1
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Nishioka ST, Snipper J, Lee J, Schapiro J, Zhang RZ, Abe H, Till A, Okumura CYM. Group A Streptococcus induces lysosomal dysfunction in THP-1 macrophages. Infect Immun 2024; 92:e0014124. [PMID: 38722166 PMCID: PMC11237432 DOI: 10.1128/iai.00141-24] [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: 04/01/2024] [Accepted: 04/11/2024] [Indexed: 06/12/2024] Open
Abstract
The human-specific bacterial pathogen group A Streptococcus (GAS) is a significant cause of morbidity and mortality. Macrophages are important to control GAS infection, but previous data indicate that GAS can persist in macrophages. In this study, we detail the molecular mechanisms by which GAS survives in THP-1 macrophages. Our fluorescence microscopy studies demonstrate that GAS is readily phagocytosed by macrophages, but persists within phagolysosomes. These phagolysosomes are not acidified, which is in agreement with our findings that GAS cannot survive in low pH environments. We find that the secreted pore-forming toxin Streptolysin O (SLO) perforates the phagolysosomal membrane, allowing leakage of not only protons but also large proteins including the lysosomal protease cathepsin B. Additionally, GAS recruits CD63/LAMP-3, which may contribute to lysosomal permeabilization, especially in the absence of SLO. Thus, although GAS does not inhibit fusion of the lysosome with the phagosome, it has multiple mechanisms to prevent proper phagolysosome function, allowing for persistence of the bacteria within the macrophage. This has important implications for not only the initial response but also the overall functionality of the macrophages, which may lead to the resulting pathologies in GAS infection. Our data suggest that therapies aimed at improving macrophage function may positively impact patient outcomes in GAS infection.
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Affiliation(s)
- Scott T Nishioka
- Biology Department, Occidental College, Los Angeles, California, USA
| | - Joshua Snipper
- Biology Department, Occidental College, Los Angeles, California, USA
| | - Jimin Lee
- Biology Department, Occidental College, Los Angeles, California, USA
| | - Joshua Schapiro
- Biology Department, Occidental College, Los Angeles, California, USA
| | - Robert Z Zhang
- Biology Department, Occidental College, Los Angeles, California, USA
| | - Hyewon Abe
- Biology Department, Occidental College, Los Angeles, California, USA
| | - Andreas Till
- Division of Biological Sciences, University of California San Diego, La Jolla, California, USA
- The San Diego Center for Systems Biology, University of California San Diego, La Jolla, California, USA
- University Hospital of Bonn, Bonn, Germany
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2
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Cheng Q, Han Y, Xiao Y, Li Z, Qin A, Ji S, Kan B, Liang W. The ArgR-Regulated ADI Pathway Facilitates the Survival of Vibrio fluvialis under Acidic Conditions. Int J Mol Sci 2024; 25:5679. [PMID: 38891866 PMCID: PMC11172107 DOI: 10.3390/ijms25115679] [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: 03/27/2024] [Revised: 05/15/2024] [Accepted: 05/21/2024] [Indexed: 06/21/2024] Open
Abstract
Vibrio fluvialis is an emerging foodborne pathogenic bacterium that can cause severe cholera-like diarrhea and various extraintestinal infections, posing challenges to public health and food safety worldwide. The arginine deiminase (ADI) pathway plays an important role in bacterial environmental adaptation and pathogenicity. However, the biological functions and regulatory mechanisms of the pathway in V. fluvialis remain unclear. In this study, we demonstrate that L-arginine upregulates the expression of the ADI gene cluster and promotes the growth of V. fluvialis. The ADI gene cluster, which we proved to be comprised of two operons, arcD and arcACB, significantly enhances the survival of V. fluvialis in acidic environments both in vitro (in culture medium and in macrophage) and in vivo (in mice). The mRNA level and reporter gene fusion analyses revealed that ArgR, a transcriptional factor, is necessary for the activation of both arcD and arcACB transcriptions. Bioinformatic analysis predicted the existence of multiple potential ArgR binding sites at the arcD and arcACB promoter regions that were further confirmed by electrophoretic mobility shift assay, DNase I footprinting, or point mutation analyses. Together, our study provides insights into the important role of the ArgR-ADI pathway in the survival of V. fluvialis under acidic conditions and the detailed molecular mechanism. These findings will deepen our understanding of how environmental changes and gene expression interact to facilitate bacterial adaptations and virulence.
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Affiliation(s)
| | | | | | | | | | | | - Biao Kan
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Weili Liang
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
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3
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Lillie IM, Booth CE, Horvath AE, Mondragon M, Engevik MA, Horvath TD. Characterizing arginine, ornithine, and putrescine pathways in enteric pathobionts. Microbiologyopen 2024; 13:e1408. [PMID: 38560776 PMCID: PMC10982811 DOI: 10.1002/mbo3.1408] [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: 10/14/2023] [Revised: 03/10/2024] [Accepted: 03/16/2024] [Indexed: 04/04/2024] Open
Abstract
Arginine-ornithine metabolism plays a crucial role in bacterial homeostasis, as evidenced by numerous studies. However, the utilization of arginine and the downstream products of its metabolism remain undefined in various gut bacteria. To bridge this knowledge gap, we employed genomic screening to pinpoint relevant metabolic targets. We also devised a targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) metabolomics method to measure the levels of arginine, its upstream precursors, and downstream products in cell-free conditioned media from enteric pathobionts, including Escherichia coli, Klebsiella aerogenes, K. pneumoniae, Pseudomonas fluorescens, Acinetobacter baumannii, Streptococcus agalactiae, Staphylococcus epidermidis, S. aureus, and Enterococcus faecalis. Our findings revealed that all selected bacterial strains consumed glutamine, glutamate, and arginine, and produced citrulline, ornithine, and GABA in our chemically defined medium. Additionally, E. coli, K. pneumoniae, K. aerogenes, and P. fluorescens were found to convert arginine to agmatine and produce putrescine. Interestingly, arginine supplementation promoted biofilm formation in K. pneumoniae, while ornithine supplementation enhanced biofilm formation in S. epidermidis. These findings offer a comprehensive insight into arginine-ornithine metabolism in enteric pathobionts.
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Affiliation(s)
- Ian M. Lillie
- Department of Materials Science & EngineeringCornell UniversityIthacaNew YorkUSA
- Department of Pathology & ImmunologyBaylor College of MedicineHoustonTexasUSA
- Department of PathologyTexas Children's HospitalHoustonTexasUSA
| | - Charles E. Booth
- Department of Regenerative Medicine & Cell BiologyMedical University of South CarolinaCharlestonSouth CarolinaUSA
| | - Adelaide E. Horvath
- Department of Regenerative Medicine & Cell BiologyMedical University of South CarolinaCharlestonSouth CarolinaUSA
- Department of Biology & BiochemistryUniversity of HoustonHoustonTexasUSA
- Department of MathematicsUniversity of HoustonHoustonTexasUSA
| | - Matthew Mondragon
- Department of Regenerative Medicine & Cell BiologyMedical University of South CarolinaCharlestonSouth CarolinaUSA
| | - Melinda A. Engevik
- Department of Regenerative Medicine & Cell BiologyMedical University of South CarolinaCharlestonSouth CarolinaUSA
- Department of Microbiology & ImmunologyMedical University of South CarolinaCharlestonSouth CarolinaUSA
| | - Thomas D. Horvath
- Department of Pathology & ImmunologyBaylor College of MedicineHoustonTexasUSA
- Department of PathologyTexas Children's HospitalHoustonTexasUSA
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4
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Happonen L, Collin M. Immunomodulating Enzymes from Streptococcus pyogenes-In Pathogenesis, as Biotechnological Tools, and as Biological Drugs. Microorganisms 2024; 12:200. [PMID: 38258026 PMCID: PMC10818452 DOI: 10.3390/microorganisms12010200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/12/2024] [Accepted: 01/16/2024] [Indexed: 01/24/2024] Open
Abstract
Streptococcus pyogenes, or Group A Streptococcus, is an exclusively human pathogen that causes a wide variety of diseases ranging from mild throat and skin infections to severe invasive disease. The pathogenesis of S. pyogenes infection has been extensively studied, but the pathophysiology, especially of the more severe infections, is still somewhat elusive. One key feature of S. pyogenes is the expression of secreted, surface-associated, and intracellular enzymes that directly or indirectly affect both the innate and adaptive host immune systems. Undoubtedly, S. pyogenes is one of the major bacterial sources for immunomodulating enzymes. Major targets for these enzymes are immunoglobulins that are destroyed or modified through proteolysis or glycan hydrolysis. Furthermore, several enzymes degrade components of the complement system and a group of DNAses degrade host DNA in neutrophil extracellular traps. Additional types of enzymes interfere with cellular inflammatory and innate immunity responses. In this review, we attempt to give a broad overview of the functions of these enzymes and their roles in pathogenesis. For those enzymes where experimentally determined structures exist, the structural aspects of the enzymatic activity are further discussed. Lastly, we also discuss the emerging use of some of the enzymes as biotechnological tools as well as biological drugs and vaccines.
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Affiliation(s)
- Lotta Happonen
- Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund University, SE-22184 Lund, Sweden
| | - Mattias Collin
- Faculty of Medicine, Department of Clinical Sciences, Division of Infection Medicine, Lund University, SE-22184 Lund, Sweden
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5
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Boukthir S, Gaudu P, Faili A, Kayal S. pBFK, a new thermosensitive shuttle vector for Streptococcus pyogenes gene deletion by homologous recombination. Heliyon 2023; 9:e16720. [PMID: 37346331 PMCID: PMC10279790 DOI: 10.1016/j.heliyon.2023.e16720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 05/23/2023] [Accepted: 05/25/2023] [Indexed: 06/23/2023] Open
Abstract
Streptococcus pyogenes, or Group A Streptococcus (GAS), is a major human pathogen for which genetic manipulation remains an ongoing challenge. We created a new temperature-sensitive plasmid pBFK expressing spectinomycin resistance adapted to homologous recombination procedure to perform a complete gene deletion in GAS. Herein the mutagenesis strategy with pBFK was performed in a highly virulent GAS emm3 genotype.
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Affiliation(s)
- S. Boukthir
- CHU de Rennes, Service de Bactériologie-Hygiène Hospitalière, Rennes, France
- Inserm, CIC 1414, Rennes, France
| | - P. Gaudu
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - A. Faili
- Inserm, CIC 1414, Rennes, France
- OSS- Oncogenesis, Stress, Signaling, INSERM 1242, Rennes, France
- Université de Rennes, Faculté de Pharmacie, Rennes, France
| | - S. Kayal
- CHU de Rennes, Service de Bactériologie-Hygiène Hospitalière, Rennes, France
- Inserm, CIC 1414, Rennes, France
- OSS- Oncogenesis, Stress, Signaling, INSERM 1242, Rennes, France
- Université de Rennes, Faculté de Médecine, Rennes, France
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6
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Pokrovsky VS, Abo Qoura L, Morozova E, Bunik VI. Predictive markers for efficiency of the amino-acid deprivation therapies in cancer. Front Med (Lausanne) 2022; 9:1035356. [PMID: 36405587 PMCID: PMC9669297 DOI: 10.3389/fmed.2022.1035356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 10/18/2022] [Indexed: 11/06/2022] Open
Abstract
Amino acid deprivation therapy (AADT) is a promising strategy for developing novel anticancer treatments, based on variations in metabolism of healthy and malignant cells. L-asparaginase was the first amino acid-degrading enzyme that received FDA approval for the treatment of acute lymphoblastic leukemia (ALL). Arginase and arginine deiminase were effective in clinical trials for the treatment of metastatic melanomas and hepatocellular carcinomas. Essential dependence of certain cancer cells on methionine explains the anticancer efficacy of methionine-g-lyase. Along with significant progress in identification of metabolic vulnerabilities of cancer cells, new amino acid-cleaving enzymes appear as promising agents for cancer treatment: lysine oxidase, tyrosine phenol-lyase, cysteinase, and phenylalanine ammonia-lyase. However, sensitivity of specific cancer cell types to these enzymes differs. Hence, search for prognostic and predictive markers for AADT and introduction of the markers into clinical practice are of great importance for translational medicine. As specific metabolic pathways in cancer cells are determined by the enzyme expression, some of these enzymes may define the sensitivity to AADT. This review considers the known predictors for efficiency of AADT, emphasizing the importance of knowledge on cancer-specific amino acid significance for such predictions.
