Diverse BF recombinants have spread widely since the introduction of HIV-1into South America

Objective: To describe the genetic diversity of HIV-1 in South America by f ull genome sequencing and analysis. Methods: Purified peripheral blood mononuclear cell DNA from HIV-infected i ndividuals in Argentina, Uruguay and Bolivia was used to amplify full HIV-1 genomes. These were sequenced using the ABI 3100 automated sequencer and p hylogenetically analysed. Results: Twenty-one HIV-1 strains from three South American countries, 17 o f which were pre-screened by envelope heteroduplex mobility assay (HMA), we re studied. Ten out of 10 HMA subtype F and four out of seven HMA subtype B strains were actually BF recombinants upon full genome analysis. Two BF re combinants from Argentina and two from Uruguay had the same structure, repr esenting a new circulating recombinant form termed CRF12_BFARMA159, Twelve other BF recombinants had structures related to CRF12 but with additional s egments of subtype B; each was unique. BF recombinants were temporally and geographically widespread, found as early as 1986-1987 in vertically infect ed Argentinian children and in Argentina, Uruguay, and Bolivia. (C) 2001 Li ppincott Williams & Wilkins.