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Hussain H, Nubgan A, Rodríguez C, Imwattana K, Knight DR, Parthala V, Mullany P, Goh S. Removal of mobile genetic elements from the genome of Clostridioides difficile and the implications for the organism's biology. Front Microbiol 2024; 15:1416665. [PMID: 38966395 PMCID: PMC11222575 DOI: 10.3389/fmicb.2024.1416665] [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: 04/12/2024] [Accepted: 06/04/2024] [Indexed: 07/06/2024] Open
Abstract
Clostridioides difficile is an emerging pathogen of One Health significance. Its highly variable genome contains mobile genetic elements (MGEs) such as transposons and prophages that influence its biology. Systematic deletion of each genetic element is required to determine their precise role in C. difficile biology and contribution to the wider mobilome. Here, Tn5397 (21 kb) and ϕ027 (56 kb) were deleted from C. difficile 630 and R20291, respectively, using allele replacement facilitated by CRISPR-Cas9. The 630 Tn5397 deletant transferred PaLoc at the same frequency (1 × 10-7) as 630 harboring Tn5397, indicating that Tn5397 alone did not mediate conjugative transfer of PaLoc. The R20291 ϕ027 deletant was sensitive to ϕ027 infection, and contained two unexpected features, a 2.7 kb remnant of the mutagenesis plasmid, and a putative catalase gene adjacent to the deleted prophage was also deleted. Growth kinetics of R20291 ϕ027 deletant was similar to wild type (WT) in rich medium but marginally reduced compared with WT in minimal medium. This work indicates the commonly used pMTL8000 plasmid series works well for CRISPR-Cas9-mediated gene deletion, resulting in the largest deleted locus (56.8 kb) described in C. difficile. Removal of MGEs was achieved by targeting conjugative/integrative regions to promote excision and permanent loss. The deletants created will be useful strains for investigating Tn5397 or ϕ027 prophage contribution to host virulence, fitness, and physiology, and a platform for other mutagenesis studies aimed at functional gene analysis without native transposon or phage interference in C. difficile 630 and R20291.
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Affiliation(s)
- Haitham Hussain
- Department of Microbial Diseases, Eastman Dental Institute, University College London, London, United Kingdom
| | - Amer Nubgan
- Department of Clinical, Pharmaceutical and Biological Sciences, University of Hertfordshire, Hatfield, United Kingdom
| | - César Rodríguez
- Facultad de Microbiología and Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San José, Costa Rica
| | - Korakrit Imwattana
- School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Salaya, Thailand
| | - Daniel R. Knight
- School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia
- Department of Microbiology, PathWest Laboratory Medicine WA, Queen Elizabeth II Medical Centre, Nedlands, WA, Australia
| | - Valerija Parthala
- Department of Clinical, Pharmaceutical and Biological Sciences, University of Hertfordshire, Hatfield, United Kingdom
| | - Peter Mullany
- Department of Microbial Diseases, Eastman Dental Institute, University College London, London, United Kingdom
| | - Shan Goh
- Department of Clinical, Pharmaceutical and Biological Sciences, University of Hertfordshire, Hatfield, United Kingdom
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2
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Weiss A, Lopez CA, Beavers WN, Rodriguez J, Skaar EP. Clostridioides difficile strain-dependent and strain-independent adaptations to a microaerobic environment. Microb Genom 2021; 7:000738. [PMID: 34908523 PMCID: PMC8767335 DOI: 10.1099/mgen.0.000738] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Clostridioides difficile (formerly Clostridium difficile) colonizes the gastrointestinal tract following disruption of the microbiota and can initiate a spectrum of clinical manifestations ranging from asymptomatic to life-threatening colitis. Following antibiotic treatment, luminal oxygen concentrations increase, exposing gut microbes to potentially toxic reactive oxygen species. Though typically regarded as a strict anaerobe, C. difficile can grow at low oxygen concentrations. How this bacterium adapts to a microaerobic environment and whether those responses to oxygen are conserved amongst strains is not entirely understood. Here, two C. difficile strains (630 and CD196) were cultured in 1.5% oxygen and the transcriptional response to long-term oxygen exposure was evaluated via RNA-sequencing. During growth in a microaerobic environment, several genes predicted to protect against oxidative stress were upregulated, including those for rubrerythrins and rubredoxins. Transcription of genes involved in metal homeostasis was also positively correlated with increased oxygen levels and these genes were amongst the most differentially transcribed. To directly compare the transcriptional landscape between C. difficile strains, a 'consensus-genome' was generated. On the basis of the identified conserved genes, basal transcriptional differences as well as variations in the response to oxygen were evaluated. While several responses were similar between the strains, there were significant differences in the abundance of transcripts involved in amino acid and carbohydrate metabolism. Furthermore, intracellular metal concentrations significantly varied both in an oxygen-dependent and oxygen-independent manner. Overall, these results indicate that C. difficile adapts to grow in a low oxygen environment through transcriptional changes, though the specific strategy employed varies between strains.
