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Gallego-López GM, Contreras Guzman E, Desa DE, Knoll LJ, Skala MC. Metabolic changes in Toxoplasma gondii-infected host cells measured by autofluorescence imaging. mBio 2024:e0072724. [PMID: 38975793 DOI: 10.1128/mbio.00727-24] [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: 04/05/2024] [Accepted: 05/06/2024] [Indexed: 07/09/2024] Open
Abstract
Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular parasite that infects warm-blooded vertebrates across the world. In humans, seropositivity rates of T. gondii range from 10% to 90% across communities. Despite its prevalence, few studies address how T. gondii infection changes the metabolism of host cells. In this study, we investigate how T. gondii manipulates the host cell metabolic environment by monitoring the metabolic response over time using noninvasive autofluorescence lifetime imaging of single cells, metabolite analysis, extracellular flux analysis, and reactive oxygen species (ROS) production. Autofluorescence lifetime imaging indicates that infected host cells become more oxidized and have an increased proportion of bound NAD(P)H compared to uninfected controls. Over time, infected cells also show decreases in levels of intracellular glucose and lactate, increases in oxygen consumption, and variability in ROS production. We further examined changes associated with the pre-invasion "kiss and spit" process using autofluorescence lifetime imaging, which also showed a more oxidized host cell with an increased proportion of bound NAD(P)H over 48 hours compared to uninfected controls, suggesting that metabolic changes in host cells are induced by T. gondii kiss and spit even without invasion.IMPORTANCEThis study sheds light on previously unexplored changes in host cell metabolism induced by T. gondii infection using noninvasive, label-free autofluorescence imaging. In this study, we use optical metabolic imaging (OMI) to measure the optical redox ratio (ORR) in conjunction with fluorescence lifetime imaging microscopy (FLIM) to noninvasively monitor single host cell response to T. gondii infection over 48 hours. Collectively, our results affirm the value of using autofluorescence lifetime imaging to noninvasively monitor metabolic changes in host cells over the time course of a microbial infection. Understanding this metabolic relationship between the host cell and the parasite could uncover new treatment and prevention options for T. gondii infections worldwide.
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Affiliation(s)
- Gina M Gallego-López
- Morgridge Institute for Research, Madison, Wisconsin, USA
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | | | - Laura J Knoll
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Melissa C Skala
- Morgridge Institute for Research, Madison, Wisconsin, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Gallego-López GM, Guzman EC, Knoll LJ, Skala M. Metabolic changes to host cells with Toxoplasma gondii infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.10.552811. [PMID: 37609172 PMCID: PMC10441426 DOI: 10.1101/2023.08.10.552811] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular parasite that infects warm-blooded vertebrates across the world. In humans, seropositivity rates of T. gondii range from 10% to 90%. Despite its prevalence, few studies address how T. gondii infection changes the metabolism of host cells. Here, we investigate how T. gondii manipulates the host cell metabolic environment by monitoring metabolic response over time using non-invasive autofluorescence lifetime imaging of single cells, seahorse metabolic flux analysis, reactive oxygen species (ROS) production, and metabolomics. Autofluorescence lifetime imaging indicates that infected host cells become more oxidized and have an increased proportion of bound NAD(P)H with infection. These findings are consistent with changes in mitochondrial and glycolytic function, decrease of intracellular glucose, fluctuations in lactate and ROS production in infected cells over time. We also examined changes associated with the pre-invasion "kiss and spit" process using autofluorescence lifetime imaging, which similarly showed a more oxidized host cell with an increased proportion of bound NAD(P)H over 48 hours. Glucose metabolic flux analysis indicated that these changes are driven by NADH and NADP+ in T. gondii infection. In sum, metabolic changes in host cells with T. gondii infection were similar during full infection, and kiss and spit. Autofluorescence lifetime imaging can non-invasively monitor metabolic changes in host cells over a microbial infection time-course.
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Affiliation(s)
- Gina M. Gallego-López
- Morgridge Institute for Research, Madison, WI, 53706
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI, 53706
| | | | - Laura J. Knoll
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI, 53706
| | - Melissa Skala
- Morgridge Institute for Research, Madison, WI, 53706
- Department of Biomedical Engineering, University of Wisconsin- Madison, WI 53706, USA
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Schwartzman JA, Lebreton F, Salamzade R, Martin MJ, Schaufler K, Urhan A, Abeel T, Camargo IL, Sgardioli BF, Prichula J, Frazzon APG, Van Tyne D, Treinish G, Innis CJ, Wagenaar JA, Whipple RM, Manson AL, Earl AM, Gilmore MS. Global diversity of enterococci and description of 18 novel species. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.18.540996. [PMID: 37293047 PMCID: PMC10245769 DOI: 10.1101/2023.05.18.540996] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Enterococci are commensal gut microbes of most land animals. They diversified over hundreds of millions of years adapting to evolving hosts and host diets. Of over 60 known enterococcal species, Enterococcus faecalis and E. faecium uniquely emerged in the antibiotic era among leading causes of multidrug resistant hospital-associated infection. The basis for the association of particular enterococcal species with a host is largely unknown. To begin deciphering enterococcal species traits that drive host association, and to assess the pool of Enterococcus-adapted genes from which known facile gene exchangers such as E. faecalis and E. faecium may draw, we collected 886 enterococcal strains from nearly 1,000 specimens representing widely diverse hosts, ecologies and geographies. This provided data on the global occurrence and host associations of known species, identifying 18 new species in the process expanding genus diversity by >25%. The novel species harbor diverse genes associated with toxins, detoxification, and resource acquisition. E. faecalis and E. faecium were isolated from a wide diversity of hosts highlighting their generalist properties, whereas most other species exhibited more restricted distributions indicative of specialized host associations. The expanded species diversity permitted the Enterococcus genus phylogeny to be viewed with unprecedented resolution, allowing features to be identified that distinguish its four deeply rooted clades as well as genes associated with range expansion, such as B-vitamin biosynthesis and flagellar motility. Collectively, this work provides an unprecedentedly broad and deep view of the genus Enterococcus, potential threats to human health, and new insights into its evolution.
