1
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Shi LD, West-Roberts J, Schoelmerich MC, Penev PI, Chen L, Amano Y, Lei S, Sachdeva R, Banfield JF. Methanotrophic Methanoperedens archaea host diverse and interacting extrachromosomal elements. Nat Microbiol 2024; 9:2422-2433. [PMID: 38918468 DOI: 10.1038/s41564-024-01740-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 05/20/2024] [Indexed: 06/27/2024]
Abstract
Methane emissions are mitigated by anaerobic methane-oxidizing archaea, including Methanoperedens. Some Methanoperedens host huge extrachromosomal genetic elements (ECEs) called Borgs that may modulate their activity, yet the broader diversity of Methanoperedens ECEs is understudied. Here we report small enigmatic linear ECEs, circular viruses and unclassified ECEs that are predicted to replicate within Methanoperedens. Linear ECEs have inverted terminal repeats, tandem repeats and coding patterns that are strongly reminiscent of Borgs, but they are only 52-145 kb in length. As they share proteins with Borgs and Methanoperedens, we refer to them as mini-Borgs. Mini-Borgs are genetically diverse and can be assigned to at least five family-level groups. We identify eight families of Methanoperedens viruses, some of which encode multi-haem cytochromes, and circular ECEs encoding transposon-associated TnpB genes with proximal population-heterogeneous CRISPR arrays. These ECEs exchange genetic information with each other and with Methanoperedens, probably impacting their archaeal host activity and evolution.
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Affiliation(s)
- Ling-Dong Shi
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Jacob West-Roberts
- Environmental Science, Policy and Management, University of California, Berkeley, Berkeley, CA, USA
| | - Marie C Schoelmerich
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- Department of Environmental Systems Sciences, ETH Zurich, Zurich, Switzerland
| | - Petar I Penev
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
| | - LinXing Chen
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Yuki Amano
- Sector of Decommissioning and Radioactive Wastes Management, Japan Atomic Energy Agency, Ibaraki, Japan
| | - Shufei Lei
- Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
| | - Rohan Sachdeva
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Jillian F Banfield
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA.
- Environmental Science, Policy and Management, University of California, Berkeley, Berkeley, CA, USA.
- Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA.
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2
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Villicaña C, Rubí-Rangel LM, Amarillas L, Lightbourn-Rojas LA, Carrillo-Fasio JA, León-Félix J. Isolation and Characterization of Two Novel Genera of Jumbo Bacteriophages Infecting Xanthomonas vesicatoria Isolated from Agricultural Regions in Mexico. Antibiotics (Basel) 2024; 13:651. [PMID: 39061333 PMCID: PMC11273794 DOI: 10.3390/antibiotics13070651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 06/27/2024] [Accepted: 07/06/2024] [Indexed: 07/28/2024] Open
Abstract
Bacterial spot is a serious disease caused by several species of Xanthomonas affecting pepper and tomato production worldwide. Since the strategies employed for disease management have been inefficient and pose a threat for environmental and human health, the development of alternative methods is gaining relevance. The aim of this study is to isolate and characterize lytic phages against Xanthomonas pathogens. Here, we isolate two jumbo phages, named XaC1 and XbC2, from water obtained from agricultural irrigation channels by the enrichment technique using X. vesicatoria as a host. We determined that both phages were specific for inducing the lysis of X. vesicatoria strains, but not of other xanthomonads. The XaC1 and XbC2 phages showed a myovirus morphology and were classified as jumbo phages due to their genomes being larger than 200 kb. Phylogenetic and comparative analysis suggests that XaC1 and XbC2 represent both different and novel genera of phages, where XaC1 possesses a low similarity to other phage genomes reported before. Finally, XaC1 and XbC2 exhibited thermal stability up to 45 °C and pH stability from 5 to 9. All these results indicate that the isolated phages are promising candidates for the development of formulations against bacterial spot, although further characterization is required.
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Affiliation(s)
- Claudia Villicaña
- CONAHCYT—Laboratorio de Biología Molecular y Genómica Funcional, Centro de Investigación en Alimentación y Desarrollo, A. C., Culiacán 80110, Sinaloa, Mexico;
| | - Lucía M. Rubí-Rangel
- Laboratorio de Biología Molecular y Genómica Funcional, Centro de Investigación en Alimentación y Desarrollo, A. C., Culiacán 80110, Sinaloa, Mexico;
| | - Luis Amarillas
- Laboratorio de Genética, Instituto de Investigación Lightbourn, A. C., Cd. Jimenez 33981, Chihuahua, Mexico; (L.A.)
| | | | - José Armando Carrillo-Fasio
- Laboratorio de Nematología Agrícola, Centro de Investigación en Alimentación y Desarrollo, A. C., Culiacán 80110, Sinaloa, Mexico;
| | - Josefina León-Félix
- Laboratorio de Biología Molecular y Genómica Funcional, Centro de Investigación en Alimentación y Desarrollo, A. C., Culiacán 80110, Sinaloa, Mexico;
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3
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Li S, Xu M, Yang D, Yang M, Wu H, Li X, Yang C, Fang Z, Wu Q, Tan L, Xiao W, Weng Q. Characterization and genomic analysis of a lytic Stenotrophomonas maltophilia short-tailed phage A1432 revealed a new genus of the family Mesyanzhinovviridae. Front Microbiol 2024; 15:1400700. [PMID: 38993489 PMCID: PMC11236537 DOI: 10.3389/fmicb.2024.1400700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 06/14/2024] [Indexed: 07/13/2024] Open
Abstract
Stenotrophomonas maltophilia (S. maltophilia) is an emerging opportunistic pathogen that exhibits resistant to a majority of commonly used antibiotics. Phages have the potential to serve as an alternative treatment for S. maltophilia infections. In this study, a lytic phage, A1432, infecting S. maltophilia YCR3A-1, was isolated and characterized from a karst cave. Transmission electron microscopy revealed that phage A1432 possesses an icosahedral head and a shorter tail. Phage A1432 demonstrated a narrow host range, with an optimal multiplicity of infection of 0.1. The one-step growth curve indicated a latent time of 10 min, a lysis period of 90 min, a burst size of 43.2 plaque-forming units per cell. In vitro bacteriolytic activity test showed that phage A1432 was capable to inhibit the growth of S. maltophilia YCR3A-1 in an MOI-dependent manner after 2 h of co-culture. BLASTn analysis showed that phage A1432 genome shares the highest similarity (81.46%) with Xanthomonas phage Xoo-sp2 in the NCBI database, while the query coverage was only 37%. The phage contains double-stranded DNA with a genome length of 61,660 bp and a GC content of 61.92%. It is predicted to have 79 open reading frames and one tRNA, with no virulence or antibiotic resistance genes. Phylogenetic analysis using terminase large subunit and DNA polymerase indicated that phage A1432 clustered with members of the Bradleyvirinae subfamily but diverged into a distinct branch. Further phylogenetic comparison analysis using Average Nucleotide Identity, proteomic phylogenetic analysis, genomic network analysis confirmed that phage A1432 belongs to a novel genus within the Bradleyvirinae subfamily, Mesyanzhinovviridae family. Additionally, phylogenetic analysis of the so far isolated S. maltophilia phages revealed significant genetic diversity among these phages. The results of this research will contribute valuable information for further studies on their morphological and genetic diversity, will aid in elucidating the evolutionary mechanisms that give rise to them.
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Affiliation(s)
- Shixia Li
- School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Man Xu
- School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Deying Yang
- School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Mei Yang
- School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Hejing Wu
- School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Xuelian Li
- School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Changzhou Yang
- School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Zheng Fang
- School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Qingshan Wu
- School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Leitao Tan
- School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Wei Xiao
- Yunnan Institute of Microbiology, Yunnan International Joint Laboratory of Virology and Immunology, Yunnan University, Kunming, China
| | - Qingbei Weng
- School of Life Sciences, Guizhou Normal University, Guiyang, China
- Qiannan Normal University for Nationalities, Duyun, China
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4
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Wang S, Zeng X, Jiang Y, Wang W, Bai L, Lu Y, Zhang L, Tan GY. Unleashing the potential: type I CRISPR-Cas systems in actinomycetes for genome editing. Nat Prod Rep 2024. [PMID: 38888887 DOI: 10.1039/d4np00010b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
Covering: up to the end of 2023Type I CRISPR-Cas systems are widely distributed, found in over 40% of bacteria and 80% of archaea. Among genome-sequenced actinomycetes (particularly Streptomyces spp.), 45.54% possess type I CRISPR-Cas systems. In comparison to widely used CRISPR systems like Cas9 or Cas12a, these endogenous CRISPR-Cas systems have significant advantages, including better compatibility, wide distribution, and ease of operation (since no exogenous Cas gene delivery is needed). Furthermore, type I CRISPR-Cas systems can simultaneously edit and regulate genes by adjusting the crRNA spacer length. Meanwhile, most actinomycetes are recalcitrant to genetic manipulation, hindering the discovery and engineering of natural products (NPs). The endogenous type I CRISPR-Cas systems in actinomycetes may offer a promising alternative to overcome these barriers. This review summarizes the challenges and recent advances in CRISPR-based genome engineering technologies for actinomycetes. It also presents and discusses how to establish and develop genome editing tools based on type I CRISPR-Cas systems in actinomycetes, with the aim of their future application in gene editing and the discovery of NPs in actinomycetes.
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Affiliation(s)
- Shuliu Wang
- State Key Laboratory of Bioreactor Engineering (SKLBE), School of Biotechnology, East China University of Science and Technology (ECUST), Shanghai 200237, China.
| | - Xiaoqian Zeng
- State Key Laboratory of Bioreactor Engineering (SKLBE), School of Biotechnology, East China University of Science and Technology (ECUST), Shanghai 200237, China.
| | - Yue Jiang
- State Key Laboratory of Bioreactor Engineering (SKLBE), School of Biotechnology, East China University of Science and Technology (ECUST), Shanghai 200237, China.
| | - Weishan Wang
- State Key Laboratory of Microbial Resources and CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing 100101, China
| | - Linquan Bai
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yinhua Lu
- College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Lixin Zhang
- State Key Laboratory of Bioreactor Engineering (SKLBE), School of Biotechnology, East China University of Science and Technology (ECUST), Shanghai 200237, China.
| | - Gao-Yi Tan
- State Key Laboratory of Bioreactor Engineering (SKLBE), School of Biotechnology, East China University of Science and Technology (ECUST), Shanghai 200237, China.
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5
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Bird JT, Burke KA, Urick CD, Braverman JL, Mzhavia N, Ellison DW, Nikolich MP, Filippov AA. Genome sequence of the Klebsiella quasipneumoniae bacteriophage EKq1 with activity against Klebsiella pneumoniae. Microbiol Resour Announc 2024; 13:e0095423. [PMID: 38032190 DOI: 10.1128/mra.00954-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 10/20/2023] [Indexed: 12/01/2023] Open
Abstract
We describe the genome of a lytic phage EKq1 isolated on Klebsiella quasipneumoniae, with activity against Klebsiella pneumoniae. EKq1 is an unclassified representative of the class Caudoviricetes, similar to Klebsiella phages VLCpiS8c, phiKp_7-2, and vB_KleS-HSE3. The 48,244-bp genome has a GC content of 56.43% and 63 predicted protein-coding genes.
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Affiliation(s)
- Jordan T Bird
- Department of Biochemistry and Molecular Biology, University of Arkansas , Little Rock, Arkansas, USA
| | - Kevin A Burke
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research , Silver Spring, Maryland, USA
| | - Caitlin D Urick
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research , Silver Spring, Maryland, USA
| | - Jamie L Braverman
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research , Silver Spring, Maryland, USA
| | - Nino Mzhavia
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research , Silver Spring, Maryland, USA
| | - Damon W Ellison
- Bacterial Diseases Branch, Walter Reed Army Institute of Research , Silver Spring, Maryland, USA
| | - Mikeljon P Nikolich
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research , Silver Spring, Maryland, USA
| | - Andrey A Filippov
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research , Silver Spring, Maryland, USA
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6
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Garcia-Fernandez A, Janowicz A, Marotta F, Napoleoni M, Arena S, Primavilla S, Pitti M, Romantini R, Tomei F, Garofolo G, Villa L. Antibiotic resistance, plasmids, and virulence-associated markers in human strains of Campylobacter jejuni and Campylobacter coli isolated in Italy. Front Microbiol 2024; 14:1293666. [PMID: 38260875 PMCID: PMC10800408 DOI: 10.3389/fmicb.2023.1293666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 12/07/2023] [Indexed: 01/24/2024] Open
Abstract
Campylobacteriosis, a prevalent foodborne gastrointestinal infection in Europe, is primarily caused by Campylobacter jejuni and Campylobacter coli, with rising global concerns over antimicrobial resistance in these species. This study comprehensively investigates 133 human-origin Campylobacter spp. strains (102 C. jejuni and 31 C. coli) collected in Italy from 2013 to 2021. The predominant Multilocus Sequence Typing Clonal complexes (CCs) were ST-21 CC and ST-206 CC in C. jejuni and ST-828 CC in C. coli. Ciprofloxacin and tetracycline resistance, mainly attributed to GyrA (T86I) mutation and tet(O) presence, were prevalent, while erythromycin resistance was associated with 23S rRNA gene mutation (A2075G), particularly in C. coli exhibiting multidrug-resistant pattern CipTE. Notable disparities in virulence factors among strains were observed, with C. jejuni exhibiting a higher abundance compared to C. coli. Notably, specific C. jejuni sequence types, including ST-21, ST-5018, and ST-1263, demonstrated significantly elevated counts of virulence genes. This finding underscores the significance of considering both the species and strain-level variations in virulence factor profiles, shedding light on potential differences in the pathogenicity and clinical outcomes associated with distinct C. jejuni lineages. Campylobacter spp. plasmids were classified into three groups comprising pVir-like and pTet-like plasmids families, exhibiting diversity among Campylobacter spp. The study underscores the importance of early detection through Whole Genome Sequencing to identify potential emergent virulence, resistance/virulence plasmids, and new antimicrobial resistance markers. This approach provides actionable public health data, supporting the development of robust surveillance programs in Italy.
