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Zou X, Nguyen M, Overbeek J, Cao B, Davis JJ. Classification of bacterial plasmid and chromosome derived sequences using machine learning. PLoS One 2022; 17:e0279280. [PMID: 36525447 PMCID: PMC9757591 DOI: 10.1371/journal.pone.0279280] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022] Open
Abstract
Plasmids are important genetic elements that facilitate horizonal gene transfer between bacteria and contribute to the spread of virulence and antimicrobial resistance. Most bacterial genome sequences in the public archives exist in draft form with many contigs, making it difficult to determine if a contig is of chromosomal or plasmid origin. Using a training set of contigs comprising 10,584 chromosomes and 10,654 plasmids from the PATRIC database, we evaluated several machine learning models including random forest, logistic regression, XGBoost, and a neural network for their ability to classify chromosomal and plasmid sequences using nucleotide k-mers as features. Based on the methods tested, a neural network model that used nucleotide 6-mers as features that was trained on randomly selected chromosomal and plasmid subsequences 5kb in length achieved the best performance, outperforming existing out-of-the-box methods, with an average accuracy of 89.38% ± 2.16% over a 10-fold cross validation. The model accuracy can be improved to 92.08% by using a voting strategy when classifying holdout sequences. In both plasmids and chromosomes, subsequences encoding functions involved in horizontal gene transfer-including hypothetical proteins, transporters, phage, mobile elements, and CRISPR elements-were most likely to be misclassified by the model. This study provides a straightforward approach for identifying plasmid-encoding sequences in short read assemblies without the need for sequence alignment-based tools.
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Affiliation(s)
- Xiaohui Zou
- Laboratory of Clinical Microbiology and Infectious Diseases, Department of Pulmonary and Critical Care Medicine, Center for Respiratory Diseases, China-Japan Friendship Hospital, National Clinical Research Centre for Respiratory Disease, Beijing, China
| | - Marcus Nguyen
- Data Science and Learning Division, Computing Environment and Life Sciences Directorate, Argonne National Laboratory, Lemont, IL, United States of America
- Consortium for Advanced Science and Engineering, University of Chicago, Chicago, IL, United States of America
| | - Jamie Overbeek
- Data Science and Learning Division, Computing Environment and Life Sciences Directorate, Argonne National Laboratory, Lemont, IL, United States of America
- Consortium for Advanced Science and Engineering, University of Chicago, Chicago, IL, United States of America
| | - Bin Cao
- Laboratory of Clinical Microbiology and Infectious Diseases, Department of Pulmonary and Critical Care Medicine, Center for Respiratory Diseases, China-Japan Friendship Hospital, National Clinical Research Centre for Respiratory Disease, Beijing, China
- * E-mail: (JJD); (BC)
| | - James J. Davis
- Data Science and Learning Division, Computing Environment and Life Sciences Directorate, Argonne National Laboratory, Lemont, IL, United States of America
- Consortium for Advanced Science and Engineering, University of Chicago, Chicago, IL, United States of America
- * E-mail: (JJD); (BC)
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2
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Global Distribution and Diversity of Prevalent Sewage Water Plasmidomes. mSystems 2022; 7:e0019122. [PMID: 36069451 PMCID: PMC9600348 DOI: 10.1128/msystems.00191-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Sewage water from around the world contains an abundance of short plasmids, several of which harbor antimicrobial resistance genes (ARGs). The global dynamics of plasmid-derived antimicrobial resistance and functions are only starting to be unveiled. Here, we utilized a previously created data set of 159,332 assumed small plasmids from 24 different global sewage samples. The detailed phylogeny, as well as the interplay between their protein domains, ARGs, and predicted bacterial host genera, were investigated to understand sewage plasmidome dynamics globally. A total of 58,429 circular elements carried genes encoding plasmid-related features, and MASH distance analyses showed a high degree of diversity. A single (yet diverse) cluster of 520 predicted Acinetobacter plasmids was predominant among the European sewage water. Our results suggested a prevalence of plasmid-backbone gene combinations over others. This could be related to selected bacterial genera that act as bacterial hosts. These combinations also mirrored the geographical locations of the sewage samples. Our functional domain network analysis identified three groups of plasmids. However, these backbone domains were not exclusive to any given group, and Acinetobacter was the dominant host genus among the theta-replicating plasmids, which contained a reservoir of the macrolide resistance gene pair msr(E) and mph(E). Macrolide resistance genes were the most common in the sewage plasmidomes and were found in the largest number of unique plasmids. While msr(E) and mph(E) were limited to Acinetobacter, erm(B) was disseminated among a range of Firmicutes plasmids, including Staphylococcus and Streptococcus, highlighting a potential reservoir of antibiotic resistance for these pathogens from around the globe. IMPORTANCE Antimicrobial resistance is a global threat to human health, as it inhibits our ability to treat infectious diseases. This study utilizes sewage water plasmidomes to identify plasmid-derived features and highlights antimicrobial resistance genes, particularly macrolide resistance genes, as abundant in sewage water plasmidomes in Firmicutes and Acinetobacter hosts. The emergence of macrolide resistance in these bacteria suggests that macrolide selective pressure exists in sewage water and that the resident bacteria can readily acquire macrolide resistance via small plasmids.
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Assessing the genomic composition, putative ecological relevance and biotechnological potential of plasmids from sponge bacterial symbionts. Microbiol Res 2022; 265:127183. [PMID: 36108440 DOI: 10.1016/j.micres.2022.127183] [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: 02/10/2022] [Revised: 02/24/2022] [Accepted: 09/01/2022] [Indexed: 11/24/2022]
Abstract
Plasmid-mediated transfer of genes can have direct consequences in several biological processes within sponge microbial communities. However, very few studies have attempted genomic and functional characterization of plasmids from marine host-associated microbial communities in general and those of sponges in particular. In the present study, we used an endogenous plasmid isolation method to obtain plasmids from bacterial symbionts of the marine sponges Stylissa carteri and Paratetilla sp. and investigated the genomic composition, putative ecological relevance and biotechnological potential of these plasmids. In total, we isolated and characterized three complete plasmids, three plasmid prophages and one incomplete plasmid. Our results highlight the importance of plasmids to transfer relevant genetic traits putatively involved in microbial symbiont adaptation and host-microbe and microbe-microbe interactions. For example, putative genes involved in bacterial response to chemical stress, competition, metabolic versatility and mediation of bacterial colonization and pathogenicity were detected. Genes coding for enzymes and toxins of biotechnological potential were also detected. Most plasmid prophage coding sequences were, however, hypothetical proteins with unknown functions. Overall, this study highlights the ecological relevance of plasmids in the marine sponge microbiome and provides evidence that plasmids of sponge bacterial symbionts may represent an untapped resource of genes of biotechnological interest.
