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Xu L, Ivanova SA, Gu T. Mitigation of galvanized steel biocorrosion by Pseudomonas aeruginosa biofilm using a biocide enhanced by trehalase. Bioelectrochemistry 2023; 154:108508. [PMID: 37451042 DOI: 10.1016/j.bioelechem.2023.108508] [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: 05/29/2023] [Revised: 07/02/2023] [Accepted: 07/08/2023] [Indexed: 07/18/2023]
Abstract
Pseudomonas aeruginosa is a facultative bacterium that is pathogenic. It is ubiquitous in the environment including air handling systems. It causes microbiologically influenced corrosion (MIC) aerobically and anaerobically. In this work, P. aeruginosa was grown as a nitrate reducing bacterium (NRB) in Luria-Bertani medium with KNO3 at 37 °C. Trehalase, an enzyme which plays a crucial role in biofilm formation was found to enhance the treatment of P. aeruginosa biofilm and its MIC against galvanized steel by tetrakis-hydroxymethyl phosphonium sulfate (THPS) green biocide. After a 7-d incubation, 30 ppm (w/w) trehalase reduced sessile cell count by 0.8-log, and it also reduced galvanized steel weight loss by 14%, compared to 2.3-log and 39%, respectively for the 30 ppm THPS treatment. The combination of 30 ppm THPS + 30 ppm trehalase reduced sessile cell count further by 0.1-log and weight loss by 13% compared to using THPS alone. Electrochemical corrosion measurements supported weight loss results. The injection of 20 ppm riboflavin into a 3-d P. aeruginosa broth failed to accelerate the corrosion rate, suggesting that nitrate reducing P. aeruginosa MIC of galvanized steel did not belong to extracellular electron transfer-MIC, because Zn was hydrolyzed after the microbe damaged the passive film.
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Affiliation(s)
- Lingjun Xu
- Department of Chemical & Biomolecular Engineering, Institute for Corrosion and Multiphase Technology, Ohio University, Athens 45701, USA
| | | | - Tingyue Gu
- Department of Chemical & Biomolecular Engineering, Institute for Corrosion and Multiphase Technology, Ohio University, Athens 45701, USA.
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Cheah H, Bae S. Multichannel Microfluidic Platform for Temporal-Spatial Investigation of Niche Roles of Pseudomonas aeruginosa and Escherichia coli within a Dual-Species Biofilm. Appl Environ Microbiol 2023; 89:e0065123. [PMID: 37382537 PMCID: PMC10370331 DOI: 10.1128/aem.00651-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 06/12/2023] [Indexed: 06/30/2023] Open
Abstract
In natural or man-made environments, microorganisms exist predominantly as biofilms forming surface-associated bacterial communities embedded in extracellular polymeric substances (EPSs). Often, biofilm reactors used for endpoint and disruptive analyses of biofilm are not suitable for periodic observation of biofilm formation and development. In this study, a microfluidic device designed with multiple channels and a gradient generator was used for high-throughput analysis and real-time monitoring of dual-species biofilm formation and development. We compared the structural parameters of monospecies and dual-species biofilms containing Pseudomonas aeruginosa (expressing mCherry) and Escherichia coli (expressing green fluorescent protein [GFP]) to understand the interactions in the biofilm. The rate of biovolume increase of each species in monospecies biofilm (2.7 × 105 μm3) was higher than those in a dual-species biofilm (9.68 × 104 μm3); however, synergism was still observed in the dual-species biofilm due to overall increases in biovolume for both species. Synergism was also observed in a dual-species biofilm, where P. aeruginosa forms a "blanket" over E. coli, providing a physical barrier against shear stress in the environment. The microfluidic chip was useful for monitoring the dual-species biofilm in the microenvironment, indicating that different species in a multispecies biofilm exhibit different niches for the survival of the biofilm community. Finally, we demonstrated that the nucleic acids can be extracted from the dual-species biofilm in situ after biofilm imaging analysis. In addition, gene expression supported that the activation and suppression of different quorum sensing genes resulted in the different phenotype seen in the biofilm. This study showed that the integration of microfluidic device with microscopy analysis and molecular techniques could be a promising tool for studying biofilm structure and gene quantification and expression simultaneously. IMPORTANCE In natural or man-made environments, microorganisms exist predominantly as biofilms forming surface-associated bacterial communities embedded in extracellular polymeric substances (EPSs). Often, biofilm reactors used for endpoint and disruptive analyses of biofilm are not suitable for periodic observation of biofilm formation and development. Here, we demonstrate that a microfluidic device with multiple channels and a gradient generator can be useful for high-throughput analysis and real-time monitoring of dual-species biofilm formation and development. Our study revealed synergism in the dual-species biofilm, where P. aeruginosa forms a "blanket" over E. coli, providing a physical barrier against shear stress in the environment. Furthermore, different species in a multispecies biofilm exhibit different niches for the survival of the biofilm community. This study showed that the integration of microfluidic device with microscopy analysis and molecular techniques could be a promising tool for studying biofilm structure and gene quantification and expression simultaneously.
