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Klupt S, Fam KT, Zhang X, Chodisetti PK, Mehmood A, Boyd T, Grotjahn D, Park D, Hang HC. Secreted antigen A peptidoglycan hydrolase is essential for Enterococcus faecium cell separation and priming of immune checkpoint inhibitor therapy. eLife 2024; 13:RP95297. [PMID: 38857064 PMCID: PMC11164530 DOI: 10.7554/elife.95297] [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] [Indexed: 06/11/2024] Open
Abstract
Enterococcus faecium is a microbiota species in humans that can modulate host immunity (Griffin and Hang, 2022), but has also acquired antibiotic resistance and is a major cause of hospital-associated infections (Van Tyne and Gilmore, 2014). Notably, diverse strains of E. faecium produce SagA, a highly conserved peptidoglycan hydrolase that is sufficient to promote intestinal immunity (Rangan et al., 2016; Pedicord et al., 2016; Kim et al., 2019) and immune checkpoint inhibitor antitumor activity (Griffin et al., 2021). However, the functions of SagA in E. faecium were unknown. Here, we report that deletion of sagA impaired E. faecium growth and resulted in bulged and clustered enterococci due to defective peptidoglycan cleavage and cell separation. Moreover, ΔsagA showed increased antibiotic sensitivity, yielded lower levels of active muropeptides, displayed reduced activation of the peptidoglycan pattern-recognition receptor NOD2, and failed to promote cancer immunotherapy. Importantly, the plasmid-based expression of SagA, but not its catalytically inactive mutant, restored ΔsagA growth, production of active muropeptides, and NOD2 activation. SagA is, therefore, essential for E. faecium growth, stress resistance, and activation of host immunity.
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Affiliation(s)
- Steven Klupt
- Department of Immunology and Microbiology, Scripps ResearchLa JollaUnited States
| | - Kyong Tkhe Fam
- Department of Immunology and Microbiology, Scripps ResearchLa JollaUnited States
| | - Xing Zhang
- Department of Immunology and Microbiology, Scripps ResearchLa JollaUnited States
| | | | - Abeera Mehmood
- Department of Immunology and Microbiology, Scripps ResearchLa JollaUnited States
| | - Tumara Boyd
- Department of Integrative Structural & Computational Biology, Scripps ResearchLa JollaUnited States
| | - Danielle Grotjahn
- Department of Integrative Structural & Computational Biology, Scripps ResearchLa JollaUnited States
| | - Donghyun Park
- Department of Integrative Structural & Computational Biology, Scripps ResearchLa JollaUnited States
| | - Howard C Hang
- Department of Immunology and Microbiology, Scripps ResearchLa JollaUnited States
- Department of Chemistry, Scripps ResearchLa JollaUnited States
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2
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Puca V, Marinacci B, Pellegrini B, Campanile F, Santagati M, Grande R. Biofilm and bacterial membrane vesicles: recent advances. Expert Opin Ther Pat 2024; 34:475-491. [PMID: 38578180 DOI: 10.1080/13543776.2024.2338101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 03/21/2024] [Indexed: 04/06/2024]
Abstract
INTRODUCTION Bacterial Membrane Vesicles (MVs) play important roles in cell-to-cell communication and transport of several molecules. Such structures are essential components of Extracellular Polymeric Substances (EPS) biofilm matrix of many bacterial species displaying a structural function and a role in virulence and pathogenesis. AREAS COVERED In this review were included original articles from the last ten years by searching the keywords 'biofilm' and 'vesicles' on PUBMED and Scopus databases. The articles available in literature mainly describe a positive correlation between bacterial MVs and biofilms formation. The research on Espacenet and Google Patent databases underlines the available patents related to the application of both biofilm MVs and planktonic MVs in inhibiting biofilm formation. EXPERT OPINION This review covers and analyzes recent advances in the study of the relationship between bacterial vesicles and biofilm. The huge number of papers discussing the role of MVs confirms the interest aimed at developing new applications in the medical field. The study of the MVs composition and biogenesis may contribute to the identification of components which could be (i) the target for the development of new drugs inhibiting the biofilm establishment; (ii) candidates for the development of vaccines; (iii) biomarkers for the diagnosis of bacterial infections.
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Affiliation(s)
- Valentina Puca
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Beatrice Marinacci
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
- Department of Innovative Technologies in Medicine & Dentistry, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Benedetta Pellegrini
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - Floriana Campanile
- Department of Biomedical and Biotechnological Sciences (BIOMETEC) - Microbiology Section, University of Catania, Catania, Italy
| | - Maria Santagati
- Department of Biomedical and Biotechnological Sciences (BIOMETEC) - Microbiology Section, University of Catania, Catania, Italy
| | - Rossella Grande
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, Chieti, Italy
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3
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Sangiorgio G, Calvo M, Migliorisi G, Campanile F, Stefani S. The Impact of Enterococcus spp. in the Immunocompromised Host: A Comprehensive Review. Pathogens 2024; 13:409. [PMID: 38787261 PMCID: PMC11124283 DOI: 10.3390/pathogens13050409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Revised: 05/05/2024] [Accepted: 05/14/2024] [Indexed: 05/25/2024] Open
Abstract
The immunocompromised host is usually vulnerable to infectious diseases due to broad-spectrum treatments and immunological dysregulation. The Enterococcus genus consists of normal gut commensals, which acquire a leading role in infective processes among individuals with compromised immune systems. These microorganisms may express a potential virulence and resistance spectrum, enabling their function as severe pathogens. The Enterococcus spp. infections in immunocompromised hosts appear to be difficult to resolve due to the immunological response impairment and the possibility of facing antimicrobial-resistant strains. As regards the related risk factors, several data demonstrated that prior antibiotic exposure, medical device insertion, prolonged hospitalization and surgical interventions may lead to Enterococcus overgrowth, antibiotic resistance and spread among critical healthcare settings. Herein, we present a comprehensive review of Enterococcus spp. in the immunocompromised host, summarizing the available knowledge about virulence factors, antimicrobial-resistance mechanisms and host-pathogen interaction. The review ultimately yearns for more substantial support to further investigations about enterococcal infections and immunocompromised host response.
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Affiliation(s)
- Giuseppe Sangiorgio
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via Santa Sofia 97, 95123 Catania, Italy; (F.C.); (S.S.)
| | - Maddalena Calvo
- U.O.C. Laboratory Analysis Unit, University Hospital Policlinico-San Marco, Via Santa Sofia 78, 95123 Catania, Italy; (M.C.); (G.M.)
| | - Giuseppe Migliorisi
- U.O.C. Laboratory Analysis Unit, University Hospital Policlinico-San Marco, Via Santa Sofia 78, 95123 Catania, Italy; (M.C.); (G.M.)
| | - Floriana Campanile
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via Santa Sofia 97, 95123 Catania, Italy; (F.C.); (S.S.)
| | - Stefania Stefani
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via Santa Sofia 97, 95123 Catania, Italy; (F.C.); (S.S.)
- U.O.C. Laboratory Analysis Unit, University Hospital Policlinico-San Marco, Via Santa Sofia 78, 95123 Catania, Italy; (M.C.); (G.M.)
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Klupt S, Fam KT, Zhang X, Chodisetti PK, Mehmood A, Boyd T, Grotjahn D, Park D, Hang HC. Secreted antigen A peptidoglycan hydrolase is essential for Enterococcus faecium cell separation and priming of immune checkpoint inhibitor therapy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.19.567738. [PMID: 38014356 PMCID: PMC10680833 DOI: 10.1101/2023.11.19.567738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Enterococcus faecium is a microbiota species in humans that can modulate host immunity1, but has also acquired antibiotic resistance and is a major cause of hospital-associated infections2. Notably, diverse strains of E. faecium produce SagA, a highly conserved peptidoglycan hydrolase that is sufficient to promote intestinal immunity3-5 and immune checkpoint inhibitor antitumor activity6. However, the functions of SagA in E. faecium were unknown. Here we report that deletion of sagA impaired E. faecium growth and resulted in bulged and clustered enterococci due to defective peptidoglycan cleavage and cell separation. Moreover, ΔsagA showed increased antibiotic sensitivity, yielded lower levels of active muropeptides, displayed reduced activation of the peptidoglycan pattern-recognition receptor NOD2, and failed to promote cancer immunotherapy. Importantly, plasmid-based expression of SagA, but not its catalytically-inactive mutant, restored ΔsagA growth, production of active muropeptides and NOD2 activation. SagA is therefore essential for E. faecium growth, stress resistance and activation of host immunity.
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Affiliation(s)
- Steven Klupt
- Department of Immunology and Microbiology, Scripps Research, La Jolla, California 92037, United States
- Contributed equally
| | - Kyong Tkhe Fam
- Department of Immunology and Microbiology, Scripps Research, La Jolla, California 92037, United States
- Contributed equally
| | - Xing Zhang
- Department of Immunology and Microbiology, Scripps Research, La Jolla, California 92037, United States
- Contributed equally
| | - Pavan Kumar Chodisetti
- Department of Immunology and Microbiology, Scripps Research, La Jolla, California 92037, United States
| | - Abeera Mehmood
- Department of Immunology and Microbiology, Scripps Research, La Jolla, California 92037, United States
| | - Tumara Boyd
- Department of Integrative Structural & Computational Biology, Scripps Research, La Jolla, California 92037, United States
| | - Danielle Grotjahn
- Department of Integrative Structural & Computational Biology, Scripps Research, La Jolla, California 92037, United States
| | - Donghyun Park
- Department of Integrative Structural & Computational Biology, Scripps Research, La Jolla, California 92037, United States
| | - Howard C. Hang
- Department of Immunology and Microbiology, Scripps Research, La Jolla, California 92037, United States
- Department of Chemistry, Scripps Research, La Jolla, California 92037, United States
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5
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Wagner TM, Romero-Saavedra F, Laverde D, Johannessen M, Hübner J, Hegstad K. Enterococcal Membrane Vesicles as Vaccine Candidates. Int J Mol Sci 2023; 24:16051. [PMID: 38003243 PMCID: PMC10671723 DOI: 10.3390/ijms242216051] [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: 10/11/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
Enterococcus faecium is a leading cause of nosocomial infections, particularly in immunocompromised patients. The rise of multidrug-resistant E. faecium, including Vancomycin-Resistant Enterococci (VRE), is a major concern. Vaccines are promising alternatives to antibiotics, but there is currently no vaccine available against enterococci. In a previous study, we identified six protein vaccine candidates associated with extracellular membrane vesicles (MVs) produced by nosocomial E. faecium. In this study, we immunized rabbits with two different VRE-derived MV preparations and characterized the resulting immune sera. Both anti-MV sera exhibited high immunoreactivity towards the homologous strain, three additional VRE strains, and eight different unrelated E. faecium strains representing different sequence types (STs). Additionally, we demonstrated that the two anti-MV sera were able to mediate opsonophagocytic killing of not only the homologous strain but also three unrelated heterologous VRE strains. Altogether, our results indicate that E. faecium MVs, regardless of the purification method for obtaining them, are promising vaccine candidates against multidrug-resistant E. faecium and suggest that these naturally occurring MVs can be used as a multi-antigen platform to elicit protective immune responses against enterococcal infections.
