scholarly journals A Versatile Processing Workflow to Enable Pathogen Detection in Clinical Samples from Organs Using VIDISCA

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 791
Author(s):  
Alba Folgueiras-González ◽  
Robin van den Braak ◽  
Martin Deijs ◽  
Lia van der Hoek ◽  
Ad de Groof

In recent years, refined molecular methods coupled with powerful high throughput sequencing technologies have increased the potential of virus discovery in clinical samples. However, host genetic material remains a complicating factor that interferes with discovery of novel viruses in solid tissue samples as the relative abundance of the virus material is low. Physical enrichment processing methods, although usually complicated, labor-intensive, and costly, have proven to be successful for improving sensitivity of virus detection in complex samples. In order to further increase detectability, we studied the application of fast and simple high-throughput virus enrichment methods on tissue homogenates. Probe sonication in high EDTA concentrations, organic extraction with Vertrel™ XF, or a combination of both, were applied prior to chromatography-like enrichment using Capto™ Core 700 resin, after which effects on virus detection sensitivity by the VIDISCA method were determined. Sonication in the presence of high concentrations of EDTA showed the best performance with an increased proportion of viral reads, up to 9.4 times, yet minimal effect on the host background signal. When this sonication procedure in high EDTA concentrations was followed by organic extraction with Vertrel™ XF and two rounds of core bead chromatography enrichment, an increase up to 10.5 times in the proportion of viral reads in the processed samples was achieved, with reduction of host background sequencing. We present a simple and semi-high-throughput method that can be used to enrich homogenized tissue samples for viral reads.

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2541
Author(s):  
Izabela Fabiańska ◽  
Stefan Borutzki ◽  
Benjamin Richter ◽  
Hon Q. Tran ◽  
Andreas Neubert ◽  
...  

High-throughput sequencing (HTS) allows detection of known and unknown viruses in samples of broad origin. This makes HTS a perfect technology to determine whether or not the biological products, such as vaccines are free from the adventitious agents, which could support or replace extensive testing using various in vitro and in vivo assays. Due to bioinformatics complexities, there is a need for standardized and reliable methods to manage HTS generated data in this field. Thus, we developed LABRADOR—an analysis pipeline for adventitious virus detection. The pipeline consists of several third-party programs and is divided into two major parts: (i) direct reads classification based on the comparison of characteristic profiles between reads and sequences deposited in the database supported with alignment of to the best matching reference sequence and (ii) de novo assembly of contigs and their classification on nucleotide and amino acid levels. To meet the requirements published in guidelines for biologicals’ safety we generated a custom nucleotide database with viral sequences. We tested our pipeline on publicly available HTS datasets and showed that LABRADOR can reliably detect viruses in mixtures of model viruses, vaccines and clinical samples.


Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1424
Author(s):  
Lia W. Liefting ◽  
David W. Waite ◽  
Jeremy R. Thompson

The adoption of Oxford Nanopore Technologies (ONT) sequencing as a tool in plant virology has been relatively slow despite its promise in more recent years to yield large quantities of long nucleotide sequences in real time without the need for prior amplification. The portability of the MinION and Flongle platforms combined with lowering costs and continued improvements in read accuracy make ONT an attractive method for both low- and high-scale virus diagnostics. Here, we provide a detailed step-by-step protocol using the ONT Flongle platform that we have developed for the routine application on a range of symptomatic post-entry quarantine and domestic surveillance plant samples. The aim of this methods paper is to highlight ONT’s feasibility as a valuable component to the diagnostician’s toolkit and to hopefully stimulate other laboratories towards the eventual goal of integrating high-throughput sequencing technologies as validated plant virus diagnostic methods in their own right.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Rachelle Bester ◽  
Glynnis Cook ◽  
Johannes H. J. Breytenbach ◽  
Chanel Steyn ◽  
Rochelle De Bruyn ◽  
...  

Abstract Background High-throughput sequencing (HTS) has been applied successfully for virus and viroid discovery in many agricultural crops leading to the current drive to apply this technology in routine pathogen detection. The validation of HTS-based pathogen detection is therefore paramount. Methods Plant infections were established by graft inoculating a suite of viruses and viroids from established sources for further study. Four plants (one healthy plant and three infected) were sampled in triplicate and total RNA was extracted using two different methods (CTAB extraction protocol and the Zymo Research Quick-RNA Plant Miniprep Kit) and sent for Illumina HTS. One replicate sample of each plant for each RNA extraction method was also sent for HTS on an Ion Torrent platform. The data were evaluated for biological and technical variation focussing on RNA extraction method, platform used and bioinformatic analysis. Results The study evaluated the influence of different HTS protocols on the sensitivity, specificity and repeatability of HTS as a detection tool. Both extraction methods and sequencing platforms resulted in significant differences between the data sets. Using a de novo assembly approach, complemented with read mapping, the Illumina data allowed a greater proportion of the expected pathogen scaffolds to be inferred, and an accurate virome profile was constructed. The complete virome profile was also constructed using the Ion Torrent data but analyses showed that more sequencing depth is required to be comparative to the Illumina protocol and produce consistent results. The CTAB extraction protocol lowered the proportion of viroid sequences recovered with HTS, and the Zymo Research kit resulted in more variation in the read counts obtained per pathogen sequence. The expression profiles of reference genes were also investigated to assess the suitability of these genes as internal controls to allow for the comparison between samples across different protocols. Conclusions This study highlights the need to measure the level of variation that can arise from the different variables of an HTS protocol, from sample preparation to data analysis. HTS is more comprehensive than any assay previously used, but with the necessary validations and standard operating procedures, the implementation of HTS as part of routine pathogen screening practices is possible.


