scholarly journals Multiple Displacement Amplification as a Solution for Low Copy Number Plasmid Sequencing

2021 ◽  
Vol 12 ◽  
Author(s):  
Kuan Yao ◽  
Narjol González-Escalona ◽  
Maria Hoffmann
Keyword(s):  
Antibiotic Resistance ◽  
Single Molecule ◽  
Plasmid Dna ◽  
Copy Number ◽  
Sequence Data ◽  
Multiple Displacement Amplification ◽  
Fast Method ◽  
Alkaline Lysis ◽  
Low Copy Number ◽  
Long Read

Plasmids play a major role in bacterial adaptation to environmental stress and often contribute to antibiotic resistance and disease virulence. Although the complete sequence of each plasmid is essential for studying plasmid biology, most antibiotic resistance and virulence plasmids in Salmonella are present only in a low copy number, making extraction and sequencing difficult. Long read sequencing technologies require higher concentrations of DNA to provide optimal results. To resolve this problem, we assessed the sufficiency of multiple displacement amplification (MDA) for replicating Salmonella plasmid DNA to a satisfactory concentration for accurate sequencing and multiplexing. Nine Salmonella enterica isolates, representing nine different serovars carrying plasmids for which sequence data are already available at NCBI, were cultured and their plasmids isolated using an alkaline lysis extraction protocol. We then used the Phi29 polymerase to perform MDA, thereby obtaining enough plasmid DNA for long read sequencing. These amplified plasmids were multiplexed and sequenced on one single molecule, real-time (SMRT) cell with the Pacific Biosciences (Pacbio) Sequel sequencer. We were able to close all Salmonella plasmids (sizes ranged from 38 to 166 Kb) with sequencing coverage from 24 to 2,582X. This protocol, consisting of plasmid isolation, MDA, and multiplex sequencing, is an effective and fast method for closing high-molecular weight and low-copy-number plasmids. This high throughput protocol reduces the time and cost of plasmid closure.

scholarly journals A draft genome sequence for the Ixodes scapularis cell line, ISE6

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 297 ◽  
Author(s):  
Jason R. Miller ◽  
Sergey Koren ◽  
Kari A. Dilley ◽  
Derek M. Harkins ◽  
Timothy B. Stockwell ◽  
...  
Keyword(s):  
Cell Line ◽  
Genome Sequence ◽  
Single Molecule ◽  
Reference Genome ◽  
Sequence Data ◽  
Ixodes Scapularis ◽  
Draft Genome ◽  
Clinical Samples ◽  
Draft Assembly ◽  
Long Read

Background:The tick cell line ISE6, derived fromIxodes scapularis, is commonly used for amplification and detection of arboviruses in environmental or clinical samples.Methods:To assist with sequence-based assays, we sequenced the ISE6 genome with single-molecule, long-read technology.Results:The draft assembly appears near complete based on gene content analysis, though it appears to lack some instances of repeats in this highly repetitive genome. The assembly appears to have separated the haplotypes at many loci. DNA short read pairs, used for validation only, mapped to the cell line assembly at a higher rate than they mapped to theIxodes scapularisreference genome sequence.Conclusions:The assembly could be useful for filtering host genome sequence from sequence data obtained from cells infected with pathogens.

scholarly journals Replication of a low-copy-number plasmid by a plasmid DNA-membrane complex extracted from minicells of Escherichia coli.

1982 ◽  
Vol 150 (3) ◽  
pp. 1234-1243 ◽  
Author(s):  
W Firshein ◽  
P Strumph ◽  
P Benjamin ◽  
K Burnstein ◽  
J Kornacki
Keyword(s):  
Escherichia Coli ◽  
Plasmid Dna ◽  
Copy Number ◽  
Membrane Complex ◽  
Copy Number Plasmid ◽  
Low Copy Number

scholarly journals Improved assembly and variant detection of a haploid human genome using single-molecule, high-fidelity long reads

