Transmitted Drug Resistance Strains Research Articles

Molecular Network Analysis Reveals Transmission of HIV-1 Drug-Resistant Strains Among Newly Diagnosed HIV-1 Infections in a Moderately HIV Endemic City in China.

Since the implementation of the “treat all” policy in China in 2016, there have been few data on the prevalence of transmitted drug resistance (TDR) in China. In this study, we describe TDR in patients newly diagnosed with human immunodeficiency virus (HIV) infection between 2016 and 2019 in Shenyang city, China. Demographic information and plasma samples from all newly reported HIV-infected individuals in Shenyang from 2016 to 2019 were collected. The HIV pol gene was amplified and sequenced for subtyping and TDR. The spread of TDR was analyzed by inferring an HIV molecular network based on pairwise genetic distance. In total, 2,882 sequences including CRF01_AE (2019/2,882, 70.0%), CRF07_BC (526/2,882, 18.3%), subtype B (132/2,882, 4.6%), and other subtypes (205/2,882, 7.1%) were obtained. The overall prevalence of TDR was 9.1% [95% confidence interval (CI): 8.1–10.2%]; the prevalence of TDR in each subtype in descending order was CRF07_BC [14.6% (95% CI: 11.7–18.0%)], subtype B [9.1% (95% CI: 4.8–15.3%)], CRF01_AE [7.9% (95% CI: 6.7–9.1%)], and other sequences [7.3% (95% CI: 4.2–11.8%)]. TDR mutations detected in more than 10 cases were Q58E (n = 51), M46ILV (n = 46), K103N (n = 26), E138AGKQ (n = 25), K103R/V179D (n = 20), and A98G (n = 12). Molecular network analysis revealed three CRF07_BC clusters with TDR [two with Q58E (29/29) and one with K103N (10/19)]; and five CRF01_AE clusters with TDR [two with M46L (6/6), one with A98G (4/4), one with E138A (3/3), and one with K103R/V179D (3/3)]. In the TDR clusters, 96.4% (53/55) of individuals were men who have sex with men (MSM). These results indicate that TDR is moderately prevalent in Shenyang (5–15%) and that TDR strains are mainly transmitted among MSM, providing precise targets for interventions in China.

Trends in the Molecular Epidemiology and Genetic Mechanisms of Transmitted Human Immunodeficiency Virus Type 1 Drug Resistance in a Large US Clinic Population.

There are few large studies of transmitted drug resistance (TDR) prevalence and the drug resistance mutations (DRMs) responsible for TDR in the United States. Human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) and protease sequences were obtained from 4253 antiretroviral therapy (ART)-naive individuals in a California clinic population from 2003 to 2016. Phylogenetic analyses were performed to study linkages between TDR strains and selection pressure on TDR-associated DRMs. From 2003 to 2016, there was a significant increase in overall (odds ratio [OR], 1.05 per year [95% confidence interval {CI}, 1.03-1.08]; P < .001) and nonnucleoside RT inhibitor (NNRTI)-associated TDR (OR, 1.11 per year [95% CI, 1.08-1.15]; P < .001). Between 2012 and 2016, TDR rates to any drug class ranged from 15.7% to 19.2%, and class-specific rates ranged from 10.0% to 12.8% for NNRTIs, 4.1% to 8.1% for nucleoside RT inhibitors (NRTIs), and 3.6% to 5.2% for protease inhibitors. The thymidine analogue mutations, M184V/I and the tenofovir-associated DRMs K65R and K70E/Q/G/N/T accounted for 82.9%, 7.3%, and 1.4% of NRTI-associated TDR, respectively. Thirty-seven percent of TDR strains clustered with other TDR strains sharing the same DRMs. Although TDR has increased significantly in this large cohort, many TDR strains are unlikely to influence the activity of currently preferred first-line ART regimens. The high proportion of DRMs associated with infrequently used regimens combined with the clustering of TDR strains suggest that some TDR strains are being transmitted between ART-naive individuals.