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Affiliation(s)
- Julia A. Schwartzman
- Departments of Ophthalmology and Microbiology, Mass Eye and Ear, and Harvard Medical School, Boston, MA,USA
- Department of Biology, University of Southern California, Los Angeles, CA, USA
| | - Francois Lebreton
- Departments of Ophthalmology and Microbiology, Mass Eye and Ear, and Harvard Medical School, Boston, MA,USA
- Multidrug-Resistant Organism Repository and Surveillance Network, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Rauf Salamzade
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Melissa J. Martin
- Departments of Ophthalmology and Microbiology, Mass Eye and Ear, and Harvard Medical School, Boston, MA,USA
- Multidrug-Resistant Organism Repository and Surveillance Network, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Katharina Schaufler
- Departments of Ophthalmology and Microbiology, Mass Eye and Ear, and Harvard Medical School, Boston, MA,USA
- University of Greifswald, Institute of Pharmacy, Greifswald, Germany
- Kiel University and University Medical Center Schleswig-Holstein, Institute of Infection Medicine, Kiel, Germany
| | - Aysun Urhan
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Delft Bioinformatics Lab, Delft University of Technology, Delft, The Netherlands
| | - Thomas Abeel
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Delft Bioinformatics Lab, Delft University of Technology, Delft, The Netherlands
| | - Ilana L.B.C Camargo
- Laboratório de Epidemiologia e Microbiologia Moleculares (LEMiMo), Departamento de Física e Ciências Interdisciplinares, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil
| | - Bruna F. Sgardioli
- Laboratório de Epidemiologia e Microbiologia Moleculares (LEMiMo), Departamento de Física e Ciências Interdisciplinares, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil
| | - Janira Prichula
- Departments of Ophthalmology and Microbiology, Mass Eye and Ear, and Harvard Medical School, Boston, MA,USA
- Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
| | - Ana Paula Guedes Frazzon
- Departments of Ophthalmology and Microbiology, Mass Eye and Ear, and Harvard Medical School, Boston, MA,USA
- Department of Microbiology, Immunology and Parasitology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Daria Van Tyne
- Departments of Ophthalmology and Microbiology, Mass Eye and Ear, and Harvard Medical School, Boston, MA,USA
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburg, PA, USA
| | | | | | - Jaap A. Wagenaar
- Department of Biomolecular Health Sciences, Utrecht University, Utrecht, Netherlands
| | - Ryan M. Whipple
- Departments of Ophthalmology and Microbiology, Mass Eye and Ear, and Harvard Medical School, Boston, MA,USA
| | - Abigail L. Manson
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Ashlee M. Earl
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Michael S. Gilmore
- Departments of Ophthalmology and Microbiology, Mass Eye and Ear, and Harvard Medical School, Boston, MA,USA
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Dong J, Liu L, Chen L, Xiang Y, Wang Y, Zhao Y. The Coexistence of Bacterial Species Restructures Biofilm Architecture and Increases Tolerance to Antimicrobial Agents. Microbiol Spectr 2023; 11:e0358122. [PMID: 36847543 PMCID: PMC10100793 DOI: 10.1128/spectrum.03581-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 02/05/2023] [Indexed: 03/01/2023] Open
Abstract
Chronic infections caused by polymicrobial biofilms are often difficult to treat effectively, partially due to the elevated tolerance of polymicrobial biofilms to antimicrobial treatments. It is known that interspecific interactions influence polymicrobial biofilm formation. However, the underlying role of the coexistence of bacterial species in polymicrobial biofilm formation is not fully understood. Here, we investigated the effect of the coexistence of Enterococcus faecalis, Escherichia coli O157:H7, and Salmonella enteritidis on triple-species biofilm formation. Our results demonstrated that the coexistence of these three species enhanced the biofilm biomass and led to restructuring of the biofilm into a tower-like architecture. Furthermore, the proportions of polysaccharides, proteins, and eDNAs in the extracellular matrix (ECM) composition of the triple-species biofilm were significantly changed compared to those in the E. faecalis mono-species biofilm. Finally, we analyzed the transcriptomic profile of E. faecalis in response to coexistence with E. coli and S. enteritidis in the triple-species biofilm. The results suggested that E. faecalis established dominance and restructured the triple-species biofilm by enhancing nutrient transport and biosynthesis of amino acids, upregulating central carbon metabolism, manipulating the microenvironment through "biological weapons," and activating versatile stress response regulators. Together, the results of this pilot study reveal the nature of E. faecalis-harboring triple-species biofilms with a static biofilm model and provide novel insights for further understanding interspecies interactions and the clinical treatment of polymicrobial biofilms. IMPORTANCE Bacterial biofilms possess distinct community properties that affect various aspects of our daily lives. In particular, biofilms exhibit increased tolerance to chemical disinfectants, antimicrobial agents, and host immune responses. Multispecies biofilms are undoubtedly the dominant form of biofilms in nature. Thus, there is a pressing need for more research directed at delineating the nature of multispecies biofilms and the effects of the properties on the development and survival of the biofilm community. Here, we address the effects of the coexistence of Enterococcus faecalis, Escherichia coli, and Salmonella enteritidis on triple-species biofilm formation with a static model. In combination with transcriptomic analyses, this pilot study explores the potential underlying mechanisms that lead to the dominance of E. faecalis in triple-species biofilms. Our findings provide novel insights into the nature of triple-species biofilms and indicate that the composition of multispecies biofilms should be a key consideration when determining antimicrobial treatments.
