scholarly journals MOLECULAR AND GENETIC CHARACTERISTICS OF SURFACE AND NONSTRUCTURE PROTEINS OF PANDEMIC INFLUENZA VIRUSES A(H1N1)PDM09 IN 2015-2016 EPIDEMIC SEASON

2016 ◽  
Vol 72 (2) ◽  
pp. 44-48
Author(s):  
O. Smutko ◽  
L. Radchenko ◽  
A. Mironenko
Keyword(s):  
Amino Acid ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Phylogenetic Trees ◽  
Influenza Viruses ◽  
Amino Acid Substitutions ◽  
Ns1 Protein ◽  
Genetic Characteristics ◽  
Epidemic Season ◽  
Influenza A H1n1

The aim of the present study was identifying of molecular and genetic changes in hemaglutinin (HA), neuraminidase (NA) and non-structure protein (NS1) genes of pandemic influenza A(H1N1)pdm09 strains, that circulated in Ukraine during 2015-2016 epidemic season. Samples (nasopharyngeal swabs from patients) were analyzed using real-time polymerase chain reaction (RTPCR). Phylogenetic trees were constructed using MEGA 7 software. 3D structures were constructed in Chimera 1.11.2rc software. Viruses were collected in 2015-2016 season fell into genetic group 6B and in two emerging subgroups, 6B.1 and 6B.2 by gene of HA and NA. Subgroups 6B.1 and 6B.2 are defined by the following amino acid substitutions. In the NS1 protein were identified new amino acid substitutions D2E, N48S, and E125D in 2015-2016 epidemic season. Specific changes were observed in HA protein antigenic sites, but viruses saved similarity to vaccine strain. NS1 protein acquired substitution associated with increased virulence of the influenza virus.

scholarly journals Amino acid substitutions in hemagglutinin of the 2009 pandemic influenza A(H1N1) viruses that might affect the viral antigenicity

2014 ◽  
Vol 7 (1) ◽  
pp. 951 ◽  
Author(s):  
Nathamon Kosoltanapiwat ◽  
Usa Boonyuen ◽  
Phisanu Pooruk ◽  
Sopon Iamsirithaworn ◽  
Anek Mungaomklang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Amino Acid Substitutions ◽  
Influenza A H1n1

scholarly journals Y155H amino acid substitution in influenza A(H1N1)pdm09 viruses does not confer a phenotype of reduced susceptibility to neuraminidase inhibitors

2014 ◽  
Vol 19 (27) ◽  
Author(s):  
U Perez-Sautu ◽  
F Pozo ◽  
I Cuesta ◽  
S Monzon ◽  
A Calderon ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Influenza A ◽  
High Throughput Sequencing ◽  
Biological Significance ◽  
H1n1 Influenza ◽  
Influenza Viruses ◽  
Neuraminidase Inhibitors ◽  
Epidemic Season ◽  
Influenza A H1n1

The Y155H amino acid substitution in the neuraminidase gene (NA) has previously been associated with highly reduced inhibition by neuraminidase inhibitors in the seasonal H1N1 influenza A virus which circulated in humans before the 2009 pandemic. During the 2012/13 epidemic season in Spain, two A(H1N1)pdm09 viruses bearing the specific Y155H substitution in the NA were detected and isolated from two patients diagnosed with severe respiratory syndrome and pneumonia requiring admission to the intensive care unit. Contrary to what was observed in the seasonal A(H1N1) viruses, neither of the Y155H A(H1N1)pdm09 viruses described here showed a phenotype of reduced inhibition by NAIs as determined by the neuraminidase enzyme inhibition assay (MUNANA). High-throughput sequencing of the NA of both Y155H viruses showed that they were composed to >99% of H155 variants. We believe that this report can contribute to a better understanding of the biological significance of amino acid substitutions in the neuraminidase protein with regard to susceptibility of influenza viruses to neuraminidase inhibitors. This is of critical importance for optimal management of influenza disease patients.

scholarly journals Epidemiological Features of Pandemic Influenza in Kyrgyzstan due to Influenza A(H1N1)pdm