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Affiliation(s)
- Andy Weiss
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Christopher A. Lopez
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Biological Sciences, California State University Sacramento, Sacramento, CA, USA
| | - William N. Beavers
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jhoana Rodriguez
- Department of Biological Sciences, California State University Sacramento, Sacramento, CA, USA
| | - Eric P. Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- *Correspondence: Eric P. Skaar,
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Kartalidis P, Skoulakis A, Tsilipounidaki K, Florou Z, Petinaki E, Fthenakis GC. Clostridioides difficile as a Dynamic Vehicle for the Dissemination of Antimicrobial-Resistance Determinants: Review and In Silico Analysis. Microorganisms 2021; 9:microorganisms9071383. [PMID: 34202117 PMCID: PMC8307371 DOI: 10.3390/microorganisms9071383] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 01/11/2023] Open
Abstract
The present paper is divided into two parts. The first part focuses on the role of Clostridioides difficile in the accumulation of genes associated with antimicrobial resistance and then the transmission of them to other pathogenic bacteria occupying the same human intestinal niche. The second part describes an in silico analysis of the genomes of C. difficile available in GenBank, with regard to the presence of mobile genetic elements and antimicrobial resistance genes. The diversity of the C. difficile genome is discussed, and the current status of resistance of the organisms to various antimicrobial agents is reviewed. The role of transposons associated with antimicrobial resistance is appraised; the importance of plasmids associated with antimicrobial resistance is discussed, and the significance of bacteriophages as a potential shuttle for antimicrobial resistance genes is presented. In the in silico study, 1101 C. difficile genomes were found to harbor mobile genetic elements; Tn6009, Tn6105, CTn7 and Tn6192, Tn6194 and IS256 were the ones more frequently identified. The genes most commonly harbored therein were: ermB, blaCDD, vanT, vanR, vanG and vanS. Tn6194 was likely associated with resistance to erythromycin, Tn6192 and CTn7 with resistance to the β-lactams and vancomycin, IS256 with resistance to aminoglycoside and Tn6105 to vancomycin.
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Affiliation(s)
- Philip Kartalidis
- Department of Clinical and Laboratory Research, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41110 Larissa, Greece; (P.K.); (A.S.); (K.T.); (Z.F.); (E.P.)
| | - Anargyros Skoulakis
- Department of Clinical and Laboratory Research, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41110 Larissa, Greece; (P.K.); (A.S.); (K.T.); (Z.F.); (E.P.)
| | - Katerina Tsilipounidaki
- Department of Clinical and Laboratory Research, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41110 Larissa, Greece; (P.K.); (A.S.); (K.T.); (Z.F.); (E.P.)
| | - Zoi Florou
- Department of Clinical and Laboratory Research, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41110 Larissa, Greece; (P.K.); (A.S.); (K.T.); (Z.F.); (E.P.)
| | - Efthymia Petinaki
- Department of Clinical and Laboratory Research, Faculty of Medicine, School of Health Sciences, University of Thessaly, 41110 Larissa, Greece; (P.K.); (A.S.); (K.T.); (Z.F.); (E.P.)
| | - George C. Fthenakis
- Veterinary Faculty, University of Thessaly, 43100 Karditsa, Greece
- Correspondence:
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Carr VR, Shkoporov A, Hill C, Mullany P, Moyes DL. Probing the Mobilome: Discoveries in the Dynamic Microbiome. Trends Microbiol 2020; 29:158-170. [PMID: 32448763 DOI: 10.1016/j.tim.2020.05.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/30/2020] [Accepted: 05/05/2020] [Indexed: 02/06/2023]
Abstract
There has been an explosion of metagenomic data representing human, animal, and environmental microbiomes. This provides an unprecedented opportunity for comparative and longitudinal studies of many functional aspects of the microbiome that go beyond taxonomic classification, such as profiling genetic determinants of antimicrobial resistance, interactions with the host, potentially clinically relevant functions, and the role of mobile genetic elements (MGEs). One of the most important but least studied of these aspects are the MGEs, collectively referred to as the 'mobilome'. Here we elaborate on the benefits and limitations of using different metagenomic protocols, discuss the relative merits of various sequencing technologies, and highlight relevant bioinformatics tools and pipelines to predict the presence of MGEs and their microbial hosts.
