Resistance to amantadine of epidemic strain of H3 subtype influenza virus: a primary study
Xu, H.; Qian, Y.; Xu, H.; Zhang, J.-h.; Zhu, R.-n.; Wang, F.
Zhonghua Yi Xue Za Zhi 86(14): 996-998
2006
ISSN/ISBN: 0376-2491 PMID: 16759544 Document Number: 604923
To study the resistance to amantadine of epidemic strain of H3 subtype influenza virus. Forty-one strains of influenza virus were isolated from pediatric patients with influenza in Beijing 2004-2005 and were identified as H3 subtype. RNA was extracted. Thirty of the 40 strains were resistant to amantadine with a resistance rate of 75%. The M2 gene ion channel fragments were amplified by one-step RT-PCR, sequenced, and then underwent systemic tree analysis. M2 ion channel associated gene fragment with a molecular size of 153 bp was obtained. The amino acid at the site 31 changed from serine into asparagines, a mutation identical to that of the reference strain A/PR8/34 resistant to amantadine. The resistance rate to amantadine is high among the epidemic strains of H3 subtype influenza virus in China. The associated mutation occurs at the site 31 of M2 protein.