promotes early humoral immune responses in young chickens.展开更多
Natural killer （NK） cell is a key component of innate immunity and plays an important role in host defense against virus infection by directly destroying infected cells. Influenza is a respiratory disease transmitte...Natural killer （NK） cell is a key component of innate immunity and plays an important role in host defense against virus infection by directly destroying infected cells. Influenza is a respiratory disease transmitted in the early phase of virus infection. Evasion of host innate immunity including NK cells is critical for the virus to expand and establish a successful acute infection. Previously, we showed that human influenza HIN1 virus infects NK cells and induces cell apoptosis, as well as inhibits NK cell activity. In this study, we further demonstrated that avian influenza virus also directly targeted NK cells as an immunoevasion strategy. The avian virus infected human NK cells and induced cell apoptosis. In addition, avian influenza virion and HA protein inhibited NK cell cytotoxicity. This novel strategy has obvious advantages for avian influenza virus, allowing the virus sufficient time to expand and subsequent spread before the onset of the specific immune response. Our findings provide an important clue for the immunopathogenesis of avian influenza, and also suggest that direct targeting NK cells may be a common strategy used by both human and avian influenza viruses to evade NK cell immunity.展开更多
The recent concurrent emergence of H5N1,H5N6,and H5N8 avian influenza viruses(AIVs)has led to significant avian mortality globally.Since 2020,frequent human-animal interactions have been documented.To gain insight int...The recent concurrent emergence of H5N1,H5N6,and H5N8 avian influenza viruses(AIVs)has led to significant avian mortality globally.Since 2020,frequent human-animal interactions have been documented.To gain insight into the novel H5 subtype AIVs(i.e.,H5N1,H5N6 and H5N8),we collected 6102 samples from various regions of China between January 2021 and September 2022,and identified 41 H5Nx strains.Comparative analyses on the evolution and biological properties of these isolates were conducted.Phylogenetic analysis revealed that the 41 H5Nx strains belonged to clade 2.3.4.4b,with 13 related to H5N1,19 to H5N6,and 9 to H5N8.Analysis based on global 2.3.4.4b viruses showed that all the viruses described in this study were likely originated from H5N8,exhibiting a heterogeneous evolutionary history between H5N1 and H5N6 during 2015–2022 worldwide.H5N1 showed a higher rate of evolution in 2021–2022 and more sites under positive selection pressure in 2015–2022.The antigenic profiles of the novel H5N1 and H5N6 exhibited notable variations.Further hemagglutination inhibition assay suggested that some A(H5N1)viruses may be antigenically distinct from the circulating H5N6 and H5N8 strains.Mammalian challenge assays demonstrated that the H5N8 virus(21GD001_H5N8)displayed the highest pathogenicity in mice,followed by the H5N1 virus(B1557_H5N1)and then the H5N6 virus(220086_H5N6),suggesting a heterogeneous virulence profile of H5 AIVs in the mammalian hosts.Based on the above results,we speculate that A(H5N1)viruses have a higher risk of emergence in the future.Collectively,these findings unveil a new landscape of different evolutionary history and biological characteristics of novel H5 AIVs in clade 2.3.4.4b,contributing to a better understanding of designing more effective strategies for the prevention and control of novel H5 AIVs.展开更多
A Objective3 This study was to understand the genetic variation characters of the H9N2 subtype avian influenza virus isolate （A/Chicken/ Hebei/WD/98, abbreviated as WD98） by comparing with other reference strains. I...A Objective3 This study was to understand the genetic variation characters of the H9N2 subtype avian influenza virus isolate （A/Chicken/ Hebei/WD/98, abbreviated as WD98） by comparing with other reference strains. I-Method3 Eight complete genes were amplified by RT-PCR and sequenced. The homology and genetic evolution relationship were analyzed between these sequences and that of the seven reference strains. [Result] The whole genomic sequence of WD98 strain was 91.1% -95.8% homologous to that of seven reference strains tested. This isolate shared the highest homology （95.8%） to D/HK/Y280/97 and the lowest homology （91.1% ） to C/Pak/2/99. The HA cleavage site of the WD98 strain was R-S-S-R G, and the 226th amino acid at receptor-binding site was Gin. [ Condmion] WD98 strain belongs to mildly pathogenic avian in- fluenza virus and may not infect human. The genetic relationship is the closest between A/Chicken/Hebei/wD/98 and A/duck/HongKong/Y280/ 97, both of which belong to the sub-line of A/Chicken/Beijing/1/94 in Eurasian line. And A/Chicken/Hebei/WD/98 and A/Chicken/Beijing/1/94 are genetically distant within the same sub-line.展开更多
We have developed a rapid microarray-based assay for the reliable detection of H5, H7 and H9 subtypes of avian influenza virus （AIV）. The strains used in the experiment were A/Goose/Guangdong/1/96 （H5N1）, A/Africa...We have developed a rapid microarray-based assay for the reliable detection of H5, H7 and H9 subtypes of avian influenza virus （AIV）. The strains used in the experiment were A/Goose/Guangdong/1/96 （H5N1）, A/African starling/983/79 （H7N1） and A/Turkey/Wiscosin/1/66 （H9N2）. The capture DNAs clones which encoding approximate 500-bp avian influenza virus gene fragments obtained by RT-PCR, were spotted on a slide-bound microarray. Cy5-labeled fluorescent cDNAs, which generated from virus RNA during reverse transcription were hybridized to these capture DNAs. These capture DNAs contained multiple fragments of the hemagglutinin and matrix protein genes of AIV respectively, for subtyping and typing AIV. The arrays were scanned to determine the probe binding sites. The hybridization pattern agreed approximately with the known grid location of each target. The results show that DNA microarray technology provides a useful diagnostic method for AIV.展开更多