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Affiliation(s)
- Theresa Maria Wagner
- Research Group for Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, N-9037 Tromsø, Norway; (T.M.W.); (M.J.)
| | - Felipe Romero-Saavedra
- Division of Pediatric Infectious Diseases, Dr. von Hauner Children’s Hospital, Ludwig Maximilians University, 80337 Munich, Germany; (F.R.-S.); (D.L.); (J.H.)
| | - Diana Laverde
- Division of Pediatric Infectious Diseases, Dr. von Hauner Children’s Hospital, Ludwig Maximilians University, 80337 Munich, Germany; (F.R.-S.); (D.L.); (J.H.)
| | - Mona Johannessen
- Research Group for Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, N-9037 Tromsø, Norway; (T.M.W.); (M.J.)
| | - Johannes Hübner
- Division of Pediatric Infectious Diseases, Dr. von Hauner Children’s Hospital, Ludwig Maximilians University, 80337 Munich, Germany; (F.R.-S.); (D.L.); (J.H.)
| | - Kristin Hegstad
- Research Group for Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, N-9037 Tromsø, Norway; (T.M.W.); (M.J.)
- Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, N-9038 Tromsø, Norway
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6
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Jang KK, Heaney T, London M, Ding Y, Putzel G, Yeung F, Ercelen D, Chen YH, Axelrad J, Gurunathan S, Zhou C, Podkowik M, Arguelles N, Srivastava A, Shopsin B, Torres VJ, Keestra-Gounder AM, Pironti A, Griffin ME, Hang HC, Cadwell K. Antimicrobial overproduction sustains intestinal inflammation by inhibiting Enterococcus colonization. Cell Host Microbe 2023; 31:1450-1468.e8. [PMID: 37652008 PMCID: PMC10502928 DOI: 10.1016/j.chom.2023.08.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 07/02/2023] [Accepted: 08/07/2023] [Indexed: 09/02/2023]
Abstract
Loss of antimicrobial proteins such as REG3 family members compromises the integrity of the intestinal barrier. Here, we demonstrate that overproduction of REG3 proteins can also be detrimental by reducing a protective species in the microbiota. Patients with inflammatory bowel disease (IBD) experiencing flares displayed heightened levels of secreted REG3 proteins that mediated depletion of Enterococcus faecium (Efm) from the gut microbiota. Efm inoculation of mice ameliorated intestinal inflammation through activation of the innate immune receptor NOD2, which was associated with the bacterial DL-endopeptidase SagA that generates NOD2-stimulating muropeptides. NOD2 activation in myeloid cells induced interleukin-1β (IL-1β) secretion to increase the proportion of IL-22-producing CD4+ T helper cells and innate lymphoid cells that promote tissue repair. Finally, Efm was unable to protect mice carrying a NOD2 gene variant commonly found in IBD patients. Our findings demonstrate that inflammation self-perpetuates by causing aberrant antimicrobial activity that disrupts symbiotic relationships with gut microbes.
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Affiliation(s)
- Kyung Ku Jang
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Thomas Heaney
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Mariya London
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Yi Ding
- Department of Laboratory Medicine, Geisinger Health, Danville, PA 17822, USA
| | - Gregory Putzel
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA; Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Frank Yeung
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Defne Ercelen
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Ying-Han Chen
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Jordan Axelrad
- Division of Gastroenterology and Hepatology, Department of Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Sakteesh Gurunathan
- Division of Gastroenterology and Hepatology, Department of Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Chaoting Zhou
- Cell and Molecular Biology Graduate Program, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Division of Gastroenterology and Hepatology, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Magdalena Podkowik
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, NY 10016, USA; Division of Infectious Diseases and Immunology, Department of Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Natalia Arguelles
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA; Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Anusha Srivastava
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA; Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Bo Shopsin
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA; Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, NY 10016, USA; Division of Infectious Diseases and Immunology, Department of Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Victor J Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA; Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - A Marijke Keestra-Gounder
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Alejandro Pironti
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY 10016, USA; Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Matthew E Griffin
- Department of Immunology and Microbiology, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Howard C Hang
- Department of Immunology and Microbiology, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA; Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Ken Cadwell
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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7
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Șchiopu P, Toc DA, Colosi IA, Costache C, Ruospo G, Berar G, Gălbău ȘG, Ghilea AC, Botan A, Pană AG, Neculicioiu VS, Todea DA. An Overview of the Factors Involved in Biofilm Production by the Enterococcus Genus. Int J Mol Sci 2023; 24:11577. [PMID: 37511337 PMCID: PMC10380289 DOI: 10.3390/ijms241411577] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/08/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
Enterococcus species are known for their ability to form biofilms, which contributes to their survival in extreme environments and involvement in persistent bacterial infections, especially in the case of multi-drug-resistant strains. This review aims to provide a comprehensive understanding of the mechanisms underlying biofilm formation in clinically important species such as Enterococcus faecalis and the less studied but increasingly multi-drug-resistant Enterococcus faecium, and explores potential strategies for their eradication. Biofilm formation in Enterococcus involves a complex interplay of genes and virulence factors, including gelatinase, cytolysin, Secreted antigen A, pili, microbial surface components that recognize adhesive matrix molecules (MSCRAMMs), and DNA release. Quorum sensing, a process of intercellular communication, mediated by peptide pheromones such as Cob, Ccf, and Cpd, plays a crucial role in coordinating biofilm development by targeting gene expression and regulation. Additionally, the regulation of extracellular DNA (eDNA) release has emerged as a fundamental component in biofilm formation. In E. faecalis, the autolysin N-acetylglucosaminidase and proteases such as gelatinase and serin protease are key players in this process, influencing biofilm development and virulence. Targeting eDNA may offer a promising avenue for intervention in biofilm-producing E. faecalis infections. Overall, gaining insights into the intricate mechanisms of biofilm formation in Enterococcus may provide directions for anti-biofilm therapeutic research, with the purpose of reducing the burden of Enterococcus-associated infections.
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Affiliation(s)
- Pavel Șchiopu
- Department of Microbiology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- Department of Pneumology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400332 Cluj-Napoca, Romania
| | - Dan Alexandru Toc
- Department of Microbiology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Ioana Alina Colosi
- Department of Microbiology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Carmen Costache
- Department of Microbiology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Giuseppe Ruospo
- Faculty of Medicine, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - George Berar
- Faculty of Medicine, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Ștefan-Gabriel Gălbău
- Faculty of Medicine, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Alexandra Cristina Ghilea
- Faculty of Medicine, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Alexandru Botan
- Faculty of Medicine, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Adrian-Gabriel Pană
- Department of Microbiology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Vlad Sever Neculicioiu
- Department of Microbiology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Doina Adina Todea
- Department of Pneumology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400332 Cluj-Napoca, Romania
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8
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Monteiro Marques J, Coelho M, Santana AR, Pinto D, Semedo-Lemsaddek T. Dissemination of Enterococcal Genetic Lineages: A One Health Perspective. Antibiotics (Basel) 2023; 12:1140. [PMID: 37508236 PMCID: PMC10376465 DOI: 10.3390/antibiotics12071140] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/22/2023] [Accepted: 06/29/2023] [Indexed: 07/30/2023] Open
Abstract
Enterococcus spp. are commensals of the gastrointestinal tracts of humans and animals and colonize a variety of niches such as water, soil, and food. Over the last three decades, enterococci have evolved as opportunistic pathogens, being considered ESKAPE pathogens responsible for hospital-associated infections. Enterococci's ubiquitous nature, excellent adaptative capacity, and ability to acquire virulence and resistance genes make them excellent sentinel proxies for assessing the presence/spread of pathogenic and virulent clones and hazardous determinants across settings of the human-animal-environment triad, allowing for a more comprehensive analysis of the One Health continuum. This review provides an overview of enterococcal fitness and pathogenic traits; the most common clonal complexes identified in clinical, veterinary, food, and environmental sources; as well as the dissemination of pathogenic genomic traits (virulome, resistome, and mobilome) found in high-risk clones worldwide, across the One Health continuum.
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Affiliation(s)
- Joana Monteiro Marques
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Av. da Universidade Técnica de Lisboa, 1300-477 Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisbon, Portugal
| | - Mariana Coelho
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Av. da Universidade Técnica de Lisboa, 1300-477 Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisbon, Portugal
| | - Andressa Rodrigues Santana
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Av. da Universidade Técnica de Lisboa, 1300-477 Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisbon, Portugal
| | - Daniel Pinto
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Av. da Universidade Técnica de Lisboa, 1300-477 Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisbon, Portugal
| | - Teresa Semedo-Lemsaddek
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Av. da Universidade Técnica de Lisboa, 1300-477 Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisbon, Portugal
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9
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Griffin ME, Klupt S, Espinosa J, Hang HC. Peptidoglycan NlpC/P60 peptidases in bacterial physiology and host interactions. Cell Chem Biol 2023; 30:436-456. [PMID: 36417916 PMCID: PMC10192474 DOI: 10.1016/j.chembiol.2022.11.001] [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: 05/18/2022] [Revised: 09/15/2022] [Accepted: 10/31/2022] [Indexed: 11/23/2022]
Abstract
The bacterial cell wall is composed of a highly crosslinked matrix of glycopeptide polymers known as peptidoglycan that dictates bacterial cell morphology and protects against environmental stresses. Regulation of peptidoglycan turnover is therefore crucial for bacterial survival and growth and is mediated by key protein complexes and enzyme families. Here, we review the prevalence, structure, and activity of NlpC/P60 peptidases, a family of peptidoglycan hydrolases that are crucial for cell wall turnover and division as well as interactions with antibiotics and different hosts. Understanding the molecular functions of NlpC/P60 peptidases should provide important insight into bacterial physiology, their interactions with different kingdoms of life, and the development of new therapeutic approaches.
