scholarly journals Rapid Detection and Differentiation of Swine-Origin Influenza A Virus (H1N1/2009) from Other Seasonal Influenza A Viruses

Viruses ◽  
2012 ◽  
Vol 4 (11) ◽  
pp. 3012-3019 ◽  
Author(s):  
Jiangqin Zhao ◽  
Xue Wang ◽  
Viswanath Ragupathy ◽  
Panhe Zhang ◽  
Wei Tang ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Rapid Detection ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Virus H1n1 ◽  
Influenza A Viruses

scholarly journals Immunogenicity, Boostability, and Sustainability of the Immune Response after Vaccination against Influenza A Virus (H1N1) 2009 in a Healthy Population

2011 ◽  
Vol 18 (9) ◽  
pp. 1401-1405 ◽  
Author(s):  
Elisabeth Huijskens ◽  
John Rossen ◽  
Paul Mulder ◽  
Ruud van Beek ◽  
Hennie van Vugt ◽  
...  
Keyword(s):  
Immune Response ◽  
Influenza Virus ◽  
Influenza A Virus ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Virus H1n1 ◽  
Prospective Longitudinal Study ◽  
Virus Vaccination ◽  
Short Period ◽  
Prospective Longitudinal

ABSTRACTThe emergence of a new influenza A virus (H1N1) variant in 2009 led to a worldwide vaccination program, which was prepared in a relatively short period of time. This study investigated the humoral immunity against this virus before and after vaccination with a 2009 influenza A virus (H1N1) monovalent MF59-adjuvanted vaccine, as well as the persistence of vaccine-induced antibodies. Our prospective longitudinal study included 498 health care workers (mean age, 43 years; median age, 44 years). Most (89%) had never or only occasionally received a seasonal influenza virus vaccine, and 11% were vaccinated annually (on average, for >10 years). Antibody titers were determined by a hemagglutination inhibition (HI) assay at baseline, 3 weeks after the first vaccination, and 5 weeks and 7 months after the second vaccination. Four hundred thirty-five persons received two doses of the 2009 vaccine. After the first dose, 79.5% developed a HI titer of ≥40. This percentage increased to 83.3% after the second dose. Persistent antibodies were found in 71.9% of the group that had not received annual vaccinations and in 43.8% of the group that had received annual vaccinations. The latter group tended to have lower HI titers (P=0.09). With increasing age, HI titers decreased significantly, by 2.4% per year. A single dose of the 2009 vaccine was immunogenic in almost 80% of the study population, whereas an additional dose resulted in significantly increased titers only in persons over 50. Finally, a reduced HI antibody response against the 2009 vaccine was found in adults who had previously received seasonal influenza virus vaccination. More studies on the effect of yearly seasonal influenza virus vaccination on the immune response are warranted.

scholarly journals Molecular Detection of Human H7N9 Influenza A Virus Causing Outbreaks in China

2013 ◽  
Vol 59 (7) ◽  
pp. 1062-1067 ◽  
Author(s):  
Chloe KS Wong ◽  
Huachen Zhu ◽  
Olive TW Li ◽  
Yin Hung C Leung ◽  
Michael CW Chan ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Rapid Detection ◽  
Influenza A ◽  
Negative Control ◽  
The Novel ◽  
H7n9 Virus ◽  
Influenza A Viruses ◽  
Reverse Transcription Pcr ◽  
Molecular Tests ◽  
Negative Controls

BACKGROUND A novel subtype of influenza A virus (H7N9) was recently identified in humans. The virus is a reassortant of avian viruses, but these human isolates contain mutations [hemagglutinin (HA) Q226L and PB2 E627K] that might make it easier for the virus to adapt to mammalian hosts. Molecular tests for rapid detection of this virus are urgently needed. METHODS We developed a 1-step quantitative real-time reverse-transcription PCR assay to detect the novel human H7N9 virus. The primer set was specific to the hemagglutinin (HA) gene of the H7N9 viruses currently causing the outbreak in China and had mismatches to all previously known avian or mammalian H7 HA sequences. In addition, the assay was evaluated using influenza A viruses of various genetic BACKGROUNDs and other negative controls. RESULTS The detection limit of the assay was approximately 0.04 TCID50 (median tissue culture infective dose) per reaction. The assay specificity was high and all negative control samples, including 8 H7 viruses not closely related to the human H7N9 virus, tested negative. CONCLUSIONS The established assay allows rapid detection of the novel human H7N9 virus, thereby allowing better pandemic preparedness.

scholarly journals Integrated Microfluidic Preconcentration and Nucleic Amplification System for Detection of Influenza A Virus H1N1 in Saliva

