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Lê-Bury P, Echenique-Rivera H, Pizarro-Cerdá J, Dussurget O. Determinants of bacterial survival and proliferation in blood. FEMS Microbiol Rev 2024; 48:fuae013. [PMID: 38734892 PMCID: PMC11163986 DOI: 10.1093/femsre/fuae013] [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: 11/06/2023] [Revised: 04/29/2024] [Accepted: 05/10/2024] [Indexed: 05/13/2024] Open
Abstract
Bloodstream infection is a major public health concern associated with high mortality and high healthcare costs worldwide. Bacteremia can trigger fatal sepsis whose prevention, diagnosis, and management have been recognized as a global health priority by the World Health Organization. Additionally, infection control is increasingly threatened by antimicrobial resistance, which is the focus of global action plans in the framework of a One Health response. In-depth knowledge of the infection process is needed to develop efficient preventive and therapeutic measures. The pathogenesis of bloodstream infection is a dynamic process resulting from the invasion of the vascular system by bacteria, which finely regulate their metabolic pathways and virulence factors to overcome the blood immune defenses and proliferate. In this review, we highlight our current understanding of determinants of bacterial survival and proliferation in the bloodstream and discuss their interactions with the molecular and cellular components of blood.
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Affiliation(s)
- Pierre Lê-Bury
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
- Université Paris-Saclay, Inserm, CEA, Center for Immunology of Viral, Autoimmune, Hematological and Bacterial Diseases (IMVA-HB/IDMIT), 18 route du Panorama, 92260 Fontenay-aux-Roses, France
| | - Hebert Echenique-Rivera
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
| | - Javier Pizarro-Cerdá
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
- Institut Pasteur, Université Paris Cité, Yersinia National Reference Laboratory, WHO Collaborating Research & Reference Centre for Plague FRA-146, 28 rue du Dr Roux, 75015 Paris, France
| | - Olivier Dussurget
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
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2
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Mikucki A, McCluskey NR, Kahler CM. The Host-Pathogen Interactions and Epicellular Lifestyle of Neisseria meningitidis. Front Cell Infect Microbiol 2022; 12:862935. [PMID: 35531336 PMCID: PMC9072670 DOI: 10.3389/fcimb.2022.862935] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 02/28/2022] [Indexed: 01/17/2023] Open
Abstract
Neisseria meningitidis is a gram-negative diplococcus and a transient commensal of the human nasopharynx. It shares and competes for this niche with a number of other Neisseria species including N. lactamica, N. cinerea and N. mucosa. Unlike these other members of the genus, N. meningitidis may become invasive, crossing the epithelium of the nasopharynx and entering the bloodstream, where it rapidly proliferates causing a syndrome known as Invasive Meningococcal Disease (IMD). IMD progresses rapidly to cause septic shock and meningitis and is often fatal despite aggressive antibiotic therapy. While many of the ways in which meningococci survive in the host environment have been well studied, recent insights into the interactions between N. meningitidis and the epithelial, serum, and endothelial environments have expanded our understanding of how IMD develops. This review seeks to incorporate recent work into the established model of pathogenesis. In particular, we focus on the competition that N. meningitidis faces in the nasopharynx from other Neisseria species, and how the genetic diversity of the meningococcus contributes to the wide range of inflammatory and pathogenic potentials observed among different lineages.
