Jpn. J. Infect. Dis., 59 (3), 197-199, 2006
To see a printable version of the article in the Adobe file format, click this [PDF] link.
Short Communication
Frequency of Amantadine-Resistant Influenza A Virus Isolated from 2001-02 to 2004-05 in Nara Prefecture
Yoshiteru Kirahori*, Mamoru Nakano and Yumiko Inoue
Virology and Bacteriology Division, Nara Prefectural Institute for Hygiene and Environment, Nara 630-8131, Japan
(Received February 2, 2006. Accepted May 8, 2006)
*Corresponding author: Mailing address: Virology and Bacteriology Division, Nara Prefectural Institute for Hygiene and Environment, Ohmori-cho, Nara 630-8131, Japan. Tel: +81-742-20-2887, Fax: +81-742-27-0634C E-mail: y.kitahori@ihe.pref.nara.jp
SUMMARY: 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.