Distribution of amantadine-resistant H5N1 avian influenza variants in Asia.
We examined the distribution of genetic mutations associated with resistance to the M2 ion channel-blocking adamantane derivatives, amantadine and rimantadine, among H5N1 viruses isolated in Vietnam, Thailand, Cambodia, Indonesia, Hong Kong, and China. More than 95% of the viruses isolated in Vietnam and Thailand contained resistance mutations, but resistant mutants were less commonly isolated in Indonesia (6.3% of isolates) and China (8.9% of isolates), where human infection was recently reported. The dual mutation motif Leu26Ile-Ser31Asn (leucine-->isoleucine at aa 26 and serine-->asparagine at aa 31) was found almost exclusively in all resistant isolates from Vietnam, Thailand, and Cambodia, suggesting the biological selection of these mutations.
Cheung
Chung-Lam
CL
State Key Laboratory of Emerging Infectious Diseases, Department of Microbiology, University of Hong Kong, Pokfulam, Hong Kong SAR, China.
Rayner
Jane M
JM
Smith
Gavin J D
GJ
Wang
Pui
P
Naipospos
T S P
TS
Zhang
Jinxia
J
Yuen
Kwok-Yung
KY
Webster
Robert G
RG
Peiris
J S Malik
JS
Guan
Yi
Y
Chen
Honglin
H
D000547:Amantadine / Q000494:pharmacology*; D019943:Amino Acid Substitution; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology; D001208:Asia; D001717:Birds; D024882:Drug Resistance, Viral / Q000235:genetics*; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D005585:Influenza in Birds / Q000821:virology; D007251:Influenza, Human / Q000821:virology; D008826:Microbial Sensitivity Tests; D020125:Mutation, Missense; D012299:Rimantadine / Q000494:pharmacology*
D000998:Antiviral Agents; D012299:Rimantadine; D000547:Amantadine