The contamination status of H5 avian influenza viruses and distribution of subtypes of H5N1 and H5N6 in poultry-related environment of Hubei areas were investigated.Urban and rural live poultry markets,poultry farms,i...The contamination status of H5 avian influenza viruses and distribution of subtypes of H5N1 and H5N6 in poultry-related environment of Hubei areas were investigated.Urban and rural live poultry markets,poultry farms,intensive livestock farms and other monitoring types of 103 counties in 17 cities were selected in Hubei.Wiping samples from cage surface,wiping samples from chopping board,fecal specimens and other environmental samples were collected and tested by real-time RT-PCR using primers and probes of influenza A,avian influenza of H5,N1 and N6 from December 2017 to March 2018.The avian influenza virus positive rate was compared among different monitoring sites,samples,time and regions.Totally,7132 environmental samples were collected in 1634 monitoring points with a positive rate of 2.24%.The positive rate of H5 avian influenza virus was the highest in urban and rural live poultry markets(3.44%,x^2=61.329,P<0.05)in 6 monitoring sites and wiping samples from chopping board(5.46%,x^2=67.072,P<0.05)in 6 sample types.H5N6 avian influenza viruses were detected more in eastern than western Hubei,and H5N6 avian influenza viruses were detected only in Xiangyang city of western Hubei.There were important high-risk places of human infection with H5 avian influenza virus in urban and rural live poultry markets and the poultry slaughtering plants.H5N6 has been the predominant subtype of H5 avian influenza viruses in the eastern and western Hubei and H5N6 avian influenza viruses were still present in a few areas of Hubei.Outbreaks of human H5N1 and H5N6 avian influenza remain at risk in Hubei province.展开更多
The DNA vaccine pCIHA5 encoding hemagglutinin can protect SPF chicken against lethal H5N1 avian influenza virus challenge. The more characters about its protection efficacity were studied. The protective rates in 10...The DNA vaccine pCIHA5 encoding hemagglutinin can protect SPF chicken against lethal H5N1 avian influenza virus challenge. The more characters about its protection efficacity were studied. The protective rates in 10, 40, 70, 100 and 150 μg groups immunized with pCIHA5 were 12.5 (1/8), 58.3 (7/12), 72.7 (8/11), 50.0 (6/12) and 66.7% (8/12), respectively. The protective rates in 5, 20, 35 and 50 μg groups were 145.5 (5/11), 58.3 (7/12), 58.3 (7/12) and 91.7% (11/12), respectively. The 70, 100 and 5 μg groups have virus shedding of 1/8, 2/6 and 1/5. Though the inactived oil-emulsion vaccine has high HI antibody titers and 100% protective rate, the AGP antibody could be detected after vaccination. Results show that the pCIHA5 is fit to boost by intramuscular injection. This would be useful to the study on gene engineering vaccine of avian influenza virus.展开更多
HA Gene of H9N2. sub-type avian influenza virus from three strains in different times was amplified, purified and then sequenced. The results of its sequence analysis showed that the whole length of the amplified HA G...HA Gene of H9N2. sub-type avian influenza virus from three strains in different times was amplified, purified and then sequenced. The results of its sequence analysis showed that the whole length of the amplified HA Gene was 1 683 bp, encoding 560 amino acids. The amino acid sequence of three virulent strains at cleavage site was R-S-S-R, which was low-pathogenicity strain. According to the amino acid sequence of the isolated strains, there were 7 potential glycosylation sites, and the receptor-binding site was the specific sequence of the avian-derived influenza virus. Amino acids on the left edge of receptor-binding site were all NGQQG, while amino acids on the right edge of receptor-binding site were GTSKA. From the comparative sequence analysis of HA Gene from some referenced strains, the results indicated that nucleotide and amino acid homology between isolated strains and referenced strains was higher. Evolutionary tree analysis showed that three strains were all Eurasian species, and there was a close relationship with the representative strains of A / duck / Hong Kong/Y280/97.展开更多
Objective In March 2012, an H7N7 subtype avian influenza virus （AIV） named A/wild goose/Dongting/PC0360/2022 （H7N7） （DT/PC0360） was recovered from a wild goose in East Dongting Lake. We performed whole-genome se...Objective In March 2012, an H7N7 subtype avian influenza virus （AIV） named A/wild goose/Dongting/PC0360/2022 （H7N7） （DT/PC0360） was recovered from a wild goose in East Dongting Lake. We performed whole-genome sequencing of the isolate, and analyzed the phylogenetic and molecular characterization. Methods RNA was extracted from environment samples （including fecal samples from wild bird or domestic ducks, and water samples） for detecting the presence of Influenza A Virus targeting Matrix gene, using realtime RT-PCR assay. The positive samples were performed virus isolation with embryonated eggs. The subtype of the isolates were identified by RT-PCR assay with the HI-HI6 and N1-N9 primer set. The whole-genome sequencing of isolates were performed. Phylogenetic and molecular characterizations of the eight genes of the isolates were analyzed. Results Our results suggested that all the eight gene segments of DT/PC0360 belonged to the Eurasian gene pool, and the HA gene were belonged to distinct sublineage with H7N9 AIV which caused outbreaks in China's Mainland in 2013. The hemagglutinin cleavage site of HA of DT/PC0360 showed characterization of low pathogenic avian influenza virus. Conclusion Strengthening the surveillance of AlVs of wild waterfowl and poultry in this region is vita for our knowledge of the ecology and mechanism of transmission to prevent an influenza pandemic.展开更多
