Preliminary Study On Genotype Of Hepatitis B Virus Detected From Shanxi In China

Objective:Hepatitis B virus(HBV)is one of the majior causative agents of acute and chronic liver disease worldwide and is believed to be responsible for a million deaths annually.Eight genotypes of HBV,A to H,have been described on the basis of similarity of the complete genomes sequence.Now genotype is a useful tool in understanding the epidemiology of HBV infection.Nucleotide variability between HBV genotypes has been used to trace routes of HBV transmission.And there is increasing evidence that the clinical picture,the response to treatment and the long-term prognosis may differ depending on which genotype has infected the patient.In our study,we used the method of sequencing and phylogenetic analysis to determine the distribution of genetypes,subtypes and S mutation of HBV deteced from Shanxi in china.Methods:Serum samples were collected from HBsAg carriers of Shanxi Medical University First Clinical Hospital.The S and C genes were amplified by nested PCR and semi-nested PCR and the PCR products obtained were used for direct sequencing.The viral genotype was identified after phylogenetic analysis of the sequences obtained and 25 GeneBank reference sequences corresponding to HBV genotype A to H.we confirm that the dominant genotype of HBV detected from ShanXi in China.And according to the amino acid sequences deduced from the nucleotide sequences of S gene,we confirm the dominant subtype of HBV detected from Shanxi in China.Results:(1)we found that the dominant genotype of HBV detected from Shanxi in China is C and the minority is B and the lest is a C/B hybrid.(2)And according to the amino acid sequences deduced from the nucleotide sequences of S gene,we found the dominant subtype of HBV detected from Shanxi in China is aywl and the minority is adr.(3)The double mutation in BCP(T1762/A1764)was obviously more frequent in genotype C(37.5%)than that in genotype B patients(11.1%,P＜0.05).However,there was no significant difference of the PreC(A1896) mutation between genotypes B(11.1%)and C(12.5%,P＞0.05).No relationship between expression of HBeAg and double-mutation of BCP(T1762/A1764)or PreC(A1896)mutation was found.The result of qPCR was that the Ct value was significantly higher in HBeAg positive group than that in anti-HBe positive group(P＜0.05).There was no significant difference of HBV DNA between BCP double mutant type and the wild type in HBeAg and anti-HBe groups.The same comparison result was obtained in preC A1896 mutant and the wild type.Conclusion:In our study,we determine the main genotype and subtype of hepatitis B virus (HBV)prevailed in Shanxi and the mutation in BCP and the PreC.It can be used to make a prevention strategy and instruct clinical treatment.