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Boeder AM, Spiller F, Carlstrom M, Izídio GS. Enterococcus faecalis: implications for host health. World J Microbiol Biotechnol 2024; 40:190. [PMID: 38702495 DOI: 10.1007/s11274-024-04007-w] [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: 03/09/2024] [Accepted: 04/26/2024] [Indexed: 05/06/2024]
Abstract
The microbiota represents a crucial area of research in maintaining human health due to its potential for uncovering novel biomarkers, therapies, and molecular mechanisms relevant to population identification and experimental model characterization. Among these microorganisms, Enterococcus faecalis, a Gram-positive bacterium found in the gastrointestinal tract of humans and animals, holds particular significance. Strains of this bacterial species have sparked considerable debate in the literature due to their dual nature; they can either be utilized as probiotics in the food industry or demonstrate resistance to antibiotics, potentially leading to severe illness, disability, and death. Given the diverse characteristics of Enterococcus faecalis strains, this review aims to provide a comprehensive understanding of their impact on various systems within the host, including the immunological, cardiovascular, metabolic, and nervous systems. Furthermore, we summarize the bacterium-host interaction characteristics and molecular effects to highlight their targets, features, and overall impact on microbial communities and host health.
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Affiliation(s)
- Ariela Maína Boeder
- Department of Pharmacology, Federal University of Santa Catarina, Florianópolis, Brazil
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Fernando Spiller
- Department of Pharmacology, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Mattias Carlstrom
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Geison Souza Izídio
- Department of Pharmacology, Federal University of Santa Catarina, Florianópolis, Brazil.
- Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, Florianópolis, Brazil.
- Department of Psychiatry and Legal Medicine, Autonomous University of Barcelona, Barcelona, Spain.
- Laboratório de Genética do Comportamento, Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Departamento de Biologia Celular, Embriologia e Genética, Florianopolis, SC, Brazil.
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Reinseth I, Diep DB, Kjos M, Tønnesen HH, Carlsen H. Exploring the feasibility of bacteriocins EntK1 and EntEJ97s in treatment of systemic vancomycin resistant enterococci infections in mice. J Appl Microbiol 2024; 135:lxae054. [PMID: 38439668 DOI: 10.1093/jambio/lxae054] [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: 12/11/2023] [Revised: 02/21/2024] [Accepted: 03/01/2024] [Indexed: 03/06/2024]
Abstract
AIMS Enterocins K1 and EJ97 have specific antimicrobial activity against Enterococcus faecium and Enterococcus faecalis, respectively. The aim of this study was to investigate the utility of these enterocins for in vivo treatment of systemic enterococcal infections. METHODS AND RESULTS The antimicrobial effect in blood was analysed and compared against the effect in saline. Colony forming unit counts revealed that the enterocins killed all the bacteria within 1 hour. Additionally, the bactericidal effect against E. faecalis was more rapid in blood, indicating a possible synergy between EntEJ97 and blood. Importantly, no enterocin resistant mutants emerged in these experiments. Injecting the enterocins intraperitoneally in an in vivo mouse model and using fluorescence and minimum inhibitory concentration determination to estimate concentrations of the peptides in plasma, indicate that the enterocins exist in circulation in therapeutic concentrations. Alanine aminotransferase detection, and haemolysis analysis indicates that there is no detectable liver damage or haemolytic effect after injection. CONCLUSIONS The study revealed that EntK1 and EntEJ97 are able to kill all bacteria ex vivo in the presence of blood. In vivo experiments determine that the enterocins exist in circulation in therapeutic concentrations without causing liver damage or haemolysis. Future experiments should test these peptides for treatment of infection in a relevant in vivo model.
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Affiliation(s)
- Ingvild Reinseth
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. Box 5003 1432 Ås, Norway
| | - Dzung B Diep
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. Box 5003 1432 Ås, Norway
| | - Morten Kjos
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. Box 5003 1432 Ås, Norway
| | - Hanne H Tønnesen
- Section of Pharmaceutics and Social Pharmacy, Department of Pharmacy, University of Oslo, P.O. Box 1068 Blindern 0316 Oslo, Norway
| | - Harald Carlsen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. Box 5003 1432 Ås, Norway
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Todd Rose FO, Darnell RL, Morris SM, Rose OE, Paxie O, Campbell G, Cook GM, Gebhard S. The two-component system CroRS acts as a master regulator of cell envelope homeostasis to confer antimicrobial tolerance in the bacterial pathogen Enterococcus faecalis. Mol Microbiol 2023; 120:408-424. [PMID: 37475106 PMCID: PMC10952268 DOI: 10.1111/mmi.15128] [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: 05/11/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 07/22/2023]
Abstract
Antimicrobial tolerance is the ability of a microbial population to survive, but not proliferate, during antimicrobial exposure. Significantly, it has been shown to precede the development of bona fide antimicrobial resistance. We have previously identified the two-component system CroRS as a critical regulator of tolerance to antimicrobials like teixobactin in the bacterial pathogen Enterococcus faecalis. To understand the molecular mechanism of this tolerance, we have carried out RNA-seq analyses in the E. faecalis wild-type and isogenic∆ croRS mutant to determine the teixobactin-induced CroRS regulon. We identified a 132 gene CroRS regulon and demonstrate that CroRS upregulates biosynthesis of all major components of the enterococcal cell envelope in response to teixobactin. This suggests a coordinating role of this regulatory system in maintaining integrity of the multiple layers of the enterococcal envelope during antimicrobial stress, likely contributing to bacterial survival. Using experimental evolution, we observed that truncation of HppS, a key enzyme in the synthesis of the quinone electron carrier demethylmenaquinone, was sufficient to rescue tolerance in the croRS deletion strain. This highlights a key role for isoprenoid biosynthesis in antimicrobial tolerance in E. faecalis. Here, we propose a model of CroRS acting as a master regulator of cell envelope biogenesis and a gate-keeper between isoprenoid biosynthesis and respiration to ensure tolerance against antimicrobial challenge.
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Affiliation(s)
- Francesca O. Todd Rose
- Department of Microbiology and ImmunologyUniversity of OtagoDunedinNew Zealand
- Maurice Wilkins Centre for Molecular BiodiscoveryUniversity of OtagoDunedinNew Zealand
| | - Rachel L. Darnell
- Department of Microbiology and ImmunologyUniversity of OtagoDunedinNew Zealand
- Maurice Wilkins Centre for Molecular BiodiscoveryUniversity of OtagoDunedinNew Zealand
| | - Sali M. Morris
- Department of Life Sciences, Milner Centre for EvolutionUniversity of BathBathUK
| | - Olivia E. Rose
- Department of Life Sciences, Milner Centre for EvolutionUniversity of BathBathUK
| | - Olivia Paxie
- Department of Microbiology and ImmunologyUniversity of OtagoDunedinNew Zealand
| | - Georgia Campbell
- Department of Microbiology and ImmunologyUniversity of OtagoDunedinNew Zealand
| | - Gregory M. Cook
- Department of Microbiology and ImmunologyUniversity of OtagoDunedinNew Zealand
- Maurice Wilkins Centre for Molecular BiodiscoveryUniversity of OtagoDunedinNew Zealand
| | - Susanne Gebhard
- Department of Life Sciences, Milner Centre for EvolutionUniversity of BathBathUK
- Institut für Molekulare Physiologie, Mikrobiologie und Biotechnologie, Johannes Gutenberg‐UniversitätMainzGermany
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Goutham PAJ, Kalaiselvam R, Ganesh A, C BP. Antibacterial Efficacy of Irrigants with Varying Osmolarity on E. faecalis Biofilm: An In Vitro Study. J Contemp Dent Pract 2023; 23:998-1003. [PMID: 37073912 DOI: 10.5005/jp-journals-10024-3417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
AIM To evaluate the role of the addition of different concentrations of sodium chloride salt to conventional intracanal irrigants to vary their osmotic values and thereby compare their antibacterial efficacy. MATERIALS AND METHODS In an active attachment biofilm model, Enterococcus faecalis (ATCC 29212) biofilms were grown. Sodium chloride salts were added to 100 mL of distilled water to make 6M (hyperosmotic), 0.5M, and 0.25M (hypoosmotic) sodium chloride solutions, respectively. The experimental groups were divided into three groups: Group I: 5.25% sodium hypochlorite, group II: 2% chlorhexidine, and group III: 2% povidone iodine, and four subgroups within these three groups, such as subgroup A (without salt solution), subgroup B (with 6M of hyperosmotic salt solution), subgroup C (with 0.5M of hypoosmotic salt solution), and subgroup D (with 0.25M of hypoosmotic salt solution), respectively. Biofilms were treated with all the subgroups for a contact time of 15 min. A crystal violet assay was done to estimate the bacterial cell biomass. RESULTS The results revealed that subgroups IIIB, IB, and IID, ID had a statistical reduction in bacterial biomass at p < 0.05. There were no significant differences between subgroups IC, IIC, and IIIC and subgroups IA, IIA, and IIIA. CONCLUSION The antibacterial efficacy of all three irrigants was significantly affected by varying the osmolarities. CLINICAL SIGNIFICANCE The results prove that the hyperosmotic and hypoosmotic salt solutions, along with irrigants, have enhanced antibacterial efficacy on E. faecalis biofilm due to its ability to vary the turgor pressure of cell wall, as well as the inherent properties of the irrigants such as hypochlorous acid formation, ionic interaction, and free radical interactions.
