Giuseppe
Emeritus
Antimicrob Agents Chemother. 2009 Aug 3. [Epub ahead of print]
Large-Scale Sequence Analysis of M Gene of Influenza A Viruses from Different Species: Mechanisms for Emergence and Spread of Amantadine Resistance.
Furuse Y, Suzuki A, Oshitani H. - Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryou-machi Aoba-ku, Sendai, 980-8575, Japan.
Influenza A virus infects many species and amantadine is used as an antiviral agent. Recently, a substantial increase in amantadine-resistant strains has been reported, most of which have a substitution at amino acid position 31 in the M2 gene. Understanding the mechanism responsible for the emergence and spread of antiviral resistance is important for developing a treatment protocol for seasonal influenza and in deciding a policy for antiviral stockpiling for pandemic influenza. The present study was conducted to identify the existence of drug pressure on the emergence and spread of amantadine-resistant influenza A viruses. We analyzed more than 5000 sequencing data of viruses and constructed a phylogenetic tree to calculate selective pressures on sites in the M2 gene associated with amantadine resistance (positions of 26, 27, 30, and 31) among different hosts. The phylogenetic tree revealed that the emergence and spread of the drug-resistant M gene in different hosts and subtypes was independent and not through reassortment. For human influenza, positive selection was detected only at position 27. Selective pressures on the sites were not always higher for human influenza compared to other hosts. Additionally, selective pressure on position 31 did not increase after the introduction of amantadine. Although there is a possibility of drug pressure on human influenza, we could not find positive pressure on position 31.
PMID: 19651904 [PubMed - as supplied by publisher]
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Large-Scale Sequence Analysis of M Gene of Influenza A Viruses from Different Species: Mechanisms for Emergence and Spread of Amantadine Resistance.
Furuse Y, Suzuki A, Oshitani H. - Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryou-machi Aoba-ku, Sendai, 980-8575, Japan.
Influenza A virus infects many species and amantadine is used as an antiviral agent. Recently, a substantial increase in amantadine-resistant strains has been reported, most of which have a substitution at amino acid position 31 in the M2 gene. Understanding the mechanism responsible for the emergence and spread of antiviral resistance is important for developing a treatment protocol for seasonal influenza and in deciding a policy for antiviral stockpiling for pandemic influenza. The present study was conducted to identify the existence of drug pressure on the emergence and spread of amantadine-resistant influenza A viruses. We analyzed more than 5000 sequencing data of viruses and constructed a phylogenetic tree to calculate selective pressures on sites in the M2 gene associated with amantadine resistance (positions of 26, 27, 30, and 31) among different hosts. The phylogenetic tree revealed that the emergence and spread of the drug-resistant M gene in different hosts and subtypes was independent and not through reassortment. For human influenza, positive selection was detected only at position 27. Selective pressures on the sites were not always higher for human influenza compared to other hosts. Additionally, selective pressure on position 31 did not increase after the introduction of amantadine. Although there is a possibility of drug pressure on human influenza, we could not find positive pressure on position 31.
Because the recent rapid increase in drug-resistant virus is associated with the substitution at position 31, the resistance may not be related to drug use.
PMID: 19651904 [PubMed - as supplied by publisher]
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