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Zhang C, Liu J, Liu X, Xu Y, Gan Q, Cheng Q, Liu W, Gao X, Wu S. Glutamine enhances pneumococcal growth under methionine semi-starvation by elevating intracellular pH. Front Microbiol 2024; 15:1430038. [PMID: 39044959 PMCID: PMC11263215 DOI: 10.3389/fmicb.2024.1430038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Accepted: 06/28/2024] [Indexed: 07/25/2024] Open
Abstract
Introduction Bacteria frequently encounter nutrient limitation in nature. The ability of living in this nutrient shortage environment is vital for bacteria to preserve their population and important for some pathogenic bacteria to cause infectious diseases. Usually, we study how bacteria survive after nutrient depletion, a total starvation condition when bacteria almost cease growth and try to survive. However, nutrient limitation may not always lead to total starvation. Methods Bacterial adaptation to nutrient shortage was studied by determining bacterial growth curves, intracellular pH, intracellular amino acid contents, gene transcription, protein expression, enzyme activity, and translation and replication activities. Results No exogenous supply of methionine results in growth attenuation of Streptococcus pneumoniae, a human pathogen. In this paper, we refer to this inhibited growth state between ceased growth under total starvation and full-speed growth with full nutrients as semi-starvation. Similar to total starvation, methionine semi-starvation also leads to intracellular acidification. Surprisingly, it is intracellular acidification but not insufficient methionine synthesis that causes growth attenuation under methionine semi-starvation. With excessive glutamine supply in the medium, intracellular methionine level was not changed, while bacterial intracellular pH was elevated to ~ 7.6 (the optimal intracellular pH for pneumococcal growth) by glutamine deamination, and bacterial growth under semi-starvation was restored fully. Our data suggest that intracellular acidification decreases translation level and glutamine supply increases intracellular pH to restore translation level, thus restoring bacterial growth. Discussion This growth with intracellular pH adjustment by glutamine is a novel strategy we found for bacterial adaptation to nutrient shortage, which may provide new drug targets to inhibit growth of pathogenic bacteria under semi-starvation.
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Affiliation(s)
- Chengwang Zhang
- Department of Basic Medical Science, School of Medicine, Lishui University, Lishui, Zhejiang, China
| | - Juncheng Liu
- Department of Basic Medical Science, School of Medicine, Lishui University, Lishui, Zhejiang, China
| | - Xiaohui Liu
- National Protein Science Facility, Tsinghua University, Beijing, China
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Yueyu Xu
- Department of Basic Medical Science, School of Medicine, Lishui University, Lishui, Zhejiang, China
| | - Qingxiu Gan
- Department of Basic Medical Science, School of Medicine, Lishui University, Lishui, Zhejiang, China
| | - Qinqian Cheng
- Department of Basic Medical Science, School of Medicine, Lishui University, Lishui, Zhejiang, China
| | - Weiping Liu
- Department of Basic Medical Science, School of Medicine, Lishui University, Lishui, Zhejiang, China
| | - Xiangmin Gao
- Department of Basic Medical Science, School of Medicine, Lishui University, Lishui, Zhejiang, China
| | - Songquan Wu
- Department of Basic Medical Science, School of Medicine, Lishui University, Lishui, Zhejiang, China
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Senthil Kumar S, Johnson MDL, Wilson JE. Insights into the enigma of oral streptococci in carcinogenesis. Microbiol Mol Biol Rev 2024; 88:e0009523. [PMID: 38506551 PMCID: PMC11338076 DOI: 10.1128/mmbr.00095-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024] Open
Abstract
SUMMARYThe genus Streptococcus consists of a taxonomically diverse group of Gram-positive bacteria that have earned significant scientific interest due to their physiological and pathogenic characteristics. Within the genus Streptococcus, viridans group streptococci (VGS) play a significant role in the oral ecosystem, constituting approximately 80% of the oral biofilm. Their primary role as pioneering colonizers in the oral cavity with multifaceted interactions like adherence, metabolic signaling, and quorum sensing contributes significantly to the complex dynamics of the oral biofilm, thus shaping oral health and disease outcomes. Perturbations in oral streptococci composition drive oral dysbiosis and therefore impact host-pathogen interactions, resulting in oral inflammation and representing VGS as an opportunistic pathogen. The association of oral streptococci in tumors across distant organs, spanning the esophagus, stomach, pancreas, and colon, illuminates a potential association between oral streptococci, inflammation, and tumorigenesis. This finding emphasizes the need for further investigations into the role of oral streptococci in mucosal homeostasis and their involvement in carcinogenesis. Hence, here, we review the significance of oral streptococci in biofilm dynamics and how the perturbation may impact mucosal immunopathogenesis in the context of cancer, with a vision of exploiting oral streptococci for cancer intervention and for the development of non-invasive cancer diagnosis.
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Affiliation(s)
- Sangeetha Senthil Kumar
- Department of
Immunobiology, The University of
Arizona, Tucson,
Arizona, USA
- The University of
Arizona Cancer Center,
Tucson, Arizona, USA
| | - Michael D. L. Johnson
- Department of
Immunobiology, The University of
Arizona, Tucson,
Arizona, USA
- Valley Fever Center
for Excellence, The University of Arizona College of
Medicine, Tucson,
Arizona, USA
- BIO5 Institute, The
University of Arizona College of
Medicine, Tucson,
Arizona, USA
- Asthma and Airway
Disease Research Center, The University of Arizona College of
Medicine, Tucson,
Arizona, USA
| | - Justin E. Wilson
- Department of
Immunobiology, The University of
Arizona, Tucson,
Arizona, USA
- The University of
Arizona Cancer Center,
Tucson, Arizona, USA
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3
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Bazant J, Weiss A, Baldauf J, Schermuly RT, Hain T, Lucas R, Mraheil MA. Pneumococcal hydrogen peroxide regulates host cell kinase activity. Front Immunol 2024; 15:1414195. [PMID: 38903521 PMCID: PMC11188345 DOI: 10.3389/fimmu.2024.1414195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 05/21/2024] [Indexed: 06/22/2024] Open
Abstract
Introduction Protein kinases are indispensable reversible molecular switches that adapt and control protein functions during cellular processes requiring rapid responses to internal and external events. Bacterial infections can affect kinase-mediated phosphorylation events, with consequences for both innate and adaptive immunity, through regulation of antigen presentation, pathogen recognition, cell invasiveness and phagocytosis. Streptococcus pneumoniae (Spn), a human respiratory tract pathogen and a major cause of community-acquired pneumoniae, affects phosphorylation-based signalling of several kinases, but the pneumococcal mediator(s) involved in this process remain elusive. In this study, we investigated the influence of pneumococcal H2O2 on the protein kinase activity of the human lung epithelial H441 cell line, a generally accepted model of alveolar epithelial cells. Methods We performed kinome analysis using PamGene microarray chips and protein analysis in Western blotting in H441 lung cells infected with Spn wild type (SpnWT) or with SpnΔlctOΔspxB -a deletion mutant strongly attenuated in H2O2 production- to assess the impact of pneumococcal hydrogen peroxide (H2O2) on global protein kinase activity profiles. Results Our kinome analysis provides direct evidence that kinase activity profiles in infected H441 cells significantly vary according to the levels of pneumococcal H2O2. A large number of kinases in H441 cells infected with SpnWT are significantly downregulated, whereas this no longer occurs in cells infected with the mutant SpnΔlctOΔspxB strain, which lacks H2O2. In particular, we describe for the first time H2O2-mediated downregulation of Protein kinase B (Akt1) and activation of lymphocyte-specific tyrosine protein kinase (Lck) via H2O2-mediated phosphorylation.
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Affiliation(s)
- Jasmin Bazant
- Institute of Medical Microbiology, German Centre for Infection Giessen-Marburg-Langen Site, Justus-Liebig University Giessen, Giessen, Germany
| | - Astrid Weiss
- Department of Internal Medicine, Cardio–Pulmonary Institute (CPI), Member of German Center for Lung Research (DZL), Justus-Liebig University Giessen, Giessen, Germany
| | - Julia Baldauf
- Department of Internal Medicine, Cardio–Pulmonary Institute (CPI), Member of German Center for Lung Research (DZL), Justus-Liebig University Giessen, Giessen, Germany
| | - Ralph Theo Schermuly
- Department of Internal Medicine, Cardio–Pulmonary Institute (CPI), Member of German Center for Lung Research (DZL), Justus-Liebig University Giessen, Giessen, Germany
| | - Torsten Hain
- Institute of Medical Microbiology, German Centre for Infection Giessen-Marburg-Langen Site, Justus-Liebig University Giessen, Giessen, Germany
| | - Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA, United States
- Division of Pulmonary, Sleep and Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Mobarak Abu Mraheil
- Institute of Medical Microbiology, German Centre for Infection Giessen-Marburg-Langen Site, Justus-Liebig University Giessen, Giessen, Germany
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Womack E, Alibayov B, Vidal JE, Eichenbaum Z. Endogenously produced H 2O 2 is intimately involved in iron metabolism in Streptococcus pneumoniae. Microbiol Spectr 2024; 12:e0329723. [PMID: 38038454 PMCID: PMC10783112 DOI: 10.1128/spectrum.03297-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 11/02/2023] [Indexed: 12/02/2023] Open
Abstract
IMPORTANCE Heme degradation provides pathogens with growth essential iron, leveraging on the host heme reservoir. Bacteria typically import and degrade heme enzymatically, and here, we demonstrated a significant deviation from this dogma. We found that Streptococcus pneumoniae liberates iron from met-hemoglobin extracellularly, in a hydrogen peroxide (H2O2)- and cell-dependent manner; this activity serves as a major iron acquisition mechanism for S. pneumoniae. Inhabiting oxygen-rich environments is a major part of pneumococcal biology, and hence, H2O2-mediated heme degradation likely supplies iron during infection. Moreover, H2O2 reaction with ferrous hemoglobin but not with met-hemoglobin is known to result in heme breakdown. Therefore, the ability of pneumococci to degrade heme from met-hemoglobin is a new paradigm. Lastly, this study will inform other research as it demonstrates that extracellular degradation must be considered in the interpretations of experiments in which H2O2-producing bacteria are given heme or hemoproteins as an iron source.
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Affiliation(s)
- Edroyal Womack
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
| | - Babek Alibayov
- Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, Mississippi, USA
- School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Jorge E. Vidal
- Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, Mississippi, USA
- School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Zehava Eichenbaum
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
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Alibayov B, Scasny A, Vidal AGJ, Murin L, Wong S, Edwards KS, Eichembaun Z, Punshon T, Jackson BP, Hopp MT, McDaniel LS, Akerley BJ, Imhof D, Vidal JE. Oxidation of hemoglobin in the lung parenchyma facilitates the differentiation of pneumococci into encapsulated bacteria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.14.567109. [PMID: 38014009 PMCID: PMC10680745 DOI: 10.1101/2023.11.14.567109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Pneumococcal pneumonia causes cytotoxicity in the lung parenchyma but the underlying mechanism involves multiple factors contributing to cell death. Here, we discovered that hydrogen peroxide produced by Streptococcus pneumoniae (Spn-H 2 O 2 ) plays a pivotal role by oxidizing hemoglobin, leading to its polymerization and subsequent release of labile heme. At physiologically relevant levels, heme selected a population of encapsulated pneumococci. In the absence of capsule and Spn-H 2 O 2 , host intracellular heme exhibited toxicity towards pneumococci, thus acting as an antibacterial mechanism. Further investigation revealed that heme-mediated toxicity required the ABC transporter GlnPQ. In vivo experiments demonstrated that pneumococci release H 2 O 2 to cause cytotoxicity in bronchi and alveoli through the non-proteolytic degradation of intracellular proteins such as actin, tubulin and GAPDH. Overall, our findings uncover a mechanism of lung toxicity mediated by oxidative stress that favor the growth of encapsulated pneumococci suggesting a therapeutic potential by targeting oxidative reactions. Graphical abstract Highlights Oxidation of hemoglobin by Streptococcus pneumoniae facilitates differentiation to encapsulated pneumococci in vivo Differentiated S. pneumoniae produces capsule and hydrogen peroxide (Spn-H 2 O 2 ) as defense mechanism against host heme-mediated toxicity. Spn-H 2 O 2 -induced lung toxicity causes the oxidation and non-proteolytic degradation of intracellular proteins tubulin, actin, and GAPDH. The ABC transporter GlnPQ is a heme-binding complex that makes Spn susceptible to heme toxicity.
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Bazant J, Ott B, Hudel M, Hain T, Lucas R, Mraheil MA. Impact of Endogenous Pneumococcal Hydrogen Peroxide on the Activity and Release of Pneumolysin. Toxins (Basel) 2023; 15:593. [PMID: 37888624 PMCID: PMC10611280 DOI: 10.3390/toxins15100593] [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: 08/10/2023] [Revised: 09/21/2023] [Accepted: 09/26/2023] [Indexed: 10/28/2023] Open
Abstract
Streptococcus pneumoniae is the leading cause of community-acquired pneumonia. The pore-forming cholesterol-dependent cytolysin (CDC) pneumolysin (PLY) and the physiological metabolite hydrogen peroxide (H2O2) can greatly increase the virulence of pneumococci. Although most studies have focused on the contribution of both virulence factors to the course of pneumococcal infection, it is unknown whether or how H2O2 can affect PLY activity. Of note, S. pneumoniae exploits endogenous H2O2 as an intracellular signalling molecule to modulate the activity of several proteins. Here, we demonstrate that H2O2 negatively affects the haemolytic activity of PLY in a concentration-dependent manner. Prevention of cysteine-dependent sulfenylation upon substitution of the unique and highly conserved cysteine residue to serine in PLY significantly reduces the toxin's susceptibility to H2O2 treatment and completely abolishes the ability of DTT to activate PLY. We also detect a clear gradual correlation between endogenous H2O2 generation and PLY release, with decreased H2O2 production causing a decline in the release of PLY. Comparative transcriptome sequencing analysis of the wild-type S. pneumoniae strain and three mutants impaired in H2O2 production indicates enhanced expression of several genes involved in peptidoglycan (PG) synthesis and in the production of choline-binding proteins (CPBs). One explanation for the impact of H2O2 on PLY release is the observed upregulation of the PG bridge formation alanyltransferases MurM and MurN, which evidentially negatively affect the PLY release. Our findings shed light on the significance of endogenous pneumococcal H2O2 in controlling PLY activity and release.