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Affiliation(s)
- Vadim S. Pokrovsky
- Laboratory of Experimental Oncology, Research Institute of Molecular and Cellular Medicine, People’s Friendship University of Russia (RUDN University), Moscow, Russia
- Laboratory of Combined Treatment, N.N. Blokhin National Medical Research Center of Oncology of Ministry of Health of Russian Federation, Moscow, Russia
- Department of Biotechnology, Sirius University of Science and Technology, Sochi, Russia
- *Correspondence: Vadim S. Pokrovsky,
| | - Louay Abo Qoura
- Laboratory of Experimental Oncology, Research Institute of Molecular and Cellular Medicine, People’s Friendship University of Russia (RUDN University), Moscow, Russia
| | - Elena Morozova
- Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, Moscow, Russia
| | - Victoria I. Bunik
- A.N. Belozersky Institute of Physicochemical Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, M.V. Lomonosov Moscow State University, Moscow, Russia
- Department of Biological Chemistry, Sechenov First Moscow State Medical University, Moscow, Russia
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7
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Chang JC, Wilkening RV, Rahbari KM, Federle MJ. Quorum Sensing Regulation of a Major Facilitator Superfamily Transporter Affects Multiple Streptococcal Virulence Factors. J Bacteriol 2022; 204:e0017622. [PMID: 35938850 PMCID: PMC9487453 DOI: 10.1128/jb.00176-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 07/19/2022] [Indexed: 01/04/2023] Open
Abstract
Cell-cell signaling mediated by Rgg-family transcription factors and their cognate pheromones is conserved in Firmicutes, including all streptococci. In Streptococcus pyogenes, or group A strep (GAS), one of these systems, the Rgg2/3 quorum sensing (QS) system, has been shown to regulate phenotypes, including cellular aggregation and biofilm formation, lysozyme resistance, and macrophage immunosuppression. Here, we show the abundance of several secreted virulence factors (streptolysin O, SpyCEP, and M protein) decreases upon induction of QS. The main mechanism underlying the changes in protein levels appears to be transcriptional, occurs downstream of the QS circuit, and is dysregulated by the deletion of an Rgg2/3 QS-regulated major facilitator superfamily (MFS) transporter. Additionally, we identify this MFS transporter as the factor responsible for a previously observed increase in aminoglycoside sensitivity in QS-induced cells. IMPORTANCE The production of virulence factors is a tightly regulated process in bacterial pathogens. Efforts to elucidate the mechanisms by which genes are regulated may advance the understanding of factors influencing pathogen behavior or cellular physiology. This work finds expression of a major facilitator superfamily (MFS) transporter, which is governed by a quorum sensing (QS) system, impacts the expression of multiple virulence factors and accounts for QS-dependent antibiotic susceptibility. Although the mechanism underlying this effect is not clear, MFS orthologs with high sequence similarity from S. pneumoniae and S. porcinus were unable to substitute indicating substrate specificity of the GAS MFS gene. These findings demonstrate novel associations between expression of a transmembrane transporter and virulence factor expression and aminoglycoside transport.
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Affiliation(s)
- Jennifer C. Chang
- Department of Pharmaceutical Sciences, University of Illinois Chicago, Chicago, Illinois, USA
| | - Reid V. Wilkening
- Department of Microbiology and Immunology, University of Illinois Chicago, Chicago, Illinois, USA
| | - Kate M. Rahbari
- Department of Microbiology and Immunology, University of Illinois Chicago, Chicago, Illinois, USA
| | - Michael J. Federle
- Department of Pharmaceutical Sciences, University of Illinois Chicago, Chicago, Illinois, USA
- Department of Microbiology and Immunology, University of Illinois Chicago, Chicago, Illinois, USA
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8
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Ghazisaeedi F, Meens J, Hansche B, Maurischat S, Schwerk P, Goethe R, Wieler LH, Fulde M, Tedin K. A virulence factor as a therapeutic: the probiotic Enterococcus faecium SF68 arginine deiminase inhibits innate immune signaling pathways. Gut Microbes 2022; 14:2106105. [PMID: 35921516 PMCID: PMC9351580 DOI: 10.1080/19490976.2022.2106105] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The probiotic bacterial strain Enterococcus faecium SF68 has been shown to alleviate symptoms of intestinal inflammation in human clinical trials and animal feed supplementation studies. To identify factors involved in immunomodulatory effects on host cells, E. faecium SF68 and other commensal and clinical Enterococcus isolates were screened using intestinal epithelial cell lines harboring reporter fusions for NF-κB and JNK(AP-1) activation to determine the responses of host cell innate immune signaling pathways when challenged with bacterial protein and cell components. Cell-free, whole-cell lysates of E. faecium SF68 showed a reversible, inhibitory effect on both NF-κB and JNK(AP-1) signaling pathway activation in intestinal epithelial cells and abrogated the response to bacterial and other Toll-like receptor (TLR) ligands. The inhibitory effect was species-specific, and was not observed for E. avium, E. gallinarum, or E. casseliflavus. Screening of protein fractions of E. faecium SF68 lysates yielded an active fraction containing a prominent protein identified as arginine deiminase (ADI). The E. faecium SF68 arcA gene encoding arginine deiminase was cloned and introduced into E. avium where it conferred the same NF-κB inhibitory effects on intestinal epithelial cells as seen for E. faecium SF68. Our results indicate that the arginine deiminase of E. faecium SF68 is responsible for inhibition of host cell NF-κB and JNK(AP-1) pathway activation, and is likely to be responsible for the anti-inflammatory and immunomodulatory effects observed in prior clinical human and animal trials. The implications for the use of this probiotic strain for preventive and therapeutic purposes are discussed.
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Affiliation(s)
- Fereshteh Ghazisaeedi
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany
| | - Jochen Meens
- Institute for Microbiology, University of Veterinary Medicine, Hannover, Germany
| | - Bianca Hansche
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany,Sanofi-AventisGmbH, Berlin, Germany
| | - Sven Maurischat
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany,German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Peter Schwerk
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany
| | - Ralph Goethe
- Institute for Microbiology, University of Veterinary Medicine, Hannover, Germany
| | - Lothar H. Wieler
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany,Robert Koch Institute, Berlin, Germany
| | - Marcus Fulde
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany
| | - Karsten Tedin
- Department of Veterinary Medicine, Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Berlin, Germany,CONTACT Karsten Tedin Institute of Microbiology and Epizootics, Centre for Infection Medicine, Free University of Berlin, Robert-von-Ostertag-Strasse7, Berlin14163Germany
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9
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Kumari N, Bansal S. Arginine depriving enzymes: applications as emerging therapeutics in cancer treatment. Cancer Chemother Pharmacol 2021; 88:565-594. [PMID: 34309734 DOI: 10.1007/s00280-021-04335-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 07/16/2021] [Indexed: 12/12/2022]
Abstract
Cancer is the second leading cause of death globally. Chemotherapy and radiation therapy and other medications are employed to treat various types of cancer. However, each treatment has its own set of side effects, owing to its low specificity. As a result, there is an urgent need for newer therapeutics that do not disrupt healthy cells' normal functioning. Depriving nutrient or non/semi-essential amino acids to which cancerous cells are auxotrophic remains one such promising anticancer strategy. L-Arginine (Arg) is a semi-essential vital amino acid involved in versatile metabolic processes, signaling pathways, and cancer cell proliferation. Hence, the administration of Arg depriving enzymes (ADE) such as arginase, arginine decarboxylase (ADC), and arginine deiminase (ADI) could be effective in cancer therapy. The Arg auxotrophic cancerous cells like hepatocellular carcinoma, human colon cancer, leukemia, and breast cancer cells are sensitive to ADE treatment due to low expression of crucial enzymes argininosuccinate synthetase (ASS), argininosuccinate lyase (ASL), and ornithine transcarbamylase (OCT). These therapeutic enzyme treatments induce cell death through inducing autophagy, apoptosis, generation of oxidative species, i.e., oxidative stress, and arresting the progression and expansion of cancerous cells at certain cell cycle checkpoints. The enzymes are undergoing clinical trials and could be successfully exploited as potential anticancer agents in the future.
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Affiliation(s)
- Neha Kumari
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology Waknaghat, Solan, 173234, Himachal Pradesh, India
| | - Saurabh Bansal
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology Waknaghat, Solan, 173234, Himachal Pradesh, India.
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10
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Sun J, Hang Y, Han Y, Zhang X, Gan L, Cai C, Chen Z, Yang Y, Song Q, Shao C, Yang Y, Zhou Y, Wang X, Cheng C, Song H. Deletion of glutaredoxin promotes oxidative tolerance and intracellular infection in Listeria monocytogenes. Virulence 2020; 10:910-924. [PMID: 31680614 PMCID: PMC6844310 DOI: 10.1080/21505594.2019.1685640] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Thiol-disulfide glutaredoxin systems of bacterial cytoplasm favor reducing conditions for the correct disulfide bonding of functional proteins, and therefore were employed by bacteria to defend against oxidative stress. Listeria monocytogenes has been shown to encode a putative glutaredoxin, Grx (encoded by lmo2344), while the underlying roles remain unknown. Here we suggest an unexpected role of L. monocytogenes Grx in oxidative tolerance and intracellular infection. The recombinant Grx was able to efficiently catalyze the thiol-disulfide oxidoreduction of insulin in the presence of DTT as an election donor. Unexpectedly, the deletion of grx resulted in a remarkably increased tolerance and survival ability of this bacteria when exposed to various oxidizing agents, including diamide, and copper and cadmium ions. Furthermore, loss of grx significantly promoted bacterial invasion and proliferation in human epithelial Caco-2 cells and murine macrophages, as well as a notably increasing invasion but not cell-to-cell spread in the murine fibroblasts L929 cells. More importantly, L. monocytogenes lacking the glutaredoxin exhibited more efficient proliferation and recovery in the spleens and livers of the infected mice, and hence became more virulent by upregulating the virulence factors, InlA and InlB. In summary, we here for the first time demonstrated that L. monocytogenes glutaredoxin plays a counterintuitive role in bacterial oxidative resistance and intracellular infection, which is the first report to provide valuable evidence for the role of glutaredoxins in bacterial infection, and more importantly suggests a favorable model to illustrate the functional diversity of bacterial Grx systems during environmental adaption and host infection.
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Affiliation(s)
- Jing Sun
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
| | - Yi Hang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
| | - Yue Han
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
| | - Xian Zhang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
| | - Li Gan
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
| | - Chang Cai
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China.,School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
| | - Zhongwei Chen
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
| | - Yang Yang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
| | - Quanjiang Song
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
| | - Chunyan Shao
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
| | - Yongchun Yang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
| | - Yingshan Zhou
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
| | - Xiaodu Wang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
| | - Changyong Cheng
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
| | - Houhui Song
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P. R. China
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11
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Freiberg JA, Le Breton Y, Harro JM, Allison DL, McIver KS, Shirtliff ME. The Arginine Deiminase Pathway Impacts Antibiotic Tolerance during Biofilm-Mediated Streptococcus pyogenes Infections. mBio 2020; 11:e00919-20. [PMID: 32636245 PMCID: PMC7343988 DOI: 10.1128/mbio.00919-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/09/2020] [Indexed: 02/06/2023] Open
Abstract
Bacterial biofilms are responsible for a variety of serious human infections and are notoriously difficult to treat due to their recalcitrance to antibiotics. Further work is necessary to elicit a full understanding of the mechanism of this antibiotic tolerance. The arginine deiminase (ADI) pathway is responsible for bacterial pH maintenance and is highly expressed during biofilm growth in multiple bacterial species. Using the group A Streptococcus (GAS) as a model human pathogen, the ADI pathway was demonstrated to contribute to biofilm growth. The inability of antibiotics to reduce GAS populations when in a biofilm was demonstrated by in vitro studies and a novel animal model of nasopharyngeal infection. However, disruption of the ADI pathway returned GAS biofilms to planktonic levels of antibiotic sensitivity, suggesting the ADI pathway is influential in biofilm-related antibiotic treatment failure and provides a new strategic target for the treatment of biofilm infections in GAS and potentially numerous other bacterial species.IMPORTANCE Biofilm-mediated bacterial infections are a major threat to human health because of their recalcitrance to antibiotic treatment. Through the study of Streptococcus pyogenes, a significant human pathogen that is known to form antibiotic-tolerant biofilms, we demonstrated the role that a bacterial pathway known for responding to acid stress plays in biofilm growth and antibiotic tolerance. This not only provides some insight into antibiotic treatment failure in S. pyogenes infections but also, given the widespread nature of this pathway, provides a potentially broad target for antibiofilm therapies. This discovery has the potential to impact the treatment of many different types of recalcitrant biofilm infections.
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Affiliation(s)
- Jeffrey A Freiberg
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland, USA
| | - Yoann Le Breton
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, USA
| | - Janette M Harro
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland, USA
| | - Devon L Allison
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland, USA
| | - Kevin S McIver
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, USA
| | - Mark E Shirtliff
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, Baltimore, Maryland, USA
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12
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Wu K, Conly J, McClure JA, Kurwa HA, Zhang K. Arginine Catabolic Mobile Element in Evolution and Pathogenicity of the Community-Associated Methicillin-Resistant Staphylococcus aureus Strain USA300. Microorganisms 2020; 8:microorganisms8020275. [PMID: 32085445 PMCID: PMC7074830 DOI: 10.3390/microorganisms8020275] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 02/14/2020] [Indexed: 01/11/2023] Open
Abstract
USA300 is a predominant community-associated methicillin-resistant Staphylococcus aureus strain which carries an arginine catabolic mobile element (ACME). ACME contains potential virulence factors including an arginine deiminase (arc) pathway and an oligopeptide permease (opp-3) system, which are proposed to play a role in bacterial virulence and transmission. However, the role of ACME in evolution and pathogenicity of USA300 remains to be elucidated. ACME and arcA deletion mutants were created by allelic replacement from a USA300 clinical isolate. By comparing wild type and isogenic ACME deletion USA300 strains, ACME was shown not to contribute to bacterial survival on plastic surfaces, and mouse skin surfaces. ACME did not contribute to bacterial virulence in cell invasion and cytotoxicity assays, invertebrate killing assays and a mouse skin infection model. Wild-type ACME negative USA300 clinical isolates showed similar associations with invasive anatomic sites as ACME positive isolates. Our experiments also demonstrated that ACME can spontaneously excise from the bacterial chromosome to generate an ACME deletion strain at a low frequency. Our results do not support that the ACME element alone is a significant factor in the transmission and virulence of USA300 strain, and ACME may have been coincidently incorporated into the genome of USA300.
