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Ogunleye SC, Islam S, Chowdhury QMMK, Ozdemir O, Lawrence ML, Abdelhamed H. Catabolite control protein C contributes to virulence and hydrogen peroxide-induced oxidative stress responses in Listeria monocytogenes. Front Microbiol 2024; 15:1403694. [PMID: 38881664 PMCID: PMC11176438 DOI: 10.3389/fmicb.2024.1403694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 05/07/2024] [Indexed: 06/18/2024] Open
Abstract
Listeria monocytogenes causes listeriosis, an infectious and potentially fatal disease of animals and humans. A diverse network of transcriptional regulators, including LysR-type catabolite control protein C (CcpC), is critical for the survival of L. monocytogenes and its ability to transition into the host environment. In this study, we explored the physiological and genetic consequences of deleting ccpC and the effects of such deletion on the ability of L. monocytogenes to cause disease. We found that ccpC deletion did not impact hemolytic activity, whereas it resulted in significant reductions in phospholipase activities. Western blotting revealed that the ΔccpC strain produced significantly reduced levels of the cholesterol-dependent cytolysin LLO relative to the wildtype F2365 strain. However, the ΔccpC mutant displayed no significant intracellular growth defect in macrophages. Furthermore, ΔccpC strain exhibited reduction in plaque numbers in fibroblasts compared to F2365, but plaque size was not significantly affected by ccpC deletion. In a murine model system, the ΔccpC strain exhibited a significantly reduced bacterial burden in the liver and spleen compared to the wildtype F2365 strain. Interestingly, the deletion of this gene also enhanced the survival of L. monocytogenes under conditions of H2O2-induced oxidative stress. Transcriptomic analyses performed under H2O2-induced oxidative stress conditions revealed that DNA repair, cellular responses to DNA damage and stress, metalloregulatory proteins, and genes involved in the biosynthesis of peptidoglycan and teichoic acids were significantly induced in the ccpC deletion strain relative to F2365. In contrast, genes encoding internalin, 1-phosphatidylinositol phosphodiesterase, and genes associated with sugar-specific phosphotransferase system components, porphyrin, branched-chain amino acids, and pentose phosphate pathway were significantly downregulated in the ccpC deletion strain relative to F2365. This finding highlights CcpC as a key factor that regulates L. monocytogenes physiology and responses to oxidative stress by controlling the expression of important metabolic pathways.
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Affiliation(s)
- Seto C Ogunleye
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi, MS, United States
| | - Shamima Islam
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi, MS, United States
| | - Q M Monzur Kader Chowdhury
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi, MS, United States
| | - Ozan Ozdemir
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi, MS, United States
| | - Mark L Lawrence
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi, MS, United States
| | - Hossam Abdelhamed
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi, MS, United States
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2
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Deery J, Carmody M, Flavin R, Tomanek M, O'Keeffe M, McGlacken GP, Reen FJ. Comparative genomics reveals distinct diversification patterns among LysR-type transcriptional regulators in the ESKAPE pathogen Pseudomonas aeruginosa. Microb Genom 2024; 10:001205. [PMID: 38421269 PMCID: PMC10926688 DOI: 10.1099/mgen.0.001205] [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: 10/05/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
Pseudomonas aeruginosa, a harmful nosocomial pathogen associated with cystic fibrosis and burn wounds, encodes for a large number of LysR-type transcriptional regulator proteins. To understand how and why LTTR proteins evolved with such frequency and to establish whether any relationships exist within the distribution we set out to identify the patterns underpinning LTTR distribution in P. aeruginosa and to uncover cluster-based relationships within the pangenome. Comparative genomic studies revealed that in the JGI IMG database alone ~86 000 LTTRs are present across the sequenced genomes (n=699). They are widely distributed across the species, with core LTTRs present in >93 % of the genomes and accessory LTTRs present in <7 %. Analysis showed that subsets of core LTTRs can be classified as either variable (typically specific to P. aeruginosa) or conserved (and found to be distributed in other Pseudomonas species). Extending the analysis to the more extensive Pseudomonas database, PA14 rooted analysis confirmed the diversification patterns and revealed PqsR, the receptor for the Pseudomonas quinolone signal (PQS) and 2-heptyl-4-quinolone (HHQ) quorum-sensing signals, to be amongst the most variable in the dataset. Successful complementation of the PAO1 pqsR - mutant using representative variant pqsR sequences suggests a degree of structural promiscuity within the most variable of LTTRs, several of which play a prominent role in signalling and communication. These findings provide a new insight into the diversification of LTTR proteins within the P. aeruginosa species and suggests a functional significance to the cluster, conservation and distribution patterns identified.
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Affiliation(s)
- Jamie Deery
- School of Microbiology, University College Cork, Cork, Ireland
| | - Muireann Carmody
- School of Microbiology, University College Cork, Cork, Ireland
- School of Chemistry, University College Cork, Cork, Ireland
| | - Rhiannon Flavin
- School of Microbiology, University College Cork, Cork, Ireland
| | - Malwina Tomanek
- School of Microbiology, University College Cork, Cork, Ireland
| | - Maria O'Keeffe
- School of Microbiology, University College Cork, Cork, Ireland
| | - Gerard P. McGlacken
- School of Chemistry, University College Cork, Cork, Ireland
- Synthesis and Solid State Pharmaceutical Centre, University College Cork, Cork, Ireland
| | - F. Jerry Reen
- School of Microbiology, University College Cork, Cork, Ireland
- Synthesis and Solid State Pharmaceutical Centre, University College Cork, Cork, Ireland
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3
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Shapira N, Zusman T, Segal G. The LysR-type transcriptional regulator LelA co-regulates various effectors in different Legionella species. Mol Microbiol 2024; 121:243-259. [PMID: 38153189 DOI: 10.1111/mmi.15214] [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: 10/12/2023] [Revised: 12/05/2023] [Accepted: 12/08/2023] [Indexed: 12/29/2023]
Abstract
The intracellular pathogen Legionella pneumophila translocates more than 300 effector proteins into its host cells. The expression levels of the genes encoding these effectors are orchestrated by an intricate regulatory network. Here, we introduce LelA, the first L. pneumophila LysR-type transcriptional regulator of effectors. Through bioinformatic and experimental analyses, we identified the LelA target regulatory element and demonstrated that it directly activates the expression of three L. pneumophila effectors (legL7, legL6, and legU1). We further found that the gene encoding LelA is positively regulated by the RpoS sigma factor, thus linking it to the known effector regulatory network. Examination of other species throughout the Legionella genus revealed that this regulatory element is found upstream of 34 genes encoding validated effectors, putative effectors, and hypothetical proteins. Moreover, ten of these genes were examined and found to be activated by the L. pneumophila LelA as well as by their orthologs in the corresponding species. LelA represents a novel type of Legionella effector regulator, which coordinates the expression of both adjacently and distantly located effector-encoding genes, thus forming small groups of co-regulated effectors.