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Affiliation(s)
- Hee Cheah
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore
| | - Sungwoo Bae
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore
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3
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Caliskan M, Poschmann G, Gudzuhn M, Waldera-Lupa D, Molitor R, Strunk CH, Streit WR, Jaeger KE, Stühler K, Kovacic F. Pseudomonas aeruginosa responds to altered membrane phospholipid composition by adjusting the production of two-component systems, proteases and iron uptake proteins. Biochim Biophys Acta Mol Cell Biol Lipids 2023; 1868:159317. [PMID: 37054907 DOI: 10.1016/j.bbalip.2023.159317] [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: 12/24/2022] [Revised: 03/16/2023] [Accepted: 03/21/2023] [Indexed: 04/15/2023]
Abstract
Membrane protein and phospholipid (PL) composition changes in response to environmental cues and during infections. To achieve these, bacteria use adaptation mechanisms involving covalent modification and remodelling of the acyl chain length of PLs. However, little is known about bacterial pathways regulated by PLs. Here, we investigated proteomic changes in the biofilm of P. aeruginosa phospholipase mutant (∆plaF) with altered membrane PL composition. The results revealed profound alterations in the abundance of many biofilm-related two-component systems (TCSs), including accumulation of PprAB, a key regulator of the transition to biofilm. Furthermore, a unique phosphorylation pattern of transcriptional regulators, transporters and metabolic enzymes, as well as differential production of several proteases, in ∆plaF, indicate that PlaF-mediated virulence adaptation involves complex transcriptional and posttranscriptional response. Moreover, proteomics and biochemical assays revealed the depletion of pyoverdine-mediated iron uptake pathway proteins in ∆plaF, while proteins from alternative iron-uptake systems were accumulated. These suggest that PlaF may function as a switch between different iron-acquisition pathways. The observation that PL-acyl chain modifying and PL synthesis enzymes were overproduced in ∆plaF reveals the interconnection of degradation, synthesis and modification of PLs for proper membrane homeostasis. Although the precise mechanism by which PlaF simultaneously affects multiple pathways remains to be elucidated, we suggest that alteration of PL composition in ∆plaF plays a role for the global adaptive response in P. aeruginosa mediated by TCSs and proteases. Our study revealed the global regulation of virulence and biofilm by PlaF and suggests that targeting this enzyme may have therapeutic potential.
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Affiliation(s)
- Muttalip Caliskan
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Jülich, Germany
| | - Gereon Poschmann
- Institute of Molecular Medicine, Proteome Research, University Hospital and Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Mirja Gudzuhn
- Department of Microbiology and Biotechnology, University of Hamburg, Ohnhorststr. 18, 22609 Hamburg, Germany
| | - Daniel Waldera-Lupa
- Institute of Molecular Medicine, Proteome Research, University Hospital and Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Rebecka Molitor
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Jülich, Germany
| | | | - Wolfgang R Streit
- Department of Microbiology and Biotechnology, University of Hamburg, Ohnhorststr. 18, 22609 Hamburg, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Jülich, Germany; Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Kai Stühler
- Institute of Molecular Medicine, Proteome Research, University Hospital and Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany; Molecular Proteomics Laboratory, Biologisch-Medizinisches Forschungszentrum, Heinrich-Heine-University, Düsseldorf, Düsseldorf, Germany
| | - Filip Kovacic
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Jülich, Germany.
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Pseudomonas aeruginosa Nonphosphorylated AlgR Induces Ribonucleotide Reductase Expression under Oxidative Stress Infectious Conditions. mSystems 2023; 8:e0100522. [PMID: 36794960 PMCID: PMC10134789 DOI: 10.1128/msystems.01005-22] [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: 02/17/2023] Open
Abstract
Ribonucleotide reductases (RNRs) are key enzymes which catalyze the synthesis of deoxyribonucleotides, the monomers needed for DNA replication and repair. RNRs are classified into three classes (I, II, and III) depending on their overall structure and metal cofactors. Pseudomonas aeruginosa is an opportunistic pathogen which harbors all three RNR classes, increasing its metabolic versatility. During an infection, P. aeruginosa can form a biofilm to be protected from host immune defenses, such as the production of reactive oxygen species by macrophages. One of the essential transcription factors needed to regulate biofilm growth and other important metabolic pathways is AlgR. AlgR is part of a two-component system with FimS, a kinase that catalyzes its phosphorylation in response to external signals. Additionally, AlgR is part of the regulatory network of cell RNR regulation. In this study, we investigated the regulation of RNRs through AlgR under oxidative stress conditions. We determined that the nonphosphorylated form of AlgR is responsible for class I and II RNR induction after an H2O2 addition in planktonic culture and during flow biofilm growth. We observed similar RNR induction patterns upon comparing the P. aeruginosa laboratory strain PAO1 with different P. aeruginosa clinical isolates. Finally, we showed that during Galleria mellonella infection, when oxidative stress is high, AlgR is crucial for transcriptional induction of a class II RNR gene (nrdJ). Therefore, we show that the nonphosphorylated form of AlgR, in addition to being crucial for infection chronicity, regulates the RNR network in response to oxidative stress during infection and biofilm formation. IMPORTANCE The emergence of multidrug-resistant bacteria is a serious problem worldwide. Pseudomonas aeruginosa is a pathogen that causes severe infections because it can form a biofilm that protects it from immune system mechanisms such as the production of oxidative stress. Ribonucleotide reductases are essential enzymes which synthesize deoxyribonucleotides used in the replication of DNA. RNRs are classified into three classes (I, II, and III), and P. aeruginosa harbors all three of these classes, increasing its metabolic versatility. Transcription factors, such as AlgR, regulate the expression of RNRs. AlgR is involved in the RNR regulation network and regulates biofilm growth and other metabolic pathways. We determined that AlgR induces class I and II RNRs after an H2O2 addition in planktonic culture and biofilm growth. Additionally, we showed that a class II RNR is essential during Galleria mellonella infection and that AlgR regulates its induction. Class II RNRs could be considered excellent antibacterial targets to be explored to combat P. aeruginosa infections.
