Cross-clade simultaneous HIV drug resistance genotyping for reverse transcriptase, protease, and integrase inhibitor mutations by Illumina MiSeq

Prevalence of Transmitted Drug Resistance among HIV-1 Patients in the Aegean Region: Results from the Western Part of Turkey

OBJECTIVES

This study aimed to analyze the antiretroviral drug resistance in antiretroviral treatment-naïve HIV-positive patients in the Aegean Region of Turkey from 2012 to 2019.

METHODS

The study included 814 plasma samples from treatment-naïve HIV-positive patients. Drug resistance analysis was performed by Sanger sequencing (SS) between 2012-2017 and by next-generation sequencing sequencing (NGS) between 2018-2019. SS was used to analyze resistance mutations in the protease (PR) and reverse transcriptase (RT) gene regions using a ViroSeq HIV-1 Genotyping System. PCR products were analyzed with an ABI3500 GeneticAnalyzer (Applied Biosystems). The sequencing of the HIV genome in the PR, RT, and integrase gene regions was carried out using MiSeq NGS technology. Drug resistance mutations and subtypes were interpreted using the Stanford University HIV-1 drug resistance database.

RESULTS

Transmitted drug resistance (TDR) mutation was detected in 34/814 (4.1 %) samples. Nonnucleoside reverse transcriptase inhibitor (NNRTI), nucleoside reverse transcriptase inhibitor (NRTI), and protease inhibitor (PI) mutations were identified in 1.4 % (n =12), 2.4 % (n =20), and 0.3 % (n = 3) of samples, respectively. The most common subtypes were B (53.1 %), A (10.9%), CRF29_BF (10.6%), and B + CRF02_AG (8,2%). The most common TDR mutations were E138A (3.4%), T215 revertants (1.7%), M41L (1.5%), and K103N (1.1%).

CONCLUSION

Transmitted drug resistance rate in the Aegean Region is compatible with national and regional data. Routine surveillance of resistance mutations may guide the safe and correct selection of initial drug combinations for antiretroviral therapy. The identification of HIV-1 subtypes and recombinant forms in Turkey may contribute to international molecular epidemiological data.

Low-frequency HIV-1 drug resistance mutations in antiretroviral naïve individuals in Botswana

BACKGROUND

Individuals living with human immunodeficiency virus (HIV) who experience virological failure (VF) after combination antiretroviral therapy (cART) initiation may have had low-frequency drug resistance mutations (DRMs) at cART initiation. There are no data on low-frequency DRMs among cART-naïve HIV-positive individuals in Botswana.

METHODS

We evaluated the prevalence of low-frequency DRMs among cART-naïve individuals previously sequenced using Sanger sequencing. The generated pol amplicons were sequenced by next-generation sequencing.

RESULTS

We observed low-frequency DRMs (detected at <20% in 33/103 (32%) of the successfully sequenced individuals, of whom four also had mutations detected at >20%. K65R was the most common low-frequency DRM detected in 8 individuals. Eighty-two of the 103 individuals had follow-up viral load data while on cART. Twenty-seven of the 82 individuals harbored low-frequency DRMs. Only 12 of 82 individuals experienced VF. The following low-frequency DRMs were observed in four individuals experiencing VF: K65R, K103N, V108I, and Y188C. No statistically significant difference was observed in the prevalence of low-frequency DRMs between individuals experiencing VF (4/12) and those not experiencing VF (23/70) (P = .97). However, individuals with non-nucleoside reverse transcriptase inhibitors-associated low-frequency DRMs were 2.68 times more likely to experience VF (odds ratio, 2.68; 95% confidential interval, 0.4-13.9) compared with those without (P = .22).

CONCLUSION

Next-generation sequencing was able to detect low-frequency DRMs in this cohort in Botswana, but these DRMs did not contribute significantly to VF.

CODEHOP-Mediated PCR Improves HIV-1 Genotyping and Detection of Variants by MinION Sequencing

HIV-1 is genetically heterogeneous, having different subtypes and circulating recombinant forms (CRFs). HIV-1 genotyping is used to determine drug resistance profiles and is based on the use of a mixture of consensus and degenerate primers targeting the pol gene. However, the use of this type of primers is associated with either PCR bias or PCR failure. Consensus-degenerate hybrid oligonucleotide primers (CODEHOPs) can detect and identify unknown and distantly related gene sequences by PCR. CODEHOPs designed using different HIV-1 subtypes and CRFs were evaluated for HIV-1 genotyping by Sanger and MinION sequencing. A total of 321 plasma samples were used for the validation of CODEHOP-mediated HIV-1 genotyping. CODEHOP-mediated PCR showed 100% sensitivity and specificity, with limits of detection and genotyping below 200 copies/ml. The head-to-head evaluation of CODEHOP-mediated PCR and standard PCR showed 97 to 98% and 82 to 84% PCR success rates, respectively. There was 100% agreement between the CODEHOP and the reference method in the drug resistance profiles determined by Sanger-based sequencing. Using MinION sequencing, the CODEHOP-mediated PCR scheme resulted in better depth of genome coverage and detection of more drug resistance variants in the protease and reverse transcriptase genes than the standard amplification scheme. The overall prevalences of drug resistance mutations were 17.1% in treatment-experienced patients and 1.2% in treatment-naive patients. They were mainly associated with resistance to reverse transcriptase inhibitors and were linked to virological failure and the patient’s treatment history. Findings from this study suggest that the performance of HIV-1 genotyping is improved by using CODEHOP-mediated PCR.

