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Wranne MS, Karami N, Kk S, Jaén-Luchoro D, Yazdanshenas S, Lin YL, Kabbinale A, Flach CF, Westerlund F, Åhrén C. Comparison of CTX-M encoding plasmids present during the early phase of the ESBL pandemic in western Sweden. Sci Rep 2024; 14:11880. [PMID: 38789462 PMCID: PMC11126669 DOI: 10.1038/s41598-024-62663-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 05/20/2024] [Indexed: 05/26/2024] Open
Abstract
Plasmids encoding blaCTX-M genes have greatly shaped the evolution of E. coli producing extended-spectrum beta-lactamases (ESBL-E. coli) and adds to the global threat of multiresistant bacteria by promoting horizontal gene transfer (HGT). Here we screened the similarity of 47 blaCTX-M -encoding plasmids, from 45 epidemiologically unrelated and disperse ESBL-E. coli strains, isolated during the early phase (2009-2014) of the ESBL pandemic in western Sweden. Using optical DNA mapping (ODM), both similar and rare plasmids were identified. As many as 57% of the plasmids formed five ODM-plasmid groups of at least three similar plasmids per group. The most prevalent type (28%, IncIl, pMLST37) encoded blaCTX-M-15 (n = 10), blaCTX-M-3 (n = 2) or blaCTX-M-55 (n = 1). It was found in isolates of various sequence types (STs), including ST131. This could indicate ongoing local HGT as whole-genome sequencing only revealed similarities with a rarely reported, IncIl plasmid. The second most prevalent type (IncFII/FIA/FIB, F1:A2:B20) harboring blaCTX-M-27, was detected in ST131-C1-M27 isolates, and was similar to plasmids previously reported for this subclade. The results also highlight the need for local surveillance of plasmids and the importance of temporospatial epidemiological links so that detection of a prevalent plasmid is not overestimated as a potential plasmid transmission event in outbreak investigations.
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Affiliation(s)
- Moa S Wranne
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research in Gothenburg (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Nahid Karami
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Guldhedsgatan 10A, 413 46, Gothenburg, Sweden.
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, Gothenburg, Sweden.
- Centre for Antibiotic Resistance Research in Gothenburg (CARe), University of Gothenburg, Gothenburg, Sweden.
| | - Sriram Kk
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Daniel Jaén-Luchoro
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Guldhedsgatan 10A, 413 46, Gothenburg, Sweden
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research in Gothenburg (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Shora Yazdanshenas
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, Gothenburg, Sweden
| | - Yii-Lih Lin
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research in Gothenburg (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Arpitha Kabbinale
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Carl-Fredrik Flach
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Guldhedsgatan 10A, 413 46, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research in Gothenburg (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Fredrik Westerlund
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research in Gothenburg (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Christina Åhrén
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Guldhedsgatan 10A, 413 46, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research in Gothenburg (CARe), University of Gothenburg, Gothenburg, Sweden
- Swedish Strategic Program Against Antimicrobial Resistance (Strama), Region Västra Götaland, Gothenburg, Sweden
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2
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Kk S, Persson F, Fritzsche J, Beech JP, Tegenfeldt JO, Westerlund F. Fluorescence Microscopy of Nanochannel-Confined DNA. Methods Mol Biol 2024; 2694:175-202. [PMID: 37824005 DOI: 10.1007/978-1-0716-3377-9_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Stretching of DNA in nanoscale confinement allows for several important studies. The genetic contents of the DNA can be visualized on the single DNA molecule level, and the polymer physics of confined DNA and also DNA/protein and other DNA/DNA-binding molecule interactions can be explored. This chapter describes the basic steps to fabricate the nanostructures, perform the experiments, and analyze the data.
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Affiliation(s)
- Sriram Kk
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | | | - Joachim Fritzsche
- Department of Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Jason P Beech
- NanoLund and Department of Physics, Lund University, Lund, Sweden
| | | | - Fredrik Westerlund
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden.
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3
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KK S, Wranne MS, Sewunet T, Ekedahl E, Coorens M, Tangkoskul T, Thamlikitkul V, Giske CG, Westerlund F. Identification and characterization of plasmids carrying the mobile colistin resistance gene mcr-1 using optical DNA mapping. JAC Antimicrob Resist 2023; 5:dlad004. [PMID: 36743530 PMCID: PMC9891347 DOI: 10.1093/jacamr/dlad004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 01/05/2023] [Indexed: 02/04/2023] Open
Abstract
Objectives Colistin is a last-resort antibiotic, but there has been a rapid increase in colistin resistance, threatening its use in the treatment of infections with carbapenem-resistant Enterobacterales (CRE). Plasmid-mediated colistin resistance, in particular the mcr-1 gene, has been identified and WGS is the go-to method in identifying plasmids carrying mcr-1 genes. The goal of this study is to demonstrate the use of optical DNA mapping (ODM), a fast, efficient and amplification-free technique, to characterize plasmids carrying mcr-1. Methods ODM is a single-molecule technique, which we have demonstrated can be used for identifying plasmids harbouring antibiotic resistance genes. We here applied the technique to plasmids isolated from 12 clinical Enterobacterales isolates from patients at a major hospital in Thailand and verified our results using Nanopore long-read sequencing. Results We successfully identified plasmids encoding the mcr-1 gene and, for the first time, demonstrated the ability of ODM to identify resistance gene sites in small (∼30 kb) plasmids. We further identified bla CTX-M genes in different plasmids than the ones encoding mcr-1 in three of the isolates studied. Finally, we propose a cut-and-stretch assay, based on similar principles, but performed using surface-functionalized cover slips for DNA immobilization and an inexpensive microscope with basic functionalities, to identify the mcr-1 gene in a plasmid sample. Conclusions Both ODM and the cut-and-stretch assay developed could be very useful in identifying plasmids encoding antibiotic resistance in hospitals and healthcare facilities. The cut-and-stretch assay is particularly useful in low- and middle-income countries, where existing techniques are limited.
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Affiliation(s)
- Sriram KK
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Moa S Wranne
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Tsegaye Sewunet
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institute, Stockholm, Sweden
| | - Elina Ekedahl
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Maarten Coorens
- Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden
| | | | | | - Christian G Giske
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institute, Stockholm, Sweden,Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden
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Kim YT, Oh H, Seo MJ, Lee DH, Shin J, Bong S, Heo S, Hapsari ND, Jo K. 21 Fluorescent Protein-Based DNA Staining Dyes. Molecules 2022; 27:5248. [PMID: 36014487 PMCID: PMC9412447 DOI: 10.3390/molecules27165248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/10/2022] [Accepted: 08/12/2022] [Indexed: 11/22/2022] Open
Abstract
Fluorescent protein-DNA-binding peptides or proteins (FP-DBP) are a powerful means to stain and visualize large DNA molecules on a fluorescence microscope. Here, we constructed 21 kinds of FP-DBPs using various colors of fluorescent proteins and two DNA-binding motifs. From the database of fluorescent proteins (FPbase.org), we chose bright FPs, such as RRvT, tdTomato, mNeonGreen, mClover3, YPet, and mScarlet, which are four to eight times brighter than original wild-type GFP. Additionally, we chose other FPs, such as mOrange2, Emerald, mTurquoise2, mStrawberry, and mCherry, for variations in emitting wavelengths. For DNA-binding motifs, we used HMG (high mobility group) as an 11-mer peptide or a 36 kDa tTALE (truncated transcription activator-like effector). Using 21 FP-DBPs, we attempted to stain DNA molecules and then analyzed fluorescence intensities. Most FP-DBPs successfully visualized DNA molecules. Even with the same DNA-binding motif, the order of FP and DBP affected DNA staining in terms of brightness and DNA stretching. The DNA staining pattern by FP-DBPs was also affected by the FP types. The data from 21 FP-DBPs provided a guideline to develop novel DNA-binding fluorescent proteins.
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Affiliation(s)
- Yurie Tehee Kim
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapogu, Seoul 04107, Korea
| | - Hyesoo Oh
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapogu, Seoul 04107, Korea
| | - Myung Jun Seo
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapogu, Seoul 04107, Korea
| | - Dong Hyeun Lee
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapogu, Seoul 04107, Korea
| | - Jieun Shin
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapogu, Seoul 04107, Korea
| | - Serang Bong
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapogu, Seoul 04107, Korea
| | - Sujeong Heo
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapogu, Seoul 04107, Korea
| | - Natalia Diyah Hapsari
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapogu, Seoul 04107, Korea
- Chemistry Education Program, Department of Mathematics and Science Education, Sanata Dharma University, Yogyakarta 55282, Indonesia
| | - Kyubong Jo
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapogu, Seoul 04107, Korea
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5
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Fernandez-Cuesta I, Llobera A, Ramos-Payán M. Optofluidic systems enabling detection in real samples: A review. Anal Chim Acta 2022; 1192:339307. [DOI: 10.1016/j.aca.2021.339307] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 11/16/2021] [Accepted: 11/17/2021] [Indexed: 12/20/2022]
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Backes N, Phillips GJ. Repurposing CRISPR-Cas Systems as Genetic Tools for the Enterobacteriales. EcoSal Plus 2021; 9:eESP00062020. [PMID: 34125584 PMCID: PMC11163844 DOI: 10.1128/ecosalplus.esp-0006-2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 03/22/2021] [Indexed: 11/20/2022]
Abstract
Over the last decade, the study of CRISPR-Cas systems has progressed from a newly discovered bacterial defense mechanism to a diverse suite of genetic tools that have been applied across all domains of life. While the initial applications of CRISPR-Cas technology fulfilled a need to more precisely edit eukaryotic genomes, creative "repurposing" of this adaptive immune system has led to new approaches for genetic analysis of microorganisms, including improved gene editing, conditional gene regulation, plasmid curing and manipulation, and other novel uses. The main objective of this review is to describe the development and current state-of-the-art use of CRISPR-Cas techniques specifically as it is applied to members of the Enterobacteriales. While many of the applications covered have been initially developed in Escherichia coli, we also highlight the potential, along with the limitations, of this technology for expanding the availability of genetic tools in less-well-characterized non-model species, including bacterial pathogens.
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Affiliation(s)
- Nicholas Backes
- Department of Veterinary Microbiology, Iowa State University, Ames, Iowa, USA
| | - Gregory J. Phillips
- Department of Veterinary Microbiology, Iowa State University, Ames, Iowa, USA
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7
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Sriram KK, Ekedahl E, Hoang NTB, Sewunet T, Berglund B, Lundberg L, Nematzadeh S, Nilsson M, Nilsson LE, Le NK, Tran DM, Hanberger H, Olson L, Larsson M, Giske CG, Westerlund F. High diversity of bla NDM-1-encoding plasmids in Klebsiella pneumoniae isolated from neonates in a Vietnamese hospital. Int J Antimicrob Agents 2021; 59:106496. [PMID: 34921976 DOI: 10.1016/j.ijantimicag.2021.106496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 09/08/2021] [Accepted: 12/01/2021] [Indexed: 11/24/2022]
Abstract
OBJECTIVES The carbapenemase-encoding gene blaNDM-1 has been reported in Vietnam over the last ten years, and blaNDM-producing Enterobacteriaceae are now silently and rapidly spreading. A key factor behind dissemination of blaNDM-1 are plasmids, mobile genetic elements that commonly carry antibiotic resistance genes and spread via conjugation. Here, we characterized the diversity of blaNDM-1-encoding plasmids from neonates at a large Vietnamese hospital . METHODS 18 fecal Klebsiella pneumoniae and Klebsiella quasipneumoniae isolates collected from 16 neonates at a large pediatric hospital in Vietnam were studied with optical DNA mapping (ODM) and next-generation sequencing (NGS). We identified the plasmid(s) carrying blaNDM-1 by combining ODM with Cas9 restriction. By comparing the plasmids between isolates, we could investigate if the same plasmid was present in different patients. RESULTS Although the same plasmid was found among some isolates, ODM confirmed that there were at least 10 different plasmids encoding blaNDM-1 among the 18 isolates collected from 16 neonates, suggesting a large plasmid diversity. The ODM results were in large agreement with the NGS data. Interestingly, some isolates had two distinct plasmids encoding blaNDM-1, which could be readily detected with ODM. Thus far, the coexistence of different plasmids carrying the same carbapenem resistance gene in an isolate encoding blaNDM-1 has rarely been reported, likely due to limitations in existing plasmid characterization techniques. CONCLUSIONS Our results show that the plasmids encoding blaNDM-1 in this cohort were very diverse, suggesting a similar picture in the Vietnamese society. The study also highlights important aspects of the usefulness of ODM for plasmid analysis.
