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Background: Antiretroviral therapy (ART) effectiveness is compromised by the emergence of HIV drug resistance mutations (DRM) and can lead to the failure of ART. Apart from intrinsic viral factors, non-compliance with drugs and/or the use of sub-optimum therapy can lead to the emergence of DRMs. In Pakistan HIV currently exists as a concentrated epidemic, however, ART coverage is very low, and drug adherence is poor. ART is selected assuming without baseline genotyping. Pakistan has recently seen a rise in treatment failures, but the country's actual burden of DRM is still unknown. In this study, we perform the genetic and drug resistance analysis of the pol gene from Pakistani HIV-positive ART-naïve and ART-experienced individuals., Methods: In this study, HIV-1 pol was sequenced from 146 HIV-1 positive individuals, divided into ART-naïve (n = 37) and ART-experienced (n = 109). The sequences were also used to determine HIV-1 subtypes, the prevalence of DRM, and pol genetic variability., Results: DRM analysis identified numerous DRMs against reverse transcriptase inhibitors in both ART-naïve and ART-experienced groups, including a few that are classified as rare. Additionally, the ART-experienced group showed mutations associated with resistance to protease inhibitors. Genetic analysis showed negative selection pressure in both groups, but a higher rate of evolution in the ART-naïve group., Conclusion: High prevalence of DRMs, especially against previous first-line treatment in ART- naïve and the accumulation of DRMs in ART-experienced groups is concerning and warrants that a more extensive DRM survey be carried out to inform first-line and second-line ART regimen recommendations., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Siddiqui et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

HIV-1 incidence is an important parameter for assessing the impact of HIV-1 interventions. The aim of this study was to evaluate HIV-1 polymerase (pol) gene sequence diversity for the prediction of recent HIV-1 infections. Complete pol Sanger sequences obtained from 45 participants confirmed to have recent or chronic HIV-1 infection were used. Shannon entropy was calculated for amino acid (aa) sequences for the entire pol and for sliding windows consisting of 50 aa each. Entropy scores for the complete HIV-1 pol were significantly higher in chronic compared to recent HIV-1 infections (p < 0.0001) and the same pattern was observed for some sliding windows (p-values ranging from 0.011 to <0.001), leading to the identification of some aa mutations that could discriminate between recent and chronic infection. Different aa mutation groups were assessed for predicting recent infection and their performance ranged from 64.3% to 100% but had a high false recency rate (FRR), which was decreased to 19.4% when another amino acid mutation (M456) was included in the analysis. The pol-based molecular method identified in this study would not be ideal for use on its own due to high FRR; however, this method could be considered for complementing existing serological assays to further reduce FRR.

Pig to human xenotransplantation is considered to be a possible approach to alleviate the shortage of human allografts. Porcine endogenous retrovirus (PERV) is the most significant pathogen in xenotransplantation. We screened for pigs that consistently did not transmit human-tropic replication competent PERVs (HTRC PERVs), namely, non-transmitting pigs. Then, we conducted whole-genome resequencing and full-length transcriptome sequencing to further investigate the sequence characteristics of one non-transmitting pig. Using in vitro transmission assays, we found 5 (out of 105) pigs of the Chinese Wuzhishan minipig inbred line that did not transmit PERV to human cells, i.e., non-transmitting pigs. Whole-genome resequencing and full-length transcriptome sequencing of one non-transmitting pig showed that all of the pol genes were defective at both the genome and transcript levels. We speculate that the defective PERV pol genes in this pig might be attributable to the long-term inbreeding process. This discovery is promising for the development of a strain of highly homozygous and genetically stable pigs with defective PERV pol genes as a source animal species for xenotransplantation., Competing Interests: Authors SF and JY are employed by Grand Life Science and Technology, Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Ma, Jia, Fan, Lu, Zhao, Zhong, Yang, Ma, Wang, Lv, Yang, Mou, Dai, Feng and Zhang.)

Background: HIV-1C has been shown to have a greater risk of virological failure and reduced susceptibility towards boosted protease inhibitors (bPIs), a component of second-line combination antiretroviral therapy (cART) in South Africa. This study entailed an evaluation of HIV-1 drug resistance-associated mutations (RAMs) among minor viral populations through high-throughput sequencing genotypic resistance testing (HTS-GRT) in patients on the South African national second-line cART regimen receiving bPIs., Methods: During 2017 and 2018, 67 patient samples were sequenced using high-throughput sequencing (HTS), of which 56 samples were included in the final analysis because the patient's treatment regimen was available at the time of sampling. All patients were receiving bPIs as part of their cART. Viral RNA was extracted, and complete pol genes were amplified and sequenced using Illumina HiSeq2500, followed by bioinformatics analysis to quantify the RAMs according to the Stanford HIV Drug Resistance Database., Results: Statistically significantly higher PI RAMs were observed in minor viral quasispecies (25%; 14/56) compared to non-nucleoside reverse transcriptase inhibitors (9%; 5/56; p = 0.042) and integrase inhibitor RAM (4%; 2/56; p = 0.002). The majority of the drug resistance mutations in the minor viral quasispecies were observed in the V82A mutation (n = 13) in protease and K65R (n = 5), K103N (n = 7) and M184V (n = 5) in reverse transcriptase., Conclusions: HTS-GRT improved the identification of PI and reverse transcriptase inhibitor (RTI) RAMs in second-line cART patients from South Africa compared to the conventional GRT with ≥20% used in Sanger-based sequencing. Several RTI RAMs, such as K65R, M184V or K103N and PI RAM V82A, were identified in < 20% of the population. Deep sequencing could be of greater value in detecting acquired resistance mutations early.

Background: HIV-transmitted drug resistance (TDR) is found in antiretroviral therapy (ART)-naïve populations infected with HIV-1 with TDR mutations and is important for guiding future first- and second-line ART regimens. We investigated TDR and its effect on CD4 count in ART-naïve youths from the China-Myanmar border near the Golden Triangle to better understand TDR and effectively guide ART., Methods: From 2009 to 2017, 10,832 HIV-1 infected individuals were newly reported along the Dehong border of China, 573 ART-naïve youths (16 ~ 25 y) were enrolled. CD4 counts were obtained from whole blood samples. HIV pol gene sequences were amplified from RNA extracted from plasma. The Stanford REGA program and jpHMM recombination prediction tool were used to determine genotypes. TDR mutations (TDRMs) were analyzed using the Stanford Calibrated Population Resistance tool., Results: The most common infection route was heterosexuals (70.51%), followed by people who inject drugs (PWID, 19.20%) and men who have sex with men (MSM) (8.90%). The distribution of HIV genotypes mainly included the unique recombinant form (URF) (44.08%), 38.68% were CRFs, 13.24% were subtype C and 4.04% were subtype B. The prevalence of TDR increased significantly from 2009 to 2017 (3.48 to 9.48%) in ART-naïve youths (4.00 to 13.16% in Burmese subjects, 3.33 to 5.93% in Chinese subjects), and the resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs), nucleoside and nucleotide reverse transcriptase inhibitors (NRTIs), and protease inhibitors (PIs) were 3.49, 2.62, and 0.52%, respectively. Most (94.40%, n = 34) of HIV-1-infected patients with TDRM had mutation that conferred resistance to a single drug class. The most common mutations Y181I/C and K103N, were found in 7 and 9 youths, respectively. The mean CD4 count was significantly lower among individuals with TDRMs (373/mm 3 vs. 496/mm 3 , p = 0.013)., Conclusions: The increase in the prevalence of HIV-1 TDR increase and a low CD4 count of patients with TDRMs in the China-Myanmar border suggests the need for considering drug resistance before initiating ART in HIV recombination hotspots.

Accurate calculation of mutation rates for viruses and viroids is necessary for evolutionary studies and to evaluate adaptation potential. However, estimation of in vivo mutation rates is complicated by selection, which leads to loss or proliferation of certain mutations. To minimize this concern, lethal mutations, including nonsense and non-synonymous mutations, have been used to determine mutation rates for several viruses and viroids, including Potato spindle tuber viroid (PSTVd). However, this approach has limitations, including focus on a relatively small number of genome sites and the possibility that mutations may not actually be lethal or may be maintained by wild type individuals. To avoid selection bias altogether, we sequenced minus-strand PSTVd dimers from concatemeric replication intermediates. The underlying rationale is that mutations found in only one of the monomers were likely generated de novo during RNA polymerase II (Pol II) transcription of the circular plus-strand RNA genome. This approach yielded an apparent Pol II error rate of ~1/1837 nucleotides per transcription cycle, and an estimated mutation rate of ~1/919 nucleotides for a single replication cycle. Remarkably, de novo mutations were nearly absent from the most conserved, replication-critical regions of the PSTVd genome, suggesting that sequence conservation is a consequence of both essential function and template optimization for greater Pol II fidelity. Such biased fidelity may constitute a novel strategy to ensure population success while allowing abundant sampling of sequence space in other genome regions. Comparison with variants in progeny populations derived from a cloned, wild type PSTVd master sequence revealed that most de novo mutations were lost through selection., Competing Interests: The authors have declared that no competing interests exist.

