title: [Susceptibility of Influenza B Viruses to Neuraminidase Inhibitors Isolated during 2013-2014 Influenza Season in Mainland China].
abstract: Data based on the antiviral-resistant phenotyping characteristics of 884 influenza B viruses circulating in mainland China from October 2013 to March 2014 were analyzed to assess the susceptibility of influenza B viruses to neuraminidase inhibitors. All 884 viruses were sensitive to oseltamivir; two viruses (0.23%) had reduced sensitivity to zanamivir and all other viruses were sensitive to zanamivir. Among the 38 viruses with a B/Victoria lineage, B/Shandong-Kuiwen/1195/2014 exhibited a half-maximal inhibitory concentration (IC50) for zanamivir that was elevated by 5. 12-fold (1.78 nM) compared with neuraminidase inhibitors sensitive to the reference virus (0.34 nM), suggesting that it exhibited reduced inhibition by zanamivir. D35G, N59D and S402T (39, 64 and 399 with N2 number) amino-acid substitutions in the NA gene were detected with no previously reported antiviral-resistant substitutions. Among viruses with the 846 B/Yamagata lineage, B/Hunan-Lingling/350/2013 exhibited a 7.99-fold elevated IC50 for zanamivir (2.72 nM) compared with neuraminidase inhibitors sensitive to the reference virus (0.34 nM), suggesting that it exhibited reduced inhibition by zanamivir. D197N (N2 number), a previously reported antiviral resistant-related amino-acid substitution in the NA gene, was detected in B/Hunan-Lingling/350/2013. These data suggest that recently circulating influenza B viruses in mainland China have retained susceptibility to neuraminidase inhibitors.
authors.forename: Weijuang
authors.initials: W
authors.lastname: Huang
authors.forename: Xiyan
authors.initials: X
authors.lastname: Li
authors.forename: Minju
authors.initials: M
authors.lastname: Tan
authors.forename: Hejiang
authors.initials: H
authors.lastname: Wei
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Cheng
authors.forename: Junfeng
authors.initials: J
authors.lastname: Guo
authors.forename: Zhao
authors.initials: Z
authors.lastname: Wang
authors.forename: Ning
authors.initials: N
authors.lastname: Xiao
authors.forename: Dayan
authors.initials: D
authors.lastname: Wang
authors.forename: Yuelong
authors.initials: Y
authors.lastname: Shu
mesh_terms: D019943:Amino Acid Substitution; D000998:Antiviral Agents / Q000494:pharmacology*; D002681:China / Q000453:epidemiology; D024882:Drug Resistance, Viral; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D009981:Influenza B virus / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D008826:Microbial Sensitivity Tests; D009439:Neuraminidase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism
chemical_list: D000998:Antiviral Agents; D004791:Enzyme Inhibitors; D014764:Viral Proteins; C541223:NA protein, influenza B virus; D009439:Neuraminidase