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Affiliation(s)
- Kaiyu Wu
- Department of Pathology & Laboratory Medicine, University of Calgary, Calgary, AL T2N 4N1, Canada; (K.W.); (J.C.)
| | - John Conly
- Department of Pathology & Laboratory Medicine, University of Calgary, Calgary, AL T2N 4N1, Canada; (K.W.); (J.C.)
- Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, AL T2N 4N1, Canada
- Department of Medicine, University of Calgary, Calgary, AL T2N 4N1, Canada;
- The Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AL T2N 4N1, Canada
- Centre for Antimicrobial Resistance, Alberta Health Services/Alberta Public Laboratories/University of Calgary, Calgary, AL T2N 4N1, Canada;
| | - Jo-Ann McClure
- Centre for Antimicrobial Resistance, Alberta Health Services/Alberta Public Laboratories/University of Calgary, Calgary, AL T2N 4N1, Canada;
| | - Habib A. Kurwa
- Department of Medicine, University of Calgary, Calgary, AL T2N 4N1, Canada;
| | - Kunyan Zhang
- Department of Pathology & Laboratory Medicine, University of Calgary, Calgary, AL T2N 4N1, Canada; (K.W.); (J.C.)
- Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, AL T2N 4N1, Canada
- Department of Medicine, University of Calgary, Calgary, AL T2N 4N1, Canada;
- The Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AL T2N 4N1, Canada
- Centre for Antimicrobial Resistance, Alberta Health Services/Alberta Public Laboratories/University of Calgary, Calgary, AL T2N 4N1, Canada;
- Correspondence: ; Tel.: +1-403-210-8484
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13
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Billard-Pomares T, Clermont O, Castellanos M, Magdoud F, Royer G, Condamine B, Fouteau S, Barbe V, Roche D, Cruveiller S, Médigue C, Pognard D, Glodt J, Dion S, Rigal O, Picard B, Denamur E, Branger C. The Arginine Deiminase Operon Is Responsible for a Fitness Trade-Off in Extended-Spectrum-β-Lactamase-Producing Strains of Escherichia coli. Antimicrob Agents Chemother 2019; 63:e00635-19. [PMID: 31138573 PMCID: PMC6658758 DOI: 10.1128/aac.00635-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 05/20/2019] [Indexed: 02/06/2023] Open
Abstract
We previously identified an operon involved in an arginine deiminase (ADI) pathway (arc operon) on a CTX-M-producing plasmid from an O102-ST405 strain of Escherichia coli As the ADI pathway was shown to be involved in the virulence of various Gram-positive bacteria, we tested whether the ADI pathway could be involved in the epidemiological success of extended-spectrum-β-lactamase (ESBL)-producing E. coli strains. We studied two collections of human E. coli isolated in France (n = 493) and England (n = 1,509) and show that the prevalence of the arc operon (i) is higher in ESBL-producing strains (12.1%) than in nonproducers (2.5%), (ii) is higher in CTX-M-producing strains (16%) than in other ESBL producers (3.5%), and (iii) increased over time in ESBL-producing strains from 0% before 2000 to 43.3% in 2011 to 2012. The arc operon, found in strains from various phylogenetic backgrounds, is carried by IncF plasmids (85%) or chromosomes (15%) in regions framed by numerous insertion sequences, indicating multiple arrivals. Competition experiments showed that the arc operon enhances fitness of the strain in vitro in lysogeny broth with arginine. In vivo competition experiments showed that the arc operon is advantageous for the strain in a mouse model of urinary tract infection (UTI), whereas it is a burden in a mouse model of intestinal colonization. In summary, we have identified a trait linked to CTX-M-producing strains that is responsible for a trade-off between two main E. coli lifestyles, UTI and gut commensalism. This trait alone cannot explain the wide spread of ESBLs in E. coli but merits epidemiological surveillance.
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Affiliation(s)
- Typhaine Billard-Pomares
- IAME, UMR 1137, INSERM, Université Paris Diderot, Université Paris 13, Sorbonne Paris Cité, Paris, France
- APHP, Hôpital Avicenne, Service de Microbiologie clinique, Bobigny, France
| | - Olivier Clermont
- IAME, UMR 1137, INSERM, Université Paris Diderot, Université Paris 13, Sorbonne Paris Cité, Paris, France
| | - Miguel Castellanos
- IAME, UMR 1137, INSERM, Université Paris Diderot, Université Paris 13, Sorbonne Paris Cité, Paris, France
| | - Fatma Magdoud
- APHP, Hôpital Avicenne, Service de Microbiologie clinique, Bobigny, France
| | - Guilhem Royer
- IAME, UMR 1137, INSERM, Université Paris Diderot, Université Paris 13, Sorbonne Paris Cité, Paris, France
- UMR 8030, CNRS, Institut de Génomique-Genoscope, Laboratoire d'Analyses Bioinformatiques pour la Génomique et le Métabolisme, Université Évry-Val-d'Essonne, CEA, Évry, France
| | - Bénédicte Condamine
- IAME, UMR 1137, INSERM, Université Paris Diderot, Université Paris 13, Sorbonne Paris Cité, Paris, France
| | - Stéphanie Fouteau
- Génomique Métabolique, Genoscope, Institut de biologie François Jacob, CEA, CNRS, Université Evry, Université Paris-Saclay, Evry, France
| | - Valérie Barbe
- Génomique Métabolique, Genoscope, Institut de biologie François Jacob, CEA, CNRS, Université Evry, Université Paris-Saclay, Evry, France
| | - David Roche
- UMR 8030, CNRS, Institut de Génomique-Genoscope, Laboratoire d'Analyses Bioinformatiques pour la Génomique et le Métabolisme, Université Évry-Val-d'Essonne, CEA, Évry, France
| | - Stéphane Cruveiller
- UMR 8030, CNRS, Institut de Génomique-Genoscope, Laboratoire d'Analyses Bioinformatiques pour la Génomique et le Métabolisme, Université Évry-Val-d'Essonne, CEA, Évry, France
| | - Claudine Médigue
- Génomique Métabolique, Genoscope, Institut de biologie François Jacob, CEA, CNRS, Université Evry, Université Paris-Saclay, Evry, France
| | - Dominique Pognard
- APHP, Hôpital Louis Mourier, Service de Microbiologie, Colombes, France
| | - Jeremy Glodt
- IAME, UMR 1137, INSERM, Université Paris Diderot, Université Paris 13, Sorbonne Paris Cité, Paris, France
- APHP, Hôpital Louis Mourier, Service de Microbiologie, Colombes, France
| | - Sara Dion
- IAME, UMR 1137, INSERM, Université Paris Diderot, Université Paris 13, Sorbonne Paris Cité, Paris, France
| | - Odile Rigal
- Service de Biochimie-Hormonologie, Hôpital Robert Debré, Paris, France
| | - Bertrand Picard
- IAME, UMR 1137, INSERM, Université Paris Diderot, Université Paris 13, Sorbonne Paris Cité, Paris, France
- APHP, Hôpital Avicenne, Service de Microbiologie clinique, Bobigny, France
| | - Erick Denamur
- IAME, UMR 1137, INSERM, Université Paris Diderot, Université Paris 13, Sorbonne Paris Cité, Paris, France
- APHP, Laboratoire de Génétique Moléculaire, Hôpital Bichat, Paris, France
| | - Catherine Branger
- IAME, UMR 1137, INSERM, Université Paris Diderot, Université Paris 13, Sorbonne Paris Cité, Paris, France
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14
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Transcriptomic Analysis of Streptococcus pyogenes Colonizing the Vaginal Mucosa Identifies hupY, an MtsR-Regulated Adhesin Involved in Heme Utilization. mBio 2019; 10:mBio.00848-19. [PMID: 31239377 PMCID: PMC6593403 DOI: 10.1128/mbio.00848-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Colonization of the host requires the ability to adapt to an environment that is often low in essential nutrients such as iron. Here we present data showing that the transcriptome of the important human pathogen Streptococcus pyogenes shows extensive remodeling during in vivo growth, resulting in, among many other differentially expressed genes and pathways, a significant increase in genes involved in acquiring iron from host heme. Data show that HupY, previously characterized as an adhesin in both S. pyogenes and the related pathogen Streptococcus agalactiae, binds heme and affects intracellular iron concentrations. HupY, a protein with no known heme binding domains, represents a novel heme binding protein playing an important role in bacterial iron homeostasis as well as vaginal colonization. Streptococcus pyogenes (group A streptococcus [GAS]) is a serious human pathogen with the ability to colonize mucosal surfaces such as the nasopharynx and vaginal tract, often leading to infections such as pharyngitis and vulvovaginitis. We present genome-wide transcriptome sequencing (RNASeq) data showing the transcriptomic changes GAS undergoes during vaginal colonization. These data reveal that the regulon controlled by MtsR, a master metal regulator, is activated during vaginal colonization. This regulon includes two genes highly expressed during vaginal colonization, hupYZ. Here we show that HupY binds heme in vitro, affects intracellular concentrations of iron, and is essential for proper growth of GAS using hemoglobin or serum as the sole iron source. HupY is also important for murine vaginal colonization of both GAS and the related vaginal colonizer and pathogen Streptococcus agalactiae (group B streptococcus [GBS]). These data provide essential information on the link between metal regulation and mucosal colonization in both GAS and GBS.
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15
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Gao T, Yuan F, Liu Z, Liu W, Zhou D, Yang K, Duan Z, Guo R, Liang W, Hu Q, Tian Y, Zhou R. MnmE, a Central tRNA-Modifying GTPase, Is Essential for the Growth, Pathogenicity, and Arginine Metabolism of Streptococcus suis Serotype 2. Front Cell Infect Microbiol 2019; 9:173. [PMID: 31179247 PMCID: PMC6543552 DOI: 10.3389/fcimb.2019.00173] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 05/08/2019] [Indexed: 12/11/2022] Open
Abstract
Streptococcus suis is an important pathogen in pigs and can also cause severe infections in humans. However, little is known about proteins associated with cell growth and pathogenicity of S. suis. In this study, a guanosine triphosphatase (GTPase) MnmE homolog was identified in a Chinese isolate (SC19) that drives a tRNA modification reaction. A mnmE deletion strain (ΔmnmE) and a complementation strain (CΔmnmE) were constructed to systematically decode the characteristics and functions of MnmE both in vitro and in vivo studies via proteomic analysis. Phenotypic analysis revealed that the ΔmnmE strain displayed deficient growth, attenuated pathogenicity, and perturbation of the arginine metabolic pathway mediated by the arginine deiminase system (ADS). Consistently, tandem mass tag -based quantitative proteomics analysis confirmed that 365 proteins were differentially expressed (174 up- and 191 down-regulated) between strains ΔmnmE and SC19. Many proteins associated with DNA replication, cell division, and virulence were down-regulated. Particularly, the core enzymes of the ADS were significantly down-regulated in strain ΔmnmE. These data also provide putative molecular mechanisms for MnmE in cell growth and survival in an acidic environment. Therefore, we propose that MnmE, by its function as a central tRNA-modifying GTPase, is essential for cell growth, pathogenicity, as well as arginine metabolism of S. suis.
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Affiliation(s)
- Ting Gao
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Fangyan Yuan
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Zewen Liu
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Wei Liu
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Danna Zhou
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Keli Yang
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Zhengying Duan
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Rui Guo
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Wan Liang
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Qiao Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Cooperative Innovation Center of Sustainable Pig Production, Wuhan, China
| | - Yongxiang Tian
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Rui Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Cooperative Innovation Center of Sustainable Pig Production, Wuhan, China
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16
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Freydlin IS, Starikova EA, Lebedeva AM. Overcoming the protective functions of macrophages by Streptococcus pyogenes virulence factors. BULLETIN OF SIBERIAN MEDICINE 2019. [DOI: 10.20538/1682-0363-2019-1-109-118] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The review is devoted to the analysis of molecular mechanisms of action ofS. pyogenesvirulence factors aimed at overcoming the protective functions of macrophages. The review describes in detail the main protective functions of macrophages and the mechanisms of their implementation in the course of streptococcal infection. The virulence factors ofS. pyogenes,which prevent the recruitment of macrophages to the site of infection, are examined. Particular attention is paid to the analysis of molecular effects that suppress the pathogen by the process of phagocytosis, intracellular bactericidal activity and the production of cytokines by macrophages. The analysis of molecular genetic mechanisms of regulation of the expression ofS. pyogenesvirulence factors that provide adaptation of the pathogen to changing conditions in the site of inflammation is carried out.