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Affiliation(s)
- Pradeeba Anandi Jeya Goutham
- Department of Conservative Dentistry & Endodontics, Sri Ramachandra College and Hospital, Sri Ramachandra Institute of Higher Education & Research (Deemed to be University), Chennai, Tamil Nadu, India
| | - Rajeswari Kalaiselvam
- Department of Conservative Dentistry & Endodontics, Sri Ramachandra College and Hospital, Sri Ramachandra Institute of Higher Education & Research (Deemed to be University), Chennai, Tamil Nadu, India, Phone: +91 9791109099, e-mail:
| | - Arathi Ganesh
- Department of Conservative Dentistry & Endodontics, Sri Ramachandra College and Hospital, Sri Ramachandra Institute of Higher Education & Research (Deemed to be University), Chennai, Tamil Nadu, India
| | - Benedict Paul C
- Department of Biotechnology, Sri Ramachandra College and Hospital, Sri Ramachandra Institute of Higher Education & Research (Deemed to be University), Chennai, Tamil Nadu, India
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Acciarri G, Gizzi FO, Torres Manno MA, Stülke J, Espariz M, Blancato VS, Magni C. Redundant potassium transporter systems guarantee the survival of Enterococcus faecalis under stress conditions. Front Microbiol 2023; 14:1117684. [PMID: 36846772 PMCID: PMC9945522 DOI: 10.3389/fmicb.2023.1117684] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 01/17/2023] [Indexed: 02/10/2023] Open
Abstract
Enterococcus is able to grow in media at pH from 5.0 to 9.0 and a high concentration of NaCl (8%). The ability to respond to these extreme conditions requires the rapid movement of three critical ions: proton (H+), sodium (Na+), and potassium (K+). The activity of the proton F0F1 ATPase and the sodium Na+ V0V1 type ATPase under acidic or alkaline conditions, respectively, is well established in these microorganisms. The potassium uptake transporters KtrI and KtrII were described in Enterococcus hirae, which were associated with growth in acidic and alkaline conditions, respectively. In Enterococcus faecalis, the presence of the Kdp (potassium ATPase) system was early established. However, the homeostasis of potassium in this microorganism is not completely explored. In this study, we demonstrate that Kup and KimA are high-affinity potassium transporters, and the inactivation of these genes in E. faecalis JH2-2 (a Kdp laboratory natural deficient strain) had no effect on the growth parameters. However, in KtrA defective strains (ΔktrA, ΔkupΔktrA) an impaired growth was observed under stress conditions, which was restored to wild type levels by external addition of K+ ions. Among the multiplicity of potassium transporters identify in the genus Enterococcus, Ktr channels (KtrAB and KtrAD), and Kup family symporters (Kup and KimA) are present and may contribute to the particular resistance of these microorganisms to different stress conditions. In addition, we found that the presence of the Kdp system in E. faecalis is strain-dependent, and this transporter is enriched in strains of clinical origin as compared to environmental, commensal, or food isolates.
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Affiliation(s)
- Giuliana Acciarri
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina
| | - Fernán O. Gizzi
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina
| | - Mariano A. Torres Manno
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina,Área Bioinformática, Departamento de Matemática y Estadística, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Jörg Stülke
- Department of General Microbiology, Georg August University, Göttingen, Germany
| | - Martín Espariz
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina,Área Bioinformática, Departamento de Matemática y Estadística, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Víctor S. Blancato
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina,Laboratorio de Biotecnología e Inocuidad de los Alimentos, Área de Biotecnología de los Alimentos, FBioyF, UNR–Municipalidad de Granadero Baigorria, Rosario, Argentina
| | - Christian Magni
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina,Laboratorio de Biotecnología e Inocuidad de los Alimentos, Área de Biotecnología de los Alimentos, FBioyF, UNR–Municipalidad de Granadero Baigorria, Rosario, Argentina,*Correspondence: Christian Magni, ✉
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6
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Guérin H, Kulakauskas S, Chapot-Chartier MP. Structural variations and roles of rhamnose-rich cell wall polysaccharides in Gram-positive bacteria. J Biol Chem 2022; 298:102488. [PMID: 36113580 PMCID: PMC9574508 DOI: 10.1016/j.jbc.2022.102488] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 09/08/2022] [Accepted: 09/10/2022] [Indexed: 11/17/2022] Open
Abstract
Rhamnose-rich cell wall polysaccharides (Rha-CWPSs) have emerged as crucial cell wall components of numerous Gram-positive, ovoid-shaped bacteria—including streptococci, enterococci, and lactococci—of which many are of clinical or biotechnological importance. Rha-CWPS are composed of a conserved polyrhamnose backbone with side-chain substituents of variable size and structure. Because these substituents contain phosphate groups, Rha-CWPS can also be classified as polyanionic glycopolymers, similar to wall teichoic acids, of which they appear to be functional homologs. Recent advances have highlighted the critical role of these side-chain substituents in bacterial cell growth and division, as well as in specific interactions between bacteria and infecting bacteriophages or eukaryotic hosts. Here, we review the current state of knowledge on the structure and biosynthesis of Rha-CWPS in several ovoid-shaped bacterial species. We emphasize the role played by multicomponent transmembrane glycosylation systems in the addition of side-chain substituents of various sizes as extracytoplasmic modifications of the polyrhamnose backbone. We provide an overview of the contribution of Rha-CWPS to cell wall architecture and biogenesis and discuss current hypotheses regarding their importance in the cell division process. Finally, we sum up the critical roles that Rha-CWPS can play as bacteriophage receptors or in escaping host defenses, roles that are mediated mainly through their side-chain substituents. From an applied perspective, increased knowledge of Rha-CWPS can lead to advancements in strategies for preventing phage infection of lactococci and streptococci in food fermentation and for combating pathogenic streptococci and enterococci.
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Affiliation(s)
- Hugo Guérin
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Saulius Kulakauskas
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
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7
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Paria P, Chakraborty HJ, Behera BK. Identification of novel salt tolerance-associated proteins from the secretome of Enterococcus faecalis. World J Microbiol Biotechnol 2022; 38:177. [PMID: 35934729 DOI: 10.1007/s11274-022-03354-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 07/04/2022] [Indexed: 11/30/2022]
Abstract
The ability of bacteria to adapt to the external environment is fundamental for their survival. A halotolerant microorganism Enterococcus faecalis able to grow under high salt stress conditions was isolated in the present study. The SDS-PAGE analysis of the secretome showed a protein band with a molecular weight of 28 kDa, gradually increased with an increase in salt concentration, and the highest intensity was observed at 15% salt stress condition. LC-MS/MS analysis of this particular band identified fourteen different proteins, out of which nine proteins were uncharacterized. Further, the function of uncharacterized proteins was predicted based on structure-function relationship using a reverse template search approach deciphering uncharacterized protein into type III polyketide synthases, stress-induced protein-1, Eed-h3k79me3, ba42 protein, 3-methyladenine DNA glycosylase, Atxa protein, membrane-bound respiratory hydrogenase, type-i restriction-modification system methylation subunit and ManxA. STRING network analysis further a showed strong association among the proteins. The processes predicted involvement of these proteins in signal transduction, ions transport, synthesis of the protective layer, cellular homeostasis and regulation of gene expression and different metabolic pathways. Thus, the fourteen proteins identified in the secretome play an essential role in maintaining cellular homeostasis in E. faecalis under high-salinity stress. This may represent a novel and previously unreported strategy by E. faecalis to maintain their normal growth and physiology under high salinity conditions.
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Affiliation(s)
- Prasenjit Paria
- Aquatic Environmental Biotechnology and Nanotechnology Division, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, 700120, India
| | - Hirak Jyoti Chakraborty
- Aquatic Environmental Biotechnology and Nanotechnology Division, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, 700120, India
| | - Bijay Kumar Behera
- Aquatic Environmental Biotechnology and Nanotechnology Division, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, 700120, India.
