Identification of a Novel HIV-1 CRF55_01B/B Recombinant Isolate in Guangxi, China.

Dynamic recombination is the driving force in the genetic diversity of human immunodeficiency virus type 1 (HIV-1). When multiple subtypes are circulating in the same area of a population, new HIV-1 strains are likely to be generated through recombination. In this study, we report a novel recombinant strain (2018GXQZLSHET001) of HIV-1, isolated from a HIV-1-positive heterosexual individual infected in Guangdong province, who recently lived in Guangxi province, China. Phylogenetic analysis of the near full-length genome suggested that 2018GXQZLSHET001 was a recombinant of strains CRF55_01B and subtype B. Similarity plotting and bootscaning showed that a subtype B segment was inserted into the CRF55_01B genome with one breakpoint in the nef and 3' long terminal repeat regions. Further subregion phylogenetic analysis demonstrated that the CRF55_01B segment originated from Guangdong. The subtype B segment was similar to a Thai B lineage. This indicated that the strain might be a novel recombinant, comprising sequences of both CRF55_01B and B. The emergence of this unique recombinant strain illustrated the complexity of the HIV-1 epidemic, and the need to strengthen molecular epidemiological surveillance and measures to reduce its spread.