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Affiliation(s)
- I. S. Freydlin
- Institute of Experimental Medicine; Pavlov First Saint Petersburg State Medical University
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17
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Starikova EA, Golovin AS, Vasilyev KA, Karaseva AB, Serebriakova MK, Sokolov AV, Kudryavtsev IV, Burova LA, Voynova IV, Suvorov AN, Vasilyev VB, Freidlin IS. Role of arginine deiminase in thymic atrophy during experimental Streptococcus pyogenes infection. Scand J Immunol 2019; 89:e12734. [PMID: 30471128 DOI: 10.1111/sji.12734] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 11/11/2018] [Accepted: 11/18/2018] [Indexed: 01/08/2023]
Abstract
Expression of gene of arginine deiminase (AD) allows adaptation of Streptococcus pyogenes to adverse environmental conditions. AD activity can lead to L-arginine deficiency in the host cells' microenvironment. Bioavailability of L-arginine is an important factor regulating the functions of the immune cells in mammals. By introducing a mutation into S pyogenes M46-16, we obtained a strain with inactivated arcA/sagp gene (M49-16 delArcA), deficient in AD. This allowed elucidating the function of AD in pathogenesis of streptococcal infection. The virulence of the parental and mutant strains was examined in a murine model of subcutaneous streptococcal infection. L-arginine concentration in the plasma of mice infected with S pyogenes M49-16 delArcA remained unchanged in course of the entire experiment. At the same time mice infected with S pyogenes M49-16 demonstrated gradual diminution of L-arginine concentration in the blood plasma, which might be due to the activity of streptococcal AD. Mice infected with S pyogenes M49-16 delArcA demonstrated less intensive bacterial growth in the primary foci and less pronounced bacterial dissemination as compared with animals infected with the parental strain S pyogenes M46-16. Similarly, thymus involution, alterations in apoptosis, thymocyte subsets and Treg cells differentiation were less pronounced in mice infected with S pyogenes M49-16 delArcA than in those infected with the parental strain. The results obtained showed that S pyogenes M49-16 delArcA, unable to produce AD, had reduced virulence in comparison with the parental S pyogenes M49-16 strain. AD is an important factor for the realization of the pathogenic potential of streptococci.
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Affiliation(s)
| | | | | | - Alena Borisovna Karaseva
- Federal State Budgetary Scientific Institution, Institute of Experimental Medicine, St. Petersburg, Russia
| | | | - Alexey Victorovich Sokolov
- Federal State Budgetary Scientific Institution, Institute of Experimental Medicine, St. Petersburg, Russia.,Saint-Petersburg State University, St. Petersburg, Russia
| | - Igor Vladimirovich Kudryavtsev
- Federal State Budgetary Scientific Institution, Institute of Experimental Medicine, St. Petersburg, Russia.,Far Eastern Federal University Vladivostok, Russia
| | | | - Irina Vitalyevna Voynova
- Federal State Budgetary Scientific Institution, Institute of Experimental Medicine, St. Petersburg, Russia
| | - Alexander Nikolaevich Suvorov
- Federal State Budgetary Scientific Institution, Institute of Experimental Medicine, St. Petersburg, Russia.,Saint-Petersburg State University, St. Petersburg, Russia
| | - Vadim Borisovich Vasilyev
- Federal State Budgetary Scientific Institution, Institute of Experimental Medicine, St. Petersburg, Russia.,Saint-Petersburg State University, St. Petersburg, Russia
| | - Irina Solomonovna Freidlin
- Federal State Budgetary Scientific Institution, Institute of Experimental Medicine, St. Petersburg, Russia.,Saint-Petersburg State University, St. Petersburg, Russia.,Pavlov First Saint-Petersburg State Medical University, St. Petersburg, Russia
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18
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RocA Has Serotype-Specific Gene Regulatory and Pathogenesis Activities in Serotype M28 Group A Streptococcus. Infect Immun 2018; 86:IAI.00467-18. [PMID: 30126898 DOI: 10.1128/iai.00467-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/13/2018] [Indexed: 12/21/2022] Open
Abstract
Serotype M28 group A streptococcus (GAS) is a common cause of infections such as pharyngitis ("strep throat") and necrotizing fasciitis ("flesh-eating" disease). Relatively little is known about the molecular mechanisms underpinning M28 GAS pathogenesis. Whole-genome sequencing studies of M28 GAS strains recovered from patients with invasive infections found an unexpectedly high number of missense (amino acid-changing) and nonsense (protein-truncating) polymorphisms in rocA (regulator of Cov), leading us to hypothesize that altered RocA activity contributes to M28 GAS molecular pathogenesis. To test this hypothesis, an isogenic rocA deletion mutant strain was created. Transcriptome sequencing (RNA-seq) analysis revealed that RocA inactivation significantly alters the level of transcripts for 427 and 323 genes at mid-exponential and early stationary growth phases, respectively, including genes for 41 transcription regulators and 21 virulence factors. In contrast, RocA transcriptomes from other GAS M protein serotypes are much smaller and include fewer transcription regulators. The rocA mutant strain had significantly increased secreted activity of multiple virulence factors and grew to significantly higher colony counts under acid stress in vitro RocA inactivation also significantly increased GAS virulence in a mouse model of necrotizing myositis. Our results demonstrate that RocA is an important regulator of transcription regulators and virulence factors in M28 GAS and raise the possibility that naturally occurring polymorphisms in rocA in some fashion contribute to human invasive infections caused by M28 GAS strains.
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19
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A Quorum Sensing-Regulated Protein Binds Cell Wall Components and Enhances Lysozyme Resistance in Streptococcus pyogenes. J Bacteriol 2018; 200:JB.00701-17. [PMID: 29555699 DOI: 10.1128/jb.00701-17] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 03/10/2018] [Indexed: 12/28/2022] Open
Abstract
The Rgg2/3 quorum sensing (QS) system is conserved among all sequenced isolates of group A Streptococcus (GAS; Streptococcus pyogenes). The molecular architecture of the system consists of a transcriptional activator (Rgg2) and a transcriptional repressor (Rgg3) under the control of autoinducing peptide pheromones (SHP2 and SHP3). Activation of the Rgg2/3 pathway leads to increases in biofilm formation and resistance to the bactericidal effects of the host factor lysozyme. In this work, we show that deletion of a small gene, spy49_0414c, abolished both phenotypes in response to pheromone signaling. The gene encodes a small, positively charged, secreted protein, referred to as StcA. Analysis of recombinant StcA showed that it can directly interact with GAS cell wall preparations containing phosphodiester-linked carbohydrate polymers but not with preparations devoid of them. Immunofluorescence microscopy detected antibody against StcA bound to the surface of paraformaldehyde-fixed wild-type cells. Expression of StcA in bacterial culture induced a shift in the electrostatic potential of the bacterial cell surface, which became more positively charged. These results suggest that StcA promotes phenotypes by way of ionic interactions with the GAS cell wall, most likely with negatively charged cell wall-associated polysaccharides.IMPORTANCE This study focuses on a small protein, StcA, that is expressed and secreted under induction of Rgg2/3 QS, ionically associating with negatively charged domains on the cell surface. These data present a novel mechanism of resistance to the host factor lysozyme by GAS and have implications in the relevance of this circuit in the interaction between the bacterium and the human host that is mediated by the bacterial cell surface.
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20
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A Vaginal Tract Signal Detected by the Group B Streptococcus SaeRS System Elicits Transcriptomic Changes and Enhances Murine Colonization. Infect Immun 2018; 86:IAI.00762-17. [PMID: 29378799 DOI: 10.1128/iai.00762-17] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/19/2018] [Indexed: 01/08/2023] Open
Abstract
Streptococcus agalactiae (group B streptococcus [GBS]) can colonize the human vaginal tract, leading to both superficial and serious infections in adults and neonates. To study bacterial colonization of the reproductive tract in a mammalian system, we employed a murine vaginal carriage model. Using transcriptome sequencing (RNA-Seq), the transcriptome of GBS growing in vivo during vaginal carriage was determined. Over one-quarter of the genes in GBS were found to be differentially regulated during in vivo colonization compared to laboratory cultures. A two-component system (TCS) homologous to the staphylococcal virulence regulator SaeRS was identified as being upregulated in vivo One of the SaeRS targets, pbsP, a proposed GBS vaccine candidate, is shown to be important for colonization of the vaginal tract. A component of vaginal lavage fluid acts as a signal to turn on pbsP expression via SaeRS. These data demonstrate the ability to quantify RNA expression directly from the murine vaginal tract and identify novel genes involved in vaginal colonization by GBS. They also provide more information about the regulation of an important virulence and colonization factor of GBS, pbsP, by the TCS SaeRS.
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21
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Cheng C, Dong Z, Han X, Wang H, Jiang L, Sun J, Yang Y, Ma T, Shao C, Wang X, Chen Z, Fang W, Freitag NE, Huang H, Song H. Thioredoxin A Is Essential for Motility and Contributes to Host Infection of Listeria monocytogenes via Redox Interactions. Front Cell Infect Microbiol 2017; 7:287. [PMID: 28702378 PMCID: PMC5487381 DOI: 10.3389/fcimb.2017.00287] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 06/12/2017] [Indexed: 12/17/2022] Open
Abstract
Microbes employ the thioredoxin system to defend against oxidative stress and ensure correct disulfide bonding to maintain protein function. Listeria monocytogenes has been shown to encode a putative thioredoxin, TrxA, but its biological roles and underlying mechanisms remain unknown. Here, we showed that expression of L. monocytogenes TrxA is significantly induced in bacteria treated with the thiol-specific oxidizing agent, diamide. Deletion of trxA markedly compromised tolerance of the pathogen to diamide, and mainly impaired early stages of infection in human intestinal epithelial Caco-2 cells. In addition, most trxA mutant bacteria were not associated with polymerized actin, and the rare bacteria that were associated with polymerized actin displayed very short tails or clouds during infection. Deletion or constitutive overexpression of TrxA, which was regulated by SigH, severely attenuated the virulence of the pathogen. Transcriptome analysis of L. monocytogenes revealed over 270 genes that were differentially transcribed in the ΔtrxA mutant compared to the wild-type, especially for the virulence-associated genes plcA, mpl, hly, actA, and plcB. Particularly, deletion of TrxA completely reduced LLO expression, and thereby led to a thoroughly impaired hemolytic activity. Expression of these virulence factors are positively regulated by the master regulator PrfA that was found here to use TrxA to maintain its reduced forms for activation. Interestingly, the trxA deletion mutant completely lacked flagella and was non-motile. We further confirmed that this deficiency is attributable to TrxA in maintaining the reduced intracellular monomer status of MogR, the key regulator for flagellar formation, to ensure correct dimerization. In summary, we demonstrated for the first time that L. monocytogenes thioredoxin A as a vital cellular reductase is essential for maintaining a highly reducing environment in the bacterial cytosol, which provides a favorable condition for protein folding and activation, and therefore contributes to bacterial virulence and motility.
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Affiliation(s)
- Changyong Cheng
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Zhimei Dong
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Xiao Han
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Hang Wang
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Li Jiang
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Jing Sun
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Yongchun Yang
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Tiantian Ma
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Chunyan Shao
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Xiaodu Wang
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Zhongwei Chen
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
| | - Weihuan Fang
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China.,Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary MedicineHangzhou, China
| | - Nancy E Freitag
- Department of Microbiology and Immunology, University of Illinois at ChicagoChicago, IL, United States
| | - Huarong Huang
- Institute of Developmental and Regenerative Biology, College of Biological and Environmental Science, Hangzhou Normal UniversityZhejiang, China
| | - Houhui Song
- China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology of Zhejiang A&F UniversityLin'an, China
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Ismail AQT. Does placental MDSC-mediated modulation of arginine levels help protect the foetus from auxotrophic pathogens? J Matern Fetal Neonatal Med 2017; 31:1667-1669. [DOI: 10.1080/14767058.2017.1319935] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Maneerat K, Yongkiettrakul S, Jiemsup S, Tongtawe P, Gottschalk M, Srimanote P. Expression and Characterization of Serotype 2 Streptococcus suis Arginine Deiminase. J Mol Microbiol Biotechnol 2017; 27:133-146. [PMID: 28456803 DOI: 10.1159/000452952] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 10/25/2016] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Arginine deiminase (ArcA) has been speculated to facilitate the intracellular survival of Streptococcus suis under acidic conditions. However, the physical and biological properties and function of SS2-ArcA have not yet been elucidated. METHODS Recombinant SS2-ArcA (rSS2-ArcA) was expressed and purified using Ni-NTA affinity chromatography. Under various pH and temperature conditions, the enzymatic properties of purified rSS2-ArcA and crude native SS2-ArcA were determined. RESULTS The SS2-arcA-deduced amino acid sequence contained a conserved catalytic triad (Cys399-His273-Glu218). The optimum temperature and pH of 47-kDa rSS2-ArcA and crude native SS2-ArcA were 42°C and pH 7.2. The rSS2-ArcA and crude native SS2-ArcA were stable for 3 h at 4 and 25°C, respectively. The pH stability and dependency tests suggested that rSS2-ArcA and crude native SS2-ArcA were functionally active in acidic conditions. The L-arginine substrate binding affinity (Km) values of rSS2-ArcA (specific activity 16.00 U/mg) and crude native SS2-ArcA (specific activity 0.23 U/mg) were 0.058 and 0.157 mM, respectively. rSS2-ArcA exhibited a weak binding affinity with the common ArcA inhibitors L-canavanine and L-NIO. Furthermore, the partial inactivation of SS2-ArcA significantly impaired the viability and growth of SS2 at pH 4.0, 6.0, and 7.5. CONCLUSIONS This study profoundly demonstrated the involvement of ArcA enzymatic activity in S. suis survival under acidic conditions.