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Affiliation(s)
- Jiajun Dong
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, China
- Key Laboratory for Animal-derived Food Safety of Henan Province, Zhengzhou, Henan, China
| | - Luhan Liu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, China
- Key Laboratory for Animal-derived Food Safety of Henan Province, Zhengzhou, Henan, China
| | - Liying Chen
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, China
- Key Laboratory for Animal-derived Food Safety of Henan Province, Zhengzhou, Henan, China
| | - Yuqiang Xiang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, China
- Key Laboratory for Animal-derived Food Safety of Henan Province, Zhengzhou, Henan, China
| | - Yabin Wang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, China
- Key Laboratory for Animal-derived Food Safety of Henan Province, Zhengzhou, Henan, China
| | - Youbao Zhao
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, China
- Key Laboratory for Animal-derived Food Safety of Henan Province, Zhengzhou, Henan, China
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Late Embryogenesis Abundant Proteins Contribute to the Resistance of Toxoplasma gondii Oocysts against Environmental Stresses. mBio 2023; 14:e0286822. [PMID: 36809045 PMCID: PMC10128015 DOI: 10.1128/mbio.02868-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Toxoplasma gondii oocysts, which are shed in large quantities in the feces from infected felines, are very stable in the environment, resistant to most inactivation procedures, and highly infectious. The oocyst wall provides an important physical barrier for sporozoites contained inside oocysts, protecting them from many chemical and physical stressors, including most inactivation procedures. Furthermore, sporozoites can withstand large temperature changes, even freeze-thawing, as well as desiccation, high salinity, and other environmental insults; however, the genetic basis for this environmental resistance is unknown. Here, we show that a cluster of four genes encoding Late Embryogenesis Abundant (LEA)-related proteins are required to provide Toxoplasma sporozoites resistance to environmental stresses. Toxoplasma LEA-like genes (TgLEAs) exhibit the characteristic features of intrinsically disordered proteins, explaining some of their properties. Our in vitro biochemical experiments using recombinant TgLEA proteins show that they have cryoprotective effects on the oocyst-resident lactate dehydrogenase enzyme and that induced expression in E. coli of two of them leads to better survival after cold stress. Oocysts from a strain in which the four LEA genes were knocked out en bloc were significantly more susceptible to high salinity, freezing, and desiccation compared to wild-type oocysts. We discuss the evolutionary acquisition of LEA-like genes in Toxoplasma and other oocyst-producing apicomplexan parasites of the Sarcocystidae family and discuss how this has likely contributed to the ability of sporozoites within oocysts to survive outside the host for extended periods. Collectively, our data provide a first molecular detailed view on a mechanism that contributes to the remarkable resilience of oocysts against environmental stresses. IMPORTANCE Toxoplasma gondii oocysts are highly infectious and may survive in the environment for years. Their resistance against disinfectants and irradiation has been attributed to the oocyst and sporocyst walls by acting as physical and permeability barriers. However, the genetic basis for their resistance against stressors like changes in temperature, salinity, or humidity, is unknown. We show that a cluster of four genes encoding Toxoplasma Late Embryogenesis Abundant (TgLEA)-related proteins are important for this resistance to environmental stresses. TgLEAs have features of intrinsically disordered proteins, explaining some of their properties. Recombinant TgLEA proteins show cryoprotective effects on the parasite's lactate dehydrogenase, an abundant enzyme in oocysts, and expression in E. coli of two TgLEAs has a beneficial effect on growth after cold stress. Moreover, oocysts from a strain lacking all four TgLEA genes were more susceptible to high salinity, freezing, and desiccation compared to wild-type oocysts, highlighting the importance of the four TgLEAs for oocyst resilience.
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Ciprofloxacin-Loaded Gold Nanoparticles against Antimicrobial Resistance: An In Vivo Assessment. NANOMATERIALS 2021; 11:nano11113152. [PMID: 34835916 PMCID: PMC8620493 DOI: 10.3390/nano11113152] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 11/04/2021] [Accepted: 11/06/2021] [Indexed: 12/11/2022]
Abstract
Metallic nanoparticles, such as gold nanoparticles (AuNPs), have been extensively studied as drug delivery systems for various therapeutic applications. However, drug-loaded-AuNPs have been rarely explored in vivo for their effect on bacteria residing inside tissues. Ciprofloxacin (CIP) is a second-generation fluoroquinolone with a broad-spectrum of antibiotic properties devoid of developing bacteria resistance. This research is focused on the synthesis and physical characterization of Ciprofloxacin-loaded gold nanoparticles (CIP-AuNPs) and their effect on the colonization of Enterococcus faecalis in the liver and kidneys of mice. The successfully prepared CIP-AuNPs were stable and exerted enhanced in vitro antibacterial activity against E. faecalis compared with free CIP. The optimized CIP-AuNPs were administered (500 µg/Kg) once a day via tail vein to infected mice for eight days and were found to be effective in eradicating E. faecalis from the host tissues. Moreover, unlike CIP, CIP-AuNPs were non-hemolytic. In summary, this study demonstrated that CIP-AuNPs are promising and biocompatible alternative therapeutics for E.-faecalis-induced infections resistant to conventional drugs (e.g., beta-lactams and vancomycin) and should be further investigated.
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Characterisation of putative lactate synthetic pathways of Coxiella burnetii. PLoS One 2021; 16:e0255925. [PMID: 34388185 PMCID: PMC8362950 DOI: 10.1371/journal.pone.0255925] [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: 05/30/2021] [Accepted: 07/26/2021] [Indexed: 11/19/2022] Open
Abstract
The zoonotic pathogen Coxiella burnetii, the causative agent of the human disease Q fever, is an ever-present danger to global public health. Investigating novel metabolic pathways necessary for C. burnetii to replicate within its unusual intracellular niche may identify new therapeutic targets. Recent studies employing stable isotope labelling established the ability of C. burnetii to synthesize lactate, despite the absence of an annotated synthetic pathway on its genome. A noncanonical lactate synthesis pathway could provide a novel anti-Coxiella target if it is essential for C. burnetii pathogenesis. In this study, two C. burnetii proteins, CBU1241 and CBU0823, were chosen for analysis based on their similarities to known lactate synthesizing enzymes. Recombinant GST-CBU1241, a putative malate dehydrogenase (MDH), did not produce measurable lactate in in vitro lactate dehydrogenase (LDH) activity assays and was confirmed to function as an MDH. Recombinant 6xHis-CBU0823, a putative NAD+-dependent malic enzyme, was shown to have both malic enzyme activity and MDH activity, however, did not produce measurable lactate in either LDH or malolactic enzyme activity assays in vitro. To examine potential lactate production by CBU0823 more directly, [13C]glucose labelling experiments compared label enrichment within metabolic pathways of a cbu0823 transposon mutant and the parent strain. No difference in lactate production was observed, but the loss of CBU0823 significantly reduced 13C-incorporation into glycolytic and TCA cycle intermediates. This disruption to central carbon metabolism did not have any apparent impact on intracellular replication within THP-1 cells. This research provides new information about the mechanism of lactate biosynthesis within C. burnetii, demonstrating that CBU1241 is not multifunctional, at least in vitro, and that CBU0823 also does not synthesize lactate. Although critical for normal central carbon metabolism of C. burnetii, loss of CBU0823 did not significantly impair replication of the bacterium inside cells.