IMPORTANCE HIV-1 drug resistance is the main cause of treatment failure. Regular surveillance of resistance-associated mutations in HIV-1 genomes is essential for the optimal management of HIV-1 infections. Due to HIV-1’s genetic diversity, different HIV-1 genotypes are circulating worldwide. Standard primers used in the amplification of HIV-1 RNA have not been designed to cover all HIV-1 genotypes and are the main cause of amplification and drug resistance test failure. In this study, new sets of PCR primers targeting the protease, reverse transcriptase, and integrase genes were designed using the CODEHOP approach. They were compared to primers recommended in part by WHO for drug resistance testing using in-house PCR. Unsuccessful HIV-1 RNA amplification was less likely to occur with CODEHOP primers, leading to fewer test failures and lower cost. Furthermore, CODEHOP primers were more effective than standard primers for the detection of minority resistant variants by MinION sequencing.

Investigation of drug resistance against protease, reverse transcriptase, and integrase inhibitors by next-generation sequencing in HIV-positive patients

Our aim was to investigate the mutations in protease (PR), reverse transcriptase (RT), and integrase (IN) gene regions in human immunodeficiency virus (HIV) using a single amplicon via next-generation sequencing (NGS). The study included plasma samples from 49 HIV-1-positive patients, which were referred for HIV-1 drug resistance testing during 2017. A nested polymerase chain reaction (PCR) was performed after the RNA extraction and one-step reverse transcription stages. The sequencing of the HIV genome in the PR, RT, and IN gene regions was carried out using MiSeq NGS technology. Sanger sequencing (SS) was used to analyze resistance mutations in the PR and RT gene regions using a ViroSeq HIV-1 Genotyping System. PCR products were analyzed with an ABI3500 GeneticAnalyzer (Applied Biosystems). Resistance mutations detected with NGS at frequencies above 20% were identical to the SS results. Resistance to at least one antiretroviral (ARV) drug was 22.4% (11 of 49) with NGS and 10.2% (5 of 49) with SS. At least one low-frequency resistance mutation was detected in 18.3% (9 of 49) of the samples. Low-frequency resistance mutations resulted in virological failure in only one patient. The cost of the analyses was reduced by sample pooling and multiplex analysis using the MiSeq system. This is the first study in Turkey to use NGS technologies for the detection of resistance mutations in all three gene (PR, RT, IN) regions using a single amplicon. Our findings suggest that NGS is more sensitive and cost-effective than the SS method.

Validation of multiplex PCR sequencing assay of SIV

Background

The generation of accurate and reproducible viral sequence data is necessary to understand the diversity present in populations of RNA viruses isolated from clinical samples. While various sequencing methods are available, they often require high quality templates and high viral titer to ensure reliable data.

Methods

We modified a multiplex PCR and sequencing approach to characterize populations of simian immunodeficiency virus (SIV) isolated from nonhuman primates. We chose this approach with the aim of reducing the number of required input templates while maintaining fidelity and sensitivity. We conducted replicate sequencing experiments using different numbers of quantified viral RNA (vRNA) or viral cDNA as input material. We performed assays with clonal SIVmac239 to detect false positives, and we mixed SIVmac239 and a variant with 24 point mutations (SIVmac239-24X) to measure variant detection sensitivity.

Results

We found that utilizing a starting material of quantified viral cDNA templates had a lower rate of false positives and increased reproducibility when compared to that of quantified vRNA templates. This study identifies the importance of rigorously validating deep sequencing methods and including replicate samples when using a new method to characterize low frequency variants in a population with a small number of templates.

Conclusions

Because the need to generate reproducible and accurate sequencing data from diverse viruses from low titer samples, we modified a multiplex PCR and sequencing approach to characterize SIV from populations from non-human primates. We found that increasing starting template numbers increased the reproducibility and decreased the number of false positives identified, and this was further seen when cDNA was used as a starting material. Ultimately, we highlight the importance of vigorously validating methods to prevent overinterpretation of low frequency variants in a sample.

SARS-CoV-2 genomic analyses in cancer patients reveal elevated intrahost genetic diversity