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Karami Fath M, Karimfar N, Fazlollahpour Naghibi A, Shafa S, Ghasemi Shiran M, Ataei M, Dehghanzadeh H, Nabi Afjadi M, Ghadiri T, Payandeh Z, Tarhriz V. Revisiting characteristics of oncogenic extrachromosomal DNA as mobile enhancers on neuroblastoma and glioma cancers. Cancer Cell Int 2022; 22:200. [PMID: 35614494 PMCID: PMC9131661 DOI: 10.1186/s12935-022-02617-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/18/2022] [Indexed: 12/21/2022] Open
Abstract
Cancer can be induced by a variety of possible causes, including tumor suppressor gene failure and proto-oncogene hyperactivation. Tumor-associated extrachromosomal circular DNA has been proposed to endanger human health and speed up the progression of cancer. The amplification of ecDNA has raised the oncogene copy number in numerous malignancies according to whole-genome sequencing on distinct cancer types. The unusual structure and function of ecDNA, and its potential role in understanding current cancer genome maps, make it a hotspot to study tumor pathogenesis and evolution. The discovery of the basic mechanisms of ecDNA in the emergence and growth of malignancies could lead researchers to develop new cancer therapies. Despite recent progress, different aspects of ecDNA require more investigation. We focused on the features, and analyzed the bio-genesis, and origin of ecDNA in this review, as well as its functions in neuroblastoma and glioma cancers.
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Affiliation(s)
- Mohsen Karami Fath
- Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Nastaran Karimfar
- Faculty of Veterinary Medicine, Islamic Azad University, Tabriz Branch, Tabriz, Iran
| | | | - Shahriyar Shafa
- School of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Melika Ghasemi Shiran
- Department of Biology, Faculty of Sciences, Central Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Mehran Ataei
- Department of Biology, Faculty of Sciences, Shahid Chamran University, Ahvaz, Iran
| | | | - Mohsen Nabi Afjadi
- Department of Biochemistry, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran.
| | - Tahereh Ghadiri
- Department of Neuroscience and Cognition, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran. .,Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran. .,Neurosiences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Zahra Payandeh
- Department Medical Biochemistry and Biophysics, Division Medical Inflammation Research, Karolinska Institute, Stockholm, Sweden.
| | - Vahideh Tarhriz
- Molecular Medicine Research Center, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran.
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5
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Meng M, Li Y, Yao H. Plasmid-Mediated Transfer of Antibiotic Resistance Genes in Soil. Antibiotics (Basel) 2022; 11:antibiotics11040525. [PMID: 35453275 PMCID: PMC9024699 DOI: 10.3390/antibiotics11040525] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/09/2022] [Accepted: 04/13/2022] [Indexed: 12/18/2022] Open
Abstract
Due to selective pressure from the widespread use of antibiotics, antibiotic resistance genes (ARGs) are found in human hosts, plants, and animals and virtually all natural environments. Their migration and transmission in different environmental media are often more harmful than antibiotics themselves. ARGs mainly move between different microorganisms through a variety of mobile genetic elements (MGEs), such as plasmids and phages. The soil environment is regarded as the most microbially active biosphere on the Earth’s surface and is closely related to human activities. With the increase in human activity, soils are becoming increasingly contaminated with antibiotics and ARGs. Soil plasmids play an important role in this process. This paper reviews the current scenario of plasmid-mediated migration and transmission of ARGs in natural environments and under different antibiotic selection pressures, summarizes the current methods of plasmid extraction and analysis, and briefly introduces the mechanism of plasmid splice transfer using the F factor as an example. However, as the global spread of drug-resistant bacteria has increased and the knowledge of MGEs improves, the contribution of soil plasmids to resistance gene transmission needs to be further investigated. The prevalence of multidrug-resistant bacteria has also made the effective prevention of the transmission of resistance genes through the plasmid-bacteria pathway a major research priority.
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Affiliation(s)
- Miaoling Meng
- Research Center for Environmental Ecology and Engineering, School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, Wuhan 430073, China;
| | - Yaying Li
- Key Laboratory of Urban Environment and Health, Ningbo Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China;
- Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control, CAS Haixi Industrial Technology Innovation Center in Beilun, Ningbo 315830, China
| | - Huaiying Yao
- Research Center for Environmental Ecology and Engineering, School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, Wuhan 430073, China;
- Key Laboratory of Urban Environment and Health, Ningbo Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China;
- Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control, CAS Haixi Industrial Technology Innovation Center in Beilun, Ningbo 315830, China
- Correspondence: ; Tel.: +86-0574-8678-4812
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Perez MF, Saona LA, Farías ME, Poehlein A, Meinhardt F, Daniel R, Dib JR. Assessment of the plasmidome of an extremophilic microbial community from the Diamante Lake, Argentina. Sci Rep 2021; 11:21459. [PMID: 34728656 PMCID: PMC8563766 DOI: 10.1038/s41598-021-00753-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 10/15/2021] [Indexed: 12/02/2022] Open
Abstract
Diamante Lake located at 4589 m.a.s.l. in the Andean Puna constitutes an extreme environment. It is exposed to multiple extreme conditions such as an unusually high concentration of arsenic (over 300 mg L-1) and low oxygen pressure. Microorganisms thriving in the lake display specific genotypes that facilitate survival, which include at least a multitude of plasmid-encoded resistance traits. Hence, the genetic information provided by the plasmids essentially contributes to understand adaptation to different stressors. Though plasmids from cultivable organisms have already been analyzed to the sequence level, the impact of the entire plasmid-borne genetic information on such microbial ecosystem is not known. This study aims at assessing the plasmidome from Diamante Lake, which facilitates the identification of potential hosts and prediction of gene functions as well as the ecological impact of mobile genetic elements. The deep-sequencing analysis revealed a large fraction of previously unknown DNA sequences of which the majority encoded putative proteins of unknown function. Remarkably, functions related to the oxidative stress response, DNA repair, as well as arsenic- and antibiotic resistances were annotated. Additionally, all necessary capacities related to plasmid replication, mobilization and maintenance were detected. Sequences characteristic for megaplasmids and other already known plasmid-associated genes were identified as well. The study highlights the potential of the deep-sequencing approach specifically targeting plasmid populations as it allows to evaluate the ecological impact of plasmids from (cultivable and non-cultivable) microorganisms, thereby contributing to the understanding of the distribution of resistance factors within an extremophilic microbial community.