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Affiliation(s)
| | - Anna Janowicz
- National Reference Laboratory for Campylobacter, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", Teramo, Italy
| | - Francesca Marotta
- National Reference Laboratory for Campylobacter, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", Teramo, Italy
| | - Maira Napoleoni
- Centro di Riferimento Regionale Patogeni Enterici, CRRPE, Istituto Zooprofilattico Sperimentale dell’Umbria e delle Marche “T. Rosati”, Perugia, Italy
| | - Sergio Arena
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Sara Primavilla
- Centro di Riferimento Regionale Patogeni Enterici, CRRPE, Istituto Zooprofilattico Sperimentale dell’Umbria e delle Marche “T. Rosati”, Perugia, Italy
| | - Monica Pitti
- Centro di Riferimento per la Tipizzazione delle Salmonelle, CeRTiS, Istituto Zooprofilattico Sperimentale del Piemonte Liguria e Valle d'Aosta, Turin, Italy
| | - Romina Romantini
- National Reference Laboratory for Campylobacter, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", Teramo, Italy
| | | | - Giuliano Garofolo
- National Reference Laboratory for Campylobacter, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", Teramo, Italy
| | - Laura Villa
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
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7
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Jordá J, Lorenzo-Rebenaque L, Montoro-Dasi L, Marco-Fuertes A, Vega S, Marin C. Phage-Based Biosanitation Strategies for Minimizing Persistent Salmonella and Campylobacter Bacteria in Poultry. Animals (Basel) 2023; 13:3826. [PMID: 38136863 PMCID: PMC10740442 DOI: 10.3390/ani13243826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/05/2023] [Accepted: 12/10/2023] [Indexed: 12/24/2023] Open
Abstract
Control strategies to minimize pathogenic bacteria in food animal production are one of the key components in ensuring safer food for consumers. The most significant challenges confronting the food industry, particularly in the major poultry and swine sectors, are antibiotic resistance and resistance to cleaning and disinfection in zoonotic bacteria. In this context, bacteriophages have emerged as a promising tool for zoonotic bacteria control in the food industry, from animals and farm facilities to the final product. Phages are viruses that infect bacteria, with several advantages as a biocontrol agent such as high specificity, self-replication, self-limitation, continuous adaptation, low inherent toxicity and easy isolation. Their development as a biocontrol agent is of particular interest, as it would allow the application of a promising and even necessary "green" technology to combat pathogenic bacteria in the environment. However, bacteriophage applications have limitations, including selecting appropriate phages, legal restrictions, purification, dosage determination and bacterial resistance. Overcoming these limitations is crucial to enhance phage therapy's effectiveness against zoonotic bacteria in poultry. Thus, this review aims to provide a comprehensive view of the phage-biosanitation strategies for minimizing persistent Salmonella and Campylobacter bacteria in poultry.
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Affiliation(s)
- Jaume Jordá
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Instituto de Ciencias Biomédicas, Universidad Cardenal Herrera-CEU, CEU Universities, Calle Santiago Ramón y Cajal 20, 46115 Alfara del Patriarca, Spain; (J.J.); (L.M.-D.); (A.M.-F.); (S.V.)
| | - Laura Lorenzo-Rebenaque
- Institute of Animal Science and Technology, Universitat Politècnica de València, 46022 Valencia, Spain;
| | - Laura Montoro-Dasi
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Instituto de Ciencias Biomédicas, Universidad Cardenal Herrera-CEU, CEU Universities, Calle Santiago Ramón y Cajal 20, 46115 Alfara del Patriarca, Spain; (J.J.); (L.M.-D.); (A.M.-F.); (S.V.)
| | - Ana Marco-Fuertes
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Instituto de Ciencias Biomédicas, Universidad Cardenal Herrera-CEU, CEU Universities, Calle Santiago Ramón y Cajal 20, 46115 Alfara del Patriarca, Spain; (J.J.); (L.M.-D.); (A.M.-F.); (S.V.)
| | - Santiago Vega
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Instituto de Ciencias Biomédicas, Universidad Cardenal Herrera-CEU, CEU Universities, Calle Santiago Ramón y Cajal 20, 46115 Alfara del Patriarca, Spain; (J.J.); (L.M.-D.); (A.M.-F.); (S.V.)
| | - Clara Marin
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Instituto de Ciencias Biomédicas, Universidad Cardenal Herrera-CEU, CEU Universities, Calle Santiago Ramón y Cajal 20, 46115 Alfara del Patriarca, Spain; (J.J.); (L.M.-D.); (A.M.-F.); (S.V.)
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8
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Flusche T, Rajan R. Molecular Details of DNA Integration by CRISPR-Associated Proteins During Adaptation in Bacteria and Archaea. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1414:27-43. [PMID: 35852729 DOI: 10.1007/5584_2022_730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins constitute an adaptive immune system in bacteria and archaea, where immunological memory is retained in the CRISPR locus as short pieces of the intruding nucleic acid, termed spacers. The adaptation to new infections occurs through the integration of a new spacer into the CRISPR array. For immune protection, spacers are transcribed into CRISPR RNAs (crRNA) that are used to guide the effector nuclease of the system in sequence-dependent target cleavage. Spacers originate as a prespacer from either DNA or RNA depending on the CRISPR-Cas system being observed, and the nearly universal Cas proteins, Cas1 and Cas2, insert the prespacer into the CRISPR locus during adaptation in all systems that contain them. The mechanism of site-specific prespacer integration varies across CRISPR classes and types, and distinct differences can even be found within the same subtype. In this review, the current knowledge on the mechanisms of prespacer integration in type II-A CRISPR-Cas systems will be described. Comparisons of the currently characterized type II-A systems show that distinct mechanisms exist within different members of this subtype and are correlated to sequence-specific interactions of Cas proteins and the DNA elements present in the CRISPR array. These observations indicate that nature has fine-tuned the mechanistic details while performing the basic step of DNA integration by Cas proteins, which offers unique advantages to develop Cas1-Cas2-based biotechnology.
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Affiliation(s)
- Tamara Flusche
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, OK, USA
| | - Rakhi Rajan
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, OK, USA.
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9
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Droubogiannis S, Pavlidi L, Tsertou MI, Kokkari C, Skliros D, Flemetakis E, Katharios P. Vibrio Phage Artemius, a Novel Phage Infecting Vibrio alginolyticus. Pathogens 2022; 11:pathogens11080848. [PMID: 36014969 PMCID: PMC9416449 DOI: 10.3390/pathogens11080848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/21/2022] [Accepted: 07/27/2022] [Indexed: 02/04/2023] Open
Abstract
Vibrio alginolyticus is an important pathogen of marine animals and has been the target of phage therapy applications in marine aquaculture for many years. Here, we report the isolation and partial characterization of a novel species of the Siphoviridae family, the Vibrio phage Artemius. The novel phage was species-specific and could only infect strains of V. alginolyticus. It could efficiently reduce the growth of the host bacterium at various multiplicities of infection as assessed by an in vitro lysis assay. It had a genome length of 43,349 base pairs. The complete genome has double-stranded DNA with a G + C content of 43.61%. In total, 57 ORFs were identified, of which 19 were assigned a predicted function. A genomic analysis indicated that Vibrio phage Artemius is lytic and does not harbor genes encoding toxins and antibiotic resistance determinants.
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Affiliation(s)
- Stavros Droubogiannis
- Hellenic Centre for Marine Research, Institute of Marine Biology, Biotechnology & Aquaculture, 71500 Heraklion, Greece; (S.D.); (L.P.); (M.I.T.); (C.K.)
- Department of Biology, School of Sciences and Engineering, University of Crete, 71500 Heraklion, Greece
| | - Lydia Pavlidi
- Hellenic Centre for Marine Research, Institute of Marine Biology, Biotechnology & Aquaculture, 71500 Heraklion, Greece; (S.D.); (L.P.); (M.I.T.); (C.K.)
| | - Maria Ioanna Tsertou
- Hellenic Centre for Marine Research, Institute of Marine Biology, Biotechnology & Aquaculture, 71500 Heraklion, Greece; (S.D.); (L.P.); (M.I.T.); (C.K.)
| | - Constantina Kokkari
- Hellenic Centre for Marine Research, Institute of Marine Biology, Biotechnology & Aquaculture, 71500 Heraklion, Greece; (S.D.); (L.P.); (M.I.T.); (C.K.)
| | - Dimitrios Skliros
- Department of Biotechnology, Agricultural University of Athens, 11855 Athens, Greece; (D.S.); (E.F.)
| | - Emmanouil Flemetakis
- Department of Biotechnology, Agricultural University of Athens, 11855 Athens, Greece; (D.S.); (E.F.)
| | - Pantelis Katharios
- Hellenic Centre for Marine Research, Institute of Marine Biology, Biotechnology & Aquaculture, 71500 Heraklion, Greece; (S.D.); (L.P.); (M.I.T.); (C.K.)
- Correspondence:
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10
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Wu WY, Jackson SA, Almendros C, Haagsma AC, Yilmaz S, Gort G, van der Oost J, Brouns SJJ, Staals RHJ. Adaptation by Type V-A and V-B CRISPR-Cas Systems Demonstrates Conserved Protospacer Selection Mechanisms Between Diverse CRISPR-Cas Types. CRISPR J 2022; 5:536-547. [PMID: 35833800 PMCID: PMC9419969 DOI: 10.1089/crispr.2021.0150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Adaptation of clustered regularly interspaced short palindromic repeats (CRISPR) arrays is a crucial process responsible for the unique, adaptive nature of CRISPR-Cas immune systems. The acquisition of new CRISPR spacers from mobile genetic elements has previously been studied for several types of CRISPR-Cas systems. In this study, we used a high-throughput sequencing approach to characterize CRISPR adaptation of the type V-A system from Francisella novicida and the type V-B system from Alicyclobacillus acidoterrestris. In contrast to other class 2 CRISPR-Cas systems, we found that for the type V-A and V-B systems, the Cas12 nucleases are dispensable for spacer acquisition, with only Cas1 and Cas2 (type V-A) or Cas4/1 and Cas2 (type V-B) being necessary and sufficient. Whereas the catalytic activity of Cas4 is not essential for adaptation, Cas4 activity is required for correct protospacer adjacent motif selection in both systems and for prespacer trimming in type V-A. In addition, we provide evidence for acquisition of RecBCD-produced DNA fragments by both systems, but with spacers derived from foreign DNA being incorporated preferentially over those derived from the host chromosome. Our work shows that several spacer acquisition mechanisms are conserved between diverse CRISPR-Cas systems, but also highlights unexpected nuances between similar systems that generally contribute to a bias of gaining immunity against invading genetic elements.
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Affiliation(s)
- Wen Y Wu
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Simon A Jackson
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Cristóbal Almendros
- Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands.,Kavli Institute of Nanoscience, Delft, The Netherlands
| | - Anna C Haagsma
- Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands.,Kavli Institute of Nanoscience, Delft, The Netherlands
| | - Suzan Yilmaz
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Gerrit Gort
- Biometris, Wageningen University and Research, Wageningen, The Netherlands
| | - John van der Oost
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Stan J J Brouns
- Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands.,Kavli Institute of Nanoscience, Delft, The Netherlands
| | - Raymond H J Staals
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
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11
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Erdrich SH, Sharma V, Schurr U, Arsova B, Frunzke J. Isolation of Novel Xanthomonas Phages Infecting the Plant Pathogens X. translucens and X. campestris. Viruses 2022; 14:1449. [PMID: 35891434 PMCID: PMC9316219 DOI: 10.3390/v14071449] [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: 05/18/2022] [Revised: 06/22/2022] [Accepted: 06/28/2022] [Indexed: 12/18/2022] Open
Abstract
The genus of Xanthomonas contains many well-known plant pathogens with the ability to infect some of the most important crop plants, thereby causing significant economic damage. Unfortunately, classical pest-control strategies are neither particularly efficient nor sustainable and we are, therefore, in demand of alternatives. Here, we present the isolation and characterization of seven novel phages infecting the plant-pathogenic species Xanthomonas translucens and Xanthomonas campestris. Transmission electron microscopy revealed that all phages show a siphovirion morphology. The analysis of genome sequences and plaque morphologies are in agreement with a lytic lifestyle of the phages making them suitable candidates for biocontrol. Moreover, three of the isolated phages form the new genus "Shirevirus". All seven phages belong to four distinct clusters underpinning their phylogenetic diversity. Altogether, this study presents the first characterized isolates for the plant pathogen X. translucens and expands the number of available phages for plant biocontrol.