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Affiliation(s)
- Jasmin Bazant
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
| | - Benjamin Ott
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
| | - Martina Hudel
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
| | - Torsten Hain
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
| | - Rudolf Lucas
- Vascular Biology Center, Department of Pharmacology and Toxicology and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Mobarak Abu Mraheil
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
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7
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Hernandez-Morfa M, Olivero NB, Zappia VE, Piñas GE, Reinoso-Vizcaino NM, Cian MB, Nuñez-Fernandez M, Cortes PR, Echenique J. The oxidative stress response of Streptococcus pneumoniae: its contribution to both extracellular and intracellular survival. Front Microbiol 2023; 14:1269843. [PMID: 37789846 PMCID: PMC10543277 DOI: 10.3389/fmicb.2023.1269843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 08/28/2023] [Indexed: 10/05/2023] Open
Abstract
Streptococcus pneumoniae is a gram-positive, aerotolerant bacterium that naturally colonizes the human nasopharynx, but also causes invasive infections and is a major cause of morbidity and mortality worldwide. This pathogen produces high levels of H2O2 to eliminate other microorganisms that belong to the microbiota of the respiratory tract. However, it also induces an oxidative stress response to survive under this stressful condition. Furthermore, this self-defense mechanism is advantageous in tolerating oxidative stress imposed by the host's immune response. This review provides a comprehensive overview of the strategies employed by the pneumococcus to survive oxidative stress. These strategies encompass the utilization of H2O2 scavengers and thioredoxins, the adaptive response to antimicrobial host oxidants, the regulation of manganese and iron homeostasis, and the intricate regulatory networks that control the stress response. Here, we have also summarized less explored aspects such as the involvement of reparation systems and polyamine metabolism. A particular emphasis is put on the role of the oxidative stress response during the transient intracellular life of Streptococcus pneumoniae, including coinfection with influenza A and the induction of antibiotic persistence in host cells.
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Affiliation(s)
- Mirelys Hernandez-Morfa
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Nadia B. Olivero
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Victoria E. Zappia
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - German E. Piñas
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Nicolas M. Reinoso-Vizcaino
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Melina B. Cian
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Mariana Nuñez-Fernandez
- Centro de Química Aplicada, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Paulo R. Cortes
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Jose Echenique
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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Battista M, Hoffmann B, Bachelot Y, Zimmermann L, Teuber L, Jost A, Linde S, Westermann M, Müller MM, Slevogt H, Hammerschmidt S, Figge MT, Vilhena C, Zipfel PF. The role of pneumococcal extracellular vesicles on the pathophysiology of the kidney disease hemolytic uremic syndrome. mSphere 2023; 8:e0014223. [PMID: 37358300 PMCID: PMC10449520 DOI: 10.1128/msphere.00142-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 04/20/2023] [Indexed: 06/27/2023] Open
Abstract
Streptococcus pneumoniae-induced hemolytic uremic syndrome (Sp-HUS) is a kidney disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. This disease is frequently underdiagnosed and its pathophysiology is poorly understood. In this work, we compared clinical strains, isolated from infant Sp-HUS patients, with a reference pathogenic strain D39, for host cytotoxicity and further explored the role of Sp-derived extracellular vesicles (EVs) in the pathogenesis of an HUS infection. In comparison with the wild-type strain, pneumococcal HUS strains caused significant lysis of human erythrocytes and increased the release of hydrogen peroxide. Isolated Sp-HUS EVs were characterized by performing dynamic light-scattering microscopy and proteomic analysis. Sp-HUS strain released EVs at a constant concentration during growth, yet the size of the EVs varied and several subpopulations emerged at later time points. The cargo of the Sp-HUS EVs included several virulence factors at high abundance, i.e., the ribosomal subunit assembly factor BipA, the pneumococcal surface protein A, the lytic enzyme LytC, several sugar utilization, and fatty acid synthesis proteins. Sp-HUS EVs strongly downregulated the expression of the endothelial surface marker platelet endothelial cell adhesion molecule-1 and were internalized by human endothelial cells. Sp-HUS EVs elicited the release of pro-inflammatory cytokines (interleukin [IL]-1β, IL-6) and chemokines (CCL2, CCL3, CXCL1) by human monocytes. These findings shed new light on the overall function of Sp-EVs, in the scope of infection-mediated HUS, and suggest new avenues of research for exploring the usefulness of Sp-EVs as therapeutic and diagnostic targets. IMPORTANCE Streptococcus pneumoniae-associated hemolytic uremic syndrome (Sp-HUS) is a serious and underdiagnosed deadly complication of invasive pneumococcal disease. Despite the introduction of the pneumococcal vaccine, cases of Sp-HUS continue to emerge, especially in children under the age of 2. While a lot has been studied regarding pneumococcal proteins and their role on Sp-HUS pathophysiology, little is known about the role of extracellular vesicles (EVs). In our work, we isolate and initially characterize EVs from a reference pathogenic strain (D39) and a strain isolated from a 2-year-old patient suffering from Sp-HUS. We demonstrate that despite lacking cytotoxicity toward human cells, Sp-HUS EVs are highly internalized by endothelial cells and can trigger cytokine and chemokine production in monocytes. In addition, this work specifically highlights the distinct morphological characteristics of Sp-HUS EVs and their unique cargo. Overall, this work sheds new light into potentially relevant players contained in EVs that might elucidate about pneumococcal EVs biogenesis or pose as interesting candidates for vaccine design.
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Affiliation(s)
- Miriana Battista
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Bianca Hoffmann
- Applied Systems Biology, HKI-Center for Systems Biology of Infection, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany
| | - Yann Bachelot
- Applied Systems Biology, HKI-Center for Systems Biology of Infection, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany
| | - Lioba Zimmermann
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Laura Teuber
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Aurélie Jost
- Microverse Imaging Center, Cluster of Excellence “Balance of the Microverse,” Friedrich Schiller University, Jena, Germany
| | - Susanne Linde
- Center for Electron Microscopy, Jena University Hospital, Jena, Germany
| | - Martin Westermann
- Center for Electron Microscopy, Jena University Hospital, Jena, Germany
| | - Mario M. Müller
- Septomics Research Center, Jena University Hospital, Jena, Germany
| | - Hortense Slevogt
- Septomics Research Center, Jena University Hospital, Jena, Germany
| | - Sven Hammerschmidt
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Marc Thilo Figge
- Applied Systems Biology, HKI-Center for Systems Biology of Infection, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany
- Faculty of Biological Sciences, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Cláudia Vilhena
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Peter F. Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
- Faculty of Biological Sciences, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
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9
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Klabunde B, Wesener A, Bertrams W, Ringshandl S, Halder LD, Vollmeister E, Schmeck B, Benedikter BJ. Streptococcus pneumoniae disrupts the structure of the golgi apparatus and subsequent epithelial cytokine response in an H 2O 2-dependent manner. Cell Commun Signal 2023; 21:208. [PMID: 37592354 PMCID: PMC10436572 DOI: 10.1186/s12964-023-01233-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/17/2023] [Indexed: 08/19/2023] Open
Abstract
BACKGROUND Lung infections caused by Streptococcus pneumonia are a global leading cause of death. The reactive oxygen species H2O2 is one of the virulence factors of Streptococcus pneumoniae. The Golgi apparatus is essential for the inflammatory response of a eukaryotic cell. Golgi fragmentation was previously shown to be induced by bacterial pathogens and in response to H2O2 treatment. This led us to investigate whether the Golgi apparatus is actively involved and targeted in host-pathogen interactions during pneumococcal infections. METHODS Following in vitro infection of BEAS-2B bronchial epithelial cells with Streptococcus pneumoniae for 16 h, the structure of the Golgi apparatus was assessed by fluorescence staining of the Golgi-associated protein, Golgin-97. To investigate the effect of H2O2 production on Golgi structure, BEAS-2B cells were treated with H2O2 or the H2O2 degrading enzyme Catalase, prior to Golgi staining. Artificial disruption of the Golgi apparatus was induced by treatment of cells with the GBF1 inhibitor, Golgicide A. A proinflammatory cellular response was induced by treatment of cells with the bacterial cell wall component and TLR4 ligand lipoteichoic acid. RESULTS In vitro infection of bronchial epithelial cells with wild type Streptococcus pneumoniae led to a disruption of normal Golgi structure. Golgi fragmentation was not observed after deletion of the pneumococcal H2O2-producing gene, spxB, or neutralization of H2O2 by catalase treatment, but could be induced by H2O2 treatment. Streptococcus pneumoniae infection significantly reduced host cell protein glycosylation and artificial disruption of Golgi structure significantly reduced bacterial adherence, but increased bacterial counts in the supernatant. To understand if this effect depended on cell-contact or soluble factors, pneumococci were treated with cell-supernatant of cells treated with Golgicide A and/or lipoteichoic acid. This approach revealed that lipoteichoic acid conditioned medium inhibits bacterial replication in presence of host cells. In contrast, artificial Golgi fragmentation by Golgicide A treatment prior to lipoteichoic acid treatment rescued bacterial replication. This effect was associated with an increase of IL-6 and IL-8 in the supernatant of lipoteichoic acid treated cells. The increased cytokine release was abolished if cells were treated with Golgicide A prior to lipoteichoic acid treatment. CONCLUSION Streptococcus pneumoniae disrupts the Golgi apparatus in an H2O2-dependent manner, thereby inhibiting paracrine anti-infective mechanisms. Video Abstract.
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Affiliation(s)
- Björn Klabunde
- Institute for Lung Research, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University Marburg, Marburg, Germany
| | - André Wesener
- Institute for Lung Research, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University Marburg, Marburg, Germany
| | - Wilhelm Bertrams
- Institute for Lung Research, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University Marburg, Marburg, Germany
| | - Stephan Ringshandl
- Institute for Lung Research, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University Marburg, Marburg, Germany
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Marburg, Germany
| | - Luke D Halder
- Institute for Lung Research, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University Marburg, Marburg, Germany
| | - Evelyn Vollmeister
- Institute for Lung Research, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University Marburg, Marburg, Germany
| | - Bernd Schmeck
- Institute for Lung Research, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University Marburg, Marburg, Germany.
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Marburg, Germany.
- Institute for Lung Health (ILH), Giessen, Germany.
- Department of Medicine, Pulmonary and Critical Care Medicine, University Medical Center Marburg, Philipps-University Marburg, Marburg, Germany.
- Member of the German Center for Lung Research (DZL), German Center for Infectious Disease Research (DZIF), Marburg, Germany.
- Core Facility Flow Cytometry - Bacterial Vesicles, Philipps-University Marburg, Marburg, Germany.
| | - Birke J Benedikter
- Institute for Lung Research, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University Marburg, Marburg, Germany
- School for Mental Health and Neuroscience, University Eye Clinic Maastricht, Maastricht University Medical Center (MUMC+), Maastricht University, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
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10
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Li H, Niu C, Luo J, Huang Z, Zhou W. Anticariogenic Activity of Celastrol and Its Enhancement of Streptococcal Antagonism in Multispecies Biofilm. Antibiotics (Basel) 2023; 12:1245. [PMID: 37627665 PMCID: PMC10451999 DOI: 10.3390/antibiotics12081245] [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: 06/27/2023] [Revised: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 08/27/2023] Open
Abstract
Dental caries is a chronic disease resulting from dysbiosis in the oral microbiome. Antagonism of commensal Streptococcus sanguinis and Streptococcus gordonii against cariogenic Streptococcus mutans is pivotal to keep the microecological balance. However, concerns are growing on antimicrobial agents in anticaries therapy, for broad spectrum antimicrobials may have a profound impact on the oral microbial community, especially on commensals. Here, we report celastrol, extracted from Traditional Chinese Medicine's Tripterygium wilfordii (TW) plant, as a promising anticaries candidate. Our results revealed that celastrol showed antibacterial and antibiofilm activity against cariogenic bacteria S. mutans while exhibiting low cytotoxicity. By using a multispecies biofilm formed by S. mutans UA159, S. sanguinis SK36, and S. gordonii DL1, we observed that even at relatively low concentrations, celastrol reduced S. mutans proportion and thereby inhibited lactic acid production as well as water-insoluble glucan formation. We found that celastrol thwarted S. mutans outgrowth through the activation of pyruvate oxidase (SpxB) and H2O2-dependent antagonism between commensal oral streptococci and S. mutans. Our data reveal new anticaries properties of celastrol that enhance oral streptococcal antagonism, which thwarts S. mutans outgrowth, indicating its potential to maintain oral microbial balance for prospective anticaries therapy.
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Affiliation(s)
- Hao Li
- Department of Endodontics, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, 500 Quxi Road, Shanghai 200011, China; (H.L.)
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, No. 639, Zhizaoju Road, Shanghai 200011, China
| | - Chenguang Niu
- Department of Endodontics, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, 500 Quxi Road, Shanghai 200011, China; (H.L.)
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, No. 639, Zhizaoju Road, Shanghai 200011, China
| | - Junyuan Luo
- Department of Endodontics, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, 500 Quxi Road, Shanghai 200011, China; (H.L.)
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, No. 639, Zhizaoju Road, Shanghai 200011, China
| | - Zhengwei Huang
- Department of Endodontics, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, 500 Quxi Road, Shanghai 200011, China; (H.L.)
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, No. 639, Zhizaoju Road, Shanghai 200011, China
| | - Wei Zhou
- Department of Endodontics, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, 500 Quxi Road, Shanghai 200011, China; (H.L.)
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, No. 639, Zhizaoju Road, Shanghai 200011, China
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11
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Scasny A, Alibayov B, Khan F, Rao SJ, Murin L, Jop Vidal AG, Smith P, Wei L, Edwards K, Warncke K, Vidal JE. Oxidation of hemoproteins by Streptococcus pneumoniae collapses the cell cytoskeleton and disrupts mitochondrial respiration leading to cytotoxicity of human lung cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.07.544089. [PMID: 37333138 PMCID: PMC10274756 DOI: 10.1101/2023.06.07.544089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Streptococcus pneumoniae (Spn) causes pneumonia that kills millions through acute toxicity and invasion of the lung parenchyma. During aerobic respiration, Spn releases hydrogen peroxide (Spn-H 2 O 2 ), as a by-product of enzymes SpxB and LctO, and causes cell death with signs of both apoptosis and pyroptosis by oxidizing unknown cell targets. Hemoproteins are molecules essential for life and prone to oxidation by H 2 O 2 . We recently demonstrated that during infection-mimicking conditions, Spn-H 2 O 2 oxidizes the hemoprotein hemoglobin (Hb), releasing toxic heme. In this study, we investigated details of the molecular mechanism(s) by which the oxidation of hemoproteins by Spn-H 2 O 2 causes human lung cell death. Spn strains, but not H 2 O 2 -deficient SpnΔ spxB Δ lctO strains caused time-dependent cell cytotoxicity characterized by the rearrangement of the actin, the loss of the microtubule cytoskeleton and nuclear contraction. Disruption of the cell cytoskeleton correlated with the presence of invasive pneumococci and an increase of intracellular reactive oxygen species. In cell culture, the oxidation of Hb or cytochrome c (Cyt c ) caused DNA degradation and mitochondrial dysfunction from inhibition of complex I-driven respiration, which was cytotoxic to human alveolar cells. Oxidation of hemoproteins resulted in the creation of a radical, which was identified as a protein derived side chain tyrosyl radical by using electron paramagnetic resonance (EPR). Thus, we demonstrate that Spn invades lung cells, releasing H 2 O 2 that oxidizes hemoproteins, including Cyt c , catalyzing the formation of a tyrosyl side chain radical on Hb and causing mitochondrial disruption, that ultimately leads to the collapse of the cell cytoskeleton.