H9 s ubtype avian influenza virus（AIV） and infectious bronchitis virus（IBV） are major pathogens circulating in poultry and have resulted in great economic losses due to respiratory disease and reduced egg producti...H9 s ubtype avian influenza virus（AIV） and infectious bronchitis virus（IBV） are major pathogens circulating in poultry and have resulted in great economic losses due to respiratory disease and reduced egg production. As similar symptoms are elicited by the two pathogens, it is difficult for their differential diagnosis. So far, no reverse transcription-polymerase chain reaction（RT-PCR） assay has been found to differentiate between H9 AIV and IBV in one reaction. Therefore, developing a sensitive and specific method is of importance to simultaneously detect and differentiate H9 AIV and IBV. In this study, a duplex RT-PCR（d RT-PCR） was established. Two primer sets target the hemagglutinin（HA） gene of H9 AIV and the nucleocapsid（N） gene of IBV, respectively. Spec ific PCR products were obtained from all tested H9 AIVs and IBVs belonging to the major clades circulating in China, but not from AIVs of other subtypes or other infectious avian viruses. The sensitivity of the d RT-PCR assay corresponding to H9 AIV, IBV and mixture of H9 AIV and IBV were at a concentration of 1×10^1, 1.5×10^1 and 1.5×10^1 50% egg infective doses（EID_（50）） m L^–1, respectively. The concordance rates between the d RT-PCR and virus isolation were 99.1 and 98.2%, respectively, for detection of samples from H9N2 AIV or IBV infected chickens, while the concordance rate was 99.1% for detection of samples from H9N2 AIV and IBV co-infected chickens. Thus, the d RT-PCR assay reported herein is specific and sensitive, and suitable for the differential diagnosis of clinical infections and survei llance of H9 AIVs and IBVs.展开更多
To investigate serologically the presence of avian influenza virus (AIV) in backyard chickens from Mandlhakazi district, Southern Mozambique.MethodsA total of 439 sera samples from unvaccinated and apparently healthy ...To investigate serologically the presence of avian influenza virus (AIV) in backyard chickens from Mandlhakazi district, Southern Mozambique.MethodsA total of 439 sera samples from unvaccinated and apparently healthy backyard chickens from 4 villages (Chidenguele, Macuacua, Chizavane, and Nwadjahane) were tested for the presence of AIV antibodies through commercial enzyme-linked immunoabsorbent assay (ELISA) kit used according to manufacturer instructions.ResultsAnti-AIV antibodies were detected in all villages surveyed. The overall seroprevalence obtained was 32.6% (95% CI 28.2%-37.0%). The highest prevalence of 51.3% (95% CI 42.3%-60.2%) was recorded in Macuacua village, while the lowest prevalence of 13.0% (95% CI 6.2%-19.9%) was found in Chizavane village. The results of logistic regression analyses suggested that chicken being located in Chizavane and Macuacua villages were more unlikely for getting the virus exposure (P < 0.05).ConclusionsOur findings suggested that AIV is widespread within backyard chickens in the studied villages. Further research is needed to identify the circulating virus genotypes and determine the potential role of backyard chickens in the zoonotic transmission of AIV in Mozambique.展开更多
The H9N2 subtype of avian influenza virus(AIV)is widely prevalent in poultry and wild birds globally,and has become the predominant subtype circulating in poultry in China.The H9N2 AIV can directly or indirectly(by se...The H9N2 subtype of avian influenza virus(AIV)is widely prevalent in poultry and wild birds globally,and has become the predominant subtype circulating in poultry in China.The H9N2 AIV can directly or indirectly(by serving as a"donor virus")infect humans,posing a significant threat to public health.Currently,there is a lack of in-depth research on the prevalence of H9N2 viruses in Shanxi Province,central China.In this study,we isolated 14 H9N2 AIVs from October 2020 to April 2022 in Shanxi Province,and genetic analysis revealed that these viruses belonged to 7 different genotypes.Our study on animals revealed that the H9N2 strains we identified displayed high transmission efficiency among chicken populations,and exhibited diverse replication abilities within these birds.These viruses could replicate efficiently in the lungs of mice,with one strain also demonstrating the capacity to reproduce in organs like the brain and kidneys.At the cellular level,the replication ability of different H9N2 strains was evaluated using plaque formation assays and multi-step growth curve assays,revealing significant differences in the replication and proliferation efficiency of the various H9N2 viruses at the cellular level.The antigenicity analysis suggested that these isolates could be classified into 2 separate antigenic clusters.Our research provides crucial data to help understand the prevalence and biological characteristics of H9N2 AIVs in central China.It also highlights the necessity of enhancing the surveillance of H9N2 AIVs.展开更多
文摘Avian influenza viruses(AIVs)represent an ongoing threat to global health due to their capacity for genetic evolution,zoonotic transmission,and pandemic emergence.This review highlights recent progress in understanding the molecular mechanisms underlying AIV infection,including viral immune evasion strategies and host-virus interactions.It discusses recent outbreaks involving reassortant strains such as H5N1 and H9N2,and examines their public health co-nsequences.Advancements in antiviral therapy,including resistance patterns,and the development of next-generation vaccines such as messenger RNA and universal influenza vaccines are reviewed.The integration of genomic surveillance,artificial intelligence-driven prediction,and One Health approaches is emphasized as essential for pandemic preparedness.This comprehensive overview aims to provide researchers and policymakers with actionable insights for controlling the evolving threat of avian influenza.