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Affiliation(s)
- Victoria R Carr
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK; The Alan Turing Institute, British Library, London, UK.
| | - Andrey Shkoporov
- APC Microbiome Ireland, School of Microbiology, University College Cork, Cork, Ireland
| | - Colin Hill
- APC Microbiome Ireland, School of Microbiology, University College Cork, Cork, Ireland
| | - Peter Mullany
- Eastman Dental Institute, University College London, London, UK
| | - David L Moyes
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK.
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Muñoz M, Restrepo-Montoya D, Kumar N, Iraola G, Herrera G, Ríos-Chaparro DI, Díaz-Arévalo D, Patarroyo MA, Lawley TD, Ramírez JD. Comparative genomics identifies potential virulence factors in Clostridium tertium and C. paraputrificum. Virulence 2019; 10:657-676. [PMID: 31304854 PMCID: PMC6629180 DOI: 10.1080/21505594.2019.1637699] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/23/2019] [Accepted: 06/25/2019] [Indexed: 01/23/2023] Open
Abstract
Some well-known Clostridiales species such as Clostridium difficile and C. perfringens are agents of high impact diseases worldwide. Nevertheless, other foreseen Clostridiales species have recently emerged such as Clostridium tertium and C. paraputrificum. Three fecal isolates were identified as Clostridium tertium (Gcol.A2 and Gcol.A43) and C. paraputrificum (Gcol.A11) during public health screening for C. difficile infections in Colombia. C. paraputrificum genomes were highly diverse and contained large numbers of accessory genes. Genetic diversity and accessory gene percentage were lower among the C. tertium genomes than in the C. paraputrificum genomes. C. difficile tcdA and tcdB toxins encoding homologous sequences and other potential virulence factors were also identified. EndoA interferase, a toxic component of the type II toxin-antitoxin system, was found among the C. tertium genomes. toxA was the only toxin encoding gene detected in Gcol.A43, the Colombian isolate with an experimentally-determined high cytotoxic effect. Gcol.A2 and Gcol.A43 had higher sporulation efficiencies than Gcol.A11 (84.5%, 83.8% and 57.0%, respectively), as supported by the greater number of proteins associated with sporulation pathways in the C. tertium genomes compared with the C. paraputrificum genomes (33.3 and 28.4 on average, respectively). This work allowed complete genome description of two clostridiales species revealing high levels of intra-taxa diversity, accessory genomes containing virulence-factors encoding genes (especially in C. paraputrificum), with proteins involved in sporulation processes more highly represented in C. tertium. These finding suggest the need to advance in the study of those species with potential importance at public health level.
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Affiliation(s)
- Marina Muñoz
- Grupo de Investigaciones Microbiológicas – UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
- Posgrado Interfacultades, Doctorado en Biotecnología, Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Daniel Restrepo-Montoya
- Grupo de Investigaciones Microbiológicas – UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
- Genomics and Bioinformatics Program, North Dakota State University, Fargo, ND, USA
| | - Nitin Kumar
- Host–Microbiota Interactions Laboratory, Wellcome Trust Sanger Institute, Hinxton, UK
| | - Gregorio Iraola
- Microbial Genomics Laboratory, Institut Pasteur Montevideo, Montevideo, Uruguay
- Center for Integrative Biology, Universidad Mayor, Santiago de Chile, Chile
| | - Giovanny Herrera
- Grupo de Investigaciones Microbiológicas – UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
| | - Dora I. Ríos-Chaparro
- Grupo de Investigaciones Microbiológicas – UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
| | - Diana Díaz-Arévalo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
- Faculty of Animal Sciences, Universidad de Ciencias Aplicadas y Ambientales (UDCA), Bogotá, Colombia
| | - Manuel A. Patarroyo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
- School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Trevor D. Lawley
- Host–Microbiota Interactions Laboratory, Wellcome Trust Sanger Institute, Hinxton, UK
| | - Juan David Ramírez
- Grupo de Investigaciones Microbiológicas – UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
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6
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Wu Y, Yang L, Li WG, Zhang WZ, Liu ZJ, Lu JX. Microevolution within ST11 group Clostridioides difficile isolates through mobile genetic elements based on complete genome sequencing. BMC Genomics 2019; 20:796. [PMID: 31666016 PMCID: PMC6822371 DOI: 10.1186/s12864-019-6184-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 10/15/2019] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Clade 5 Clostridioides difficile diverges significantly from the other clades and is therefore, attracting increasing attention due its great heterogeneity. In this study, we used third-generation sequencing techniques to sequence the complete whole genomes of three ST11 C. difficile isolates, RT078 and another two new ribotypes (RTs), obtained from three independent hospitalized elderly patients undergoing antibiotics treatment. Mobile genetic