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12
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Kant S, Sun Y, Pancholi V. StkP- and PhpP-Mediated Posttranslational Modifications Modulate the S. pneumoniae Metabolism, Polysaccharide Capsule, and Virulence. Infect Immun 2023; 91:e0029622. [PMID: 36877045 PMCID: PMC10112228 DOI: 10.1128/iai.00296-22] [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: 07/15/2022] [Accepted: 02/09/2023] [Indexed: 03/07/2023] Open
Abstract
Pneumococcal Ser/Thr kinase (StkP) and its cognate phosphatase (PhpP) play a crucial role in bacterial cytokinesis. However, their individual and reciprocal metabolic and virulence regulation-related functions have yet to be adequately investigated in encapsulated pneumococci. Here, we demonstrate that the encapsulated pneumococcal strain D39-derived D39ΔPhpP and D39ΔStkP mutants displayed differential cell division defects and growth patterns when grown in chemically defined media supplemented with glucose or nonglucose sugars as the sole carbon source. Microscopic and biochemical analyses supported by RNA-seq-based global transcriptomic analyses of these mutants revealed significantly down- and upregulated polysaccharide capsule formation and cps2 genes in D39ΔPhpP and D39ΔStkP mutants, respectively. While StkP and PhpP individually regulated several unique genes, they also participated in sharing the regulation of the same set of differentially regulated genes. Cps2 genes were reciprocally regulated in part by the StkP/PhpP-mediated reversible phosphorylation but independent of the MapZ-regulated cell division process. StkP-mediated dose-dependent phosphorylation of CcpA proportionately inhibited CcpA-binding to Pcps2A, supporting increased cps2 gene expression and capsule formation in D39ΔStkP. While the attenuation of the D39ΔPhpP mutant in two mouse infection models corroborated with several downregulated capsules-, virulence-, and phosphotransferase systems (PTS)-related genes, the D39ΔStkP mutant with increased amounts of polysaccharide capsules displayed significantly decreased virulence in mice compared to the D39 wild-type, but more virulence compared to D39ΔPhpP. NanoString technology-based inflammation-related gene expression and Meso Scale Discovery-based multiplex chemokine analysis of human lung cells cocultured with these mutants confirmed their distinct virulence phenotypes. StkP and PhpP may, therefore, serve as critical therapeutic targets.
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Affiliation(s)
- Sashi Kant
- Department of Pathology, Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Youcheng Sun
- Department of Pathology, Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Vijay Pancholi
- Department of Pathology, Ohio State University College of Medicine, Columbus, Ohio, USA
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13
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Ma X, Lang J, Chen P, Tang W, Shindler S, Yang R. A cascade nanozyme with antimicrobial effects against nontypeable Haemophilus influenzae. NANOSCALE 2023; 15:1014-1023. [PMID: 36602182 DOI: 10.1039/d2nr04306h] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Otitis media (OM) is the main cause of pediatric antibiotic prescriptions. Nontypeable Haemophilus influenzae (NTHi) is a major OM pathogen, which forms a biofilm that resists conventional antimicrobials and immune clearance. Thus, novel treatments that are effective against NTHi and its biofilm are urgently required. Nanozymes (often inorganic nanoparticles) mimic natural enzymes' catalytic activities to generate strong antimicrobials at the site of infection, and thus represent one of the emerging solutions to the crisis of antimicrobial resistance. They mimic natural enzymes' activities, such as generating strong antimicrobials catalytically at the site of infection, to minimize overexposure. However, that in situ generation often relies on Reactive Oxygen Species (ROS) as precursors, a prerequisite that limits the broad deployment of nanozymes. To address this challenge, we designed a cascade nanozyme that generates an antiseptic, HOBr, from a ubiquitous non-ROS, i.e., O2, which successfully eradicates NTHi. The cascade nanozyme simultaneously exhibits glucose oxidase (GOx)-like activity from gold nanoparticles (AuNPs) and haloperoxidase (HPO)-mimicking activity from vanadium pentoxide nanowires (V2O5 NWs) connected using dopamine (DPA). The cascade nanozyme demonstrated strong antimicrobial efficacy against NTHi and its biofilm, while showing improved biocompatibility compared to the nanozyme of V2O5 NWs alone. The cascade nanozyme thus points to a material-oriented infectious disease treatment strategy, where small-molecule antimicrobials are generated in real time at the site of infection for the benefit of autonomous dosing. This strategy potentially mitigates the development of antimicrobial resistance and reduces side effects.
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Affiliation(s)
- Xiaojing Ma
- Robert F. Smith School of Chemical & Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA.
| | - Jiayan Lang
- Robert F. Smith School of Chemical & Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA.
| | - Pengyu Chen
- Robert F. Smith School of Chemical & Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA.
| | - Wenjing Tang
- Robert F. Smith School of Chemical & Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA.
| | - Simon Shindler
- Robert F. Smith School of Chemical & Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA.
| | - Rong Yang
- Robert F. Smith School of Chemical & Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA.
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14
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Geerts N, De Vooght L, Passaris I, Delputte P, Van den Bergh B, Cos P. Antibiotic Tolerance Indicative of Persistence Is Pervasive among Clinical Streptococcus pneumoniae Isolates and Shows Strong Condition Dependence. Microbiol Spectr 2022; 10:e0270122. [PMID: 36374111 PMCID: PMC9769776 DOI: 10.1128/spectrum.02701-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Accepted: 10/16/2022] [Indexed: 11/16/2022] Open
Abstract
Streptococcus pneumoniae is an important human pathogen, being one of the most common causes of community-acquired pneumonia and otitis media. Antibiotic resistance in S. pneumoniae is an emerging problem, as it depletes our arsenal of effective drugs. In addition, persistence also contributes to the antibiotic crisis in many other pathogens, yet for S. pneumoniae, little is known about antibiotic-tolerant persisters and robust experimental means are lacking. Persister cells are phenotypic variants that exist as a subpopulation within a clonal culture. Being tolerant to lethal antibiotics, they underly the chronic nature of a variety of infections and even help in acquiring genetic resistance. In this study, we set out to identify and characterize persistence in S. pneumoniae. Specifically, we followed different strategies to overcome the self-limiting nature of S. pneumoniae as a confounding factor in the prolonged monitoring of antibiotic survival needed to study persistence. Under optimized conditions, we identified genuine persisters in various growth phases and for four relevant antibiotics through biphasic survival dynamics and heritability assays. Finally, we detected a high variety in antibiotic survival levels across a diverse collection of S. pneumoniae clinical isolates, which assumes that a high natural diversity in persistence is widely present in S. pneumoniae. Collectively, this proof of concept significantly progresses the understanding of the importance of antibiotic persistence in S. pneumoniae infections, which will set the stage for characterizing its relevance to clinical outcomes and advocates for increased attention to the phenotype in both fundamental and clinical research. IMPORTANCE S. pneumoniae is considered a serious threat by the Centers for Disease Control and Prevention because of rising antibiotic resistance. In addition to resistance, bacteria can also survive lethal antibiotic treatment by developing antibiotic tolerance, more specifically, antibiotic tolerance through persistence. This phenotypic variation seems omnipresent among bacterial life, is linked to therapy failure, and acts as a catalyst for resistance development. This study gives the first proof of the presence of persister cells in S. pneumoniae and shows a high variety in persistence levels among diverse strains, suggesting that persistence is a general trait in S. pneumoniae cultures. Our work advocates for higher interest for persistence in S. pneumoniae as a contributing factor for therapy failure and resistance development.
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Affiliation(s)
- Nele Geerts
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), Wilrijk, Belgium
| | - Linda De Vooght
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), Wilrijk, Belgium
| | | | - Peter Delputte
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), Wilrijk, Belgium
| | - Bram Van den Bergh
- Centre of Microbial and Plant Genetics, Department of Molecular and Microbial Systems, KU Leuven, Leuven, Belgium
- Center for Microbiology, Flanders Institute for Biotechnology, VIB, Leuven, Belgium
| | - Paul Cos
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), Wilrijk, Belgium
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15
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Hernandez-Morfa M, Reinoso-Vizcaíno NM, Olivero NB, Zappia VE, Cortes PR, Jaime A, Echenique J. Host Cell Oxidative Stress Promotes Intracellular Fluoroquinolone Persisters of Streptococcus pneumoniae. Microbiol Spectr 2022; 10:e0436422. [PMID: 36445159 PMCID: PMC9769771 DOI: 10.1128/spectrum.04364-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 11/11/2022] [Indexed: 12/02/2022] Open
Abstract
Bacterial persisters represent a small subpopulation that tolerates high antibiotic concentrations without acquiring heritable resistance, and it may be generated by environmental factors. Here, we report the first antibiotic persistence mechanism in Streptococcus pneumoniae, which is induced by oxidative stress conditions and allows the pneumococcus to survive in the presence of fluoroquinolones. We demonstrated that fluoroquinolone persistence is prompted by both the impact of growth arrest and the oxidative stress response induced by H2O2 in bacterial cells. This process protected pneumococci against the deleterious effects of high ROS levels induced by fluoroquinolones. Importantly, S. pneumoniae develops persistence during infection, and is dependent on the oxidative stress status of the host cells, indicating that its transient intracellular life contributes to this mechanism. Furthermore, our findings suggest persistence may influence the outcome of antibiotic therapy and be part of a multistep mechanism in the evolution of fluoroquinolone resistance. IMPORTANCE In S. pneumoniae, different mechanisms that counteract antibiotic effects have been described, such as vancomycin tolerance, heteroresistance to penicillin and fluoroquinolone resistance, which critically affect the therapeutic efficacy. Antibiotic persistence is a type of antibiotic tolerance that allows a bacterial subpopulation to survive lethal antimicrobial concentrations. In this work, we used a host-cell infection model to reveal fluoroquinolone persistence in S. pneumoniae. This mechanism is induced by oxidative stress that the pneumococcus must overcome to survive in host cells. Many fluoroquinolones, such as levofloxacin and moxifloxacin, have a broad spectrum of activity against bacterial pathogens of community-acquired pneumonia, and they are used to treat pneumococcal diseases. However, the emergence of fluoroquinolone-resistant strains complicates antibiotic treatment of invasive infections. Consequently, antibiotic persistence in S. pneumoniae is clinically relevant due to prolonged exposure to fluoroquinolones likely favors the acquisition of mutations that generate antibiotic resistance in persisters. In addition, this work contributes to the knowledge of antibiotic persistence mechanisms in bacteria.
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Affiliation(s)
- Mirelys Hernandez-Morfa
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Nicolás M. Reinoso-Vizcaíno
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Nadia B. Olivero
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Victoria E. Zappia
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Paulo R. Cortes
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Andrea Jaime
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - José Echenique
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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Alibayov B, Scasny A, Khan F, Creel A, Smith P, Vidal AGJ, Fitisemanu FM, Padilla-Benavides T, Weiser JN, Vidal JE. Oxidative Reactions Catalyzed by Hydrogen Peroxide Produced by Streptococcus pneumoniae and Other Streptococci Cause the Release and Degradation of Heme from Hemoglobin. Infect Immun 2022; 90:e0047122. [PMID: 36409115 PMCID: PMC9753736 DOI: 10.1128/iai.00471-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 10/25/2022] [Indexed: 11/23/2022] Open
Abstract
Streptococcus pneumoniae (Spn) strains cause pneumonia that kills millions every year worldwide. Spn produces Ply, a hemolysin that lyses erythrocytes releasing hemoglobin, and also produces the pro-oxidant hydrogen peroxide (Spn-H2O2) during growth. The hallmark of the pathophysiology of hemolytic diseases is the oxidation of hemoglobin, but oxidative reactions catalyzed by Spn-H2O2 have been poorly studied. We characterized the oxidation of hemoglobin by Spn-H2O2. We prepared a series of single-mutant (ΔspxB or ΔlctO), double-mutant (ΔspxB ΔlctO), and complemented strains in TIGR4, D39, and EF3030. We then utilized an in vitro model with oxyhemoglobin to demonstrate that oxyhemoglobin was oxidized rapidly, within 30 min of incubation, by Spn-H2O2 to methemoglobin and that the main source of Spn-H2O2 was pyruvate oxidase (SpxB). Moreover, extended incubation caused the release and the degradation of heme. We then assessed oxidation of hemoglobin and heme degradation by other bacterial inhabitants of the respiratory tract. All hydrogen peroxide-producing streptococci tested caused the oxidation of hemoglobin and heme degradation, whereas bacterial species that produce <1 μM H2O2 neither oxidized hemoglobin nor degraded heme. An ex vivo bacteremia model confirmed that oxidation of hemoglobin and heme degradation occurred concurrently with hemoglobin that was released from erythrocytes by Ply. Finally, gene expression studies demonstrated that heme, but not red blood cells or hemoglobin, induced upregulated transcription of the spxB gene. Oxidation of hemoglobin may be important for pathogenesis and for the symbiosis of hydrogen peroxide-producing bacteria with other species by providing nutrients such as iron.
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Affiliation(s)
- Babek Alibayov
- Department of Cell and Molecular Biology, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Anna Scasny
- Department of Cell and Molecular Biology, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Faidad Khan
- Department of Cell and Molecular Biology, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Aidan Creel
- Department of Cell and Molecular Biology, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
- Summer Undergraduate Research Experience Program, School of Graduate Studies in the Health Sciences, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Perriann Smith
- Department of Cell and Molecular Biology, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
- Mississippi INBRE program, University of Southern Mississippi, Hattiesburg, Mississippi, USA
| | - Ana G. Jop Vidal
- Department of Cell and Molecular Biology, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | | | | | - Jeffrey N. Weiser
- Department of Microbiology, NYU Langone Health, New York, New York, USA
| | - Jorge E. Vidal
- Department of Cell and Molecular Biology, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
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17
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Lang J, Ma X, Liu SS, Streever DL, Serota MD, Franklin T, Loew ER, Yang R. On-Demand Synthesis of Antiseptics at the Site of Infection for Treatment of Otitis Media. NANO TODAY 2022; 47:101672. [PMID: 36968792 PMCID: PMC10035358 DOI: 10.1016/j.nantod.2022.101672] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Otitis media (OM) is the main reason for pediatric antibiotic prescriptions. The current treatment mandates a rigorous regimen of multidose antibiotics over 5-10 days. The systemic antibiotic exposure and often prematurely terminated treatment due to the challenge of drug administration to young patients are believed to breed antibiotic resistance. To address these challenges, we designed a local treatment that converted a metabolic product (H2O2) of an OM pathogen (Streptococcus pneumoniae) into a potent antiseptic (HOBr), a reaction catalyzed by locally administered vanadium pentoxide nanowires. The therapeutic, HOBr, was only synthesized in the presence of the pathogen, enabling on-demand generation of therapeutics for OM treatment. Hypohalous acids are broad-spectrum and have a long history in general disinfection applications without breeding substantial drug resistance. A single dose of the nanowire formulation eradicated OM in a standard chinchilla model in 7 days with no observable tissue toxicity or negative impact on hearing sensitivity.