Objectives: Transgender people are disproportionately affected by the HIV-1 epidemic. We evaluated the origin of HIV-1 variants carried by South American transgenders living in Milan by combining accurate phylogenetic methods and epidemiological data., Methods: We collected 156 HIV-1 pol sequences obtained from transgender patients engaged in sex work (TSWs) followed between 1999 and 2015 at L. Sacco Hospital, Milan, Italy. Phylogenetic analyses were conducted by HIV-TRACE, MrBayes, MacClade and Beast programs. Reference sequences were retrieved from Los Alamos and local databases. Last negative testing or proxy data from clinical records of infected individuals were used to investigate the country of infection., Results: Among South American TSWs, the most represented HIV-1 subtypes were B (70.5%), F1 (12.8%) and C (4.4%). Gene flow migrations of B subtype indicated significant fluxes from TSWs to Italians (21.3%) belonging to all risk groups (26.4% to heterosexuals (HEs), 18.9% to men who have sex with men (MSM), 15.1% to injecting drug users). The largest proportion of bidirectional fluxes were observed between Italians and TSWs (24.6%). For F1 subtype, bidirectional viral fluxes involved TSWs and Italians (7.1% and 14.3%), and a similar proportion of fluxes linked TSWs and Italian HEs or MSM (both 15.8%). Significant fluxes were detected from Italians to TSWs for subtype C involving both MSM (30%) and HEs (40%). Country of HIV-1 acquisition was identified for 72 subjects; overall, the largest proportion of patients with B subtype (73.5%) acquired HIV-1 infection in South America., Conclusions: Our results indicated that South American transgenders largely contribute to the heterogeneity of HIV-1 variants in our country. The high number of clusters based on all subtypes indicated numerous transmission chains in which TSWs were constantly intermixed with HEs and MSM. Our results strongly advocate interventions to facilitate prevention, diagnosis and HIV-1 care continuum among transgender people., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Tanzania has recently adapted World Health Organization antiretroviral guidelines that include integrase strand transfer inhibitors (INSTIs) in the first-line regimen. However, there is lack of evidence on integrase (IN) gene polymorphisms in viral strains circulating in Tanzania. In this study, we characterize IN gene polymorphisms in viral strains circulating in Dar es Salaam, Tanzania, before introduction of INSTIs. Plasma viral RNAs were prepared from 158 HIV-1-infected subjects, including 111 treated, but viremic (INSTI-naïve), subjects. A part of the pol gene encompassing the IN-coding region was amplified and directly sequenced by the Sanger sequencing method. Subtype analysis revealed that subtypes A1, C, and D and intersubtype recombinants were 42%, 38%, 11%, and 9%, respectively. Although multiple subtypes cocirculate, the IN gene exhibited a relatively conserved amino acid sequence pattern with an average Shannon entropy score of 0.16. No major INSTI resistance mutations were found; however, accessory resistance mutations at positions T97A, E157Q, G163E/K, and 128A/T were detected in 5% of subjects.

We determined HIV-1 pol gene sequences from self-collected rectal swabs of HIV-positive young men who have sex with men and transgender women. HIV-1 pol was amplified from 39/96 (41%) rectal swabs, including 29/77 (38%) prevalent and 10/19 (53%) incident HIV-1 infections ( p  < .001). Pol did not amplify from rectal swabs from participants with plasma viral load <1,000 copies/mL. Each rectal swab-derived amplicon consensus sequence was most closely related to the paired plasma virion RNA-derived sequence from the same participant. Results document a rectal mucosal source of HIV-1 in infected persons and suggest usefulness for noninvasive study of biological mechanisms underlying the epidemiologic risk to an insertive partner of HIV-1 acquisition during condomless anal sex.

The HIV genome is rich in A but not G or U and deficient in C. This nucleotide bias controls HIV phenotype by determining the highly unusual composition of all major HIV proteins. The bias is also responsible for the high frequency of narrow DNA minor groove sites in the double-stranded HIV genome as compared to cellular protein coding sequences and the bulk of the human genome. Since drugs that bind in the DNA minor groove disrupt nucleosomes on sequences that contain closely spaced oligo-A tracts which are prevalent in HIV DNA because of its bias, it was of interest to determine if these drugs exert this selective inhibitory effect on HIV chromatin. To test this possibility, nucleosomes were reconstituted onto five double-stranded DNA fragments from the HIV-1 pol gene in the presence and in the absence of several minor groove binding drugs (MGBDs). The results demonstrated that the MGBDs inhibited the assembly of nucleosomes onto all of the HIV-1 segments in a manner that was proportional to the A-bias, but had no detectable effect on the formation of nucleosomes on control cloned fragments or genomic DNA from chicken and human. Nucleosomes preassembled onto HIV DNA were also preferentially destabilized by the drugs as evidenced by enhanced nuclease accessibility in physiological ionic strength and by the preferential loss of the histone octamer in hyper-physiological salt solutions. The drugs also selectively disrupted HIV-containing nucleosomes in yeast as revealed by enhanced nuclease accessibility of the in vivo assembled HIV chromatin and reductions in superhelical densities of plasmid chromatin containing HIV sequences. A comparison of these results to the density of A-tracts in the HIV genome indicates that a large fraction of the nucleosomes that make up HIV chromatin should be preferred in vitro targets for the MGBDs. These results show that the MGBDs preferentially disrupt HIV-1 chromatin in vitro and in vivo and raise the possibility that non-toxic derivatives of certain MGBDs might serve as a novel class of anti-HIV agents., Competing Interests: The authors have declared that no competing interests exist.

Feline Foamy Virus (FFV) is an important retroviral agent affecting domestic cats in Turkey that has been studied less intensively than Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV). Accordingly, we aimed to investigate the presence and prevalence of FFV among domestic cats by molecular techniques. PCR was used to amplify the gag-pol gene overlap in order to detect the presence of FFV. The gene encoding bet, an important accessory gene, was also characterized. Molecular characteristics were analyzed and phylogenetic trees were constructed. We determined the positivity rate as 10% in all samples (20/200) based on the gag-pol test. The phylogenetic analysis indicated that the Turkish FFV sequences form a separate cluster among other isolates in the constructed maximum likelihood (ML) tree. bet-based products were obtained for two samples (1%; 2/200) that were also positive for gag-pol. These bet gene sequences confirm the presence of a separate cluster for the Turkish FFV isolates. The results suggest that FFV is prevalent and widespread in Turkish domestic cats. Additionally, these new FFV sequences represent the first FFV sequences from Turkey to be submitted to GenBank. This study paves the way for studies on the pathogenicity of FFV., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The detection of drug resistance mutations (DRMs) in minor viral populations is of potential clinical importance. However, sophisticated computational infrastructure and competence for analysis of high-throughput sequencing (HTS) data lack at most diagnostic laboratories. Thus, we have proposed a new pipeline, MiDRM pol , to quantify DRM from the HIV-1 pol region. The gag-vpu region of 87 plasma samples from HIV-infected individuals from three cohorts was amplified and sequenced by Illumina HiSeq2500. The sequence reads were adapter-trimmed, followed by analysis using in-house scripts. Samples from Swedish and Ethiopian cohorts were also sequenced by Sanger sequencing. The pipeline was validated against the online tool PASeq (Polymorphism Analysis by Sequencing). Based on an error rate of <1%, a value of >1% was set as reliable to consider a minor variant. Both pipelines detected the mutations in the dominant viral populations, while discrepancies were observed in minor viral populations. In five HIV-1 subtype C samples, minor mutations were detected at the <5% level by MiDRM pol but not by PASeq. MiDRM pol is a computationally as well as labor efficient bioinformatics pipeline for the detection of DRM from HTS data. It identifies minor viral populations (<20%) of DRMs. Our method can be incorporated into large-scale surveillance of HIV-1 DRM.

HIV-1 disseminates to a broad range of tissue compartments during acute HIV-1 infection (AHI). The central nervous system (CNS) can serve as an early and persistent site of viral replication, which poses a potential challenge for HIV-1 remission strategies that target the HIV reservoir. CNS compartmentalization is a key feature of HIV-1 neuropathogenesis. Thus far, the timing of how early CNS compartmentalization develops after infection is unknown. We examined whether HIV-1 transmitted/founder (T/F) viruses differ between CNS and blood during AHI using single-genome sequencing of envelope gene and further examined subregions in pol and env using next-generation sequencing in paired plasma and cerebrospinal fluid (CSF) from 18 individuals. Different proportions of mostly minor variants were found in six of the eight multiple T/F-infected individuals, indicating enrichment of some variants in CSF that may lead to significant compartmentalization in the later stages of infection. This study provides evidence for the first time that HIV-1 compartmentalization in the CNS can occur within days of HIV-1 exposure in multiple T/F infections. Further understanding of factors that determine enrichment of T/F variants in the CNS, as well as potential long-term implications of these findings for persistence of HIV-1 reservoirs and neurological impairment in HIV, is needed.

Four cases infected by HIV-1 subtype G strain were identified in Guangdong, China. The nearly full-length genome was amplified and sequenced for phylogenetic analysis. The four sequences clustered together with subtype G references in the tree (bootstrap value ≥98%). To determine whether HIV-1 subtype G has been spreading in China, all subtype G sequences identified in China were downloaded from HIV Database for further phylogenetic analysis. In the phylogenetic tree of pol gene (nucleotides 2283-3245 by using HXB2 as a calibrator), four clusters with bootstrap value >70% comprised nine sequences from China were identified, suggesting that subtype G might have been spreading in local areas in China. The detailed sequence data in this study will provide more information on HIV epidemic in China. The result also highlighted that more surveillance on subtype G prevalence in China is necessary.