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Affiliation(s)
- August Mikucki
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | - Nicolie R. McCluskey
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
- College of Science, Health, Engineering and Education, Telethon Kids Institute, Murdoch University, Perth, WA, Australia
| | - Charlene M. Kahler
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
- *Correspondence: Charlene M. Kahler,
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3
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Sun J, Zhu D, Xu J, Jia R, Chen S, Liu M, Zhao X, Yang Q, Wu Y, Zhang S, Liu Y, Zhang L, Yu Y, You Y, Wang M, Cheng A. Rifampin resistance and its fitness cost in Riemerella anatipestifer. BMC Microbiol 2019; 19:107. [PMID: 31122209 PMCID: PMC6533769 DOI: 10.1186/s12866-019-1478-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 05/07/2019] [Indexed: 11/25/2022] Open
Abstract
Background Riemerella anatipestifer (R. anatipestifer) is one of the most important poultry pathogens worldwide, with associated infections causing significant economic losses. Rifampin Resistance is an important mechanism of drug resistance. However, there is no information about rpoB mutations conferring rifampin resistance and its fitness cost in Riemerella anatipestifer. Results Comparative analysis of 18 R.anatipestifer rpoB sequences and the determination of rifampin minimum inhibitory concentrations showed that five point mutations, V382I, H491N, G502K, R494K and S539Y, were related to rifampin resistance. Five overexpression strains were constructed using site-directed mutagenesis to validate these sites. To investigate the origin and fitness costs of the rpoB mutations, 15 types of rpoB mutations were isolated from R. anatipestifer ATCC 11845 by using spontaneous mutation in which R494K was identical to the type of mutation detected in the isolates. The mutation frequency of the rpoB gene was calculated to be 10− 8. A total of 98.8% (247/250) of the obtained mutants were located in cluster I of the rifampin resistance-determining region of the rpoB gene. With the exception of D481Y, I537N and S539F, the rifampin minimum inhibitory concentrations of the remaining mutants were at least 64 μg/mL. The growth performance and competitive experiments of the mutant strains in vitro showed that H491D and 485::TAA exhibit growth delay and severely impaired fitness. Finally, the colonization abilities and sensitivities of the R494K and H491D mutants were investigated. The sensitivity of the two mutants to hydrogen peroxide (H2O2) and sodium nitroprusside (SNP) increased compared to the parental strain. The number of live colonies colonized by the two mutants in the duckling brain and trachea were lower than that of the parental strain within 24 h. Conclusions Mutations of rpoB gene in R. anatipestifer mediate rifampin resistance and result in fitness costs. And different single mutations confer different levels of fitness costs. Our study provides, to our knowledge, the first estimates of the fitness cost associated with the R. anatipestifer rifampin resistance in vitro and in vivo. Electronic supplementary material The online version of this article (10.1186/s12866-019-1478-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jiakai Sun
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | - Dekang Zhu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Jinge Xu
- Guizhou Animal Husbandry and Veterinary Research Institute, Guiyang, 550005, Guizhou, China
| | - Renyong Jia
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Shun Chen
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Mafeng Liu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Xinxin Zhao
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Qiao Yang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Ying Wu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Shaqiu Zhang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China
| | - Yunya Liu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | - Ling Zhang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | - Yanling Yu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | - Yu You
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | - Mingshu Wang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China. .,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China. .,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China.
| | - Anchun Cheng
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan, Agricultural University, Chengdu, 611130, Sichuan, China. .,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China. .,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, 611130, Sichuan, China.
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The Meningococcal Cysteine Transport System Plays a Crucial Role in Neisseria meningitidis Survival in Human Brain Microvascular Endothelial Cells. mBio 2018; 9:mBio.02332-18. [PMID: 30538184 PMCID: PMC6299482 DOI: 10.1128/mbio.02332-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Neisseria meningitidis colonizes at a nasopharynx of human as a unique host and has many strains that are auxotrophs for amino acids for their growth. To cause invasive meningococcal diseases (IMD) such as sepsis and meningitis, N. meningitidis passes through epithelial and endothelial barriers and infiltrates into blood and cerebrospinal fluid as well as epithelial and endothelial cells. However, meningococcal nutrients, including cysteine, become less abundant when it more deeply infiltrates the human body even during inflammation, such that N. meningitidis has to acquire nutrients in order to survive/persist, disseminate, and proliferate in humans. This was the first study to examine the relationship between meningococcal cysteine acquisition and the pathogenesis of meningococcal infections. The results of the present study provide insights into the mechanisms by which pathogens with auxotrophs acquire nutrients in hosts and may also contribute to the development of treatments and prevention strategies for IMD. While Neisseria meningitidis typically exists in an asymptomatic nasopharyngeal carriage state, it may cause potentially lethal diseases in humans, such as septicemia or meningitis, by invading deeper sites in the body. Since the nutrient compositions of human cells are not always conducive to meningococci, N. meningitidis needs to exploit nutrients from host environments. In the present study, the utilization of cysteine by the meningococcal cysteine transport system (CTS) was analyzed for the pathogenesis of meningococcal infections. A N. meningitidis strain deficient in one of the three cts genes annotated as encoding cysteine-binding protein (cbp) exhibited approximately 100-fold less internalization into human brain microvascular endothelial cells (HBMEC) than the wild-type strain. This deficiency was restored by complementation with the three cts genes together, and the infectious phenotype of HBMEC internalization correlated with cysteine uptake activity. However, efficient accumulation of ezrin was observed beneath the cbp mutant. The intracellular survival of the cbp mutant in HBMEC was markedly reduced, whereas equivalent reductions of glutathione concentrations and of resistance to reactive oxygens species in the cbp mutant were not found. The cbp mutant grew well in complete medium but not in synthetic medium supplemented with less than 300 μM cysteine. Taking cysteine concentrations in human cells and other body fluids, including blood and cerebrospinal fluid, into consideration, the present results collectively suggest that the meningococcal CTS is crucial for the acquisition of cysteine from human cells and participates in meningococcal nutrient virulence.