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Affiliation(s)
- María Florencia Perez
- grid.423606.50000 0001 1945 2152Planta Piloto de Procesos Industriales Microbiológicos, Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán, Tucumán Argentina
| | - Luis Alberto Saona
- grid.423606.50000 0001 1945 2152Planta Piloto de Procesos Industriales Microbiológicos, Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán, Tucumán Argentina
| | - María Eugenia Farías
- grid.423606.50000 0001 1945 2152Planta Piloto de Procesos Industriales Microbiológicos, Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán, Tucumán Argentina
| | - Anja Poehlein
- grid.7450.60000 0001 2364 4210Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Friedhelm Meinhardt
- grid.5949.10000 0001 2172 9288Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms Universität Münster, Münster, Germany
| | - Rolf Daniel
- grid.7450.60000 0001 2364 4210Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Julián Rafael Dib
- grid.423606.50000 0001 1945 2152Planta Piloto de Procesos Industriales Microbiológicos, Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán, Tucumán Argentina ,grid.108162.c0000000121496664Instituto de Microbiología, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Miguel de Tucumán, Tucumán Argentina
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7
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Wang T, Zhang H, Zhou Y, Shi J. Extrachromosomal circular DNA: a new potential role in cancer progression. J Transl Med 2021; 19:257. [PMID: 34112178 PMCID: PMC8194206 DOI: 10.1186/s12967-021-02927-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 06/04/2021] [Indexed: 12/15/2022] Open
Abstract
Extrachromosomal circular DNA (eccDNA) is considered a circular DNA molecule that exists widely in nature and is independent of conventional chromosomes. eccDNA can be divided into small polydispersed circular DNA (spcDNA), telomeric circles (t-circles), microDNA, and extrachromosomal DNA (ecDNA) according to its size and sequence. Multiple studies have shown that eccDNA is the product of genomic instability, has rich and important biological functions, and is involved in the occurrence of many diseases, including cancer. In this review, we focus on the discovery history, formation process, characteristics, and physiological functions of eccDNAs; the potential functions of various eccDNAs in human cancer; and the research methods employed to study eccDNA.
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Affiliation(s)
- Tianyi Wang
- Nantong Key Laboratory of Translational Medicine in Cardiothoracic Diseases, and Research Institution of Translational Medicine in Cardiothoracic Diseases, Affiliated Hospital of Nantong University, No. 20, Xisi Road, Nantong, 226001, Jiangsu, China.,Department of Thoracic Surgery, Affiliated Hospital of Nantong University, No. 20, Xisi Road, Nantong, 226001, Jiangsu, China
| | - Haijian Zhang
- Research Center of Clinical Medicine, Affiliated Hospital of Nantong University, No. 20, Xisi Road, Nantong, 226001, Jiangsu, China
| | - Youlang Zhou
- Research Center of Clinical Medicine, Affiliated Hospital of Nantong University, No. 20, Xisi Road, Nantong, 226001, Jiangsu, China
| | - Jiahai Shi
- Nantong Key Laboratory of Translational Medicine in Cardiothoracic Diseases, and Research Institution of Translational Medicine in Cardiothoracic Diseases, Affiliated Hospital of Nantong University, No. 20, Xisi Road, Nantong, 226001, Jiangsu, China. .,Department of Thoracic Surgery, Affiliated Hospital of Nantong University, No. 20, Xisi Road, Nantong, 226001, Jiangsu, China.
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8
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Blake KS, Choi J, Dantas G. Approaches for characterizing and tracking hospital-associated multidrug-resistant bacteria. Cell Mol Life Sci 2021; 78:2585-2606. [PMID: 33582841 PMCID: PMC8005480 DOI: 10.1007/s00018-020-03717-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 10/26/2020] [Accepted: 11/17/2020] [Indexed: 12/24/2022]
Abstract
Hospital-associated infections are a major concern for global public health. Infections with antibiotic-resistant pathogens can cause empiric treatment failure, and for infections with multidrug-resistant bacteria which can overcome antibiotics of "last resort" there exists no alternative treatments. Despite extensive sanitization protocols, the hospital environment is a potent reservoir and vector of antibiotic-resistant organisms. Pathogens can persist on hospital surfaces and plumbing for months to years, acquire new antibiotic resistance genes by horizontal gene transfer, and initiate outbreaks of hospital-associated infections by spreading to patients via healthcare workers and visitors. Advancements in next-generation sequencing of bacterial genomes and metagenomes have expanded our ability to (1) identify species and track distinct strains, (2) comprehensively profile antibiotic resistance genes, and (3) resolve the mobile elements that facilitate intra- and intercellular gene transfer. This information can, in turn, be used to characterize the population dynamics of hospital-associated microbiota, track outbreaks to their environmental reservoirs, and inform future interventions. This review provides a detailed overview of the approaches and bioinformatic tools available to study isolates and metagenomes of hospital-associated bacteria, and their multi-layered networks of transmission.
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Affiliation(s)
- Kevin S Blake
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - JooHee Choi
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Gautam Dantas
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
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9
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Oliveira V, Polónia ARM, Cleary DFR, Huang YM, de Voogd NJ, da Rocha UN, Gomes NCM. Characterization of putative circular plasmids in sponge-associated bacterial communities using a selective multiply-primed rolling circle amplification. Mol Ecol Resour 2020; 21:110-121. [PMID: 32866335 DOI: 10.1111/1755-0998.13248] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 07/22/2020] [Accepted: 08/14/2020] [Indexed: 11/28/2022]
Abstract
Plasmid transfers among bacterial populations can directly influence the ecological adaptation of these populations and their interactions with host species and environment. In this study, we developed a selective multiply-primed rolling circle amplification (smRCA) approach to enrich and characterize circular plasmid DNA from sponge microbial symbionts via high-throughput sequencing (HTS). DNA (plasmid and total community DNA) obtained from sponge (Cinachyrella sp.) samples and a bacterial symbiont (Vibrio sp. CyArs1) isolated from the same sponge species (carrying unknown plasmids) were used to develop and validate our methodology. The smRCA was performed during 16 hr with 141 plasmid-specific primers covering all known circular plasmid groups. The amplified products were purified and subjected to a reamplification with random hexamer primers (2 hr) and then sequenced using Illumina MiSeq. The developed method resulted in the successful amplification and characterization of the sponge plasmidome and allowed us to detect plasmids associated with the bacterial symbiont Vibrio sp. CyArs1 in the sponge host. In addition to this, a large number of small (<2 kbp) and cryptic plasmids were also amplified in sponge samples. Functional analysis identified proteins involved in the control of plasmid partitioning, maintenance and replication. However, most plasmids contained unknown genes, which could potentially serve as a resource of unknown genetic information and novel replication systems. Overall, our results indicate that the smRCA-HTS approach developed here was able to selectively enrich and characterize plasmids from bacterial isolates and sponge host microbial communities, including plasmids larger than 20 kbp.