2016 ◽  
Vol 15 (5) ◽  
pp. 30-37
Author(s):  
K. T. Kasymbekova ◽  
Z. S. Nurmatov ◽  
A. B. Komissarov ◽  
A. V. Fadeev ◽  
D. V. Pereyaslov ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Molecular Genetic ◽  
Influenza Viruses ◽  
Kyrgyz Republic ◽  
Genetic Characteristics ◽  
Influenza A H1n1 ◽  
The Republic ◽  
Reference Strains

Relevance. Virological laboratory of the Department of prevention of diseases and Sanitary Inspection Healthcare Ministry f of the Kyrgyz Republic is nominated as the National Centre for Influenza Surveillance and accreditated by WHO, and in 2009 is included into a global network of influenza Goal. The purpose of this study - Assessment of epidemic features of manifestations of pandemic influenza A (H1N1) pdm09 in 2009 on the territory of the Kyrgyz Republic, as a comparative study of the molecular and genetic characteristics of influenza A virus (H1N1) pdm09, circulating on the territory of the Republic and the influenza virus reference strains recommended WHO for inclusion in the vaccine for the northern hemisphere. Materials and methods. On the basis of long-term retrospective analysis of the incidence of influenza and severe acute respiratory infections (SARI), and sentinel epidemiological surveillance (SS) data studied pandemic especially in Kyrgyzstan due to influenza A(H1N1)pdm09. Comparative molecular genetic characteristics of influenza viruses A(H1N1)pdm09 allocated in Kyrgyzstan, with reference strains recommended by the World Health Organization (WHO) for inclusion in the vaccine. Results. Overall, the analysis of the results of laboratory tests carried out as part of the routine and sentinel surveillance showed that from January 2009 to March 2010 at 38.8% of those surveyed from among, influenza viruses (at 655 out of 1687) were found. From January to April 2009 in the main circulating influenza A virus (H3N2), which accounted for 55.9 - 77.9% of the number of positive findings. Seasonal influenza A virus (H1N1) was detected in January - February (35.3 and 13.4%, respectively). The share of the flu virus in January accounted for 8%, in March-April - 25%. Not typeable influenza A virus was detected in February in 8.7% of cases. Conclusions. The results of the molecular genetic and virological studies have shown that the influenza pandemic in 2009 in the Republic was due to the spread of pandemic influenza virus A (H1N1) pdm09.

scholarly journals Phylogenetic Analysis of the Entire Genome of Influenza A (H3N2) Viruses from Japan: Evidence for Genetic Reassortment of the Six Internal Genes

1998 ◽  
Vol 72 (10) ◽  
pp. 8021-8031 ◽  
Author(s):  
Stephen E. Lindstrom ◽  
Yasuaki Hiromoto ◽  
Reiko Nerome ◽  
Katsuhiko Omoe ◽  
Shigeo Sugita ◽  
...  
Keyword(s):  
Amino Acid ◽  
Influenza A ◽  
Phylogenetic Trees ◽  
Influenza Viruses ◽  
Entire Genome ◽  
Epidemic Season ◽  
Genetic Reassortment ◽  
Evolutionary Pathways ◽  
H3n2 Influenza ◽  
Surface Glycoproteins

ABSTRACT Nucleotide sequences of all eight RNA segments of 10 human H3N2 influenza viruses isolated during a 5-year period from 1993 to 1997 were determined and analyzed phylogenetically in order to define the evolutionary pathways of all genes in a parallel fashion. It was evident that the hemagglutinin and neuraminidase genes of these viruses evolved essentially in a single lineage and that amino acid changes accumulated sequentially with respect to time. In contrast, amino acid differences in the internal proteins were erratic and did not accumulate over time. Parallel analysis of the phylogenetic patterns of all genes revealed that the evolutionary pathways of the six internal genes were not linked to the surface glycoproteins. Genes coding for the basic polymerase-1, nucleoprotein, and matrix proteins of 1997 isolates were closest phylogenetically to those of earlier isolates of 1993 and 1994. Furthermore, all six internal genes of four viruses isolated in the 1995 epidemic season consistently divided into two distinct branch clusters, and two 1995 isolates contained PB2 genes apparently originating from those of viruses before 1993. It was apparent that the lack of correlation between the topologies of the phylogenetic trees of the genes coding for the surface glycoproteins and internal proteins was a reflection of genetic reassortment among human H3N2 viruses. This is the first evidence demonstrating the occurrence of genetic reassortment involving the internal genes of human H3N2 viruses. Furthermore, internal protein variability coincided with marked increases in the activity of H3N2 viruses in 1995 and 1997.

