title: Prevalence of Influenza A(H1N1)pdm09 Virus Resistant to Oseltamivir in Shiraz, Iran, During 2012 - 2013.
abstract: BACKGROUND
  Oseltamivir has been used as a drug of choice for the prophylaxis and treatment of human influenza A(H1N1)pdm09 infection across the world. However, the most frequently identified oseltamivir resistant virus, influenza A(H1N1)pdm09, exhibit the H275Y substitution in NA gene.
  
  
  OBJECTIVE
  This study aimed to determine the prevalence and phylogenetic relationships of oseltamivir resistance in influenza A(H1N1)pdm09 viruses isolated in Shiraz, Iran.
  
  
  METHODS
  Throat swab samples were collected from 200 patients with influenza-like disease from December 2012 until February 2013. A total of 77 influenza A(H1N1)pdm09 positive strains were identified by real-time polymerase chain reaction (PCR). Oseltamivir resistance was detected using quantal assay and nested-PCR method. The NA gene sequencing was conducted to detect oseltamivir-resistant mutants and establish the phylogeny of the prevalent influenza variants.
  
  
  RESULTS
  Our results revealed that A(H1N1)pdm09 viruses present in these samples were susceptible to oseltamivir, and contained 5 site specific mutations (V13G, V106I, V241I, N248D, and N369K) in NA gene. These mutations correlated with increasing expression and enzymatic activity of NA protein in the influenza A(H1N1)pdm09 viruses, which were closely related to a main influenza A(H1N1)pdm09 cluster isolated around the world.
  
  
  CONCLUSIONS
  A(H1N1)pdm09 viruses, identified in this study in Shiraz, Iran, contained 5 site specific mutations and were susceptible to oseltamivir.
authors.affiliation: Department of Bacteriology and Virology, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors.forename: Nastaran
authors.initials: N
authors.lastname: Khodadad
authors.affiliation: Department of Bacteriology and Virology, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors.forename: Afagh
authors.initials: A
authors.lastname: Moattari
authors.affiliation: Department of Virology, Tehran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Shamsi Shahr Abadi
authors.affiliation: Department of Pediatrics, Namazi Hospital, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors.forename: Mohammad Rahim
authors.initials: MR
authors.lastname: Kadivar
authors.affiliation: Department of Bacteriology and Virology, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors.forename: Jamal
authors.initials: J
authors.lastname: Sarvari
authors.affiliation: Department of Bacteriology and Virology, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors.forename: Forough
authors.initials: F
authors.lastname: Tavakoli
authors.affiliation: Department of Bacteriology and Virology, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors.forename: Neda
authors.initials: N
authors.lastname: Pirbonyeh
authors.affiliation: Department of Bacteriology and Virology, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors.forename: Amir
authors.initials: A
authors.lastname: Emami
keywords: Influenza A(H1N1) Virus; Iran; Oseltamivir