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Dubach VRA, San Segundo-Acosta P, Murphy BJ. Structural and mechanistic insights into Streptococcus pneumoniae NADPH oxidase. Nat Struct Mol Biol 2024:10.1038/s41594-024-01348-w. [PMID: 39039317 DOI: 10.1038/s41594-024-01348-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 06/06/2024] [Indexed: 07/24/2024]
Abstract
Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs) have a major role in the physiology of eukaryotic cells by mediating reactive oxygen species production. Evolutionarily distant proteins with the NOX catalytic core have been found in bacteria, including Streptococcus pneumoniae NOX (SpNOX), which is proposed as a model for studying NOXs because of its high activity and stability in detergent micelles. We present here cryo-electron microscopy structures of substrate-free and nicotinamide adenine dinucleotide (NADH)-bound SpNOX and of NADPH-bound wild-type and F397A SpNOX under turnover conditions. These high-resolution structures provide insights into the electron-transfer pathway and reveal a hydride-transfer mechanism regulated by the displacement of F397. We conducted structure-guided mutagenesis and biochemical analyses that explain the absence of substrate specificity toward NADPH and suggest the mechanism behind constitutive activity. Our study presents the structural basis underlying SpNOX enzymatic activity and sheds light on its potential in vivo function.
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Affiliation(s)
- Victor R A Dubach
- Redox and Metalloprotein Research Group, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
- Redox and Metalloprotein Research Group, IMPRS on Cellular Biophysics, Frankfurt am Main, Germany
| | - Pablo San Segundo-Acosta
- Redox and Metalloprotein Research Group, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
- Chronic Disease Programme, UFIEC, Carlos III Health Institute, Madrid, Spain.
| | - Bonnie J Murphy
- Redox and Metalloprotein Research Group, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
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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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Shi J, Wang Y, Zhang L, Wang F, Miao Y, Yang J, Wang L, Shi S, Ma L, Duan J. Inorganic catalase-powered nanomotors with hyaluronic acid coating for pneumonia therapy. Int J Biol Macromol 2024; 270:132028. [PMID: 38704066 DOI: 10.1016/j.ijbiomac.2024.132028] [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: 12/07/2023] [Revised: 04/27/2024] [Accepted: 04/29/2024] [Indexed: 05/06/2024]
Abstract
Clinical therapy for widespread infections caused by Streptococcus pneumoniae (S. pneumoniae), such as community-acquired pneumonia, is highly challenging. As an important bacterial toxin, hydrogen peroxide (H2O2) secreted by S. pneumoniae can suppress the host's immune system and cause more severe disease. To address this problem, a hyaluronic acid (HA)-coated inorganic catalase-driven Janus nanomotor was developed, which can cleverly utilize and decompose H2O2 to reduce the burden of bacterial infection, and have excellent drug loading capacity. HA coating prevents rapid leakage of loaded antibiotics and improves the biocompatibility of the nanomaterials. The Janus nanomotor converted H2O2 into oxygen (O2), gave itself the capacity to move actively, and encouraged widespread dispersion in the lesion site. Encouragingly, animal experiments demonstrated that the capability of the nanomotors to degrade H2O2 contributes to diminishing the proliferation of S. pneumoniae and lung tissue damage. This self-propelled drug delivery platform provides a new therapeutic strategy for infections with toxin-secreting bacteria.
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Affiliation(s)
- Jingru Shi
- College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Yu Wang
- College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Lingjiao Zhang
- College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Fei Wang
- College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Yu Miao
- College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Jialun Yang
- College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Liping Wang
- College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Shuo Shi
- College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Lili Ma
- Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
| | - Jinyou Duan
- College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, Shaanxi, China.
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Sakuma C, Shizukuishi S, Ogawa M, Honjo Y, Takeyama H, Guan JL, Weiser J, Sasai M, Yamamoto M, Ohnishi M, Akeda Y. Individual Atg8 paralogs and a bacterial metabolite sequentially promote hierarchical CASM-xenophagy induction and transition. Cell Rep 2024; 43:114131. [PMID: 38656870 DOI: 10.1016/j.celrep.2024.114131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 03/06/2024] [Accepted: 04/04/2024] [Indexed: 04/26/2024] Open
Abstract
Atg8 paralogs, consisting of LC3A/B/C and GBRP/GBRPL1/GATE16, function in canonical autophagy; however, their function is controversial because of functional redundancy. In innate immunity, xenophagy and non-canonical single membranous autophagy called "conjugation of Atg8s to single membranes" (CASM) eliminate bacteria in various cells. Previously, we reported that intracellular Streptococcus pneumoniae can induce unique hierarchical autophagy comprised of CASM induction, shedding, and subsequent xenophagy. However, the molecular mechanisms underlying these processes and the biological significance of transient CASM induction remain unknown. Herein, we profile the relationship between Atg8s, autophagy receptors, poly-ubiquitin, and Atg4 paralogs during pneumococcal infection to understand the driving principles of hierarchical autophagy and find that GATE16 and GBRP sequentially play a pivotal role in CASM shedding and subsequent xenophagy induction, respectively, and LC3A and GBRPL1 are involved in CASM/xenophagy induction. Moreover, we reveal ingenious bacterial tactics to gain intracellular survival niches by manipulating CASM-xenophagy progression by generating intracellular pneumococci-derived H2O2.
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Affiliation(s)
- Chisato Sakuma
- Department of Bacteriology I, National Institute of Infectious Diseases, 1-23-1, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Sayaka Shizukuishi
- Department of Bacteriology I, National Institute of Infectious Diseases, 1-23-1, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Michinaga Ogawa
- Department of Bacteriology I, National Institute of Infectious Diseases, 1-23-1, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
| | - Yuko Honjo
- Department of Bacteriology I, National Institute of Infectious Diseases, 1-23-1, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan; Department of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Haruko Takeyama
- Department of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan; Computational Bio Big-Data Open Innovation Laboratory, AIST-Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-0072, Japan; Research Organization for Nano & Life Innovation, Waseda University, 513 Wasedatsurumaki-cho, Shinjuku-ku, Tokyo 162-0041, Japan; Institute for Advanced Research of Biosystem Dynamics, Waseda Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan
| | - Jun-Lin Guan
- Department of Cancer Biology, University of Cincinnati College of Medicine, CARE/Crawley Building, Suite E-870 3230 Eden Avenue, Cincinnati, OH 45267, USA
| | - Jeffery Weiser
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Miwa Sasai
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan; Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan; Department of Immunoparasitology, Center for Infectious Disease Education and Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan; Laboratory of Immunoparasitology, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan; Department of Immunoparasitology, Center for Infectious Disease Education and Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Makoto Ohnishi
- Department of Bacteriology I, National Institute of Infectious Diseases, 1-23-1, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Yukihiro Akeda
- Department of Bacteriology I, National Institute of Infectious Diseases, 1-23-1, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
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Jennert F, Schaaf D, Nau R, Kohler TP, Hammerschmidt S, Häusler D, Valentin-Weigand P, Seele J. Hydrogen peroxide is responsible for the cytotoxic effects of Streptococcus pneumoniae on primary microglia in the absence of pneumolysin. J Innate Immun 2024; 16:000536514. [PMID: 38569474 PMCID: PMC11060703 DOI: 10.1159/000536514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 01/25/2024] [Indexed: 04/05/2024] Open
Abstract
INTRODUCTION Streptococcus pneumoniae is the most common cause of bacterial meningitis and meningoencephalitis in humans. The bacterium produces numerous virulence determinants, among them hydrogen peroxide (H2O2) and pneumolysin (Ply), which contribute to bacterial cytotoxicity. Microglia, the resident phagocytes in the brain, are distinct from other macrophages, and we thus compared their susceptibility to pneumococcal toxicity and their ability to phagocytose pneumococci with those of bone marrow-derived macrophages (BMDM). METHODS Microglia and BMDM were co-incubated with S. pneumoniae D39 to analyze survival of phagocytes by fluorescence microscopy, bacterial growth by quantitative plating, and phagocytosis by an antibiotic protection assay. Ply was detected by hemolysis assay and Western blot analysis. RESULTS We found that microglia were killed during pneumococcal infection with a wild-type and an isogenic ply-deficient mutant, whereas viability of BMDM was not affected by pneumococci. Treatment with recombinant Ply showed a dose-dependent cytotoxic effect on microglia and BMDM. However, high concentrations of recombinant Ply were required and under the chosen experimental conditions, Ply was not detectable in the supernatant during infection of microglia. Inactivation of H2O2 by exogenously added catalase abolished its cytotoxic effect. Consequently, infection of microglia with pneumococci deficient for the pyruvate oxidase SpxB, primarily producing H2O2, resulted in reduced killing of microglia. CONCLUSION Taken together, in the absence of Ply, H2O2 caused cell death in primary phagocytes in concentrations produced by pneumococci.