Jiangsu province has severe HIV-1 epidemic in China. Suqian which is located in north of the province has limited HIV epidemic information. Therefore, this study aimed to characterize the epidemic details in the area. A total of 196 plasma samples were collected from treated HIV-1-positive cases and viral RNA was extracted. Then HIV partial pol genes (nucleotide 2147-3462 by using HXB2 as calibrator) were amplified and sequenced. Finally, 84 partial pol genes were successfully obtained. The subtyping results indicate that multiple HIV-1 subtypes are circulating in Suqian district. Thereinto, CRF01&#95;AE has been the dominant stains here and belonged to multiple lineages of CRF01&#95;AE identified in China previously. Moreover, there is a high level of HIV drug resistance. All these results suggest HIV-1 epidemic in Suqian is rather complex and more measures must be performed for prevention and intervention in the area.

Background: Shenzhen City is a rapidly growing area with a large number of floating populations, thus making it difficult to control HIV. Serial cross-sectional studies are helpful for the prediction of epidemiological tendency. In this study, two parallel cross-sectional studies were compared to explore changes in HIV epidemiology in Shenzhen, China., Methods: Two hundred and fifty newly reported HIV-positive cases were randomly selected in Shenzhen City in 2013 and 2015. Socio-demographical information was collected with informed consent. Full-length gag and partial pol genes were amplified using nested RT-PCR followed by sequencing and phylogenetic analysis. The genotypes of anti-HIV drug resistance were also analyzed. The characteristics of the HIV epidemics of 2013 and 2015 were compared to identify patterns., Results: The proportion of single, young MSMs dramatically increased in 2015 compared to 2013. Many subtypes, including CRF07&#95;BC (36.4%), CRF01&#95;AE (34.1%), CRF55&#95;01B (10.2%), B (6.4%), CRF08&#95;BC (3.4%), CRF59&#95;01B (0.9%), C (0.7%), D (0.2%), CRF68&#95;01B (0.2%), CRF67&#95;01B (0.2%), and unique recombinant forms (URFs, 7.3%), were identified. Close phylogenetic relationships between strains prevalent in Shenzhen and other areas of China was observed. No epidemic cluster confined to single, young MSMs was identified. 0.4 and 2.8% of the strains contained transmitted drug-resistant mutations in 2013 and 2015, respectively., Conclusion: Although the interval period is short, changes in HIV epidemiology in Shenzhen City are distinct. Frequent surveillance of HIV epidemics in Shenzhen City is thus necessary. Single, young MSMs have become a high-risk population for HIV infection and should be considered as focus population for HIV prevention and behavior intervention in Shenzhen City.

In 1936, John Joseph Bittner identified mouse mammary tumor virus (MMTV), a milk transmitted beta retrovirus, a form of single-stranded positive-sense RNA virus. A retrovirus inserts a copy of its genome into the DNA of a host cell, thus altering the cell's genome. In the current analysis, we searched for MMTV sequences within the human genome. To compare the MMTV genome to the human genome, we used BLAT, the Blast-Like Alignment Tool of the UCSC Genome Browser. BLAT can align a user sequence of 25 bases or more to the genome. 60 MMTV sequences were in the human genome. Of 56 sequences from the MMTV POL gene, 36 POL sequences were from the same part of the gene, beginning at viral nucleotide 4800 but of different lengths. 8 viral sequences began at nucleotide ∼3430 of the POL gene. Four viral sequences were from GAGdUTPase, encoded by the MMTV PRO gene. Deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) is an enzyme present in several major retroviral families. In MMTV dUTPase may be essential for viral replication. Since BLAT identified no MMTV envelope (env) sequence in the human genome, the env sequences from breast tumors and normal breast tissue found in other studies may have come from an MMTV infection. However, no one is certain how MMTV could enter human cells, since the cells do not have a cellular receptor for MMTV, as do mouse cells., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: To understand the prevalence of drug resistance in treatment-naive injecting drug users (IDUs) infected with HIV-1 in Guangzhou. Methods: HIV-1 RNA were extracted from the serum specimens of the newly confirmed HIV-1 positive IDUs living in Guangzhou, being infected through injecting drug use and receiving no antiretroviral therapy at the time of confirmation during 2008-2015. Full sequence of pol protease (PR) gene and partial sequence of reverse transcriptase (RT) gene were amplified by nested reverse transcription polymerase chain reaction (nested-PCR) and sequenced. After that, data were submitted to the HIV resistance database of Stanford University for drug resistance analysis. Results: Among the 518 HIV-1 infected IDUs, HIV-1 pol gene segments were successfully obtained from the serum samples of 407 HIV-1 infected IDUs (78.57%) aged 18-64 (37.44±8.14) years. Among them, males accounted for 89.68% (365/407), those of Han ethnic group accounted for 89.93% (366/407), the unmarried accounted for 55.28% (225/407), and those with education level of junior high school or below accounted for 83.78% (341/407). The distribution of subtypes was predominated by CRF07&#95;BC (47.18%, 192/407), followed by CRF01&#95;AE (23.83%, 97/407), CRF08&#95;BC (22.85%, 93/407), and other subtypes (6.14%, 25/407). The overall prevalence of drug resistance was 3.44% (14/407). The prevalence of drug resistance to protease inhibitors, nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors were 1.47%(6/407), 0.25% (1/407) and 1.72% (7/407) respectively. The mutation rate was 12.29% (50/407). No major drug resistance mutation was detected in protease and nucleoside reverse transcriptase regions. Higher rate of V179E mutation in the non-nucleoside reverse transcriptase region was detected in other subtypes and subtype CRF07&#95;BC. Mutation seemed to have occurred in all 8 cases of subtype CRF55&#95;01B in other subtypes. The highest mutation rate of E138A was detected in subtype CRF08&#95;BC (3.23%). Two cases were resistant to all four drugs of NNRTIs. Conclusions: The prevalence of drug resistance in treatment-naive HIV-1 positive IDUs remained at a relatively low level during 2008-2015, in Guangzhou. Most infections were sensitive to existing antiviral drugs. However, drug resistance surveillance in IDUs infected with HIV should be strengthened to prevent the prevalence of multi-drug resistance and cross drug resistance.

Background noise in metagenomic studies is often of high importance and its removal requires extensive post-analytic, bioinformatics filtering. This is relevant as significant signals may be lost due to a low signal-to-noise ratio. The presence of plasmid residues, that are frequently present in reagents as contaminants, has not been investigated so far, but may pose a substantial bias. Here we show that plasmid sequences from different sources are omnipresent in molecular biology reagents. Using a metagenomic approach, we identified the presence of the (pol) of equine infectious anemia virus in human samples and traced it back to the expression plasmid used for generation of a commercial reverse transcriptase. We found fragments of multiple other expression plasmids in human samples as well as commercial polymerase preparations. Plasmid contamination sources included production chain of molecular biology reagents as well as contamination of reagents from environment or human handling of samples and reagents. Retrospective analyses of published metagenomic studies revealed an inaccurate signal-to-noise differentiation. Hence, the plasmid sequences that seem to be omnipresent in molecular biology reagents may misguide conclusions derived from genomic/metagenomics datasets and thus also clinical interpretations. Critical appraisal of metagenomic data sets for the possibility of plasmid background noise is required to identify reliable and significant signals.

Background: South Africa has one of the highest rates of HIV-1 (HIV) infection world-wide, with the highest rates among young women. We analyzed the molecular epidemiology and evolutionary history of HIV in young women attending high school in rural South Africa., Methods: Samples were obtained from the HPTN 068 randomized controlled trial, which evaluated the effect of cash transfers for school attendance on HIV incidence in women aged 13-20 years (Mpumalanga province, 2011-2015). Plasma samples from HIV-infected participants were analyzed using the ViroSeq HIV-1 Genotyping assay. Phylogenetic analysis was performed using 200 pol gene study sequences and 2,294 subtype C reference sequences from South Africa. Transmission clusters were identified using Cluster Picker and HIV-TRACE, and were characterized using demographic and other epidemiological data. Phylodynamic analyses were performed using the BEAST software., Results: The study enrolled 2,533 young women who were followed through their expected high school graduation date (main study); some participants had a post-study assessment (follow-up study). Two-hundred-twelve of 2,533 enrolled young women had HIV infection. HIV pol sequences were obtained for 94% (n = 201/212) of the HIV-infected participants. All but one of the sequences were HIV-1 subtype C; the non-C subtype sequence was excluded from further analysis. Median pairwise genetic distance between the subtype C sequences was 6.4% (IQR: 5.6-7.2). Overall, 26% of study sequences fell into 21 phylogenetic clusters with 2-6 women per cluster. Thirteen (62%) clusters included women who were HIV-infected at enrollment. Clustering was not associated with study arm, demographic or other epidemiological factors. The estimated date of origin of HIV subtype C in the study population was 1958 (95% highest posterior density [HPD]: 1931-1980), and the median estimated substitution rate among study pol sequences was 1.98x10-3 (95% HPD: 1.15x10-3-2.81x10-3) per site per year., Conclusions: Phylogenetic analysis suggests that multiple HIV subtype C sublineages circulate among school age girls in South Africa. There were no substantive differences in the molecular epidemiology of HIV between control and intervention arms in the HPTN 068 trial., Competing Interests: None of the authors has a conflict of interest or potential conflict of interest, with the following exceptions: Susan Eshleman has collaborated on research studies with investigators from Abbott Laboratories (distributor of the ViroSeq HIV-1 Genotyping System); Abbott Laboratories has provided reagents for other research studies. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

HIV has a high mutation rate, which contributes to its ability to evolve quickly. However, we know little about the fitness costs of individual HIV mutations in vivo, their distribution and the different factors shaping the viral fitness landscape. We calculated the mean frequency of transition mutations at 870 sites of the pol gene in 160 patients, allowing us to determine the cost of these mutations. As expected, we found high costs for non-synonymous and nonsense mutations as compared to synonymous mutations. In addition, we found that non-synonymous mutations that lead to drastic amino acid changes are twice as costly as those that do not and mutations that create new CpG dinucleotides are also twice as costly as those that do not. We also found that G→A and C→T mutations are more costly than A→G mutations. We anticipate that our new in vivo frequency-based approach will provide insights into the fitness landscape and evolvability of not only HIV, but a variety of microbes., Competing Interests: The authors have declared that no competing interests exist.