基金funded by the National Key Research and Development Program of China(Grant No.2021YFD1800201).
文摘The H4 subtype of avian influenza virus(AIV)is prevalent worldwide,but only receives little attention due to its low pathogenicity in poultry.Consequently,it remains largely unclear whether H4 AIVs pose a potential threat to the poultry industry and public health.During the period from 2011 to 2022,we conducted an active surveillance programm.A total of 154,762 swab samples were collected across various provinces,and 427 H4 viruses were detected,resulting in a positivity rate of 0.28%.All H4 viruses were isolated from poultry,primarily from ducks in live poultry markets.We further investigated the genetic evolutionary characteristics and pathogenicity of 20 H4Nx viruses isolated in our program.Phylogenetic analysis revealed that the 20 H4Nx viruses belonged to the Eurasian lineage and exhibited significant genetic diversity,with 19 distinct genotypes identified.Molecular characterization indicated that these viruses were low-pathogenicity AIVs with limited binding affinity to human receptors,yet they contained mutations associated with enhanced viral replication and pathogenicity in mammals.Pathogenicity tests conducted in ducks demonstrated that H4 viruses were weakly pathogenic,exhibiting limited replication and transmission capabilities.However,some viruses were able to replicate effectively in mice and induce weight loss.For instance,DK/AH/AG61/11(H4N6)can replicate efficiently in MDCK cells,indicating a potential threat to mammals.These findings underscore the importance of ongoing surveillance of H4 AIVs to better understand their evolution and transmission dynamics and to prevent potential public health risks.
基金funded by the National Natural Science Foundation of China(81872673)the Shanghai New Three-year Action Plan for Public Health(GWVI-11.1-03).
文摘On January 30,2024,China announced the first human case of H10N5 influenza infection.Prior to this,human cases of H10N7 and H10N8 had been reported.It is now appropriate to re-examine the evolution and future epidemiological trends of the H10 and N5 subtypes of avian influenza viruses(AIVs).In this study,we analyzed the reassortment characteristics of the first human-derived H10N5 AIV(A/Zhejiang/ZJU01/2023),as well as the evolutionary dynamics of the wild bird-derived H10 and N5 subtypes of AIVs over the past decade.Our findings indicate that the human-derived H10N5 AIV exhibited low pathogenicity.A/bean_goose/Korea/KNU-10/2022(H10N7)and A/mallard/Novosibirsk_region/962k/2018(H12N5)were identified as the potential reassortment parents.The virus has existed since 2022 and several isolations have been reported in Bangladesh.Phylogenetic analysis showed that H10Ny and HxN5 AIVs in China are clustered differently based on the East Asian-Australian(eastern)and Central Asian-Indian(western)migratory flyways.The H10Ny and HxN5 AIV reassortant strains may cause human infections through accidental spillover.It is possible that another center of AIV evolution,mutation,and reassortment may be developing along the migratory flyways in northeastern Asia,distinct from Europe,the Americas,and China's Yangtze River Delta and Pearl River Delta,which should be closely monitored to ensure the safety of the public.
基金Supported by the National Key Technologies Research and Develop-ment Program of China during the 10th Five-Year Plan Period(2004BA519A05)Technologies Research and Development Program of China during the 10th Five-Year Plan Period in Jiangsu Province(BE2002346).~~
文摘Five monoclonal antibodies（Mabs） to nuclear protein of avain influenza virus（AIV） were developed by syncretizing SP 2/0 and the spleen cells from BALB of mice immuized with H9 subtype AIV. Specificity of these Mabs were identified by immunofluorescent assay（IFA） and enzyme linked immunosorbent assay （ELISA）. These five Mabs which were named as AIV-NP-2C3, AIV-NP-6A5, AIV-NP-3 H9, AIV-NP-7B4, AIV-NP-2H4 could react with all viruses of AIV-H9 strains in tests. The result of Western blotting showed that only the 60 ku protein antigen of AIV-H9 could be recognized by the Mabs but never recognized by New castle disease virus, REV and infectious bursa disease virus. The result of preliminary application showed that avian influenza viruses could be deetected bv Mabs in IFA and ELISA. All these Mabs will probably play important roles in preventing and monitoring avian influenza viruses.