Transmitted drug resistance among HIV infected men who have sex with men in Tianjin, 2014-2017

Objective: To understand prevalence and transmission of transmitted drug resistance (TDR) among HIV infected men who have sex with men (MSM) in Tianjin from 2014 to 2017. Methods: A total of 225 blood samples were collected from HIV infected MSM in Tianjin from 2014 to 2017. Pol gene fragments were obtained by viral RNA extraction and nested PCR amplification. Phylogenetic and drug resistance analyses were conducted. Results: A total of 205 samples were successfully sequenced and analyzed. Based on pol sequences, 53.2% (109/205), 28.8% (59/205), 10.2% (21/205), 4.9% (10/205) and 2.9% (6/205) of the samples were positive for HIV subtypes CRF01_AE, CRF07_BC, B, CRF55_01B and unique recombinant forms (URFs). Twenty transmission clusters, including 75 sequences, were identified and 62.5% (10/16) of sequences with TDR were in 5 clusters. The prevalence of TDR was 7.8% between 2014 and 2017. The annual prevalence rate increased from 3.9% (2/51) in 2014, 5.7% (3/53) in 2015, 9.6% (5/52) in 2016 to 12.2%(6/49) in 2017, the difference was not significant (χ(2)=2.504, P=0.127). CRF01_AE and B strains had high TDR prevalence (3.4%, 7/205) and (2.9%, 6/205), respectively. The TDR mutation was mainly NNRTIs, the TDR prevalence was 6.3% (13/205). In contract, the TDR prevalence of NRTIs and PIs were 1.5% (3/205) and 1.0% (2/205) respectively. Conclusion: Results from this study suggested that the prevalence of HIV-1 TDR strains in MSM was serious in Tianjin. It is necessary to take effective prevention and control measures.

Insights about minority HIV-1 strains in transmitted drug resistance mutation dynamics and disease progression.

The presence of minority transmitted drug resistance mutations was assessed using ultra-deep sequencing and correlated with disease progression among recently HIV-1-infected individuals from Brazil. Samples at baseline during recent infection and 1 year after the establishment of the infection were analysed. Viral RNA and proviral DNA from 25 individuals were subjected to ultra-deep sequencing of the reverse transcriptase and protease regions of HIV-1. Viral strains carrying transmitted drug resistance mutations were detected in 9 out of the 25 patients, for all major antiretroviral classes, ranging from one to five mutations per patient. Ultra-deep sequencing detected strains with frequencies as low as 1.6% and only strains with frequencies >20% were detected by population plasma sequencing (three patients). Transmitted drug resistance strains with frequencies <14.8% did not persist upon established infection. The presence of transmitted drug resistance mutations was negatively correlated with the viral load and with CD4+ T cell count decay. Transmitted drug resistance mutations representing small percentages of the viral population do not persist during infection because they are negatively selected in the first year after HIV-1 seroconversion.

Geographic and temporal trends in the molecular epidemiology and genetic mechanisms of transmitted HIV-1 drug resistance: an individual-patient- and sequence-level meta-analysis.