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Affiliation(s)
- Sebastian H. Erdrich
- Institute of Bio- and Geosciences, Department for Plant Sciences (IBG-2), Forschungszentrum Jülich, 52425 Jülich, Germany; (S.H.E.); (U.S.); (B.A.)
| | - Vikas Sharma
- Institute of Bio- and Geosciences, Department for Biotechnology (IBG-1), Forschungszentrum Jülich, 52425 Jülich, Germany;
| | - Ulrich Schurr
- Institute of Bio- and Geosciences, Department for Plant Sciences (IBG-2), Forschungszentrum Jülich, 52425 Jülich, Germany; (S.H.E.); (U.S.); (B.A.)
| | - Borjana Arsova
- Institute of Bio- and Geosciences, Department for Plant Sciences (IBG-2), Forschungszentrum Jülich, 52425 Jülich, Germany; (S.H.E.); (U.S.); (B.A.)
| | - Julia Frunzke
- Institute of Bio- and Geosciences, Department for Biotechnology (IBG-1), Forschungszentrum Jülich, 52425 Jülich, Germany;
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12
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McCutcheon JG, Lin A, Dennis JJ. Characterization of Stenotrophomonas maltophilia phage AXL1 as a member of the genus Pamexvirus encoding resistance to trimethoprim-sulfamethoxazole. Sci Rep 2022; 12:10299. [PMID: 35717537 PMCID: PMC9206674 DOI: 10.1038/s41598-022-14025-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 05/31/2022] [Indexed: 11/08/2022] Open
Abstract
Stenotrophomonas maltophilia is a ubiquitous environmental bacterium capable of causing disease in humans. Antibiotics are largely ineffective against this pathogen due to numerous chromosomally encoded antibiotic resistance mechanisms. An alternative treatment option is phage therapy, the use of bacteriophages to selectively kill target bacteria that are causing infection. To this aim, we isolated the Siphoviridae bacteriophage AXL1 (vB_SmaS-AXL_1) from soil and herein describe its characterization. Host range analysis on a panel of 30 clinical S. maltophilia strains reveals a moderate tropism that includes cross-species infection of Xanthomonas, with AXL1 using the type IV pilus as its host surface receptor for infection. Complete genome sequencing and analysis revealed a 63,962 bp genome encoding 83 putative proteins. Comparative genomics place AXL1 in the genus Pamexvirus, along with seven other phages that infect one of Stenotrophomonas, Pseudomonas or Xanthomonas species. Functional genomic analyses identified an AXL1-encoded dihydrofolate reductase enzyme that provides additional resistance to the antibiotic combination trimethoprim-sulfamethoxazole, the current recommended treatment option for S. maltophilia infections. This research characterizes the sixth type IV pilus-binding phage of S. maltophilia and is an example of phage-encoded antibiotic resistance.
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Affiliation(s)
- Jaclyn G McCutcheon
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Andrea Lin
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Jonathan J Dennis
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada.
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13
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Alternative functions of CRISPR-Cas systems in the evolutionary arms race. Nat Rev Microbiol 2022; 20:351-364. [PMID: 34992260 DOI: 10.1038/s41579-021-00663-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2021] [Indexed: 12/14/2022]
Abstract
CRISPR-Cas systems of bacteria and archaea comprise chromosomal loci with typical repetitive clusters and associated genes encoding a range of Cas proteins. Adaptation of CRISPR arrays occurs when virus-derived and plasmid-derived sequences are integrated as new CRISPR spacers. Cas proteins use CRISPR-derived RNA guides to specifically recognize and cleave nucleic acids of invading mobile genetic elements. Apart from this role as an adaptive immune system, some CRISPR-associated nucleases are hijacked by mobile genetic elements: viruses use them to attack their prokaryotic hosts, and transposons have adopted CRISPR systems for guided transposition. In addition, some CRISPR-Cas systems control the expression of genes involved in bacterial physiology and virulence. Moreover, pathogenic bacteria may use their Cas nuclease activity indirectly to evade the human immune system or directly to invade the nucleus and damage the chromosomal DNA of infected human cells. Thus, the evolutionary arms race has led to the expansion of exciting variations in CRISPR mechanisms and functionalities. In this Review, we explore the latest insights into the diverse functions of CRISPR-Cas systems beyond adaptive immunity and discuss the implications for the development of CRISPR-based applications.
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14
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Olson EG, Micciche AC, Rothrock MJ, Yang Y, Ricke SC. Application of Bacteriophages to Limit Campylobacter in Poultry Production. Front Microbiol 2022; 12:458721. [PMID: 35069459 PMCID: PMC8766974 DOI: 10.3389/fmicb.2021.458721] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 11/29/2021] [Indexed: 12/22/2022] Open
Abstract
Campylobacter is a major foodborne pathogen with over a million United States cases a year and is typically acquired through the consumption of poultry products. The common occurrence of Campylobacter as a member of the poultry gastrointestinal tract microbial community remains a challenge for optimizing intervention strategies. Simultaneously, increasing demand for antibiotic-free products has led to the development of several alternative control measures both at the farm and in processing operations. Bacteriophages administered to reduce foodborne pathogens are one of the alternatives that have received renewed interest. Campylobacter phages have been isolated from both conventionally and organically raised poultry. Isolated and cultivated Campylobacter bacteriophages have been used as an intervention in live birds to target colonized Campylobacter in the gastrointestinal tract. Application of Campylobacter phages to poultry carcasses has also been explored as a strategy to reduce Campylobacter levels during poultry processing. This review will focus on the biology and ecology of Campylobacter bacteriophages in poultry production followed by discussion on current and potential applications as an intervention strategy to reduce Campylobacter occurrence in poultry production.
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Affiliation(s)
- Elena G. Olson
- Meat Science and Animal Biologics Discovery Program, Department of Animal and Dairy Sciences, University of Wisconsin–Madison, Madison, WI, United States
| | - Andrew C. Micciche
- Center for Food Safety, Department of Food Science, University of Arkansas, Fayetteville, AR, United States
| | - Michael J. Rothrock
- Agricultural Research Service, United States Department of Agriculture, Athens, GA, United States
| | - Yichao Yang
- Department of Poultry Science, University of Arkansas, Fayetteville, AR, United States
| | - Steven C. Ricke
- Meat Science and Animal Biologics Discovery Program, Department of Animal and Dairy Sciences, University of Wisconsin–Madison, Madison, WI, United States
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15
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Pan S, Zhang H. Discovery in CRISPR-Cas9 system. ZHONG NAN DA XUE XUE BAO. YI XUE BAN = JOURNAL OF CENTRAL SOUTH UNIVERSITY. MEDICAL SCIENCES 2021; 46:1392-1402. [PMID: 35232910 PMCID: PMC10930580 DOI: 10.11817/j.issn.1672-7347.2021.210169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Indexed: 06/14/2023]
Abstract
The 2020 Nobel Prize in Chemistry was awarded to the American scientist Jennifer A. Doudna and the French scientist Emmanuelle Charpentier, in recognition of their discovery in one of the greatest weapons in genetic technology: CRISPR-Cas9 gene scissors. The CRISPR-Cas system is a bacterial defense immune system against exogenous genetic material. Because the system can specifically recognize and cut DNA, this technology is widely used for precise editing of animal, plant, and microbial DNA. The discovery of CRISPR-Cas9 gene scissors enables the tedious and complicated cell gene editing work to be completed in a few weeks or even less, which has promoted the development of gene editing technology in various fields and brought revolutionary influence to the field of life sciences. At the same time, CRISPR gene editing technology has become one of the new therapies for tumors because of its large number of targets and relatively simple operation, and it also makes gene therapy possible. Although the technology still needs to solve technical problems such as off-target and promoter inefficiency, the CRISPR-Cas system will show its unique advantages in more fields with the continuous development of life science and basic medicine.
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Affiliation(s)
- Shaowei Pan
- Department of Pathophysiology, School of Basic Medical Science, Central South University, Changsha 410013, China.
| | - Huali Zhang
- Department of Pathophysiology, School of Basic Medical Science, Central South University, Changsha 410013, China.
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16
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van Vliet AHM, Charity OJ, Reuter M. A Campylobacter integrative and conjugative element with a CRISPR-Cas9 system targeting competing plasmids: a history of plasmid warfare? Microb Genom 2021; 7. [PMID: 34766904 PMCID: PMC8743540 DOI: 10.1099/mgen.0.000729] [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] [Indexed: 12/16/2022] Open
Abstract
Microbial genomes are highly adaptable, with mobile genetic elements (MGEs) such as integrative conjugative elements (ICEs) mediating the dissemination of new genetic information throughout bacterial populations. This is countered by defence mechanisms such as CRISPR-Cas systems, which limit invading MGEs by sequence-specific targeting. Here we report the distribution of the pVir, pTet and PCC42 plasmids and a new 70–129 kb ICE (CampyICE1) in the foodborne bacterial pathogens Campylobacter jejuni and Campylobacter coli. CampyICE1 contains a degenerated Type II-C CRISPR system consisting of a sole Cas9 protein, which is distinct from the previously described Cas9 proteins from C. jejuni and C. coli. CampyICE1 is conserved in structure and gene order, containing blocks of genes predicted to be involved in recombination, regulation and conjugation. CampyICE1 was detected in 134/5829 (2.3 %) C. jejuni genomes and 92/1347 (6.8 %) C. coli genomes. Similar ICEs were detected in a number of non-jejuni/coli Campylobacter species, although these lacked a CRISPR-Cas system. CampyICE1 carries three separate short CRISPR spacer arrays containing a combination of 108 unique spacers and 16 spacer-variant families. A total of 69 spacers and 10 spacer-variant families (63.7 %) were predicted to target Campylobacter plasmids. The presence of a functional CampyICE1 Cas9 protein and matching anti-plasmid spacers was associated with the absence of the pVir, pTet and pCC42 plasmids (188/214 genomes, 87.9 %), suggesting that the CampyICE1-encoded CRISPR-Cas has contributed to the exclusion of competing plasmids. In conclusion, the characteristics of the CRISPR-Cas9 system on CampyICE1 suggests a history of plasmid warfare in Campylobacter.
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Affiliation(s)
- Arnoud H M van Vliet
- Department of Pathology and Infectious Diseases, School of Veterinary Medicine, University of Surrey, Guildford, UK
| | - Oliver J Charity
- Quadram Institute Bioscience, Microbes in the Food Chain programme, Norwich, UK
| | - Mark Reuter
- Quadram Institute Bioscience, Microbes in the Food Chain programme, Norwich, UK
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17
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Guzmán NM, Esquerra-Ruvira B, Mojica FJM. Digging into the lesser-known aspects of CRISPR biology. Int Microbiol 2021; 24:473-498. [PMID: 34487299 PMCID: PMC8616872 DOI: 10.1007/s10123-021-00208-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 12/26/2022]
Abstract
A long time has passed since regularly interspaced DNA repeats were discovered in prokaryotes. Today, those enigmatic repetitive elements termed clustered regularly interspaced short palindromic repeats (CRISPR) are acknowledged as an emblematic part of multicomponent CRISPR-Cas (CRISPR associated) systems. These systems are involved in a variety of roles in bacteria and archaea, notably, that of conferring protection against transmissible genetic elements through an adaptive immune-like response. This review summarises the present knowledge on the diversity, molecular mechanisms and biology of CRISPR-Cas. We pay special attention to the most recent findings related to the determinants and consequences of CRISPR-Cas activity. Research on the basic features of these systems illustrates how instrumental the study of prokaryotes is for understanding biology in general, ultimately providing valuable tools for diverse fields and fuelling research beyond the mainstream.
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Affiliation(s)
- Noemí M Guzmán
- Dpto. Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Belén Esquerra-Ruvira
- Dpto. Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Francisco J M Mojica
- Dpto. Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain.
- Instituto Multidisciplinar para el Estudio del Medio, Universidad de Alicante, Alicante, Spain.
