title: [Rapid detection of genotypes of TT virus using a heteroduplex mobility assay].
abstract: OBJECTIVE
  To establish a simple, sensitive, specific and less-costly method for detecting genotypes of TT virus (TTV).
  
  
  METHODS
  TTV DNA was tested by nested polymerase chain reaction (nPCR) in sera from 180 patients with different types of viral hepatitis and 96 normal individuals in Beijing. TTV genotypes were determined in 40 sera collected from TTV DNA positive patients by heteroduplex mobility assay (HMA) and through sequencing.
  
  
  RESULTS
  The positive rates of TTV DNA in viral hepatitis patients and normal individuals were 22.2% (40/180) and 19.8% (19/96), respectively (chi(2) = 0.220, P = 0.639). TTV DNA positive rates of patients with hepatitis A, B, C, E and non-A to E were 20.0% (6/30), 16.7% (5/30), 23.3% (7/30), 36.7% (11/30) and 18.3% (11/60), respectively. Of 40 TTV DNA positive patients, 20 (50.0%) were TTV G1, 7 (17.5%) TTV G2, 10 (25.0%) coinfected with different genotypes of TTV, and 3 untyped by HMA. Twenty G1 and 7 G2 detected by HMA were confirmed by sequence analysis. Of 10 patients coinfected with different genotypes of TTV, 5 were G1 and G2, 2 G1 and G3, 1 G1 and G4, 1 G1 and G3, and 1 with G1, G2 and G3 coinfections.
  
  
  CONCLUSIONS
  HMA was recognized as simple, sensitive, specific and less-costly, thus could be used for genotyping of TTV.
authors.affiliation: Department of Microbiology, Peking University Health Science Center, Beijing 100083, China.
authors.forename: Zhong-ping
authors.initials: ZP
authors.lastname: He
authors.forename: Hui
authors.initials: H
authors.lastname: Zhuang
authors.forename: Jun
authors.initials: J
authors.lastname: Yao
authors.forename: Qing-ming
authors.initials: QM
authors.lastname: Dong
authors.forename: Wang-su
authors.initials: WS
authors.lastname: Dai
authors.forename: Shu-jing
authors.initials: SJ
authors.lastname: Song
mesh_terms: D004279:DNA, Viral / Q000032:analysis; D005838:Genotype; D006525:Hepatitis, Viral, Human / Q000821:virology; D020180:Heteroduplex Analysis / Q000379:methods*; D006801:Humans; D010802:Phylogeny; D022783:Torque teno virus / Q000145:classification / Q000235:genetics*
chemical_list: D004279:DNA, Viral