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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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Mullally CA, Fahriani M, Mowlaboccus S, Coombs GW. Non- faecium non- faecalis enterococci: a review of clinical manifestations, virulence factors, and antimicrobial resistance. Clin Microbiol Rev 2024; 37:e0012123. [PMID: 38466110 DOI: 10.1128/cmr.00121-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024] Open
Abstract
SUMMARYEnterococci are a diverse group of Gram-positive bacteria that are typically found as commensals in humans, animals, and the environment. Occasionally, they may cause clinically relevant diseases such as endocarditis, septicemia, urinary tract infections, and wound infections. The majority of clinical infections in humans are caused by two species: Enterococcus faecium and Enterococcus faecalis. However, there is an increasing number of clinical infections caused by non-faecium non-faecalis (NFF) enterococci. Although NFF enterococcal species are often overlooked, studies have shown that they may harbor antimicrobial resistance (AMR) genes and virulence factors that are found in E. faecium and E. faecalis. In this review, we present an overview of the NFF enterococci with a particular focus on human clinical manifestations, epidemiology, virulence genes, and AMR genes.
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Affiliation(s)
- Christopher A Mullally
- Antimicrobial Resistance and Infectious Diseases (AMRID) Research Laboratory, Murdoch University, Murdoch, Western Australia, Australia
- The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Marhami Fahriani
- Antimicrobial Resistance and Infectious Diseases (AMRID) Research Laboratory, Murdoch University, Murdoch, Western Australia, Australia
| | - Shakeel Mowlaboccus
- Antimicrobial Resistance and Infectious Diseases (AMRID) Research Laboratory, Murdoch University, Murdoch, Western Australia, Australia
- The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, The University of Western Australia, Perth, Western Australia, Australia
- PathWest Laboratory Medicine-WA, Department of Microbiology, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
| | - Geoffrey W Coombs
- Antimicrobial Resistance and Infectious Diseases (AMRID) Research Laboratory, Murdoch University, Murdoch, Western Australia, Australia
- The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, The University of Western Australia, Perth, Western Australia, Australia
- PathWest Laboratory Medicine-WA, Department of Microbiology, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
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3
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Singh KV, Galloway-Peña J, Montealegre MC, Dong X, Murray BE. Genomic context as well as sequence of both psr and penicillin-binding protein 5 contributes to β-lactam resistance in Enterococcus faecium. mBio 2024; 15:e0017024. [PMID: 38564699 PMCID: PMC11077988 DOI: 10.1128/mbio.00170-24] [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: 01/29/2024] [Accepted: 03/04/2024] [Indexed: 04/04/2024] Open
Abstract
Penicillin-binding protein 5 (PBP5) of Enterococcus faecium (Efm) is vital for ampicillin resistance (AMP-R). We previously designated three forms of PBP5, namely, PBP5-S in Efm clade B strains [ampicillin susceptible (AMP-S)], PBP5-S/R (AMP-S or R), and PBP5-R (AMP-R) in clade A strains. Here, pbp5 deletion resulted in a marked reduction in AMP minimum inhibitory concentrations (MICs) to 0.01-0.09 µg/mL for clade B and 0.12-0.19 µg/mL for clade A strains; in situ complementation restored parental AMP MICs. Using D344SRF (lacking ftsW/psr/pbp5), constructs with ftsWA/psrA (from a clade A1 strain) cloned upstream of pbp5-S and pbp5-S/R alleles resulted in modest increases in MICs to 3-8 µg/mL, while high MICs (>64 µg/mL) were seen using pbp5 from A1 strains. Next, using ftsW ± psr from clade B and clade A/B and B/A hybrid constructs, the presence of psrB, even alone or in trans, resulted in much lower AMP MICs (3-8 µg/mL) than when psrA was present (MICs >64 µg/mL). qRT PCR showed relatively greater pbp5 expression (P = 0.007) with pbp5 cloned downstream of clade A1 ftsW/psr (MIC >128 µg/mL) vs when cloned downstream of clade B ftsW/psr (MIC 4-16 µg/mL), consistent with results in western blots. In conclusion, we report the effect of clade A vs B psr on AMP MICs as well as the impact of pbp5 alleles from different clades. While previously, Psr was not thought to contribute to AMP MICs in Efm, our results showed that the presence of psrB resulted in a major decrease in Efm AMP MICs. IMPORTANCE The findings of this study shed light on ampicillin resistance in Enterococcus faecium clade A strains. They underscore the significance of alterations in the amino acid sequence of penicillin-binding protein 5 (PBP5) and the pivotal role of the psr region in PBP5 expression and ampicillin resistance. Notably, the presence of a full-length psrB leads to reduced PBP5 expression and lower minimum inhibitory concentrations (MICs) of ampicillin compared to the presence of a shorter psrA, regardless of the pbp5 allele involved. Additionally, clade B E. faecium strains exhibit lower AMP MICs when both psr alleles from clades A and B are present, although it is important to consider other distinctions between clade A and B strains that may contribute to this effect. It is intriguing to note that the divergence between clade A and clade B E. faecium and the subsequent evolution of heightened AMP MICs in hospital-associated strains appear to coincide with changes in Pbp5 and psr. These changes in psr may have resulted in an inactive Psr, facilitating increased PBP5 expression and greater ampicillin resistance. These results raise the possibility that a mimicker of PsrB, if one could be designed, might be able to lower MICs of ampicillin-resistant E. faecium, thus potentially resorting ampicillin to our therapeutic armamentarium for this species.
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Affiliation(s)
- Kavindra V. Singh
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA
| | - Jessica Galloway-Peña
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA
| | - Maria Camila Montealegre
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA
- Department of Microbiology and Infectious Diseases, University of Texas Health Science Center, Houston, Texas, USA
| | - Xingxing Dong
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA
| | - Barbara E. Murray
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA
- Department of Microbiology and Infectious Diseases, University of Texas Health Science Center, Houston, Texas, USA
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4
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Liu Y, Guo Y, Hu S, Wang Y, Zhang L, Yu L, Geng F. Analysis of the dynamic changes in gut microbiota in patients with different severity in sepsis. BMC Infect Dis 2023; 23:614. [PMID: 37723420 PMCID: PMC10507951 DOI: 10.1186/s12879-023-08608-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 09/13/2023] [Indexed: 09/20/2023] Open
Abstract
BACKGROUND The gastrointestinal tract contains a massive microbiota, and targeting the gut could be a potential intervention for sepsis. However, the interaction between sepsis and the intestinal microbiota is defined as an "incompletely understood bidirectional relationship". METHODS This retrospective observational cohort study investigated the fecal microbiota of sepsis patients admitted to the Department of Critical Care Medicine of the Central Hospital of Wuhan, China, from May 2019 to January 2020. 14 septic patients were divided into the non-severe group and the severe group according to the Acute Physiology and Chronic Health Evaluation II (APACHE II) score. Herein, fecal samples were serially collected on admission, the third, fourth, and fifth days, and ICU discharge. The fecal microbiota was analyzed by 16S rRNA gene sequencing and its correlation with clinical parameters was evaluated. RESULTS Bacteroidetes, Firmicutes, and Proteobacteria were dominant phyla at ICU admission, and fecal biodiversity was not significantly different between the non-severe group (APACHE II < 15) and the severe group (APACHE II > 15). However, the diversity of the gut microbiota was significantly lower at ICU discharge than that at ICU admission with the extension of treatment time. Further significant difference flora analysis (LEfSe) showed that the genera Veillonella and Ruminococcus were the most discriminant biomarkers at ICU admission in non-severe and severe patients, respectively, while Enterococcus was the most discriminant biomarker at ICU discharge in all septic patients. Of note, liver function tests, including ALT, AST, TBIL, and DBIL correlated with the prevalence of various bacterial genera. CONCLUSIONS The diversity of the gut microbiota in patients with sepsis decreases dramatically during ICU stay, and there are distinct dynamic changes in gut microbiota among patients with different severity in sepsis.
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Affiliation(s)
- Yanli Liu
- Intensive Care Unit, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yanan Guo
- Intensive Care Unit, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Su Hu
- Intensive Care Unit, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yujun Wang
- Intensive Care Unit, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lijuan Zhang
- Intensive Care Unit, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Li Yu
- Intensive Care Unit, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Feng Geng
- Intensive Care Unit, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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5
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Onaran Acar B, Cengız G, Goncuoglu M. Vancomycin-variable enterococci in sheep and cattle isolates and whole-genome sequencing analysis of isolates harboring vanM and vanB genes. IRANIAN JOURNAL OF VETERINARY RESEARCH 2023; 24:182-192. [PMID: 38269016 PMCID: PMC10804430 DOI: 10.22099/ijvr.2023.47465.6855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/26/2023] [Accepted: 09/11/2023] [Indexed: 01/26/2024]
Abstract
Background Vancomycin resistance encoded by the vanA/B/M genes in enterococci is clinically important because of the transmission of these genes between bacteria. While vancomycin resistance is determined by detecting only vanA and vanB genes by routine analyses, failure to detect vanM resistance causes vancomycin resistance to be overlooked, and clinically appropriate treatment cannot be provided. Aims The study aimed to examine the presence of vanM-positive enterococcal isolates in Ankara, Turkey, and to have detailed information about them with sequence analyses. Methods Caecal samples were collected from sheep and cattle during slaughter at different slaughterhouses in Ankara, Turkey. Enterococci isolates were identified, confirmed, and analyzed for the presence of vanA/B/M genes. Antibiotic resistance profiles of isolates were determined by the broth microdilution method. A whole genome sequence analysis of the isolates harboring the vanM and vanB genes was performed. Results 13.7% of enterococcal isolates were determined as Enterococcus faecium and Enterococcus faecalis. 15% of these isolates contained vanB, and 40% were vanM-positive. S98b and C32 isolates were determined to contain 16 CRISPR-Cas elements. 80% of the enterococci isolates were resistant to nitrofurantoin and 15% to ciprofloxacin. The first vanM-positive vancomycin-variable enterococci (VVE) isolates from food-producing animals were identified, and the S98b strain has been assigned to Genbank with the accession number CP104083.1. Conclusion Therefore, new studies are needed to facilitate the identification of vanM-resistant enterococci and VVE strains.
