Substitutions at the receptor-binding site of the pandemic H1N1 2009 influenza A virus (H1N1pdm) hemagglutinin (HA) gene may be critical in determining whether a virus binds to human or avian receptors. Previous reports suggest that HA Gly(222) and/or Arg(223) allow viruses to bind preferentially to the α2,3-linked sialic acid found in avian species. We also demonstrated that serial passaging of influenza A virus in embryonated chicken eggs increased viral growth 32- to 64-fold, coincident with the increased prevalence of Gly(222) or Arg(223) in HA protein (Yasugi et al., 2012). In this study, we showed that the minor genotype of α2,3-linkage-tropic viruses in upper airways became dominant after passaging through chicken eggs. Viruses possessing HA containing N125D-Q223R, N125D-D187E-Q223R, K119N-D222G, and K119N-N129S-D222G, were detected in both clinical specimens and egg-passaged samples. These results might suggest that egg-adapted viruses, likely represented by α2,3-linkage-tropic virus, were also present in human upper airways as a minor population and transmitted in humans during the outbreak of H1N1pdm.
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http://dx.doi.org/10.3389/fmicb.2012.00128 | DOI Listing |
Commun Biol
January 2025
School of Population Medicine and Public Health, Public Health Emergency Management Innovation Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Acute respiratory infections (ARI) with multiple types of viruses are common in infants and children. This study was conducted to assess the difference of oropharyngeal microbiome during acute respiratory viral infection using whole-genome shotgun metagenomic sequencing. The overall taxonomic alpha diversity did not differ by the types of infected virus.
View Article and Find Full Text PDFBiochemistry (Mosc)
December 2024
Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
Nuclear export protein (NEP) of the influenza A virus, being one of the key components of the virus life cycle, is a promising model for studying characteristics of formation of amyloids by viral proteins. Using atomic force microscopy, comparative study of aggregation properties of the recombinant NEP variants, including the protein of natural structure, as well as modified variants with N- and C-terminal affinity His-tags, was carried out. All protein variants under physiological conditions are capable of forming aggregates of various morphologies: micelle-like nanoparticles, flexible protofibrils, rigid amyloid fibrils, etc.
View Article and Find Full Text PDFInfect Dis (Lond)
January 2025
Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, GA, USA.
Background: Whether a detected virus or bacteria is a pathogen that may require treatment, or is merely a commensal 'passenger', remains confusing for many infections. This confusion is likely to increase with the wider use of multi-pathogen PCR.
Objectives: To propose a new statistical procedure to analyse and present data from case-control studies clarifying the probability of causality.
Vet Microbiol
January 2025
College of Veterinary Medicine, Jilin Provincial Engineering Research Center of Animal Probiotics, Jilin Provincial Key Laboratory of Animal Microecology and Healthy Breeding, Engineering Research Center of Microecological Vaccines (Drugs) for Major Animal Diseases, Ministry of Education, Jilin Agricultural University, Changchun 130118, China. Electronic address:
Swine influenza virus invades the host through the respiratory mucosa, which severely restricts the development of the pig breeding industry. To construct monomeric and trimeric vaccines, we developed recombinant Escherichia coli Nissle 1917 (EcN) strains that express the receptor binding site (RBS) of the hemagglutinin (HA) antigen from H1N1 swine influenza virus. After the mucosal immunization of mice, we found that probiotics activated CD40 and CD86 in DCs and increased the levels of IL-4 and IFN-γ secretion by T cells.
View Article and Find Full Text PDFPoult Sci
January 2025
Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, PR China; Jiangsu Key Laboratory of Zoonoses, Yangzhou University, Yangzhou, PR China. Electronic address:
H7N9 avian influenza virus (AIV) first emerged in February 2013 in China, and early isolates were all low pathogenic (LP). After circulation for a few years in live poultry markets of China, LP H7N9 AIVs evolved into a highly pathogenic (HP) form in late 2016. Deduced amino acid sequence analysis of hemagglutinin (HA) gene revealed that all HP H7N9 AIVs have obtained four-amino-acid insertion at position 339-342 (H7 numbering), making the cleavage site from a monobasic motif (LP AIVs) to a polybasic form (HP AIVs).
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