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Affiliation(s)
- K K Sriram
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Elina Ekedahl
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Ngoc Thi Bich Hoang
- Department of Microbiology, Vietnam National Children's Hospital, Hanoi, Vietnam
| | - Tsegaye Sewunet
- Division of Clinical Microbiology, Department of Laboratory medicine, Karolinska Institutet, Stockholm, Sweden
| | - Björn Berglund
- Department of Biomedical and Clinical Sciences, Faculty of medicine, Linköping University, Linköping, Sweden
| | - Ludwig Lundberg
- Department of Biomedical and Clinical Sciences, Faculty of medicine, Linköping University, Linköping, Sweden; Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Shoeib Nematzadeh
- Division of Clinical Microbiology, Department of Laboratory medicine, Karolinska Institutet, Stockholm, Sweden
| | - Maud Nilsson
- Department of Biomedical and Clinical Sciences, Faculty of medicine, Linköping University, Linköping, Sweden
| | - Lennart E Nilsson
- Department of Biomedical and Clinical Sciences, Faculty of medicine, Linköping University, Linköping, Sweden
| | - Ngai Kien Le
- Department of Surgery, Vietnam National Children's Hospital, Hanoi, Vietnam
| | - Dien Minh Tran
- Department of Infection Control, Vietnam National Children's Hospital, Hanoi, Vietnam
| | - Håkan Hanberger
- Department of Biomedical and Clinical Sciences, Faculty of medicine, Linköping University, Linköping, Sweden
| | - Linus Olson
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden; Department of Women and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Mattias Larsson
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden
| | - Christian G Giske
- Division of Clinical Microbiology, Department of Laboratory medicine, Karolinska Institutet, Stockholm, Sweden; Clinical microbiology, Karolinska University Hospital, Stockholm, Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
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8
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Wu Y, Battalapalli D, Hakeem MJ, Selamneni V, Zhang P, Draz MS, Ruan Z. Engineered CRISPR-Cas systems for the detection and control of antibiotic-resistant infections. J Nanobiotechnology 2021; 19:401. [PMID: 34863214 PMCID: PMC8642896 DOI: 10.1186/s12951-021-01132-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 11/11/2021] [Indexed: 12/13/2022] Open
Abstract
Antibiotic resistance is spreading rapidly around the world and seriously impeding efforts to control microbial infections. Although nucleic acid testing is widely deployed for the detection of antibiotic resistant bacteria, the current techniques-mainly based on polymerase chain reaction (PCR)-are time-consuming and laborious. There is an urgent need to develop new strategies to control bacterial infections and the spread of antimicrobial resistance (AMR). The CRISPR-Cas system is an adaptive immune system found in many prokaryotes that presents attractive opportunities to target and edit nucleic acids with high precision and reliability. Engineered CRISPR-Cas systems are reported to effectively kill bacteria or even revert bacterial resistance to antibiotics (resensitizing bacterial cells to antibiotics). Strategies for combating antimicrobial resistance using CRISPR (i.e., Cas9, Cas12, Cas13, and Cas14) can be of great significance in detecting bacteria and their resistance to antibiotics. This review discusses the structures, mechanisms, and detection methods of CRISPR-Cas systems and how these systems can be engineered for the rapid and reliable detection of bacteria using various approaches, with a particular focus on nanoparticles. In addition, we summarize the most recent advances in applying the CRISPR-Cas system for virulence modulation of bacterial infections and combating antimicrobial resistance.
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Affiliation(s)
- Yuye Wu
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | | | - Mohammed J Hakeem
- Department of Food Science and Human Nutrition, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Venkatarao Selamneni
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Pengfei Zhang
- Department of Central Laboratory, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China.
| | - Mohamed S Draz
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
| | - Zhi Ruan
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.
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Torstensson E, Goyal G, Johnning A, Westerlund F, Ambjörnsson T. Combining dense and sparse labeling in optical DNA mapping. PLoS One 2021; 16:e0260489. [PMID: 34843574 PMCID: PMC8629184 DOI: 10.1371/journal.pone.0260489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 11/10/2021] [Indexed: 11/19/2022] Open
Abstract
Optical DNA mapping (ODM) is based on fluorescent labeling, stretching and imaging of single DNA molecules to obtain sequence-specific fluorescence profiles, DNA barcodes. These barcodes can be mapped to theoretical counterparts obtained from DNA reference sequences, which in turn allow for DNA identification in complex samples and for detecting structural changes in individual DNA molecules. There are several types of DNA labeling schemes for ODM and for each labeling type one or several types of match scoring methods are used. By combining the information from multiple labeling schemes one can potentially improve mapping confidence; however, combining match scores from different labeling assays has not been implemented yet. In this study, we introduce two theoretical methods for dealing with analysis of DNA molecules with multiple label types. In our first method, we convert the alignment scores, given as output from the different assays, into p-values using carefully crafted null models. We then combine the p-values for different label types using standard methods to obtain a combined match score and an associated combined p-value. In the second method, we use a block bootstrap approach to check for the uniqueness of a match to a database for all barcodes matching with a combined p-value below a predefined threshold. For obtaining experimental dual-labeled DNA barcodes, we introduce a novel assay where we cut plasmid DNA molecules from bacteria with restriction enzymes and the cut sites serve as sequence-specific markers, which together with barcodes obtained using the established competitive binding labeling method, form a dual-labeled barcode. All experimental data in this study originates from this assay, but we point out that our theoretical framework can be used to combine data from all kinds of available optical DNA mapping assays. We test our multiple labeling frameworks on barcodes from two different plasmids and synthetically generated barcodes (combined competitive-binding- and nick-labeling). It is demonstrated that by simultaneously using the information from all label types, we can substantially increase the significance when we match experimental barcodes to a database consisting of theoretical barcodes for all sequenced plasmids.
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Affiliation(s)
- Erik Torstensson
- Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Gaurav Goyal
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Anna Johnning
- Department of Mathematical Sciences, Chalmers University of Technology and the University of Gothenburg, Gothenburg, Sweden
- Systems and Data Analysis, Fraunhofer-Chalmers Centre, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research, CARe, University of Gothenburg, Gothenburg, Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Tobias Ambjörnsson
- Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
- * E-mail:
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10
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Dvirnas A, Stewart C, Müller V, Bikkarolla SK, Frykholm K, Sandegren L, Kristiansson E, Westerlund F, Ambjörnsson T. Detection of structural variations in densely-labelled optical DNA barcodes: A hidden Markov model approach. PLoS One 2021; 16:e0259670. [PMID: 34739528 PMCID: PMC8570516 DOI: 10.1371/journal.pone.0259670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 10/22/2021] [Indexed: 11/19/2022] Open
Abstract
Large-scale genomic alterations play an important role in disease, gene expression, and chromosome evolution. Optical DNA mapping (ODM), commonly categorized into sparsely-labelled ODM and densely-labelled ODM, provides sequence-specific continuous intensity profiles (DNA barcodes) along single DNA molecules and is a technique well-suited for detecting such alterations. For sparsely-labelled barcodes, the possibility to detect large genomic alterations has been investigated extensively, while densely-labelled barcodes have not received as much attention. In this work, we introduce HMMSV, a hidden Markov model (HMM) based algorithm for detecting structural variations (SVs) directly in densely-labelled barcodes without access to sequence information. We evaluate our approach using simulated data-sets with 5 different types of SVs, and combinations thereof, and demonstrate that the method reaches a true positive rate greater than 80% for randomly generated barcodes with single variations of size 25 kilobases (kb). Increasing the length of the SV further leads to larger true positive rates. For a real data-set with experimental barcodes on bacterial plasmids, we successfully detect matching barcode pairs and SVs without any particular assumption of the types of SVs present. Instead, our method effectively goes through all possible combinations of SVs. Since ODM works on length scales typically not reachable with other techniques, our methodology is a promising tool for identifying arbitrary combinations of genomic alterations.
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Affiliation(s)
- Albertas Dvirnas
- Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Callum Stewart
- Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Vilhelm Müller
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Santosh Kumar Bikkarolla
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Karolin Frykholm
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Linus Sandegren
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Erik Kristiansson
- Department of Mathematical Sciences, Chalmers University of Technology and the University of Gothenburg, Gothenburg, Sweden
| | - Fredrik Westerlund
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Tobias Ambjörnsson
- Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
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11
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KK S, Lin YL, Sewunet T, Wrande M, Sandegren L, Giske CG, Westerlund F. A Parallelized Nanofluidic Device for High-Throughput Optical DNA Mapping of Bacterial Plasmids. MICROMACHINES 2021; 12:1234. [PMID: 34683285 PMCID: PMC8538381 DOI: 10.3390/mi12101234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/05/2021] [Accepted: 10/08/2021] [Indexed: 12/03/2022]
Abstract
Optical DNA mapping (ODM) has developed into an important technique for DNA analysis, where single DNA molecules are sequence-specifically labeled and stretched, for example, in nanofluidic channels. We have developed an ODM assay to analyze bacterial plasmids-circular extrachromosomal DNA that often carry genes that make bacteria resistant to antibiotics. As for most techniques, the next important step is to increase throughput and automation. In this work, we designed and fabricated a nanofluidic device that, together with a simple automation routine, allows parallel analysis of up to 10 samples at the same time. Using plasmids encoding extended-spectrum beta-lactamases (ESBL), isolated from Escherichiacoli and Klebsiellapneumoniae, we demonstrate the multiplexing capabilities of the device when it comes to both many samples in parallel and different resistance genes. As a final example, we combined the device with a novel protocol for rapid cultivation and extraction of plasmids from fecal samples collected from patients. This combined protocol will make it possible to analyze many patient samples in one device already on the day the sample is collected, which is an important step forward for the ODM analysis of plasmids in clinical diagnostics.
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Affiliation(s)
- Sriram KK
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden; (S.K.); (Y.-L.L.)
| | - Yii-Lih Lin
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden; (S.K.); (Y.-L.L.)
| | - Tsegaye Sewunet
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institute, 141 52 Stockholm, Sweden; (T.S.); (C.G.G.)
| | - Marie Wrande
- Department of Medical Biochemistry and Microbiology, Uppsala University, 752 37 Uppsala, Sweden; (M.W.); (L.S.)
| | - Linus Sandegren
- Department of Medical Biochemistry and Microbiology, Uppsala University, 752 37 Uppsala, Sweden; (M.W.); (L.S.)
| | - Christian G. Giske
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institute, 141 52 Stockholm, Sweden; (T.S.); (C.G.G.)
- Clinical Microbiology, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Fredrik Westerlund
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden; (S.K.); (Y.-L.L.)
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12
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KK S, Sewunet T, Wangchinda W, Tangkoskul T, Thamlikitkul V, Giske CG, Westerlund F. Optical DNA Mapping of Plasmids Reveals Clonal Spread of Carbapenem-Resistant Klebsiella pneumoniae in a Large Thai Hospital. Antibiotics (Basel) 2021; 10:antibiotics10091029. [PMID: 34572611 PMCID: PMC8466775 DOI: 10.3390/antibiotics10091029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/16/2021] [Accepted: 08/20/2021] [Indexed: 12/26/2022] Open
Abstract
Carbapenem-resistant Klebsiella pneumoniae (CR-KP) in patients admitted to hospitals pose a great challenge to treatment. The genes causing resistance to carbapenems are mostly found in plasmids, mobile genetic elements that can spread easily to other bacterial strains, thus exacerbating the problem. Here, we studied 27 CR-KP isolates collected from different types of samples from 16 patients admitted to the medical ward at Siriraj Hospital in Bangkok, Thailand, using next generation sequencing (NGS) and optical DNA mapping (ODM). The majority of the isolates belonged to sequence type (ST) 16 and are described in detail herein. Using ODM, we identified the plasmid carrying the blaNDM-1 gene in the ST16 isolates and the plasmids were very similar, highlighting the possibility of using ODM of plasmids as a surrogate marker of nosocomial spread of bacteria. We also demonstrated that ODM could identify that the blaCTX-M-15 and blaOXA-232 genes in the ST16 isolates were encoded on separate plasmids from the blaNDM-1 gene and from each other. The other three isolates belonged to ST147 and each of them had distinct plasmids encoding blaNDM-1.
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Affiliation(s)
- Sriram KK
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden;
| | - Tsegaye Sewunet
- Department of Laboratory Medicine, Karolinska Institute, 141 52 Stockholm, Sweden; (T.S.); (C.G.G.)
| | - Walaiporn Wangchinda
- Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand; (W.W.); (T.T.); (V.T.)
| | - Teerawit Tangkoskul
- Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand; (W.W.); (T.T.); (V.T.)
| | - Visanu Thamlikitkul
- Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand; (W.W.); (T.T.); (V.T.)
| | - Christian G. Giske
- Department of Laboratory Medicine, Karolinska Institute, 141 52 Stockholm, Sweden; (T.S.); (C.G.G.)
