scholarly journals Recovery of small plasmid sequences via Oxford Nanopore sequencing

2021 ◽  
Vol 7 (8) ◽  
Author(s):  
Ryan R. Wick ◽  
Louise M. Judd ◽  
Kelly L. Wyres ◽  
Kathryn E. Holt
Keyword(s):  
Whole Genome ◽  
Bacterial Isolates ◽  
Small Plasmid ◽  
Dna Library ◽  
Oxford Nanopore ◽  
Sequencing Platforms ◽  
Plasmid Size ◽  
Plasmid Recovery ◽  
Oxford Nanopore Technologies ◽  
Do So

Oxford Nanopore Technologies (ONT) sequencing platforms currently offer two approaches to whole-genome native-DNA library preparation: ligation and rapid. In this study, we compared these two approaches for bacterial whole-genome sequencing, with a specific aim of assessing their ability to recover small plasmid sequences. To do so, we sequenced DNA from seven plasmid-rich bacterial isolates in three different ways: ONT ligation, ONT rapid and Illumina. Using the Illumina read depths to approximate true plasmid abundance, we found that small plasmids (<20 kbp) were underrepresented in ONT ligation read sets (by a mean factor of ~4) but were not underrepresented in ONT rapid read sets. This effect correlated with plasmid size, with the smallest plasmids being the most underrepresented in ONT ligation read sets. We also found lower rates of chimaeric reads in the rapid read sets relative to ligation read sets. These results show that when small plasmid recovery is important, ONT rapid library preparations are preferable to ligation-based protocols.

scholarly journals Recovery of small plasmid sequences via Oxford Nanopore sequencing

2021 ◽  
Author(s):  
Ryan R. Wick ◽  
Louise M. Judd ◽  
Kelly L. Wyres ◽  
Kathryn E. Holt
Keyword(s):  
Single Step ◽  
Whole Genome ◽  
Virulence Determinants ◽  
Library Preparation ◽  
Bacterial Genomes ◽  
Preparation Methods ◽  
Small Plasmid ◽  
Oxford Nanopore ◽  
Plasmid Recovery ◽  
Oxford Nanopore Technologies

AbstractOxford Nanopore Technologies (ONT) sequencing platforms currently offer two approaches to whole-genome native-DNA library preparation: ligation and rapid. In this study, we compared these two approaches for bacterial whole-genome sequencing, with a specific aim of assessing their ability to recover small plasmid sequences. To do so, we sequenced DNA from seven plasmid-rich bacterial isolates in three different ways: ONT ligation, ONT rapid and Illumina. Using the Illumina read depths to approximate true plasmid abundance, we found that small plasmids (<20 kbp) were underrepresented in ONT ligation read sets (by a mean factor of ∼4) but were not underrepresented in ONT rapid read sets. This effect correlated with plasmid size, with the smallest plasmids being the most underrepresented in ONT ligation read sets. We also found lower rates of chimeric reads in the rapid read sets relative to ligation read sets. These results show that when small plasmid recovery is important, ONT rapid library preparations are preferable to ligation-based protocols.Impact statementResearchers who use Oxford Nanopore Technologies (ONT) platforms to sequence bacterial genomes can currently choose from two library preparation methods. The first is a ligation-based approach, which uses ligase to attach sequencing adapters to the ends of DNA molecules. The second is a rapid approach, which uses a transposase enzyme to cleave DNA and attach adapters in a single step. There are advantages to each preparation, for example ligation can produce better yields but rapid is a simpler procedure. Our study reveals another advantage of rapid preparations: they are more effective at sequencing small plasmids. We show that sequencing of ligation-based libraries yields fewer reads derived from small plasmids, making such plasmids harder to detect in bacterial genomes. Since small plasmids can contain clinically relevant genes, including antimicrobial resistance (AMR) or virulence determinants, their exclusion could lead to unreliable conclusions that have serious consequences for AMR surveillance and prediction. We therefore recommend that researchers performing ONT-only sequencing of bacterial genomes should consider using rapid preparations whenever small plasmid recovery is important.Data summarySupplementary figures, tables, data and code can be found at: github.com/rrwick/Small-plasmid-Nanopore

Generating 1200bp tiled Amplicons for SARS-CoV2 Whole Genome Sequencing v2

2022 ◽  
Author(s):  
jason.nguyen not provided ◽  
Tracy Lee ◽  
Rebecca Hickman ◽  
Natalie Prystajecky ◽  
John Tyson
Keyword(s):  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Illumina Miseq ◽  
Whole Genome ◽  
Oxford Nanopore ◽  
Sequencing Platforms

This procedure provides instructions for how to generate amplicons across the entire SARS-CoV-2 genome to be used for downstream whole genome sequencing applications, including Illumina MiSeq/NextSeq or Oxford Nanopore MinION sequencing platforms. The steps involved in this protocol were derived from version 3 of Freed et al protocol nCoV-2019 sequencing protocol (RAPID barcoding, 1200bp amplicon)V.3 available at https://dx.doi.org/10.17504/protocols.io.bgggjttw

