title: Characterization of HIV-1 subtypes and viral antiretroviral drug resistance in men who have sex with men in Beijing, China.
abstract: OBJECTIVE
  To characterize the HIV subtypes prevalent among men who have sex with men (MSM) in Beijing and to perform baseline genotypic analysis of anti-HIV drug resistance in this population.
  
  
  METHODS
  In 2005, half of new HIV-1 infections occurred through unprotected sex in China. MSM have become the second most vulnerable group to HIV infection. HIV-1-prevalent subtypes among this population as well as their genetic and biological characteristics have not been well defined.
  
  
  METHODS
  A cohort consisting of 54 HIV-seropositive MSM were recruited with written informed consent. Samples of plasma and whole blood were collected to characterize prevalent HIV-1 subtypes with overlapped polymerase chain reaction followed by sequencing and phylogenic analysis. The genotypes of anti-HIV drug resistance were analysed.
  
  
  RESULTS
  Among the amplified gag sequences, HIV-1 subtype B accounted for 71.1% (32/45), followed by CRF01_AE for 24.4% (11/45) and CRF07_BC for 4.4% (2/45). A similar trend was observed among the amplified env sequences. Six antiretroviral therapy (ART)-naive participants (15%) carried drug-resistant mutations, with intermediate to high-level resistance both to drugs used in China including zidovudine, didanosine, nevirapine, stavudine, and lamivudine, and drugs not used in China such as delavirdine, efavirenz, tenofovir, emtricitabine and abacavir. We also have concerns over nelfinavir and atazanavir regarding their future use in China because low-level resistance was also seen against those drugs.
  
  
  CONCLUSIONS
  The HIV-1 strains prevalent among Beijing MSM include complex subtypes derived from recombination. High rates of HIV drug-resistant mutations in ART-naive patients represent a serious challenge for HIV prevention and treatment programmes in China.
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, China CDC, Beijing 100050, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhang
authors.forename: Shenwei
authors.initials: S
authors.lastname: Li
authors.forename: Xinping
authors.initials: X
authors.lastname: Li
authors.forename: Xinxu
authors.initials: X
authors.lastname: Li
authors.forename: Jianqing
authors.initials: J
authors.lastname: Xu
authors.forename: Dongliang
authors.initials: D
authors.lastname: Li
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Ruan
authors.forename: Hui
authors.initials: H
authors.lastname: Xing
authors.forename: Xiaoxi
authors.initials: X
authors.lastname: Zhang
authors.forename: Yiming
authors.initials: Y
authors.lastname: Shao
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000494:pharmacology; D001727:Bisexuality; D015331:Cohort Studies; D024921:Drug Resistance, Multiple, Viral / Q000235:genetics; D024882:Drug Resistance, Viral / Q000235:genetics; D019143:Evolution, Molecular; D015658:HIV Infections / Q000453:epidemiology / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D012367:RNA, Viral / Q000097:blood / Q000235:genetics; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D014505:Urban Population / Q000706:statistics & numerical data
chemical_list: D019380:Anti-HIV Agents; D012367:RNA, Viral