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A Review of Pseudomonas aeruginosa Metallophores: Pyoverdine, Pyochelin and Pseudopaline. BIOLOGY 2022; 11:biology11121711. [PMID: 36552220 PMCID: PMC9774294 DOI: 10.3390/biology11121711] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022]
Abstract
P. aeruginosa is a common Gram-negative bacterium found in nature that causes severe infections in humans. As a result of its natural resistance to antibiotics and the ability of biofilm formation, the infection with this pathogen can be therapeutic challenging. During infection, P. aeruginosa produces secondary metabolites such as metallophores that play an important role in their virulence. Metallophores are metal ions chelating molecules secreted by bacteria, thus allowing them to survive in the host under metal scarce conditions. Pyoverdine, pyochelin and pseudopaline are the three metallophores secreted by P. aeruginosa. Pyoverdines are the primary siderophores that acquire iron from the surrounding medium. These molecules scavenge and transport iron to the bacterium intracellular compartment. Pyochelin is another siderophore produced by this bacterium, but in lower quantities and its affinity for iron is less than that of pyoverdine. The third metallophore, pseudopaline, is an opine narrow spectrum ion chelator that enables P. aeruginosa to uptake zinc in particular but can transport nickel and cobalt as well. This review describes all the aspects related to these three metallophore, including their main features, biosynthesis process, secretion and uptake when loaded by metals, in addition to the genetic regulation responsible for their synthesis and secretion.
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6
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Sequence Polymorphisms in Vibrio cholerae HapR Affect Biofilm Formation under Aerobic and Anaerobic Conditions. Appl Environ Microbiol 2022; 88:e0104422. [PMID: 35969071 PMCID: PMC9469714 DOI: 10.1128/aem.01044-22] [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: 11/20/2022] Open
Abstract
We investigated the influence of hapR sequence mutations on the biofilm formation of Vibrio cholerae. In this study, hapR sequences from 85 V. cholerae strains belonging to both pandemic and nonpandemic serogroup were investigated through phylogenetic and sequence analyses. Biofilm formation assays under aerobic and anaerobic conditions were also performed. Sequence variations include single point mutations and insertions/deletions (indels) leading to either truncated or frameshifted HapR. Population structure analysis revealed two major hapR haplogroups, hapR1 and hapR2. Phylogenetic reconstruction displayed a hypothetical ancestral hapR sequence located within the hapR1 haplogroup. Higher numbers of single nucleotide polymorphisms and genetic diversity indices were observed in hapR1, while indels occurred dominantly in hapR2. Aerobic conditions supported more robust biofilms compared to anaerobic conditions. Strains with frameshifted HapR produced the largest amount of biofilm under both oxygen conditions. Quantitative real-time PCR assay confirmed that strains with truncated and frameshifted HapR resulted in a nonfunctional regulator as exhibited by the significantly low hapA gene expression. The present study shows that HapR mutations had a strong influence on biofilm formation and that sequence polymorphisms leading to the disruption of DNA-binding sites or dimerization of the HapR will result in more-robust V. cholerae biofilms. IMPORTANCE Our study revealed an ancestral hapR sequence from a phylogenetic reconstruction that displayed the evolutionary lineage of the nonpandemic to the pandemic strains. Here, we established hapR1 and hapR2 as major hapR haplogroups. The association of the O1 and O139 serogroups with the hapR2 haplogroup demonstrated the distinction of hapR2 in causing cholera infection. Moreover, mutations in this regulator that could lead to the disruption of transcription factor-binding sites or dimerization of the HapR can significantly affect the biofilm formation of V. cholerae. These observations on the relationship of the hapR polymorphism and V. cholerae biofilm formation will provide additional considerations for future biofilm studies and insights into the epidemiology of the pathogen that could ultimately help in the surveillance and mitigation of future cholera disease outbreaks.
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7
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Lu J, Hu X, Ren L. Biofilm control strategies in food industry: Inhibition and utilization. Trends Food Sci Technol 2022. [DOI: 10.1016/j.tifs.2022.03.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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8
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Biofilm Maintenance as an Active Process: Evidence that Biofilms Work Hard to Stay Put. J Bacteriol 2022; 204:e0058721. [PMID: 35311557 DOI: 10.1128/jb.00587-21] [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] [Indexed: 01/02/2023] Open
Abstract
Biofilm formation represents a critical strategy whereby bacteria can tolerate otherwise damaging environmental stressors and antimicrobial insults. While the mechanisms bacteria use to establish a biofilm and disperse from these communities have been well-studied, we have only a limited understanding of the mechanisms required to maintain these multicellular communities. Indeed, until relatively recently, it was not clear that maintaining a mature biofilm could be considered an active, regulated process with dedicated machinery. Using Pseudomonas aeruginosa as a model system, we review evidence from recent studies that support the model that maintenance of these persistent, surface-attached communities is indeed an active process. Biofilm maintenance mechanisms include transcriptional regulation and second messenger signaling (including the production of extracellular polymeric substances). We also discuss energy-conserving pathways that play a key role in the maintenance of these communities. We hope to highlight the need for further investigation to uncover novel biofilm maintenance pathways and suggest the possibility that such pathways can serve as novel antibiofilm targets.
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McLean JT, Benny A, Nolan MD, Swinand G, Scanlan EM. Cysteinyl radicals in chemical synthesis and in nature. Chem Soc Rev 2021; 50:10857-10894. [PMID: 34397045 DOI: 10.1039/d1cs00254f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nature harnesses the unique properties of cysteinyl radical intermediates for a diverse range of essential biological transformations including DNA biosynthesis and repair, metabolism, and biological photochemistry. In parallel, the synthetic accessibility and redox chemistry of cysteinyl radicals renders them versatile reactive intermediates for use in a vast array of synthetic applications such as lipidation, glycosylation and fluorescent labelling of proteins, peptide macrocyclization and stapling, desulfurisation of peptides and proteins, and development of novel therapeutics. This review provides the reader with an overview of the role of cysteinyl radical intermediates in both chemical synthesis and biological systems, with a critical focus on mechanistic details. Direct insights from biological systems, where applied to chemical synthesis, are highlighted and potential avenues from nature which are yet to be explored synthetically are presented.