Objective: To understand the molecular subtypes and recombinant structure of HIV-1 infection in Zhejiang Province. Methods: According to the method of stratified random sampling method, a total of 302 newly HIV infected people (excluding AIDS patients) were selected as the subjects of the investigation from April to June, 2015, who were all newly HIV positive patients reported in Zhejiang Province and were diagnosed as HIV positive and had not received antiretroviral treatment. Questionnaires were used to collect information such as gender, residency, marital status, route of transmission and case reporting area. At least 8 ml of venous blood was collected from HIV infected people, reverse transcription-polymerase chain reaction (RT-PCR) and nested PCR were used to amplify the pol gene sequence of HIV-1 strains and circulating recombination forms (CRF) and unique recombinant form (URF) strains were screened using phylogenetic tree, and molecular subtype analysis and recombinant analysis were performed. Results: Of the 302 HIV infected people, 18 cases were infected with new CRFs or URFs, among which 15 were male (83.3%), 3 were heterosexual transmission (17.7%); 8 cases (44.4%) were infected with new CRFs, which included CRF55&#95;01B 5(27.8%), CRF67&#95;01B 2 (11.1%), CRF69&#95;01B 1 (5.6%); 10 cases (55.6%) were infected with URFs, in which 6 cases were infected with two groups of recombinant strains composed of CRF01&#95;AE subtype and CRF07&#95;BC subtypes in pol region, 3 cases were infected with three groups of recombinant strains of the two subtypes in pol region, and 1 case could not be accurately determined of the recombinant structure. The results of recombinant source analysis showed that the newly recombinant strains found from Zhejiang province were highly homologous to the strains from Guangdong, Anhui, Hebei, Yunnan, Liaoning province, and the sequence similarity was 94.4%-98.0%. Conclusion: The new recombinant strains of Zhejiang province included CRFs strains and URFs strains with CRF01&#95;AE and CRF07&#95;BC as the main recombinant structure mode, and all of them were introduced from other places and formed a trans-regional chain of HIV transmission.

Efficiency of artificial restriction enzymes toward curing HIV has only been separately examined, using differing delivery vehicles. We compared the in vitro transduction and target-mutagenesis efficiency of consortium plasmid and adenoviral vector delivered HIV-1 pol gene targeting zinc finger nuclease (ZFN) with CRISPR/Cas, Custom-ZFN, CRISPR-Cas-9, and plasmids and vectors (murCTSD&#95;pZFN, pGS-U-gRNA, pCMV-Cas-D01A, Ad5-RGD); cell lines (TZM-bl and ACH-2/J-Lat cells); and the latency reversing agents prostratin, suberoylanilide hydroxamic acid, and phorbol myristate acetate. Cell lines were grown in either Dulbecco's modified Eagle's medium or Roswell Park Memorial Institute with the antibiotics kanamycin, zeocin, and efavirenz. Efficiency was assayed by GFP/luciferase activity and/or validated by yeast MEL1 reporter assay, CEL1 restriction fragment assay, and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Ad5-RGD vectors had better transduction efficiency than murCTSD and pGS-U-gRNA/pCMV-Cas-D01A plasmids. CRISPR/Cas9 exhibited better target-mutagenesis efficiency relative to ZFN (delivered by either plasmid or Ad5 vector) based on gel electrophoresis of pol gene amplicons within ACH-2 and J-Lat cells. Ad-5-RGD vectors enhanced target mutagenesis of ZFN, relative to murCTSD&#95;pZFN plasmids, to levels of CRISPR/Cas9 plasmids. Similar reduction of luciferase activity among TZM-bl treated with Ad5-ZFN vectors relative to CRISPR/Cas-9 and murCTSD&#95;pZFN plasmids was observed on challenge with HIV-1. qRT-PCR of HIV-1 pol gene transcripts affirmed that Ad5 (RGD) vectors enhanced target mutagenesis of ZFN. Whereas CRISPR/Cas-9 may possess inherent superior target-mutagenesis efficiency; the efficiency of ZFN (off-target toxicity withstanding) can be enhanced by altering delivery vehicle from plasmid to Ad5 (RGD) vectors.

Objective: To understand the distribution of HIV-1 subtype diversity and its transmission characteristics in Zhejiang province. Methods: A total of 302 newly diagnosed HIV-1 positive patients were selected through stratified random sampling in Zhejiang in 2015. HIV-1 pol genes were sequenced successfully with reverse transcription PCR/nested PCR and phylogenetic analysis was conducted for 276 patients. Then a molecular epidemiologic study was performed combined with field epidemiological investigation. Results: Of 276 sequence samples analyzed, 122 CRF07&#95;BC strains (44.2%), 103 CRF01&#95;AE strains (37.3%), 17 CRF08&#95;BC strains (6.1%), 9 B strains (3.2%), 6 CRF55&#95;01B strains (2.2%), 5 C strains (1.8%), 1 CRF59&#95;01B strain (0.4%), 1 CRF67&#95;01B strain (0.4%), 1 A1 strain (0.4%), and 11 URFs strains (4.0%) were identified. Phylogenetic analysis revealed 16 clusters with only 15.1% (34/225) sequences involved among CRF07&#95;BC and CRF01&#95;AE strains. The clustered cases in MSM were higher than that in populations with other transmission routes. And clusters existed between the populations with different transmission routes. Conclusion: The major strains of HIV-1 in Zhejiang are CRF07&#95;BC and CRF01&#95;AE. The HIV subtypes showed more complexity in Zhejiang. It is necessary to strengthen the surveillance for HIV subtypes, carry out classified management and conduct effective prevention and control in the population at high risk.

Background: There might be much benefit in xenotransplantation, however, the risk of infections across species barriers remains, especially porcine endogenous retrovirus (PERV). To date, many attempts have been made to knock down active PERVs by inhibitory RNA (RNAi) and micro RNA (miRNA), which target different genes of PERV. There are a few studies that have explored whether targeting promoter regions of PERV could exert an inhibition effect., Methods: miRNAs were automatically selected based on an online program BLOCK-iT RNAi Designer. The inhibition efficiency between miRNAs was compared based on their inhibition of different PERV genes: long terminal repeats (LTR), gag, and pol. Both relative quantitative real-time polymerase chain reaction (PCR) and C-type reverse transcriptase activity were performed., Results: The results demonstrated that miRNA targeting the LTR region degraded the target sequence, and simultaneously inhibited the mRNA expression of both gag and pol genes of PERV. The LTR1, LTR2, and dual LTR1 + LTR2 miRNA inhibited 76.2%, 22%, and 76.8% of gag gene expression, respectively. Similarly, the miRNA was found to knock down the pol gene expression of 69.8%, 25.5%, and 77.7% for single targeting miRNA (LTR1 and LTR2) and multi-targeting miRNA (LTR1 + LTR2), respectively. A stable PK15 clone constitutively expressed dual LTR1 + LTR2 miRNA and exhibited higher inhibitory up to 82.8% and 92.7% of the expressions of the gag and pol genes, respectively. Also, the result of co-cultivation of dual LTR1 + LTR2 miRNA transfected PK15 cell with a human cell line inhibited expression of LTR, gag, and pol genes of PERV., Conclusions: In conclusion, this study suggested that the LTR might be an alternative target for gene silencing of PERV, and that multi-targeting miRNA had better inhibitory effect than single- targeting miRNA. In an in vitro model, the presence of miRNA was able to reduce PERV infectivity in a human cell line., (Copyright © 2017. Published by Elsevier Inc.)

