Characterization of a novel HIV-1 second-generation circulating recombinant form (CRF102_0107) among men who have sex with men in Anhui, China

Identification of Two Novel HIV-1 Unique Recombinant Forms Among Men Who Have Sex with Men in Northern China

Although HIV-1 infection has now become a treatable chronic condition and not the deadly illness it once was, the costs of that treatment are substantial, and each infection prevented saves both financial and other costs. In China, the most predominant subtypes are CRF07_BC, CRF01_AE, and CRF55_01B, and the various second-generation recombinants are produced from the recombination between these subtypes. HIV full-length genome sequences can provide important information on their epidemiology. In this study, we identified two unique recombinant forms (URFs) designated as JLCC230106 and XJWQ230011, which are composed of CRF01_AE/CRF07_BC and CRF07_BC/CRF55_01B, respectively. Phylogenetic and recombinant analyses utilizing near-full-length genome (NFLG) confirmed that these URFs originated from CRF01_AE/CRF07_BC and CRF07_BC/CRF55_01B strains. The emergence of novel recombinants is increasing the genetic diversity of HIV in China. This information can be shared with clinicians, human behavior specialists, or public health policymakers and used as an aid in discovering which methods are best or most cost-effective in combating the spread of HIV.

Near Full-Length Genome Characterization of Two Novel Unique Recombinants (CRF01_AE/CRF07_BC) in Beijing, China

With the prevalence of human immunodeficiency virus type 1 (HIV-1) CRF01_AE and CRF07_BC subtypes in China, the co-circulation of multiple subtypes in the HIV-1-positive population may result in dual infection or superinfection in the population, leading to the emergence of unique recombinant forms (URFs) of the HIV-1 virus. In this study, two second-generation unique recombinant strains, BI0114 and BI0116, were identified, and their near full-length genome sequences were obtained. Recombination analysis showed that both sequences were isoforms of URF_0107, and they were second-generation unique recombinant strains formed by the recombination of CRF01_AE and CRF07_BC, with the isoforms being CRF01_AE and CRF0107_BC, respectively. The continued emergence of novel CRF01_AE/CRF07_BC recombinant strains suggests that the epidemiological, preventive, and control situation of HIV-1 is complex and that the relevant health authorities urgently need to establish responses to the challenges posed by changes in the pattern of strain recombination.

Identification of the Near Full-length Genome of a Novel HIV-1 CRF01_AE/CRF07_BC Recombinant with a Complex Genomic Structure Isolated in Hebei Province, China

BACKGROUND

During HIV genotypic drug resistance testing of patient samples in Baoding, Hebei Province, China, in 2022, a recombinant fragment was detected in the pol region of an HIV-1 strain.

OBJECTIVE

The objective of the study was to analyze the near full-length genome of a novel HIV-1 CRF01_AE/CRF07_BC recombinant with a complex genomic structure.

METHODS

Viral RNA was extracted from the blood of the infected individual and reverse transcribed to cDNA. Two overlapping segments of the HIV-1 genome were amplified using a nearendpoint dilution method and sequenced. Recombinant breakpoints were determined using RIP, jpHMM, and SimPlot 3.5.1 software. MEGA 6.0 software was used to construct a neighbor-joining phylogenetic tree.

RESULTS

We obtained the near full-length genome sequence (8680 bp) of a novel HIV-1 CRF01_AE/CRF07_BC recombinant. Recombination analysis showed that the genome comprised at least 12 overlapping segments, including six CRF07_BC and six CRF01_AE segments, with CRF07_BC as the backbone. The emergence of CRF01_AE/CRF07_BC recombinant strains indicated that HIV-1 co-infection is common. However, the increasing genetic complexity of the HIV-1 epidemic in China warrants continued investigation.

CONCLUSION

The increase in CRF01_AE/CRF07_BC recombinant viruses suggests that HIV-1 has a high genetic mutation rate in Hebei, China. This highlights the need for close monitoring of HIV-1 molecular epidemiologic changes to provide accurate, up-to-date information for effective disease control.

Three Novel CRF01_AE/CRF07_BC Recombinant Forms of HIV-1 Identified in Shijiazhuang City, China

BACKGROUND

Hebei, a province with a low Human Immunodeficiency Virus (HIV) prevalence, is also a region with the most abundant HIV-1 genetic diversity. HIV-1 recombinant forms have been the key factor influencing the effectiveness of HIV-1 control and therapy.

OBJECTIVES

We aimed to study inter-subtype recombinant structures of new HIV-1-second generation recombinant forms.