PSXIV-24 Real-time, on-site whole genome sequencing with oxford nanopore technologies’ MinION

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 257-258
Author(s):  
Hanna Ostrovski ◽  
Rodrigo Pelicioni Savegnago ◽  
Wen Huang ◽  
Cedric Gondro
Keyword(s):  
Real Time ◽  
Ease Of Use ◽  
Whole Genome Sequence ◽  
Genomic Sequencing ◽  
Whole Genome ◽  
Illumina Hiseq ◽  
Base Calling ◽  
Oxford Nanopore ◽  
Oxford Nanopore Technologies

Abstract Most quantitative geneticists are traditionally trained for data analysis in genetic evaluation and genomic prediction, but rarely have extensive knowledge of molecular genetics or experience in experimental labs. Recent products, such as those launched by Oxford Nanopore Technologies (ONT), give those quantitative geneticists a comprehensible and hands-on toolkit to explore DNA sequencing. The ‘MinION’, a small DNA sequencer, is of interest for quantitative geneticists due to both the minimal learning curve and the non-proprietary USB connectivity. This device is small enough to be portable, allowing for potential real-time, on-farm sequencing. The objective of this project is to compare the whole genome sequence (WGS) output of the MinION sequencer to that of the Illumina HiSeq 4000. Blood was collected from a 6-month-old Akaushi calf born on a Michigan State University farm. DNA was extracted from the sample using the QIAamp DNA Blood Kit from Qiagen, and library DNA ligation preparation (SQK-LSK109) from ONT was used. After base-calling with guppy software (provided by ONT), the data were preprocessed and experimental runs with the MinION were compared using quality control. Finally, the data were aligned with guppy software, and was compared to the aligned WGS obtained with Illumina HiSeq. Quality results from each MinION indicate that, despite the low amount of sequence collected in each run (~225,303 reads per run), the quality of bases sequenced was high (Q≥7). The aligned data from the Illumina sequencer provided 40x coverage of the genome, with a total of 739,339,742 reads. Although the amount of data obtained with MinION is much smaller than that of Illumina HiSeq, the high quality of MinION’s data combined with its ease of use give an opportunity of genomic sequencing for users who are either inexperienced or do not have access to large genomic sequencing devices.

scholarly journals Updated Genome Sequence for the Probiotic Bacterium Bifidobacterium animalis subsp. lactis BB-12

2021 ◽  
Vol 10 (27) ◽  
Author(s):  
Kristian Jensen ◽  
Kosai Al-Nakeeb ◽  
Anna Koza ◽  
Ahmad A. Zeidan
Keyword(s):  
Genome Sequence ◽  
Probiotic Bacterium ◽  
Content Type ◽  
Short Read Sequencing ◽  
Bifidobacterium Animalis ◽  
Oxford Nanopore ◽  
Hybrid Genome ◽  
Long Read ◽  
Sequencing Platforms ◽  
Oxford Nanopore Technologies

The genome of Bifidobacterium animalis subsp. lactis BB-12 was sequenced using Oxford Nanopore Technologies long-read and Illumina short-read sequencing platforms. A hybrid genome assembly approach was used to construct an updated complete genome sequence for BB-12 containing 1,944,152 bp, with a G+C content of 60.5% and 1,615 genes.

scholarly journals Methplotlib: analysis of modified nucleotides from nanopore sequencing

2019 ◽  
Author(s):  
Wouter De Coster ◽  
Mojca Strazisar
Keyword(s):  
Gene Expression Regulation ◽  
Command Line ◽  
Nanopore Sequencing ◽  
Modified Nucleotides ◽  
Oxford Nanopore ◽  
Command Line Tool ◽  
Within Subjects ◽  
Allele Specific ◽  
Sequencing Platforms ◽  
Oxford Nanopore Technologies

AbstractSummaryModified nucleotides play a crucial role in gene expression regulation. Here we describe methplotlib, a tool developed for the visualization of modified nucleotides detected from Oxford Nanopore Technologies sequencing platforms, together with additional scripts for statistical analysis of allele specific modification within subjects and differential modification frequency across subjects.Availability and implementationThe methplotlib command-line tool is written in Python3, is compatible with Linux, Mac OS and the MS Windows 10 Subsystem for Linux and released under the MIT license. The source code can be found at https://github.com/wdecoster/methplotlib and can be installed from PyPI and bioconda. Our repository includes test data and the tool is continuously tested at [email protected]

scholarly journals Complete Circular Genome Sequences of Brachyspira hyodysenteriae Isolates of the Four Different Sequence Types Causing Swine Dysentery in Switzerland