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8
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Radzieta M, Malone M, Ahmad M, Dickson HG, Schwarzer S, Jensen SO, Lavery LA. Metatranscriptome sequencing identifies Escherichia are major contributors to pathogenic functions and biofilm formation in diabetes related foot osteomyelitis. Front Microbiol 2022; 13:956332. [PMID: 35979499 PMCID: PMC9376677 DOI: 10.3389/fmicb.2022.956332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 07/11/2022] [Indexed: 11/26/2022] Open
Abstract
Osteomyelitis in the feet of persons with diabetes is clinically challenging and is associated with high rates of amputation. In this study RNA-sequencing was employed to explore microbial metatranscriptomes with a view to understand the relative activity and functions of the pathogen/s responsible for diabetes foot osteomyelitis (DFO). We obtained 25 intraoperative bone specimens from persons with confirmed DFO, observing that Escherichia spp. (7%), Streptomyces spp. (7%), Staphylococcus spp. (6%), Klebsiella spp. (5%) and Proteus spp. (5%) are the most active taxa on average. Data was then subset to examine functions associated with pathogenesis (virulence and toxins), biofilm formation and antimicrobial/multi-drug resistance. Analysis revealed Escherichia spp. are the most active taxa relative to pathogenic functions with K06218 (mRNA interferase relE), K03699 (membrane damaging toxin tlyC) and K03980 (putative peptidoglycan lipid II flippase murJ), K01114 (membrane damaging toxin plc) and K19168 (toxin cptA) being the most prevalent pathogenic associated transcripts. The most abundant transcripts associated with biofilm pathways included components of the biofilm EPS matrix including glycogen synthesis, cellulose synthesis, colonic acid synthesis and flagella synthesis. We further observed enrichment of a key enzyme involved in the biosynthesis of L-rhamnose (K01710 -dTDP-glucose 4,6-dehydratase rfbB, rmlB, rffG) which was present in all but four patients with DFO.
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Affiliation(s)
- Michael Radzieta
- South West Sydney Limb Preservation and Wound Research, South Western Sydney Local Health District (LHD), Sydney, NSW, Australia
- Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Matthew Malone
- South West Sydney Limb Preservation and Wound Research, South Western Sydney Local Health District (LHD), Sydney, NSW, Australia
- Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, NSW, Australia
- *Correspondence: Matthew Malone
| | - Mehtab Ahmad
- Department of Vascular Surgery, Liverpool Hospital, South Western Sydney Local Health District (LHD), Sydney, NSW, Australia
| | - Hugh G. Dickson
- South West Sydney Limb Preservation and Wound Research, South Western Sydney Local Health District (LHD), Sydney, NSW, Australia
- South Western Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Saskia Schwarzer
- South West Sydney Limb Preservation and Wound Research, South Western Sydney Local Health District (LHD), Sydney, NSW, Australia
- Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Slade O. Jensen
- South West Sydney Limb Preservation and Wound Research, South Western Sydney Local Health District (LHD), Sydney, NSW, Australia
- South Western Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Lawrence A. Lavery
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, United States
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9
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Antimicrobial tolerance and its role in the development of resistance: Lessons from enterococci. Adv Microb Physiol 2022; 81:25-65. [PMID: 36167442 DOI: 10.1016/bs.ampbs.2022.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Bacteria have developed resistance against every antimicrobial in clinical use at an alarming rate. There is a critical need for more effective use of antimicrobials to both extend their shelf life and prevent resistance from arising. Significantly, antimicrobial tolerance, i.e., the ability to survive but not proliferate during antimicrobial exposure, has been shown to precede the development of bona fide antimicrobial resistance (AMR), sparking a renewed and rapidly increasing interest in this field. As a consequence, problematic infections for the first time are now being investigated for antimicrobial tolerance, with increasing reports demonstrating in-host evolution of antimicrobial tolerance. Tolerance has been identified in a wide array of bacterial species to all bactericidal antimicrobials. Of particular interest are enterococci, which contain the opportunistic bacterial pathogens Enterococcus faecalis and Enterococcus faecium. Enterococci are one of the leading causes of hospital-acquired infection and possess intrinsic tolerance to a number of antimicrobial classes. Persistence of these infections in the clinic is of growing concern, particularly for the immunocompromised. Here, we review current known mechanisms of antimicrobial tolerance, and include an in-depth analysis of those identified in enterococci with implications for both the development and prevention of AMR.
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10
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RNA-Seq Transcriptomic Analysis of Green Tea Polyphenols Modulation of Differently Expressed Genes in Enterococcus faecalis Under Bile Salt Stress. Curr Microbiol 2022; 79:147. [PMID: 35397017 DOI: 10.1007/s00284-022-02844-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 03/17/2022] [Indexed: 11/03/2022]
Abstract
Enterococcus faecalis (E. faecalis) belongs to lactic acid bacteria which can be used as a probiotic additive and feed, bringing practical value to the health of humans and animals. The prebiotic function of tea polyphenols lays a foundation for green tea polyphenols (GTP) to repair the adverse changes of E. faecalis under stress conditions. In this study, RNA-sequence analysis was used to explore the protective effect of GTP on E. faecalis under bile salt stress. A total of 50 genes were found to respond to GTP under bile salts stress, containing 18 up-regulated and 32 down-regulated genes. The results showed that multiple genes associated with cell wall and membrane, transmembrane transport, nucleotide transport and metabolism were significantly differentially expressed (P < 0.05), while GTP intervention can partly alleviate the detrimental effects of bile salt on amino acid metabolism and transport. The present study provides the whole genome transcriptomics of E. faecalis under bile salt stress and GTP intervention which help us understand the growth and mechanism of continuous adaptation of E. faecalis under stress conditions.
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11
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Yan R, Zhou H, Zheng X, Zhang X. RNA-seq analysis of green tea polyphenols modulation of differently expressed genes in Enterococcus faecalis under low pH. Lett Appl Microbiol 2022; 74:970-980. [PMID: 35247280 DOI: 10.1111/lam.13686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 02/23/2022] [Accepted: 02/24/2022] [Indexed: 11/29/2022]
Abstract
Enterococcus faecalis (E. faecalis) is a resident bacterium in the host. The increase of internal stress like low pH may affect the biological effects of E. faecalis. The prebiotic-like function of tea polyphenols can enhance the beneficial effects of its tolerance to environmental stress. In this study, RNA-sequence analysis was used to explore the protective effect of green tea polyphenols (GTP) on E. faecalis under low pH stress. A total of 28 genes were found to be responsive to GTP under low pH stress, including 16 up-regulated and 12 down-regulated. GTP intervention can partly relieve some undesired negative influences, such as the down-regulation of the base excision repair gene and amino acid transport and metabolism gene. The significantly changes were associated with selenocompound metabolism and aminoacyl-tRNA biosynthesis after the intervention of GTP. The present study provided new insights into the growth and continuous adaptation of E. faecalis under stress.
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Affiliation(s)
- Ruonan Yan
- Department of Food Science and Engineering, Ningbo University, Ningbo, 315211, P.R. China
| | - Huan Zhou
- Department of Agriculture and Biotechnology, Wenzhou Vocational College of Science and Technology, Wenzhou, 325006, China
| | - Xiaojie Zheng
- Department of Agriculture and Biotechnology, Wenzhou Vocational College of Science and Technology, Wenzhou, 325006, China
| | - Xin Zhang
- Department of Food Science and Engineering, Ningbo University, Ningbo, 315211, P.R. China
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12
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Ramos Y, Sansone S, Morales DK. Sugarcoating it: Enterococcal polysaccharides as key modulators of host-pathogen interactions. PLoS Pathog 2021; 17:e1009822. [PMID: 34499702 PMCID: PMC8428557 DOI: 10.1371/journal.ppat.1009822] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Yusibeska Ramos
- Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, New York, United States of America
| | - Stephanie Sansone
- Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, New York, United States of America
- Department of Urology, Weill Cornell Medicine, New York, New York, United States of America
| | - Diana K. Morales
- Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, New York, United States of America
- * E-mail:
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13
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Zhang L, Song D, Wu Z. Transcriptome analysis of Cyclocarya paliurus flavonoids regulation of differently expressed genes in Enterococcus faecalis under low pH stress. Arch Microbiol 2021; 203:2147-2155. [PMID: 33611635 DOI: 10.1007/s00203-021-02215-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 01/19/2021] [Accepted: 02/09/2021] [Indexed: 01/23/2023]
Abstract
Enterococcus faecalis (E. faecalis) is an indigenous intestinal bacterium and has potential to be applied as probiotic supplement. Low pH is one of the main stresses that E. faecalis has to deal with to colonize in the gastrointestinal tract. Previous study indicated low concentration of flavonoids may enhance the tolerance of probiotic to environmental stress. In the present research, transcriptome analysis was employed to investigate the influence of Cyclocarya paliurus flavonoids (CPF) on E. faecalis exposed to low pH environment. The results revealed that under the stress of low pH, genes related to cell wall and membrane, transmembrane transport, metabolism process, energy production, and conversion stress proteins were significantly differentially expressed. And certain undesired changes of which (such as genes for MFS transporter were downregulated) could be partially mitigated by CPF intervention, indicating their capacity to improve the low pH tolerance of E. faecalis. Results from this study deepened our understanding of the beneficial role of CPF on the probiotic in the gastrointestinal environment.
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Affiliation(s)
- Li Zhang
- Department of Physical Education, China University of Mining and Technology, Beijing, 100083, People's Republic of China
| | - Dan Song
- Department of Food Science and Engineering, Ningbo University, Ningbo, 315211, People's Republic of China
| | - Zufang Wu
- Department of Food Science and Engineering, Ningbo University, Ningbo, 315211, People's Republic of China.