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Affiliation(s)
- Matthew E Griffin
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Steven Klupt
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA
| | - Juliel Espinosa
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY 10065, USA
| | - Howard C Hang
- Department of Immunology and Microbiology, Scripps Research, La Jolla, CA 92037, USA; Department of Chemistry, Scripps Research, La Jolla, CA 92037, USA.
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10
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Jang KK, Heaney T, London M, Ding Y, Yeung F, Ercelen D, Chen YH, Axelrad J, Gurunathan S, Marijke Keestra-Gounder A, Griffin ME, Hang HC, Cadwell K. Antimicrobial overproduction sustains intestinal inflammation by inhibiting Enterococcus colonization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.29.526128. [PMID: 36778381 PMCID: PMC9915521 DOI: 10.1101/2023.01.29.526128] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Loss of antimicrobial proteins such as REG3 family members compromises the integrity of the intestinal barrier. Here, we demonstrate that overproduction of REG3 proteins can also be detrimental by reducing a protective species in the microbiota. Patients with inflammatory bowel disease (IBD) experiencing flares displayed heightened levels of secreted REG3 proteins that mediated depletion of Enterococcus faecium ( Efm ) from the gut microbiota. Efm inoculation of mice ameliorated intestinal inflammation through activation of the innate immune receptor NOD2, which was associated with the bacterial DL-endopeptidase SagA. Microbiota sensing by NOD2 in myeloid cells mediated IL-1β secretion and increased the proportion of IL-22-producing CD4 + T helper cells and innate lymphoid cells. Finally, Efm was unable to protect mice carrying a NOD2 gene variant commonly found in IBD patients. Our findings demonstrate that inflammation self-perpetuates by causing aberrant antimicrobial activity that disrupts symbiotic relationships with gut microbes.
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11
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Yang X, Zhao X, Chen V, Hang HC. Chemical proteomic analysis of bile acid-protein targets in Enterococcus faecium. RSC Chem Biol 2022; 3:1397-1402. [PMID: 36544573 PMCID: PMC9709779 DOI: 10.1039/d2cb00178k] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 09/19/2022] [Indexed: 12/24/2022] Open
Abstract
Bile acids are important gut microbiota metabolites that regulate both host and microbial functions. To identify the direct protein targets of bile acids in Enterococcus, we synthesized and validated the activity of a lithocholic acid (LCA) photoaffinity reporter, x-alk-LCA-3. Chemical proteomics of x-alk-LCA-3 in E. faecium Com15 reveals many candidate LCA-interacting proteins, which are involved in cell well synthesis, transcriptional regulation and metabolism. To validate the utility of bile acid photoaffinity labeling, we characterized a putative bile salt hydrolase (BSH) crosslinked by x-alk-LCA-3, and demonstrated that this BSH was effective in converting taurolithocholic acid (TLCA) to LCA in E. faecium and in vitro. Chemical proteomics should afford new opportunities to characterize bile acid-protein targets and mechanisms of action in the future.
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Affiliation(s)
- Xinglin Yang
- Department of Immunology and Microbiology, Scripps Research La Jolla California 92037 USA
| | - Xiaohui Zhao
- Department of Immunology and Microbiology, Scripps Research La Jolla California 92037 USA
| | - Victor Chen
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University New York New York 10065 USA
| | - Howard C Hang
- Department of Immunology and Microbiology, Scripps Research La Jolla California 92037 USA
- Department of Chemistry, Scripps Research La Jolla California 92037 USA
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12
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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: 15] [Impact Index Per Article: 7.5] [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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13
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Griffin ME, Espinosa J, Becker JL, Luo JD, Carroll TS, Jha JK, Fanger GR, Hang HC. Enterococcus peptidoglycan remodeling promotes checkpoint inhibitor cancer immunotherapy. Science 2021; 373:1040-1046. [PMID: 34446607 DOI: 10.1126/science.abc9113] [Citation(s) in RCA: 168] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/27/2021] [Indexed: 12/17/2022]
Abstract
The antitumor efficacy of cancer immunotherapy can correlate with the presence of certain bacterial species within the gut microbiome. However, many of the molecular mechanisms that influence host response to immunotherapy remain elusive. In this study, we show that members of the bacterial genus Enterococcus improve checkpoint inhibitor immunotherapy in mouse tumor models. Active enterococci express and secrete orthologs of the NlpC/p60 peptidoglycan hydrolase SagA that generate immune-active muropeptides. Expression of SagA in nonprotective E. faecalis was sufficient to promote immunotherapy response, and its activity required the peptidoglycan sensor NOD2. Notably, SagA-engineered probiotics or synthetic muropeptides also augmented anti-PD-L1 antitumor efficacy. Taken together, our data suggest that microbiota species with specialized peptidoglycan remodeling activity and muropeptide-based therapeutics may enhance cancer immunotherapy and could be leveraged as next-generation adjuvants.
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Affiliation(s)
- Matthew E Griffin
- Departments of Immunology and Microbiology and Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.,Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA.,Bioinformatics Resource Center, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA.,Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA.,Departments of Immunology and Microbiology and Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Juliel Espinosa
- Departments of Immunology and Microbiology and Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.,Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA
| | - Jessica L Becker
- Departments of Immunology and Microbiology and Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.,Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA
| | - Ji-Dung Luo
- Bioinformatics Resource Center, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA
| | - Thomas S Carroll
- Bioinformatics Resource Center, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA
| | - Jyoti K Jha
- Rise Therapeutics, 1405 Research Blvd. Suite 220, Rockville, MD 20850, USA
| | - Gary R Fanger
- Rise Therapeutics, 1405 Research Blvd. Suite 220, Rockville, MD 20850, USA
| | - Howard C Hang
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA. .,Departments of Immunology and Microbiology and Department of Chemistry, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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14
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Li Y, Zhang P, Zhang X, Bi X, Wu M, Zou J, Wang Z, Lu F, Dong Z, Gao J. Adipose matrix complex: a high-rigidity collagen-rich adipose-derived material for fat grafting. Aging (Albany NY) 2021; 13:14910-14923. [PMID: 34111029 PMCID: PMC8221321 DOI: 10.18632/aging.203120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 02/09/2021] [Indexed: 12/21/2022]
Abstract
Due to the low percentage of collagen, the rigid support capacity of fat grafts remains unsatisfactory for some clinical applications. In this study, we evaluated a strategy in which adipose matrix complex (AMC) was collected via a mechanical process and transplanted for supportive filling of the face. Our AMC samples were collected from adipose tissue by a filter device consisting of a sleeve, three internal sieves, and a filter bag (100 mesh). AMC derived from adipose tissue had fewer cells than Coleman fat, but much higher levels of collagen and stiffness. Retention rates 90 days after transplantation in nude mice were higher for AMC than for Coleman fat (75±7.5% vs. 42±13.5%; P < 0.05). In addition, AMC maintained a higher stiffness (~6 kPa vs. ~2 kPa; P < 0.01) and stably retained a higher level of collagen. Our findings demonstrate that mechanical collection of AMC from adipose tissue is a practical method for improving fat graft retention and rigid support. This strategy has the potential to improve the quality of lipoaspirates for patients requiring rigid supportive filling.
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Affiliation(s)
- Ye Li
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Pan Zhang
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Xue Zhang
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Xin Bi
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Mengfan Wu
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Jialiang Zou
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Zijue Wang
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Feng Lu
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Ziqing Dong
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Jianhua Gao
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, P.R. China
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15
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Lytic bacteriophages facilitate antibiotic sensitization of Enterococcus faecium. Antimicrob Agents Chemother 2021; 65:AAC.00143-21. [PMID: 33649110 PMCID: PMC8092871 DOI: 10.1128/aac.00143-21] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Enterococcus faecium, a commensal of the human intestine, has emerged as a hospital-adapted, multi-drug resistant (MDR) pathogen. Bacteriophages (phages), natural predators of bacteria, have regained attention as therapeutics to stem the rise of MDR bacteria. Despite their potential to curtail MDR E. faecium infections, the molecular events governing E. faecium-phage interactions remain largely unknown. Such interactions are important to delineate because phage selective pressure imposed on E. faecium will undoubtedly result in phage resistance phenotypes that could threaten the efficacy of phage therapy. In an effort to understand the emergence of phage resistance in E. faecium, three newly isolated lytic phages were used to demonstrate that E. faecium phage resistance is conferred through an array of cell wall-associated molecules, including secreted antigen A (SagA), enterococcal polysaccharide antigen (Epa), wall teichoic acids, capsule, and an arginine-aspartate-aspartate (RDD) protein of unknown function. We find that capsule and Epa are important for robust phage adsorption and that phage resistance mutations in sagA, epaR, and epaX enhance E. faecium susceptibility to ceftriaxone, an antibiotic normally ineffective due to its low affinity for enterococcal penicillin binding proteins. Consistent with these findings, we provide evidence that phages potently synergize with cell wall (ceftriaxone and ampicillin) and membrane-acting (daptomycin) antimicrobials to slow or completely inhibit the growth of E. faecium Our work demonstrates that the evolution of phage resistance comes with fitness defects resulting in drug sensitization and that lytic phages could serve as effective antimicrobials for the treatment of E. faecium infections.
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16
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Espinosa J, Lin TY, Estrella Y, Kim B, Molina H, Hang HC. Enterococcus NlpC/p60 Peptidoglycan Hydrolase SagA Localizes to Sites of Cell Division and Requires Only a Catalytic Dyad for Protease Activity. Biochemistry 2020; 59:4470-4480. [PMID: 33136372 DOI: 10.1021/acs.biochem.0c00755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Peptidoglycan is a vital component of the bacterial cell wall, and its dynamic remodeling by NlpC/p60 hydrolases is crucial for proper cell division and survival. Beyond these essential functions, we previously discovered that Enterococcus species express and secrete the NlpC/p60 hydrolase-secreted antigen A (SagA), whose catalytic activity can modulate host immune responses in animal models. However, the localization and peptidoglycan hydrolase activity of SagA in Enterococcus was still unclear. In this study, we show that SagA contributes to a triseptal structure in dividing cells of enterococci and localizes to sites of cell division through its N-terminal coiled-coil domain. Using molecular modeling and site-directed mutagenesis, we identify amino acid residues within the SagA-NlpC/p60 domain that are crucial for catalytic activity and potential substrate binding. Notably, these studies revealed that SagA may function via a catalytic Cys-His dyad instead of the predicted Cys-His-His triad, which is conserved in SagA orthologs from other Enterococcus species. Our results provide key additional insight into peptidoglycan remodeling in Enterococcus by SagA NlpC/p60 hydrolases.