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Affiliation(s)
- Franziska Jennert
- University of Veterinary Medicine Hannover, Institute for Microbiology, Center for Infection Medicine, Hannover, Germany
| | - Désirée Schaaf
- University of Veterinary Medicine Hannover, Institute for Microbiology, Center for Infection Medicine, Hannover, Germany
| | - Roland Nau
- University Medical Center Göttingen, Department of Neuropathology, Göttingen, Germany
- Evangelisches Krankenhaus Göttingen-Weende, Department of Geriatrics, Göttingen, Germany
| | - Thomas P. Kohler
- Greifswald University, Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Greifswald, Germany
| | - Sven Hammerschmidt
- Greifswald University, Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Greifswald, Germany
| | - Darius Häusler
- University Medical Center Göttingen, Department of Neuropathology, Göttingen, Germany
- Fraunhofer-Institute for Translational Medicine and Pharmacology ITMP, Göttingen, Germany
| | - Peter Valentin-Weigand
- University of Veterinary Medicine Hannover, Institute for Microbiology, Center for Infection Medicine, Hannover, Germany
| | - Jana Seele
- University Medical Center Göttingen, Department of Neuropathology, Göttingen, Germany
- Evangelisches Krankenhaus Göttingen-Weende, Department of Geriatrics, Göttingen, Germany
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Benameur F, Belkaaloul K, Kheroua O. Isolation of 60 strains from fermented milk of mares and donkeys in Algeria and identification by 16S rRNA sequencing of lactobacilli: Assessment of probiotic skills of important strains and aromatic productivity power. Vet World 2024; 17:829-841. [PMID: 38798294 PMCID: PMC11111728 DOI: 10.14202/vetworld.2024.829-841] [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: 12/20/2023] [Accepted: 03/14/2024] [Indexed: 05/29/2024] Open
Abstract
Background and Aim Donkey and mare milk have high nutritional and functional values, but their lactic acid bacteria (LAB) content remains poorly studied and undervalued in the Algerian dairy industry. This study aimed to isolate and select LAB strains that produce antimicrobial substances during fermentation and to characterize the probiotic profiles of each extracted strain to indicate their potential for antioxidant and proteolytic activity. Materials and Methods This study focuses on isolating and identifying lactic acid bacterial strains from 10 Equid-fermented milk samples collected in two regions of El Bayed Wilaya (Algeria). Identification of LAB strains was obtained by 16S rRNA sequencing. The probiotic properties of important strains and their aromatic productivity power are assessed. To evaluate their antibacterial activity against Listeria monocytogenes, Staphylococcus aureus, Chryseobacterium joostei, Pseudomonas aeruginosa, and Escherichia coli, we selected 21 strains. Different induction methods have been used to amplify the antibacterial effects against these pathogenic strains. Results Among a total of 60 identified strains, 31 had a probiotic profile, and most were catalase-negative. Aromatic productivity power was observed in eight strains: Lactiplantibacillus plantarum, Lactobacillus casei, Lactobacillus paracasei, Weissella confusa, Weissella cibaria, Leuconostoc mesenteroides, Leuconostoc lactis, and Lactobacillus sp1. Conclusion Our results provide insight into the considerable diversity of LAB present in fermented donkey and mare milk. To meet the expectations of the Algerian dairy industry, it is important that the probiotic skills of the nine selected strains are met. In addition, a significant number of these strains may have important probiotic activity and biotechnological potential.
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Affiliation(s)
- Fouzia Benameur
- Laboratory of Physiology of Nutrition and Food Safety, Department of Biology, Faculty of Natural and Life Sciences, University Oran 1 Ahmed Ben Bella, Oran, Algeria
| | - Kawthar Belkaaloul
- Laboratory of Physiology of Nutrition and Food Safety, Department of Biology, Faculty of Natural and Life Sciences, University Oran 1 Ahmed Ben Bella, Oran, Algeria
| | - Omar Kheroua
- Laboratory of Physiology of Nutrition and Food Safety, Department of Biology, Faculty of Natural and Life Sciences, University Oran 1 Ahmed Ben Bella, Oran, Algeria
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Dao TH, Echlin H, McKnight A, Marr ES, Junker J, Jia Q, Hayden R, van Opijnen T, Isberg RR, Cooper VS, Rosch JW. Streptococcus pneumoniae favors tolerance via metabolic adaptation over resistance to circumvent fluoroquinolones. mBio 2024; 15:e0282823. [PMID: 38193698 PMCID: PMC10865975 DOI: 10.1128/mbio.02828-23] [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: 10/17/2023] [Accepted: 12/01/2023] [Indexed: 01/10/2024] Open
Abstract
Streptococcus pneumoniae is a major human pathogen of global health concern and the rapid emergence of antibiotic resistance poses a serious public health problem worldwide. Fluoroquinolone resistance in S. pneumoniae is an intriguing case because the prevalence of fluoroquinolone resistance does not correlate with increasing usage and has remained rare. Our data indicate that deleterious fitness costs in the mammalian host constrain the emergence of fluoroquinolone resistance both by de novo mutation and recombination. S. pneumoniae was able to circumvent such deleterious fitness costs via the development of antibiotic tolerance through metabolic adaptation that reduced the production of reactive oxygen species, resulting in a fitness benefit during infection of mice treated with fluoroquinolones. These data suggest that the emergence of fluoroquinolone resistance is tightly constrained in S. pneumoniae by fitness tradeoffs and that mutational pathways involving metabolic networks to enable tolerance phenotypes are an important contributor to the evasion of antibiotic-mediated killing.IMPORTANCEThe increasing prevalence of antibiotic resistant bacteria is a major global health concern. While many species have the potential to develop antibiotic resistance, understanding the barriers to resistance emergence in the clinic remains poorly understood. A prime example of this is fluroquinolone resistance in Streptococcus pneumoniae, whereby, despite continued utilization, resistance to this class of antibiotic remains rare. In this study, we found that the predominant pathways for developing resistance to this antibiotic class severely compromised the infectious capacity of the pneumococcus, providing a key impediment for the emergence of resistance. Using in vivo models of experimental evolution, we found that S. pneumoniae responds to repeated fluoroquinolone exposure by modulating key metabolic pathways involved in the generation of redox molecules, which leads to antibiotic treatment failure in the absence of appreciable shifts in resistance levels. These data underscore the complex pathways available to pathogens to evade antibiotic mediating killing via antibiotic tolerance.
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Affiliation(s)
- Tina H. Dao
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Haley Echlin
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Abigail McKnight
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Enolia S. Marr
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Julia Junker
- Nationales Referenzzentrum für Streptokokken Abteilung Medizinische Mikrobiologie, Universitätsklinikum RWTH Aachen, Aachen, Germany
| | - Qidong Jia
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Randall Hayden
- Department of Pathology, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Tim van Opijnen
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Ralph R. Isberg
- Deptartment of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Vaughn S. Cooper
- Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jason W. Rosch
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
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Liang Z, Lu J, Bao Y, Chen X, Yao H, Wu Z. Glycerol metabolic repressor GlpR contributes to Streptococcus suis oxidative stress resistance and virulence. Microbes Infect 2024:105307. [PMID: 38309574 DOI: 10.1016/j.micinf.2024.105307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 01/30/2024] [Accepted: 01/30/2024] [Indexed: 02/05/2024]
Abstract
Bacterial DeoR family transcription regulators regulate multiple physiological processes. Little is known about the function of DeoR family regulators in streptococci. Here, we identified a novel DeoR family regulator, GlpR, from Streptococcus suis, a pathogen causing severe diseases in pigs and humans. GlpR was involved in glycerol utilization and exhibited specific signature residues at positions 30-31 (KV) which are crucial for DNA binding. Deletion of glpR (ΔglpR) showed a significant increase in relative growth rate in glycerol medium compared to the wild-type (WT) and complementary strains (CΔglpR). Employing RNA-seq analysis, β-galactosidase activity analysis, and electrophoretic mobility shift assay, we discovered that GlpR directly represses the expression of glycerol metabolism-related genes pflB2, pflA1, and fsaA, encoding pyruvate formate-lyase and its activating enzyme, and fructose-6-phosphate aldolase, respectively. Compared to WT and CΔglpR, ΔglpR showed a reduced survival rate under oxidative stress and in murine macrophages and attenuated virulence in mice. GlpR probably enhances oxidative stress resistance and virulence in S. suis by functioning as a glycerol metabolic repressor decreasing energy consumption. These findings contribute to a better understanding of S. suis pathogenesis and enrich our knowledge of the biological functions of DeoR family regulators in streptococci.
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Affiliation(s)
- Zijing Liang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; WOAH Reference Lab for Swine Streptococcosis, Nanjing 210014, China
| | - Jiaxuan Lu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; WOAH Reference Lab for Swine Streptococcosis, Nanjing 210014, China
| | - Yinli Bao
- Engineering Research Center for the Prevention and Control of Animal Original Zoonosis, College of Life Science, Longyan University, Longyan 364012, China
| | - Xiang Chen
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Huochun Yao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; WOAH Reference Lab for Swine Streptococcosis, Nanjing 210014, China
| | - Zongfu Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; WOAH Reference Lab for Swine Streptococcosis, Nanjing 210014, China; Guangdong Provincial Key Laboratory of Research on the Technology of Pig-breeding and Pig-disease Prevention, Guangzhou 511400, China.
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Scasny A, Alibayov B, Khan F, Rao SJ, Murin L, Jop Vidal AG, Smith P, Li W, Edwards K, Warncke K, Vidal JE. Oxidation of hemoproteins by Streptococcus pneumoniae collapses the cell cytoskeleton and disrupts mitochondrial respiration leading to the cytotoxicity of human lung cells. Microbiol Spectr 2024; 12:e0291223. [PMID: 38084982 PMCID: PMC10783075 DOI: 10.1128/spectrum.02912-23] [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: 07/24/2023] [Accepted: 11/06/2023] [Indexed: 12/21/2023] Open
Abstract
IMPORTANCE Streptococcus pneumoniae (Spn) colonizes the lungs, killing millions every year. During its metabolism, Spn produces abundant amounts of hydrogen peroxide. When produced in the lung parenchyma, Spn-hydrogen peroxide (H2O2) causes the death of lung cells, and details of the mechanism are studied here. We found that Spn-H2O2 targets intracellular proteins, resulting in the contraction of the cell cytoskeleton and disruption of mitochondrial function, ultimately contributing to cell death. Intracellular proteins targeted by Spn-H2O2 included cytochrome c and, surprisingly, a protein of the cell cytoskeleton, beta-tubulin. To study the details of oxidative reactions, we used, as a surrogate model, the oxidation of another hemoprotein, hemoglobin. Using the surrogate model, we specifically identified a highly reactive radical whose creation was catalyzed by Spn-H2O2. In sum, we demonstrated that the oxidation of intracellular targets by Spn-H2O2 plays an important role in the cytotoxicity caused by Spn, thus providing new targets for interventions.