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Affiliation(s)
- B. Onaran Acar
- Department of Food Hygiene and Technology, Faculty of Veterinary Medicine, Ankara University, 06110, Altindag, Ankara, Turkey
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6
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Opoku-Temeng C, Freedman B, Porter AR, Kobayashi SD, Chen L, Kreiswirth BN, DeLeo FR. Subinhibitory Concentrations of Antibiotics Alter the Response of Klebsiella pneumoniae to Components of Innate Host Defense. Microbiol Spectr 2022; 10:e0151722. [PMID: 36264264 PMCID: PMC9769900 DOI: 10.1128/spectrum.01517-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 10/04/2022] [Indexed: 01/05/2023] Open
Abstract
Carbapenem-resistant Klebsiella pneumoniae isolates classified as multilocus sequence type 258 (ST258) are a problem in health care settings in many countries globally. ST258 isolates are resistant to multiple classes of antibiotics and can cause life-threatening infections, such as pneumonia and sepsis, in susceptible individuals. Treatment strategies for such infections are limited. Understanding the response of K. pneumoniae to host factors in the presence of antibiotics could reveal mechanisms employed by the pathogen to evade killing in the susceptible host, as well as inform treatment of infections. Here, we investigated the ability of antibiotics at subinhibitory concentrations to alter K. pneumoniae capsular polysaccharide (CPS) production and survival in normal human serum (NHS). Unexpectedly, pretreatment with some of the antibiotics tested enhanced ST258 survival in NHS. For example, a subinhibitory concentration of mupirocin increased survival for 7 of 10 clinical isolates evaluated and there was increased cell-associated CPS for 3 of these isolates compared with untreated controls. Additionally, mupirocin pretreatment caused concomitant reduction in the deposition of the serum complement protein C5b-9 on the surface of these three isolates. Transcriptome analyses with a selected ST258 isolate (34446) indicated that genes implicated in the stringent response and/or serum resistance were upregulated following mupirocin treatment and/or culture in NHS. In conclusion, mupirocin and/or human serum causes changes in the K. pneumoniae transcriptome that likely contribute to the observed decrease in serum susceptibility via a multifactorial process. Whether these responses can be extended more broadly and thus impact clinical outcome in the human host merits further investigation. IMPORTANCE The extent to which commensal bacteria are altered by exposure to subinhibitory concentrations of antibiotics (outside resistance) remains incompletely determined. To gain a better understanding of this phenomenon, we tested the ability of selected antibiotics (at subinhibitory concentrations) to alter survival of ST258 clinical isolates in normal human serum. We found that exposure of ST258 to antibiotics at low concentrations differentially altered gene expression, capsule production, serum complement deposition, and bacterial survival. The findings were isolate and antibiotic dependent but provide insight into a potential confounding issue associated with ST258 infections.
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Affiliation(s)
- Clement Opoku-Temeng
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Brett Freedman
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Adeline R. Porter
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Scott D. Kobayashi
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Liang Chen
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Barry N. Kreiswirth
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Frank R. DeLeo
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
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Sadaqat MH, Mobarez AM, Nikkhah M. Curcumin carbon dots inhibit biofilm formation and expression of esp and gelE genes of Enterococcus faecium. Microb Pathog 2022; 173:105860. [DOI: 10.1016/j.micpath.2022.105860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 10/26/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022]
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8
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Enterococcus Virulence and Resistant Traits Associated with Its Permanence in the Hospital Environment. Antibiotics (Basel) 2022; 11:antibiotics11070857. [PMID: 35884110 PMCID: PMC9311936 DOI: 10.3390/antibiotics11070857] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 11/17/2022] Open
Abstract
Enterococcus are opportunistic pathogens that have been gaining importance in the clinical setting, especially in terms of hospital-acquired infections. This problem has mainly been associated with the fact that these bacteria are able to present intrinsic and extrinsic resistance to different classes of antibiotics, with a great deal of importance being attributed to vancomycin-resistant enterococci. However, other aspects, such as the expression of different virulence factors including biofilm-forming ability, and its capacity of trading genetic information, makes this bacterial genus more capable of surviving harsh environmental conditions. All these characteristics, associated with some reports of decreased susceptibility to some biocides, all described in this literary review, allow enterococci to present a longer survival ability in the hospital environment, consequently giving them more opportunities to disseminate in these settings and be responsible for difficult-to-treat infections.
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Akpınar Kankaya D, Tuncer Y. Detection of Virulence Factors, Biofilm Formation and Biogenic Amine Production in
Vancomycin‐Resistant
Lactic Acid Bacteria (
VRLAB
) Isolated From Foods of Animal Origin. J FOOD PROCESS PRES 2022. [DOI: 10.1111/jfpp.16423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Didem Akpınar Kankaya
- Department of Food Technology, Gelendost Vocational School Isparta University of Applied Sciences Isparta Turkey
| | - Yasin Tuncer
- Department of Food Engineering, Faculty of Engineering Süleyman Demirel University Isparta Turkey
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Xu W, Fang Y, Hu Q, Zhu K. Emerging Risks in Food: Probiotic Enterococci Pose a Threat to Public Health through the Food Chain. Foods 2021; 10:foods10112846. [PMID: 34829127 PMCID: PMC8623795 DOI: 10.3390/foods10112846] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 11/16/2022] Open
Abstract
Probiotics have been associated with clinical infections, toxicity, and antimicrobial resistance transfer, raising public concerns. Probiotic enterococci are emerging food risks as opportunistic pathogens, yet little attention has been paid to them. Herein, we collected 88 enterococcal isolates from probiotic products used for humans, companion animals, livestock, and aquaculture. Results showed that all 88 probiotic enterococcal isolates harbored diverse virulence genes, multiple antimicrobial resistance genes, and mobile genetic elements. Notably, 77 isolates were highly resistant to gentamicin. Representative enterococcal isolates exerted toxic activities in both in vitro and in vivo models. Collectively, our findings suggest that probiotic enterococci may be harmful to hosts and pose a potential threat to public health.
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Affiliation(s)
| | | | | | - Kui Zhu
- Correspondence: ; Tel.: +86-10-62733695
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Efficacy of Omadacycline against Multidrug-Resistant Enterococcus faecium Strains in a Mouse Peritonitis Model. Antimicrob Agents Chemother 2021; 65:e0070921. [PMID: 34125596 DOI: 10.1128/aac.00709-21] [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
Omadacycline (OMC) showed better in vitro potency than daptomycin (DAP) or vancomycin (VAN) against Vanr, Ampr, DAP-nonsusceptible, linezolid-resistant, cfr(B)+ Enterococcus faecium strains. In a mouse peritonitis model, OMC also showed significantly better animal survival during the study and at its end than DAP or VAN with these E. faecium strains. However, OMC, DAP, and VAN showed comparable in vitro and in vivo efficacies against a non-vancomycin-resistant, tetracycline-resistant, DAP-susceptible E. faecium strain.
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12
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Revtovich AV, Tjahjono E, Singh KV, Hanson BM, Murray BE, Kirienko NV. Development and Characterization of High-Throughput Caenorhabditis elegans - Enterococcus faecium Infection Model. Front Cell Infect Microbiol 2021; 11:667327. [PMID: 33996637 PMCID: PMC8116795 DOI: 10.3389/fcimb.2021.667327] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 04/13/2021] [Indexed: 12/16/2022] Open
Abstract
The genus Enterococcus includes two Gram-positive pathogens of particular clinical relevance: E. faecalis and E. faecium. Infections with each of these pathogens are becoming more frequent, particularly in the case of hospital-acquired infections. Like most other bacterial species of clinical importance, antimicrobial resistance (and, specifically, multi-drug resistance) is an increasing threat, with both species considered to be of particular importance by the World Health Organization and the US Centers for Disease Control. The threat of antimicrobial resistance is exacerbated by the staggering difference in the speeds of development for the discovery and development of the antimicrobials versus resistance mechanisms. In the search for alternative strategies, modulation of host-pathogen interactions in general, and virulence inhibition in particular, have drawn substantial attention. Unfortunately, these approaches require a fairly comprehensive understanding of virulence determinants. This requirement is complicated by the fact that enterococcal infection models generally require vertebrates, making them slow, expensive, and ethically problematic, particularly when considering the thousands of animals that would be needed for the early stages of experimentation. To address this problem, we developed the first high-throughput C. elegans-E. faecium infection model involving host death. Importantly, this model recapitulates many key aspects of murine peritonitis models, including utilizing similar virulence determinants. Additionally, host death is independent of peroxide production, unlike other E. faecium-C. elegans virulence models, which allows the assessment of other virulence factors. Using this system, we analyzed a panel of lab strains with deletions of targeted virulence factors. Although removal of certain virulence factors (e.g., Δfms15) was sufficient to affect virulence, multiple deletions were generally required to affect pathogenesis, suggesting that host-pathogen interactions are multifactorial. These data were corroborated by genomic analysis of selected isolates with high and low levels of virulence. We anticipate that this platform will be useful for identifying new treatments for E. faecium infection.
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Affiliation(s)
| | - Elissa Tjahjono
- Department of BioSciences, Rice University, Houston, TX, United States
| | - Kavindra V. Singh
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX, United States
| | - Blake M. Hanson
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX, United States
- Center for Infectious Diseases, School of Public Health, University of Texas Health Science Center, Houston, TX, United States
| | - Barbara E. Murray
- Division of Infectious Diseases, McGovern Medical School, University of Texas Health Science Center, Houston, TX, United States
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX, United States
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Arora S, Gordon J, Hook M. Collagen Binding Proteins of Gram-Positive Pathogens. Front Microbiol 2021; 12:628798. [PMID: 33613497 PMCID: PMC7893114 DOI: 10.3389/fmicb.2021.628798] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 01/11/2021] [Indexed: 12/12/2022] Open
Abstract
Collagens are the primary structural components of mammalian extracellular matrices. In addition, collagens regulate tissue development, regeneration and host defense through interaction with specific cellular receptors. Their unique triple helix structure, which requires a glycine residue every third amino acid, is the defining structural feature of collagens. There are 28 genetically distinct collagens in humans. In addition, several other unrelated human proteins contain a collagen domain. Gram-positive bacteria of the genera Staphylococcus, Streptococcus, Enterococcus, and Bacillus express cell surface proteins that bind to collagen. These proteins of Gram-positive pathogens are modular proteins that can be classified into different structural families. This review will focus on the different structural families of collagen binding proteins of Gram-positive pathogen. We will describe how these proteins interact with the triple helix in collagens and other host proteins containing a collagenous domain and discuss how these interactions can contribute to the pathogenic processes.