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Hexabromocyclododecanes Are Dehalogenated by CYP168A1 from Pseudomonas aeruginosa Strain HS9. Appl Environ Microbiol 2021; 87:e0082621. [PMID: 34132585 DOI: 10.1128/aem.00826-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hexabromocyclododecanes (HBCDs) are widely used brominated flame retardants that cause antidiuretic hormone syndrome and even induce cancer. However, little information is available about the degradation mechanisms of HBCDs. In this study, genomic and proteomic analyses, reverse transcription-quantitative PCR, and gene knockout assays reveal that a cytochrome P450-encoding gene is responsible for HBCD catabolism in Pseudomonas aeruginosa HS9. The CO difference spectrum of the enzyme CYP168A1 was matched to P450 characteristics via UV visibility. We demonstrate that the reactions of debromination and hydrogenation are carried out one after another based on detection of the metabolites pentabromocyclododecanols (PBCDOHs), tetrabromocyclododecadiols (TBCDDOHs), and bromide ion. In the 18O isotope experiments, PBCD18OHs were only detected in the H218O group, proving that the added oxygen is derived from H2O, not from O2. This study elucidates the degradation mechanism of HBCDs by Pseudomonas. IMPORTANCE Hexabromocyclododecanes (HBCDs) are environmental pollutants that are widely used in industry. In this study, we identified and characterized a novel key dehalogenase, CYP168A1, that is responsible for HBCD degradation from Pseudomonas aeruginosa strain HS9. This study provides new insights into understanding biodegradation of HBCDs.
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Riaz S, Fatima Rana N, Hussain I, Tanweer T, Nawaz A, Menaa F, Janjua HA, Alam T, Batool A, Naeem A, Hameed M, Ali SM. Effect of Flavonoid-Coated Gold Nanoparticles on Bacterial Colonization in Mice Organs. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E1769. [PMID: 32906828 PMCID: PMC7559771 DOI: 10.3390/nano10091769] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/25/2020] [Accepted: 07/28/2020] [Indexed: 12/11/2022]
Abstract
Multidrug resistance (MDR) has been a potentiator for the exploration of antibiotics. Nano drug delivery systems have opened new avenues to overcome this challenge. Although antibacterial nanocarriers are extensively realized, their effect on the bacteria residing inside the tissues and their toxicity is rarely explored. This study investigated the effects of flavonoid coated gold nanoparticles (FAuNPs) on the colonization of Enterococcus faecalis in the mouse liver and kidneys. Flavonoids were extracted from the leaves of Berberis lycium Royle and used to stabilize gold following a green synthesis approach. FAuNPs were characterized by ultraviolet-visible (UV-Vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning transmission electron microscopy (STEM), X-ray powder diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS). FAuNPs showed significantly higher reduction in bacterial counts in in-vitro and in-vivo in mice organs as compared to the free flavonoids owing to their biocompatibility and effectiveness.
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Affiliation(s)
- Sundus Riaz
- Department of Biomedical Engineering and Sciences, School of Mechanical & Manufacturing Engineering, National University of Sciences & Technology, Islamabad 44000, Pakistan; (S.R.); (T.T.); (A.N.); (A.B.); (A.N.); (M.H.)
- Ministry of National Food Security and Research, Pakistan Agricultural Research Council, Karachi 75270, Pakistan
| | - Nosheen Fatima Rana
- Department of Biomedical Engineering and Sciences, School of Mechanical & Manufacturing Engineering, National University of Sciences & Technology, Islamabad 44000, Pakistan; (S.R.); (T.T.); (A.N.); (A.B.); (A.N.); (M.H.)
| | - Irshad Hussain
- School of Science and Engineering, Lahore University of Management Sciences, Lahore 54000, Pakistan;
| | - Tahreem Tanweer
- Department of Biomedical Engineering and Sciences, School of Mechanical & Manufacturing Engineering, National University of Sciences & Technology, Islamabad 44000, Pakistan; (S.R.); (T.T.); (A.N.); (A.B.); (A.N.); (M.H.)
| | - Afrah Nawaz
- Department of Biomedical Engineering and Sciences, School of Mechanical & Manufacturing Engineering, National University of Sciences & Technology, Islamabad 44000, Pakistan; (S.R.); (T.T.); (A.N.); (A.B.); (A.N.); (M.H.)
| | - Farid Menaa
- Department of Internal Medicine and Nanomedicine, California Innovations Corporation, San Diego, CA 92093, USA;
| | - Hussnain A. Janjua
- Atta Ur Rahman School of Applied Biosciences, National University of Sciences & Technology, Islamabad 44000, Pakistan; (H.A.J.); (T.A.)
| | - Tahseen Alam
- Atta Ur Rahman School of Applied Biosciences, National University of Sciences & Technology, Islamabad 44000, Pakistan; (H.A.J.); (T.A.)
| | - Amna Batool
- Department of Biomedical Engineering and Sciences, School of Mechanical & Manufacturing Engineering, National University of Sciences & Technology, Islamabad 44000, Pakistan; (S.R.); (T.T.); (A.N.); (A.B.); (A.N.); (M.H.)
| | - Ayesha Naeem
- Department of Biomedical Engineering and Sciences, School of Mechanical & Manufacturing Engineering, National University of Sciences & Technology, Islamabad 44000, Pakistan; (S.R.); (T.T.); (A.N.); (A.B.); (A.N.); (M.H.)
| | - Maryam Hameed
- Department of Biomedical Engineering and Sciences, School of Mechanical & Manufacturing Engineering, National University of Sciences & Technology, Islamabad 44000, Pakistan; (S.R.); (T.T.); (A.N.); (A.B.); (A.N.); (M.H.)
| | - Syed Mohsin Ali
- Department of Biomedical Engineering and Sciences, School of Mechanical & Manufacturing Engineering, National University of Sciences & Technology, Islamabad 44000, Pakistan; (S.R.); (T.T.); (A.N.); (A.B.); (A.N.); (M.H.)
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Ballén V, Ratia C, Cepas V, Soto SM. Enterococcus faecalis inhibits Klebsiella pneumoniae growth in polymicrobial biofilms in a glucose-enriched medium. BIOFOULING 2020; 36:846-861. [PMID: 32972252 DOI: 10.1080/08927014.2020.1824272] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 09/03/2020] [Accepted: 09/09/2020] [Indexed: 06/11/2023]
Abstract
Catheter-related urinary tract infections are one of the most common biofilm-associated diseases. Within biofilms, bacteria cooperate, compete, or have neutral interactions. This study aimed to investigate the interactions in polymicrobial biofilms of Klebsiella pneumoniae and Enterococcus faecalis, two of the most common uropathogens. Although K. pneumoniae was the most adherent strain, it could not maintain dominance in the polymicrobial biofilm due to the lactic acid produced by E. faecalis in a glucose-enriched medium. This result was supported by the use of E. faecalis V583 ldh-1/ldh-2 double mutant (non-producer of lactic acid), which did not inhibit the growth of K. pneumoniae. Lyophilized cell-free supernatants obtained from E. faecalis biofilms also showed antimicrobial/anti-biofilm activity against K. pneumoniae. Conversely, there were no significant differences in planktonic polymicrobial cultures. In summary, E. faecalis modifies the pH by lactic acid production in polymicrobial biofilms, which impairs the growth of K. pneumoniae.
