title: Hemagglutinin and neuraminidase genes of influenza B viruses circulating in Riyadh, Saudi Arabia during 2010-2011: evolution and sequence analysis.
abstract: Influenza viruses are known as continuing threats to human public health every year worldwide. Evolutionary dynamics of influenza B viruses in humans are in a unique progression having two lineages; B/Yam and B/Vic-like viruses, which are circulating simultaneously worldwide. There is a considerable lack of data on influenza B viruses circulating in Saudi Arabia. During the winter-spring season of 2010-2011, 80 nasopharyngeal aspirates were collected from hospitalized patients with flu-like symptoms in Riyadh. Screening of samples by one-step RT-PCR identified three (3.8%) influenza B viruses. Sequencing of hemagglutinin (HA) and neuraminidase (NA) genes was performed to analyze influenza B viruses circulating in Riyadh as compared to the globally circulating strains. Several common and six unique amino acid substitutions were observed for both HA and NA genes of influenza B Saudi strains. Three unique substitutions (T182A, D196N, and K254R) were identified in HA gene of the B/Yam-like Riyadh strains. In NA gene, a unique common substitution (D53G) was found in all Riyadh strains, while two unique substitutions (L38P, G233R) were recognized only in B/Vic-like Riyadh strains. Riyadh strains were also found to contain N-glycosylation site in HA gene of both B/Vic and B/Yam lineages at positions 197-199 (NET) and 196-198 (NNK/DNK), respectively. The significance of these mutations on the antigenicity of both lineages is discussed herein. The unique changes observed in HA and NA genes of influenza B Riyadh strains support strongly the need for continuous surveillance and monitoring of new evolving strains that might pose threat to the Saudi community.
authors.affiliation: Center of Excellence in Biotechnology Research, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Ghazanfar
authors.initials: G
authors.lastname: Ali
authors.forename: Haitham M
authors.initials: HM
authors.lastname: Amer
authors.forename: Fahad N
authors.initials: FN
authors.lastname: Almajhdi
mesh_terms: D019943:Amino Acid Substitution; D014644:Genetic Variation; D005838:Genotype; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics*; D006760:Hospitalization; D006801:Humans; D009981:Influenza B virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D009305:Nasopharynx / Q000821:virology; D009439:Neuraminidase / Q000235:genetics*; D010802:Phylogeny; D012367:RNA, Viral; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012529:Saudi Arabia / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D012367:RNA, Viral; D014764:Viral Proteins; C541223:NA protein, influenza B virus; D009439:Neuraminidase
keywords: DNA sequencing; Saudi Arabia; hemagglutinin; influenza B virus; neuraminidase; phylogenetic Analysis