- Department of Clinical Microbiology, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden;
- Correspondence: ; Tel.: +46-31-772-3049
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13
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Lin YL, Sewunet T, KK S, Giske CG, Westerlund F. Optical maps of plasmids as a proxy for clonal spread of MDR bacteria: a case study of an outbreak in a rural Ethiopian hospital. J Antimicrob Chemother 2021; 75:2804-2811. [PMID: 32653928 PMCID: PMC7678893 DOI: 10.1093/jac/dkaa258] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 04/24/2020] [Accepted: 05/14/2020] [Indexed: 01/09/2023] Open
Abstract
Objectives MDR bacteria have become a prevailing health threat worldwide. We here aimed to use optical DNA mapping (ODM) as a rapid method to trace nosocomial spread of bacterial clones and gene elements. We believe that this method has the potential to be a tool of pivotal importance for MDR control. Methods Twenty-four Escherichia coli samples of ST410 from three different wards were collected at an Ethiopian hospital and their plasmids were analysed by ODM. Plasmids were specifically digested with Cas9 targeting the antibiotic resistance genes, stained by competitive binding and confined in nanochannels for imaging. The resulting intensity profiles (barcodes) for each plasmid were compared to identify potential clonal spread of resistant bacteria. Results ODM demonstrated that a large fraction of the patients carried bacteria with a plasmid of the same origin, carrying the ESBL gene blaCTX-M-15, suggesting clonal spread. The results correlate perfectly with core genome (cg)MLST data, where bacteria with the same plasmid also had very similar cgMLST profiles. Conclusions ODM is a rapid discriminatory method for identifying plasmids and antibiotic resistance genes. Long-range deletions/insertions, which are challenging for short-read next-generation sequencing, can be easily identified and used to trace bacterial clonal spread. We propose that plasmid typing can be a useful tool to identify clonal spread of MDR bacteria. Furthermore, the simplicity of the method enables possible future application in low- and middle-income countries.
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Affiliation(s)
- Yii-Lih Lin
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Tsegaye Sewunet
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- School of Laboratory Sciences, Department of Microbiology, Jimma University, Jimma, Ethiopia
| | - Sriram KK
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Christian G Giske
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
- Corresponding author. E-mail:
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14
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Jiang K, Humbert N, K K S, Rouzina I, Mely Y, Westerlund F. The HIV-1 nucleocapsid chaperone protein forms locally compacted globules on long double-stranded DNA. Nucleic Acids Res 2021; 49:4550-4563. [PMID: 33872352 PMCID: PMC8096146 DOI: 10.1093/nar/gkab236] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 03/09/2021] [Accepted: 03/22/2021] [Indexed: 01/14/2023] Open
Abstract
The nucleocapsid (NC) protein plays key roles in Human Immunodeficiency Virus 1 (HIV-1) replication, notably by condensing and protecting the viral RNA genome and by chaperoning its reverse transcription into double-stranded DNA (dsDNA). Recent findings suggest that integration of viral dsDNA into the host genome, and hence productive infection, is linked to a small subpopulation of viral complexes where reverse transcription was completed within the intact capsid. Therefore, the synthesized dsDNA has to be tightly compacted, most likely by NC, to prevent breaking of the capsid in these complexes. To investigate NC’s ability to compact viral dsDNA, we here characterize the compaction of single dsDNA molecules under unsaturated NC binding conditions using nanofluidic channels. Compaction is shown to result from accumulation of NC at one or few compaction sites, which leads to small dsDNA condensates. NC preferentially initiates compaction at flexible regions along the dsDNA, such as AT-rich regions and DNA ends. Upon further NC binding, these condensates develop into a globular state containing the whole dsDNA molecule. These findings support NC’s role in viral dsDNA compaction within the mature HIV-1 capsid and suggest a possible scenario for the gradual dsDNA decondensation upon capsid uncoating and NC loss.
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Affiliation(s)
- Kai Jiang
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg SE 412 96, Sweden
| | - Nicolas Humbert
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch F 67401, France
| | - Sriram K K
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg SE 412 96, Sweden
| | - Ioulia Rouzina
- Department of Chemistry and Biochemistry, The Ohio State University, Center for Retroviral Research, and Center for RNA Biology, Columbus, OH 43210, USA
| | - Yves Mely
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch F 67401, France
| | - Fredrik Westerlund
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg SE 412 96, Sweden
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Karami N, KK S, Yazdanshenas S, Lin YL, Jaén-Luchoro D, Ekedahl E, Parameshwaran S, Lindblom A, Åhrén C, Westerlund F. Identity of blaCTX-M Carrying Plasmids in Sequential ESBL- E. coli Isolates from Patients with Recurrent Urinary Tract Infections. Microorganisms 2021; 9:microorganisms9061138. [PMID: 34070515 PMCID: PMC8226486 DOI: 10.3390/microorganisms9061138] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/10/2021] [Accepted: 05/20/2021] [Indexed: 11/16/2022] Open
Abstract
Plasmid-mediated multidrug resistance in E. coli is becoming increasingly prevalent. Considering this global threat to human health, it is important to understand how plasmid-mediated resistance spreads. From a cohort of 123 patients with recurrent urinary tract infections (RUTI) due to extended spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL E. coli), only five events with a change of ESBL E. coli strain between RUTI episodes were identified. Their blaCTX-M encoding plasmids were compared within each pair of isolates using optical DNA mapping (ODM) and PCR-based replicon typing. Despite similar blaCTX-M genes and replicon types, ODM detected only one case with identical plasmids in the sequential ESBL E. coli strains, indicating that plasmid transfer could have occurred. For comparison, plasmids from seven patients with the same ESBL E. coli strain reoccurring in both episodes were analyzed. These plasmids (encoding blaCTX-M-3, blaCTX-M-14, and blaCTX-M-15) were unaltered for up to six months between recurrent infections. Thus, transmission of blaCTX-M plasmids appears to be a rare event during the course of RUTI. Despite the limited number (n = 23) of plasmids investigated, similar blaCTX-M-15 plasmids in unrelated isolates from different patients were detected, suggesting that some successful plasmids could be associated with specific strains, or are more easily transmitted.
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Affiliation(s)
- Nahid Karami
- Institute of Biomedicine, Department of Infectious Diseases and Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Guldhedsgatan 10 A, 413 46 Gothenburg, Sweden; (S.Y.); (D.J.-L.); (A.L.); (C.Å.)
- Västra Götaland Region, Sahlgrenska University Hospital, Department of Clinical Microbiology, Guldhedsgatan 10A, 413 46 Gothenburg, Sweden
- Correspondence: (N.K.); (F.W.); Tel.: +46-31-342-6173 (N.K.); +46-31-772-3049 (F.W.)
| | - Sriram KK
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, 412 96 Gothenburg, Sweden; (S.K.); (Y.-L.L.); (E.E.); (S.P.)
| | - Shora Yazdanshenas
- Institute of Biomedicine, Department of Infectious Diseases and Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Guldhedsgatan 10 A, 413 46 Gothenburg, Sweden; (S.Y.); (D.J.-L.); (A.L.); (C.Å.)
- Västra Götaland Region, Sahlgrenska University Hospital, Department of Clinical Microbiology, Guldhedsgatan 10A, 413 46 Gothenburg, Sweden
| | - Yii-Lih Lin
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, 412 96 Gothenburg, Sweden; (S.K.); (Y.-L.L.); (E.E.); (S.P.)
| | - Daniel Jaén-Luchoro
- Institute of Biomedicine, Department of Infectious Diseases and Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Guldhedsgatan 10 A, 413 46 Gothenburg, Sweden; (S.Y.); (D.J.-L.); (A.L.); (C.Å.)
| | - Elina Ekedahl
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, 412 96 Gothenburg, Sweden; (S.K.); (Y.-L.L.); (E.E.); (S.P.)
| | - Sanjana Parameshwaran
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, 412 96 Gothenburg, Sweden; (S.K.); (Y.-L.L.); (E.E.); (S.P.)
| | - Anna Lindblom
- Institute of Biomedicine, Department of Infectious Diseases and Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Guldhedsgatan 10 A, 413 46 Gothenburg, Sweden; (S.Y.); (D.J.-L.); (A.L.); (C.Å.)
- Västra Götaland Region, Sahlgrenska University Hospital, Department of Clinical Microbiology, Guldhedsgatan 10A, 413 46 Gothenburg, Sweden
| | - Christina Åhrén
- Institute of Biomedicine, Department of Infectious Diseases and Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Guldhedsgatan 10 A, 413 46 Gothenburg, Sweden; (S.Y.); (D.J.-L.); (A.L.); (C.Å.)
- Swedish Strategic Program against Antimicrobial Resistance (Strama), Västra Götaland Region, Regionens Hus, 405 44 Gothenburg, Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, 412 96 Gothenburg, Sweden; (S.K.); (Y.-L.L.); (E.E.); (S.P.)
- Correspondence: (N.K.); (F.W.); Tel.: +46-31-342-6173 (N.K.); +46-31-772-3049 (F.W.)
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16
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Jeffet J, Margalit S, Michaeli Y, Ebenstein Y. Single-molecule optical genome mapping in nanochannels: multidisciplinarity at the nanoscale. Essays Biochem 2021; 65:51-66. [PMID: 33739394 PMCID: PMC8056043 DOI: 10.1042/ebc20200021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/24/2021] [Accepted: 02/26/2021] [Indexed: 12/12/2022]
Abstract
The human genome contains multiple layers of information that extend beyond the genetic sequence. In fact, identical genetics do not necessarily yield identical phenotypes as evident for the case of two different cell types in the human body. The great variation in structure and function displayed by cells with identical genetic background is attributed to additional genomic information content. This includes large-scale genetic aberrations, as well as diverse epigenetic patterns that are crucial for regulating specific cell functions. These genetic and epigenetic patterns operate in concert in order to maintain specific cellular functions in health and disease. Single-molecule optical genome mapping is a high-throughput genome analysis method that is based on imaging long chromosomal fragments stretched in nanochannel arrays. The access to long DNA molecules coupled with fluorescent tagging of various genomic information presents a unique opportunity to study genetic and epigenetic patterns in the genome at a single-molecule level over large genomic distances. Optical mapping entwines synergistically chemical, physical, and computational advancements, to uncover invaluable biological insights, inaccessible by sequencing technologies. Here we describe the method's basic principles of operation, and review the various available mechanisms to fluorescently tag genomic information. We present some of the recent biological and clinical impact enabled by optical mapping and present recent approaches for increasing the method's resolution and accuracy. Finally, we discuss how multiple layers of genomic information may be mapped simultaneously on the same DNA molecule, thus paving the way for characterizing multiple genomic observables on individual DNA molecules.
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Affiliation(s)
- Jonathan Jeffet
- Raymond and Beverly Sackler Faculty of Exact Sciences, Center for Nanoscience and Nanotechnology, Center for Light Matter Interaction, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sapir Margalit
- Raymond and Beverly Sackler Faculty of Exact Sciences, Center for Nanoscience and Nanotechnology, Center for Light Matter Interaction, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yael Michaeli
- Raymond and Beverly Sackler Faculty of Exact Sciences, Center for Nanoscience and Nanotechnology, Center for Light Matter Interaction, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yuval Ebenstein
- Raymond and Beverly Sackler Faculty of Exact Sciences, Center for Nanoscience and Nanotechnology, Center for Light Matter Interaction, Tel Aviv University, Tel Aviv 6997801, Israel
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17
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Kumra Ahnlide V, de Neergaard T, Sundwall M, Ambjörnsson T, Nordenfelt P. A Predictive Model of Antibody Binding in the Presence of IgG-Interacting Bacterial Surface Proteins. Front Immunol 2021; 12:629103. [PMID: 33828549 PMCID: PMC8019711 DOI: 10.3389/fimmu.2021.629103] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 02/19/2021] [Indexed: 11/24/2022] Open
Abstract
Many bacteria can interfere with how antibodies bind to their surfaces. This bacterial antibody targeting makes it challenging to predict the immunological function of bacteria-associated antibodies. The M and M-like proteins of group A streptococci (GAS) exhibit IgGFc-binding regions, which they use to reverse IgG binding orientation depending on the host environment. Unraveling the mechanism behind these binding characteristics may identify conditions under which bound IgG can drive an efficient immune response. Here, we have developed a biophysical model for describing these complex protein-antibody interactions. We show how the model can be used as a tool for studying the binding behavior of various IgG samples to M protein by performing in silico simulations and correlating this data with experimental measurements. Besides its use for mechanistic understanding, this model could potentially be used as a tool to aid in the development of antibody treatments. We illustrate this by simulating how IgG binding to GAS in serum is altered as specified amounts of monoclonal or pooled IgG is added. Phagocytosis experiments link this altered antibody binding to a physiological function and demonstrate that it is possible to predict the effect of an IgG treatment with our model. Our study gives a mechanistic understanding of bacterial antibody targeting and provides a tool for predicting the effect of antibody treatments in the presence of bacteria with IgG-modulating surface proteins.