elements (MGEs), antibiotic-resistance, drug resistance genes, and virulent-related genes were analyzed and compared within these three isolates. RESULTS Isolates 10,010 and 12,038 carried a distinct deletion in tcdA compared with isolate 21,062. Furthermore, all three isolates had identical deletions and point-mutations in tcdC, which was once thought to be a unique characteristic of RT078. Isolate 21,062 (RT078) had a unique plasmid, different numbers of transposons and genetic organization, and harboring special CRISPR spacers. All three isolates retained high-level sensitivity to 11 drugs and isolate 21,062 (RT078) carried distinct drug-resistance genes and loss of numerous flagellum-related genes. CONCLUSIONS We concluded that capillary electrophoresis based PCR-ribotyping is important for confirming RT078. Furthermore, RT078 isolates displayed specific MGEs, indicating an independent evolutionary process. In the further study, we could testify these findings with more RT078 isolates of divergent origins.
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Affiliation(s)
- Yuan Wu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China. .,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China.
| | - Lin Yang
- BGI-Shen zhen, main building, Beishan industry zone, Yan tian District, Shenzhen, China
| | - Wen-Ge Li
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Wen Zhu Zhang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Zheng Jie Liu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jin-Xing Lu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China. .,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China.
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7
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Independent Microevolution Mediated by Mobile Genetic Elements of Individual Clostridium difficile Isolates from Clade 4 Revealed by Whole-Genome Sequencing. mSystems 2019; 4:mSystems00252-18. [PMID: 30944881 PMCID: PMC6435816 DOI: 10.1128/msystems.00252-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 01/18/2019] [Indexed: 12/15/2022] Open
Abstract
Mobile genetic elements play a key role in the continuing evolution of Clostridium difficile, resulting in the emergence of new phenotypes for individual isolates. On the basis of whole-genome sequencing analysis, we comprehensively explored transposons, CRISPR, prophage, and genetic sites for drug resistance within clade 4 C. difficile isolates with different sequence types. Great diversity in MGEs and a high rate of multidrug resistance were found within this clade, including new transposons, Tn4453a/b with aac(6′) aph(2′′) instead of catD, and a relatively high rate of prophage-carried CRISPR arrays. These findings provide important new insights into the mechanism of genome remodeling within clade 4 and offer a new method for typing and tracing the origins of closely related isolates. Horizontal gene transfer of mobile genetic elements (MGEs) accounts for the mosaic genome of Clostridium difficile, leading to acquisition of new phenotypes, including drug resistance and reconstruction of the genomes. MGEs were analyzed according to the whole-genome sequences of 37 C. difficile isolates with a variety of sequence types (STs) within clade 4 from China. Great diversity was found in each transposon even within isolates with the same ST. Two novel transposons were identified in isolates ZR9 and ZR18, of which approximately one third to half of the genes showed heterogenous origins compared with the usual intestinal bacterial genes. Most importantly, catD, known to be harbored by Tn4453a/b, was replaced by aac(6′) aph(2′′) in isolates 2, 7, and 28. This phenomenon illustrated the frequent occurrence of gene exchanges between C. difficile and other enterobacteria with individual heterogeneity. Numerous prophages and CRISPR arrays were identified in C. difficile isolates of clade 4. Approximately 20% of spacers were located in prophage-carried CRISPR arrays, providing a new method for typing and tracing the origins of closely related isolates, as well as in-depth studies of the mechanism underlying genome remodeling. The rates of drug resistance were obviously higher than those reported previously around the world, although all isolates retained high sensitivity to vancomycin and metronidazole. The increasing number of C. difficile isolates resistant to all antibiotics tested here suggests the ease with which resistance is acquired in vivo. This study gives insights into the genetic mechanism of microevolution within clade 4. IMPORTANCE Mobile genetic elements play a key role in the continuing evolution of Clostridium difficile, resulting in the emergence of new phenotypes for individual isolates. On the basis of whole-genome sequencing analysis, we comprehensively explored transposons, CRISPR, prophage, and genetic sites for drug resistance within clade 4 C. difficile isolates with different sequence types. Great diversity in MGEs and a high rate of multidrug resistance were found within this clade, including new transposons, Tn4453a/b with aac(6′) aph(2′′) instead of catD, and a relatively high rate of prophage-carried CRISPR arrays. These findings provide important new insights into the mechanism of genome remodeling within clade 4 and offer a new method for typing and tracing the origins of closely related isolates.