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Affiliation(s)
- Krissana Maneerat
- Graduate Program in Biomedical Sciences, Faculty of Allied Health Sciences, Thammasat University, Pathumthani, Thailand
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24
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Techawiwattanaboon T, Chareonsudjai S. A predicted cation transporter protein, BPSS1228, is involved in intracellular behaviour of Burkholderia pseudomallei in a human lung epithelial cell line (A549). FEMS Microbiol Lett 2016; 363:fnw259. [PMID: 28003338 DOI: 10.1093/femsle/fnw259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/10/2016] [Accepted: 11/10/2016] [Indexed: 12/15/2022] Open
Abstract
Burkholderia pseudomallei causes melioidosis, a potentially fatal infectious disease in tropical and subtropical countries worldwide. The intracellular behaviour of this pathogen in host cells has been reported to impact the severity of melioidosis, including the development of septicaemia, a consequence of pneumonia melioidosis. We previously identified a predicted cation transporter protein, BPSS1228, that participates in the transitional stage of this intracellular pathogen. For further analysis, in this study B. pseudomallei bpss1228 mutant and complemented strains were constructed and bacterial infectivity on human lung epithelial cells, A549, investigated in vitro Burkholderia pseudomallei bpss1228 mutant showed impaired bacterial adhesion and invasion into A549 cells compared with wild-type strain, while the deficient phenotypes were restored to wild-type levels by the complemented strain. Additionally, the inactivation of bpss1228 in the mutant strain affected flagella-based swimming on a semi-solid surface and resistance to acid stresses simulating intracellular environments. These observations of BPSS1228 relating to B. pseudomallei infection strategies shed a new light on its association with intracellular B. pseudomallei during the interaction with host cells.
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Affiliation(s)
- Teerasit Techawiwattanaboon
- Department of Microbiology, Faculty of Medicine, Melioidosis Research Center and Biofilm Research Group, Khon Kaen University, Khon Kaen, Thailand
| | - Sorujsiri Chareonsudjai
- Department of Microbiology, Faculty of Medicine, Melioidosis Research Center and Biofilm Research Group, Khon Kaen University, Khon Kaen, Thailand
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25
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Chang JC, Federle MJ. PptAB Exports Rgg Quorum-Sensing Peptides in Streptococcus. PLoS One 2016; 11:e0168461. [PMID: 27992504 PMCID: PMC5167397 DOI: 10.1371/journal.pone.0168461] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 12/01/2016] [Indexed: 11/30/2022] Open
Abstract
A transposon mutagenesis screen designed to identify mutants that were defective in peptide-pheromone signaling of the Rgg2/Rgg3 pathway in Streptococcus pyogenes generated insertions in sixteen loci displaying diminished reporter activity. Fourteen unique transposon insertions were mapped to pptAB, an ABC-type transporter recently described to export sex pheromones of Enterococcus faecalis. Consistent with an idea that PptAB exports signaling peptides, the pheromones known as SHPs (short hydrophobic peptides) were no longer detected in cell-free culture supernatants in a generated deletion mutant of pptAB. PptAB exporters are conserved among the Firmicutes, but their function and substrates remain unclear. Therefore, we tested a pptAB mutant generated in Streptococcus mutans and found that while secretion of heterologously expressed SHP peptides required PptAB, secretion of the S. mutans endogenous pheromone XIP (sigX inducing peptide) was only partially disrupted, indicating that a secondary secretion pathway for XIP exists.
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Affiliation(s)
- Jennifer C. Chang
- Department of Medicinal Chemistry and Pharmacognosy, Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Michael J. Federle
- Department of Medicinal Chemistry and Pharmacognosy, Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
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26
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Zhu J, Zhang T, Su Z, Li L, Wang D, Xiao R, Teng M, Tan M, Zhou R. (p)ppGpp synthetases regulate the pathogenesis of zoonotic Streptococcus suis. Microbiol Res 2016; 191:1-11. [DOI: 10.1016/j.micres.2016.05.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Revised: 05/05/2016] [Accepted: 05/15/2016] [Indexed: 01/03/2023]
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27
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Willenborg J, Goethe R. Metabolic traits of pathogenic streptococci. FEBS Lett 2016; 590:3905-3919. [PMID: 27442496 DOI: 10.1002/1873-3468.12317] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/12/2016] [Accepted: 07/18/2016] [Indexed: 12/13/2022]
Abstract
Invasive and noninvasive diseases caused by facultative pathogenic streptococci depend on their equipment with virulence factors and on their ability to sense and adapt to changing nutrients in different host environments. The knowledge of the principal metabolic mechanisms which allow these bacteria to recognize and utilize nutrients in host habitats is a prerequisite for our understanding of streptococcal pathogenicity and the development of novel control strategies. This review aims to summarize and compare the central carbohydrate metabolic and amino acid biosynthetic pathways of a selected group of streptococcal species, all belonging to the naso-oropharyngeal microbiome in humans and/or animals. We also discuss the urgent need of comprehensive metabolomics approaches for a better understanding of the streptococcal metabolism during host-pathogen interaction.
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Affiliation(s)
- Jörg Willenborg
- Institute for Microbiology, University of Veterinary Medicine Hannover, Germany
| | - Ralph Goethe
- Institute for Microbiology, University of Veterinary Medicine Hannover, Germany
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28
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Gao T, Tan M, Liu W, Zhang C, Zhang T, Zheng L, Zhu J, Li L, Zhou R. GidA, a tRNA Modification Enzyme, Contributes to the Growth, and Virulence of Streptococcus suis Serotype 2. Front Cell Infect Microbiol 2016; 6:44. [PMID: 27148493 PMCID: PMC4835480 DOI: 10.3389/fcimb.2016.00044] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 03/27/2016] [Indexed: 11/16/2022] Open
Abstract
Glucose-inhibited division protein (GidA), is a tRNA modification enzyme functioning together with MnmE in the addition of a carboxymethylaminomethyl group to position 5 of the anticodon wobble uridine of tRNA. Here, we report a GidA homolog from a Chinese isolate SC-19 of the zoonotic Streptococcus suis serotype 2 (SS2). gidA disruption led to a defective growth, increased capsule thickness, and reduced hemolytic activity. Moreover, the gidA deletion mutant (ΔgidA) displayed reduced mortality and bacterial loads in mice, reduced ability of adhesion to and invasion in epithelial cells, and increased sensitivity to phagocytosis. The iTRAQ analysis identified 372 differentially expressed (182 up- and 190 down-regulated) proteins in ΔgidA and SC-19. Numerous DNA replication, cell division, and virulence associated proteins were downregulated, whereas many capsule synthesis enzymes were upregulated by gidA disruption. This is consistent with the phenotypes of the mutant. Thus, GidA is a translational regulator that plays an important role in the growth, cell division, capsule biosynthesis, and virulence of SS2. Our findings provide new insight into the regulatory function of GidA in bacterial pathogens.
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Affiliation(s)
- Ting Gao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China; Veterinary Medicine Laboratory, Institute of Animal Husbandry and Veterinary Science, Hubei Academy of Agricultural ScienceWuhan, China; Wuhan Chopper Biology Co., Ltd.Wuhan, China
| | - Meifang Tan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University Wuhan, China
| | - Wanquan Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University Wuhan, China
| | - Chunyan Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University Wuhan, China
| | - Tengfei Zhang
- Veterinary Medicine Laboratory, Institute of Animal Husbandry and Veterinary Science, Hubei Academy of Agricultural Science Wuhan, China
| | - Linlin Zheng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University Wuhan, China
| | - Jiawen Zhu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University Wuhan, China
| | - Lu Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China; Cooperative Innovation Center of Sustainable Pig ProductionWuhan, China
| | - Rui Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China; Cooperative Innovation Center of Sustainable Pig ProductionWuhan, China
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29
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Xu B, Yang X, Zhang P, Ma Z, Lin H, Fan H. The arginine deiminase system facilitates environmental adaptability of Streptococcus equi ssp. zooepidemicus through pH adjustment. Res Microbiol 2016; 167:403-12. [PMID: 27068185 DOI: 10.1016/j.resmic.2016.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 03/29/2016] [Accepted: 03/29/2016] [Indexed: 10/22/2022]
Abstract
The arginine deiminase system (ADS) is a secondary metabolic system found in many different bacterial pathogens and it is often associated with virulence. Here, a systematic study of ADS functions in Streptococcus equi subsp. zooepidemicus (SEZ) was performed. Transcriptional levels of ADS operon genes were observed to be significantly increased when SEZ was grown under acidic conditions. We constructed arcA and arcD deletion mutants (SEZ ΔarcA and SEZ ΔarcD, respectively) and found that SEZ ΔarcA was unable to metabolize arginine and synthesize ammonia; however, arcD deletion resulted in an initial decrease in arginine consumption and ammonia production, followed by recovery to the levels of wild-type SEZ after 24 h of cultivation. Cell extracts of SEZ ΔarcA showed no arginine deiminase (AD) activity, whereas no difference in AD activity between SEZ ΔarcD and wild-type SEZ was observed. SEZ survival tests demonstrated a significant decrease in survival for SEZ ΔarcA, when compared with wild-type SEZ, under acidic conditions and in epithelial cells. These findings indicate that ADS in SEZ contributes to environmental adaptability via ammonia synthesis to reduce pH stress.
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Affiliation(s)
- Bin Xu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Xinyi Yang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Ping Zhang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhe Ma
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Huixing Lin
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Hongjie Fan
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China.
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30
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Arginine Metabolism in Bacterial Pathogenesis and Cancer Therapy. Int J Mol Sci 2016; 17:363. [PMID: 26978353 PMCID: PMC4813224 DOI: 10.3390/ijms17030363] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 01/29/2016] [Accepted: 03/04/2016] [Indexed: 02/06/2023] Open
Abstract
Antibacterial resistance to infectious diseases is a significant global concern for health care organizations; along with aging populations and increasing cancer rates, it represents a great burden for government healthcare systems. Therefore, the development of therapies against bacterial infection and cancer is an important strategy for healthcare research. Pathogenic bacteria and cancer have developed a broad range of sophisticated strategies to survive or propagate inside a host and cause infection or spread disease. Bacteria can employ their own metabolism pathways to obtain nutrients from the host cells in order to survive. Similarly, cancer cells can dysregulate normal human cell metabolic pathways so that they can grow and spread. One common feature of the adaption and disruption of metabolic pathways observed in bacterial and cancer cell growth is amino acid pathways; these have recently been targeted as a novel approach to manage bacterial infections and cancer therapy. In particular, arginine metabolism has been illustrated to be important not only for bacterial pathogenesis but also for cancer therapy. Therefore, greater insights into arginine metabolism of pathogenic bacteria and cancer cells would provide possible targets for controlling of bacterial infection and cancer treatment. This review will summarize the recent progress on the relationship of arginine metabolism with bacterial pathogenesis and cancer therapy, with a particular focus on arginase and arginine deiminase pathways of arginine catabolism.
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31
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Wilkening RV, Chang JC, Federle MJ. PepO, a CovRS-controlled endopeptidase, disrupts Streptococcus pyogenes quorum sensing. Mol Microbiol 2015; 99:71-87. [PMID: 26418177 DOI: 10.1111/mmi.13216] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2015] [Indexed: 01/09/2023]
Abstract
Group A Streptococcus (GAS, Streptococcus pyogenes) is a human-restricted pathogen with a capacity to both colonize asymptomatically and cause illnesses ranging from pharyngitis to necrotizing fasciitis. An understanding of how and when GAS switches between genetic programs governing these different lifestyles has remained an enduring mystery and likely requires carefully tuned environmental sensors to activate and silence genetic schemes when appropriate. Herein, we describe the relationship between the Control of Virulence (CovRS, CsrRS) two-component system and the Rgg2/3 quorum-sensing pathway. We demonstrate that responses of CovRS to the stress signals Mg(2+) and a fragment of the antimicrobial peptide LL-37 result in modulated activity of pheromone signaling of the Rgg2/3 pathway through a means of proteolysis of SHP peptide pheromones. This degradation is mediated by the cytoplasmic endopeptidase PepO, which is the first identified enzymatic silencer of an RRNPP-type quorum-sensing pathway. These results suggest that under conditions in which the virulence potential of GAS is elevated (i.e. enhanced virulence gene expression), cellular responses mediated by the Rgg2/3 pathway are abrogated and allow individuals to escape from group behavior. These results also indicate that Rgg2/3 signaling is instead functional during non-virulent GAS lifestyles.