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Affiliation(s)
- Joshua T McLean
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
| | - Alby Benny
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
| | - Mark D Nolan
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
| | - Glenna Swinand
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
| | - Eoin M Scanlan
- Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse St., Dublin, D02 R590, Ireland.
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Motta JP, Wallace JL, Buret AG, Deraison C, Vergnolle N. Gastrointestinal biofilms in health and disease. Nat Rev Gastroenterol Hepatol 2021; 18:314-334. [PMID: 33510461 DOI: 10.1038/s41575-020-00397-y] [Citation(s) in RCA: 108] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/25/2020] [Indexed: 01/30/2023]
Abstract
Microorganisms colonize various ecological niches in the human habitat, as they do in nature. Predominant forms of multicellular communities called biofilms colonize human tissue surfaces. The gastrointestinal tract is home to a profusion of microorganisms with intertwined, but not identical, lifestyles: as isolated planktonic cells, as biofilms and in biofilm-dispersed form. It is therefore of major importance in understanding homeostatic and altered host-microorganism interactions to consider not only the planktonic lifestyle, but also biofilms and biofilm-dispersed forms. In this Review, we discuss the natural organization of microorganisms at gastrointestinal surfaces, stratification of microbiota taxonomy, biogeographical localization and trans-kingdom interactions occurring within the biofilm habitat. We also discuss existing models used to study biofilms. We assess the contribution of the host-mucosa biofilm relationship to gut homeostasis and to diseases. In addition, we describe how host factors can shape the organization, structure and composition of mucosal biofilms, and how biofilms themselves are implicated in a variety of homeostatic and pathological processes in the gut. Future studies characterizing biofilm nature, physical properties, composition and intrinsic communication could shed new light on gut physiology and lead to potential novel therapeutic options for gastrointestinal diseases.
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Affiliation(s)
- Jean-Paul Motta
- Institute of Digestive Health Research, IRSD, INSERM U1220, Toulouse, France.
| | - John L Wallace
- Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Antibe Therapeutics Inc., Toronto, ON, Canada
| | - André G Buret
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Céline Deraison
- Institute of Digestive Health Research, IRSD, INSERM U1220, Toulouse, France
| | - Nathalie Vergnolle
- Institute of Digestive Health Research, IRSD, INSERM U1220, Toulouse, France. .,Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
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11
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Monitoring Gene Expression during a Galleria mellonella Bacterial Infection. Microorganisms 2020; 8:microorganisms8111798. [PMID: 33207842 PMCID: PMC7697238 DOI: 10.3390/microorganisms8111798] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 12/05/2022] Open
Abstract
Galleria mellonella larvae are an alternative in vivo model that has been extensively used to study the virulence and pathogenicity of different bacteria due to its practicality and lack of ethical constraints. However, the larvae possess intrinsic autofluorescence that obstructs the use of fluorescent proteins to study bacterial infections, hence better methodologies are needed. Here, we report the construction of a promoter probe vector with bioluminescence expression as well as the optimization of a total bacterial RNA extraction protocol to enhance the monitoring of in vivo infections. By employing the vector to construct different gene promoter fusions, variable gene expression levels were efficiently measured in G. mellonella larvae at various time points during the course of infection and without much manipulation of the larvae. Additionally, our optimized RNA extraction protocol facilitates the study of transcriptional gene levels during an in vivo infection. The proposed methodologies will greatly benefit bacterial infection studies as they can contribute to a better understanding of the in vivo infection processes and pathogen–mammalian host interactions.
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12
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Comparative Analysis of the Core Proteomes among the Pseudomonas Major Evolutionary Groups Reveals Species-Specific Adaptations for Pseudomonas aeruginosa and Pseudomonas chlororaphis. DIVERSITY 2020. [DOI: 10.3390/d12080289] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The Pseudomonas genus includes many species living in diverse environments and hosts. It is important to understand which are the major evolutionary groups and what are the genomic/proteomic components they have in common or are unique. Towards this goal, we analyzed 494 complete Pseudomonas proteomes and identified 297 core-orthologues. The subsequent phylogenomic analysis revealed two well-defined species (Pseudomonas aeruginosa and Pseudomonas chlororaphis) and four wider phylogenetic groups (Pseudomonas fluorescens, Pseudomonas stutzeri, Pseudomonas syringae, Pseudomonas putida) with a sufficient number of proteomes. As expected, the genus-level core proteome was highly enriched for proteins involved in metabolism, translation, and transcription. In addition, between 39–70% of the core proteins in each group had a significant presence in each of all the other groups. Group-specific core proteins were also identified, with P. aeruginosa having the highest number of these and P. fluorescens having none. We identified several P. aeruginosa-specific core proteins (such as CntL, CntM, PlcB, Acp1, MucE, SrfA, Tse1, Tsi2, Tse3, and EsrC) that are known to play an important role in its pathogenicity. Finally, a holin family bacteriocin and a mitomycin-like biosynthetic protein were found to be core-specific for P. cholororaphis and we hypothesize that these proteins may confer a competitive advantage against other root-colonizers.
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13
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Bueno E, Pinedo V, Cava F. Adaptation of Vibrio cholerae to Hypoxic Environments. Front Microbiol 2020; 11:739. [PMID: 32425907 PMCID: PMC7212424 DOI: 10.3389/fmicb.2020.00739] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 03/30/2020] [Indexed: 01/02/2023] Open
Abstract
Bacteria can colonize virtually any environment on Earth due to their remarkable capacity to detect and respond quickly and adequately to environmental stressors. Vibrio cholerae is a cosmopolitan bacterium that inhabits a vast range of environments. The V. cholerae life cycle comprises diverse environmental and infective stages. The bacterium is found in aquatic ecosystems both under free-living conditions or associated with a wide range of aquatic organisms, and some strains are also capable of causing epidemics in humans. In order to adapt between environments, V. cholerae possesses a versatile metabolism characterized by the rapid cross-regulation of energy-producing pathways. Low oxygen concentration is a key environmental factor that governs V. cholerae physiology. This article reviews the metabolic plasticity that enables V. cholerae to thrive on low oxygen concentrations and its role in environmental and host adaptation.