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Affiliation(s)
- Anna Scasny
- Department of Cell and Molecular Biology, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
- Center for Immunology and Microbial Research, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Babek Alibayov
- Department of Cell and Molecular Biology, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
- Center for Immunology and Microbial Research, 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
- Center for Immunology and Microbial Research, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Shambavi J. Rao
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State School of Medicine, The Ohio State Wexner Medical Center, Columbus, Ohio, USA
| | - Landon Murin
- Department of Cell and Molecular Biology, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
- Center for Immunology and Microbial Research, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Ana G. Jop Vidal
- Department of Cell and Molecular Biology, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
- Center for Immunology and Microbial Research, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Perriann Smith
- Mississippi INBRE Research Scholar, University of Southern Mississippi, Jackson, Mississippi, USA
| | - Wei Li
- Department of Physics, Emory University, Atlanta, Georgia, USA
| | - Kristin Edwards
- Department of Cell and Molecular Biology, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Kurt Warncke
- Department of Physics, Emory University, Atlanta, Georgia, USA
| | - Jorge E. Vidal
- Department of Cell and Molecular Biology, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
- Center for Immunology and Microbial Research, School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA
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10
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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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11
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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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12
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Shearer HL, Pace PE, Smith LM, Fineran PC, Matthews AJ, Camilli A, Dickerhof N, Hampton MB. Identification of Streptococcus pneumoniae genes associated with hypothiocyanous acid tolerance through genome-wide screening. J Bacteriol 2023; 205:e0020823. [PMID: 37791755 PMCID: PMC10601753 DOI: 10.1128/jb.00208-23] [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: 07/05/2023] [Accepted: 09/01/2023] [Indexed: 10/05/2023] Open
Abstract
Streptococcus pneumoniae is a commensal bacterium and invasive pathogen that causes millions of deaths worldwide. The pneumococcal vaccine offers limited protection, and the rise of antimicrobial resistance will make treatment increasingly challenging, emphasizing the need for new antipneumococcal strategies. One possibility is to target antioxidant defenses to render S. pneumoniae more susceptible to oxidants produced by the immune system. Human peroxidase enzymes will convert bacterial-derived hydrogen peroxide to hypothiocyanous acid (HOSCN) at sites of colonization and infection. Here, we used saturation transposon mutagenesis and deep sequencing to identify genes that enable S. pneumoniae to tolerate HOSCN. We identified 37 genes associated with S. pneumoniae HOSCN tolerance, including genes involved in metabolism, membrane transport, DNA repair, and oxidant detoxification. Single-gene deletion mutants of the identified antioxidant defense genes sodA, spxB, trxA, and ahpD were generated and their ability to survive HOSCN was assessed. With the exception of ΔahpD, all deletion mutants showed significantly greater sensitivity to HOSCN, validating the result of the genome-wide screen. The activity of hypothiocyanous acid reductase or glutathione reductase, known to be important for S. pneumoniae tolerance of HOSCN, was increased in three of the mutants, highlighting the compensatory potential of antioxidant systems. Double deletion of the gene encoding glutathione reductase and sodA sensitized the bacteria significantly more than single deletion. The HOSCN defense systems identified in this study may be viable targets for novel therapeutics against this deadly pathogen. IMPORTANCE Streptococcus pneumoniae is a human pathogen that causes pneumonia, bacteremia, and meningitis. Vaccination provides protection only against a quarter of the known S. pneumoniae serotypes, and the bacterium is rapidly becoming resistant to antibiotics. As such, new treatments are required. One strategy is to sensitize the bacteria to killing by the immune system. In this study, we performed a genome-wide screen to identify genes that help this bacterium resist oxidative stress exerted by the host at sites of colonization and infection. By identifying a number of critical pneumococcal defense mechanisms, our work provides novel targets for antimicrobial therapy.
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Affiliation(s)
- Heather L. Shearer
- Department of Pathology and Biomedical Science, Mātai Hāora - Centre for Redox Biology and Medicine, University of Otago Christchurch, Christchurch, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Otago, New Zealand
| | - Paul E. Pace
- Department of Pathology and Biomedical Science, Mātai Hāora - Centre for Redox Biology and Medicine, University of Otago Christchurch, Christchurch, New Zealand
| | - Leah M. Smith
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
| | - Peter C. Fineran
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Otago, New Zealand
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
- Bioprotection Aotearoa, University of Otago, Dunedin, New Zealand
| | - Allison J. Matthews
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Andrew Camilli
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Nina Dickerhof
- Department of Pathology and Biomedical Science, Mātai Hāora - Centre for Redox Biology and Medicine, University of Otago Christchurch, Christchurch, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Otago, New Zealand
| | - Mark B. Hampton
- Department of Pathology and Biomedical Science, Mātai Hāora - Centre for Redox Biology and Medicine, University of Otago Christchurch, Christchurch, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Otago, New Zealand
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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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14
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Bardi G, Boselli L, Pompa PP. Anti-inflammatory potential of platinum nanozymes: mechanisms and perspectives. NANOSCALE 2023; 15:14284-14300. [PMID: 37584343 DOI: 10.1039/d3nr03016d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
Inflammation is a complex process of the body in response to pathogen infections or dysregulated metabolism, involving the recruitment and activation of immune system components. Repeated dangerous stimuli or uncontrolled immune effector mechanisms can result in tissue injury. Reactive Oxygen Species (ROS) play key roles in physiological cell signaling as well as in the destruction of internalized pathogens. However, aberrant ROS production and release have deleterious effects on the surrounding environment, making ROS regulation a priority to reduce inflammation. Most of the current anti-inflammatory therapies rely on drugs that impair the release of pro-inflammatory mediators. Nevertheless, increasing the enzymatic activity to reduce ROS levels could be an alternative or complementary therapeutic approach to decrease inflammation. Nanozymes are nanomaterials with high catalytic activity that mimic natural enzymes, allowing biochemical reactions to take place. Such functional particles typically show different and regenerable oxidation states or catalytically reactive surfaces offering long-term activity and stability. In this scenario, platinum-based nanozymes (PtNZs) exhibit broad and efficient catalytic functionalities and can reduce inflammation mainly through ROS scavenging, e.g. by catalase and superoxide dismutase reactions. Dose-dependent biocompatibility and immune compatibility of PtNZs have been shown in different cells and tissues, both in vitro and in vivo. Size/shape/surface engineering of the nanozymes could also potentiate their efficacy to act at different sites and/or steps of the inflammation process, such as cytokine removal or specific targeting of activated leukocytes. In the present review, we analyze key inflammation triggering processes and the effects of platinum nanozymes under exemplificative inflammatory conditions. We further discuss potential platinum nanozyme design and improvements to modulate and expand their anti-inflammatory action.
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Affiliation(s)
- Giuseppe Bardi
- Nanobiointeractions & Nanodiagnostics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
| | - Luca Boselli
- Nanobiointeractions & Nanodiagnostics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
| | - Pier Paolo Pompa
- Nanobiointeractions & Nanodiagnostics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
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15
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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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16
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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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17
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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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18
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Park DY, Hwang J, Kim Y, Lee D, Kim YY, Kim HS, Hwang I. Antimicrobial activity of Limosilactobacillus fermentum strains isolated from the human oral cavity against Streptococcus mutans. Sci Rep 2023; 13:7969. [PMID: 37198248 DOI: 10.1038/s41598-023-35168-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 05/13/2023] [Indexed: 05/19/2023] Open
Abstract
Oral probiotics have been recently gaining much attention owing to their potential to inhibit the progression of dental caries by controlling the cariogenic effects of Streptococcus mutans. We isolated and genotypically identified 77 lactic acid bacteria including 12 Limosilactobacillus fermentum probiotic candidates from the oral cavity of healthy volunteers. Among the 12 L. fermentum isolates, nine isolates effectively inhibited the growth of S. mutans via hydrogen peroxide (H2O2) production. The others neither suppressed the growth of S. mutans nor produced H2O2. Eight out of the nine H2O2-producing L. fermentum isolates exhibited strong adherence to oral epithelial KB cells while inhibiting the adherence of S. mutans to KB cells. The eight H2O2-producing isolates were neither haemolytic based on a blood-agar test, cytotoxic according to lactate dehydrogenase assay, nor resistant to eight antibiotics represented by the European Food Safety Authority guideline, indicating that the isolates have potential to suppress the cariogenesis driven by S. mutans while providing general probiotic benefits.
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Affiliation(s)
| | | | - Yunji Kim
- Apple Tree Institute of Biomedical Science, Apple Tree Medical Foundation, Goyang-Si, South Korea
| | - Dahye Lee
- Apple Tree Dental Hospital, Apple Tree Medical Foundation, Goyang-Si, South Korea
| | - Young-Youn Kim
- Apple Tree Institute of Biomedical Science, Apple Tree Medical Foundation, Goyang-Si, South Korea
- Apple Tree Dental Hospital, Apple Tree Medical Foundation, Goyang-Si, South Korea
| | - Hye-Sung Kim
- Apple Tree Institute of Biomedical Science, Apple Tree Medical Foundation, Goyang-Si, South Korea
- Apple Tree Dental Hospital, Apple Tree Medical Foundation, Goyang-Si, South Korea
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19
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Fritsch VN, Linzner N, Busche T, Said N, Weise C, Kalinowski J, Wahl MC, Antelmann H. The MerR-family regulator NmlR is involved in the defense against oxidative stress in Streptococcus pneumoniae. Mol Microbiol 2023; 119:191-207. [PMID: 36349475 DOI: 10.1111/mmi.14999] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 10/25/2022] [Accepted: 10/30/2022] [Indexed: 11/11/2022]
Abstract
Streptococcus pneumoniae has to cope with the strong oxidant hypochlorous acid (HOCl), during host-pathogen interactions. Thus, we analyzed the global gene expression profile of S. pneumoniae D39 towards HOCl stress. In the RNA-seq transcriptome, the NmlR, SifR, CtsR, HrcA, SczA and CopY regulons and the etrx1-ccdA1-msrAB2 operon were most strongly induced under HOCl stress, which participate in the oxidative, electrophile and metal stress response in S. pneumoniae. The MerR-family regulator NmlR harbors a conserved Cys52 and controls the alcohol dehydrogenase-encoding adhC gene under carbonyl and NO stress. We demonstrated that NmlR senses also HOCl stress to activate transcription of the nmlR-adhC operon. HOCl-induced transcription of adhC required Cys52 of NmlR in vivo. Using mass spectrometry, NmlR was shown to be oxidized to intersubunit disulfides or S-glutathionylated under oxidative stress in vitro. A broccoli-FLAP-based assay further showed that both NmlR disulfides significantly increased transcription initiation at the nmlR promoter by RNAP in vitro, which depends on Cys52. Phenotype analyses revealed that NmlR functions in the defense against oxidative stress and promotes survival of S. pneumoniae during macrophage infections. In conclusion, NmlR was characterized as HOCl-sensing transcriptional regulator, which activates transcription of adhC under oxidative stress by thiol switches in S. pneumoniae.