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Affiliation(s)
- Reid V Wilkening
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Jennifer C Chang
- Department of Medicinal Chemistry and Pharmacognosy, Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Michael J Federle
- Department of Medicinal Chemistry and Pharmacognosy, Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, 60607, USA
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32
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Xiong L, Teng JLL, Watt RM, Liu C, Lau SKP, Woo PCY. Molecular characterization of arginine deiminase pathway in Laribacter hongkongensis and unique regulation of arginine catabolism and anabolism by multiple environmental stresses. Environ Microbiol 2015; 17:4469-83. [PMID: 25950829 DOI: 10.1111/1462-2920.12897] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/22/2015] [Accepted: 05/03/2015] [Indexed: 12/29/2022]
Abstract
The betaproteobacterium Laribacter hongkongensis is associated with invasive bacteremic infections and gastroenteritis. Its genome contains two adjacent arc gene cassettes (arc1 and arc2) under independent transcriptional control, which are essential for acid resistance. Laribacter hongkongensis also encodes duplicate copies of the argA and argB genes from the arginine biosynthesis pathway. We show that arginine enhances the transcription of arcA2 but suppresses arcA1 expression. We demonstrate that ArgR acts as a transcriptional regulator of the two arc operons through binding to ARG operator sites (ARG boxes). Upon temperature shift from 20°C to 37°C, arcA1 transcription is upregulated while arcA2, argA2, argB2 and argG are downregulated. The transcription of arcA1 and arcA2 are augmented under anaerobic and acidic conditions. The transcription levels of argA1, argA2, argB1, argB2 and argG are significantly increased under anaerobic and acidic conditions but are repressed by the addition of arginine. Deletion of argR significantly decreases bacterial survival in macrophages, while expression of both arc operons, argR and all five of the anabolic arg genes increases 8 h post-infection. Our results show that arginine catabolism in L. hongkongensis is finely regulated by controlling the transcription of two arc operons, whereas arginine anabolism is controlled by two copies of argA and argB.
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Affiliation(s)
- Lifeng Xiong
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Jade L L Teng
- Department of Microbiology, The University of Hong Kong, Hong Kong, China.,Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China
| | - Rory M Watt
- Oral Biosciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Cuihua Liu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Susanna K P Lau
- Department of Microbiology, The University of Hong Kong, Hong Kong, China.,Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China.,State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China.,Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
| | - Patrick C Y Woo
- Department of Microbiology, The University of Hong Kong, Hong Kong, China.,Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China.,State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China.,Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
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33
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Identification of Quorum-Sensing Inhibitors Disrupting Signaling between Rgg and Short Hydrophobic Peptides in Streptococci. mBio 2015; 6:e00393-15. [PMID: 25968646 PMCID: PMC4436074 DOI: 10.1128/mbio.00393-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Bacteria coordinate a variety of social behaviors, important for both environmental and pathogenic bacteria, through a process of intercellular chemical signaling known as quorum sensing (QS). As microbial resistance to antibiotics grows more common, a critical need has emerged to develop novel anti-infective therapies, such as an ability to attenuate bacterial pathogens by means of QS interference. Rgg quorum-sensing pathways, widespread in the phylum Firmicutes, employ cytoplasmic pheromone receptors (Rgg transcription factors) that directly bind and elicit gene expression responses to imported peptide signals. In the human-restricted pathogen Streptococcus pyogenes, the Rgg2/Rgg3 regulatory circuit controls biofilm development in response to the short hydrophobic peptides SHP2 and SHP3. Using Rgg-SHP as a model receptor-ligand target, we sought to identify chemical compounds that could specifically inhibit Rgg quorum-sensing circuits. Individual compounds from a diverse library of known drugs and drug-like molecules were screened for their ability to disrupt complexes of Rgg and FITC (fluorescein isothiocyanate)-conjugated SHP using a fluorescence polarization (FP) assay. The best hits were found to bind Rgg3 in vitro with submicromolar affinities, to specifically abolish transcription of Rgg2/3-controlled genes, and to prevent biofilm development in S. pyogenes without affecting bacterial growth. Furthermore, the top hit, cyclosporine A, as well as its nonimmunosuppressive analog, valspodar, inhibited Rgg-SHP pathways in multiple species of Streptococcus. The Rgg-FITC-peptide-based screen provides a platform to identify inhibitors specific for each Rgg type. Discovery of Rgg inhibitors constitutes a step toward the goal of manipulating bacterial behavior for purposes of improving health. The global emergence of antibiotic-resistant bacterial infections necessitates discovery not only of new antimicrobials but also of novel drug targets. Since antibiotics restrict microbial growth, strong selective pressures to develop resistance emerge quickly in bacteria. A new strategy to fight microbial infections has been proposed, namely, development of therapies that decrease pathogenicity of invading organisms while not directly inhibiting their growth, thus decreasing selective pressure to establish resistance. One possible means to this goal is to interfere with chemical communication networks used by bacteria to coordinate group behaviors, which can include the synchronized expression of genes that lead to disease. In this study, we identified chemical compounds that disrupt communication pathways regulated by Rgg proteins in species of Streptococcus. Treatment of cultures of S. pyogenes with the inhibitors diminished the development of biofilms, demonstrating an ability to control bacterial behavior with chemicals that do not inhibit growth.
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34
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Citrulline protects Streptococcus pyogenes from acid stress using the arginine deiminase pathway and the F1Fo-ATPase. J Bacteriol 2015; 197:1288-96. [PMID: 25645553 DOI: 10.1128/jb.02517-14] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED A common stress encountered by both pathogenic and environmental bacteria is exposure to a low-pH environment, which can inhibit cell growth and lead to cell death. One major defense mechanism against this stress is the arginine deiminase (ADI) pathway, which catabolizes arginine to generate two ammonia molecules and one molecule of ATP. While this pathway typically relies on the utilization of arginine, citrulline has also been shown to enter into the pathway and contribute to protection against acid stress. In the pathogenic bacterium Streptococcus pyogenes, the utilization of citrulline has been demonstrated to contribute to pathogenesis in a murine model of soft tissue infection, although the mechanism underlying its role in infection is unknown. To gain insight into this question, we analyzed a panel of mutants defective in different steps in the ADI pathway to dissect how arginine and citrulline protect S. pyogenes in a low-pH environment. While protection provided by arginine utilization occurred through the buffering of the extracellular environment, citrulline catabolism protection was pH independent, requiring the generation of ATP via the ADI pathway and a functional F1Fo-ATP synthase. This work demonstrates that arginine and citrulline catabolism protect against acid stress through distinct mechanisms and have unique contributions to virulence during an infection. IMPORTANCE An important aspect of bacterial pathogenesis is the utilization of host-derived nutrients during an infection for growth and virulence. Previously published work from our lab identified a unique role for citrulline catabolism in Streptococcus pyogenes during a soft tissue infection. The present article probes the role of citrulline utilization during this infection and its contribution to protection against acid stress. This work reveals a unique and concerted action between the catabolism of citrulline and the F1Fo-ATPase that function together to provide protection for bacteria in a low-pH environment. Dissection of these collaborative pathways highlights the complexity of bacterial infections and the contribution of atypical nutrients, such as citrulline, to pathogenesis.
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Regulation of the arginine deiminase system by ArgR2 interferes with arginine metabolism and fitness of Streptococcus pneumoniae. mBio 2014; 5:mBio.01858-14. [PMID: 25538192 PMCID: PMC4278536 DOI: 10.1128/mbio.01858-14] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae is auxotrophic for arginine, and molecular analysis of the pneumococcal genome showed that the gene encoding an arginine-ornithine antiporter (ArcD) is organized in a cluster together with the arcABC genes encoding the arginine deiminase system (ADS) of pneumococci. The ADS consists of the arginine deiminase (AD), the catabolic ornithine carbamoyltransferase (cOCT), and the carbamate kinase (CK). Pneumococcal genomes contain three ArgR-type regulators (ArgR1, ArgR2, and AhrC) that are supposed to be involved in the regulation of arginine metabolism. Here, we identified ArgR2 of TIGR4 as the regulator of the ADS and ArcD. ArgR2 binds to promoter sequences of the arc operon, and the deficiency of ArgR2 in TIGR4 abrogates expression of the ADS, including the arginine-ornithine antiporter ArcD. Intranasal infection of mice and real-time bioimaging revealed that deletion of the arcABCDT genes attenuates TIGR4. However, the acute-pneumonia model and coinfection experiments indicated that the arginine-ornithine antiporter ArcD is essential to maintain fitness, while the deficiency of ADS enzymes has a minor impact on pneumococcal fitness under in vivo conditions. Strikingly, argR2 mutant TIGR4 outcompeted the wild type in the respiratory tract, suggesting an increase in fitness and further regulatory functions of ArgR2. In contrast to TIGR4, other pneumococci, such as D39, lacking expression of ArgR2, constitutively express the ADS with a truncated nonfunctional AD. On the basis of these results, we propose that the arginine-ornithine antiporter is essential to maintain pneumococcal fitness and that the genes of the ADS cluster are positively regulated in a strain-specific manner by ArgR2. Pneumococci are the major etiologic agents of community-acquired pneumonia, causing more than 1.5 million deaths annually worldwide. These versatile pathogens are highly adapted to the nutrients provided by the host niches encountered. Physiological fitness is of major importance for colonization of the nasopharyngeal cavity and dissemination during invasive infections. This work identifies the regulator ArgR2 as the activator of the S. pneumoniae TIGR4 ADS and the arginine-ornithine transporter ArcD, which is needed for uptake of the essential amino acid arginine. Although ArgR2 activates ArcD expression and uptake of arginine is required to maintain pneumococcal fitness, the deficiency of ArgR2 increases TIGR4 virulence under in vivo conditions, suggesting that other factors regulated by ArgR2 counterbalance the reduced uptake of arginine by ArcD. Thus, this work illustrates that the physiological homeostasis of pneumococci is complex and that ArgR2 plays a key role in maintaining bacterial fitness.
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Lund P, Tramonti A, De Biase D. Coping with low pH: molecular strategies in neutralophilic bacteria. FEMS Microbiol Rev 2014; 38:1091-125. [PMID: 24898062 DOI: 10.1111/1574-6976.12076] [Citation(s) in RCA: 272] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 02/26/2014] [Accepted: 03/14/2014] [Indexed: 12/31/2022] Open
Abstract
As part of their life cycle, neutralophilic bacteria are often exposed to varying environmental stresses, among which fluctuations in pH are the most frequent. In particular, acid environments can be encountered in many situations from fermented food to the gastric compartment of the animal host. Herein, we review the current knowledge of the molecular mechanisms adopted by a range of Gram-positive and Gram-negative bacteria, mostly those affecting human health, for coping with acid stress. Because organic and inorganic acids have deleterious effects on the activity of the biological macromolecules to the point of significantly reducing growth and even threatening their viability, it is not unexpected that neutralophilic bacteria have evolved a number of different protective mechanisms, which provide them with an advantage in otherwise life-threatening conditions. The overall logic of these is to protect the cell from the deleterious effects of a harmful level of protons. Among the most favoured mechanisms are the pumping out of protons, production of ammonia and proton-consuming decarboxylation reactions, as well as modifications of the lipid content in the membrane. Several examples are provided to describe mechanisms adopted to sense the external acidic pH. Particular attention is paid to Escherichia coli extreme acid resistance mechanisms, the activity of which ensure survival and may be directly linked to virulence.
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Affiliation(s)
- Peter Lund
- School of Biosciences, University of Birmingham, Birmingham, UK
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Aggarwal C, Jimenez JC, Nanavati D, Federle MJ. Multiple length peptide-pheromone variants produced by Streptococcus pyogenes directly bind Rgg proteins to confer transcriptional regulation. J Biol Chem 2014; 289:22427-36. [PMID: 24958729 DOI: 10.1074/jbc.m114.583989] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Streptococcus pyogenes, a human-restricted pathogen, accounts for substantial mortality related to infections worldwide. Recent studies indicate that streptococci produce and respond to several secreted peptide signaling molecules (pheromones), including those known as short hydrophobic peptides (SHPs), to regulate gene expression by a quorum-sensing mechanism. Upon transport into the bacterial cell, pheromones bind to and modulate activity of receptor proteins belonging to the Rgg family of transcription factors. Previously, we reported biofilm regulation by the Rgg2/3 quorum-sensing circuit in S. pyogenes. The aim of this study was to identify the composition of mature pheromones from cell-free culture supernatants that facilitate biofilm formation. Bioluminescent reporters were employed to detect active pheromones in culture supernatants fractionated by reverse-phase chromatography, and mass spectrometry was used to characterize their properties. Surprisingly, multiple SHPs that varied by length were detected. Synthetic peptides of each variant were tested individually using bioluminescence reporters and biofilm growth assays, and although activities differed widely among the group, peptides comprising the C-terminal eight amino acids of the full-length native peptide were most active. Direct Rgg/SHP interactions were determined using a fluorescence polarization assay that utilized FITC-labeled peptide ligands. Peptide receptor affinities were seen to be as low as 500 nm and their binding affinities directly correlated with observed bioactivity. Revelation of naturally produced pheromones along with determination of their affinity for cognate receptors are important steps forward in designing compounds whose purpose is positioned for future therapeutics aimed at treating infections through the interference of bacterial communication.