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Affiliation(s)
- Juliel Espinosa
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, New York 10065, United States
| | - Ti-Yu Lin
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, New York 10065, United States
| | - Yadyvic Estrella
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, New York 10065, United States
| | - Byungchul Kim
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, New York 10065, United States
| | - Henrik Molina
- Proteomics Resource Center, The Rockefeller University, New York, New York 10065, United States
| | - Howard C Hang
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, New York 10065, United States.,Departments of Immunology & Microbiology and Chemistry, Scripps Research, La Jolla, California 92037, United States
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17
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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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18
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Scardaci R, Varese F, Manfredi M, Marengo E, Mazzoli R, Pessione E. Enterococcus faecium NCIMB10415 responds to norepinephrine by altering protein profiles and phenotypic characters. J Proteomics 2020; 231:104003. [PMID: 33038511 DOI: 10.1016/j.jprot.2020.104003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 09/29/2020] [Accepted: 10/04/2020] [Indexed: 12/13/2022]
Abstract
The long-term established symbiosis between gut microbiota and humans is based upon a dynamic equilibrium that, if unbalanced, could lead to the development of diseases. Despite the huge amount of data concerning the microbiota-gut-brain-axis, little information is available on what happens at the molecular level in bacteria, when exposed to human signals. In the present study, the physiological effects exerted by norepinephrine (NE), a human hormone present in significant amounts in the host gut, were analyzed using the commensal/probiotic strain Enterococcus faecium NCIMB10415 as a target. The aim was to compare the protein profiles of treated and untreated bacteria and relating these proteome patterns to some phenotypic modifications important for bacteria-host interaction. Actually, to date, only pathogens have been considered. Combining a gel-free/label-free proteomic analysis with the evaluation of bile salts resistance, biofilm formation and autoaggregation ability (as well as with the bacterial growth kinetics), allowed to detect changes induced by NE treatment on all the tested probiotic properties. Furthermore, exposure to the bioactive molecule increased the abundance of proteins related to stress response and to host-microbe interaction, such as moonlight proteins involved in adhesion and immune stimulation. The results of this investigation demonstrated that, not only pathogens, but also commensal gut bacteria are affected by host-derived hormones, underlining the importance of a correct cross-signalling in the maintenance of gut homeostasis. SIGNIFICANCE: The crucial role played by the human gut microbiota in ensuring host homeostasis and health is definitively ascertained as suggested by the holobiome concept. The present research was intended to shed light on the endocrinological perturbations possibly affecting microbiota. The microbial model used in this study belongs to Enterococcus faecium species, whose controversial role as gut commensal and opportunistic pathogen in the gut ecosystem is well recognized. The results obtained in the present investigation clearly demonstrate that E. faecium NCIMB10415 can sense and respond to norepinephrine, a human hormone abundant at the gut level, by changing protein profiles and physiology, inducing changes that could favor survival and colonization of the host tissues. To our knowledge, this is the first proteomic report concerning the impact of a human hormone on a commensal/probiotic bacterium, since previous research has focused on exploring the effects of neuroendocrine molecules on growth and virulence of pathogenic species.
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Affiliation(s)
- R Scardaci
- Structural and Functional Biochemistry, Laboratory of Microbial Biochemistry and Proteomics, Department of Life Sciences and Systems Biology, Università di Torino, Torino, Italy.
| | - F Varese
- Structural and Functional Biochemistry, Laboratory of Microbial Biochemistry and Proteomics, Department of Life Sciences and Systems Biology, Università di Torino, Torino, Italy
| | - M Manfredi
- Center for Translational Research on Autoimmune and Allergic Diseases, Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - E Marengo
- Center for Translational Research on Autoimmune and Allergic Diseases, Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - R Mazzoli
- Structural and Functional Biochemistry, Laboratory of Microbial Biochemistry and Proteomics, Department of Life Sciences and Systems Biology, Università di Torino, Torino, Italy
| | - E Pessione
- Structural and Functional Biochemistry, Laboratory of Microbial Biochemistry and Proteomics, Department of Life Sciences and Systems Biology, Università di Torino, Torino, Italy.
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19
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Another Breaker of the Wall: the Biological Function of the Usp45 Protein of Lactococcus lactis. Appl Environ Microbiol 2020; 86:AEM.00903-20. [PMID: 32532874 DOI: 10.1128/aem.00903-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 06/01/2020] [Indexed: 11/20/2022] Open
Abstract
Lactococcus lactis is a Gram-positive bacterium that is widely used as a cell factory for the expression of heterologous proteins that are relevant in the pharmaceutical and nutraceutical fields. The signal peptide of the major secreted protein of L. lactis, Usp45, has been employed extensively in engineering strategies to secrete proteins of interest. However, the biological function of Usp45 has remained obscure despite more than 25 years of research. Studies on Usp45 homologs in other Gram-positive bacteria suggest that Usp45 may play a role in cell wall turnover processes. Here, we show the effect of inactivation and overexpression of the usp45 gene on L. lactis growth, phenotype, and cell division. Our results are in agreement with those obtained in streptococci and demonstrate that the L. lactis Usp45 protein is essential for proper cell division. We also show that the usp45 promoter is highly activated by galactose. Overall, our results indicate that Usp45 mediates cell separation, probably by acting as a peptidoglycan hydrolase.IMPORTANCE The cell wall, composed mainly of peptidoglycan, is key to maintaining the cell shape and protecting the cell from bursting. Peptidoglycan degradation by peptidoglycan hydrolysis and autolysins occurs during growth and cell division. Since peptidoglycan hydrolases are important for virulence, envelope integrity, and regulation of cell division, it is valuable to investigate their function and regulation. Notably, PcsB-like proteins such as Usp45 have been proposed as new targets for antimicrobial drugs and could also be target for the development of food-grade suicide systems. In addition, although various other expression and secretion systems have been developed for use in Lactococcus lactis, the most-used signal peptide for protein secretion in this bacterium is that of the Usp45 protein. Thus, elucidating the biological function of Usp45 and determining the factors affecting its expression would contribute to optimize several applications.
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Probiotic Cocktail Identified by Microbial Network Analysis Inhibits Growth, Virulence Gene Expression, and Host Cell Colonization of Vancomycin-Resistant Enterococci. Microorganisms 2020; 8:microorganisms8060816. [PMID: 32486106 PMCID: PMC7357164 DOI: 10.3390/microorganisms8060816] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 05/24/2020] [Accepted: 05/27/2020] [Indexed: 12/16/2022] Open
Abstract
The prevalence of vancomycin resistant enterococcus (VRE) carrier-state has been increasing in patients of intensive care unit and it would be a public health threat. Different research groups conducted decolonizing VRE with probiotic and the results were controversial. Therefore, a systemic approach to search for the probiotic species capable of decolonizing VRE is necessary. Thus, VRE was co-cultured with ten probiotic species. The fluctuations of each bacterial population were analyzed by 16S rRNA sequencing. Microbial network analysis (MNA) was exploited to identify the most critical species in inhibiting the VRE population. The MNA-selected probiotic cocktail was then validated for its efficacy in inhibiting VRE, decolonizing VRE from Caco-2 cells via three approaches: exclusion, competition, and displacement. Finally, the expression of VRE virulence genes after co-incubation with the probiotic cocktail were analyzed with quantitative real-time PCR (qRT-PCR). The MNA-selected probiotic cocktail includes Bacillus coagulans, Lactobacillus rhamnosus GG, Lactobacillus reuteri, and Lactobacillus acidophilus. This probiotic combination significantly reduces the population of co-cultured VRE and prevents VRE from binding to Caco-2 cells by down-regulating several host-adhesion genes of VRE. Our results suggested the potential of this four-strain probiotic cocktail in clinical application for the decolonization of VRE in human gut.
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21
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Abstract
The NlpC/p60-family of peptidoglycan hydrolases are key enzymes that facilitate bacterial cell division and also modulate microbe-host interactions. These endopeptidases utilize conserved Cys-His residues in their active site and are expressed in most bacterial species as well as some eukaryotes. Here we describe methods for biochemical analysis of Enterococcus faecium SagA-NlpC/p60 peptidoglycan hydrolase activity (Kim et al., 2019; Rangan et al., 2016), which includes recombinant protein preparation and biochemical analysis using both gel-based and LC-MS profiling of peptidoglycan fragments. These protocols should also facilitate the biochemical analysis of other NlpC/p60 peptidoglycan hydrolases.
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22
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Fibronectin and Its Role in Human Infective Diseases. Cells 2019; 8:cells8121516. [PMID: 31779172 PMCID: PMC6952806 DOI: 10.3390/cells8121516] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 11/19/2019] [Accepted: 11/22/2019] [Indexed: 01/25/2023] Open
Abstract
Fibronectin is a multidomain glycoprotein ubiquitously detected in extracellular fluids and matrices of a variety of animal and human tissues where it functions as a key link between matrices and cells. Fibronectin has also emerged as the target for a large number of microorganisms, particularly bacteria. There are clear indications that the binding of microorganism’ receptors to fibronectin promotes attachment to and infection of host cells. Each bacterium may use different receptors which recognize specific fibronectin domains, mostly the N-terminal domain and the central cell-binding domain. In many cases, fibronectin receptors have actions over and above that of simple adhesion: In fact, adhesion is often the prerequisite for invasion and internalization of microorganisms in the cells of colonized tissues. This review updates the current understanding of fibronectin receptors of several microorganisms with emphasis on their biochemical and structural properties and the role they can play in the onset and progression of host infection diseases. Furthermore, we describe the antigenic profile and discuss the possibility of designing adhesion inhibitors based on the structure of the fibronectin-binding site in the receptor or the receptor-binding site in fibronectin.