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Affiliation(s)
| | - Nico Linzner
- Institute of Biology-Microbiology, Freie Universität Berlin, Berlin, Germany
| | - Tobias Busche
- Center for Biotechnology, University Bielefeld, Bielefeld, Germany.,NGS Core Facility, Medical School OWL, Bielefeld University, Bielefeld, Germany
| | - Nelly Said
- Laboratory of Structural Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Christoph Weise
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Jörn Kalinowski
- Center for Biotechnology, University Bielefeld, Bielefeld, Germany
| | - Markus C Wahl
- Laboratory of Structural Biochemistry, Freie Universität Berlin, Berlin, Germany.,Macromolecular Crystallography, Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany
| | - Haike Antelmann
- Institute of Biology-Microbiology, Freie Universität Berlin, Berlin, Germany
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20
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The Cell Wall Deacetylases Spy1094 and Spy1370 Contribute to Streptococcus pyogenes Virulence. Microorganisms 2023; 11:microorganisms11020305. [PMID: 36838272 PMCID: PMC9966966 DOI: 10.3390/microorganisms11020305] [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: 11/24/2022] [Revised: 01/21/2023] [Accepted: 01/22/2023] [Indexed: 01/26/2023] Open
Abstract
Streptococcus pyogenes, or Group A Streptococcus (GAS), is a strictly human pathogen that causes a wide range of diseases, including skin and soft tissue infections, toxic shock syndrome and acute rheumatic fever. We have recently reported that Spy1094 and Spy1370 of S. pyogenes serotype M1 are N-acetylglucosamine (GlcNAc) deacetylases. We have generated spy1094 and spy1370 gene deletion mutants in S. pyogenes and gain-of-function mutants in Lactococcus lactis. Similar to other cell wall deacetylases, our results show that Spy1094 and Spy1370 confer lysozyme-resistance. Furthermore, deletion of the genes decreased S. pyogenes virulence in a human whole blood killing assay and a Galleria mellonella (Greater wax moth) larvae infection model. Expression of the two genes in L. lactis resulted in increased lysozyme resistance and survival in whole human blood, and reduced survival of infected G. mellonella larvae. Deletion of the spy1370, but not the spy1094 gene, decreased resistance to the cationic antimicrobial peptide cecropin B, whereas both enzymes increased biofilm formation, probably resulting from the increase in positive charges due to deacetylation of the cell wall. In conclusion, Spy1094 and Spy1370 are important S. pyogenes virulence factors and might represent attractive targets for the development of antibacterial agents.
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21
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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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22
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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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23
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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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24
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Mitochondrial ROS production by neutrophils is required for host antimicrobial function against Streptococcus pneumoniae and is controlled by A2B adenosine receptor signaling. PLoS Pathog 2022; 18:e1010700. [DOI: 10.1371/journal.ppat.1010700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 11/28/2022] [Accepted: 11/07/2022] [Indexed: 11/15/2022] Open
Abstract
Polymorphonuclear cells (PMNs) control Streptococcus pneumoniae (pneumococcus) infection through various antimicrobial activities. We previously found that reactive oxygen species (ROS) were required for optimal antibacterial function, however, the NADPH oxidase is known to be dispensable for the ability of PMNs to kill pneumococci. In this study, we explored the role of ROS produced by the mitochondria in PMN antimicrobial defense against pneumococci. We found that the mitochondria are an important source of overall intracellular ROS produced by murine PMNs in response to infection. We investigated the host and bacterial factors involved and found that mitochondrial ROS (MitROS) are produced independent of bacterial capsule or pneumolysin but presence of live bacteria that are in direct contact with PMNs enhanced the response. We further found that MyD88-/- PMNs produced less MitROS in response to pneumococcal infection suggesting that released bacterial products acting as TLR ligands are sufficient for inducing MitROS production in PMNs. To test the role of MitROS in PMN function, we used an opsonophagocytic killing assay and found that MitROS were required for the ability of PMNs to kill pneumococci. We then investigated the role of MitROS in host resistance and found that MitROS are produced by PMNs in response to pneumococcal infection. Importantly, treatment of mice with a MitROS scavenger prior to systemic challenge resulted in reduced survival of infected hosts. In exploring host pathways that control MitROS, we focused on extracellular adenosine, which is known to control PMN anti-pneumococcal activity, and found that signaling through the A2B adenosine receptor inhibits MitROS production by PMNs. A2BR-/- mice produced more MitROS and were significantly more resistant to infection. Finally, we verified the clinical relevance of our findings using human PMNs. In summary, we identified a novel pathway that controls MitROS production by PMNs, shaping host resistance against S. pneumoniae.
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25
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Desai A, Aliberti S, Amati F, Stainer A, Voza A. Cardiovascular Complications in Community-Acquired Pneumonia. Microorganisms 2022; 10:2177. [PMID: 36363769 PMCID: PMC9695472 DOI: 10.3390/microorganisms10112177] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 10/26/2022] [Accepted: 10/31/2022] [Indexed: 11/15/2023] Open
Abstract
Community-acquired pneumonia (CAP) is accountable for high mortality in both pediatric and adult populations worldwide, about one-third of hospitalized patients pass away within a year of being discharged from the facility. The high mortality and morbidity rates are closely related to cardiovascular complications that are consequent or concomitant to the acute episode of pneumonia. An updated perspective on the major pathophysiological mechanisms, prevalence, risk factors, outcomes, and relevant treatments of cardiovascular events in CAP patients is provided in the current study. It is possible to evaluate the pathophysiology of cardiac disease in this population based on plaque-related events, such as acute myocardial infarction, or events unrelated to plaque, such as arrhythmias and heart failure. With an absolute rate of cardiovascular problems ranging broadly from 10% to 30%, CAP raises the risk of both plaque-related and plaque-unrelated events. Both in- and out-patients may experience these issues at admission, throughout hospitalization, or even up to a year following discharge. At long-term follow-up, cardiac events account for more than 30% of deaths in CAP patients, making them a significant cause of mortality. If patients at risk for cardiac events are stratified, diagnostic tools, monitoring, and preventive measures may be applied to these patients. A prospective evaluation of cardioprotective treatments is urgently required from a research point of view.
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Affiliation(s)
- Antonio Desai
- IRCCS Humanitas Research Hospital, Emergency Department, Via Manzoni 56, Rozzano, 20089 Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
| | - Stefano Aliberti
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
- IRCCS Humanitas Research Hospital, Respiratory Unit, Via Manzoni 56, Rozzano, 20089 Milan, Italy
| | - Francesco Amati
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
- IRCCS Humanitas Research Hospital, Respiratory Unit, Via Manzoni 56, Rozzano, 20089 Milan, Italy
| | - Anna Stainer
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
- IRCCS Humanitas Research Hospital, Respiratory Unit, Via Manzoni 56, Rozzano, 20089 Milan, Italy
| | - Antonio Voza
- IRCCS Humanitas Research Hospital, Emergency Department, Via Manzoni 56, Rozzano, 20089 Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, 20072 Milan, Italy
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26
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Mousa WK. The microbiome-product colibactin hits unique cellular targets mediating host–microbe interaction. Front Pharmacol 2022; 13:958012. [PMID: 36172175 PMCID: PMC9510844 DOI: 10.3389/fphar.2022.958012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/18/2022] [Indexed: 11/20/2022] Open
Abstract
The human microbiota produces molecules that are evolved to interact with the diverse cellular machinery of both the host and microbes, mediating health and diseases. One of the most puzzling microbiome molecules is colibactin, a genotoxin encoded in some commensal and extraintestinal microbes and is implicated in initiating colorectal cancer. The colibactin cluster was discovered more than 15 years ago, and most of the research studies have been focused on revealing the biosynthesis and precise structure of the cryptic encoded molecule(s) and the mechanism of carcinogenesis. In 2022, the Balskus group revealed that colibactin not only hits targets in the eukaryotic cell machinery but also in the prokaryotic cell. To that end, colibactin crosslinks the DNA resulting in activation of the SOS signaling pathway, leading to prophage induction from bacterial lysogens and modulation of virulence genes in pathogenic species. These unique activities of colibactin highlight its ecological role in shaping gut microbial communities and further consequences that impact human health. This review dives in-depth into the molecular mechanisms underpinning colibactin cellular targets in eukaryotic and prokaryotic cells, aiming to understand the fine details of the role of secreted microbiome chemistry in mediating host–microbe and microbe–microbe interactions. This understanding translates into a better realization of microbiome potential and how this could be advanced to future microbiome-based therapeutics or diagnostic biomarkers.
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Affiliation(s)
- Walaa K. Mousa
- College of Pharmacy, Al Ain University, Abu Dhabi, United Arab Emirates
- College of Pharmacy, Mansoura University, Mansoura, Egypt
- *Correspondence: Walaa K. Mousa,
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27
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A newly identified flavoprotein disulfide reductase Har protects Streptococcus pneumoniae against hypothiocyanous acid. J Biol Chem 2022; 298:102359. [PMID: 35952759 PMCID: PMC9483559 DOI: 10.1016/j.jbc.2022.102359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 11/25/2022] Open
Abstract
Hypothiocyanous acid (HOSCN) is an antimicrobial oxidant produced from hydrogen peroxide and thiocyanate anions by heme peroxidases in secretory fluids such as in the human respiratory tract. Some respiratory tract pathogens display tolerance to this oxidant, which suggests that there might be therapeutic value in targeting HOSCN defense mechanisms. However, surprisingly little is known about how bacteria protect themselves from HOSCN. We hypothesized that tolerant pathogens have a flavoprotein disulfide reductase that uses NAD(P)H to directly reduce HOSCN, similar to thioredoxin reductase in mammalian cells. Here, we report the discovery of a previously uncharacterized flavoprotein disulfide reductase with HOSCN reductase activity, which we term Har (hypothiocyanous acid reductase), in Streptococcus pneumoniae, a bacterium previously found to be tolerant of HOSCN. S. pneumoniae generates large amounts of hydrogen peroxide that can be converted to HOSCN in the respiratory tract. Using deletion mutants, we demonstrate that the HOSCN reductase is dispensable for growth of S. pneumoniae in the presence of lactoperoxidase and thiocyanate. However, bacterial growth in the HOSCN-generating system was completely crippled when deletion of HOSCN reductase activity was combined with disruption of GSH import or recycling. Our findings identify a new bacterial HOSCN reductase and demonstrate a role for this protein in combination with GSH utilization to protect S. pneumoniae from HOSCN.