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Affiliation(s)
- Vibha Kumra Ahnlide
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Therese de Neergaard
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Martin Sundwall
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Tobias Ambjörnsson
- Computational Biology and Biological Physics, Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Pontus Nordenfelt
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
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18
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Ferreira C, Bikkarolla SK, Frykholm K, Pohjanen S, Brito M, Lameiras C, Nunes OC, Westerlund F, Manaia CM. Polyphasic characterization of carbapenem-resistant Klebsiella pneumoniae clinical isolates suggests vertical transmission of the blaKPC-3 gene. PLoS One 2021; 16:e0247058. [PMID: 33635888 PMCID: PMC7909683 DOI: 10.1371/journal.pone.0247058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 01/30/2021] [Indexed: 11/18/2022] Open
Abstract
Carbapenem-resistant Klebsiella pneumoniae are a major global threat in healthcare facilities. The propagation of carbapenem resistance determinants can occur through vertical transmission, with genetic elements being transmitted by the host bacterium, or by horizontal transmission, with the same genetic elements being transferred among distinct bacterial hosts. This work aimed to track carbapenem resistance transmission by K. pneumoniae in a healthcare facility. The study involved a polyphasic approach based on conjugation assays, resistance phenotype and genotype analyses, whole genome sequencing, and plasmid characterization by pulsed field gel electrophoresis and optical DNA mapping. Out of 40 K. pneumoniae clinical isolates recovered over two years, five were carbapenem- and multidrug-resistant and belonged to multilocus sequence type ST147. These isolates harboured the carbapenemase encoding blaKPC-3 gene, integrated in conjugative plasmids of 140 kbp or 55 kbp, belonging to replicon types incFIA/incFIIK or incN/incFIIK, respectively. The two distinct plasmids encoding the blaKPC-3 gene were associated with distinct genetic lineages, as confirmed by optical DNA mapping and whole genome sequence analyses. These results suggested vertical (bacterial strain-based) transmission of the carbapenem-resistance genetic elements. Determination of the mode of transmission of antibiotic resistance in healthcare facilities, only possible based on polyphasic approaches as described here, is essential to control resistance propagation.
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Affiliation(s)
- Catarina Ferreira
- CBQF - Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Porto, Portugal
| | - Santosh K. Bikkarolla
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Karolin Frykholm
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Saga Pohjanen
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | | | | | - Olga C. Nunes
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Porto, Portugal
| | - Fredrik Westerlund
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
- * E-mail: (CMM); (FW)
| | - Célia M. Manaia
- CBQF - Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Porto, Portugal
- * E-mail: (CMM); (FW)
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19
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Abstract
The DNA of our cells is constantly exposed to various types of damaging agents. One of the most critical types of damage is when both strands of the DNA break, and thus such breaks need to be efficiently repaired. It is known that CtIP promotes nucleases in DNA break repair. Here we show that CtIP can also hold the two DNA strands together in solution when DNA is free to move, using novel methodology that allows the monitoring of thousands of single DNA molecules in nanofabricated devices. DNA bridging likely facilitates the enzymatic repair steps and identifies novel CtIP functions that are crucial for repairing broken DNA. The early steps of DNA double-strand break (DSB) repair in human cells involve the MRE11-RAD50-NBS1 (MRN) complex and its cofactor, phosphorylated CtIP. The roles of these proteins in nucleolytic DSB resection are well characterized, but their role in bridging the DNA ends for efficient and correct repair is much less explored. Here we study the binding of phosphorylated CtIP, which promotes the endonuclease activity of MRN, to single long (∼50 kb) DNA molecules using nanofluidic channels and compare it to the yeast homolog Sae2. CtIP bridges DNA in a manner that depends on the oligomeric state of the protein, and truncated mutants demonstrate that the bridging depends on CtIP regions distinct from those that stimulate the nuclease activity of MRN. Sae2 is a much smaller protein than CtIP, and its bridging is significantly less efficient. Our results demonstrate that the nuclease cofactor and structural functions of CtIP may depend on the same protein population, which may be crucial for CtIP functions in both homologous recombination and microhomology-mediated end-joining.
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20
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Solgi H, Nematzadeh S, Giske CG, Badmasti F, Westerlund F, Lin YL, Goyal G, Nikbin VS, Nemati AH, Shahcheraghi F. Molecular Epidemiology of OXA-48 and NDM-1 Producing Enterobacterales Species at a University Hospital in Tehran, Iran, Between 2015 and 2016. Front Microbiol 2020; 11:936. [PMID: 32547503 PMCID: PMC7270168 DOI: 10.3389/fmicb.2020.00936] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 04/20/2020] [Indexed: 01/09/2023] Open
Abstract
Carbapenem-resistant Enterobacterales (CRE) is an increasing problem worldwide. Here, we examined the clonal relatedness of 71 non-repetitive CRE isolates collected in a university hospital in Tehran, Iran, between February 2015 and March 2016. Pulsed-field gel electrophoresis (PFGE) and MLST were used for epidemiological analysis. Screening for antibiotic resistance genes, PCR-based replicon typing, conjugation experiments, and optical DNA mapping were also performed. Among all 71 isolates, 47 isolates of Klebsiella pneumoniae (66.2%), eight Escherichia coli (11.2%), five Serratia marcescens (7%), and two Enterobacter cloacae (2.8%) harbored blaNDM–1 and blaOXA–48 genes together or alone. PFGE analysis revealed that most of the OXA-48- and NDM-1-producing K. pneumoniae and all of OXA-48-producing S. marcescens were clonally related, while all eight E. coli and two E. cloacae isolates were clonally unrelated. The predominant clones of carbapenemase-producing K. pneumoniae associated with outbreaks within the hospital were ST147 (n = 13) and ST893 (n = 10). Plasmids carrying blaNDM–1 and blaOXA–48 were successfully transferred to an E. coli K12-recipient strain. The blaOXA–48 gene was located on an IncL/M conjugative plasmid, while the blaNDM–1 gene was located on both IncFII ∼86-kb to ∼140-kb and IncA/C conjugative plasmids. Our findings provide novel epidemiologic data on carbapenemase-producing Enterobacterales (CPE) in Iran and highlight the importance of horizontal gene transfer in the dissemination of blaNDM–1 and blaOXA–48 genes. The occurrence and transmission of distinct K. pneumoniae clones call for improved infection control to prevent further spread of these pathogens in Iran.
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Affiliation(s)
- Hamid Solgi
- Division of Clinical Microbiology, Department of Laboratory Medicine, Amin Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Shoeib Nematzadeh
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Christian G Giske
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Farzad Badmasti
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | - Fredrik Westerlund
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Yii-Lih Lin
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Gaurav Goyal
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
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21
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Müller V, Nyblom M, Johnning A, Wrande M, Dvirnas A, KK S, Giske CG, Ambjörnsson T, Sandegren L, Kristiansson E, Westerlund F. Cultivation-Free Typing of Bacteria Using Optical DNA Mapping. ACS Infect Dis 2020; 6:1076-1084. [PMID: 32294378 PMCID: PMC7304876 DOI: 10.1021/acsinfecdis.9b00464] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Indexed: 01/06/2023]
Abstract
A variety of pathogenic bacteria can infect humans, and rapid species identification is crucial for the correct treatment. However, the identification process can often be time-consuming and depend on the cultivation of the bacterial pathogen(s). Here, we present a stand-alone, enzyme-free, optical DNA mapping assay capable of species identification by matching the intensity profiles of large DNA molecules to a database of fully assembled bacterial genomes (>10 000). The assay includes a new data analysis strategy as well as a general DNA extraction protocol for both Gram-negative and Gram-positive bacteria. We demonstrate that the assay is capable of identifying bacteria directly from uncultured clinical urine samples, as well as in mixtures, with the potential to be discriminative even at the subspecies level. We foresee that the assay has applications both within research laboratories and in clinical settings, where the time-consuming step of cultivation can be minimized or even completely avoided.
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Affiliation(s)
- Vilhelm Müller
- Department of Biology
and Biological Engineering, Chalmers University
of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden
| | - My Nyblom
- Department of Biology
and Biological Engineering, Chalmers University
of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden
| | - Anna Johnning
- Department of Mathematical
Sciences, Chalmers University of Technology
and the University of Gothenburg, 412 96 Gothenburg, Sweden
- Systems and Data Analysis, Fraunhofer-Chalmers
Centre, Chalmers Science
Park, 412 88 Gothenburg, Sweden
- Centre for Antibiotic Resistance Research,
CARe, University of Gothenburg, Box 440, 405 30 Gothenburg, Sweden
| | - Marie Wrande
- Department of Medical
Biochemistry and Microbiology, Uppsala University, Husargatan 3, Box
582, 751 23 Uppsala, Sweden
| | - Albertas Dvirnas
- Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, 223 62 Lund, Sweden
| | - Sriram KK
- Department of Biology
and Biological Engineering, Chalmers University
of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden
| | - Christian G. Giske
- Department of Laboratory Medicine, Karolinska
Institutet, Alfred Nobels
Allé 8, 141 86 Stockholm, Sweden
- Department of Clinical
Microbiology, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Tobias Ambjörnsson
- Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, 223 62 Lund, Sweden
| | - Linus Sandegren
- Department of Medical
Biochemistry and Microbiology, Uppsala University, Husargatan 3, Box
582, 751 23 Uppsala, Sweden
| | - Erik Kristiansson
- Department of Mathematical
Sciences, Chalmers University of Technology
and the University of Gothenburg, 412 96 Gothenburg, Sweden
- Centre for Antibiotic Resistance Research,
CARe, University of Gothenburg, Box 440, 405 30 Gothenburg, Sweden
| | - Fredrik Westerlund
- Department of Biology
and Biological Engineering, Chalmers University
of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden
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22
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Bouwens A, Deen J, Vitale R, D’Huys L, Goyvaerts V, Descloux A, Borrenberghs D, Grussmayer K, Lukes T, Camacho R, Su J, Ruckebusch C, Lasser T, Van De Ville D, Hofkens J, Radenovic A, Frans Janssen KP. Identifying microbial species by single-molecule DNA optical mapping and resampling statistics. NAR Genom Bioinform 2020; 2:lqz007. [PMID: 33575560 PMCID: PMC7671359 DOI: 10.1093/nargab/lqz007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 09/12/2019] [Indexed: 12/13/2022] Open
Abstract
Single-molecule DNA mapping has the potential to serve as a powerful complement to high-throughput sequencing in metagenomic analysis. Offering longer read lengths and forgoing the need for complex library preparation and amplification, mapping stands to provide an unbiased view into the composition of complex viromes and/or microbiomes. To fully enable mapping-based metagenomics, sensitivity and specificity of DNA map analysis and identification need to be improved. Using detailed simulations and experimental data, we first demonstrate how fluorescence imaging of surface stretched, sequence specifically labeled DNA fragments can yield highly sensitive identification of targets. Second, a new analysis technique is introduced to increase specificity of the analysis, allowing even closely related species to be resolved. Third, we show how an increase in resolution improves sensitivity. Finally, we demonstrate that these methods are capable of identifying species with long genomes such as bacteria with high sensitivity.
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Affiliation(s)
- Arno Bouwens
- Department of Chemistry, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Jochem Deen
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Raffaele Vitale
- Department of Chemistry, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
- LASIR CNRS, Université de Lille, 59655 Villeneuve d’Ascq, France
| | - Laurens D’Huys
- Department of Chemistry, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
| | - Vince Goyvaerts
- Department of Chemistry, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
| | - Adrien Descloux
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | | | - Kristin Grussmayer
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Tomas Lukes
- School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Rafael Camacho
- Department of Chemistry, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
| | - Jia Su
- Department of Chemistry, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
| | - Cyril Ruckebusch
- LASIR CNRS, Université de Lille, 59655 Villeneuve d’Ascq, France
| | - Theo Lasser
- School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Dimitri Van De Ville
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- Center for Neuroprosthetics, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- Department of Radiology and Medical Informatics, Université de Genève, 1205 Genève, Switzerland
| | - Johan Hofkens
- Department of Chemistry, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
| | - Aleksandra Radenovic
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- School of Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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23
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Müller V, Dvirnas A, Andersson J, Singh V, Kk S, Johansson P, Ebenstein Y, Ambjörnsson T, Westerlund F. Enzyme-free optical DNA mapping of the human genome using competitive binding. Nucleic Acids Res 2019; 47:e89. [PMID: 31165870 PMCID: PMC6735870 DOI: 10.1093/nar/gkz489] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/03/2019] [Accepted: 05/22/2019] [Indexed: 01/24/2023] Open
Abstract
Optical DNA mapping (ODM) allows visualization of long-range sequence information along single DNA molecules. The data can for example be used for detecting long range structural variations, for aiding DNA sequence assembly of complex genomes and for mapping epigenetic marks and DNA damage across the genome. ODM traditionally utilizes sequence specific marks based on nicking enzymes, combined with a DNA stain, YOYO-1, for detection of the DNA contour. Here we use a competitive binding approach, based on YOYO-1 and netropsin, which highlights the contour of the DNA molecules, while simultaneously creating a continuous sequence specific pattern, based on the AT/GC variation along the detected molecule. We demonstrate and validate competitive-binding-based ODM using bacterial artificial chromosomes (BACs) derived from the human genome and then turn to DNA extracted from white blood cells. We generalize our findings with in-silico simulations that show that we can map a vast majority of the human genome. Finally, we demonstrate the possibility of combining competitive binding with enzymatic labeling by mapping DNA damage sites induced by the cytotoxic drug etoposide to the human genome. Overall, we demonstrate that competitive-binding-based ODM has the potential to be used both as a standalone assay for studies of the human genome, as well as in combination with enzymatic approaches, some of which are already commercialized.