Author(s):  
Stella C. Yuan ◽  
Eric Malekos ◽  
Melissa T. R. Hawkins

AbstractThe use of museum specimens held in natural history repositories for population and conservation genetic research is increasing in tandem with the use of massively parallel sequencing technologies. Short Tandem Repeats (STRs), or microsatellite loci, are commonly used genetic markers in wildlife and population genetic studies. However, they traditionally suffered from a host of issues including length homoplasy, high costs, low throughput, and difficulties in reproducibility across laboratories. Massively parallel sequencing technologies can address these problems, but the incorporation of museum specimen derived DNA suffers from significant fragmentation and exogenous DNA contamination. Combatting these issues requires extra measures of stringency in the lab and during data analysis, yet there have not been any high-throughput sequencing studies evaluating microsatellite allelic dropout from museum specimen extracted DNA. In this study, we evaluate genotyping errors derived from mammalian museum skin DNA extracts for previously characterized microsatellites across PCR replicates utilizing high-throughput sequencing. We found it useful to classify samples based on DNA concentration, which determined the rate by which genotypes were accurately recovered. Longer microsatellites performed worse in all museum specimens. Allelic dropout rates across loci were dependent on sample quantity, with high concentration museum specimens performing as well and recovering quality metrics nearly as high as the frozen tissue sample. Based on our results, we provide a set of best practices for quality assurance and incorporation of reliable genotypes from museum specimens.


Plant Disease ◽  
2021 ◽  
Author(s):  
Dan Edward Veloso Villamor ◽  
Karen E Keller ◽  
Robert Martin ◽  
Ioannis Emmanouil Tzanetakis

A comprehensive study comparing virus detection between high throughput sequencing (HTS) and standard protocols in 30 berry selections (12 Fragaria, 10 Vaccinium and 8 Rubus) with known virus profiles was completed. The study examined temporal detection of viruses at four sampling times encompassing two growing seasons. Within the standard protocols, RT-PCR proved better than biological indexing. Detection of known viruses by HTS and RT-PCR nearly mirrored each other. HTS provided superior detection compared to RT-PCR on a wide spectrum of virus variants and discovery of novel viruses. More importantly, in most cases where the two protocols showed parallel virus detection, 11 viruses in 16 berry selections were not consistently detected by both methods at all sampling points. Based on these data we propose a four sampling times/two-year testing requirement for berry and potentially other crops to ensure that no virus remains undetected independent of titer, distribution or other virus/virus or virus/host interactions.


Viruses ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 566 ◽  
Author(s):  
Siemon Ng ◽  
Cassandra Braxton ◽  
Marc Eloit ◽  
Szi Feng ◽  
Romain Fragnoud ◽  
...  

A key step for broad viral detection using high-throughput sequencing (HTS) is optimizing the sample preparation strategy for extracting viral-specific nucleic acids since viral genomes are diverse: They can be single-stranded or double-stranded RNA or DNA, and can vary from a few thousand bases to over millions of bases, which might introduce biases during nucleic acid extraction. In addition, viral particles can be enveloped or non-enveloped with variable resistance to pre-treatment, which may influence their susceptibility to extraction procedures. Since the identity of the potential adventitious agents is unknown prior to their detection, efficient sample preparation should be unbiased toward all different viral types in order to maximize the probability of detecting any potential adventitious viruses using HTS. Furthermore, the quality assessment of each step for sample processing is also a critical but challenging aspect. This paper presents our current perspectives for optimizing upstream sample processing and library preparation as part of the discussion in the Advanced Virus Detection Technologies Interest group (AVDTIG). The topics include: Use of nuclease treatment to enrich for encapsidated nucleic acids, techniques for amplifying low amounts of virus nucleic acids, selection of different extraction methods, relevant controls, the use of spike recovery experiments, and quality control measures during library preparation.


2019 ◽  
Author(s):  
Reneth Millas ◽  
Mary Espina ◽  
CM Sabbir Ahmed ◽  
Angelina Bernardini ◽  
Ekundayo Adeleke ◽  
...  