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28
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Gaire TN, Odland C, Zhang B, Ray T, Doster E, Nerem J, Dee S, Davies P, Noyes N. The impacts of viral infection and subsequent antimicrobials on the microbiome-resistome of growing pigs. MICROBIOME 2022; 10:118. [PMID: 35922873 PMCID: PMC9351240 DOI: 10.1186/s40168-022-01312-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Antimicrobials are used in food-producing animals for purposes of preventing, controlling, and/or treating infections. In swine, a major driver of antimicrobial use is porcine reproductive and respiratory syndrome (PRRS), which is caused by a virus that predisposes infected animals to secondary bacterial infections. Numerous antimicrobial protocols are used to treat PRRS, but we have little insight into how these treatment schemes impact antimicrobial resistance (AMR) dynamics within the fecal microbiome of commercial swine. The aim of this study was to determine whether different PRRS-relevant antimicrobial treatment protocols were associated with differences in the fecal microbiome and resistome of growing pigs. To accomplish this, we used a metagenomics approach to characterize and compare the longitudinal wean-to-market resistome and microbiome of pigs challenged with PRRS virus and then exposed to different antimicrobial treatments, and a group of control pigs not challenged with PRRS virus and having minimal antimicrobial exposure. Genomic DNA was extracted from pen-level composite fecal samples from each treatment group and subjected to metagenomic sequencing and microbiome-resistome bioinformatic and statistical analysis. Microbiome-resistome profiles were compared over time and between treatment groups. RESULTS Fecal microbiome and resistome compositions both changed significantly over time, with a dramatic and stereotypic shift between weaning and 9 days post-weaning (dpw). Antimicrobial resistance gene (ARG) richness and diversity were significantly higher at earlier time points, while microbiome richness and diversity were significantly lower. The post-weaning shift was characterized by transition from a Bacteroides-dominated enterotype to Lactobacillus- and Streptococcus-dominated enterotypes. Both the microbiome and resistome stabilized by 44 dpw, at which point the trajectory of microbiome-resistome maturation began to diverge slightly between the treatment groups, potentially due to physical clustering of the pigs. Challenge with PRRS virus seemed to correspond to the re-appearance of many very rare and low-abundance ARGs within the feces of challenged pigs. Despite very different antimicrobial exposures after challenge with PRRS virus, resistome composition remained largely similar between the treatment groups. Differences in ARG abundance between the groups were mostly driven by temporal changes in abundance that occurred prior to antimicrobial exposures, with the exception of ermG, which increased in the feces of treated pigs, and was significantly more abundant in the feces of these pigs compared to the pigs that did not receive post-PRRS antimicrobials. CONCLUSIONS The fecal microbiome-resistome of growing pigs exhibited a stereotypic trajectory driven largely by weaning and physiologic aging of the pigs. Events such as viral illness, antimicrobial exposures, and physical grouping of the pigs exerted significant yet relatively minor influence over this trajectory. Therefore, the AMR profile of market-age pigs is the culmination of the life history of the individual pigs and the populations to which they belong. Disease status alone may be a significant driver of AMR in market-age pigs, and understanding the interaction between disease processes and antimicrobial exposures on the swine microbiome-resistome is crucial to developing effective, robust, and reproducible interventions to control AMR. Video Abstract.
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Affiliation(s)
- Tara N Gaire
- Department of Veterinary Population Medicine (VPM), College of Veterinary Medicine, University of Minnesota, Saint Paul, Minnesota, USA
| | - Carissa Odland
- Pipestone Veterinary Services, Pipestone, Minnesota, USA
| | - Bingzhou Zhang
- State Key Laboratory of Agricultural Microbiology, College of Animal Sciences and Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Tui Ray
- Department of Veterinary Population Medicine (VPM), College of Veterinary Medicine, University of Minnesota, Saint Paul, Minnesota, USA
| | - Enrique Doster
- Department of Veterinary Population Medicine (VPM), College of Veterinary Medicine, University of Minnesota, Saint Paul, Minnesota, USA
| | - Joel Nerem
- Pipestone Applied Research, Pipestone, Minnesota, USA
| | - Scott Dee
- Pipestone Applied Research, Pipestone, Minnesota, USA
| | - Peter Davies
- Department of Veterinary Population Medicine (VPM), College of Veterinary Medicine, University of Minnesota, Saint Paul, Minnesota, USA
| | - Noelle Noyes
- Department of Veterinary Population Medicine (VPM), College of Veterinary Medicine, University of Minnesota, Saint Paul, Minnesota, USA.
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29
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Wasselin V, Budin-Verneuil A, Rincé I, Léger L, Boukerb AM, Hartke A, Benachour A, Riboulet-Bisson E. The enigmatic physiological roles of AhpCF, Gpx, Npr and Kat in peroxide stress response of Enterococcus faecium. Res Microbiol 2022; 173:103982. [PMID: 35931249 DOI: 10.1016/j.resmic.2022.103982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 06/16/2022] [Accepted: 07/20/2022] [Indexed: 10/16/2022]
Abstract
In this work, the physiological roles of the primary peroxide scavenging activities of Enterococcus faecium AUS0004 strain were analysed. This healthcare-associated pathogen harbours genes encoding putative NADH peroxidase (Npr), alkyl hydroperoxide reductase (AhpCF), glutathione peroxidase (Gpx) and manganese-dependent catalase (Mn-Kat). Gene expression analyses showed that npr and kat genes are especially and significantly induced in cells treated with hydrogen peroxide (H2O2) and cumene hydroperoxide (CuOOH), which suggested an important function of these enzymes to protect E. faecium against peroxide stress. Mutants affected in one or several predicted anti-oxidative activities mentioned above showed that neither the peroxidases nor the catalase are implicated in the defence against peroxide challenges. However, our investigations allowed us to show that Npr is responsible for the degradation of approximately 45% of metabolically derived H2O2 which avoids accumulation of the peroxide to lethal concentrations.
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Affiliation(s)
- Valentin Wasselin
- Normandie Univ, UNICAEN U2RM-Stress and Virulence, Esplanade de la Paix, 14032 Caen, France.
| | - Aurélie Budin-Verneuil
- Normandie Univ, UNICAEN U2RM-Stress and Virulence, Esplanade de la Paix, 14032 Caen, France.
| | - Isabelle Rincé
- Normandie Univ, UNICAEN U2RM-Stress and Virulence, Esplanade de la Paix, 14032 Caen, France.
| | - Loïc Léger
- Normandie Univ, UNICAEN U2RM-Stress and Virulence, Esplanade de la Paix, 14032 Caen, France.
| | - Amine Mohamed Boukerb
- Normandie Univ, LMSM EA4312-Microbiology Signals and Microenvironment, 27000 Evreux, France.
| | - Axel Hartke
- Normandie Univ, UNICAEN U2RM-Stress and Virulence, Esplanade de la Paix, 14032 Caen, France.
| | - Abdellah Benachour
- Normandie Univ, UNICAEN U2RM-Stress and Virulence, Esplanade de la Paix, 14032 Caen, France.
| | - Eliette Riboulet-Bisson
- Normandie Univ, UNICAEN U2RM-Stress and Virulence, Esplanade de la Paix, 14032 Caen, France.
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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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Sabra W, Wang W, Goepfert C, Zeng AP. Food-web and metabolic interactions of the lung inhabitants Streptococcus pneumoniae and Pseudomonas aeruginosa. Environ Microbiol 2022; 24:4885-4898. [PMID: 35706134 DOI: 10.1111/1462-2920.16105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 06/03/2022] [Accepted: 06/13/2022] [Indexed: 11/29/2022]
Abstract
Bacteria that successfully adapt to different substrates and environmental niches within the lung and overcome the immune defence can cause serious lung infections. Such infections are generally complex, and recognised as polymicrobial in nature. Both Pseudomonas aeruginosa and Streptococcus pneumoniae can cause chronic lung infections and were both detected in cystic fibrosis (CF) lung at different stages. In this study, single and dual species cultures of Pseudomonas aeruginosa and Streptococcus pneumoniae were studied under well controlled planktonic growth conditions. Under pH-controlled conditions, both species apparently benefited from the presence of the other. In co-culture with P. aeruginosa, S. pneumoniae grew efficiently under aerobic conditions, whereas in pure S. pneumoniae culture, growth inhibition occurred in bioreactors with dissolved oxygen concentrations above the microaerobic range. Lactic acid and acetoin that are produced by S. pneumoniae was efficiently utilised by P. aeruginosa. In pH-uncontrolled co-cultures, the low pH triggered by S. pneumoniae assimilation of glucose and lactic acid production negatively affected the growth of both strains. Nevertheless, ammonia production improved significantly, and P. aeruginosa growth dominated at later growth stages. This study revealed unreported metabolic interactions of two important pathogenic microorganisms and shed new lights into pathophysiology of bacterial lung infection. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Wael Sabra
- Faculty of life science, Rheine-Waal University of applied sciences, Marie-Curie-Straße 1, Kleve.,Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestrasse 15, Hamburg, Germany
| | - Wei Wang
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestrasse 15, Hamburg, Germany
| | - Christiane Goepfert
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestrasse 15, Hamburg, Germany
| | - An-Ping Zeng
- Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestrasse 15, Hamburg, Germany.,Beijing Advanced Innovation Center for Soft Matter Science and Engineering
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Rastinfard A, Dalisson B, Barralet J. Aqueous decomposition behavior of solid peroxides: Effect of pH and buffer composition on oxygen and hydrogen peroxide formation. Acta Biomater 2022; 145:390-402. [PMID: 35405328 DOI: 10.1016/j.actbio.2022.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 03/29/2022] [Accepted: 04/01/2022] [Indexed: 12/11/2022]
Abstract
The ability of solid peroxides to provide sustained release of both oxygen and hydrogen peroxide makes them potentially suitable for oxygen release or antibacterial applications. Most recent reports using solid peroxides to augment oxygen levels do so by compounding solid peroxide powders in polymers to retard the aqueous decomposition. Compounds with peroxidase activity may be added to reduce hydrogen peroxide toxicity. Peroxides are rarely pure and are mixed with oxide and themselves decompose to form hydroxides in water. Therefore, even if buffering strategies are used, locally the pH at the surface of aqueously immersed peroxide particles is inevitably alkaline. Since pH affects the decomposition of peroxides and hydrogen peroxide stability, this study compared for the first-time the aqueous decomposition products of hydrogen and inorganic peroxides that are in use or have been used for medical applications of have been evaluated preclinically; calcium peroxide (CaO2), magnesium peroxide (MgO2), zinc peroxide (ZnO2), sodium percarbonate (Na2CO3.1.5H2O2) and hydrogen peroxide (H2O2). Since plasma can be approximated to be carbonate buffered phosphate solution, we maintained pH using carbonate and phosphate buffers and compared results with citrate buffers. For a given peroxide compound, we identified not only a strong effect of pH but also of buffer composition on the extent to which oxygen and hydrogen peroxide formation occurred. The influence of buffer composition was not previously appreciated, thereby establishing in vitro parameters for better design of intentional release of specific decomposition species. STATEMENT OF SIGNIFICANCE: This paper compares for the first time the aqueous decomposition products oxygen and hydrogen peroxide of solid peroxy compounds of metal cations, (calcium, magnesium, sodium and zinc) across a pH range that could feasibly be found in the body, (pH 5,7, 9) either physiologically or pathologically. We find that in addition to pH, buffer composition is also a critically important factor, making translation from in vitro models challenging. Cytotoxicity was related to hydrogen peroxide release, alkalinity and in the case of zinc peroxide to the cation itself. In vitro and preclinical studies generally report release data from polymer-peroxide composites and rarely compare peroxides with one another. Together our data provide guidance for oxygen and ROS delivery from these inorganic materials.
