title: Drug susceptibility profile and pathogenicity of H7N9 influenza virus (Anhui1 lineage) with R292K substitution.
abstract: Neuraminidase inhibitors (NAIs) are the only available licensed therapeutics against human H7N9 influenza virus infections. The emergence of NAI-resistant variants of H7N9viruses with an NA R292K mutation poses a therapeutic challenge. A comprehensive understanding of the susceptibility of these viruses to clinically available NAIs, non-NAIs and their combinations is crucial for effective treatment. In this study, by using limited serial passage and plaque purification, an R292K variant of the Anhui1 lineage was isolated from a patient with clinical evidence of resistance to oseltamivir. In vitro and cell-based assays confirmed a high level of resistance conferred by the R292K mutation to oseltamivir carboxylate and a moderate level of resistance to zanamivir and peramivir. Non-NAI antivirals, such as T-705, ribavirin and NT-300, efficiently inhibited both the variant and the wild-type in cell-based assays. A combination of NAIs and non-NAIs did not exhibit a marked synergistic effect against the R292K variant. However, the combination of two non-NAIs (T-705 and ribavirin) exhibited significant synergism against the mutant virus. In experimentally infected mice, the variant showed delayed onset of symptoms, a reduced viral load and attenuated lethality compared with the wild-type. Our study suggested non-NAIs should be tested clinically for H7N9 patients with a sustained high viral load. Possible drug combination regimens, such as T-705 plus ribavirin, should be further tested in animal models. The pathogenicity and transmissibility of the R292K H7N9 variant should be further assessed with genetically well-characterized pairs of viruses and, most-desirably, with competitive fitness experiments.
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Song
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Jing
authors.initials: J
authors.lastname: He
authors.affiliation: State Key Laboratory of Emerging Infectious Disease, School of Public Health, University of Hong Kong , Hong Kong, China.
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Yen
authors.affiliation: Key Lab of Medical Molecular Virology, School of Basic Medical Science, Fudan University , Shanghai 200032, China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Zhaoqin
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Di
authors.initials: D
authors.lastname: Tian
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Wencai
authors.initials: W
authors.lastname: Guan
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China ; Key Lab of Medical Molecular Virology, School of Basic Medical Science, Fudan University , Shanghai 200032, China.
authors.forename: Sen
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Bisheng
authors.initials: B
authors.lastname: Shi
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Wanju
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Animal Center, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Boyin
authors.initials: B
authors.lastname: Qin
authors.affiliation: Animal Center, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Jialin
authors.initials: J
authors.lastname: Cai
authors.affiliation: Scientific Research Center, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Yanmin
authors.initials: Y
authors.lastname: Wan
authors.affiliation: Animal Center, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Chunhua
authors.initials: C
authors.lastname: Xu
authors.affiliation: Animal Center, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Ren
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Haili
authors.initials: H
authors.lastname: Chen
authors.affiliation: Scientific Research Center, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Liu
authors.affiliation: Animal Center, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Yuqin
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Animal Center, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Animal Center, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Wenjiang
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Key Lab of Medical Molecular Virology, School of Basic Medical Science, Fudan University , Shanghai 200032, China ; Scientific Research Center, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Jianqing
authors.initials: J
authors.lastname: Xu
authors.affiliation: Key Lab of Medical Molecular Virology, School of Basic Medical Science, Fudan University , Shanghai 200032, China ; Scientific Research Center, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Emerging Infectious Disease, School of Public Health, University of Hong Kong , Hong Kong, China.
authors.forename: Malik
authors.initials: M
authors.lastname: Peiris
authors.affiliation: Department of Pathogen Diagnosis and Biosafety, Shanghai Public Health Clinical Center, Fudan University , Shanghai 201508, China.
authors.forename: Yunwen
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Key Lab of Medical Molecular Virology, School of Basic Medical Science, Fudan University , Shanghai 200032, China.
authors.forename: Zhenghong
authors.initials: Z
authors.lastname: Yuan
keywords: H7N9; influenza virus; neuraminidase; oseltamivir; peramivir