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Affiliation(s)
- Naomi Shapira
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Tal Zusman
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Gil Segal
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
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4
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da Cruz Nizer WS, Adams ME, Inkovskiy V, Beaulieu C, Overhage J. The secondary metabolite hydrogen cyanide protects Pseudomonas aeruginosa against sodium hypochlorite-induced oxidative stress. Front Microbiol 2023; 14:1294518. [PMID: 38033579 PMCID: PMC10687435 DOI: 10.3389/fmicb.2023.1294518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 11/01/2023] [Indexed: 12/02/2023] Open
Abstract
The high pathogenicity of Pseudomonas aeruginosa is attributed to the production of many virulence factors and its resistance to several antimicrobials. Among them, sodium hypochlorite (NaOCl) is a widely used disinfectant due to its strong antimicrobial effect. However, bacteria develop many mechanisms to survive the damage caused by this agent. Therefore, this study aimed to identify novel mechanisms employed by P. aeruginosa to resist oxidative stress induced by the strong oxidizing agent NaOCl. We analyzed the growth of the P. aeruginosa mutants ΔkatA, ΔkatE, ΔahpC, ΔahpF, ΔmsrA at 1 μg/mL NaOCl, and showed that these known H2O2 resistance mechanisms are also important for the survival of P. aeruginosa under NaOCl stress. We then conducted a screening of the P. aeruginosa PA14 transposon insertion mutant library and identified 48 mutants with increased susceptibility toward NaOCl. Among them were 10 mutants with a disrupted nrdJa, bvlR, hcnA, orn, sucC, cysZ, nuoJ, PA4166, opmQ, or thiC gene, which also exhibited a significant growth defect in the presence of NaOCl. We focussed our follow-up experiments (i.e., growth analyzes and kill-kinetics) on mutants with defect in the synthesis of the secondary metabolite hydrogen cyanide (HCN). We showed that HCN produced by P. aeruginosa contributes to its resistance toward NaOCl as it acts as a scavenger molecule, quenching the toxic effects of NaOCl.
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Affiliation(s)
| | | | | | | | - Joerg Overhage
- Department of Health Sciences, Carleton University, Ottawa, ON, Canada
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5
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Zhang Y, Wang L, Chen L, Zhu P, Huang N, Chen T, Chen L, Wang Z, Liao W, Cao J, Zhou T. Novel Insight of Transcription Factor PtrA on Pathogenicity and Carbapenems Resistance in Pseudomonas aeruginosa. Infect Drug Resist 2022; 15:4213-4227. [PMID: 35959145 PMCID: PMC9359796 DOI: 10.2147/idr.s371597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 07/23/2022] [Indexed: 11/23/2022] Open
Affiliation(s)
- Ying Zhang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, People’s Republic of China
| | - Lingbo Wang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, People’s Republic of China
| | - Liqiong Chen
- Department of Medical Laboratory Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, People’s Republic of China
| | - Peiwu Zhu
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, People’s Republic of China
| | - Na Huang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, People’s Republic of China
| | - Tao Chen
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, People’s Republic of China
| | - Lijiang Chen
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, People’s Republic of China
| | - Zhongyong Wang
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, People’s Republic of China
| | - Wenli Liao
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, People’s Republic of China
| | - Jianming Cao
- Department of Medical Laboratory Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, People’s Republic of China
- Jianming Cao, Department of Medical Laboratory Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, 325035, People’s Republic of China, Tel +86-577-88069595, Email
| | - Tieli Zhou
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, People’s Republic of China
- Correspondence: Tieli Zhou, Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, 325035, People’s Republic of China, Tel +86-577-8668-9885, Email
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Hassett DJ, Kovall RA, Schurr MJ, Kotagiri N, Kumari H, Satish L. The Bactericidal Tandem Drug, AB569: How to Eradicate Antibiotic-Resistant Biofilm Pseudomonas aeruginosa in Multiple Disease Settings Including Cystic Fibrosis, Burns/Wounds and Urinary Tract Infections. Front Microbiol 2021; 12:639362. [PMID: 34220733 PMCID: PMC8245851 DOI: 10.3389/fmicb.2021.639362] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 04/07/2021] [Indexed: 11/13/2022] Open
Abstract
The life-threatening pandemic concerning multi-drug resistant (MDR) bacteria is an evolving problem involving increased hospitalizations, billions of dollars in medical costs and a remarkably high number of deaths. Bacterial pathogens have demonstrated the capacity for spontaneous or acquired antibiotic resistance and there is virtually no pool of organisms that have not evolved such potentially clinically catastrophic properties. Although many diseases are linked to such organisms, three include cystic fibrosis (CF), burn/blast wounds and urinary tract infections (UTIs), respectively. Thus, there is a critical need to develop novel, effective antimicrobials for the prevention and treatment of such problematic infections. One of the most formidable, naturally MDR bacterial pathogens is Pseudomonas aeruginosa (PA) that is particularly susceptible to nitric oxide (NO), a component of our innate immune response. This susceptibility sets the translational stage for the use of NO-based therapeutics during the aforementioned human infections. First, we discuss how such NO therapeutics may be able to target problematic infections in each of the aforementioned infectious scenarios. Second, we describe a recent discovery based on years of foundational information, a novel drug known as AB569. AB569 is capable of forming a "time release" of NO from S-nitrosothiols (RSNO). AB569, a bactericidal tandem consisting of acidified NaNO2 (A-NO2 -) and Na2-EDTA, is capable of killing all pathogens that are associated with the aforementioned disorders. Third, we described each disease state in brief, the known or predicted effects of AB569 on the viability of PA, its potential toxicity and highly remote possibility for resistance to develop. Finally, we conclude that AB569 can be a viable alternative or addition to conventional antibiotic regimens to treat such highly problematic MDR bacterial infections for civilian and military populations, as well as the economical burden that such organisms pose.