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Affiliation(s)
- Jiayan Lang
- Robert F. Smith School of Chemical & Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
- These authors contributed equally to this work
| | - Xiaojing Ma
- Robert F. Smith School of Chemical & Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
- These authors contributed equally to this work
| | - Sophie S. Liu
- Robert F. Smith School of Chemical & Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Danielle L. Streever
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Max D. Serota
- Robert F. Smith School of Chemical & Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Trevor Franklin
- Robert F. Smith School of Chemical & Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Ellis R. Loew
- College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Rong Yang
- Robert F. Smith School of Chemical & Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
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18
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The Catalase KatA Contributes to Microaerophilic H2O2 Priming to Acquire an Improved Oxidative Stress Resistance in Staphylococcus aureus. Antioxidants (Basel) 2022; 11:antiox11091793. [PMID: 36139867 PMCID: PMC9495333 DOI: 10.3390/antiox11091793] [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: 08/08/2022] [Revised: 08/29/2022] [Accepted: 09/07/2022] [Indexed: 11/16/2022] Open
Abstract
Staphylococcus aureus has to cope with oxidative stress during infections. In this study, S. aureus was found to be resistant to 100 mM H2O2 during aerobic growth. While KatA was essential for this high aerobic H2O2 resistance, the peroxiredoxin AhpC contributed to detoxification of 0.4 mM H2O2 in the absence of KatA. In addition, the peroxiredoxins AhpC, Tpx and Bcp were found to be required for detoxification of cumene hydroperoxide (CHP). The high H2O2 tolerance of aerobic S. aureus cells was associated with priming by endogenous H2O2 levels, which was supported by an oxidative shift of the bacillithiol redox potential to −291 mV compared to −310 mV in microaerophilic cells. In contrast, S. aureus could be primed by sub-lethal doses of 100 µM H2O2 during microaerophilic growth to acquire an improved resistance towards the otherwise lethal triggering stimulus of 10 mM H2O2. This microaerophilic priming was dependent on increased KatA activity, whereas aerobic cells showed constitutive high KatA activity. Thus, KatA contributes to the high H2O2 resistance of aerobic cells and to microaerophilic H2O2 priming in order to survive the subsequent lethal triggering doses of H2O2, allowing the adaptation of S. aureus under infections to different oxygen environments.
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19
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Pham H, Tran TDT, Yang Y, Ahn JH, Hur HG, Kim YH. Analysis of phylogenetic markers for classification of a hydrogen peroxide producing Streptococcus oralis isolated from saliva by a newly devised differential medium. J Microbiol 2022; 60:795-805. [DOI: 10.1007/s12275-022-2261-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 11/30/2022]
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20
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Induction of the macrolide-resistance efflux pump Mega inhibits intoxication of Staphylococcus aureus strains by Streptococcus pneumoniae. Microbiol Res 2022; 263:127134. [PMID: 35905580 DOI: 10.1016/j.micres.2022.127134] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 07/06/2022] [Accepted: 07/13/2022] [Indexed: 11/21/2022]
Abstract
Streptococcus pneumoniae (Spn) kills Staphylococcus aureus (Sau) through a contact-dependent mechanism that is catalyzed by cations, including iron, to convert hydrogen peroxide (H2O2) to highly toxic hydroxyl radicals (•OH). There are two well-characterized ABC transporters that contribute to the pool of iron in Spn, named Pia and Piu. Some Spn strains have acquired genes mef(E)/mel encoding another ABC trasporter (Mega) that produces an inducible efflux pump for resistance to macrolides. In macrolide-resistant Spn clinical isolates the insertion of Mega class 1. IV and 2. IVc deleted the locus piaABCD and these strains were attenuated for intoxicating Sau. The goal of this study was to investigate if the disruption of iron acquisition, or the antimicrobial-resistance activity of Mega, contributed to inhibiting the killing mechanism. Neither depletion of iron with 2,2'-dipyridyl-d8 (DP) nor incubating with a double knockout mutant SpnΔpiaAΔpiuA, inhibited killing of Sau. Clinical Spn strains carrying Mega1. IV or Mega2. IVc showed a significant delay for killing Sau. An ex vivo recombination system was used to transfer Mega1. IV or Mega2. IVc to reference Spn strains, which was confirmed by whole genome sequencing, and recombinants TIGR4Mega2. IVc, D39Mega2. IVc, and D39Mega1. IV were delayed for killing Sau. We then compared Sau killing of selected Mega-carrying Spn strains when incubated with sub-inhibitory erythromycin (Mega-induced) or sub-inhibitory cefuroxime. Remarkably, killing of Sau was completely inhibited under the Mega-induced condition whereas incubation with cefuroxime did not interfere with killing. Both mef(E) and mel were upregulated > 400-fold, and spxB (encoding an enzyme responsible for production of most H2O2) was upregulated 14.2-fold, whereas transcription of the autolysin (lytA) gene was downregulated when incubated with erythromycin. We demonstrated that erythromycin induction of Mega inhibits the •OH-mediated intoxication of Sau and that the inhibition occurred at the post-translational level suggesting that an imbalance of ions in the membrane inhibits these reactions.
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21
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Zhang Y, Martin JE, Edmonds KA, Winkler ME, Giedroc DP. SifR is an Rrf2-family quinone sensor associated with catechol iron uptake in Streptococcus pneumoniae D39. J Biol Chem 2022; 298:102046. [PMID: 35597283 PMCID: PMC9218516 DOI: 10.1016/j.jbc.2022.102046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/29/2022] [Accepted: 05/03/2022] [Indexed: 01/15/2023] Open
Abstract
Streptococcus pneumoniae (pneumococcus) is a Gram-positive commensal and human respiratory pathogen. How this bacterium satisfies its nutritional iron (Fe) requirement in the context of endogenously produced hydrogen peroxide is not well understood. Here, we characterize a novel virulence-associated Rrf2-family transcriptional repressor that we term SifR (streptococcal IscR-like family transcriptional repressor) encoded by spd_1448 and conserved in Streptococci. Global transcriptomic analysis of a ΔsifR strain defines the SifR regulon as genes encoding a candidate catechol dioxygenase CatE, an uncharacterized oxidoreductase YwnB, a candidate flavin-dependent ferric reductase YhdA, a candidate heme-based ferric reductase domain-containing protein and the Piu (pneumococcus iron uptake) Fe transporter (piuBCDA). Previous work established that membrane-anchored PiuA binds FeIII-bis-catechol or monocatechol complexes with high affinity, including the human catecholamine stress hormone, norepinephrine. We demonstrate that SifR senses quinone via a single conserved cysteine that represses its regulon when in the reduced form. Upon reaction with catechol-derived quinones, we show that SifR dissociates from the DNA leading to regulon derepression, allowing the pneumococcus to access a catechol-derived source of Fe while minimizing reactive electrophile stress induced by quinones. Consistent with this model, we show that CatE is an FeII-dependent 2,3-catechol dioxygenase with broad substrate specificity, YwnB is an NAD(P)H-dependent quinone reductase capable of reducing the oxidized and cyclized norepinephrine, adrenochrome, and YhdA is capable of reducing a number of FeIII complexes, including PiuA-binding transport substrates. These findings are consistent with a model where FeIII-catechol complexes serve as significant nutritional Fe sources in the host.
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Affiliation(s)
- Yifan Zhang
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA; Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, USA
| | - Julia E Martin
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA; Department of Biological Sciences, Idaho State University, Pocatello, Idaho, USA
| | | | - Malcolm E Winkler
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, USA; Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, Indiana, USA; Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, USA.
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22
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Fakhoury JN, Zhang Y, Edmonds KA, Bringas M, Luebke JL, Gonzalez-Gutierrez G, Capdevila DA, Giedroc DP. Functional asymmetry and chemical reactivity of CsoR family persulfide sensors. Nucleic Acids Res 2021; 49:12556-12576. [PMID: 34755876 PMCID: PMC8643695 DOI: 10.1093/nar/gkab1040] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/12/2021] [Accepted: 10/14/2021] [Indexed: 01/14/2023] Open
Abstract
CstR is a persulfide-sensing member of the functionally diverse copper-sensitive operon repressor (CsoR) superfamily. While CstR regulates the bacterial response to hydrogen sulfide (H2S) and more oxidized reactive sulfur species (RSS) in Gram-positive pathogens, other dithiol-containing CsoR proteins respond to host derived Cu(I) toxicity, sometimes in the same bacterial cytoplasm, but without regulatory crosstalk in cells. It is not clear what prevents this crosstalk, nor the extent to which RSS sensors exhibit specificity over other oxidants. Here, we report a sequence similarity network (SSN) analysis of the entire CsoR superfamily, which together with the first crystallographic structure of a CstR and comprehensive mass spectrometry-based kinetic profiling experiments, reveal new insights into the molecular basis of RSS specificity in CstRs. We find that the more N-terminal cysteine is the attacking Cys in CstR and is far more nucleophilic than in a CsoR. Moreover, our CstR crystal structure is markedly asymmetric and chemical reactivity experiments reveal the functional impact of this asymmetry. Substitution of the Asn wedge between the resolving and the attacking thiol with Ala significantly decreases asymmetry in the crystal structure and markedly impacts the distribution of species, despite adopting the same global structure as the parent repressor. Companion NMR, SAXS and molecular dynamics simulations reveal that the structural and functional asymmetry can be traced to fast internal dynamics of the tetramer. Furthermore, this asymmetry is preserved in all CstRs and with all oxidants tested, giving rise to markedly distinct distributions of crosslinked products. Our exploration of the sequence, structural, and kinetic features that determine oxidant-specificity suggest that the product distribution upon RSS exposure is determined by internal flexibility.
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Affiliation(s)
- Joseph N Fakhoury
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave, Bloomington, IN 47405-7102, USA
| | - Yifan Zhang
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave, Bloomington, IN 47405-7102, USA.,Department of Molecular and Cellular Biochemistry, Indiana University, 212 S. Hawthorne Drive, Bloomington, IN 47405 USA
| | - Katherine A Edmonds
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave, Bloomington, IN 47405-7102, USA
| | - Mauro Bringas
- Fundación Instituto Leloir, Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Justin L Luebke
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave, Bloomington, IN 47405-7102, USA
| | - Giovanni Gonzalez-Gutierrez
- Department of Molecular and Cellular Biochemistry, Indiana University, 212 S. Hawthorne Drive, Bloomington, IN 47405 USA
| | - Daiana A Capdevila
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave, Bloomington, IN 47405-7102, USA.,Fundación Instituto Leloir, Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - David P Giedroc
- Department of Chemistry, Indiana University, 800 E. Kirkwood Ave, Bloomington, IN 47405-7102, USA.,Department of Molecular and Cellular Biochemistry, Indiana University, 212 S. Hawthorne Drive, Bloomington, IN 47405 USA
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23
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RNase Z Oxidative Degradation Impedes tRNA Maturation and is Involved in Streptococcal Translation Regulation in Response to Oxidative Stress. Microbiol Spectr 2021; 9:e0116721. [PMID: 34704809 PMCID: PMC8549757 DOI: 10.1128/spectrum.01167-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
When encountering oxidative stress, organisms selectively upregulate antioxidant genes and simultaneously suppress the translation of most other proteins. Eukaryotes employ multiple strategies to adjust translation at both the initiation and elongation stages; however, how prokaryotes modulate translation under oxidative stress remains unclear. Here, we report that upon hydrogen peroxide (H2O2) challenge, Streptococcus oligofermentans reduced translation via RNase Z (So-RNaseZ) oxidative degradation, thus hindering tRNA maturation. S. oligofermentans encodes all CCA-less tRNAs that require So-RNaseZ for 3′ end maturation. A combination of nonreducing SDS-PAGE and liquid chromatography/tandem mass spectrometry (LC/MS-MS) assays demonstrated that H2O2 oxidation induced Cys38-Cys149 disulfide linkages in recombinant So-RNaseZ protein, and serine substitution of Cys38 or Cys149 abolished these disulfide linkages. Consistently, redox Western blotting also determined intramolecular disulfide-linked So-RNaseZ in H2O2-treated S. oligofermentans cells. The disulfide-linked So-RNaseZ and monomer were both subject to proteolysis, whereas C149S mutation alleviated oxidative degradation of So-RNaseZ, suggesting that H2O2-mediated disulfide linkages substantially contributed to So-RNaseZ degradation. Accordingly, Northern blotting determined that tRNA precursor accumulation and mature tRNA species decrease in H2O2-treated S. oligofermentans. Moreover, reduced overall protein synthesis, as indicated by puromycin incorporation, and retarded growth of S. oligofermentans occurred in an H2O2 concentration-dependent manner. Overexpression of So-RNaseZ not only elevated tRNA precursor processing and protein synthesis but also partly rescued H2O2-suppressed S. oligofermentans growth. Moreover, So-RNaseZ oxidative degradation-mediated translation repression elevated S. oligofermentans survival under high H2O2 stress. Therefore, this work found that So-RNaseZ oxidative degradation-impeded tRNA maturation contributes to streptococcal translation repression and provides the oxidative stress adaptability for S. oligofermentans. IMPORTANCE Translation regulation is a common strategy used by organisms to reduce oxidative damage. Catalase-negative streptococci produce as well as tolerate high levels of H2O2. This work reports a novel translation regulation mechanism employed by Streptococcus oligofermentans in response to H2O2 challenge, in which the key tRNA endonuclease So-RNaseZ is oxidized to form Cys38-Cys149 disulfide linkages and both the disulfide-linked So-RNaseZ and monomers are subject to proteolysis; thus, tRNA maturation, protein translation, and growth are all suppressed. Notably, So-RNaseZ oxidative degradation-mediated translation repression offers oxidative adaptability to S. oligofermentans and enhances its survival against high H2O2 challenge. So-RNaseZ orthologs and H2O2-sensitive cysteines (Cys38 and Cys149) are widely distributed in Streptococcus and Lactococcus species genomes, which also encode all CCA-less tRNAs and lack catalase. Therefore, RNase Z oxidative degradation-based translation regulation could be widely employed by these lactic acid bacteria, including pathogenic streptococci, to cope with H2O2.
