title: The HIV epidemic in the Amazon Basin is driven by prototypic and recombinant HIV-1 subtypes B and F.
abstract: This paper describes genetic subtypes of HIV-1 found in blood samples from 31 HIV-1-infected people who visited the Counseling and Testing AIDS Center of Instituto de Medicina Tropical in Manaus, Brazil. Manaus, the main city in Brazil's Amazon Basin, is also the closest urban connection for more than 100,000 Indians living in the rain forests of this region. Although to date there is no evidence of increased incidence of HIV-1 infection among the indigenous population, our understanding of both the prevalence and nature of the epidemic in the region as a whole is limited. From the 31 samples analyzed by C2V3 sequencing, we found almost equal proportions of HIV-1 strains belonging to subtype B (n = 16; 51.6%) and subtype F (n = 15; 48.4%), a finding that differs from results from previous studies conducted in urban areas of southeastern Brazil. We also observed the presence of the GWGR amino-acid sequence in the critical tetra-peptide crown of the env V3 loop in the HIV-1 subtype B samples analyzed. Among these samples, we also found 14 mosaic genomes (45.16%) in which different combinations of subtypes B, C, and F were identified between the p24 gag, pro, and env regions. Our data support the hypothesis that the Amazonian HIV-1 infections linked to the urban epidemic in southeastern Brazil. The genetic diversity and the prevalence of mosaic genomes among the isolates in our study confirm an integral role of recombination in the complex Brazilian epidemic.
authors.affiliation: Genetics Department, Instituto Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: A C
authors.initials: AC
authors.lastname: Vicente
authors.forename: K
authors.initials: K
authors.lastname: Otsuki
authors.forename: N B
authors.initials: NB
authors.lastname: Silva
authors.forename: M C
authors.initials: MC
authors.lastname: Castilho
authors.forename: F S
authors.initials: FS
authors.lastname: Barros
authors.forename: D
authors.initials: D
authors.lastname: Pieniazek
authors.forename: D
authors.initials: D
authors.lastname: Hu
authors.forename: M A
authors.initials: MA
authors.lastname: Rayfield
authors.forename: G
authors.initials: G
authors.lastname: Bretas
authors.forename: A
authors.initials: A
authors.lastname: Tanuri
mesh_terms: D000328:Adult; D001938:Brazil / Q000453:epidemiology; D004279:DNA, Viral / Q000032:analysis; D004196:Disease Outbreaks; D005260:Female; D015684:Gene Products, pol / Q000235:genetics; D016655:HIV Core Protein p24 / Q000235:genetics; D015699:HIV Envelope Protein gp120 / Q000235:genetics; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology; D016333:HIV Protease / Q000235:genetics; D015497:HIV-1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007199:Indians, South American; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA
chemical_list: D004279:DNA, Viral; D015684:Gene Products, pol; D016655:HIV Core Protein p24; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments; D016333:HIV Protease