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Affiliation(s)
- Daniel J Hassett
- Department of Molecular Genetics, Biochemistry and Microbiology, Cincinnati, OH, United States
| | - Rhett A Kovall
- Department of Molecular Genetics, Biochemistry and Microbiology, Cincinnati, OH, United States
| | - Michael J Schurr
- Department of Immunology and Microbiology, University of Colorado Health Sciences, Denver, CO, United States
| | - Nalinikanth Kotagiri
- Division of Pharmacy, University of Colorado Health Sciences, Denver, CO, United States
| | - Harshita Kumari
- Division of Pharmacy, University of Colorado Health Sciences, Denver, CO, United States
| | - Latha Satish
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States.,Shriners Hospitals for Children-Cincinnati, Cincinnati, OH, United States
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7
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Parise D, Teixeira Dornelles Parise M, Pinto Gomide AC, Figueira Aburjaile F, Bentes Kato R, Salgado-Albarrán M, Tauch A, Ariston de Carvalho Azevedo V, Baumbach J. The Transcriptional Regulatory Network of Corynebacterium pseudotuberculosis. Microorganisms 2021; 9:microorganisms9020415. [PMID: 33671149 PMCID: PMC7923171 DOI: 10.3390/microorganisms9020415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 02/11/2021] [Accepted: 02/14/2021] [Indexed: 12/26/2022] Open
Abstract
Corynebacterium pseudotuberculosis is a Gram-positive, facultative intracellular, pathogenic bacterium that infects several different hosts, yielding serious economic losses in livestock farming. It causes several diseases including oedematous skin disease (OSD) in buffaloes, ulcerative lymphangitis (UL) in horses, and caseous lymphadenitis (CLA) in sheep, goats and humans. Despite its economic and medical-veterinary importance, our understanding concerning this organism’s transcriptional regulatory mechanisms is still limited. Here, we review the state of the art knowledge on transcriptional regulatory mechanisms of this pathogenic species, covering regulatory interactions mediated by two-component systems, transcription factors and sigma factors. Key transcriptional regulatory players involved in virulence and pathogenicity of C. pseudotuberculosis, such as the PhoPR system and DtxR, are in the focus of this review, as these regulators are promising targets for future vaccine design and drug development. We conclude that more experimental studies are needed to further understand the regulatory repertoire of this important zoonotic pathogen, and that regulators are promising targets for future vaccine design and drug development.
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Affiliation(s)
- Doglas Parise
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354 Freising-Weihenstephan, Germany; (M.T.D.P.); (M.S.-A.); (J.B.)
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
- Correspondence: or
| | - Mariana Teixeira Dornelles Parise
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354 Freising-Weihenstephan, Germany; (M.T.D.P.); (M.S.-A.); (J.B.)
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
| | - Anne Cybelle Pinto Gomide
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
| | | | - Rodrigo Bentes Kato
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
| | - Marisol Salgado-Albarrán
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354 Freising-Weihenstephan, Germany; (M.T.D.P.); (M.S.-A.); (J.B.)
- Departamento de Ciencias Naturales, Universidad Autónoma Metropolitana Cuajimalpa, Mexico City 05348, Mexico
| | - Andreas Tauch
- Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany;
| | - Vasco Ariston de Carvalho Azevedo
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
| | - Jan Baumbach
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354 Freising-Weihenstephan, Germany; (M.T.D.P.); (M.S.-A.); (J.B.)
- Computational BioMedicine lab, Institute of Mathematics and Computer Science, University of Southern Denmark, 5230 Odense, Denmark
- Chair of Computational Systems Biology, University of Hamburg, 22607 Hamburg, Germany
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8
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Heredia-Ponce Z, Gutiérrez-Barranquero JA, Purtschert-Montenegro G, Eberl L, de Vicente A, Cazorla FM. Role of extracellular matrix components in the formation of biofilms and their contribution to the biocontrol activity of Pseudomonas chlororaphis PCL1606. Environ Microbiol 2020; 23:2086-2101. [PMID: 33314481 DOI: 10.1111/1462-2920.15355] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 12/15/2022]
Abstract
Pseudomonas chlororaphis PCL1606 (PcPCL1606) displays plant-colonizing features and exhibits antagonistic traits against soil-borne phytopathogenic fungi. Biofilm formation could be relevant for the PcPCL1606 lifestyle, and in this study the role of some putative extracellular matrix components (EMC; Fap-like fibre, alginate and Psl-like polysaccharides) in the biofilm architecture and biocontrol activity of this bacterium were determined. EMC such as the Fap-like fibre and alginate polysaccharide play secondary roles in biofilm formation in PcPCL1606, because they are not fundamental to its biofilm architecture in flow cell chamber, but synergistically they have shown to favour bacterial competition during biofilm formation. Conversely, studies on Psl-like polysaccharide have revealed that it may contain mannose, and that it is strongly involved in the PcPCL1606 biofilm architecture and niche competition. Furthermore, the Fap-like fibre and Psl-like exopolysaccharide play roles in early surface attachment and contribute to biocontrol activity against the white root rot disease caused by Rosellinia necatrix in avocado plants. These results constitute the first report regarding the study of the extracellular matrix of the PcPCL1606 strain and highlight the importance of a putative Fap-like fibre and Psl-like exopolysaccharide produced by PcPCL1606 in the biofilm formation process and interactions with the host plant root.