Numerous factors have been identified to influence susceptibility to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and disease severity. Cancer patients are more prone to clinically evolve to more severe COVID-19 conditions, but the determinants of such a more severe outcome remain largely unknown. We have determined the full-length SARS-CoV-2 genomic sequences of cancer patients and healthcare workers (non-cancer controls) by deep sequencing and investigated the within-host viral population of each infection, quantifying intrahost genetic diversity. Naso- and oropharyngeal SARS-CoV-2+ swabs from 57 cancer patients and 14 healthcare workers from the Brazilian National Cancer Institute were collected in April to May 2020. Complete genome amplification using ARTIC network V3 multiplex primers was performed followed by next-generation sequencing. Assemblies were conducted in Geneious R11, where consensus sequences were extracted and intrahost single nucleotide variants were identified. Maximum likelihood phylogenetic analysis was performed using PhyMLv.3.0 and lineages were classified using Pangolin and CoV-GLUE. Phylogenetic analysis showed that all but one strain belonged to clade B1.1. Four genetically linked mutations known as the globally dominant SARS-CoV-2 haplotype (C241T, C3037T, C14408T and A23403G) were found in the majority of consensus sequences. SNV signatures of previously characterized Brazilian genomes were also observed in most samples. Another 85 SNVs were found at a lower frequency (1.4%-19.7%) among the consensus sequences. Cancer patients displayed a significantly higher intrahost viral genetic diversity compared to healthcare workers. This difference was independent of SARS-CoV-2 Ct values obtained at the diagnostic tests, which did not differ between the two groups. The most common nucleotide changes of intrahost SNVs in both groups were consistent with APOBEC and ADAR activities. Intrahost genetic diversity in cancer patients was not associated with disease severity, use of corticosteroids, or use of antivirals, characteristics that could influence viral diversity. Moreover, the presence of metastasis, either in general or specifically in the lung, was not associated with intrahost diversity among cancer patients. Cancer patients carried significantly higher numbers of minor variants compared to non-cancer counterparts. Further studies on SARS-CoV-2 diversity in especially vulnerable patients will shed light onto the understanding of the basis of COVID-19 different outcomes in humans.

Study of HIV Resistance Mutations Against Antiretrovirals using Bioinformatics Tools

BACKGROUND

Antiretroviral drugs to HIV-1 (ARV) are divided into classes: Nucleotide Reverse Transcriptase Inhibitors (NRTIs); Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs); Protease Inhibitors (PIs); Integrase Inhibitors (INIs); fusion inhibitors and entry Inhibitors. The occurrence of mutations developing resistance to antiretroviral drugs used in HIV treatment take place in a considerable proportion and has accumulated over its long period of therapy.

OBJECTIVE

This study aimed to identify resistance mutations to antiretrovirals used in the treatment of HIV-1 in strains isolated from Brazilian territory deposited at Genbank, as well as to relate to the clinical significance and mechanism of action.

METHODS

Elucidation of these mutations was by comparative method of peptide sequence resulting from genes encoding therapeutic targets in HIV antiretroviral therapy (ART) of the strains with a reference sequence through bioinformatic genetic information manipulation techniques.

RESULTS

Of the 399 sequences analyzed, 121 (30.3%) had some type of mutations associated with resistance to some class of antiretroviral drug. Resistance to NNRTIs was the most prevalent, detected in 77 (63.6%) of the 121 mutated sequences, compared to NRTIs and PIs, whose resistance was detected in 60 (49.6%) and 21 (17.3%), respectively, and to INIs, only 1 (0.8%) sample showed associated resistance mutation.

CONCLUSION

Resistance to HIV ARV was detected at a considerable rate of 30.3%, showing some concerns about the percentage of viral strains that escape the established therapeutic regimen and that circulate currently in Brazil. The non-use of NNRTIs in Brazil is justified by the emergence of resistance mutations. The low prevalence of mutations against INIs is because drugs in this class have a high genetic barrier.

Validation of Variant Assembly Using HAPHPIPE with Next-Generation Sequence Data from Viruses

Next-generation sequencing (NGS) offers a powerful opportunity to identify low-abundance, intra-host viral sequence variants, yet the focus of many bioinformatic tools on consensus sequence construction has precluded a thorough analysis of intra-host diversity. To take full advantage of the resolution of NGS data, we developed HAplotype PHylodynamics PIPEline (HAPHPIPE), an open-source tool for the de novo and reference-based assembly of viral NGS data, with both consensus sequence assembly and a focus on the quantification of intra-host variation through haplotype reconstruction. We validate and compare the consensus sequence assembly methods of HAPHPIPE to those of two alternative software packages, HyDRA and Geneious, using simulated HIV and empirical HIV, HCV, and SARS-CoV-2 datasets. Our validation methods included read mapping, genetic distance, and genetic diversity metrics. In simulated NGS data, HAPHPIPE generated pol consensus sequences significantly closer to the true consensus sequence than those produced by HyDRA and Geneious and performed comparably to Geneious for HIV gp120 sequences. Furthermore, using empirical data from multiple viruses, we demonstrate that HAPHPIPE can analyze larger sequence datasets due to its greater computational speed. Therefore, we contend that HAPHPIPE provides a more user-friendly platform for users with and without bioinformatics experience to implement current best practices for viral NGS assembly than other currently available options.

Measurement error and variant-calling in deep Illumina sequencing of HIV

MOTIVATION

Next-generation deep sequencing of viral genomes, particularly on the Illumina platform, is increasingly applied in HIV research. Yet, there is no standard protocol or method used by the research community to account for measurement errors that arise during sample preparation and sequencing. Correctly calling high and low-frequency variants while controlling for erroneous variants is an important precursor to downstream interpretation, such as studying the emergence of HIV drug-resistance mutations, which in turn has clinical applications and can improve patient care.