2019 ◽  
Author(s):  
Mitchell R. Vollger ◽  
Glennis A. Logsdon ◽  
Peter A. Audano ◽  
Arvis Sulovari ◽  
David Porubsky ◽  
...  
Keyword(s):  
Human Genome ◽  
Single Molecule ◽  
Tandem Repeats ◽  
De Novo ◽  
Sequence Data ◽  
Gene Annotation ◽  
Hydatidiform Mole ◽  
High Fidelity ◽  
Human Genomes ◽  
Long Read

AbstractThe sequence and assembly of human genomes using long-read sequencing technologies has revolutionized our understanding of structural variation and genome organization. We compared the accuracy, continuity, and gene annotation of genome assemblies generated from either high-fidelity (HiFi) or continuous long-read (CLR) datasets from the same complete hydatidiform mole human genome. We find that the HiFi sequence data assemble an additional 10% of duplicated regions and more accurately represent the structure of tandem repeats, as validated with orthogonal analyses. As a result, an additional 5 Mbp of pericentromeric sequences are recovered in the HiFi assembly, resulting in a 2.5-fold increase in the NG50 within 1 Mbp of the centromere (HiFi 480.6 kbp, CLR 191.5 kbp). Additionally, the HiFi genome assembly was generated in significantly less time with fewer computational resources than the CLR assembly. Although the HiFi assembly has significantly improved continuity and accuracy in many complex regions of the genome, it still falls short of the assembly of centromeric DNA and the largest regions of segmental duplication using existing assemblers. Despite these shortcomings, our results suggest that HiFi may be the most effective stand-alone technology for de novo assembly of human genomes.

scholarly journals Addressing the Requirements of High-Sensitivity Single-Molecule Imaging of Low-Copy-Number Proteins in Bacteria

ChemPhysChem ◽  
2016 ◽  
Vol 17 (10) ◽  
pp. 1435-1440 ◽  
Author(s):  
Hannah H. Tuson ◽  
Alisa Aliaj ◽  
Eileen R. Brandes ◽  
Lyle A. Simmons ◽  
Julie S. Biteen
Keyword(s):  
Single Molecule ◽  
Copy Number ◽  
High Sensitivity ◽  
Single Molecule Imaging ◽  
Low Copy Number

scholarly journals Facile Recovery of Individual High-Molecular-Weight, Low-Copy-Number Natural Plasmids for Genomic Sequencing

2006 ◽  
Vol 72 (7) ◽  
pp. 4899-4906 ◽  
Author(s):  
Laura E. Williams ◽  
Chris Detter ◽  
Kerrie Barry ◽  
Alla Lapidus ◽  
Anne O. Summers
Keyword(s):  
Plasmid Dna ◽  
Copy Number ◽  
Mobile Genetic Element ◽  
Large Plasmid ◽  
Bacterial Artificial Chromosomes ◽  
High Coverage ◽  
Artificial Chromosomes ◽  
Gram Positive Bacteria ◽  
Low Copy Number ◽  
Plasmid Isolation

ABSTRACT Sequencing of the large (>50 kb), low-copy-number (<5 per cell) plasmids that mediate horizontal gene transfer has been hindered by the difficulty and expense of isolating DNA from individual plasmids of this class. We report here that a kit method previously devised for purification of bacterial artificial chromosomes (BACs) can be adapted for effective preparation of individual plasmids up to 220 kb from wild gram-negative and gram-positive bacteria. Individual plasmid DNA recovered from less than 10 ml of Escherichia coli, Staphylococcus, and Corynebacterium cultures was of sufficient quantity and quality for construction of high-coverage libraries, as shown by sequencing five native plasmids ranging in size from 30 kb to 94 kb. We also report recommendations for vector screening to optimize plasmid sequence assembly, preliminary annotation of novel plasmid genomes, and insights on mobile genetic element biology derived from these sequences. Adaptation of this BAC method for large plasmid isolation removes one major technical hurdle to expanding our knowledge of the natural plasmid gene pool.

scholarly journals Genomic Surveillance for Antimicrobial Resistance inMannheimia haemolyticaUsing Nanopore Single Molecule Sequencing Technology