scholarly journals Evolution and Adaptation of the Avian H7N9 Virus into the Human Host

2020 ◽  
Vol 8 (5) ◽  
pp. 778
Author(s):  
Andrew T. Bisset ◽  
Gerard F. Hoyne
Keyword(s):  
Amino Acid ◽  
Avian Influenza ◽  
Influenza A ◽  
Amino Acid Sequences ◽  
Influenza Viruses ◽  
Amino Acid Substitutions ◽  
Upper Respiratory Tract ◽  
Viral Polymerase ◽  
Evolutionary Changes ◽  
Avian Origin

Influenza viruses arise from animal reservoirs, and have the potential to cause pandemics. In 2013, low pathogenic novel avian influenza A(H7N9) viruses emerged in China, resulting from the reassortment of avian-origin viruses. Following evolutionary changes, highly pathogenic strains of avian influenza A(H7N9) viruses emerged in late 2016. Changes in pathogenicity and virulence of H7N9 viruses have been linked to potential mutations in the viral glycoproteins hemagglutinin (HA) and neuraminidase (NA), as well as the viral polymerase basic protein 2 (PB2). Recognizing that effective viral transmission of the influenza A virus (IAV) between humans requires efficient attachment to the upper respiratory tract and replication through the viral polymerase complex, experimental evidence demonstrates the potential H7N9 has for increased binding affinity and replication, following specific amino acid substitutions in HA and PB2. Additionally, the deletion of extended amino acid sequences in the NA stalk length was shown to produce a significant increase in pathogenicity in mice. Research shows that significant changes in transmissibility, pathogenicity and virulence are possible after one or a few amino acid substitutions. This review aims to summarise key findings from that research. To date, all strains of H7N9 viruses remain restricted to avian reservoirs, with no evidence of sustained human-to-human transmission, although mutations in specific viral proteins reveal the efficacy with which these viruses could evolve into a highly virulent and infectious, human-to-human transmitted virus.

scholarly journals Contemporary Seasonal Influenza A (H1N1) Virus Infection Primes for a More Robust Response To Split Inactivated Pandemic Influenza A (H1N1) Virus Vaccination in Ferrets

2010 ◽  
Vol 17 (12) ◽  
pp. 1998-2006 ◽  
Author(s):  
Ali H. Ellebedy ◽  
Thomas P. Fabrizio ◽  
Ghazi Kayali ◽  
Thomas H. Oguin ◽  
Scott A. Brown ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Seasonal Influenza ◽  
H1n1 Virus ◽  
H1n1 Influenza ◽  
Influenza Viruses ◽  
Inactivated Vaccine ◽  
H1n1 Influenza Virus ◽  
Influenza A H1n1

ABSTRACT Human influenza pandemics occur when influenza viruses to which the population has little or no immunity emerge and acquire the ability to achieve human-to-human transmission. In April 2009, cases of a novel H1N1 influenza virus in children in the southwestern United States were reported. It was retrospectively shown that these cases represented the spread of this virus from an ongoing outbreak in Mexico. The emergence of the pandemic led to a number of national vaccination programs. Surprisingly, early human clinical trial data have shown that a single dose of nonadjuvanted pandemic influenza A (H1N1) 2009 monovalent inactivated vaccine (pMIV) has led to a seroprotective response in a majority of individuals, despite earlier studies showing a lack of cross-reactivity between seasonal and pandemic H1N1 viruses. Here we show that previous exposure to a contemporary seasonal H1N1 influenza virus and to a lesser degree a seasonal influenza virus trivalent inactivated vaccine is able to prime for a higher antibody response after a subsequent dose of pMIV in ferrets. The more protective response was partially dependent on the presence of CD8+ cells. Two doses of pMIV were also able to induce a detectable antibody response that provided protection from subsequent challenge. These data show that previous infection with seasonal H1N1 influenza viruses likely explains the requirement for only a single dose of pMIV in adults and that vaccination campaigns with the current pandemic influenza vaccines should reduce viral burden and disease severity in humans.

scholarly journals Functional Replacement of the Carboxy-Terminal Two-Thirds of the Influenza A Virus NS1 Protein with Short Heterologous Dimerization Domains