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8
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Murillo T, Ramírez-Vargas G, Riedel T, Overmann J, Andersen JM, Guzmán-Verri C, Chaves-Olarte E, Rodríguez C. Two Groups of Cocirculating, Epidemic Clostridiodes difficile Strains Microdiversify through Different Mechanisms. Genome Biol Evol 2018; 10:982-998. [PMID: 29617810 PMCID: PMC5888409 DOI: 10.1093/gbe/evy059] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/13/2018] [Indexed: 02/04/2023] Open
Abstract
Clostridiodes difficile strains from the NAPCR1/ST54 and NAP1/ST01 types have caused outbreaks despite of their notable differences in genome diversity. By comparing whole genome sequences of 32 NAPCR1/ST54 isolates and 17 NAP1/ST01 recovered from patients infected with C. difficile we assessed whether mutation, homologous recombination (r) or nonhomologous recombination (NHR) through lateral gene transfer (LGT) have differentially shaped the microdiversification of these strains. The average number of single nucleotide polymorphisms (SNPs) in coding sequences (NAPCR1/ST54 = 24; NAP1/ST01 = 19) and SNP densities (NAPCR1/ST54 = 0.54/kb; NAP1/ST01 = 0.46/kb) in the NAPCR1/ST54 and NAP1/ST01 isolates was comparable. However, the NAP1/ST01 isolates showed 3× higher average dN/dS rates (8.35) that the NAPCR1/ST54 isolates (2.62). Regarding r, whereas 31 of the NAPCR1/ST54 isolates showed 1 recombination block (3,301–8,226 bp), the NAP1/ST01 isolates showed no bases in recombination. As to NHR, the pangenome of the NAPCR1/ST54 isolates was larger (4,802 gene clusters, 26% noncore genes) and more heterogeneous (644 ± 33 gene content changes) than that of the NAP1/ST01 isolates (3,829 gene clusters, ca. 6% noncore genes, 129 ± 37 gene content changes). Nearly 55% of the gene content changes seen among the NAPCR1/ST54 isolates (355 ± 31) were traced back to MGEs with putative genes for antimicrobial resistance and virulence factors that were only detected in single isolates or isolate clusters. Congruently, the LGT/SNP rate calculated for the NAPCR1/ST54 isolates (26.8 ± 2.8) was 4× higher than the one obtained for the NAP1/ST1 isolates (6.8 ± 2.0). We conclude that NHR-LGT has had a greater role in the microdiversification of the NAPCR1/ST54 strains, opposite to the NAP1/ST01 strains, where mutation is known to play a more prominent role.