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Affiliation(s)
- Zaira Heredia-Ponce
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC) - Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur, 31 (Campus Universitario de Teatinos), Málaga, 29071, Spain
| | - José Antonio Gutiérrez-Barranquero
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC) - Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur, 31 (Campus Universitario de Teatinos), Málaga, 29071, Spain
| | | | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, Zurich, CH-8008, Switzerland
| | - Antonio de Vicente
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC) - Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur, 31 (Campus Universitario de Teatinos), Málaga, 29071, Spain
| | - Francisco M Cazorla
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC) - Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur, 31 (Campus Universitario de Teatinos), Málaga, 29071, Spain
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9
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Maunders EA, Triniman RC, Western J, Rahman T, Welch M. Global reprogramming of virulence and antibiotic resistance in Pseudomonas aeruginosa by a single nucleotide polymorphism in elongation factor, fusA1. J Biol Chem 2020; 295:16411-16426. [PMID: 32943550 DOI: 10.1074/jbc.ra119.012102] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 09/11/2020] [Indexed: 11/06/2022] Open
Abstract
Clinical isolates of the opportunistic pathogen Pseudomonas aeruginosa from patients with cystic fibrosis (CF) frequently contain mutations in the gene encoding an elongation factor, FusA1. Recent work has shown that fusA1 mutants often display elevated aminoglycoside resistance due to increased expression of the efflux pump, MexXY. However, we wondered whether these mutants might also be affected in other virulence-associated phenotypes. Here, we isolated a spontaneous gentamicin-resistant fusA1 mutant (FusA1P443L) in which mexXY expression was increased. Proteomic and transcriptomic analyses revealed that the fusA1 mutant also exhibited discrete changes in the expression of key pathogenicity-associated genes. Most notably, the fusA1 mutant displayed greatly increased expression of the Type III secretion system (T3SS), widely considered to be the most potent virulence factor in the P. aeruginosa arsenal, and also elevated expression of the Type VI (T6) secretion machinery. This was unexpected because expression of the T3SS is usually reciprocally coordinated with T6 secretion system expression. The fusA1 mutant also displayed elevated exopolysaccharide production, dysregulated siderophore production, elevated ribosome synthesis, and transcriptomic signatures indicative of translational stress. Each of these phenotypes (and almost all of the transcriptomic and proteomic changes associated with the fusA1 mutation) were restored to levels comparable with that in the progenitor strain by expression of the WT fusA1 gene in trans, indicating that the mutant gene is recessive. Our data show that in addition to elevating antibiotic resistance through mexXY expression (and also additional contributory resistance mechanisms), mutations in fusA1 can lead to highly selective dysregulation of virulence gene expression.
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Affiliation(s)
- Eve A Maunders
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Rory C Triniman
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom; Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Joshua Western
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Taufiq Rahman
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Martin Welch
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
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10
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Maslova E, Shi Y, Sjöberg F, Azevedo HS, Wareham DW, McCarthy RR. An Invertebrate Burn Wound Model That Recapitulates the Hallmarks of Burn Trauma and Infection Seen in Mammalian Models. Front Microbiol 2020; 11:998. [PMID: 32582051 PMCID: PMC7283582 DOI: 10.3389/fmicb.2020.00998] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 04/24/2020] [Indexed: 11/13/2022] Open
Abstract
The primary reason for skin graft failure and the mortality of burn wound patients, particularly those in burn intensive care centers, is bacterial infection. Several animal models exist to study burn wound pathogens. The most commonly used model is the mouse, which can be used to study virulence determinants and pathogenicity of a wide range of clinically relevant burn wound pathogens. However, animal models of burn wound pathogenicity are governed by strict ethical guidelines and hindered by high levels of animal suffering and the high level of training that is required to achieve consistent reproducible results. In this study, we describe for the first time an invertebrate model of burn trauma and concomitant wound infection. We demonstrate that this model recapitulates many of the hallmarks of burn trauma and wound infection seen in mammalian models and in human patients. We outline how this model can be used to discriminate between high and low pathogenicity strains of two of the most common burn wound colonizers Pseudomonas aeruginosa and Staphylococcus aureus, and multi-drug resistant Acinetobacter baumannii. This model is less ethically challenging than traditional vertebrate burn wound models and has the capacity to enable experiments such as high throughput screening of both anti-infective compounds and genetic mutant libraries.