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24
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Nakamya MF, Ayoola MB, Shack LA, Swiatlo E, Nanduri B. The Effect of Impaired Polyamine Transport on Pneumococcal Transcriptome. Pathogens 2021; 10:pathogens10101322. [PMID: 34684271 PMCID: PMC8540371 DOI: 10.3390/pathogens10101322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/10/2021] [Accepted: 10/12/2021] [Indexed: 12/13/2022] Open
Abstract
Infections due to Streptococcus pneumoniae, a commensal in the nasopharynx, still claim a significant number of lives worldwide. Genome plasticity, antibiotic resistance, and limited serotype coverage of the available polysaccharide-based conjugate vaccines confounds therapeutic interventions to limit the spread of this pathogen. Pathogenic mechanisms that allow successful adaption and persistence in the host could be potential innovative therapeutic targets. Polyamines are ubiquitous polycationic molecules that regulate many cellular processes. We previously reported that deletion of polyamine transport operon potABCD, which encodes a putrescine/spermidine transporter (ΔpotABCD), resulted in an unencapsulated attenuated phenotype. Here, we characterize the transcriptome, metabolome, and stress responses of polyamine transport-deficient S. pneumoniae. Compared with the wild-type strain, the expression of genes involved in oxidative stress responses and the nucleotide sugar metabolism was reduced, while expression of genes involved in the Leloir, tagatose, and pentose phosphate pathways was higher in ΔpotABCD. A metabolic shift towards the pentose phosphate pathway will limit the synthesis of precursors of capsule polysaccharides. Metabolomics results show reduced levels of glutathione and pyruvate in the mutant. Our results also show that the potABCD operon protects pneumococci against hydrogen peroxide and nitrosative stress. Our findings demonstrate the importance of polyamine transport in pneumococcal physiology that could impact in vivo fitness. Thus, polyamine transport in pneumococci represents a novel target for therapeutic interventions.
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Affiliation(s)
- Mary F. Nakamya
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS 39762, USA; (M.F.N.); (M.B.A.); (L.A.S.)
| | - Moses B. Ayoola
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS 39762, USA; (M.F.N.); (M.B.A.); (L.A.S.)
| | - Leslie A. Shack
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS 39762, USA; (M.F.N.); (M.B.A.); (L.A.S.)
| | - Edwin Swiatlo
- Section of Infectious Diseases, Southeast Louisiana Veterans Health Care System, New Orleans, LA 70112, USA;
| | - Bindu Nanduri
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS 39762, USA; (M.F.N.); (M.B.A.); (L.A.S.)
- Correspondence: ; Tel.: +1-662-325-5859; Fax: +1-662-325-1031
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25
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A Novel Aquaporin Subfamily Imports Oxygen and Contributes to Pneumococcal Virulence by Controlling the Production and Release of Virulence Factors. mBio 2021; 12:e0130921. [PMID: 34399618 PMCID: PMC8406300 DOI: 10.1128/mbio.01309-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Aquaporins, integral membrane proteins widely distributed in organisms, facilitate the transport of water, glycerol, and other small uncharged solutes across cellular membranes and play important physiological roles in eukaryotes. However, characterizations and physiological functions of the prokaryotic aquaporins remain largely unknown. Here, we report that Streptococcus pneumoniae (pneumococcus) AqpC (Pn-AqpC), representing a new aquaporin subfamily possessing a distinct substrate-selective channel, functions as an oxygen porin by facilitating oxygen movement across the cell membrane and contributes significantly to pneumococcal virulence. The use of a phosphorescent oxygen probe showed that Pn-AqpC facilitates oxygen permeation into pneumococcal and Pn-AqpC-expressing yeast cells. Reconstituting Pn-AqpC into liposomes prepared with pneumococcal and Escherichia coli cellular membranes further verified that Pn-AqpC transports O2 but not water or glycerol. Alanine substitution showed that Pro232 in the substrate channel is key for Pn-AqpC in O2 transport. The deletion of Pn-aqpC significantly reduced H2O2 production and resistance to H2O2 and NO of pneumococci, whereas low-H2O2 treatment helped the ΔPn-aqpC mutant resist higher levels of H2O2 and even NO, indicating that Pn-AqpC-facilitated O2 permeation contributes to pneumococcal resistance to H2O2 and NO. Remarkably, the lack of Pn-aqpC alleviated cell autolysis, thus reducing pneumolysin (Ply) release and decreasing the hemolysis of pneumococci. Accordingly, the ΔPn-aqpC mutant markedly reduced survival in macrophages, decreased damage to macrophages, and significantly reduced lethality in mice. Therefore, the oxygen porin Pn-AqpC, through modulating H2O2 production and pneumolysin release, the two major pneumococcal virulence factors, controls the virulence of pneumococcus. Pn-AqpC orthologs are widely distributed in various pneumococcal serotypes, highlighting that the oxygen porin is important for pneumococcal pathogenicity.
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26
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A Tn-seq Screen of Streptococcus pneumoniae Uncovers DNA Repair as the Major Pathway for Desiccation Tolerance and Transmission. Infect Immun 2021; 89:e0071320. [PMID: 34031124 DOI: 10.1128/iai.00713-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Streptococcus pneumoniae is an opportunistic pathogen that is a common cause of serious invasive diseases such as pneumonia, bacteremia, meningitis, and otitis media. Transmission of this bacterium has classically been thought to occur through inhalation of respiratory droplets and direct contact with nasal secretions. However, the demonstration that S. pneumoniae is desiccation tolerant and, therefore, environmentally stable for extended periods of time opens up the possibility that this pathogen is also transmitted via contaminated surfaces (fomites). To better understand the molecular mechanisms that enable S. pneumoniae to survive periods of desiccation, we performed a high-throughput transposon sequencing (Tn-seq) screen in search of genetic determinants of desiccation tolerance. We identified 42 genes whose disruption reduced desiccation tolerance and 45 genes that enhanced desiccation tolerance. The nucleotide excision repair pathway was the most enriched category in our Tn-seq results, and we found that additional DNA repair pathways are required for desiccation tolerance, demonstrating the importance of maintaining genome integrity after desiccation. Deletion of the nucleotide excision repair gene uvrA resulted in a delay in transmission between infant mice, indicating a correlation between desiccation tolerance and pneumococcal transmssion. Understanding the molecular mechanisms that enable pneumococcal persistence in the environment may enable targeting of these pathways to prevent fomite transmission, thereby preventing the establishment of new colonization and any resulting invasive disease.
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27
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Mraheil MA, Toque HA, La Pietra L, Hamacher J, Phanthok T, Verin A, Gonzales J, Su Y, Fulton D, Eaton DC, Chakraborty T, Lucas R. Dual Role of Hydrogen Peroxide as an Oxidant in Pneumococcal Pneumonia. Antioxid Redox Signal 2021; 34:962-978. [PMID: 32283950 PMCID: PMC8035917 DOI: 10.1089/ars.2019.7964] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Significance:Streptococcus pneumoniae (Spn), a facultative anaerobic Gram-positive human pathogen with increasing rates of penicillin and macrolide resistance, is a major cause of lower respiratory tract infections worldwide. Pneumococci are a primary agent of severe pneumonia in children younger than 5 years and of community-acquired pneumonia in adults. A major defense mechanism toward Spn is the generation of reactive oxygen species, including hydrogen peroxide (H2O2), during the oxidative burst of neutrophils and macrophages. Paradoxically, Spn produces high endogenous levels of H2O2 as a strategy to promote colonization. Recent Advances: Pneumococci, which express neither catalase nor common regulators of peroxide stress resistance, have developed unique mechanisms to protect themselves from H2O2. Spn generates high levels of H2O2 as a strategy to promote colonization. Production of H2O2 moreover constitutes an important virulence phenotype and its cellular activities overlap and complement those of other virulence factors, such as pneumolysin, in modulating host immune responses and promoting organ injury. Critical Issues: This review examines the dual role of H2O2 in pneumococcal pneumonia, from the viewpoint of both the pathogen (defense mechanisms, lytic activity toward competing pathogens, and virulence) and the resulting host-response (inflammasome activation, endoplasmic reticulum stress, and damage to the alveolar-capillary barrier in the lungs). Future Directions: An understanding of the complexity of H2O2-mediated host-pathogen interactions is necessary to develop novel strategies that target these processes to enhance lung function during severe pneumonia.
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Affiliation(s)
- Mobarak Abu Mraheil
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Haroldo A Toque
- Vascular Biology Center and Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Luigi La Pietra
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Juerg Hamacher
- Internal Medicine and Pneumology, Lindenhofspital, Bern, Switzerland.,Lungen- und Atmungsstiftung Bern, Bern, Switzerland.,Internal Medicine V-Pneumology, Allergology, Respiratory and Environmental Medicine, Faculty of Medicine, Saarland University, Saarbrücken, Germany
| | - Tenzing Phanthok
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Alexander Verin
- Vascular Biology Center and Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Joyce Gonzales
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Yunchao Su
- Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - David Fulton
- Vascular Biology Center and Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Douglas C Eaton
- Department of Medicine, Emory School of Medicine, Atlanta, Georgia, USA
| | - Trinad Chakraborty
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Rudolf Lucas
- Vascular Biology Center and Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
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28
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Sanchez-Rosario Y, Johnson MDL. Media Matters, Examining Historical and Modern Streptococcus pneumoniae Growth Media and the Experiments They Affect. Front Cell Infect Microbiol 2021; 11:613623. [PMID: 33834003 PMCID: PMC8021847 DOI: 10.3389/fcimb.2021.613623] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 03/02/2021] [Indexed: 12/18/2022] Open
Abstract
While some bacteria can thrive for generations in minerals and salts, many require lavish nutrition and specific chemicals to survive to the point where they can be observed and researched. Although researchers once boiled and rendered animal flesh and bones to obtain a media that facilitated bacterial growth, we now have a plethora of formulations and manufacturers to provide dehydrated flavors of historical, modified, and modern media. The purpose of media has evolved from simple isolation to more measured study. However, in some instances, media formulated to aid the metabolic, nutritional, or physical properties of microbes may not be best suited for studying pathogen behavior or resilience as a function of host interactions. While there have been comparative studies on handfuls of these media in Streptococcus pneumoniae, this review focuses on describing both the historical and modern composition of common complex (Todd Hewitt and M17), semi-defined (Adams and Roe), and defined pneumococcal media (RPMI and Van de Rijn and Kessler), key components discovered/needed for cultivation/growth enhancement, and effects these different media have on bacterial phenotypes and experimental outcomes. While many researchers find the best conditions to grow and experiment on their bacteria of choice, the reasons for some researchers to use a specific medium is at best, not discussed, and at worst, arbitrary. As such, the goal of this review is to highlight the differences in pneumococcal media to encourage investigators to challenge their decisions on why they use a given medium, discuss the recipe, and explain their reasoning.
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Affiliation(s)
| | - Michael D L Johnson
- Department of Immunobiology, University of Arizona, Tucson, AZ, United States.,BIO5 Institute, University of Arizona, Tucson, AZ, United States.,Valley Fever Center for Excellence, University of Arizona, Tucson, AZ, United States
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29
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Streptococcus pneumoniae and Its Virulence Factors H 2O 2 and Pneumolysin Are Potent Mediators of the Acute Chest Syndrome in Sickle Cell Disease. Toxins (Basel) 2021; 13:toxins13020157. [PMID: 33671422 PMCID: PMC7922783 DOI: 10.3390/toxins13020157] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/08/2021] [Accepted: 02/11/2021] [Indexed: 01/27/2023] Open
Abstract
Sickle cell disease (SCD) is one of the most common autosomal recessive disorders in the world. Due to functional asplenia, a dysfunctional antibody response, antibiotic drug resistance and poor response to immunization, SCD patients have impaired immunity. A leading cause of hospitalization and death in SCD patients is the acute chest syndrome (ACS). This complication is especially manifested upon infection of SCD patients with Streptococcus pneumoniae (Spn)—a facultative anaerobic Gram-positive bacterium that causes lower respiratory tract infections. Spn has developed increased rates of antibiotics resistance and is particularly virulent in SCD patients. The primary defense against Spn is the generation of reactive oxygen species (ROS) during the oxidative burst of neutrophils and macrophages. Paradoxically, Spn itself produces high levels of the ROS hydrogen peroxide (H2O2) as a virulence strategy. Apart from H2O2, Spn also secretes another virulence factor, i.e., the pore-forming exotoxin pneumolysin (PLY), a potent mediator of lung injury in patients with pneumonia in general and particularly in those with SCD. PLY is released early on in infection either by autolysis or bacterial lysis following the treatment with antibiotics and has a broad range of biological activities. This review will discuss recent findings on the role of pneumococci in ACS pathogenesis and on strategies to counteract the devastating effects of its virulence factors on the lungs in SCD patients.
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Su T, Nakamoto R, Chun YY, Chua WZ, Chen JH, Zik JJ, Sham LT. Decoding capsule synthesis in Streptococcus pneumoniae. FEMS Microbiol Rev 2020; 45:6041728. [PMID: 33338218 DOI: 10.1093/femsre/fuaa067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 12/07/2020] [Indexed: 12/20/2022] Open
Abstract
Streptococcus pneumoniae synthesizes more than one hundred types of capsular polysaccharides (CPS). While the diversity of the enzymes and transporters involved is enormous, it is not limitless. In this review, we summarized the recent progress on elucidating the structure-function relationships of CPS, the mechanisms by which they are synthesized, how their synthesis is regulated, the host immune response against them, and the development of novel pneumococcal vaccines. Based on the genetic and structural information available, we generated provisional models of the CPS repeating units that remain unsolved. In addition, to facilitate cross-species comparisons and assignment of glycosyltransferases, we illustrated the biosynthetic pathways of the known CPS in a standardized format. Studying the intricate steps of pneumococcal CPS assembly promises to provide novel insights for drug and vaccine development as well as improve our understanding of related pathways in other species.
