Abstract : Genotypes (A to H) of hepatitis B virus (HBV) influence liver disease progression and response to a
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Abstract : Genotypes (A to H) of hepatitis B virus (HBV) influence liver disease progression and response to antiviral therapy in HBV-infected patients. Several methods have been developed for rapid genotyping of HBV strains. However some of these methods may not be suitable for developing countries. The performance of INNO-LiPA HBV Genotyping assay (LiPA) direct DNA sequencing and subtractive PCR-RFLP of genotype-specific HBV genome regions were evaluated for accurately determining the HBV genotypes by analyzing sera (n = 80) samples from chronic HBV patients. Both LiPA and DNA sequencing identified 63 4 and 13 HBV strains as belonging to genotype D genotype A and mixed genotype A and D respectively. On the contrary the PCR-RFLP-based method correctly identified all 4 genotype A but only 56 of 63 genotype D strains. Seven genotype D strains yielded indeterminate results. DNA sequence comparisons showed that a single nucleotide change in the target region generated an additional restriction site for Nla IV that compromised the accuracy of this method. Furthermore all the mixed genotype A and D strains were identified only as genotype A strains. The data show that the PCR-RFLP-based method incorrectly identified some genotype D strains and failed to identify mixed genotype infections while LiPA and DNA sequencing yielded accurate results.
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