BackgroundRegional and subtype-specific mutational patterns of HIV-1 transmitted drug resistance (TDR) are essential for informing first-line antiretroviral (ARV) therapy guidelines and designing diagnostic assays for use in regions where standard genotypic resistance testing is not affordable. We sought to understand the molecular epidemiology of TDR and to identify the HIV-1 drug-resistance mutations responsible for TDR in different regions and virus subtypes.Methods and FindingsWe reviewed all GenBank submissions of HIV-1 reverse transcriptase sequences with or without protease and identified 287 studies published between March 1, 2000, and December 31, 2013, with more than 25 recently or chronically infected ARV-naïve individuals. These studies comprised 50,870 individuals from 111 countries. Each set of study sequences was analyzed for phylogenetic clustering and the presence of 93 surveillance drug-resistance mutations (SDRMs). The median overall TDR prevalence in sub-Saharan Africa (SSA), south/southeast Asia (SSEA), upper-income Asian countries, Latin America/Caribbean, Europe, and North America was 2.8%, 2.9%, 5.6%, 7.6%, 9.4%, and 11.5%, respectively. In SSA, there was a yearly 1.09-fold (95% CI: 1.05–1.14) increase in odds of TDR since national ARV scale-up attributable to an increase in non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance. The odds of NNRTI-associated TDR also increased in Latin America/Caribbean (odds ratio [OR] = 1.16; 95% CI: 1.06–1.25), North America (OR = 1.19; 95% CI: 1.12–1.26), Europe (OR = 1.07; 95% CI: 1.01–1.13), and upper-income Asian countries (OR = 1.33; 95% CI: 1.12–1.55). In SSEA, there was no significant change in the odds of TDR since national ARV scale-up (OR = 0.97; 95% CI: 0.92–1.02). An analysis limited to sequences with mixtures at less than 0.5% of their nucleotide positions—a proxy for recent infection—yielded trends comparable to those obtained using the complete dataset. Four NNRTI SDRMs—K101E, K103N, Y181C, and G190A—accounted for >80% of NNRTI-associated TDR in all regions and subtypes. Sixteen nucleoside reverse transcriptase inhibitor (NRTI) SDRMs accounted for >69% of NRTI-associated TDR in all regions and subtypes. In SSA and SSEA, 89% of NNRTI SDRMs were associated with high-level resistance to nevirapine or efavirenz, whereas only 27% of NRTI SDRMs were associated with high-level resistance to zidovudine, lamivudine, tenofovir, or abacavir. Of 763 viruses with TDR in SSA and SSEA, 725 (95%) were genetically dissimilar; 38 (5%) formed 19 sequence pairs. Inherent limitations of this study are that some cohorts may not represent the broader regional population and that studies were heterogeneous with respect to duration of infection prior to sampling.ConclusionsMost TDR strains in SSA and SSEA arose independently, suggesting that ARV regimens with a high genetic barrier to resistance combined with improved patient adherence may mitigate TDR increases by reducing the generation of new ARV-resistant strains. A small number of NNRTI-resistance mutations were responsible for most cases of high-level resistance, suggesting that inexpensive point-mutation assays to detect these mutations may be useful for pre-therapy screening in regions with high levels of TDR. In the context of a public health approach to ARV therapy, a reliable point-of-care genotypic resistance test could identify which patients should receive standard first-line therapy and which should receive a protease-inhibitor-containing regimen.

Increase of RT-related transmitted drug resistance in non-CRF01_AE among HIV type 1-infected men who have sex with men in the 7 cities of China.

To elucidate new features in the prevalence of HIV-1 transmitted drug resistance (TDR) in men who have sex with men (MSM) in China. A total of 441 HIV-1-positive subjects were recruited from high-risk MSM populations in 7 cities across China between 2012 and 2013. Nucleotide sequences of 1.1-kb pol-RT regions were amplified and sequenced from 367 of the 441 samples. Phylogenetic and genetic drug-resistant analyses were performed. The overall distribution of HIV-1 genotypes was as the following: CRF01_AE, 52.3%; CRF07_BC, 33.2%; 01/B recombinants, 6.0%; subtype B (United States-European), 3.8%; subtype B', 3.8%; and CRF08_BC, 0.8%. About 91.3% of the sequences clustered together. An overall 4.6% TDR rate was found. Reverse transcriptase (RT)-related TDR reached 2.7%. TDR of 2.2% was detected in protease region. Most of RT-related TDRs were detected in non-CRF01_AE subtypes (90.0%, 9/10), including T215A/S, K101E, K103N, V106M, and E138G. Most of the strains with TDRs (88.2%, 15/17) were presented in the clusters. TDR strains against non-nucleoside reverse transcriptase inhibitors in non-CRF01_AE subtypes also formed some subclusters (70.0%, 7/10). One CRF07_BC subject with K103N in Kunming had a very close genetic distance with one that received highly active antiretroviral therapy locally (bootstrap = 99%). Two CRF55_01B subjects carrying K103N in Changsha and Nanjing also had a very close genetic distance (bootstrap = 100%). RT-related TDR of non-CRF01_AE became the main TDR among MSM in China. There is an increasing trend and a potential transmission risk for the RT-related TDR among MSM throughout China. Some TDRs could have already been transmitted among different cities. Intervention efforts should be strengthened among MSM to prevent further transmission of HIV and the proliferation of the strains with TDR.