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 203 ◽  
Author(s):  
Yonghee Kim ◽  
Abdurhaman Teyib Abafogi ◽  
Buu Minh Tran ◽  
Jaewon Kim ◽  
Jinyeop Lee ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Molecular Diagnostics ◽  
Influenza A ◽  
Limit Of Detection ◽  
Immunomagnetic Separation ◽  
Clinical Samples ◽  
Virus H1n1 ◽  
Influenza A Viruses ◽  
Virus Particles ◽  
Amplification System

Influenza A viruses are often present in environmental and clinical samples at concentrations below the limit of detection (LOD) of molecular diagnostics. Here we report an integrated microfluidic preconcentration and nucleic amplification system (μFPNAS) which enables both preconcentration of influenza A virus H1N1 (H1N1) and amplification of its viral RNA, thereby lowering LOD for H1N1. H1N1 virus particles were first magnetically preconcentrated using magnetic nanoparticles conjugated with an antibody specific for the virus. Their isolated RNA was amplified to cDNA through thermocycling in a trapezoidal chamber of the μFPNAS. A detection limit as low as 100 TCID50 (50% tissue culture infective dose) in saliva can be obtained within 2 hours. These results suggest that the LOD of molecular diagnostics for virus can be lowered by systematically combining immunomagnetic separation and reverse transcriptase-polymerase chain reaction (RT-PCR) in one microfluidic device.

scholarly journals Development of Two Types of Rapid Diagnostic Test Kits To Detect the Hemagglutinin or Nucleoprotein of the Swine-Origin Pandemic Influenza A Virus H1N1

2011 ◽  
Vol 18 (3) ◽  
pp. 494-499 ◽  
Author(s):  
Rika Mizuike ◽  
Tadahiro Sasaki ◽  
Koichi Baba ◽  
Hisahiko Iwamoto ◽  
Yusuke Shibai ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Virus Detection ◽  
Virus H1n1 ◽  
Viral Hemagglutinin ◽  
Detection Assay ◽  
Influenza A H1n1 ◽  
New Type

ABSTRACTSince its emergence in April 2009, pandemic influenza A virus H1N1 (H1N1 pdm), a new type of influenza A virus with a triple-reassortant genome, has spread throughout the world. Initial attempts to diagnose the infection in patients using immunochromatography (IC) relied on test kits developed for seasonal influenza A and B viruses, many of which proved significantly less sensitive to H1N1 pdm. Here, we prepared monoclonal antibodies that react with H1N1 pdm but not seasonal influenza A (H1N1 and H3N2) or B viruses. Using two of these antibodies, one recognizing viral hemagglutinin (HA) and the other recognizing nucleoprotein (NP), we developed kits for the specific detection of H1N1 pdm and tested them using clinical specimens of nasal wash fluid or nasopharyngeal fluid from patients with influenza-like illnesses. The specificities of both IC test kits were very high (93% for the HA kit, 100% for the NP kit). The test sensitivities for detection of H1N1 pdm were 85.5% with the anti-NP antibody, 49.4% with the anti-HA antibody, and 79.5% with a commercially available influenza A virus detection assay. Use of the anti-NP antibody could allow the rapid and accurate diagnosis of H1N1 pdm infections.

scholarly journals Investigating Influenza A Virus Infection: Tools To Track Infection and Limit Tropism: TABLE 1

2015 ◽  
Vol 89 (12) ◽  
pp. 6167-6170 ◽  
Author(s):  
Jessica K. Fiege ◽  
Ryan A. Langlois
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Therapeutic Interventions ◽  
Microrna Target ◽  
Influenza A Viruses ◽  
Host Interactions ◽  
Target Sites ◽  
Recent Developments ◽  
Cellular Tropism ◽  
The Relationship

Influenza A viruses display a broad cellular tropism within the respiratory tracts of mammalian hosts. Uncovering the relationship between tropism and virus immunity, pathogenesis, and transmission will be critical for the development of therapeutic interventions. Here we discuss recent developments of several recombinant strains of influenza A virus. These viruses have inserted reporters to track tropism, microRNA target sites to restrict tropism, or barcodes to assess transmission dynamics, expanding our understanding of pathogen-host interactions.

scholarly journals Unexpected Functional Divergence of Bat Influenza Virus NS1 Proteins