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18
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Reduced Infection Efficiency of Phage NCTC 12673 on Non-Motile Campylobacter jejuni Strains Is Related to Oxidative Stress. Viruses 2021; 13:v13101955. [PMID: 34696385 PMCID: PMC8540345 DOI: 10.3390/v13101955] [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: 07/06/2021] [Revised: 09/08/2021] [Accepted: 09/20/2021] [Indexed: 01/26/2023] Open
Abstract
Campylobacter jejuni is a Gram-negative foodborne pathogen that causes diarrheal disease and is associated with severe post-infectious sequelae. Bacteriophages (phages) are a possible means of reducing Campylobacter colonization in poultry to prevent downstream human infections. However, the factors influencing phage-host interactions must be better understood before this strategy can be predictably employed. Most studies have focused on Campylobacter phage binding to the host surface, with all phages classified as either capsule- or flagella-specific. Here we describe the characterization of a C. jejuni phage that requires functional flagellar glycosylation and motor genes for infection, without needing the flagella for adsorption to the cell surface. Through phage infectivity studies of targeted C. jejuni mutants, transcriptomic analysis of phage-resistant mutants, and genotypic and phenotypic analysis of a spontaneous phage variant capable of simultaneously overcoming flagellar gene dependence and sensitivity to oxidative stress, we have uncovered a link between oxidative stress, flagellar motility, and phage infectivity. Taken together, our results underscore the importance of understanding phage-host interactions beyond the cell surface and point to host oxidative stress state as an important and underappreciated consideration for future phage-host interaction studies.
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19
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Mäntynen S, Laanto E, Oksanen HM, Poranen MM, Díaz-Muñoz SL. Black box of phage-bacterium interactions: exploring alternative phage infection strategies. Open Biol 2021; 11:210188. [PMID: 34520699 PMCID: PMC8440029 DOI: 10.1098/rsob.210188] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The canonical lytic-lysogenic binary has been challenged in recent years, as more evidence has emerged on alternative bacteriophage infection strategies. These infection modes are little studied, and yet they appear to be more abundant and ubiquitous in nature than previously recognized, and can play a significant role in the ecology and evolution of their bacterial hosts. In this review, we discuss the extent, causes and consequences of alternative phage lifestyles, and clarify conceptual and terminological confusion to facilitate research progress. We propose distinct definitions for the terms 'pseudolysogeny' and 'productive or non-productive chronic infection', and distinguish them from the carrier state life cycle, which describes a population-level phenomenon. Our review also finds that phages may change their infection modes in response to environmental conditions or the physiological state of the host cell. We outline known molecular mechanisms underlying the alternative phage-host interactions, including specific genetic pathways and their considerable biotechnological potential. Moreover, we discuss potential implications of the alternative phage lifestyles for microbial biology and ecosystem functioning, as well as applied topics such as phage therapy.
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Affiliation(s)
- Sari Mäntynen
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland,Department of Microbiology and Molecular Genetics, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - Elina Laanto
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland,Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Survontie 9, 40014 Jyväskylä, Finland
| | - Hanna M. Oksanen
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland
| | - Minna M. Poranen
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland
| | - Samuel L. Díaz-Muñoz
- Department of Microbiology and Molecular Genetics, University of California, One Shields Avenue, Davis, CA 95616, USA,Genome Center, University of California, One Shields Avenue, Davis, CA 95616, USA
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20
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Kittler S, Steffan S, Peh E, Plötz M. Phage Biocontrol of Campylobacter: A One Health Approach. Curr Top Microbiol Immunol 2021; 431:127-168. [PMID: 33620651 DOI: 10.1007/978-3-030-65481-8_6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Human infections by Campylobacter species are among the most reported bacterial gastrointestinal diseases in the European Union and worldwide with severe outcomes in rare cases. Considering the transmission routes and farm animal reservoirs of these zoonotic pathogens, a comprehensive One Health approach will be necessary to reduce human infection rates. Bacteriophages are viruses that specifically infect certain bacterial genera, species, strains or isolates. Multiple studies have demonstrated the general capacity of phage treatments to reduce Campylobacter loads in the chicken intestine. However, phage treatments are not yet approved for extensive use in the agro-food industry in Europe. Technical inconvenience is mainly related to the efficacy of phages, depending on the optimal choice of phages and their combination, as well as application route, concentration and timing. Additionally, regulatory uncertainties have been a major concern for investment in commercial phage-based products. This review addresses the question as to how phages can be put into practice and can help to solve the issue of human campylobacteriosis in a sustainable One Health approach. By compiling the reported findings from the literature in a standardized manner, we enabled inter-experimental comparisons to increase our understanding of phage infection in Campylobacter spp. and practical on-farm studies. Further, we address some of the hurdles that still must be overcome before this new methodology can be adapted on an industrial scale. We envisage that phage treatment can become an integrated and standardized part of a multi-hurdle anti-bacterial strategy in food production. The last part of this chapter deals with some of the issues raised by legal authorities, bringing together current knowledge on Campylobacter-specific phages and the biosafety requirements for approval of phage treatment in the food industry.
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Affiliation(s)
- Sophie Kittler
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173, Hannover, Germany.
| | - Severin Steffan
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173, Hannover, Germany
| | - Elisa Peh
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173, Hannover, Germany
| | - Madeleine Plötz
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, 30173, Hannover, Germany
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21
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Abstract
Thermophilic Campylobacter, in particular Campylobacter jejuni, C. coli and C. lari are the main relevant Campylobacter species for human infections. Due to their high capacity of genetic exchange by horizontal gene transfer (HGT), rapid adaptation to changing environmental and host conditions contribute to successful spreading and persistence of these foodborne pathogens. However, extensive HGT can exert dangerous side effects for the bacterium, such as the incorporation of gene fragments leading to disturbed gene functions. Here we discuss mechanisms of HGT, notably natural transformation, conjugation and bacteriophage transduction and limiting regulatory strategies of gene transfer. In particular, we summarize the current knowledge on how the DNA macromolecule is exchanged between single cells. Mechanisms to stimulate and to limit HGT obviously coevolved and maintained an optimal balance. Chromosomal rearrangements and incorporation of harmful mutations are risk factors for survival and can result in drastic loss of fitness. In Campylobacter, the restricted recognition and preferential uptake of free DNA from relatives are mediated by a short methylated DNA pattern and not by a classical DNA uptake sequence as found in other bacteria. A class two CRISPR-Cas system is present but also other DNases and restriction-modification systems appear to be important for Campylobacter genome integrity. Several lytic and integrated bacteriophages have been identified, which contribute to genome diversity. Furthermore, we focus on the impact of gene transfer on the spread of antibiotic resistance genes (resistome) and persistence factors. We discuss remaining open questions in the HGT field, supposed to be answered in the future by current technologies like whole-genome sequencing and single-cell approaches.
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Affiliation(s)
- Julia Carolin Golz
- Department of Biological Safety, National Reference Laboratory for Campylobacter, German Federal Institute for Risk Assessment (BfR), Diedersdorfer Weg 1, 12277, Berlin, Germany
| | - Kerstin Stingl
- Department of Biological Safety, National Reference Laboratory for Campylobacter, German Federal Institute for Risk Assessment (BfR), Diedersdorfer Weg 1, 12277, Berlin, Germany.
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22
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Yu L, Marchisio MA. Types I and V Anti-CRISPR Proteins: From Phage Defense to Eukaryotic Synthetic Gene Circuits. Front Bioeng Biotechnol 2020; 8:575393. [PMID: 33102460 PMCID: PMC7556299 DOI: 10.3389/fbioe.2020.575393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/31/2020] [Indexed: 12/26/2022] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas (CRISPR-associated proteins), a prokaryotic RNA-mediated adaptive immune system, has been repurposed for gene editing and synthetic gene circuit construction both in bacterial and eukaryotic cells. In the last years, the emergence of the anti-CRISPR proteins (Acrs), which are natural OFF-switches for CRISPR-Cas, has provided a new means to control CRISPR-Cas activity and promoted a further development of CRISPR-Cas-based biotechnological toolkits. In this review, we focus on type I and type V-A anti-CRISPR proteins. We first narrate Acrs discovery and analyze their inhibitory mechanisms from a structural perspective. Then, we describe their applications in gene editing and transcription regulation. Finally, we discuss the potential future usage-and corresponding possible challenges-of these two kinds of anti-CRISPR proteins in eukaryotic synthetic gene circuits.
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23
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McCutcheon JG, Lin A, Dennis JJ. Isolation and Characterization of the Novel Bacteriophage AXL3 against Stenotrophomonas maltophilia. Int J Mol Sci 2020; 21:E6338. [PMID: 32882851 PMCID: PMC7504290 DOI: 10.3390/ijms21176338] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/27/2020] [Accepted: 08/29/2020] [Indexed: 12/26/2022] Open
Abstract
The rapid increase in the number of worldwide human infections caused by the extremely antibiotic resistant bacterial pathogen Stenotrophomonas maltophilia is cause for concern. An alternative treatment solution in the post-antibiotic era is phage therapy, the use of bacteriophages to selectively kill bacterial pathogens. In this study, the novel bacteriophage AXL3 (vB_SmaS-AXL_3) was isolated from soil and characterized. Host range analysis using a panel of 29 clinical S. maltophilia isolates shows successful infection of five isolates and electron microscopy indicates that AXL3 is a member of the Siphoviridae family. Complete genome sequencing and analysis reveals a 47.5 kb genome predicted to encode 65 proteins. Functionality testing suggests AXL3 is a virulent phage and results show that AXL3 uses the type IV pilus, a virulence factor on the cell surface, as its receptor across its host range. This research identifies a novel virulent phage and characterization suggests that AXL3 is a promising phage therapy candidate, with future research examining modification through genetic engineering to broaden its host range.
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Affiliation(s)
| | | | - Jonathan J. Dennis
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada; (J.G.M.); (A.L.)
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24
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Abstract
CRISPR research began over 30 years ago with the incidental discovery of an unusual nucleotide arrangement in the Escherichia coli genome. It took 20 years to find the main function of CRISPR-Cas systems as an adaptive defence mechanism against invading nucleic acids, and our knowledge of their biology has steadily increased ever since. In parallel, the number of applications derived from CRISPR-Cas systems has risen spectacularly. The CRISPR-based genome editing tool is arguably the most exciting application in both basic and applied research. Lately, CRISPR-Cas research has partially shifted to the least understood aspect of its biology: the ability of CRISPR-Cas systems to acquire new immunities during the so-called adaptation step. To date, the most efficient natural system to readily acquire new spacers is the type II-A system of the gram-positive dairy bacterium Streptococcus thermophilus. The discovery of additional systems able to acquire new spacers will hopefully draw more attention to this step of CRISPR-Cas biology. This review focuses on the breakthroughs that have helped to unravel the adaptation phase and on questions that remain to be answered.
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Affiliation(s)
- Cas Mosterd
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, QC G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, QC G1V 0A6, Canada
| | - Geneviève M Rousseau
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, QC G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, QC G1V 0A6, Canada
| | - Sylvain Moineau
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, QC G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, QC G1V 0A6, Canada.,Félix d'Hérelle Reference Center for Bacterial Viruses, Faculté de médecine dentaire, Université Laval, QC G1V 0A6, Canada
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Hooton S, D'Angelantonio D, Hu Y, Connerton PL, Aprea G, Connerton IF. Campylobacter bacteriophage DA10: an excised temperate bacteriophage targeted by CRISPR-cas. BMC Genomics 2020; 21:400. [PMID: 32532247 PMCID: PMC7291426 DOI: 10.1186/s12864-020-06808-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 06/05/2020] [Indexed: 12/14/2022] Open
Abstract
Background Lytic bacteriophages that infect Campylobacter spp. have been utilized to develop therapeutic/decontamination techniques. However, the association of Campylobacter spp. and bacteriophages has been the focus of several strands of research aimed at understanding the complex relationships that have developed between predators and prey over evolutionary time. The activities of endogenous temperate bacteriophages have been used to evaluate genomic rearrangements and differential protein expression in host cells, and mechanisms of resistance to bacteriophage infection in campylobacters such as phase variation and CRISPR-mediated immunity. Results Temperate bacteriophage DA10 represents a novel excised and infective virus capable of replication in a restricted set of C. jejuni and C. coli hosts. Whole genome sequencing reveals that DA10 (35,379 bp) forms part of a novel group of temperate bacteriophages that have limited distribution among database host genome sequences. Analysis of potential host genomes reveals a robust response against DA10 and DA10-like bacteriophages is driven by CRISPR-mediated immunity with 75% of DA10 ORFs represented as ~ 30 bp spacer sequences in numerous Campylobacter Type II-C CRISPR arrays. Several DA10-like homologues have been identified in a small sub-set of C. jejuni and C. coli genome sequences (ranging from near complete integrated prophage sequences to fragments recognisable in the sequence read archive). Conclusions A complete intact DA10-like prophage in C. jejuni CJ677CC520 provides evidence that the associations between host and DA10-like bacteriophages are long-standing in evolutionary timescales. Extensive nucleotide substitution and loss can be observed in the integrated DA10-like prophage of CJ677CC520 compared to other relatives as observed through pairwise genome comparisons. Examining factors that have limited the population expansion of the prophage, while others appear to have thrived and prospered (Mu-like, CJIE-like, and lytic Campylobacter bacteriophages) will assist in identifying the underlying evolutionary processes in the natural environment.
