title: S-gene sequences and genotype-related restriction sites in hepatitis B virus carriers in Turkey.
abstract: BACKGROUND
  Although hepatitis B virus (HBV) infections are a major health problem in Turkey, there is little information on the genotype distribution of the virus. In this study, HBV genotypes were determined by DNA sequencing and restriction enzyme analysis of the S gene.
  
  
  METHODS
  The S genes of hepatitis B virus isolated from 23 chronically infected HBV-DNA-positive Turkish patients were amplified and directly sequenced. Nucleotide sequences were then aligned with reference isolates from the GenBank database and subjected to phylogenetic analysis. HBsAg subtype-specific amino acid substitutions at codons 122, 127, 134, 159, and 160 were analyzed using translated sequences. The amplified products were also subjected to restriction enzyme analysis using endonucleases Mva I, Rsa I, and Hinf I.
  
  
  RESULTS
  Phylogenetic analysis showed clustering of all samples with genotype D sequences. The mean intragroup divergence was 0.95% (range 0.00%-4.00%). All isolates were ayw2, as predicted from translated sequences. The results of the restriction enzyme analysis of the samples were consistent with the phylogenetic analysis.
  
  
  CONCLUSIONS
  Our data complement the findings that genotype D viruses are prevalent in the Turkish population. Being rapid and inexpensive, restriction enzyme analysis described in this study should be useful for large-scale epidemiological analysis of HBV infections.
authors.affiliation: Dept. of Microbiology, Dokuz Eylül University Faculty of Medicine, Balcova 35340, Izmir-Turkey.
authors.forename: N
authors.initials: N
authors.lastname: Sentürker Güldas
authors.forename: Y H
authors.initials: YH
authors.lastname: Abacioğlu
mesh_terms: D000595:Amino Acid Sequence; D002353:Carrier State; D004269:DNA, Bacterial / Q000032:analysis*; D016021:Epidemiologic Studies; D005838:Genotype; D006509:Hepatitis B / Q000453:epidemiology*; D006515:Hepatitis B virus / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity*; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D015995:Prevalence; D017422:Sequence Analysis, DNA; D014421:Turkey / Q000453:epidemiology
chemical_list: D004269:DNA, Bacterial