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Affiliation(s)
- Srishtee Arora
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, United States
| | - Jay Gordon
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, United States
| | - Magnus Hook
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, United States
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14
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Mihos CG, Nappi F. A narrative review of echocardiography in infective endocarditis of the right heart. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:1622. [PMID: 33437821 PMCID: PMC7791248 DOI: 10.21037/atm-20-5198] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Infective endocarditis (IE) is characterized by bacterial or fungal masses that form in the cardiac chambers and valves, and in severe cases invade the endocardium or intra-cardiac vessels. Right-sided IE accounts for 5% to 10% of cases, with a low mortality cited at 6%. A history of intravenous drug abuse (IVDU) is present in 90% of isolated right-sided IE cases, with normal intra-cardiac anatomy prior to infection in approximately 80%. Nevertheless, up to 50% of patients require early surgical intervention which is associated with significant peri-operative morbidity. Echocardiography is the gold standard for diagnosis with a sensitivity of 80% for the transthoracic modality and 95% for transesophageal studies; it provides important clinical information regarding the severity of infection and development of secondary complications. This includes identification of active infective vegetations, healed IE, prosthetic valve IE, and abscess formation and rupture. Prompt clinical, microbiologic, and imaging assessment of patients with suspected left or right-sided IE is of paramount importance and is reflected in the modified Duke criteria, the well-validated algorithm for accurate and timely diagnosis of IE. Data suggests the criteria sensitivity may be decreased in right-sided IE only, and thus, care must be taken to perform skilled and detailed echocardiographic assessments of the right heart in suspected cases. Herein we provide a review of IE of the right heart, with a focus on pathophysiology and its echocardiographic presentation and characteristics.
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Affiliation(s)
- Christos G Mihos
- Echocardiography Laboratory, Columbia University Division of Cardiology, Mount Sinai Heart Institute, Miami Beach, FL, USA
| | - Francesco Nappi
- Department of Cardiac Surgery, Centre Cardiologique du Nord de Saint-Denis, Paris, France
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Kalfopoulou E, Huebner J. Advances and Prospects in Vaccine Development against Enterococci. Cells 2020; 9:cells9112397. [PMID: 33147722 PMCID: PMC7692742 DOI: 10.3390/cells9112397] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 10/29/2020] [Accepted: 10/30/2020] [Indexed: 12/26/2022] Open
Abstract
Enterococci are the second most common Gram-positive pathogen responsible for nosocomial infections. Due to the limited number of new antibiotics that reach the medical practice and the resistance of enterococci to the current antibiotic options, passive and active immunotherapies have emerged as a potential prevention and/or treatment strategy against this opportunistic pathogen. In this review, we explore the pathogenicity of these bacteria and their interaction with the host immune response. We provide an overview of the capsular polysaccharides and surface-associated proteins that have been described as potential antigens in anti-enterococcal vaccine formulations. In addition, we describe the current status in vaccine development against enterococci and address the importance and the current advances toward the development of well-defined vaccines with broad coverage against enterococci.
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Affiliation(s)
- Ermioni Kalfopoulou
- Institute for Medical Microbiology, Immunology and Hygiene, Technical University of Munich, 81675 Munich, Germany;
| | - Johannes Huebner
- Division of Paediatric Infectious Diseases, Dr. von Hauner Children’s Hospital, Ludwig Maximilians University, 80337 Munich, Germany
- Correspondence: ; Tel.: +49-89-44005-7970
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16
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Bin-Asif H, Abid Ali S. The Genus Enterococcus and Its Associated Virulent Factors. Microorganisms 2020. [DOI: 10.5772/intechopen.89083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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17
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Zheng C, Cai J, Liu H, Zhang S, Zhong L, Xuan N, Zhou H, Zhang K, Wang Y, Zhang X, Tian B, Zhang Z, Wang C, Cui W, Zhang G. Clinical Characteristics And Risk Factors In Mixed-Enterococcal Bloodstream Infections. Infect Drug Resist 2019; 12:3397-3407. [PMID: 31802919 PMCID: PMC6827512 DOI: 10.2147/idr.s217905] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 10/02/2019] [Indexed: 12/23/2022] Open
Abstract
Purpose Although the enterococcal bloodstream infections (EBSI) are often observed in clinic, the mixed-EBSI are few reported. The aim of this study was to investigate the clinical characteristics and risk factors of mixed-EBSI in comparison with monomicrobial EBSI (mono-EBSI). Methods A single-center retrospective observational study was performed between Jan 1, 2013 and Dec 31, 2018 in a tertiary hospital. All patients with EBSI were enrolled, and their data were collected by reviewing electronic medical records. Results A total of 451 patients with EBSI were enrolled including 157 cases (34.8%) with mixed-EBSI. The most common co-pathogens were Coagulase-negative Staphylococcus (26.86%), followed by Acinetobacter baumannii (23.43%) and Klebsiella pneumoniae (8.57%). In multivariable analysis, burn injury (adjusted odds ratio [aOR], 7.39; 95% confidence interval [CI], 2.69-20.28), and length of prior hospital stay (aOR, 1.01; 95% CI, 1.00-1.02) were associated with mixed-EBSI. Patients with mixed-EBSI developed with more proportion of septic shock (19% vs. 31.8%, p=0.002), prolonged length of intensive care unit (ICU) stay [9(0,25) vs. 15(2.5,36), p<0.001] and hospital stay [29(16,49) vs. 33(18.5,63), p=0.031]. The mortality was not significantly different between mixed-EBSI and mono-EBSI (p=0.219). Conclusion A high rate of mixed-EBSI is among EBSI, and Acinetobacter baumannii is the second predominant co-existed species, except for Coagulase-negative Staphylococcus. Burn injury and length of prior hospital stay are independent risk factors for mixed-EBSI. Although the mortality is not different, patients with mixed-EBSI might have poor outcomes in comparison with mono-EBSI, which merits more attention by physicians in the future.
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Affiliation(s)
- Cheng Zheng
- Department of Critical Care Medicine, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, People's Republic of China.,Department of Critical Care Medicine, Taizhou Municipal Hospital, Taizhou, Zhejiang, People's Republic of China
| | - Jiachang Cai
- Clinical Microbiology Laboratory, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, People's Republic of China
| | - Haizhou Liu
- Department of Critical Care Medicine, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, People's Republic of China.,Department of Critical Care Medicine, Zhejiang Rehabilitation Hospital, Hangzhou, Zhejiang, People's Republic of China
| | - Shufang Zhang
- Department of Cardiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, People's Republic of China
| | - Li Zhong
- Department of Critical Care Medicine, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, People's Republic of China.,Department of Critical Care Medicine, Huzhou First People's Hospital, Huzhou, Zhejiang, People's Republic of China
| | - Nanxia Xuan
- Department of Critical Care Medicine, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, People's Republic of China
| | - Hongwei Zhou
- Clinical Microbiology Laboratory, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, People's Republic of China
| | - Kai Zhang
- Department of Critical Care Medicine, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, People's Republic of China
| | - Yesong Wang
- Department of Critical Care Medicine, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, People's Republic of China
| | - Xijiang Zhang
- Department of Critical Care Medicine, Taizhou Municipal Hospital, Taizhou, Zhejiang, People's Republic of China
| | - Baoping Tian
- Department of Critical Care Medicine, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, People's Republic of China
| | - Zhaocai Zhang
- Department of Critical Care Medicine, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, People's Republic of China
| | - Changming Wang
- Department of Critical Care Medicine, Taizhou Municipal Hospital, Taizhou, Zhejiang, People's Republic of China
| | - Wei Cui
- Department of Critical Care Medicine, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, People's Republic of China
| | - Gensheng Zhang
- Department of Critical Care Medicine, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, People's Republic of China
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18
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Adaptation to Adversity: the Intermingling of Stress Tolerance and Pathogenesis in Enterococci. Microbiol Mol Biol Rev 2019; 83:83/3/e00008-19. [PMID: 31315902 DOI: 10.1128/mmbr.00008-19] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Enterococcus is a diverse and rugged genus colonizing the gastrointestinal tract of humans and numerous hosts across the animal kingdom. Enterococci are also a leading cause of multidrug-resistant hospital-acquired infections. In each of these settings, enterococci must contend with changing biophysical landscapes and innate immune responses in order to successfully colonize and transit between hosts. Therefore, it appears that the intrinsic durability that evolved to make enterococci optimally competitive in the host gastrointestinal tract also ideally positioned them to persist in hospitals, despite disinfection protocols, and acquire new antibiotic resistances from other microbes. Here, we discuss the molecular mechanisms and regulation employed by enterococci to tolerate diverse stressors and highlight the role of stress tolerance in the biology of this medically relevant genus.
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19
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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: 195] [Impact Index Per Article: 39.0] [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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20
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Lim SY, Teh CSJ, Thong KL. Biofilm-Related Diseases and Omics: Global Transcriptional Profiling of Enterococcus faecium Reveals Different Gene Expression Patterns in the Biofilm and Planktonic Cells. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2018; 21:592-602. [PMID: 29049010 DOI: 10.1089/omi.2017.0119] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Enterococcus faecium is an opportunistic pathogen with a remarkable ability to acquire resistance toward multiple antibiotics, including those of last-resort drugs such as vancomycin and daptomycin. The occurrence of vancomycin-resistant E. faecium is on the rise and there is a need to understand the virulence of this organism. One of the factors that contributes to the virulence is the ability to form biofilms. Since bacteria in biofilm state are more resistant to antibiotics and host immune response, understanding the molecular mechanism of biofilm development is important to control biofilm-related diseases. The aim of this study was to determine the global gene expression profiles of an E. faecium strain, VREr5, during the early event of sessile growth compared with its planktonic phase through RNA-sequencing approach. The results clearly illustrated distinct expression profiles of the planktonic and biofilm cells. A total of 177 genes were overexpressed in the biofilm cells. Most of them encode for proteins involved in adherence, such as the ebpABCfm locus. Genes associated with plasmid replication, gene exchange, and protein synthesis were also upregulated during the early event of biofilm development. Furthermore, the transcriptome analysis also identified genes such as fsrB, luxS, and spx that might suppress biofilm formation in VREr5. The putative biofilm-related bee locus was found to be downregulated. These new findings could provide caveats for future studies on the regulation and maintenance of biofilm and development of biomarkers for biofilm-related diseases.