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Affiliation(s)
- Steven Hooton
- School of Biosciences, Division of Microbiology Brewing and Biotechnology, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD, UK
| | - Daniela D'Angelantonio
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", Teramo, Italy
| | - Yang Hu
- School of Biosciences, Division of Microbiology Brewing and Biotechnology, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD, UK
| | - Phillippa L Connerton
- School of Biosciences, Division of Microbiology Brewing and Biotechnology, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD, UK
| | - Giuseppe Aprea
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G. Caporale", Teramo, Italy
| | - Ian F Connerton
- School of Biosciences, Division of Microbiology Brewing and Biotechnology, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD, UK.
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26
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Lee JY, Jang YJ, Bae JH, Lee YH, Bae HS, Kim S, Park SG, Koo OJ, Yeom SC. Efficient and specific generation of knockout mice using Campylobacter jejuni CRISPR/Cas9 system. Biochem Biophys Rep 2020; 22:100752. [PMID: 32258440 PMCID: PMC7118303 DOI: 10.1016/j.bbrep.2020.100752] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 01/31/2020] [Accepted: 03/12/2020] [Indexed: 11/28/2022] Open
Abstract
The Streptococcus pyogenes CRISPR/Cas9 (SpCas9) system is now widely utilized to generate genome engineered mice; however, some studies raised issues related to off-target mutations with this system. Herein, we utilized the Campylobacter jejuni Cas9 (CjCas9) system to generate knockout mice. We designed sgRNAs targeting mouse Tyr or Foxn1 and microinjected into zygotes along with CjCas9 mRNA. We obtained newborn mice from the microinjected embryos and confirmed that 50% (Tyr) and 38.5% (Foxn1) of the newborn mice have biallelic mutation on the intended target sequences, indicating efficient genome targeting by CjCas9. In addition, we analyzed off-target mutations in founder mutant mice by targeted deep sequencing and whole genome sequencing. Both analyses revealed no off-target mutations at potential off-target sites predicted in silico and no unexpected random mutations in analyzed founder animals. In conclusion, the CjCas9 system can be utilized to generate genome edited mice in a precise manner. Generate genetically engineered mice using the Campylobacter jejuni Cas9 (CjCas9) system. CjCas9 showed reasonably high biallelic InDel mutation rate (up to 50%) in newborn mice. CjCas9 system showed relatively higher specificity compared to SpCas9 system.
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Affiliation(s)
- Jae Young Lee
- Toolgen Inc, Gasan Digital-Ro, Geumcheon, 08594, Seoul, Republic of Korea
| | - Yoo Jin Jang
- Graduate School of International Agricultural Technology, Designed Animal and Transplantation Research Institute, Seoul National University, 1447 Pyeongchang-Ro, Daewha, Pyeongchang, Kangwon, 25354, Republic of Korea
| | - Ji Hyun Bae
- Graduate School of International Agricultural Technology, Designed Animal and Transplantation Research Institute, Seoul National University, 1447 Pyeongchang-Ro, Daewha, Pyeongchang, Kangwon, 25354, Republic of Korea
| | - Yoon Hoo Lee
- Graduate School of International Agricultural Technology, Designed Animal and Transplantation Research Institute, Seoul National University, 1447 Pyeongchang-Ro, Daewha, Pyeongchang, Kangwon, 25354, Republic of Korea
| | - Hee Sook Bae
- Toolgen Inc, Gasan Digital-Ro, Geumcheon, 08594, Seoul, Republic of Korea
| | - Seokjoong Kim
- Toolgen Inc, Gasan Digital-Ro, Geumcheon, 08594, Seoul, Republic of Korea
| | - Sin-Gi Park
- TheragenEtex Bio Institute, Suwon, 16229, Republic of Korea
| | - Ok Jae Koo
- Toolgen Inc, Gasan Digital-Ro, Geumcheon, 08594, Seoul, Republic of Korea
| | - Su Cheong Yeom
- Graduate School of International Agricultural Technology, Designed Animal and Transplantation Research Institute, Seoul National University, 1447 Pyeongchang-Ro, Daewha, Pyeongchang, Kangwon, 25354, Republic of Korea
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27
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Wimmer F, Beisel CL. CRISPR-Cas Systems and the Paradox of Self-Targeting Spacers. Front Microbiol 2020; 10:3078. [PMID: 32038537 PMCID: PMC6990116 DOI: 10.3389/fmicb.2019.03078] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 12/19/2019] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas immune systems in bacteria and archaea record prior infections as spacers within each system’s CRISPR arrays. Spacers are normally derived from invasive genetic material and direct the immune system to complementary targets as part of future infections. However, not all spacers appear to be derived from foreign genetic material and instead can originate from the host genome. Their presence poses a paradox, as self-targeting spacers would be expected to induce an autoimmune response and cell death. In this review, we discuss the known frequency of self-targeting spacers in natural CRISPR-Cas systems, how these spacers can be incorporated into CRISPR arrays, and how the host can evade lethal attack. We also discuss how self-targeting spacers can become the basis for alternative functions performed by CRISPR-Cas systems that extend beyond adaptive immunity. Overall, the acquisition of genome-targeting spacers poses a substantial risk but can aid in the host’s evolution and potentially lead to or support new functionalities.
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Affiliation(s)
- Franziska Wimmer
- Helmholtz Institute for RNA-Based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Chase L Beisel
- Helmholtz Institute for RNA-Based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany.,Medical Faculty, University of Würzburg, Würzburg, Germany
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28
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Cas4 Facilitates PAM-Compatible Spacer Selection during CRISPR Adaptation. Cell Rep 2019; 22:3377-3384. [PMID: 29590607 PMCID: PMC5896167 DOI: 10.1016/j.celrep.2018.02.103] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 01/25/2018] [Accepted: 02/27/2018] [Indexed: 12/20/2022] Open
Abstract
CRISPR-Cas systems adapt their immunological memory against their invaders by integrating short DNA fragments into clustered regularly interspaced short palindromic repeat (CRISPR) loci. While Cas1 and Cas2 make up the core machinery of the CRISPR integration process, various class I and II CRISPR-Cas systems encode Cas4 proteins for which the role is unknown. Here, we introduced the CRISPR adaptation genes cas1, cas2, and cas4 from the type I-D CRISPR-Cas system of Synechocystis sp. 6803 into Escherichia coli and observed that cas4 is strictly required for the selection of targets with protospacer adjacent motifs (PAMs) conferring I-D CRISPR interference in the native host Synechocystis. We propose a model in which Cas4 assists the CRISPR adaptation complex Cas1-2 by providing DNA substrates tailored for the correct PAM. Introducing functional spacers that target DNA sequences with the correct PAM is key to successful CRISPR interference, providing a better chance of surviving infection by mobile genetic elements. Cas4 facilitates the integration of PAM-compatible spacers Spacer length variation is dictated by Cas1-2 Cas4 shortens spacer length Cas4-selected PAMs license type I-D CRISPR interference
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29
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Raoultella bacteriophage RP180, a new member of the genus Kagunavirus, subfamily Guernseyvirinae. Arch Virol 2019; 164:2637-2640. [DOI: 10.1007/s00705-019-04349-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 06/16/2019] [Indexed: 11/27/2022]
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30
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Cas4 Nucleases Can Effect Specific Integration of CRISPR Spacers. J Bacteriol 2019; 201:JB.00747-18. [PMID: 30936372 DOI: 10.1128/jb.00747-18] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 03/26/2019] [Indexed: 01/19/2023] Open
Abstract
Clustered regularly interspaced short palindromic repeat (CRISPR)-Cas systems incorporate short DNA fragments from invasive genetic elements into host CRISPR arrays in order to generate host immunity. Recently, we demonstrated that the Csa3a regulator protein triggers CCN protospacer-adjacent motif (PAM)-dependent CRISPR spacer acquisition in the subtype I-A CRISPR-Cas system of Sulfolobus islandicus However, the mechanisms underlying specific protospacer selection and spacer insertion remained unclear. Here, we demonstrate that two Cas4 family proteins (Cas4 and Csa1) have essential roles (i) in recognizing the 5' PAM and 3' nucleotide motif of protospacers and (ii) in determining both the spacer length and its orientation. Furthermore, we identify amino acid residues of the Cas4 proteins that facilitate these functions. Overexpression of the Cas4 and Csa1 proteins, and also that of an archaeal virus-encoded Cas4 protein, resulted in strongly reduced adaptation efficiency, and the former proteins yielded a high incidence of PAM-dependent atypical spacer integration or of PAM-independent spacer integration. We further demonstrated that in plasmid challenge experiments, overexpressed Cas4-mediated defective spacer acquisition in turn potentially enabled targeted DNA to escape subtype I-A CRISPR-Cas interference. In summary, these results define the specific involvement of diverse Cas4 proteins in in vivo CRISPR spacer acquisition. Furthermore, we provide support for an anti-CRISPR role for virus-encoded Cas4 proteins that involves compromising CRISPR-Cas interference activity by hindering spacer acquisition.IMPORTANCE The Cas4 family endonuclease is an essential component of the adaptation module in many variants of CRISPR-Cas adaptive immunity systems. The Crenarchaeota Sulfolobus islandicus REY15A carries two cas4 genes (cas4 and csa1) linked to the CRISPR arrays. Here, we demonstrate that Cas4 and Csa1 are essential to CRISPR spacer acquisition in this organism. Both proteins specify the upstream and downstream conserved nucleotide motifs of the protospacers and define the spacer length and orientation in the acquisition process. Conserved amino acid residues, in addition to those recently reported, were identified to be important for these functions. More importantly, overexpression of the Sulfolobus viral Cas4 abolished spacer acquisition, providing support for an anti-CRISPR role for virus-encoded Cas4 proteins that inhibit spacer acquisition.
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31
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Chen LX, Al-Shayeb B, Méheust R, Li WJ, Doudna JA, Banfield JF. Candidate Phyla Radiation Roizmanbacteria From Hot Springs Have Novel and Unexpectedly Abundant CRISPR-Cas Systems. Front Microbiol 2019; 10:928. [PMID: 31130929 PMCID: PMC6509639 DOI: 10.3389/fmicb.2019.00928] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 04/12/2019] [Indexed: 11/13/2022] Open
Abstract
The Candidate Phyla Radiation (CPR) comprises a huge group of bacteria that have small genomes that rarely encode CRISPR-Cas systems for phage defense. Consequently, questions remain about their mechanisms of phage resistance and the nature of phage that infect them. The compact CRISPR-CasY system (Cas12d) with potential value in genome editing was first discovered in these organisms. Relatively few CasY sequences have been reported to date, and little is known about the function and activity of these systems in the natural environment. Here, we conducted a genome-resolved metagenomic investigation of hot spring microbiomes and recovered CRISPR systems mostly from Roizmanbacteria that involve CasY proteins that are divergent from published sequences. Within population diversity in the spacer set indicates current in situ diversification of most of the loci. In addition to CasY, some Roizmanbacteria genomes also encode large type I-B and/or III-A systems that, based on spacer targeting, are used in phage defense. CRISPR targeting identified three phage represented by complete genomes and a prophage, which are the first reported for bacteria of the Microgenomates superphylum. Interestingly, one phage encodes a Cas4-like protein, a scenario that has been suggested to drive acquisition of self-targeting spacers. Consistent with this, the Roizmanbacteria population that it infects has a CRISPR locus that includes self-targeting spacers and a fragmented CasY gene (fCasY). Despite gene fragmentation, the PAM sequence is the same as that of other CasY reported in this study. Fragmentation of CasY may avoid the lethality of self-targeting spacers. However, the spacers may still have some biological role, possibly in genome regulation. The findings expand our understanding of CasY diversity, and more broadly, CRISPR-Cas systems and phage of CPR bacteria.