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Affiliation(s)
- Tong Su
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Rei Nakamoto
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Ye Yu Chun
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Wan Zhen Chua
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Jia Hui Chen
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Justin J Zik
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Lok-To Sham
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
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Hydrogen Peroxide Production by Streptococcus pneumoniae Results in Alpha-hemolysis by Oxidation of Oxy-hemoglobin to Met-hemoglobin. mSphere 2020; 5:5/6/e01117-20. [PMID: 33298575 PMCID: PMC7729260 DOI: 10.1128/msphere.01117-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
There is a misconception that alpha-hemolysis observed on blood agar plate cultures of Streptococcus pneumoniae and other alpha-hemolytic streptococci is produced by a hemolysin or, alternatively, by lysis of erythrocytes caused by hydrogen peroxide. We noticed in the course of our investigations that wild-type S. pneumoniae strains and hemolysin (e.g., pneumolysin) knockout mutants produced the alpha-hemolytic halo on blood agar plates. Streptococcus pneumoniae and other streptococci produce a greenish halo on blood agar plates referred to as alpha-hemolysis. This phenotype is utilized by clinical microbiology laboratories to report culture findings of alpha-hemolytic streptococci, including S. pneumoniae, and other bacteria. The alpha-hemolysis halo on blood agar plates has been related to the hemolytic activity of pneumococcal pneumolysin (Ply) or, to a lesser extent, to lysis of erythrocytes by S. pneumoniae-produced hydrogen peroxide. We investigated the molecular basis of the alpha-hemolysis halo produced by S. pneumoniae. Wild-type strains TIGR4, D39, R6, and EF3030 and isogenic derivative Δply mutants produced similar alpha-hemolytic halos on blood agar plates, while cultures of hydrogen peroxide knockout ΔspxB ΔlctO mutants lacked this characteristic halo. Moreover, in the presence of catalase, the alpha-hemolysis halo was absent in cultures of the wild-type (wt) and Δply mutant strains. Spectroscopic studies demonstrated that culture supernatants of TIGR4 released hemoglobin-bound heme (heme-hemoglobin) from erythrocytes and oxidized oxy-hemoglobin to met-hemoglobin within 30 min of incubation. As expected, given Ply hemolytic activity and that hydrogen peroxide contributes to the release of Ply, TIGR4Δply and ΔspxB ΔlctO isogenic mutants had significantly decreased release of heme-hemoglobin from erythrocytes. However, TIGR4Δply that produces hydrogen peroxide oxidized oxy-hemoglobin to met-hemoglobin, whereas TIGR4ΔspxB ΔlctO failed to produce oxidation of oxy-hemoglobin. Studies conducted with all other wt strains and isogenic mutants resulted in similar findings. We demonstrated that the so-called alpha-hemolysis halo is caused by the oxidation of oxy-hemoglobin (Fe+2) to a non-oxygen-binding met-hemoglobin (Fe+3) by S. pneumoniae-produced hydrogen peroxide. IMPORTANCE There is a misconception that alpha-hemolysis observed on blood agar plate cultures of Streptococcus pneumoniae and other alpha-hemolytic streptococci is produced by a hemolysin or, alternatively, by lysis of erythrocytes caused by hydrogen peroxide. We noticed in the course of our investigations that wild-type S. pneumoniae strains and hemolysin (e.g., pneumolysin) knockout mutants produced the alpha-hemolytic halo on blood agar plates. In contrast, hydrogen peroxide-defective mutants prepared in four different strains lacked the characteristic alpha-hemolysis halo. We also demonstrated that wild-type strains and pneumolysin mutants oxidized oxy-hemoglobin to met-hemoglobin. Hydrogen peroxide knockout mutants, however, failed to oxidize oxy-hemoglobin. Therefore, the greenish halo formed on cultures of S. pneumoniae and other so-called alpha-hemolytic streptococci is caused by the oxidation of oxy-hemoglobin produced by hydrogen peroxide. Oxidation of oxy-hemoglobin to the nonbinding oxygen form, met-hemoglobin, might occur in the lungs during pneumococcal pneumonia.
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Gingras H, Patron K, Leprohon P, Ouellette M. Azithromycin resistance mutations in Streptococcus pneumoniae as revealed by a chemogenomic screen. Microb Genom 2020; 6. [PMID: 33074087 PMCID: PMC7725334 DOI: 10.1099/mgen.0.000454] [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] [Indexed: 12/02/2022] Open
Abstract
We report on the combination of chemical mutagenesis, azithromycin selection and next-generation sequencing (Mut-Seq) for the identification of small nucleotide variants that decrease the susceptibility of Streptococcus pneumoniae to the macrolide antibiotic azithromycin. Mutations in the 23S ribosomal RNA or in ribosomal proteins can confer resistance to macrolides and these were detected by Mut-Seq. By concentrating on recurrent variants, we could associate mutations in genes implicated in the metabolism of glutamine with decreased azithromycin susceptibility among S. pneumoniae mutants. Glutamine synthetase catalyses the transformation of glutamate and ammonium into glutamine and its chemical inhibition is shown to sensitize S. pneumoniae to antibiotics. A mutation affecting the ribosomal-binding site of a putative ribonuclease J2 is also shown to confer low-level resistance. Mut-Seq has the potential to reveal chromosomal changes enabling high resistance as well as novel events conferring more subtle phenotypes.
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Affiliation(s)
- Hélène Gingras
- Axe des Maladies Infectieuses et Immunitaires du Centre de Recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, Québec, Canada
| | - Kévin Patron
- Axe des Maladies Infectieuses et Immunitaires du Centre de Recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, Québec, Canada
| | - Philippe Leprohon
- Axe des Maladies Infectieuses et Immunitaires du Centre de Recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, Québec, Canada
| | - Marc Ouellette
- Axe des Maladies Infectieuses et Immunitaires du Centre de Recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, Québec, Canada
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Pedram N, Rashedi H, Motamedian E. A systematic strategy using a reconstructed genome-scale metabolic network for pathogen Streptococcuspneumoniae D39 to find novel potential drug targets. Pathog Dis 2020; 78:5900975. [PMID: 32880642 DOI: 10.1093/femspd/ftaa051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 09/01/2020] [Indexed: 11/14/2022] Open
Abstract
Streptococcus pneumoniae is a Gram-positive bacterium that is one of the major causes of various infections such as pneumonia, meningitis, otitis media and endocarditis. Since antibiotic resistance of S. pneumoniae is pointed out as a challenge in the treatment of these infections, more studies are required to focus on disease prevention. In this research, a first manually curated genome-scale metabolic network of the pathogen S. pneumoniae D39 was reconstructed based on its genome annotation data, and biochemical knowledge from literature and databases. The model was validated by amino acid auxotrophies, gene essentiality analysis, and different carbohydrate sources. Then, a two-stage strategy was developed to find target genes for growth reduction of the pathogen and their importance in the various infection sites. In the first stage, growth-associated genes were identified by integration of transcriptomic data with the model and in the second stage, the importance of each gene in the metabolism for growth was evaluated using principal component analysis. The reports presented in the literature confirm the effect of some found genes on the growth of S. pneumoniae.
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Affiliation(s)
- Narges Pedram
- Department of Biotechnology, School of Chemical Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran, Iran
| | - Hamid Rashedi
- Department of Biotechnology, School of Chemical Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran, Iran
| | - Ehsan Motamedian
- Department of Biotechnology, Faculty of Chemical Engineering, Tarbiat Modares University, P.O. Box 14155-4838, Tehran, Iran
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S1 Domain RNA-Binding Protein CvfD Is a New Posttranscriptional Regulator That Mediates Cold Sensitivity, Phosphate Transport, and Virulence in Streptococcus pneumoniae D39. J Bacteriol 2020; 202:JB.00245-20. [PMID: 32601068 DOI: 10.1128/jb.00245-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 06/24/2020] [Indexed: 02/07/2023] Open
Abstract
Posttranscriptional gene regulation often involves RNA-binding proteins that modulate mRNA translation and/or stability either directly through protein-RNA interactions or indirectly by facilitating the annealing of small regulatory RNAs (sRNAs). The human pathogen Streptococcus pneumoniae D39 (pneumococcus) does not encode homologs to RNA-binding proteins known to be involved in promoting sRNA stability and function, such as Hfq or ProQ, even though it contains genes for at least 112 sRNAs. However, the pneumococcal genome contains genes for other RNA-binding proteins, including at least six S1 domain proteins: ribosomal protein S1 (rpsA), polynucleotide phosphorylase (pnpA), RNase R (rnr), and three proteins with unknown functions. Here, we characterize the function of one of these conserved, yet uncharacterized, S1 domain proteins, SPD_1366, which we have renamed CvfD (conserved virulence factor D), since loss of the protein results in attenuation of virulence in a murine pneumonia model. We report that deletion of cvfD impacts the expression of 144 transcripts, including the pst1 operon, encoding phosphate transport system 1 in S. pneumoniae We further show that CvfD posttranscriptionally regulates the PhoU2 master regulator of the pneumococcal dual-phosphate transport system by binding phoU2 mRNA and impacting PhoU2 translation. CvfD not only controls expression of phosphate transporter genes but also functions as a pleiotropic regulator that impacts cold sensitivity and the expression of sRNAs and genes involved in diverse cellular functions, including manganese uptake and zinc efflux. Together, our data show that CvfD exerts a broad impact on pneumococcal physiology and virulence, partly by posttranscriptional gene regulation.IMPORTANCE Recent advances have led to the identification of numerous sRNAs in the major human respiratory pathogen S. pneumoniae However, little is known about the functions of most sRNAs or RNA-binding proteins involved in RNA biology in pneumococcus. In this paper, we characterize the phenotypes and one target of the S1 domain RNA-binding protein CvfD, a homolog of general stress protein 13 identified, but not extensively characterized, in other Firmicutes species. Pneumococcal CvfD is a broadly pleiotropic regulator, whose absence results in misregulation of divalent cation homeostasis, reduced translation of the PhoU2 master regulator of phosphate uptake, altered metabolism and sRNA amounts, cold sensitivity, and attenuation of virulence. These findings underscore the critical roles of RNA biology in pneumococcal physiology and virulence.
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Zhang Y, Edmonds KA, Raines DJ, Murphy BA, Wu H, Guo C, Nolan EM, VanNieuwenhze MS, Duhme-Klair AK, Giedroc DP. The Pneumococcal Iron Uptake Protein A (PiuA) Specifically Recognizes Tetradentate Fe IIIbis- and Mono-Catechol Complexes. J Mol Biol 2020; 432:5390-5410. [PMID: 32795535 DOI: 10.1016/j.jmb.2020.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/02/2020] [Accepted: 08/05/2020] [Indexed: 12/15/2022]
Abstract
Streptococcus pneumoniae (Spn) is an important Gram-positive human pathogen that causes millions of infections worldwide with an increasing occurrence of antibiotic resistance. Fe acquisition is a crucial virulence determinant in Spn; further, Spn relies on exogenous FeIII-siderophore scavenging to meet nutritional Fe needs. Recent studies suggest that the human catecholamine stress hormone, norepinephrine (NE), facilitates Fe acquisition in Spn under conditions of transferrin-mediated Fe starvation. Here we show that the solute binding lipoprotein PiuA from the piu Fe acquisition ABC transporter PiuBCDA, previously described as an Fe-hemin binding protein, binds tetradentate catechol FeIII complexes, including NE and the hydrolysis products of enterobactin. Two protein-derived ligands (H238, Y300) create a coordinately saturated FeIII complex, which parallel recent studies in the Gram-negative intestinal pathogen Campylobacter jejuni. Our in vitro studies using NMR spectroscopy and 54Fe LC-ICP-MS confirm the FeIII can move from transferrin to apo-PiuA in an NE-dependent manner. Structural analysis of PiuA FeIII-bis-catechol and GaIII-bis-catechol and GaIII-(NE)2 complexes by NMR spectroscopy reveals only localized structural perturbations in PiuA upon ligand binding, largely consistent with recent descriptions of other solute binding proteins of type II ABC transporters. We speculate that tetradentate FeIII complexes formed by mono- and bis-catechol species are important Fe sources in Gram-positive human pathogens, since PiuA functions in the same way as SstD from Staphylococcus aureus.
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Affiliation(s)
- Yifan Zhang
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA; Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Katherine A Edmonds
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - Daniel J Raines
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Brennan A Murphy
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - Hongwei Wu
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - Chuchu Guo
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Elizabeth M Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Anne-K Duhme-Klair
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA; Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA.
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Gingerich AD, Doja F, Thomason R, Tóth E, Bradshaw JL, Douglass MV, McDaniel LS, Rada B. Oxidative killing of encapsulated and nonencapsulated Streptococcus pneumoniae by lactoperoxidase-generated hypothiocyanite. PLoS One 2020; 15:e0236389. [PMID: 32730276 PMCID: PMC7392276 DOI: 10.1371/journal.pone.0236389] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 07/06/2020] [Indexed: 01/04/2023] Open
Abstract
Streptococcus pneumoniae (Pneumococcus) infections affect millions of people worldwide, cause serious mortality and represent a major economic burden. Despite recent successes due to pneumococcal vaccination and antibiotic use, Pneumococcus remains a significant medical problem. Airway epithelial cells, the primary responders to pneumococcal infection, orchestrate an extracellular antimicrobial system consisting of lactoperoxidase (LPO), thiocyanate anion and hydrogen peroxide (H2O2). LPO oxidizes thiocyanate using H2O2 into the final product hypothiocyanite that has antimicrobial effects against a wide range of microorganisms. However, hypothiocyanite’s effect on Pneumococcus has never been studied. Our aim was to determine whether hypothiocyanite can kill S. pneumoniae. Bactericidal activity was measured in a cell-free in vitro system by determining the number of surviving pneumococci via colony forming units on agar plates, while bacteriostatic activity was assessed by measuring optical density of bacteria in liquid cultures. Our results indicate that hypothiocyanite generated by LPO exerted robust killing of both encapsulated and nonencapsulated pneumococcal strains. Killing of S. pneumoniae by a commercially available hypothiocyanite-generating product was even more pronounced than that achieved with laboratory reagents. Catalase, an H2O2 scavenger, inhibited killing of pneumococcal by hypothiocyanite under all circumstances. Furthermore, the presence of the bacterial capsule or lytA-dependent autolysis had no effect on hypothiocyanite-mediated killing of pneumococci. On the contrary, a pneumococcal mutant deficient in pyruvate oxidase (main bacterial H2O2 source) had enhanced susceptibility to hypothiocyanite compared to its wild-type strain. Overall, results shown here indicate that numerous pneumococcal strains are susceptible to LPO-generated hypothiocyanite.
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Affiliation(s)
- Aaron D. Gingerich
- Department of Infectious Diseases, College of Veterinary Medicine, The University of Georgia, Athens, Georgia, United States of America
| | - Fayhaa Doja
- Department of Infectious Diseases, College of Veterinary Medicine, The University of Georgia, Athens, Georgia, United States of America
| | - Rachel Thomason
- Department of Infectious Diseases, College of Veterinary Medicine, The University of Georgia, Athens, Georgia, United States of America
| | - Eszter Tóth
- Department of Infectious Diseases, College of Veterinary Medicine, The University of Georgia, Athens, Georgia, United States of America
| | - Jessica L. Bradshaw
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
| | - Martin V. Douglass
- Department of Infectious Diseases, College of Veterinary Medicine, The University of Georgia, Athens, Georgia, United States of America
| | - Larry S. McDaniel
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
| | - Balázs Rada
- Department of Infectious Diseases, College of Veterinary Medicine, The University of Georgia, Athens, Georgia, United States of America
- * E-mail:
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Echlin H, Frank M, Rock C, Rosch JW. Role of the pyruvate metabolic network on carbohydrate metabolism and virulence in Streptococcus pneumoniae. Mol Microbiol 2020; 114:536-552. [PMID: 32495474 DOI: 10.1111/mmi.14557] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/27/2020] [Accepted: 05/22/2020] [Indexed: 11/30/2022]
Abstract
Streptococcus pneumoniae is a major human pathogen that must adapt to unique nutritional environments in several host niches. The pneumococcus can metabolize a range of carbohydrates that feed into glycolysis ending in pyruvate, which is catabolized by several enzymes. We investigated how the pneumococcus utilizes these enzymes to metabolize different carbohydrates and how this impacts survival in the host. Loss of ldh decreased bacterial burden in the nasopharynx and enhanced bacteremia in mice. Loss of spxB, pdhC or pfl2 decreased bacteremia and increased host survival. In glucose or galactose, loss of ldh increased capsule production, whereas loss of spxB and pdhC reduced capsule production. The pfl2 mutant exhibited reduced capsule production only in galactose. In glucose, pyruvate was metabolized primarily by LDH to generate lactate and NAD+ and by SpxB and PDHc to generate acetyl-CoA. In galactose, pyruvate metabolism was shunted toward acetyl-CoA production. The majority of acetyl-CoA generated by PFL was used to regenerate NAD+ with a subset used in capsule production, while the acetyl-CoA generated by SpxB and PDHc was utilized primarily for capsule biosynthesis. These data suggest that the pneumococcus can alter flux of pyruvate metabolism dependent on the carbohydrate present to succeed in distinct host niches.