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Affiliation(s)
- Shu Yong Lim
- 1 Institute of Biological Sciences, Faculty of Science, University of Malaya , Kuala Lumpur, Malaysia
| | - Cindy Shuan Ju Teh
- 2 Department of Medical Microbiology, Faculty of Medicine, University of Malaya , Kuala Lumpur, Malaysia
| | - Kwai Lin Thong
- 1 Institute of Biological Sciences, Faculty of Science, University of Malaya , Kuala Lumpur, Malaysia
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21
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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: 134] [Impact Index Per Article: 19.1] [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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22
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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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23
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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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24
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Madani A, Garakani K, Mofrad MRK. Molecular mechanics of Staphylococcus aureus adhesin, CNA, and the inhibition of bacterial adhesion by stretching collagen. PLoS One 2017; 12:e0179601. [PMID: 28665944 PMCID: PMC5493303 DOI: 10.1371/journal.pone.0179601] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 05/31/2017] [Indexed: 02/05/2023] Open
Abstract
Bacterial adhesion to collagen, the most abundant protein in humans, is a critical step in the initiation and persistence of numerous bacterial infections. In this study, we explore the collagen binding mechanism of the multi-modular cell wall anchored collagen adhesin (CNA) in Staphylococcus aureus and examine how applied mechanical forces can modulate adhesion ability. The common structural-functional elements and domain organization of CNA are present across over 50 genera of bacteria. Through the use of molecular dynamics models and normal mode analysis, we shed light on the CNA's structural and conformational dynamics and its interactions with collagen that lead to collagen binding. Our results suggest that the linker region, CNA165-173, acts as a hinge exhibiting bending, extensional, and torsional modes of structural flexibility and its residues are key in the interaction of the CNA-collagen complex. Steered molecular dynamics simulations were conducted with umbrella sampling. During the course of these simulations, the 'locking' latch from the CNA N2 domain was dissociated from its groove in the CNA N1 domain, implying the importance of the latch for effective ligand binding. Finally, we observed that the binding efficiency of the CNA N1-N2 domains to collagen decreases greatly with increasing tensile force application to the collagen peptides. Thus, CNA and similar adhesins might preferentially bind to sites in which collagen fibers are cleaved, such as in wounded, injured, or inflamed tissues, or in which the collagenous tissue is less mature. As alternative techniques for control of bacterial infection are in-demand due to the rise of bacterial antibiotic resistance, results from our computational studies with respect to the mechanoregulation of the collagen binding site may inspire new therapeutics and engineering solutions by mechanically preventing colonization and/or further pathogenesis.
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Affiliation(s)
- Ali Madani
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, California, United States of America
| | - Kiavash Garakani
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, California, United States of America
| | - Mohammad R. K. Mofrad
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, California, United States of America
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Lab, Berkeley, California, United States of America
- * E-mail:
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25
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Subinhibitory Concentrations of Ciprofloxacin Enhance Antimicrobial Resistance and Pathogenicity of Enterococcus faecium. Antimicrob Agents Chemother 2017; 61:AAC.02763-16. [PMID: 28193670 DOI: 10.1128/aac.02763-16] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 02/08/2017] [Indexed: 11/20/2022] Open
Abstract
Enterococcus faecium has emerged as a major opportunistic pathogen for 2 decades with the spread of hospital-adapted multidrug-resistant clones. As members of the intestinal microbiota, they are subjected to numerous bacterial stresses, including antibiotics at subinhibitory concentrations (SICs). Since fluoroquinolones are extensively prescribed, SICs are very likely to occur in vivo, with potential effects on bacterial metabolism with subsequent modulation of opportunistic traits. The aim of this study was to evaluate globally the impact of SICs of ciprofloxacin on antimicrobial resistance and pathogenicity of E. faecium Transcriptomic analysis was performed by RNA sequencing (RNA-seq) (HiSeq 2500; Illumina) using the vanB-positive reference strain E. faecium Aus0004 in the absence or presence of ciprofloxacin SIC (0.38 mg/liter, i.e., 1/8 of the MIC). Several genetic and phenotypic tests were used for validation. In the presence of ciprofloxacin SIC, 196 genes were significantly induced, whereas 286 genes were significantly repressed, meaning that 16.8% of the E. faecium genome was altered. Among upregulated genes, EFAU004_02294 (fold change, 14.3) encoded a protein (Qnr of E. faecium [EfmQnr]) homologue of Qnr proteins involved in quinolone resistance in Gram-negative bacilli. Its implication in intrinsic and adaptive fluoroquinolone (FQ) resistance in E. faecium was experimentally ascertained. Moreover, EFAU004_02292, coding for the collagen adhesin Acm, was also induced by the SIC of ciprofloxacin (fold change, 8.2), and higher adhesion capabilities were demonstrated phenotypically. Both EfmQnr and Acm determinants may play an important role in the transition from a commensal to a pathogenic state of E. faecium that resides in the gut of patients receiving fluoroquinolone therapy.
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26
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Lim SY, Yap KP, Teh CSJ, Jabar KA, Thong KL. Comparative genome analysis of multiple vancomycin-resistant Enterococcus faecium isolated from two fatal cases. INFECTION GENETICS AND EVOLUTION 2017; 49:55-65. [PMID: 28039075 DOI: 10.1016/j.meegid.2016.12.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 12/22/2016] [Accepted: 12/25/2016] [Indexed: 12/31/2022]
Abstract
Enterococcus faecium is both a commensal of the human intestinal tract and an opportunistic pathogen. The increasing incidence of enterococcal infections is mainly due to the ability of this organism to develop resistance to multiple antibiotics, including vancomycin. The aim of this study was to perform comparative genome analyses on four vancomycin-resistant Enterococcus faecium (VREfm) strains isolated from two fatal cases in a tertiary hospital in Malaysia. Two sequence types, ST80 and ST203, were identified which belong to the clinically important clonal complex (CC) 17. This is the first report on the emergence of ST80 strains in Malaysia. Three of the studied strains (VREr5, VREr6, VREr7) were each isolated from different body sites of a single patient (patient Y) and had different PFGE patterns. While VREr6 and VREr7 were phenotypically and genotypically similar, the initial isolate, VREr5, was found to be more similar to VRE2 isolated from another patient (patient X), in terms of the genome contents, sequence types and phylogenomic relationship. Both the clinical records and genome sequence data suggested that patient Y was infected by multiple strains from different clones and the strain that infected patient Y could have derived from the same clone from patient X. These multidrug resistant strains harbored a number of virulence genes such as the epa locus and pilus-associated genes which could enhance their persistence. Apart from that, a homolog of E. faecalis bee locus was identified in VREr5 which might be involved in biofilm formation. Overall, our comparative genomic analyses had provided insight into the genetic relatedness, as well as the virulence potential, of the four clinical strains.
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Affiliation(s)
- Shu Yong Lim
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Kien-Pong Yap
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Cindy Shuan Ju Teh
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kartini Abdul Jabar
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kwai Lin Thong
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.
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27
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Abstract
Enterococci belong to the group of lactic acid bacteria (LAB), and inhabit the gastrointestinal tracts of a wide variety of animals from insects and to human, and the commensal organism in humans and animals. The commensal/probiotic role of enterococci has evolved through thousands of years in mutual coexistence. Enterococcus have many favorable traits that have been appreciated in food fermentation and preservation, and many serve as probiotics to promote health. While lactobacillus have been shown to confer numerous benefits on and often regarded as health bringing organisms, enterococci have become more recognized as emerging human pathogens in recent years. Mac Callum and Hastings characterized an organism, now known to be Enterococcal faecalis, which was isolated from a lethal case of endocarditis on 1899. The report was the first detailed description of its pathogenic capabilities. Over the past few decades, multi-drug resistance enterococci have become as important health-care associated pathogen, and leading causes of drug resistance infection. The modern life style including the broad use of antibiotics in medical practice and animal husbandry have selected for the convergence of potential virulence factors to the specific enterococcus species such as E. faecium and E. faecalis. The development of modern medical care of intensive and invasive medical therapies and treatments for human disease, and existence of severe compromised patients in hospitals has contributed to the increased prevalence of these opportunistic organisms. The virulence factors converged in E. faecalis and E. faecium which have been isolated in nosocomial infections, include antibiotic resistance, extracellular proteins (toxins), extrachromosome and mobile genetic elements, cell wall components, biofilm formation, adherence factors, and colonization factor such as bacteriocin, etc. In these potential virulence factors, I presented characteristics of enterococcal conjugative plasmid, cytolysin, collagen binding protein of adhesion, bacteriocins, and drug resistances. I made reference to our original reports, and review books for this review. The review books are "Enterococci: from Commensals to Leading Causes of Drug Resistant Infection, NCBI Bookshelf. A service of the National Library of Medicine, National Institute of Health. Ed. by Michael S Gilmore, Don B Clewell, Yasuyoshi Ike, and Nathan Shankar", and "The Enterococci: Pathogenesis, Molecular Biology, and Antibiotic Resistance, Gilmore M., Clewell D., Courvadin P., Dunny G., Murray B., Rice L., (ed) 2002. ASM Press".
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Affiliation(s)
- Yasuyoshi Ike
- Professor Emeritus, Gunma University Graduate School of Medicine
- Representative Director, Association for Education in Bacterial Drug Resistance
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28
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Abstract
Infective endocarditis affects approximately 100,000 individuals in the USA. Medical advances have contributed to the rise of the disease, and no new therapies have emerged in the last 50 years to control the surge of this life-threatening infection. The rabbit vascular physiology and immune response mechanisms are similar to humans. Hence, the rabbit model of infective endocarditis is an excellent research tool with which to address many questions regarding development of endocarditis, for the testing of new therapies, and for the study of the molecular mechanisms used by infectious agents to cause disease. This chapter describes the surgical procedure required to study infective endocarditis in damaged native valves, therefore closely mimicking human disease.