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Affiliation(s)
- Vilhelm Müller
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Albertas Dvirnas
- Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - John Andersson
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Vandana Singh
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Sriram Kk
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Pegah Johansson
- Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Yuval Ebenstein
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Tobias Ambjörnsson
- Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
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24
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Optical DNA Mapping Combined with Cas9-Targeted Resistance Gene Identification for Rapid Tracking of Resistance Plasmids in a Neonatal Intensive Care Unit Outbreak. mBio 2019; 10:mBio.00347-19. [PMID: 31289171 PMCID: PMC6747713 DOI: 10.1128/mbio.00347-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
This study presents how a novel method, based on visualizing single plasmids using sequence-specific fluorescent labeling, could be used to analyze the genetic dynamics of an outbreak of resistant bacteria in a neonatal intensive care unit at a Swedish hospital. Plasmids are a central reason for the rapid global spread of bacterial resistance to antibiotics. In a single experimental procedure, this method replaces many traditional plasmid analysis techniques that together provide limited details and are slow to perform. The method is much faster than long-read whole-genome sequencing and offers direct genetic comparison of patient samples. We could conclude that no transfer of resistance plasmids had occurred between different bacteria during the outbreak and that secondary cases of ESBL-producing Enterobacteriaceae carriage were instead likely due to influx of new strains. We believe that the method offers potential in improving surveillance and infection control of resistant bacteria in hospitals. The global spread of antibiotic resistance among Enterobacteriaceae is largely due to multidrug resistance plasmids that can transfer between different bacterial strains and species. Horizontal gene transfer of resistance plasmids can complicate hospital outbreaks and cause problems in epidemiological tracing, since tracing is usually based on bacterial clonality. We have developed a method, based on optical DNA mapping combined with Cas9-assisted identification of resistance genes, which is used here to characterize plasmids during an extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae outbreak at a Swedish neonatal intensive care unit. The outbreak included 17 neonates initially colonized with ESBL-producing Klebsiella pneumoniae (ESBL-KP), some of which were found to carry additional ESBL-producing Escherichia coli (ESBL-EC) in follow-up samples. We demonstrate that all ESBL-KP isolates contained two plasmids with the blaCTX-M-15 gene located on the smaller one (~80 kbp). The same ESBL-KP clone was present in follow-up samples for up to 2 years in some patients, and the plasmid carrying the blaCTX-M-15 gene was stable throughout this time period. However, extensive genetic rearrangements within the second plasmid were observed in the optical DNA maps for several of the ESBL-KP isolates. Optical mapping also demonstrated that even though other bacterial clones and species carrying blaCTX-M group 1 genes were found in some neonates, no transfer of resistance plasmids had occurred. The data instead pointed toward unrelated acquisition of ESBL-producing Enterobacteriaceae (EPE). In addition to revealing important information about the specific outbreak, the method presented is a promising tool for surveillance and infection control in clinical settings.
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25
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Ferreira C, Bogas D, Bikarolla SK, Varela AR, Frykholm K, Linheiro R, Nunes OC, Westerlund F, Manaia CM. Genetic variation in the conjugative plasmidome of a hospital effluent multidrug resistant Escherichia coli strain. CHEMOSPHERE 2019; 220:748-759. [PMID: 30611073 DOI: 10.1016/j.chemosphere.2018.12.130] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 11/23/2018] [Accepted: 12/18/2018] [Indexed: 06/09/2023]
Abstract
Bacteria harboring conjugative plasmids have the potential for spreading antibiotic resistance through horizontal gene transfer. It is described that the selection and dissemination of antibiotic resistance is enhanced by stressors, like metals or antibiotics, which can occur as environmental contaminants. This study aimed at unveiling the composition of the conjugative plasmidome of a hospital effluent multidrug resistant Escherichia coli strain (H1FC54) under different mating conditions. To meet this objective, plasmid pulsed field gel electrophoresis, optical mapping analyses and DNA sequencing were used in combination with phenotype analysis. Strain H1FC54 was observed to harbor five plasmids, three of which were conjugative and two of these, pH1FC54_330 and pH1FC54_140, contained metal and antibiotic resistance genes. Transconjugants obtained in the absence or presence of tellurite (0.5 μM or 5 μM), arsenite (0.5 μM, 5 μM or 15 μM) or ceftazidime (10 mg/L) and selected in the presence of sodium azide (100 mg/L) and tetracycline (16 mg/L) presented distinct phenotypes, associated with the acquisition of different plasmid combinations, including two co-integrate plasmids, of 310 kbp and 517 kbp. The variable composition of the conjugative plasmidome, the formation of co-integrates during conjugation, as well as the transfer of non-transferable plasmids via co-integration, and the possible association between antibiotic, arsenite and tellurite tolerance was demonstrated. These evidences bring interesting insights into the comprehension of the molecular and physiological mechanisms that underlie antibiotic resistance propagation in the environment.
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Affiliation(s)
- Catarina Ferreira
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina, Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital, 172, 4200-374, Porto, Portugal
| | - Diana Bogas
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina, Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital, 172, 4200-374, Porto, Portugal
| | - Santosh K Bikarolla
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, SE-412 96, Gothenburg, Sweden
| | - Ana Rita Varela
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina, Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital, 172, 4200-374, Porto, Portugal; LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - Karolin Frykholm
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, SE-412 96, Gothenburg, Sweden
| | - Raquel Linheiro
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina, Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital, 172, 4200-374, Porto, Portugal
| | - Olga C Nunes
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - Fredrik Westerlund
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, SE-412 96, Gothenburg, Sweden
| | - Célia M Manaia
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina, Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital, 172, 4200-374, Porto, Portugal.
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26
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Sharim H, Grunwald A, Gabrieli T, Michaeli Y, Margalit S, Torchinsky D, Arielly R, Nifker G, Juhasz M, Gularek F, Almalvez M, Dufault B, Chandra SS, Liu A, Bhattacharya S, Chen YW, Vilain E, Wagner KR, Pevsner J, Reifenberger J, Lam ET, Hastie AR, Cao H, Barseghyan H, Weinhold E, Ebenstein Y. Long-read single-molecule maps of the functional methylome. Genome Res 2019; 29:646-656. [PMID: 30846530 PMCID: PMC6442387 DOI: 10.1101/gr.240739.118] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 02/25/2019] [Indexed: 01/23/2023]
Abstract
We report on the development of a methylation analysis workflow for optical detection of fluorescent methylation profiles along chromosomal DNA molecules. In combination with Bionano Genomics genome mapping technology, these profiles provide a hybrid genetic/epigenetic genome-wide map composed of DNA molecules spanning hundreds of kilobase pairs. The method provides kilobase pair–scale genomic methylation patterns comparable to whole-genome bisulfite sequencing (WGBS) along genes and regulatory elements. These long single-molecule reads allow for methylation variation calling and analysis of large structural aberrations such as pathogenic macrosatellite arrays not accessible to single-cell second-generation sequencing. The method is applied here to study facioscapulohumeral muscular dystrophy (FSHD), simultaneously recording the haplotype, copy number, and methylation status of the disease-associated, highly repetitive locus on Chromosome 4q.
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Affiliation(s)
- Hila Sharim
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| | - Assaf Grunwald
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| | - Tslil Gabrieli
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| | - Yael Michaeli
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| | - Sapir Margalit
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| | - Dmitry Torchinsky
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| | - Rani Arielly
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| | - Gil Nifker
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
| | - Matyas Juhasz
- Institute of Organic Chemistry RWTH Aachen University, D-52056 Aachen, Germany
| | - Felix Gularek
- Institute of Organic Chemistry RWTH Aachen University, D-52056 Aachen, Germany
| | - Miguel Almalvez
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Brandon Dufault
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Sreetama Sen Chandra
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Alexander Liu
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Surajit Bhattacharya
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Yi-Wen Chen
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Eric Vilain
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Kathryn R Wagner
- Kennedy Krieger Institute and Departments of Neurology and Neuroscience, The Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA
| | - Jonathan Pevsner
- Kennedy Krieger Institute and Departments of Neurology and Neuroscience, The Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA
| | | | - Ernest T Lam
- Bionano Genomics, Incorporated, San Diego, California 92121, USA
| | - Alex R Hastie
- Bionano Genomics, Incorporated, San Diego, California 92121, USA
| | - Han Cao
- Bionano Genomics, Incorporated, San Diego, California 92121, USA
| | - Hayk Barseghyan
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Elmar Weinhold
- Institute of Organic Chemistry RWTH Aachen University, D-52056 Aachen, Germany
| | - Yuval Ebenstein
- School of Chemistry, Center for Nanoscience and Nanotechnology, Center for Light-Matter Interaction, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 6997801, Israel
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27
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Krog J, Alizadehheidari M, Werner E, Bikkarolla SK, Tegenfeldt JO, Mehlig B, Lomholt MA, Westerlund F, Ambjörnsson T. Stochastic unfolding of nanoconfined DNA: Experiments, model and Bayesian analysis. J Chem Phys 2019; 149:215101. [PMID: 30525714 DOI: 10.1063/1.5051319] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Nanochannels provide a means for detailed experiments on the effect of confinement on biomacromolecules, such as DNA. Here we introduce a model for the complete unfolding of DNA from the circular to linear configuration. Two main ingredients are the entropic unfolding force and the friction coefficient for the unfolding process, and we describe the associated dynamics by a non-linear Langevin equation. By analyzing experimental data where DNA molecules are photo-cut and unfolded inside a nanochannel, our model allows us to extract values for the unfolding force as well as the friction coefficient for the first time. In order to extract numerical values for these physical quantities, we employ a recently introduced Bayesian inference framework. We find that the determined unfolding force is in agreement with estimates from a simple Flory-type argument. The estimated friction coefficient is in agreement with theoretical estimates for motion of a cylinder in a channel. We further validate the estimated friction constant by extracting this parameter from DNA's center-of-mass motion before and after unfolding, yielding decent agreement. We provide publically available software for performing the required image and Bayesian analysis.
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Affiliation(s)
- Jens Krog
- MEMPHYS-Center for Biomembrane Physics, Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, Odense, Denmark
| | | | - Erik Werner
- Department of Physics, Gothenburg University, Gothenburg, Sweden
| | - Santosh Kumar Bikkarolla
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | | | - Bernhard Mehlig
- Department of Physics, Gothenburg University, Gothenburg, Sweden
| | - Michael A Lomholt
- MEMPHYS-Center for Biomembrane Physics, Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, Odense, Denmark
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Tobias Ambjörnsson
- Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
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28
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Johnning A, Karami N, Tång Hallbäck E, Müller V, Nyberg L, Buongermino Pereira M, Stewart C, Ambjörnsson T, Westerlund F, Adlerberth I, Kristiansson E. The resistomes of six carbapenem-resistant pathogens - a critical genotype-phenotype analysis. Microb Genom 2018; 4. [PMID: 30461373 PMCID: PMC6321870 DOI: 10.1099/mgen.0.000233] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Carbapenem resistance is a rapidly growing threat to our ability to treat refractory bacterial infections. To understand how carbapenem resistance is mobilized and spread between pathogens, it is important to study the genetic context of the underlying resistance mechanisms. In this study, the resistomes of six clinical carbapenem-resistant isolates of five different species – Acinetobacter baumannii, Escherichia coli, two Klebsiella pneumoniae, Proteus mirabilis and Pseudomonas aeruginosa – were characterized using whole genome sequencing. All Enterobacteriaceae isolates and the A. baumannii isolate had acquired a large number of antimicrobial resistance genes (7–18 different genes per isolate), including the following encoding carbapenemases: blaKPC-2, blaOXA-48, blaOXA-72, blaNDM-1, blaNDM-7 and blaVIM-1. In addition, a novel version of blaSHV was discovered. Four new resistance plasmids were identified and their fully assembled sequences were verified using optical DNA mapping. Most of the resistance genes were co-localized on these and other plasmids, suggesting a risk for co-selection. In contrast, five out of six carbapenemase genes were present on plasmids with no or few other resistance genes. The expected level of resistance – based on acquired resistance determinants – was concordant with measured levels in most cases. There were, however, several important discrepancies for four of the six isolates concerning multiple classes of antibiotics. In conclusion, our results further elucidate the diversity of carbapenemases, their mechanisms of horizontal transfer and possible patterns of co-selection. The study also emphasizes the difficulty of using whole genome sequencing for antimicrobial susceptibility testing of pathogens with complex genotypes.