Syphilis is a systemic and sexually transmitted infection caused by Treponema pallidum ssp. pallidum. This spirochete causes different clinical and subclinical stages depending on the duration of infection and immune status of the host. Several tests have been developed for diagnosis, and are classified into direct and indirect methods. The first one includes dark field microscopy, direct fluorescent antibody test in fluids or tissue, and molecular biology techniques. In the indirect method (serologic), the routine tests are used, and are divided in two categories: non-treponemal and treponemal ones. The objective of this work was to identify T. pallidum ssp. pallidum in paraffin-embedded skin biopsies positive by immunohistochemistry, using conventional polymerase chain reaction (PCR) and quantitative real time PCR (qPCR). We included a sample of 17 paraffin-embedded biopsies. DNA was extracted and processed by conventional PCR and real-time PCR with a TaqMan® probe to identify the polA gene. Using PCR, 11 tested positive (64.7%) and 6 (35.3%) were negative. With qPCR and TaqMan® probe, 100% of samples tested positive. The minimum number of spirochetes detected in each sample was 2. With this work, we can conclude that qPCR is a fast and very accurate method for diagnosis of syphilis in tissue specimens.

Background: The HIV-1 RNA genome has a biased nucleotide composition with a surplus of As. Several hypotheses have been put forward to explain this striking phenomenon, but the A-count of the HIV-1 genome has thus far not been systematically manipulated. The reason for this reservation is the likelihood that known and unknown sequence motifs will be affected by such a massive mutational approach, thus resulting in replication-impaired virus mutants. We present the first attempt to increase and decrease the A-count in a relatively small polymerase (pol) gene segment of HIV-1 RNA., Results: To minimize the mutational impact, a new mutational approach was developed that is inspired by natural sequence variation as present in HIV-1 isolates. This phylogeny-instructed mutagenesis allowed us to create replication-competent HIV-1 mutants with a significantly increased or decreased local A-count. The local A-count of the wild-type (wt) virus (40.2%) was further increased to 46.9% or reduced to 31.7 and 26.3%. These HIV-1 variants replicate efficiently in vitro, despite the fact that the pol changes cause a quite profound move in HIV-SIV sequence space., Conclusions: Extrapolating these results to the complete 9 kb RNA genome, we may cautiously suggest that the A-rich signature does not have to be maintained. This survey also provided clues that silent codon changes, in particular from G-to-A, determine the subtype-specific sequence signatures.

Hepatitis B virus (HBV)-HIV coinfections are becoming common with information on HBV genetic diversity and drug resistance still remaining elusive. To evaluate the HBV genetic diversity and drug resistance-associated mutations among drug-experienced HIV patients, the genetic analysis of the partial HBV-pol-reverse trancriptase gene was successfully sequenced from 13 samples. Analysis of the sequences showed that all (11) the sequences belonged to genotype A. Nucleos(t)ide drug resistance mutations were found in 6 patients. Five subjects had rtV173L, rtL180M, and rtM204V and one with rtL180M and rtM204V major mutations. HBV genotype A remains the most predominant genotype circulating in Nairobi city with detected high level of HBV drug resistance to lamivudine, telbivudine, and emtricitabine. The detected circulating HBV genotype A in Nairobi reflects its possible spread in the population with its origin being within the country. We suggest that patients should not be on lamivudine monotherapy. These individuals should be managed on combination of tenofovir plus lamivudine or emtricitabine therapy to prevent the emergence of HBV drug resistant variants alongside a continuous surveillance monitoring of drug resistance and HBV genotypes.

HIV primary resistance, drug resistance in treatment-naïve patients, is an emerging public health issue. The prevalence of HIV primary resistance mutations down to the level of 1% minor variants was investigated using ultradeep pyrosequencing (UDPS) in HIV-positive Korean blood donors and in treatment naïve chronic patients for the comparison. The entire pol region was sequenced from 25 HIV-positive blood donors, and 18 treatment-naïve chronic HIV patients. UDPS was successful in 19 blood donors and 18 chronic patients. In total, 1,011,338 sequence reads were aligned, and 28,093 sequence reads were aligned on average per sample. The prevalence of HIV primary resistance mutations in the HIV-positive blood donors and chronic HIV patients were 63.2% and 44.4% according to UDPS, respectively. Protease inhibitor (PI) drugs demonstrated different patterns in HIV-positive blood donors and chronic HIV patients, whereas non-nucleoside reverse transcriptase inhibitors (NNRTI), nucleoside reverse transcriptase inhibitors (NRTI), and integrase inhibitor (INI) drugs showed similar patterns between the two groups. Higher level of primary resistance prevalence was observed mainly because UDPS method could detect mutations in minor variants with 1-10% frequency. The higher resistance prevalence was observed in HIV-positive blood donors than in chronic patients. Considering that treatments for HIV-infected patients were recently amended to start at an earlier stage, information about degree of drug resistance to each drug between the two groups would help to establish future policies, design additional clinical trials, assess HIV patient care in Korea., (Copyright © 2016 Elsevier B.V. All rights reserved.)

HIV-1 subtypes and drug resistance are routinely tested by many international surveillance groups. However, results from different sites often vary. A systematic comparison of results from multiple sites is needed to determine whether a standardized protocol is required for consistent and accurate data analysis. A panel of well-characterized HIV-1 isolates (N = 50) from the External Quality Assurance Program Oversight Laboratory (EQAPOL) was assembled for evaluation at seven international sites. This virus panel included seven subtypes, six circulating recombinant forms (CRFs), nine unique recombinant forms (URFs) and three group O viruses. Seven viruses contained 10 major drug resistance mutations (DRMs). HIV-1 isolates were prepared at a concentration of 107 copies/ml and compiled into blinded panels. Subtypes and DRMs were determined with partial or full pol gene sequences by conventional Sanger sequencing and/or Next Generation Sequencing (NGS). Subtype and DRM results were reported and decoded for comparison with full-length genome sequences generated by EQAPOL. The partial pol gene was amplified by RT-PCR and sequenced for 89.4%-100% of group M viruses at six sites. Subtyping results of majority of the viruses (83%-97.9%) were correctly determined for the partial pol sequences. All 10 major DRMs in seven isolates were detected at these six sites. The complete pol gene sequence was also obtained by NGS at one site. However, this method missed six group M viruses and sequences contained host chromosome fragments. Three group O viruses were only characterized with additional group O-specific RT-PCR primers employed by one site. These results indicate that PCR protocols and subtyping tools should be standardized to efficiently amplify diverse viruses and more consistently assign virus genotypes, which is critical for accurate global subtype and drug resistance surveillance. Targeted NGS analysis of partial pol sequences can serve as an alternative approach, especially for detection of low-abundance DRMs.

The development of a rapid, high-throughput and cost-effective HIV-1 drug resistance (HIV-DR) testing system is a challenge for areas consisting different HIV-1 strains. In this study, we established a broadly reactive multiplex assay that could simultaneously detect major drug resistance mutations at 8 loci, which are associated with resistance to commonly used nucleoside reverse transcriptase inhibitors (NRTIs) and Non-nucleoside reverse transcriptase inhibitors (NNRTIs), in specimens of HIV-1 CRF01&#95;AE, CRF07&#95;BC and subtype B, the three major circulating strains in China, using the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) provided by Sequenom MassARRAY® system. To establish the assay, pol gene fragments were prepared from the plasma viral RNA of 159 patients by nested PCR and the presence of wild type and mutant alleles at the 8 loci were analyzed by MALDI-TOF MS. In terms of loci, the detection rate of the alleles was greater than 97% for M41L, K65R, M184V and G190A, 91.2% for K101E/Q/P, 91.2% for T215F/Y, 89.9% for K103N/S and 80.5% for L210W. In terms of individuals, 80% of the alleles were detected in 95.4% CRF01&#95;AE patients, 100% CRF07&#95;BC patients and 83.3% subtype B patients. Importantly, the MALDI-TOF MS results were concordant to the drug resistance profiles of patients obtained from conventional sequencing analysis after excluded the failed detections. Using plasmid templates, the assay was estimated to be sensitive to detect drug resistant variants at level about 20% of the circulating viral population. The capability of this assay to detect mixed viral populations was further verified by two different patient specimens. In conclusion, this study evaluated the use of Sequenom MassARRAY® system for high-throughput detection of HIV-DR mutations towards the commonly used reverse transcriptase inhibitors in China.

Introduction: Multiple specific populations, including MSMs, IDUs, and FPDs, are involved in HIV epidemic in China. In the recent years, HIV transmission due to heterosexual transmission also contributed greatly to HIV epidemic in China. Very few studies have been fulfilled to characterize relationships of HIV-1 strains prevalent in different populations. In this study, the phylogenetic relationships of HIV-1 spreading in different populations were investigated., Materials and Methods: HIV-1 sero-positive patients infected through different routes were enrolled into the study. Nested RT-PCR was used to amplify HIV gag and pol genes followed by sequencing., Results: Multiple subtypes, including subtype B (52.1%), CRF01&#95;AE (34.4%), CRF07&#95;BC (6.3%), subtype C (4.2%), CRF02&#95;AG (1.0%), CRF08&#95;BC (1.0%) and unique recombination forms (1.0%) were identified. Phylogenetic analysis showed that strains from MSM, IDU, and FPDs grouped into clusters separately. However, strains identified in heterosexual transmitted population intermixed with all of other high risk populations., Discussion and Conclusion: The genetic data supposed that HIV-1 was spreading out of MSMs, IDUs, and FPDs through heterosexual transmission in Hebei, China. Urgent prevention and behavior intervention in the population will be necessary. Furthermore, the detailed sequence data will help the design of HIV-1 vaccines in China. Sequence Data: All of sequences have been deposited into the GenBank with the accession number: KJ820007-KJ820144.