Low Prevalence of Transmitted Drug Resistance in Patients Newly Diagnosed with HIV-1 Infection in Sweden 2003–2010

Transmitted drug resistance (TDR) is a clinical and epidemiological problem because it may contribute to failure of antiretroviral treatment. The prevalence of TDR varies geographically, and its prevalence in Sweden during the last decade has not been reported. Plasma samples from 1,463 patients newly diagnosed with HIV-1 infection between 2003 and 2010, representing 44% of all patients diagnosed in Sweden during this period, were analyzed using the WHO 2009 list of mutations for surveillance of TDR. Maximum likelihood phylogenetic analyses were used to determine genetic subtype and to investigate the relatedness of the sequences. Eighty-two patients showed evidence of TDR, representing a prevalence of 5.6% (95% CI: 4.5%–6.9%) without any significant time trends or differences between patients infected in Sweden or abroad. Multivariable logistic regression showed that TDR was positively associated with men who have sex with men (MSM) and subtype B infection and negatively associated with CD4 cell counts. Among patients with TDR, 54 (68%) had single resistance mutations, whereas five patients had multi-drug resistant HIV-1. Phylogenetic analyses identified nine significantly supported clusters involving 29 of the patients with TDR, including 23 of 42 (55%) of the patients with TDR acquired in Sweden. One cluster contained 18 viruses with a M41L resistance mutation, which had spread among MSM in Stockholm over a period of at least 16 years (1994–2010). Another cluster, which contained the five multidrug resistant viruses, also involved MSM from Stockholm. The prevalence of TDR in Sweden 2003–2010 was lower than in many other European countries. TDR was concentrated among MSM, where clustering of TDR strains was observed, which highlights the need for continued and improved measures for targeted interventions.

Phylogenetic Investigation of Transmission Pathways of Drug-Resistant HIV-1 Utilizing Pol Sequences Derived From Resistance Genotyping

To investigate the nature of transmission links existing between patients recently infected with HIV strains containing transmitted drug resistance (TDR) mutations. Virus from 63 individuals recently infected with HIV-1 containing TDR mutations was analyzed phylogenetically to determine virological links. Phylogenetic trees were reconstructed using maximum likelihood and distance-based methods. Monophyletic clusters detected on the basis of pol sequences were confirmed using env and gag sequences. Potential bias caused by the presence of drug resistance mutations was assessed by reanalyzing the pol sequence set after the omission of 16 drug resistance codons identified in the TDR population. Phylogenetic analysis revealed 9 apparent transmission clusters involving 24 of the 63 (38%) TDR patients. Each cluster was supported by high bootstrap values and low intracluster genetic distances. The 9 transmission clusters were confirmed in separate analyses using env and gag sequences and in pol sequences after the removal of codons associated with drug resistance. Pol sequences generated during baseline resistance genotyping for newly HIV-infected patients provide the opportunity for real-time phylogenetics to identify sources of multiple HIV transmission events. This study demonstrated the existence of several distinct clusters of patients whose TDR strains were linked. Several discrete clusters involving transmission of K103N- and/or M41L-resistant virus to multiple recipients were detected, suggesting that multiple transmission pathways can exist for viruses with the same resistance mutations.