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Cong X, Mazierski P, Miodyńska M, Zaleska-Medynska A, Horn H, Schwartz T, Gmurek M. The role of TiO 2 and gC 3N 4 bimetallic catalysts in boosting antibiotic resistance gene removal through photocatalyst assisted peroxone process. Sci Rep 2024; 14:22897. [PMID: 39358462 PMCID: PMC11447026 DOI: 10.1038/s41598-024-74147-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Accepted: 09/24/2024] [Indexed: 10/04/2024] Open
Abstract
Antibiotics are extensively used in human medicine, aquaculture, and animal husbandry, leading to the release of antimicrobial resistance into the environment. This contributes to the rapid spread of antibiotic-resistant genes (ARGs), posing a significant threat to human health and aquatic ecosystems. Conventional wastewater treatment methods often fail to eliminate ARGs, prompting the adoption of advanced oxidation processes (AOPs) to address this growing risk. The study investigates the efficacy of visible light-driven photocatalytic systems utilizing two catalyst types (TiO2-Pd/Cu and g-C3N4-Pd/Cu), with a particular emphasis on their effectiveness in eliminating blaTEM, ermB, qnrS, tetM. intl1, 16 S rDNA and 23 S rDNA through photocatalytic ozonation and peroxone processes. Incorporating O3 into photocatalytic processes significantly enhances target removal efficiency, with the photocatalyst-assisted peroxone process emerging as the most effective AOP. The reemergence of targeted contaminants following treatment highlights the pivotal importance of AOPs and the meticulous selection of catalysts in ensuring sustained treatment efficacy. Furthermore, Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) analysis reveals challenges in eradicating GC-rich bacteria with TiO2 and g-C3N4 processes, while slight differences in Cu/Pd loadings suggest g-C3N4-based ozonation improved antibacterial effectiveness. Terminal Restriction Fragment Length Polymorphism analysis highlights the efficacy of the photocatalyst-assisted peroxone process in treating diverse samples.
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Affiliation(s)
- Xiaoyu Cong
- Institute of Functional Interfaces (IFG), Microbiology/Molecular Biology Department, Karlsruhe Institute of Technology (KIT), Hermann von Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Paweł Mazierski
- Department of Environmental Technology, Faculty of Chemistry, University of Gdansk, Gdansk, 80-308, Poland
| | - Magdalena Miodyńska
- Department of Environmental Technology, Faculty of Chemistry, University of Gdansk, Gdansk, 80-308, Poland
| | - Adriana Zaleska-Medynska
- Department of Environmental Technology, Faculty of Chemistry, University of Gdansk, Gdansk, 80-308, Poland
| | - Harald Horn
- Water Chemistry and Water Technology, Karlsruhe Institute of Technology, Engler-Bunte-Institut, 76131, Karlsruhe, Germany
- Water Chemistry and Water Technology, DVGW German Technical and Scientific Association for Gas and Water Research Laboratories, 76131, Karlsruhe, Germany
| | - Thomas Schwartz
- Institute of Functional Interfaces (IFG), Microbiology/Molecular Biology Department, Karlsruhe Institute of Technology (KIT), Hermann von Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Marta Gmurek
- Institute of Functional Interfaces (IFG), Microbiology/Molecular Biology Department, Karlsruhe Institute of Technology (KIT), Hermann von Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
- Department of Molecular Engineering, Faculty of Process and Environmental Engineering, Lodz University of Technology, Lodz, 93-005, Poland.
- Water Chemistry and Water Technology, Karlsruhe Institute of Technology, Engler-Bunte-Institut, 76131, Karlsruhe, Germany.
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2
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Sharon BM, Arute AP, Nguyen A, Tiwari S, Reddy Bonthu SS, Hulyalkar NV, Neugent ML, Palacios Araya D, Dillon NA, Zimmern PE, Palmer KL, De Nisco NJ. Genetic and functional enrichments associated with Enterococcus faecalis isolated from the urinary tract. mBio 2023; 14:e0251523. [PMID: 37962362 PMCID: PMC10746210 DOI: 10.1128/mbio.02515-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 10/05/2023] [Indexed: 11/15/2023] Open
Abstract
IMPORTANCE Urinary tract infection (UTI) is a global health issue that imposes a substantial burden on healthcare systems. Women are disproportionately affected by UTI, with >60% of women experiencing at least one UTI in their lifetime. UTIs can recur, particularly in postmenopausal women, leading to diminished quality of life and potentially life-threatening complications. Understanding how pathogens colonize and survive in the urinary tract is necessary to identify new therapeutic targets that are urgently needed due to rising rates of antimicrobial resistance. How Enterococcus faecalis, a bacterium commonly associated with UTI, adapts to the urinary tract remains understudied. Here, we generated a collection of high-quality closed genome assemblies of clinical urinary E. faecalis isolated from the urine of postmenopausal women that we used alongside detailed clinical metadata to perform a robust comparative genomic investigation of genetic factors that may be involved in E. faecalis survival in the urinary tract.
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Affiliation(s)
- Belle M. Sharon
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Amanda P. Arute
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Amber Nguyen
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Suman Tiwari
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | | | - Neha V. Hulyalkar
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Michael L. Neugent
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Dennise Palacios Araya
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Nicholas A. Dillon
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Philippe E. Zimmern
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Kelli L. Palmer
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Nicole J. De Nisco
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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3
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Sharon BM, Arute AP, Nguyen A, Tiwari S, Bonthu SSR, Hulyalkar NV, Neugent ML, Araya DP, Dillon NA, Zimmern PE, Palmer KL, De Nisco NJ. Functional and genetic adaptations contributing to Enterococcus faecalis persistence in the female urinary tract. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.18.541374. [PMID: 37293065 PMCID: PMC10245761 DOI: 10.1101/2023.05.18.541374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Enterococcus faecalis is the leading Gram-positive bacterial species implicated in urinary tract infection (UTI). An opportunistic pathogen, E. faecalis is a commensal of the human gastrointestinal tract (GIT) and its presence in the GIT is a predisposing factor for UTI. The mechanisms by which E. faecalis colonizes and survives in the urinary tract (UT) are poorly understood, especially in uncomplicated or recurrent UTI. The UT is distinct from the GIT and is characterized by a sparse nutrient landscape and unique environmental stressors. In this study, we isolated and sequenced a collection of 37 clinical E. faecalis strains from the urine of primarily postmenopausal women. We generated 33 closed genome assemblies and four highly contiguous draft assemblies and conducted a comparative genomics to identify genetic features enriched in urinary E. faecalis with respect to E. faecalis isolated from the human GIT and blood. Phylogenetic analysis revealed high diversity among urinary strains and a closer relatedness between urine and gut isolates than blood isolates. Plasmid replicon (rep) typing further underscored possible UT-GIT interconnection identifying nine shared rep types between urine and gut E. faecalis . Both genotypic and phenotypic analysis of antimicrobial resistance among urinary E. faecalis revealed infrequent resistance to front-line UTI antibiotics nitrofurantoin and fluoroquinolones and no vancomycin resistance. Finally, we identified 19 candidate genes enriched among urinary strains that may play a role in adaptation to the UT. These genes are involved in the core processes of sugar transport, cobalamin import, glucose metabolism, and post-transcriptional regulation of gene expression. IMPORTANCE Urinary tract infection (UTI) is a global health issue that imposes substantial burden on healthcare systems. Women are disproportionately affected by UTI with >60% of women experiencing at least one UTI in their lifetime. UTIs can recur, particularly in postmenopausal women, leading to diminished quality of life and potentially life-threatening complications. Understanding how pathogens colonize and survive in the urinary tract is necessary to identify new therapeutic targets that are urgently needed due to rising rates of antimicrobial resistance. How Enterococcus faecalis , a bacterium commonly associated with UTI, adapts to the urinary tract remains understudied. Here, we generated a collection of high-quality closed genome assemblies of clinical urinary E. faecalis isolated from the urine of postmenopausal women that we used alongside detailed clinical metadata to perform a robust comparative genomic investigation of genetic factors that may mediate urinary E. faecalis adaptation to the female urinary tract.
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4
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Alrafaie AM, Stafford GP. Enterococcal bacteriophage: A survey of the tail associated lysin landscape. Virus Res 2023; 327:199073. [PMID: 36787848 DOI: 10.1016/j.virusres.2023.199073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 02/05/2023] [Accepted: 02/10/2023] [Indexed: 02/16/2023]
Abstract
Bacteriophages are viruses that exclusively infect bacteria which require local degradation of cell barriers. This degradation is accomplished by various lysins located mainly within the phage tail structure. In this paper we surveyed and analysed the genomes of 506 isolated bacteriophage and prophage infecting or harboured within the genomes of the medically important Enterococcus faecalis and faecium. We highlight and characterise the major features of the genomes of phage in the morphological groups podovirus, siphovirus and myovirus, and explore their categorisation according to the new ICTV classifications, with a focus on putative extracellular lysins chiefly within tail modules. Our analysis reveals a range of potential cell-wall targeting enzyme domains that are part of tail, tape measure or other predicted base structures of these phages or prophages. These largely fall into protein domains targeting pentapeptide or glycosidic linkages within peptidoglycan but also potentially the enterococcal polysaccharide antigen (EPA) and wall teichoic acids of these species (i.e., Pectinesterases and Phosphodiesterases). Notably, there is a great variety of domain architectures that reveal the diversity of evolutionary solutions to attack the Enterococcus cell wall. Despite this variety, most phage and prophage possess a putative endopeptidase (70%), reflecting the ubiquity of this cell surface barrier. We also identified a predicted lytic transglycosylase domain belonging to the glycosyl hydrolase (GH) family 23 and present exclusively within tape measure proteins. Our data also reveal distinct features of the genomes of podo-, sipho- and myo-type viruses that most likely relate to their size and complexity. Overall, we lay a foundation for expression of recombinant TAL proteins and engineering of enterococcal and other phage that will be invaluable for researchers in this field.