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5
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Tanaka KJ, Song S, Mason K, Pinkett HW. Selective substrate uptake: The role of ATP-binding cassette (ABC) importers in pathogenesis. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2018; 1860:868-877. [PMID: 28847505 PMCID: PMC5807212 DOI: 10.1016/j.bbamem.2017.08.011] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/11/2017] [Accepted: 08/16/2017] [Indexed: 01/14/2023]
Abstract
The uptake of nutrients, including metals, amino acids and peptides are required for many biological processes. Pathogenic bacteria scavenge these essential nutrients from microenvironments to survive within the host. Pathogens must utilize a myriad of mechanisms to acquire these essential nutrients from the host while mediating the effects of toxicity. Bacteria utilize several transport proteins, including ATP-binding cassette (ABC) transporters to import and expel substrates. ABC transporters, conserved across all organisms, are powered by the energy from ATP to move substrates across cellular membranes. In this review, we will focus on nutrient uptake, the role of ABC importers at the host-pathogen interface, and explore emerging therapies to combat pathogenesis. This article is part of a Special Issue entitled: Beyond the Structure-Function Horizon of Membrane Proteins edited by Ute Hellmich, Rupak Doshi and Benjamin McIlwain.
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Affiliation(s)
- Kari J Tanaka
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Saemee Song
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Kevin Mason
- The Research Institute at Nationwide Children's Hospital and The Ohio State University, College of Medicine, Department of Pediatrics, Center for Microbial Pathogenesis, Columbus, OH, USA
| | - Heather W Pinkett
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.
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6
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Complement C5a Receptor 1 Exacerbates the Pathophysiology of N. meningitidis Sepsis and Is a Potential Target for Disease Treatment. mBio 2018; 9:mBio.01755-17. [PMID: 29362231 PMCID: PMC5784250 DOI: 10.1128/mbio.01755-17] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Sepsis caused by Neisseria meningitidis (meningococcus) is a rapidly progressing, life-threatening disease. Because its initial symptoms are rather unspecific, medical attention is often sought too late, i.e., when the systemic inflammatory response is already unleashed. This in turn limits the success of antibiotic treatment. The complement system is generally accepted as the most important innate immune determinant against invasive meningococcal disease since it protects the host through the bactericidal membrane attack complex. However, complement activation concomitantly liberates the C5a peptide, and it remains unclear whether this potent anaphylatoxin contributes to protection and/or drives the rapidly progressing immunopathogenesis associated with meningococcal disease. Here, we dissected the specific contribution of C5a receptor 1 (C5aR1), the canonical receptor for C5a, using a mouse model of meningococcal sepsis. Mice lacking C3 or C5 displayed susceptibility that was enhanced by >1,000-fold or 100-fold, respectively, consistent with the contribution of these components to protection. In clear contrast, C5ar1−/− mice resisted invasive meningococcal infection and cleared N. meningitidis more rapidly than wild-type (WT) animals. This favorable outcome stemmed from an ameliorated inflammatory cytokine response to N. meningitidis in C5ar1−/− mice in both in vivo and ex vivo whole-blood infections. In addition, inhibition of C5aR1 signaling without interference with the complement bactericidal activity reduced the inflammatory response also in human whole blood. Enticingly, pharmacologic C5aR1 blockade enhanced mouse survival and lowered meningococcal burden even when the treatment was administered after sepsis induction. Together, our findings demonstrate that C5aR1 drives the pathophysiology associated with meningococcal sepsis and provides a promising target for adjunctive therapy. The devastating consequences of N. meningitidis sepsis arise due to the rapidly arising and self-propagating inflammatory response that mobilizes antibacterial defenses but also drives the immunopathology associated with meningococcemia. The complement cascade provides innate broad-spectrum protection against infection by directly damaging the envelope of pathogenic microbes through the membrane attack complex and triggers an inflammatory response via the C5a peptide and its receptor C5aR1 aimed at mobilizing cellular effectors of immunity. Here, we consider the potential of separating the bactericidal activities of the complement cascade from its immune activating function to improve outcome of N. meningitidis sepsis. Our findings demonstrate that the specific genetic or pharmacological disruption of C5aR1 rapidly ameliorates disease by suppressing the pathogenic inflammatory response and, surprisingly, allows faster clearance of the bacterial infection. This outcome provides a clear demonstration of the therapeutic benefit of the use of C5aR1-specific inhibitors to improve the outcome of invasive meningococcal disease.