RESULTS

We developed a new variant-calling pipeline, hivmmer, for Illumina sequences from HIV viral genomes. First, we validated hivmmer by comparing it to other variant-calling pipelines on real HIV plasmid datasets. We found that hivmmer achieves a lower rate of erroneous variants, and that all methods agree on the frequency of correctly called variants. Next, we compared the methods on an HIV plasmid dataset that was sequenced using Primer ID, an amplicon-tagging protocol, which is designed to reduce errors and amplification bias during library preparation. We show that the Primer ID consensus exhibits fewer erroneous variants compared to the variant-calling pipelines, and that hivmmer more closely approaches this low error rate compared to the other pipelines. The frequency estimates from the Primer ID consensus do not differ significantly from those of the variant-calling pipelines.

AVAILABILITY AND IMPLEMENTATION

hivmmer is freely available for non-commercial use from https://github.com/kantorlab/hivmmer.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Performance comparison of next generation sequencing analysis pipelines for HIV-1 drug resistance testing

Next generation sequencing (NGS) is a trending new standard for genotypic HIV-1 drug resistance (HIVDR) testing. Many NGS HIVDR data analysis pipelines have been independently developed, each with variable outputs and data management protocols. Standardization of such analytical methods and comparison of available pipelines are lacking, yet may impact subsequent HIVDR interpretation and other downstream applications. Here we compared the performance of five NGS HIVDR pipelines using proficiency panel samples from NIAID Virology Quality Assurance (VQA) program. Ten VQA panel specimens were genotyped by each of six international laboratories using their own in-house NGS assays. Raw NGS data were then processed using each of the five different pipelines including HyDRA, MiCall, PASeq, Hivmmer and DEEPGEN. All pipelines detected amino acid variants (AAVs) at full range of frequencies (1~100%) and demonstrated good linearity as compared to the reference frequency values. While the sensitivity in detecting low abundance AAVs, with frequencies between 1~20%, is less a concern for all pipelines, their specificity dramatically decreased at AAV frequencies <2%, suggesting that 2% threshold may be a more reliable reporting threshold for ensured specificity in AAV calling and reporting. More variations were observed among the pipelines when low abundance AAVs are concerned, likely due to differences in their NGS read quality control strategies. Findings from this study highlight the need for standardized strategies for NGS HIVDR data analysis, especially for the detection of minority HIVDR variants.

Performance evaluation of the Vela Dx Sentosa next-generation sequencing system for HIV-1 DNA genotypic resistance

BACKGROUND

Patients on antiretroviral therapy could benefit from HIV-1 DNA resistance genotyping for exploring virological failure with low viral load or to guide treatment simplification. Few new generation sequencing data are available.

OBJECTIVE

To check that the automated deep sequencing Sentosa platform (Vela DX) detected minority resistant variants well enough for HIV DNA genotyping.

STUDY DESIGN

We evaluated the Sentosa SQ HIV genotyping assay with automated extraction on 40 DNA longitudinal samples from treatment-experienced patients by comparison with Sanger sequencing. HIV drug resistance was interpreted using the ANRS algorithm (v29) at the threshold of 20 % and 3 %.

RESULTS

The Sentosa SQ HIV genotyping assay was 100 % successful to amplify and sequence PR and RT and 86 % to amplify and sequence IN when the HIV DNA load was >2.5 log copies/million cells. The Sentosa and Sanger sequencing were concordant for predicting PR-RT resistance at the threshold of 20 % in 14/18 samples successfully sequenced. A higher level of resistance was predicted by Sentosa in three samples and by Sanger in one sample. The prevalence of resistance was 7 % to PI, 59 % to NRTI, 31 % to NNRTI and 20 % to integrase inhibitors using the Sentosa SQ genotyping assay at the threshold of 3 %. Seven additional mutations <20 % were detected using the Sentosa assay.

CONCLUSION

Automated DNA extraction and sequencing using the Sentosa SQ HIV genotyping assay accurately predicted HIV DNA drug resistance by comparison with Sanger. Prospective studies are needed to evaluate the clinical interest of HIV DNA genotyping.

HIV-1 genotypic resistance testing using the Vela automated next-generation sequencing platform

Objectives

To evaluate the diagnostic performance of the Vela next-generation sequencing (NGS) system in conjunction with the Sentosa SQ HIV Genotyping Assay for genotyping HIV-1.

Methods

Plasma RNA was extracted and templates prepared with the Sentosa SX instrument before sequencing the HIV-1 polymerase on the Sentosa SQ301 Sequencer (PGM IonTorrent). The Vela NGS System was compared with direct sequencing and the 454 GS-FLX (Roche) and MiSeq (Illumina) systems for genotypic resistance testing on clinical samples.

Results

The Vela NGS system detected majority resistance mutations in subtype B and CRF02-AG samples at 500 copies/mL and minority variants with a sensitivity of 5% at 100 000 copies/mL. The Vela NGS system and direct sequencing identified resistance mutations with 97% concordance in 46 clinical samples. Vela identified 1/20 of the 1%-5% mutations identified by 454, 5/12 of the 5%-20% mutations and 60/61 of the >20% mutations. Vela identified 3/14 of the 1%-5% mutations identified by MiSeq, 0/2 of the 5%-20% mutations and 47/47 of the >20% mutations. The resistance mutation quantifications by Vela and 454 were concordant (bias: 2.31%), as were those by Vela and MiSeq (bias: 1.06%).

Conclusions

The Vela NGS system provides automated nucleic acid extraction, PCR reagent distribution, library preparation and bioinformatics analysis. The analytical performance was very good when compared with direct sequencing, but was less sensitive than two other NGS platforms for detecting minority variants.