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Affiliation(s)
- Alhassan M Alrafaie
- Integrated BioSciences, School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom; Department of Medical Laboratory Sciences, College of Applied Medical Sciences in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia.
| | - Graham P Stafford
- Integrated BioSciences, School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom.
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5
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Panwar S, Kumari S, Verma J, Bakshi S, Narendrakumar L, Paul D, Das B. Toxin-linked mobile genetic elements in major enteric bacterial pathogens. GUT MICROBIOME (CAMBRIDGE, ENGLAND) 2023; 4:e5. [PMID: 39295911 PMCID: PMC11406385 DOI: 10.1017/gmb.2023.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 12/31/2022] [Accepted: 02/24/2023] [Indexed: 09/21/2024]
Abstract
One of the fascinating outcomes of human microbiome studies adopting multi-omics technology is its ability to decipher millions of microbial encoded functions in the most complex and crowded microbial ecosystem, including the human gastrointestinal (GI) tract without cultivating the microbes. It is well established that several functions that modulate the human metabolism, nutrient assimilation, immunity, infections, disease severity and therapeutic efficacy of drugs are mostly of microbial origins. In addition, these microbial functions are dynamic and can disseminate between microbial taxa residing in the same ecosystem or other microbial ecosystems through horizontal gene transfer. For clinicians and researchers alike, understanding the toxins, virulence factors and drug resistance traits encoded by the microbes associated with the human body is of utmost importance. Nevertheless, when such traits are genetically linked with mobile genetic elements (MGEs) that make them transmissible, it creates an additional burden to public health. This review mainly focuses on the functions of gut commensals and the dynamics and crosstalk between commensal and pathogenic bacteria in the gut. Also, the review summarises the plethora of MGEs linked with virulence genes present in the genomes of various enteric bacterial pathogens, which are transmissible among other pathogens and commensals.
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Affiliation(s)
- Shruti Panwar
- Functional Genomics Laboratory, Infection and Immunology Division, Translational Health Science and Technology Institute, Faridabad, India
| | - Shashi Kumari
- Functional Genomics Laboratory, Infection and Immunology Division, Translational Health Science and Technology Institute, Faridabad, India
| | - Jyoti Verma
- Functional Genomics Laboratory, Infection and Immunology Division, Translational Health Science and Technology Institute, Faridabad, India
| | - Susmita Bakshi
- Functional Genomics Laboratory, Infection and Immunology Division, Translational Health Science and Technology Institute, Faridabad, India
| | - Lekshmi Narendrakumar
- Functional Genomics Laboratory, Infection and Immunology Division, Translational Health Science and Technology Institute, Faridabad, India
| | - Deepjyoti Paul
- Functional Genomics Laboratory, Infection and Immunology Division, Translational Health Science and Technology Institute, Faridabad, India
| | - Bhabatosh Das
- Functional Genomics Laboratory, Infection and Immunology Division, Translational Health Science and Technology Institute, Faridabad, India
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6
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Segawa T, Johnson CM, Berntsson RPA, Dunny GM. Two ABC transport systems carry out peptide uptake in Enterococcus faecalis: Their roles in growth and in uptake of sex pheromones. Mol Microbiol 2021; 116:459-469. [PMID: 33817866 DOI: 10.1111/mmi.14725] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 04/01/2021] [Accepted: 04/01/2021] [Indexed: 11/29/2022]
Abstract
Enterococcal pheromone-inducible plasmids encode a predicted OppA-family secreted lipoprotein. In the case of plasmid pCF10, the protein is PrgZ, which enhances the mating response to cCF10 pheromone. OppA proteins generally function with associated OppBCDF ABC transporters to import peptides. In this study, we analyzed the potential interactions of PrgZ with two host-encoded Opp transporters using two pheromone-inducible fluorescent reporter constructs. Based on our results, we propose renaming these loci opp1 (OG1RF_10634-10639) and opp2 (OG1RF_12366-12370). We also examined the ability of the Opp1 and Opp2 systems to mediate import in the absence of PrgZ. Cells expressing PrgZ were able to import pheromone if either opp1 or opp2 was functional, but not if both opp loci were disrupted. In the absence of PrgZ, pheromone import was dependent on a functional opp2 system, including opp2A. Comparative structural analysis of the peptide-binding pockets of PrgZ, Opp1A, Opp2A, and the related Lactococcus lactis OppA protein, suggested that the robust pheromone-binding ability of PrgZ relates to a nearly optimal fit of the hydrophobic peptide, whereas binding ability of Opp2A likely results from a more open, promiscuous peptide-binding pocket similar to L. lactis OppA.
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Affiliation(s)
- Takaya Segawa
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Christopher M Johnson
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Ronnie P-A Berntsson
- Department of Medical Biochemistry and Biophysics, Umea University, Umea, Sweden.,Wallenberg Center for Molecular Medicine, Umea University, Umea, Sweden
| | - Gary M Dunny
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, MN, USA
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7
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Reinseth I, Tønnesen HH, Carlsen H, Diep DB. Exploring the Therapeutic Potenital of the Leaderless Enterocins K1 and EJ97 in the Treatment of Vancomycin-Resistant Enterococcal Infection. Front Microbiol 2021; 12:649339. [PMID: 33679682 PMCID: PMC7925398 DOI: 10.3389/fmicb.2021.649339] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 01/26/2021] [Indexed: 12/13/2022] Open
Abstract
The membrane-bound protease Eep is an important virulence factor in pathogenic enterococci. The protein is involved in stress response via the RIP pathway which is crucial for pathogenic enterococci to evade host immune attacks during infection. Eep serves also as a receptor for the bacteriocins enterocin K1 and enterocin EJ97. The bacteriocins kill Enterococcus faecium and E. faecalis, respectively, and their antibiotic resistant derivatives including vancomycin resistant enterococci (VRE). This functional duality of Eep makes these two enterocins very promising as options in the prospective treatment of enterococcal infections because wildtype enterococcal cells (with an intact Eep) are sensitive to the bacteriocins while bacteriocin-resistant-mutants (without a functional Eep) become less virulent. As a first step to explore their therapeutic potential in the treatment of systemic enterococcal infections, we investigated the compatibility of the bacteriocins with human blood, and the phenotypic changes of eep-mutants toward different stress conditions. We found that the bacteriocins were compatible with blood, as they did not cause haemolysis and that the bacteriocins retained most of their antibacterial effect when incubated in blood. The bacteriocins were autoclavable which is a crucial criterium for the development of parenteral administration. Eep-mutants, which became resistant to the bacteriocin were, as expected, less capable to withstand stress conditions such as exposure to lysozyme and desiccation. Further, their ability to chain, a trait implicated in niche adaptation as well as being necessary for genetic transfer via conjugation, was also severely affected. Together, these results indicate that the bacteriocins are promising for treatment of VRE infection.
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Affiliation(s)
- Ingvild Reinseth
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Hanne H Tønnesen
- Section of Pharmaceutics and Social Pharmacy, Department of Pharmacy, University of Oslo, Blindern, Oslo, Norway
| | - Harald Carlsen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Dzung B Diep
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
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8
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Suryaletha K, Chandrika SK, Thomas S. Comprehensive genomics depict accessory genes encoding pathogenicity and biofilm determinants in Enterococcus faecalis. Future Microbiol 2021; 16:175-184. [PMID: 33528277 DOI: 10.2217/fmb-2020-0111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Aim: Enterococcus faecalis is a leading nosocomial pathogen in biofilm-associated polymicrobial infections. The study aims to understand pathogenicity and biofilm determinants of the pathogen by genome analysis. Methodology: Genome sequencing of a strong biofilm forming clinical isolate Enterococcus faecalis SK460 devoid of Fsr quorum-signaling system, was performed and comparative genomics was carried out among a set of pathogenic biofilm formers and nonpathogenic weak biofilm formers. Results: Analysis revealed a pool of virulence and adhesion related factors associated with pathogenicity. Absence of CRISPR-Cas system facilitated acquisition of pheromone responsive plasmid, pathogenicity island and phages. Comprehensive analysis identified a subset of accessory genes encoding polysaccharide lyase, sugar phosphotransferase system, phage proteins and transcriptional regulators exclusively in pathogenic biofilm formers. Conclusion: The study identified a set of genes specific to pathogenic biofilm formers and these can act as targets which in turn help to develop future treatment endeavors against enterococcal infections.
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Affiliation(s)
- Karthika Suryaletha
- Cholera & Biofilm Research Laboratory, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695 014, Kerala, India
| | - Sivakumar K Chandrika
- Distributed Information Sub-Centre, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695 014, Kerala, India
| | - Sabu Thomas
- Cholera & Biofilm Research Laboratory, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695 014, Kerala, India
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9
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Pinholt M, Bayliss SC, Gumpert H, Worning P, Jensen VVS, Pedersen M, Feil EJ, Westh H. WGS of 1058 Enterococcus faecium from Copenhagen, Denmark, reveals rapid clonal expansion of vancomycin-resistant clone ST80 combined with widespread dissemination of a vanA-containing plasmid and acquisition of a heterogeneous accessory genome. J Antimicrob Chemother 2020; 74:1776-1785. [PMID: 30929020 DOI: 10.1093/jac/dkz118] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 02/25/2019] [Accepted: 02/27/2019] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVES From 2012 to 2015, a sudden significant increase in vancomycin-resistant (vanA) Enterococcus faecium (VREfm) was observed in the Capital Region of Denmark. Clonal relatedness of VREfm and vancomycin-susceptible E. faecium (VSEfm) was investigated, transmission events between hospitals were identified and the pan-genome and plasmids from the largest VREfm clonal group were characterized. METHODS WGS of 1058 E. faecium isolates was carried out on the Illumina platform to perform SNP analysis and to identify the pan-genome. One isolate was also sequenced on the PacBio platform to close the genome. Epidemiological data were collected from laboratory information systems. RESULTS Phylogeny of 892 VREfm and 166 VSEfm revealed a polyclonal structure, with a single clonal group (ST80) accounting for 40% of the VREfm isolates. VREfm and VSEfm co-occurred within many clonal groups; however, no VSEfm were related to the dominant VREfm group. A similar vanA plasmid was identified in ≥99% of isolates belonging to the dominant group and 69% of the remaining VREfm. Ten plasmids were identified in the completed genome, and ∼29% of this genome consisted of dispensable accessory genes. The size of the pan-genome among isolates in the dominant group was 5905 genes. CONCLUSIONS Most probably, VREfm emerged owing to importation of a successful VREfm clone which rapidly transmitted to the majority of hospitals in the region whilst simultaneously disseminating a vanA plasmid to pre-existing VSEfm. Acquisition of a heterogeneous accessory genome may account for the success of this clone by facilitating adaptation to new environmental challenges.
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Affiliation(s)
- Mette Pinholt
- Department of Clinical Microbiology, Hvidovre Hospital, Hvidovre, Denmark.,Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Sion C Bayliss
- Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, UK
| | - Heidi Gumpert
- Department of Clinical Microbiology, Hvidovre Hospital, Hvidovre, Denmark
| | - Peder Worning
- Department of Clinical Microbiology, Hvidovre Hospital, Hvidovre, Denmark
| | - Veronika V S Jensen
- Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Michael Pedersen
- Department of Clinical Microbiology, Hvidovre Hospital, Hvidovre, Denmark.,Department of Clinical Microbiology, Herlev Hospital, Herlev, Denmark
| | - Edward J Feil
- Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, UK
| | - Henrik Westh
- Department of Clinical Microbiology, Hvidovre Hospital, Hvidovre, Denmark.,Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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10
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Kami S, Tsuchikado R, Nishida H. DNA replication and cell enlargement of Enterococcus faecalis protoplasts. AIMS Microbiol 2020; 5:347-357. [PMID: 31915747 PMCID: PMC6946640 DOI: 10.3934/microbiol.2019.4.347] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 10/23/2019] [Indexed: 11/18/2022] Open
Abstract
Protoplasts of Enterococcus faecalis did not divide but enlarged in Difco Marine Broth containing penicillin. Our previous studies have demonstrated that transcription and translation were essential for bacterial cell enlargement. However, it was uncertain whether replication was also essential. In this study, we measured the amount of DNA in E. faecalis cells during the course of enlargement using quantitative polymerase chain reaction. The growth of normally divided cells (native forms) of E. faecalis exhibited a log phase before 6 h of incubation was reached. Although a difference in quantitation cycle (Cq) values between the replication initiation and termination regions was observed in the log phase, it was not present in the stationary growth phase. On the other hand, the amount of DNA in E. faecalis protoplasts increased during the cell enlargement incubation. The difference of Cq values between the protoplasts at 0 and 96 h of incubation was 8–9, indicating that the DNA amount at 96 h was 200–500 times higher than that at 0 h. The Cq values differed between the replication initiation and termination regions, indicating that the replication level was high. When novobiocin, a DNA replication inhibitor, was added to the medium at 24 h of incubation, DNA replication and cell enlargement were almost stopped. Thus, replication plays an important role in the enlargement of E. faecalis protoplasts.
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Affiliation(s)
- Satoshi Kami
- Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Rintaro Tsuchikado
- Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Hiromi Nishida
- Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
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11
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Hashimoto Y, Taniguchi M, Uesaka K, Nomura T, Hirakawa H, Tanimoto K, Tamai K, Ruan G, Zheng B, Tomita H. Novel Multidrug-Resistant Enterococcal Mobile Linear Plasmid pELF1 Encoding vanA and vanM Gene Clusters From a Japanese Vancomycin-Resistant Enterococci Isolate. Front Microbiol 2019; 10:2568. [PMID: 31798546 PMCID: PMC6863802 DOI: 10.3389/fmicb.2019.02568] [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: 08/07/2019] [Accepted: 10/23/2019] [Indexed: 11/13/2022] Open
Abstract
Vancomycin-resistant enterococci are troublesome pathogens in clinical settings because of few treatment options. A VanA/VanM-type vancomycin-resistant Enterococcus faecium clinical isolate was identified in Japan. This strain, named AA708, harbored five plasmids, one of which migrated during agarose gel electrophoresis without S1 nuclease treatment, which is indicative of a linear topology. We named this plasmid pELF1. Whole genome sequencing (WGS) analysis of the AA708 strain revealed that the complete sequence of pELF1 was 143,316 bp long and harbored both the vanA and vanM gene clusters. Furthermore, mfold analysis and WGS data show that the left end of pELF1 presumably forms a hairpin structure, unlike its right end. The pELF1 plasmid was not digested by lambda exonuclease, indicating that terminal proteins were bound to the 5′ end of the plasmid, similar to the Streptomyces linear plasmids. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis results were also consistent with the exonuclease assay results. In retardation assays, DNAs containing the right end of proteinase K-untreated pELF1 did not appear to move as well as the proteinase K-treated pELF1, suggesting that terminal proteins might be attached to the right end of pELF1. Palindromic sequences formed hairpin structures at the right terminal sequence of pELF1; however, sequence similarity with the well-known linear plasmids of Streptomyces spp. was not high. pELF1 was unique as it possessed two different terminal structures. Conjugation experiments revealed that pELF1 could be transferred to E. faecalis, E. faecium, E. casseliflavus, and E. hirae. These transconjugants exhibited not only high resistance levels to vancomycin, but also resistance to streptomycin, kanamycin, and erythromycin. These results indicate that pELF1 has the ability to confer multidrug resistance to Enterococcus spp. simultaneously, which might lead to clinical hazards.
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Affiliation(s)
- Yusuke Hashimoto
- Department of Bacteriology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Makoto Taniguchi
- Oral Microbiome Center, Taniguchi Dental Clinic, Takamatsu, Japan
| | - Kazuma Uesaka
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Takahiro Nomura
- Department of Bacteriology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Hidetada Hirakawa
- Department of Bacteriology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Koichi Tanimoto
- Laboratory of Bacterial Drug Resistance, Gunma University Graduate School of Medicine, Maebashi, Japan
| | | | - Genjie Ruan
- Institute of Clinical Pharmacology, Peking University First Hospital, Beijing, China
| | - Bo Zheng
- Institute of Clinical Pharmacology, Peking University First Hospital, Beijing, China
| | - Haruyoshi Tomita
- Department of Bacteriology, Gunma University Graduate School of Medicine, Maebashi, Japan.,Laboratory of Bacterial Drug Resistance, Gunma University Graduate School of Medicine, Maebashi, Japan
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Chai Y, Gu X, Wu Q, Guo B, Qi Y, Wang X, Zhou X, Li J, Han M, Zhong F. Genome sequence analysis reveals potential for virulence genes and multi-drug resistance in an Enterococcus faecalis 2A (XJ05) strain that causes lamb encephalitis. BMC Vet Res 2019; 15:235. [PMID: 31286947 PMCID: PMC6615116 DOI: 10.1186/s12917-019-1936-3] [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: 02/11/2019] [Accepted: 05/29/2019] [Indexed: 01/06/2023] Open
Abstract
Background Enterococcus is an important component of normal flora in human and animals, but in recent years, the pathogenicity of Enterococcus has been confirmed in clinical medicine. More and more animal infections have been reported in veterinary clinics. For the last decades, outbreaks of encephalitis in lambs have become much more common in Northern Xinjiang, China. Consequent studies have confirmed that these affected lambs had been commonly infected with E. faecalis. More than 60 E. faecalis were isolated from the brain of infected lambs, A highly virulent strain entitled E. faecalis 2A (XJ05) were selected, sequenced and analyzed. Result Using whole genome sequence and de novo assembly, 18 contigs with NGS and annotation were obtained. It is confirmed that the genome has a size of 2.9 Mb containing 2783 protein-coding genes, as well as 54 tRNA genes and 4 rRNA genes. Some key features of this strain were identified, which included 7 predicted antibiotic resistance genes and 18 candidate virulence factor genes. Conclusion The E. faecalis 2A (XJ05) genome is conspicuous smaller than E.faecalis V583, but not significantly different from other non-pathogenic E. faecalis. It carried 7 resistance genes including 4 kind of antibiotics which were consistent with the results of extensive drug resistance phenotypic, including aminoglycoside, macrolide, phenicol, and tetracycline. 2A (XJ05) also carried 18 new virulence factor genes related to virulence, hemolysin genes (cylA, cylB, cylM, cylL) may play an important role in lamb encephalitis by E. faecalis 2A (XJ05).
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Affiliation(s)
- Yingjin Chai
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000, Xinjiang, China
| | - Xiaoxiao Gu
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000, Xinjiang, China
| | - Qin Wu
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000, Xinjiang, China
| | - Bingjiao Guo
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000, Xinjiang, China
| | - Yayin Qi
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000, Xinjiang, China
| | - Xiaolan Wang
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000, Xinjiang, China
| | - Xia Zhou
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000, Xinjiang, China.
| | - Jie Li
- College of Animal Science and Technology, Shihezi University, Shihezi, 832000, Xinjiang, China.
| | - Mengli Han
- State Key Laboratory for Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agricultural and Reclamation Science, Shihezi, 832000, Xinjiang, China.
| | - Fagang Zhong
- State Key Laboratory for Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agricultural and Reclamation Science, Shihezi, 832000, Xinjiang, China
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Bacteriophage φEf11 ORF28 Endolysin, a Multifunctional Lytic Enzyme with Properties Distinct from All Other Identified Enterococcus faecalis Phage Endolysins. Appl Environ Microbiol 2019; 85:AEM.00555-19. [PMID: 30979842 DOI: 10.1128/aem.00555-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 04/09/2019] [Indexed: 02/01/2023] Open
Abstract
ϕEf11 is a temperate Siphoviridae bacteriophage that infects strains of Enterococcus faecalis The ϕEf11 genome, encompassing 65 open reading frames (ORFs), is contained within 42,822 bp of DNA. Within this genome, a module of six lysis-related genes was identified. Based upon sequence homology, one of these six genes, ORF28, was predicted to code for an N-acetylmuramoyl-l-alanine amidase endolysin of 46.133 kDa, composed of 421 amino acids. The PCR-amplified ORF28 was cloned and expressed, and the resulting gene product was affinity purified to homogeneity. The purified protein was obtained from a fusion protein that exhibited a molecular mass of 72.5 kDa, consistent with a 46.1-kDa protein combined with a fused 26.5-kDa glutathione S-transferase tag. It produced rapid, profound lysis in E. faecalis populations and was active against 73 of 103 (71%) E. faecalis strains tested. In addition, it caused substantial destruction of E. faecalis biofilms. The lysin was quite stable, retaining its activity for three years in refrigerated storage, was stable over a wide range of pHs, and was unaffected by the presence of a reducing agent; however, it was inhibited by increasing concentrations of Ca2+ Liquid chromatography-mass spectrometry analysis of E. faecalis cell wall digestion products produced by the ORF28 endolysin indicated that the lysin acted as an N-acetylmuramidase, an endo-β-N-acetylglucosaminidase, and an endopeptidase, rather than an N-acetylmuramoyl-l-alanine amidase. The ϕEf11 ORF28 lysin shared 10% to 37% amino acid identity with the lytic enzymes of all other characterized E. faecalis bacteriophages.IMPORTANCE The emergence of multidrug-resistant pathogenic microorganisms has brought increasing attention to the urgent need for the development of alternative antimicrobial strategies. One such alternative to conventional antibiotics employs lytic enzymes (endolysins) that are produced by bacteriophages in the course of lytic infection. During lytic infection by a bacteriophage, these enzymes hydrolyze the cell wall peptidoglycan, resulting in the lysis of the host cell. However, external endolysin application can result in lysis from without. In this study, we have cloned, expressed, purified, and characterized an endolysin produced by a bacteriophage infecting strains of Enterococcus faecalis The lysin is broadly active against most of the tested E. faecalis strains and exhibits multifunctional enzymatic specificities that differ from all other characterized endolysins produced by E. faecalis bacteriophages.
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Bolocan AS, Upadrasta A, Bettio PHDA, Clooney AG, Draper LA, Ross RP, Hill C. Evaluation of Phage Therapy in the Context of Enterococcus faecalis and Its Associated Diseases. Viruses 2019; 11:E366. [PMID: 31010053 PMCID: PMC6521178 DOI: 10.3390/v11040366] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/16/2019] [Accepted: 04/17/2019] [Indexed: 12/11/2022] Open
Abstract
Bacteriophages (phages) or bacterial viruses have been proposed as natural antimicrobial agents to fight against antibiotic-resistant bacteria associated with human infections. Enterococcus faecalis is a gut commensal, which is occasionally found in the mouth and vaginal tract, and does not usually cause clinical problems. However, it can spread to other areas of the body and cause life-threatening infections, such as septicemia, endocarditis, or meningitis, in immunocompromised hosts. Although E. faecalis phage cocktails are not commercially available within the EU or USA, there is an accumulated evidence from in vitro and in vivo studies that have shown phage efficacy, which supports the idea of applying phage therapy to overcome infections associated with E. faecalis. In this review, we discuss the potency of bacteriophages in controlling E. faecalis, in both in vitro and in vivo scenarios. E. faecalis associated bacteriophages were compared at the genome level and an attempt was made to categorize phages with respect to their suitability for therapeutic application, using orthocluster analysis. In addition, E. faecalis phages have been examined for the presence of antibiotic-resistant genes, to ensure their safe use in clinical conditions. Finally, the domain architecture of E. faecalis phage-encoded endolysins are discussed.
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Affiliation(s)
- Andrei S Bolocan
- APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland.
- School of Microbiology, University College Cork, Cork T12 YN60, Ireland.
| | - Aditya Upadrasta
- APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland.
- School of Microbiology, University College Cork, Cork T12 YN60, Ireland.
| | - Pedro H de Almeida Bettio
- APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland.
- School of Microbiology, University College Cork, Cork T12 YN60, Ireland.
| | - Adam G Clooney
- APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland.
- School of Microbiology, University College Cork, Cork T12 YN60, Ireland.
| | - Lorraine A Draper
- APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland.
- School of Microbiology, University College Cork, Cork T12 YN60, Ireland.
| | - R Paul Ross
- APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland.
- School of Microbiology, University College Cork, Cork T12 YN60, Ireland.
- Teagasc Food Research Centre, Moorepark, Fermoy, Cork P61 C996, Ireland.
| | - Colin Hill
- APC Microbiome Ireland, University College Cork, Cork T12 YT20, Ireland.
- School of Microbiology, University College Cork, Cork T12 YN60, Ireland.
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Troha K, Buchon N. Methods for the study of innate immunity in Drosophila melanogaster. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2019; 8:e344. [PMID: 30993906 DOI: 10.1002/wdev.344] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 02/25/2019] [Accepted: 03/20/2019] [Indexed: 12/12/2022]
Abstract
From flies to humans, many components of the innate immune system have been conserved during metazoan evolution. This foundational observation has allowed us to develop Drosophila melanogaster, the fruit fly, into a powerful model to study innate immunity in animals. Thanks to an ever-growing arsenal of genetic tools, an easily manipulated genome, and its winning disposition, Drosophila is now employed to study not only basic molecular mechanisms of pathogen recognition and immune signaling, but also the nature of physiological responses activated in the host by microbial challenge and how dysregulation of these processes contributes to disease. Here, we present a collection of methods and protocols to challenge the fly with an assortment of microbes, both systemically and orally, and assess its humoral, cellular, and epithelial response to infection. Our review covers techniques for measuring the reaction to microbial infection both qualitatively and quantitatively. Specifically, we describe survival, bacterial load, BLUD (a measure of disease tolerance), phagocytosis, melanization, clotting, and ROS production assays, as well as efficient protocols to collect hemolymph and measure immune gene expression. We also offer an updated catalog of online resources and a collection of popular reporter lines and mutants to facilitate research efforts. This article is categorized under: Technologies > Analysis of Cell, Tissue, and Animal Phenotypes.
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Affiliation(s)
- Katia Troha
- Department of Entomology, Cornell Institute of Host-Microbe Interactions and Disease, Cornell University, Ithaca, New York
| | - Nicolas Buchon
- Department of Entomology, Cornell Institute of Host-Microbe Interactions and Disease, Cornell University, Ithaca, New York
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Ó Cuív P, Giri R, Hoedt EC, McGuckin MA, Begun J, Morrison M. Enterococcus faecalis AHG0090 is a Genetically Tractable Bacterium and Produces a Secreted Peptidic Bioactive that Suppresses Nuclear Factor Kappa B Activation in Human Gut Epithelial Cells. Front Immunol 2018; 9:790. [PMID: 29720977 PMCID: PMC5915459 DOI: 10.3389/fimmu.2018.00790] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 03/29/2018] [Indexed: 12/20/2022] Open
Abstract
Enterococcus faecalis is an early coloniser of the human infant gut and contributes to the development of intestinal immunity. To better understand the functional capacity of E. faecalis, we constructed a broad host range RP4 mobilizable vector, pEHR513112, that confers chloramphenicol resistance and used a metaparental mating approach to isolate E. faecalis AHG0090 from a fecal sample collected from a healthy human infant. We demonstrated that E. faecalis AHG0090 is genetically tractable and could be manipulated using traditional molecular microbiology approaches. E. faecalis AHG0090 was comparable to the gold-standard anti-inflammatory bacterium Faecalibacterium prausnitzii A2-165 in its ability to suppress cytokine-mediated nuclear factor kappa B (NF-κB) activation in human gut-derived LS174T goblet cell like and Caco-2 enterocyte-like cell lines. E. faecalis AHG0090 and F. prausnitzii A2-165 produced secreted low molecular weight NF-κB suppressive peptidic bioactives. Both bioactives were sensitive to heat and proteinase K treatments although the E. faecalis AHG0090 bioactive was more resilient to both forms of treatment. As expected, E. faecalis AHG0090 suppressed IL-1β-induced NF-κB-p65 subunit nuclear translocation and expression of the NF-κB regulated genes IL-6, IL-8 and CXCL-10. Finally, we determined that E. faecalis AHG0090 is distantly related to other commensal strains and likely encodes niche factors that support effective colonization of the infant gut.
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Affiliation(s)
- Páraic Ó Cuív
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Rabina Giri
- Mater Research Institute - The University of Queensland, Translational Research Institute, Brisbane, QLD, Australia
| | - Emily C Hoedt
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Michael A McGuckin
- Mater Research Institute - The University of Queensland, Translational Research Institute, Brisbane, QLD, Australia
| | - Jakob Begun
- Mater Research Institute - The University of Queensland, Translational Research Institute, Brisbane, QLD, Australia
| | - Mark Morrison
- The University of Queensland Diamantina Institute, Translational Research Institute, The University of Queensland, Brisbane, QLD, Australia
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Olvera-García M, Sanchez-Flores A, Quirasco Baruch M. Genomic and functional characterisation of two Enterococcus strains isolated from Cotija cheese and their potential role in ripening. Appl Microbiol Biotechnol 2018; 102:2251-2267. [PMID: 29372297 DOI: 10.1007/s00253-018-8765-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 12/18/2017] [Accepted: 12/26/2017] [Indexed: 12/12/2022]
Abstract
Enterococcus spp. are present in the native microbiota of many traditional fermented foods. Their ability to produce antibacterial compounds, mainly against Listeria monocytogenes, has raised interest recently. However, there is scarce information about their proteolytic and lipolytic potential, and their biotechnological application is currently limited because enterococcal strains have been related to nosocomial infections. In this work, next-generation sequencing and optimised bioinformatic pipelines were used to annotate the genomes of two Enterococcus strains-one E. faecium and one E. faecalis-isolated from the Mexican artisanal ripened Cotija cheese. A battery of genes involved in their proteolytic system was annotated. Genes coding for lipases, esterases and other enzymes whose final products contribute to cheese aroma and flavour were identified as well. As for the production of antibacterial compounds, several peptidoglycan hydrolase- and bacteriocin-coding genes were identified in both genomes experimentally and by bioinformatic analyses. E. faecalis showed resistance to aminoglycosides and E. faecium to aminoglycosides and macrolides, as predicted by the genome functional annotation. No pathogenicity islands were found in any of the strains, although traits such as the ability of biofilm formation and cell aggregation were observed. Finally, a comparative genomic analysis was able to discriminate between the food strains isolated and nosocomial strains. In summary, pathogenic strains are resistant to a wide range of antibiotics and contain virulence factors that cause host damage; in contrast, food strains display less antibiotic resistance, include genes that encode class II bacteriocins and express virulence factors associated with host colonisation rather than invasion.
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Affiliation(s)
- Myrna Olvera-García
- Fac. de Química, Departamento de Alimentos y Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 3000, C. U, 04510, Ciudad de México, Mexico
| | - Alejandro Sanchez-Flores
- Instituto de Biotecnología, Unidad de Secuenciación Masiva y Bioinformática, Av. Universidad 2001, Chamilpa, 62210, Cuernavaca, Morelos, Mexico
| | - Maricarmen Quirasco Baruch
- Fac. de Química, Departamento de Alimentos y Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 3000, C. U, 04510, Ciudad de México, Mexico.
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Jäger T, Alexander J, Kirchen S, Dötsch A, Wieland A, Hiller C, Schwartz T. Live-dead discrimination analysis, qPCR assessment for opportunistic pathogens, and population analysis at ozone wastewater treatment plants. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 232:571-579. [PMID: 29032906 DOI: 10.1016/j.envpol.2017.09.089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
In respect to direct and indirect water reuse, the microbiological quality of treated wastewater is highly important. Conventional wastewater treatment plants are normally not equipped with advanced technologies for the elimination of bacteria. Molecular biology analyses were combined with live-dead discrimination analysis of wastewater population using Propidium monoazide (PMA) to study population shifts during ozonation (1 g ozone/g DOC) at a municipal wastewater treatment plant. Escherichia coli, enterococci, and Pseudomonas aeruginosa were quantified by polymerase chain reaction (qPCR) and the whole wastewater population was analyzed by metagenomic sequencing. The PMA-qPCR experiments showed that the abundances of P. aeruginosa didn't change by ozone treatment, whereas a reduction was observed for E. coli and enterococci. Results comparing conventional cultivation experiments with PMA-qPCR underlined the presence of viable but not culturable cells (VBNC) and their regrowth potential after ozone treatment. Illumina HiSeq sequencing results with and without PMA treatment demonstrated high population similarities in water samples originating from ozone inflow sampling sides. Upon using PMA treatment after ozonation, population shifts became visible and also underlined the importance of PMA treatment for the evaluation of elimination and selection processes during ozonation at WWTPs. Amongst a number of 14 most abundant genera identified in the inflow samples, 9 genera were found to be reduced, whereas 4 genera increased in relative abundance and 1 genus almost remained constant. The strongest increase in relative abundance after ozonation was detected for Oscillatoria spp., Microcoleus spp. and Nitrospira spp. Beside this, a continuous release of Pseudomonas spp. (including P. aeruginosa) to the downstream receiving body was confirmed. Regrowth experiments demonstrated a high prevalence of P. aeruginosa as part of the surviving bacterial population. Summing up, molecular biology analyses in combination with live-dead discrimination are comprehensive methods to evaluate the elimination processes targeting specific species and/or whole microbial populations.
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Affiliation(s)
- Thomas Jäger
- Karlsruhe Institute of Technology (KIT) - Campus North, Institute of Functional Interfaces (IFG), Department of Bioengineering and Biosystems, P.O. Box 3640, 76021 Karlsruhe, Germany
| | - Johannes Alexander
- Karlsruhe Institute of Technology (KIT) - Campus North, Institute of Functional Interfaces (IFG), Department of Bioengineering and Biosystems, P.O. Box 3640, 76021 Karlsruhe, Germany
| | - Silke Kirchen
- Karlsruhe Institute of Technology (KIT) - Campus North, Institute of Functional Interfaces (IFG), Department of Bioengineering and Biosystems, P.O. Box 3640, 76021 Karlsruhe, Germany
| | - Andreas Dötsch
- Karlsruhe Institute of Technology (KIT) - Campus North, Institute of Functional Interfaces (IFG), Department of Bioengineering and Biosystems, P.O. Box 3640, 76021 Karlsruhe, Germany
| | - Arne Wieland
- Xylem Services GmbH, Boschstraße 4 - 14, 32051 Herford, Germany
| | - Christian Hiller
- Zweckverband Klärwerk Steinhäule, Reinzstrasse 1, 89233 Neu-Ulm, Germany
| | - Thomas Schwartz
- Karlsruhe Institute of Technology (KIT) - Campus North, Institute of Functional Interfaces (IFG), Department of Bioengineering and Biosystems, P.O. Box 3640, 76021 Karlsruhe, Germany.
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Biofilm formation in enterococci: genotype-phenotype correlations and inhibition by vancomycin. Sci Rep 2017; 7:5733. [PMID: 28720810 PMCID: PMC5515943 DOI: 10.1038/s41598-017-05901-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 06/06/2017] [Indexed: 11/08/2022] Open
Abstract
Enterococci are nosocomial pathogens that can form biofilms, which contribute to their virulence and antibiotic resistance. Although many genes involved in biofilm formation have been defined, their distribution among enterococci has not been comprehensively studied on a genome scale, and their diagnostic ability to predict biofilm phenotypes is not fully established. Here, we assessed the biofilm-forming ability of 90 enterococcal clinical isolates. Major patterns of virulence gene distribution in enterococcal genomes were identified, and the differentiating virulence genes were screened by polymerase chain reaction (PCR) in 31 of the clinical isolates. We found that detection of gelE in Enterococcus faecalis is not sufficient to predict gelatinase activity unless fsrAB, or fsrB alone, is PCR-positive (P = 0.0026 and 0.0012, respectively). We also found that agg is significantly enriched in isolates with medium and strong biofilm formation ability (P = 0.0026). Additionally, vancomycin, applied at sub minimal inhibitory concentrations, inhibited biofilm in four out of five strong biofilm-forming isolates. In conclusion, we suggest using agg and fsrB genes, together with the previously established gelE, for better prediction of biofilm strength and gelatinase activity, respectively. Future studies should explore the mechanism of biofilm inhibition by vancomycin and its possible use for antivirulence therapy.
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Christoffersen TE, Hult LTO, Kuczkowska K, Moe KM, Skeie S, Lea T, Kleiveland CR. In vitro comparison of the effects of probiotic, commensal and pathogenic strains on macrophage polarization. Probiotics Antimicrob Proteins 2016; 6:1-10. [PMID: 24676762 DOI: 10.1007/s12602-013-9152-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Macrophages are important with respect to both innate and adaptive immune responses and are known to differentiate into pro-inflammatory M1- or anti-inflammatory M2-phenotypes following activation. In order to study how different bacteria affect macrophage polarization, we exposed murine RAW 264.7 macrophages to sixteen different strains representing probiotic strains, pathogens, commensals and strains of food origin. Increased inducible nitric oxide synthase (iNOS) or arginase-1 gene expression indicates M1 or M2 polarization, respectively, and was quantified by qRT-PCR. Strains of Escherichia and Salmonella elevated iNOS expression more so than strains of Enterococcus, Lactobacillus and Lactococcus, indicating that Gram-negative strains are more potent M1 inducers. However, strain-specific responses were observed. For instance, Escherichia coli Nissle 1917 was a poor inducer of iNOS gene expression compared to the other E. coli strains, while Enterococcus faecalis Symbioflor-1 was more potent in this respect compared to all the eleven Gram-positive strains tested. Macrophage polarization was further characterized by quantifying secreted pro- and anti-inflammatory cytokines. Exposure to the pathogen E. coli 042 produced a cytokine profile indicating M1 differentiation, which is in accordance with the PCR data. However, exposure to most strains resulted in either high or low secretion levels of all cytokines tested, rather than a clear M1 or M2 profile. In general, the Gram-negative strains induced high levels of cytokine secretion compared to the Gram-positive strains. Interestingly, strains of human origin had a higher impact on macrophages compared to strains of food origin.