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Affiliation(s)
- Chaitanya Aggarwal
- From the Center for Pharmaceutical Biotechnology, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, and
| | - Juan Cristobal Jimenez
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois 60607 and
| | - Dhaval Nanavati
- the Chemistry of Life Processes Institute, Proteomics Core, Northwestern University, Evanston, Illinois 60208
| | - Michael J Federle
- From the Center for Pharmaceutical Biotechnology, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, and
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Yam H, Abdul Rahim A, Mohamad S, Mahadi NM, Abdul Manaf U, Shu-Chien AC, Najimudin N. The multiple roles of hypothetical gene BPSS1356 in Burkholderia pseudomallei. PLoS One 2014; 9:e99218. [PMID: 24927285 PMCID: PMC4057154 DOI: 10.1371/journal.pone.0099218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 05/12/2014] [Indexed: 11/26/2022] Open
Abstract
Burkholderia pseudomallei is an opportunistic pathogen and the causative agent of melioidosis. It is able to adapt to harsh environments and can live intracellularly in its infected hosts. In this study, identification of transcriptional factors that associate with the β' subunit (RpoC) of RNA polymerase was performed. The N-terminal region of this subunit is known to trigger promoter melting when associated with a sigma factor. A pull-down assay using histidine-tagged B. pseudomallei RpoC N-terminal region as bait showed that a hypothetical protein BPSS1356 was one of the proteins bound. This hypothetical protein is conserved in all B. pseudomallei strains and present only in the Burkholderia genus. A BPSS1356 deletion mutant was generated to investigate its biological function. The mutant strain exhibited reduced biofilm formation and a lower cell density during the stationary phase of growth in LB medium. Electron microscopic analysis revealed that the ΔBPSS1356 mutant cells had a shrunken cytoplasm indicative of cell plasmolysis and a rougher surface when compared to the wild type. An RNA microarray result showed that a total of 63 genes were transcriptionally affected by the BPSS1356 deletion with fold change values of higher than 4. The expression of a group of genes encoding membrane located transporters was concurrently down-regulated in ΔBPSS1356 mutant. Amongst the affected genes, the putative ion transportation genes were the most severely suppressed. Deprivation of BPSS1356 also down-regulated the transcriptions of genes for the arginine deiminase system, glycerol metabolism, type III secretion system cluster 2, cytochrome bd oxidase and arsenic resistance. It is therefore obvious that BPSS1356 plays a multiple regulatory roles on many genes.
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Affiliation(s)
- Hokchai Yam
- School of Biological Sciences, Universiti Sains Malaysia, Minden, Pulau Pinang, Malaysia
| | - Ainihayati Abdul Rahim
- School of Biological Sciences, Universiti Sains Malaysia, Minden, Pulau Pinang, Malaysia
- Faculty of Agro Based Industry, Universiti Malaysia Kelantan, Jeli, Kelantan, Malaysia
| | - Suriani Mohamad
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, Pulau Pinang, Malaysia
| | - Nor Muhammad Mahadi
- Comparative Genomics and Genetics Research Centre, Malaysia Genome Institute, Kajang, Selangor, Malaysia
| | - Uyub Abdul Manaf
- School of Biological Sciences, Universiti Sains Malaysia, Minden, Pulau Pinang, Malaysia
| | | | - Nazalan Najimudin
- School of Biological Sciences, Universiti Sains Malaysia, Minden, Pulau Pinang, Malaysia
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Arginine deiminase in Staphylococcus epidermidis functions to augment biofilm maturation through pH homeostasis. J Bacteriol 2014; 196:2277-89. [PMID: 24727224 DOI: 10.1128/jb.00051-14] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Allelic replacement mutants were constructed within arginine deiminase (arcA1 and arcA2) to assess the function of the arginine deiminase (ADI) pathway in organic acid resistance and biofilm formation of Staphylococcus epidermidis 1457. A growth-dependent acidification assay (pH ∼5.0 to ∼5.2) determined that strain 1457 devoid of arginine deiminase activity (1457 ΔADI) was significantly less viable than the wild type following depletion of glucose and in the presence of arginine. However, no difference in viability was noted for individual 1457 ΔarcA1 (native) or ΔarcA2 (arginine catabolic mobile element [ACME]-derived) mutants, suggesting that the native and ACME-derived ADIs are compensatory in S. epidermidis. Furthermore, flow cytometry and electron paramagnetic resonance spectroscopy results suggested that organic acid stress resulted in oxidative stress that could be partially rescued by the iron chelator dipyridyl. Collectively, these results suggest that formation of hydroxyl radicals is partially responsible for cell death via organic acid stress and that ADI-derived ammonia functions to counteract this acid stress. Finally, static biofilm assays determined that viability, ammonia synthesis, and pH were reduced in strain 1457 ΔADI following 120 h of growth in comparison to strain 1457 and the arcA1 and arcA2 single mutants. It is hypothesized that ammonia synthesis via the ADI pathway is important to reduce pH stress in specific microniches that contain high concentrations of organic acids.
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Xiong L, Teng JLL, Watt RM, Kan B, Lau SKP, Woo PCY. Arginine deiminase pathway is far more important than urease for acid resistance and intracellular survival in Laribacter hongkongensis: a possible result of arc gene cassette duplication. BMC Microbiol 2014; 14:42. [PMID: 24533585 PMCID: PMC3936950 DOI: 10.1186/1471-2180-14-42] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 02/10/2014] [Indexed: 12/27/2022] Open
Abstract
Background Laribacter hongkongensis is a Gram-negative, urease-positive bacillus associated with invasive bacteremic infections in liver cirrhosis patients and fish-borne community-acquired gastroenteritis and traveler’s diarrhea. Its mechanisms of adaptation to various environmental niches and host defense evasion are largely unknown. During the process of analyzing the L. hongkongensis genome, a complete urease cassette and two adjacent arc gene cassettes were found. We hypothesize that the urease cassette and/or the arc gene cassettes are important for L. hongkongensis to survive in acidic environment and macrophages. In this study, we tested this hypothesis by constructing single, double and triple non-polar deletion mutants of the urease and two arc gene cassettes of L. hongkongensis using the conjugation-mediated gene deletion system and examining their effects in acidic environment in vitro, in macrophages and in a mouse model. Results HLHK9∆ureA, HLHK9∆ureC, HLHK9∆ureD and HLHK9∆ureE all exhibited no urease activity. HLHK9∆arcA1 and HLHK9∆arcA2 both exhibited arginine deiminase (ADI) activities, but HLHK9∆arcA1/arcA2 double deletion mutant exhibited no ADI activity. At pH 2 and 3, survival of HLHK9∆arcA1/arcA2 and HLHK9∆ureA/arcA1/arcA2 were markedly decreased (p < 0.001) but that of HLHK9∆ureA was slightly decreased (p < 0.05), compared to wild type L. hongkongensis HLHK9. Survival of HLHK9∆ureA/arcA1/arcA2 and HLHK9∆arcA1/arcA2 in macrophages were also markedly decreased (p < 0.001 and p < 0.01 respectively) but that of HLHK9∆ureA was slightly decreased (p < 0.05), compared to HLHK9, although expression of arcA1, arcA2 and ureA genes were all upregulated. Using a mouse model, HLHK9∆ureA exhibited similar survival compared to HLHK9 after passing through the murine stomach, but survival of HLHK9∆arcA1/arcA2 and HLHK9∆ureA/arcA1/arcA2 were markedly reduced (p < 0.01). Conclusions In contrast to other important gastrointestinal tract pathogens, ADI pathway is far more important than urease for acid resistance and intracellular survival in L. hongkongensis. The gene duplication of the arc gene cassettes could be a result of their functional importance in L. hongkongensis.
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Affiliation(s)
| | | | | | | | - Susanna K P Lau
- Department of Microbiology, Queen Mary Hospital, The University of Hong Kong, University Pathology Building, Hong Kong, China.
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Identification of genes required by Bacillus thuringiensis for survival in soil by transposon-directed insertion site sequencing. Curr Microbiol 2013; 68:477-85. [PMID: 24310935 DOI: 10.1007/s00284-013-0502-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Accepted: 10/14/2013] [Indexed: 10/25/2022]
Abstract
Transposon-directed insertion site sequencing was used to identify genes required by Bacillus thuringiensis to survive in non-axenic plant/soil microcosms. A total of 516 genetic loci fulfilled the criteria as conferring survival characteristics. Of these, 127 (24.6 %) were associated with uptake and transport systems; 227 loci (44.0 %) coded for enzymatic properties; 49 (9.5 %) were gene regulation or sensory loci; 40 (7.8 %) were structural proteins found in the cell envelope or had enzymatic activities related to it and 24 (4.7 %) were involved in the production of antibiotics or resistance to them. Eighty-three (16.1 %) encoded hypothetical proteins or those of unknown function. The ability to form spores was a key survival characteristic in the microcosms: bacteria, inoculated in either spore or vegetative form, were able to multiply and colonise the soil, whereas a sporulation-deficient mutant was not. The presence of grass seedlings was critical to colonisation. Bacteria labelled with green fluorescent protein were observed to adhere to plant roots. The sporulation-specific promoter of spo0A, the key regulator of sporulation, was strongly activated in the rhizosphere. In contrast, the vegetative-specific promoters of spo0A and PlcR, a pleiotropic regulator of genes with diverse activities, were only very weakly activated.
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Streptococcus pyogenes arginine and citrulline catabolism promotes infection and modulates innate immunity. Infect Immun 2013; 82:233-42. [PMID: 24144727 DOI: 10.1128/iai.00916-13] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
A bacterium's ability to acquire nutrients from its host during infection is an essential component of pathogenesis. For the Gram-positive pathogen Streptococcus pyogenes, catabolism of the amino acid arginine via the arginine deiminase (ADI) pathway supplements energy production and provides protection against acid stress in vitro. Its expression is enhanced in murine models of infection, suggesting an important role in vivo. To gain insight into the function of the ADI pathway in pathogenesis, the virulence of mutants defective in each of its enzymes was examined. Mutants unable to use arginine (ΔArcA) or citrulline (ΔArcB) were attenuated for carriage in a murine model of asymptomatic mucosal colonization. However, in a murine model of inflammatory infection of cutaneous tissue, the ΔArcA mutant was attenuated but the ΔArcB mutant was hyperattenuated, revealing an unexpected tissue-specific role for citrulline metabolism in pathogenesis. When mice defective for the arginine-dependent production of nitric oxide (iNOS(-/-)) were infected with the ΔArcA mutant, cutaneous virulence was rescued, demonstrating that the ability of S. pyogenes to utilize arginine was dispensable in the absence of nitric oxide-mediated innate immunity. This work demonstrates the importance of arginine and citrulline catabolism and suggests a novel mechanism of virulence by which S. pyogenes uses its metabolism to modulate innate immunity through depletion of an essential host nutrient.
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Structure-informed design of an enzymatically inactive vaccine component for group A Streptococcus. mBio 2013; 4:mBio.00509-13. [PMID: 23919999 PMCID: PMC3735194 DOI: 10.1128/mbio.00509-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Streptococcus pyogenes (group A Streptococcus [GAS]) causes ~700 million human infections/year, resulting in >500,000 deaths. There is no commercial GAS vaccine available. The GAS surface protein arginine deiminase (ADI) protects mice against a lethal challenge. ADI is an enzyme that converts arginine to citrulline and ammonia. Administration of a GAS vaccine preparation containing wild-type ADI, a protein with inherent enzymatic activity, may present a safety risk. In an approach intended to maximize the vaccine safety of GAS ADI, X-ray crystallography and structural immunogenic epitope mapping were used to inform vaccine design. This study aimed to knock out ADI enzyme activity without disrupting the three-dimensional structure or the recognition of immunogenic epitopes. We determined the crystal structure of ADI at 2.5 Å resolution and used it to select a number of amino acid residues for mutagenesis to alanine (D166, E220, H275, D277, and C401). Each mutant protein displayed abrogated activity, and three of the mutant proteins (those with the D166A, H275A, and D277A mutations) possessed a secondary structure and oligomerization state equivalent to those of the wild type, produced high-titer antisera, and avoided disruption of B-cell epitopes of ADI. In addition, antisera raised against the D166A and D277A mutant proteins bound to the GAS cell surface. The inactivated D166A and D277A mutant ADIs are ideal for inclusion in a GAS vaccine preparation. There is no human ortholog of ADI, and we confirm that despite limited structural similarity in the active-site region to human peptidyl ADI 4 (PAD4), ADI does not functionally mimic PAD4 and antiserum raised against GAS ADI does not recognize human PAD4. We present an example of structural biology informing human vaccine design. We previously showed that the administration of the enzyme arginine deiminase (ADI) to mice protected the mice against infection with multiple GAS serotypes. In this study, we determined the structure of GAS ADI and used this information to improve the vaccine safety of GAS ADI. Catalytically inactive mutant forms of ADI retained structure, recognition by antisera, and immunogenic epitopes, rendering them ideal for inclusion in GAS vaccine preparations. This example of structural biology informing vaccine design may underpin the formulation of a safe and efficacious GAS vaccine.