基金Supported by Important Project of Jinlin Provincial Science and Technology Department(20065020)~~
文摘[Objective] The research aimed to design primers that are suitable for detecting H5 and H7 subtypes of avian influenza virus （AIV） ; [Method] DNAStar was used to analyze the homology of the sequences of H5 and H7 subtypes of AIV accessed in GenBank, and design primers（ by Primer Premier 5.0） on high homologous region of these sequences, and then amplified by RT-PCR. [Result] The multiplex RT-PCR amplification, agarose gel electrophoresis and sequencing results showed that the self-designed primers are successful for detecting AIV. [Conclusion] It is feasible to rapidly diagnose AIV through this method.
基金Supported by a Sub-project of 973 Program of China(2005CB523001)~~
文摘[Objective] The study aimed to investigate the genetic variation characters of entire sequences between two H9N2 subtype avian influenza virus strains and other reference strains.[Method] The entire sequences of 8 genes were obtained by using RT-PCR,and these sequences were analyzed with that of six H9N2 subtype avian influenza isolates in homology comparison and genetic evolution relation.[Result] The results showed that the nucleotide sequence of entire gene of the strain shared 91.1%-95.4% homology with other seven reference strains,and PG08 shared the highest homology 91.3% with C/BJ/1/94;ZD06 shared the highest homology 92.3% with D/HK/Y280/97.HA cleavage sites of two H9N2 subtype avian influenza virus isolated strains were PARSSR/GLF,typical of mildly pathogenic avian influenza virus.[Conclusion] Phylogenetic tree for entire gene of eight strains showed that the genetic relationship was the closest between ZD06 and C/Pak/2/99 strains,which belonged to the Eurasian lineage;PG08 shared the highest homology 91.3% with ZD06,it may be the product of gene rearrangements of other sub-lines.
基金supported by the Russian Government(Government Project#11.519.11.2014)the Bio Industry Initiative(BII) USA (ISTC#3436)
文摘Wild birds of the orders Anseriformes and Charadriiformes represent a natural reservoir of low pathogenic avian influenza(LPAI) viruses(family Orthomyxoviridae).Wild geese(order Anseriformes)relating to waterfowls undertake extensive migration flights reaching thousands of kilometers.Isolation of the avian influenza virus(AIV) from wild geese is quite low or absent.The aims of this study are to monitor the AIV in different wild goose species,nesting on Russian territory and the Tibet Plateau and to analyze the derived data for the purpose of determining the role of these wild bird species in spreading pathogens.In our study 3245 samples from nine wild goose species in nine regions of Russia and on the territory of the Tibet Plateau(the Xizang Autonomous Region) were tested and no AIV were detected.Our study shows the non-essential role of wild geese in the spread of the AIV over long distances and reaches theconclusion that geese are probably not natural reservoirs for the primary viruses.However,further inquiry of AIV in wild goose populations is required.Studies of wild geese and AIV ecology will allow us to obtainmore information about pathogen-host relationships and to make arrangements for the maintenance ofwild goose populations.
基金Supported by the Supporting Program of the"Eleventh Five-year Plan"for Sci&Tech Research of China(2006BAK20A29)Strategical Project for Science and Technology of Guangdong Province(2004A2090102)~~
文摘[Objective] The aim is to develop the piezoelectric immunosensor to detect H9-subtype avian influenza virus（AIV）.[Method] The immunosensor chip was constructed by self-assembling mercaptopmpionic acid（MPA） to be monolayer on the silver-coated electrode of quartz crystal and coupling the monoclonal antibody to H9 subtype AIV with N-ethy-N＇-（3-dimethyl aminopropyl）carbodiimide hydrochloride（EDC） and N-hydroxysuccinimide（NHS）.The immunosensor to detect H9 subtype AIV was established.[Result] The results showed that the immunosensor displayed better specificity to H9 AIV and had no response to H5AIV and NDV when it was used for detection.The sensitivity test indicated the detection sensitivity for the H9 subtype AIV could reach 20-100 EID50.[Conclusion] The research provided a foundation for further research on the immunosensor for detecting AIV and it could be a new approach to detect other related viruses.
基金supported by funds provided by South China Agricultural University and Guangzhou work team project(No 2011A020102009)
文摘This study investigated the humoral immunization of Astragalus polysaccharide （APS） against HgN2 avian influenza virus （H9N2 AIV） infection in chickens. The effects of APS treatment on H9N2 infection was evaluated by an Mqq- [3（4, 5-dimethylthiazol-2-yl）-2, 3-diphenyl tetrazolium bromide] assay and analysis of MFIC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to H9N2 AIV wet enhanced in the first week after APS treatment. The results indicated that APS treatment reduces H9N2 AIV replication and promotes early humoral immune responses in young chickens.This study investigated the humoral immunization of Astragalus polysaccharide （APS） against HgN2 avian influenza virus （H9N2 AIV） infection in chickens. The effects of APS treatment on HgN2 infection was evaluated by an M]q- [3（4, 5-dimethylthiazol-2-yl）-2, 3-diphenyl tetrazolium bromide] assay and analysis of MHC and cytokine mRNA expression. The effect on lymphocyte and serum antibody titers in vivo was also investigated. IL-4, IL-6, IL-10, LITAF, IL-12 and antibody titers to PIgN2 AIV were enhanced in the first week after APS treatment. The results indicated that APS treatment reduces HgN2 AIV replication and promotes early humoral immune responses in young chickens.
