title: Hepatitis B virus genotyping among chronic hepatitis B individuals with resistance to Lamivudine in shahrekord, iran.
abstract: BACKGROUND
  Hepatitis B infection, caused by hepatitis B Virus (HBV), is one of the major global public health problems. Hepatitis B Virus genotypes appear to show varying geographic distribution with possible pathogenic and therapeutic differences. Knowledge of HBV genotypes is very important for clinical treatment. Lamivudine is a nucleoside analogue that is clinically used to treat chronic hepatitis B infection. However, the main problem with the application of lamivudine is the development of viral resistance to the treatment with this anti viral drug. Besides, it has been suggested that lamivudine -resistant HBV may be genotype dependent. However, HBV genotype distribution and the biological relevance in this region are poorly understood.
  
  
  OBJECTIVE
  The current study aimed to determine hepatitis B genotypes and their correlation with lamivudine- resistant HBV frequency among patients with chronic hepatitis B from Shahrekord, Iran.
  
  
  METHODS
  Hepatitis B virus DNA was detected by conventional PCR in some of the serum samples obtained from HBsAg-positive Chronic Hepatitis B (CHB) patients who were referred to Health Centers of Shahrekord for routine monitoring of the disease. Subsequently, using real-time PCR, the DNA samples were used for genotyping and analysis of resistance to lamivudine.
  
  
  RESULTS
  The DNA was detected in 23 out of 116 (19.82%) of the studied samples. Genotypes D and C were found in 17 out of 23 (73.9%), and in 6 out of 23 (26.1%) of the samples, respectively. To the authors' best knowledge, the current study is the first report on isolation of Genotype C from Iran. Two out of 17 (11.76%), and 6 out of 6 (100%) of genotypes D and C were resistant to lamivudine, respectively. Resistance to this drug was significantly different between genotypes C and D (P <0.001).
  
  
  CONCLUSIONS
  In addition to genotype D, other lamivudine resistant hepatitis B genotypes might be distributed in Iran.
authors.affiliation: Medicinal Plant Research Center, Shahrekord University of Medical Sciences, Shahrekord, IR Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Karimi
authors.affiliation: Medicinal Plant Research Center, Shahrekord University of Medical Sciences, Shahrekord, IR Iran.
authors.forename: Loghman
authors.initials: L
authors.lastname: Salimzadeh
authors.affiliation: Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Nader
authors.initials: N
authors.lastname: Bagheri
keywords: Genotyping Techniques; Hepatitis B, Chronic; Polymerase Chain Reaction