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Affiliation(s)
- Emilio Bueno
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | | | - Felipe Cava
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
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14
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Pedraz L, Blanco‐Cabra N, Torrents E. Gradual adaptation of facultative anaerobic pathogens to microaerobic and anaerobic conditions. FASEB J 2019; 34:2912-2928. [DOI: 10.1096/fj.201902861r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/10/2019] [Accepted: 12/13/2019] [Indexed: 01/02/2023]
Affiliation(s)
- Lucas Pedraz
- "Bacterial Infections: Antimicrobial Therapies” group Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute of Science and Technology (BIST) Barcelona Spain
| | - Núria Blanco‐Cabra
- "Bacterial Infections: Antimicrobial Therapies” group Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute of Science and Technology (BIST) Barcelona Spain
| | - Eduard Torrents
- "Bacterial Infections: Antimicrobial Therapies” group Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute of Science and Technology (BIST) Barcelona Spain
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15
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Kampers LFC, van Heck RGA, Donati S, Saccenti E, Volkers RJM, Schaap PJ, Suarez-Diez M, Nikel PI, Martins Dos Santos VAP. In silico-guided engineering of Pseudomonas putida towards growth under micro-oxic conditions. Microb Cell Fact 2019; 18:179. [PMID: 31640713 PMCID: PMC6805499 DOI: 10.1186/s12934-019-1227-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 10/09/2019] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Pseudomonas putida is a metabolically versatile, genetically accessible, and stress-robust species with outstanding potential to be used as a workhorse for industrial applications. While industry recognises the importance of robustness under micro-oxic conditions for a stable production process, the obligate aerobic nature of P. putida, attributed to its inability to produce sufficient ATP and maintain its redox balance without molecular oxygen, severely limits its use for biotechnology applications. RESULTS Here, a combination of genome-scale metabolic modelling and comparative genomics is used to pinpoint essential [Formula: see text]-dependent processes. These explain the inability of the strain to grow under anoxic conditions: a deficient ATP generation and an inability to synthesize essential metabolites. Based on this, several P. putida recombinant strains were constructed harbouring acetate kinase from Escherichia coli for ATP production, and a class I dihydroorotate dehydrogenase and a class III anaerobic ribonucleotide triphosphate reductase from Lactobacillus lactis for the synthesis of essential metabolites. Initial computational designs were fine-tuned by means of adaptive laboratory evolution. CONCLUSIONS We demonstrated the value of combining in silico approaches, experimental validation and adaptive laboratory evolution for microbial design by making the strictly aerobic Pseudomonas putida able to grow under micro-oxic conditions.
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Affiliation(s)
- Linde F C Kampers
- Systems and Synthetic Biology, Wageningen University and Research Centre, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Ruben G A van Heck
- Systems and Synthetic Biology, Wageningen University and Research Centre, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Stefano Donati
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 16, 35043, Marburg, Germany
| | - Edoardo Saccenti
- Systems and Synthetic Biology, Wageningen University and Research Centre, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Rita J M Volkers
- Systems and Synthetic Biology, Wageningen University and Research Centre, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Peter J Schaap
- Systems and Synthetic Biology, Wageningen University and Research Centre, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Maria Suarez-Diez
- Systems and Synthetic Biology, Wageningen University and Research Centre, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Pablo I Nikel
- The Novo Nordisk Foundation Center for Biosustainability, Kgs Lyngby, Denmark
| | - Vitor A P Martins Dos Santos
- Systems and Synthetic Biology, Wageningen University and Research Centre, Stippeneng 4, 6708 WE, Wageningen, The Netherlands. .,LifeGlimmer GmbH, Berlin, Germany.
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16
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Dupre JM, Johnson WL, Ulanov AV, Li Z, Wilkinson BJ, Gustafson JE. Transcriptional profiling and metabolomic analysis of Staphylococcus aureus grown on autoclaved chicken breast. Food Microbiol 2019; 82:46-52. [DOI: 10.1016/j.fm.2019.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 12/21/2018] [Accepted: 01/11/2019] [Indexed: 10/27/2022]
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17
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Panmanee W, Su S, Schurr MJ, Lau GW, Zhu X, Ren Z, McDaniel CT, Lu LJ, Ohman DE, Muruve DA, Panos RJ, Yu HD, Thompson TB, Tseng BS, Hassett DJ. The anti-sigma factor MucA of Pseudomonas aeruginosa: Dramatic differences of a mucA22 vs. a ΔmucA mutant in anaerobic acidified nitrite sensitivity of planktonic and biofilm bacteria in vitro and during chronic murine lung infection. PLoS One 2019; 14:e0216401. [PMID: 31158231 PMCID: PMC6546240 DOI: 10.1371/journal.pone.0216401] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 04/20/2019] [Indexed: 11/29/2022] Open
Abstract
Mucoid mucA22 Pseudomonas aeruginosa (PA) is an opportunistic lung pathogen of cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) patients that is highly sensitive to acidified nitrite (A-NO2-). In this study, we first screened PA mutant strains for sensitivity or resistance to 20 mM A-NO2- under anaerobic conditions that represent the chronic stages of the aforementioned diseases. Mutants found to be sensitive to A-NO2- included PA0964 (pmpR, PQS biosynthesis), PA4455 (probable ABC transporter permease), katA (major catalase, KatA) and rhlR (quorum sensing regulator). In contrast, mutants lacking PA0450 (a putative phosphate transporter) and PA1505 (moaA2) were A-NO2- resistant. However, we were puzzled when we discovered that mucA22 mutant bacteria, a frequently isolated mucA allele in CF and to a lesser extent COPD, were more sensitive to A-NO2- than a truncated ΔmucA deletion (Δ157–194) mutant in planktonic and biofilm culture, as well as during a chronic murine lung infection. Subsequent transcriptional profiling of anaerobic, A-NO2--treated bacteria revealed restoration of near wild-type transcript levels of protective NO2- and nitric oxide (NO) reductase (nirS and norCB, respectively) in the ΔmucA mutant in contrast to extremely low levels in the A-NO2--sensitive mucA22 mutant. Proteins that were S-nitrosylated by NO derived from A-NO2- reduction in the sensitive mucA22 strain were those involved in anaerobic respiration (NirQ, NirS), pyruvate fermentation (UspK), global gene regulation (Vfr), the TCA cycle (succinate dehydrogenase, SdhB) and several double mutants were even more sensitive to A-NO2-. Bioinformatic-based data point to future studies designed to elucidate potential cellular binding partners for MucA and MucA22. Given that A-NO2- is a potentially viable treatment strategy to combat PA and other infections, this study offers novel developments as to how clinicians might better treat problematic PA infections in COPD and CF airway diseases.