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Affiliation(s)
- Lin-Xing Chen
- Department of Earth and Planetary Sciences, University of California, Berkeley, Berkeley, CA, United States
| | - Basem Al-Shayeb
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Raphaël Méheust
- Department of Earth and Planetary Sciences, University of California, Berkeley, Berkeley, CA, United States
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, United States
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jennifer A. Doudna
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, United States
- The Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States
| | - Jillian F. Banfield
- Department of Earth and Planetary Sciences, University of California, Berkeley, Berkeley, CA, United States
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, United States
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Peters DL, McCutcheon JG, Stothard P, Dennis JJ. Novel Stenotrophomonas maltophilia temperate phage DLP4 is capable of lysogenic conversion. BMC Genomics 2019; 20:300. [PMID: 30991961 PMCID: PMC6469090 DOI: 10.1186/s12864-019-5674-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 04/08/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Temperate bacteriophages are capable of lysogenic conversion of new bacterial hosts. This phenomenon is often ascribed to "moron" elements that are acquired horizontally and transcribed independently from the rest of the phage genes. Whereas some bacterial species exhibit relatively little prophage-dependent phenotypic changes, other bacterial species such as Stenotrophomonas maltophilia appear to commonly adopt prophage genetic contributions. RESULTS The novel S. maltophilia bacteriophage DLP4 was isolated from soil using the highly antibiotic-resistant S. maltophilia strain D1585. Genome sequence analysis and functionality testing showed that DLP4 is a temperate phage capable of lysogenizing D1585. Two moron genes of interest, folA (BIT20_024) and ybiA (BIT20_065), were identified and investigated for their putative activities using complementation testing and phenotypic and transcriptomic changes between wild-type D1585 and the D1585::DLP4 lysogen. The gp24 / folA gene encodes dihydrofolate reductase (DHFR: FolA), an enzyme responsible for resistance to the antibiotic trimethoprim. I-TASSER analysis of DLP4 FolA predicted structural similarity to Bacillus anthracis DHFR and minimum inhibitory concentration experiments demonstrated that lysogenic conversion of D1585 by DLP4 provided the host cell with an increase in trimethoprim resistance. The gp65 / ybiA gene encodes N-glycosidase YbiA, which in E. coli BW25113 is required for its swarming motility phenotype. Expressing DLP4 ybiA in strain ybiA770(del)::kan restored its swarming motility activity to wildtype levels. Reverse transcription-PCR confirmed the expression of both of these genes during DLP4 lysogeny. CONCLUSIONS S. maltophilia temperate phage DLP4 contributes to the antibiotic resistance exhibited by its lysogenized host strain. Genomic analyses can greatly assist in the identification of phage moron genes potentially involved in lysogenic conversion. Further research is required to fully understand the specific contributions temperate phage moron genes provide with respect to the antibiotic resistance and virulence of S. maltophilia host cells.
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Affiliation(s)
- Danielle L. Peters
- Department of Biological Sciences, 6-065 Centennial Centre for Interdisciplinery Science, University of Alberta, Edmonton, Alberta T6G 2E9 Canada
| | - Jaclyn G. McCutcheon
- Department of Biological Sciences, 6-065 Centennial Centre for Interdisciplinery Science, University of Alberta, Edmonton, Alberta T6G 2E9 Canada
| | - Paul Stothard
- Department of Biological Sciences, 6-065 Centennial Centre for Interdisciplinery Science, University of Alberta, Edmonton, Alberta T6G 2E9 Canada
| | - Jonathan J. Dennis
- Department of Biological Sciences, 6-065 Centennial Centre for Interdisciplinery Science, University of Alberta, Edmonton, Alberta T6G 2E9 Canada
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Koonin EV. CRISPR: a new principle of genome engineering linked to conceptual shifts in evolutionary biology. BIOLOGY & PHILOSOPHY 2019; 34:9. [PMID: 30930513 PMCID: PMC6404382 DOI: 10.1007/s10539-018-9658-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 11/27/2018] [Indexed: 06/09/2023]
Abstract
The CRISPR-Cas systems of bacterial and archaeal adaptive immunity have become a household name among biologists and even the general public thanks to the unprecedented success of the new generation of genome editing tools utilizing Cas proteins. However, the fundamental biological features of CRISPR-Cas are of no lesser interest and have major impacts on our understanding of the evolution of antivirus defense, host-parasite coevolution, self versus non-self discrimination and mechanisms of adaptation. CRISPR-Cas systems present the best known case in point for Lamarckian evolution, i.e. generation of heritable, adaptive genomic changes in response to encounters with external factors, in this case, foreign nucleic acids. CRISPR-Cas systems employ multiple mechanisms of self versus non-self discrimination but, as is the case with immune systems in general, are nevertheless costly because autoimmunity cannot be eliminated completely. In addition to the autoimmunity, the fitness cost of CRISPR-Cas systems appears to be determined by their inhibitory effect on horizontal gene transfer, curtailing evolutionary innovation. Hence the dynamic evolution of CRISPR-Cas loci that are frequently lost and (re)acquired by archaea and bacteria. Another fundamental biological feature of CRISPR-Cas is its intimate connection with programmed cell death and dormancy induction in microbes. In this and, possibly, other immune systems, active immune response appears to be coupled to a different form of defense, namely, "altruistic" shutdown of cellular functions resulting in protection of neighboring cells. Finally, analysis of the evolutionary connections of Cas proteins reveals multiple contributions of mobile genetic elements (MGE) to the origin of various components of CRISPR-Cas systems, furthermore, different biological systems that function by genome manipulation appear to have evolved convergently from unrelated MGE. The shared features of adaptive defense systems and MGE, namely the ability to recognize and cleave unique sites in genomes, make them ideal candidates for genome editing and engineering tools.
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Affiliation(s)
- Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894 USA
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Kongrueng J, Srinitiwarawong K, Nishibuchi M, Mittraparp-Arthorn P, Vuddhakul V. Characterization and CRISPR-based genotyping of clinical trh-positive Vibrio parahaemolyticus. Gut Pathog 2018; 10:48. [PMID: 30459849 PMCID: PMC6233571 DOI: 10.1186/s13099-018-0275-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 11/08/2018] [Indexed: 01/15/2023] Open
Abstract
Background Vibrio parahaemolyticus is a causative agent of gastroenteritis. Most of the clinical isolates carry either tdh and/or trh genes which are considered as the major virulence genes of this pathogen. In this study, the clinical isolates of V. parahaemolyticus carrying trh gene (n = 73) obtained from 1886 to 2012 from various countries were investigated for the urease production, haemolytic activity, and biofilm formation. In addition, the potential of clustered regularly interspaced short palindromic repeats (CRISPR)-based genotyping among these isolates was investigated. Results In this study, no significant differences were observed in the urease production between tdh + trh1+ and tdh + trh2+ isolates (p = 0.063) and between the tdh - trh1+ and tdh - trh2+ isolates (p = 0.788). The isolates carrying only the trh gene showed variation in their haemolytic activity. The ratio of urease production and haemolytic activity between the trh1+ and trh2+ isolates and biofilm formation of trh + V. parahaemolyticus isolates were not significantly different. Sixteen of thirty-four tested isolates (47.0%) of trh + V. parahaemolyticus were positive for CRISPR detection. The discriminatory power index (DI) of CRISPR-virulence typing was higher than the DI obtained by CRISPR typing alone. Conclusion The tdh and trh genes were not involved in urease production in the trh + V. parahaemolyticus, and variation of haemolytic activity detected in V. parahaemolyticus carrying only the trh gene might be correlated to the sequence variation within trh1 and trh2 genes. Additionally, biofilm production of V. parahaemolyticus was not associated with harboring of virulence genes. For genotyping, CRISPR sequences combined with virulence genes can be used as genetic markers to differentiate trh + V. parahaemolyticus strains.
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Affiliation(s)
- Jetnapang Kongrueng
- 1Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Thailand
| | - Kanchana Srinitiwarawong
- 1Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Thailand
| | | | | | - Varaporn Vuddhakul
- 1Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Thailand
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Liang L, Connerton IF. FlhF(T368A) modulates motility in the bacteriophage carrier state of Campylobacter jejuni. Mol Microbiol 2018; 110:616-633. [PMID: 30230632 PMCID: PMC6282759 DOI: 10.1111/mmi.14120] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 08/28/2018] [Accepted: 09/05/2018] [Indexed: 12/13/2022]
Abstract
The carrier state is an alternative bacteriophage life cycle by which virulent bacteriophage can persist in association with host bacteria. Campylobacter jejuni carrier state strains exhibit growth phase dependent motility due to a truncated flagella phenotype. Genome sequencing identified a T368A substitution in the G3 domain of the SRP-like GTPase FlhF from C. jejuni PT14CP30A carrier state strains, which we hypothesized to be the cause of the complex motility phenotype. We have analyzed the role of this mutation in C. jejuni PT14 and demonstrated that flhF(T368A) leads to a large proportion of cells unable to synthesize flagella, while the remaining cells form a single flagellum at one pole leading to significantly reduced motility. The flhF(T368A) mutation causes a reduction in the phage adsorption constant, which leads to a decrease in infection efficiency. Down-regulation of σ28 and σ54 dependent flagellar genes were observed as responses to the flhF(T368A) mutation. FlhF(T368A) protein is impaired in GTPase activity and exhibits reduced stability. C. jejuni carrying flhF(T368A) are less sensitive to bacteriophage infection and formation of the carrier state. The acquisition of flhF(T368A) in carrier state strains acts to prevent super-infection and maintain association with the bacteriophage that provoked the interaction.
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Affiliation(s)
- Lu Liang
- Division of Food Sciences, School of BiosciencesUniversity of NottinghamSutton Bonington CampusLoughboroughLeicestershireLE12 5RDUK
| | - Ian F. Connerton
- Division of Food Sciences, School of BiosciencesUniversity of NottinghamSutton Bonington CampusLoughboroughLeicestershireLE12 5RDUK
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36
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Goodman DA, Stedman KM. Comparative genetic and genomic analysis of the novel fusellovirus Sulfolobus spindle-shaped virus 10. Virus Evol 2018; 4:vey022. [PMID: 30094064 PMCID: PMC6080066 DOI: 10.1093/ve/vey022] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Viruses that infect thermophilic Archaea are unique in both their structure and genetic makeup. The lemon-shaped fuselloviruses—which infect members of the order Sulfolobales, growing optimally at 80 °C and pH 3—are some of the most ubiquitous and best studied viruses of the thermoacidophilic Archaea. Nonetheless, much remains to be learned about these viruses. In order to investigate fusellovirus evolution, we have isolated and characterized a novel fusellovirus, Sulfolobus spindle-shaped virus 10 (formerly SSV-L1). Comparative genomic analyses highlight significant similarity with both SSV8 and SSV9, as well as conservation of promoter elements within the Fuselloviridae. SSV10 encodes five ORFs with no homology within or outside of the Fuselloviridae, as well as a putatively functional Cas4-like ORF, which may play a role in evading CRISPR-mediated host defenses. Moreover, we demonstrate the ability of SSV10 to withstand mutation in a fashion consistent with mutagenesis in SSV1.
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Affiliation(s)
- David A Goodman
- Biology Department, Center for Life in Extreme Environments, Portland State University, Portland, OR, USA
| | - Kenneth M Stedman
- Biology Department, Center for Life in Extreme Environments, Portland State University, Portland, OR, USA
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Sacher JC, Flint A, Butcher J, Blasdel B, Reynolds HM, Lavigne R, Stintzi A, Szymanski CM. Transcriptomic Analysis of the Campylobacter jejuni Response to T4-Like Phage NCTC 12673 Infection. Viruses 2018; 10:E332. [PMID: 29914170 PMCID: PMC6024767 DOI: 10.3390/v10060332] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 06/13/2018] [Accepted: 06/13/2018] [Indexed: 12/14/2022] Open
Abstract
Campylobacter jejuni is a frequent foodborne pathogen of humans. As C. jejuni infections commonly arise from contaminated poultry, phage treatments have been proposed to reduce the C. jejuni load on farms to prevent human infections. While a prior report documented the transcriptome of C. jejuni phages during the carrier state life cycle, transcriptomic analysis of a lytic C. jejuni phage infection has not been reported. We used RNA-sequencing to profile the infection of C. jejuni NCTC 11168 by the lytic T4-like myovirus NCTC 12673. Interestingly, we found that the most highly upregulated host genes upon infection make up an uncharacterized operon (cj0423⁻cj0425), which includes genes with similarity to T4 superinfection exclusion and antitoxin genes. Other significantly upregulated genes include those involved in oxidative stress defense and the Campylobactermultidrug efflux pump (CmeABC). We found that phage infectivity is altered by mutagenesis of the oxidative stress defense genes catalase (katA), alkyl-hydroxyperoxidase (ahpC), and superoxide dismutase (sodB), and by mutagenesis of the efflux pump genes cmeA and cmeB. This suggests a role for these gene products in phage infection. Together, our results shed light on the phage-host dynamics of an important foodborne pathogen during lytic infection by a T4-like phage.
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Affiliation(s)
- Jessica C Sacher
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada.
| | - Annika Flint
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
| | - James Butcher
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
| | - Bob Blasdel
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Leuven 3001, Belgium.
| | - Hayley M Reynolds
- Department of Microbiology and Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA.
| | - Rob Lavigne
- Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Leuven 3001, Belgium.
| | - Alain Stintzi
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
| | - Christine M Szymanski
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada.
- Department of Microbiology and Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA.