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Affiliation(s)
- Tatiana Murillo
- Facultad de Microbiología and Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San José, Costa Rica
| | - Gabriel Ramírez-Vargas
- Facultad de Microbiología and Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San José, Costa Rica
| | - Thomas Riedel
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Braunschweig, Germany
| | - Jörg Overmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Braunschweig, Germany
| | - Joakim M Andersen
- Department of Food, Processing and Nutritional Sciences, North Carolina State University
| | - Caterina Guzmán-Verri
- Programa de Investigación en Enfermedades Tropicales (PIET), Escuela de Medicina Veterinaria, Universidad Nacional, Heredia, Costa Rica
| | - Esteban Chaves-Olarte
- Facultad de Microbiología and Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San José, Costa Rica
| | - César Rodríguez
- Facultad de Microbiología and Centro de Investigación en Enfermedades Tropicales (CIET), Universidad de Costa Rica, San José, Costa Rica
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9
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Knight DR, Squire MM, Collins DA, Riley TV. Genome Analysis of Clostridium difficile PCR Ribotype 014 Lineage in Australian Pigs and Humans Reveals a Diverse Genetic Repertoire and Signatures of Long-Range Interspecies Transmission. Front Microbiol 2017; 7:2138. [PMID: 28123380 PMCID: PMC5225093 DOI: 10.3389/fmicb.2016.02138] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 12/19/2016] [Indexed: 12/19/2022] Open
Abstract
Clostridium difficile PCR ribotype (RT) 014 is well-established in both human and porcine populations in Australia, raising the possibility that C. difficile infection (CDI) may have a zoonotic or foodborne etiology. Here, whole genome sequencing and high-resolution core genome phylogenetics were performed on a contemporaneous collection of 40 Australian RT014 isolates of human and porcine origin. Phylogenies based on MLST (7 loci, STs 2, 13, and 49) and core orthologous genes (1260 loci) showed clustering of human and porcine strains indicative of very recent shared ancestry. Core genome single nucleotide variant (SNV) analysis found 42% of human strains showed a clonal relationship (separated by ≤2 SNVs in their core genome) with one or more porcine strains, consistent with recent inter-host transmission. Clones were spread over a vast geographic area with 50% of the human cases occurring without recent healthcare exposure. These findings suggest a persistent community reservoir with long-range dissemination, potentially due to agricultural recycling of piggery effluent. We also provide the first pan-genome analysis for this lineage, characterizing its resistome, prophage content, and in silico virulence potential. The RT014 is defined by a large "open" pan-genome (7587 genes) comprising a core genome of 2296 genes (30.3% of the total gene repertoire) and an accessory genome of 5291 genes. Antimicrobial resistance genotypes and phenotypes varied across host populations and ST lineages and were characterized by resistance to tetracycline [tetM, tetA(P), tetB(P) and tetW], clindamycin/erythromycin (ermB), and aminoglycosides (aph3-III-Sat4A-ant6-Ia). Resistance was mediated by clinically important mobile genetic elements, most notably Tn6194 (harboring ermB) and a novel variant of Tn5397 (harboring tetM). Numerous clinically important prophages (Siphoviridae and Myoviridae) were identified as well as an uncommon accessory gene regulator locus (agr3). Conservation in the pathogenicity locus and S-layer correlated with ST affiliation, further extending the concept of clonal C. difficile lineages. This study provides novel insights on the genetic variability and strain relatedness of C. difficile RT014, a lineage of emerging One Health importance. Ongoing molecular and genomic surveillance of strains in humans, animals, food, and the environment is imperative to identify opportunities to reduce the overall CDI burden.
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Affiliation(s)
- Daniel R. Knight
- Microbiology and Immunology, School of Pathology and Laboratory Medicine, The University of Western AustraliaNedlands, WA, Australia
| | - Michele M. Squire
- Microbiology and Immunology, School of Pathology and Laboratory Medicine, The University of Western AustraliaNedlands, WA, Australia
| | - Deirdre A. Collins
- Microbiology and Immunology, School of Pathology and Laboratory Medicine, The University of Western AustraliaNedlands, WA, Australia
- Department of Population Health, School of Medical and Health Sciences, Edith Cowan UniversityJoondalup, WA, Australia
| | - Thomas V. Riley
- Department of Population Health, School of Medical and Health Sciences, Edith Cowan UniversityJoondalup, WA, Australia
- PathWest Laboratory Medicine, Department of Microbiology, Queen Elizabeth II Medical CentreNedlands, WA, Australia
- Department of Medical and Molecular Sciences, School of Veterinary and Life Sciences, Murdoch UniversityMurdoch, WA, Australia
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10