2002 ◽  
Vol 76 (24) ◽  
pp. 12951-12962 ◽  
Author(s):  
Xiuyan Wang ◽  
Christopher F. Basler ◽  
Bryan R. G. Williams ◽  
Robert H. Silverman ◽  
Peter Palese ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Influenza A Virus ◽  
Influenza A ◽  
Rna Binding ◽  
Influenza Viruses ◽  
Ns1 Protein ◽  
Wild Type ◽  
Dimerization Domain ◽  
Carboxy Terminal

ABSTRACT The NS1 protein of influenza A/WSN/33 virus is a 230-amino-acid-long protein which functions as an interferon alpha/beta (IFN-α/β) antagonist by preventing the synthesis of IFN during viral infection. In tissue culture, the IFN inhibitory function of the NS1 protein has been mapped to the RNA binding domain, the first 73 amino acids. Nevertheless, influenza viruses expressing carboxy-terminally truncated NS1 proteins are attenuated in mice. Dimerization of the NS1 protein has previously been shown to be essential for its RNA binding activity. We have explored the ability of heterologous dimerization domains to functionally substitute in vivo for the carboxy-terminal domains of the NS1 protein. Recombinant influenza viruses were generated that expressed truncated NS1 proteins of 126 amino acids, fused to 28 or 24 amino acids derived from the dimerization domains of either the Saccharomyces cerevisiae PUT3 or the Drosophila melanogaster Ncd (DmNcd) proteins. These viruses regained virulence and lethality in mice. Moreover, a recombinant influenza virus expressing only the first 73 amino acids of the NS1 protein was able to replicate in mice lacking three IFN-regulated antiviral enzymes, PKR, RNaseL, and Mx, but not in wild-type (Mx-deficient) mice, suggesting that the attenuation was mainly due to an inability to inhibit the IFN system. Remarkably, a virus with an NS1 truncated at amino acid 73 but fused to the dimerization domain of DmNcd replicated and was also highly pathogenic in wild-type mice. These results suggest that the main biological function of the carboxy-terminal region of the NS1 protein of influenza A virus is the enhancement of its IFN antagonist properties by stabilizing the NS1 dimeric structure.

scholarly journals Amino Acid Substitutions Analysis of the Putative Epitopes of Neuraminidase Protein from Influenza A H1N1 Virus

2021 ◽  
Vol 22 (1) ◽  
pp. 1-16
Author(s):  
Ludmila Alves Dias Souto ◽  
Alessandra Rejane Ericsson de Oliveira Xavier ◽  
Mauro Aparecido de Sousa Xavier
Keyword(s):  
Amino Acid ◽  
Influenza A ◽  
H1n1 Virus ◽  
Epitope Prediction ◽  
Viral Population ◽  
Amino Acid Substitutions ◽  
Specific Amino Acid ◽  
Influenza A H1n1 ◽  
Virus Sequence ◽  
Clustal Omega

Objective: This study verified whether the neuraminidase protein of Influenza A H1N1 virus sequence has modified from 2009–2017 and its impact on the 2018 Brazilian vaccine. Method: The reference neuraminidase protein sequence from H1N1 Puerto Rico/1934 strain was subjected to three different methods of epitope prediction and the top five from each method were aligned using Clustal omega, resulting in eight putative epitopes. These epitopes were aligned to 7,438 neuraminidase sequences spanning from 2009–2017 and analyzed for specific amino acid substitutions and counted. The resultant neuraminidase protein was aligned against the 2015 and 2018 neuraminidase proteins, from Influenza A H1N1 virus subtypes, used for vaccine production. Result: Twenty-one main substitutions were detected, of which 16/21 (76.2%) substitutions points remained stable and 1/21 (4.8%) returned to the original amino acid residue in the viral population from 2009–2017. Additionally, 19% (4/21) substitutions occurred in Brazil and worldwide in this period, indicating that changes in the neuraminidase viral population profile is time-dependent rather than geographical. Conclusion: The neuraminidase protein containing these amino acid substitutions is more closely related to the neuraminidase protein from influenza A/Michigan/45/2015 than A/California/7/2009, supporting the replacement of this virus subtype in the Brazilian vaccine in 2018.

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