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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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Elevated Levels of Three Reactive Oxygen Species and Fe(II) in the Antibiotic-Surviving Population of Mycobacteria Facilitate De Novo Emergence of Genetic Resisters to Antibiotics. Antimicrob Agents Chemother 2022; 66:e0228521. [PMID: 35435709 DOI: 10.1128/aac.02285-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We had earlier reported the de novo emergence of genetic resisters of Mycobacterium tuberculosis and Mycobacterium smegmatis to rifampicin and moxifloxacin from the antibiotic-surviving population containing elevated levels of the non-DNA-specific mutagenic reactive oxygen species (ROS) hydroxyl radical. Since hydroxyl radical is generated by Fenton reaction between Fe(II) and H2O2, which is produced by superoxide dismutation, we here report significantly elevated levels of these three ROS and Fe(II) in the M. smegmatis rifampicin-surviving population. Elevated levels of superoxide and the consequential formation of high levels of H2O2 and Fe(II) led to the generation of hydroxyl radical, facilitating de novo high frequency emergence of antibiotic resisters. The M. smegmatis cultures, exposed to nontoxic concentrations of the ROS scavenger, thiourea (TU), and the NADH oxidase (one of the superoxide producers) inhibitor, diphenyleneiodonium chloride (DPI), showed a reduction in the levels of the three ROS, Fe(II), and antibiotic resister generation frequency. The non-antibiotic-exposed cultures grown in the absence/presence of TU/DPI did not show increased ROS, Fe(II) levels, or antibiotic resister generation frequency. The antibiotic-surviving population showed significantly increased expression and activity of superoxide-producing genes and decreased expression of antioxidant and DNA repair genes, revealing an environment conducive for the acquisition and retention of mutations. Since we recently reported significant comparability between the antibiotic-survival gene expression profiles of the saprophyte-cum-opportunistic pathogens M. smegmatis and the M. tuberculosis in tuberculosis patients undergoing treatment, we discuss the clinical relevance of the findings on the mechanism of emergence of antibiotic-resistant mycobacterial strains.
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Streptococcus pneumoniae exerts oxidative stress, subverts antioxidant signaling and autophagy in human corneal epithelial cells that is alleviated by tert-Butylhydroquinone. Med Microbiol Immunol 2022; 211:119-132. [PMID: 35325292 DOI: 10.1007/s00430-022-00731-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 03/07/2022] [Indexed: 10/18/2022]
Abstract
Streptococcus pneumoniae is one of the leading causes of bacterial keratitis in the developing world and globally. In the current study, we have determined oxidative stress as pathogenesis of S. pneumoniae infection in corneal tissues and human corneal epithelial cells (HCEC) and explored host immune response of HCEC towards S. pneumoniae. We also determined whether treatment with tert-Butylhydroquinone (tBHQ), a Nrf2 inducer, could alleviate oxidative stress and reduce bacterial cytotoxicity in these cells. Oxidative stress was determined in corneal tissues of patients and HCEC by immunohistochemistry and immunofluorescence analysis, respectively. The expression of antioxidant genes, cytokines and antimicrobial peptides was determined by quantitative PCR. Infection of HCEC by S. pneumoniae was determined by colony-forming units. The autophagy and cell death were determined by fluorescence microscopy. The phosphorylation of signaling proteins was evaluated by immunoblot analysis. S. pneumoniae induced oxidative stress during corneal infections and inhibited antioxidant signaling pathways and immune responses like autophagy. tBHQ aided in restoring Nrf2 activation, reduced reactive oxygen species generation and prevented cytotoxicity and cell death in S. pneumoniae-infected HCEC. tBHQ also induced autophagy in a Nrf2-dependent manner and reduced bacterial survival in HCEC. Increased expression of antimicrobial peptides by tBHQ might have contributed to a reduction of bacterial load and cytotoxicity, as exemplified in LL-37 depleted corneal epithelial cells exposed to S. pneumoniae compared to control siRNA-transfected cells. tBHQ mediates alleviation of oxidative stress induced by S. pneumoniae by activating Nrf2-mediated antioxidant signaling in corneal epithelial cells. tBHQ also enhances expression of antimicrobial peptides in corneal cells and aids in inhibition of bacterial survival and cytotoxicity of HCEC.
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Resistance of Streptococcus pneumoniae to hypothiocyanous acid generated by host peroxidases. Infect Immun 2022; 90:e0053021. [PMID: 35156851 DOI: 10.1128/iai.00530-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae is a serious human respiratory pathogen. It generates hydrogen peroxide (H2O2) as part of its normal metabolism, yet it lacks enzymes that remove this oxidant. Here we show that lactoperoxidase and myeloperoxidase, two host enzymes present in the respiratory tract, convert bacterial H2O2 into HOSCN that S. pneumoniae can resist. We found that incubation of S. pneumoniae with myeloperoxidase in chloride-rich buffer killed the bacteria due to formation of toxic hypochlorous acid (HOCl). However, the addition of physiological concentrations of thiocyanate protected the bacteria. Similarly, S. pneumoniae remained viable in the presence of lactoperoxidase and thiocyanate even though the majority of bacterial H2O2 was converted to hypothiocyanous acid (HOSCN). S. pneumoniae and Pseudomonas aeruginosa, another respiratory pathogen, were similarly sensitive to H2O2 and HOCl. In contrast, S. pneumoniae tolerated much higher doses of HOSCN than P. aeruginosa. When associated with neutrophil extracellular traps (NETs), S. pneumoniae continued to generate H2O2, which was converted to HOCl by MPO present on NETs. However, there was no loss in bacterial viability because HOCl was scavenged by the NET proteins. We conclude that at sites of infection, bacteria will be protected from HOCl by thiocyanate and extracellular proteins including those associated with NETs. Resistance to HOSCN may give S. pneumoniae a survival advantage over other pathogenic bacteria. Understanding the mechanisms by which S. pneumoniae protects itself from HOSCN may reveal novel strategies for limiting the colonization and pathogenicity of this deadly pathogen.
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Shearer HL, Paton JC, Hampton MB, Dickerhof N. Glutathione utilization protects Streptococcus pneumoniae against lactoperoxidase-derived hypothiocyanous acid. Free Radic Biol Med 2022; 179:24-33. [PMID: 34923101 DOI: 10.1016/j.freeradbiomed.2021.12.261] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/01/2021] [Accepted: 12/14/2021] [Indexed: 12/31/2022]
Abstract
Streptococcus pneumoniae is the leading cause of community-acquired pneumonia, resulting in more than one million deaths each year worldwide. This pathogen generates large amounts of hydrogen peroxide (H2O2), which will be converted to hypothiocyanous acid (HOSCN) by lactoperoxidase (LPO) in the human respiratory tract. S. pneumoniae has been shown to be more resistant to HOSCN than some bacteria, and sensitizing S. pneumoniae to HOSCN may be a novel treatment strategy for combating this deadly pathogen. In this study we investigated the role of the low molecular weight thiol glutathione in HOSCN resistance. S. pneumoniae does not synthesize glutathione but imports it from the environment via an ABC transporter. Upon treatment of S. pneumoniae with HOSCN, bacterial glutathione was reversibly oxidized in a time- and dose-dependent manner, and intracellular proteins became glutathionylated. Bacterial death was observed when the reduced glutathione pool dropped below 20%. A S. pneumoniae mutant unable to import glutathione (ΔgshT) was more readily killed by exogenous HOSCN. Furthermore, bacterial growth in the presence of LPO converting bacterial H2O2 to HOSCN was significantly impeded in mutants that were unable to import glutathione, or mutants unable to recycle oxidized glutathione (Δgor). This research highlights the importance of glutathione in protecting S. pneumoniae from HOSCN. Limiting glutathione utilization by S. pneumoniae may be a way to limit colonization and pathogenicity.
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Affiliation(s)
- Heather L Shearer
- From the Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - James C Paton
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, University of Adelaide, Australia
| | - Mark B Hampton
- From the Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand
| | - Nina Dickerhof
- From the Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, New Zealand.
