scholarly journals Whole genome sequencing of marine organisms by Oxford Nanopore Technologies: Assessment and optimization of HMW‐DNA extraction protocols

2021 ◽  
Author(s):  
Sonia Boughattas ◽  
Dana Albatesh ◽  
Albandari Al‐Khater ◽  
Bruno W. Giraldes ◽  
Asma A. Althani ◽  
...  
2018 ◽  
Author(s):  
Jennifer M. Bouso ◽  
Paul J. Planet

AbstractNontuberculous mycobacteria (NTM) are a major cause of pulmonary and systemic disease in at-risk populations. Gaps in knowledge about transmission patterns, evolution, and pathogenicity during infection have prompted a recent surge in genomic NTM research. Increased availability and affordability of whole genome sequencing (WGS) techniques, including the advent of Oxford Nanopore Technologies, provide new opportunities to sequence complete NTM genomes at a fraction of the previous cost. However, extracting large quantities of pure genomic DNA is particularly challenging with NTM due to their slow growth and recalcitrant cell wall. Here we report a DNA extraction protocol that is optimized for long-read WGS of NTM, yielding large quantities of highly pure DNA. Our refined method was compared to 6 other methods with variations in timing of mechanical and enzymatic digestion, quantity of matrix material, and reagents used in extraction and precipitation. We also demonstrate the ability of our optimized protocol to produce sufficient DNA to yield near-complete NTM genome assemblies using Oxford Nanopore Technologies long-read sequencing.


2020 ◽  
Vol 9 (10) ◽  
Author(s):  
Inbar Cohen-Gihon ◽  
Ofir Israeli ◽  
Ohad Shifman ◽  
Noam Erez ◽  
Sharon Melamed ◽  
...  

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.


2020 ◽  
Vol 96 (6) ◽  
Author(s):  
Ingvild Falkum Ullmann ◽  
Anders Benteson Nygaard ◽  
Hege Smith Tunsjø ◽  
Colin Charnock

ABSTRACT A total of four strains of the ‘environmental superbug’ Pedobacter isolated from sludge produced at Norwegian drinking water treatment plants, were characterized by whole genome sequencing and antibiotic susceptibility assays. As with previous studies on members of this genus, we found that the isolates were multi-drug resistant, and that this resistance included clinically important beta-lactams, aminoglycosides and the fluoroquinolone ciprofloxacin. Using the minION sequencing platform (Oxford Nanopore Technologies) combined with HiSeq PE150 Illumina sequencing data, the four isolates were assembled into genomes of single contigs. Analysis of the genomes revealed potential genetic factors possibly underlying some of the specific resistances observed. Metallo-beta-lactamase activity was detected in one isolate, and the same isolate contained a putative metallo-betalactamase gene resembling pedo-2. Furthermore, several genes related to multidrug efflux systems were found using the resistance database CARD. Additionally, the present study extends our knowledge on the phylogeny of this genus, adding four new genomes to the existing 50.


2020 ◽  
Author(s):  
Sophie George ◽  
Yifei Xu ◽  
Gillian Rodger ◽  
Marcus Morgan ◽  
Nicholas D. Sanderson ◽  
...  

ABSTRACTMycobacterium tuberculosis (MTB) is the leading cause of death from bacterial infection. Improved rapid diagnosis and antimicrobial resistance determination, such as by whole genome sequencing, are required. Our aim was to develop a simple, low-cost method of preparing DNA for Oxford Nanopore Technologies (ONT) sequencing direct from MTB positive clinical samples (without culture). Simultaneous sputum liquefaction, bacteria heat-inactivation (99°C/30min) and enrichment for Mycobacteria DNA was achieved using an equal volume of thermo-protection buffer (4M KCl, 0.05M HEPES buffer pH7.5, 0.1% DTT). The buffer emulated intracellular conditions found in hyperthermophiles, thus protecting DNA from rapid thermo-degradation, which renders it a poor template for sequencing. Initial validation employed Mycobacteria DNA (extracted or intracellular). Next, mock clinical samples (infection-negative human sputum spiked 0-105 BCG cells/ml) underwent liquefaction in thermo-protection buffer and heat-inactivation. DNA was extracted and sequenced. Human DNA degraded faster than Mycobacteria DNA, resulting in target enrichment. Four replicate experiments each demonstrated detection at 101 BCG cells/ml, with 31-59 MTB complex reads. Maximal genome coverage (>97% at 5x-depth) was achieved at 104 BCG cells/ml; >91% coverage (1x depth) at 103 BCG cells/ml. Final validation employed MTB positive clinical samples (n=20), revealed initial sample volumes ≥1ml typically yielded higher mean depth of MTB genome coverage, the overall range 0.55-81.02. A mean depth of 3 gave >96% one-fold TB genome coverage (in 15/20 clinical samples). A mean depth of 15 achieved >99% five-fold genome coverage (in 9/20 clinical samples). In summary, direct-from-sample sequencing of MTB genomes was facilitated by a low cost thermo-protection buffer.


2020 ◽  
Author(s):  
Femke Wolters ◽  
Jordy P.M. Coolen ◽  
Alma Tostmann ◽  
Lenneke F.J. van Groningen ◽  
Chantal P. Bleeker-Rovers ◽  
...  