2018 ◽  
Author(s):  
Alexander Lim ◽  
Bryan Naidenov ◽  
Haley Bates ◽  
Karyn Willyerd ◽  
Timothy Snider ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Single Molecule ◽  
Resistant Strain ◽  
De Novo ◽  
Gene Annotation ◽  
Cost Effective ◽  
Multidrug Resistant ◽  
Oxford Nanopore ◽  
Long Read

AbstractDisruptive innovations in long-range, cost-effective direct template nucleic acid sequencing are transforming clinical and diagnostic medicine. A multidrug resistant strain and a pan-susceptible strain ofMannheimia haemolytica, isolated from pneumonic bovine lung samples, were respectively sequenced at 146x and 111x coverage with Oxford Nanopore Technologies MinION.De novoassembly produced a complete genome for the non-resistant strain and a nearly complete assembly for the drug resistant strain. Functional annotation using RAST (Rapid Annotations using Subsystems Technology), CARD (Comprehensive Antibiotic Resistance Database) and ResFinder databases identified genes conferring resistance to different classes of antibiotics including beta lactams, tetracyclines, lincosamides, phenicols, aminoglycosides, sulfonamides and macrolides. Antibiotic resistance phenotypes of theM. haemolyticastrains were confirmed with minimum inhibitory concentration (MIC) assays. The sequencing capacity of highly portable MinION devices was verified by sub-sampling sequencing reads; potential for antimicrobial resistance determined by identification of resistance genes in the draft assemblies with as little as 5,437 MinION reads corresponded to all classes of MIC assays. The resulting quality assemblies and AMR gene annotation highlight efficiency of ultra long-read, whole-genome sequencing (WGS) as a valuable tool in diagnostic veterinary medicine.

scholarly journals GtTR: Bayesian estimation of absolute tandem repeat copy number using sequence capture and high throughput sequencing

2018 ◽  
Author(s):  
Devika Ganesamoorthy ◽  
Minh Duc Cao ◽  
Tania Duarte ◽  
Wenhan Chen ◽  
Lachlan Coin
Keyword(s):  
High Throughput ◽  
Tandem Repeat ◽  
Copy Number ◽  
Tandem Repeats ◽  
High Throughput Sequencing ◽  
Sequence Data ◽  
Complex Diseases ◽  
Sequencing Analysis ◽  
Reference Dataset ◽  
Long Read

ABSTRACTBackgroundTandem repeats comprise significant proportion of the human genome including coding and regulatory regions. They are highly prone to repeat number variation and nucleotide mutation due to their repetitive and unstable nature, making them a major source of genomic variation between individuals. Despite recent advances in high throughput sequencing, analysis of tandem repeats in the context of complex diseases is still hindered by technical limitations.MethodsWe report a novel targeted sequencing approach, which allows simultaneous analysis of hundreds of repeats. We developed a Bayesian algorithm, namely – GtTR - which combines information from a reference long-read dataset with a short read counting approach to genotype tandem repeats at population scale. PCR sizing analysis was used for validation.ResultsWe used a PacBio long-read sequenced sample to generate a reference tandem repeat genotype dataset with on average 13% absolute deviation from PCR sizing results. Using this reference dataset GtTR generated estimates of VNTR copy number with accuracy within 95% high posterior density (HPD) intervals of 68% and 83% for capture sequence data and 200X WGS data respectively, improving to 87% and 94% with use of a PCR reference. We show that the genotype resolution increases as a function of depth, such that the median 95% HPD interval lies within 25%, 14%, 12% and 8% of the its midpoint copy number value for 30X, 200X WGS, 395X and 800X capture sequence data respectively. We validated nine targets by PCR sizing analysis and genotype estimates from sequencing results correlated well with PCR results.ConclusionsThe novel genotyping approach described here presents a new cost-effective method to explore previously unrecognized class of repeat variation in GWAS studies of complex diseases at the population level. Further improvements in accuracy can be obtained by improving accuracy of the reference dataset.