基金supported in part by Theme-based Research Scheme (Project No. T11-705/14N)the General Research Fund (HKU 780113M,17121214 and 17115015)+1 种基金Research Grants Council of the Hong Kong SARShenzhen Science and Technology Innovation Committee (JCYJ20140411175241066),China
文摘Natural killer （NK） cell is a key component of innate immunity and plays an important role in host defense against virus infection by directly destroying infected cells. Influenza is a respiratory disease transmitted in the early phase of virus infection. Evasion of host innate immunity including NK cells is critical for the virus to expand and establish a successful acute infection. Previously, we showed that human influenza HIN1 virus infects NK cells and induces cell apoptosis, as well as inhibits NK cell activity. In this study, we further demonstrated that avian influenza virus also directly targeted NK cells as an immunoevasion strategy. The avian virus infected human NK cells and induced cell apoptosis. In addition, avian influenza virion and HA protein inhibited NK cell cytotoxicity. This novel strategy has obvious advantages for avian influenza virus, allowing the virus sufficient time to expand and subsequent spread before the onset of the specific immune response. Our findings provide an important clue for the immunopathogenesis of avian influenza, and also suggest that direct targeting NK cells may be a common strategy used by both human and avian influenza viruses to evade NK cell immunity.
基金supported by the Science and Technology Program of Guangdong Province(2022B1111010004,2021B1212030015)China Agriculture Research System of MOF and MARA(CARS-41)China National Animal Disease Surveillance and Epidemiological Survey Program(2021–2025)(No.202111).
文摘The recent concurrent emergence of H5N1,H5N6,and H5N8 avian influenza viruses(AIVs)has led to significant avian mortality globally.Since 2020,frequent human-animal interactions have been documented.To gain insight into the novel H5 subtype AIVs(i.e.,H5N1,H5N6 and H5N8),we collected 6102 samples from various regions of China between January 2021 and September 2022,and identified 41 H5Nx strains.Comparative analyses on the evolution and biological properties of these isolates were conducted.Phylogenetic analysis revealed that the 41 H5Nx strains belonged to clade 2.3.4.4b,with 13 related to H5N1,19 to H5N6,and 9 to H5N8.Analysis based on global 2.3.4.4b viruses showed that all the viruses described in this study were likely originated from H5N8,exhibiting a heterogeneous evolutionary history between H5N1 and H5N6 during 2015–2022 worldwide.H5N1 showed a higher rate of evolution in 2021–2022 and more sites under positive selection pressure in 2015–2022.The antigenic profiles of the novel H5N1 and H5N6 exhibited notable variations.Further hemagglutination inhibition assay suggested that some A(H5N1)viruses may be antigenically distinct from the circulating H5N6 and H5N8 strains.Mammalian challenge assays demonstrated that the H5N8 virus(21GD001_H5N8)displayed the highest pathogenicity in mice,followed by the H5N1 virus(B1557_H5N1)and then the H5N6 virus(220086_H5N6),suggesting a heterogeneous virulence profile of H5 AIVs in the mammalian hosts.Based on the above results,we speculate that A(H5N1)viruses have a higher risk of emergence in the future.Collectively,these findings unveil a new landscape of different evolutionary history and biological characteristics of novel H5 AIVs in clade 2.3.4.4b,contributing to a better understanding of designing more effective strategies for the prevention and control of novel H5 AIVs.
基金supported by subproject of National Program on Key Basic Research Project (973 Program )(2005CB523001)
文摘A Objective3 This study was to understand the genetic variation characters of the H9N2 subtype avian influenza virus isolate （A/Chicken/ Hebei/WD/98, abbreviated as WD98） by comparing with other reference strains. I-Method3 Eight complete genes were amplified by RT-PCR and sequenced. The homology and genetic evolution relationship were analyzed between these sequences and that of the seven reference strains. [Result] The whole genomic sequence of WD98 strain was 91.1% -95.8% homologous to that of seven reference strains tested. This isolate shared the highest homology （95.8%） to D/HK/Y280/97 and the lowest homology （91.1% ） to C/Pak/2/99. The HA cleavage site of the WD98 strain was R-S-S-R G, and the 226th amino acid at receptor-binding site was Gin. [ Condmion] WD98 strain belongs to mildly pathogenic avian in- fluenza virus and may not infect human. The genetic relationship is the closest between A/Chicken/Hebei/wD/98 and A/duck/HongKong/Y280/ 97, both of which belong to the sub-line of A/Chicken/Beijing/1/94 in Eurasian line. And A/Chicken/Hebei/WD/98 and A/Chicken/Beijing/1/94 are genetically distant within the same sub-line.
基金Chinese National S&T“1Oth Five-Year"Plan (2004BA519A23) the National Natural Science Foundation ofChina (30200201 , 30440009).