AbstractBackgroundCurrent transmission rates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are still increasing and many countries are facing second waves of infections. Rapid SARS-CoV-2 whole-genome sequencing (WGS) is often unavailable but could support public health organizations and hospitals in monitoring and determining transmission links. Here we report the use of reverse complement polymerase chain reaction (RC-PCR), a novel technology for WGS of SARS-CoV-2 enabling library preparation in a single PCR saving time, resources and enables high throughput screening. Additionally, we show SARS-CoV-2 diversity and possible transmission within the Radboud university medical center (Radboudumc) during September 2020 using RC-PCR WGS.MethodsA total of 173 samples tested positive for SARS-CoV-2 between March and September 2020 were selected for whole-genome sequencing. Ct values of the samples ranged from 16 to 42. They were collected from 83 healthcare workers and three patients at the Radboudumc, in addition to 64 people living in the area around the hospital and tested by the local health services. For validation purposes, nineteen of the included samples were previously sequenced using Oxford Nanopore Technologies and compared to RC-PCR WGS results. The applicability of RC-PCR WGS in outbreak analysis for public health service and hospitals was tested on six suspected clusters containing samples of healthcare workers and patients with an epidemiological link.FindingsRC-PCR resulted in sequencing data for 146 samples. It showed a genome coverage of up to 98,2% for samples with a maximum Ct value of 32. Comparison to Oxford Nanopore technologies gives a near-perfect agreement on 95% of the samples (18 out of 19). Three out of six clusters with a suspected epidemiological link were fully confirmed, in the others, four healthcare workers were not associated. In the public health service samples, a previously unknown chain of transmission was confirmed.Significance statementSAR-CoV-2 whole-genome sequencing using RC-PCR is a reliable technique and applicable for use in outbreak analysis and surveillance. Its ease of use, high-trough screening capacity and wide applicability makes it a valuable addition or replacement during this ongoing SARS-CoV-2 pandemic.FundingNoneResearch in contextEvidence before this studyAt present whole genome sequencing techniques for SARS-CoV-2 have a large turnover time and are not widely available. Only a few laboratories are currently able to perform large scale SARS-CoV-2 sequencing. This restricts the use of sequencing to aid hospital and community infection prevention.Added value of this studyHere we present clinical and technical data on a novel Whole Genome Sequencing technology, implementing reverse-complement PCR. It is able to obtain high genome coverage of SARS-CoV-2 and confirm and exclude epidemiological links in 173 healthcare workers and patients. The RC-PCR technology simplifies the workflow thereby reducing hands on time. It combines targeted PCR and sequence library construction in a single PCR, which normally takes several steps. Additionally, this technology can be used in concordance with the widely available range of Illumina sequencers.Implications of all the available evidenceRC-PCR whole genome sequencing technology enables rapid and targeted surveillance and response to an ongoing outbreak that has great impact on public health and society. Increased use of sequencing technologies in local laboratories can help prevent increase of SARS-CoV-2 spreading by better understanding modes of transmission.


Author(s):  
Marina Panova ◽  
Henrik Aronsson ◽  
R. Andrew Cameron ◽  
Peter Dahl ◽  
Anna Godhe ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kathy E. Raven ◽  
Sophia T. Girgis ◽  
Asha Akram ◽  
Beth Blane ◽  
Danielle Leek ◽  
...  

AbstractWhole-genome sequencing is likely to become increasingly used by local clinical microbiology laboratories, where sequencing volume is low compared with national reference laboratories. Here, we describe a universal protocol for simultaneous DNA extraction and sequencing of numerous different bacterial species, allowing mixed species sequence runs to meet variable laboratory demand. We assembled test panels representing 20 clinically relevant bacterial species. The DNA extraction process used the QIAamp mini DNA kit, to which different combinations of reagents were added. Thereafter, a common protocol was used for library preparation and sequencing. The addition of lysostaphin, lysozyme or buffer ATL (a tissue lysis buffer) alone did not produce sufficient DNA for library preparation across the species tested. By contrast, lysozyme plus lysostaphin produced sufficient DNA across all 20 species. DNA from 15 of 20 species could be extracted from a 24-h culture plate, while the remainder required 48–72 h. The process demonstrated 100% reproducibility. Sequencing of the resulting DNA was used to recapitulate previous findings for species, outbreak detection, antimicrobial resistance gene detection and capsular type. This single protocol for simultaneous processing and sequencing of multiple bacterial species supports low volume and rapid turnaround time by local clinical microbiology laboratories.


2022 ◽  
Author(s):  
jason.nguyen not provided ◽  
Tracy Lee ◽  
Rebecca Hickman ◽  
Natalie Prystajecky ◽  
John Tyson

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


2020 ◽  
Vol 9 (21) ◽  
Author(s):  
Daniel L. Vera ◽  
Arman Seuylemezian ◽  
Kyle S. Landry ◽  
Ryan Hendrickson

ABSTRACT Whole-genome sequencing and annotation have allowed planetary protection engineers to assess the functional capabilities of microorganisms isolated from spacecraft hardware and associated surfaces. Here, we report draft genomes of six strains isolated from the InSight mission, determined using Oxford Nanopore- and Illumina-based sequencing.


2017 ◽  
Vol 5 (42) ◽  
Author(s):  
S. Wesley Long ◽  
Sarah E. Linson ◽  
Matthew Ojeda Saavedra ◽  
Concepcion Cantu ◽  
James J. Davis ◽  
...  

ABSTRACT In a study of 1,777 Klebsiella strains, we discovered KPN1705, which was distinct from all recognized Klebsiella spp. We closed the genome of strain KPN1705 using a hybrid of Illumina short-read and Oxford Nanopore long-read technologies. For this novel species, we propose the name Klebsiella quasivariicola sp. nov.


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