Subtype and sequence analysis of gag genes among HIV-1 strains circulating in Beijing immigration during 2006
Objective To investigate the subtype distribution and sequence characteristics of HIV-1 strains prevalent in Beijing during 2006, and to analyze the relationship between distribution of HTV-1 subtypes and transmission routines. Methods We collected the blood samples from 80 HIV-1 infected individuals from immigration in Beijing during 2006 and separated plasma specimens. RNA was extracted and the gag gene was amplified by RT-PCR and nest-PCR. The PCR products were sequenced directly and phylogenetic analysis of gag gene was performed using the MEGA2 software. Results Among 80 HIV-1 plasma samples,59 gag HIV-1 gene fragments were amplified and analyzed. Eight HIV-1 subtypes or circulating recombinant forms(CRF) of HIV-1 including B(4 strains), Thai B(15 strains), C(1 strains), CRP01 _ AE (5 strains), CRF02_ AG(1 strains), CRP07_BC (29 strains), CRF08_BC(3 strain),CRF15_ 01B (1 strains) were identified circulating in Beijing. The gene divergences inside the subtypes were different, with 6.8 % , 25.4 % , 1.7 % , 5.5 % , 1.7 % , 49.2 % , 5.1 % and 1.7% in subtype B, Thai B, C, CRF01 _ AE, CRF02_ AG, CRF07_ BC, CRF08_ BC, CRF15_01B respectively. Subtypes CRF07_ BC were predominant in Beijing immigration account for 49.2% among 59 samples. Conclusion Eight HIV-1 subtypes exist in Beijing and the surveillance of HIV-1 gene variation should be paid more attention.