scholarly journals Extensive Gene Amplification as a Mechanism for Piperacillin-Tazobactam Resistance in Escherichia coli

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Lisa M. Schechter ◽  
David P. Creely ◽  
Cherilyn D. Garner ◽  
Dee Shortridge ◽  
Hoan Nguyen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Copy Number ◽  
Sequence Data ◽  
Gene Dosage ◽  
Clinical Isolates ◽  
Whole Genome Sequence ◽  
Content Type ◽  
E Coli ◽  
Protein Levels

ABSTRACT Although the TEM-1 β-lactamase (Bla TEM-1 ) hydrolyzes penicillins and narrow-spectrum cephalosporins, organisms expressing this enzyme are typically susceptible to β-lactam/β-lactamase inhibitor combinations such as piperacillin-tazobactam (TZP). However, our previous work led to the discovery of 28 clinical isolates of Escherichia coli resistant to TZP that contained only bla TEM-1 . One of these isolates, E. coli 907355, was investigated further in this study. E. coli 907355 exhibited significantly higher β-lactamase activity and Bla TEM-1 protein levels when grown in the presence of subinhibitory concentrations of TZP. A corresponding TZP-dependent increase in bla TEM-1 copy number was also observed, with as many as 113 copies of the gene detected per cell. These results suggest that TZP treatment promotes an increase in bla TEM-1 gene dosage, allowing Bla TEM-1 to reach high enough levels to overcome inactivation by the available tazobactam in the culture. To better understand the nature of the bla TEM-1 copy number proliferation, whole-genome sequence (WGS) analysis was performed on E. coli 907355 in the absence and presence of TZP. The WGS data revealed that the bla TEM-1 gene is located in a 10-kb genomic resistance module (GRM) that contains multiple resistance genes and mobile genetic elements. The GRM was found to be tandemly repeated at least 5 times within a p1ESCUM/p1ECUMN-like plasmid when bacteria were grown in the presence of TZP. IMPORTANCE Understanding how bacteria acquire resistance to antibiotics is essential for treating infected patients effectively, as well as preventing the spread of resistant organisms. In this study, a clinical isolate of E. coli was identified that dedicated more than 15% of its genome toward tandem amplification of a ~10-kb resistance module, allowing it to escape antibiotic-mediated killing. Our research is significant in that it provides one possible explanation for clinical isolates that exhibit discordant behavior when tested for antibiotic resistance by different phenotypic methods. Our research also shows that GRM amplification is difficult to detect by short-read WGS technologies. Analysis of raw long-read sequence data was required to confirm GRM amplification as a mechanism of antibiotic resistance.

scholarly journals Adaptive archaic introgression of copy number variants and the discovery of previously unknown human genes

Science ◽  
2019 ◽  
Vol 366 (6463) ◽  
pp. eaax2083 ◽  
Author(s):  
PingHsun Hsieh ◽  
Mitchell R. Vollger ◽  
Vy Dang ◽  
David Porubsky ◽  
Carl Baker ◽  
...  
Keyword(s):  
Copy Number ◽  
Large Scale ◽  
Sequence Data ◽  
Local Population ◽  
Copy Number Variants ◽  
Human Populations ◽  
Single Nucleotide Variants ◽  
Human Genes ◽  
Long Read ◽  
Archaic Introgression

Copy number variants (CNVs) are subject to stronger selective pressure than single-nucleotide variants, but their roles in archaic introgression and adaptation have not been systematically investigated. We show that stratified CNVs are significantly associated with signatures of positive selection in Melanesians and provide evidence for adaptive introgression of large CNVs at chromosomes 16p11.2 and 8p21.3 from Denisovans and Neanderthals, respectively. Using long-read sequence data, we reconstruct the structure and complex evolutionary history of these polymorphisms and show that both encode positively selected genes absent from most human populations. Our results collectively suggest that large CNVs originating in archaic hominins and introgressed into modern humans have played an important role in local population adaptation and represent an insufficiently studied source of large-scale genetic variation.

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