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Affiliation(s)
- Warunya Panmanee
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH United States of America
| | - Shengchang Su
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH United States of America
| | - Michael J. Schurr
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO United States of America
| | - Gee W. Lau
- College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL United States of America
| | - Xiaoting Zhu
- Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH United States of America
| | - Zhaowei Ren
- Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH United States of America
| | - Cameron T. McDaniel
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH United States of America
| | - Long J. Lu
- Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH United States of America
| | - Dennis E. Ohman
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA United States of America
- McGuire Veterans Affairs Medical Center, Richmond, VA United States of America
| | - Daniel A. Muruve
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Ralph J. Panos
- Department of Medicine, Cincinnati Veterans Affairs Medical Center, Cincinnati, OH United States of America
- Pulmonary, Critical Care, and Sleep Division, Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, OH United States of America
| | - Hongwei D. Yu
- Department of Biochemistry and Microbiology, Marshall University, Huntington, WV United States of America
| | - Thomas B. Thompson
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH United States of America
| | - Boo Shan Tseng
- Department of Life Sciences, University of Nevada-Las Vegas, Las Vegas, NV United States of America
| | - Daniel J. Hassett
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH United States of America
- * E-mail:
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18
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Hickey C, Schaible B, Nguyen S, Hurley D, Srikumar S, Fanning S, Brown E, Crifo B, Matallanas D, McClean S, Taylor CT, Schaffer K. Increased Virulence of Bloodstream Over Peripheral Isolates of P. aeruginosa Identified Through Post-transcriptional Regulation of Virulence Factors. Front Cell Infect Microbiol 2018; 8:357. [PMID: 30416988 PMCID: PMC6212473 DOI: 10.3389/fcimb.2018.00357] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 09/18/2018] [Indexed: 11/13/2022] Open
Abstract
The factors influencing the virulence of P. aeruginosa in the development of invasive infection remain poorly understood. Here, we investigated the role of the host microenvironment in shaping pathogen virulence and investigated the mechanisms involved. Comparing seven paired genetically indistinguishable clinical bloodstream and peripheral isolates of P. aeruginosa, we demonstrate that isolates derived from bloodstream infections are more virulent than their peripheral counterparts (p = 0.025). Bloodstream and peripheral isolates elicited similar NF-kB responses in a THP-1 monocyte NF-kappaB reporter cell line implicating similar immunogenicity. Proteomic analysis by mass spectrometry identified multiple virulence and virulence-related factors including LecA and RpoN in significantly greater abundance in the bacterial supernatant from the bloodstream isolate in comparison to that from the corresponding peripheral isolate. Investigation by qPCR revealed that control of expression of these virulence factors was not due to altered levels of transcription. Based on these data, we hypothesize a post-transcriptional mechanism of virulence regulation in P. aeruginosa bloodstream infections influenced by surrounding microenvironmental conditions.
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Affiliation(s)
| | | | - Scott Nguyen
- School of Public Health, Physiotherapy & Sports Science, University College Dublin, Dublin, Ireland
| | - Daniel Hurley
- School of Public Health, Physiotherapy & Sports Science, University College Dublin, Dublin, Ireland
| | - Shabarinath Srikumar
- School of Public Health, Physiotherapy & Sports Science, University College Dublin, Dublin, Ireland
| | - Séamus Fanning
- School of Public Health, Physiotherapy & Sports Science, University College Dublin, Dublin, Ireland
| | - Eric Brown
- Conway Institute, University College Dublin, Dublin, Ireland
| | - Bianca Crifo
- Conway Institute, University College Dublin, Dublin, Ireland
| | - David Matallanas
- Systems Biology Ireland, University College Dublin, Dublin, Ireland.,School of Medicine, University College Dublin, Dublin, Ireland
| | - Siobhán McClean
- Biomedical and Biomolecular Science, University College Dublin, Dublin, Ireland
| | - Cormac T Taylor
- Conway Institute, University College Dublin, Dublin, Ireland.,Systems Biology Ireland, University College Dublin, Dublin, Ireland.,School of Medicine, University College Dublin, Dublin, Ireland
| | - Kirsten Schaffer
- School of Medicine, University College Dublin, Dublin, Ireland.,Department of Clinical Microbiology, St. Vincent's University Hospital, Dublin, Ireland
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19
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Crespo A, Blanco-Cabra N, Torrents E. Aerobic Vitamin B 12 Biosynthesis Is Essential for Pseudomonas aeruginosa Class II Ribonucleotide Reductase Activity During Planktonic and Biofilm Growth. Front Microbiol 2018; 9:986. [PMID: 29867886 PMCID: PMC5962746 DOI: 10.3389/fmicb.2018.00986] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 04/26/2018] [Indexed: 11/18/2022] Open
Abstract
Pseudomonas aeruginosa is a major pathogenic bacterium in chronic infections and is a model organism for studying biofilms. P. aeruginosa is considered an aerobic bacterium, but in the presence of nitrate, it also grows in anaerobic conditions. Oxygen diffusion through the biofilm generates metabolic and genetic diversity in P. aeruginosa growth, such as in ribonucleotide reductase activity. These essential enzymes are necessary for DNA synthesis and repair. Oxygen availability determines the activity of the three-ribonucleotide reductase (RNR) classes. Class II and III RNRs are active in the absence of oxygen; however, class II RNRs, which are important in P. aeruginosa biofilm growth, require a vitamin B12 cofactor for their enzymatic activity. In this work, we elucidated the conditions in which class II RNRs are active due to vitamin B12 concentration constraints (biosynthesis or environmental availability). We demonstrated that increased vitamin B12 levels during aerobic, stationary and biofilm growth activate class II RNR activity. We also established that the cobN gene is essentially responsible for B12 biosynthesis under planktonic and biofilm growth. Our results unravel the mechanisms of dNTP synthesis by P. aeruginosa during biofilm growth, which appear to depend on the bacterial strain (laboratory-type or clinical isolate).
