Genetic and Phylogenetic Analyses of HIV-1 Subtype Bā from Professional Plasma Donors in the Peopleās Republic of China: Evidence for Common Source Infection

             In a collaborative study with the Chinese Academy of Preventive Medicine in Beijing, we have analyzed the HIV-1 among professional plasma donors in the Peopleās Republic of China.  Genomic DNA, extracted from filter paper-blotted blood samples, collected in December 1996, from 19 HIV-1-seropositive professional plasma donors (16 women and 3 men; age range, 25-59 years) living in rural areas of eastern China, were analyzed by amplification and sequencing of a 273-nucleotide region spanning the V3 loop of the gp120-encoding env gene and a 560-nucleotide region encompassing the 5ā p24 gag gene of HIV-1.  Nucleotide sequence alignment and comparison based on the 273-nucleotide env region, indicated that the HIV-1 strains from rural eastern China were genetically most similar to subtype Bā isolates, diverging from Thai and southwestern Chinese (from Yunnan) subtype Bā strains by 1.8-7.3% and 1.5-5.9%, respectively, and differing from HXB2, the North American subtype B prototype, by 19-20.9%.  However, the mean  nucleotide sequence similarity based on the 526-nucleotide gag gene indicated that the HIV-1 strains from eastern China were genetically similar to the subtype B isolate HXB2 by 95%, and differed from subtype A/E strains from Thailand by 15%.   The interstrain gag and env nucleotide sequence similarity among the eastern China HIV-1 strains was 2-3% and 0.4-4.4%, respectively.  Phylogenetic analysis based on gag and env gene sequences, revealed that the eastern China HIV-1 strains formed a monophyletic group.  Although 60% of the nearly 5,000 HIV-1/AIDS cases reported in PRC have been from the southwestern province of Yunnan, infection is becoming widespread within the interior of PRC.  Thus far, HIV-1 subtypes B, C and E have been identified among high-risk behavior groups in China. The uniform occurrence and high interstrain similarity of subtype Bā strains among PD in eastern China is consistent with a common source of infection.  Intensified efforts are underway to analyze proviral HIV-1 sequences from additional DNA samples from high-risk behavior groups in the Peopleās Republic of China.

Nerurkar, V.R., Wu, Z., Dashwood, W-M., Woodward, C.L., Zhang, M., Detels, R., and Yanagihara, R.:  Complete nef gene sequence of HIV type 1 subtype Bā from professional plasma donors in the Peoplesās Republic of China.  AIDS Research and Human Retroviruses 1998;14:461-464.


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