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Affiliation(s)
- Vanessa Oliveira
- Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal
| | - Ana R M Polónia
- Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal
| | - Daniel F R Cleary
- Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal
| | - Yusheng M Huang
- Tropical Island Sustainable Development Research Center, National Penghu University of Science and Technology, Magong City Penghu, Taiwan.,Department of Marine Recreation, National Penghu University of Science and Technology, Magong City Penghu, Taiwan
| | - Nicole J de Voogd
- Marine Biodiversity, Naturalis Biodiversity Center, Leiden, The Netherlands.,Institute of Environmental Sciences (CML), Leiden University, Leiden, The Netherlands
| | - Ulisses N da Rocha
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Newton C M Gomes
- Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal
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10
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Saak CC, Dinh CB, Dutton RJ. Experimental approaches to tracking mobile genetic elements in microbial communities. FEMS Microbiol Rev 2020; 44:606-630. [PMID: 32672812 PMCID: PMC7476777 DOI: 10.1093/femsre/fuaa025] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 06/29/2020] [Indexed: 12/19/2022] Open
Abstract
Horizontal gene transfer is an important mechanism of microbial evolution and is often driven by the movement of mobile genetic elements between cells. Due to the fact that microbes live within communities, various mechanisms of horizontal gene transfer and types of mobile elements can co-occur. However, the ways in which horizontal gene transfer impacts and is impacted by communities containing diverse mobile elements has been challenging to address. Thus, the field would benefit from incorporating community-level information and novel approaches alongside existing methods. Emerging technologies for tracking mobile elements and assigning them to host organisms provide promise for understanding the web of potential DNA transfers in diverse microbial communities more comprehensively. Compared to existing experimental approaches, chromosome conformation capture and methylome analyses have the potential to simultaneously study various types of mobile elements and their associated hosts. We also briefly discuss how fermented food microbiomes, given their experimental tractability and moderate species complexity, make ideal models to which to apply the techniques discussed herein and how they can be used to address outstanding questions in the field of horizontal gene transfer in microbial communities.
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Affiliation(s)
- Christina C Saak
- Division of Biological Sciences, Section of Molecular Biology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Cong B Dinh
- Division of Biological Sciences, Section of Molecular Biology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Rachel J Dutton
- Division of Biological Sciences, Section of Molecular Biology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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11
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Perez MF, Kurth D, Farías ME, Soria MN, Castillo Villamizar GA, Poehlein A, Daniel R, Dib JR. First Report on the Plasmidome From a High-Altitude Lake of the Andean Puna. Front Microbiol 2020; 11:1343. [PMID: 32655530 PMCID: PMC7324554 DOI: 10.3389/fmicb.2020.01343] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Accepted: 05/26/2020] [Indexed: 12/11/2022] Open
Abstract
Mobile genetic elements, including plasmids, drive the evolution of prokaryotic genomes through the horizontal transfer of genes allowing genetic exchange between bacteria. Moreover, plasmids carry accessory genes, which encode functions that may offer an advantage to the host. Thus, it is expected that in a certain ecological niche, plasmids are enriched in accessory functions, which are important for their hosts to proliferate in that niche. Puquio de Campo Naranja is a high-altitude lake from the Andean Puna exposed to multiple extreme conditions, including high UV radiation, alkalinity, high concentrations of arsenic, heavy metals, dissolved salts, high thermal amplitude and low O2 pressure. Microorganisms living in this lake need to develop efficient mechanisms and strategies to cope under these conditions. The aim of this study was to characterize the plasmidome of microbialites from Puquio de Campo Naranja, and identify potential hosts and encoded functions using a deep-sequencing approach. The potential ecological impact of the plasmidome, including plasmids from cultivable and non-cultivable microorganisms, is described for the first time in a lake representing an extreme environment of the Puna. This study showed that the recovered genetic information for the plasmidome was novel in comparison to the metagenome derived from the same environment. The study of the total plasmid population allowed the identification of genetic features typically encoded by plasmids, such as resistance and virulence factors. The resistance genes comprised resistances to heavy metals, antibiotics and stress factors. These results highlight the key role of plasmids for their hosts and impact of extrachromosomal elements to thrive in a certain ecological niche.
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Affiliation(s)
- María Florencia Perez
- Planta Piloto de Procesos Industriales Microbiológicos, Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán, Argentina
| | - Daniel Kurth
- Planta Piloto de Procesos Industriales Microbiológicos, Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán, Argentina
| | - María Eugenia Farías
- Planta Piloto de Procesos Industriales Microbiológicos, Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán, Argentina
| | - Mariana Noelia Soria
- Planta Piloto de Procesos Industriales Microbiológicos, Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán, Argentina
| | - Genis Andrés Castillo Villamizar
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Göttingen, Germany.,Línea Tecnológica Biocorrosión, Corporación para la Investigación de la Corrosión C.I.C., Piedecuesta, Colombia
| | - Anja Poehlein
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Göttingen, Germany
| | - Rolf Daniel
- Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Göttingen, Germany
| | - Julián Rafael Dib
- Planta Piloto de Procesos Industriales Microbiológicos, Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán, Argentina.,Facultad de Bioquímica, Química y Farmacia, Instituto de Microbiología, Universidad Nacional de Tucumán, San Miguel de Tucumán, Argentina
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12
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Browne PD, Kot W, Jørgensen TS, Hansen LH. The Mobilome: Metagenomic Analysis of Circular Plasmids, Viruses, and Other Extrachromosomal Elements. Methods Mol Biol 2020; 2075:253-264. [PMID: 31584168 DOI: 10.1007/978-1-4939-9877-7_18] [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: 03/24/2023]
Abstract
Isolation, sequencing, and analysis of circular genetic elements bring new insights to mobile genetic elements related to microbial ecology. One method used to study circular plasmids, viruses, and other elements is called the mobilome method. The mobilome method presented here is an unamplified mobilome approach allowing fast isolation of circular DNA elements from a variety of samples followed by directly building unamplified Illumina-compatible sequencing libraries using enzymatic tagging and fragmentation. Several methods for bioinformatic analysis of mobilome data are also suggested.
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Affiliation(s)
- Patrick Denis Browne
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Witold Kot
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Tue Sparholt Jørgensen
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
- DTU BIOSUSTAIN, Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Lars Hestbjerg Hansen
- Department of Environmental Science, Aarhus University, Roskilde, Denmark.
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark.
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13
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Fang Z, Tan J, Wu S, Li M, Xu C, Xie Z, Zhu H. PPR-Meta: a tool for identifying phages and plasmids from metagenomic fragments using deep learning. Gigascience 2019; 8:giz066. [PMID: 31220250 PMCID: PMC6586199 DOI: 10.1093/gigascience/giz066] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 03/26/2019] [Accepted: 05/14/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Phages and plasmids are the major components of mobile genetic elements, and fragments from such elements generally co-exist with chromosome-derived fragments in sequenced metagenomic data. However, there is a lack of efficient methods that can simultaneously identify phages and plasmids in metagenomic data, and the existing tools identifying either phages or plasmids have not yet presented satisfactory performance. FINDINGS We present PPR-Meta, a 3-class classifier that allows simultaneous identification of both phage and plasmid fragments from metagenomic assemblies. PPR-Meta consists of several modules for predicting sequences of different lengths. Using deep learning, a novel network architecture, referred to as the Bi-path Convolutional Neural Network, is designed to improve the performance for short fragments. PPR-Meta demonstrates much better performance than currently available similar tools individually for phage or plasmid identification, while testing on both artificial contigs and real metagenomic data. PPR-Meta is freely available via http://cqb.pku.edu.cn/ZhuLab/PPR_Meta or https://github.com/zhenchengfang/PPR-Meta. CONCLUSIONS To the best of our knowledge, PPR-Meta is the first tool that can simultaneously identify phage and plasmid fragments efficiently and reliably. The software is optimized and can be easily run on a local PC by non-computer professionals. We developed PPR-Meta to promote the research on mobile genetic elements and horizontal gene transfer.
