title: [Naturally occurring NS5B variants resistant to non-nucleoside or nucleoside polymerase inhibitors among treatment-naïve hepatitis C patients in south China].
abstract: OBJECTIVE
  To determine the prevalence of mutations in the non-structural protein 5B (NS5B) of the hepatitis C virus (HCV),which are associated with natural resistance to non-nucleoside and nucleoside polymerase inhibitors (PIs),in treatment-naive hepatitis C patients in south China.
  
  
  METHODS
  A nested PCR protocol that amplified three different regions of NS5B was used to detect the naturally occurring drag-resistant substitutions.Direct PCR sequencing was performed to analyze the sequences.
  
  
  RESULTS
  NS5B mutations known to confer resistance to nucleoside PIs,such as A15G,S96T and S282T,were mainly detected in HCV genotype 6a (20/88,22.73%).Of the NS5B mutations known to confer resistance to non-nucleoside PIs,C316N and S365A were detected in HCV genotype lb (60/60,100% and 2/60,3.33%, respectively) and I482L and V499A were mainly detected in HCV genotype 2a (9/9,100% and 4/4,100%, respectively) and HCV genotype 6a (9/9,100% and 4/4,100%, respectively).Other NS5B mutations found in the study population included A1 5S,S365F,S365P,S368A and S368L;although none of these has been previously shown to confer resistance to PIs.
  
  
  CONCLUSIONS
  Naturally occurring dominant PI resistance mutations in NS5B exist in treatment-na(i)ve hepatitis C patients in south China and may be related to the virus genotype.
authors.affiliation: Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou 510630, China.
authors.forename: Zhanyi
authors.initials: Z
authors.lastname: Li
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Qingxian
authors.initials: Q
authors.lastname: Cai
authors.forename: Xiaoqiong
authors.initials: X
authors.lastname: Shao
authors.forename: Ying
authors.initials: Y
authors.lastname: Yan
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Zhao
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology; D002681:China; D024882:Drug Resistance, Viral; D005838:Genotype; D016174:Hepacivirus / Q000187:drug effects / Q000235:genetics*; D006526:Hepatitis C / Q000188:drug therapy / Q000821:virology*; D006801:Humans; D009154:Mutation; D017361:Viral Nonstructural Proteins / Q000235:genetics*; D012324:RNA-Dependent RNA Polymerase
chemical_list: D000998:Antiviral Agents; D017361:Viral Nonstructural Proteins; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase