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Wei Y, Palacios Araya D, Palmer KL. Enterococcus faecium: evolution, adaptation, pathogenesis and emerging therapeutics. Nat Rev Microbiol 2024:10.1038/s41579-024-01058-6. [PMID: 38890478 DOI: 10.1038/s41579-024-01058-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/10/2024] [Indexed: 06/20/2024]
Abstract
The opportunistic pathogen Enterococcus faecium colonizes humans and a wide range of animals, endures numerous stresses, resists antibiotic treatment and stubbornly persists in clinical environments. The widespread application of antibiotics in hospitals and agriculture has contributed to the emergence of vancomycin-resistant E. faecium, which causes many hospital-acquired infections. In this Review, we explore recent discoveries about the evolutionary history, the environmental adaptation and the colonization and dissemination mechanisms of E. faecium and vancomycin-resistant E. faecium. These studies provide critical insights necessary for developing novel preventive and therapeutic approaches against vancomycin-resistant E. faecium and also reveal the intricate interrelationships between the environment, the microorganism and the host, providing knowledge that is broadly relevant to how antibiotic-resistant pathogens emerge and endure.
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Affiliation(s)
- Yahan Wei
- School of Podiatric Medicine, The University of Texas Rio Grande Valley, Harlingen, TX, USA
| | - Dennise Palacios Araya
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Kelli L Palmer
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA.
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2
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Hallenbeck M, Chua M, Collins J. The role of the universal sugar transport system components PtsI (EI) and PtsH (HPr) in Enterococcus faecium. FEMS MICROBES 2024; 5:xtae018. [PMID: 38988831 PMCID: PMC11234649 DOI: 10.1093/femsmc/xtae018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/08/2024] [Accepted: 05/31/2024] [Indexed: 07/12/2024] Open
Abstract
Vancomycin-resistant enterococci (VRE) pose a serious threat to public health because of their limited treatment options. Therefore, there is an increasing need to identify novel targets to develop new drugs. Here, we examined the roles of the universal PTS components, PtsI and PtsH, in Enterococcus faecium to determine their roles in carbon metabolism, biofilm formation, stress response, and the ability to compete in the gastrointestinal tract. Clean deletion of ptsHI resulted in a significant reduction in the ability to import and metabolize simple sugars, attenuated growth rate, reduced biofilm formation, and decreased competitive fitness both in vitro and in vivo. However, no significant difference in stress survival was observed when compared with the wild type. These results suggest that targeting universal or specific PTS may provide a novel treatment strategy by reducing the fitness of E. faecium.
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Affiliation(s)
- Michelle Hallenbeck
- Department of Microbiology & Immunology, University of Louisville, Louisville, KY 40202, United States
- Center for Predictive Medicine, University of Louisville, Louisville, KY 40202, United States
| | - Michelle Chua
- Department of Microbiology & Immunology, University of Louisville, Louisville, KY 40202, United States
- Center for Predictive Medicine, University of Louisville, Louisville, KY 40202, United States
| | - James Collins
- Department of Microbiology & Immunology, University of Louisville, Louisville, KY 40202, United States
- Center for Predictive Medicine, University of Louisville, Louisville, KY 40202, United States
- Center for Microbiomics, Inflammation and Pathogenicity, University of Louisville, Louisville, KY 40202, United States
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Top J, Zhang X, Hendrickx APA, Boeren S, van Schaik W, Huebner J, Willems RJL, Leavis HL, Paganelli FL. YajC, a predicted membrane protein, promotes Enterococcus faecium biofilm formation in vitro and in a rat endocarditis model. FEMS MICROBES 2024; 5:xtae017. [PMID: 38860142 PMCID: PMC11163983 DOI: 10.1093/femsmc/xtae017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/25/2024] [Accepted: 05/17/2024] [Indexed: 06/12/2024] Open
Abstract
Biofilm formation is a critical step in the pathogenesis of difficult-to-treat Gram-positive bacterial infections. We identified that YajC, a conserved membrane protein in bacteria, plays a role in biofilm formation of the clinically relevant Enterococcus faecium strain E1162. Deletion of yajC conferred significantly impaired biofilm formation in vitro and was attenuated in a rat endocarditis model. Mass spectrometry analysis of supernatants of washed ΔyajC cells revealed increased amounts in cytoplasmic and cell-surface-located proteins, including biofilm-associated proteins, suggesting that proteins on the surface of the yajC mutant are only loosely attached. In Streptococcus mutans YajC has been identified in complex with proteins of two cotranslational membrane protein-insertion pathways; the signal recognition particle (SRP)-SecYEG-YajC-YidC1 and the SRP-YajC-YidC2 pathway, but its function is unknown. In S. mutans mutation of yidC1 and yidC2 resulted in impaired protein insertion in the cell membrane and secretion in the supernatant. The E. faecium genome contains all homologous genes encoding for the cotranslational membrane protein-insertion pathways. By combining the studies in S. mutans and E. faecium, we propose that YajC is involved in the stabilization of the SRP-SecYEG-YajC-YidC1 and SRP-YajC-Yid2 pathway or plays a role in retaining proteins for proper docking to the YidC insertases for translocation in and over the membrane.
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Affiliation(s)
- Janetta Top
- Department of Medical Microbiology, University Medical Center Utrecht, PO box 85500, 3584 CX Utrecht, the Netherlands
| | - Xinglin Zhang
- College of Agriculture and Forestry, Linyi University, Building 60, Yujingwan, Linyi City, Shandong Province, 276000, China
| | - Antoni P A Hendrickx
- Centre for Infectious Disease Control (Clb), National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, the Netherlands
| | - Sjef Boeren
- Laboratory of Biochemistry, Wageningen University, PO box 8128, 6700 ET Wageningen, the Netherlands
| | - Willem van Schaik
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Johannes Huebner
- Division of Pediatric Infectious Diseases, Hauner Children's Hospital, Ludwig-Maximilian Universität München, Lindwurmstr. 4, 80337 Munich, Germany
| | - Rob J L Willems
- Department of Medical Microbiology, University Medical Center Utrecht, PO box 85500, 3584 CX Utrecht, the Netherlands
| | - Helen L Leavis
- Department of Medical Microbiology, University Medical Center Utrecht, PO box 85500, 3584 CX Utrecht, the Netherlands
| | - Fernanda L Paganelli
- Department of Medical Microbiology, University Medical Center Utrecht, PO box 85500, 3584 CX Utrecht, the Netherlands
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Sangiorgio G, Calvo M, Migliorisi G, Campanile F, Stefani S. The Impact of Enterococcus spp. in the Immunocompromised Host: A Comprehensive Review. Pathogens 2024; 13:409. [PMID: 38787261 PMCID: PMC11124283 DOI: 10.3390/pathogens13050409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Revised: 05/05/2024] [Accepted: 05/14/2024] [Indexed: 05/25/2024] Open
Abstract
The immunocompromised host is usually vulnerable to infectious diseases due to broad-spectrum treatments and immunological dysregulation. The Enterococcus genus consists of normal gut commensals, which acquire a leading role in infective processes among individuals with compromised immune systems. These microorganisms may express a potential virulence and resistance spectrum, enabling their function as severe pathogens. The Enterococcus spp. infections in immunocompromised hosts appear to be difficult to resolve due to the immunological response impairment and the possibility of facing antimicrobial-resistant strains. As regards the related risk factors, several data demonstrated that prior antibiotic exposure, medical device insertion, prolonged hospitalization and surgical interventions may lead to Enterococcus overgrowth, antibiotic resistance and spread among critical healthcare settings. Herein, we present a comprehensive review of Enterococcus spp. in the immunocompromised host, summarizing the available knowledge about virulence factors, antimicrobial-resistance mechanisms and host-pathogen interaction. The review ultimately yearns for more substantial support to further investigations about enterococcal infections and immunocompromised host response.
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Affiliation(s)
- Giuseppe Sangiorgio
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via Santa Sofia 97, 95123 Catania, Italy; (F.C.); (S.S.)
| | - Maddalena Calvo
- U.O.C. Laboratory Analysis Unit, University Hospital Policlinico-San Marco, Via Santa Sofia 78, 95123 Catania, Italy; (M.C.); (G.M.)
| | - Giuseppe Migliorisi
- U.O.C. Laboratory Analysis Unit, University Hospital Policlinico-San Marco, Via Santa Sofia 78, 95123 Catania, Italy; (M.C.); (G.M.)
| | - Floriana Campanile
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via Santa Sofia 97, 95123 Catania, Italy; (F.C.); (S.S.)
| | - Stefania Stefani
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via Santa Sofia 97, 95123 Catania, Italy; (F.C.); (S.S.)
- U.O.C. Laboratory Analysis Unit, University Hospital Policlinico-San Marco, Via Santa Sofia 78, 95123 Catania, Italy; (M.C.); (G.M.)
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Grunnvåg JS, Hegstad K, Lentz CS. Activity-based protein profiling of serine hydrolases and penicillin-binding proteins in Enterococcus faecium. FEMS MICROBES 2024; 5:xtae015. [PMID: 38813097 PMCID: PMC11134295 DOI: 10.1093/femsmc/xtae015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/18/2024] [Accepted: 05/14/2024] [Indexed: 05/31/2024] Open
Abstract
Enterococcus faecium is a gut commensal bacterium which is gaining increasing relevance as an opportunistic, nosocomial pathogen. Its high level of intrinsic and acquired antimicrobial resistance is causing a lack of treatment options, particularly for infections with vancomycin-resistant strains, and prioritizes the identification and functional validation of novel druggable targets. Here, we use activity-based protein profiling (ABPP), a chemoproteomics approach using functionalized covalent inhibitors, to detect active serine hydrolases across 11 E. faecium and Enterococcus lactis strains. Serine hydrolases are a big and diverse enzyme family, that includes known drug targets such as penicillin-binding proteins (PBPs), whereas other subfamilies are underexplored. Comparative gel-based ABPP using Bocillin-FL revealed strain- and growth condition-dependent variations in PBP activities. Profiling with the broadly serine hydrolase-reactive fluorescent probe fluorophosphonate-TMR showed a high similarity across E. faecium clade A1 strains, but higher variation across A2 and E. lactis strains. To identify these serine hydrolases, we used a biotinylated probe analog allowing for enrichment and identification via liquid chromatography-mass spectrometry. We identified 11 largely uncharacterized targets (α,β-hydrolases, SGNH-hydrolases, phospholipases, and amidases, peptidases) that are druggable and accessible in live vancomycin-resistant E. faecium E745 and may possess vital functions that are to be characterized in future studies.
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Affiliation(s)
- Jeanette S Grunnvåg
- Research Group for Host-Microbe Interactions, Department of Medical Biology, UiT – The Arctic University of Norway, Postboks 6050 Langnes, 9037 Tromsø, Norway
- Centre for New Antibacterial Strategies (CANS), UiT – The Arctic University of Norway, Postboks 6050 Langnes, 9037 Tromsø, Norway
| | - Kristin Hegstad
- Research Group for Host-Microbe Interactions, Department of Medical Biology, UiT – The Arctic University of Norway, Postboks 6050 Langnes, 9037 Tromsø, Norway
- Centre for New Antibacterial Strategies (CANS), UiT – The Arctic University of Norway, Postboks 6050 Langnes, 9037 Tromsø, Norway
- Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, P.O. Box 56, 9038 Tromsø, Norway
| | - Christian S Lentz
- Research Group for Host-Microbe Interactions, Department of Medical Biology, UiT – The Arctic University of Norway, Postboks 6050 Langnes, 9037 Tromsø, Norway
- Centre for New Antibacterial Strategies (CANS), UiT – The Arctic University of Norway, Postboks 6050 Langnes, 9037 Tromsø, Norway
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Roer L, Kaya H, Tedim AP, Novais C, Coque TM, Aarestrup FM, Peixe L, Hasman H, Hammerum AM, Freitas AR. VirulenceFinder for Enterococcus faecium and Enterococcus lactis: an enhanced database for detection of putative virulence markers by using whole-genome sequencing data. Microbiol Spectr 2024; 12:e0372423. [PMID: 38329344 PMCID: PMC10913372 DOI: 10.1128/spectrum.03724-23] [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: 10/23/2023] [Accepted: 01/20/2024] [Indexed: 02/09/2024] Open
Abstract
Enterococcus faecium (Efm) is a leading cause of hospital-associated (HA) infections, often enriched in putative virulence markers (PVMs). Recently, the Efm clade B was assigned as Enterococcus lactis (Elts), which usually lack HA-Efm infection markers. Available databases for extracting PVM are incomplete and/or present an intermix of genes from Efm and Enterococcus faecalis, with distinct virulence profiles. In this study, we constructed a new database containing 27 PVMs [acm, scm, sgrA, ecbA, fnm, sagA, hylEfm, ptsD, orf1481, fms15, fms21-fms20 (pili gene cluster 1, PGC-1), fms14-fms17-fms13 (PGC-2), empA-empB-empC (PGC-3), fms11-fms19-fms16 (PGC-4), ccpA, bepA, gls20-glsB1, and gls33-glsB] from nine reference genomes (seven Efm + two Elts). The database was validated against these reference genomes and further evaluated using a collection of well-characterized Efm (n = 43) and Elts (n = 7) control strains, by assessing PVM presence/absence and its variants together with a genomic phylogeny constructed as single-nucleotide polymorphisms. We found a high concordance between the phylogeny and in silico findings of the PVM, with Elts clustering separately and mostly carrying Elts-specific PVM gene variants. Based on our validation results, we recommend using the database with raw reads instead of assemblies to avoid missing gene variants. This newly constructed database of 27 PVMs will enable a more comprehensive characterization of Efm and Elts based on WGS data. The developed database exhibits scalability and boasts a range of applications in public health, including diagnostics, outbreak investigations, and epidemiological studies. It can be further used in risk assessment for distinguishing between safe and unsafe enterococci.IMPORTANCEThe newly constructed database, consisting of 27 putative virulence markers, is highly scalable and serves as a valuable resource for the comprehensive characterization of these closely related species using WGS data. It holds significant potential for various public health applications, including hospital outbreak investigations, surveillance, and risk assessment for probiotics and feed additives.
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Affiliation(s)
- Louise Roer
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Hülya Kaya
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Ana P. Tedim
- Group for Biomedical Research in Sepsis (BioSepsis), Instituto de Investigación Biomédica de Salamanca, Salamanca, Spain
- Grupo de Investigación Biomédica en Sepsis-BioSepsis, Hospital Universitario Río Hortega, Instituto de Investigación Biomédica de Salamanca (IBSAL), Valladollid, Spain
| | - Carla Novais
- UCIBIO, Departamento de Ciências Biológicas, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
- Associate Laboratory i4HB, Faculty of Pharmacy, University of Porto, Institute for Health and Bioeconomy, Porto, Portugal
| | - Teresa M. Coque
- Department of Microbiology, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
- Network Research Centre for Infectious Diseases (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Frank M. Aarestrup
- Research Group for Genomic Epidemiology, Technical University of Denmark, National Food Institute, Lyngby, Denmark
| | - Luísa Peixe
- UCIBIO, Departamento de Ciências Biológicas, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
- Associate Laboratory i4HB, Faculty of Pharmacy, University of Porto, Institute for Health and Bioeconomy, Porto, Portugal
| | - Henrik Hasman
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Anette M. Hammerum
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Ana R. Freitas
- UCIBIO, Departamento de Ciências Biológicas, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
- Associate Laboratory i4HB, Faculty of Pharmacy, University of Porto, Institute for Health and Bioeconomy, Porto, Portugal
- 1H-TOXRUN—One Health Toxicology Research Unit, University Institute of Health Sciences, CESPU, CRL, Gandra, Portugal
| | - On behalf of the ESCMID Study Group for Epidemiological Markers (ESGEM)
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
- Group for Biomedical Research in Sepsis (BioSepsis), Instituto de Investigación Biomédica de Salamanca, Salamanca, Spain
- Grupo de Investigación Biomédica en Sepsis-BioSepsis, Hospital Universitario Río Hortega, Instituto de Investigación Biomédica de Salamanca (IBSAL), Valladollid, Spain
- UCIBIO, Departamento de Ciências Biológicas, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
- Associate Laboratory i4HB, Faculty of Pharmacy, University of Porto, Institute for Health and Bioeconomy, Porto, Portugal
- Department of Microbiology, Ramón y Cajal University Hospital and Ramón y Cajal Health Research Institute (IRYCIS), Madrid, Spain
- Network Research Centre for Infectious Diseases (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
- Research Group for Genomic Epidemiology, Technical University of Denmark, National Food Institute, Lyngby, Denmark
- 1H-TOXRUN—One Health Toxicology Research Unit, University Institute of Health Sciences, CESPU, CRL, Gandra, Portugal
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Rhoads DD, Pummill J, Alrubaye AAK. Molecular Genomic Analyses of Enterococcus cecorum from Sepsis Outbreaks in Broilers. Microorganisms 2024; 12:250. [PMID: 38399654 PMCID: PMC10892122 DOI: 10.3390/microorganisms12020250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/25/2024] Open
Abstract
Extensive genomic analyses of Enterococcus cecorum isolates from sepsis outbreaks in broilers suggest a polyphyletic origin, likely arising from core genome mutations rather than gene acquisition. This species is a normal intestinal flora of avian species with particular isolates associated with osteomyelitis. More recently, this species has been associated with sepsis outbreaks affecting broilers during the first 3 weeks post-hatch. Understanding the genetic and management basis of this new phenotype is critical for developing strategies to mitigate this emerging problem. Phylogenomic analyses of 227 genomes suggest that sepsis isolates are polyphyletic and closely related to both commensal and osteomyelitis isolate genomes. Pangenome analyses detect no gene acquisitions that distinguish all the sepsis isolates. Core genome single nucleotide polymorphism analyses have identified a number of mutations, affecting the protein-coding sequences, that are enriched in sepsis isolates. The analysis of the protein substitutions supports the mutational origins of sepsis isolates.
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Affiliation(s)
- Douglas D. Rhoads
- Program in Cell and Molecular Biology, University of Arkansas, Fayetteville, AR 72701, USA; (J.P.); (A.A.K.A.)
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
| | - Jeff Pummill
- Program in Cell and Molecular Biology, University of Arkansas, Fayetteville, AR 72701, USA; (J.P.); (A.A.K.A.)
- Arkansas High Performance Computing Center, University of Arkansas, Fayetteville, AR 72701, USA
| | - Adnan Ali Khalaf Alrubaye
- Program in Cell and Molecular Biology, University of Arkansas, Fayetteville, AR 72701, USA; (J.P.); (A.A.K.A.)
- Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
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Functional Genomics Identified Novel Genes Involved in Growth at Low Temperatures in Listeria monocytogenes. Microbiol Spectr 2022; 10:e0071022. [PMID: 35735974 PMCID: PMC9431668 DOI: 10.1128/spectrum.00710-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Listeria monocytogenes (Lm) is a foodborne pathogen that can cause severe human illness. Standard control measures for restricting bacterial growth, such as refrigeration, are often inadequate as Lm grows well at low temperatures. To identify genes involved in growth at low temperatures, a powerful functional genomics method Tn-seq was performed in this study. This genome-wide screening comprehensively identified the known and novel genetic determinants involved in low-temperature growth. A novel gene lmo1366, encoding rRNA methyltransferase, was identified to play an essential role in Lm growth at 16°C. In contrast, the inactivation of lmo2301, a gene encoding the terminase of phage A118, significantly enhanced the growth of Lm at 16°C. The deletion of lmo1366 or lmo2301 resulted in cell morphology alterations and impaired the growth rate in milk and other conditions at low temperatures. Transcriptomic analysis revealed that the Δlmo1366 and Δlmo2301 mutants exhibited altered transcriptional patterns compared to the wild-type strain at 16°C with significant differences in genes involved in ribosome structural stability and function, and membrane biogenesis, respectively. This work uncovered novel genetic determinants involved in Lm growth at 16°C, which could lead to a better understanding of how bacteria survive and multiply at low temperatures. Furthermore, these findings could potentially contribute to developing novel antibacterial strategies under low-temperature conditions. IMPORTANCEListeria monocytogenes is a Gram-positive pathogen that contributes to foodborne outbreaks due to its ability to survive at low temperatures. However, the genetic determinants of Lm involved in growth at low temperatures have not been fully defined. Here, the genetic determinants involved in the low-temperature growth of Lm were comprehensively identified on a genome-wide scale by Tn-seq. The gene lmo1366, encoding rRNA methyltransferase, was identified essential for growth under low-temperature conditions. On the other hand, the gene lmo2301, encoding terminase of phage A118, plays a negative role in bacterial growth at low temperatures. The transcriptomic analysis revealed the potential mechanisms. These findings lead to a better understanding of how bacteria survive and multiply at low temperatures and could provide unique targets for novel antibacterial strategies under low-temperature conditions.
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Regulation of Mannitol Metabolism in Enterococcus faecalis and Association with parEF0409 Toxin-Antitoxin Locus Function. J Bacteriol 2022; 204:e0004722. [PMID: 35404112 DOI: 10.1128/jb.00047-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The parEF0409 type I toxin-antitoxin locus is situated between genes for two paralogous mannitol family phosphoenolpyruvate phosphotransferase systems (PTSs). In order to address the possibility that parEF0409 function was associated with sugar metabolism, genetic and phenotypic analyses were performed on the flanking genes. It was found that the genes were transcribed as two operons: the downstream operon essential for mannitol transport and metabolism and the upstream operon performing a regulatory function. In addition to genes for the PTS components, the upstream operon harbors a gene similar to mtlR, the key regulator of mannitol metabolism in other Gram-positive bacteria. We confirmed that this gene is essential for the regulation of the downstream operon and identified putative phosphorylation sites required for carbon catabolite repression and mannitol-specific regulation. Genomic comparisons revealed that this dual-operon organization of mannitol utilization genes is uncommon in enterococci and that the association with a toxin-antitoxin system is unique to Enterococcus faecalis. Finally, we consider possible links between parEF0409 function and mannitol utilization. IMPORTANCE Enterococcus faecalis is both a common member of the human gut microbiota and an opportunistic pathogen. Its evolutionary success is partially due to its metabolic flexibility, in particular its ability to import and metabolize a wide variety of sugars. While a large number of phosphoenolpyruvate phosphotransferase sugar transport systems have been identified in the E. faecalis genome bioinformatically, the specificity and regulation of most of these systems remain undetermined. Here, we characterize a complex system of two operons flanking a type I toxin-antitoxin system required for the transport and metabolism of the common dietary sugar mannitol. We also determine the phylogenetic distribution of mannitol utilization genes in the enterococcal genus and discuss the significance of the association with toxin-antitoxin systems.
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Chen Z, Xiong Y, Tang Y, Zhao Y, Chen J, Zheng J, Wu Y, Deng Q, Qu D, Yu Z. In vitro activities of thiazolidione derivatives combined with daptomycin against clinical Enterococcus faecium strains. BMC Microbiol 2022; 22:16. [PMID: 34996348 PMCID: PMC8740470 DOI: 10.1186/s12866-021-02423-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 12/06/2021] [Indexed: 11/19/2022] Open
Abstract
Background Previous reports have demonstrated two thiazolidione derivatives (H2-60 and H2-81) can robustly inhibit the planktonic growth and biofilm formation of S. epidermidis and S. aureus by targeting the histidine kinase YycG. Whereas the antibacterial and anti-biofilm activity of these two thiazolidione derivatives (H2-60 and H2-81) against Enterococcus faecium remains elusive. Here, the pET28a-YycG recombinant plasmid were in vitro expressed in E. coli competent cell BL21 (DE3) and induced to express YycG’ protein (conding HisKA and HATPase_c domain) by 0.5 mM IPTG and was purified by Ni – NTA agarose and then for the autophosphorylation test. Antimicrobial testing and time-killing assay were also be determined. Anti-biofilm activity of two derivatives with sub-MIC concentration towards positive biofilm producers of clinical E. faecium were detected using polystyrene microtiter plate and CLSM. Results The MICs of H2-60 and H2-81 in the clinical isolates of E. faecium were in the range from 3.125 mg/L to 25 mg/L. Moreover, either H2-60 or H2-81 showed the excellent bactericidal activity against E. faecium with monotherapy or its combination with daptomycin by time-killing assay. E. faecium planktonic cells can be decreased by H2-60 or H2-81 for more than 3 × log10 CFU/mL after 24 h treatment when combined with daptomycin. Furthermore, over 90% of E. faecium biofilm formation could markedly be inhibited by H2-60 and H2-81 at 1/4 × MIC value. In addition, the frequency of the eradicated viable cells embedded in mature biofilm were evaluated by the confocal laser microscopy, suggesting that of H2-60 combined with ampicillin or daptomycin was significantly high when compared with single treatment (78.17 and 74.48% vs. 41.59%, respectively, P < 0.01). Conclusion These two thiazolidione derivatives (H2-60 and H2-81) could directly impact the kinase phosphoration activity of YycG of E. faecium. H2-60 combined with daptomycin exhibit the excellent antibacterial and anti-biofilm activity against E. faecium by targeting YycG. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02423-8.
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Affiliation(s)
- Zhong Chen
- Department of Infectious Diseases and the Key Lab of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, 518052, China.,Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Department of Medical Microbiology and Parasitology, School of Basic Medical Science and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Yanpeng Xiong
- Department of Infectious Diseases and the Key Lab of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, 518052, China
| | - Yuanyuan Tang
- Department of Infectious Diseases and the Key Lab of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, 518052, China
| | - Yuxi Zhao
- Department of Infectious Diseases and the Key Lab of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, 518052, China
| | - Junwen Chen
- Department of Infectious Diseases and the Key Lab of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, 518052, China
| | - Jinxin Zheng
- Department of Infectious Diseases and the Key Lab of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, 518052, China
| | - Yang Wu
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Department of Medical Microbiology and Parasitology, School of Basic Medical Science and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Qiwen Deng
- Department of Infectious Diseases and the Key Lab of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, 518052, China
| | - Di Qu
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Department of Medical Microbiology and Parasitology, School of Basic Medical Science and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, China.
| | - Zhijian Yu
- Department of Infectious Diseases and the Key Lab of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, 518052, China.
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11
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Goodarzi F, Hallajzadeh M, Sholeh M, Talebi M, Mahabadi VP, Amirmozafari N. Biological characteristics and anti-biofilm activity of a lytic phage against vancomycin-resistant Enterococcus faecium. IRANIAN JOURNAL OF MICROBIOLOGY 2021; 13:691-702. [PMID: 34900167 PMCID: PMC8629820 DOI: 10.18502/ijm.v13i5.7436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND OBJECTIVES An important leading cause of the emergence of vancomycin-resistant enterococci, especially Enterococcus faecium, is the inefficiency of antibiotics in the elimination of drug-resistant pathogens. Consequently, the need for alternative treatments is more necessary than ever. MATERIALS AND METHODS A highly effective bacteriophage against vancomycin-resistant E. faecium called vB-EfmS-S2 was isolated from hospital sewage. The biological properties of phage S2 and its effect on biofilm structures were determined. RESULTS Phage S2 was specifically capable of lysing a wide range of clinical E. faecium isolates. According to Electron microscopy observations, the phage S2 belonged to the Siphoviridea family. Suitable pH spectra for phage survival was 5-11, at which the phage showed 100% activity. The optimal temperature for phage growth was 30-45°C, with the highest growth at 37°C. Based on one-step growth curve results, the latent period of phage S2 was 14 min with a burst size of 200 PFU/ml. The phage S2 was also able to tolerate bile at concentrations of 1 and 2% and required Mg2+ for an effective infection cycle. Biofilms were significantly inhibited and disrupted in the presence of the phage. CONCLUSION According to the results, phage S2 could potentially be an alternative for the elimination and control of vancomycin-resistant E. faecium biofilm.
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Affiliation(s)
- Forough Goodarzi
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Masoumeh Hallajzadeh
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Sholeh
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Malihe Talebi
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Vahid Pirhajati Mahabadi
- Neuroscience Research Center, Iran University of Medical Sciences, Tehran, Iran
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Nour Amirmozafari
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
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12
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Top J, Baan J, Bisschop A, Arredondo-Alonso S, van Schaik W, Willems RJL. Functional characterization of a gene cluster responsible for inositol catabolism associated with hospital-adapted isolates of Enterococcus faecium. MICROBIOLOGY-SGM 2021; 167. [PMID: 34491894 DOI: 10.1099/mic.0.001085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Enterococcus faecium is a nosocomial, multidrug-resistant pathogen. Whole genome sequence studies revealed that hospital-associated E. faecium isolates are clustered in a separate clade A1. Here, we investigated the distribution, integration site and function of a putative iol gene cluster that encodes for myo-inositol (MI) catabolism. This iol gene cluster was found as part of an ~20 kbp genetic element (iol element), integrated in ICEEfm1 close to its integrase gene in E. faecium isolate E1679. Among 1644 E. faecium isolates, ICEEfm1 was found in 789/1227 (64.3 %) clade A1 and 3/417 (0.7 %) non-clade A1 isolates. The iol element was present at a similar integration site in 180/792 (22.7 %) ICEEfm1-containing isolates. Examination of the phylogenetic tree revealed genetically closely related isolates that differed in presence/absence of ICEEfm1 and/or iol element, suggesting either independent acquisition or loss of both elements. E. faecium iol gene cluster containing isolates E1679 and E1504 were able to grow in minimal medium with only myo-inositol as carbon source, while the iolD-deficient mutant in E1504 (E1504∆iolD) lost this ability and an iol gene cluster negative recipient strain gained this ability after acquisition of ICEEfm1 by conjugation from donor strain E1679. Gene expression profiling revealed that the iol gene cluster is only expressed in the absence of other carbon sources. In an intestinal colonization mouse model the colonization ability of E1504∆iolD mutant was not affected relative to the wild-type E1504 strain. In conclusion, we describe and functionally characterise a gene cluster involved in MI catabolism that is associated with the ICEEfm1 island in hospital-associated E. faecium isolates. We were unable to show that this gene cluster provides a competitive advantage during gut colonisation in a mouse model. Therefore, to what extent this gene cluster contributes to the spread and ecological specialisation of ICEEfm1-carrying hospital-associated isolates remains to be investigated.
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Affiliation(s)
- Janetta Top
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jery Baan
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Adinda Bisschop
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Sergio Arredondo-Alonso
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Willem van Schaik
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.,Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Rob J L Willems
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
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13
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de Maat V, Arredondo-Alonso S, Willems RJL, van Schaik W. Conditionally essential genes for survival during starvation in Enterococcus faecium E745. BMC Genomics 2020; 21:568. [PMID: 32811437 PMCID: PMC7437932 DOI: 10.1186/s12864-020-06984-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 08/12/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND The nosocomial pathogen Enterococcus faecium can survive for prolonged periods of time on surfaces in the absence of nutrients. This trait is thought to contribute to the ability of E. faecium to spread among patients in hospitals. There is currently a lack of data on the mechanisms that are responsible for the ability of E. faecium to survive in the absence of nutrients. RESULTS We performed a high-throughput transposon mutant library screening (Tn-seq) to identify genes that have a role in long-term survival during incubation in phosphate-buffered saline (PBS) at 20 °C. A total of 24 genes were identified by Tn-seq to contribute to survival in PBS, with functions associated with the general stress response, DNA repair, metabolism, and membrane homeostasis. The gene which was quantitatively most important for survival in PBS was usp (locus tag: EfmE745_02439), which is predicted to encode a 17.4 kDa universal stress protein. After generating a targeted deletion mutant in usp, we were able to confirm that usp significantly contributes to survival in PBS and this defect was restored by in trans complementation. The usp gene is present in 99% of a set of 1644 E. faecium genomes that collectively span the diversity of the species. CONCLUSIONS We postulate that usp is a key determinant for the remarkable environmental robustness of E. faecium. Further mechanistic studies into usp and other genes identified in this study may shed further light on the mechanisms by which E. faecium can survive in the absence of nutrients for prolonged periods of time.
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Affiliation(s)
- Vincent de Maat
- Department of Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands
| | - Sergio Arredondo-Alonso
- Department of Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands
| | - Rob J L Willems
- Department of Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands
| | - Willem van Schaik
- Department of Medical Microbiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands. .,Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
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14
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Sanchez-Herrero JF, Bernabeu M, Prieto A, Hüttener M, Juárez A. Gene Duplications in the Genomes of Staphylococci and Enterococci. Front Mol Biosci 2020; 7:160. [PMID: 32850954 PMCID: PMC7396535 DOI: 10.3389/fmolb.2020.00160] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 06/24/2020] [Indexed: 12/28/2022] Open
Abstract
Gene duplications are a feature of bacterial genomes. In the present work we analyze the extent of gene duplications in the genomes of three microorganisms that belong to the Firmicutes phylum and that are etiologic agents of several nosocomial infections: Staphylococcus aureus, Enterococcus faecium, and Enterococcus faecalis. In all three groups, there is an irregular distribution of duplications in the genomes of the strains analyzed. Whereas in some of the strains duplications are scarce, hundreds of duplications are present in others. In all three species, mobile DNA accounts for a large percentage of the duplicated genes: phage DNA in S. aureus, and plasmid DNA in the enterococci. Duplicates also include core genes. In all three species, a reduced group of genes is duplicated in all strains analyzed. Duplication of the deoC and rpmG genes is a hallmark of S. aureus genomes. Duplication of the gene encoding the PTS IIB subunit is detected in all enterococci genomes. In E. faecalis it is remarkable that the genomes of some strains encode duplicates of the prgB and prgU genes. They belong to the prgABCU cluster, which responds to the presence of the peptide pheromone cCF10 by expressing the surface adhesins PrgA, PrgB, and PrgC.
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Affiliation(s)
- José Francisco Sanchez-Herrero
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Spain.,Biodiversity Research Institute (IRBio), University of Barcelona, Barcelona, Spain.,High Content Genomics and Bioinformatics Unit, Germans Trias i Pujol Research Institute (IGTP), Campus Can Ruti, Badalona, Spain
| | - Manuel Bernabeu
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Spain
| | - Alejandro Prieto
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Spain
| | - Mário Hüttener
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Spain
| | - Antonio Juárez
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Spain.,Institute for Bioengineering of Catalonia, The Barcelona Institute of Science and Technology, Barcelona, Spain
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15
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Devaux CA, Million M, Raoult D. The Butyrogenic and Lactic Bacteria of the Gut Microbiota Determine the Outcome of Allogenic Hematopoietic Cell Transplant. Front Microbiol 2020; 11:1642. [PMID: 32793150 PMCID: PMC7387665 DOI: 10.3389/fmicb.2020.01642] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/24/2020] [Indexed: 12/12/2022] Open
Abstract
Graft versus host disease (GVHD) is a post-transplant pathology in which donor-derived T cells present in the Peyer's patches target the cell-surface alloantigens of the recipient, causing host tissue damages. Therefore, the GVHD has long been considered only a purely immunological process whose prevention requires an immunosuppressive treatment. However, since the early 2010s, the impact of gut microbiota on GVHD has received increased attention. Both a surprising fall in gut microbiota diversity and a shift toward Enterobacteriaceae were described in this disease. Recently, unexpected results were reported that further link GVHD with changes in bacterial composition in the gut and disruption of intestinal epithelial tight junctions leading to abnormal intestinal barrier permeability. Patients receiving allogenic hematopoietic stem cell transplant (allo-HCT) as treatment of hematologic malignancies showed a decrease of the overall diversity of the gut microbiota that affects Clostridia and Blautia spp. and a predominance of lactic acid bacteria (LAB) of the Enterococcus genus, in particular the lactose auxotroph Enterococcus faecium. The reduced microbiota diversity (likely including Actinobacteria, such as Bifidobacterium adolescentis that cross feed butyrogenic bacteria) deprives the butyrogenic bacteria (such as Roseburia intestinalis or Eubacterium) of their capacity to metabolize acetate to butyrate. Indeed, administration of butyrate protects against the GVHD. Here, we review the data highlighting the possible link between GVHD and lactase defect, accumulation of lactose in the gut lumen, reduction of Reg3 antimicrobial peptides, narrower enzyme equipment of bacteria that predominate post-transplant, proliferation of En. faecium that use lactose as metabolic fuels, induction of innate and adaptive immune response against these bacteria which maintains an inflammatory process, elevated expression of myosin light chain kinase 210 (MLCK210) and subsequent disruption of intestinal barrier, and translocation of microbial products (lactate) or transmigration of LAB within the liver. The analysis of data from the literature confirms that the gut microbiota plays a major role in the GVHD. Moreover, the most recent publications uncover that the LAB, butyrogenic bacteria and bacterial cross feeding were the missing pieces in the puzzle. This opens new bacteria-based strategies in the treatment of GVHD.
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Affiliation(s)
- Christian Albert Devaux
- Aix-Marseille Univ, IRD, APHM, MEPHI, IHU-Méditerranée Infection, Marseille, France
- Centre National de la Recherche Scientifique (CNRS), Marseille, France
| | - Matthieu Million
- Aix-Marseille Univ, IRD, APHM, MEPHI, IHU-Méditerranée Infection, Marseille, France
| | - Didier Raoult
- Aix-Marseille Univ, IRD, APHM, MEPHI, IHU-Méditerranée Infection, Marseille, France
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16
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Risks associated with enterococci as probiotics. Food Res Int 2019; 129:108788. [PMID: 32036912 DOI: 10.1016/j.foodres.2019.108788] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/07/2019] [Accepted: 10/29/2019] [Indexed: 01/01/2023]
Abstract
Probiotics are naturally occurring microorganisms that confer health benefits by altering host commensal microbiota, modulating immunity, enhancing intestinal barrier function, or altering pain perception. Enterococci are human and animal intestinal commensals that are used as probiotics and in food production. These microorganisms, however, express many virulence traits including cytolysin, proteases, aggregation substance, capsular polysaccharide, enterococcal surface protein, biofilm formation, extracellular superoxide, intestinal translocation, and resistance to innate immunity that can lead to serious hospital-acquired infections. In addition, enterococci are facile in acquiring antibiotic resistance genes to many clinically important antibiotics encoded on a wide variety of conjugative plasmids, transposons, and bacteriophages. The pathogenicity and disease burden caused by enterococci render them poor choices as probiotics. No large, randomized, placebo-controlled clinical trials have demonstrated the safety and efficacy of any enterococcal probiotic. As a result, no enterococcal probiotic has been approved by the United States Food and Drug Administration for the treatment, cure, or amelioration of human disease. In 2007, the European Food Safety Authority concluded that enterococci do not meet the standard for "Qualified Presumption of Safety". Enterococcal strains used or proposed for use as probiotics should be carefully screened for efficacy and safety.
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17
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Lee RS, Gonçalves da Silva A, Baines SL, Strachan J, Ballard S, Carter GP, Kwong JC, Schultz MB, Bulach DM, Seemann T, Stinear TP, Howden BP. The changing landscape of vancomycin-resistant Enterococcus faecium in Australia: a population-level genomic study. J Antimicrob Chemother 2019; 73:3268-3278. [PMID: 30189014 DOI: 10.1093/jac/dky331] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/23/2018] [Indexed: 12/17/2022] Open
Abstract
Background Vancomycin-resistant Enterococcus faecium (VREfm) represent a major source of nosocomial infection worldwide. In Australia, there has been a recent concerning increase in bacteraemia associated with the vanA genotype, prompting investigation into the genomic epidemiology of VREfm. Methods A population-level study of VREfm (10 November-9 December 2015) was conducted. A total of 321 VREfm isolates (from 286 patients) across Victoria State were collected and sequenced with Illumina NextSeq. SNPs were used to assess relatedness. STs and genes associated with resistance and virulence were identified. The vanA-harbouring plasmid from an isolate from each ST was assembled using long-read data. Illumina reads from remaining isolates were then mapped to these assemblies to identify their probable vanA-harbouring plasmid. Results vanA-VREfm comprised 17.8% of isolates. ST203, ST80 and a pstS(-) clade, ST1421, predominated (30.5%, 30.5% and 37.2%, respectively). Most vanB-VREfm were ST796 (77.7%). vanA-VREfm were more closely related within hospitals versus between them [core SNPs 10 (IQR 1-357) versus 356 (179-416), respectively], suggesting discrete introductions of vanA-VREfm, with subsequent intra-hospital transmission. In contrast, vanB-VREfm had similar core SNP distributions within versus between hospitals, due to widespread dissemination of ST796. Different vanA-harbouring plasmids were found across STs. With the exception of ST78 and ST796, Tn1546 transposons also varied. Phylogenetic analysis revealed Australian strains were often interspersed with those from other countries, suggesting ongoing cross-continental transmission. Conclusions Emerging vanA-VREfm in Australia is polyclonal, indicating repeat introductions of vanA-VREfm into hospitals and subsequent dissemination. The close relationship to global strains reinforces the need for ongoing screening and control of VREfm in Australia and abroad.
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Affiliation(s)
- Robyn S Lee
- The Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Level 1, Melbourne, Victoria, Australia.,Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T. H. Chan School of Public Health, 677 Huntington Avenue, Level 5, Boston, MA, USA
| | - Anders Gonçalves da Silva
- The Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Level 1, Melbourne, Victoria, Australia
| | - Sarah L Baines
- Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Level 1, Melbourne, Victoria, Australia
| | - Janet Strachan
- The Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Level 1, Melbourne, Victoria, Australia
| | - Susan Ballard
- The Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Level 1, Melbourne, Victoria, Australia
| | - Glen P Carter
- The Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Level 1, Melbourne, Victoria, Australia
| | - Jason C Kwong
- Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Level 1, Melbourne, Victoria, Australia
| | - Mark B Schultz
- The Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Level 1, Melbourne, Victoria, Australia
| | - Dieter M Bulach
- The Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Level 1, Melbourne, Victoria, Australia
| | - Torsten Seemann
- Melbourne Bioinformatics Group, Lab-14, 700 Swanston Street, Carlton, Victoria, Australia
| | - Timothy P Stinear
- Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Level 1, Melbourne, Victoria, Australia
| | - Benjamin P Howden
- The Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, 792 Elizabeth Street, Level 1, Melbourne, Victoria, Australia.,Infectious Diseases Department, Austin Health, Studley Rd, Heidelberg, Victoria, Australia
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18
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Grand M, Aubourg M, Pikis A, Thompson J, Deutscher J, Hartke A, Sauvageot N. Characterization of the gen locus involved in β-1,6-oligosaccharide utilization by Enterococcus faecalis. Mol Microbiol 2019; 112:1744-1756. [PMID: 31529727 DOI: 10.1111/mmi.14390] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2019] [Indexed: 11/30/2022]
Abstract
The bicistronic genBA operon (formerly named celBA) of the opportunistic pathogen Enterococcus faecalis, encodes a 6-phospho-β-glucosidase (GenA) and a phosphotransferase system permease EIIC (GenB). It resembles the cel operon of Streptococcus pyogenes, which is implicated in the metabolism of cellobiose. However, genBA mutants grew normally on cellobiose, but not (genA) or only slowly (genB) on gentiobiose and amygdalin. The two glucosides were also found to be the main inducers of the operon, confirming that the encoded proteins are involved in the utilization of β-1,6- rather than β-1,4-linked oligosaccharides. Expression of the genBA operon is regulated by the transcriptional activator GenR, which is encoded by the gene upstream from genB. Thermal shift analysis showed that it binds gentiobiose-6'-P with a Kd of 0.04 mM and with lower affinity also other phospho-sugars. The GenR/gentiobiose-6'-P complex binds to the promoter region upstream from genB. The genBA promoter region contains a cre box and gel-shift experiments demonstrated that the operon is under negative control of the global carbon catabolite regulator CcpA. We also show that the orphan EIIC (GenB) protein needs the EIIA component of the putative OG1RF_10750-OG1RF_10755 operon situated elsewhere on the chromosome to form a functional PTS transporter.
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Affiliation(s)
- Maxime Grand
- Normandie Univ, UNICAEN, U2RM Stress/Virulence, Caen, 14000, France
| | - Marion Aubourg
- Normandie Univ, UNICAEN, U2RM Antibio-résistance et Pathologies équines, Caen, 14000, France
| | - Andreas Pikis
- Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA.,Microbial Biochemistry and Genetics Unit, Laboratory of Cell and Developmental Biology, NIDCR, National Institutes of Health, Bethesda, MD, 20892, USA
| | - John Thompson
- Microbial Biochemistry and Genetics Unit, Laboratory of Cell and Developmental Biology, NIDCR, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Josef Deutscher
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France.,UMR 8261, CNRS, Université Paris VII, Institut de Biologie Physico-Chimique, 75005, Paris, France
| | - Axel Hartke
- Normandie Univ, UNICAEN, U2RM Stress/Virulence, Caen, 14000, France
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19
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Pidot SJ, Gao W, Buultjens AH, Monk IR, Guerillot R, Carter GP, Lee JYH, Lam MMC, Grayson ML, Ballard SA, Mahony AA, Grabsch EA, Kotsanas D, Korman TM, Coombs GW, Robinson JO, Gonçalves da Silva A, Seemann T, Howden BP, Johnson PDR, Stinear TP. Increasing tolerance of hospital Enterococcus faecium to handwash alcohols. Sci Transl Med 2019; 10:10/452/eaar6115. [PMID: 30068573 DOI: 10.1126/scitranslmed.aar6115] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 02/10/2018] [Accepted: 04/03/2018] [Indexed: 11/03/2022]
Abstract
Alcohol-based disinfectants and particularly hand rubs are a key way to control hospital infections worldwide. Such disinfectants restrict transmission of pathogens, such as multidrug-resistant Staphylococcus aureus and Enterococcus faecium Despite this success, health care infections caused by E. faecium are increasing. We tested alcohol tolerance of 139 hospital isolates of E. faecium obtained between 1997 and 2015 and found that E. faecium isolates after 2010 were 10-fold more tolerant to killing by alcohol than were older isolates. Using a mouse gut colonization model of E. faecium transmission, we showed that alcohol-tolerant E. faecium resisted standard 70% isopropanol surface disinfection, resulting in greater mouse gut colonization compared to alcohol-sensitive E. faecium We next looked for bacterial genomic signatures of adaptation. Alcohol-tolerant E. faecium accumulated mutations in genes involved in carbohydrate uptake and metabolism. Mutagenesis confirmed the roles of these genes in the tolerance of E. faecium to isopropanol. These findings suggest that bacterial adaptation is complicating infection control recommendations, necessitating additional procedures to prevent E. faecium from spreading in hospital settings.
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Affiliation(s)
- Sacha J Pidot
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Wei Gao
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Andrew H Buultjens
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Ian R Monk
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Romain Guerillot
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Glen P Carter
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Jean Y H Lee
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Margaret M C Lam
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - M Lindsay Grayson
- Infectious Diseases Department, Austin Health, Heidelberg, Victoria 3084, Australia.,Department of Medicine, University of Melbourne, Heidelberg, Victoria 3084, Australia.,Department of Epidemiology and Preventive Medicine, Monash University, Victoria 3800, Australia
| | - Susan A Ballard
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Andrew A Mahony
- Infectious Diseases Department, Austin Health, Heidelberg, Victoria 3084, Australia
| | - Elizabeth A Grabsch
- Infectious Diseases Department, Austin Health, Heidelberg, Victoria 3084, Australia
| | - Despina Kotsanas
- Monash Infectious Diseases, Monash Health, Clayton, Victoria 3168, Australia
| | - Tony M Korman
- Monash Infectious Diseases, Monash Health, Clayton, Victoria 3168, Australia
| | - Geoffrey W Coombs
- Antimicrobial Resistance and Infectious Diseases Research Laboratory, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia.,Department of Microbiology, PathWest Laboratory Medicine WA, Fiona Stanley Hospital, Murdoch, Western Australia 6150, Australia
| | - J Owen Robinson
- Antimicrobial Resistance and Infectious Diseases Research Laboratory, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia.,Department of Microbiology, PathWest Laboratory Medicine WA, Fiona Stanley Hospital, Murdoch, Western Australia 6150, Australia
| | - Anders Gonçalves da Silva
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Torsten Seemann
- Melbourne Bioinformatics, University of Melbourne, Carlton, Victoria 3053, Australia
| | - Benjamin P Howden
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia.,Infectious Diseases Department, Austin Health, Heidelberg, Victoria 3084, Australia.,Department of Medicine, University of Melbourne, Heidelberg, Victoria 3084, Australia.,Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Paul D R Johnson
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia. .,Infectious Diseases Department, Austin Health, Heidelberg, Victoria 3084, Australia.,Department of Medicine, University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Timothy P Stinear
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia.
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20
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Fiore E, Van Tyne D, Gilmore MS. Pathogenicity of Enterococci. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0053-2018. [PMID: 31298205 PMCID: PMC6629438 DOI: 10.1128/microbiolspec.gpp3-0053-2018] [Citation(s) in RCA: 208] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Indexed: 12/19/2022] Open
Abstract
Enterococci are unusually well adapted for survival and persistence in a variety of adverse environments, including on inanimate surfaces in the hospital environment and at sites of infection. This intrinsic ruggedness undoubtedly played a role in providing opportunities for enterococci to interact with other overtly drug-resistant microbes and acquire additional resistances on mobile elements. The rapid rise of antimicrobial resistance among hospital-adapted enterococci has rendered hospital-acquired infections a leading therapeutic challenge. With about a quarter of a genome of additional DNA conveyed by mobile elements, there are undoubtedly many more properties that have been acquired that help enterococci persist and spread in the hospital setting and cause diseases that have yet to be defined. Much remains to be learned about these ancient and rugged microbes, particularly in the area of pathogenic mechanisms involved with human diseases.
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Affiliation(s)
- Elizabeth Fiore
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
| | - Daria Van Tyne
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
| | - Michael S Gilmore
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
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21
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Detection and characterization of bacterial polysaccharides in drug-resistant enterococci. Glycoconj J 2019; 36:429-438. [PMID: 31230165 DOI: 10.1007/s10719-019-09881-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 03/18/2019] [Accepted: 06/17/2019] [Indexed: 01/26/2023]
Abstract
Enterococcus faecium (E. faecium) has emerged as one of today's leading causes of health care-associated infections that is difficult to treat with the available antibiotics. These pathogens produce capsular polysaccharides on the cell surface which play a significant role in adhesion, virulence and evasion. Therefore, we aimed at the identification and characterization of bacterial polysaccharide antigens which are central for the development of vaccine-based prophylactic approaches. The crude cell wall-associated polysaccharides from E. faecium, its mutant and complemented strains were purified and analyzed by a primary antibody raised against lipoteichoic acid (LTA) and diheteroglycan (DHG). The resistant E. faecium strains presumably possess novel capsular polysaccharides that allow them to avoid the evasion from opsonic killing. The E. faecium U0317 strain was very well opsonized by anti-U0317 (~95%), an antibody against the whole bacterial cell. The deletion mutant showed a significantly increased susceptibility to opsonophagocytic killing (90-95%) against the penicillin binding protein (anti-PBP-5). By comparison, in a mouse urinary tract and rat endocarditis infection model, respectively, there were no significant differences in virulence. In this study we explored the biological role of the capsule of E. faecium. Our findings showed that the U0317 strain is not only sensitive to anti-LTA but also to antibodies against other enterococcal surface proteins. Our findings demonstrate that polysaccharides capsule mediated-resistance to opsonophagocytosis. We also found that the capsular polysaccharides do not play an important role in bacterial virulence in urinary tract and infective endocarditis in vivo models.
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22
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Abstract
The genus Enterococcus comprises a ubiquitous group of Gram-positive bacteria that are of great relevance to human health for their role as major causative agents of health care-associated infections. The enterococci are resilient and versatile species able to survive under harsh conditions, making them well adapted to the health care environment. Two species cause the majority of enterococcal infections: Enterococcus faecalis and Enterococcus faecium Both species demonstrate intrinsic resistance to common antibiotics, such as virtually all cephalosporins, aminoglycosides, clindamycin, and trimethoprim-sulfamethoxazole. Additionally, a remarkably plastic genome allows these two species to readily acquire resistance to further antibiotics, such as high-level aminoglycoside resistance, high-level ampicillin resistance, and vancomycin resistance, either through mutation or by horizontal transfer of genetic elements conferring resistance determinants.
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Affiliation(s)
- Mónica García-Solache
- Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Louis B Rice
- Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
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23
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Enterococcus faecium TIR-Domain Genes Are Part of a Gene Cluster Which Promotes Bacterial Survival in Blood. Int J Microbiol 2019; 2018:1435820. [PMID: 30631364 PMCID: PMC6304867 DOI: 10.1155/2018/1435820] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/14/2018] [Indexed: 11/29/2022] Open
Abstract
Enterococcus faecium has undergone a transition to a multidrug-resistant nosocomial pathogen. The population structure of E. faecium is characterized by a sharp distinction of clades, where the hospital-adapted lineage is primarily responsible for bacteremia. So far, factors that were identified in hospital-adapted strains and that promoted pathogenesis of nosocomial E. faecium mainly play a role in adherence and biofilm production, while less is known about factors contributing to survival in blood. This study identified a gene cluster, which includes genes encoding bacterial Toll/interleukin-1 receptor- (TIR-) domain-containing proteins (TirEs). The cluster was found to be unique to nosocomial strains and to be located on a putative mobile genetic element of phage origin. The three genes within the cluster appeared to be expressed as an operon. Expression was detected in bacterial culture media and in the presence of human blood. TirEs are released into the bacterial supernatant, and TirE2 is associated with membrane vesicles. Furthermore, the tirE-gene cluster promotes bacterial proliferation in human blood, indicating that TirE may contribute to the pathogenesis of bacteremia.
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24
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Abstract
Enterococcus faecium has a highly variable genome prone to recombination and horizontal gene transfer. Here, we have identified a novel genetic island with an insertion locus and mobilization genes similar to those of staphylococcus cassette chromosome elements SCCmec This novel element termed the enterococcus cassette chromosome (ECC) element was located in the 3' region of rlmH and encoded large serine recombinases ccrAB similar to SCCmec Horizontal transfer of an ECC element termed ECC::cat containing a knock-in cat chloramphenicol resistance determinant occurred in the presence of a conjugative rep pLG1 plasmid. We determined the ECC::cat insertion site in the 3' region of rlmH in the E. faecium recipient by long-read sequencing. ECC::cat also mobilized by homologous recombination through sequence identity between flanking insertion sequence (IS) elements in ECC::cat and the conjugative plasmid. The ccrABEnt genes were found in 69 of 516 E. faecium genomes in GenBank. Full-length ECC elements were retrieved from 32 of these genomes. ECCs were flanked by attR and attL sites of approximately 50 bp. The attECC sequences were found by PCR and sequencing of circularized ECCs in three strains. The genes in ECCs contained an amalgam of common and rare E. faecium genes. Taken together, our data imply that ECC elements act as hot spots for genetic exchange and contribute to the large variation of accessory genes found in E. faecium IMPORTANCE Enterococcus faecium is a bacterium found in a great variety of environments, ranging from the clinic as a nosocomial pathogen to natural habitats such as mammalian intestines, water, and soil. They are known to exchange genetic material through horizontal gene transfer and recombination, leading to great variability of accessory genes and aiding environmental adaptation. Identifying mobile genetic elements causing sequence variation is important to understand how genetic content variation occurs. Here, a novel genetic island, the enterococcus cassette chromosome, is shown to contain a wealth of genes, which may aid E. faecium in adapting to new environments. The transmission mechanism involves the only two conserved genes within ECC, ccrAB Ent, large serine recombinases that insert ECC into the host genome similarly to SCC elements found in staphylococci.
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25
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Enterococcus faecium produces membrane vesicles containing virulence factors and antimicrobial resistance related proteins. J Proteomics 2018; 187:28-38. [DOI: 10.1016/j.jprot.2018.05.017] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/25/2018] [Accepted: 05/29/2018] [Indexed: 11/19/2022]
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26
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Group IIA-Secreted Phospholipase A 2 in Human Serum Kills Commensal but Not Clinical Enterococcus faecium Isolates. Infect Immun 2018; 86:IAI.00180-18. [PMID: 29784864 DOI: 10.1128/iai.00180-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 05/18/2018] [Indexed: 11/20/2022] Open
Abstract
Human innate immunity employs cellular and humoral mechanisms to facilitate rapid killing of invading bacteria. The direct killing of bacteria by human serum is attributed mainly to the activity of the complement system, which forms pores in Gram-negative bacteria. Although Gram-positive bacteria are considered resistant to killing by serum, we uncover here that normal human serum effectively kills Enterococcus faecium Comparison of a well-characterized collection of commensal and clinical E. faecium isolates revealed that human serum specifically kills commensal E. faecium strains isolated from normal gut microbiota but not clinical isolates. Inhibitor studies show that the human group IIA secreted phospholipase A2 (hGIIA), but not complement, is responsible for killing of commensal E. faecium strains in human normal serum. This is remarkable since the hGIIA concentration in "noninflamed" serum was considered too low to be bactericidal against Gram-positive bacteria. Mechanistic studies showed that serum hGIIA specifically causes permeabilization of commensal E. faecium membranes. Altogether, we find that a normal concentration of hGIIA in serum effectively kills commensal E. faecium and that resistance of clinical E. faecium to hGIIA could have contributed to the ability of these strains to become opportunistic pathogens in hospitalized patients.
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27
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Gao W, Howden BP, Stinear TP. Evolution of virulence in Enterococcus faecium, a hospital-adapted opportunistic pathogen. Curr Opin Microbiol 2017; 41:76-82. [PMID: 29227922 DOI: 10.1016/j.mib.2017.11.030] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 11/28/2017] [Accepted: 11/30/2017] [Indexed: 12/29/2022]
Abstract
Enterococci are long-standing members of the human microbiome and they are also widely distributed in nature. However, with the surge of antibiotic-resistance in recent decades, two enterococcal species (Enterococcus faecalis and Enterococcus faecium) have emerged to become significant nosocomial pathogens, acquiring extensive antibiotic resistance. In this review, we summarize what is known about the evolution of virulence in E. faecium, highlighting a specific clone of E. faecium called ST796 that has emerged recently and spread globally.
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Affiliation(s)
- Wei Gao
- Department of Microbiology and Immunology, The Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Benjamin P Howden
- Department of Microbiology and Immunology, The Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia; Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia; Infectious Diseases Department, Austin Health, Heidelberg, Victoria 3084, Australia
| | - Timothy P Stinear
- Department of Microbiology and Immunology, The Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia.
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28
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Zhang X, de Maat V, Guzmán Prieto AM, Prajsnar TK, Bayjanov JR, de Been M, Rogers MRC, Bonten MJM, Mesnage S, Willems RJL, van Schaik W. RNA-seq and Tn-seq reveal fitness determinants of vancomycin-resistant Enterococcus faecium during growth in human serum. BMC Genomics 2017; 18:893. [PMID: 29162049 PMCID: PMC5699109 DOI: 10.1186/s12864-017-4299-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 11/13/2017] [Indexed: 12/30/2022] Open
Abstract
Background The Gram-positive bacterium Enterococcus faecium is a commensal of the human gastrointestinal tract and a frequent cause of bloodstream infections in hospitalized patients. The mechanisms by which E. faecium can survive and grow in blood during an infection have not yet been characterized. Here, we identify genes that contribute to growth of E. faecium in human serum through transcriptome profiling (RNA-seq) and a high-throughput transposon mutant library sequencing approach (Tn-seq). Results We first sequenced the genome of E. faecium E745, a vancomycin-resistant clinical isolate, using a combination of short- and long read sequencing, revealing a 2,765,010 nt chromosome and 6 plasmids, with sizes ranging between 9.3 kbp and 223.7 kbp. We then compared the transcriptome of E. faecium E745 during exponential growth in rich medium and in human serum by RNA-seq. This analysis revealed that 27.8% of genes on the E. faecium E745 genome were differentially expressed in these two conditions. A gene cluster with a role in purine biosynthesis was among the most upregulated genes in E. faecium E745 upon growth in serum. The E. faecium E745 transposon mutant library was then used to identify genes that were specifically required for growth of E. faecium in serum. Genes involved in de novo nucleotide biosynthesis (including pyrK_2, pyrF, purD, purH) and a gene encoding a phosphotransferase system subunit (manY_2) were thus identified to be contributing to E. faecium growth in human serum. Transposon mutants in pyrK_2, pyrF, purD, purH and manY_2 were isolated from the library and their impaired growth in human serum was confirmed. In addition, the pyrK_2 and manY_2 mutants were tested for their virulence in an intravenous zebrafish infection model and exhibited significantly attenuated virulence compared to E. faecium E745. Conclusions Genes involved in carbohydrate metabolism and nucleotide biosynthesis of E. faecium are essential for growth in human serum and contribute to the pathogenesis of this organism. These genes may serve as targets for the development of novel anti-infectives for the treatment of E. faecium bloodstream infections. Electronic supplementary material The online version of this article (10.1186/s12864-017-4299-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xinglin Zhang
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China.,Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Vincent de Maat
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Ana M Guzmán Prieto
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Tomasz K Prajsnar
- Krebs Institute, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Jumamurat R Bayjanov
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Mark de Been
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Malbert R C Rogers
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Marc J M Bonten
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Stéphane Mesnage
- Krebs Institute, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Rob J L Willems
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Willem van Schaik
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands. .,Institute of Microbiology and Infection, College of Medical and Dental Sciences, The University of Birmingham, Birmingham, B15 2TT, United Kingdom.
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29
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Goh HMS, Yong MHA, Chong KKL, Kline KA. Model systems for the study of Enterococcal colonization and infection. Virulence 2017; 8:1525-1562. [PMID: 28102784 PMCID: PMC5810481 DOI: 10.1080/21505594.2017.1279766] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 12/30/2016] [Accepted: 01/04/2017] [Indexed: 02/07/2023] Open
Abstract
Enterococcus faecalis and Enterococcus faecium are common inhabitants of the human gastrointestinal tract, as well as frequent opportunistic pathogens. Enterococci cause a range of infections including, most frequently, infections of the urinary tract, catheterized urinary tract, bloodstream, wounds and surgical sites, and heart valves in endocarditis. Enterococcal infections are often biofilm-associated, polymicrobial in nature, and resistant to antibiotics of last resort. Understanding Enterococcal mechanisms of colonization and pathogenesis are important for identifying new ways to manage and intervene with these infections. We review vertebrate and invertebrate model systems applied to study the most common E. faecalis and E. faecium infections, with emphasis on recent findings examining Enterococcal-host interactions using these models. We discuss strengths and shortcomings of each model, propose future animal models not yet applied to study mono- and polymicrobial infections involving E. faecalis and E. faecium, and comment on the significance of anti-virulence strategies derived from a fundamental understanding of host-pathogen interactions in model systems.
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Affiliation(s)
- H. M. Sharon Goh
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
| | - M. H. Adeline Yong
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Kelvin Kian Long Chong
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
- Singapore Centre for Environmental Life Sciences Engineering, Interdisciplinary Graduate School, Nanyang Technological University, Singapore
| | - Kimberly A. Kline
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
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30
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Sinel C, Augagneur Y, Sassi M, Bronsard J, Cacaci M, Guérin F, Sanguinetti M, Meignen P, Cattoir V, Felden B. Small RNAs in vancomycin-resistant Enterococcus faecium involved in daptomycin response and resistance. Sci Rep 2017; 7:11067. [PMID: 28894187 PMCID: PMC5593968 DOI: 10.1038/s41598-017-11265-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/22/2017] [Indexed: 02/07/2023] Open
Abstract
Vancomycin-resistant Enterococcus faecium is a leading cause of hospital-acquired infections and outbreaks. Regulatory RNAs (sRNAs) are major players in adaptive responses, including antibiotic resistance. They were extensively studied in gram-negative bacteria, but less information is available for gram-positive pathogens. No sRNAs are described in E. faecium. We sought to identify a set of sRNAs expressed in vancomycin-resistant E. faecium Aus0004 strain to assess their roles in daptomycin response and resistance. Genomic and transcriptomic analyses revealed a set of 61 sRNA candidates, including 10 that were further tested and validated by Northern and qPCR. RNA-seq was performed with and without subinhibitory concentrations (SICs) of daptomycin, an antibiotic used to treat enterococcal infections. After daptomycin SIC exposure, the expression of 260 coding and srna genes was altered, with 80 upregulated and 180 downregulated, including 51% involved in carbohydrate and transport metabolisms. Daptomycin SIC exposure significantly affected the expression of seven sRNAs, including one experimentally confirmed, sRNA_0160. We studied sRNA expression in isogenic mutants with increasing levels of daptomycin resistance and observed that expression of several sRNAs, including sRNA_0160, was modified in the stepwise mutants. This first genome-wide sRNA identification in E. faecium suggests that some sRNAs are linked to antibiotic stress response and resistance.
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Affiliation(s)
- Clara Sinel
- University of Caen Normandie, EA4655, Caen, France
| | - Yoann Augagneur
- Inserm U1230-Biochimie pharmaceutique, Rennes University, Rennes, France
| | - Mohamed Sassi
- Inserm U1230-Biochimie pharmaceutique, Rennes University, Rennes, France
| | - Julie Bronsard
- Inserm U1230-Biochimie pharmaceutique, Rennes University, Rennes, France
| | - Margherita Cacaci
- Catholic University of Sacred Heart, Institute of Microbiology, Rome, Italy
| | - François Guérin
- University of Caen Normandie, EA4655, Caen, France.,Caen University Hospital, Department of Clinical Microbiology, Caen, France
| | | | - Pierrick Meignen
- University of Caen Normandie, IUT (department "STID"), Caen, France
| | - Vincent Cattoir
- University of Caen Normandie, EA4655, Caen, France. .,Caen University Hospital, Department of Clinical Microbiology, Caen, France. .,National Reference Center for Antimicrobial Resistance (lab Enterococci), Caen, France. .,Inserm U1230-Biochimie pharmaceutique, Rennes University, Rennes, France.
| | - Brice Felden
- Inserm U1230-Biochimie pharmaceutique, Rennes University, Rennes, France.
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31
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32
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McKenney ES, Kendall MM. Microbiota and pathogen 'pas de deux': setting up and breaking down barriers to intestinal infection. Pathog Dis 2016; 74:ftw051. [PMID: 27252177 PMCID: PMC5985477 DOI: 10.1093/femspd/ftw051] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 02/04/2016] [Accepted: 05/24/2016] [Indexed: 02/07/2023] Open
Abstract
The gut microbiota plays essential roles in human health and disease. In this review, we focus on the role of the intestinal microbiota in promoting resistance to infection by bacterial pathogens as well as how pathogens overcome this barrier. We discuss how the resident microbiota restricts growth and colonization of invading pathogens by limiting availability of nutrients and through generation of a hostile environment. Additionally, we examine how microbiota-derived signaling molecules interfere with bacterial virulence. In turn, we discuss how pathogens exploit non-competitive metabolites to replicate in vivo as well as to precisely control virulence and cause disease. This bacterial two step of creating and overcoming challenges important in preventing and establishing infection highlights the complexities of elucidating interactions between the commensal bacteria and pathogens. Better understanding of microbiota-pathogen interplay will have significant implications for developing novel therapeutics to treat infectious diseases.
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Affiliation(s)
- Elizabeth S McKenney
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Melissa M Kendall
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
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33
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Guzman Prieto AM, van Schaik W, Rogers MRC, Coque TM, Baquero F, Corander J, Willems RJL. Global Emergence and Dissemination of Enterococci as Nosocomial Pathogens: Attack of the Clones? Front Microbiol 2016; 7:788. [PMID: 27303380 PMCID: PMC4880559 DOI: 10.3389/fmicb.2016.00788] [Citation(s) in RCA: 202] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/09/2016] [Indexed: 12/13/2022] Open
Abstract
Enterococci are Gram-positive bacteria that are found in plants, soil and as commensals of the gastrointestinal tract of humans, mammals, and insects. Despite their commensal nature, they have also become globally important nosocomial pathogens. Within the genus Enterococcus, Enterococcus faecium, and Enterococcus faecalis are clinically most relevant. In this review, we will discuss how E. faecium and E. faecalis have evolved to become a globally disseminated nosocomial pathogen. E. faecium has a defined sub-population that is associated with hospitalized patients and is rarely encountered in community settings. These hospital-associated clones are characterized by the acquisition of adaptive genetic elements, including genes involved in metabolism, biofilm formation, and antibiotic resistance. In contrast to E. faecium, clones of E. faecalis isolated from hospitalized patients, including strains causing clinical infections, are not exclusively found in hospitals but are also present in healthy individuals and animals. This observation suggests that the division between commensals and hospital-adapted lineages is less clear for E. faecalis than for E. faecium. In addition, genes that are reported to be associated with virulence of E. faecalis are often not unique to clinical isolates, but are also found in strains that originate from commensal niches. As a reflection of more ancient association of E. faecalis with different hosts, these determinants Thus, they may not represent genuine virulence genes but may act as host-adaptive functions that are useful in a variety of intestinal environments. The scope of the review is to summarize recent trends in the emergence of antibiotic resistance and explore recent developments in the molecular epidemiology, population structure and mechanisms of adaptation of E. faecium and E. faecalis.
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Affiliation(s)
- Ana M Guzman Prieto
- Department of Medical Microbiology, University Medical Center Utrecht Utrecht, Netherlands
| | - Willem van Schaik
- Department of Medical Microbiology, University Medical Center Utrecht Utrecht, Netherlands
| | - Malbert R C Rogers
- Department of Medical Microbiology, University Medical Center Utrecht Utrecht, Netherlands
| | - Teresa M Coque
- Hospital Universitario Ramon y Cajal, Instituto Ramón y Cajal de Investigación SanitariaMadrid, Spain; CIBER Epidemiología y Salud PúblicaMadrid, Spain; Unidad de Resistencia a Antibióticos y Virulencia Bacteriana Asociada al Consejo Superior de Investigaciones CientíficasMadrid, Spain
| | - Fernando Baquero
- Hospital Universitario Ramon y Cajal, Instituto Ramón y Cajal de Investigación SanitariaMadrid, Spain; CIBER Epidemiología y Salud PúblicaMadrid, Spain; Unidad de Resistencia a Antibióticos y Virulencia Bacteriana Asociada al Consejo Superior de Investigaciones CientíficasMadrid, Spain
| | - Jukka Corander
- Department of Mathematics and Statistics, University of Helsinki Helsinki, Finland
| | - Rob J L Willems
- Department of Medical Microbiology, University Medical Center Utrecht Utrecht, Netherlands
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