title: Phylogenetic analysis of torque teno virus in hepatitis C virus infected patients in shiraz.
abstract: BACKGROUND
  Torque teno virus (TTV) was the first human Circoviridae detected in a Japanese patient with unknown hepatitis in 1997. Subsequently, several studies performed to evaluate different aspects of Torque teno virus pathogenesis.
  
  
  OBJECTIVE
  The present study aimed to determine dominant genotype of Torque teno virus in chronic hepatitis disease using 5΄-UTR sequence among patients infected by hepatitis C virus in Shiraz - Iran.
  
  
  METHODS
  The study conducted in 240 patients with chronic hepatitis C from Prof. Alborzi Clinical Microbiology Research Center. The presence of Torque teno virus DNA and its genotype in plasma was assessed by nested polymerase chain reaction using two primer sets for 5΄-UTR and N22 regions. Phylogenetic analysis was performed based on 5΄-UTR region.
  
  
  RESULTS
  DNA of Torque teno virus was detected in 220 out of 240 (92 %) patients with chronic hepatitis C by the use of 5΄-UTR primer based PCR method and in 12 out of 240 (5%) by the use of N22 primer. Based on phylogenetic analysis it was shown that the Dominant genotype in this study was 11. Genotypes 1, 3, 17, and 22 were also detected. Some sequences could not be classified to a specific genotype.
  
  
  CONCLUSIONS
  The prevalence of Torque teno virus DNA in patients with chronic hepatitis C disease by the use of 5΄-UTR primer appeared to be higher compared to that revealed by N22 primer. We observed five genotypes among hepatitis C chronic patients in our study.
authors.affiliation: Department of Virology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, IR Iran.
authors.forename: Azra
authors.initials: A
authors.lastname: Kenar Koohi
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Ravanshad
authors.forename: Manouchehr
authors.initials: M
authors.lastname: Rasouli
authors.forename: Shahab
authors.initials: S
authors.lastname: Falahi
authors.forename: Ashraf
authors.initials: A
authors.lastname: Baghban