title: Susceptibility of highly pathogenic A(H5N1) avian influenza viruses to the neuraminidase inhibitors and adamantanes.
abstract: Since 2003, highly pathogenic A(H5N1) influenza viruses have been the cause of large-scale death in poultry and the subsequent infection and death of over 140 humans. A group of 55 influenza A(H5N1) viruses isolated from various regions of South East Asia between 2004 and 2006 were tested for their susceptibility to the anti-influenza drugs the neuraminidase inhibitors and adamantanes. The majority of strains were found to be fully sensitive to the neuraminidase inhibitors oseltamivir carboxylate, zanamivir and peramivir; however two strains demonstrated increased IC50 values. Sequence analysis of these strains revealed mutations in the normally highly conserved residues 116 and 117 of the N1 neuraminidase. Sequence analysis of the M2 gene showed that all of the A(H5N1) viruses from Vietnam, Malaysia and Cambodia contained mutations (L26I and S31N) associated with resistance to the adamantane drugs (rimantadine and amantadine), while strains from Indonesia were found to be a mix of both adamantane resistant (S31N) and sensitive viruses. None of the A(H5N1) viruses from Myanmar contained mutations known to confer adamantane resistance. These results support the use of neuraminidase inhibitors as the most appropriate class of antiviral drug to prevent or treat human A(H5N1) virus infections.
authors.affiliation: World Health Organisation Collaborating Centre for Reference and Research on Influenza, 45 Poplar Road, Parkville, Victoria 3052, Australia. Aeron.Hurt@influenzacentre.org
authors.forename: A C
authors.initials: AC
authors.lastname: Hurt
authors.forename: P
authors.initials: P
authors.lastname: Selleck
authors.forename: N
authors.initials: N
authors.lastname: Komadina
authors.forename: R
authors.initials: R
authors.lastname: Shaw
authors.forename: L
authors.initials: L
authors.lastname: Brown
authors.forename: I G
authors.initials: IG
authors.lastname: Barr
mesh_terms: D000146:Acids, Carbocyclic; D000547:Amantadine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D001483:Base Sequence; D001717:Birds; D003517:Cyclopentanes / Q000494:pharmacology; D024882:Drug Resistance, Viral; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006146:Guanidines / Q000494:pharmacology; 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*; D009439:Neuraminidase / Q000037:antagonists & inhibitors* / Q000235:genetics; D053139:Oseltamivir / Q000494:pharmacology; D053243:Zanamivir / Q000494:pharmacology
chemical_list: D000146:Acids, Carbocyclic; D000998:Antiviral Agents; D003517:Cyclopentanes; D004791:Enzyme Inhibitors; D006146:Guanidines; D053139:Oseltamivir; C005660:adamantanine; D000547:Amantadine; D009439:Neuraminidase; D053243:Zanamivir; C414210:peramivir