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Effects of Osmotic Stress and Sodium Hypochlorite on Endodontic Microbiota: An In-Vitro Study. Eur Endod J 2020; 5:242-247. [PMID: 33353919 PMCID: PMC7881376 DOI: 10.14744/eej.2020.70883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Objective: To assess the effect of osmotic stress on various bacteria in a planktonic milieu and the effect of exposure to sodium hypochlorite (NaOCl) on the microbial cells previously subjected to osmotic stress. Methods: Enterococcus faecalis, Streptococcus sanguinis, Fusobacterium nucleatum, Porphyromonas gingivalis and Prevotella intermedia were suspended as follows: Iso-osmotic group 0.9% NaCl; Hypo-osmotic group “ultrapure water”; Hyper-osmotic group 9% NaCl solution for 120 hours before exposure to 0.0001% NaOCl for 10 minutes. Quantitative analyses of viable cells were performed at 0 and 120 hours and after exposure to NaOCl to obtain colony forming units (CFU/mL). A linear mixed-effects model was used to find the association between mean CFU/mL (logarithmic transformation) and the interaction of solution Group and Time (P<0.001). Results: F. nucleatum, P. gingivalis and P. intermedia did not survive after 24 hours in any of the solutions and were excluded from further testing. For S. sanguinis there were significant differences at each time interval, when holding solution group constant. After 120 hours, the Hyper-osmotic group presented with the highest CFU/mL and was significantly different to the Iso-osmotic group (P<0.001). For E. Faecalis, there was a significant difference for each pairwise comparison of time (P<0.001) in mean CFU/mL between 0 hours and 120 hours for the Iso-osmotic and Hyper-osmotic groups. At 120 hours, no significant differences were found between the three groups. Significant differences were also found between 0 hours and Post-NaOCl administration, and between 120 hours and Post-NaOCl administration for all three groups (P<0.001). Exposure to NaOCl after hypo-osmotic stress was associated with significantly less CFU/mL for S. sanguinis compared to hyperosmosis and iso-osmosis (P<0.001) and for E. Faecalis only compared to hyperosmosis (P<0.001). Conclusion: S. sanguinis and E. faecalis were able to withstand osmotic stress for 120 hours. Hypo-osmotic stress before contact with NaOCl was associated with lower viable bacterial numbers, when compared to the other media for the above species. Hyper-osmotic stress was associated with higher viable bacterial numbers after NaOCl exposure for E. faecalis.
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15
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Maltas J, Krasnick B, Wood KB. Using Selection by Nonantibiotic Stressors to Sensitize Bacteria to Antibiotics. Mol Biol Evol 2020; 37:1394-1406. [PMID: 31851309 PMCID: PMC7182213 DOI: 10.1093/molbev/msz303] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Evolutionary adaptation of bacteria to nonantibiotic selective forces, such as osmotic stress, has been previously associated with increased antibiotic resistance, but much less is known about potentially sensitizing effects of nonantibiotic stressors. In this study, we use laboratory evolution to investigate adaptation of Enterococcus faecalis, an opportunistic bacterial pathogen, to a broad collection of environmental agents, ranging from antibiotics and biocides to extreme pH and osmotic stress. We find that nonantibiotic selection frequently leads to increased sensitivity to other conditions, including multiple antibiotics. Using population sequencing and whole-genome sequencing of single isolates from the evolved populations, we identify multiple mutations in genes previously linked with resistance to the selecting conditions, including genes corresponding to known drug targets or multidrug efflux systems previously tied to collateral sensitivity. Finally, we hypothesized based on the measured sensitivity profiles that sequential rounds of antibiotic and nonantibiotic selection may lead to hypersensitive populations by harnessing the orthogonal collateral effects of particular pairs of selective forces. To test this hypothesis, we show experimentally that populations evolved to a sequence of linezolid (an oxazolidinone antibiotic) and sodium benzoate (a common preservative) exhibit increased sensitivity to more stressors than adaptation to either condition alone. The results demonstrate how sequential adaptation to drug and nondrug environments can be used to sensitize bacteria to antibiotics and highlight new potential strategies for exploiting shared constraints governing adaptation to diverse environmental challenges.
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Affiliation(s)
- Jeff Maltas
- Department of Biophysics, University of Michigan, Ann Arbor, MI
| | - Brian Krasnick
- Department of Biophysics, University of Michigan, Ann Arbor, MI
| | - Kevin B Wood
- Department of Biophysics, University of Michigan, Ann Arbor, MI
- Department of Physics, University of Michigan, Ann Arbor, MI
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16
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Chilambi GS, Hinks J, Matysik A, Zhu X, Choo PY, Liu X, Chan-Park MB, Bazan GC, Kline KA, Rice SA. Enterococcus faecalis Adapts to Antimicrobial Conjugated Oligoelectrolytes by Lipid Rearrangement and Differential Expression of Membrane Stress Response Genes. Front Microbiol 2020; 11:155. [PMID: 32117172 PMCID: PMC7033496 DOI: 10.3389/fmicb.2020.00155] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 01/22/2020] [Indexed: 11/17/2022] Open
Abstract
Conjugated oligoelectrolytes (COEs) are emerging antimicrobials with broad spectrum activity against Gram positive and Gram negative bacteria as well as fungi. Our previous in vitro evolution studies using Enterococcus faecalis grown in the presence of two related COEs (COE1-3C and COE1-3Py) led to the emergence of mutants (changes in liaF and liaR) with a moderate 4- to16-fold increased resistance to COEs. The contribution of liaF and liaR mutations to COE resistance was confirmed by complementation of the mutants, which restored sensitivity to COEs. To better understand the cellular target of COEs, and the mechanism of resistance to COEs, transcriptional changes associated with resistance in the evolved mutants were investigated in this study. The differentially transcribed genes encoded membrane transporters, in addition to proteins associated with cell envelope synthesis and stress responses. Genes encoding membrane transport proteins from the ATP binding cassette superfamily were the most significantly induced or repressed in COE tolerant mutants compared to the wild type when exposed to COEs. Additionally, differences in the membrane localization of a lipophilic dye in E. faecalis exposed to COEs suggested that resistance was associated with lipid rearrangement in the cell membrane. The membrane adaptation to COEs in EFC3C and EFC3Py resulted in an improved tolerance to bile salt and sodium chloride stress. Overall, this study showed that bacterial cell membranes are the primary target of COEs and that E. faecalis adapts to membrane interacting COE molecules by both lipid rearrangement and changes in membrane transporter activity. The level of resistance to COEs suggests that E. faecalis does not have a specific response pathway to elicit resistance against these molecules and this is supported by the rather broad and diverse suite of genes that are induced upon COE exposure as well as cross-resistance to membrane perturbing stressors.
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Affiliation(s)
- Gayatri Shankar Chilambi
- Interdisciplinary Graduate School, Nanyang Technological University, Singapore, Singapore
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Jamie Hinks
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Artur Matysik
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Xinyi Zhu
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Pei Yi Choo
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Xianghui Liu
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Mary B. Chan-Park
- School of Chemical and Biomedical Engineering, College of Engineering, Nanyang Technological University, Singapore, Singapore
| | - Guillermo C. Bazan
- School of Chemical and Biomedical Engineering, College of Engineering, Nanyang Technological University, Singapore, Singapore
- Center for Polymers and Organic Solids, Department of Chemistry and Biochemistry and Materials, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Kimberly A. Kline
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Scott A. Rice
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- The ithree Institute, University of Technology Sydney, Sydney, NSW, Australia
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17
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Das P, Behera BK, Chatterjee S, Das BK, Mohapatra T. De novo transcriptome analysis of halotolerant bacterium Staphylococcus sp. strain P-TSB-70 isolated from East coast of India: In search of salt stress tolerant genes. PLoS One 2020; 15:e0228199. [PMID: 32040520 PMCID: PMC7010390 DOI: 10.1371/journal.pone.0228199] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 01/09/2020] [Indexed: 12/20/2022] Open
Abstract
In the present study, we identified salt stress tolerant genes from the marine bacterium Staphylococcus sp. strain P-TSB-70 through transcriptome sequencing. In favour of whole-genome transcriptome profiling of Staphylococcus sp. strain P-TSB-70 (GenBank Accn. No. KP117091) which tolerated upto 20% NaCl stress, the strain was cultured in the laboratory condition with 20% NaCl stress. Transcriptome analyses were performed by SOLiD4.0 sequencing technology from which 10280 and 9612 transcripts for control and treated, respectively, were obtained. The coverage per base (CPB) statistics were analyzed for both the samples. Gene ontology (GO) analysis has been categorized at varied graph levels based on three primary ontology studies viz. cellular components, biological processes, and molecular functions. The KEGG analysis of the assembled transcripts using KAAS showed presumed components of metabolic pathways which perhaps implicated in diverse metabolic pathways responsible for salt tolerance viz. glycolysis/gluconeogenesis, oxidative phosphorylation, glutathione metabolism, etc. further involving in salt tolerance. Overall, 90 salt stress tolerant genes were identified as of 186 salt-related transcripts. Several genes have been found executing normally in the TCA cycle pathway, integral membrane proteins, generation of the osmoprotectants, enzymatic pathway associated with salt tolerance. Recognized genes fit diverse groups of salt stress genes viz. abc transporter, betaine, sodium antiporter, sodium symporter, trehalose, ectoine, and choline, that belong to different families of genes involved in the pathway of salt stress. The control sample of the bacterium showed elevated high proportion of transcript contigs (29%) while upto 20% salt stress treated sample of the bacterium showed a higher percentage of transcript contigs (31.28%). A total of 1,288 and 1,133 transcript contigs were measured entirely as novel transcript contigs in both control and treated samples, respectively. The structure and function of 10 significant salt stress tolerant genes of Staphylococcus sp. have been analyzed in this study. The information acquired in the present study possibly used to recognize and clone the salt stress tolerant genes and support in developing the salt stress-tolerant plant varieties to expand the agricultural productivity in the saline system.