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Affiliation(s)
- Evgenia Maslova
- Division of Biosciences, Centre for Inflammation Research and Translational Medicine, Department of Life Sciences, College of Health and Life Sciences, Brunel University London, London, United Kingdom
| | - Yejiao Shi
- School of Engineering and Materials Science, Institute of Bioengineering, Queen Mary, University of London, London, United Kingdom
| | - Folke Sjöberg
- The Burn Centre, Department of Hand and Plastic Surgery, Linköping University, Linköping, Sweden.,Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Helena S Azevedo
- School of Engineering and Materials Science, Institute of Bioengineering, Queen Mary, University of London, London, United Kingdom
| | - David W Wareham
- Antimicrobial Research Group, Blizard Institute, Queen Mary, University of London, London, United Kingdom
| | - Ronan R McCarthy
- Division of Biosciences, Centre for Inflammation Research and Translational Medicine, Department of Life Sciences, College of Health and Life Sciences, Brunel University London, London, United Kingdom
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11
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Dong Y, Wang Y, Liu J, Ma S, Awan F, Lu C, Liu Y. Discovery of lahS as a Global Regulator of Environmental Adaptation and Virulence in Aeromonas hydrophila. Int J Mol Sci 2018; 19:E2709. [PMID: 30208624 PMCID: PMC6163582 DOI: 10.3390/ijms19092709] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 09/03/2018] [Accepted: 09/04/2018] [Indexed: 01/06/2023] Open
Abstract
Aeromonas hydrophila is an important aquatic microorganism that can cause fish hemorrhagic septicemia. In this study, we identified a novel LysR family transcriptional regulator (LahS) in the A. hydrophila Chinese epidemic strain NJ-35 from a library of 947 mutant strains. The deletion of lahS caused bacteria to exhibit significantly decreased hemolytic activity, motility, biofilm formation, protease production, and anti-bacterial competition ability when compared to the wild-type strain. In addition, the determination of the fifty percent lethal dose (LD50) in zebrafish demonstrated that the lahS deletion mutant (ΔlahS) was highly attenuated in virulence, with an approximately 200-fold increase in LD50 observed as compared with that of the wild-type strain. However, the ΔlahS strain exhibited significantly increased antioxidant activity (six-fold). Label-free quantitative proteome analysis resulted in the identification of 34 differentially expressed proteins in the ΔlahS strain. The differentially expressed proteins were involved in flagellum assembly, metabolism, redox reactions, and cell density induction. The data indicated that LahS might act as a global regulator to directly or indirectly regulate various biological processes in A. hydrophila NJ-35, contributing to a greater understanding the pathogenic mechanisms of A. hydrophila.
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Affiliation(s)
- Yuhao Dong
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
| | - Yao Wang
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
| | - Jin Liu
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
| | - Shuiyan Ma
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
| | - Furqan Awan
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
| | - Chengping Lu
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
| | - Yongjie Liu
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
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12
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Gomide ACP, Ibraim IC, Alves JTC, de Sá PG, de Oliveira Silva YR, Santana MP, Silva WM, Folador EL, Mariano DCB, de Paula Castro TL, Barbosa S, Dorella FA, Carvalho AF, Pereira FL, Leal CAG, Figueiredo HCP, Azevedo V, Silva A, Folador ARC. Transcriptome analysis of Corynebacterium pseudotuberculosis biovar Equi in two conditions of the environmental stress. Gene 2018; 677:349-360. [PMID: 30098432 DOI: 10.1016/j.gene.2018.08.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/10/2018] [Accepted: 08/06/2018] [Indexed: 11/30/2022]
Abstract
Corynebacterium pseudotuberculosis has been widely studied in an effort to understand its biological evolution. Transcriptomics has revealed possible candidates for virulence and pathogenicity factors of strain 1002 (biovar Ovis). Because C. pseudotuberculosis is classified into two biovars, Ovis and Equi, it was interesting to assess the transcriptional profile of biovar Equi strain 258, the causative agent of ulcerative lymphangitis. The genome of this strain was re-sequenced; the reassembly was completed using optical mapping technology, and the sequence was subsequently re-annotated. Two growth conditions that occur during the host infection process were simulated for the transcriptome: the osmotic and acid medium. Genes that may be associated with the microorganism's resilience under unfavorable conditions were identified through RNAseq, including genes present in pathogenicity islands. The RT-qPCR was performed to confirm the results in biological triplicate for each condition for some genes. The results extend our knowledge of the factors associated with the spread and persistence of C. pseudotuberculosis during the infection process and suggest possible avenues for studies related to the development of vaccines, diagnosis, and therapies that might help minimize damage to agribusinesses.
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Affiliation(s)
- Anne Cybelle Pinto Gomide
- Department of General Biology, Institute of Biological Sciences, Federal University of Minas Gerais, Av. Antônio Carlos, Belo Horizonte 31.270-901, Brazil.
| | - Izabela Coimbra Ibraim
- Department of General Biology, Institute of Biological Sciences, Federal University of Minas Gerais, Av. Antônio Carlos, Belo Horizonte 31.270-901, Brazil
| | - Jorianne T C Alves
- Laboratory of Genomic and Bioinformatics, Center of Genomics and System Biology, Institute of Biological Science, Federal University of Para, Belém, Pará, Brazil, Rua Augusto Corrêa, Belém 66.075-110, Brazil
| | - Pablo Gomes de Sá
- Federal Rural University of Amazonia, Rodovia PA 140, 2428 Tomé-Açu, PA, Brazil
| | - Yuri Rafael de Oliveira Silva
- Laboratory of Genomic and Bioinformatics, Center of Genomics and System Biology, Institute of Biological Science, Federal University of Para, Belém, Pará, Brazil, Rua Augusto Corrêa, Belém 66.075-110, Brazil
| | - Mariana Passos Santana
- Department of General Biology, Institute of Biological Sciences, Federal University of Minas Gerais, Av. Antônio Carlos, Belo Horizonte 31.270-901, Brazil
| | - Wanderson Marques Silva
- National Institute of Agricultural Technology, Los Reseros y Nicolás Repetto, Hurlingham 1686, Argentina
| | - Edson Luiz Folador
- Biotechnology Center, Federal University of Paraíba, João Pessoa, Brazil.
| | - Diego C B Mariano
- Department of Computer Sciences, Institute of Exact Sciences, Federal University of Minas Gerais, Av. Antônio Carlos, Belo Horizonte 31.270-901, Brazil.
| | - Thiago Luiz de Paula Castro
- Department of Biointeraction, Institute of Health Sciences, Federal University of Bahia, Av. Reitor Miguel Calmon, s/n, Vale do Canela, Bahia, Brazil
| | - Silvanira Barbosa
- Laboratory of Genomic and Bioinformatics, Center of Genomics and System Biology, Institute of Biological Science, Federal University of Para, Belém, Pará, Brazil, Rua Augusto Corrêa, Belém 66.075-110, Brazil
| | - Fernanda Alves Dorella
- AQUACEN - National Reference Laboratory of Aquatic Animal Diseases, Ministry of Fisheries and Aquaculture, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Alex F Carvalho
- AQUACEN - National Reference Laboratory of Aquatic Animal Diseases, Ministry of Fisheries and Aquaculture, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Felipe L Pereira
- AQUACEN - National Reference Laboratory of Aquatic Animal Diseases, Ministry of Fisheries and Aquaculture, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil.