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Warriner K, Xu C, Habash M, Sultan S, Weese S. Dissemination ofClostridium difficilein food and the environment: Significant sources ofC. difficilecommunity-acquired infection? J Appl Microbiol 2016; 122:542-553. [DOI: 10.1111/jam.13338] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 10/25/2016] [Accepted: 10/27/2016] [Indexed: 12/11/2022]
Affiliation(s)
- K. Warriner
- Department of Food Science; University of Guelph; Guelph ON Canada
| | - C. Xu
- Shanghai Ocean University; Shanghai China
| | - M. Habash
- School of Environmental Biology; University of Guelph; Guelph ON Canada
| | - S. Sultan
- School of Environmental Biology; University of Guelph; Guelph ON Canada
| | - S.J. Weese
- Pathobiology; University of Guelph; Guelph ON Canada
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11
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Broecker F, Klumpp J, Moelling K. Long-term microbiota and virome in a Zürich patient after fecal transplantation against Clostridium difficile infection. Ann N Y Acad Sci 2016; 1372:29-41. [PMID: 27286042 DOI: 10.1111/nyas.13100] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 04/18/2016] [Accepted: 04/19/2016] [Indexed: 12/14/2022]
Abstract
Fecal microbiota transplantation (FMT) is an emerging therapeutic option for Clostridium difficile infections that are refractory to conventional treatment. FMT introduces fecal microbes into the patient's intestine that prevent the recurrence of C. difficile, leading to rapid expansion of bacteria characteristic of healthy microbiota. However, the long-term effects of FMT remain largely unknown. The C. difficile patient described in this paper revealed protracted microbiota adaptation processes from 6 to 42 months post-FMT. Ultimately, bacterial communities were donor similar, suggesting sustainable stool engraftment. Since little is known about the consequences of transmitted viruses during C. difficile infection, we also interrogated virome changes. Our approach allowed identification of about 10 phage types per sample that represented larger viral communities, and phages were found to be equally abundant in the cured patient and donor. The healthy microbiota appears to be characterized by low phage abundance. Although viruses were likely transferred, the patient established a virome distinct from the donor. Surprisingly, the patient had sequences of algal giant viruses (chloroviruses) that have not previously been reported for the human gut. Chloroviruses have not been associated with intestinal disease, but their presence in the oropharynx may influence cognitive abilities. The findings suggest that the virome is an important indicator of health or disease. A better understanding of the role of viruses in the gut ecosystem may uncover novel microbiota-modulating therapeutic strategies.
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Affiliation(s)
- Felix Broecker
- Max Planck Institute for Molecular Genetics, Berlin, Germany.,Institute for Medical Microbiology, University of Zürich, Zürich, Switzerland.,Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Jochen Klumpp
- Institute of Food, Nutrition, and Health, ETH Zürich, Zürich, Switzerland
| | - Karin Moelling
- Max Planck Institute for Molecular Genetics, Berlin, Germany.,Institute for Medical Microbiology, University of Zürich, Zürich, Switzerland
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12
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Carraro N, Libante V, Morel C, Charron-Bourgoin F, Leblond P, Guédon G. Plasmid-like replication of a minimal streptococcal integrative and conjugative element. MICROBIOLOGY-SGM 2016; 162:622-632. [PMID: 26825653 DOI: 10.1099/mic.0.000219] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Integrative and conjugative elements (ICEs) are mobile genetic elements encoding their own excision from a replicon of their bacterial host, transfer by conjugation to a recipient bacterium and reintegration for maintenance. The conjugation, recombination and regulation modules of ICEs of the ICESt3 family are grouped together in a region called the ICE 'core region'. In addition to this core region, elements belonging to this family carry a highly variable region including cargo genes that could be involved in bacterial adaptation or in the maintenance of the element. Although ICEs are a major class of mobile elements through bacterial genomes, the functionality of an element encoding only its excision, transfer, integration and regulation has never been demonstrated experimentally. We engineered MiniICESt3, an artificial ICE derived from ICESt3, devoid of its cargo genes and thus only harbouring the core region. The functionality of this minimal element was assessed. MiniICESt3 was found to be able to excise at a rate of 3.1 %, transfer with a frequency of 1.0 × 10- 5 transconjugants per donor cell and stably maintain by site-specific integration into the 3' end of the fda gene, the same as ICESt3. Furthermore, MiniICESt3 was found in ∼10 copies per chromosome, this multicopy state likely contributing to its stability for >100 generations even in the absence of selection. Therefore, although ICEs were primarily assumed to only replicate along with the chromosome, our results uncovered extrachromosomal rolling-circle replicating plasmid-like forms of MiniICESt3.
