Genetic characterization of a novel unique recombinant form of HIV-1 originating from subtype A1 and C in Guangdong Province, China

Identification of integrase inhibitor-related drug resistance mutations in newly diagnosed ART-naïve HIV patients

BACKGROUND

In China, the recommended treatment regimens for HIV-infected individuals were tenofovir in combination with lamivudine or emtricitabine as NRTIs, efavirenz or rilpivirine as NNRTIs, lopinavir/ritonavir as protease inhibitors, and raltegravir or dolutegravir as INSTIs. The development of drug resistance increases the risk of viral rebound, opportunistic infections, and ultimately treatment failure such that the early detection of resistance is ideal. This study was developed to explore primary drug resistance characteristics and genotypic distributions in newly diagnosed antiretroviral therapy (ART)-naïve HIV-1 patients in Nanjing with the goal of establishing a basis for their individualized treatment in the clinic.

METHODS

Samples of serum were collected from newly diagnosed ART-naïve HIV patients from the Second Hospital of Nanjing between May 2021 and May 2022. The HIV-1 integrase (IN), protease (PR), and reverse transcriptase (RT) gene coding sequences were amplified from these samples, sequenced, and assessed for drug resistance-related mutations.

RESULTS

Major integrase resistance-related mutations were detected in 4/360 amplified samples, with 5 other patient samples exhibiting accessory resistance mutations. The overall prevalence of PR and RT inhibitor-related transmitted drug resistance mutations (TDRMs) in this patient population was 16.99% (61/359). The most common mutations were non-nucleoside reverse transcriptase inhibitor-related mutations (51/359; 14.21%), followed by those associated with nucleoside reverse transcriptase inhibitors (7/359; 1.95%) and protease inhibitors (7/359; 1.95%). Dual-resistant strains were also observed in a subset of patients.

CONCLUSIONS

In summary, this study is the first to have surveyed the prevalence of integrase inhibitor resistance-related mutations and other drug resistance-related mutations among newly diagnosed ART-naïve HIV-positive patients in Nanjing, China. These results highlight the need for further molecular surveillance-based monitoring of the HIV epidemic in Nanjing.

Genetic Characteristics of HIV-1 CRF12_BF First Identified in Guangdong Province, China

Multiple HIV-1 genotypes were found circulating in Guangdong Province, China, as this province is located in South China and has a high frequency of international trade. In this study, we report the near full-length genome (NFLG) of CRF12_BF that was identified from a male patient in Guangzhou city, Guangdong Province; this is the first time CRF12_BF has been reported in mainland China. The NFLG was amplified, and then PCR products were sequenced by Sanger sequencing. The CRF12_BF strain was confirmed by the Basic Local Alignment Search Tool and a neighbor-joining phylogenetic tree. In addition, this CRF12_BF strain was confirmed to contain the non-nucleoside reverse transcriptase inhibitor mutation E138A associated with potential low-level resistance against efavirenz and low-level resistance against rilpivirine by the Stanford University HIV Drug Resistance Database program. The analyzed sequence data in this study will provide more information on the HIV epidemic in China.

HIV-1 drug resistance and genotypes circulating among HIV-positive key populations in Bangladesh: 2016 update

OBJECTIVE

HIV-1 subtyping data of Bangladeshi strains are available in global HIV Sequence Database up to 2007, and there is no sequence of drug resistance profile based on the pol gene segment. This study aimed to update HIV genotyping data and describe the drug resistance mutations for the first time from Bangladesh using specimens from the latest HIV sero-surveillance conducted in 2016.

STUDY DESIGN AND METHODS

During HIV sero-surveillance, a total of 1268 people who inject drugs (PWID) and 3765 female sex workers (FSW) were screened and among them, 230 (18.1%) PWID and 7 (0.2%) FSW were HIV positive. Among HIV positives, randomly selected 74 specimens (60 male-PWID, 7 female-PWID, and 7 FSW) were subjected to gag, pol, and env gene sequencing using gene-specific primers. Genotyping was decided based on the partial gag and env genes while transmission dynamics was based on the gag sequence (n = 237). Drug resistance profiles were obtained by using the algorithm of the established available drug resistance database.

RESULTS

HIV subtype C and C-related recombinants have remained the major circulating genotypes in Bangladesh. Although the recurring transmission of subtype C occurred among PWID, we identified possible transmission to other key populations (KPs), which suggests spillover from PWID through the sexual route. The prevalence of drug-resistant mutation was low, and all strains were susceptible to NRTIs and NNRTIs drugs. Unique recombination forms (URF) with genotype C for gag-pol and A1 for env was also identified.

CONCLUSIONS

The study findings warrant continuous monitoring of HIV-positive individuals and future investigation to identify social networks within and between KPs to halt the transmission and prevent new infections.

Molecular characteristic of HIV-1 CRF01_AE in Nanjing from 2015 to 2017

OBJECTIVE

To investigate the evolutionary dynamics and characteristic of the molecular transmission networks of HIV-1 CRF01_AE in Nanjing.

METHODS

Viral samples were collected from 580 newly diagnosed HIV-1-infected patients. HIV-1 pol sequences were obtained and used for for molecular evolutionary analyses. The ML trees were constructed by MEGA 6.0 using under GTR+ G + I model with 1000 bootstrap replicates. The emergence and estimation of tMRCA and the evolutionary rate of the different CRF01_AE clusters were inferred using Bayesian phylogenetic analysis approaches implemented in the BEAST package. Pairwise genetic distances were calculated under the Tamura-Nei 93 model, a genetic distance threshold of ≤1.2% was used to identify potential transmission clusters. Network diagrams were plotted using Cytoscape 3.3.0.

RESULTS

Of these HIV-1-infected patients, 551 (91.5%) were males. The largest number of infections were attributed to homosexual (462, 79.7%). A total of 518 full-length pol genes were successfully amplified, based on the phylogenetic analysis CRF01_AE was the most predominantly circulating strain (45.0%, 233/518). As shown in the ML tree, three distinct clusters were observed. The 'Nanjing lineage' 1, 2, 3 has an estimated tMRCA around1996.61, 1993.61, 1984.61 respectively. Of 233 Nanjing sequences, 123 (55.2%) distributed in 30 molecular clusters, average Links/node was 7.8 with range (1-33), most of Nanjing strains shared links with local strains.

CONCLUSION

HIV-1 CRF01_AE was the most predominantly circulating strain, the epidemic of CRF01_AE in Nanjing was driven by multiple clusters of HIV-1 strains, and most CRF01_AE stains in our study were estimated to have originated in China in the 1990s.