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de Vries LE, Hasman H, Jurado Rabadán S, Agersø Y. Sequence-Based Characterization of Tn5801-Like Genomic Islands in Tetracycline-Resistant Staphylococcus pseudintermedius and Other Gram-positive Bacteria from Humans and Animals. Front Microbiol 2016; 7:576. [PMID: 27199912 PMCID: PMC4844618 DOI: 10.3389/fmicb.2016.00576] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 04/08/2016] [Indexed: 01/18/2023] Open
Abstract
Antibiotic resistance in pathogens is often associated with mobile genetic elements, such as genomic islands (GI) including integrative and conjugative elements (ICEs). These can transfer resistance genes within and between bacteria from humans and/or animals. The aim of this study was to investigate whether Tn5801-like GIs carrying the tetracycline resistance gene, tet(M), are common in Staphylococcus pseudintermedius from pets, and to do an overall sequences-based characterization of Tn5801-like GIs detected in Gram-positive bacteria from humans and animals. A total of 27 tetracycline-resistant S. pseudintermedius isolates from Danish pets (1998–2005) were screened for tet(M) by PCR. Selected isolates (13) were screened for GI- or ICE-specific genes (intTn5801 or xisTn916) and their tet(M) gene was sequenced (Sanger-method). Long-range PCR mappings and whole-genome-sequencing (Illumina) were performed for selected S. pseudintermedius-isolates (seven and three isolates, respectively) as well as for human S. aureus isolates (seven and one isolates, respectively) and one porcine Enterococcus faecium isolate known to carry Tn5801-like GIs. All 27 S. pseudintermedius were positive for tet(M). Out of 13 selected isolates, seven contained Tn5801-like GIs and six contained Tn916-like ICEs. Two different Tn5801-like GI types were detected among S. pseudintermedius (Tn5801 and GI6287) - both showed high similarity compared to GenBank sequences from human pathogens. Two distinct Tn5801-like GI types were detected among the porcine E. faecium and human S. aureus isolates (Tn6014 and GI6288). Tn5801-like GIs were detected in GenBank-sequences from Gram-positive bacteria of human, animal or food origin worldwide. Known Tn5801-like GIs were divided into seven types. The results showed that Tn5801-like GIs appear to be relatively common in tetracycline-resistant S. pseudintermedius in Denmark. Almost identical Tn5801-like GIs were identified in different Gram-positive species of pet and human origin, suggesting that horizontal transfer of these elements has occurred between S. pseudintermedius from pets and human pathogens, including S. aureus.
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Affiliation(s)
- Lisbeth E de Vries
- Department of Technology, Metropolitan University College Copenhagen, Denmark
| | - Henrik Hasman
- National Food Institute, Technical University of Copenhagen Lyngby, Denmark
| | | | - Yvonne Agersø
- National Food Institute, Technical University of Copenhagen Lyngby, Denmark
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Cui Y, Hu T, Qu X, Zhang L, Ding Z, Dong A. Plasmids from Food Lactic Acid Bacteria: Diversity, Similarity, and New Developments. Int J Mol Sci 2015; 16:13172-202. [PMID: 26068451 PMCID: PMC4490491 DOI: 10.3390/ijms160613172] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 05/09/2015] [Accepted: 05/22/2015] [Indexed: 12/24/2022] Open
Abstract
Plasmids are widely distributed in different sources of lactic acid bacteria (LAB) as self-replicating extrachromosomal genetic materials, and have received considerable attention due to their close relationship with many important functions as well as some industrially relevant characteristics of the LAB species. They are interesting with regard to the development of food-grade cloning vectors. This review summarizes new developments in the area of lactic acid bacteria plasmids and aims to provide up to date information that can be used in related future research.
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Affiliation(s)
- Yanhua Cui
- School of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, China.
| | - Tong Hu
- School of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, China.
| | - Xiaojun Qu
- Institute of Microbiology, Heilongjiang Academy of Sciences, Harbin 150010, China.
| | - Lanwei Zhang
- School of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, China.
| | - Zhongqing Ding
- School of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, China.
| | - Aijun Dong
- School of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, China.
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Borst LB, Suyemoto MM, Scholl EH, Fuller FJ, Barnes HJ. Comparative genomic analysis identifies divergent genomic features of pathogenic Enterococcus cecorum including a type IC CRISPR-Cas system, a capsule locus, an epa-like locus, and putative host tissue binding proteins. PLoS One 2015; 10:e0121294. [PMID: 25860249 PMCID: PMC4393107 DOI: 10.1371/journal.pone.0121294] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 01/29/2015] [Indexed: 12/21/2022] Open
Abstract
Enterococcus cecorum (EC) is the dominant enteric commensal of adult chickens and contributes to the gut consortia of many avian and mammalian species. While EC infection is an uncommon zoonosis, like other enterococcal species it can cause life-threating nosocomial infection in people. In contrast to other enterococci which are considered opportunistic pathogens, emerging pathogenic strains of EC cause outbreaks of musculoskeletal disease in broiler chickens. Typical morbidity and mortality is comparable to other important infectious diseases of poultry. In molecular epidemiologic studies, pathogenic EC strains were found to be genetically clonal. These findings suggested acquisition of specific virulence determinants by pathogenic EC. To identify divergent genomic features and acquired virulence determinants in pathogenic EC; comparative genomic analysis was performed on genomes of 3 pathogenic and 3 commensal strains of EC. Pathogenic isolates had smaller genomes with a higher GC content, and they demonstrated large regions of synteny compared to commensal isolates. A molecular phylogenetic analysis demonstrated sequence divergence in pathogenic EC genomes. At a threshold of 98% identity, 414 predicted proteins were identified that were highly conserved in pathogenic EC but not in commensal EC. Among these, divergent CRISPR-cas defense loci were observed. In commensal EC, the type IIA arrangement typical for enterococci was present; however, pathogenic EC had a type IC locus, which is novel in enterococci but commonly observed in streptococci. Potential mediators of virulence identified in this analysis included a polysaccharide capsular locus similar to that recently described for E. faecium, an epa-like locus, and cell wall associated proteins which may bind host extracellular matrix. This analysis identified specific genomic regions, coding sequences, and predicted proteins which may be related to the divergent evolution and increased virulence of emerging pathogenic strains of EC.
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Affiliation(s)
- Luke B. Borst
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail:
| | - M. Mitsu Suyemoto
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Elizabeth H. Scholl
- Bioinformatics Consulting and Service Core, Bioinformatics Research Center, College of Agriculture and Life Sciences, College of Sciences, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Fredrick J. Fuller
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
| | - H. John Barnes
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
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The fsr Quorum-Sensing System and Cognate Gelatinase Orchestrate the Expression and Processing of Proprotein EF_1097 into the Mature Antimicrobial Peptide Enterocin O16. J Bacteriol 2015; 197:2112-2121. [PMID: 25733609 DOI: 10.1128/jb.02513-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 02/20/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED A novel antimicrobial peptide designated enterocin O16 was purified from Enterococcus faecalis. Mass spectrometry showed a monoisotopic mass of 7,231 Da, and N-terminal Edman degradation identified a 29-amino-acid sequence corresponding to residues 90 to 119 of the EF_1097 protein. Bioinformatic analysis showed that enterocin O16 is composed of the 68 most C-terminal residues of the EF_1097 protein. Introduction of an in-frame isogenic deletion in the ef1097 gene abolished the production of enterocin O16. Enterocin O16 has a narrow inhibitory spectrum, as it inhibits mostly lactobacilli. Apparently, E. faecalis is intrinsically resistant to the antimicrobial peptide, as no immunity connected to the production of enterocin O16 could be identified. ef1097 has previously been identified as one of three loci regulated by the fsr quorum-sensing system. The introduction of a nonsense mutation into fsrB consistently impaired enterocin O16 production, but externally added gelatinase biosynthesis-activating pheromone restored the antimicrobial activity. Functional genetic analysis showed that the EF_1097 proprotein is processed extracellularly into enterocin O16 by the metalloprotease GelE. Thus, it is evident that the fsr quorum-sensing system constitutes the regulatory unit that controls the expression of the EF_1097 precursor protein and the protease GelE and that the latter is required for the formation of enterocin O16. On the basis of these results, this study identified antibacterial antagonism as a novel aspect related to the function of fsr and provides a rationale for why ef1097 is part of the fsr regulon. IMPORTANCE The fsr quorum-sensing system modulates important physiological functions in E. faecalis via the activity of GelE. The present study presents a new facet of fsr signaling. The system controls the expression of three primary target operons (fsrABCD, gelE-sprE, and ef1097-ef1097b). We demonstrate that the concerted expression of these operons constitutes the elements necessary for the production of a bacteriocin-type peptide and that antimicrobial antagonism is an intrinsic function of fsr. The bacteriocin enterocin O16 consists of the 68 most C-terminal residues of the EF_1097 secreted proprotein. The GelE protease processes the EF_1097 proprotein into enterocin O16. In this manner, fsr signaling enables E. faecalis populations to express antimicrobial activity in a cell density-dependent manner.