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23
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Development of Opsonic Mouse Monoclonal Antibodies against Multidrug-Resistant Enterococci. Infect Immun 2019; 87:IAI.00276-19. [PMID: 31285252 PMCID: PMC6704603 DOI: 10.1128/iai.00276-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 07/02/2019] [Indexed: 12/11/2022] Open
Abstract
Multidrug-resistant enterococci are major causes of hospital-acquired infections. Immunotherapy with monoclonal antibodies (MAbs) targeting bacterial antigens would be a valuable treatment option in this setting. Here, we describe the development of two MAbs through hybridoma technology that target antigens from the most clinically relevant enterococcal species. Multidrug-resistant enterococci are major causes of hospital-acquired infections. Immunotherapy with monoclonal antibodies (MAbs) targeting bacterial antigens would be a valuable treatment option in this setting. Here, we describe the development of two MAbs through hybridoma technology that target antigens from the most clinically relevant enterococcal species. Diheteroglycan (DHG), a well-characterized capsular polysaccharide of Enterococcus faecalis, and the secreted antigen A (SagA), an immunogenic protein from Enterococcus faecium, are both immunogens that have been proven to raise opsonic and cross-reactive antibodies against enterococcal strains. For this purpose, a conjugated form of the native DHG with SagA was used to raise the antibodies in mice, while enzyme-linked immunosorbent assay and opsonophagocytic assay were combined in the selection process of hybridoma cells producing immunoreactive and opsonic antibodies targeting the selected antigens. From this process, two highly specific IgG1(κ) MAbs were obtained, one against the polysaccharide (DHG.01) and one against the protein (SagA.01). Both MAbs exhibited good opsonic killing against the target bacterial strains: DHG.01 showed 90% killing against E. faecalis type 2, and SagA.01 showed 40% killing against E. faecium 11231/6. In addition, both MAbs showed cross-reactivity toward other E. faecalis and E. faecium strains. The sequences from the variable regions of the heavy and light chains were reconstructed in expression vectors, and the activity of the MAbs upon expression in eukaryotic cells was confirmed with the same immunological assays. In summary, we identified two opsonic MAbs against enterococci which could be used for therapeutic or prophylactic approaches against enterococcal infections.
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Bäuerl C, Abitayeva G, Sosa-Carrillo S, Mencher-Beltrán A, Navarro-Lleó N, Coll-Marqués JM, Zúñiga-Cabrera M, Shaikhin S, Pérez-Martinez G. P40 and P75 Are Singular Functional Muramidases Present in the Lactobacillus casei /paracasei/rhamnosus Taxon. Front Microbiol 2019; 10:1420. [PMID: 31297099 PMCID: PMC6607858 DOI: 10.3389/fmicb.2019.01420] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 06/05/2019] [Indexed: 01/29/2023] Open
Abstract
Lactobacillus casei and Lactobacillus rhamnosus proteins P40 and P75 belong to a large family of secreted cell wall proteins that contain a carboxy(C)-terminal CHAP or NlpC/P60 superfamily domains. In addition to their peptidoglycan hydrolases activity, proteins in this family are specific antigens of pathogens, frequently responsible of interactions with the host. L. rhamnosus GG and L. casei BL23 purified P40 and P75 proteins have antiapoptotic activity by inducing the EGF/Akt pathway. The aim of this work was to study the genetics, phylogeny and dissemination of this family of proteins in the genus Lactobacillus as well as their characteristics and likely function. The scrutiny of their DNA encoding sequences revealed the presence of minisatellite DNA in the P75 encoding gene of L. casei/paracasei strains (cmuB) with intraspecific indels that gave raise to four different alleles (cmuB1-4), which are exclusive of this species. Phylogenic analyses suggest that both proteins are present mainly in the L. casei and Lactobacillus sakei phylogenomic groups. A P40 ancestral gene was possibly present in the common ancestor of Enterococcaceae, Lactobacillaceae and Streptococcaceae. P75 is also present in L. casei and L. sakei groups, but its evolution is difficult to explain only by vertical transmission. Antibodies raised against the N-terminal regions of P40 and P75 improved their immunological detection in culture supernatants as they recognized almost exclusively proteins of L. casei/paracasei/rhamnosus strains, highlighting their structural similarity, that allowed to detect them in different fermented dairy products that contained probiotic L. casei strains. Purified P40 and P75 proteins showed no evident lytic activity but they complemented L. casei BL23 cmuA and cmuB defective mutants, respectively, thus proving that they actively participate in cell division.
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Affiliation(s)
- Christine Bäuerl
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (C.S.I.C.), Valencia, Spain
| | - Gulyaim Abitayeva
- Department of Microbiology, L.N. Gumilyov Eurasian National University, Astana, Kazakhstan.,Laboratory of Genetics and Biochemistry of Microorganisms, Republican Collection of Microorganisms at Science Committee of Ministry of Education and Science RK, Astana, Kazakhstan
| | - Sebastián Sosa-Carrillo
- Computational Biology Department, Inria, Institut Pasteur and Université Paris Diderot, Paris, France
| | | | - Noemí Navarro-Lleó
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (C.S.I.C.), Valencia, Spain
| | - José M Coll-Marqués
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (C.S.I.C.), Valencia, Spain
| | - Manuel Zúñiga-Cabrera
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (C.S.I.C.), Valencia, Spain
| | - Serik Shaikhin
- Department of Microbiology, L.N. Gumilyov Eurasian National University, Astana, Kazakhstan.,Laboratory of Genetics and Biochemistry of Microorganisms, Republican Collection of Microorganisms at Science Committee of Ministry of Education and Science RK, Astana, Kazakhstan
| | - Gaspar Pérez-Martinez
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (C.S.I.C.), Valencia, Spain
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25
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Ben Braïek O, Smaoui S. Enterococci: Between Emerging Pathogens and Potential Probiotics. BIOMED RESEARCH INTERNATIONAL 2019; 2019:5938210. [PMID: 31240218 PMCID: PMC6556247 DOI: 10.1155/2019/5938210] [Citation(s) in RCA: 115] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/06/2019] [Accepted: 05/14/2019] [Indexed: 11/17/2022]
Abstract
Enterococci are ubiquitous microorganisms that could be found everywhere; in water, plant, soil, foods, and gastrointestinal tract of humans and animals. They were previously used as starters in food fermentation due to their biotechnological traits (enzymatic and proteolytic activities) or protective cultures in food biopreservation due to their produced antimicrobial bacteriocins called enterocins or as probiotics, live cells with different beneficial characteristics such as stimulation of immunity, anti-inflammatory activity, hypocholesterolemic effect, and prevention/treatment of some diseases. However, in the last years, the use of enterococci in foods or as probiotics caused an important debate because of their opportunistic pathogenicity implicated in several nosocomial infections due to virulence factors and antibiotic resistance, particularly the emergence of vancomycin-resistant enterococci. These virulence traits of some enterococci are associated with genetic transfer mechanisms. Therefore, the development of new enterococcal probiotics needs a strict assessment with regard to safety aspects for selecting the truly harmless enterococcal strains for safe applications. This review tries to give some data of the different points of view about this question.
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Affiliation(s)
- Olfa Ben Braïek
- Laboratory of Transmissible Diseases and Biologically Active Substances (LR99ES27), Faculty of Pharmacy, University of Monastir, Tunisia
| | - Slim Smaoui
- Laboratory of Microorganisms and Biomolecules of the Centre of Biotechnology of Sfax, Tunisia
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26
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Kim B, Wang YC, Hespen CW, Espinosa J, Salje J, Rangan KJ, Oren DA, Kang JY, Pedicord VA, Hang HC. Enterococcus faecium secreted antigen A generates muropeptides to enhance host immunity and limit bacterial pathogenesis. eLife 2019; 8:e45343. [PMID: 30969170 PMCID: PMC6483599 DOI: 10.7554/elife.45343] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 04/04/2019] [Indexed: 12/16/2022] Open
Abstract
We discovered that Enterococcus faecium (E. faecium), a ubiquitous commensal bacterium, and its secreted peptidoglycan hydrolase (SagA) were sufficient to enhance intestinal barrier function and pathogen tolerance, but the precise biochemical mechanism was unknown. Here we show E. faecium has unique peptidoglycan composition and remodeling activity through SagA, which generates smaller muropeptides that more effectively activates nucleotide-binding oligomerization domain-containing protein 2 (NOD2) in mammalian cells. Our structural and biochemical studies show that SagA is a NlpC/p60-endopeptidase that preferentially hydrolyzes crosslinked Lys-type peptidoglycan fragments. SagA secretion and NlpC/p60-endopeptidase activity was required for enhancing probiotic bacteria activity against Clostridium difficile pathogenesis in vivo. Our results demonstrate that the peptidoglycan composition and hydrolase activity of specific microbiota species can activate host immune pathways and enhance tolerance to pathogens.
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Affiliation(s)
- Byungchul Kim
- Laboratory of Chemical Biology and Microbial PathogenesisThe Rockefeller UniversityNew YorkUnited States
| | - Yen-Chih Wang
- Laboratory of Chemical Biology and Microbial PathogenesisThe Rockefeller UniversityNew YorkUnited States
| | - Charles W Hespen
- Laboratory of Chemical Biology and Microbial PathogenesisThe Rockefeller UniversityNew YorkUnited States
| | - Juliel Espinosa
- Laboratory of Chemical Biology and Microbial PathogenesisThe Rockefeller UniversityNew YorkUnited States
| | - Jeanne Salje
- Centre for Tropical Medicine and Global Health, Nuffield Department of MedicineUniversity of OxfordOxfordUnited Kingdom
| | - Kavita J Rangan
- Laboratory of Chemical Biology and Microbial PathogenesisThe Rockefeller UniversityNew YorkUnited States
| | - Deena A Oren
- Structural Biology Resource CenterThe Rockefeller UniversityNew YorkUnited States
| | - Jin Young Kang
- Laboratory of Molecular BiophysicsThe Rockefeller UniversityNew YorkUnited States
| | - Virginia A Pedicord
- Laboratory of Chemical Biology and Microbial PathogenesisThe Rockefeller UniversityNew YorkUnited States
- Cambridge Institute of Therapeutic Immunology & Infectious DiseaseUniversity of CambridgeCambridgeUnited Kingdom
| | - Howard C Hang
- Laboratory of Chemical Biology and Microbial PathogenesisThe Rockefeller UniversityNew YorkUnited States
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27
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Wang L, Deng S, Wang S, Su H. Analysis of aerobic granules under the toxic effect of ampicillin in sequencing batch reactors: Performance and microbial community. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2017; 204:152-159. [PMID: 28869824 DOI: 10.1016/j.jenvman.2017.08.027] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 07/29/2017] [Accepted: 08/15/2017] [Indexed: 06/07/2023]
Abstract
To study the change of the aerobic granules' microbial community in the present of antibiotics, ampicillin (AMP) was selected as a model component. With acetate as carbon source, different concentrations of AMP (5, 10 and 15 mg L-1) were applied to the inflow intermittently and the results showed that the stability of the aerobic granules was maintained below 10 mg L-1 AMP. Simultaneously, under exposure to 5 and 10 mg L-1 AMP, the COD removal efficiency in the batch reactors remained at 86% and AMP was degraded almost completely with a removal efficiency of 97%. However, the EPS concentration and dehydrogenase activity decreased constantly with increasing AMP dosage. High-throughput sequencing analysis revealed that Proteobacteria was the most prominent phylum in the whole experiment and contributed to the degradation of AMP. The percentages of Azoarcus and Mycoplana increased at 10 mg L-1 AMP. In addition, Hydrogenophaga and Enterococcus played a key role in the microbial metabolism.