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Affiliation(s)
- Anna Johnning
- 2Centre for Antibiotic Resistance Research, CARe, University of Gothenburg, Gothenburg, Sweden.,1Department of Mathematical Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Nahid Karami
- 2Centre for Antibiotic Resistance Research, CARe, University of Gothenburg, Gothenburg, Sweden.,3Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Erika Tång Hallbäck
- 3Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Vilhelm Müller
- 4Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Lena Nyberg
- 4Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Mariana Buongermino Pereira
- 1Department of Mathematical Sciences, Chalmers University of Technology, Gothenburg, Sweden.,2Centre for Antibiotic Resistance Research, CARe, University of Gothenburg, Gothenburg, Sweden
| | - Callum Stewart
- 5Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Tobias Ambjörnsson
- 5Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Fredrik Westerlund
- 4Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Ingegerd Adlerberth
- 2Centre for Antibiotic Resistance Research, CARe, University of Gothenburg, Gothenburg, Sweden.,3Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Erik Kristiansson
- 1Department of Mathematical Sciences, Chalmers University of Technology, Gothenburg, Sweden.,2Centre for Antibiotic Resistance Research, CARe, University of Gothenburg, Gothenburg, Sweden
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29
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Lima DC, Nyberg LK, Westerlund F, Batistuzzo de Medeiros SR. Identification and DNA annotation of a plasmid isolated from Chromobacterium violaceum. Sci Rep 2018; 8:5327. [PMID: 29593241 PMCID: PMC5871888 DOI: 10.1038/s41598-018-23708-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 03/12/2018] [Indexed: 12/18/2022] Open
Abstract
Chromobacterium violaceum is a ß-proteobacterium found widely worldwide with important biotechnological properties and is associated to lethal sepsis in immune-depressed individuals. In this work, we report the discover, complete sequence and annotation of a plasmid detected in C. violaceum that has been unnoticed until now. We used DNA single-molecule analysis to confirm that the episome found was a circular molecule and then proceeded with NGS sequencing. After DNA annotation, we found that this extra-chromosomal DNA is probably a defective bacteriophage of approximately 44 kilobases, with 39 ORFs comprising, mostly hypothetical proteins. We also found DNA sequences that ensure proper plasmid replication and partitioning as well as a toxin addiction system. This report sheds light on the biology of this important species, helping us to understand the mechanisms by which C. violaceum endures to several harsh conditions. This discovery could also be a first step in the development of a DNA manipulation tool in this bacterium.
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Affiliation(s)
- Daniel C Lima
- Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte, Natal, Brazil.,Laboratório de Biologia Molecular e Genômica, Universidade Federal do Rio Grande do Norte, Natal, Brazil
| | - Lena K Nyberg
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
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Abstract
The output from whole genome sequencing is a set of contigs, i.e. short non-overlapping DNA sequences (sizes 1-100 kilobasepairs). Piecing the contigs together is an especially difficult task for previously unsequenced DNA, and may not be feasible due to factors such as the lack of sufficient coverage or larger repetitive regions which generate gaps in the final sequence. Here we propose a new method for scaffolding such contigs. The proposed method uses densely labeled optical DNA barcodes from competitive binding experiments as scaffolds. On these scaffolds we position theoretical barcodes which are calculated from the contig sequences. This allows us to construct longer DNA sequences from the contig sequences. This proof-of-principle study extends previous studies which use sparsely labeled DNA barcodes for scaffolding purposes. Our method applies a probabilistic approach that allows us to discard “foreign” contigs from mixed samples with contigs from different types of DNA. We satisfy the contig non-overlap constraint by formulating the contig placement challenge as a combinatorial auction problem. Our exact algorithm for solving this problem reduces computational costs compared to previous methods in the combinatorial auction field. We demonstrate the usefulness of the proposed scaffolding method both for synthetic contigs and for contigs obtained using Illumina sequencing for a mixed sample with plasmid and chromosomal DNA.
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Abstract
Stretching of DNA in nanoscale confinement allows for several important studies. The genetic contents of the DNA can be visualized on the single DNA molecule level and both the polymer physics of confined DNA and also DNA/protein and other DNA/DNA-binding molecule interactions can be explored. This chapter describes the basic steps to fabricate the nanostructures, perform the experiments and analyze the data.
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32
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Pyle JR, Chen J. Photobleaching of YOYO-1 in super-resolution single DNA fluorescence imaging. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2017; 8:2296-2306. [PMID: 29181286 PMCID: PMC5687005 DOI: 10.3762/bjnano.8.229] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/05/2017] [Indexed: 06/07/2023]
Abstract
Super-resolution imaging of single DNA molecules via point accumulation for imaging in nanoscale topography (PAINT) has great potential to visualize fine DNA structures with nanometer resolution. In a typical PAINT video acquisition, dye molecules (YOYO-1) in solution sparsely bind to the target surfaces (DNA) whose locations can be mathematically determined by fitting their fluorescent point spread function. Many YOYO-1 molecules intercalate into DNA and remain there during imaging, and most of them have to be temporarily or permanently fluorescently bleached, often stochastically, to allow for the visualization of a few fluorescent events per DNA per frame of the video. Thus, controlling the fluorescence on-off rate is important in PAINT. In this paper, we study the photobleaching of YOYO-1 and its correlation with the quality of the PAINT images. At a low excitation laser power density, the photobleaching of YOYO-1 is too slow and a minimum required power density was identified, which can be theoretically predicted with the proposed method in this report.
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Affiliation(s)
- Joseph R Pyle
- Department of Chemistry and Biochemistry, Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, Ohio 45701, USA
| | - Jixin Chen
- Department of Chemistry and Biochemistry, Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, Ohio 45701, USA
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33
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Abstract
In optical DNA mapping technologies sequence-specific intensity variations (DNA barcodes) along stretched and stained DNA molecules are produced. These “fingerprints” of the underlying DNA sequence have a resolution of the order one kilobasepairs and the stretching of the DNA molecules are performed by surface adsorption or nano-channel setups. A post-processing challenge for nano-channel based methods, due to local and global random movement of the DNA molecule during imaging, is how to align different time frames in order to produce reproducible time-averaged DNA barcodes. The current solutions to this challenge are computationally rather slow. With high-throughput applications in mind, we here introduce a parameter-free method for filtering a single time frame noisy barcode (snap-shot optical map), measured in a fraction of a second. By using only a single time frame barcode we circumvent the need for post-processing alignment. We demonstrate that our method is successful at providing filtered barcodes which are less noisy and more similar to time averaged barcodes. The method is based on the application of a low-pass filter on a single noisy barcode using the width of the Point Spread Function of the system as a unique, and known, filtering parameter. We find that after applying our method, the Pearson correlation coefficient (a real number in the range from -1 to 1) between the single time-frame barcode and the time average of the aligned kymograph increases significantly, roughly by 0.2 on average. By comparing to a database of more than 3000 theoretical plasmid barcodes we show that the capabilities to identify plasmids is improved by filtering single time-frame barcodes compared to the unfiltered analogues. Since snap-shot experiments and computational time using our method both are less than a second, this study opens up for high throughput optical DNA mapping with improved reproducibility.
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34
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Abstract
Optical mapping (OM) has been used in microbiology for the past 20 years, initially as a technique to facilitate DNA sequence-based studies; however, with decreases in DNA sequencing costs and increases in sequence output from automated sequencing platforms, OM has grown into an important auxiliary tool for genome assembly and comparison. Currently, there are a number of new and exciting applications for OM in the field of microbiology, including investigation of disease outbreaks, identification of specific genes of clinical and/or epidemiological relevance, and the possibility of single-cell analysis when combined with cell-sorting approaches. In addition, designing lab-on-a-chip systems based on OM is now feasible and will allow the integrated and automated microbiological analysis of biological fluids. Here, we review the basic technology of OM, detail the current state of the art of the field, and look ahead to possible future developments in OM technology for microbiological applications.
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35
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Müller V, Westerlund F. Optical DNA mapping in nanofluidic devices: principles and applications. LAB ON A CHIP 2017; 17:579-590. [PMID: 28098301 DOI: 10.1039/c6lc01439a] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Optical DNA mapping has over the last decade emerged as a very powerful tool for obtaining long range sequence information from single DNA molecules. In optical DNA mapping, intact large single DNA molecules are labeled, stretched out, and imaged using a fluorescence microscope. This means that sequence information ranging over hundreds of kilobasepairs (kbp) can be obtained in one single image. Nanochannels offer homogeneous and efficient stretching of DNA that is crucial to maximize the information that can be obtained from optical DNA maps. In this review, we highlight progress in the field of optical DNA mapping in nanochannels. We discuss the different protocols for sequence specific labeling and divide them into two main categories, enzymatic labeling and affinity-based labeling. Examples are highlighted where optical DNA mapping is used to gain information on length scales that would be inaccessible with traditional techniques. Enzymatic labeling has been commercialized and is mainly used in human genetics and assembly of complex genomes, while the affinity-based methods have primarily been applied in bacteriology, for example for rapid analysis of plasmids encoding antibiotic resistance. Next, we highlight how the design of nanofluidic channels can been altered in order to obtain the desired information and discuss how recent advances in the field make it possible to retrieve information beyond DNA sequence. In the outlook section, we discuss future directions of optical DNA mapping, such as fully integrated devices and portable microscopes.
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Affiliation(s)
- Vilhelm Müller
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
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36
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Müller V, Rajer F, Frykholm K, Nyberg LK, Quaderi S, Fritzsche J, Kristiansson E, Ambjörnsson T, Sandegren L, Westerlund F. Direct identification of antibiotic resistance genes on single plasmid molecules using CRISPR/Cas9 in combination with optical DNA mapping. Sci Rep 2016; 6:37938. [PMID: 27905467 PMCID: PMC5131345 DOI: 10.1038/srep37938] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 11/01/2016] [Indexed: 12/03/2022] Open
Abstract
Bacterial plasmids are extensively involved in the rapid global spread of antibiotic resistance. We here present an assay, based on optical DNA mapping of single plasmids in nanofluidic channels, which provides detailed information about the plasmids present in a bacterial isolate. In a single experiment, we obtain the number of different plasmids in the sample, the size of each plasmid, an optical barcode that can be used to identify and trace the plasmid of interest and information about which plasmid that carries a specific resistance gene. Gene identification is done using CRISPR/Cas9 loaded with a guide-RNA (gRNA) complementary to the gene of interest that linearizes the circular plasmids at a specific location that is identified using the optical DNA maps. We demonstrate the principle on clinically relevant extended spectrum beta-lactamase (ESBL) producing isolates. We discuss how the gRNA sequence can be varied to obtain the desired information. The gRNA can either be very specific to identify a homogeneous group of genes or general to detect several groups of genes at the same time. Finally, we demonstrate an example where we use a combination of two gRNA sequences to identify carbapenemase-encoding genes in two previously not characterized clinical bacterial samples.
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Affiliation(s)
- Vilhelm Müller
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Fredrika Rajer
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Karolin Frykholm
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Lena K. Nyberg
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Saair Quaderi
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
- Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Joachim Fritzsche
- Department of Applied Physics, Chalmers University of Technology, Gothenburg, Sweden
| | - Erik Kristiansson
- Department of Mathematical Sciences, Chalmers University of Technology/University of Gothenburg, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Tobias Ambjörnsson
- Department of Astronomy and Theoretical Physics, Lund University, Lund, Sweden
| | - Linus Sandegren
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
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37
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Jeffet J, Kobo A, Su T, Grunwald A, Green O, Nilsson AN, Eisenberg E, Ambjörnsson T, Westerlund F, Weinhold E, Shabat D, Purohit PK, Ebenstein Y. Super-Resolution Genome Mapping in Silicon Nanochannels. ACS NANO 2016; 10:9823-9830. [PMID: 27646634 DOI: 10.1021/acsnano.6b05398] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Optical genome mapping in nanochannels is a powerful genetic analysis method, complementary to deoxyribonucleic acid (DNA) sequencing. The method is based on detecting a pattern of fluorescent labels attached along individual DNA molecules. When such molecules are extended in nanochannels, the labels create a fluorescent genetic barcode that is used for mapping the DNA molecule to its genomic locus and identifying large-scale variation from the genome reference. Mapping resolution is currently limited by two main factors: the optical diffraction limit and the thermal fluctuations of DNA molecules suspended in the nanochannels. Here, we utilize single-molecule tracking and super-resolution localization in order to improve the mapping accuracy and resolving power of this genome mapping technique and achieve a 15-fold increase in resolving power compared to currently practiced methods. We took advantage of a naturally occurring genetic repeat array and labeled each repeat with custom-designed Trolox conjugated fluorophores for enhanced photostability. This model system allowed us to acquire extremely long image sequences of the equally spaced fluorescent markers along DNA molecules, enabling detailed characterization of nanoconfined DNA dynamics and quantitative comparison to the Odijk theory for confined polymer chains. We present a simple method to overcome the thermal fluctuations in the nanochannels and exploit single-step photobleaching to resolve subdiffraction spaced fluorescent markers along fluctuating DNA molecules with ∼100 bp resolution. In addition, we show how time-averaging over just ∼50 frames of 40 ms enhances mapping accuracy, improves mapping P-value scores by 3 orders of magnitude compared to nonaveraged alignment, and provides a significant advantage for analyzing structural variations between DNA molecules with similar sequence composition.
