title: Genetic diversity of influenza B virus in 2009-2010 and 2010-2011 in Tunisia.
abstract: OBJECTIVE
  The authors had for aim to characterize influenza B strains having circulated in Tunisia to identify new mutations and compare them with reference strains.
  
  
  METHODS
  The epidemiological surveillance of influenza allowed identifying 19 patients with symptoms related to respiratory infection, who had been infected by influenza B strains isolated in several regions of Tunisia in 2009-2010 and in 2010-2011. Laboratory identification and detection of mutations in the segment encoding hemagglutinin of influenza viruses was performed by real time PCR and sequencing.
  
  
  RESULTS
  The two influenza B Tunisian strains of the 2009-2010 season belonged to the Victoria lineage, whereas 2010-2011 season strains belonged to B/Victoria/2/87 and B/Yamagata/16/88 lineages with a dominance of the Yamagata lineage (76%). This study allowed identifying amino acid substitutions: T121A, S150I, N165Y, T181A, G183R, D196N, S229D, M251V and K253R in the B/Yamagata lineage; L58P, N75K, K109N, N165K, S172P and K257R into the B/Victoria lineage. These mutations were specific of Tunisian groups of variants. Most influenza B-Yamagata lineage viruses (69%) were associated with severe cases.
  
  
  CONCLUSIONS
  Molecular analysis of the various influenza B strains circulating in Tunisia is useful to detect new mutations that can modify the phenotype of influenza strains.
authors.affiliation: National Influenza Centre-Tunis, Unit Virology, Microbiology Laboratory, Charles Nicolle's Hospital, boulevard 9-Avril, 1006 Tunis, Tunisia. awatefbio@ymail.com
authors.forename: A
authors.initials: A
authors.lastname: El Moussi
authors.forename: M A
authors.initials: MA
authors.lastname: Ben Hadj Kacem
authors.forename: J
authors.initials: J
authors.lastname: Ledesma
authors.forename: F
authors.initials: F
authors.lastname: Pozo
authors.forename: M
authors.initials: M
authors.lastname: Teresa Cuevas
authors.forename: I
authors.initials: I
authors.lastname: Casas
authors.forename: A
authors.initials: A
authors.lastname: Slim
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D004196:Disease Outbreaks; D014644:Genetic Variation; D006389:Hemagglutinins, Viral / Q000737:chemistry / Q000235:genetics; D006801:Humans; D009981:Influenza B virus / Q000235:genetics* / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D017354:Point Mutation; D011159:Population Surveillance; D012367:RNA, Viral / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014416:Tunisia / Q000453:epidemiology
chemical_list: D006389:Hemagglutinins, Viral; D012367:RNA, Viral
keywords: B/Victoria lineage; B/Yamagata lineage; Grippe B; Influenza B; Lignée B-Victoria; Lignée B-Yamagata; Mutation; Phylogeny; Phylogénie; Sequencing; Séquençage