| | - Carlos A G Leal
- AQUACEN - National Reference Laboratory of Aquatic Animal Diseases, Ministry of Fisheries and Aquaculture, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil.
| | - Henrique C P Figueiredo
- AQUACEN - National Reference Laboratory of Aquatic Animal Diseases, Ministry of Fisheries and Aquaculture, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Vasco Azevedo
- Department of General Biology, Institute of Biological Sciences, Federal University of Minas Gerais, Av. Antônio Carlos, Belo Horizonte 31.270-901, Brazil.
| | - Artur Silva
- Laboratory of Genomic and Bioinformatics, Center of Genomics and System Biology, Institute of Biological Science, Federal University of Para, Belém, Pará, Brazil, Rua Augusto Corrêa, Belém 66.075-110, Brazil.
| | - Adriana Ribeiro Carneiro Folador
- Laboratory of Genomic and Bioinformatics, Center of Genomics and System Biology, Institute of Biological Science, Federal University of Para, Belém, Pará, Brazil, Rua Augusto Corrêa, Belém 66.075-110, Brazil.
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13
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Yu Y, Qian Y, Du D, Li Q, Xu C, Liu H, Chen M, Yao H, Lu C, Zhang W. Infection and adaption-based proteomic changes of Streptococcus suis serotype 2 in a pig model. J Proteomics 2017; 180:41-52. [PMID: 29247804 DOI: 10.1016/j.jprot.2017.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 11/10/2017] [Accepted: 12/01/2017] [Indexed: 12/28/2022]
Abstract
Streptococcus suis (S. suis) is an emerging zoonotic agent that is responsible for significant economic losses to the porcine industry worldwide. However, most research regarding the pathogenic mechanisms has used in vitro cultures of S. suis, which may not provide an accurate representation of the in vivo biological activities. In this study, 188 differential abundance S. suis proteins were identified in in vivo samples obtained from the blood of the infected pigs. These were compared with in vitro samples by a Tandem Mass Tags (TMT) experiment. Thus, a virulence associated network was established using the enriched differential abundance proteins (obtained via bioinformatics analysis in this study) and the previously reported putative virulence factors associated with in vivo infection. One of the most important up-regulated hubs in this network, adhE (an acetaldehyde-CoA/alcohol dehydrogenase) was found. Furthermore, knocking out adhE in S. suis serotype 2 strain ZY05719 decreased virulence. Cell culture experiments and far-western blot analysis showed that adhE is involved in adhesion to Caco-2 cells; Hsp60 could be one of the receptors for this protein. SIGNIFICANCE This study is a systematical research to identify in vivo regulated virulence associated proteins of S. suis in pigs. It constructs a network consisting of in vivo infection related factors for the first time to get to know the coordinated actions of a multitude of factors that lead to host pathogenicity and filter the most important hubs. The individual factors that contribute to infection is also identified. A novel differential protein adhE which is one of the most important hubs of this network and is up-regulated in abundance in vivo is found to moonlight as an important adhesion by binding Hsp60 and finally contributes to virulence.
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Affiliation(s)
- Yanfei Yu
- Key Lab of Animal Bacteriology of Ministry of Agriculture, College of Veterinary Medicine & OIE Swine Streptococcosis Diagnostic Laboratory, Nanjing Agricultural University, Nanjing 210095, China; Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China
| | - Yunyun Qian
- Key Lab of Animal Bacteriology of Ministry of Agriculture, College of Veterinary Medicine & OIE Swine Streptococcosis Diagnostic Laboratory, Nanjing Agricultural University, Nanjing 210095, China.
| | - Dechao Du
- Key Lab of Animal Bacteriology of Ministry of Agriculture, College of Veterinary Medicine & OIE Swine Streptococcosis Diagnostic Laboratory, Nanjing Agricultural University, Nanjing 210095, China.
| | - Quan Li
- Key Lab of Animal Bacteriology of Ministry of Agriculture, College of Veterinary Medicine & OIE Swine Streptococcosis Diagnostic Laboratory, Nanjing Agricultural University, Nanjing 210095, China.
| | - Chenyang Xu
- Key Lab of Animal Bacteriology of Ministry of Agriculture, College of Veterinary Medicine & OIE Swine Streptococcosis Diagnostic Laboratory, Nanjing Agricultural University, Nanjing 210095, China.
| | - Hanze Liu
- Key Lab of Animal Bacteriology of Ministry of Agriculture, College of Veterinary Medicine & OIE Swine Streptococcosis Diagnostic Laboratory, Nanjing Agricultural University, Nanjing 210095, China.
| | - Mianmian Chen
- Key Lab of Animal Bacteriology of Ministry of Agriculture, College of Veterinary Medicine & OIE Swine Streptococcosis Diagnostic Laboratory, Nanjing Agricultural University, Nanjing 210095, China.
| | - Huochun Yao
- Key Lab of Animal Bacteriology of Ministry of Agriculture, College of Veterinary Medicine & OIE Swine Streptococcosis Diagnostic Laboratory, Nanjing Agricultural University, Nanjing 210095, China.
| | - Chengping Lu
- Key Lab of Animal Bacteriology of Ministry of Agriculture, College of Veterinary Medicine & OIE Swine Streptococcosis Diagnostic Laboratory, Nanjing Agricultural University, Nanjing 210095, China.
| | - Wei Zhang
- Key Lab of Animal Bacteriology of Ministry of Agriculture, College of Veterinary Medicine & OIE Swine Streptococcosis Diagnostic Laboratory, Nanjing Agricultural University, Nanjing 210095, China.