The human cytomegalovirus (HCMV) is an important human pathogen primarily affecting immunocompromised patients, like transplant recipients or HIV- infected individuals. Early diagnosis of cytomegalovirus (CMV) infection in high-risk patients is essential in order to start preemptive treatments. pol (UL54) gene encoding for HCMV viral DNA polymerase is a well-defined target for HCMV detection in clinical samples and identifying most highly conserved regions for primer design remains crucial. Though real-time polymerase chain reaction (qPCR) is a rapid and sensitive method for HCMV detection, failure to detect some HCMV strains due to primer and target mismatches have led the researchers to explore more sensitive and reliable methods. Hence, to understand the broader diversity of the pol mutations in HCMV and to specify the most suitable region for primer-probe design to be used in qPCR assay, we studied both nucleotide and amino acid heterogeneities in 60 HCMV positive samples that were collected to represent national mutational prevalence of pol gene of HCMV in Turkey. The test was designed with a new set of primers- probe for HCMV detection and quantification based on the sequencing data which revealed the most conserved region on the pol gene. Statistical probit analysis was applied on qPCR studies which revealed a 95% detection limit of 100 copies/mL. In addition, linearity, reproducibility, and precision of the new test were assessed for diagnostic purposes.

The aim of this study was to analyze the distribution of clusters and drug resistance of CRF01&#95;AE among newly diagnosed, treatment-naïve HIV-infected teenagers and young adults in 3 major HIV-affected geographic regions of Guangxi Province, including the cities of Hezhou, Liuzhou, and Nanning. Samples were sequentially collected from newly diagnosed HIV-infected 16- to 25-year olds in these 3 regions from 2009 to 2013. The viral genome was extracted, and the partial pol gene was amplified and sequenced. Phylogenetic analyses were used to determine HIV-1 subtypes and CRF01&#95;AE clusters. Transmitted drug resistance (TDR) mutations were identified using the 2009 WHO list of TDR mutations. A total of 216 sequences were obtained from CRF01&#95;AE strains, which accounted for 83.1% of the 260 genotyped samples, of which 36 were from Hezhou, 147 from Liuzhou, and 33 in Nanning. Most (83.3%, 180/216) were from heterosexuals, followed by injection drug users (5.6%), homosexuals (4.2%), and unknown risk group (6.9%). Based on phylogenetic analyses by the maximum likelihood method, 5 distinct clusters (cluster 1-5) were identified with 213 (98.6%) sequences, whereas 3 (1.4%) sequences were ungrouped. In Hezhou, 88.9% (32/36) of CRF01&#95;AE infections were caused by cluster 2, and 11.1% (4/36) were caused by cluster 1. In Liuzhou, 83.0% (122/147) of the CRF01&#95;AE strains were found in cluster 1, 11.6% (17/147) from cluster 2, 1.4% (2/147) from cluster 3, 2.7% (4/147) from cluster 4, and 0.7% (1/147) from cluster 5. The distribution of CRF01&#95;AE clusters was more even in Nanning than it was in the other 2 regions, with 18.2% (6/33) from cluster 1, 36.3% (12/33) from cluster 2, 9.1% (3/33) from cluster 3, 18.2% (6/33) from cluster 4, and 12.1% (4/33) from cluster 5. The most frequent TDR mutations were M46I (2) in the protease region and Y181C (2) from the reverse transcriptase fragment. Clusters 1 and 2 of CRF01&#95;AE strains were prevalent in Liuzhou and Hezhou, respectively. However, multiple CRF01&#95;AE clusters existed in Nanning. This can be partially explained by the high mobility of laborers in Nanning, the capital city of Guangxi. The prevalence of TDR was low.

HIV-1-specific CD4+ and CD8+ T lymphocytes are important for HIV-1 replication control. F4/AS01 consists of F4 recombinant fusion protein (containing clade B Gag/p24, Pol/RT, Nef and Gag/p17) formulated in AS01 Adjuvant System, and was shown to induce F4-specific polyfunctional CD4+ T-cell responses in humans. While replication-incompetent recombinant HIV-1/SIV antigen-expressing human adenoviral vectors can elicit high-frequency antigen-specific CD8+ T-cell responses, their use is hampered by widespread pre-existing immunity to human serotypes. Non-human adenovirus serotypes associated with lower prevalence may offer an alternative strategy. We evaluated the immunogenicity of AdC7-GRN ('A'), a recombinant chimpanzee adenovirus type 7 vector expressing clade B Gag, RT and Nef, and F4/AS01 ('P'), when delivered intramuscularly in homologous (PP or AA) and heterologous (AAPP or PPAA) prime-boost regimens, in macaques and mice. Vaccine-induced HIV-1-antigen-specific T cells in peripheral blood (macaques), liver, spleen, and intestinal and genital mucosa (mice) were characterized by intracellular cytokine staining. Vaccine-specific IgG antibodies (macaques) were detected using ELISA. In macaques, only the heterologous prime-boost regimens induced polyfunctional, persistent and balanced CD4+ and CD8+ T-cell responses specific to each HIV-1 vaccine antigen. AdC7-GRN priming increased the polyfunctionality of F4/AS01-induced CD4+ T cells. Approximately 50% of AdC7-GRN-induced memory CD8+ T cells exhibited an effector-memory phenotype. HIV-1-specific antibodies were detected with each regimen. In mice, antigen-specific CD4+ and CD8+ T-cell responses were detected in the mucosal and systemic anatomical compartments assessed. When administered in heterologous prime-boost regimens, AdC7-GRN and F4/AS01 candidate vaccines acted complementarily in inducing potent and persistent peripheral blood HIV-1-specific CD4+ and CD8+ T-cell responses and antibodies in macaques. Besides, adenoviral vector priming modulated the cytokine-expression profile of the protein-induced CD4+ T cells. Each regimen induced HIV-1-specific T-cell responses in systemic/local tissues in mice. This suggests that prime-boost regimens combining adjuvanted protein and low-seroprevalent chimpanzee adenoviral vectors represent an attractive vaccination strategy for clinical evaluation.

Objective: To assess the presence of two major non-nucleoside reverse transcriptase inhibitors (NNRTI) drug resistance mutations (DRMs), Y181C and K103N, in minor viral quasispecies of treatment naïve HIV-1 infected East-African and Swedish patients by allele-specific polymerase chain reaction (AS-PCR)., Methods: Treatment naïve adults (n=191) with three epidemiological backgrounds were included: 92 Ethiopians living in Ethiopia; 55 East-Africans who had migrated to Sweden; and 44 Caucasians living in Sweden. The pol gene was analysed by standard population sequencing and by AS-PCR for the detection of Y181C and K103N., Results: The Y181C was detected in the minority quasispecies of six Ethiopians (6.5%), in two Caucasians (4.5%), and in one East-African (1.8%). The K103N was detected in one East- African (1.8%), by both methods. The proportion of mutants ranged from 0.25% to 17.5%. Additional DRMs were found in all three treatment naïve patient groups by population sequencing., Conclusions: Major NNRTI mutations can be found by AS-PCR in minor quasispecies of treatment naïve HIV-1 infected Ethiopians living in Ethiopia, in East-African and Caucasian patients living in Sweden in whom population sequencing reveal wild-type virus only. Surveys with standard sequencing are likely to underestimate transmitted drug resistance and the presence of resistant minor quasispecies in treatment naïve patients should be topic for future large scale studies.

Detection of recent HIV infections is a prerequisite for reliable estimations of transmitted HIV drug resistance (t-HIVDR) and incidence. However, accurately identifying recent HIV infection is challenging due partially to the limitations of current serological tests. Ambiguous nucleotides are newly emerged mutations in quasispecies, and accumulate by time of viral infection. We utilized ambiguous mutations to establish a measurement for detecting recent HIV infection and monitoring early HIVDR development. Ambiguous nucleotides were extracted from HIV-1 pol-gene sequences in the datasets of recent (HIVDR threshold surveys [HIVDR-TS] in 7 countries; n=416) and established infections (1 HIVDR monitoring survey at baseline; n=271). An ambiguous mutation index of 2.04×10(-3) nts/site was detected in HIV-1 recent infections which is equivalent to the HIV-1 substitution rate (2×10(-3) nts/site/year) reported before. However, significantly higher index (14.41×10(-3) nts/site) was revealed with established infections. Using this substitution rate, 75.2% subjects in HIVDR-TS with the exception of the Vietnam dataset and 3.3% those in HIVDR-baseline were classified as recent infection within one year. We also calculated mutation scores at amino acid level at HIVDR sites based on ambiguous or fitted mutations. The overall mutation scores caused by ambiguous mutations increased (0.54×10(-2)3.48×10(-2)/DR-site) whereas those caused by fitted mutations remained stable (7.50-7.89×10(-2)/DR-site) in both recent and established infections, indicating that t-HIVDR exists in drug-naïve populations regardless of infection status in which new HIVDR continues to emerge. Our findings suggest that characterization of ambiguous mutations in HIV may serve as an additional tool to differentiate recent from established infections and to monitor HIVDR emergence.