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Detection of Virulence Genes in Enterococci Isolated From the Human Normal Flora by Multiplex-Polymerase Chain Reaction. INFECTIOUS DISEASES IN CLINICAL PRACTICE 2016. [DOI: 10.1097/ipc.0000000000000397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Joghataei M, Yavarmanesh M, Dovom MRE. Safety Evaluation and Antibacterial Activity of Enterococci Isolated from Lighvan Cheese. J Food Saf 2016. [DOI: 10.1111/jfs.12289] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mehri Joghataei
- Department of Food science and Technology, Faculty of Agriculture; Ferdowsi University of Mashhad; Mashhad Iran
| | - Masoud Yavarmanesh
- Department of Food science and Technology, Faculty of Agriculture; Ferdowsi University of Mashhad; Mashhad Iran
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Montealegre MC, Singh KV, Murray BE. Gastrointestinal Tract Colonization Dynamics by Different Enterococcus faecium Clades. J Infect Dis 2016; 213:1914-22. [PMID: 26671890 PMCID: PMC4878718 DOI: 10.1093/infdis/jiv597] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 11/03/2015] [Indexed: 12/21/2022] Open
Abstract
Colonization of the gastrointestinal tract (GIT) generally precedes infection with antibiotic-resistant Enterococcus faecium We used a mouse GIT colonization model to test differences in the colonization levels by strains from different E. faecium lineages: clade B, part of the healthy human microbiota; subclade A1, associated with infections; and subclade A2, primarily associated with animals. After mono-inoculation, there was no significant difference in colonization (measured as the geometric mean number of colony-forming units per gram) by the E. faecium clades at any time point (P > .05). However, in competition assays, with 6 of the 7 pairs, clade B strains outcompeted clade A strains in their ability to persist in the GIT; this difference was significant in some pairs by day 2 and in all pairs by day 14 (P < .0008-.0283). This observation may explain the predominance of clade B in the community and why antibiotic-resistant hospital-associated E. faecium are often replaced by clade B strains once patients leave the hospital.
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Affiliation(s)
- Maria Camila Montealegre
- Department of Internal Medicine, Division of Infectious Diseases Center for the Study of Emerging and Re-emerging Pathogens Department of Microbiology and Molecular Genetics, University of Texas Graduate School of Biomedical Sciences at Houston, University of Texas Health Science Center at Houston
| | - Kavindra V Singh
- Department of Internal Medicine, Division of Infectious Diseases Center for the Study of Emerging and Re-emerging Pathogens
| | - Barbara E Murray
- Department of Internal Medicine, Division of Infectious Diseases Center for the Study of Emerging and Re-emerging Pathogens Department of Microbiology and Molecular Genetics, University of Texas Graduate School of Biomedical Sciences at Houston, University of Texas Health Science Center at Houston
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Paganelli FL, Huebner J, Singh KV, Zhang X, van Schaik W, Wobser D, Braat JC, Murray BE, Bonten MJM, Willems RJL, Leavis HL. Genome-wide Screening Identifies Phosphotransferase System Permease BepA to Be Involved in Enterococcus faecium Endocarditis and Biofilm Formation. J Infect Dis 2016; 214:189-95. [PMID: 26984142 DOI: 10.1093/infdis/jiw108] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/07/2016] [Indexed: 02/02/2023] Open
Abstract
Enterococcus faecium is a common cause of nosocomial infections, of which infective endocarditis is associated with substantial mortality. In this study, we used a microarray-based transposon mapping (M-TraM) approach to evaluate a rat endocarditis model and identified a gene, originally annotated as "fruA" and renamed "bepA," putatively encoding a carbohydrate phosphotransferase system (PTS) permease (biofilm and endocarditis-associated permease A [BepA]), as important in infective endocarditis. This gene is highly enriched in E. faecium clinical isolates and absent in commensal isolates that are not associated with infection. Confirmation of the phenotype was established in a competition experiment of wild-type and a markerless bepA mutant in a rat endocarditis model. In addition, deletion of bepA impaired biofilm formation in vitro in the presence of 100% human serum and metabolism of β-methyl-D-glucoside. β-glucoside metabolism has been linked to the metabolism of glycosaminoglycans that are exposed on injured heart valves, where bacteria attach and form vegetations. Therefore, we propose that the PTS permease BepA is directly implicated in E. faecium pathogenesis.
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Affiliation(s)
- Fernanda L Paganelli
- Department of Medical Microbiology, University Medical Center Utrecht, The Netherlands
| | - Johannes Huebner
- Division of Pediatric Infectious Diseases, Hauner Children's Hospital, Ludwigs-Maximilian Universität München Center for Infectious Disease and Travel Medicine, University Medical Center Freiburg, Germany
| | - Kavindra V Singh
- Department of Internal Medicine, Division of Infectious Diseases Center for the Study of Emerging and Re-emerging Pathogens
| | - Xinglin Zhang
- Department of Medical Microbiology, University Medical Center Utrecht, The Netherlands
| | - Willem van Schaik
- Department of Medical Microbiology, University Medical Center Utrecht, The Netherlands
| | - Dominique Wobser
- Center for Infectious Disease and Travel Medicine, University Medical Center Freiburg, Germany
| | - Johanna C Braat
- Department of Medical Microbiology, University Medical Center Utrecht, The Netherlands
| | - Barbara E Murray
- Department of Internal Medicine, Division of Infectious Diseases Center for the Study of Emerging and Re-emerging Pathogens Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston
| | - Marc J M Bonten
- Department of Medical Microbiology, University Medical Center Utrecht, The Netherlands
| | - Rob J L Willems
- Department of Medical Microbiology, University Medical Center Utrecht, The Netherlands
| | - Helen L Leavis
- Department of Medical Microbiology, University Medical Center Utrecht, The Netherlands
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Complete Genome Sequence of the Gut Commensal and Laboratory Strain Enterococcus faecium 64/3. GENOME ANNOUNCEMENTS 2015; 3:3/6/e01275-15. [PMID: 26586871 PMCID: PMC4653773 DOI: 10.1128/genomea.01275-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The genome sequence of the commensal and widely used laboratory strain Enterococcus faecium 64/3 was resolved by means of PacificBioscience and Illumina whole-genome sequencing. The genome comprises 2,575,333 bp with 2,382 coding sequences as assigned by NCBI.
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The fibronectin-binding protein Fnm contributes to adherence to extracellular matrix components and virulence of Enterococcus faecium. Infect Immun 2015; 83:4653-61. [PMID: 26371130 DOI: 10.1128/iai.00885-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 09/10/2015] [Indexed: 12/29/2022] Open
Abstract
The interaction between bacteria and fibronectin is believed to play an important role in the pathogenicity of clinically important Gram-positive cocci. In the present study, we identified a gene encoding a predicted fibronectin-binding protein of Enterococcus faecium (fnm), a homologue of Streptococcus pneumoniae pavA, in the genomes of E. faecium strain TX82 and all other sequenced E. faecium isolates. Full-length recombinant Fnm from strain TX82 bound to immobilized fibronectin in a concentration-dependent manner and also appeared to bind collagen type V and laminin, but not other proteins, such as transferrin, heparin, bovine serum albumin, mucin, or collagen IV. We demonstrated that the N-terminal fragment of Fnm is required for full fibronectin binding, since truncation of this region caused a 2.4-fold decrease (P < 0.05) in the adhesion of E. faecium TX82 to fibronectin. Deletion of fnm resulted in a significant reduction (P < 0.001) in the ability of the mutant, TX6128, to bind fibronectin relative to that of the wild-type strain; in situ reconstitution of fnm in the deletion mutant strain restored adherence. In addition, the Δfnm mutant was highly attenuated relative to TX82 (P ≤ 0.0001) in a mixed-inoculum rat endocarditis model. Taken together, these results demonstrate that Fnm affects the adherence of E. faecium to fibronectin and is important in the pathogenesis of experimental endocarditis.
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Wang H, Lee M, Peng Z, Blázquez B, Lastochkin E, Kumarasiri M, Bouley R, Chang M, Mobashery S. Synthesis and evaluation of 1,2,4-triazolo[1,5-a]pyrimidines as antibacterial agents against Enterococcus faecium. J Med Chem 2015; 58:4194-203. [PMID: 25923368 DOI: 10.1021/jm501831g] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Rapid emergence of antibiotic resistance is one of the most challenging global public health concerns. In particular, vancomycin-resistant Enterococcus faecium infections have been increasing in frequency, representing 25% of enterococci infections in intensive care units. A novel class of 1,2,4-triazolo[1,5-a]pyrimidines active against E. faecium is reported herein. We used a three-component Biginelli-like heterocyclization reaction for the synthesis of a series of these derivatives based on reactions of aldehydes, β-dicarbonyl compounds, and 3-alkylthio-5-amino-1,2,4-triazoles. The resulting compounds were assayed for antimicrobial activity against the ESKAPE panel of bacteria, followed by investigation of their in vitro activities. These analyses identified a subset of 1,2,4-triazolo[1,5-a]pyrimidines that had good narrow-spectrum antibacterial activity against E. faecium and exhibited metabolic stability with low intrinsic clearance. Macromolecular synthesis assays revealed cell-wall biosynthesis as the target of these antibiotics.