2017 ◽  
Vol 92 (5) ◽  
Author(s):  
Hannah L. Turkington ◽  
Mindaugas Juozapaitis ◽  
Nikos Tsolakos ◽  
Eugenia Corrales-Aguilar ◽  
Martin Schwemmle ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Virulence Factor ◽  
Influenza A ◽  
Nonstructural Protein ◽  
Functional Divergence ◽  
Protein A ◽  
Regulatory Subunit ◽  
Ns1 Protein ◽  
Influenza A Viruses ◽  
Hydrophobic Patch

ABSTRACT Recently, two influenza A virus (FLUAV) genomes were identified in Central and South American bats. These sequences exhibit notable divergence from classical FLUAV counterparts, and functionally, bat FLUAV glycoproteins lack canonical receptor binding and destroying activity. Nevertheless, other features that distinguish these viruses from classical FLUAVs have yet to be explored. Here, we studied the viral nonstructural protein NS1, a virulence factor that modulates host signaling to promote efficient propagation. Like all FLUAV NS1 proteins, bat FLUAV NS1s bind double-stranded RNA and act as interferon antagonists. Unexpectedly, we found that bat FLUAV NS1s are unique in being unable to bind host p85β, a regulatory subunit of the cellular metabolism-regulating enzyme, phosphoinositide 3-kinase (PI3K). Furthermore, neither bat FLUAV NS1 alone nor infection with a chimeric bat FLUAV efficiently activates Akt, a PI3K effector. Structure-guided mutagenesis revealed that the bat FLUAV NS1-p85β interaction can be reengineered (in a strain-specific manner) by changing two to four NS1 residues (96L, 99M, 100I, and 145T), thereby creating a hydrophobic patch. Notably, ameliorated p85β-binding is insufficient for bat FLUAV NS1 to activate PI3K, and a chimeric bat FLUAV expressing NS1 with engineered hydrophobic patch mutations exhibits cell-type-dependent, but species-independent, propagation phenotypes. We hypothesize that bat FLUAV hijacking of PI3K in the natural bat host has been selected against, perhaps because genes in this metabolic pathway were differentially shaped by evolution to suit the unique energy use strategies of this flying mammal. These data expand our understanding of the enigmatic functional divergence between bat FLUAVs and classical mammalian and avian FLUAVs. IMPORTANCE The potential for novel influenza A viruses to establish infections in humans from animals is a source of continuous concern due to possible severe outbreaks or pandemics. The recent discovery of influenza A-like viruses in bats has raised questions over whether these entities could be a threat to humans. Understanding unique properties of the newly described bat influenza A-like viruses, such as their mechanisms to infect cells or how they manipulate host functions, is critical to assess their likelihood of causing disease. Here, we characterized the bat influenza A-like virus NS1 protein, a key virulence factor, and found unexpected functional divergence of this protein from counterparts in other influenza A viruses. Our study dissects the molecular changes required by bat influenza A-like virus NS1 to adopt classical influenza A virus properties and suggests consequences of bat influenza A-like virus infection, potential future evolutionary trajectories, and intriguing virus-host biology in bat species.

scholarly journals Characterization of a Human H5N1 Influenza A Virus Isolated in 2003

2005 ◽  
Vol 79 (15) ◽  
pp. 9926-9932 ◽  
Author(s):  
Kyoko Shinya ◽  
Masato Hatta ◽  
Shinya Yamada ◽  
Ayato Takada ◽  
Shinji Watanabe ◽  
...  
Keyword(s):  
Hong Kong ◽  
Avian Influenza ◽  
Influenza A Virus ◽  
Influenza A ◽  
Mainland China ◽  
Virus Infections ◽  
Influenza A Viruses ◽  
H5n1 Avian Influenza Virus ◽  
H5n1 Influenza ◽  
Avian Influenza A Virus

ABSTRACT In 2003, H5N1 avian influenza virus infections were diagnosed in two Hong Kong residents who had visited the Fujian province in mainland China, affording us the opportunity to characterize one of the viral isolates, A/Hong Kong/213/03 (HK213; H5N1). In contrast to H5N1 viruses isolated from humans during the 1997 outbreak in Hong Kong, HK213 retained several features of aquatic bird viruses, including the lack of a deletion in the neuraminidase stalk and the absence of additional oligosaccharide chains at the globular head of the hemagglutinin molecule. It demonstrated weak pathogenicity in mice and ferrets but caused lethal infection in chickens. The original isolate failed to produce disease in ducks but became more pathogenic after five passages. Taken together, these findings portray the HK213 isolate as an aquatic avian influenza A virus without the molecular changes associated with the replication of H5N1 avian viruses in land-based poultry such as chickens. This case challenges the view that adaptation to land-based poultry is a prerequisite for the replication of aquatic avian influenza A viruses in humans.

Sign in / Sign up

Export Citation Format

Share Document