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Affiliation(s)
- Zhencheng Fang
- State Key Laboratory for Turbulence and Complex Systems and Department of Biomedical Engineering, College of Engineering, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
- Center for Quantitative Biology, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
| | - Jie Tan
- State Key Laboratory for Turbulence and Complex Systems and Department of Biomedical Engineering, College of Engineering, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
- Center for Quantitative Biology, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
| | - Shufang Wu
- State Key Laboratory for Turbulence and Complex Systems and Department of Biomedical Engineering, College of Engineering, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
- Center for Quantitative Biology, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
| | - Mo Li
- State Key Laboratory for Turbulence and Complex Systems and Department of Biomedical Engineering, College of Engineering, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
- Center for Quantitative Biology, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
- Peking University-Tsinghua University - National Institute of Biological Sciences (PTN) joint PhD program, School of Life Sciences, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
| | - Congmin Xu
- State Key Laboratory for Turbulence and Complex Systems and Department of Biomedical Engineering, College of Engineering, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
- Center for Quantitative Biology, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 631 Cherry St, Atlanta, Georgia 30332, GA, USA
| | - Zhongjie Xie
- State Key Laboratory for Turbulence and Complex Systems and Department of Biomedical Engineering, College of Engineering, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
- Center for Quantitative Biology, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
| | - Huaiqiu Zhu
- State Key Laboratory for Turbulence and Complex Systems and Department of Biomedical Engineering, College of Engineering, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
- Center for Quantitative Biology, Peking University, No.5 Yiheyuan Road Haidian District, Beijing 100871, China
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14
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Martini MC, Wibberg D, Lozano M, Torres Tejerizo G, Albicoro FJ, Jaenicke S, van Elsas JD, Petroni A, Garcillán-Barcia MP, de la Cruz F, Schlüter A, Pühler A, Pistorio M, Lagares A, Del Papa MF. Genomics of high molecular weight plasmids isolated from an on-farm biopurification system. Sci Rep 2016; 6:28284. [PMID: 27321040 PMCID: PMC4913263 DOI: 10.1038/srep28284] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 05/31/2016] [Indexed: 12/02/2022] Open
Abstract
The use of biopurification systems (BPS) constitutes an efficient strategy to eliminate pesticides from polluted wastewaters from farm activities. BPS environments contain a high microbial density and diversity facilitating the exchange of information among bacteria, mediated by mobile genetic elements (MGEs), which play a key role in bacterial adaptation and evolution in such environments. Here we sequenced and characterized high-molecular-weight plasmids from a bacterial collection of an on-farm BPS. The high-throughput-sequencing of the plasmid pool yielded a total of several Mb sequence information. Assembly of the sequence data resulted in six complete replicons. Using in silico analyses we identified plasmid replication genes whose encoding proteins represent 13 different Pfam families, as well as proteins involved in plasmid conjugation, indicating a large diversity of plasmid replicons and suggesting the occurrence of horizontal gene transfer (HGT) events within the habitat analyzed. In addition, genes conferring resistance to 10 classes of antimicrobial compounds and those encoding enzymes potentially involved in pesticide and aromatic hydrocarbon degradation were found. Global analysis of the plasmid pool suggest that the analyzed BPS represents a key environment for further studies addressing the dissemination of MGEs carrying catabolic genes and pathway assembly regarding degradation capabilities.
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Affiliation(s)
- María C Martini
- Instituto de Biotecnología y Biología Molecular (IBBM), CONICET- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Daniel Wibberg
- Center for Biotechnology (CeBiTec), Bielefeld University, Institute for Genome Research and Systems Biology, D-33615 Bielefeld, Germany
| | - Mauricio Lozano
- Instituto de Biotecnología y Biología Molecular (IBBM), CONICET- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Gonzalo Torres Tejerizo
- Instituto de Biotecnología y Biología Molecular (IBBM), CONICET- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Francisco J Albicoro
- Instituto de Biotecnología y Biología Molecular (IBBM), CONICET- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Sebastian Jaenicke
- Center for Biotechnology (CeBiTec), Bielefeld University, Institute for Genome Research and Systems Biology, D-33615 Bielefeld, Germany
| | | | - Alejandro Petroni
- Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS Dr. Carlos G. Malbrán, Buenos Aires, Argentina
| | - M Pilar Garcillán-Barcia
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-Consejo Superior de Investigaciones Científicas (CSIC), 39011 Santander, Spain
| | - Fernando de la Cruz
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-Consejo Superior de Investigaciones Científicas (CSIC), 39011 Santander, Spain
| | - Andreas Schlüter
- Center for Biotechnology (CeBiTec), Bielefeld University, Institute for Genome Research and Systems Biology, D-33615 Bielefeld, Germany
| | - Alfred Pühler
- Center for Biotechnology (CeBiTec), Bielefeld University, Institute for Genome Research and Systems Biology, D-33615 Bielefeld, Germany
| | - Mariano Pistorio
- Instituto de Biotecnología y Biología Molecular (IBBM), CONICET- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - Antonio Lagares
- Instituto de Biotecnología y Biología Molecular (IBBM), CONICET- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
| | - María F Del Papa
- Instituto de Biotecnología y Biología Molecular (IBBM), CONICET- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calles 47 y 115 (1900) La Plata, Argentina
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15
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Møller HD, Bojsen RK, Tachibana C, Parsons L, Botstein D, Regenberg B. Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells. J Vis Exp 2016:e54239 |. [PMID: 27077531 DOI: 10.3791/54239] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Extrachromosomal circular DNAs (eccDNAs) are common genetic elements in Saccharomyces cerevisiae and are reported in other eukaryotes as well. EccDNAs contribute to genetic variation among somatic cells in multicellular organisms and to evolution of unicellular eukaryotes. Sensitive methods for detecting eccDNA are needed to clarify how these elements affect genome stability and how environmental and biological factors induce their formation in eukaryotic cells. This video presents a sensitive eccDNA-purification method called Circle-Seq. The method encompasses column purification of circular DNA, removal of remaining linear chromosomal DNA, rolling-circle amplification of eccDNA, deep sequencing, and mapping. Extensive exonuclease treatment was required for sufficient linear chromosomal DNA degradation. The rolling-circle amplification step by φ29 polymerase enriched for circular DNA over linear DNA. Validation of the Circle-Seq method on three S. cerevisiae CEN.PK populations of 10(10) cells detected hundreds of eccDNA profiles in sizes larger than 1 kilobase. Repeated findings of ASP3-1, COS111, CUP1, RSC30, HXT6, HXT7 genes on circular DNA in both S288c and CEN.PK suggests that DNA circularization is conserved between strains at these loci. In sum, the Circle-Seq method has broad applicability for genome-scale screening for eccDNA in eukaryotes as well as for detecting specific eccDNA types.