Unlabelled: Anti-hepatitis B virus (HBV) nucleos(t)ides analogs (NA) exert selective pressures on polymerase (pol) and surface (S) genes, inducing treatment resistance and increasing the risk of vaccine escape mutants. The rate of emergence for these mutations is largely unknown in patients coinfected with human immunodeficiency virus (HIV) and HBV undergoing dual-active therapy. In a 3-year, repeat-sampling, prospective cohort study, HBV viral genome sequences of 171 HIV-HBV coinfected patients, presenting with HBV viremia for at least one visit, were analyzed every 12 months via DNA chip. Logistic and Cox proportional hazard models were used to determine risk factors specifically for S gene mutations at baseline and during follow-up, respectively. HBV-DNA levels >190 IU/mL substantially decreased from 91.8% at inclusion to 40.3% at month 36 (P < 0.001), while lamivudine (LAM) or emtricitabine (FTC) use remained steady (71.9%) and tenofovir (TDF) use expanded (month 0, 17.5%; month 36, 66.7%; P < 0.001). The largest increase of any mutation class was observed in l-nucleoside-associated pol gene/antiviral-associated S gene mutations (cumulative incidence at the end of follow-up, 17.5%) followed by alkyl phosphonate-associated pol-gene (7.4%), immune-associated S gene (specifically any amino acid change at positions s120/s145, 6.4%), and d-cyclopentane-associated pol-gene mutations (2.4%). Incidence of l-nucleoside-associated pol-gene/antiviral-associated S gene mutations was significantly associated with concomitant LAM therapy (adjusted hazard ratio [HR], 4.61; 95% confidence interval [CI], 1.36-15.56), but inversely associated with TDF use (adjusted HR/month, 0.94; 95% CI,0.89-0.98). Cumulative duration of TDF was significantly associated with a reduction in the occurrence of immune-associated S gene mutations (HR/month, 0.88; 95% CI, 0.79-0.98). No major liver-related complications (e.g., fulminant hepatitis, decompensated liver, and hepatocellular carcinoma) were observed in patients with incident mutations., Conclusion: Vaccine escape mutants selected by NA exposure were frequent and steadily increasing during follow-up. Although the high antiviral potency of TDF can mitigate incident mutations, other antiviral options are limited in this respect. The public health implications of their transmission need to be addressed., (Copyright © 2013 by the American Association for the Study of Liver Diseases.)

HERV-K (human endogenous retrovirus type K) type 1-encoded Np9 is a tumor-specific biomarker, but its oncogenic role and targets in human leukemia remain elusive. We first identified Np9 as a potent viral oncogene in human leukemia. Silencing of Np9 inhibited the growth of myeloid and lymphoblastic leukemic cells, whereas expression of Np9 significantly promoted the growth of leukemia cells in vitro and in vivo. Np9 not only activated ERK, AKT and Notch1 pathways but also upregulated β-catenin essential for survival of leukemia stem cells. In human leukemia, Np9 protein level in leukemia patients was substantially higher than that in normal donors (56% vs 4.5%). Moreover, Np9 protein level was correlated with the number of leukemia stem/progenitor cells but not detected in normal CD34(+) hematopoietic stem cells. In addition, Np9-positive samples highly expressed leukemia-specific pol-env polyprotein, env and transmembrane proteins as well as viral particles. Thus, the viral oncogene Np9 is a critical molecular switch of multiple signaling pathways regulating the growth of leukemia stem/progenitor cells. These findings open a new perspective to understand the etiology of human common leukemia and provide a novel target for treating leukemia.

The hepatitis B virus (HBV) polymerase (pol) gene completely overlaps with the envelope (S) gene. Nucleos(t)ide analogue (NA) resistance mutations in the pol gene of HBV, either from selection of primary or secondary resistance mutations, typically result in changes in the overlapping hepatitis B surface antigen (HBsAg). Recent studies have conferred a new acronym to these HBV pol/S gene overlap mutants; ADAPVEMs, for antiviral drug-associated potential vaccine-escape mutants. The present report aimed to assess the determined multiple HBV vaccine-escape mutants in a Turkish patient with chronic hepatitis B (CHB), undergoing NAs treatment. The liver biopsy of HBsAg positive, HBeAg negative 53-year old female patient with CHB, revealed a score as histological activity index; 9 and fibrosis; 2 according to Ishak classification. NA treatment backgrounds consisted of 24 months lamivudine, followed by 18 months entacavir and lastly 3 months tenofovir monotherapies. Since HBV DNA load was determined as 7.030.000 IU/ml at the 4th month of tenofovir therapy, entecavir was added as current treatment regimen, and tenofovir + entecavir therapy decreased the HBV DNA load (400 IU/ml). Sequence analysis was performed for HBV pol/S gene and overlapping pol/S gene amino acid substitutions, primary/compensatory NA resistance mutations and antiviral drug-associated potential vaccine-escape mutations (ADAPVEM) were analysed. The patient isolate was identified as genotype D/subgenotype D1 of HBV. Primary drug resistance mutations (rtV173L + rtL180M + rtM204V) to lamivudine and telbivudine and a compensatory mutation (rtQ215H) to lamivudine and adefovir were described in the HBV pol gene sequence. However, multiple HBV vaccine-escape mutations (sS143T + sD144E + sG145R + sE164D + sI195M) have been determined on the HBV overlapping pol/S gene region. Lamivudine and telbivudine which are the frequently preferred drugs for the treatment of CHB in Turkey, have the potential to lead to ADAPVEMs. Thus ADAPVEMs should be monitored in infected and NA treated CHB patients and their public health risks should be assessed.

Objective: Characterize intra-individual HIV-1 subtype B pol evolution in antiretroviral naive individuals., Design: Longitudinal cohort study of individuals enrolled during primary infection., Methods: Eligible individuals were antiretroviral naïve participants enrolled in the cohort from December 1997-December 2005 and having at least two blood samples available with the first one collected within a year of their estimated date of infection. Population-based pol sequences were generated from collected blood samples and analyzed for genetic divergence over time in respect to dual infection status, HLA, CD4 count and viral load., Results: 93 participants were observed for a median of 1.8 years (Mean = 2.2 years, SD =1.9 years). All participants classified as mono-infected had less than 0.7% divergence between any two of their pol sequences using the Tamura-Nei model (TN93), while individuals with dual infection had up to 7.0% divergence. The global substitution rates (substitutions/nucleotide/year) for mono and dually infected individuals were significantly different (p<0.001); however, substitution rates were not associated with HLA haplotype, CD4 or viral load., Conclusions: Even after a maximum of almost 9 years of follow-up, all mono-infected participants had less than 1% divergence between baseline and longitudinal sequences, while participants with dual infection had 10 times greater divergence. These data support the use of HIV-1 pol sequence data to evaluate transmission events, networks and HIV-1 dual infection.

Transmitted drug resistance (TDR) is an important public health issue, because it may affect the outcome of antiretroviral treatment. The prevalence of human immunodeficiency virus type 1 (HIV-1) with TDR mutations defined according to the list of the World Health Organization was investigated among 53 therapy-naïve persons with confirmed recent HIV-1 infection diagnosed in Poland, in the years 2008-2010. Proviral DNA was amplified, sequenced, and screened for the TDR mutations in the pol gene fragments coding for the whole protease and the initial 256 residues of the reverse transcriptase. The frequency of sequences with at least one TDR mutation was 11.3%. In four (7.5%) sequences at least one resistance mutation related to reverse transcriptase inhibitors was identified, and in further two (3.8%) sequences one mutation related to protease inhibitors' resistance was present. The moderate rate of TDR highlights the need for a continuous surveillance and resistance testing among treatment-naïve individuals to optimize treatment effects within a country.

HIV-1 subtype B is the most frequent strain in Sicily. To date, there is no available data about the genetic diversity of HIV-1 viral strains circulating in Sicily among antiretroviral (ARV) naïve subjects and the role of immigration as potential determinant of evolutionary dynamics of HIV-1 molecular epidemiology. For this purpose, HIV-1 polymerase (pol) sequences obtained from 155 ARV naïve individuals from 2004 to 2009 were phylogenetically analysed. The overall rate of HIV-1 non-B infections was 31.0% (n=48/155), increasing from 7.8% in 2004-2006 to 40.9% in 2009, and about one-third were identified as unique recombinant forms. CRF02&#95;AG was the prevalent non-B clade (n=28/48, 58.3%), while subtype C-related strains were responsible for about 30% HIV-1 infections. Non-B viruses strictly associated with heterosexual transmission (85.4%) and were mostly found among immigrants (77.1%). Phylogenetic analysis of non-B sequences found in foreign-born subjects was geographically correlated to the respective country of origin. Moreover, the detection of non-B viral variants in the autochthonous population may support an increasing genetic diversity in Sicily as well as a local circulation of HIV strains also uncommon in our country. In Sicily, HIV-1 epidemic is still mostly attributable to the B subtype. Nevertheless, migration and population movements are progressively introducing novel HIV-1 subtypes causing a continuous increase of HIV-1 molecular dynamic at local level. Molecular surveillance is needed to monitor the genetic evolution of HIV-1 epidemic., (Copyright © 2013 Elsevier B.V. All rights reserved.)

An SRV-like virus was isolated from a colony-born Japanese monkey. To identify this SRV-like virus, we designed universal primers at regions that were conserved among the reported SRV sequences in the 5'-LTR and the short ORF and we obtained plasmid clones containing the complete gag, prt, pol and env genes. The full-length sequences of the isolate were determined from the plasmids and by direct sequencing. Sequence comparisons and phylogenetic analyses indicated that this SRV-like virus had a sequence identical to the reported 626 bp of SRV-5. In this study, we isolated SRV5/JPN/2005/V1 from a Japanese monkey and characterized the full-length SRV-5 sequence.