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Affiliation(s)
- Victoria Ballén
- ISGlobal, Barcelona Center for International Health Research (CRESIB), Hospital Clinic - Universitat de Barcelona, Barcelona, Spain
| | - Carlos Ratia
- ISGlobal, Barcelona Center for International Health Research (CRESIB), Hospital Clinic - Universitat de Barcelona, Barcelona, Spain
| | - Virginio Cepas
- ISGlobal, Barcelona Center for International Health Research (CRESIB), Hospital Clinic - Universitat de Barcelona, Barcelona, Spain
| | - Sara M Soto
- ISGlobal, Barcelona Center for International Health Research (CRESIB), Hospital Clinic - Universitat de Barcelona, Barcelona, Spain
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11
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Major role of lactate dehydrogenase D-LDH1 for the synthesis of lactic acid in Fructobacillus tropaeoli CRL 2034. Appl Microbiol Biotechnol 2020; 104:7409-7426. [DOI: 10.1007/s00253-020-10776-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/23/2020] [Accepted: 07/05/2020] [Indexed: 02/04/2023]
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12
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Metabolic Shift of an Isogenic Strain of Enterococcus faecalis 14, Deficient in Its Own Bacteriocin Synthesis, as Revealed by a Transcriptomic Analysis. Int J Mol Sci 2020; 21:ijms21134653. [PMID: 32629918 PMCID: PMC7369866 DOI: 10.3390/ijms21134653] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/19/2020] [Accepted: 06/29/2020] [Indexed: 01/07/2023] Open
Abstract
The production of antimicrobial molecules often involves complex biological pathways. This study aimed at understanding the metabolic and physiological networks of enterocin EntDD14-associated function, in the bacteriocinogenic strain, Enterococcus faecalis 14. A global and comparative transcriptomic study was carried out on E. faecalis 14 and its isogenic mutant Δbac, inactivated in genes coding for EntDD14. The in vitro ability to form biofilm on polystyrene plates was assessed by the crystal violet method, while the cytotoxicity on human colorectal adenocarcinoma Caco-2 cells was determined by the Cell Counting Kit-8. Transcriptomic data revealed that 71 genes were differentially expressed in both strains. As expected, genes coding for EntDD14 were downregulated in the Δbac mutant, whereas the other 69 genes were upregulated. Upregulated genes were associated with phage-related chromosomal islands, biofilm formation capability, resistance to environmental stresses, and metabolic reprogramming. Interestingly, the Δbac mutant showed an improved bacterial growth, a high capacity to form biofilm on inanimate surfaces and a very weak cytotoxicity level. These multiple metabolic rearrangements delineate a new line of defense to counterbalance the loss of EntDD14.
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13
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Abstract
Enterococci are important human commensals and significant opportunistic pathogens. Biofilm-related enterococcal infections, such as endocarditis, urinary tract infections, wound and surgical site infections, and medical device-associated infections, often become chronic upon the formation of biofilm. The biofilm matrix establishes properties that distinguish this state from free-living bacterial cells and increase tolerance to antimicrobial interventions. The metabolic versatility of the enterococci is reflected in the diversity and complexity of environments and communities in which they thrive. Understanding metabolic factors governing colonization and persistence in different host niches can reveal factors influencing the transition to biofilm pathogenicity. Here, we report a form of iron-dependent metabolism for Enterococcus faecalis where, in the absence of heme, extracellular electron transfer (EET) and increased ATP production augment biofilm growth. We observe alterations in biofilm matrix depth and composition during iron-augmented biofilm growth. We show that the ldh gene encoding l-lactate dehydrogenase is required for iron-augmented energy production and biofilm formation and promotes EET. Bacterial metabolic versatility can often influence the outcome of host-pathogen interactions, yet causes of metabolic shifts are difficult to resolve. The bacterial biofilm matrix provides the structural and functional support that distinguishes this state from free-living bacterial cells. Here, we show that the biofilm matrix can immobilize iron, providing access to this growth-promoting resource which is otherwise inaccessible in the planktonic state. Our data show that in the absence of heme, Enterococcus faecalisl-lactate dehydrogenase promotes EET and uses matrix-associated iron to carry out EET. Therefore, the presence of iron within the biofilm matrix leads to enhanced biofilm growth.
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14
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Goh HMS, Yong MHA, Chong KKL, Kline KA. Model systems for the study of Enterococcal colonization and infection. Virulence 2017; 8:1525-1562. [PMID: 28102784 PMCID: PMC5810481 DOI: 10.1080/21505594.2017.1279766] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 12/30/2016] [Accepted: 01/04/2017] [Indexed: 02/07/2023] Open
Abstract
Enterococcus faecalis and Enterococcus faecium are common inhabitants of the human gastrointestinal tract, as well as frequent opportunistic pathogens. Enterococci cause a range of infections including, most frequently, infections of the urinary tract, catheterized urinary tract, bloodstream, wounds and surgical sites, and heart valves in endocarditis. Enterococcal infections are often biofilm-associated, polymicrobial in nature, and resistant to antibiotics of last resort. Understanding Enterococcal mechanisms of colonization and pathogenesis are important for identifying new ways to manage and intervene with these infections. We review vertebrate and invertebrate model systems applied to study the most common E. faecalis and E. faecium infections, with emphasis on recent findings examining Enterococcal-host interactions using these models. We discuss strengths and shortcomings of each model, propose future animal models not yet applied to study mono- and polymicrobial infections involving E. faecalis and E. faecium, and comment on the significance of anti-virulence strategies derived from a fundamental understanding of host-pathogen interactions in model systems.