A MiSeq-HyDRA platform for enhanced HIV drug resistance genotyping and surveillance

Conventional HIV drug resistance (HIVDR) genotyping utilizes Sanger sequencing (SS) methods, which are limited by low data throughput and the inability of detecting low abundant drug resistant variants (LADRVs). Here we present a next generation sequencing (NGS)-based HIVDR typing platform that leverages the advantages of Illumina MiSeq and HyDRA Web. The platform consists of a fully validated sample processing protocol and HyDRA web, an open web portal that allows automated customizable NGS-based HIVDR data processing. This platform was characterized and validated using a panel of HIV-spiked plasma representing all major HIV-1 subtypes, pedigreed plasmids, HIVDR proficiency specimens and clinical specimens. All examined major HIV-1 subtypes were consistently amplified at viral loads of ≥1,000 copies/ml. The gross error rate of this platform was determined at 0.21%, and minor variations were reliably detected down to 0.50% in plasmid mixtures. All HIVDR mutations identifiable by SS were detected by the MiSeq-HyDRA protocol, while LADRVs at frequencies of 1~15% were detected by MiSeq-HyDRA only. As compared to SS approaches, the MiSeq-HyDRA platform has several notable advantages including reduced cost and labour, and increased sensitivity for LADRVs, making it suitable for routine HIVDR monitoring for both patient care and surveillance purposes.

Estimating HIV-1 Genetic Diversity in Brazil Through Next-Generation Sequencing

Approximately 36.7 million people were living with the human immunodeficiency virus (HIV) at the end of 2016 according to UNAIDS, representing a global prevalence rate of 0.8%. In Brazil, an HIV prevalence of 0.24% has been estimated, which represents approximately 830,000 individuals living with the virus. As a touristic and commercial hub in Latin America, Brazil harbors an elevated HIV genetic variability, further contributed by the selective pressure exerted by the host immune system and by antiretroviral treatment. Through the progress of the next-generation sequencing (NGS) techniques, it has been possible to expand the study of HIV genetic diversity, evolutionary, and epidemic processes, allowing the generation of HIV complete or near full-length genomes (NFLG) and improving the characterization of intra- and interhost diversity of viral populations. Greater sensitivity in the detection of viral recombinant forms represents one of the major improvements associated with this development. It is possible to identify unique or circulating recombinant forms using the near full-length viral genomes with increasing accuracy. It also permits the characterization of multiple viral infections within individual hosts. Previous Brazilian studies using NGS to analyze HIV diversity were able to identify several distinct unique and circulating recombinant forms and evidenced dual infections. These data unveiled unprecedented high rates of viral recombination and highlighted that novel recombinants are continually arising in the Brazilian epidemic. In the pooled analysis depicted in this report, HIV subtypes have been determined from HIV-positive patients in five states of Brazil with some of the highest HIV prevalence, three in the Southeast (Rio de Janeiro, São Paulo, and Minas Gerais), one in the Northeast (Pernambuco) and one in the South (Rio Grande do Sul). Combined data analysis showed a significant prevalence of recombinant forms (29%; 101/350), and a similar 26% when only NFLGs were considered. Moreover, the analysis was able to evidence the occurrence of multiple infections in some individuals. Our data highlight the great HIV genetic diversity found in Brazil and unveils a more accurate scenario of the HIV evolutionary dynamics in the region.

Diagnosis of Human Immunodeficiency Virus Infection

HIV diagnostics have played a central role in the remarkable progress in identifying, staging, initiating, and monitoring infected individuals on life-saving antiretroviral therapy. They are also useful in surveillance and outbreak responses, allowing for assessment of disease burden and identification of vulnerable populations and transmission "hot spots," thus enabling planning, appropriate interventions, and allocation of appropriate funding. HIV diagnostics are critical in achieving epidemic control and require a hybrid of conventional laboratory-based diagnostic tests and new technologies, including point-of-care (POC) testing, to expand coverage, increase access, and positively impact patient management. In this review, we provide (i) a historical perspective on the evolution of HIV diagnostics (serologic and molecular) and their interplay with WHO normative guidelines, (ii) a description of the role of conventional and POC testing within the tiered laboratory diagnostic network, (iii) information on the evaluations and selection of appropriate diagnostics, (iv) a description of the quality management systems needed to ensure reliability of testing, and (v) strategies to increase access while reducing the time to return results to patients. Maintaining the central role of HIV diagnostics in programs requires periodic monitoring and optimization with quality assurance in order to inform adjustments or alignment to achieve epidemic control.

HIV Reverse Transcriptase and Protease Genes Variability Can Be a Biomarker Associated with HIV and Hepatitis B or C Coinfection

Variability of the HIV reverse transcriptase (RT) and protease (PR) genes has been used as indicators of drug resistance and as a mean to evaluate phylogenetic relationships among circulating virus. However, these studies have been carried in HIV mono-infected populations. The goal of this study was to evaluate, for the first time, the HIV PR and RT sequences from HIV/HBV and HIV/HCV co-infected patients. HIV PR and RT genes were amplificated and sequenced to resistance analysis. The bioinformatics analysis was performed to infer about sequences clustering and molecular evolution. The results showed that the most frequent amino acid substitutions in RT were L214F (67.6%), I135T (55.9%), and in PR was V15I (41.2%). The molecular clock analysis showed that the HIV circulating in co-infected patients were separated in two clusters in the years 1999-2000. Some patients included as HIV mono-infected according patients' medical records and inside the co-infected cluster were, in fact, co-infected by PCR analysis. Analysis of the decision trees showed susceptibility to lamivudine and emtricitabine were important attribute to characterize co-infected patients. In conclusion, the results obtained in this study suggest, for the first time, that HIV RT and PR genes variability could be a genetic biomarker to coinfection.