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Affiliation(s)
- Priyanka Das
- Fishery Resource and Environmental Management Division, Biotechnology Laboratory, ICAR- Central Inland Fisheries Research Institute, Barrackpore, West Bengal, India
| | - Bijay Kumar Behera
- Fishery Resource and Environmental Management Division, Biotechnology Laboratory, ICAR- Central Inland Fisheries Research Institute, Barrackpore, West Bengal, India
- * E-mail:
| | - Soumendranath Chatterjee
- Parasitology and Microbiology Research Laboratory, Department of Zoology, University of Burdwan, Burdwan, West Bengal, India
| | - Basanta Kumar Das
- Fishery Resource and Environmental Management Division, Biotechnology Laboratory, ICAR- Central Inland Fisheries Research Institute, Barrackpore, West Bengal, India
| | - Trilochan Mohapatra
- Secretary, DARE and Director General, Indian Council of Agricultural Research, New Delhi, India
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18
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Kurylo CM, Parks MM, Juette MF, Zinshteyn B, Altman RB, Thibado JK, Vincent CT, Blanchard SC. Endogenous rRNA Sequence Variation Can Regulate Stress Response Gene Expression and Phenotype. Cell Rep 2020; 25:236-248.e6. [PMID: 30282032 PMCID: PMC6312700 DOI: 10.1016/j.celrep.2018.08.093] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 08/16/2018] [Accepted: 08/30/2018] [Indexed: 11/30/2022] Open
Abstract
Prevailing dogma holds that ribosomes are uniform in composition and function. Here, we show that nutrient limitation-induced stress in E. coli changes the relative expression of rDNA operons to alter the rRNA composition within the actively translating ribosome pool. The most upregulated operon encodes the unique 16S rRNA, rrsH, distinguished by conserved sequence variation within the small ribosomal subunit. rrsH-bearing ribosomes affect the expression of functionally coherent gene sets and alter the levels of the RpoS sigma factor, the master regulator of the general stress response. These impacts are associated with phenotypic changes in antibiotic sensitivity, biofilm formation, and cell motility and are regulated by stress response proteins, RelA and RelE, as well as the metabolic enzyme and virulence-associated protein, AdhE. These findings establish that endogenously encoded, naturally occurring rRNA sequence variation can modulate ribosome function, central aspects of gene expression regulation, and cellular physiology. Most organisms encode multiple, distinct copies of rRNA genes, rendering the composition of the ribosome pool intrinsically heterogeneous. Here, Kurylo et al. show that nutrient limitation in E. coli upregulates the expression of ribosomes bearing conserved sequence variation in 16S rRNA that can regulate gene expression and phenotype.
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Affiliation(s)
- Chad M Kurylo
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - Matthew M Parks
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - Manuel F Juette
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - Boris Zinshteyn
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Roger B Altman
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - Jordana K Thibado
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - C Theresa Vincent
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Scott C Blanchard
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA; Tri-Institutional Training Program in Chemical Biology, Weill Cornell Medicine, New York, NY, USA.
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Abstract
Fecal microorganisms can enter water bodies in diverse ways, including runoff, sewage discharge, and direct fecal deposition. Once in water, the microorganisms experience conditions that are very different from intestinal habitats. The transition from host to aquatic environment may lead to rapid inactivation, some degree of persistence, or growth. Microorganisms may remain planktonic, be deposited in sediment, wash up on beaches, or attach to aquatic vegetation. Each of these habitats offers a panoply of different stressors or advantages, including UV light exposure, temperature fluctuations, salinity, nutrient availability, and biotic interactions with the indigenous microbiota (e.g., predation and/or competition). The host sources of fecal microorganisms are likewise numerous, including wildlife, pets, livestock, and humans. Most of these microorganisms are unlikely to affect human health, but certain taxa can cause waterborne disease. Others signal increased probability of pathogen presence, e.g., the fecal indicator bacteria Escherichia coli and enterococci and bacteriophages, or act as fecal source identifiers (microbial source tracking markers). The effects of environmental factors on decay are frequently inconsistent across microbial species, fecal sources, and measurement strategies (e.g., culture versus molecular). Therefore, broad generalizations about the fate of fecal microorganisms in aquatic environments are problematic, compromising efforts to predict microbial decay and health risk from contamination events. This review summarizes the recent literature on decay of fecal microorganisms in aquatic environments, recognizes defensible generalizations, and identifies knowledge gaps that may provide particularly fruitful avenues for obtaining a better understanding of the fates of these organisms in aquatic environments.
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20
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Resistance of Escherichia coli O157:H7 ATCC 35150 to ohmic heating as influenced by growth temperature and sodium chloride concentration in salsa. Food Control 2019. [DOI: 10.1016/j.foodcont.2019.03.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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21
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Adaptation to Adversity: the Intermingling of Stress Tolerance and Pathogenesis in Enterococci. Microbiol Mol Biol Rev 2019; 83:83/3/e00008-19. [PMID: 31315902 DOI: 10.1128/mmbr.00008-19] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Enterococcus is a diverse and rugged genus colonizing the gastrointestinal tract of humans and numerous hosts across the animal kingdom. Enterococci are also a leading cause of multidrug-resistant hospital-acquired infections. In each of these settings, enterococci must contend with changing biophysical landscapes and innate immune responses in order to successfully colonize and transit between hosts. Therefore, it appears that the intrinsic durability that evolved to make enterococci optimally competitive in the host gastrointestinal tract also ideally positioned them to persist in hospitals, despite disinfection protocols, and acquire new antibiotic resistances from other microbes. Here, we discuss the molecular mechanisms and regulation employed by enterococci to tolerate diverse stressors and highlight the role of stress tolerance in the biology of this medically relevant genus.
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22
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Suryaletha K, Narendrakumar L, John J, Radhakrishnan MP, George S, Thomas S. Decoding the proteomic changes involved in the biofilm formation of Enterococcus faecalis SK460 to elucidate potential biofilm determinants. BMC Microbiol 2019; 19:146. [PMID: 31253082 PMCID: PMC6599329 DOI: 10.1186/s12866-019-1527-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 06/20/2019] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Enterococcus faecalis is a major clinically relevant nosocomial bacterial pathogen frequently isolated from polymicrobial infections. The biofilm forming ability of E. faecalis attributes a key role in its virulence and drug resistance. Biofilm cells are phenotypically and metabolically different from their planktonic counterparts and many aspects involved in E. faecalis biofilm formation are yet to be elucidated. The strain E. faecalis SK460 used in the present study is esp (Enterococcal surface protein) and fsr (two-component signal transduction system) negative non-gelatinase producing strong biofilm former isolated from a chronic diabetic foot ulcer patient. We executed a label-free quantitative proteomic approach to elucidate the differential protein expression pattern at planktonic and biofilm stages of SK460 to come up with potential determinants associated with Enterococcal biofilm formation. RESULTS The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of proteomic data revealed that biofilm cells expressed higher levels of proteins which are associated with glycolysis, amino acid biosynthesis, biosynthesis of secondary metabolites, microbial metabolism in diverse environments and stress response factors. Besides these basic survival pathways, LuxS-mediated quorum sensing, arginine metabolism, rhamnose biosynthesis, pheromone and adhesion associated proteins were found to be upregulated during the biofilm transit from planktonic stages. The selected subsets were validated by quantitative real-time PCR. In silico functional interaction analysis revealed that the genes involved in upregulated pathways pose a close molecular interaction thereby coordinating the regulatory network to thrive as a biofilm community. CONCLUSIONS The present study describes the first report of the quantitative proteome analysis of an esp and fsr negative non gelatinase producing E. faecalis. Proteome analysis evidenced enhanced expression of glycolytic pathways, stress response factors, LuxS quorum signaling system, rhamnopolysaccharide synthesis and pheromone associated proteins in biofilm phenotype. We also pointed out the relevance of LuxS quorum sensing and pheromone associated proteins in the biofilm development of E. faecalis which lacks the Fsr quorum signaling system. These validated biofilm determinants can act as potential inhibiting targets in Enterococcal infections.