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Affiliation(s)
- Luxi Wang
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, PR China
| | - Shuang Deng
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, PR China
| | - Shaojie Wang
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, PR China
| | - Haijia Su
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, PR China.
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28
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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: 139] [Impact Index Per Article: 19.9] [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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29
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Djorić D, Kristich CJ. Extracellular SalB Contributes to Intrinsic Cephalosporin Resistance and Cell Envelope Integrity in Enterococcus faecalis. J Bacteriol 2017; 199:e00392-17. [PMID: 28874409 PMCID: PMC5686589 DOI: 10.1128/jb.00392-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 08/30/2017] [Indexed: 11/20/2022] Open
Abstract
Enterococci are major causes of hospital-acquired infections. Intrinsic resistance to cephalosporins is a universal trait among clinically relevant enterococci. Cephalosporin resistance enables enterococci to proliferate to high densities in the intestines of patients undergoing cephalosporin treatment, a precursor to the emergence of infection. However, the genetic and biochemical mechanisms of intrinsic cephalosporin resistance in enterococci are not well understood. A two-component signal transduction system, CroR/S, is required for cephalosporin resistance in enterococci. Although the CroR/S regulon is not well defined, one gene reported to be CroR dependent in Enterococcus faecalis JH2-2 encodes an extracellular putative peptidoglycan hydrolase, SalB. To test the hypothesis that SalB is responsible for CroR-dependent cephalosporin resistance, we examined ΔsalB mutants in multiple genetic lineages of E. faecalis, revealing that SalB is required not only for intrinsic cephalosporin resistance but also for maintenance of cell envelope integrity in the absence of antibiotic stress. The N-terminal signal sequence is necessary for SalB secretion, and secretion is required for SalB to promote cephalosporin resistance. Functional dissection revealed that the C-terminal SCP domain of SalB is essential for biological activity and identified three residues within the SCP domain that are required for the stability and function of SalB. Additionally, we found that in contrast to what is seen in E. faecalis JH2-2, SalB is not regulated by the CroR/S two-component system in E. faecalis OG1, suggesting diversity in the CroR/S regulon among distinct lineages of E. faecalis IMPORTANCE Resistance to cephalosporins is universal among clinically relevant enterococci, enabling enterococcal proliferation to high densities in the intestines of patients undergoing cephalosporin treatment, a precursor to the emergence of infection. Disabling cephalosporin resistance could therefore reduce the incidence of enterococcal infections. However, the genetic and biochemical mechanisms of cephalosporin resistance are not well understood. The significance of this work is the identification of a novel extracellular factor (SalB) that promotes cephalosporin resistance in E. faecalis, which could potentially serve as a target for therapeutics that impair enterococcal cephalosporin resistance. Additionally, our work highlights the importance of the C-terminal SCP domain of SalB, including several conserved residues within the SCP domain, for the ability of SalB to promote cephalosporin resistance.
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Affiliation(s)
- Dušanka Djorić
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Christopher J Kristich
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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30
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Rangan KJ, Pedicord VA, Wang YC, Kim B, Lu Y, Shaham S, Mucida D, Hang HC. A secreted bacterial peptidoglycan hydrolase enhances tolerance to enteric pathogens. Science 2016; 353:1434-1437. [PMID: 27708039 DOI: 10.1126/science.aaf3552] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 08/26/2016] [Indexed: 12/18/2022]
Abstract
The intestinal microbiome modulates host susceptibility to enteric pathogens, but the specific protective factors and mechanisms of individual bacterial species are not fully characterized. We show that secreted antigen A (SagA) from Enterococcus faecium is sufficient to protect Caenorhabditis elegans against Salmonella pathogenesis by promoting pathogen tolerance. The NlpC/p60 peptidoglycan hydrolase activity of SagA is required and generates muramyl-peptide fragments that are sufficient to protect C. elegans against Salmonella pathogenesis in a tol-1-dependent manner. SagA can also be heterologously expressed and secreted to improve the protective activity of probiotics against Salmonella pathogenesis in C. elegans and mice. Our study highlights how protective intestinal bacteria can modify microbial-associated molecular patterns to enhance pathogen tolerance.
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Affiliation(s)
- Kavita J Rangan
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY 10065, USA.
| | - Virginia A Pedicord
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY 10065, USA. Laboratory of Mucosal Immunology, The Rockefeller University, New York, NY 10065, USA
| | - Yen-Chih Wang
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY 10065, USA
| | - Byungchul Kim
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY 10065, USA
| | - Yun Lu
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY 10065, USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY 10065, USA
| | - Daniel Mucida
- Laboratory of Mucosal Immunology, The Rockefeller University, New York, NY 10065, USA
| | - Howard C Hang
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY 10065, USA.
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31
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Pedicord VA, Lockhart AAK, Rangan KJ, Craig JW, Loschko J, Rogoz A, Hang HC, Mucida D. Exploiting a host-commensal interaction to promote intestinal barrier function and enteric pathogen tolerance. Sci Immunol 2016; 1. [PMID: 28580440 DOI: 10.1126/sciimmunol.aai7732] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Commensal intestinal bacteria can prevent pathogenic infection; however, limited knowledge of the mechanisms by which individual bacterial species contribute to pathogen resistance has restricted their potential for therapeutic application. Here, we examined how colonization of mice with a human commensal Enterococcus faecium protects against enteric infections. We show that E. faecium improves host intestinal epithelial defense programs to limit Salmonella enterica serotype Typhimurium pathogenesis in vivo in multiple models of susceptibility. E. faecium protection is mediated by a unique peptidoglycan hydrolase, SagA, and requires epithelial expression of pattern recognition receptor components and antimicrobial peptides. Ectopic expression of SagA in non-protective and probiotic bacteria is sufficient to enhance intestinal barrier function and confer resistance against S. Typhimurium and Clostridium difficile pathogenesis. These studies demonstrate that specific factors from commensal bacteria can be used to improve host barrier function and limit the pathogenesis of distinct enteric infections.
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Affiliation(s)
- Virginia A Pedicord
- Laboratory of Mucosal Immunology, The Rockefeller University, New York, NY, USA.,Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY, USA
| | | | - Kavita J Rangan
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY, USA
| | - Jeffrey W Craig
- Department of Pathology, Brigham & Women's Hospital, Boston, MA, USA
| | - Jakob Loschko
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY, USA
| | - Aneta Rogoz
- Laboratory of Mucosal Immunology, The Rockefeller University, New York, NY, USA
| | - Howard C Hang
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, NY, USA
| | - Daniel Mucida
- Laboratory of Mucosal Immunology, The Rockefeller University, New York, NY, USA
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32
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The N-terminal domain of the thermo-regulated surface protein PrpA of Enterococcus faecium binds to fibrinogen, fibronectin and platelets. Sci Rep 2015; 5:18255. [PMID: 26675410 PMCID: PMC4682149 DOI: 10.1038/srep18255] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 11/16/2015] [Indexed: 02/08/2023] Open
Abstract
Enterococcus faecium is a commensal of the mammalian gastrointestinal tract, but is also found in non-enteric environments where it can grow between 10 °C and 45 °C. E. faecium has recently emerged as a multi-drug resistant nosocomial pathogen. We hypothesized that genes involved in the colonization and infection of mammals exhibit temperature-regulated expression control and we therefore performed a transcriptome analysis of the clinical isolate E. faecium E1162, during mid-exponential growth at 25 °C and 37 °C. One of the genes that exhibited differential expression between 25 °C and 37 °C, was predicted to encode a peptidoglycan-anchored surface protein. The N-terminal domain of this protein is unique to E. faecium and closely related enterococci, while the C-terminal domain is homologous to the Streptococcus agalactiae surface protein BibA. This region of the protein contains proline-rich repeats, leading us to name the protein PrpA for proline-rich protein A. We found that PrpA is a surface-exposed protein which is most abundant during exponential growth at 37 °C in E. faecium E1162. The heterologously expressed and purified N-terminal domain of PrpA was able to bind to the extracellular matrix proteins fibrinogen and fibronectin. In addition, the N-terminal domain of PrpA interacted with both non-activated and activated platelets.
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33
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Sinnige JC, de Been M, Zhou M, Bonten MJM, Willems RJL, Top J. Growth condition-dependent cell surface proteome analysis of Enterococcus faecium. Proteomics 2015; 15:3806-14. [PMID: 26316380 DOI: 10.1002/pmic.201500138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 07/16/2015] [Accepted: 08/24/2015] [Indexed: 01/25/2023]
Abstract
The last 30 years Enterococcus faecium has become an important nosocomial pathogen in hospitals worldwide. The aim of this study was to obtain insight in the cell surface proteome of E. faecium when grown in laboratory and clinically relevant conditions. Enterococcus faecium E1162, a clinical blood stream isolate, was grown until mid-log phase in brain heart infusion medium (BHI) with, or without 0.02% bile salts, Tryptic Soy Broth with 1% glucose (TSBg) and urine, and its cell surface was "shaved" using immobilized trypsin. Peptides were identified using MS/MS. Mapping against the translated E1162 whole genome sequence identified 67 proteins that were differentially detected in different conditions. In urine, 14 proteins were significantly more and nine proteins less abundant relative to the other conditions. Growth in BHI-bile and TSBg, revealed four and six proteins, respectively, which were uniquely present in these conditions while two proteins were uniquely present in both conditions. Thus, proteolytic shaving of E. faecium cells identified differentially surface exposed proteins in different growth conditions. These proteins are of special interest as they provide more insight in the adaptive mechanisms and may serve as targets for the development of novel therapeutics against this multi-resistant emerging pathogen. All MS data have been deposited in the ProteomeXchange with identifier PXD002497 (http://proteomecentral.proteomexchange.org/dataset/PXD002497).