2021 ◽  
Vol 10 (39) ◽  
Author(s):  
Ana B. García-Martín ◽  
Sarah Schmitt ◽  
Friederike Zeeh ◽  
Vincent Perreten
Keyword(s):  
High Throughput Sequencing ◽  
De Novo ◽  
Hybrid Assembly ◽  
Swine Dysentery ◽  
Content Type ◽  
Brachyspira Hyodysenteriae ◽  
Oxford Nanopore ◽  
Sequencing Platforms ◽  
Sequence Types ◽  
Oxford Nanopore Technologies

The complete genomes of four Brachyspira hyodysenteriae isolates of the four different sequence types (STs) (ST6, ST66, ST196, and ST197) causing swine dysentery in Switzerland were generated by whole-genome sequencing and de novo hybrid assembly of reads obtained from second (Illumina) and third (Oxford Nanopore Technologies and Pacific Biosciences) high-throughput sequencing platforms.

scholarly journals Identification and Whole-Genome Sequencing of a Monkeypox Virus Strain Isolated in Israel

2020 ◽  
Vol 9 (10) ◽  
Author(s):  
Inbar Cohen-Gihon ◽  
Ofir Israeli ◽  
Ohad Shifman ◽  
Noam Erez ◽  
Sharon Melamed ◽  
...  
Keyword(s):  
West Africa ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Virus Strain ◽  
Illumina Miseq ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Monkeypox Virus ◽  
Oxford Nanopore ◽  
Oxford Nanopore Technologies

We report the whole-genome sequence of a monkeypox virus strain isolated in Israel. The strain was isolated in 2018 from a patient travelling back from West Africa. The virus was fully sequenced on the Illumina MiSeq and Oxford Nanopore Technologies MinION platforms.

scholarly journals Benchmarking of long-read assemblers for prokaryote whole genome sequencing

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 2138 ◽  
Author(s):  
Ryan R. Wick ◽  
Kathryn E. Holt
Keyword(s):  
Data Sets ◽  
Computationally Efficient ◽  
Short Read Sequencing ◽  
Oxford Nanopore ◽  
Long Read ◽  
Sequencing Platforms ◽  
Computational Resources ◽  
Assembly Algorithms ◽  
Oxford Nanopore Technologies ◽  
Multiple Assembly

Background: Data sets from long-read sequencing platforms (Oxford Nanopore Technologies and Pacific Biosciences) allow for most prokaryote genomes to be completely assembled – one contig per chromosome or plasmid. However, the high per-read error rate of long-read sequencing necessitates different approaches to assembly than those used for short-read sequencing. Multiple assembly tools (assemblers) exist, which use a variety of algorithms for long-read assembly. Methods: We used 500 simulated read sets and 120 real read sets to assess the performance of six long-read assemblers (Canu, Flye, Miniasm/Minipolish, Raven, Redbean and Shasta) across a wide variety of genomes and read parameters. Assemblies were assessed on their structural accuracy/completeness, sequence identity, contig circularisation and computational resources used. Results: Canu v1.9 produced moderately reliable assemblies but had the longest runtimes of all assemblers tested. Flye v2.6 was more reliable and did particularly well with plasmid assembly. Miniasm/Minipolish v0.3 was the only assembler which consistently produced clean contig circularisation. Raven v0.0.5 was the most reliable for chromosome assembly, though it did not perform well on small plasmids and had circularisation issues. Redbean v2.5 and Shasta v0.3.0 were computationally efficient but more likely to produce incomplete assemblies. Conclusions: Of the assemblers tested, Flye, Miniasm/Minipolish and Raven performed best overall. However, no single tool performed well on all metrics, highlighting the need for continued development on long-read assembly algorithms.

scholarly journals Performance of neural network basecalling tools for Oxford Nanopore sequencing

2019 ◽  
Author(s):  
Ryan R. Wick ◽  
Louise M. Judd ◽  
Kathryn E. Holt
Keyword(s):  
Neural Network ◽  
Electrical Signal ◽  
Specific Data ◽  
Consensus Sequences ◽  
Additional Signal ◽  
Oxford Nanopore ◽  
Majority Rules ◽  
Sequencing Platforms ◽  
Oxford Nanopore Technologies ◽  
Level Analysis

AbstractBasecalling, the computational process of translating raw electrical signal to nucleotide sequence, is of critical importance to the sequencing platforms produced by Oxford Nanopore Technologies (ONT). Here we examine the performance of different basecalling tools, looking at accuracy at the level of bases within individual reads and at majority-rules consensus basecalls in an assembly. We also investigate some additional aspects of basecalling: training using a taxon-specific dataset, using a larger neural network model and improving consensus basecalls in an assembly via additional signal-level analysis with Nanopolish. Training basecallers on taxon-specific data resulted in a significant boost in consensus accuracy, mostly due to the reduction of errors in methylation motifs. A larger neural network was able to improve both read and consensus accuracy, but at a cost to speed. Improving consensus sequences (‘polishing’) with Nanopolish somewhat negates the accuracy differences in basecallers, but pre-polish accuracy does have an effect on post-polish accuracy, so basecaller choice is still relevant even when Nanopolish is used.

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