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Affiliation(s)
- Karthika Suryaletha
- Cholera and Biofilm Research Laboratory, Pathogen Biology, Rajiv Gandhi Centre for Biotechnology, (National Institute under the Department of Biotechnology, Government of India), Trivandrum, Kerala, 695014, India
| | - Lekshmi Narendrakumar
- Cholera and Biofilm Research Laboratory, Pathogen Biology, Rajiv Gandhi Centre for Biotechnology, (National Institute under the Department of Biotechnology, Government of India), Trivandrum, Kerala, 695014, India
| | - Joby John
- Department of Surgery, Government Medical College Hospital, Trivandrum, Kerala, 695011, India
| | - Megha Periyappilly Radhakrishnan
- Cholera and Biofilm Research Laboratory, Pathogen Biology, Rajiv Gandhi Centre for Biotechnology, (National Institute under the Department of Biotechnology, Government of India), Trivandrum, Kerala, 695014, India
| | - Sanil George
- Interdisciplinary Biology, Rajiv Gandhi Centre for Biotechnology, Trivandrum, Kerala, 695014, India
| | - Sabu Thomas
- Cholera and Biofilm Research Laboratory, Pathogen Biology, Rajiv Gandhi Centre for Biotechnology, (National Institute under the Department of Biotechnology, Government of India), Trivandrum, Kerala, 695014, India.
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23
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Korajkic A, McMinn BR, Ashbolt NJ, Sivaganesan M, Harwood VJ, Shanks OC. Extended persistence of general and cattle-associated fecal indicators in marine and freshwater environment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 650:1292-1302. [PMID: 30308816 PMCID: PMC8982556 DOI: 10.1016/j.scitotenv.2018.09.108] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 09/06/2018] [Accepted: 09/08/2018] [Indexed: 05/26/2023]
Abstract
Fecal contamination of recreational waters with cattle manure can pose a risk to public health due to the potential presence of various zoonotic pathogens. Fecal indicator bacteria (FIB) have a long history of use in the assessment of recreational water quality, but FIB quantification provides no information about pollution sources. Microbial source tracking (MST) markers have been developed in response to a need to identify pollution sources, yet factors that influence their decay in ambient waters are often poorly understood. We investigated the influence of water type (freshwater versus marine) and select environmental parameters (indigenous microbiota, ambient sunlight) on the decay of FIB and MST markers originating from cattle manure. Experiments were conducted in situ using a submersible aquatic mesocosm containing dialysis bags filled with a mixture of cattle manure and ambient water. Culturable FIB (E. coli, enterococci) were enumerated by membrane filtration and general fecal indicator bacteria (GenBac3, Entero1a, EC23S857) and MST markers (Rum2Bac, CowM2, CowM3) were estimated by qPCR. Water type was the most significant factor influencing decay (three-way ANOVA, p: 0.006 to <0.001), although the magnitude of the effect differed among microbial targets and over time. The presence of indigenous microbiota and exposure to sunlight were significantly correlated (three-way ANOVA, p: 0.044 to <0.001) with decay of enterococci and CowM2, while E. coli, EC23S857, Rum2Bac, and CowM3 (three-way ANOVA, p: 0.044 < 0.001) were significantly impacted by sunlight or indigenous microbiota. Results indicate extended persistence of both cultivated FIB and genetic markers in marine and freshwater water types. Findings suggest that multiple environmental stressors are important determinants of FIB and MST marker persistence, but their magnitude can vary across indicators. Selective exclusion of natural aquatic microbiota and/or sunlight typically resulted in extended survival, but the effect was minor and limited to select microbial targets.
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Affiliation(s)
- Asja Korajkic
- National Exposure Research Laboratory, Office of Research and Development, 26 West Martin Luther King Drive, Cincinnati, OH 45268, United States.
| | - Brian R McMinn
- National Exposure Research Laboratory, Office of Research and Development, 26 West Martin Luther King Drive, Cincinnati, OH 45268, United States
| | - Nicholas J Ashbolt
- University of Alberta, School of Public Health, 3-57D South Academic Building, Edmonton, AB T6G 2G7, Canada
| | - Mano Sivaganesan
- National Risk Management Research Laboratory, Office of Research and Development, United States Environmental Protection Laboratory, 26 West Martin Luther King Drive, Cincinnati, OH 45268, United States
| | - Valerie J Harwood
- University of South Florida, Department of Integrative Biology, 4202 E Fowler Ave SCA 110, Tampa, FL 33620, United States
| | - Orin C Shanks
- National Risk Management Research Laboratory, Office of Research and Development, United States Environmental Protection Laboratory, 26 West Martin Luther King Drive, Cincinnati, OH 45268, United States
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24
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Barbieri F, Montanari C, Gardini F, Tabanelli G. Biogenic Amine Production by Lactic Acid Bacteria: A Review. Foods 2019; 8:E17. [PMID: 30621071 PMCID: PMC6351943 DOI: 10.3390/foods8010017] [Citation(s) in RCA: 221] [Impact Index Per Article: 44.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/18/2018] [Accepted: 01/02/2019] [Indexed: 12/12/2022] Open
Abstract
Lactic acid bacteria (LAB) are considered as the main biogenic amine (BA) producers in fermented foods. These compounds derive from amino acid decarboxylation through microbial activities and can cause toxic effects on humans, with symptoms (headache, heart palpitations, vomiting, diarrhea) depending also on individual sensitivity. Many studies have focused on the aminobiogenic potential of LAB associated with fermented foods, taking into consideration the conditions affecting BA accumulation and enzymes/genes involved in the biosynthetic mechanisms. This review describes in detail the different LAB (used as starter cultures to improve technological and sensorial properties, as well as those naturally occurring during ripening or in spontaneous fermentations) able to produce BAs in model or in real systems. The groups considered were enterococci, lactobacilli, streptococci, lactococci, pediococci, oenococci and, as minor producers, LAB belonging to Leuconostoc and Weissella genus. A deeper knowledge of this issue is important because decarboxylase activities are often related to strains rather than to species or genera. Moreover, this information can help to improve the selection of strains for further applications as starter or bioprotective cultures, in order to obtain high quality foods with reduced BA content.
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Affiliation(s)
- Federica Barbieri
- Interdepartmental Center for Industrial Agri-Food Research, University of Bologna, Cesena 47521, Italy.
| | - Chiara Montanari
- Interdepartmental Center for Industrial Agri-Food Research, University of Bologna, Cesena 47521, Italy.
| | - Fausto Gardini
- Interdepartmental Center for Industrial Agri-Food Research, University of Bologna, Cesena 47521, Italy.
- Department of Agricultural and Food Sciences, University of Bologna, Bologna 40126, Italy.
| | - Giulia Tabanelli
- Interdepartmental Center for Industrial Agri-Food Research, University of Bologna, Cesena 47521, Italy.
- Department of Agricultural and Food Sciences, University of Bologna, Bologna 40126, Italy.
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Loss-of-Function Mutations in epaR Confer Resistance to ϕNPV1 Infection in Enterococcus faecalis OG1RF. Antimicrob Agents Chemother 2018; 62:AAC.00758-18. [PMID: 30104266 PMCID: PMC6153818 DOI: 10.1128/aac.00758-18] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 08/01/2018] [Indexed: 02/06/2023] Open
Abstract
Enterococcus faecalis is a Gram-positive opportunistic pathogen that inhabits the human gastrointestinal tract. Because of the high frequency of antibiotic resistance among Enterococcus clinical isolates, interest in using phage to treat enterococcal infections and to decolonize high-risk patients for antibiotic-resistant Enterococcus is rising. Bacteria can evolve phage resistance, but there is little published information on these mechanisms in E. faecalis In this report, we identified genetic determinants of E. faecalis resistance to phage NPV1 (ϕNPV1). We found that loss-of-function mutations in epaR confer ϕNPV1 resistance by blocking phage adsorption. We attribute the inability of the phage to adsorb to the modification or loss of an extracellular polymer in strains with inactivated epaR Phage-resistant epaR mutants exhibited increased daptomycin and osmotic stress susceptibilities. Our results demonstrate that in vitro spontaneous resistance to ϕNPV1 comes at a cost in E. faecalis OG1RF.
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Andrés-Barrao C, Lafi FF, Alam I, de Zélicourt A, Eida AA, Bokhari A, Alzubaidy H, Bajic VB, Hirt H, Saad MM. Complete Genome Sequence Analysis of Enterobacter sp. SA187, a Plant Multi-Stress Tolerance Promoting Endophytic Bacterium. Front Microbiol 2017; 8:2023. [PMID: 29163376 PMCID: PMC5664417 DOI: 10.3389/fmicb.2017.02023] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 10/04/2017] [Indexed: 11/13/2022] Open
Abstract
Enterobacter sp. SA187 is an endophytic bacterium that has been isolated from root nodules of the indigenous desert plant Indigofera argentea. SA187 could survive in the rhizosphere as well as in association with different plant species, and was able to provide abiotic stress tolerance to Arabidopsis thaliana. The genome sequence of SA187 was obtained by using Pacific BioScience (PacBio) single-molecule sequencing technology, with average coverage of 275X. The genome of SA187 consists of one single 4,429,597 bp chromosome, with an average 56% GC content and 4,347 predicted protein coding DNA sequences (CDS), 153 ncRNA, 7 rRNA, and 84 tRNA. Functional analysis of the SA187 genome revealed a large number of genes involved in uptake and exchange of nutrients, chemotaxis, mobilization and plant colonization. A high number of genes were also found to be involved in survival, defense against oxidative stress and production of antimicrobial compounds and toxins. Moreover, different metabolic pathways were identified that potentially contribute to plant growth promotion. The information encoded in the genome of SA187 reveals the characteristics of a dualistic lifestyle of a bacterium that can adapt to different environments and promote the growth of plants. This information provides a better understanding of the mechanisms involved in plant-microbe interaction and could be further exploited to develop SA187 as a biological agent to improve agricultural practices in marginal and arid lands.