文摘We have developed a rapid microarray-based assay for the reliable detection of H5, H7 and H9 subtypes of avian influenza virus （AIV）. The strains used in the experiment were A/Goose/Guangdong/1/96 （H5N1）, A/African starling/983/79 （H7N1） and A/Turkey/Wiscosin/1/66 （H9N2）. The capture DNAs clones which encoding approximate 500-bp avian influenza virus gene fragments obtained by RT-PCR, were spotted on a slide-bound microarray. Cy5-labeled fluorescent cDNAs, which generated from virus RNA during reverse transcription were hybridized to these capture DNAs. These capture DNAs contained multiple fragments of the hemagglutinin and matrix protein genes of AIV respectively, for subtyping and typing AIV. The arrays were scanned to determine the probe binding sites. The hybridization pattern agreed approximately with the known grid location of each target. The results show that DNA microarray technology provides a useful diagnostic method for AIV.
基金the Natural Science Foundation of Hubei Province,China(No.2017CFB710).
文摘The contamination status of H5 avian influenza viruses and distribution of subtypes of H5N1 and H5N6 in poultry-related environment of Hubei areas were investigated.Urban and rural live poultry markets,poultry farms,intensive livestock farms and other monitoring types of 103 counties in 17 cities were selected in Hubei.Wiping samples from cage surface,wiping samples from chopping board,fecal specimens and other environmental samples were collected and tested by real-time RT-PCR using primers and probes of influenza A,avian influenza of H5,N1 and N6 from December 2017 to March 2018.The avian influenza virus positive rate was compared among different monitoring sites,samples,time and regions.Totally,7132 environmental samples were collected in 1634 monitoring points with a positive rate of 2.24%.The positive rate of H5 avian influenza virus was the highest in urban and rural live poultry markets(3.44%,x^2=61.329,P<0.05)in 6 monitoring sites and wiping samples from chopping board(5.46%,x^2=67.072,P<0.05)in 6 sample types.H5N6 avian influenza viruses were detected more in eastern than western Hubei,and H5N6 avian influenza viruses were detected only in Xiangyang city of western Hubei.There were important high-risk places of human infection with H5 avian influenza virus in urban and rural live poultry markets and the poultry slaughtering plants.H5N6 has been the predominant subtype of H5 avian influenza viruses in the eastern and western Hubei and H5N6 avian influenza viruses were still present in a few areas of Hubei.Outbreaks of human H5N1 and H5N6 avian influenza remain at risk in Hubei province.
文摘The DNA vaccine pCIHA5 encoding hemagglutinin can protect SPF chicken against lethal H5N1 avian influenza virus challenge. The more characters about its protection efficacity were studied. The protective rates in 10, 40, 70, 100 and 150 μg groups immunized with pCIHA5 were 12.5 (1/8), 58.3 (7/12), 72.7 (8/11), 50.0 (6/12) and 66.7% (8/12), respectively. The protective rates in 5, 20, 35 and 50 μg groups were 145.5 (5/11), 58.3 (7/12), 58.3 (7/12) and 91.7% (11/12), respectively. The 70, 100 and 5 μg groups have virus shedding of 1/8, 2/6 and 1/5. Though the inactived oil-emulsion vaccine has high HI antibody titers and 100% protective rate, the AGP antibody could be detected after vaccination. Results show that the pCIHA5 is fit to boost by intramuscular injection. This would be useful to the study on gene engineering vaccine of avian influenza virus.
文摘HA Gene of H9N2. sub-type avian influenza virus from three strains in different times was amplified, purified and then sequenced. The results of its sequence analysis showed that the whole length of the amplified HA Gene was 1 683 bp, encoding 560 amino acids. The amino acid sequence of three virulent strains at cleavage site was R-S-S-R, which was low-pathogenicity strain. According to the amino acid sequence of the isolated strains, there were 7 potential glycosylation sites, and the receptor-binding site was the specific sequence of the avian-derived influenza virus. Amino acids on the left edge of receptor-binding site were all NGQQG, while amino acids on the right edge of receptor-binding site were GTSKA. From the comparative sequence analysis of HA Gene from some referenced strains, the results indicated that nucleotide and amino acid homology between isolated strains and referenced strains was higher. Evolutionary tree analysis showed that three strains were all Eurasian species, and there was a close relationship with the representative strains of A / duck / Hong Kong/Y280/97.
文摘Objective In March 2012, an H7N7 subtype avian influenza virus （AIV） named A/wild goose/Dongting/PC0360/2022 （H7N7） （DT/PC0360） was recovered from a wild goose in East Dongting Lake. We performed whole-genome sequencing of the isolate, and analyzed the phylogenetic and molecular characterization. Methods RNA was extracted from environment samples （including fecal samples from wild bird or domestic ducks, and water samples） for detecting the presence of Influenza A Virus targeting Matrix gene, using realtime RT-PCR assay. The positive samples were performed virus isolation with embryonated eggs. The subtype of the isolates were identified by RT-PCR assay with the HI-HI6 and N1-N9 primer set. The whole-genome sequencing of isolates were performed. Phylogenetic and molecular characterizations of the eight genes of the isolates were analyzed. Results Our results suggested that all the eight gene segments of DT/PC0360 belonged to the Eurasian gene pool, and the HA gene were belonged to distinct sublineage with H7N9 AIV which caused outbreaks in China's Mainland in 2013. The hemagglutinin cleavage site of HA of DT/PC0360 showed characterization of low pathogenic avian influenza virus. Conclusion Strengthening the surveillance of AlVs of wild waterfowl and poultry in this region is vita for our knowledge of the ecology and mechanism of transmission to prevent an influenza pandemic.