METHODS

Monitoring the HIV-1 subtype by phylogenetic and recombinant breakpoint analyses are the two most frequent methods among men who have sex with men (MSM). Here, three near full-length genomes (NFLGs) were obtained from HIV-1 seropositive MSM in Shijiazhuang City, China, who have never received antiretroviral therapy in 2021.

RESULTS

Phylogenetic analysis indicated that three NFLGs were novel inter-subtype recombinant forms between CRF07_BC and CRF01_AE. For the NFLG 21S009, four CRF07_BC gene fragments were inserted into the pol, vif-vpr, vpu-env, and nef-3` LTR gene regions within a CRF01_ AE backbone, respectively. For the NFLG 21S095, four breakpoints were identified in HIV-1 pol and vpu regions. The NFLG 21S370 contained four gene recombinant breakpoints within HIV-1 pol and vpu-env gene regions. Of these three NFLGs, the NFLG 21S009 contained the most breakpoints, distributed in the pol, vif, vpr, vpu, env, and nef regions, respectively. In the gag-pol regions, three NFLGs had only one CRF07_BC gene fragment inserted into gene points between 4250 and 4792.

CONCLUSION

Our findings provide strong evidence that the surveillance of novel recombinant forms is necessary for the increase in better control of HIV.

Identification of a New HIV-1 CRF68_01B/CRF01_AE Recombinant Form Among Men Who Have Sex with Men in Hebei Province, China

In recent years, homosexual contact has been the most frequent route of human immunodeficiency virus type one (HIV-1) transmission in Hebei, China. The number of circulating recombinant forms (CRFs) and unique recombinant forms found in this key population were more and more. In this study, we identified a novel HIV-1 second-generation recombinant form originated from CRF68_01B and CRF01_AE among men who have sex with men (MSM) through the phylogenetic and recombinant breakpoints analyses based on the near full-length genome. Both CRF68_01B and CRF01_AE were circulating in the Hebei province of China, and this MSM was diagnosed as the recent HIV-1 infection in fact. The result reminds that we should constantly monitor HIV-1 diversity in Hebei and take further effective to control the recombination of not only HIV-1 major strains but also minor strains.

Multiple CRF01_AE/CRF07_BC Recombinants Enhanced the HIV-1 Epidemic Complexity Among MSM in Shenyang City, Northeast China

The transmission of Unique Recombinant Forms (URFs) has complicated the molecular epidemic of HIV-1. This increasing genetic diversity has implications for prevention surveillance, diagnosis, and vaccine design. In this study, we characterized the HIV-1 URFs from 135 newly diagnosed HIV-1 infected cases between 2016 and 2020 in Shenyang, northeast China and analyzed the evolutionary relationship of them by phylogenetic and recombination approaches. Among 135 URFs, we found that the CRF01_AE/CRF07_BC recombinants were the most common (81.5%, 110/135), followed by CRF01_AE/B (11.9%, 16/135), B/C (3.7%, 5/135), and others (3.0%, 4/135). 94.8% (128/135) of patients infected by URFs were through homosexual contact. Among 110 URFs_0107, 60 (54.5%) formed 11 subclusters (branch support value = 1) and shared the consistent recombination structure, respectively. Four subclusters have caused small-scale spread among different high-risk populations. Although the recombination structures of URFs_0107 are various, the hotspots of recombinants gathered between position 2,508 and 2,627 (relative to the HXB2 position). Moreover, the CRF07_BC and CRF01AE fragments of URFs_0107 were mainly derived from the MSM population. In brief, our results reveal the complex recombinant modes and the high transmission risk of URFs_0107, which calls for more attention on the new URFs_0107 monitoring and strict control in the areas led by homosexual transmission route.

Identification of Two Novel HIV-1 Second-Generation Recombinant Forms (CRF01_AE/CRF07_BC) in Hebei, China

Homosexual contact is one of the main transmission routes of HIV-1 epidemic in Hebei, China. Several subtypes of HIV are prevalent simultaneously in the population, which always lead to the emergency of unique recombinant forms (URFs). In this study, we reported two new URFs from two HIV-1 positive subjects infected through homosexual contact route in Hebei, China. Phylogenetic and recombinant analyses based on the near full-length genome of the two URFs both revealed the two URFs are the second generation of recombinant strains originated from CRF01_AE and CRF07_BC. The CRF01_AE segments of two URFs located in cluster 4 of CRF01_AE strains in the phylogenetic tree. The emergence of the novel CRF01_AE/CRF07_BC recombinant forms with complicated genomic structures indicated the importance of the continuous monitoring of the HIV-1 epidemic and new URFs among the men who have sex with men populations.