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Affiliation(s)
- Cristina Andrés-Barrao
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Feras F Lafi
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.,Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Intikhab Alam
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Axel de Zélicourt
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Abdul A Eida
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Ameerah Bokhari
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Hanin Alzubaidy
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Vladimir B Bajic
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Heribert Hirt
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Maged M Saad
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
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Ali L, Goraya MU, Arafat Y, Ajmal M, Chen JL, Yu D. Molecular Mechanism of Quorum-Sensing in Enterococcus faecalis: Its Role in Virulence and Therapeutic Approaches. Int J Mol Sci 2017; 18:ijms18050960. [PMID: 28467378 PMCID: PMC5454873 DOI: 10.3390/ijms18050960] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Accepted: 04/26/2017] [Indexed: 12/22/2022] Open
Abstract
Quorum-sensing systems control major virulence determinants in Enterococcusfaecalis, which causes nosocomial infections. The E. faecalis quorum-sensing systems include several virulence factors that are regulated by the cytolysin operon, which encodes the cytolysin toxin. In addition, the E. faecalis Fsr regulator system controls the expression of gelatinase, serine protease, and enterocin O16. The cytolysin and Fsr virulence factor systems are linked to enterococcal diseases that affect the health of humans and other host models. Therefore, there is substantial interest in understanding and targeting these regulatory pathways to develop novel therapies for enterococcal infection control. Quorum-sensing inhibitors could be potential therapeutic agents for attenuating the pathogenic effects of E. faecalis. Here, we discuss the regulation of cytolysin, the LuxS system, and the Fsr system, their role in E. faecalis-mediated infections, and possible therapeutic approaches to prevent E. faecalis infection.
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Affiliation(s)
- Liaqat Ali
- College of Animal Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Department of Biosciences, Faculty of Science, COMSATS Institute of Information Technology, Islamabad 45550, Pakistan.
| | - Mohsan Ullah Goraya
- College of Animal Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Yasir Arafat
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Muhammad Ajmal
- Department of Biosciences, Faculty of Science, COMSATS Institute of Information Technology, Islamabad 45550, Pakistan.
| | - Ji-Long Chen
- College of Animal Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing 100101, China.
| | - Daojin Yu
- College of Animal Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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Kurt-Kızıldoğan A, Abanoz B, Okay S. Global transcriptome analysis of Halolamina sp. to decipher the salt tolerance in extremely halophilic archaea. Gene 2016; 601:56-64. [PMID: 27919704 DOI: 10.1016/j.gene.2016.11.042] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/17/2016] [Accepted: 11/30/2016] [Indexed: 12/21/2022]
Abstract
Extremely halophilic archaea survive in the hypersaline environments such as salt lakes or salt mines. Therefore, these microorganisms are good sources to investigate the molecular mechanisms underlying the tolerance to high salt concentrations. In this study, a global transcriptome analysis was conducted in an extremely halophilic archaeon, Halolamina sp. YKT1, isolated from a salt mine in Turkey. A comparative RNA-seq analysis was performed using YKT1 isolate grown either at 2.7M NaCl or 5.5M NaCl concentrations. A total of 2149 genes were predicted to be up-regulated and 1638 genes were down-regulated in the presence of 5.5M NaCl. The salt tolerance of Halolamina sp. YKT1 involves the up-regulation of genes related with membrane transporters, CRISPR-Cas systems, osmoprotectant solutes, oxidative stress proteins, and iron metabolism. On the other hand, the genes encoding the proteins involved in DNA replication, transcription, translation, mismatch and nucleotide excision repair were down-regulated. The RNA-seq data were verified for seven up-regulated genes as well as six down-regulated genes via qRT-PCR analysis. This comprehensive transcriptome analysis showed that the halophilic archaeon canalizes its energy towards keeping the intracellular osmotic balance minimizing the production of nucleic acids and peptides.
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Affiliation(s)
- Aslıhan Kurt-Kızıldoğan
- Department of Agricultural Biotechnology, Faculty of Agriculture, Ondokuz Mayıs University, 55139 Samsun, Turkey
| | - Büşra Abanoz
- Department of Agricultural Biotechnology, Faculty of Agriculture, Ondokuz Mayıs University, 55139 Samsun, Turkey
| | - Sezer Okay
- Department of Biology, Faculty of Science, Çankırı Karatekin University, 18100 Çankırı, Turkey.
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Abstract
Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance.
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Vicari LO, Castiglione R, Salemi M, Vicari BO, Mazzarino MC, Vicari E. Effect of levofloxacin treatment on semen hyperviscosity in chronic bacterial prostatitis patients. Andrologia 2015; 48:380-8. [DOI: 10.1111/and.12456] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/09/2015] [Indexed: 12/31/2022] Open
Affiliation(s)
- L. O. Vicari
- Section of Endocrinology and Andrology; Department of Experimental and Clinical Medicine; International Master in Experimental and Clinical Medicine and Cellular Physiopathology; University of Catania; Catania Italy
| | - R. Castiglione
- Section of Endocrinology and Andrology; Department of Experimental and Clinical Medicine; International Master in Experimental and Clinical Medicine and Cellular Physiopathology; University of Catania; Catania Italy
| | - M. Salemi
- IRCCS Oasi Institute for Research on Mental Retardation and Brain Aging; Troina (EN) Italy
| | - B. O. Vicari
- Department of Bio-Medical Sciences; University of Catania; Catania Italy
| | - M. C. Mazzarino
- Department of Bio-Medical Sciences; University of Catania; Catania Italy
| | - E. Vicari
- Section of Endocrinology and Andrology; Department of Experimental and Clinical Medicine; International Master in Experimental and Clinical Medicine and Cellular Physiopathology; University of Catania; Catania Italy
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Adaptation to NaCl Reduces the Susceptibility of Enterococcus faecalis to Melaleuca alternifolia (Tea Tree) Oil. Curr Microbiol 2015; 71:429-33. [PMID: 26159776 DOI: 10.1007/s00284-015-0871-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 05/30/2015] [Indexed: 10/23/2022]
Abstract
This study investigated the hypothesis that the salt adaptation response of Enterococcus faecalis alters susceptibility to tea tree oil (TTO). Six E. faecalis isolates were adapted to 6.5 % NaCl, and then exposed to TTO in phosphate-buffered saline (PBS). One isolate was also exposed to TTO in Brain Heart Infusion Broth (BHIB). The viability of salt-adapted and non-adapted control cells was determined at 0, 45 and 90 min and compared. MICs for several antibiotics and TTO were also determined by E test and broth microdilution, respectively. Results showed that susceptibility to TTO in PBS was significantly reduced after salt adaptation for five isolates (83 %) (P < 0.05). Mean differences between salt-adapted and non-adapted cell counts were 2.51 log at 45 min and 2.13 log at 90 min. However, when E. faecalis ATCC 19433 was exposed to TTO in BHIB, no significant differences were seen. In conclusion, salt adaptation resulted in reduced susceptibility to TTO in PBS for the majority of isolates, indicating that cross protection had occurred. This effect was absent in BHIB, suggesting that the uptake of compatible solutes from the growth medium protected non-adapted cells from TTO. Whether this has implications for the clinical effectiveness of TTO remains to be determined.
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Arntzen MØ, Karlskås IL, Skaugen M, Eijsink VGH, Mathiesen G. Proteomic Investigation of the Response of Enterococcus faecalis V583 when Cultivated in Urine. PLoS One 2015; 10:e0126694. [PMID: 25915650 PMCID: PMC4411035 DOI: 10.1371/journal.pone.0126694] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 04/07/2015] [Indexed: 11/19/2022] Open
Abstract
Enterococcus faecalis is a robust bacterium, which is able to survive in and adapt to hostile environments such as the urinary tract and bladder. In this label-free quantitative proteomic study based on MaxQuant LFQ algorithms, we identified 127 proteins present in the secretome of the clinical vancomycin-resistant isolate E. faecalis V583 and we compared proteins secreted in the initial phase of cultivation in urine with the secretome during cultivation in standard laboratory medium, 2xYT. Of the 54 identified proteins predicted to be secreted, six were exclusively found after cultivation in urine including the virulence factor EfaA ("endocarditis specific antigen") and its homologue EF0577 ("adhesion lipoprotein"). These two proteins are both involved in manganese transport, known to be an important determinant of colonization and infection, and may additionally function as adhesins. Other detected urine-specific proteins are involved in peptide transport (EF0063 and EF3106) and protease inhibition (EF3054). In addition, we found an uncharacterized protein (EF0764), which had not previously been linked to the adaptation of V583 to a urine environment, and which is unique to E. faecalis. Proteins found in both environments included a histone-like protein, EF1550, that was up-regulated during cultivation in urine and that has a homologue in streptococci (HlpA) known to be involved in bacterial adhesion to host cells. Up-regulated secreted proteins included autolysins. These results from secretome analyses are largely compatible with previously published data from transcriptomics studies. All in all, the present data indicate that transport, in particular metal transport, adhesion, cell wall remodelling and the unknown function carried out by the unique EF0764 are important for enterococcal adaptation to the urine environment. These results provide a basis for a more targeted exploration of novel proteins involved in the adaptability and pathogenicity of E. faecalis.