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Affiliation(s)
- Anna Crespo
- Bacterial Infections and Antimicrobial Therapies, Institute for Bioengineering of Catalonia, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Núria Blanco-Cabra
- Bacterial Infections and Antimicrobial Therapies, Institute for Bioengineering of Catalonia, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Eduard Torrents
- Bacterial Infections and Antimicrobial Therapies, Institute for Bioengineering of Catalonia, Barcelona Institute of Science and Technology, Barcelona, Spain
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20
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Pattnaik S, Ahmed T, Ranganathan SK, Ampasala DR, Sarma VV, Busi S. Aspergillus ochraceopetaliformis SSP13 modulates quorum sensing regulated virulence and biofilm formation in Pseudomonas aeruginosa PAO1. BIOFOULING 2018; 34:410-425. [PMID: 29745728 DOI: 10.1080/08927014.2018.1460748] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 03/26/2018] [Indexed: 06/08/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic nosocomial pathogen causing the majority of acute and persistent infections in human beings. The ability to form biofilm adds a new dimension to its resistance to conventional therapeutic agents. In the present study, down-regulation of quorum sensing regulated virulence and biofilm development resulting from exposure to Aspergillus ochraceopetaliformis SSP13 extract was investigated. The in vitro results inferred impairment in the production of LasA protease, LasB elastase, chitinase, pyocyanin, exopolysaccharides and rhamnolipids. In addition, motility and biofilm formation by P. aeruginosa PAO1 was significantly altered. The in vitro results were further supported by molecular docking studies of the metabolites obtained from GC-MS analysis depicting the quorum sensing attenuation by targeting the receptor proteins LasR and RhlR. The in vitro and in silico studies suggested new avenues for the development of bioactive metabolites from A. ochraceopetaliformis SSP13 extract as potential anti-infective agents.
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Affiliation(s)
- Subhaswaraj Pattnaik
- a Department of Microbiology, School of Life Sciences , Pondicherry University , Puducherry , India
| | - Tanveer Ahmed
- b Department of Biotechnology, School of Life Sciences , Pondicherry University , Puducherry , India
| | | | - Dinakara Rao Ampasala
- c Centre for Bioinformatics, School of Life Sciences , Pondicherry University , Puducherry , India
| | - V Venkateswara Sarma
- b Department of Biotechnology, School of Life Sciences , Pondicherry University , Puducherry , India
| | - Siddharha Busi
- a Department of Microbiology, School of Life Sciences , Pondicherry University , Puducherry , India
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21
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Abstract
Pseudomonas aeruginosa, a Gram-negative bacterium, is characterized by its versatility that enables persistent survival under adverse conditions. It can grow on diverse energy sources and readily acquire resistance to antimicrobial agents. As an opportunistic human pathogen, it also causes chronic infections inside the anaerobic mucus airways of cystic fibrosis patients. As a strict respirer, P. aeruginosa can grow by anaerobic nitrate ( [Formula: see text] ) respiration. Nitric oxide (NO) produced as an intermediate during anaerobic respiration exerts many important effects on the biological characteristics of P. aeruginosa. This review provides information regarding (i) how P. aeruginosa grows by anaerobic respiration, (ii) mechanisms by which NO is produced under such growth, and (iii) bacterial adaptation to NO. We also review the clinical relevance of NO in the fitness of P. aeruginosa and the use of NO as a potential therapeutic for treating P. aeruginosa infection.
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22
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Regulation of ribonucleotide synthesis by the Pseudomonas aeruginosa two-component system AlgR in response to oxidative stress. Sci Rep 2017; 7:17892. [PMID: 29263410 PMCID: PMC5738425 DOI: 10.1038/s41598-017-17917-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/04/2017] [Indexed: 11/11/2022] Open
Abstract
Ribonucleotide reductases (RNR) catalyze the last step of deoxyribonucleotide synthesis, and are therefore essential to DNA-based life. Three forms of RNR exist: classes I, II, and III. While eukaryotic cells use only class Ia RNR, bacteria can harbor any combination of classes, granting them adaptability. The opportunistic pathogen Pseudomonas aeruginosa surprisingly encodes all three classes, allowing it to thrive in different environments. Here we study an aspect of the complex RNR regulation whose molecular mechanism has never been elucidated, the well-described induction through oxidative stress, and link it to the AlgZR two-component system, the primary regulator of the mucoid phenotype. Through bioinformatics, we identify AlgR binding locations in RNR promoters, which we characterize functionally through EMSA and physically through AFM imaging. Gene reporter assays in different growth models are used to study the AlgZR-mediated control on the RNR network under various environmental conditions and physiological states. Thereby, we show that the two-component system AlgZR, which is crucial for bacterial conversion to the mucoid phenotype associated with chronic disease, controls the RNR network and directs how the DNA synthesis pathway is modulated in mucoid and non-mucoid biofilms, allowing it to respond to oxidative stress.