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Regulator LdhR and d-Lactate Dehydrogenase LdhA of Burkholderia multivorans Play Roles in Carbon Overflow and in Planktonic Cellular Aggregate Formation. Appl Environ Microbiol 2017; 83:AEM.01343-17. [PMID: 28733286 DOI: 10.1128/aem.01343-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 07/17/2017] [Indexed: 11/20/2022] Open
Abstract
LysR-type transcriptional regulators (LTTRs) are the most commonly found regulators in Burkholderia cepacia complex, comprising opportunistic pathogens causing chronic respiratory infections in cystic fibrosis (CF) patients. Despite LTTRs being global regulators of pathogenicity in several types of bacteria, few have been characterized in Burkholderia Here, we show that gene ldhR of B. multivorans encoding an LTTR is cotranscribed with ldhA encoding a d-lactate dehydrogenase and evaluate their implication in virulence traits such as exopolysaccharide (EPS) synthesis and biofilm formation. A comparison of the wild type (WT) and its isogenic ΔldhR mutant grown in medium with 2% d-glucose revealed a negative impact on EPS biosynthesis and on cell viability in the presence of LdhR. The loss of viability in WT cells was caused by intracellular acidification as a consequence of the cumulative secretion of organic acids, including d-lactate, which was absent from the ΔldhR mutant supernatant. Furthermore, LdhR is implicated in the formation of planktonic cellular aggregates. WT cell aggregates reached 1,000 μm in size after 24 h in liquid cultures, in contrast to ΔldhR mutant aggregates that never grew more than 60 μm. The overexpression of d-lactate dehydrogenase LdhA in the ΔldhR mutant partially restored the formed aggregate size, suggesting a role for fermentation inside aggregates. Similar results were obtained for surface-attached biofilms, with WT cells producing more biofilm. A systematic evaluation of planktonic aggregates in Burkholderia CF clinical isolates showed aggregates in 40 of 74. As CF patients' lung environments are microaerophilic and bacteria are found as free aggregates/biofilms, LdhR and LdhA might have central roles in adapting to this environment.IMPORTANCE Cystic fibrosis patients often suffer from chronic respiratory infections caused by several types of microorganisms. Among them are the Burkholderia cepacia complex bacteria, which cause progressive deterioration of lung function that, in some patients, might develop into fatal necrotizing pneumoniae with bacteremia, known as "cepacia syndrome." Burkholderia pathogenesis is multifactorial as they express several virulence factors, form biofilms, and are highly resistant to antimicrobial compounds, making their eradication from the CF patients' airways very difficult. As Burkholderia is commonly found in CF lungs in the form of cell aggregates and biofilms, the need to investigate the mechanisms of cellular aggregation is obvious. In this study, we demonstrate the importance of a d-lactate dehydrogenase and a regulator in regulating carbon overflow, cellular aggregates, and surface-attached biofilm formation. This not only enhances our understanding of Burkholderia pathogenesis but can also lead to the development of drugs against these proteins to circumvent biofilm formation.
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A Low-Molecular-Weight Alginate Oligosaccharide Disrupts Pseudomonal Microcolony Formation and Enhances Antibiotic Effectiveness. Antimicrob Agents Chemother 2017. [PMID: 28630204 DOI: 10.1128/aac.00762-17] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
In chronic respiratory disease, the formation of dense, 3-dimensional "microcolonies" by Pseudomonas aeruginosa within the airway plays an important role in contributing to resistance to treatment. An in vitro biofilm model of pseudomonal microcolony formation using artificial-sputum (AS) medium was established to study the effects of low-molecular-weight alginate oligomers (OligoG CF-5/20) on pseudomonal growth, microcolony formation, and the efficacy of colistin. The studies employed clinical cystic fibrosis (CF) isolates (n = 3) and reference nonmucoid and mucoid multidrug-resistant (MDR) CF isolates (n = 7). Bacterial growth and biofilm development and disruption were studied using cell viability assays and image analysis with scanning electron and confocal laser scanning microscopy. Pseudomonal growth in AS medium was associated with increased ATP production (P < 0.05) and the formation (at 48 h) of discrete (>10-μm) microcolonies. In conventional growth medium, colistin retained an ability to inhibit growth of planktonic bacteria, although the MIC was increased (0.1 to 0.4 μg/ml) in AS medium compared to Mueller-Hinton (MH) medium. In contrast, in an established-biofilm model in AS medium, the efficacy of colistin was decreased. OligoG CF-5/20 (≥2%) treatment, however, induced dose-dependent biofilm disruption (P < 0.05) and led to colistin retaining its antimicrobial activity (P < 0.05). While circular dichroism indicated that OligoG CF-5/20 did not change the orientation of the alginate carboxyl groups, mass spectrometry demonstrated that the oligomers induced dose-dependent (>0.2%; P < 0.05) reductions in pseudomonal quorum-sensing signaling. These findings reinforce the potential clinical significance of microcolony formation in the CF lung and highlight a novel approach to treat MDR pseudomonal infections.
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Maunders E, Welch M. Matrix exopolysaccharides; the sticky side of biofilm formation. FEMS Microbiol Lett 2017; 364:3866592. [PMID: 28605431 PMCID: PMC5812517 DOI: 10.1093/femsle/fnx120] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/07/2017] [Indexed: 12/20/2022] Open
Abstract
The Gram-negative pathogen Pseudomonas aeruginosa is found ubiquitously within the environment and is recognised as an opportunistic human pathogen that commonly infects burn wounds and immunocompromised individuals, or patients suffering from the autosomal recessive disorder cystic fibrosis (CF). During chronic infection, P. aeruginosa is thought to form structured aggregates known as biofilms characterised by a self-produced matrix which encases the bacteria, protecting them from antimicrobial attack and the host immune response. In many cases, antibiotics are ineffective at eradicating P. aeruginosa from chronically infected CF airways. Cyclic-di-GMP has been identified as a key regulator of biofilm formation; however, the way in which its effector proteins elicit a change in biofilm formation remains unclear. Identifying regulators of biofilm formation is a key theme of current research and understanding the factors that activate biofilm formation may help to expose potential new drug targets that slow the onset of chronic infection. This minireview outlines the contribution made by exopolysaccharides to biofilm formation, and describes the current understanding of biofilm regulation in P. aeruginosa with a particular focus on CF airway-associated infections.