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Affiliation(s)
- H. M. Sharon Goh
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
| | - M. H. Adeline Yong
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Kelvin Kian Long Chong
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
- Singapore Centre for Environmental Life Sciences Engineering, Interdisciplinary Graduate School, Nanyang Technological University, Singapore
| | - Kimberly A. Kline
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
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15
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Biaggini K, Borrel V, Szunerits S, Boukherroub R, N'Diaye A, Zébré A, Bonnin-Jusserand M, Duflos G, Feuilloley M, Drider D, Déchelotte P, Connil N. Substance P enhances lactic acid and tyramine production in Enterococcus faecalis V583 and promotes its cytotoxic effect on intestinal Caco-2/TC7 cells. Gut Pathog 2017; 9:20. [PMID: 28439299 PMCID: PMC5399405 DOI: 10.1186/s13099-017-0171-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 04/13/2017] [Indexed: 12/22/2022] Open
Abstract
Background Enterococcus faecalis, generally considered as a saprophytic bowel commensal, has recently emerged as an important nosocomial pathogen causing severe urinary tract infections, surgical wound infections, bacteremia, and bacterial endocarditis. This bacterium is capable of forming biofilms on various surfaces and its high level of antibiotic resistance contributes to its pathogenicity. The aim of this study was to evaluate the effect on E. faecalis, of Substance P (SP), an antimicrobial peptide that is produced in the gut and skin. Results We found that SP did not have antibacterial activity against E. faecalis V583 (MIC >1000 µg/ml). Conversely, SP stimulated aggregation, hydrophobicity, lactic acid and tyramine production in this bacterium. The cytotoxicity and bacterial translocation were also accelerated when E. faecalis V583 were pretreated with SP before infection of intestinal Caco-2/TC7 cells. Conclusion SP can modulate the physiology of E. faecalis. Extensive studies are now needed to screen within the human microbiota which bacteria are responsive to host molecules, and to identify their sensors.
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Affiliation(s)
- Kelly Biaggini
- Laboratoire de Microbiologie, Signaux et Microenvironnement (EA4312), Université de Rouen/IUT d'Evreux, 55, rue saint Germain, 27000 Evreux, France
| | - Valérie Borrel
- Laboratoire de Microbiologie, Signaux et Microenvironnement (EA4312), Université de Rouen/IUT d'Evreux, 55, rue saint Germain, 27000 Evreux, France
| | - Sabine Szunerits
- Institute of Electronics, Microelectronics and Nanotechnology, UMR-CNRS 8520, Université Lille 1, Villeneuve d'Ascq, France
| | - Rabah Boukherroub
- Institute of Electronics, Microelectronics and Nanotechnology, UMR-CNRS 8520, Université Lille 1, Villeneuve d'Ascq, France
| | - Awa N'Diaye
- Laboratoire de Microbiologie, Signaux et Microenvironnement (EA4312), Université de Rouen/IUT d'Evreux, 55, rue saint Germain, 27000 Evreux, France
| | - Arthur Zébré
- Laboratoire de Microbiologie, Signaux et Microenvironnement (EA4312), Université de Rouen/IUT d'Evreux, 55, rue saint Germain, 27000 Evreux, France
| | - Maryse Bonnin-Jusserand
- Institut Charles Viollette, EA7394, Université du Littoral Côte d'Opale, Boulogne Sur Mer, France
| | - Guillaume Duflos
- Laboratoire de Sécurité des Aliments, Département des Produits de la Pêche et de l'Aquaculture, ANSES, Boulogne Sur Mer, France
| | - Marc Feuilloley
- Laboratoire de Microbiologie, Signaux et Microenvironnement (EA4312), Université de Rouen/IUT d'Evreux, 55, rue saint Germain, 27000 Evreux, France
| | - Djamel Drider
- Institut Charles Viollette, EA7394, Université Lille 1 - Sciences et Technologies, Villeneuve d'Ascq, France
| | - Pierre Déchelotte
- INSERM Unité 1073 «Nutrition, Inflammation et dysfonction de l'axe intestin-cerveau», Université de Rouen, Rouen, France
| | - Nathalie Connil
- Laboratoire de Microbiologie, Signaux et Microenvironnement (EA4312), Université de Rouen/IUT d'Evreux, 55, rue saint Germain, 27000 Evreux, France
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16
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Rossi F, Zotta T, Iacumin L, Reale A. Theoretical insight into the heat shock response (HSR) regulation in Lactobacillus casei and L. rhamnosus. J Theor Biol 2016; 402:21-37. [DOI: 10.1016/j.jtbi.2016.04.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Revised: 04/18/2016] [Accepted: 04/25/2016] [Indexed: 02/07/2023]
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17
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Souza JME, Chang MR, Brito DZ, Farias KS, Damasceno-Junior GA, Turatti ICC, Lopes NP, Santos EA, Carollo CA. Antimicrobial activity of Aspilia latissima (Asteraceae). Braz J Microbiol 2015; 46:1103-10. [PMID: 26691468 PMCID: PMC4704628 DOI: 10.1590/s1517-838246420131281] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 12/31/2014] [Indexed: 11/27/2022] Open
Abstract
We evaluated the antimicrobial activity of Aspilia latissima - an
abundant plant from the Brazilian Pantanal region - against Candida albicans,
Candida parapsilosis, Candida krusei, Candida tropicalis, Pseudomonas aeruginosa,
Enterococcus faecalis, Escherichia coli and Staphylococcus
aureus. The crude extracts and fractions showed activity in all tested
microorganisms. The chloroform fraction of the leaves and roots showed the most
antimicrobial activity against S. aureus, with an MIC of 500 μg/mL.
This fraction was submitted to bioautographic assays to characterize the activity of
the compounds. Two bands from the leaves (L-A and L-B) and three bands from the roots
(R-C, R-D and R-E) were bioactive. Within the root-derived bands, the terpene
derivatives stigmasterol, kaurenoic acid and kaura-9(11), 16-dien-18-oic acid were
identified. Antibiotic activity of A. latissima is reported for the
first time.
