Genetic characterization of a novel HIV-1 circulating recombinant form (CRF162_cpx) involving CRF01_AE, CRF07_BC and subtype B in Guangdong, China.

Human immunodeficiency virus type 1 (HIV-1) is characterized by its extremely high level of genetic diversity. The spread of different subtypes in the same population often leads to the emergence of circulating recombinant forms (CRFs) and unique recombinant forms (URFs). At present, the main recombinant subtypes of HIV-1 in China originate from CRF07_BC, CRF01_AE, CRF55_01B and subtype B. Here, we obtained the nearly full-length genomes (NFLGs) from eight HIV-1 infected patients in Guangdong Province, which shared highly similar recombinant patterns, involving two CRF01_AE, one CRF07_BC and two subtype B segments. The eight NFLG sequences own four similar breakpoints as follows: 1220 nucleotide (nt), 2243 nt, 2673 nt, and 5820 nt according to the HXB2 reference sequence, and they therefore were assigned as CRF162_cpx. This is the first complex CRF derived from CRF01_AE, CRF07_BC and subtype B in China. The Bayesian inference of the segments showed that HIV-1 CRF162_cpx was inferred to have approximately originated around 2010-2015. The emergence of CRF162_cpx indicates that the HIV diversity in southeast China constantly accumulates and evolves. Thus, intensive surveillance of HIV-1 molecular epidemiology should be reinforced.