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38
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He Y, Wang M, Liu M, Huang L, Liu C, Zhang X, Yi H, Cheng A, Zhu D, Yang Q, Wu Y, Zhao X, Chen S, Jia R, Zhang S, Liu Y, Yu Y, Zhang L. Cas1 and Cas2 From the Type II-C CRISPR-Cas System of Riemerella anatipestifer Are Required for Spacer Acquisition. Front Cell Infect Microbiol 2018; 8:195. [PMID: 29951376 PMCID: PMC6008519 DOI: 10.3389/fcimb.2018.00195] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 05/24/2018] [Indexed: 12/22/2022] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins provide acquired genetic immunity against the entry of mobile genetic elements (MGEs). The immune defense provided by various subtypes of the CRISPR-Cas system has been confirmed and is closely associated with the formation of immunological memory in CRISPR arrays, called CRISPR adaptation or spacer acquisition. However, whether type II-C CRISPR-Cas systems are also involved in spacer acquisition remains largely unknown. This study explores and provides some definitive evidence regarding spacer acquisition of the type II-C CRISPR-Cas system from Riemerella anatipestifer (RA) CH-2 (RA-CH-2). Firstly, introducing an exogenous plasmid into RA-CH-2 triggered spacer acquisition of RA CRISPR-Cas system, and the acquisition of new spacers led to plasmid instability in RA-CH-2. Furthermore, deletion of cas1 or cas2 of RA-CH-2 abrogated spacer acquisition and subsequently stabilized the exogenous plasmid, suggesting that both Cas1 and Cas2 are required for spacer acquisition of RA-CH-2 CRISPR-Cas system, consistent with the reported role of Cas1 and Cas2 in type I-E and II-A systems. Finally, assays for studying Cas1 nuclease activity and the interaction of Cas1 with Cas2 contributed to a better understanding of the adaptation mechanism of RA CRISPR-Cas system. This is the first experimental identification of the naïve adaptation of type II-C CRISPR-Cas system.
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Affiliation(s)
- Yang He
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Li Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Chaoyue Liu
- Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Department of Microbiology and Immunology, North Sichuan Medical College, Nanchong, China
| | - Xin Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Haibo Yi
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Dekang Zhu
- Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xinxin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yunya Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yanling Yu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ling Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
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Hille F, Richter H, Wong SP, Bratovič M, Ressel S, Charpentier E. The Biology of CRISPR-Cas: Backward and Forward. Cell 2018. [DOI: 10.1016/j.cell.2017.11.032] [Citation(s) in RCA: 333] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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40
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Abstract
Bacteria and archaea possess numerous defense systems to combat viral infections and other mobile genetic elements. Uniquely among these, CRISPR-Cas (clustered, regularly interspaced short palindromic repeats-CRISPR associated) provides adaptive genetic interference against foreign nucleic acids. Here we review recent advances on the CRISPR-Cas9 system in Neisseria spp, with a focus on its biological functions in genetic transfer, its mechanistic features that establish new paradigms and its technological applications in eukaryotic genome engineering.
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41
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Abstract
Genome editing technologies have been revolutionized by the discovery of prokaryotic RNA-guided defense system called CRISPR-Cas. Cas9, a single effector protein found in type II CRISPR systems, has been at the heart of this genome editing revolution. Nearly half of the Cas9s discovered so far belong to the type II-C subtype but have not been explored extensively. Type II-C CRISPR-Cas systems are the simplest of the type II systems, employing only three Cas proteins. Cas9s are central players in type II-C systems since they function in multiple steps of the CRISPR pathway, including adaptation and interference. Type II-C CRISPR systems are found in bacteria and archaea from very diverse environments, resulting in Cas9s with unique and potentially useful properties. Certain type II-C Cas9s possess unusually long PAMs, function in unique conditions (e.g., elevated temperature), and tend to be smaller in size. Here, we review the biology, mechanism, and applications of the type II-C CRISPR systems with particular emphasis on their Cas9s.
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Affiliation(s)
- Aamir Mir
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, U.S.A
| | - Alireza Edraki
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, U.S.A
| | - Jooyoung Lee
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, U.S.A
| | - Erik J. Sontheimer
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, U.S.A
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, U.S.A
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42
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Gencay YE, Sørensen MCH, Wenzel CQ, Szymanski CM, Brøndsted L. Phase Variable Expression of a Single Phage Receptor in Campylobacter jejuni NCTC12662 Influences Sensitivity Toward Several Diverse CPS-Dependent Phages. Front Microbiol 2018; 9:82. [PMID: 29467727 PMCID: PMC5808241 DOI: 10.3389/fmicb.2018.00082] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Accepted: 01/12/2018] [Indexed: 12/17/2022] Open
Abstract
Campylobacter jejuni NCTC12662 is sensitive to infection by many Campylobacter bacteriophages. Here we used this strain to investigate the molecular mechanism behind phage resistance development when exposed to a single phage and demonstrate how phase variable expression of one surface component influences phage sensitivity against many diverse C. jejuni phages. When C. jejuni NCTC12662 was exposed to phage F207 overnight, 25% of the bacterial cells were able to grow on a lawn of phage F207, suggesting that resistance develops at a high frequency. One resistant variant, 12662R, was further characterized and shown to be an adsorption mutant. Plaque assays using our large phage collection showed that seven out of 36 diverse capsular polysaccharide (CPS)-dependent phages could not infect 12662R, whereas the remaining phages formed plaques on 12662R with reduced efficiencies. Analysis of the CPS composition of 12662R by high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) showed a diminished signal for O-methyl phosphoramidate (MeOPN), a phase variable modification of the CPS. This suggested that the majority of the 12662R population did not express this phase variable modification in the CPS, indicating that MeOPN serves as a phage receptor in NCTC12662. Whole genome analysis of 12662R showed a switch in the length of the phase variable homopolymeric G tract of gene 06810, encoding a putative MeOPN-transferase located in the CPS locus, resulting in a non-functional protein. To confirm the role of 06810 in phage resistance development of NCTC12662, a 06810 knockout mutant in NCTC12662 was constructed and analyzed by HR-MAS NMR demonstrating the absence of MeOPN in the CPS of the mutant. Plaque assays using NCTC12662Δ06810 demonstrated that seven of our CPS-dependent Campylobacter phages are dependent on the presence of MeOPN for successful infection of C. jejuni, whereas the remaining 29 phages infect independently of MeOPN, although with reduced efficiencies. Our data indicate that CPS-dependent phages uses diverse mechanisms for their initial interaction with their C. jejuni host.
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Affiliation(s)
- Yilmaz Emre Gencay
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Martine C H Sørensen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Cory Q Wenzel
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
| | - Christine M Szymanski
- Department of Biological Sciences, University of Alberta, Edmonton, Canada.,Department of Microbiology and Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia
| | - Lone Brøndsted
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
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43
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Hudaiberdiev S, Shmakov S, Wolf YI, Terns MP, Makarova KS, Koonin EV. Phylogenomics of Cas4 family nucleases. BMC Evol Biol 2017; 17:232. [PMID: 29179671 PMCID: PMC5704561 DOI: 10.1186/s12862-017-1081-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 11/16/2017] [Indexed: 12/31/2022] Open
Abstract
Background The Cas4 family endonuclease is a component of the adaptation module in many variants of CRISPR-Cas adaptive immunity systems. Unlike most of the other Cas proteins, Cas4 is often encoded outside CRISPR-cas loci (solo-Cas4) and is also found in mobile genetic elements (MGE-Cas4). Results As part of our ongoing investigation of CRISPR-Cas evolution, we explored the phylogenomics of the Cas4 family. About 90% of the archaeal genomes encode Cas4 compared to only about 20% of the bacterial genomes. Many archaea encode both the CRISPR-associated form (CAS-Cas4) and solo-Cas4, whereas in bacteria, this combination is extremely rare. The solo-cas4 genes are over-represented in environmental bacteria and archaea with small genomes that typically lack CRISPR-Cas, suggesting that Cas4 could perform uncharacterized defense or repair functions in these microbes. Phylogenomic analysis indicates that both the CRISPR-associated cas4 genes are often transferred horizontally but almost exclusively, as part of the adaptation module. The evolutionary integrity of the adaptation module sharply contrasts the rampant shuffling of CRISPR-cas modules whereby a given variant of the adaptation module can combine with virtually any effector module. The solo-cas4 genes evolve primarily via vertical inheritance and are subject only to occasional horizontal transfer. The selection pressure on cas4 genes does not substantially differ between CAS-Cas4 and solo-cas4, and is close to the genomic median. Thus, cas4 genes, similarly to cas1 and cas2, evolve similarly to ‘regular’ microbial genes involved in various cellular functions, showing no evidence of direct involvement in virus-host arms races. A notable feature of the Cas4 family evolution is the frequent recruitment of cas4 genes by various mobile genetic elements (MGE), particularly, archaeal viruses. The functions of Cas4 in these elements are unknown and potentially might involve anti-defense roles. Conclusions Unlike most of the other Cas proteins, Cas4 family members are as often encoded by stand-alone genes as they are incorporated in CRISPR-Cas systems. In addition, cas4 genes were repeatedly recruited by MGE, perhaps, for anti-defense functions. Experimental characterization of the solo and MGE-encoded Cas4 nucleases is expected to reveal currently uncharacterized defense and anti-defense systems and their interactions with CRISPR-Cas systems. Electronic supplementary material The online version of this article (10.1186/s12862-017-1081-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sanjarbek Hudaiberdiev
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, USA
| | - Sergey Shmakov
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, USA.,Skolkovo Institute of Science and Technology, Skolkovo, 143025, Russia
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, USA
| | - Michael P Terns
- Departments of Biochemistry and Molecular Biology, Genetics, and Microbiology, University of Georgia, Athens, GA, USA
| | - Kira S Makarova
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, USA
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, USA.
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Tomida J, Morita Y, Shibayama K, Kikuchi K, Sawa T, Akaike T, Kawamura Y. Diversity and microevolution of CRISPR loci in Helicobacter cinaedi. PLoS One 2017; 12:e0186241. [PMID: 29028814 PMCID: PMC5640232 DOI: 10.1371/journal.pone.0186241] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 09/27/2017] [Indexed: 12/30/2022] Open
Abstract
Helicobacter cinaedi is associated with nosocomial infections. The CRISPR-Cas system provides adaptive immunity against foreign genetic elements. We investigated the CRISPR-Cas system in H. cinaedi to assess the potential of the CRISPR-based microevolution of H. cinaedi strains. A genotyping method based on CRISPR spacer organization was carried out using 42 H. cinaedi strains. The results of sequence analysis showed that the H. cinaedi strains used in this study had two CRISPR loci (CRISPR1 and CRISPR2). The lengths of the consensus direct repeat sequences in CRISPR1 and CRISPR2 were both 36 bp-long, and 224 spacers were found in the 42 H. cinaedi strains. Analysis of the organization and sequence similarity of the spacers of the H. cinaedi strains showed that CRISPR arrays could be divided into 7 different genotypes. Each genotype had a different ancestral spacer, and spacer acquisition/deletion events occurred while isolates were spreading. Spacer polymorphisms of conserved arrays across the strains were instrumental for differentiating closely-related strains collected from the same hospital. MLST had little variability, while the CRISPR sequences showed remarkable diversity. Our data revealed the structural features of H. cinaedi CRISPR loci for the first time. CRISPR sequences constitute a valuable basis for genotyping, provide insights into the divergence and relatedness between closely-related strains, and reflect the microevolutionary process of H. cinaedi.
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Affiliation(s)
- Junko Tomida
- Department of Microbiology, School of Pharmacy, Aichi Gakuin University, Nagoya, Japan
- * E-mail:
| | - Yuji Morita
- Department of Microbiology, School of Pharmacy, Aichi Gakuin University, Nagoya, Japan
| | - Keigo Shibayama
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Ken Kikuchi
- Department of Infectious Diseases, Tokyo Women’s Medical University, Tokyo, Japan
| | - Tomohiro Sawa
- Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Takaaki Akaike
- Department of Environmental Health Sciences and Molecular Toxicology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yoshiaki Kawamura
- Department of Microbiology, School of Pharmacy, Aichi Gakuin University, Nagoya, Japan
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Koonin EV, Makarova KS. Mobile Genetic Elements and Evolution of CRISPR-Cas Systems: All the Way There and Back. Genome Biol Evol 2017; 9:2812-2825. [PMID: 28985291 PMCID: PMC5737515 DOI: 10.1093/gbe/evx192] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2017] [Indexed: 12/13/2022] Open
Abstract
The Clustered Regularly Interspaced Palindromic Repeats (CRISPR)-CRISPR-associated proteins (Cas) systems of bacterial and archaeal adaptive immunity show multifaceted evolutionary relationships with at least five classes of mobile genetic elements (MGE). First, the adaptation module of CRISPR-Cas that is responsible for the formation of the immune memory apparently evolved from a Casposon, a self-synthesizing transposon that employs the Cas1 protein as the integrase and might have brought additional cas genes to the emerging immunity loci. Second, a large subset of type III CRISPR-Cas systems recruited a reverse transcriptase from a Group II intron, providing for spacer acquisition from RNA. Third, effector nucleases of Class 2 CRISPR-Cas systems that are responsible for the recognition and cleavage of the target DNA were derived from transposon-encoded TnpB nucleases, most likely, on several independent occasions. Fourth, accessory nucleases in some variants of types I and III toxin and type VI effectors RNases appear to be ultimately derived from toxin nucleases of microbial toxin-antitoxin modules. Fifth, the opposite direction of evolution is manifested in the recruitment of CRISPR-Cas systems by a distinct family of Tn7-like transposons that probably exploit the capacity of CRISPR-Cas to recognize unique DNA sites to facilitate transposition as well as by bacteriophages that employ them to cope with host defense. Additionally, individual Cas proteins, such as the Cas4 nuclease, were recruited by bacteriophages and transposons. The two-sided evolutionary connection between CRISPR-Cas and MGE fits the "guns for hire" paradigm whereby homologous enzymatic machineries, in particular nucleases, are shuttled between MGE and defense systems and are used alternately as means of offense or defense.