Background: The emergence of an HIV-1 epidemic in China was first recognized in Dehong, western Yunnan. Due to its geographic location, Dehong contributed greatly in bridging HIV-1 epidemics in Southeast Asia and China through drug trafficking and injection drug use; and also extensively to the HIV genetic diversity in Yunnan and China. We attempt to monitor HIV-1 in this area by studying the HIV-1 genetic distribution and transmitted drug resistance (TDR) in various at-risk populations., Methods: Blood samples from a total of 320 newly HIV-1 diagnosed individuals, who were antiretroviral therapy (ART)-naive, were collected from January 2009 to December 2010 in 2 counties in Dehong. HIV-1 subtypes and pol gene drug resistance (DR) mutations were genotyped., Results: Among 299 pol sequences successfully genotyped (93.4%), subtype C accounted for 43.1% (n=129), unique recombinant forms (URFs) for 18.4% (n=55), CRF01&#95;AE for 17.7% (n=54), B for 10.7% (n=32), CRF08&#95;BC for 8.4% (n=25) and CRF07&#95;BC for 1.7% (n=5). Subtype distribution in patients infected by different transmission routes varied. In contract to the previous finding of CRF01&#95;AE predominance in 2002-2006, subtype C predominated in both injecting drug users (IDUs) and heterosexually transmitted populations in this study. Furthermore, we found a high level of BC, CRF01&#95;AE/C and CRF01&#95;AE/B/C recombinants suggesting the presence of active viral recombination in the area. TDR associated mutations were identified in 4.3% (n=13) individuals. A total of 1.3% of DR were related to protease inhibitors (PIs), including I85IV, M46I and L90M; 0.3% to nucleoside reverse transcriptase inhibitors (NRTIs), including M184I; and 2.7% to non-nucleoside reverse transcriptase inhibitors (NNRTIs), including K103N/S, Y181C, K101E and G190A., Conclusion: Our work revealed diverse HIV-1 subtype distributions and intersubtype recombinations. We also identified a low but significant TDR mutation rate among ART-naive patients. These findings enhance our understanding of HIV-1 evolution and are valuable for the development and implementation of a comprehensive public health approach to HIV-1 DR prevention and treatment in the region.

Introduction: Human immunodeficiency virus type 1 (HIV-1) genotyping resistance test (GRT) is essential for monitoring HIV-1 drug resistance mutations (DRMs). High cost and HIV-1 genetic variability are challenges to assay availability in Singapore. An in-house Sanger sequencing-based GRT method was developed at the Communicable Disease Centre (CDC), Singapore's HIV national treatment reference centre for both subtype B and non-subtype B HIV-1., Materials and Methods: The in-house GRT sequenced the fi rst 99 codons of protease (PR) and 244 codons of reverse transcriptase (RT) in the pol gene. The results were compared with the Food and Drug Administration (FDA)-approved ViroSeq™ HIV-1 Genotyping System., Results: Subtype assignment for the 46 samples were as follows: 31 (67.4%) CRF01&#95;AE, 14 (30.5%) subtype B and 1 (2.1%) subtype C. All 46 samples had viral load of ≥500 copies/mL, and were successfully amplified by the in-house primer sets. Compared to the ViroSeq™ test, our in-house assay showed drug-resistance conferring codon concordance of 99.9% at PR and 98.9% at RT, and partial concordance of 0.1% at PR and 1.1% at RT. No discordant result was observed., Conclusion: The assay successfully identified DRMs in both subtype AE and B, making it suitable for the efficient treatment monitoring in genetically diverse population. At less than half of the running cost compared to the ViroSeq™ assay, the broadly sensitive in-house assay could serve as a useful addition to the currently limited HIV genotyping assay options for resource-limited settings, thereby enhancing the DRM surveillance and monitoring in the region.

Exploring graphene oxide (GO), DNA hybridization detection usually relies on either GO decoration or DNA sequences labeling. The former endows GO with desired chemical, optical, and biological properties. The latter adopts labeled molecules to indicate hybridization. In the present work, we propose a simple, label-free DNA assay using undecorated GO directly as the sensing platform. GO is anchored on diazonium functionalized electrode through electrostatic attraction, hydrogen bonding or epoxy ring-opening. The π-π stacking interaction between hexagonal cells of GO and DNA base rings facilitates DNA immobilization. The adsorbed DNA sequence is specially designed with two parts, including immobilization sequence and probe sequence. In the absence of target, the two sequences lie nearly flat on GO platform. In the presence of target, probe hybridizes with it to form double helix DNA, which 'stands' on GO. While the immobilization sequence part remains 'lying' on GO surface. Hence, DNA hybridization induces GO interfacial property changes, including negative charge and conformational transition from 'lying' ssDNA to 'standing' dsDNA. These changes are monitored by electrochemical impedance spectroscopy and adopted as the analytical signal. This strategy eliminates the requirement for GO decoration or DNA labeling, representing a comparatively simple and effective way. Finally, the principle is applied to the detection of conserved sequence of the human immunodeficiency virus 1 pol gene fragment. The dynamic detection range is from 1.0×10(-12) to 1.0×10(-6) M with detection limit of 1.1×10(-13) M with 3σ. And the sequences with double- or four-base mismatched are readily distinguishable. In addition, this strategy may hold great promise for potential applications from DNA biosensing to nanostructure framework construction based on the versatile DNA self-assembly., (Copyright © 2012 Elsevier B.V. All rights reserved.)

HIV-1 CRF02&#95;AG is the most prevalent intersubtype recombinant form worldwide. Six HIV-1 samples from patients living in Rio de Janeiro, Brazil, were subtyped as CRF02&#95;AG at the pol gene between 2004 and 2011. To trace the origin of these viruses, they were compared with 793 CRF02&#95;AG pol sequences of African origin and another four Brazilian CRF02&#95;AG pol sequences previously described. Phylogenetic analysis reveals that there have been at least four introductions of the CRF02&#95;AG clade in Brazil, as signified by the presence of four phylogenetically distinct lineages, probably originated from western African countries (Benin, Ghana, and Guinea-Bissau). At least two CRF02&#95;AG Brazilian lineages were successful in getting established and disseminated throughout the Rio de Janeiro state, with evidence of both horizontal and vertical transmission. Continuous epidemiological surveillance of HIV-1 strains circulating in Brazil is of paramount importance to the early detection of newly emerging viral lineages.

The distribution of HIV-1 subtypes and genetic characterization of CRF01&#95;AE in Guangxi, southern China were identified. The distribution of HIV-1 genotypes based on gag, pol, and partial env sequences (n=349) was as follows: CRF01&#95;AE (66.5%), CRF08&#95;BC (19.2%), CRF07&#95;BC (7.2%), URF (4.6%), subtype B (1.7%), and subtype B' (0.9%). CRF01&#95;AE predominated in all geographic regions and risk populations and there were multiple introductions of CRF01&#95;AE strains in Guangxi. We found a peculiar CRF01&#95;AE monophyletic lineage distinct from other CRF01&#95;AE viruses, and we designated it "CRF01&#95;AE-v" for convenience. CRF01&#95;AE-v circulating in both heterosexuals and injecting drug users (IDUs) had accounted for 39.7% of CRF01&#95;AE. It showed a selective advantage in the Guangxi population and formed its own characteristic compared with all the CRF01&#95;AE references. Our results suggested that CRF01&#95;AE-v was a new variant of CRF01&#95;AE and it might lead to a new epidemic in Guangxi.

Background: Clinically, human immunodeficiency virus type 1 (HIV-1) pol sequences are used to evaluate for drug resistance. These data can also be used to evaluate transmission networks and help describe factors associated with transmission risk., Methods: HIV-1 pol sequences from participants at 5 sites in the CFAR Network of Integrated Clinical Systems (CNICS) cohort from 2000-2009 were analyzed for genetic relatedness. Only the first available sequence per participant was included. Inferred transmission networks ("clusters") were defined as ≥2 sequences with ≤1.5% genetic distance. Clusters including ≥3 patients ("networks") were evaluated for clinical and demographic associations., Results: Of 3697 sequences, 24% fell into inferred clusters: 155 clusters of 2 individuals ("dyads"), 54 clusters that included 3-14 individuals ("networks"), and 1 large cluster that included 336 individuals across all study sites. In multivariable analyses, factors associated with being in a cluster included not using antiretroviral (ARV) drugs at time of sampling (P < .001), sequence collected after 2004 (P < .001), CD4 cell count >350 cells/mL (P < .01), and viral load 10,000-100,000 copies/mL (P < .001) or >100,000 copies/mL (P < .001). In networks, women were more likely to cluster with other women (P < .001), and African Americans with other African Americans (P < .001)., Conclusions: Molecular epidemiology can be applied to study HIV transmission networks in geographically and demographically diverse cohorts. Clustering was associated with lack of ARV use and higher viral load, implying transmission may be interrupted by earlier diagnosis and treatment. Observed female and African American networks reinforce the importance of diagnosis and prevention efforts targeted by sex and race.