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Affiliation(s)
| | - Rasmus K Bojsen
- National Veterinary Institute, Technical University of Denmark
| | | | - Lance Parsons
- Lewis-Sigler Institute for Integrative Genomics, Princeton University
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16
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Abstract
Plasmids are important vehicles for rapid adaptation of bacterial populations to changing environmental conditions. It is thought that to reduce the cost of plasmid carriage, only a fraction of a local population carries plasmids or is permissive to plasmid uptake. Plasmids provide various accessory traits which might be beneficial under particular conditions. The genetic variation generated by plasmid carriage within populations ensures the robustness toward environmental changes. Plasmid-mediated gene transfer plays an important role not only in the mobilization and dissemination of antibiotic resistance genes but also in the spread of degradative pathways and pathogenicity determinants of pathogens. Here we summarize the state-of-the-art methods to study the occurrence, abundance, and diversity of plasmids in environmental bacteria. Increasingly, cultivation-independent total-community DNA-based methods are being used to characterize and quantify the diversity and abundance of plasmids in relation to various biotic and abiotic factors. An improved understanding of the ecology of plasmids and their hosts is crucial in the development of intervention strategies for antibiotic-resistance-gene spread. We discuss the potentials and limitations of methods used to determine the host range of plasmids, as the ecology of plasmids is tightly linked to their hosts. The recent advances in sequencing technologies provide an enormous potential for plasmid classification, diversity, and evolution studies, but numerous challenges still exist.
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17
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Abstract
Examples of extrachromosomal circular DNAs (eccDNAs) are found in many organisms, but their impact on genetic variation at the genome scale has not been investigated. We mapped 1,756 eccDNAs in the Saccharomyces cerevisiae genome using Circle-Seq, a highly sensitive eccDNA purification method. Yeast eccDNAs ranged from an arbitrary lower limit of 1 kb up to 38 kb and covered 23% of the genome, representing thousands of genes. EccDNA arose both from genomic regions with repetitive sequences ≥ 15 bases long and from regions with short or no repetitive sequences. Some eccDNAs were identified in several yeast populations. These eccDNAs contained ribosomal genes, transposon remnants, and tandemly repeated genes (HXT6/7, ENA1/2/5, and CUP1-1/-2) that were generally enriched on eccDNAs. EccDNAs seemed to be replicated and 80% contained consensus sequences for autonomous replication origins that could explain their maintenance. Our data suggest that eccDNAs are common in S. cerevisiae, where they might contribute substantially to genetic variation and evolution.
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18
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Dib JR, Wagenknecht M, Farías ME, Meinhardt F. Strategies and approaches in plasmidome studies-uncovering plasmid diversity disregarding of linear elements? Front Microbiol 2015; 6:463. [PMID: 26074886 PMCID: PMC4443254 DOI: 10.3389/fmicb.2015.00463] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 04/28/2015] [Indexed: 01/01/2023] Open
Abstract
The term plasmid was originally coined for circular, extrachromosomal genetic elements. Today, plasmids are widely recognized not only as important factors facilitating genome restructuring but also as vehicles for the dissemination of beneficial characters within bacterial communities. Plasmid diversity has been uncovered by means of culture-dependent or -independent approaches, such as endogenous or exogenous plasmid isolation as well as PCR-based detection or transposon-aided capture, respectively. High-throughput-sequencing made possible to cover total plasmid populations in a given environment, i.e., the plasmidome, and allowed to address the quality and significance of self-replicating genetic elements. Since such efforts were and still are rather restricted to circular molecules, here we put equal emphasis on the linear plasmids which—despite their frequent occurrence in a large number of bacteria—are largely neglected in prevalent plasmidome conceptions.
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Affiliation(s)
- Julián R Dib
- Planta Piloto de Procesos Industriales Microbiológicos-Consejo Nacional de Investigaciones Científicas y Técnicas , Tucumán, Argentina ; Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster , Münster, Germany ; Instituto de Microbiología, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán , Tucumán, Argentina
| | - Martin Wagenknecht
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster , Münster, Germany ; Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster , Münster, Germany
| | - María E Farías
- Planta Piloto de Procesos Industriales Microbiológicos-Consejo Nacional de Investigaciones Científicas y Técnicas , Tucumán, Argentina
| | - Friedhelm Meinhardt
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster , Münster, Germany
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19
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Jørgensen TS, Kiil AS, Hansen MA, Sørensen SJ, Hansen LH. Current strategies for mobilome research. Front Microbiol 2015; 5:750. [PMID: 25657641 PMCID: PMC4302988 DOI: 10.3389/fmicb.2014.00750] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 12/10/2014] [Indexed: 11/30/2022] Open
Abstract
Mobile genetic elements (MGEs) are pivotal for bacterial evolution and adaptation, allowing shuffling of genes even between distantly related bacterial species. The study of these elements is biologically interesting as the mode of genetic propagation is kaleidoscopic and important, as MGEs are the main vehicles of the increasing bacterial antibiotic resistance that causes thousands of human deaths each year. The study of MGEs has previously focused on plasmids from individual isolates, but the revolution in sequencing technology has allowed the study of mobile genomic elements of entire communities using metagenomic approaches. The problem in using metagenomic sequencing for the study of MGEs is that plasmids and other mobile elements only comprise a small fraction of the total genetic content that are difficult to separate from chromosomal DNA based on sequence alone. The distinction between plasmid and chromosome is important as the mobility and regulation of genes largely depend on their genetic context. Several different approaches have been proposed that specifically enrich plasmid DNA from community samples. Here, we review recent approaches used to study entire plasmid pools from complex environments, and point out possible future developments for and pitfalls of these approaches. Further, we discuss the use of the PacBio long-read sequencing technology for MGE discovery.
