title: Distribution of HIV-1 subtypes seen in an AIDS clinic in Sao Paulo City, Brazil.
abstract: OBJECTIVE
  To determine the distribution of HIV-1 subtypes in Sao Paulo, Brazil.
  
  
  METHODS
  Samples were obtained from 80 consecutive HIV-1-infected individuals attending the Immunodeficiency Clinic at the University of Sao Paulo in 1993. Peripheral blood mononuclear cells (PBMC) were separated by Ficoll-Hypaque gradient and a portion was used for routine CD4 counts; the remainder were frozen. PBMC were proteinase-K-digested and DNA-purified by organic extraction. Samples were amplified for the env region of HIV, and envelope sequence subtypes determined by heteroduplex mobility analysis using prototypic subtypes as references. A subset of these were also sequenced through the C2-V3 region of env.
  
  
  RESULTS
  A total 69 of 80 samples yielded env polymerase chain reaction product enabling subtype determination; samples that did not amplify were those with low DNA yields. Among 12 injecting drug users (IDU) or sexual partners of IDU, four were typed as clade F and eight as clade B. Forty-three homosexual men or female sexual partners of bisexual men were typed as clade B. The 14 additional cases without known risk factors were typed as clade B.
  
  
  CONCLUSIONS
  These data suggest that subtype F is related to injecting drug use in Brazil.
authors.affiliation: Instituto Adolfo Lutz, Sao Paulo, Brazil.
authors.forename: E C
authors.initials: EC
authors.lastname: Sabino
authors.forename: R S
authors.initials: RS
authors.lastname: Diaz
authors.forename: L F
authors.initials: LF
authors.lastname: Brigido
authors.forename: G H
authors.initials: GH
authors.lastname: Learn
authors.forename: J I
authors.initials: JI
authors.lastname: Mullins
authors.forename: A L
authors.initials: AL
authors.lastname: Reingold
authors.forename: A J
authors.initials: AJ
authors.lastname: Duarte
authors.forename: A
authors.initials: A
authors.lastname: Mayer
authors.forename: M P
authors.initials: MP
authors.lastname: Busch
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000821:virology*; D000595:Amino Acid Sequence; D001483:Base Sequence; D001938:Brazil / Q000453:epidemiology; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D015752:Genes, env; D015497:HIV-1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009692:Nucleic Acid Heteroduplexes; D012189:Retrospective Studies
chemical_list: D004279:DNA, Viral; D009692:Nucleic Acid Heteroduplexes