基金supported by the National High-Tech R&D Program of China(2012AA101303)
文摘H9 s ubtype avian influenza virus（AIV） and infectious bronchitis virus（IBV） are major pathogens circulating in poultry and have resulted in great economic losses due to respiratory disease and reduced egg production. As similar symptoms are elicited by the two pathogens, it is difficult for their differential diagnosis. So far, no reverse transcription-polymerase chain reaction（RT-PCR） assay has been found to differentiate between H9 AIV and IBV in one reaction. Therefore, developing a sensitive and specific method is of importance to simultaneously detect and differentiate H9 AIV and IBV. In this study, a duplex RT-PCR（d RT-PCR） was established. Two primer sets target the hemagglutinin（HA） gene of H9 AIV and the nucleocapsid（N） gene of IBV, respectively. Spec ific PCR products were obtained from all tested H9 AIVs and IBVs belonging to the major clades circulating in China, but not from AIVs of other subtypes or other infectious avian viruses. The sensitivity of the d RT-PCR assay corresponding to H9 AIV, IBV and mixture of H9 AIV and IBV were at a concentration of 1×10^1, 1.5×10^1 and 1.5×10^1 50% egg infective doses（EID_（50）） m L^–1, respectively. The concordance rates between the d RT-PCR and virus isolation were 99.1 and 98.2%, respectively, for detection of samples from H9N2 AIV or IBV infected chickens, while the concordance rate was 99.1% for detection of samples from H9N2 AIV and IBV co-infected chickens. Thus, the d RT-PCR assay reported herein is specific and sensitive, and suitable for the differential diagnosis of clinical infections and survei llance of H9 AIVs and IBVs.
基金funded by Fundo Nacional de Investigacao,Mozambique and Centre for Coordination of Agricultural Research and Development for Southern Africa(CCARDESA)with grant number CPRJ/INT/WB/CFP1/14/03
文摘To investigate serologically the presence of avian influenza virus (AIV) in backyard chickens from Mandlhakazi district, Southern Mozambique.MethodsA total of 439 sera samples from unvaccinated and apparently healthy backyard chickens from 4 villages (Chidenguele, Macuacua, Chizavane, and Nwadjahane) were tested for the presence of AIV antibodies through commercial enzyme-linked immunoabsorbent assay (ELISA) kit used according to manufacturer instructions.ResultsAnti-AIV antibodies were detected in all villages surveyed. The overall seroprevalence obtained was 32.6% (95% CI 28.2%-37.0%). The highest prevalence of 51.3% (95% CI 42.3%-60.2%) was recorded in Macuacua village, while the lowest prevalence of 13.0% (95% CI 6.2%-19.9%) was found in Chizavane village. The results of logistic regression analyses suggested that chicken being located in Chizavane and Macuacua villages were more unlikely for getting the virus exposure (P < 0.05).ConclusionsOur findings suggested that AIV is widespread within backyard chickens in the studied villages. Further research is needed to identify the circulating virus genotypes and determine the potential role of backyard chickens in the zoonotic transmission of AIV in Mozambique.
基金Fundamental Research Program of Shanxi Province,China(202103021224156)National Natural Science Foundation of China(32202788)+5 种基金Special Research Fund of Shanxi Agricultural University for High-level Talents,China(2021XG004)Science and Technology Innovation Program of Shanxi Agricultural University,China(2021BQ78)special fund for Science and Technology Innovation Teams of Shanxi Province,China(202304051001041)?Shanxi Province Excellent Doctoral Work Award-Scientific Research Project,China(SXBYKY2021005,SXBYKY2021063,SXBYKY2022014)the Fund for Shanxi“1331 Project”,China(20211331-13)earmarked fund for Modern Agro-industry Technology Research System of Shanxi Province,China.
文摘The H9N2 subtype of avian influenza virus(AIV)is widely prevalent in poultry and wild birds globally,and has become the predominant subtype circulating in poultry in China.The H9N2 AIV can directly or indirectly(by serving as a"donor virus")infect humans,posing a significant threat to public health.Currently,there is a lack of in-depth research on the prevalence of H9N2 viruses in Shanxi Province,central China.In this study,we isolated 14 H9N2 AIVs from October 2020 to April 2022 in Shanxi Province,and genetic analysis revealed that these viruses belonged to 7 different genotypes.Our study on animals revealed that the H9N2 strains we identified displayed high transmission efficiency among chicken populations,and exhibited diverse replication abilities within these birds.These viruses could replicate efficiently in the lungs of mice,with one strain also demonstrating the capacity to reproduce in organs like the brain and kidneys.At the cellular level,the replication ability of different H9N2 strains was evaluated using plaque formation assays and multi-step growth curve assays,revealing significant differences in the replication and proliferation efficiency of the various H9N2 viruses at the cellular level.The antigenicity analysis suggested that these isolates could be classified into 2 separate antigenic clusters.Our research provides crucial data to help understand the prevalence and biological characteristics of H9N2 AIVs in central China.It also highlights the necessity of enhancing the surveillance of H9N2 AIVs.