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Affiliation(s)
- Jan C Sinnige
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mark de Been
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Miaomiao Zhou
- Fungal Biodiversity Centre, Royal Netherlands Academy of Arts and Sciences, Utrecht, The Netherlands.,Fungal Molecular Physiology, Utrecht University, Utrecht, The Netherlands
| | - Marc J M Bonten
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Rob J L Willems
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Janetta Top
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
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34
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Distinct SagA from Hospital-Associated Clade A1 Enterococcus faecium Strains Contributes to Biofilm Formation. Appl Environ Microbiol 2015. [PMID: 26209668 DOI: 10.1128/aem.01716-15] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Enterococcus faecium is an important nosocomial pathogen causing biofilm-mediated infections. Elucidation of E. faecium biofilm pathogenesis is pivotal for the development of new strategies to treat these infections. In several bacteria, extracellular DNA (eDNA) and proteins act as matrix components contributing to biofilm development. In this study, we investigated biofilm formation capacity and the roles of eDNA and secreted proteins for 83 E. faecium strains with different phylogenetic origins that clustered in clade A1 and clade B. Although there was no significant difference in biofilm formation between E. faecium strains from these two clades, the addition of DNase I or proteinase K to biofilms demonstrated that eDNA is essential for biofilm formation in most E. faecium strains, whereas proteolysis impacted primarily biofilms of E. faecium clade A1 strains. Secreted antigen A (SagA) was the most abundant protein in biofilms from E. faecium clade A1 and B strains, although its localization differed between the two groups. sagA was present in all sequenced E. faecium strains, with a consistent difference in the repeat region between the clades, which correlated with the susceptibility of biofilms to proteinase K. This indicates an association between the SagA variable repeat profile and the localization and contribution of SagA in E. faecium biofilms.
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35
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Roy U, Chalasani AG, Shekh MR. The anti-Candida activity by Ancillary Proteins of an Enterococcus faecium strain. Front Microbiol 2015; 6:339. [PMID: 26005434 PMCID: PMC4424852 DOI: 10.3389/fmicb.2015.00339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Accepted: 04/06/2015] [Indexed: 11/13/2022] Open
Abstract
An antimycotic activity toward seven strains of Candida albicans was demonstrated erstwhile by a wild-type Enterococcus faecium isolated from a penguin rookery of the Antarctic region. In the present study the antimicrobial principle was purified by ion exchange and gel permeation chromatography and further was analyzed by LC-ESI-MS/MS. In the purification steps, the dialyzed concentrate and ion exchange fractions inhibited C. albicans MTCC 3958, 183, and SC 5314. However, the gel filtration purified fractions inhibited MTCC 3958 and 183. The data obtained from the LC-ESI-MS/MS indicate that the antimicrobial activity of the anti-Candida protein produced by E. faecium is facilitated by Sag A/Bb for the binding of the indicator organism's cell membrane. Partial N-terminal sequence revealed 12 N-terminal amino acid residues and its analysis shown that it belongs to the LysM motif. The nucleotide sequence of PCR-amplified product could detect 574 nucleotides of the LysM gene responsible for binding to chitin of the cell wall of Candida sp.
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Affiliation(s)
- Utpal Roy
- Department of Biological Sciences, Birla Institute of Technology and Science Pilani KK Birla Goa Campus Vasco Da Gama, India
| | - Ajay G Chalasani
- Department of Biological Sciences, Birla Institute of Technology and Science Pilani KK Birla Goa Campus Vasco Da Gama, India
| | - M Raeesh Shekh
- Department of Biological Sciences, Birla Institute of Technology and Science Pilani KK Birla Goa Campus Vasco Da Gama, India
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36
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Repizo GD, Espariz M, Blancato VS, Suárez CA, Esteban L, Magni C. Genomic comparative analysis of the environmental Enterococcus mundtii against enterococcal representative species. BMC Genomics 2014; 15:489. [PMID: 24942651 PMCID: PMC4076982 DOI: 10.1186/1471-2164-15-489] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 06/02/2014] [Indexed: 11/30/2022] Open
Abstract
Background Enterococcus mundtii is a yellow-pigmented microorganism rarely found in human infections. The draft genome sequence of E. mundtii was recently announced. Its genome encodes at least 2,589 genes and 57 RNAs, and 4 putative genomic islands have been detected. The objective of this study was to compare the genetic content of E. mundtii with respect to other enterococcal species and, more specifically, to identify genes coding for putative virulence traits present in enterococcal opportunistic pathogens. Results An in-depth mining of the annotated genome was performed in order to uncover the unique properties of this microorganism, which allowed us to detect a gene encoding the antimicrobial peptide mundticin among other relevant features. Moreover, in this study a comparative genomic analysis against commensal and pathogenic enterococcal species, for which genomic sequences have been released, was conducted for the first time. Furthermore, our study reveals significant similarities in gene content between this environmental isolate and the selected enterococci strains (sharing an “enterococcal gene core” of 805 CDS), which contributes to understand the persistence of this genus in different niches and also improves our knowledge about the genetics of this diverse group of microorganisms that includes environmental, commensal and opportunistic pathogens. Conclusion Although E. mundtii CRL1656 is phylogenetically closer to E. faecium, frequently responsible of nosocomial infections, this strain does not encode the most relevant relevant virulence factors found in the enterococcal clinical isolates and bioinformatic predictions indicate that it possesses the lowest number of putative pathogenic genes among the most representative enterococcal species. Accordingly, infection assays using the Galleria mellonella model confirmed its low virulence. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-489) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | - Christian Magni
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET) and Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario S2002LRK, Argentina.
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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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Haynes E, Helgason T, Young JPW, Thwaites R, Budge GE. A typing scheme for the honeybee pathogen Melissococcus plutonius allows detection of disease transmission events and a study of the distribution of variants. ENVIRONMENTAL MICROBIOLOGY REPORTS 2013; 5:525-529. [PMID: 23864566 DOI: 10.1111/1758-2229.12057] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 03/20/2013] [Indexed: 06/02/2023]
Abstract
Melissococcus plutonius is the bacterial pathogen that causes European Foulbrood of honeybees, a globally important honeybee brood disease. We have used next-generation sequencing to identify highly polymorphic regions in an otherwise genetically homogenous organism, and used these loci to create a modified MLST scheme. This synthesis of a proven typing scheme format with next-generation sequencing combines reliability and low costs with insights only available from high-throughput sequencing technologies. Using this scheme we show that the global distribution of M.plutonius variants is not uniform. We use the scheme in epidemiological studies to trace movements of infective material around England, insights that would have been impossible to confirm without the typing scheme. We also demonstrate the persistence of local variants over time.
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Affiliation(s)
- Edward Haynes
- University of York, Wentworth Way, York, YO10 5DD, UK
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Use of a mariner-based transposon mutagenesis system to isolate Clostridium perfringens mutants deficient in gliding motility. J Bacteriol 2012. [PMID: 23204460 DOI: 10.1128/jb.01288-12] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clostridium perfringens is an anaerobic Gram-positive pathogen that causes many human and animal diseases, including food poisoning and gas gangrene. C. perfringens lacks flagella but possesses type IV pili (TFP). We have previously shown that C. perfringens can glide across an agar surface in long filaments composed of individual bacteria attached end to end and that two TFP-associated proteins, PilT and PilC, are needed for this. To discover additional gene products that play a role in gliding, we developed a plasmid-based mariner transposon mutagenesis system that works effectively in C. perfringens. More than 10,000 clones were screened for mutants that lacked the ability to move away from the edge of a colony. Twenty-four mutants (0.24%) were identified that fit the criteria. The genes containing insertions that affected gliding motility fell into nine different categories. One gene, CPE0278, which encodes a homolog of the SagA cell wall-dependent endopeptidase, acquired distinct transposon insertions in two independent mutants. sagA mutants were unable to form filaments due to a complete lack of end-to-end connections essential for gliding motility. Complementation of the sagA mutants with a wild-type copy of the gene restored gliding motility. We constructed an in-frame deletion mutation in the sagA gene and found that this mutant had a phenotype similar to those of the transposon mutants. We hypothesize that the sagA mutant strains are unable to form the molecular complexes which are needed to keep the cells in an end-to-end orientation, leading to separation of daughter cells and the inability to carry out gliding motility.
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SalB inactivation modulates culture supernatant exoproteins and affects autolysis and viability in Enterococcus faecalis OG1RF. J Bacteriol 2012; 194:3569-78. [PMID: 22563054 DOI: 10.1128/jb.00376-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The culture supernatant fraction of an Enterococcus faecalis gelE mutant of strain OG1RF contained elevated levels of the secreted antigen SalB. Using differential fluorescence gel electrophoresis (DIGE) the salB mutant was shown to possess a unique complement of exoproteins. Differentially abundant exoproteins were identified using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Stress-related proteins including DnaK, Dps family protein, SOD, and NADH peroxidase were present in greater quantity in the OG1RF salB mutant culture supernatant. Moreover, several proteins involved in cell wall synthesis and cell division, including d-Ala-d-Lac ligase and EzrA, were present in reduced quantity in OG1RF salB relative to the parent strain. The salB mutant displayed reduced viability and anomalous cell division, and these phenotypes were exacerbated in a gelE salB double mutant. An epistatic relationship between gelE and salB was not identified with respect to increased autolysis and cell morphological changes observed in the salB mutant. SalB was purified as a six-histidine-tagged protein to investigate peptidoglycan hydrolytic activity; however, activity was not evident. High-pressure liquid chromatography (HPLC) analysis of reduced muropeptides from peptidoglycan digested with mutanolysin revealed that the salB mutant and OG1RF were indistinguishable.
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Synthetic lethality of the lytE cwlO genotype in Bacillus subtilis is caused by lack of D,L-endopeptidase activity at the lateral cell wall. J Bacteriol 2011; 194:796-803. [PMID: 22139507 DOI: 10.1128/jb.05569-11] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial peptidoglycan acts as an exoskeleton to protect the bacterial cell. Although peptidoglycan biosynthesis by penicillin-binding proteins is well studied, few studies have described peptidoglycan disassembly, which is necessary for a dynamic structure that allows cell growth. In Bacillus subtilis, more than 35 genes encoding cell wall lytic enzymes have been identified; however, only two D,L-endopeptidases (lytE and cwlO) are involved in cell proliferation. In this study, we demonstrated that the D,L-endopeptidase activity at the lateral cell wall is essential for cell proliferation. Inactivation of LytE and CwlO by point mutation of the catalytic residues caused cell growth defects. However, the forced expression of LytF or CwlS, which are paralogs of LytE, did not suppress lytE cwlO synthetic lethality. Subcellular localization studies of these D,L-endopeptidases showed LytF and CwlS at the septa and poles, CwlO at the cylindrical part of the cell, and LytE at the septa and poles as well as the cylindrical part. Furthermore, construction of N-terminal and C-terminal domain-swapped enzymes of LytE, LytF, CwlS, and CwlO revealed that localization was dependent on the N-terminal domains. Only the chimeric proteins that were enzymatically active and localized to the sidewall were able to suppress the synthetic lethality, suggesting that the lack of D,L-endopeptidase activity at the cylindrical part of the cell leads to a growth defect. The functions of LytE and CwlO in cell morphogenesis were discussed.