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Affiliation(s)
- Nicolas Carraro
- INRA, DynAMic, UMR1128, Vandoeuvre-lès-Nancy, France.,Université de Lorraine, DynAMic, UMR1128, Vandoeuvre-lès-Nancy, France
| | - Virginie Libante
- INRA, DynAMic, UMR1128, Vandoeuvre-lès-Nancy, France.,Université de Lorraine, DynAMic, UMR1128, Vandoeuvre-lès-Nancy, France
| | - Catherine Morel
- Université de Lorraine, DynAMic, UMR1128, Vandoeuvre-lès-Nancy, France.,INRA, DynAMic, UMR1128, Vandoeuvre-lès-Nancy, France
| | - Florence Charron-Bourgoin
- Université de Lorraine, DynAMic, UMR1128, Vandoeuvre-lès-Nancy, France.,INRA, DynAMic, UMR1128, Vandoeuvre-lès-Nancy, France
| | - Pierre Leblond
- Université de Lorraine, DynAMic, UMR1128, Vandoeuvre-lès-Nancy, France.,INRA, DynAMic, UMR1128, Vandoeuvre-lès-Nancy, France
| | - Gérard Guédon
- Université de Lorraine, DynAMic, UMR1128, Vandoeuvre-lès-Nancy, France.,INRA, DynAMic, UMR1128, Vandoeuvre-lès-Nancy, France
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13
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Abstract
Clostridium difficile infection (CDI) is the leading cause of antimicrobial and health care-associated diarrhea in humans, presenting a significant burden to global health care systems. In the last 2 decades, PCR- and sequence-based techniques, particularly whole-genome sequencing (WGS), have significantly furthered our knowledge of the genetic diversity, evolution, epidemiology, and pathogenicity of this once enigmatic pathogen. C. difficile is taxonomically distinct from many other well-known clostridia, with a diverse population structure comprising hundreds of strain types spread across at least 6 phylogenetic clades. The C. difficile species is defined by a large diverse pangenome with extreme levels of evolutionary plasticity that has been shaped over long time periods by gene flux and recombination, often between divergent lineages. These evolutionary events are in response to environmental and anthropogenic activities and have led to the rapid emergence and worldwide dissemination of virulent clonal lineages. Moreover, genome analysis of large clinically relevant data sets has improved our understanding of CDI outbreaks, transmission, and recurrence. The epidemiology of CDI has changed dramatically over the last 15 years, and CDI may have a foodborne or zoonotic etiology. The WGS era promises to continue to redefine our view of this significant pathogen.
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Abstract
Clostridium difficile is the cause of most frequently occurring nosocomial diarrhea worldwide. As an enteropathogen, C. difficile must be exposed to multiple exogenous genetic elements in bacteriophage-rich gut communities. CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) systems allow bacteria to adapt to foreign genetic invaders. Our recent data revealed active expression and processing of CRISPR RNAs from multiple type I-B CRISPR arrays in C. difficile reference strain 630. Here, we demonstrate active expression of CRISPR arrays in strain R20291, an epidemic C. difficile strain. Through genome sequencing and host range analysis of several new C. difficile phages and plasmid conjugation experiments, we provide evidence of defensive function of the CRISPR-Cas system in both C. difficile strains. We further demonstrate that C. difficile Cas proteins are capable of interference in a heterologous host, Escherichia coli. These data set the stage for mechanistic and physiological analyses of CRISPR-Cas-mediated interactions of important global human pathogen with its genetic parasites. Clostridium difficile is the major cause of nosocomial infections associated with antibiotic therapy worldwide. To survive in bacteriophage-rich gut communities, enteropathogens must develop efficient systems for defense against foreign DNA elements. CRISPR-Cas systems have recently taken center stage among various anti-invader bacterial defense systems. We provide experimental evidence for the function of the C. difficile CRISPR system against plasmid DNA and bacteriophages. These data demonstrate the original features of active C. difficile CRISPR system and bring important insights into the interactions of this major enteropathogen with foreign DNA invaders during its infection cycle.
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15
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Amy J, Johanesen P, Lyras D. Extrachromosomal and integrated genetic elements in Clostridium difficile. Plasmid 2015; 80:97-110. [PMID: 25929174 DOI: 10.1016/j.plasmid.2015.04.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 12/21/2022]
Abstract
Clostridium difficile is a major nosocomial pathogen, causing gastrointestinal disease in patients undergoing antibiotic therapy. This bacterium contains many extrachromosomal and integrated genetic elements, with recent genomic work giving new insights into their variability and distribution. This review summarises research conducted in this area over the last 30 years and includes a discussion on the functional contributions of these elements to host cell phenotypes, as well as encompassing recent genome sequencing studies that have contributed to our understanding of their evolution and dissemination. Importantly, we also include a review of antibiotic resistance determinants associated with mobile genetic elements since antibiotic use and the spread of antibiotic resistance are currently of significant global clinical importance.
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Affiliation(s)
- Jacob Amy
- Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Priscilla Johanesen
- Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Dena Lyras
- Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia.
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