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Ghasemi SM, Bouzari M, Yoon BH, Chang HI. Comparative genomic analysis of Lactococcus garvieae phage WP-2, a new member of Picovirinae subfamily of Podoviridae. Gene 2014; 551:222-9. [DOI: 10.1016/j.gene.2014.08.060] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 08/10/2014] [Accepted: 08/29/2014] [Indexed: 10/24/2022]
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Repizo GD, Espariz M, Blancato VS, Suárez CA, Esteban L, Magni C. Genomic comparative analysis of the environmental Enterococcus mundtii against enterococcal representative species. BMC Genomics 2014; 15:489. [PMID: 24942651 PMCID: PMC4076982 DOI: 10.1186/1471-2164-15-489] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 06/02/2014] [Indexed: 11/30/2022] Open
Abstract
Background Enterococcus mundtii is a yellow-pigmented microorganism rarely found in human infections. The draft genome sequence of E. mundtii was recently announced. Its genome encodes at least 2,589 genes and 57 RNAs, and 4 putative genomic islands have been detected. The objective of this study was to compare the genetic content of E. mundtii with respect to other enterococcal species and, more specifically, to identify genes coding for putative virulence traits present in enterococcal opportunistic pathogens. Results An in-depth mining of the annotated genome was performed in order to uncover the unique properties of this microorganism, which allowed us to detect a gene encoding the antimicrobial peptide mundticin among other relevant features. Moreover, in this study a comparative genomic analysis against commensal and pathogenic enterococcal species, for which genomic sequences have been released, was conducted for the first time. Furthermore, our study reveals significant similarities in gene content between this environmental isolate and the selected enterococci strains (sharing an “enterococcal gene core” of 805 CDS), which contributes to understand the persistence of this genus in different niches and also improves our knowledge about the genetics of this diverse group of microorganisms that includes environmental, commensal and opportunistic pathogens. Conclusion Although E. mundtii CRL1656 is phylogenetically closer to E. faecium, frequently responsible of nosocomial infections, this strain does not encode the most relevant relevant virulence factors found in the enterococcal clinical isolates and bioinformatic predictions indicate that it possesses the lowest number of putative pathogenic genes among the most representative enterococcal species. Accordingly, infection assays using the Galleria mellonella model confirmed its low virulence. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-489) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | - Christian Magni
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET) and Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario S2002LRK, Argentina.
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Complete genome sequencing and comparative analysis of the linezolid-resistant Enterococcus faecalis strain DENG1. Arch Microbiol 2014; 196:513-6. [DOI: 10.1007/s00203-014-0986-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Accepted: 04/14/2014] [Indexed: 10/25/2022]
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Zhang W, Mi Z, Yin X, Fan H, An X, Zhang Z, Chen J, Tong Y. Characterization of Enterococcus faecalis phage IME-EF1 and its endolysin. PLoS One 2013; 8:e80435. [PMID: 24236180 PMCID: PMC3827423 DOI: 10.1371/journal.pone.0080435] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 10/03/2013] [Indexed: 01/21/2023] Open
Abstract
Enterococcus faecalis is increasingly becoming an important nosocomial infection opportunistic pathogen. E. faecalis can easily obtain drug resistance, making it difficult to be controlled in clinical settings. Using bacteriophage as an alternative treatment to drug-resistant bacteria has been revitalized recently, especially for fighting drug-resistant bacteria. In this research, an E. faecalis bacteriophage named IME-EF1 was isolated from hospital sewage. Whole genomic sequence analysis demonstrated that the isolated IME-EF1 belong to the Siphoviridae family, and has a linear double-stranded DNA genome consisting of 57,081 nucleotides. The IME-EF1 genome has a 40.04% G+C content and contains 98 putative coding sequences. In addition, IME-EF1 has an isometric head with a width of 35 nm to 60 nm and length of 75 nm to 90 nm, as well as morphology resembling a tadpole. IME-EF1 can adsorb to its host cells within 9 min, with an absorbance rate more than 99% and a latent period time of 25 min. The endolysin of IME-EF1 contains a CHAP domain in its N-terminal and has a wider bactericidal spectrum than its parental bacteriophage, including 2 strains of vancomycin-resistant E. faecalis. When administrated intraperitoneally, one dose of IME-EF1 or its endolysin can reduce bacterial count in the blood and protected the mice from a lethal challenge of E. faecalis, with a survival rate of 60% or 80%, respectively. Although bacteriophage could rescue mice from bacterial challenge, to the best of our knowledge, this study further supports the potential function of bacteriophage in dealing with E. faecalis infection in vivo. The results also indicated that the newly isolated bacteriophage IME-EF1 enriched the arsenal library of lytic E. faecalis bacteriophages and presented another choice for phage therapy in the future.
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Affiliation(s)
- Wenhui Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zhiqiang Mi
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Xiuyun Yin
- Affiliated Hospital, Academy of Military Medical Sciences, Beijing, China
| | - Hang Fan
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Xiaoping An
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zhiyi Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Jiankui Chen
- Affiliated Hospital, Academy of Military Medical Sciences, Beijing, China
- * E-mail: (YT); (JC)
| | - Yigang Tong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
- * E-mail: (YT); (JC)
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Nonclinical and clinical Enterococcus faecium strains, but not Enterococcus faecalis strains, have distinct structural and functional genomic features. Appl Environ Microbiol 2013; 80:154-65. [PMID: 24141120 DOI: 10.1128/aem.03108-13] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Certain strains of Enterococcus faecium and Enterococcus faecalis contribute beneficially to animal health and food production, while others are associated with nosocomial infections. To determine whether there are structural and functional genomic features that are distinct between nonclinical (NC) and clinical (CL) strains of those species, we analyzed the genomes of 31 E. faecium and 38 E. faecalis strains. Hierarchical clustering of 7,017 orthologs found in the E. faecium pangenome revealed that NC strains clustered into two clades and are distinct from CL strains. NC E. faecium genomes are significantly smaller than CL genomes, and this difference was partly explained by significantly fewer mobile genetic elements (ME), virulence factors (VF), and antibiotic resistance (AR) genes. E. faecium ortholog comparisons identified 68 and 153 genes that are enriched for NC and CL strains, respectively. Proximity analysis showed that CL-enriched loci, and not NC-enriched loci, are more frequently colocalized on the genome with ME. In CL genomes, AR genes are also colocalized with ME, and VF are more frequently associated with CL-enriched loci. Genes in 23 functional groups are also differentially enriched between NC and CL E. faecium genomes. In contrast, differences were not observed between NC and CL E. faecalis genomes despite their having larger genomes than E. faecium. Our findings show that unlike E. faecalis, NC and CL E. faecium strains are equipped with distinct structural and functional genomic features indicative of adaptation to different environments.
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Characterization of Tn5801.Sag, a variant of Staphylococcus aureus Tn916 family transposon Tn5801 that is widespread in clinical isolates of Streptococcus agalactiae. Antimicrob Agents Chemother 2013; 57:4570-4. [PMID: 23817370 DOI: 10.1128/aac.00521-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Tn5801, originally detected in Staphylococcus aureus Mu50, is a Tn916 family element in which a unique int gene (int5801) replaces the int and xis genes in Tn916 (int916 and xis916). Among 62 tet(M)-positive tetracycline-resistant Streptococcus agalactiae isolates, 43 harbored Tn916, whereas 19 harbored a Tn5801-like element (Tn5801.Sag, ∼20.6 kb). Tn5801.Sag was characterized (PCR mapping, partial sequencing, and chromosomal integration) and compared to other Tn5801-like elements. Similar to Tn5801 from S. aureus Mu50, tested in parallel, Tn5801.Sag was unable to undergo circularization and conjugal transfer.
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In vivo assessment of growth and virulence gene expression during commensal and pathogenic lifestyles of luxABCDE-tagged Enterococcus faecalis strains in murine gastrointestinal and intravenous infection models. Appl Environ Microbiol 2013; 79:3986-97. [PMID: 23603680 DOI: 10.1128/aem.00831-13] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cytolysin and gelatinase are prominent pathogenicity determinants associated with highly virulent Enterococcus faecalis strains. In an effort to explore the expression profiles of these virulence traits in vivo, we have employed E. faecalis variants expressing the luxABCDE cassette under the control of either the P16S, cytolysin, or gelatinase promoter for infections of Galleria mellonella caterpillars and mice. Systemic infection of G. mellonella with bioluminescence-tagged E. faecalis MMH594 revealed temporal regulation of both gelatinase and cytolysin promoters and demonstrated that these traits were induced in response to the host environment. Gavage of mice pretreated perorally with antibiotics resulted in efficient colonization of the murine gastrointestinal tract (GIT) in a strain-dependent manner, where the commensal baby isolate EF62 was more persistent than the nosocomial isolate MMH594. A highly significant correlation (R(2) > 0.94) was found between bioluminescence and the CFU counts in mouse fecal samples. Both strains showed similar preferences for growth and persistence in the ileum, cecum, and colon. Cytolysin expression was uniform in these compartments of the intestinal lumen. In spite of high numbers (10(9) CFU/g of intestinal matter) in the ileum, cecum, and colon, no evidence of translocation or systemic infection could be observed. In the murine intravenous infection model, cytolysin expression was readily detected in the liver, kidneys, and bladder. At 72 h postinfection, the highest bacterial loads were found in the liver, kidneys, and spleen, with organ-specific expression levels of cytolysin ~400- and ~900-fold higher in the spleen and heart, respectively, than in the liver and kidneys. Taken together, this system based on the bioluminescence imaging technology is established as a new, powerful method to monitor the differential regulation of E. faecalis virulence determinants and to study the spatiotemporal course of infection in living animals in real time.