Performance comparison of deep sequencing platforms for detecting HIV-1 variants in the pol gene

The present study compares the performances of an in-house sequencing protocol developed on MiSeq, the Sanger method, and the 454 GS-FLX for detecting and quantifying drug-resistant mutations (DRMs) in the human immunodeficiency virus polymerase gene (reverse transcriptase [RT] and protease [PR]). MiSeq sequencing identified all the resistance mutations detected by bulk sequencing (n = 84). Both the MiSeq and 454 GS-FLX platforms identified 67 DRMs in the RT and PR regions, but a further 25 DRMs were identified by only one or other of them. Pearson's analysis showed good concordance between the percentage of drug-resistant variants determined by MiSeq and 454 GS-FLX sequencing (ρ = .77, P < .0001). The MiSeq platform is as accurate as the 454 GS-FLX Roche system for determining RT and PR DRMs and could be used for monitoring human immunodeficiency virus type 1 drug resistance.

Characterization of HIV-1 Near Full-Length Proviral Genome Quasispecies from Patients with Undetectable Viral Load Undergoing First-Line HAART Therapy

Increased access to highly active antiretroviral therapy (HAART) by human immunodeficiency virus postive (HIV⁺) individuals has become a reality worldwide. In Brazil, HAART currently reaches over half of HIV-infected subjects. In the context of a remarkable HIV-1 genetic variability, highly related variants, called quasispecies, are generated. HIV quasispecies generated during infection can influence virus persistence and pathogenicity, representing a challenge to treatment. However, the clinical relevance of minority quasispecies is still uncertain. In this study, we have determined the archived proviral sequences, viral subtype and drug resistance mutations from a cohort of HIV⁺ patients with undetectable viral load undergoing HAART as first-line therapy using next-generation sequencing for near full-length virus genome (NFLG) assembly. HIV-1 consensus sequences representing NFLG were obtained for eleven patients, while for another twelve varying genome coverage rates were obtained. Phylogenetic analysis showed the predominance of subtype B (83%; 19/23). Considering the minority variants, 18 patients carried archived virus harboring at least one mutation conferring antiretroviral resistance; for six patients, the mutations correlated with the current ARVs used. These data highlight the importance of monitoring HIV minority drug resistant variants and their clinical impact, to guide future regimen switches and improve HIV treatment success.

Next-Generation Human Immunodeficiency Virus Sequencing for Patient Management and Drug Resistance Surveillance

High-quality, simplified, and low-cost human immunodeficiency virus (HIV) drug resistance tests that are able to provide timely actionable HIV resistance data at individual, population, and programmatic levels are needed to confront the emerging drug-resistant HIV epidemic. Next-generation sequencing technologies embedded in automated cloud-computing analysis environments are ideally suited for such endeavor. Whereas NGS can reduce costs over Sanger sequencing, automated analysis pipelines make NGS accessible to molecular laboratories regardless of the available bioinformatic skills. They can also produce highly structured, high-quality data that could be examined by healthcare officials and program managers on a real-time basis to allow timely public health action. Here we discuss the opportunities and challenges of such an approach.

No Substantial Evidence for Sexual Transmission of Minority HIV Drug Resistance Mutations in Men Who Have Sex with Men

During primary HIV infection, the presence of minority drug resistance mutations (DRM) may be a consequence of sexual transmission, de novo mutations, or technical errors in identification. Baseline blood samples were collected from 24 HIV-infected antiretroviral-naive, genetically and epidemiologically linked source and recipient partners shortly after the recipient's estimated date of infection. An additional 32 longitudinal samples were available from 11 recipients. Deep sequencing of HIV reverse transcriptase (RT) was performed (Roche/454), and the sequences were screened for nucleoside and nonnucleoside RT inhibitor DRM. The likelihood of sexual transmission and persistence of DRM was assessed using Bayesian-based statistical modeling. While the majority of DRM (>20%) were consistently transmitted from source to recipient, the probability of detecting a minority DRM in the recipient was not increased when the same minority DRM was detected in the source (Bayes factor [BF] = 6.37). Longitudinal analyses revealed an exponential decay of DRM (BF = 0.05) while genetic diversity increased. Our analysis revealed no substantial evidence for sexual transmission of minority DRM (BF = 0.02). The presence of minority DRM during early infection, followed by a rapid decay, is consistent with the "mutation-selection balance" hypothesis, in which deleterious mutations are more efficiently purged later during HIV infection when the larger effective population size allows more efficient selection. Future studies using more recent sequencing technologies that are less prone to single-base errors should confirm these results by applying a similar Bayesian framework in other clinical settings.IMPORTANCE The advent of sensitive sequencing platforms has led to an increased identification of minority drug resistance mutations (DRM), including among antiretroviral therapy-naive HIV-infected individuals. While transmission of DRM may impact future therapy options for newly infected individuals, the clinical significance of the detection of minority DRM remains controversial. In the present study, we applied deep-sequencing techniques within a Bayesian hierarchical framework to a cohort of 24 transmission pairs to investigate whether minority DRM detected shortly after transmission were the consequence of (i) sexual transmission from the source, (ii) de novo emergence shortly after infection followed by viral selection and evolution, or (iii) technical errors/limitations of deep-sequencing methods. We found no clear evidence to support the sexual transmission of minority resistant variants, and our results suggested that minor resistant variants may emerge de novo shortly after transmission, when the small effective population size limits efficient purge by natural selection.