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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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When anaerobes encounter oxygen: mechanisms of oxygen toxicity, tolerance and defence. Nat Rev Microbiol 2021; 19:774-785. [PMID: 34183820 PMCID: PMC9191689 DOI: 10.1038/s41579-021-00583-y] [Citation(s) in RCA: 92] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2021] [Indexed: 02/06/2023]
Abstract
The defining trait of obligate anaerobes is that oxygen blocks their growth, yet the underlying mechanisms are unclear. A popular hypothesis was that these microorganisms failed to evolve defences to protect themselves from reactive oxygen species (ROS) such as superoxide and hydrogen peroxide, and that this failure is what prevents their expansion to oxic habitats. However, studies reveal that anaerobes actually wield most of the same defences that aerobes possess, and many of them have the capacity to tolerate substantial levels of oxygen. Therefore, to understand the structures and real-world dynamics of microbial communities, investigators have examined how anaerobes such as Bacteroides, Desulfovibrio, Pyrococcus and Clostridium spp. struggle and cope with oxygen. The hypoxic environments in which these organisms dwell - including the mammalian gut, sulfur vents and deep sediments - experience episodic oxygenation. In this Review, we explore the molecular mechanisms by which oxygen impairs anaerobes and the degree to which bacteria protect their metabolic pathways from it. The emergent view of anaerobiosis is that optimal strategies of anaerobic metabolism depend upon radical chemistry and low-potential metal centres. Such catalytic sites are intrinsically vulnerable to direct poisoning by molecular oxygen and ROS. Observations suggest that anaerobes have evolved tactics that either minimize the extent to which oxygen disrupts their metabolism or restore function shortly after the stress has dissipated.
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Anil A, Apte S, Joseph J, Parthasarathy A, Madhavan S, Banerjee A. Pyruvate Oxidase as a Key Determinant of Pneumococcal Viability during Transcytosis across Brain Endothelium. J Bacteriol 2021; 203:e0043921. [PMID: 34606370 PMCID: PMC8604078 DOI: 10.1128/jb.00439-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 09/23/2021] [Indexed: 01/23/2023] Open
Abstract
Streptococcus pneumoniae invades a myriad of host tissues following efficient breaching of cellular barriers. However, strategies adopted by pneumococcus for evasion of host intracellular defenses governing successful transcytosis across host cellular barriers remain elusive. In this study, using brain endothelium as a model host barrier, we observed that pneumococcus containing endocytic vacuoles (PCVs), formed following S. pneumoniae internalization into brain microvascular endothelial cells (BMECs), undergo early maturation and acidification, with a major subset acquiring lysosome-like characteristics. Exploration of measures that would preserve pneumococcal viability in the lethal acidic pH of these lysosome-like vacuoles revealed a critical role of the two-component system response regulator, CiaR, which was previously implicated in induction of acid tolerance response. Pyruvate oxidase (SpxB), a key sugar-metabolizing enzyme that catalyzes oxidative decarboxylation of pyruvate to acetyl phosphate, was found to contribute to acid stress tolerance, presumably via acetyl phosphate-mediated phosphorylation and activation of CiaR, independent of its cognate kinase CiaH. Hydrogen peroxide, the by-product of an SpxB-catalyzed reaction, was also found to improve pneumococcal intracellular survival by oxidative inactivation of lysosomal cysteine cathepsins, thus compromising the degradative capacity of the host lysosomes. As expected, a ΔspxB mutant was found to be significantly attenuated in its ability to survive inside the BMEC endocytic vacuoles, reflecting its reduced transcytosis ability. Collectively, our studies establish SpxB as an important virulence determinant facilitating pneumococcal survival inside host cells, ensuring successful trafficking across host cellular barriers. IMPORTANCE Host cellular barriers have innate immune defenses to restrict microbial passage into sterile compartments. Here, by focusing on the blood-brain barrier endothelium, we investigated mechanisms that enable Streptococcus pneumoniae to traverse through host barriers. Pyruvate oxidase, a pneumococcal sugar-metabolizing enzyme, was found to play a crucial role in this via generation of acetyl phosphate and hydrogen peroxide. A two-pronged approach consisting of acetyl phosphate-mediated activation of acid tolerance response and hydrogen peroxide-mediated inactivation of lysosomal enzymes enabled pneumococci to maintain viability inside the degradative vacuoles of the brain endothelium for successful transcytosis across the barrier. Thus, pyruvate oxidase is a key virulence determinant and can potentially serve as a viable candidate for therapeutic interventions for better management of invasive pneumococcal diseases.
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Affiliation(s)
- Anjali Anil
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India
| | - Shruti Apte
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India
| | - Jincy Joseph
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India
| | - Akhila Parthasarathy
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India
| | - Shilpa Madhavan
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India
| | - Anirban Banerjee
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India
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Demonstration of N, N-Dimethyldithiocarbamate as a Copper-Dependent Antibiotic against Multiple Upper Respiratory Tract Pathogens. Microbiol Spectr 2021; 9:e0077821. [PMID: 34468162 PMCID: PMC8557878 DOI: 10.1128/spectrum.00778-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Transition metals are necessary cofactors and structural elements in living systems. Exposure to high concentrations of biologically important transition metals, such as zinc and copper, results in cell toxicity. At the infection site, the immune system deploys metal sorbent proteins (e.g., lactoferrin and calprotectin) to starve pathogens of necessary metals (such as iron), while phagocytes expose engulfed pathogens to high levels of other metals, such as copper and zinc. The opportunistic pathogen Streptococcus pneumoniae (the pneumococcus) encounters macrophages during initial and protracted infections. The pneumococcus employs a copper export pathway, which improves colonization and persistent infection of the nasopharynx and the upper respiratory tract. Because copper is tightly regulated in the host, we instead sought to leverage the localized power of nutritional immunity by identifying small molecules with copper-dependent toxicity (CDT) through a targeted screen of compounds for antibiotic efficacy. We chose to include dithiocarbamates, based on the copper synergy observed in other organisms with 1-(diethylthiocarbamoyldisulfanyl)-N,N-diethyl-methanethioamide (tetraethylthiuram disulfide, disulfiram). We observed CDT of some dithiocarbamates in S. pneumoniae. Only N,N-dimethyldithiocarbamate (DMDC) was consistently toxic across a range of concentrations with copper both in vitro and in vivo against the pneumococcus. We also observed various degrees of CDT in vitro using DMDC in Staphylococcus aureus, Coccidioides posadasii, and Schistosoma mansoni. Collectively, we demonstrate that the compound DMDC is a potent bactericidal compound against S. pneumoniae with antimicrobial efficacy against bacterial and fungal pathogens. IMPORTANCE With the rise of antibiotic resistance, approaches that add new antimicrobials to the current repertoire are vital. Here, we investigate putative and known copper ionophores in an attempt to intoxicate bacteria and use ionophore/copper synergy, and we ultimately find success with N,N-dimethyldithiocarbamate (DMDC). We show that DMDC has in vitro efficacy in a copper-dependent manner and kills pathogens across three different kingdoms, Streptococcus pneumoniae, Coccidioides posadasii, and Schistosoma mansoni, and in vivo efficacy against S. pneumoniae. As such, dithiocarbamates represent a new potential class of antimicrobials and thus warrant further mechanistic investigation.
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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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Papiran R, Hamedi J. Adaptive Evolution of Lactococcus Lactis to Thermal and Oxidative Stress Increases Biomass and Nisin Production. Appl Biochem Biotechnol 2021; 193:3425-3441. [PMID: 34196920 DOI: 10.1007/s12010-021-03609-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/21/2021] [Indexed: 02/07/2023]
Abstract
High values of agitation and temperature lead to stressful conditions in the fermentations of Lactococcus lactis due to its aero-tolerant and mesophilic nature. Here, the adaptive laboratory evolution (ALE) technique was applied to increase biomass and nisin production yields by enhancing L. lactis subsp. lactis robustness at higher growth temperature and aeration rates. In two separate ALE experiments, after 162 serial transfers, optimum agitation and growth temperature of L. lactis were shifted from 40 rpm and 30 °C to 200 rpm and 37 °C, respectively. Oxidative and acid resistance were enhanced in the evolved strain. Whole-genome sequencing revealed the emergence of five single-nucleotide polymorphisms in the genome of the evolved strain in jag, DnaB, ArgR, cation transporter genes, and one putative protein. The evolved strain of L. lactis in this study has more industrial desirable features and improved nisin production capability and can act more efficiently in nisin production in stressful conditions.
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Affiliation(s)
- Reyhaneh Papiran
- Department of Microbial Biotechnology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran
- Microbial Technology and Products (MTP) Research Center, University of Tehran, Tehran, Iran
| | - Javad Hamedi
- Department of Microbial Biotechnology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran.
- Microbial Technology and Products (MTP) Research Center, University of Tehran, Tehran, Iran.
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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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Fuji N, Pichichero ME, Kaur R. Comparison of specific in-vitro virulence gene expression and innate host response in locally invasive vs colonizer strains of Streptococcus pneumoniae. Med Microbiol Immunol 2021; 210:111-120. [PMID: 33751214 DOI: 10.1007/s00430-021-00701-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 02/27/2021] [Indexed: 10/21/2022]
Abstract
Among Rochester NY children, a dramatic increase in nasopharyngeal (NP) colonization by non-vaccine pneumococcal serotypes 35B and 15A occurred during years 2010-2015, after introduction of 13-valent pneumococcal conjugate vaccine (PCV13). In our population, serotype 35B strains colonized in the nasopharynx (NP) but infrequently caused acute otitis media (AOM) whereas serotype 15A strains displayed virulence, evidenced by causing AOM. To explain the virulence difference, virulence genes expression between 35B and 15A, as well as the host's immune response during asymptomatic colonization were analyzed. We investigated differences in regulation of 19 virulence genes for differences in virulence using RT-PCR in 20 35B and 14 15A strains and measured gene expression of 9 host innate cytokines in the NP to assess the mucosal inflammatory response during asymptomatic colonization. Comparing 35B versus 15A strains, genes for competence ComA and RrgC were upregulated; capsular (Cps2D) and virulence genes (PfbA, PcpA and PhtE) were downregulated among 35B strains. PavB, LytA, LytB, NanA, CiaR, PhtD, LuxS, PspA and pneumolysin (Ply) showed no difference. IL17 and IL23 gene expression were > tenfold higher during 35B compared to 15A strain asymptomatic colonization. Only IL23 showed significant difference. In the first 5 years after introduction of PCV13, serotype 35B strains emerged as asymptomatic colonizers and 15A strains emerged to cause AOM in young children. Various genes (PfbA, PcpA, Cps2D and PhtE) among tested in this analysis were downregulated in 35B whereas ComA and RrgC were significantly upregulated. For the host's cytokine response, IL23 proinflammatory response which is essential for the differentiation of Th17 lymphocytes in the NP of children with 35B strains was significantly higher than the response to 15A during asymptomatic colonization.
