[Genetic variability of hepatitis B virus isolates among population of Shuryskarsky area of Yamal-Nenets autonomous region]

Abstract

The purpose of this work was to determine occurrence of serological markers of hepatites B and to describe subtypes of a superficial antigen and genotypes of hepatitis B virus (HBV) isolates among indigenous population of Yamal-Nenets Autonomous Region (YNAR), Russia.

Methods: We investigated 657 serum samples from inhabitants of Shuryskarsky area of YNAR. ELISA method was used to define the hepatitis B markers: HBsAg, anti-HBs (total) and anti-HBc (IgG and IgM). The HBsAg-positive samples were PCR-tested for the presence of HBV DNA. Genotyping of isolates was by sequencing of the Pre-Sl/Pre-82/S region of HBV genome and phylogenetic analysis. Definition of HBsAg subtypes was executed by two methods: ELISA with subtype-specific monoclonal antibodies and S-gene nucleotide sequence analysis.

Results: The following occurrence of hepatitis B markers was observed: HBsAg - 3.2%, anti-HBs (total) - 36.2%, anti-HBc IgG - 30.3%, anti-HBc IgM - 1.6%. Frequency of carrying even one of the markers in the observed population was 47.5%. HBV DNA was found in 17 HBsAg-positive samples. Pre-SI, Pre-S2 and S regions sequences were determined for all HBV DNA-positive samples. The phylogenetic analysis showed an accessory of all investigated HBV isolates to genotype D. HBsAg subtypes distribution appeared the following: ayw2 - 23.5%, ayw3 - 70.6%, adw2 - 5.9%. Results of definition of the subtype ELISA method and by the analysis of S gene nucleotide sequences have coincided in 10/11 (90.1%) cases.

Conclusions: The indigenous population of Shuryskarsky area of YNAR belongs to groups with average HBV carrying. Absolute domination of genotype D (subtypes ayw2, ayw3 and adw2) was revealed. High percentage of concurrence of HBsAg subtypes detected by the ELISA method and method of the analysis of S gene primary structure (90%) was observed. Sequencing of HBV S-gene is preferable to define HBsAg subtypes.