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Affiliation(s)
- Haley Echlin
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Matthew Frank
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Charles Rock
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jason W Rosch
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, USA
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Abstract
The catalase-negative streptococci produce as well as tolerate high levels of H2O2. This work reports the molecular mechanisms of low-H2O2-concentration-induced adaptation to higher H2O2 stress in a Streptococcus species, in which the peroxide-responsive repressor PerR and its redox regulons play the major role. Distinct from the Bacillus subtilis PerR, which is inactivated by H2O2 through histidine oxidation by the Fe2+-triggered Fenton reaction, the streptococcal PerR is inactivated by H2O2 oxidation of the structural Zn2+ binding cysteine residues and thus derepresses the expression of genes defending against oxidative stress. The reversible cysteine oxidation could provide flexibility for PerR regulation in streptococci, and the mechanism might be widely used by lactic acid bacteria, including pathogenic streptococci, containing high levels of cellular manganese, in coping with oxidative stress. The adaptation mechanism could also be applied in oral hygiene by facilitating the fitness and adaptability of the oral commensal streptococci to suppress the pathogens. Preexposure to a low concentration of H2O2 significantly increases the survivability of catalase-negative streptococci in the presence of a higher concentration of H2O2. However, the mechanisms of this adaptation remain unknown. Here, using a redox proteomics assay, we identified 57 and 35 cysteine-oxidized proteins in Streptococcus oligofermentans bacteria that were anaerobically cultured and then pulsed with 40 μM H2O2 and that were statically grown in a 40-ml culture, respectively. The oxidized proteins included the peroxide-responsive repressor PerR, the manganese uptake repressor MntR, thioredoxin system proteins Trx and Tpx, and most glycolytic proteins. Cysteine oxidations of these proteins were verified through redox Western blotting, immunoprecipitation, and liquid chromatography-tandem mass spectrometry assays. In particular, Zn2+-coordinated Cys139 and Cys142 mutations eliminated the H2O2 oxidation of PerR, and inductively coupled plasma mass spectrometry detected significantly decreased amounts of Zn2+ in H2O2-treated PerR, demonstrating that cysteine oxidation results in Zn2+ loss. An electrophoretic mobility shift assay (EMSA) determined that the DNA binding of Mn2+-bound PerR protein (PerR:Zn,Mn) was abolished by H2O2 treatment but was restored by dithiothreitol reduction, verifying that H2O2 inactivates streptococcal PerR:Zn,Mn through cysteine oxidation, analogous to the findings for MntR. Quantitative PCR and EMSA demonstrated that tpx, mntA, mntR, and dpr belonged to the PerR regulons but that only dpr was directly regulated by PerR; mntA was also controlled by MntR. Deletion of mntR significantly reduced the low-H2O2-concentration-induced adaptation of S. oligofermentans to a higher H2O2 concentration, while the absence of PerR completely abolished the self-protection. Therefore, a low H2O2 concentration resulted in the cysteine-reversible oxidations of PerR and MntR to derepress their regulons, which function in cellular metal and redox homeostasis and which endow streptococci with the antioxidative capability. This work reveals a novel Cys redox-based H2O2 defense strategy employed by catalase-negative streptococci in Mn2+-rich cellular environments. IMPORTANCE The catalase-negative streptococci produce as well as tolerate high levels of H2O2. This work reports the molecular mechanisms of low-H2O2-concentration-induced adaptation to higher H2O2 stress in a Streptococcus species, in which the peroxide-responsive repressor PerR and its redox regulons play the major role. Distinct from the Bacillus subtilis PerR, which is inactivated by H2O2 through histidine oxidation by the Fe2+-triggered Fenton reaction, the streptococcal PerR is inactivated by H2O2 oxidation of the structural Zn2+ binding cysteine residues and thus derepresses the expression of genes defending against oxidative stress. The reversible cysteine oxidation could provide flexibility for PerR regulation in streptococci, and the mechanism might be widely used by lactic acid bacteria, including pathogenic streptococci, containing high levels of cellular manganese, in coping with oxidative stress. The adaptation mechanism could also be applied in oral hygiene by facilitating the fitness and adaptability of the oral commensal streptococci to suppress the pathogens.
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Wang J, Li JW, Li J, Huang Y, Wang S, Zhang JR. Regulation of pneumococcal epigenetic and colony phases by multiple two-component regulatory systems. PLoS Pathog 2020; 16:e1008417. [PMID: 32187228 PMCID: PMC7105139 DOI: 10.1371/journal.ppat.1008417] [Citation(s) in RCA: 15] [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: 10/07/2019] [Revised: 03/30/2020] [Accepted: 02/19/2020] [Indexed: 11/19/2022] Open
Abstract
Streptococcus pneumoniae is well known for phase variation between opaque (O) and transparent (T) colonies within clonal populations. While the O variant is specialized in invasive infection (with a thicker capsule and higher resistance to host clearance), the T counterpart possesses a relatively thinner capsule and thereby higher airway adherence and colonization. Our previous study found that phase variation is caused by reversible switches of the "opaque ON-or-OFF" methylomes or methylation patterns of pneumococcal genome, which is dominantly driven by the PsrA-catalyzed inversions of the DNA methyltransferase hsdS genes. This study revealed that switch frequency between the O and T variants is regulated by five transcriptional response regulators (rr) of the two-component systems (TCSs). The mutants of rr06, rr08, rr09, rr11 and rr14 produced significantly fewer O and more T colonies. Further mutagenesis revealed that RR06, RR08, RR09 and RR11 enrich the O variant by modulating the directions of the PsrA-catalyzed inversion reactions. In contrast, the impact of RR14 (RitR) on phase variation is independent of PsrA. Consistently, SMRT sequencing uncovered significantly diminished "opaque ON" methylome in the mutants of rr06, rr08, rr09 and rr11 but not that of rr14. Lastly, the phosphorylated form of RR11 was shown to activate the transcription of comW and two sugar utilization systems that are necessary for maintenance of the "opaque ON" genotype and phenotype. This work has thus uncovered multiple novel mechanisms that balance pneumococcal epigenetic status and physiology.
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Affiliation(s)
- Juanjuan Wang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
| | - Jing-Wen Li
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
| | - Jing Li
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
| | - Yijia Huang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
| | - Shaomeng Wang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
| | - Jing-Ren Zhang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
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Mitochondrial DNA: A Key Regulator of Anti-Microbial Innate Immunity. Genes (Basel) 2020; 11:genes11010086. [PMID: 31940818 PMCID: PMC7017290 DOI: 10.3390/genes11010086] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 12/25/2022] Open
Abstract
During the last few years, mitochondrial DNA has attained much attention as a modulator of immune responses. Due to common evolutionary origin, mitochondrial DNA shares various characteristic features with DNA of bacteria, as it consists of a remarkable number of unmethylated DNA as 2′-deoxyribose cytidine-phosphate-guanosine (CpG) islands. Due to this particular feature, mitochondrial DNA seems to be recognized as a pathogen-associated molecular pattern by the innate immune system. Under the normal physiological situation, mitochondrial DNA is enclosed in the double membrane structure of mitochondria. However, upon pathological conditions, it is usually released into the cytoplasm. Growing evidence suggests that this cytosolic mitochondrial DNA induces various innate immune signaling pathways involving NLRP3, toll-like receptor 9, and stimulator of interferon genes (STING) signaling, which participate in triggering downstream cascade and stimulating to produce effector molecules. Mitochondrial DNA is responsible for inflammatory diseases after stress and cellular damage. In addition, it is also involved in the anti-viral and anti-bacterial innate immunity. Thus, instead of entire mitochondrial importance in cellular metabolism and energy production, mitochondrial DNA seems to be essential in triggering innate anti-microbial immunity. Here, we describe existing knowledge on the involvement of mitochondrial DNA in the anti-microbial immunity by modulating the various immune signaling pathways.
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Wu X, Gordon O, Jiang W, Antezana BS, Angulo-Zamudio UA, Del Rio C, Moller A, Brissac T, Tierney ARP, Warncke K, Orihuela CJ, Read TD, Vidal JE. Interaction between Streptococcus pneumoniae and Staphylococcus aureus Generates ·OH Radicals That Rapidly Kill Staphylococcus aureus Strains. J Bacteriol 2019; 201:e00474-19. [PMID: 31405914 PMCID: PMC6779455 DOI: 10.1128/jb.00474-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 08/08/2019] [Indexed: 12/26/2022] Open
Abstract
Streptococcus pneumoniae rapidly kills Staphylococcus aureus by producing membrane-permeable hydrogen peroxide (H2O2). The mechanism by which S. pneumoniae-produced H2O2 mediates S. aureus killing was investigated. An in vitro model that mimicked S. pneumoniae-S. aureus contact during colonization of the nasopharynx demonstrated that S. aureus killing required outcompeting densities of S. pneumoniae Compared to the wild-type strain, isogenic S. pneumoniae ΔlctO and S. pneumoniae ΔspxB, both deficient in production of H2O2, required increased density to kill S. aureus While residual H2O2 activity produced by single mutants was sufficient to eradicate S. aureus, an S. pneumoniae ΔspxB ΔlctO double mutant was unable to kill S. aureus A collection of 20 diverse methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) strains showed linear sensitivity (R2 = 0.95) for S. pneumoniae killing, but the same strains had different susceptibilities when challenged with pure H2O2 (5 mM). There was no association between the S. aureus clonal complex and sensitivity to either S. pneumoniae or H2O2 To kill S. aureus, S. pneumoniae produced ∼180 μM H2O2 within 4 h of incubation, while the killing-defective S. pneumoniae ΔspxB and S. pneumoniae ΔspxB ΔlctO mutants produced undetectable levels. Remarkably, a sublethal dose (1 mM) of pure H2O2 incubated with S. pneumoniae ΔspxB eradicated diverse S. aureus strains, suggesting that S. pneumoniae bacteria may facilitate conversion of H2O2 to a hydroxyl radical (·OH). Accordingly, S. aureus killing was completely blocked by incubation with scavengers of ·OH radicals, dimethyl sulfoxide (Me2SO), thiourea, or sodium salicylate. The ·OH was detected in S. pneumoniae cells by spin trapping and electron paramagnetic resonance. Therefore, S. pneumoniae produces H2O2, which is rapidly converted to a more potent oxidant, hydroxyl radicals, to rapidly intoxicate S. aureus strains.IMPORTANCEStreptococcus pneumoniae strains produce hydrogen peroxide (H2O2) to kill bacteria in the upper airways, including pathogenic Staphylococcus aureus strains. The targets of S. pneumoniae-produced H2O2 have not been discovered, in part because of a lack of knowledge about the underlying molecular mechanism. We demonstrated that an increased density of S. pneumoniae kills S. aureus by means of H2O2 produced by two enzymes, SpxB and LctO. We discovered that SpxB/LctO-produced H2O2 is converted into a hydroxyl radical (·OH) that rapidly intoxicates and kills S. aureus We successfully inhibited the toxicity of ·OH with three different scavengers and detected ·OH in the supernatant. The target(s) of the hydroxyl radicals represents a new alternative for the development of antimicrobials against S. aureus infections.
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Affiliation(s)
- Xueqing Wu
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- Department of Infectious Disease, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Oren Gordon
- Department of Pediatrics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Wenxin Jiang
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | - Brenda S Antezana
- Graduate Program in Microbiology and Molecular Genetics, Emory University, Atlanta, Georgia, USA
| | - Uriel A Angulo-Zamudio
- Regional Program for the Doctorate in Biotechnology, Faculty of Chemical Sciences Biological, Autonomous University of Sinaloa, Sinaloa, Mexico
| | - Carlos Del Rio
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | - Abraham Moller
- Graduate Program in Microbiology and Molecular Genetics, Emory University, Atlanta, Georgia, USA
| | - Terry Brissac
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Aimee R P Tierney
- Graduate Program in Microbiology and Molecular Genetics, Emory University, Atlanta, Georgia, USA
| | - Kurt Warncke
- Department of Physics, Emory University, Atlanta, Georgia, USA
| | - Carlos J Orihuela
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Timothy D Read
- Graduate Program in Microbiology and Molecular Genetics, Emory University, Atlanta, Georgia, USA
- Antibiotic Research Center, Emory University, Atlanta, Georgia, USA
- School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Jorge E Vidal
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
- Graduate Program in Microbiology and Molecular Genetics, Emory University, Atlanta, Georgia, USA
- Antibiotic Research Center, Emory University, Atlanta, Georgia, USA
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Ball R, Brindley J. The Power Without the Glory: Multiple Roles of Hydrogen Peroxide in Mediating the Origin of Life. ASTROBIOLOGY 2019; 19:675-684. [PMID: 30707597 DOI: 10.1089/ast.2018.1886] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The hydrogen peroxide (HP) crucible hypothesis proposed here holds that life began in a localized environment on Earth that was perfused with a flow of hydrogen peroxide from a sustained external source, which powered and mediated molecular evolution and the protocellular RNA world. In this article, we consolidate and review recent evidence, both circumstantial and tested in simulation in our work and in the laboratory in others' work, for its multiple roles in the evolution of the first living systems: (1) it provides a periodic power source as the thiosulfate-hydrogen peroxide (THP) redox oscillator, (2) it may act as an agent of molecular change and evolution and mediator of homochirality, and (3) the THP oscillator, subject to Brownian input perturbations, produces a weighted distribution of output thermal fluctuations that favor polymerization and chemical diversification over chemical degradation and simplification. The hypothesis can help to clarify the hero and villain roles of hydrogen peroxide in cell function, and on the singularity of life: of necessity, life evolved early an armory of catalases, the continuing, and all-pervasive presence of which prevents hydrogen peroxide from accumulating anywhere in sufficient quantities to host a second origin. The HP crucible hypothesis is radical, but based on well-known chemistry and physics, it is eminently testable in the laboratory, and many of our simulations provide recipes for such experiments.