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Werner G, Coque TM, Franz CMAP, Grohmann E, Hegstad K, Jensen L, van Schaik W, Weaver K. Antibiotic resistant enterococci-tales of a drug resistance gene trafficker. Int J Med Microbiol 2013; 303:360-79. [PMID: 23602510 DOI: 10.1016/j.ijmm.2013.03.001] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Enterococci have been recognized as important hospital-acquired pathogens in recent years, and isolates of E. faecalis and E. faecium are the third- to fourth-most prevalent nosocomial pathogen worldwide. Acquired resistances, especially against penicilin/ampicillin, aminoglycosides (high-level) and glycopeptides are therapeutically important and reported in increasing numbers. On the other hand, isolates of E. faecalis and E. faecium are commensals of the intestines of humans, many vertebrate and invertebrate animals and may also constitute an active part of the plant flora. Certain enterococcal isolates are used as starter cultures or supplements in food fermentation and food preservation. Due to their preferred intestinal habitat, their wide occurrence, robustness and ease of cultivation, enterococci are used as indicators for fecal pollution assessing hygiene standards for fresh- and bathing water and they serve as important key indicator bacteria for various veterinary and human resistance surveillance systems. Enterococci are widely prevalent and genetically capable of acquiring, conserving and disseminating genetic traits including resistance determinants among enterococci and related Gram-positive bacteria. In the present review we aimed at summarizing recent advances in the current understanding of the population biology of enterococci, the role mobile genetic elements including plasmids play in shaping the population structure and spreading resistance. We explain how these elements could be classified and discuss mechanisms of plasmid transfer and regulation and the role and cross-talk of enterococcal isolates from food and food animals to humans.
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Affiliation(s)
- Guido Werner
- National Reference Centre for Stapyhlococci and Enterococci, Division of Nosocomial Pathogens and Antibiotic Resistances, Robert Koch Institute, Wernigerode Branch, Burgstr. 37, 38855 Wernigerode, Germany.
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Novel Podoviridae family bacteriophage infecting Weissella cibaria isolated from Kimchi. Appl Environ Microbiol 2012; 78:7299-308. [PMID: 22885743 DOI: 10.1128/aem.00031-12] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The first complete genome sequence of a phage infecting Weissella cibaria (Weissella kimchii) is presented. The bacteriophage YS61 was isolated from kimchi, a Korean fermented vegetable dish. Bacteriophages are recognized as a serious problem in industrial fermentations; however, YS61 differed from many virulent phages associated with food fermentations since it was difficult to propagate and was very susceptible to resistance development. Sequence analysis revealed that YS61 resembles Podoviridae of the subfamily Picovirinae. Within the subfamily Picovirinae, the 29-like phages have been extensively studied, and their terminal protein-primed DNA replication is well characterized. Our data strongly suggest that YS61 also replicates by a protein-primed mechanism. Weissella phage YS61 is, however, markedly different from members of the Picovirinae with respect to genome size and morphology. Picovirinae are characterized by small (approximately 20-kb) genomes which contrasts with the 33,594-bp genome of YS61. Based on electron microscopy analysis, YS61 was classified as a member of the Podoviridae of morphotype C2, similar to the 29-like phages, but its capsid dimensions are significantly larger than those reported for these phages. The novelty of YS61 was also emphasized by the low number of open reading frames (ORFs) showing significant similarity to database sequences. We propose that the bacteriophage YS61 should represent a new subfamily within the family Podoviridae.
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Construction and application of a luxABCDE reporter system for real-time monitoring of Enterococcus faecalis gene expression and growth. Appl Environ Microbiol 2012; 78:7003-11. [PMID: 22843522 DOI: 10.1128/aem.02018-12] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The present work describes the construction of a novel molecular tool for luciferase-based bioluminescence (BL) tagging of Enterococcus faecalis. To this end, a vector (pSL101) and its derivatives conferring a genetically encoded bioluminescent phenotype on all tested strains of E. faecalis were constructed. pSL101 harbors the luxABCDE operon from pPL2lux and the pREG696 broad-host-range replicon and axe-txe toxin-antitoxin cassette, providing segregational stability for long-term plasmid persistence in the absence of antibiotic selection. The bioluminescent signals obtained from three highly expressed promoters correlated linearly (R(2) > 0.98) with the viable-cell count. We employed lux-tagged E. faecalis strains to monitor growth in real time in milk and urine in vitro. Furthermore, bioluminescence imaging (BLI) was used to visualize the magnitude of the bacterial burden during infection in the Galleria mellonella model system. To our knowledge, pSL101 is the first substrate addition-independent reporter system developed for BLI of E. faecalis and an efficient tool for spatiotemporal tracking of bacterial growth and quantitative determination of promoter activity in real time, noninvasively, in infection model systems.
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In vitrocomparison of commensal, probiotic and pathogenic strains ofEnterococcus faecalis. Br J Nutr 2012; 108:2043-53. [DOI: 10.1017/s0007114512000220] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In vivostudies have provided evidence that micro-organisms have important roles in immunological, digestive and respiratory functions, conferring health benefits on the host. Severalin vitromethods have been advised for the initial screening of microbes with potential health effects. The objective of the present study was to employ suchin vitromethodology to characterise different strains ofEnterococcus faecalis. The characteristics of a commercial product marketed as a probiotic, Symbioflor-1 (Symbiopharm), were compared with the characteristics of both pathogenic and commensal strains. Tolerance towards low pH and viability after exposure to human gastric and duodenal juices were assayed. Symbioflor-1 was the most susceptible strain to these treatments when compared with the otherE. faecalisstrains. Furthermore, Symbioflor-1 exhibited the lowest adhesion capacity to intestinal epithelial cells (IEC) and mucus. Competitive binding studies using heparin indicated that glycosaminoglycans might be involved in the adhesion to IEC, but also that differences in these putative bacteria–host interactions do not cause the relative low adhesion capacity of Symbioflor-1. Maturation of dendritic cells (DC) after exposure to bacteria was assayed as an indication of an immunomodulatory effect. All strains induced a moderate elevation of the DC maturation markers CD83 and CD86; however, no strain-specific differences were detected. Correlations betweenin vitroandin vivostudies are discussed. Althoughin vitroassaying is a rational starting point for the selection of microbes with a potential health benefit, it is emphasised that human clinical trials are the definite tool for establishing probiotic status.
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Hinse D, Vollmer T, Rückert C, Blom J, Kalinowski J, Knabbe C, Dreier J. Complete genome and comparative analysis of Streptococcus gallolyticus subsp. gallolyticus, an emerging pathogen of infective endocarditis. BMC Genomics 2011; 12:400. [PMID: 21824414 PMCID: PMC3173452 DOI: 10.1186/1471-2164-12-400] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 08/08/2011] [Indexed: 11/13/2022] Open
Abstract
Background Streptococcus gallolyticus subsp. gallolyticus is an important causative agent of infectious endocarditis, while the pathogenicity of this species is widely unclear. To gain insight into the pathomechanisms and the underlying genetic elements for lateral gene transfer, we sequenced the entire genome of this pathogen. Results We sequenced the whole genome of S. gallolyticus subsp. gallolyticus strain ATCC BAA-2069, consisting of a 2,356,444 bp circular DNA molecule with a G+C-content of 37.65% and a novel 20,765 bp plasmid designated as pSGG1. Bioinformatic analysis predicted 2,309 ORFs and the presence of 80 tRNAs and 21 rRNAs in the chromosome. Furthermore, 21 ORFs were detected on the plasmid pSGG1, including tetracycline resistance genes telL and tet(O/W/32/O). Screening of 41 S. gallolyticus subsp. gallolyticus isolates revealed one plasmid (pSGG2) homologous to pSGG1. We further predicted 21 surface proteins containing the cell wall-sorting motif LPxTG, which were shown to play a functional role in the adhesion of bacteria to host cells. In addition, we performed a whole genome comparison to the recently sequenced S. gallolyticus subsp. gallolyticus strain UCN34, revealing significant differences. Conclusions The analysis of the whole genome sequence of S. gallolyticus subsp. gallolyticus promotes understanding of genetic factors concerning the pathogenesis and adhesion to ECM of this pathogen. For the first time we detected the presence of the mobilizable pSGG1 plasmid, which may play a functional role in lateral gene transfer and promote a selective advantage due to a tetracycline resistance.
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Affiliation(s)
- Dennis Hinse
- Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, 32545 Bad Oeynhausen, Germany
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37
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Nelson OW, Garrity GM. Genome sequences published outside of Standards in Genomic Sciences, January – June 2011. Stand Genomic Sci 2011. [DOI: 10.4056/sigs.2044675] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Oranmiyan W. Nelson
- 1Editorial Office, Standards in Genomic Sciences and Department of Microbiology, Michigan State University, East Lansing, MI, USA
| | - George M. Garrity
- 1Editorial Office, Standards in Genomic Sciences and Department of Microbiology, Michigan State University, East Lansing, MI, USA
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