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Abstract
Quorum sensing (QS) regulates diverse and coordinated behaviors in bacteria, including the production of virulence factors, biofilm formation, sporulation, and competence development. It is now established that some streptococci utilize Rgg-type proteins in concert with short hydrophobic peptides (SHPs) to mediate QS, and sequence analysis reveals that several streptococcal species contain highly homologous Rgg/SHP pairs. In group A streptococcus (GAS), two SHPs (SHP2 and SHP3 [SHP2/3]) were previously identified to be important in GAS biofilm formation. SHP2/3 are detected by two antagonistic regulators, Rgg2 and Rgg3, which control expression of the shp genes. In group B streptococcus (GBS), RovS is a known virulence gene regulator and ortholog of Rgg2, whereas no apparent Rgg3 homolog exists. Adjacent to rovS is a gene (shp1520) encoding a peptide nearly identical to SHP2. Using isogenic mutant strains and transcriptional reporters, we confirmed that RovS/SHP1520 comprise a QS circuit in GBS. More important, we performed experiments demonstrating that production and secretion of SHP1520 by GBS can modulate Rgg2/3-regulated gene expression in GAS in trans; likewise, SHP2/3 production by GAS can stimulate RovS-mediated gene regulation in GBS. An isolate of Streptococcus dysgalactiae subsp. equisimilis also produced a secreted factor capable of simulating the QS circuits of both GAS and GBS, and sequencing confirms the presence of an orthologous Rgg2/SHP2 pair in this species as well. To our knowledge, this is the first documented case of bidirectional signaling between streptococcal species in coculture and suggests a role for orthologous Rgg/SHP systems in interspecies communication between important human pathogens. Pathogenic streptococci, such as group A (GAS) and group B (GBS) streptococcus, are able to persist in the human body without causing disease but become pathogenic under certain conditions that are not fully characterized. Environmental cues and interspecies signaling between members of the human flora likely play an important role in the transition to a disease state. Since quorum-sensing (QS) peptides have been consistently shown to regulate virulence factor production in pathogenic species, the ability of bacteria to signal via these peptides may prove to be an important link between the carrier and pathogenic states. Here we provide evidence of a bidirectional QS system between GAS, GBS, and Streptococcus dysgalactiae subsp. equisimilis, demonstrating the possibility of evolved communication systems between human pathogens.
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Abstract
UNLABELLED Quorum sensing (QS) regulates diverse and coordinated behaviors in bacteria, including the production of virulence factors, biofilm formation, sporulation, and competence development. It is now established that some streptococci utilize Rgg-type proteins in concert with short hydrophobic peptides (SHPs) to mediate QS, and sequence analysis reveals that several streptococcal species contain highly homologous Rgg/SHP pairs. In group A streptococcus (GAS), two SHPs (SHP2 and SHP3 [SHP2/3]) were previously identified to be important in GAS biofilm formation. SHP2/3 are detected by two antagonistic regulators, Rgg2 and Rgg3, which control expression of the shp genes. In group B streptococcus (GBS), RovS is a known virulence gene regulator and ortholog of Rgg2, whereas no apparent Rgg3 homolog exists. Adjacent to rovS is a gene (shp1520) encoding a peptide nearly identical to SHP2. Using isogenic mutant strains and transcriptional reporters, we confirmed that RovS/SHP1520 comprise a QS circuit in GBS. More important, we performed experiments demonstrating that production and secretion of SHP1520 by GBS can modulate Rgg2/3-regulated gene expression in GAS in trans; likewise, SHP2/3 production by GAS can stimulate RovS-mediated gene regulation in GBS. An isolate of Streptococcus dysgalactiae subsp. equisimilis also produced a secreted factor capable of simulating the QS circuits of both GAS and GBS, and sequencing confirms the presence of an orthologous Rgg2/SHP2 pair in this species as well. To our knowledge, this is the first documented case of bidirectional signaling between streptococcal species in coculture and suggests a role for orthologous Rgg/SHP systems in interspecies communication between important human pathogens. IMPORTANCE Pathogenic streptococci, such as group A (GAS) and group B (GBS) streptococcus, are able to persist in the human body without causing disease but become pathogenic under certain conditions that are not fully characterized. Environmental cues and interspecies signaling between members of the human flora likely play an important role in the transition to a disease state. Since quorum-sensing (QS) peptides have been consistently shown to regulate virulence factor production in pathogenic species, the ability of bacteria to signal via these peptides may prove to be an important link between the carrier and pathogenic states. Here we provide evidence of a bidirectional QS system between GAS, GBS, and Streptococcus dysgalactiae subsp. equisimilis, demonstrating the possibility of evolved communication systems between human pathogens.
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Redundant group a streptococcus signaling peptides exhibit unique activation potentials. J Bacteriol 2013; 195:4310-8. [PMID: 23873915 DOI: 10.1128/jb.00684-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
All bacterial quorum sensing (QS) systems are based on the production, secretion, and detection of small signaling molecules. Gram-positive bacteria typically use small peptides as QS effectors, and each QS circuit generally requires the interaction of a single signaling molecule with a single receptor protein. The recently described Rgg2 and Rgg3 (Rgg2/3) regulatory circuit of Streptococcus pyogenes (group A streptococcus [GAS]) is one of only a few QS circuits known to utilize multiple signaling peptides. In this system, two distinct, endogenously produced peptide pheromones (SHP2 and SHP3) both function to activate the QS circuit. The aim of this study was to further define the roles of SHP2 and SHP3 in activation of the Rgg2/3 QS system, specifically with regard to shp gene identity and dosage. Results from our studies using transcriptional reporters and isogenic GAS mutants demonstrate that shp gene dosage does contribute to Rgg2/3 system induction, as decreased gene dosage results in decreased or absent induction. Beyond this, however, data indicate that the shp genes possess distinct potentials for supporting system activation, with shp3 more readily able to support system activation than shp2. Studies using synthetic peptides and shp gene mutants indicate that the disparate activities of endogenous SHPs are due to production, rather than signaling, differences and are conferred by the N-terminal regions rather than the C-terminal signaling regions of the peptides. These data provide evidence that the N-terminal, noneffector sequences of SHP pheromones influence their production efficiencies and thereby the relative activation potentials of endogenous SHPs.
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Hering S, Sieg A, Kreikemeyer B, Fiedler T. Kinetic characterization of arginine deiminase and carbamate kinase from Streptococcus pyogenes M49. Protein Expr Purif 2013; 91:61-8. [PMID: 23867361 DOI: 10.1016/j.pep.2013.07.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 06/27/2013] [Accepted: 07/08/2013] [Indexed: 11/28/2022]
Abstract
Streptococcus pyogenes (group A Streptococcus, GAS) is an important human pathogen causing mild superficial infections of skin and mucous membranes, but also life-threatening systemic diseases. S. pyogenes and other prokaryotic organisms use the arginine deiminase system (ADS) for survival in acidic environments. In this study, the arginine deiminase (AD), and carbamate kinase (CK) from S. pyogenes M49 strain 591 were heterologously expressed in Escherichia coli DH5α, purified, and kinetically characterized. AD and CK from S. pyogenes M49 share high amino acid sequence similarity with the respective enzymes from Lactococcus lactis subsp. lactis IL1403 (45.6% and 53.5% identical amino acids) and Enterococcus faecalis V583 (66.8% and 66.8% identical amino acids). We found that the arginine deiminase of S. pyogenes is not allosterically regulated by the intermediates and products of the arginine degradation (e.g., ATP, citrulline, carbamoyl phosphate). The Km and Vmax values for arginine were 1.13±0.12mM (mean±SD) and 1.51±0.07μmol/min/mg protein. The carbamate kinase is inhibited by ATP but unaffected by arginine and citrulline. The Km and Vmax values for ADP were 0.72±0.08mM and 1.10±0.10μmol/min/mg protein and the Km for carbamoyl phosphate was 0.65±0.07mM. The optimum pH and temperature for both enzymes were 6.5 and 37°C, respectively.
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Affiliation(s)
- Silvio Hering
- Rostock University Medical Centre, Institute of Medical Microbiology, Virology, and Hygiene, Schillingallee 70, 18057 Rostock, Germany
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Cheng C, Chen J, Shan Y, Fang C, Liu Y, Xia Y, Song H, Fang W. Listeria monocytogenes ArcA contributes to acid tolerance. J Med Microbiol 2013; 62:813-821. [PMID: 23518652 DOI: 10.1099/jmm.0.055145-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The foodborne pathogen Listeria monocytogenes is able to colonize the human and animal intestinal tracts and subsequently crosses the intestinal barrier, causing systemic infection. For successful establishment of infection, L. monocytogenes must survive and adapt to the low pH environment of the stomach. Gene sequence analysis indicates that lmo0043, an orthologue of arcA, encodes a protein containing conserved motifs and critical active amino acids characteristic of arginine deiminase that mediates an arginine deimination reaction. We attempted to characterize the role of ArcA in acid tolerance in vitro and in mice models. Transcription of arcA was significantly increased in L. monocytogenes culture subjected to acid stress at pH 4.8, as compared with that at pH 7.0. Deletion of arcA impaired growth of L. monocytogenes under mild acidic conditions at pH 5.5, and reduced its survival in synthetic human gastric fluid at pH 2.5 and in the murine stomach. Bacterial load in the spleen of mice intraperitoneally inoculated with an arcA deletion mutant was significantly lower than that of the wild-type strain. These phenotypic changes were recoverable by genetic complementation. Thus, we conclude that L. monocytogenes arcA not only mediates acid tolerance in vitro but also participates in gastric survival and virulence in mice.
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Affiliation(s)
- Changyong Cheng
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang 310058, PR China
| | - Jianshun Chen
- Zhejiang Aquatic Disease Prevention and Quarantine Center, 20 Yile Road, Hangzhou, Zhejiang 310012, PR China
| | - Ying Shan
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang 310058, PR China
| | - Chun Fang
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang 310058, PR China
| | - Yuan Liu
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang 310058, PR China
| | - Ye Xia
- Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang 310058, PR China
| | - Houhui Song
- Zhejiang A&F University College of Animal Science & Technology, Lin'an, Zhejiang 311300, PR China
| | - Weihuan Fang
- Zhejiang A&F University College of Animal Science & Technology, Lin'an, Zhejiang 311300, PR China.,Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang 310058, PR China
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A new local variant (ST764) of the globally disseminated ST5 lineage of hospital-associated methicillin-resistant Staphylococcus aureus (MRSA) carrying the virulence determinants of community-associated MRSA. Antimicrob Agents Chemother 2013; 57:1589-95. [PMID: 23318800 DOI: 10.1128/aac.01147-12] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The ST5 lineage of methicillin-resistant Staphylococcus aureus (MRSA) is one of the most globally disseminated hospital-associated MRSA (HA-MRSA) lineages. We isolated a new local variant (designated ST764) over at least 5 years that causes invasive infections, including necrotizing fasciitis, and is carried by medical students, as well as household members. Analysis of the genome sequence of one isolate compared to that of the reference ST5 strain revealed that ST764 had acquired virulence traits similar to those of community-associated MRSA (CA-MRSA) through the acquisition of two new mobile genetic elements, ACMEII and SaPInn54, which carried ACME arcA and the staphylococcal enterotoxin B gene (seb), respectively, and through enhanced expression of cytolytic peptide genes, although ST764 was negative for Panton-Valentine leukocidin. Other differences between ST764 and ST5 included the acquisition of an ACMEII-related cassette (cJR1), prophage φ2NN54, and streptococcal Tn5251 and decreased numbers of copies of Tn554. As for superantigen genes, although the two possessed seg, sei, sem, sen, and seo, ST764 lacked tst, sec, sel, and sep. The data suggest that ST764 MRSA is a novel hybrid variant of ST5 HA-MRSA with the characteristics of CA-MRSA and that the evolution of ST764 includes multiple steps, e.g., acquisition of novel or nonstaphylococcal mobile elements.
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Expression of STM4467-encoded arginine deiminase controlled by the STM4463 regulator contributes to Salmonella enterica serovar Typhimurium virulence. Infect Immun 2012; 80:4291-7. [PMID: 23006851 DOI: 10.1128/iai.00880-12] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Arginine deiminase (ADI), carbamate kinase (CK), and ornithine transcarbamoylase (OTC) constitute the ADI system. In addition to metabolic functions, the ADI system has been implicated in the virulence of certain pathogens. The pathogenic intracellular bacterium Salmonella enterica serovar Typhimurium possesses the STM4467, STM4466, and STM4465 genes, which are predicted to encode ADI, CK, and OTC, respectively. Here we report that the STM4467 gene encodes an ADI and that ADI activity plays a role in the successful infection of a mammalian host by S. Typhimurium. An STM4467 deletion mutant was defective for replication inside murine macrophages and was attenuated for virulence in mice. We determined that a regulatory protein encoded by the STM4463 gene functions as an activator for STM4467 expression. The expression of the ADI pathway genes was enhanced inside macrophages in a process that required STM4463. Lack of STM4463 impaired the ability of S. Typhimurium to replicate within macrophages. A mutant defective in STM4467-encoded ADI displayed normal production of nitric oxide by macrophages.
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