Identification of a novel second-generation HIV-1 circulating recombinant form, CRF182_0708, in Yunnan, China.

BACKGROUND

To report a novel HIV-1 circulating recombinant form (CRF) identified in Yunnan Province, China, through a molecular epidemiological study based on near-full-length HIV-1 genome sequencing and phylogenetic analyses.

METHODS

Plasma samples were collected from five HIV-1 seropositive individuals. Viral RNA was extracted, and near-full-length genomes (NFLG) were amplified and sequenced. Maximum likelihood (ML) phylogenetic analysis was performed using IQ-TREE v2.4.0. Recombination patterns were characterized using SimPlot v3.5.1. The time to the most recent common ancestor (tMRCA) was estimated using Bayesian phylogenetic analysis in BEAST v1.10.5.

RESULTS

In the ML tree, the five NFLG sequences clustered into a distinct monophyletic clade. Recombination analyses revealed a mosaic genome composed of multiple fragments derived from subtype B and subtype C. Comparative genomic mapping and subregion phylogenetic analyses further confirmed that this strain represents a second-generation recombinant form derived from CRF07_BC and CRF08_BC, with CRF08_BC serving as the backbone and incorporating several fragments from CRF07_BC. The novel CRF was designated CRF182_0708. Bayesian analysis estimated that CRF182_0708 originated around 2002.7–2003.1.

CONCLUSION

We identified a novel second-generation HIV-1 CRF derived from CRF07_BC and CRF08_BC, designated CRF182_0708, among HIV-1-positive individuals in relatively developed cities in Yunnan Province, China.