title: Hepatitis B virus (HBV) genotype and YMDD motif mutation profile among patients infected with HBV and untreated with lamivudine.
abstract: OBJECTIVE
  A few reports exist on hepatitis B virus (HBV) genotype distribution in Iran; however the sample sizes of these studies are insufficient. The first objective of this study was to determine the HBV genotype distribution with a large sample size (147 specimens). The second objective was to determine the incidence of the lamivudine-resistant YMDD mutant profile among HBV-infected patients not treated with lamivudine; some studies have reported that YMDD mutants are detectable even before antiviral treatment.
  
  
  METHODS
  We used two cost-effective PCR-based methods that have been developed in-house: gap-PCR and artificially created restriction site-PCR (ACRS-PCR). Also, 11 samples were randomly selected and bi-directionally sequenced and subjected to phylogenetic analysis.
  
  
  RESULTS
  Gap-PCR results revealed genotype D of HBV in all patients, and ACRS-PCR results disclosed the absence of mutation within the YMDD motif before antiviral therapy in the study population. Phylogenetic analysis supported the former genotyping results with the segregation of all Iranian HBV isolates in the genotype D branch with a high bootstrap value (99%, 1000 replicates).
  
  
  CONCLUSIONS
  The present study using two cost-effective methods showed that genotype D of HBV is dominant among Iranian HBV-infected subjects, and HBV lamivudine-resistant strains do not exist naturally among Iranian patients not treated with lamivudine.
authors: Biotechnology Department, Pasteur Institute of Iran, 13164 Tehran, Iran. samini@ukaachen.de
authors: Samad
authors: S
authors: Amini-Bavil-Olyaee
authors: Sayed Younes
authors: SY
authors: Hosseini
authors: Farzaneh
authors: F
authors: Sabahi
authors: Seyed-Moayed
authors: SM
authors: Alavian
mesh_terms: D000328:Adult; D000368:Aged; D020816:Amino Acid Motifs / Q000187:drug effects / Q000235:genetics*; D024882:Drug Resistance, Viral / Q000235:genetics; D005260:Female; D015684:Gene Products, pol / Q000235:genetics*; D005838:Genotype; D006515:Hepatitis B virus / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D007492:Iran / Q000453:epidemiology; D019259:Lamivudine / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D010802:Phylogeny; D018894:Reverse Transcriptase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D017422:Sequence Analysis, DNA
chemical_list: D015684:Gene Products, pol; C066027:P protein, Hepatitis B virus; D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine