Frequency of amantadine-resistant influenza A virus isolated from 2001-02 to 2004-05 in Nara Prefecture.
We investigated the frequency of amantadine-resistant influenza A viruses in Nara Prefecture during four epidemic seasons from 2001-02 to 2004-05. Point mutations within the M2 gene were identified using RT-PCR and DNA sequencing analysis. Five viruses (3.4%) with point mutation were observed from 145 strains analyzed. Three viruses (2.0%) possessed a change at position 31 (AGT-->AAT, Ser to Asn), one virus (0.7%) showed a change at position 26 (CTT-->TTT, Leu to Phe), one virus (0.7%) showed a change at position 27 (GTT-->ATT, Val to Ile), and none showed a change at position 30. All of these changes were the transition type of mutation. These results indicated that the possible circulation of drug-resistant viruses to the community was not supported by the findings obtained during the 2004-05 season in Nara.
Kitahori
Yoshiteru
Y
Virology and Bacteriology Division, Nara Prefectural Institute for Hygiene and Environment, Nara 630-8131, Japan. y.kitahori@ihe.pref.nara.jp
Nakano
Mamoru
M
Inoue
Yumiko
Y
D000547:Amantadine / Q000494:pharmacology*; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002460:Cell Line; D004196:Disease Outbreaks; D004285:Dogs; D024882:Drug Resistance, Viral; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D007564:Japan / Q000453:epidemiology; D017354:Point Mutation; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014763:Viral Matrix Proteins / Q000235:genetics; D000086082:Viroporin Proteins
D000547:Amantadine; D000998:Antiviral Agents; D014763:Viral Matrix Proteins; C488937:M2 protein, Influenza A virus; D000086082:Viroporin Proteins