Emergence of truncated PB1-F2 protein of H3N2 influenza virus during its epidemic period in Jiangsu Province, China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>PB1-F2 protein has been proven to increase the pathogenicity of influenza A virus (IAV) strains in primary infection and in secondary bacterial infection. It can also regulate the activity of viral polymerase. However, it was shown in another retrospective study that a portion of IAVs do not express full-length PB1-F2 protein during virus development; different kinds of stop codons cause exits in the open reading frames and form PB1-F2 gene products with the corresponding genotypes. Truncated PB1-F2 in human H3N2 IAVs has long been detected in North America but its evolution in China is still unclear.</p><p><b>METHODS</b>Influenza-like illnesses (ILIs) from the whole of Jiangsu Province were collected and inspected to determine the type and subtype of the viruses. A portion of isolates collected in the epidemic period were selected as samples for later whole-genome sequencing, and the exact sequences were determined and analyzed.</p><p><b>RESULTS</b>H3N2 influenza virus was one of the epidemical strains which had been prevalent during 2009-2010, in Jiangsu. Five H3N2 isolates with truncated PB1-F2 protein (25aa) were detected in influenza samples from Nanjing and Xuzhou, while seven similar H3N2 isolates were also reported in Niigata, Japan.</p><p><b>CONCLUSION</b>This emergence indicates the possibility that there has been transmission of the H3N2 virus between the two countries.</p>

Molecular characteristics of the hemagglutinin and neuraminidase of influenza B viruses isolated in Jiangsu province, 2011 / 中华微生物学和免疫学杂志

Objective To characterize the molecular characteristics of hemagglutinin (HA) and neuraminidase (NA) of influenza B viruses isolated in Jiangsu province,2011.Methods Thirteen strains of influenza B virus in different areas and epidemic period in Jiangsu province,2011 were selected for whole-genome sequencing,and analysis of molecule epidemic characteristics for HA and NA was carried out by bioinformatics method.Results Of the 13 randomly selected influeuza B strains,10 strains were assorted to Victoria lineage strains with NA genes from Yamagata lineage,and 3 strains belong to Yamagata lineage.Compared nucleotide and amino acid sequences of HA and NA genes with their vaccine strains respectiuely,196/197 glycosylation site appeared on HA1 gene in Yamagata/Victoria isolates virus.Conclusion Both B/Victoria and B/Yamagata lineage viruses co-circulated in Jiangsu province,and reassortant virus of Victoria lineage were predominant virus.