Identification of a Novel HIV-1 Second-Generation (CRF01_AE/B) Among Men Who Have Sex with Men in Tianjin, China

Identification of Two Novel HIV-1 Recombinant Forms Originated from CRF01_AE and Subtype B in the Sexual Contact Population in Hebei Province, China

Two near full-length genome (NFLG) sequences of HIV-1 with undefined subtypes were analyzed to confirm the recombinant characteristics. To analyze the gene recombination patterns and breakpoints of these two NFLGs, the phylogenetic trees based on the NFLG sequences and their subregions were constructed, respectively. Sequences 233 and 953 are novel second-generation recombinant forms of HIV-1 CRF01_AE and subtype B. The NFLG phylogenetic tree analysis showed that these two NFLG sequences formed a unique monophyletic branch, respectively. The recombination breakpoints analysis showed that the recombination pattern of both sequences was that a subtype B fragment was inserted into a CRF01_AE backbone. Subregions I, II, and III were from CRF01_AE, subtype B, and CRF01_AE, respectively. The recombination breakpoints relative to HXB2 of sequences 233 and 953 were 2400 and 4870, and 3363 and 4828, respectively. The emergence of novel recombinant forms of CRF01_AE/B demonstrates that we should carry out the ongoing surveillance of HIV-1 recombinant forms in the sexually transmitted population.

Identification of two near-identical novel HIV-1 unique recombinant forms (CRF01_AE/B) among men who have sex with men in baoding, hebei, China

Men who have sex with men (MSM) are the most frequent infection route of the human immunodeficiency virus (HIV) in Baoding, China, creating chances for the occurrence of unique recombinant forms (URFs) of the virus, i.e., recombination of different subtypes caused by co-circulation of multiple subtypes. In this report, two near-identical URFs (BDD002A and BDD069A) isolated from MSM in Baoding were identified. Phylogenetic tree analysis based on nearly full-length genomes (NFLGs) revealed that the two URFs formed a distinct monophyletic cluster with a bootstrap value of 100%. Recombinant breakpoints analysis identified that the NFLGs of BDD002A and BDD069A were both composed of CRF01_AE and subtype B, with six subtype B mosaic segments inserted into the CRF01_AE backbone. The CRF01_AE segments of the URFs clustered closely with the CRF01_AE reference sequences, and the B subregions clustered with the B reference sequences. The recombinant breakpoints of the two URFs were almost identical. These results suggest that effective interventions are urgently needed to prevent the formation of complex HIV-1 recombinant forms in Baoding, China.

Identification of a New HIV-1 Circulating Recombinant Form CRF112_01B Strain in Baoding City, Hebei Province, China

BACKGROUND

A large number of HIV-1 recombinants that originated from CRF01_AE and B strains are constantly emerging in men who have sex with men populations in China and deserve more attention and further monitoring.

OBJECTIVE

To analyze the near-full-length genome structure and recombination characteristics of a new HIV-1 strain (BD226AJ) detected in Baoding City and determine its subtype.

CASE REPRESENTATION

Viral RNA was extracted from a blood sample collected from an infected individual and reverse transcribed to cDNA. Two overlapping segments of the HIV-1 genome were amplified using a near-endpoint dilution method and sequenced. Recombinant breakpoints were determined using RIP, jpHMM, and SimPlot 3.5.1 software. MEGA v6.0 was used to construct a neighbor-joining phylogenetic tree to determine the homology relationships of this strain.

RESULTS AND DISCUSSION

We obtained 8830 nucleotides (nt) of the HIV-1 genome sequence by amplification and sequencing, and four recombinant fragments were identified by recombination analysis, namely CRF01_AE (HXB2, 823-4224 nt), subtype B (HXB2, 4225-5991 nt), CRF01_AE (HXB2, 5992-9295 nt), and subtype B (HXB2, 9296-9406 nt). The BLAST results showed that 96% of the sequence was similar to CRF112_01B. The jpHMM results confirmed that BD226AJ was the CRF112_01B strain.

CONCLUSION

Our results confirm the first epidemic of CRF112_01B in Hebei Province. This finding suggests that HIV-1 CRF112_01B may have been introduced into Hebei by men who have sex with men and indicates that the epidemic trend of this strain should be closely monitored.

Characterization of a New HIV-1 CRF01_AE/B Recombinant Virus Form Among Men Who Have Sex with Men in Baoding, Hebei, China

We analyzed the near full-length genome (NFLG) of an HIV-1-positive sample(027A) with an undetermined subtype to determine the recombinant characteristics and possible source of the parental virus. 027A is a novel HIV-1 second-generation recombinant form composed of CRF01_AE and subtype B, detected from a married HIV-1-positive male subject who was infected through homosexual transmission in Baoding, Hebei province, China. The NFLG phylogenetic tree analysis suggested that the strain was close to circulation recombinant forms' (CRFs') reference sequences involved with CRF01_AE, but formed a distinct monophyletic cluster separately from them. This indicated that the strain might be a unique CRF01_AE-related recombinant from. Furthermore, the results of RIP and jpHMM further demonstrated that the NFLG sequence of the strain was composed of CRF01_AE and subtype B. The strain was two CRF01_AE fragments inserted into B backbone. Phylogenetic analysis illustrated that the CRF01_AE subregions were from the previously identified CRF01_AE cluster 4, and the B subregions were correlated with the B strains originated from Europe and America. They were all the lineages widely prevalent in men who have sex with men (MSM) population in China. In recent years, a large number of recombinant originated from CRF01_AE and B strains are constantly emerging in MSM population in China. This continual and recurrent recombination between CRF01_AE and B in high-risk group people deserves more attention and further monitoring.