Genetic diversification and recombination of HIV type 1 group M in Kinshasa, Democratic Republic of Congo.

As the HIV-1 pandemic becomes increasingly complex, the genetic characterization of HIV strains bears important implications for vaccine research. To better understand the molecular evolution of HIV-1 viral diversity, we performed a comparative molecular analysis of HIV strains collected from high-risk persons in Kinshasa, Democratic Republic of Congo (DRC). Analysis of the gag-p24, env-C2V3 and -gp41 regions from 83 specimens collected in 1999-2000 revealed that 44 (53%) had concordant subtypes in the three regions (14 subsubtype A1, 10 subtype G, 8 subtype D, 5 subtype C, 2 each subsubtype F1 and CRF01_AE, and one each of subtypes H and J, and subsubtype A2, while the remaining 39 (47%) had mosaic genomes comprising multiple subtype combinations. Similar multisubtype patterns were also observed in 24 specimens collected in 1985. Sequence analysis of the gag-pol region (2.1 kb) from 21 discordant specimens in the gag-p24, env-C2V3 and -gp41 regions in 1985 and 1999-2000 further confirmed the complex recombinant patterns. Despite the remarkable similarity in overall subtype distribution, the intra- and intersubtype distances of major subtypes A1 and G increased significantly from 1985 to 1999-2000 (p=0.018 and p=0.0016, respectively). Given the complexity of HIV-1 viruses circulating in DRC, efforts should focus on the development of vaccines that result in cross-clade immunity.