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Affiliation(s)
- Tue S Jørgensen
- Section of Microbiology, Department of Biology, University of Copenhagen Copenhagen, Denmark
| | - Anne S Kiil
- Section of Microbiology, Department of Biology, University of Copenhagen Copenhagen, Denmark
| | - Martin A Hansen
- Section of Microbiology, Department of Biology, University of Copenhagen Copenhagen, Denmark
| | - Søren J Sørensen
- Section of Microbiology, Department of Biology, University of Copenhagen Copenhagen, Denmark
| | - Lars H Hansen
- Section of Microbiology, Department of Biology, University of Copenhagen Copenhagen, Denmark ; Environmental Microbiology and Biotechnology, Department of Environmental Science, Aarhus University Roskilde, Denmark
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20
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Hargreaves KR, Flores CO, Lawley TD, Clokie MRJ. Abundant and diverse clustered regularly interspaced short palindromic repeat spacers in Clostridium difficile strains and prophages target multiple phage types within this pathogen. mBio 2014; 5:e01045-13. [PMID: 25161187 PMCID: PMC4173771 DOI: 10.1128/mbio.01045-13] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 07/01/2014] [Indexed: 01/04/2023] Open
Abstract
UNLABELLED Clostridium difficile is an important human-pathogenic bacterium causing antibiotic-associated nosocomial infections worldwide. Mobile genetic elements and bacteriophages have helped shape C. difficile genome evolution. In many bacteria, phage infection may be controlled by a form of bacterial immunity called the clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR/Cas) system. This uses acquired short nucleotide sequences (spacers) to target homologous sequences (protospacers) in phage genomes. C. difficile carries multiple CRISPR arrays, and in this paper we examine the relationships between the host- and phage-carried elements of the system. We detected multiple matches between spacers and regions in 31 C. difficile phage and prophage genomes. A subset of the spacers was located in prophage-carried CRISPR arrays. The CRISPR spacer profiles generated suggest that related phages would have similar host ranges. Furthermore, we show that C. difficile strains of the same ribotype could either have similar or divergent CRISPR contents. Both synonymous and nonsynonymous mutations in the protospacer sequences were identified, as well as differences in the protospacer adjacent motif (PAM), which could explain how phages escape this system. This paper illustrates how the distribution and diversity of CRISPR spacers in C. difficile, and its prophages, could modulate phage predation for this pathogen and impact upon its evolution and pathogenicity. IMPORTANCE Clostridium difficile is a significant bacterial human pathogen which undergoes continual genome evolution, resulting in the emergence of new virulent strains. Phages are major facilitators of genome evolution in other bacterial species, and we use sequence analysis-based approaches in order to examine whether the CRISPR/Cas system could control these interactions across divergent C. difficile strains. The presence of spacer sequences in prophages that are homologous to phage genomes raises an extra level of complexity in this predator-prey microbial system. Our results demonstrate that the impact of phage infection in this system is widespread and that the CRISPR/Cas system is likely to be an important aspect of the evolutionary dynamics in C. difficile.
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Affiliation(s)
- Katherine R Hargreaves
- Department of Infection, Inflammation and Immunity, University of Leicester, Leicester, United Kingdom
| | - Cesar O Flores
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Trevor D Lawley
- Microbial Pathogenesis Laboratory, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Martha R J Clokie
- Department of Infection, Inflammation and Immunity, University of Leicester, Leicester, United Kingdom
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21
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Norman A, Riber L, Luo W, Li LL, Hansen LH, Sørensen SJ. An improved method for including upper size range plasmids in metamobilomes. PLoS One 2014; 9:e104405. [PMID: 25116381 PMCID: PMC4130580 DOI: 10.1371/journal.pone.0104405] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 07/14/2014] [Indexed: 12/24/2022] Open
Abstract
Two recently developed isolation methods have shown promise when recovering pure community plasmid DNA (metamobilomes/plasmidomes), which is useful in conducting culture-independent investigations into plasmid ecology. However, both methods employ multiple displacement amplification (MDA) to ensure suitable quantities of plasmid DNA for high-throughput sequencing. This study demonstrates that MDA greatly favors smaller circular DNA elements (<10 Kbp), which, in turn, leads to stark underrepresentation of upper size range plasmids (>10 Kbp). Throughout the study, we used two model plasmids, a 4.4 Kbp cloning vector (pBR322), and a 56 Kbp conjugative plasmid (pKJK10), to represent lower- and upper plasmid size ranges, respectively. Subjecting a mixture of these plasmids to the overall isolation protocol revealed a 34-fold over-amplification of pBR322 after MDA. To address this bias, we propose the addition of an electroelution step that separates different plasmid size ranges prior to MDA in order to reduce size-dependent competition during incubation. Subsequent analyses of metamobilome data from wastewater spiked with the model plasmids showed in silica recovery of pKJK10 to be very poor with the established method and a 1,300-fold overrepresentation of pBR322. Conversely, complete recovery of pKJK10 was enabled with the new modified protocol although considerable care must be taken during electroelution to minimize cross-contamination between samples. For further validation, non-spiked wastewater metamobilomes were mapped to more than 2,500 known plasmid genomes. This displayed an overall recovery of plasmids well into the upper size range (median size: 30 kilobases) with the modified protocol. Analysis of de novo assembled metamobilome data also suggested distinctly better recovery of larger plasmids, as gene functions associated with these plasmids, such as conjugation, was exclusively encoded in the data output generated through the modified protocol. Thus, with the suggested modification, access to a large uncharacterized pool of accessory elements that reside on medium-to-large plasmids has been improved.
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Affiliation(s)
- Anders Norman
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Department of Earth and Planetary Science, University of California, Berkeley, California, United States of America
| | - Leise Riber
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Wenting Luo
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Li Li Li
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Lars Hestbjerg Hansen
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
- * E-mail:
| | - Søren Johannes Sørensen
- Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
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22
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Jørgensen TS, Xu Z, Hansen MA, Sørensen SJ, Hansen LH. Hundreds of circular novel plasmids and DNA elements identified in a rat cecum metamobilome. PLoS One 2014; 9:e87924. [PMID: 24503942 PMCID: PMC3913684 DOI: 10.1371/journal.pone.0087924] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 12/30/2013] [Indexed: 01/09/2023] Open
Abstract
Metagenomic approaches are widespread in microbiological research, but so far, the knowledge on extrachromosomal DNA diversity and composition has largely remained dependant on cultivating host organisms. Even with the emergence of metagenomics, complete circular sequences are rarely identified, and have required manual curation. We propose a robust in silico procedure for identifying complete small plasmids in metagenomic datasets from whole genome shotgun sequencing. From one very pure and exhaustively sequenced metamobilome from rat cecum, we identified a total of 616 circular sequences, 160 of which were carrying a gene with plasmid replication domain. Further homology analyses indicated that the majority of these plasmid sequences are novel. We confirmed the circularity of the complete plasmid candidates using an inverse-type PCR approach on a subset of sequences with 95% success, confirming the existence and length of discrete sequences. The implication of these findings is a broadened understanding of the traits of circular elements in nature and the possibility of massive data mining in existing metagenomic datasets to discover novel pools of complete plasmids thus vastly expanding the current plasmid database.
