[Sequence analysis of gag and env genes of HIV type 1 circulating in former blood donors of Fuyang city, Anhui province].

Objective To determine the subtype and analyze the genetic characteristics of the HIV-1 predominantly circulating in the former blood donors of Fuyang city,Anhui province.Methods Whole blood samples were collected from 294 HIV-positive former blood donors of Fuyang city,157 males and 137 females,aged 42±8.The fragments of HIV-1 env and gag genes were amplified by nested-PCR from the whole blood samples and thereafter sequenced.The env and gag sequences derived from 244 and 245 HIV infected individuals respectively were analyzed by using MEGA software,and related researches were also done according to the disease progression of the HIV infected individuals.Results Phylogenetic trees showed that both the env and gag strains were clustered with the Thailand B reference strains.The internal nucleotide distances of the env and gag genes were 9.11% and 3.59% respectively.The nucleotide distances of both env and gag genes significantly increased as the CD4 T-cell counts decreased or as the viral load rose(both P0.001).The V3 loop tip motifs were dramatically dominated by GPGQ in the long-time non-progressors,and by GPGR in the slow progressors(P=0.038).Conclusion The predominant strains circulating in the HIV-1 infected former blood donors of Fuyang city are of the Thailand B clade.Low CD4 T-cell count and high viral load are associated with the increase of genetic distances among viral isolates. The V3 loop tip motif changes from GPGQ to GPGR along with the progression of disease.