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Affiliation(s)
- Naoko Fuji
- Center for Infectious Diseases and Immunology, Rochester General Hospital Research Institute, Rochester General Hospital, 1425 Portland Avenue, Rochester, NY, 14621, USA
| | - Michael E Pichichero
- Center for Infectious Diseases and Immunology, Rochester General Hospital Research Institute, Rochester General Hospital, 1425 Portland Avenue, Rochester, NY, 14621, USA
| | - Ravinder Kaur
- Center for Infectious Diseases and Immunology, Rochester General Hospital Research Institute, Rochester General Hospital, 1425 Portland Avenue, Rochester, NY, 14621, USA.
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Sender V, Hentrich K, Henriques-Normark B. Virus-Induced Changes of the Respiratory Tract Environment Promote Secondary Infections With Streptococcus pneumoniae. Front Cell Infect Microbiol 2021; 11:643326. [PMID: 33828999 PMCID: PMC8019817 DOI: 10.3389/fcimb.2021.643326] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/01/2021] [Indexed: 01/08/2023] Open
Abstract
Secondary bacterial infections enhance the disease burden of influenza infections substantially. Streptococcus pneumoniae (the pneumococcus) plays a major role in the synergism between bacterial and viral pathogens, which is based on complex interactions between the pathogen and the host immune response. Here, we discuss mechanisms that drive the pathogenesis of a secondary pneumococcal infection after an influenza infection with a focus on how pneumococci senses and adapts to the influenza-modified environment. We briefly summarize what is known regarding secondary bacterial infection in relation to COVID-19 and highlight the need to improve our current strategies to prevent and treat viral bacterial coinfections.
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Affiliation(s)
- Vicky Sender
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Karina Hentrich
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Birgitta Henriques-Normark
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,Clinical Microbiology, Karolinska University Hospital, Solna, Sweden
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The PTS Components in Klebsiella pneumoniae Affect Bacterial Capsular Polysaccharide Production and Macrophage Phagocytosis Resistance. Microorganisms 2021; 9:microorganisms9020335. [PMID: 33567595 PMCID: PMC7914778 DOI: 10.3390/microorganisms9020335] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 12/04/2022] Open
Abstract
Capsular polysaccharide (CPS) is a crucial virulence factor for Klebsiella pneumoniae infection. We demonstrated an association of CPS production with two phosphoenolpyruvate:carbohydrate phosphotransferase systems (PTSs). Deficiency of crr, encoding enzyme IIA of PTS, in K. pneumoniae enhanced the transcriptional activities of galF, wzi and gnd, which are in the cps gene cluster, leading to high CPS production. A crr mutant exhibited a higher survival rate in 1% hydrogen peroxide than the wild-type. The crr mutant showed less sensitivity to engulfment by macrophage (RAW 264.7) than the wild-type by observing the intracellular bacteria using confocal laser scanning microscopy (CLSM) and by calculating the colony-forming units (CFU) of intracellular bacteria. After long-term incubation, the survival rate of the intracellular crr mutant was higher than that of the wild-type. Deficiency of crr enhanced the transcriptional activities of etcABC which encodes another putative enzyme II complex of a PTS. Deletion of etcABC in the crr mutant reduced CPS production and the transcriptional activities of galF compared to those of the crr mutant. These results indicated that one PTS component, Crr, represses CPS production by repressing another PTS component, EtcABC, in K. pneumoniae. In addition, PTS plays a role in bacterial resistance to macrophage phagocytosis.
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48
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Kaiser S, Hoppstädter LM, Bilici K, Heieck K, Brückner R. Control of acetyl phosphate-dependent phosphorylation of the response regulator CiaR by acetate kinase in Streptococcus pneumoniae. MICROBIOLOGY-SGM 2021; 166:411-421. [PMID: 32553069 DOI: 10.1099/mic.0.000894] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The two-component regulatory system CiaRH of Streptococcus pneumoniae affects a large variety of physiological processes including ß-lactam resistance, competence development, maintenance of cell integrity, bacteriocin production, but also host colonization and virulence. The response regulator CiaR is active under a wide variety of conditions and the cognate CiaH kinase is not always needed to maintain CiaR activity. Using tetracycline-controlled expression of ciaR and variants, acetyl phosphate was identified in vivo as the alternative source of CiaR phosphorylation in the absence of CiaH. Concomitant inactivation of ciaH and the acetate kinase gene ackA led to very high levels of CiaR-mediated promoter activation. Strong transcriptional activation was accompanied by a high phosphorylation status of CiaR as determined by Phos-tag gel electrophoresis of S. pneumoniae cell extracts. Furthermore, AckA acted negatively upon acetyl phosphate-dependent phosphorylation of CiaR. Experiments using the Escherichia coli two-hybrid system based on adenylate cyclase reconstitution indicated binding of AckA to CiaR and therefore direct regulation. Subsequent in vitro CiaR phosphorylation experiments confirmed in vivo observations. Purified AckA was able to inhibit acetyl phosphate-dependent phosphorylation. Inhibition required the presence of ADP. AckA-mediated regulation of CiaR phosphorylation is the first example for a regulatory connection of acetate kinase to a response regulator besides controlling acetyl phosphate levels. It will be interesting to see if this novel regulation applies to other response regulators in S. pneumoniae or even in other organisms.
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Affiliation(s)
- Sabrina Kaiser
- Present address: Department of Plant Pathology, University of Kaiserslautern, Kaiserslautern, Germany.,Department of Microbiology, University of Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - Lisa Marie Hoppstädter
- Department of Microbiology, University of Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - Kevser Bilici
- Department of Microbiology, University of Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - Kevin Heieck
- Present address: Werner Siemens Chair of Synthetic Biotechnology, Department of Chemistry, Technical University Munich, Munich, Germany.,Department of Microbiology, University of Kaiserslautern, D-67663 Kaiserslautern, Germany
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Capillary leakage provides nutrients and antioxidants for rapid pneumococcal proliferation in influenza-infected lower airways. Proc Natl Acad Sci U S A 2020; 117:31386-31397. [PMID: 33229573 PMCID: PMC7733805 DOI: 10.1073/pnas.2012265117] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Mechanisms for why influenza A virus (IAV) infections sensitize for pneumococcal infections are not clear. Here, we show that IAV-induced capillary leakage results in influx of nutrients and antioxidants to the lungs, thereby promoting pneumococcal growth in the lower respiratory tract. The evoked inflammation leads to redox imbalances that require bacterial adaptation to the oxidized environment, including induction of the pneumococcal chaperone/protease HtrA that protects the bacteria from clearance by the immune system. The results give us insight into the delicate interplay between the bacteria and the host environment during coinfections that needs to be explored in order to find novel therapeutic approaches. Influenza A virus (IAV)-related mortality is often due to secondary bacterial infections, primarily by pneumococci. Here, we study how IAV-modulated changes in the lungs affect bacterial replication in the lower respiratory tract (LRT). Bronchoalveolar lavages (BALs) from coinfected mice showed rapid bacterial proliferation 4 to 6 h after pneumococcal challenge. Metabolomic and quantitative proteomic analyses demonstrated capillary leakage with efflux of nutrients and antioxidants into the alveolar space. Pneumococcal adaptation to IAV-induced inflammation and redox imbalance increased the expression of the pneumococcal chaperone/protease HtrA. Presence of HtrA resulted in bacterial growth advantage in the IAV-infected LRT and protection from complement-mediated opsonophagocytosis due to capsular production. Absence of HtrA led to growth arrest in vitro that was partially restored by antioxidants. Pneumococcal ability to grow in the IAV-infected LRT depends on the nutrient-rich milieu with increased levels of antioxidants such as ascorbic acid and its ability to adapt to and cope with oxidative damage and immune clearance.
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Feng T, Wang J. Oxidative stress tolerance and antioxidant capacity of lactic acid bacteria as probiotic: a systematic review. Gut Microbes 2020; 12:1801944. [PMID: 32795116 PMCID: PMC7524341 DOI: 10.1080/19490976.2020.1801944] [Citation(s) in RCA: 183] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 07/15/2020] [Indexed: 02/03/2023] Open
Abstract
Lactic acid bacteria (LAB) are the most frequently used probiotics in fermented foods and beverages and as food supplements for humans or animals, owing to their multiple beneficial features, which appear to be partially associated with their antioxidant properties. LAB can help improve food quality and flavor and prevent numerous disorders caused by oxidation in the host. In this review, we discuss the oxidative stress tolerance, the antioxidant capacity related herewith, and the underlying mechanisms and signaling pathways in probiotic LAB. In addition, we discuss appropriate methods used to evaluate the antioxidant capacity of probiotic LAB. The aim of the present review is to provide an overview of the current state of the research associated with the oxidative stress tolerance and antioxidant capacity of LAB.
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Affiliation(s)
- Tao Feng
- Institute of Animal Husbandry and Veterinary Medicine (IAHVM), Beijing Academy of Agriculture and Forestry Sciences (BAAFS), Beijing, China
- Sino-US Joint Laboratory of Animal Science, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Jing Wang
- Institute of Animal Husbandry and Veterinary Medicine (IAHVM), Beijing Academy of Agriculture and Forestry Sciences (BAAFS), Beijing, China
- Sino-US Joint Laboratory of Animal Science, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
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