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Affiliation(s)
- Magnus Øverlie Arntzen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
- * E-mail:
| | - Ingrid Lea Karlskås
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Morten Skaugen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Vincent G. H. Eijsink
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Geir Mathiesen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
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A genomic virulence reference map of Enterococcus faecalis reveals an important contribution of phage03-like elements in nosocomial genetic lineages to pathogenicity in a Caenorhabditis elegans infection model. Infect Immun 2015; 83:2156-67. [PMID: 25776747 DOI: 10.1128/iai.02801-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 03/07/2015] [Indexed: 02/07/2023] Open
Abstract
In the present study, the commensal and pathogenic host-microbe interaction of Enterococcus faecalis was explored using a Caenorhabditis elegans model system. The virulence of 28 E. faecalis isolates representing 24 multilocus sequence types (MLSTs), including human commensal and clinical isolates as well as isolates from animals and of insect origin, was investigated using C. elegans strain glp-4 (bn2ts); sek-1 (km4). This revealed that 6 E. faecalis isolates behaved in a commensal manner with no nematocidal effect, while the remaining strains showed a time to 50% lethality ranging from 47 to 120 h. Principal component analysis showed that the difference in nematocidal activity explained 94% of the variance in the data. Assessment of known virulence traits revealed that gelatinase and cytolysin production accounted for 40.8% and 36.5% of the observed pathogenicity, respectively. However, coproduction of gelatinase and cytolysin did not increase virulence additively, accounting for 50.6% of the pathogenicity and therefore indicating a significant (26.7%) saturation effect. We employed a comparative genomic analysis approach using the 28 isolates comprising a collection of 82,356 annotated coding sequences (CDS) to identify 2,325 patterns of presence or absence among the investigated strains. Univariate statistical analysis of variance (ANOVA) established that individual patterns positively correlated (n = 61) with virulence. The patterns were investigated to identify potential new virulence traits, among which we found five patterns consisting of the phage03-like gene clusters. Strains harboring phage03 showed, on average, 17% higher killing of C. elegans (P = 4.4e(-6)). The phage03 gene cluster was also present in gelatinase-and-cytolysin-negative strain E. faecalis JH2-2. Deletion of this phage element from the JH2-2 clinical strain rendered the mutant apathogenic in C. elegans, and a similar mutant of the nosocomial V583 isolate showed significantly attenuated virulence. Bioinformatics investigation indicated that, unlike other E. faecalis virulence traits, phage03-like elements were found at a higher frequency among nosocomial isolates. In conclusion, our report provides a valuable virulence map that explains enhancement in E. faecalis virulence and contributes to a deeper comprehension of the genetic mechanism leading to the transition from commensalism to a pathogenic lifestyle.
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The fsr Quorum-Sensing System and Cognate Gelatinase Orchestrate the Expression and Processing of Proprotein EF_1097 into the Mature Antimicrobial Peptide Enterocin O16. J Bacteriol 2015; 197:2112-2121. [PMID: 25733609 DOI: 10.1128/jb.02513-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 02/20/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED A novel antimicrobial peptide designated enterocin O16 was purified from Enterococcus faecalis. Mass spectrometry showed a monoisotopic mass of 7,231 Da, and N-terminal Edman degradation identified a 29-amino-acid sequence corresponding to residues 90 to 119 of the EF_1097 protein. Bioinformatic analysis showed that enterocin O16 is composed of the 68 most C-terminal residues of the EF_1097 protein. Introduction of an in-frame isogenic deletion in the ef1097 gene abolished the production of enterocin O16. Enterocin O16 has a narrow inhibitory spectrum, as it inhibits mostly lactobacilli. Apparently, E. faecalis is intrinsically resistant to the antimicrobial peptide, as no immunity connected to the production of enterocin O16 could be identified. ef1097 has previously been identified as one of three loci regulated by the fsr quorum-sensing system. The introduction of a nonsense mutation into fsrB consistently impaired enterocin O16 production, but externally added gelatinase biosynthesis-activating pheromone restored the antimicrobial activity. Functional genetic analysis showed that the EF_1097 proprotein is processed extracellularly into enterocin O16 by the metalloprotease GelE. Thus, it is evident that the fsr quorum-sensing system constitutes the regulatory unit that controls the expression of the EF_1097 precursor protein and the protease GelE and that the latter is required for the formation of enterocin O16. On the basis of these results, this study identified antibacterial antagonism as a novel aspect related to the function of fsr and provides a rationale for why ef1097 is part of the fsr regulon. IMPORTANCE The fsr quorum-sensing system modulates important physiological functions in E. faecalis via the activity of GelE. The present study presents a new facet of fsr signaling. The system controls the expression of three primary target operons (fsrABCD, gelE-sprE, and ef1097-ef1097b). We demonstrate that the concerted expression of these operons constitutes the elements necessary for the production of a bacteriocin-type peptide and that antimicrobial antagonism is an intrinsic function of fsr. The bacteriocin enterocin O16 consists of the 68 most C-terminal residues of the EF_1097 secreted proprotein. The GelE protease processes the EF_1097 proprotein into enterocin O16. In this manner, fsr signaling enables E. faecalis populations to express antimicrobial activity in a cell density-dependent manner.
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Bioluminescence based biosensors for quantitative detection of enterococcal peptide-pheromone activity reveal inter-strain telesensing in vivo during polymicrobial systemic infection. Sci Rep 2015; 5:8339. [PMID: 25661457 PMCID: PMC4321189 DOI: 10.1038/srep08339] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 01/14/2015] [Indexed: 12/20/2022] Open
Abstract
Enterococcus faecalis is a significant threat in the nosocomial setting due to the emergence of isolates that are multi-antibiotic resistant, refractory to the available therapies and equipped with a variety of pathogenicity determinants. This bacterium uses quorum-sensing systems to regulate its physiological processes, including the expression of virulence traits, to adapt and proliferate within a host. Here, we describe the construction and application of two bioluminescence-based reporter systems for the direct detection of the quorum-sensing regulated expression of (i) the gelatinase biosynthesis-activating pheromone (GBAP) and (ii) the cytolysin small subunit (CylLS) in natural samples. The two E. faecalis reporters conditionally expressed bioluminescence in the presence of GBAP and CylLS both in the supernatants of liquid cultures and in an agar-overlay assay in as little as three hours, with a high level of sensitivity. Biosensors employed to investigate the interaction between the fsr and cyl systems revealed that fsr impeded CylLS activity by 75%. Furthermore, we identified a clinical E. faecalis isolate that acted as a biological cheater, producing cytolysin only upon sensing CylLS-producers in its environment. This isolate enhanced its virulence during polymicrobial systemic infection of Galleria mellonella.
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Liu L, Si L, Meng X, Luo L. Comparative transcriptomic analysis reveals novel genes and regulatory mechanisms of Tetragenococcus halophilus in response to salt stress. J Ind Microbiol Biotechnol 2015; 42:601-16. [PMID: 25563971 DOI: 10.1007/s10295-014-1579-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Accepted: 12/25/2014] [Indexed: 11/29/2022]
Abstract
Tetragenococcus halophilus, a moderately halophilic Gram-positive bacterium, was isolated from Chinese style soy sauce. This species is a valuable resource for investigating salt tolerance mechanisms and improving salinity resistance in microorganisms. RNA-seq was used to sequence T. halophilus samples treated with 0 M (T1), 1 M (T2), and 3.5 M NaCl (T3). Comparative transcriptomic analyses of the different treatments were performed using gene ontology and Kyoto encyclopedia of genes and genome. The comparison of T1 and T2 by RNA-seq revealed that genes involved in transcription, translation, membrane system, and division were highly up-regulated under optimum salt condition. The comparison of T2 and T3 showed that genes related to heat shock proteins or the ATP-binding cassette transport systems were significantly up-regulated under maximum-salt condition. In addition, a considerable proportion of the significantly differently expressed genes identified in this study are novel. These data provide a crucial resource that may determine specific responses to salt stress in T. halophilus.
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Affiliation(s)
- Licui Liu
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, China
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Tyramine biosynthesis is transcriptionally induced at low pH and improves the fitness of Enterococcus faecalis in acidic environments. Appl Microbiol Biotechnol 2014; 99:3547-58. [DOI: 10.1007/s00253-014-6301-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 12/04/2014] [Accepted: 12/06/2014] [Indexed: 10/24/2022]
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