High prevalence of HIV-1 transmitted drug-resistance mutations from proviral DNA massively parallel sequencing data of therapy-naïve chronically infected Brazilian blood donors

BACKGROUND

An improved understanding of the prevalence of low-abundance transmitted drug-resistance mutations (TDRM) in therapy-naïve HIV-1-infected patients may help determine which patients are the best candidates for therapy. In this study, we aimed to obtain a comprehensive picture of the evolving HIV-1 TDRM across the massive parallel sequences (MPS) of the viral entire proviral genome in a well-characterized Brazilian blood donor naïve to antiretroviral drugs.

MATERIALS AND METHODS

The MPS data from 128 samples used in the analysis were sourced from Brazilian blood donors and were previously classified by less-sensitive (LS) or "detuned" enzyme immunoassay as non-recent or longstanding HIV-1 infections. The Stanford HIV Resistance Database (HIVDBv 6.2) and IAS-USA mutation lists were used to interpret the pattern of drug resistance. The minority variants with TDRM were identified using a threshold of ≥ 1.0% and ≤ 20% of the reads sequenced. The rate of TDRM in the MPS data of the proviral genome were compared with the corresponding published consensus sequences of their plasma viruses.

RESULTS

No TDRM were detected in the integrase or envelope regions. The overall prevalence of TDRM in the protease (PR) and reverse transcriptase (RT) regions of the HIV-1 pol gene was 44.5% (57/128), including any mutations to the nucleoside analogue reverse transcriptase inhibitors (NRTI) and non-nucleoside analogue reverse transcriptase inhibitors (NNRTI). Of the 57 subjects, 43 (75.4%) harbored a minority variant containing at least one clinically relevant TDRM. Among the 43 subjects, 33 (76.7%) had detectable minority resistant variants to NRTIs, 6 (13.9%) to NNRTIs, and 16 (37.2%) to PR inhibitors. The comparison of viral sequences in both sources, plasma and cells, would have detected 48 DNA provirus disclosed TDRM by MPS previously missed by plasma bulk analysis.

CONCLUSION

Our findings revealed a high prevalence of TDRM found in this group, as the use of MPS drastically increased the detection of these mutations. Sequencing proviral DNA provided additional information about TDRM, which may impact treatment decisions. The overall results emphasize the importance of continuous monitoring.

Decoding HIV resistance: from genotype to therapy

Genetic variation in HIV poses a major challenge for prevention and treatment of the AIDS pandemic. Resistance occurs by mutations in the target proteins that lower affinity for the drug or alter the protein dynamics, thereby enabling viral replication in the presence of the drug. Due to the prevalence of drug-resistant strains, monitoring the genotype of the infecting virus is recommended. Computational approaches for predicting resistance from genotype data and guiding therapy are discussed. Many prediction methods rely on rules derived from known resistance-associated mutations, however, statistical or machine learning can improve the classification accuracy and assess unknown mutations. Adding classifiers such as information on the atomic structure of the protein can further enhance the predictions.

Evaluation of a Multidrug Assay for Monitoring Adherence to a Regimen for HIV Preexposure Prophylaxis in a Clinical Study, HIV Prevention Trials Network 073

Daily oral tenofovir disoproxil fumarate (TDF)-emtricitabine (FTC) is a safe and effective intervention for HIV preexposure prophylaxis (PrEP). We evaluated the performance of a qualitative assay that detects 20 antiretroviral (ARV) drugs (multidrug assay) in assessing recent PrEP exposure (detection limit, 2 to 20 ng/ml). Samples were obtained from 216 Black men who have sex with men (208 HIV-uninfected men and 8 seroconverters) who were enrolled in a study in the United States evaluating the acceptability of TDF-FTC PrEP (165 of the uninfected men and 5 of the seroconverters accepted PrEP). Samples from 163 of the 165 HIV-uninfected men who accepted PrEP and samples from all 8 seroconverters were also tested for tenofovir (TFV) and FTC using a quantitative assay (detection limit for both drugs, 0.31 ng/ml). HIV drug resistance was assessed in seroconverter samples. The multidrug assay detected TFV and/or FTC in 3 (1.4%) of the 208 uninfected men at enrollment, 84 (40.4%) of the 208 uninfected men at the last study visit, and 1 (12.5%) of the 8 seroconverters. No other ARV drugs were detected. The quantitative assay confirmed all positive results from the multidrug assay and detected TFV and/or FTC in 9 additional samples (TFV range, 0.65 to 16.5 ng/ml; FTC range, 0.33 to 14.6 ng/ml). Resistance mutations were detected in 4 of the 8 seroconverter samples. The multidrug assay had 100% sensitivity and specificity for detecting TFV and FTC at drug concentrations consistent with daily PrEP use. The quantitative assay detected TFV and FTC at lower levels, which also might have provided protection against HIV infection.

