title: Spreading of HIV-1 subtype G and envB/gagG recombinant strains among injecting drug users in Lisbon, Portugal.
abstract: We have evaluated the genetic diversity of HIV-1 strains infecting injecting drug users (IDUs) in Lisbon, Portugal. Heteroduplex mobility assay and/or phylogenetic analysis revealed that env (C2V3C3 or gp41) subtype B is present in 63.7% of the 135 viral samples studied, followed by subtypes G (23.7%), A (6.7%), F (5.2%), and D (0.7%). Similar analysis of gag (p24/p7) performed on 91 of the specimens demonstrated that 49.5% of the infections were caused by subtype G viruses; other gag subtypes identified were B (39.5%), F (3.3%), A and D (1.1.% each), and the recombinant circulating form CRF02_AG (5.5%). Discordant env/gag sub-types were detected in 34.1% of the strains and may reflect the presence of dual infections and/or recombinant viruses. The presumptive B/G recombinant form was highly predominant (21 of 31). The genetic pattern of HIV-1 subtype B and G strains is suggestive of multiple introductions and recombination episodes and of a longstanding presence of both subtypes in the country. C2V3C3 amino acid sequences from IDU-derived subtype G viruses presented highly significant signatures, which distinguish the variants from this transmission group. The unusually high prevalence of subtype G sequences (34.1%), independent of the geographic origin of the infected individuals, makes this IDU HIV-1 epidemic unique.
authors.affiliation: Unidade de Virologia, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal. aidaesteves@ihmt.unl.pt
authors.forename: Aida
authors.initials: A
authors.lastname: Esteves
authors.forename: Ricardo
authors.initials: R
authors.lastname: Parreira
authors.forename: João
authors.initials: J
authors.lastname: Piedade
authors.forename: Teresa
authors.initials: T
authors.lastname: Venenno
authors.forename: Margarida
authors.initials: M
authors.lastname: Franco
authors.forename: José
authors.initials: J
authors.lastname: Germano de Sousa
authors.forename: Luis
authors.initials: L
authors.lastname: Patrício
authors.forename: Paula
authors.initials: P
authors.lastname: Brum
authors.forename: António
authors.initials: A
authors.lastname: Costa
authors.forename: Wanda F
authors.initials: WF
authors.lastname: Canas-Ferreira
mesh_terms: D000293:Adolescent; D000328:Adult; D000595:Amino Acid Sequence; D005260:Female; D015752:Genes, env / Q000235:genetics*; D015750:Genes, gag / Q000235:genetics*; D015658:HIV Infections / Q000453:epidemiology / Q000635:transmission* / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000235:genetics; D020180:Heteroduplex Analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D011174:Portugal / Q000453:epidemiology; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D015819:Substance Abuse, Intravenous / Q000150:complications*