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Affiliation(s)
- Rowena Ball
- 1 Mathematical Sciences Institute and Research School of Chemistry, Australian National University, Canberra, Australia
| | - John Brindley
- 2 School of Mathematics, University of Leeds, Leeds, United Kingdom
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Gao Y, Xu W, Dou X, Wang H, Zhang X, Yang S, Liao H, Hu X, Wang H. Mitochondrial DNA Leakage Caused by Streptococcus pneumoniae Hydrogen Peroxide Promotes Type I IFN Expression in Lung Cells. Front Microbiol 2019; 10:630. [PMID: 30984149 PMCID: PMC6447684 DOI: 10.3389/fmicb.2019.00630] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Accepted: 03/13/2019] [Indexed: 12/17/2022] Open
Abstract
Streptococcus pneumoniae (S. pn), the bacterial pathogen responsible for invasive pneumococcal diseases, is capable of producing substantial amounts of hydrogen peroxide. However, the impact of S. pn-secreted hydrogen peroxide (H2O2) on the host immune processes is not completely understood. Here, we demonstrated that S. pn-secreted H2O2 caused mitochondrial damage and severe histopathological damage in mouse lung tissue. Additionally, S. pn-secreted H2O2 caused not only oxidative damage to mitochondrial deoxyribonucleic acid (mtDNA), but also a reduction in the mtDNA content in alveolar epithelia cells. This resulted in the release of mtDNA into the cytoplasm, which subsequently induced type I interferons (IFN-I) expression. We also determined that stimulator of interferon genes (STING) signaling was probably involved in S. pn H2O2-inducing IFN-I expression in response to mtDNA damaged by S. pn-secreted H2O2. In conclusion, our study demonstrated that H2O2 produced by S. pn resulted in mtDNA leakage from damaged mitochondria and IFN-I production in alveolar epithelia cells, and STING may be required in this process, and this is a novel mitochondrial damage mechanism by which S. pn potentiates the IFN-I cascade in S. pn infection.
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Affiliation(s)
- Yue Gao
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Wenchun Xu
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Xiaoyun Dou
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Hong Wang
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Xuemei Zhang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Shenghui Yang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Hongyi Liao
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Xuexue Hu
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
| | - Hong Wang
- Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China.,School of Laboratory Medicine, Chongqing Medical University, Chongqing, China
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Gain- and Loss-of-Function Screens Coupled to Next-Generation Sequencing for Antibiotic Mode of Action and Resistance Studies in Streptococcus pneumoniae. Antimicrob Agents Chemother 2019; 63:AAC.02381-18. [PMID: 30783004 DOI: 10.1128/aac.02381-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 02/08/2019] [Indexed: 12/23/2022] Open
Abstract
Two whole-genome screening approaches are described for studying the mode of action and the mechanisms of resistance to trimethoprim (TMP) in the Gram-positive Streptococcus pneumoniae The gain-of-function approach (Int-Seq) relies on a genomic library of DNA fragments integrated into a fucose-inducible cassette. The second approach, leading to both gain- and loss-of-function mutation, is based on chemical mutagenesis coupled to next-generation sequencing (Mut-Seq). Both approaches pointed at the drug target dihydrofolate reductase (DHFR) as a major resistance mechanism to TMP. Resistance was achieved by dhfr overexpression either through the addition of fucose (Int-Seq) or by mutations upstream of the gene (Mut-Seq). Three types of mutations increased expression by disrupting a predicted Rho-independent terminator upstream of dhfr Known and novel DHFR mutations were also detected by Mut-Seq, and these were functionally validated for TMP resistance. The two approaches also suggested that an increase in the metabolic flux from purine synthesis to GTP and then to folate can modulate the susceptibility to TMP. Finally, we provide evidence for a novel role of the ABC transporter PatAB in TMP susceptibility. Our genomic screens highlighted novel aspects on the mode of action and mechanisms of resistance to antibiotics.
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Redanz S, Cheng X, Giacaman RA, Pfeifer CS, Merritt J, Kreth J. Live and let die: Hydrogen peroxide production by the commensal flora and its role in maintaining a symbiotic microbiome. Mol Oral Microbiol 2018; 33:337-352. [PMID: 29897662 DOI: 10.1111/omi.12231] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2018] [Indexed: 02/05/2023]
Abstract
The majority of commensal oral streptococci are able to generate hydrogen peroxide (H2 O2 ) during aerobic growth, which can diffuse through the cell membrane and inhibit competing species in close proximity. Competing H2 O2 production is mainly dependent upon the pyruvate oxidase SpxB, and to a lesser extent the lactate oxidase LctO, both of which are important for energy generation in aerobic environments. Several studies point to a broad impact of H2 O2 production in the oral environment, including a potential role in biofilm homeostasis, signaling, and interspecies interactions. Here, we summarize the current research regarding oral streptococcal H2 O2 generation, resistance mechanisms, and the ecological impact of H2 O2 production. We also discuss the potential therapeutic utility of H2 O2 for the prevention/treatment of dysbiotic diseases as well as its potential role as a biomarker of oral health.
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Affiliation(s)
- Sylvio Redanz
- Department of Restorative Dentistry, Oregon Health and Science University, Portland, Oregon
| | - Xingqun Cheng
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,The Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Rodrigo A Giacaman
- Cariology Unit, Department of Oral Rehabilitation and Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), University of Talca, Talca, Chile
| | - Carmen S Pfeifer
- Department of Restorative Dentistry, Oregon Health and Science University, Portland, Oregon
| | - Justin Merritt
- Department of Restorative Dentistry, Oregon Health and Science University, Portland, Oregon
| | - Jens Kreth
- Department of Restorative Dentistry, Oregon Health and Science University, Portland, Oregon
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46
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Cao K, Lai F, Zhao XL, Wei QX, Miao XY, Ge R, He QY, Sun X. The mechanism of iron-compensation for manganese deficiency of Streptococcus pneumoniae. J Proteomics 2018; 184:62-70. [DOI: 10.1016/j.jprot.2018.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/17/2018] [Accepted: 06/07/2018] [Indexed: 12/18/2022]
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47
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Glanville DG, Han L, Maule AF, Woodacre A, Thanki D, Abdullah IT, Morrissey JA, Clarke TB, Yesilkaya H, Silvaggi NR, Ulijasz AT. RitR is an archetype for a novel family of redox sensors in the streptococci that has evolved from two-component response regulators and is required for pneumococcal colonization. PLoS Pathog 2018; 14:e1007052. [PMID: 29750817 PMCID: PMC5965902 DOI: 10.1371/journal.ppat.1007052] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 05/23/2018] [Accepted: 04/23/2018] [Indexed: 01/07/2023] Open
Abstract
To survive diverse host environments, the human pathogen Streptococcus pneumoniae must prevent its self-produced, extremely high levels of peroxide from reacting with intracellular iron. However, the regulatory mechanism(s) by which the pneumococcus accomplishes this balance remains largely enigmatic, as this pathogen and other related streptococci lack all known redox-sensing transcription factors. Here we describe a two-component-derived response regulator, RitR, as the archetype for a novel family of redox sensors in a subset of streptococcal species. We show that RitR works to both repress iron transport and enable nasopharyngeal colonization through a mechanism that exploits a single cysteine (Cys128) redox switch located within its linker domain. Biochemical experiments and phylogenetics reveal that RitR has diverged from the canonical two-component virulence regulator CovR to instead dimerize and bind DNA only upon Cys128 oxidation in air-rich environments. Atomic structures show that Cys128 oxidation initiates a "helical unravelling" of the RitR linker region, suggesting a mechanism by which the DNA-binding domain is then released to interact with its cognate regulatory DNA. Expanded computational studies indicate this mechanism could be shared by many microbial species outside the streptococcus genus.
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Affiliation(s)
- David G. Glanville
- Department of Microbiology and Immunology, Loyola University Chicago; Maywood, IL, United States of America
- MRC Centre for Molecular Bacteriology and Infection (CMBI), Imperial College London, London, United Kingdom
| | - Lanlan Han
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Andrew F. Maule
- Department of Horticulture, University of Wisconsin–Madison, Linden Drive, Madison, Wisconsin, United States of America
| | - Alexandra Woodacre
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - Devsaagar Thanki
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - Iman Tajer Abdullah
- Department of Infection and Immunity, University of Leicester, Leicester, United Kingdom
| | - Julie A. Morrissey
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - Thomas B. Clarke
- MRC Centre for Molecular Bacteriology and Infection (CMBI), Imperial College London, London, United Kingdom
| | - Hasan Yesilkaya
- Department of Infection and Immunity, University of Leicester, Leicester, United Kingdom
| | - Nicholas R. Silvaggi
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Andrew T. Ulijasz
- Department of Microbiology and Immunology, Loyola University Chicago; Maywood, IL, United States of America
- MRC Centre for Molecular Bacteriology and Infection (CMBI), Imperial College London, London, United Kingdom
- * E-mail:
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48
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Anderson R, Feldman C. Review manuscript: Mechanisms of platelet activation by the pneumococcus and the role of platelets in community-acquired pneumonia. J Infect 2017; 75:473-485. [PMID: 28943342 DOI: 10.1016/j.jinf.2017.09.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 09/13/2017] [Accepted: 09/15/2017] [Indexed: 12/11/2022]
Abstract
There is increasing recognition of the involvement of platelets in orchestrating inflammatory responses, driving the activation of neutrophils, monocytes and vascular endothelium, which, if poorly controlled, may lead to microvascular dysfunction. Importantly, hyperreactivity of platelets has been implicated in the pathogenesis of myocardial injury and the associated particularly high prevalence of acute cardiovascular events in patients with severe community-acquired pneumonia (CAP), of which Streptococcus pneumoniae (pneumococcus) is the most commonly encountered aetiologic agent. In this context, it is noteworthy that a number of studies have documented various mechanisms by which the pneumococcus may directly promote platelet aggregation and activation. The major contributors to platelet activation include several different types of pneumococcal adhesin, the pore-forming toxin, pneumolysin, and possibly pathogen-derived hydrogen peroxide, which collectively represent a major focus of the current review. This is followed by an overview of the limited experimental studies together with a larger series of clinical studies mainly focused on all-cause CAP, which have provided evidence in support of associations between alterations in circulating platelet counts, most commonly thrombocytopenia, and a poor clinical outcome. The final section of the review covers, albeit briefly, systemic biomarkers of platelet activation which may have prognostic potential.
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Affiliation(s)
- Ronald Anderson
- Department of Immunology and Institute for Cellular and Molecular Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
| | - Charles Feldman
- Division of Pulmonology, Department of Internal Medicine, Charlotte Maxeke Johannesburg Academic Hospital and Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Integrated proteomic and metabolomic analysis reveals that rhodomyrtone reduces the capsule in Streptococcus pneumoniae. Sci Rep 2017; 7:2715. [PMID: 28578394 PMCID: PMC5457420 DOI: 10.1038/s41598-017-02996-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 04/21/2017] [Indexed: 01/12/2023] Open
Abstract
The emergence of antibiotic-resistant pathogenic bacteria is a healthcare problem worldwide. We evaluated the antimicrobial activity of rhodomyrtone, an acylphloroglucinol present in Rhodomyrtus tomentosa leaves, against the human Gram-positive pathogen Streptococcus pneumoniae. The compound exhibited pronounced anti-pneumococcal activity against a broad collection of clinical isolates. We studied the effects at the molecular level by integrated proteomic and metabolomic analysis. The results revealed alterations in enzymes and metabolites involved in several metabolic pathways including amino acid biosynthesis, nucleic acid biosynthesis, glucid, and lipid metabolism. Notably, the levels of two enzymes (glycosyltransferase and UTP-glucose-1-phosphate uridylyltransferase) and three metabolites (UDP-glucose, UDP-glucuronic acid and UDP-N-acetyl-D-galactosamine) participating in the synthesis of the pneumococcal capsule clearly diminished in the bacterial cells exposed to rhodomyrtone. Rhodomyrtone-treated pneumococci significantly possessed less amount of capsule, as measured by a colorimetric assay and visualized by electron microscopy. These findings reveal the utility of combining proteomic and metabolomic analyses to provide insight into phenotypic features of S. pneumoniae treated with this potential novel antibiotic. This can lead to an alternative antibiotic for the treatment of S. pneumoniae infections, because of the growing concern regarding antimicrobial resistance.
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50
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Hajaj B, Yesilkaya H, Shafeeq S, Zhi X, Benisty R, Tchalah S, Kuipers OP, Porat N. CodY Regulates Thiol Peroxidase Expression as Part of the Pneumococcal Defense Mechanism against H 2O 2 Stress. Front Cell Infect Microbiol 2017; 7:210. [PMID: 28596944 PMCID: PMC5443158 DOI: 10.3389/fcimb.2017.00210] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 05/09/2017] [Indexed: 12/21/2022] Open
Abstract
Streptococcus pneumoniae is a facultative anaerobic pathogen. Although it maintains fermentative metabolism, during aerobic growth pneumococci produce high levels of H2O2, which can have adverse effects on cell viability and DNA, and influence pneumococcal interaction with its host. The pneumococcus is unusual in its dealing with toxic reactive oxygen species (ROS) in that it neither has catalase nor the global regulators of peroxide stress resistance. Previously, we identified pneumococcal thiol peroxidase (TpxD) as the key enzyme for enzymatic removal of H2O2, and showed that TpxD synthesis is up-regulated upon exposure to H2O2. This study aimed to reveal the mechanism controlling TpxD expression under H2O2 stress. We hypothesize that H2O2 activates a transcription factor which in turn up-regulates tpxD expression. Microarray analysis revealed a pneumococcal global transcriptional response to H2O2. Mutation of tpxD abolished H2O2-mediated response to high H2O2 levels, signifying the need for an active TpxD under oxidative stress conditions. Bioinformatic tools, applied to search for a transcription factor modulating tpxD expression, pointed toward CodY as a potential candidate. Indeed, a putative 15-bp consensus CodY binding site was found in the proximal region of tpxD-coding sequence. Binding of CodY to this site was confirmed by EMSA, and genetic engineering techniques demonstrated that this site is essential for TpxD up-regulation under H2O2 stress. Furthermore, tpxD expression was reduced in a ΔcodY mutant. These data indicate that CodY is an activator of tpxD expression, triggering its up-regulation under H2O2 stress. In addition we show that H2O2 specifically oxidizes the 2 CodY cysteines. This oxidation may trigger a conformational change in CodY, resulting in enhanced binding to DNA. A schematic model illustrating the contribution of TpxD and CodY to pneumococcal global transcriptional response to H2O2 is proposed.
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Affiliation(s)
- Barak Hajaj
- Pediatric Infectious Disease Unit, Department of Microbiology and Immunology, Faculty of Health Sciences, Soroka University Medical Center, Ben-Gurion University of the NegevBeer Sheva, Israel
| | - Hasan Yesilkaya
- Department of Infection, Immunity and Inflammation, University of LeicesterLeicester, United Kingdom
| | - Sulman Shafeeq
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands
| | - Xiangyun Zhi
- Department of Infection, Immunity and Inflammation, University of LeicesterLeicester, United Kingdom
| | - Rachel Benisty
- Pediatric Infectious Disease Unit, Department of Microbiology and Immunology, Faculty of Health Sciences, Soroka University Medical Center, Ben-Gurion University of the NegevBeer Sheva, Israel
| | - Shiran Tchalah
- Pediatric Infectious Disease Unit, Department of Microbiology and Immunology, Faculty of Health Sciences, Soroka University Medical Center, Ben-Gurion University of the NegevBeer Sheva, Israel
| | - Oscar P Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands
| | - Nurith Porat
- Pediatric Infectious Disease Unit, Department of Microbiology and Immunology, Faculty of Health Sciences, Soroka University Medical Center, Ben-Gurion University of the NegevBeer Sheva, Israel
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