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Affiliation(s)
- Huan Wang
- Department of Chemistry and Biochemistry and Eck Institute for Global Health, University of Notre Dame, 423 Nieuwland Hall, Notre Dame, Indiana 46556, United States
| | - Mijoon Lee
- Department of Chemistry and Biochemistry and Eck Institute for Global Health, University of Notre Dame, 423 Nieuwland Hall, Notre Dame, Indiana 46556, United States
| | - Zhihong Peng
- Department of Chemistry and Biochemistry and Eck Institute for Global Health, University of Notre Dame, 423 Nieuwland Hall, Notre Dame, Indiana 46556, United States
| | - Blas Blázquez
- Department of Chemistry and Biochemistry and Eck Institute for Global Health, University of Notre Dame, 423 Nieuwland Hall, Notre Dame, Indiana 46556, United States
| | - Elena Lastochkin
- Department of Chemistry and Biochemistry and Eck Institute for Global Health, University of Notre Dame, 423 Nieuwland Hall, Notre Dame, Indiana 46556, United States
| | - Malika Kumarasiri
- Department of Chemistry and Biochemistry and Eck Institute for Global Health, University of Notre Dame, 423 Nieuwland Hall, Notre Dame, Indiana 46556, United States
| | - Renee Bouley
- Department of Chemistry and Biochemistry and Eck Institute for Global Health, University of Notre Dame, 423 Nieuwland Hall, Notre Dame, Indiana 46556, United States
| | - Mayland Chang
- Department of Chemistry and Biochemistry and Eck Institute for Global Health, University of Notre Dame, 423 Nieuwland Hall, Notre Dame, Indiana 46556, United States
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry and Eck Institute for Global Health, University of Notre Dame, 423 Nieuwland Hall, Notre Dame, Indiana 46556, United States
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Galloway-Peña JR, Liang X, Singh KV, Yadav P, Chang C, La Rosa SL, Shelburne S, Ton-That H, Höök M, Murray BE. The identification and functional characterization of WxL proteins from Enterococcus faecium reveal surface proteins involved in extracellular matrix interactions. J Bacteriol 2015; 197:882-92. [PMID: 25512313 PMCID: PMC4325096 DOI: 10.1128/jb.02288-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 12/10/2014] [Indexed: 11/20/2022] Open
Abstract
The WxL domain recently has been identified as a novel cell wall binding domain found in numerous predicted proteins within multiple Gram-positive bacterial species. However, little is known about the function of proteins containing this novel domain. Here, we identify and characterize 6 Enterococcus faecium proteins containing the WxL domain which, by reverse transcription-PCR (RT-PCR) and genomic analyses, are located in three similarly organized operons, deemed WxL loci A, B, and C. Western blotting, electron microscopy, and enzyme-linked immunosorbent assays (ELISAs) determined that genes of WxL loci A and C encode antigenic, cell surface proteins exposed at higher levels in clinical isolates than in commensal isolates. Secondary structural analyses of locus A recombinant WxL domain-containing proteins found they are rich in β-sheet structure and disordered segments. Using Biacore analyses, we discovered that recombinant WxL proteins from locus A bind human extracellular matrix proteins, specifically type I collagen and fibronectin. Proteins encoded by locus A also were found to bind to each other, suggesting a novel cell surface complex. Furthermore, bile salt survival assays and animal models using a mutant from which all three WxL loci were deleted revealed the involvement of WxL operons in bile salt stress and endocarditis pathogenesis. In summary, these studies extend our understanding of proteins containing the WxL domain and their potential impact on colonization and virulence in E. faecium and possibly other Gram-positive bacterial species.
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Affiliation(s)
- Jessica R Galloway-Peña
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas, USA Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA Center for the Study of Emerging and Re-emerging Pathogens, University of Texas Health Science Center, Houston, Texas, USA
| | - Xiaowen Liang
- Center for Infectious and Inflammatory Diseases, Institute for Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, USA
| | - Kavindra V Singh
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA Center for the Study of Emerging and Re-emerging Pathogens, University of Texas Health Science Center, Houston, Texas, USA
| | - Puja Yadav
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas, USA Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA Center for the Study of Emerging and Re-emerging Pathogens, University of Texas Health Science Center, Houston, Texas, USA
| | - Chungyu Chang
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas, USA
| | - Sabina Leanti La Rosa
- Department of Chemistry, Biotechnology and Food Science, Laboratory of Microbial Gene Technology and Food Microbiology, The Norwegian University of Life Sciences, Aas, Norway
| | - Samuel Shelburne
- Department of Infectious Diseases, Infection Control and Employee Health, M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Hung Ton-That
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas, USA
| | - Magnus Höök
- Center for Infectious and Inflammatory Diseases, Institute for Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, USA
| | - Barbara E Murray
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas, USA Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA Center for the Study of Emerging and Re-emerging Pathogens, University of Texas Health Science Center, Houston, Texas, USA
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Moreno B, Bolea R, Martín-Burriel I, Sanz-Rubio D, Romero A, Vázquez FJ, Badiola JJ. Valvular Endocarditis due to Enterococcus casseliflavus in a 4-Month-Old Female Foal. J Equine Vet Sci 2014. [DOI: 10.1016/j.jevs.2014.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Abstract
The collagen adhesin Acm was the first virulence determinant reported to be important for the pathogenesis of Enterococcus faecium in a rat infective endocarditis model. We had previously reported that there was a slight growth delay associated with acm allelic replacement (cat) mutant strain TX6051 used in that study. Recently, we generated a nonpolar markerless acm deletion mutant and did not observe a delay in growth. We therefore performed comparative genome sequence analysis of wild-type strain TX82 and TX6051 and found a single mutation, a nonsense mutation in the ccpA gene of TX6051. After correcting this mutation, the growth defect of TX6051 was abolished, implicating a role for CcpA in the growth of E. faecium. To confirm this, we created a ccpA deletion mutant of TX82, which also exhibited a slight delay in growth. Furthermore, the ccpA deletion mutant was attenuated (P = 0.0024) in a mixed-inoculum (TX82 plus TX82 ΔccpA) rat endocarditis model and also in an in vitro competitive growth assay; a ccpA-complemented strain showed neither reduced growth nor reduced virulence. We also found attenuation in the endocarditis model with the new acm deletion mutant although not as great as that previously observed with TX6051 carrying the ccpA mutation. Taken together, our data confirm the role of Acm in the pathogenesis of endocarditis. We also show that CcpA affects the growth of E. faecium, that an intact ccpA gene is important for full virulence, and that a ccpA mutation was partly responsible for the highly attenuated phenotype of TX6051.
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Almohamad S, Somarajan SR, Singh KV, Nallapareddy SR, Murray BE. Influence of isolate origin and presence of various genes on biofilm formation by Enterococcus faecium. FEMS Microbiol Lett 2014; 353:151-6. [PMID: 24606170 DOI: 10.1111/1574-6968.12418] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 01/08/2014] [Accepted: 03/04/2014] [Indexed: 11/28/2022] Open
Abstract
Enterococcus faecium, a major cause of nosocomial infections, is often isolated from conditions where biofilm is considered to be important in the establishment of infections. We investigated biofilm formation among E. faecium isolates from diverse sources and found that the occurrence and amount of biofilm formation were significantly greater in clinical isolates than fecal isolates from community volunteers. We also found that the presence of the empfm (E. faecium pilus) operon was associated with the amount of biofilm formation. Furthermore, we analyzed the possible association between the distribution of 16 putative virulence genes and the occurrence of biofilm production. Even though the prevalence of these virulence genes was significantly higher in clinical isolates, we did not observe any correlation with the occurrence of biofilm formation.
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Affiliation(s)
- Sam Almohamad
- Jordan University of Science and Technology, Irbid, Jordan
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Hendrickx APA, van Schaik W, Willems RJL. The cell wall architecture of Enterococcus faecium: from resistance to pathogenesis. Future Microbiol 2014; 8:993-1010. [PMID: 23902146 DOI: 10.2217/fmb.13.66] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The cell wall of Gram-positive bacteria functions as a surface organelle that continuously interacts with its environment through a plethora of cell wall-associated molecules. Enterococcus faecium is a normal inhabitant of the GI tract of mammals, but has recently become an important etiological agent of hospital-acquired infections in debilitated patients. Insights into the assembly and function of enterococcal cell wall components and their interactions with the host during colonization and infection are essential to explain the worldwide emergence of E. faecium as an important multiantibiotic-resistant nosocomial pathogen. Understanding the biochemistry of cell wall biogenesis and principles of antibiotic resistance at the molecular level may open up new frontiers in research on enterococci, particularly for the development of novel antimicrobial strategies. In this article, we outline the current knowledge on the most important antimicrobial resistance mechanisms that involve peptidoglycan synthesis and the role of cell wall constituents, including lipoteichoic acid, wall teichoic acid, capsular polysaccharides, LPxTG cell wall-anchored surface proteins, WxL-type surface proteins and pili, in the pathogenesis of E. faecium.
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Affiliation(s)
- Antoni P A Hendrickx
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
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Safety of the surrogate microorganism Enterococcus faecium NRRL B-2354 for use in thermal process validation. Appl Environ Microbiol 2014; 80:1899-909. [PMID: 24413604 DOI: 10.1128/aem.03859-13] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Enterococcus faecium NRRL B-2354 is a surrogate microorganism used in place of pathogens for validation of thermal processing technologies and systems. We evaluated the safety of strain NRRL B-2354 based on its genomic and functional characteristics. The genome of E. faecium NRRL B-2354 was sequenced and found to comprise a 2,635,572-bp chromosome and a 214,319-bp megaplasmid. A total of 2,639 coding sequences were identified, including 45 genes unique to this strain. Hierarchical clustering of the NRRL B-2354 genome with 126 other E. faecium genomes as well as pbp5 locus comparisons and multilocus sequence typing (MLST) showed that the genotype of this strain is most similar to commensal, or community-associated, strains of this species. E. faecium NRRL B-2354 lacks antibiotic resistance genes, and both NRRL B-2354 and its clonal relative ATCC 8459 are sensitive to clinically relevant antibiotics. This organism also lacks, or contains nonfunctional copies of, enterococcal virulence genes including acm, cyl, the ebp operon, esp, gelE, hyl, IS16, and associated phenotypes. It does contain scm, sagA, efaA, and pilA, although either these genes were not expressed or their roles in enterococcal virulence are not well understood. Compared with the clinical strains TX0082 and 1,231,502, E. faecium NRRL B-2354 was more resistant to acidic conditions (pH 2.4) and high temperatures (60°C) and was able to grow in 8% ethanol. These findings support the continued use of E. faecium NRRL B-2354 in thermal process validation of food products.
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Molecular analysis and distribution of multidrug-resistant Enterococcus faecium isolates belonging to clonal complex 17 in a tertiary care center in Mexico City. BMC Microbiol 2013; 13:291. [PMID: 24330424 PMCID: PMC4029522 DOI: 10.1186/1471-2180-13-291] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 12/02/2013] [Indexed: 11/13/2022] Open
Abstract
Background Enterococcus faecium has recently emerged as a multidrug-resistant nosocomial pathogen involved in outbreaks worldwide. A high rate of resistance to different antibiotics has been associated with virulent clonal complex 17 isolates carrying the esp and hyl genes and the purK1 allele. Results Twelve clinical vancomycin-resistant Enterococcus faecium (VREF) isolates were obtained from pediatric patients at the Hospital Infantil de México Federico Gómez (HIMFG). Among these VREF isolates, 58.3% (7/12) were recovered from urine, while 41.7% (5/12) were recovered from the bloodstream. The VREF isolates showed a 100% rate of resistance to ampicillin, amoxicillin-clavulanate, ciprofloxacin, clindamycin, chloramphenicol, streptomycin, gentamicin, rifampicin, erythromycin and teicoplanin. In addition, 16.7% (2/12) of the isolates were resistant to linezolid, and 66.7% (8/12) were resistant to tetracycline and doxycycline. PCR analysis revealed the presence of the vanA gene in all 12 VREF isolates, esp in 83.3% (10/12) of the isolates and hyl in 50% (6/12) of the isolates. Phylogenetic analysis via molecular typing was performed using pulsed-field gel electrophoresis (PFGE) and demonstrated 44% similarity among the VREF isolates. MLST analysis identified four different sequence types (ST412, ST757, ST203 and ST612). Conclusion This study provides the first report of multidrug-resistant VREF isolates belonging to clonal complex 17 from a tertiary care center in Mexico City. Multidrug resistance and genetic determinants of virulence confer advantages among VREF in the colonization of their host. Therefore, the prevention and control of the spread of nosocomial infections caused by VREF is crucial for identifying new emergent subclones that could be challenging to treat in subsequent years.