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Affiliation(s)
- Jonathan Jeffet
- Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University , Tel Aviv 6997801, Israel
| | - Asaf Kobo
- Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University , Tel Aviv 6997801, Israel
| | - Tianxiang Su
- School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States
| | - Assaf Grunwald
- Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University , Tel Aviv 6997801, Israel
| | - Ori Green
- Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University , Tel Aviv 6997801, Israel
| | - Adam N Nilsson
- Department of Astronomy and Theoretical Physics, Lund University , SE-221 00 Lund, Sweden
| | - Eli Eisenberg
- Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University , Tel Aviv 6997801, Israel
| | - Tobias Ambjörnsson
- Department of Astronomy and Theoretical Physics, Lund University , SE-221 00 Lund, Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology , SE-412 96 Gothenburg, Sweden
| | - Elmar Weinhold
- Institute of Organic Chemistry, RWTH Aachen University , Aachen D-52056, Germany
| | - Doron Shabat
- Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University , Tel Aviv 6997801, Israel
| | - Prashant K Purohit
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
| | - Yuval Ebenstein
- Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University , Tel Aviv 6997801, Israel
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38
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Lacroix J, Pélofy S, Blatché C, Pillaire MJ, Huet S, Chapuis C, Hoffmann JS, Bancaud A. Analysis of DNA Replication by Optical Mapping in Nanochannels. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 12:5963-5970. [PMID: 27624455 DOI: 10.1002/smll.201503795] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 06/21/2016] [Indexed: 06/06/2023]
Abstract
DNA replication is essential to maintain genome integrity in S phase of the cell division cycle. Accumulation of stalled replication forks is a major source of genetic instability, and likely constitutes a key driver of tumorigenesis. The mechanisms of regulation of replication fork progression have therefore been extensively investigated, in particular with DNA combing, an optical mapping technique that allows the stretching of single molecules and the mapping of active region for DNA synthesis by fluorescence microscopy. DNA linearization in nanochannels has been successfully used to probe genomic information patterns along single chromosomes, and has been proposed to be a competitive alternative to DNA combing. Yet this conjecture remains to be confirmed experimentally. Here, two complementary techniques are established to detect the genomic distribution of tracks of newly synthesized DNA in human cells by optical mapping in nanochannels. Their respective advantages and limitations are compared, and applied them to detect deregulations of the replication program induced by the antitumor drug hydroxyurea. The developments here thus broaden the field of applications accessible to nanofluidic technologies, and can be used in the future as part for molecular diagnostics in the context of high throughput cancer drug screening.
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Affiliation(s)
- Joris Lacroix
- CNRS, LAAS, 7 avenue du colonel Roche, F-31400, Toulouse, France
- Univ de Toulouse, LAAS, F-31400, Toulouse, France
| | - Sandrine Pélofy
- CNRS, LAAS, 7 avenue du colonel Roche, F-31400, Toulouse, France
- Univ de Toulouse, LAAS, F-31400, Toulouse, France
| | - Charline Blatché
- CNRS, LAAS, 7 avenue du colonel Roche, F-31400, Toulouse, France
- Univ de Toulouse, LAAS, F-31400, Toulouse, France
| | - Marie-Jeanne Pillaire
- Univ de Toulouse, LAAS, F-31400, Toulouse, France
- Equipe "Labellisée LA LIGUE CONTRE LE CANCER 2013" - Laboratoire d'Excellence Toulouse Cancer LABEX TOUCAN - Cancer Research Center of Toulouse, Inserm U1037, CNRS ERL5294, 2 Avenue Hubert Curien, CS 53717, 31037, Toulouse, France
| | - Sébastien Huet
- CNRS, UMR 6061, Institut Génétique et Développement de Rennes, F-35043, Rennes, France
- Université Rennes 1, UEB, UMR 6290, Faculté de Médecine, F-35043, Rennes, France
| | - Catherine Chapuis
- CNRS, UMR 6061, Institut Génétique et Développement de Rennes, F-35043, Rennes, France
- Université Rennes 1, UEB, UMR 6290, Faculté de Médecine, F-35043, Rennes, France
| | - Jean-Sébastien Hoffmann
- Univ de Toulouse, LAAS, F-31400, Toulouse, France
- Equipe "Labellisée LA LIGUE CONTRE LE CANCER 2013" - Laboratoire d'Excellence Toulouse Cancer LABEX TOUCAN - Cancer Research Center of Toulouse, Inserm U1037, CNRS ERL5294, 2 Avenue Hubert Curien, CS 53717, 31037, Toulouse, France
| | - Aurélien Bancaud
- CNRS, LAAS, 7 avenue du colonel Roche, F-31400, Toulouse, France
- Univ de Toulouse, LAAS, F-31400, Toulouse, France
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39
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Fornander LH, Frykholm K, Fritzsche J, Araya J, Nevin P, Werner E, Çakır A, Persson F, Garcin EB, Beuning PJ, Mehlig B, Modesti M, Westerlund F. Visualizing the Nonhomogeneous Structure of RAD51 Filaments Using Nanofluidic Channels. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:8403-8412. [PMID: 27479732 DOI: 10.1021/acs.langmuir.6b01877] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
RAD51 is the key component of the homologous recombination pathway in eukaryotic cells and performs its task by forming filaments on DNA. In this study we investigate the physical properties of RAD51 filaments formed on DNA using nanofluidic channels and fluorescence microscopy. Contrary to the bacterial ortholog RecA, RAD51 forms inhomogeneous filaments on long DNA in vitro, consisting of several protein patches. We demonstrate that a permanent "kink" in the filament is formed where two patches meet if the stretch of naked DNA between the patches is short. The kinks are readily seen in the present microscopy approach but would be hard to identify using conventional single DNA molecule techniques where the DNA is more stretched. We also demonstrate that protein patches separated by longer stretches of bare DNA roll up on each other and this is visualized as transiently overlapping filaments. RAD51 filaments can be formed at several different conditions, varying the cation (Mg(2+) or Ca(2+)), the DNA substrate (single-stranded or double-stranded), and the RAD51 concentration during filament nucleation, and we compare the properties of the different filaments formed. The results provide important information regarding the physical properties of RAD51 filaments but also demonstrate that nanofluidic channels are perfectly suited to study protein-DNA complexes.
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Affiliation(s)
| | | | | | - Joshua Araya
- Department of Chemistry and Chemical Biology, Northeastern University , Boston, Massachusetts 02115, United States
| | - Philip Nevin
- Department of Chemistry and Chemical Biology, Northeastern University , Boston, Massachusetts 02115, United States
| | - Erik Werner
- Department of Physics, University of Gothenburg , 412 96 Gothenburg, Sweden
| | - Ali Çakır
- Department of Physics, University of Gothenburg , 412 96 Gothenburg, Sweden
| | - Fredrik Persson
- Department for Cell and Molecular Biology, Science for Life Laboratory, Uppsala University , 751 24 Uppsala, Sweden
| | - Edwige B Garcin
- Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Université , 13273 Marseille, France
| | - Penny J Beuning
- Department of Chemistry and Chemical Biology, Northeastern University , Boston, Massachusetts 02115, United States
| | - Bernhard Mehlig
- Department of Physics, University of Gothenburg , 412 96 Gothenburg, Sweden
| | - Mauro Modesti
- Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Université , 13273 Marseille, France
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40
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Rapid identification of intact bacterial resistance plasmids via optical mapping of single DNA molecules. Sci Rep 2016; 6:30410. [PMID: 27460437 PMCID: PMC4961956 DOI: 10.1038/srep30410] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 07/05/2016] [Indexed: 11/08/2022] Open
Abstract
The rapid spread of antibiotic resistance – currently one of the greatest threats to human health according to WHO – is to a large extent enabled by plasmid-mediated horizontal transfer of resistance genes. Rapid identification and characterization of plasmids is thus important both for individual clinical outcomes and for epidemiological monitoring of antibiotic resistance. Toward this aim, we have developed an optical DNA mapping procedure where individual intact plasmids are elongated within nanofluidic channels and visualized through fluorescence microscopy, yielding barcodes that reflect the underlying sequence. The assay rapidly identifies plasmids through statistical comparisons with barcodes based on publicly available sequence repositories and also enables detection of structural variations. Since the assay yields holistic sequence information for individual intact plasmids, it is an ideal complement to next generation sequencing efforts which involve reassembly of sequence reads from fragmented DNA molecules. The assay should be applicable in microbiology labs around the world in applications ranging from fundamental plasmid biology to clinical epidemiology and diagnostics.
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41
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Müller V, Karami N, Nyberg LK, Pichler C, Torche Pedreschi PC, Quaderi S, Fritzsche J, Ambjörnsson T, Åhrén C, Westerlund F. Rapid Tracing of Resistance Plasmids in a Nosocomial Outbreak Using Optical DNA Mapping. ACS Infect Dis 2016; 2:322-8. [PMID: 27627201 DOI: 10.1021/acsinfecdis.6b00017] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Resistance to life-saving antibiotics increases rapidly worldwide, and multiresistant bacteria have become a global threat to human health. Presently, the most serious threat is the increasing spread of Enterobacteriaceae carrying genes coding for extended spectrum β-lactamases (ESBL) and carbapenemases on highly mobile plasmids. We here demonstrate how optical DNA maps of single plasmids can be used as fingerprints to trace plasmids, for example, during resistance outbreaks. We use the assay to demonstrate a potential transmission route of an ESBL-carrying plasmid between bacterial strains/species and between patients, during a polyclonal outbreak at a neonatal ward at Sahlgrenska University Hospital (Gothenburg, Sweden). Our results demonstrate that optical DNA mapping is an easy and rapid method for detecting the spread of plasmids mediating resistance. With the increasing prevalence of multiresistant bacteria, diagnostic tools that can aid in solving ongoing routes of transmission, in particular in hospital settings, will be of paramount importance.
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Affiliation(s)
- Vilhelm Müller
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296 Gothenburg, Sweden
| | - Nahid Karami
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska
Academy, University of Gothenburg, Guldhedsgatan 10, 41346 Gothenburg, Sweden
| | - Lena K. Nyberg
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296 Gothenburg, Sweden
| | - Christoffer Pichler
- Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, 22362 Lund, Sweden
| | - Paola C. Torche Pedreschi
- Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, 22362 Lund, Sweden
| | - Saair Quaderi
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296 Gothenburg, Sweden
- Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, 22362 Lund, Sweden
| | - Joachim Fritzsche
- Department of Applied
Physics, Chalmers University of Technology, Kemivägen 9, 41296 Gothenburg, Sweden
| | - Tobias Ambjörnsson
- Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, 22362 Lund, Sweden
| | - Christina Åhrén
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska
Academy, University of Gothenburg, Guldhedsgatan 10, 41346 Gothenburg, Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296 Gothenburg, Sweden
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42
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Frykholm K, Berntsson RPA, Claesson M, de Battice L, Odegrip R, Stenmark P, Westerlund F. DNA compaction by the bacteriophage protein Cox studied on the single DNA molecule level using nanofluidic channels. Nucleic Acids Res 2016; 44:7219-27. [PMID: 27131370 PMCID: PMC5009727 DOI: 10.1093/nar/gkw352] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 03/30/2016] [Indexed: 01/10/2023] Open
Abstract
The Cox protein from bacteriophage P2 forms oligomeric filaments and it has been proposed that DNA can be wound up around these filaments, similar to how histones condense DNA. We here use fluorescence microscopy to study single DNA–Cox complexes in nanofluidic channels and compare how the Cox homologs from phages P2 and WΦ affect DNA. By measuring the extension of nanoconfined DNA in absence and presence of Cox we show that the protein compacts DNA and that the binding is highly cooperative, in agreement with the model of a Cox filament around which DNA is wrapped. Furthermore, comparing microscopy images for the wild-type P2 Cox protein and two mutants allows us to discriminate between compaction due to filament formation and compaction by monomeric Cox. P2 and WΦ Cox have similar effects on the physical properties of DNA and the subtle, but significant, differences in DNA binding are due to differences in binding affinity rather than binding mode. The presented work highlights the use of single DNA molecule studies to confirm structural predictions from X-ray crystallography. It also shows how a small protein by oligomerization can have great impact on the organization of DNA and thereby fulfill multiple regulatory functions.