Near Full-Length Genomic Characterization of Two Novel HIV-1 Unique Recombinant Forms (CRF01_AE/CRF07_BC) Among Men Who Have Sex with Men in Shijiazhuang City, Hebei Province, China

Unique recombinant forms (URFs) are more likely developed among HIV-1 infections through men who have sex with men (MSM) because of cocirculation of multiple subtypes. In this study, two novel URFs deriving from two HIV-positive subjects (HB010014, HB010063) were identified in Shijiazhuang, Hebei province, China, and two sequences formed a distinct monophyletic cluster. Further recombination analysis showed that of two new URFs were consisted of circulating recombinant form (CRF)01_AE and CRF07_BC. The subregion phylogenetic analysis indicated that CRF01_AE segments were traced back to cluster 4 of CRF01_AE strains, which were prevalent among HIV-1 infections through MSM in China. New URFs being developing gradually and spreading released that more and more novel recombinant strains of HIV-1 could be developed, which means that the past prevention strategies need to be adjusted.

Phylogenetic Analysis of Sequences in the HIV Database Revealed Multiple Potential Circulating Recombinant Forms in China

HIV recombination contributes greatly to its diversity and produces many circulating recombinant forms (CRFs) and unique recombinant forms (URFs). In China, 24 CRFs have been reported to date, and CRFs cause more than 80% of HIV infections. However, the prevalence of CRFs might still be underestimated, as a high level of onward transmission of URFs has been reported. In this study, we analyzed all Chinese pol region (2,253-3,252) sequences in the HIV Database to evaluate potential new CRFs in China. HIV-1 genotypes were verified by the Context-based Modeling for Expeditious Typing (COMET) tool. Maximum-likelihood (ML) trees were constructed based on sequences with unassigned genotypes. Cluster Picker 1.2.1 was used to identify transmission clusters. Meanwhile, a jumping-profile hidden Markov model (jpHMM) was used to perform recombination breakpoint analysis. Beast 1.7.5 was used to estimate the time of the most recent common ancestor of new CRFs. In the HIV databases, CRF01_AE was the most prevalent genetic form in China, accounting for 39.69% of all national infections, followed by CRF07_BC (20.47%), subtype B (17.50%), CRF08_BC (6.60%), subtype C (6.28%), CRF55_01B (2.06%), and other CRFs (1.77%). The URFs were responsible for 5.31% of all infections nationwide. Among URFs, genomes comprising BC, 01BC, 01B, and 01C were dominant. Finally, 17 potential CRFs and 1 novel CRF were identified. BEAST analysis indicates that novel CRF originated around in 2009. The data highlight that more CRFs have been spreading in China. HIV-1 pol sequences that are commonly used to explore drug resistance are helpful for the surveillance of epidemics of different HIV-1 genotypes.

Near Full-Length Genomic Characterization of a Novel HIV-1 Circulating Recombinant Form (CRF107_01B) Identified Among Men Who Have Sex with Men in Heilongjiang Province of China

We reported a novel human immunodeficiency virus type 1 (HIV-1) circulating recombinant form (CRF) among four epidemiologically unlinked patients through men having sex with men in Heilongjiang Province, China. It was named CRF107_01B (this is temporary as we have not received the CRF number from HIV databases). A near full-length genome phylogenetic tree showed that CRF107_01B was generated by two CRF01_AE segments that was described as cluster 5 lineage of CRF01_AE (CRF01-5) inserted into the B (Western origin) backbone. The emergence of CRF107_01B increased the complexity of HIV-1.

First Detection of a Circulating Recombinant Form of HIV-1 CRF01_AE/08_BC (CRF105_0108) with Drug-Resistant Mutations in Sichuan, China

In this study, we identified a novel circulating recombinant form (CRF) of HIV (CRF105_0108) in a total of five patients with no obvious epidemiological linkage in Sichuan, China. Four strains were found in this study, and another strain (XC2014EU01) was reported in a previous study. The phylogenetic analysis of the five near full-length genomes showed that a CRF08_BC segment was inserted into the CRF01_AE backbone with one recombinant breakpoint in the pol region, which is the first HIV-1 CRF of CRF01_AE and CRF08_BC. Three genetic sequences had drug-resistant mutations, E138Q and V179D, indicating that there were low resistance levels to efavirenz (EFV) and nevirapine (NVP) in Liangshan Yi Autonomous Prefecture. CRF105_0108 increases the diversity and complexity of the prevalent HIV-1 CRFs in Sichuan. Simultaneously, drug-resistant mutations in this CRF may influence the efficacy of highly active antiretroviral treatments (ARTs) in Liangshan Yi Autonomous Prefecture.