Evidence of “non B-non BF” HIV-1 subtypes in newly diagnosed patients from Buenos Aires, Argentina

DILERNIA D; LOSSO MH; LOURTAU L; PARLANTE A; SALOMON H; GÓMEZ CARRILLO M

Rio de Janeiro, Brasil

Congreso; 3rd IAS Conference on HIV Pathogenesis and Treatment.; 2005

International AIDS Society

Introduction: Recent studies showed that African/Asian "non B-non BF" viruses were introduced in Argentina. Our objective was to describe HIV-1diversity at a Volunteering Testing Center in Buenos Aires. Methods: Subtype characterization was performed by using nucleotide sequences obtained from RT-PCR products of pol and vpu genes. Sequence similarities were obtained by BLAST, and phylogenetic trees were constructed by Neighbor-Joining and Maximum Likelihood. Recombination patterns were obtained by bootscanning. Results: We analyzed viral variants from 100 HIV-positive individuals, naïve of ARV, who attended a Volunteering Testing Center in Buenos Aires city between March 2003 and April 2004. Four of them (4%) were recently infected, 67% were newly diagnosed and 29% were previously known diagnostics. 66% were BF recombinants, 24% subtype B, 9% "non B-non BF" variants (all of these 9 samples belonging to newly diagnosed individuals) and one could not be fully characterized. The 9 "non B-non BF" variants were two subtype C, two BA recombinants and one of each BD, A2D, BC, BK and GKA recombinants. The GKA recombinant showed the same mosaic pattern with the CRF06_cpx in pol but it was subtype K in vpu. One of the two subtype C samples was related with "Brazilian" C isolates, whereas the other one was closely related with isolates characterized from Senegal. Likewise, the subtype C segment of the BC recombinant was also closely related with the same Senegalese subtype C. Finally the A2D sample was found to be closely related with the CRF16_A2D in both pol and vpu genes suggesting a close relationship with the Argentinean CRF16 sequences than the references from Korea and Kenya. Conclusions: Our findings reveal a continuous change in the distribution pattern of HIV-1 variants circulating in Argentina. A recently diagnosed patient infected with the CRF16 is an evidence of its successful spread in our population.