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23
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McFarlane JS, Lamb AL. Biosynthesis of an Opine Metallophore by Pseudomonas aeruginosa. Biochemistry 2017; 56:5967-5971. [PMID: 29091735 DOI: 10.1021/acs.biochem.7b00804] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Bacterial pathogenesis frequently requires metal acquisition by specialized, small-molecule metallophores. We hypothesized that the Gram-negative Pseudomonas aeruginosa encodes the enzymes nicotianamine synthase (NAS) and opine dehydrogenase (ODH), biosynthesizing a new class of opine metallophore, previously characterized only in the unrelated Gram-positive organism Staphylococcus aureus. The identity of this metallophore, herein named pseudopaline, was determined through measurements of binding affinity, the in vitro reconstitution of the biosynthetic pathway to screen potential substrates, and the confirmation of product formation by mass spectrometry. Pseudopaline and the S. aureus metallophore staphylopine exhibit opposite stereochemistry for the histidine moiety, indicating unique recognition by NAS. Additionally, we demonstrate SaODH catalysis in the presence of pyruvate, as previously shown, but also oxaloacetate, suggesting the potential for the production of a variant form of staphylopine, while PaODH specifically recognizes α-ketoglutarate. Both the staphylopine and pseudopaline operons have been implicated in the pathogenesis of key infectious disease states and warrant further study.
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Affiliation(s)
- Jeffrey S McFarlane
- Department of Molecular Biosciences, University of Kansas , Lawrence, Kansas 66045, United States
| | - Audrey L Lamb
- Department of Molecular Biosciences, University of Kansas , Lawrence, Kansas 66045, United States
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24
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Crespo A, Gavaldà J, Julián E, Torrents E. A single point mutation in class III ribonucleotide reductase promoter renders Pseudomonas aeruginosa PAO1 inefficient for anaerobic growth and infection. Sci Rep 2017; 7:13350. [PMID: 29042684 PMCID: PMC5645315 DOI: 10.1038/s41598-017-14051-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 10/04/2017] [Indexed: 11/09/2022] Open
Abstract
Pseudomonas aeruginosa strain PAO1 has become the reference strain in many laboratories. One enzyme that is essential for its cell division is the ribonucleotide reductase (RNR) enzyme that supplies the deoxynucleotides required for DNA synthesis and repair. P. aeruginosa is one of the few microorganisms that encodes three different RNR classes (Ia, II and III) in its genome, enabling it to grow and adapt to diverse environmental conditions, including during infection. In this work, we demonstrate that a lack of RNR activity induces cell elongation in P. aeruginosa PAO1. Moreover, RNR gene expression during anaerobiosis differs among P. aeruginosa strains, with class III highly expressed in P. aeruginosa clinical isolates relative to the laboratory P. aeruginosa PAO1 strain. A single point mutation was identified in the P. aeruginosa PAO1 strain class III RNR promoter region that disrupts its anaerobic transcription by the Dnr regulator. An engineered strain that induces the class III RNR expression allows P. aeruginosa PAO1 anaerobic growth and increases its virulence to resemble that of clinical strains. Our results demonstrate that P. aeruginosa PAO1 is adapted to laboratory conditions and is not the best reference strain for anaerobic or infection studies.
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Affiliation(s)
- Anna Crespo
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology. Bacterial infections and antimicrobial therapies; Baldiri Reixac 15-21, 08028, Barcelona, Spain
| | - Joan Gavaldà
- Infectious Diseases Research Laboratory, Infectious Diseases Department, Vall d'Hebron Research Institute VHIR, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Esther Julián
- Departament de Genètica i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Eduard Torrents
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology. Bacterial infections and antimicrobial therapies; Baldiri Reixac 15-21, 08028, Barcelona, Spain.
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25
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Backman LRF, Funk MA, Dawson CD, Drennan CL. New tricks for the glycyl radical enzyme family. Crit Rev Biochem Mol Biol 2017; 52:674-695. [PMID: 28901199 DOI: 10.1080/10409238.2017.1373741] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Glycyl radical enzymes (GREs) are important biological catalysts in both strict and facultative anaerobes, playing key roles both in the human microbiota and in the environment. GREs contain a backbone glycyl radical that is post-translationally installed, enabling radical-based mechanisms. GREs function in several metabolic pathways including mixed acid fermentation, ribonucleotide reduction and the anaerobic breakdown of the nutrient choline and the pollutant toluene. By generating a substrate-based radical species within the active site, GREs enable C-C, C-O and C-N bond breaking and formation steps that are otherwise challenging for nonradical enzymes. Identification of previously unknown family members from genomic data and the determination of structures of well-characterized GREs have expanded the scope of GRE-catalyzed reactions as well as defined key features that enable radical catalysis. Here, we review the structures and mechanisms of characterized GREs, classifying members into five categories. We consider the open questions about each of the five GRE classes and evaluate the tools available to interrogate uncharacterized GREs.
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Affiliation(s)
- Lindsey R F Backman
- a Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA , USA
| | - Michael A Funk
- a Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA , USA.,b Department of Chemistry , University of Illinois at Urbana-Champaign , Urbana , IL , USA
| | - Christopher D Dawson
- c Department of Biology , Massachusetts Institute of Technology , Cambridge , MA , USA
| | - Catherine L Drennan
- a Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA , USA.,c Department of Biology , Massachusetts Institute of Technology , Cambridge , MA , USA.,d Howard Hughes Medical Institute , Massachusetts Institute of Technology , Cambridge , MA , USA
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