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Affiliation(s)
| | - Zhuofei Xu
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Lars Hestbjerg Hansen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Department of Environmental Science, Aarhus Universitet, Roskilde, Denmark
- * E-mail: (SJS); (LHH)
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23
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de Lorenzo V. From theselfish genetoselfish metabolism: Revisiting the central dogma. Bioessays 2014; 36:226-35. [DOI: 10.1002/bies.201300153] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Víctor de Lorenzo
- Systems & Synthetic Biology Program; Centro Nacional de Biotecnología CSIC Cantoblanco; Madrid Spain
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24
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Diverse broad-host-range plasmids from freshwater carry few accessory genes. Appl Environ Microbiol 2013; 79:7684-95. [PMID: 24096417 DOI: 10.1128/aem.02252-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Broad-host-range self-transferable plasmids are known to facilitate bacterial adaptation by spreading genes between phylogenetically distinct hosts. These plasmids typically have a conserved backbone region and a variable accessory region that encodes host-beneficial traits. We do not know, however, how well plasmids that do not encode accessory functions can survive in nature. The goal of this study was to characterize the backbone and accessory gene content of plasmids that were captured from freshwater sources without selecting for a particular phenotype or cultivating their host. To do this, triparental matings were used such that the only required phenotype was the plasmid's ability to mobilize a nonconjugative plasmid. Based on complete genome sequences of 10 plasmids, only 5 carried identifiable accessory gene regions, and none carried antibiotic resistance genes. The plasmids belong to four known incompatibility groups (IncN, IncP-1, IncU, and IncW) and two potentially new groups. Eight of the plasmids were shown to have a broad host range, being able to transfer into alpha-, beta-, and gammaproteobacteria. Because of the absence of antibiotic resistance genes, we resampled one of the sites and compared the proportion of captured plasmids that conferred antibiotic resistance to their hosts with the proportion of such plasmids captured from the effluent of a local wastewater treatment plant. Few of the captured plasmids from either site encoded antibiotic resistance. A high diversity of plasmids that encode no or unknown accessory functions is thus readily found in freshwater habitats. The question remains how the plasmids persist in these microbial communities.
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Biswas A, Gagnon JN, Brouns SJ, Fineran PC, Brown CM. CRISPRTarget: bioinformatic prediction and analysis of crRNA targets. RNA Biol 2013; 10:817-27. [PMID: 23492433 PMCID: PMC3737339 DOI: 10.4161/rna.24046] [Citation(s) in RCA: 217] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 02/15/2013] [Accepted: 02/19/2013] [Indexed: 12/19/2022] Open
Abstract
The bacterial and archaeal CRISPR/Cas adaptive immune system targets specific protospacer nucleotide sequences in invading organisms. This requires base pairing between processed CRISPR RNA and the target protospacer. For type I and II CRISPR/Cas systems, protospacer adjacent motifs (PAM) are essential for target recognition, and for type III, mismatches in the flanking sequences are important in the antiviral response. In this study, we examine the properties of each class of CRISPR. We use this information to provide a tool (CRISPRTarget) that predicts the most likely targets of CRISPR RNAs (http://bioanalysis.otago.ac.nz/CRISPRTarget). This can be used to discover targets in newly sequenced genomic or metagenomic data. To test its utility, we discover features and targets of well-characterized Streptococcus thermophilus and Sulfolobus solfataricus type II and III CRISPR/Cas systems. Finally, in Pectobacterium species, we identify new CRISPR targets and propose a model of temperate phage exposure and subsequent inhibition by the type I CRISPR/Cas systems.
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Affiliation(s)
- Ambarish Biswas
- Department of Biochemistry; University of Otago; Dunedin, New Zealand
| | - Joshua N. Gagnon
- Department of Biochemistry; University of Otago; Dunedin, New Zealand
| | - Stan J.J. Brouns
- Laboratory of Microbiology; Wageningen University; Wageningen, Netherlands
| | - Peter C. Fineran
- Laboratory of Microbiology; Wageningen University; Wageningen, Netherlands
- Department of Microbiology and Immunology; University of Otago; Dunedin, New Zealand
- Genetics Otago; University of Otago; New Zealand
| | - Chris M. Brown
- Department of Biochemistry; University of Otago; Dunedin, New Zealand
- Genetics Otago; University of Otago; New Zealand
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Penders J, Stobberingh EE, Savelkoul PHM, Wolffs PFG. The human microbiome as a reservoir of antimicrobial resistance. Front Microbiol 2013; 4:87. [PMID: 23616784 PMCID: PMC3627978 DOI: 10.3389/fmicb.2013.00087] [Citation(s) in RCA: 169] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 03/27/2013] [Indexed: 12/12/2022] Open
Abstract
The gut microbiota is amongst the most densely populated microbial ecosystem on earth. While the microbiome exerts numerous health beneficial functions, the high density of micro-organisms within this ecosystem also facilitates horizontal transfer of antimicrobial resistance (AMR) genes to potential pathogenic bacteria. Over the past decades antibiotic susceptibility testing of specific indicator bacteria from the microbiome, such as Escherichia coli, has been the method of choice in most studies. These studies have greatly enlarged our understanding on the prevalence and distribution of AMR and associated risk factors. Recent studies using (functional) metagenomics, however, highlighted the unappreciated diversity of AMR genes in the human microbiome and identified genes that had not been described previously. Next to metagenomics, more targeted approaches such as polymerase chain reaction for detection and quantification of AMR genes within a population are promising, in particular for large-scale epidemiological screening. Here we present an overview of the indigenous microbiota as a reservoir of AMR genes, the current knowledge on this “resistome” and the recent and upcoming advances in the molecular diagnostic approaches to unravel this reservoir.
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Affiliation(s)
- John Penders
- Department of Medical Microbiology, Maastricht University Medical Centre+ Maastricht, Netherlands
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Shkoporov AN, Khokhlova EV, Kulagina EV, Smeianov VV, Kuchmiy AA, Kafarskaya LI, Efimov BA. Analysis of a novel 8.9kb cryptic plasmid from Bacteroides uniformis, its long-term stability and spread within human microbiota. Plasmid 2012. [PMID: 23201047 DOI: 10.1016/j.plasmid.2012.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The analysis of plasmid content in dominant Bacteroidales order intestinal strains isolated from the same child at a 5 year interval identified a 8.9 kb plasmid in Bacteroides uniformis BUN24 strain isolated at age 6 and indistinguishably sized plasmids in the isolates of B. uniformis, B. vulgatus, B. intesinalis, and Parabacteroides distasonis at age 11. We sequenced a B. uniformis BUN24 plasmid, designated pBUN24, and using molecular surveys of diverse species we established that this 8944bp molecule (G+C content 43.5%) represents a novel family of small cryptic Bacteroidales plasmids. The replication region of pBUN24 was experimentally localized to a 1707-bp fragment that includes a putative repA gene, coding for a protein of Rep_3 superfamily of replication proteins of theta-type plasmids preceded by a putative iteron-containing origin of replication. The other open reading frames (ORFs) identified in pBUN24 sequence include a putative tad-ata-type toxin-antitoxin and mobA-mobB mobilization modules, as well as seven additional cryptic ORFs. The interaction of Tad and Ada components demonstrated by a pull-down assay and the toxicity of Tad in Escherichia coli host suggests the functionality of the plasmid addiction module. Re-sequencing of plasmids in two Bacteroides strains isolated at the age of 11 showed 100% nucleotide identity to pBUN24. This data supports the notion that this plasmid is transmissible to other Bacteroidales strains in the natural ecosystem. The possible roles of toxin-antitoxin system and other proteins encoded by pBUN24 in providing an apparent ecological advantage to the plasmid-harbouring strains of a bacterial symbiont in the human gut deserve further investigation.
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Affiliation(s)
- Andrei N Shkoporov
- Department of Microbiology and Virology, The Russian National Research Medical University, 1, Ostrovitjanova St., Moscow 117997, Russia.
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