Performance comparison of next-generation sequencing platforms for determining HIV-1 coreceptor use

The coreceptor used by HIV-1 must be determined before a CCR5 antagonist, part of the arsenal of antiretroviral drugs, is prescribed because viruses that enter cells using the CXCR4 coreceptor are responsible for treatment failure. HIV-1 tropism is also correlated with disease progression and so must be determined for virological studies. Tropism can be determined by next-generation sequencing (NGS), but not all of these new technologies have been fully validated for use in clinical practice. The Illumina NGS technology is used in many laboratories but its ability to predict HIV-1 tropism has not been evaluated while the 454 GS-Junior (Roche) is used for routine diagnosis. The genotypic prediction of HIV-1 tropism is based on sequencing the V3 region and interpreting the results with an appropriate algorithm. We compared the performances of the MiSeq (Illumina) and 454 GS-Junior (Roche) systems with a reference phenotypic assay. We used clinical samples for the NGS tropism predictions and assessed their ability to quantify CXCR4-using variants. The data show that the Illumina platform can be used to detect minor CXCR4-using variants in clinical practice but technical optimization are needed to improve quantification.

A Follow-Up of the Multicenter Collaborative Study on HIV-1 Drug Resistance and Tropism Testing Using 454 Ultra Deep Pyrosequencing

BACKGROUND

Ultra deep sequencing is of increasing use not only in research but also in diagnostics. For implementation of ultra deep sequencing assays in clinical laboratories for routine diagnostics, intra- and inter-laboratory testing are of the utmost importance.

METHODS

A multicenter study was conducted to validate an updated assay design for 454 Life Sciences' GS FLX Titanium system targeting protease/reverse transcriptase (RTP) and env (V3) regions to identify HIV-1 drug-resistance mutations and determine co-receptor use with high sensitivity. The study included 30 HIV-1 subtype B and 6 subtype non-B samples with viral titers (VT) of 3,940-447,400 copies/mL, two dilution series (52,129-1,340 and 25,130-734 copies/mL), and triplicate samples. Amplicons spanning PR codons 10-99, RT codons 1-251 and the entire V3 region were generated using barcoded primers. Analysis was performed using the GS Amplicon Variant Analyzer and geno2pheno for tropism. For comparison, population sequencing was performed using the ViroSeq HIV-1 genotyping system.

RESULTS

The median sequencing depth across the 11 sites was 1,829 reads per position for RTP (IQR 592-3,488) and 2,410 for V3 (IQR 786-3,695). 10 preselected drug resistant variants were measured across sites and showed high inter-laboratory correlation across all sites with data (P<0.001). The triplicate samples of a plasmid mixture confirmed the high inter-laboratory consistency (mean% ± stdev: 4.6 ±0.5, 4.8 ±0.4, 4.9 ±0.3) and revealed good intra-laboratory consistency (mean% range ± stdev range: 4.2-5.2 ± 0.04-0.65). In the two dilutions series, no variants >20% were missed, variants 2-10% were detected at most sites (even at low VT), and variants 1-2% were detected by some sites. All mutations detected by population sequencing were also detected by UDS.

CONCLUSIONS

This assay design results in an accurate and reproducible approach to analyze HIV-1 mutant spectra, even at variant frequencies well below those routinely detectable by population sequencing.

Identification of minority resistance mutations in the HIV-1 integrase coding region using next generation sequencing

BACKGROUND

The current widely applied standard method to screen for HIV-1 genotypic resistance is based on Sanger population sequencing (Sseq), which does not allow for the identification of minority variants (MVs) below the limit of detection for the Sseq-method in patients receiving integrase strand-transfer inhibitors (INSTI). Next generation sequencing (NGS) has facilitated the detection of MVs at a much deeper level than Sseq.

OBJECTIVES

Here, we compared Illumina MiSeq and Sseq approaches to evaluate the detection of MVs involved in resistance to the three commonly used INSTI: raltegravir (RAL), elvitegravir (EVG) and dolutegravir (DTG).

STUDY DESIGN

NGS and Sseq were used to analyze RT-PCR products of the HIV-1 integrase coding region from six patients and in serial samples from two patients. NGS sequences were assembled and analyzed using the low frequency variant detection (LFVDT) tool in CLC genomic workbench.

RESULTS

Sseq detected INSTI resistance and accessory mutations in three of the patients (called INSTI Res+), while no resistance or accessory mutations were detected in the remaining three patients (called INSTI Res-). Additional INSTI resistance and/or accessory mutations were detected by NGS analysis of integrase sequences from all three INSTI Res+ and one INSTI Res- patient.

CONCLUSION

Our observations suggested that NGS demonstrated a higher sensitivity than sSEQ in the identification of INSTI relevant MVs both in patients at treatment baseline and in patients receiving INSTI therapy. Thus NGS can be a valuable tool in monitoring of antiretroviral minority resistance in patients receiving INSTI therapy.