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Affiliation(s)
- Karolin Frykholm
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden
| | - Ronnie Per-Arne Berntsson
- Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-10691 Stockholm, Sweden
| | - Magnus Claesson
- Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-10691 Stockholm, Sweden
| | - Laura de Battice
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden
| | - Richard Odegrip
- Department of Molecular Biosciences, The Wenner-Gren Institute, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-10691 Stockholm, Sweden
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-10691 Stockholm, Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden
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43
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Iarko V, Werner E, Nyberg LK, Müller V, Fritzsche J, Ambjörnsson T, Beech JP, Tegenfeldt JO, Mehlig K, Westerlund F, Mehlig B. Extension of nanoconfined DNA: Quantitative comparison between experiment and theory. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:062701. [PMID: 26764721 DOI: 10.1103/physreve.92.062701] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Indexed: 05/27/2023]
Abstract
The extension of DNA confined to nanochannels has been studied intensively and in detail. However, quantitative comparisons between experiments and model calculations are difficult because most theoretical predictions involve undetermined prefactors, and because the model parameters (contour length, Kuhn length, effective width) are difficult to compute reliably, leading to substantial uncertainties. Here we use a recent asymptotically exact theory for the DNA extension in the "extended de Gennes regime" that allows us to compare experimental results with theory. For this purpose, we performed experiments measuring the mean DNA extension and its standard deviation while varying the channel geometry, dye intercalation ratio, and ionic strength of the buffer. The experimental results agree very well with theory at high ionic strengths, indicating that the model parameters are reliable. At low ionic strengths, the agreement is less good. We discuss possible reasons. In principle, our approach allows us to measure the Kuhn length and the effective width of a single DNA molecule and more generally of semiflexible polymers in solution.
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Affiliation(s)
- V Iarko
- Department of Physics, University of Gothenburg, 412 96 Göteborg, Sweden
| | - E Werner
- Department of Physics, University of Gothenburg, 412 96 Göteborg, Sweden
| | - L K Nyberg
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Göteborg, Sweden
| | - V Müller
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Göteborg, Sweden
| | - J Fritzsche
- Department of Applied Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden
| | - T Ambjörnsson
- Department of Astronomy and Theoretical Physics, Lund University, 22 100 Lund, Sweden
| | - J P Beech
- Department of Physics, Division of Solid State Physics, Lund University, 22 100 Lund, Sweden
| | - J O Tegenfeldt
- Department of Physics, Division of Solid State Physics, Lund University, 22 100 Lund, Sweden
- NanoLund, Lund University, 22 100 Lund, Sweden
| | - K Mehlig
- Department of Public Health and Community Medicine, University of Gothenburg, 413 46 Göteborg, Sweden
| | - F Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Göteborg, Sweden
| | - B Mehlig
- Department of Physics, University of Gothenburg, 412 96 Göteborg, Sweden
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44
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Grunwald A, Dahan M, Giesbertz A, Nilsson A, Nyberg LK, Weinhold E, Ambjörnsson T, Westerlund F, Ebenstein Y. Bacteriophage strain typing by rapid single molecule analysis. Nucleic Acids Res 2015; 43:e117. [PMID: 26019180 PMCID: PMC4605287 DOI: 10.1093/nar/gkv563] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 05/14/2015] [Accepted: 05/15/2015] [Indexed: 01/12/2023] Open
Abstract
Rapid characterization of unknown biological samples is under the focus of many current studies. Here we report a method for screening of biological samples by optical mapping of their DNA. We use a novel, one-step chemo-enzymatic reaction to covalently bind fluorophores to DNA at the four-base recognition sites of a DNA methyltransferase. Due to the diffraction limit of light, the dense distribution of labels results in a continuous fluorescent signal along the DNA. The amplitude modulations (AM) of the fluorescence intensity along the stretched DNA molecules exhibit a unique molecular fingerprint that can be used for identification. We show that this labelling scheme is highly informative, allowing accurate genotyping. We demonstrate the method by labelling the genomes of λ and T7 bacteriophages, resulting in a consistent, unique AM profile for each genome. These profiles are also successfully used for identification of the phages from a background phage library. Our method may provide a facile route for screening and typing of various organisms and has potential applications in metagenomics studies of various ecosystems.
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Affiliation(s)
- Assaf Grunwald
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Moran Dahan
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Anna Giesbertz
- Institute of Organic Chemistry, RWTH Aachen University, Aachen D-52056 Germany
| | - Adam Nilsson
- Department of Astronomy and Theoretical Physics, Lund University, Lund 223 62, Sweden
| | - Lena K Nyberg
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg 412 96, Sweden
| | - Elmar Weinhold
- Institute of Organic Chemistry, RWTH Aachen University, Aachen D-52056 Germany
| | - Tobias Ambjörnsson
- Department of Astronomy and Theoretical Physics, Lund University, Lund 223 62, Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg 412 96, Sweden
| | - Yuval Ebenstein
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 6997801, Israel
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45
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Reifenberger JG, Dorfman KD, Cao H. Topological events in single molecules of E. coli DNA confined in nanochannels. Analyst 2015; 140:4887-94. [PMID: 25991508 PMCID: PMC4486629 DOI: 10.1039/c5an00343a] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present experimental data concerning potential topological events such as folds, internal backfolds, and/or knots within long molecules of double-stranded DNA when they are stretched by confinement in a nanochannel. Genomic DNA from E. coli was labeled near the 'GCTCTTC' sequence with a fluorescently labeled dUTP analog and stained with the DNA intercalator YOYO. Individual long molecules of DNA were then linearized and imaged using methods based on the NanoChannel Array technology (Irys® System) available from BioNano Genomics. Data were collected on 189 153 molecules of length greater than 50 kilobases. A custom code was developed to search for abnormal intensity spikes in the YOYO backbone profile along the length of individual molecules. By correlating the YOYO intensity spikes with the aligned barcode pattern to the reference, we were able to correlate the bright intensity regions of YOYO with abnormal stretching in the molecule, which suggests these events were either a knot or a region of internal backfolding within the DNA. We interpret the results of our experiments involving molecules exceeding 50 kilobases in the context of existing simulation data for relatively short DNA, typically several kilobases. The frequency of these events is lower than the predictions from simulations, while the size of the events is larger than simulation predictions and often exceeds the molecular weight of the simulated molecules. We also identified DNA molecules that exhibit large, single folds as they enter the nanochannels. Overall, topological events occur at a low frequency (∼7% of all molecules) and pose an easily surmountable obstacle for the practice of genome mapping in nanochannels.
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46
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Frykholm K, Nyberg LK, Lagerstedt E, Noble C, Fritzsche J, Karami N, Ambjörnsson T, Sandegren L, Westerlund F. Fast size-determination of intact bacterial plasmids using nanofluidic channels. LAB ON A CHIP 2015; 15:2739-2743. [PMID: 25997119 DOI: 10.1039/c5lc00378d] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We demonstrate how nanofluidic channels can be used as a tool to rapidly determine the number and sizes of plasmids in bacterial isolates. Each step can be automated at low cost, opening up opportunities for general use in microbiology labs.
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Affiliation(s)
- K Frykholm
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.
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47
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Gupta D, Miller JJ, Muralidhar A, Mahshid S, Reisner W, Dorfman KD. Experimental evidence of weak excluded volume effects for nanochannel confined DNA. ACS Macro Lett 2015; 4:759-763. [PMID: 26664782 PMCID: PMC4671635 DOI: 10.1021/acsmacrolett.5b00340] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present experimental demonstration that weak excluded volume effects arise in DNA nanochannel confinement. In particular, by performing measurements of the variance in chain extension as a function of nanochannel dimension for effective channel size ranging from 305 nm to 453 nm, we show that the scaling of the variance in extension with channel size rejects the de Gennes scaling δ2X ~ D1/3 in favor of δ2X ~ D0 using uncertainty at the 95% confidence level. We also show how simulations and confinement spectroscopy can be combined to reduce molecular weight dispersity effects arising from shearing, photocleavage, and nonuniform staining of DNA.
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Affiliation(s)
- Damini Gupta
- Department of Chemical Engineering and Materials Science, University of Minnesota – Twin Cities, 421 Washington Ave SE, Minneapolis, Minnesota 55455, USA
| | - Jeremy J. Miller
- Department of Chemical Engineering and Materials Science, University of Minnesota – Twin Cities, 421 Washington Ave SE, Minneapolis, Minnesota 55455, USA
| | - Abhiram Muralidhar
- Department of Chemical Engineering and Materials Science, University of Minnesota – Twin Cities, 421 Washington Ave SE, Minneapolis, Minnesota 55455, USA
| | - Sara Mahshid
- Physics Department, McGill University, 3600 rue University, Montreal QC H3A 2T8, Canada
| | - Walter Reisner
- Physics Department, McGill University, 3600 rue University, Montreal QC H3A 2T8, Canada
| | - Kevin D. Dorfman
- Department of Chemical Engineering and Materials Science, University of Minnesota – Twin Cities, 421 Washington Ave SE, Minneapolis, Minnesota 55455, USA
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48
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A fast and scalable kymograph alignment algorithm for nanochannel-based optical DNA mappings. PLoS One 2015; 10:e0121905. [PMID: 25875920 PMCID: PMC4395267 DOI: 10.1371/journal.pone.0121905] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 02/05/2015] [Indexed: 11/26/2022] Open
Abstract
Optical mapping by direct visualization of individual DNA molecules, stretched in nanochannels with sequence-specific fluorescent labeling, represents a promising tool for disease diagnostics and genomics. An important challenge for this technique is thermal motion of the DNA as it undergoes imaging; this blurs fluorescent patterns along the DNA and results in information loss. Correcting for this effect (a process referred to as kymograph alignment) is a common preprocessing step in nanochannel-based optical mapping workflows, and we present here a highly efficient algorithm to accomplish this via pattern recognition. We compare our method with the one previous approach, and we find that our method is orders of magnitude faster while producing data of similar quality. We demonstrate proof of principle of our approach on experimental data consisting of melt mapped bacteriophage DNA.
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49
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Reinhart WF, Reifenberger JG, Gupta D, Muralidhar A, Sheats J, Cao H, Dorfman KD. Distribution of distances between DNA barcode labels in nanochannels close to the persistence length. J Chem Phys 2015; 142:064902. [PMID: 25681938 PMCID: PMC4327924 DOI: 10.1063/1.4907552] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 01/25/2015] [Indexed: 11/14/2022] Open
Abstract
We obtained experimental extension data for barcoded E. coli genomic DNA molecules confined in nanochannels from 40 nm to 51 nm in width. The resulting data set consists of 1 627 779 measurements of the distance between fluorescent probes on 25 407 individual molecules. The probability density for the extension between labels is negatively skewed, and the magnitude of the skewness is relatively insensitive to the distance between labels. The two Odijk theories for DNA confinement bracket the mean extension and its variance, consistent with the scaling arguments underlying the theories. We also find that a harmonic approximation to the free energy, obtained directly from the probability density for the distance between barcode labels, leads to substantial quantitative error in the variance of the extension data. These results suggest that a theory for DNA confinement in such channels must account for the anharmonic nature of the free energy as a function of chain extension.
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Affiliation(s)
- Wesley F Reinhart
- Department of Chemical Engineering and Materials Science, University of Minnesota-Twin Cities, 421 Washington Ave SE, Minneapolis, Minnesota 55455, USA
| | - Jeff G Reifenberger
- BioNano Genomics, 9640 Towne Centre Dr., Ste. 100, San Diego, California 92121, USA
| | - Damini Gupta
- Department of Chemical Engineering and Materials Science, University of Minnesota-Twin Cities, 421 Washington Ave SE, Minneapolis, Minnesota 55455, USA
| | - Abhiram Muralidhar
- Department of Chemical Engineering and Materials Science, University of Minnesota-Twin Cities, 421 Washington Ave SE, Minneapolis, Minnesota 55455, USA
| | - Julian Sheats
- Department of Chemical Engineering and Materials Science, University of Minnesota-Twin Cities, 421 Washington Ave SE, Minneapolis, Minnesota 55455, USA
| | - Han Cao
- BioNano Genomics, 9640 Towne Centre Dr., Ste. 100, San Diego, California 92121, USA
| | - Kevin D Dorfman
- Department of Chemical Engineering and Materials Science, University of Minnesota-Twin Cities, 421 Washington Ave SE, Minneapolis, Minnesota 55455, USA
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50
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Alizadehheidari M, Werner E, Noble C, Reiter-Schad M, Nyberg LK, Fritzsche J, Mehlig B, Tegenfeldt JO, Ambjörnsson T, Persson F, Westerlund F. Nanoconfined Circular and Linear DNA: Equilibrium Conformations and Unfolding Kinetics. Macromolecules 2015. [DOI: 10.1021/ma5022067] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
| | - Erik Werner
- Department
of Physics, Gothenburg University, Gothenburg, Sweden
| | | | | | | | | | - Bernhard Mehlig
- Department
of Physics, Gothenburg University, Gothenburg, Sweden
| | | | | | - Fredrik Persson
- Department of Cell and
Molecular Biology, Uppsala University, Uppsala, Sweden
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