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Kang M, Ko YP, Liang X, Ross CL, Liu Q, Murray BE, Höök M. Collagen-binding microbial surface components recognizing adhesive matrix molecule (MSCRAMM) of Gram-positive bacteria inhibit complement activation via the classical pathway. J Biol Chem 2013; 288:20520-31. [PMID: 23720782 DOI: 10.1074/jbc.m113.454462] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Members of a family of collagen-binding microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) from Gram-positive bacteria are established virulence factors in several infectious diseases models. Here, we report that these adhesins also can bind C1q and act as inhibitors of the classical complement pathway. Molecular analyses of Cna from Staphylococcus aureus suggested that this prototype MSCRAMM bound to the collagenous domain of C1q and interfered with the interactions of C1r with C1q. As a result, C1r2C1s2 was displaced from C1q, and the C1 complex was deactivated. This novel function of the Cna-like MSCRAMMs represents a potential immune evasion strategy that could be used by numerous Gram-positive pathogens.
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Affiliation(s)
- Mingsong Kang
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, USA
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Deng Y, Zhang Z, Xie Y, Xiao Y, Kang M, Fan H. A mixed infection of Leuconostoc lactis and vancomycin-resistant Enterococcus in a liver transplant recipient. J Med Microbiol 2012; 61:1621-1624. [PMID: 22878250 DOI: 10.1099/jmm.0.045161-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Bacterial infection in patients who have undergone liver transplantation is a major complication of the procedure. Leuconostoc spp. are important pathogenic bacteria in individuals with poor immune function, especially transplant patients. In this report, we describe the case of a 45-year-old Asian male liver transplant recipient who was initially preliminarily diagnosed with infection with Leuconostoc pseudomesenteroides by using the microbial tests of the VITEK 2 system and the aesculin hydrolysis test, and with vancomycin-resistant Enterococcus. Subsequently, the Leuconostoc isolate was identified as Leuconostoc lactis by 16S rRNA gene partial sequencing. In this paper, we discuss our identification of L. lactis based on physiological characteristics and molecular methodology. Accurate identification of these infections is important for the outcome; use of 16S rRNA gene sequence analysis offers a rapid and precise diagnostic approach. Administration of the drug linezolid may be useful for the treatment of both Leuconostoc spp. and vancomycin-resistant Enterococcus infections. We suggest that clinical analysts should use molecular methods in addition to biochemical tests in order to identify Leuconostoc at the species level more accurately.
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Affiliation(s)
- Yao Deng
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Zhongwei Zhang
- Intensive Care Units, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, PR China
| | - Yi Xie
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Yulin Xiao
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Mei Kang
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Hong Fan
- Department of Respiratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, PR China
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Lebreton F, van Schaik W, Sanguinetti M, Posteraro B, Torelli R, Le Bras F, Verneuil N, Zhang X, Giard JC, Dhalluin A, Willems RJL, Leclercq R, Cattoir V. AsrR is an oxidative stress sensing regulator modulating Enterococcus faecium opportunistic traits, antimicrobial resistance, and pathogenicity. PLoS Pathog 2012; 8:e1002834. [PMID: 22876178 PMCID: PMC3410868 DOI: 10.1371/journal.ppat.1002834] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 06/18/2012] [Indexed: 12/20/2022] Open
Abstract
Oxidative stress serves as an important host/environmental signal that triggers a wide range of responses in microorganisms. Here, we identified an oxidative stress sensor and response regulator in the important multidrug-resistant nosocomial pathogen Enterococcus faecium belonging to the MarR family and called AsrR (antibiotic and stress response regulator). The AsrR regulator used cysteine oxidation to sense the hydrogen peroxide which results in its dissociation to promoter DNA. Transcriptome analysis showed that the AsrR regulon was composed of 181 genes, including representing functionally diverse groups involved in pathogenesis, antibiotic and antimicrobial peptide resistance, oxidative stress, and adaptive responses. Consistent with the upregulated expression of the pbp5 gene, encoding a low-affinity penicillin-binding protein, the asrR null mutant was found to be more resistant to β-lactam antibiotics. Deletion of asrR markedly decreased the bactericidal activity of ampicillin and vancomycin, which are both commonly used to treat infections due to enterococci, and also led to over-expression of two major adhesins, acm and ecbA, which resulted in enhanced in vitro adhesion to human intestinal cells. Additional pathogenic traits were also reinforced in the asrR null mutant including greater capacity than the parental strain to form biofilm in vitro and greater persistance in Galleria mellonella colonization and mouse systemic infection models. Despite overexpression of oxidative stress-response genes, deletion of asrR was associated with a decreased oxidative stress resistance in vitro, which correlated with a reduced resistance to phagocytic killing by murine macrophages. Interestingly, both strains showed similar amounts of intracellular reactive oxygen species. Finally, we observed a mutator phenotype and enhanced DNA transfer frequencies in the asrR deleted strain. These data indicate that AsrR plays a major role in antimicrobial resistance and adaptation for survival within the host, thereby contributes importantly to the opportunistic traits of E. faecium. Multiple antibiotic-resistant isolates of the opportunistic pathogen Enterococcus faecium have emerged and spread worldwide. However, studies aimed at identifying mechanisms that underlie the transformation of E. faecium from its commensal nature into a nosocomial pathogen are scarce. We report pleiotropic roles for a novel oxidative-sensing regulator, called AsrR (antibiotic and stress response regulator), in E. faecium. Based on transcriptomic analysis, phenotypic studies, and animal models, we demonstrate that asrR deletion is responsible for i) diminished susceptibility to penicillins, vancomycin, and cationic antimicrobial peptides, ii) increased adhesion to human cells and biofilm formation, iii) a mutator phenotype and enhanced DNA transfer frequencies, iv) decreased resistance to oxidative stress both in vitro and in murine macrophages, and v) increased host-persistence in both insect and mouse models. AsrR is a stress-sensor and is promptly inactivated in the presence of hydrogen peroxide. Therefore, oxidative stress, which is a main challenge during infection, may be a significant signal used by E. faecium to promote opportunistic traits. This provides a significant resource combining, for the first time in E. faecium, a global transcriptomic approach and a thorough phenotypic study, which places AsrR as a key regulator modulating pathogenicity, antimicrobial resistance, and environmental adaptation.
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Affiliation(s)
- François Lebreton
- University of Caen Basse-Normandie, EA4655 (team “Antibioresistance”), Medical School, Caen, France
| | - Willem van Schaik
- University Medical Center Utrecht, Department of Medical Microbiology, Utrecht, The Netherlands
| | | | | | - Riccardo Torelli
- Catholic University of Sacred Heart, Institute of Microbiology, Rome, Italy
| | - Florian Le Bras
- University of Caen Basse-Normandie, EA4655 (team “Antibioresistance”), Medical School, Caen, France
| | - Nicolas Verneuil
- University of Caen Basse-Normandie, EA4655 (team “Stress and Virulence”), Caen, France
| | - Xinglin Zhang
- University Medical Center Utrecht, Department of Medical Microbiology, Utrecht, The Netherlands
| | - Jean-Christophe Giard
- University of Caen Basse-Normandie, EA4655 (team “Antibioresistance”), Medical School, Caen, France
| | - Anne Dhalluin
- University of Caen Basse-Normandie, EA4655 (team “Antibioresistance”), Medical School, Caen, France
| | - Rob J. L. Willems
- University Medical Center Utrecht, Department of Medical Microbiology, Utrecht, The Netherlands
| | - Roland Leclercq
- University of Caen Basse-Normandie, EA4655 (team “Antibioresistance”), Medical School, Caen, France
- University Hospital of Caen, Department of Microbiology, Caen, France
| | - Vincent Cattoir
- University of Caen Basse-Normandie, EA4655 (team “Antibioresistance”), Medical School, Caen, France
- University Hospital of Caen, Department of Microbiology, Caen, France
- * E-mail:
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Abstract
Treatment of enterococcal infections has long been recognized as an important clinical challenge, particularly in the setting of infective endocarditis (IE). Furthermore, the increase prevalence of isolates exhibiting multidrug resistance (MDR) to traditional anti-enterococcal antibiotics such as ampicillin, vancomycin and aminoglycosides (high-level resistance) poses immense therapeutic dilemmas in hospitals around the world. Unlike IE caused by most isolates of Enterococcus faecalis, which still retain susceptibility to ampicillin and vancomycin, the emergence and dissemination of a hospital-associated genetic clade of multidrug resistant Enterococcus faecium, markedly limits the therapeutic options. The best treatment of IE MDR enterococcal endocarditis is unknown and the paucity of antibiotics with bactericidal activity against these organisms is a cause of serious concern. Although it appears that we are winning the war against E. faecalis, the battle rages on against isolates of multidrug-resistant E. faecium.
