tailieunhanh - Báo cáo y học: " Molecular analysis of HBV genotypes and subgenotypes in the Central-East region of Tunisia"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Molecular analysis of HBV genotypes and subgenotypes in the Central-East region of Tunisia | Hannachi et al. Virology Journal 2010 7 302 http content 7 1 302 VIROLOGY JOURNAL RESEARCH Open Access Molecular analysis of HBV genotypes and subgenotypes in the Central-East region of Tunisia 1 1 2 3 A I- 1 4 2 Naila Hannachi Nadia Ben Fredj Olfa Bahri Vincent Thibault Asma Ferjani Jawhar Gharbi Henda Triki Jalel Boukadida 1 Abstract Background In Tunisia country of intermediate endemicity for Hepatitis B virus HBV infection most molecular studies on the virus have been carried out in the North of the country and little is known about other regions. The aim of this study was to determine HBV genotype and subgenotypes in Central-East Tunisia. A total of 217 HBs antigen positive patients were enrolled and determination of genotype was investigated in 130 patients with detectable HBV DNA. HBV genotyping methods were PCR-RFLP on the pre-S region a PCR using type-specific primers in the S region TSP-PCR and partial sequencing in the pre-S region. Results Three genotypes D B and A were detected by the PCR-RFLP method and two D and A with the TSP-PCR method the concordance between the two methods was 93 . Sequencing and phylogenetic analysis of 32 strains retrieved the same genotype D and A for samples with concordant results and genotype D for samples with discordant results. The sequences of discordant genotypes had a restriction site in the pre-S gene which led to erroneous result by the PCR-RFLP method. Thus prevalence of genotype D and A was 96 and 4 respectively. Phylogenetic analysis showed the predominance of two subgenotypes D1 55 and D7 41 . Only one strain clustered with D3 subgenotype 3 . Conclusions Predominance of subgenotype D7 appears to occur in northern regions of Africa with transition to subgenotype D1 in the East of the continent. HBV genetic variability may lead to wrong results in rapid genotyping methods and sequence analysis is needed to clarify atypical results. Background Hepatitis B virus HBV infection is one of the major .