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Kropec A, Sava IG, Vonend C, Sakinc T, Grohmann E, Huebner J. Identification of SagA as a novel vaccine target for the prevention of Enterococcus faecium infections. Microbiology (Reading) 2011; 157:3429-3434. [DOI: 10.1099/mic.0.053207-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Infections caused by multiresistant Gram-positive bacteria represent a major health burden in the community as well as in hospitalized patients. Enterococci, especially Enterococcus faecium, are well-known pathogens of hospitalized patients and are frequently linked with resistance against multiple antibiotics, which compromises effective therapy. Rabbit immune serum raised against heat-killed E. faecium E155, a HiRECC clone, was used in an opsonophagocytic assay, an inhibition assay and a mouse bacteraemia model to identify targets of opsonic and protective antibodies. Serum against whole heat-killed bacteria was opsonic and recognized a protein of about 72 kDa that was abundantly secreted. This protein, identified as SagA by LC-ES-MS/MS, was expressed in Escherichia coli and purified. Rabbit serum raised against the purified protein showed opsonic killing activity that was inhibited by almost 100 % using 100 µg purified protein ml−1. In a mouse bacteraemia model, a statistically significant reduction of the colony counts in blood was shown with immune rabbit serum compared with preimmune serum using the homologous and a heterologous vancomycin-resistant enterococci (VRE) strain. These results indicate that SagA could be used as a promising vaccine target to treat and/or prevent VRE bacteraemia.
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Affiliation(s)
- A. Kropec
- Division of Infectious Diseases, Department of Medicine, University Medical Center Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany
| | - I. G. Sava
- Division of Infectious Diseases, Department of Medicine, University Medical Center Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany
| | - C. Vonend
- Division of Infectious Diseases, Department of Medicine, University Medical Center Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany
| | - T. Sakinc
- Division of Infectious Diseases, Department of Medicine, University Medical Center Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany
| | - E. Grohmann
- Division of Infectious Diseases, Department of Medicine, University Medical Center Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany
| | - J. Huebner
- Division of Infectious Diseases, Department of Medicine, University Medical Center Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany
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Franz CMAP, Huch M, Abriouel H, Holzapfel W, Gálvez A. Enterococci as probiotics and their implications in food safety. Int J Food Microbiol 2011; 151:125-40. [PMID: 21962867 DOI: 10.1016/j.ijfoodmicro.2011.08.014] [Citation(s) in RCA: 451] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 08/03/2011] [Accepted: 08/13/2011] [Indexed: 11/29/2022]
Abstract
Enterococci belong to the lactic acid bacteria (LAB) and they are of importance in foods due to their involvement in food spoilage and fermentations, as well as their utilisation as probiotics in humans and slaughter animals. However, they are also important nosocomial pathogens that cause bacteraemia, endocarditis and other infections. Some strains are resistant to many antibiotics and possess virulence factors such as adhesins, invasins, pili and haemolysin. The role of enterococci in disease has raised questions on their safety for use in foods or as probiotics. Studies on the incidence of virulence traits among enterococcal strains isolated from food showed that some can harbour virulence traits, but it is also thought that virulence is not the result of the presence of specific virulence determinants alone, but is rather a more intricate process. Specific genetic lineages of hospital-adapted strains have emerged, such as E. faecium clonal complex (CC) 17 and E. faecalis CC2, CC9, CC28 and CC40, which are high risk enterococcal clonal complexes. These are characterised by the presence of antibiotic resistance determinants and/or virulence factors, often located on pathogenicity islands or plasmids. Mobile genetic elements thus are considered to play a major role in the establishment of problematic lineages. Although enterococci occur in high numbers in certain types of fermented cheeses and sausages, they are not deliberately added as starter cultures. Some E. faecium and E. faecalis strains are used as probiotics and are ingested in high numbers, generally in the form of pharmaceutical preparations. Such probiotics are administered to treat diarrhoea, antibiotic-associated diarrhoea or irritable bowel syndrome, to lower cholesterol levels or to improve host immunity. In animals, enterococcal probiotics are mainly used to treat or prevent diarrhoea, for immune stimulation or to improve growth. From a food microbiological point of view, the safety of the bacteria used as probiotics must be assured, and data on the major strains in use so far indicate that they are safe. The advantage of use of probiotics in slaughter animals, from a food microbiological point of view, lies in the reduction of zoonotic pathogens in the gastrointestinal tract of animals which prevents the transmission of these pathogens via food. The use of enterococcal probiotics should, in view of the development of problematic lineages and the potential for gene transfer in the gastrointestinal tract of both humans and animals, be carefully monitored, and the advantages of using these and new strains should be considered in a well contemplated risk/benefit analysis.
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Affiliation(s)
- Charles M A P Franz
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institute, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Str.9, D-76131 Karlsruhe, Germany.
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Giefing-Kröll C, Jelencsics KE, Reipert S, Nagy E. Absence of pneumococcal PcsB is associated with overexpression of LysM domain-containing proteins. MICROBIOLOGY-SGM 2011; 157:1897-1909. [PMID: 21474534 DOI: 10.1099/mic.0.045211-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The streptococcal protein required for cell separation B (PcsB) is predicted to play an important role in peptidoglycan metabolism, based on sequence motifs and altered phenotypes of gene deletion mutant cells exhibiting defects in cell separation. However, no enzymic activity has been demonstrated for PcsB so far. By generating gene deletion mutant strains in four different genetic backgrounds we could demonstrate that pcsB is not essential for cell survival in Streptococcus pneumoniae, but is essential for proper cell division. Deletion mutant cells displayed cluster formation due to aberrant cell division, reduced growth and antibiotic sensitivity that were fully reverted by transformation with a plasmid carrying pcsB. Immunofluorescence staining revealed that PcsB was localized to the cell poles, similarly to PBP3 and LytB, enzymes with demonstrated peptidoglycan-degrading activity required for daughter cell separation. Similarly to other studies with PcsB homologues, we could not detect peptidoglycan-lytic activity with recombinant or native pneumococcal PcsB in vitro. In addition to defects in septum placement and separation, the absence of PcsB induced an increased release of several proteins, such as enolase, MalX and the SP0107 LysM domain protein. Interestingly, genes encoding both LysM domain-containing proteins that are present in the pneumococcal genome (SP0107 and SP2063) and predicted to be involved in cell wall metabolism were found to be highly overexpressed (14-33-fold increase) in ΔpcsB cells in two different genetic backgrounds. Otherwise, we detected very few changes in the global gene expression profile of cells lacking PcsB. Thus our data suggest that LysM domain proteins partially compensate for the lack of PcsB function and allow the survival and slow growth of the pneumococcus.
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Affiliation(s)
| | | | | | - Eszter Nagy
- Intercell AG, Vienna Biocenter 3, 1030 Vienna, Austria
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Henderson B, Nair S, Pallas J, Williams MA. Fibronectin: a multidomain host adhesin targeted by bacterial fibronectin-binding proteins. FEMS Microbiol Rev 2011; 35:147-200. [DOI: 10.1111/j.1574-6976.2010.00243.x] [Citation(s) in RCA: 227] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Sol A, Feuerstein O, Featherstone JDB, Steinberg D. Effect of Sublethal CO 2 Laser Irradiation on Gene Expression of Streptococcus mutans Immobilized in a Biofilm. Caries Res 2011; 45:361-9. [PMID: 21778724 DOI: 10.1159/000329390] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 04/27/2011] [Indexed: 11/19/2022] Open
Affiliation(s)
- A Sol
- Institute of Dental Sciences, Faculty of Dental Medicine, Hebrew University-Hadassah, Jerusalem, Israel
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van Reenen CA, Dicks LMT. Horizontal gene transfer amongst probiotic lactic acid bacteria and other intestinal microbiota: what are the possibilities? A review. Arch Microbiol 2010; 193:157-68. [DOI: 10.1007/s00203-010-0668-3] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 12/07/2010] [Accepted: 12/10/2010] [Indexed: 01/12/2023]
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Bäuerl C, Pérez-Martínez G, Yan F, Polk DB, Monedero V. Functional analysis of the p40 and p75 proteins from Lactobacillus casei BL23. J Mol Microbiol Biotechnol 2010; 19:231-41. [PMID: 21178363 DOI: 10.1159/000322233] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The genomes of Lactobacillus casei/paracasei and Lactobacillus rhamnosus strains carry two genes encoding homologues of p40 and p75 from L. rhamnosus GG, two secreted proteins which display anti-apoptotic and cell protective effects on human intestinal epithelial cells. p40 and p75 carry cysteine, histidine-dependent aminohydrolase/peptidase (CHAP) and NLPC/P60 domains, respectively, which are characteristic of proteins with cell-wall hydrolase activity. In L. casei BL23 both proteins were secreted to the growth medium and were also located at the bacterial cell surface. The genes coding for both proteins were inactivated in this strain. Inactivation of LCABL_00230 (encoding p40) did not result in a significant difference in phenotype, whereas a mutation in LCABL_02770 (encoding p75) produced cells that formed very long chains. Purified glutathione-S-transferase (GST)-p40 and -p75 fusion proteins were able to hydrolyze the muropeptides from L. casei cell walls. Both fusions bound to mucin, collagen and to intestinal epithelial cells and, similar to L. rhamnosus GG p40, stimulated epidermal growth factor receptor phosphorylation in mouse intestine ex vivo. These results indicate that extracellular proteins belonging to the machinery of cell-wall metabolism in the closely related L. casei/paracasei-L. rhamnosus group are most likely involved in the probiotic effects described for these bacteria.
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Affiliation(s)
- Christine Bäuerl
- Laboratorio de Bacterias Lácticas y Probióticos, Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Burjassot, Valencia, Spain
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