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Affiliation(s)
- Jose M. Munita
- Laboratory for Antimicrobial Research, University of Texas Medical School at Houston, Houston, TX, USA. Clínica Alemana – Universidad del Desarrollo School of Medicine, Santiago, Chile
| | - Cesar A. Arias
- Department of Internal Medicine, Division of Infectious Diseases, Center for the Study of Emerging and Reemerging Pathogens, Houston, TX, USA. Laboratory for Antimicrobial Research, University of Texas Medical School at Houston, Houston, TX, USA. Molecular Genetics and Antimicrobial Resistance Unit, Universidad El Bosque, Bogotá, Colombia. University of Texas Medical School, 6431 Fannin St, Room 2.112 MSB, Houston, TX 77030, USA
| | - Barbara E. Murray
- Department of Internal Medicine, Division of Infectious Diseases, Center for the Study of Emerging and Reemerging Pathogens, Houston, TX, USA. Laboratory of Enterococcal Research, University of Texas Medical School at Houston, Houston, TX, USA. Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, Houston, TX, USA. University of Texas Medical School, 6431 Fannin St, Room 2.112 MSB, Houston, TX 77030, USA
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47
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Qin X, Galloway-Peña JR, Sillanpaa J, Roh JH, Nallapareddy SR, Chowdhury S, Bourgogne A, Choudhury T, Muzny DM, Buhay CJ, Ding Y, Dugan-Rocha S, Liu W, Kovar C, Sodergren E, Highlander S, Petrosino JF, Worley KC, Gibbs RA, Weinstock GM, Murray BE. Complete genome sequence of Enterococcus faecium strain TX16 and comparative genomic analysis of Enterococcus faecium genomes. BMC Microbiol 2012; 12:135. [PMID: 22769602 PMCID: PMC3433357 DOI: 10.1186/1471-2180-12-135] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 06/14/2012] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Enterococci are among the leading causes of hospital-acquired infections in the United States and Europe, with Enterococcus faecalis and Enterococcus faecium being the two most common species isolated from enterococcal infections. In the last decade, the proportion of enterococcal infections caused by E. faecium has steadily increased compared to other Enterococcus species. Although the underlying mechanism for the gradual replacement of E. faecalis by E. faecium in the hospital environment is not yet understood, many studies using genotyping and phylogenetic analysis have shown the emergence of a globally dispersed polyclonal subcluster of E. faecium strains in clinical environments. Systematic study of the molecular epidemiology and pathogenesis of E. faecium has been hindered by the lack of closed, complete E. faecium genomes that can be used as references. RESULTS In this study, we report the complete genome sequence of the E. faecium strain TX16, also known as DO, which belongs to multilocus sequence type (ST) 18, and was the first E. faecium strain ever sequenced. Whole genome comparison of the TX16 genome with 21 E. faecium draft genomes confirmed that most clinical, outbreak, and hospital-associated (HA) strains (including STs 16, 17, 18, and 78), in addition to strains of non-hospital origin, group in the same clade (referred to as the HA clade) and are evolutionally considerably more closely related to each other by phylogenetic and gene content similarity analyses than to isolates in the community-associated (CA) clade with approximately a 3-4% average nucleotide sequence difference between the two clades at the core genome level. Our study also revealed that many genomic loci in the TX16 genome are unique to the HA clade. 380 ORFs in TX16 are HA-clade specific and antibiotic resistance genes are enriched in HA-clade strains. Mobile elements such as IS16 and transposons were also found almost exclusively in HA strains, as previously reported. CONCLUSIONS Our findings along with other studies show that HA clonal lineages harbor specific genetic elements as well as sequence differences in the core genome which may confer selection advantages over the more heterogeneous CA E. faecium isolates. Which of these differences are important for the success of specific E. faecium lineages in the hospital environment remain(s) to be determined.
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Affiliation(s)
- Xiang Qin
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza MSC-226, Houston, TX, USA
| | - Jessica R Galloway-Peña
- Department of Medicine, Division of Infectious Disease, Houston, TX, USA,Center for the Study of Emerging and Reemerging Pathogens, Houston, TX, USA,Department of Microbiology and Molecular Genetics, University of Texas Medical School, 6431 Fannin Street, Houston, TX, 77030, USA
| | - Jouko Sillanpaa
- Department of Medicine, Division of Infectious Disease, Houston, TX, USA,Center for the Study of Emerging and Reemerging Pathogens, Houston, TX, USA
| | - Jung Hyeob Roh
- Department of Medicine, Division of Infectious Disease, Houston, TX, USA,Center for the Study of Emerging and Reemerging Pathogens, Houston, TX, USA
| | - Sreedhar R Nallapareddy
- Department of Medicine, Division of Infectious Disease, Houston, TX, USA,Center for the Study of Emerging and Reemerging Pathogens, Houston, TX, USA
| | - Shahreen Chowdhury
- Department of Medicine, Division of Infectious Disease, Houston, TX, USA,Center for the Study of Emerging and Reemerging Pathogens, Houston, TX, USA
| | - Agathe Bourgogne
- Department of Medicine, Division of Infectious Disease, Houston, TX, USA,Center for the Study of Emerging and Reemerging Pathogens, Houston, TX, USA
| | - Tina Choudhury
- Department of Medicine, Division of Infectious Disease, Houston, TX, USA,Center for the Study of Emerging and Reemerging Pathogens, Houston, TX, USA
| | - Donna M Muzny
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza MSC-226, Houston, TX, USA
| | - Christian J Buhay
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza MSC-226, Houston, TX, USA
| | - Yan Ding
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza MSC-226, Houston, TX, USA
| | - Shannon Dugan-Rocha
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza MSC-226, Houston, TX, USA
| | - Wen Liu
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza MSC-226, Houston, TX, USA
| | - Christie Kovar
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza MSC-226, Houston, TX, USA
| | - Erica Sodergren
- The Genome Institute, Washington University, 4444 Forest Park Avenue, Campus Box 8501, St. Louis, MO, 63108, USA
| | - Sarah Highlander
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, One Baylor Plaza MSC-226, Houston, TX, USA
| | - Joseph F Petrosino
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, One Baylor Plaza MSC-226, Houston, TX, USA
| | - Kim C Worley
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza MSC-226, Houston, TX, USA
| | - Richard A Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza MSC-226, Houston, TX, USA
| | - George M Weinstock
- The Genome Institute, Washington University, 4444 Forest Park Avenue, Campus Box 8501, St. Louis, MO, 63108, USA
| | - Barbara E Murray
- Department of Medicine, Division of Infectious Disease, Houston, TX, USA,Center for the Study of Emerging and Reemerging Pathogens, Houston, TX, USA,Department of Microbiology and Molecular Genetics, University of Texas Medical School, 6431 Fannin Street, Houston, TX, 77030, USA
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Rathnayake IU, Hargreaves M, Huygens F. Antibiotic resistance and virulence traits in clinical and environmental Enterococcus faecalis and Enterococcus faecium isolates. Syst Appl Microbiol 2012; 35:326-33. [PMID: 22742879 DOI: 10.1016/j.syapm.2012.05.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 05/21/2012] [Accepted: 05/29/2012] [Indexed: 10/28/2022]
Abstract
This study compared virulence and antibiotic resistance traits in clinical and environmental Enterococcus faecalis and Enterococcus faecium isolates. E. faecalis isolates harboured a broader spectrum of virulence determinants compared to E. faecium isolates. The virulence traits Cyl-A, Cyl-B, Cyl-M, gel-E, esp and acm were tested and environmental isolates predominantly harboured gel-E (80% of E. faecalis and 31.9% of E. faecium) whereas esp was more prevalent in clinical isolates (67.8% of E. faecalis and 70.4% of E. faecium). E. faecalis and E. faecium isolated from water had different antibiotic resistance patterns compared to those isolated from clinical samples. Linezolid resistance was not observed in any isolates tested and vancomycin resistance was observed only in clinical isolates. Resistance to other antibiotics (tetracycline, gentamicin, ciprofloxacin and ampicillin) was detected in both clinical and water isolates. Clinical isolates were more resistant to all the antibiotics tested compared to water isolates. Multi-drug resistance was more prevalent in clinical isolates (71.2% of E. faecalis and 70.3% of E. faecium) compared to water isolates (only 5.7% E. faecium). tet L and tet M genes were predominantly identified in tetracycline-resistant isolates. All water and clinical isolates resistant to ciprofloxacin and ampicillin contained mutations in the gyrA, parC and pbp5 genes. A significant correlation was found between the presence of virulence determinants and antibiotic resistance in all the isolates tested in this study (p<0.05). The presence of antibiotic resistant enterococci, together with associated virulence traits, in surface recreational water could be a public health risk.
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Affiliation(s)
- I U Rathnayake
- School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Australia
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49
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Lebreton F, Le Bras F, Reffuveille F, Ladjouzi R, Giard JC, Leclercq R, Cattoir V. Galleria mellonella as a model for studying Enterococcus faecium host persistence. J Mol Microbiol Biotechnol 2012; 21:191-6. [PMID: 22286046 DOI: 10.1159/000332737] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Enterococcus faecium is an opportunistic pathogen responsible for numerous outbreaks worldwide. The basis for the colonization capacities, host persistence and environmental stress response of the hospital-adapted clones emerging from E. faecium are poorly understood. In this study, we propose the use of Galleria mellonella as a simple nonmammalian model to assess E. faecium host persistence. Various strains (n = 10), including hospital-adapted, commensal or animal isolates and a SodA-deficient strain were used to assess the relevance of this model. Compared to Enterococcus faecalis, E. faecium strains do not appear very lethal in a Galleria killing assay. The ability of E. faecium strains to overcome host-immune responses and multiply within the host system was evaluated by monitoring bacterial loads following Galleria infection. Among the E. faecium strains, two hospital-adapted isolates displayed increased colonization ability. In contrast, inactivation of sodA, encoding a putative manganese-dependent superoxide dismutase, significantly reduced survival of E. faecium to Galleria defenses. Galleria appears to be a suitable and convenient surrogate model to study E. faecium survival to host defenses and the role of suspected virulence factors in the colonization process.
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Affiliation(s)
- François Lebreton
- EA2128, Service de Microbiologie, Centre Hospitalier Universitaire, Université de Caen Basse-Normandie, Caen, France
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50
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Paganelli FL, Willems RJ, Leavis HL. Optimizing future treatment of enterococcal infections: attacking the biofilm? Trends Microbiol 2011; 20:40-9. [PMID: 22169461 DOI: 10.1016/j.tim.2011.11.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 10/19/2011] [Accepted: 11/02/2011] [Indexed: 11/16/2022]
Abstract
Enterococcus faecalis and Enterococcus faecium are among the leading causative agents of nosocomial infections and are infamous for their resistance to many antibiotics. They cause difficult-to-treat infections, often originating from biofilm-mediated infections associated with implanted medical devices or endocarditis. Biofilms protect bacteria against antibiotics and phagocytosis, and physical removal of devices or infected tissue is often needed but is frequently not possible. Currently there are no clinically available compounds that disassemble biofilms. In this review we discuss all known structural and regulatory genes involved in enterococcal biofilm formation, the compounds directed against biofilm formation that have been studied, and potentially useful targets for future drugs to treat enterococcal biofilm-associated infections.
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Affiliation(s)
- Fernanda L Paganelli
- Department of Medical Microbiology, University Medical Center Utrecht, The Netherlands
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