ABSTRACTOne of the most important tools in genetic improvement is mutagenesis, which is a useful tool to induce genetic and phenotypic variation for trait improvement and discovery of novel genes. JTN-5203 (MG V) mutant population was generated using an induced ethyl methane sulfonate (EMS) mutagenesis and was used for detection of induced mutations in FAD2-1A and FAD2-1B genes using reverse genetics approach. Optimum concentration of EMS was used to treat 15,000 bulk JTN-5203 seeds producing 1,820 M2 population. DNA was extracted, normalized, and pooled from these individuals. Specific primers were designed from FAD2-1A and FAD2-1B genes that are involved in the fatty acid biosynthesis pathway for further analysis using next-generation sequencing. High throughput mutation discovery through TILLING-by-Sequencing approach was used to detect novel allelic variations in this population. Several mutations and allelic variations with high impacts were detected for FAD2-1A and FAD2-1B. This includes GC to AT transition mutations in FAD2-1A (20%) and FAD2-1B (69%). Mutation density for this population is estimated to be about 1/136kb. Through mutagenesis and high-throughput sequencing technologies, novel alleles underlying the mutations observed in mutants with reduced polyunsaturated fatty acids will be identified, and these mutants can be further used in breeding soybean lines with improved fatty acid profile, thereby developing heart-healthy-soybeans.


Author(s):  
AA Kliuchnikova ◽  
SA Moshkovskii

Adenosine-to-inosine (A-to-I) RNA editing is a common mechanism of post-transcriptional modification in many metazoans including vertebrates; the process is catalyzed by adenosine deaminases acting on RNA (ADARs). Using high-throughput sequencing technologies resulted in finding thousands of RNA editing sites throughout the human transcriptome however, their functions are still poorly understood. The aim of this brief review is to draw attention of clinicians and biomedical researchers to ADAR-mediated RNA editing phenomenon and its possible implication in development of neuropathologies, antiviral immune responses and cancer.


2016 ◽  
Vol 106 (5) ◽  
pp. 519-527 ◽  
Author(s):  
D. E. V. Villamor ◽  
T. A. Mekuria ◽  
S. S. Pillai ◽  
K. C. Eastwell

Recent studies have shown the superiority of high-throughput sequencing (HTS) technology over many standard protocols for pathogen detection. HTS was initiated on fruit tree accessions from disparate sources to improve and advance virus-testing procedures. A virus with genomic features resembling most closely that of the recently described Nectarine stem-pitting-associated virus, putative member of genus Luteovirus, was found in three nectarine trees (Prunus persica cv. nectarina), each exhibiting stem-pitting symptoms on the woody cylinder above the graft union. In these samples, HTS also revealed the presence of a coinfecting virus with genome characteristics typical of members of the genus Marafivirus. The same marafivirus- and luteovirus-like viruses were detected in nonsymptomatic nectarine and peach selections, indicating only a loose relationship between these two viruses with nectarine stem-pitting disease symptoms. Two selections infected with each of these viruses had previously tested free of known virus or virus-like agents using the current biological, serological, and molecular tests employed at the Clean Plant Center Northwest. Overall, this study presents the characterization by HTS of novel marafivirus- and luteovirus-like viruses of nectarine, and provides further insights into the etiology of nectarine stem-pitting disease. The discovery of these new viruses emphasizes the ability of HTS to reveal viruses that are not detected by existing protocols.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e13045-e13045
Author(s):  
Chang Gong ◽  
Qun Lin ◽  
Xiaolin Fang ◽  
Wenguo Jiang ◽  
Jun Li ◽  
...  

e13045 Background: Compared to lumial breast cancer, the proporation of triple-negative breast cancer (TNBC) with bone metastases (BMs) is relatively low and few data focusing on the mechanism of the BMs in TNBC are available, Here, we screened that CTNND1 was associated with BMs of TNBC by integrating high-throughput sequencing, and further investigated the role of CTNND1 in BMs of TNBC in vitro. Methods: TNBC tissue samples with only BMs (n = 6) and without any metastasis (n = 10) were tested using high-throughput sequencing and 11 differentially expressed relative genes were identified. We then quantified these 11 genes in normal breast tissue samples (n = 26), TNBC tissue samples with only BMs (n = 10), TNBC tissue samples without any metastasis (n = 88) as well as luminal tissue samples with BMs(n = 10)through qPCR and immunohistochemical staining (IHC). The effects of knocking down CTNND1 on the interaction between TNBC cells and osteoblasts were examined by cell adhesion, transwell migration and matrigel invasion assays. To explorethe role of CTNND1 in mediating bone metastasis in TNBC, we used RNA-sequencing to find out the relative downstream gene CXCR4 and PI3K-AKT-mTOR pathway and verified it in vitro by Western Blotting. Results: Combining our high-throughput sequencing data, qPCR and IHC in clinical tissue samples, we verified that CTNND1 was decreased in TNBC patients with bone metastasis compared to normal tissue and luminal tissue with BMs. Knocking down of CTNND1 in TNBC cells including MDA-MB-231, MDA-MB-468 and BT549 weakened cells adhesion, but facilitated cells migration and invasion. Mechanically, knocking down of CTNND1 upregulated CXCR4 via activating PI3K-AKT-mTOR pathway in TNBC but not luminal and HER2- positive breast cancer cells lines. Conclusions: CTNND1 mediates bone metastasis in triple-negative breast cancer via regulating CXCR4.CTNND1 may serve as a potential predictor of bone metastasis for TNBC patients.


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