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Affiliation(s)
| | - Martin Welch
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Hopkins Building, Cambridge CB2 1QW, UK. Tel: +44 01223 333653; E-mail:
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Dou Y, Huan J, Guo F, Zhou Z, Shi Y. Pseudomonas aeruginosa prevalence, antibiotic resistance and antimicrobial use in Chinese burn wards from 2007 to 2014. J Int Med Res 2017; 45:1124-1137. [PMID: 28443385 PMCID: PMC5536433 DOI: 10.1177/0300060517703573] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Objective To assess the application of antibacterial agents, alongside pathogen prevalence and Pseudomonas aeruginosa drug resistance, with the aim of understanding the impact of inappropriate antibacterial use. Methods This retrospective study assessed bacteria from wounds, catheters, blood, faeces, urine and sputum of hospitalized patients in burn wards between 2007 and 2014. The intensity of use of antibacterial agents and resistance of P. aeruginosa to common anti-Gram-negative antibiotics were measured. Results Annual detection rates of Staphylococcus aureus were significantly decreased, whereas annual detection rates of P. aeruginosa and Klebsiella pneumoniae were significantly increased. Multidrug-resistant strains of P. aeruginosa were increased. The intensity of use of some anti-Gramnegative antibiotics positively correlated with resistance rates of P. aeruginosa to similar antimicrobials. Conclusion In burn wards, more attention should be paid to P. aeruginosa and K. pneumoniae. The use of ciprofloxacin, ceftazidime and cefoperazone/sulbactam should be limited to counter the related increase in resistance levels.
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Affiliation(s)
- Yi Dou
- Burn and Plastic Surgery Department, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 200025 China
| | - Jingning Huan
- Burn and Plastic Surgery Department, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 200025 China
| | - Feng Guo
- Burn and Plastic Surgery Department, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 200025 China
| | - Zengding Zhou
- Burn and Plastic Surgery Department, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 200025 China
| | - Yan Shi
- Burn and Plastic Surgery Department, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, 200025 China
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Cystic fibrosis lung environment and Pseudomonas aeruginosa infection. BMC Pulm Med 2016; 16:174. [PMID: 27919253 PMCID: PMC5139081 DOI: 10.1186/s12890-016-0339-5] [Citation(s) in RCA: 225] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/24/2016] [Indexed: 12/20/2022] Open
Abstract
Background The airways of patients with cystic fibrosis (CF) are highly complex, subject to various environmental conditions as well as a distinct microbiota. Pseudomonas aeruginosa is recognized as one of the most important pulmonary pathogens and the predominant cause of morbidity and mortality in CF. A multifarious interplay between the host, pathogens, microbiota, and the environment shapes the course of the disease. There have been several excellent reviews detailing CF pathology, Pseudomonas and the role of environment in CF but only a few reviews connect these entities with regards to influence on the overall course of the disease. A holistic understanding of contributing factors is pertinent to inform new research and therapeutics. Discussion In this article, we discuss the deterministic alterations in lung physiology as a result of CF. We also revisit the impact of those changes on the microbiota, with special emphasis on P. aeruginosa and the influence of other non-genetic factors on CF. Substantial past and current research on various genetic and non-genetic aspects of cystic fibrosis has been reviewed to assess the effect of different factors on CF pulmonary infection. A thorough review of contributing factors in CF and the alterations in lung physiology indicate that CF lung infection is multi-factorial with no isolated cause that should be solely targeted to control disease progression. A combinatorial approach may be required to ensure better disease outcomes. Conclusion CF lung infection is a complex disease and requires a broad multidisciplinary approach to improve CF disease outcomes. A holistic understanding of the underlying mechanisms and non-genetic contributing factors in CF is central to development of new and targeted therapeutic strategies.
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Gutiérrez-Barranquero JA, Reen FJ, McCarthy RR, O'Gara F. Deciphering the role of coumarin as a novel quorum sensing inhibitor suppressing virulence phenotypes in bacterial pathogens. Appl Microbiol Biotechnol 2015; 99:3303-16. [PMID: 25672848 DOI: 10.1007/s00253-015-6436-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 01/06/2015] [Accepted: 01/25/2015] [Indexed: 12/31/2022]
Abstract
The rapid unchecked rise in antibiotic resistance over the last few decades has led to an increased focus on the need for alternative therapeutic strategies for the treatment and clinical management of microbial infections. In particular, small molecules that can suppress microbial virulence systems independent of any impact on growth are receiving increased attention. Quorum sensing (QS) is a cell-to-cell signalling communication system that controls the virulence behaviour of a broad spectrum of bacterial pathogens. QS systems have been proposed as an effective target, particularly as they control biofilm formation in pathogens, a key driver of antibiotic ineffectiveness. In this study, we identified coumarin, a natural plant phenolic compound, as a novel QS inhibitor, with potent anti-virulence activity in a broad spectrum of pathogens. Using a range of biosensor systems, coumarin was active against short, medium and long chain N-acyl-homoserine lactones, independent of any effect on growth. To determine if this suppression was linked to anti-virulence activity, key virulence systems were studied in the nosocomial pathogen Pseudomonas aeruginosa. Consistent with suppression of QS, coumarin inhibited biofilm, the production of phenazines and swarming motility in this organism potentially linked to reduced expression of the rhlI and pqsA quorum sensing genes. Furthermore, coumarin significantly inhibited biofilm formation and protease activity in other bacterial pathogens and inhibited bioluminescence in Aliivibrio fischeri. In light of these findings, coumarin would appear to have potential as a novel quorum sensing inhibitor with a broad spectrum of action.
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Affiliation(s)
- José A Gutiérrez-Barranquero
- BIOMERIT Research Centre, School of Microbiology, University College Cork, National University of Ireland, Cork, Ireland
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