Genetic Diversity of HIV-1 Non-B Strains in Sicily: Evidence of Intersubtype Recombinants by Sequence Analysis ofgag,pol, andenvGenes

The molecular epidemiology of HIV-1 strains in Sicily (Italy) was phylogenetically investigated by the analysis of HIV-1 gag, pol, and env gene sequences from 11 HIV-1 non-B strains from 408 HIV-1-seropositive patients observed from September 2001 to August 2006. Sequences suggestive of recombination were further investigated by bootscanning analysis of various fragments. Overall, we identified several second-generation recombinant (SGRs) strains, which contained genetic material of CRF02_AG in at least one gene. Notably, three individuals were found to be infected with subsubtype A3, and one of them showed genetic recombination with subsubtype A4. The current study emphasizes the genetic analysis of gag, pol, and env genes as a powerful tool to trace the spread of complex HIV-1 recombinant forms, and highlight the genetic diversity of HIV-1 non-B strains in Italy.