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Affiliation(s)
- Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland
| | - Kira S. Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland
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46
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Abstract
Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein (CRISPR-Cas) systems store the memory of past encounters with foreign DNA in unique spacers that are inserted between direct repeats in CRISPR arrays. For only a small fraction of the spacers, homologous sequences, called protospacers, are detectable in viral, plasmid, and microbial genomes. The rest of the spacers remain the CRISPR “dark matter.” We performed a comprehensive analysis of the spacers from all CRISPR-cas loci identified in bacterial and archaeal genomes, and we found that, depending on the CRISPR-Cas subtype and the prokaryotic phylum, protospacers were detectable for 1% to about 19% of the spacers (~7% global average). Among the detected protospacers, the majority, typically 80 to 90%, originated from viral genomes, including proviruses, and among the rest, the most common source was genes that are integrated into microbial chromosomes but are involved in plasmid conjugation or replication. Thus, almost all spacers with identifiable protospacers target mobile genetic elements (MGE). The GC content, as well as dinucleotide and tetranucleotide compositions, of microbial genomes, their spacer complements, and the cognate viral genomes showed a nearly perfect correlation and were almost identical. Given the near absence of self-targeting spacers, these findings are most compatible with the possibility that the spacers, including the dark matter, are derived almost completely from the species-specific microbial mobilomes. The principal function of CRISPR-Cas systems is thought to be protection of bacteria and archaea against viruses and other parasitic genetic elements. The CRISPR defense function is mediated by sequences from parasitic elements, known as spacers, that are inserted into CRISPR arrays and then transcribed and employed as guides to identify and inactivate the cognate parasitic genomes. However, only a small fraction of the CRISPR spacers match any sequences in the current databases, and of these, only a minority correspond to known parasitic elements. We show that nearly all spacers with matches originate from viral or plasmid genomes that are either free or have been integrated into the host genome. We further demonstrate that spacers with no matches have the same properties as those of identifiable origins, strongly suggesting that all spacers originate from mobile elements.
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47
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Environmental Viral Genomes Shed New Light on Virus-Host Interactions in the Ocean. mSphere 2017; 2:mSphere00359-16. [PMID: 28261669 PMCID: PMC5332604 DOI: 10.1128/msphere.00359-16] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/02/2017] [Indexed: 11/27/2022] Open
Abstract
Viruses are diverse and play significant ecological roles in marine ecosystems. However, our knowledge of genome-level diversity in viruses is biased toward those isolated from few culturable hosts. Here, we determined 1,352 nonredundant complete viral genomes from marine environments. Lifting the uncertainty that clouds short incomplete sequences, whole-genome-wide analysis suggests that these environmental genomes represent hundreds of putative novel viral genera. Predicted hosts include dominant groups of marine bacteria and archaea with no isolated viruses to date. Some of the viral genomes encode many functionally related enzymes, suggesting a strong selection pressure on these marine viruses to control cellular metabolisms by accumulating genes. Metagenomics has revealed the existence of numerous uncharacterized viral lineages, which are referred to as viral “dark matter.” However, our knowledge regarding viral genomes is biased toward culturable viruses. In this study, we analyzed 1,600 (1,352 nonredundant) complete double-stranded DNA viral genomes (10 to 211 kb) assembled from 52 marine viromes. Together with 244 previously reported uncultured viral genomes, a genome-wide comparison delineated 617 genus-level operational taxonomic units (OTUs) for these environmental viral genomes (EVGs). Of these, 600 OTUs contained no representatives from known viruses, thus putatively corresponding to novel viral genera. Predicted hosts of the EVGs included major groups of marine prokaryotes, such as marine group II Euryarchaeota and SAR86, from which no viruses have been isolated to date, as well as Flavobacteriaceae and SAR116. Our analysis indicates that marine cyanophages are already well represented in genome databases and that one of the EVGs likely represents a new cyanophage lineage. Several EVGs encode many enzymes that appear to function for an efficient utilization of iron-sulfur clusters or to enhance host survival. This suggests that there is a selection pressure on these marine viruses to accumulate genes for specific viral propagation strategies. Finally, we revealed that EVGs contribute to a 4-fold increase in the recruitment of photic-zone viromes compared with the use of current reference viral genomes. IMPORTANCE Viruses are diverse and play significant ecological roles in marine ecosystems. However, our knowledge of genome-level diversity in viruses is biased toward those isolated from few culturable hosts. Here, we determined 1,352 nonredundant complete viral genomes from marine environments. Lifting the uncertainty that clouds short incomplete sequences, whole-genome-wide analysis suggests that these environmental genomes represent hundreds of putative novel viral genera. Predicted hosts include dominant groups of marine bacteria and archaea with no isolated viruses to date. Some of the viral genomes encode many functionally related enzymes, suggesting a strong selection pressure on these marine viruses to control cellular metabolisms by accumulating genes.
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Zhu DK, Yang XQ, He Y, Zhou WS, Song XH, Wang JB, Zhang Y, Liu MF, Wang MS, Jia RY, Chen S, Sun KF, Yang Q, Wu Y, Chen XY, Cheng AC. Comparative genomic analysis identifies structural features of CRISPR-Cas systems in Riemerella anatipestifer. BMC Genomics 2016; 17:689. [PMID: 27577199 PMCID: PMC5006608 DOI: 10.1186/s12864-016-3040-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 08/24/2016] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Riemerella anatipestifer infection is a contagious disease that has resulted in major economic losses in the duck industry worldwide. This study attempted to characterize CRISPR-Cas systems in the disease-causing agent, Riemerella anatipestifer (R. anatipestifer). The CRISPR-Cas system provides adaptive immunity against foreign genetic elements in prokaryotes and CRISPR-cas loci extensively exist in the genomes of archaea and bacteria. However, the structure characteristics of R. anatipestifer CRISPR-Cas systems remains to be elucidated due to the limited availability of genomic data. RESULTS To identify the structure and components associated with CRISPR-Cas systems in R. anatipestifer, we performed comparative genomic analysis of CRISPR-Cas systems in 25 R. anatipestifer strains using high-throughput sequencing. The results showed that most of the R. anatipestifer strains (20/25) that were analyzed have two CRISPR loci (CRISPR1 and CRISPR2). CRISPR1 was shown to be flanked on one side by cas genes, while CRISPR2 was designated as an orphan. The other analyzed strains harbored only one locus, either CRISPR1 or CRISPR2. The length and content of consensus direct repeat sequences, as well as the length of spacer sequences associated with the two loci, differed from each other. Only three cas genes (cas1, cas2 and cas9) were located upstream of CRISPR1. CRISPR1 was also shown to be flanked by a 107 bp-long putative leader sequence and a 16 nt-long anti-repeat sequence. Combined with analysis of spacer organization similarity and phylogenetic tree of the R. anatipestifer strains, CRISPR arrays can be divided into different subgroups. The diversity of spacer organization was observed in the same subgroup. In general, spacer organization in CRISPR1 was more divergent than that in CRISPR2. Additionally, only 8 % of spacers (13/153) were homologous with phage or plasmid sequences. The cas operon flanking CRISPR1 was observed to be relatively conserved based on multiple sequence alignments of Cas amino acid sequences. The phylogenetic analysis associated with Cas9 showed Cas9 sequence from R. anatipestifer was closely related to that of Bacteroides fragilis and formed part of the subtype II-C subcluster. CONCLUSIONS Our data revealed for the first time the structural features of R. anatipestifer CRISPR-Cas systems. The illumination of structural features of CRISPR-Cas system may assist in studying the specific mechanism associated with CRISPR-mediated adaptive immunity and other biological functions in R. anatipestifer.
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Affiliation(s)
- De-Kang Zhu
- Research Center of Avian Diseases, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
| | - Xue-Qin Yang
- Research Center of Avian Diseases, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
| | - Yang He
- Research Center of Avian Diseases, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
| | - Wang-Shu Zhou
- Research Center of Avian Diseases, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
| | - Xiao-Heng Song
- Research Center of Avian Diseases, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
| | - Jiang-Bo Wang
- Research Center of Avian Diseases, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
| | - Yu Zhang
- Research Center of Avian Diseases, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
| | - Ma-Feng Liu
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
- Institute of Preventive Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
| | - Ming-Shu Wang
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
- Institute of Preventive Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
| | - Ren-Yong Jia
- Research Center of Avian Diseases, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
| | - Shun Chen
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
- Institute of Preventive Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
| | - Kun-Feng Sun
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
- Institute of Preventive Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
| | - Qiao Yang
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
- Institute of Preventive Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
| | - Ying Wu
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
- Institute of Preventive Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
| | - Xiao-Yue Chen
- Research Center of Avian Diseases, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
| | - An-Chun Cheng
- Research Center of Avian Diseases, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan China
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Hooton SPT, Brathwaite KJ, Connerton IF. The Bacteriophage Carrier State of Campylobacter jejuni Features Changes in Host Non-coding RNAs and the Acquisition of New Host-derived CRISPR Spacer Sequences. Front Microbiol 2016; 7:355. [PMID: 27047470 PMCID: PMC4804229 DOI: 10.3389/fmicb.2016.00355] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 03/07/2016] [Indexed: 12/21/2022] Open
Abstract
Incorporation of self-derived CRISPR DNA protospacers in Campylobacter jejuni PT14 occurs in the presence of bacteriophages encoding a CRISPR-like Cas4 protein. This phenomenon was evident in carrier state infections where both bacteriophages and host are maintained for seemingly indefinite periods as stable populations following serial passage. Carrier state cultures of C. jejuni PT14 have greater aerotolerance in nutrient limited conditions, and may have arisen as an evolutionary response to selective pressures imposed during periods in the extra-intestinal environment. A consequence of this is that bacteriophage and host remain associated and able to survive transition periods where the chances of replicative success are greatly diminished. The majority of the bacteriophage population do not commit to lytic infection, and conversely the bacterial population tolerates low-level bacteriophage replication. We recently examined the effects of Campylobacter bacteriophage/C. jejuni PT14 CRISPR spacer acquisition using deep sequencing strategies of DNA and RNA-Seq to analyze carrier state cultures. This approach identified de novo spacer acquisition in C. jejuni PT14 associated with Class III Campylobacter phages CP8/CP30A but spacer acquisition was oriented toward the capture of host DNA. In the absence of bacteriophage predation the CRISPR spacers in uninfected C. jejuni PT14 cultures remain unchanged. A distinct preference was observed for incorporation of self-derived protospacers into the third spacer position of the C. jejuni PT14 CRISPR array, with the first and second spacers remaining fixed. RNA-Seq also revealed the variation in the synthesis of non-coding RNAs with the potential to bind bacteriophage genes and/or transcript sequences.
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Affiliation(s)
- Steven P T Hooton
- Division of Food Sciences, School of Biosciences, University of Nottingham Loughborough, UK
| | - Kelly J Brathwaite
- Division of Food Sciences, School of Biosciences, University of Nottingham Loughborough, UK
| | - Ian F Connerton
- Division of Food Sciences, School of Biosciences, University of Nottingham Loughborough, UK
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Abstract
Since the first demonstration that CRISPR-Cas systems provide bacteria and archaea with adaptive immunity against phages and plasmids, numerous studies have yielded key insights into the molecular mechanisms governing how these systems attack and degrade foreign DNA. However, the molecular mechanisms underlying the adaptation stage, in which new immunological memory is formed, have until recently represented a major unresolved question. In this Progress article, we discuss recent discoveries that have shown both how foreign DNA is identified by the CRISPR-Cas adaptation machinery and the molecular basis for its integration into the chromosome to form an immunological memory. Furthermore, we describe the roles of each of the specific CRISPR-Cas components that are involved in memory formation, and consider current models for their evolutionary origin.
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