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Affiliation(s)
- Jeana M E Souza
- Laboratório de Produtos Naturais e Espectrometria de Massas, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil
| | - Marilene R Chang
- Laboratório de Pesquisa em Microbiologia, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil
| | - Daniela Z Brito
- Laboratório de Pesquisa em Microbiologia, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil
| | - Katyuce S Farias
- Laboratório de Produtos Naturais e Espectrometria de Massas, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil
| | | | - Izabel C C Turatti
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Norberto P Lopes
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Edson A Santos
- Coordenação do Curso de Licenciatura em Química, Universidade Tecnológica Federal do Paraná, Apucarana, PR, Brazil
| | - Carlos A Carollo
- Laboratório de Produtos Naturais e Espectrometria de Massas, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil
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18
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Garcia-Simon M, Morales JM, Modesto-Alapont V, Gonzalez-Marrachelli V, Vento-Rehues R, Jorda-Miñana A, Blanquer-Olivas J, Monleon D. Prognosis Biomarkers of Severe Sepsis and Septic Shock by 1H NMR Urine Metabolomics in the Intensive Care Unit. PLoS One 2015; 10:e0140993. [PMID: 26565633 PMCID: PMC4643898 DOI: 10.1371/journal.pone.0140993] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 10/02/2015] [Indexed: 12/12/2022] Open
Abstract
Early diagnosis and patient stratification may improve sepsis outcome by a timely start of the proper specific treatment. We aimed to identify metabolomic biomarkers of sepsis in urine by 1H-NMR spectroscopy to assess the severity and to predict outcomes. Urine samples were collected from 64 patients with severe sepsis or septic shock in the ICU for a 1H NMR spectra acquisition. A supervised analysis was performed on the processed spectra, and a predictive model for prognosis (30-days mortality/survival) of sepsis was constructed using partial least-squares discriminant analysis (PLS-DA). In addition, we compared the prediction power of metabolomics data respect the Sequential Organ Failure Assessment (SOFA) score. Supervised multivariate analysis afforded a good predictive model to distinguish the patient groups and detect specific metabolic patterns. Negative prognosis patients presented higher values of ethanol, glucose and hippurate, and on the contrary, lower levels of methionine, glutamine, arginine and phenylalanine. These metabolites could be part of a composite biopattern of the human metabolic response to sepsis shock and its mortality in ICU patients. The internal cross-validation showed robustness of the metabolic predictive model obtained and a better predictive ability in comparison with SOFA values. Our results indicate that NMR metabolic profiling might be helpful for determining the metabolomic phenotype of worst-prognosis septic patients in an early stage. A predictive model for the evolution of septic patients using these metabolites was able to classify cases with more sensitivity and specificity than the well-established organ dysfunction score SOFA.
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Affiliation(s)
- Monica Garcia-Simon
- Department of Critical Care, Clinical University Hospital of Valencia, Valencia, Spain
| | - Jose M. Morales
- Central Unit of Research in Medicine, University of Valencia, Valencia, Spain
| | - Vicente Modesto-Alapont
- Department of Paediatric Critical Care, University and Polytechnic Hospital La Fe, Valencia, Spain
| | | | - Rosa Vento-Rehues
- Department of Critical Care, Clinical University Hospital of Valencia, Valencia, Spain
| | - Angela Jorda-Miñana
- Department of Critical Care, Clinical University Hospital of Valencia, Valencia, Spain
| | - Jose Blanquer-Olivas
- Department of Critical Care, Clinical University Hospital of Valencia, Valencia, Spain
| | - Daniel Monleon
- Clinical Hospital Research Foundation-INCLIVA, Valencia, Spain
- * E-mail:
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19
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Muller C, Cacaci M, Sauvageot N, Sanguinetti M, Rattei T, Eder T, Giard JC, Kalinowski J, Hain T, Hartke A. The Intraperitoneal Transcriptome of the Opportunistic Pathogen Enterococcus faecalis in Mice. PLoS One 2015; 10:e0126143. [PMID: 25978463 PMCID: PMC4433114 DOI: 10.1371/journal.pone.0126143] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 03/29/2015] [Indexed: 01/22/2023] Open
Abstract
Enterococcus faecalis is a Gram-positive lactic acid intestinal opportunistic bacterium with virulence potential. For a better understanding of the adapation of this bacterium to the host conditions, we performed a transcriptome analysis of bacteria isolated from an infection site (mouse peritonitis) by RNA-sequencing. We identified a total of 211 genes with significantly higher transcript levels and 157 repressed genes. Our in vivo gene expression database reflects well the infection process since genes encoding important virulence factors like cytolysin, gelatinase or aggregation substance as well as stress response proteins, are significantly induced. Genes encoding metabolic activities are the second most abundant in vivo induced genes demonstrating that the bacteria are metabolically active and adapt to the special nutrient conditions of the host. α- and β- glucosides seem to be important substrates for E. faecalis inside the host. Compared to laboratory conditions, the flux through the upper part of glycolysis seems to be reduced and more carbon may enter the pentose phosphate pathway. This may reflect the need of the bacteria under infection conditions to produce more reducing power for biosynthesis. Another important substrate is certainly glycerol since both pathways of glycerol catabolism are strongly induced. Strongly in vivo induced genes should be important for the infection process. This assumption has been verified in a virulence test using well characterized mutants affected in glycerol metabolism. This showed indeed that mutants unable to metabolize this sugar alcohol are affected in organ colonisation in a mouse model.
