title: Identification of oseltamivir resistance among pandemic and seasonal influenza A (H1N1) viruses by an His275Tyr genotyping assay using the cycling probe method.
abstract: Neuraminidase inhibitors are agents used against influenza viruses; however, the emergence of drug-resistant strains is a major concern. Recently, the prevalence of oseltamivir-resistant seasonal influenza A (H1N1) virus increased globally and the emergence of oseltamivir-resistant pandemic influenza A (H1N1) 2009 viruses was reported. In this study, we developed a cycling probe real-time PCR method for the detection of oseltamivir-resistant seasonal influenza A (H1N1) and pandemic influenza A (H1N1) 2009 viruses. We designed two sets of primers and probes that were labeled with 6-carboxyfluorescein or 6-carboxy-X-rhodamine to identify single nucleotide polymorphisms (SNPs) that correspond to a histidine and a tyrosine at position 275 in the neuraminidase protein, respectively. These SNPs confer susceptibility and resistance to oseltamivir, respectively. In the 2007-2008 season, the prevalence of oseltamivir-resistant H1N1 viruses was 0% (0/72), but in the 2008-2009 season, it increased to 100% (282/282). In the 2009-2010 season, all of the pandemic influenza A (H1N1) 2009 viruses were susceptible to oseltamivir (0/73, 0%). This method is sensitive and specific for the screening of oseltamivir-resistant influenza A (H1N1) viruses. This method is applicable to routine laboratory-based monitoring of drug resistance and patient management during antiviral therapy.
authors.affiliation: Division of Public Health, Department of Infectious Disease Control and International Medicine, Niigata University, Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-Dori, Chuo Ward, Niigata City, Niigata Prefecture 951-8510, Japan. yasshi@med.niigata-u.ac.jp
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Reiko
authors.initials: R
authors.lastname: Saito
authors.forename: Isamu
authors.initials: I
authors.lastname: Sato
authors.forename: Hassan
authors.initials: H
authors.lastname: Zaraket
authors.forename: Makoto
authors.initials: M
authors.lastname: Nishikawa
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tamura
authors.forename: Clyde
authors.initials: C
authors.lastname: Dapat
authors.forename: Isolde
authors.initials: I
authors.lastname: Caperig-Dapat
authors.forename: Tatiana
authors.initials: T
authors.lastname: Baranovich
authors.forename: Takako
authors.initials: T
authors.lastname: Suzuki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuki
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics*; D000998:Antiviral Agents / Q000494:pharmacology*; D005838:Genotype; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects* / Q000235:genetics; D007251:Influenza, Human / Q000821:virology*; D008826:Microbial Sensitivity Tests / Q000379:methods; D058889:Molecular Typing / Q000379:methods*; D009439:Neuraminidase / Q000235:genetics*; D053139:Oseltamivir / Q000494:pharmacology*; D020641:Polymorphism, Single Nucleotide; D012680:Sensitivity and Specificity; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D000998:Antiviral Agents; D014764:Viral Proteins; D053139:Oseltamivir; C487630:NA protein, influenza A virus; D009439:Neuraminidase