Genetic Characterization of HIV-1 Strains Among the Injecting Drug Users in Nagaland, India.

Global HIV-1 surveillance has led to the detection of its new recombinant forms. This study was carried out for the first time to elucidate the genetic characterization and evolutionary relationship of HIV-1 strains among injecting drug users of Nagaland, northeastern India. A total of 156 injecting drug users participated in this study voluntarily. Among them 18 were seropositive for HIV-1 (11.5%).The Heteroduplex Mobility Assay (HMA) of HIV-1 based on p24-p7 region of gag gene and C2-V3 region of env gene revealed 11 samples to be subtype C (gag/env), 1 sample as subtype B (gag/env) and 6 samples to be recombinants between subtype C and B. Also, the sequencing and phylogenetic analysis of gag (p24-p7) and env (C2-V3) genes from eighteen samples of Nagaland IDUs with different global HIV-1 strains showed the presence of Indian, African, Thai and their recombinant forms. However, more recombinant strains based on different genomic regions of HIV-1 were detected using Multiregional Hybridization Assay (MHA) where 8 out of 18 samples were found to be recombinants between subtype C and B. Thus, multiregional hybridization assay along with heteroduplex mobility assay can serve as an efficient tool in the characterization of recombination pattern among the newly emerging HIV-1 recombinants.