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Affiliation(s)
- Cécile Muller
- U2RM-Stress and Virulence, University of Caen Basse-Normandie, EA4655, 14032 Caen, France
- * E-mail: (AH); (CM)
| | - Margherita Cacaci
- U2RM-Stress and Virulence, University of Caen Basse-Normandie, EA4655, 14032 Caen, France
- Institute of Microbiology, Catholic University of Sacred Heart, 00168, Rome, Italy
| | - Nicolas Sauvageot
- U2RM-Stress and Virulence, University of Caen Basse-Normandie, EA4655, 14032 Caen, France
| | - Maurizio Sanguinetti
- Institute of Microbiology, Catholic University of Sacred Heart, 00168, Rome, Italy
| | - Thomas Rattei
- CUBE-Division for Computational Systems Biology, Dept. of Microbiology and Ecosystem Science, University of Vienna, 1090 Vienna, Austria
| | - Thomas Eder
- CUBE-Division for Computational Systems Biology, Dept. of Microbiology and Ecosystem Science, University of Vienna, 1090 Vienna, Austria
| | - Jean-Christophe Giard
- U2RM-Stress and Virulence, University of Caen Basse-Normandie, EA4655, 14032 Caen, France
| | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, 33594 Bielefeld, Germany
| | - Torsten Hain
- Institute of Medicine Microbiology, Gießen University, 35392 Gießen, Germany
| | - Axel Hartke
- U2RM-Stress and Virulence, University of Caen Basse-Normandie, EA4655, 14032 Caen, France
- * E-mail: (AH); (CM)
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20
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Lactate dehydrogenase is the key enzyme for pneumococcal pyruvate metabolism and pneumococcal survival in blood. Infect Immun 2014; 82:5099-109. [PMID: 25245810 DOI: 10.1128/iai.02005-14] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Streptococcus pneumoniae is a fermentative microorganism and causes serious diseases in humans, including otitis media, bacteremia, meningitis, and pneumonia. However, the mechanisms enabling pneumococcal survival in the host and causing disease in different tissues are incompletely understood. The available evidence indicates a strong link between the central metabolism and pneumococcal virulence. To further our knowledge on pneumococcal virulence, we investigated the role of lactate dehydrogenase (LDH), which converts pyruvate to lactate and is an essential enzyme for redox balance, in the pneumococcal central metabolism and virulence using an isogenic ldh mutant. Loss of LDH led to a dramatic reduction of the growth rate, pinpointing the key role of this enzyme in fermentative metabolism. The pattern of end products was altered, and lactate production was totally blocked. The fermentation profile was confirmed by in vivo nuclear magnetic resonance (NMR) measurements of glucose metabolism in nongrowing cell suspensions of the ldh mutant. In this strain, a bottleneck in the fermentative steps is evident from the accumulation of pyruvate, revealing LDH as the most efficient enzyme in pyruvate conversion. An increase in ethanol production was also observed, indicating that in the absence of LDH the redox balance is maintained through alcohol dehydrogenase activity. We also found that the absence of LDH renders the pneumococci avirulent after intravenous infection and leads to a significant reduction in virulence in a model of pneumonia that develops after intranasal infection, likely due to a decrease in energy generation and virulence gene expression.
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21
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Meadows JA, Wargo MJ. Catabolism of host-derived compounds during extracellular bacterial infections. J Cell Biochem 2014; 115:217-23. [PMID: 24038340 DOI: 10.1002/jcb.24664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 09/03/2013] [Indexed: 11/07/2022]
Abstract
Efficient catabolism of host-derived compounds is essential for bacterial survival and virulence. While these links in intracellular bacteria are well studied, such studies in extracellular bacteria lag behind, mostly for technical reasons. The field has identified important metabolic pathways, but the mechanisms by which they impact infection and in particular, establishing the importance of a compound's catabolism versus alternate metabolic roles has been difficult. In this review we will examine evidence for catabolism during extracellular bacterial infections in animals and known or potential roles in virulence. In the process, we point out key gaps in the field that will require new or newly adapted techniques.
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Affiliation(s)
- Jamie A Meadows
- Department of Microbiology and Molecular Genetics, University of Vermont College of Medicine, Burlington, Vermont, 05405
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22
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Riboldi GP, Bierhals CG, de Mattos EP, Frazzon APG, d‘Azevedo PA, Frazzon J. Oxidative stress enhances the expression of sulfur assimilation genes: preliminary insights on the Enterococcus faecalis iron-sulfur cluster machinery regulation. Mem Inst Oswaldo Cruz 2014; 109:408-13. [PMID: 24936909 PMCID: PMC4155840 DOI: 10.1590/0074-0276140006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 03/27/2014] [Indexed: 11/21/2022] Open
Abstract
The Firmicutes bacteria participate extensively in virulence and pathological processes. Enterococcus faecalis is a commensal microorganism; however, it is also a pathogenic bacterium mainly associated with nosocomial infections in immunocompromised patients. Iron-sulfur [Fe-S] clusters are inorganic prosthetic groups involved in diverse biological processes, whose in vivo formation requires several specific protein machineries. Escherichia coli is one of the most frequently studied microorganisms regarding [Fe-S] cluster biogenesis and encodes the iron-sulfur cluster and sulfur assimilation systems. In Firmicutes species, a unique operon composed of the sufCDSUB genes is responsible for [Fe-S] cluster biogenesis. The aim of this study was to investigate the potential of the E. faecalis sufCDSUB system in the [Fe-S] cluster assembly using oxidative stress and iron depletion as adverse growth conditions. Quantitative real-time polymerase chain reaction demonstrated, for the first time, that Gram-positive bacteria possess an OxyR component responsive to oxidative stress conditions, as fully described for E. coli models. Likewise, strong expression of the sufCDSUB genes was observed in low concentrations of hydrogen peroxide, indicating that the lowest concentration of oxygen free radicals inside cells, known to be highly damaging to [Fe-S] clusters, is sufficient to trigger the transcriptional machinery for prompt replacement of [Fe-S] clusters.
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Affiliation(s)
- Gustavo Pelicioli Riboldi
- Laboratório de Cocos Gram-positivos e Microbiologia Molecular,
Departamento de Microbiologia, Universidade Federal de Ciências da Saúde de Porto
Alegre, Porto Alegre, RS, Brasil
| | | | | | | | - Pedro Alves d‘Azevedo
- Laboratório de Cocos Gram-positivos e Microbiologia Molecular,
Departamento de Microbiologia, Universidade Federal de Ciências da Saúde de Porto
Alegre, Porto Alegre, RS, Brasil
| | - Jeverson Frazzon
- Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do
Rio Grande do Sul, Porto Alegre, RS, Brasil
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23
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Van Tyne D, Gilmore MS. Friend turned foe: evolution of enterococcal virulence and antibiotic resistance. Annu Rev Microbiol 2014; 68:337-56. [PMID: 25002090 DOI: 10.1146/annurev-micro-091213-113003] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The enterococci are an ancient genus that evolved along with the tree of life. These intrinsically rugged bacteria are highly adapted members of the intestinal consortia of a range of hosts that spans the animal kingdom. Enterococci are also leading opportunistic hospital pathogens, causing infections that are often resistant to treatment with most antibiotics. Despite the importance of enterococci as hospital pathogens, the vast majority live outside of humans, and nearly all of their evolutionary history took place before the appearance of modern humans. Because hospital infections represent evolutionary end points, traits that exacerbate human infection are unlikely to have evolved for that purpose. However, clusters of traits have converged in specific lineages that are well adapted to colonize the antibiotic-perturbed gastrointestinal tracts of patients and that thrive in the hospital environment. Here we discuss these traits in an evolutionary context, as well as how comparative genomics is providing new insights into the evolution of the enterococci.
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Affiliation(s)
- Daria Van Tyne
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts 02114
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