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7
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Ampattu BJ, Hagmann L, Liang C, Dittrich M, Schlüter A, Blom J, Krol E, Goesmann A, Becker A, Dandekar T, Müller T, Schoen C. Transcriptomic buffering of cryptic genetic variation contributes to meningococcal virulence. BMC Genomics 2017; 18:282. [PMID: 28388876 PMCID: PMC5383966 DOI: 10.1186/s12864-017-3616-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 03/10/2017] [Indexed: 01/06/2023] Open
Abstract
Background Commensal bacteria like Neisseria meningitidis sometimes cause serious disease. However, genomic comparison of hyperinvasive and apathogenic lineages did not reveal unambiguous hints towards indispensable virulence factors. Here, in a systems biological approach we compared gene expression of the invasive strain MC58 and the carriage strain α522 under different ex vivo conditions mimicking commensal and virulence compartments to assess the strain-specific impact of gene regulation on meningococcal virulence. Results Despite indistinguishable ex vivo phenotypes, both strains differed in the expression of over 500 genes under infection mimicking conditions. These differences comprised in particular metabolic and information processing genes as well as genes known to be involved in host-damage such as the nitrite reductase and numerous LOS biosynthesis genes. A model based analysis of the transcriptomic differences in human blood suggested ensuing metabolic flux differences in energy, glutamine and cysteine metabolic pathways along with differences in the activation of the stringent response in both strains. In support of the computational findings, experimental analyses revealed differences in cysteine and glutamine auxotrophy in both strains as well as a strain and condition dependent essentiality of the (p)ppGpp synthetase gene relA and of a short non-coding AT-rich repeat element in its promoter region. Conclusions Our data suggest that meningococcal virulence is linked to transcriptional buffering of cryptic genetic variation in metabolic genes including global stress responses. They further highlight the role of regulatory elements for bacterial virulence and the limitations of model strain approaches when studying such genetically diverse species as N. meningitidis. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3616-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Biju Joseph Ampattu
- Institute for Hygiene and Microbiology, Joseph-Schneider-Straße 2, University of Würzburg, 97080, Würzburg, Germany
| | - Laura Hagmann
- Institute for Hygiene and Microbiology, Joseph-Schneider-Straße 2, University of Würzburg, 97080, Würzburg, Germany
| | - Chunguang Liang
- Department of Bioinformatics, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Marcus Dittrich
- Department of Bioinformatics, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.,Department of Human Genetics, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Andreas Schlüter
- Center for Biotechnology (CeBiTec), Bielefeld University, Universitätsstr. 27, 33615, Bielefeld, Germany
| | - Jochen Blom
- Institute for Bioinformatics and Systems Biology, Justus Liebig University Gießen, Heinrich-Buff-Ring 58, 35392, Gießen, Germany
| | - Elizaveta Krol
- LOEWE-Center for Synthetic Microbiology, Hans-Meerwein-Straße, 35032, Marburg, Germany
| | - Alexander Goesmann
- Institute for Bioinformatics and Systems Biology, Justus Liebig University Gießen, Heinrich-Buff-Ring 58, 35392, Gießen, Germany
| | - Anke Becker
- LOEWE-Center for Synthetic Microbiology, Hans-Meerwein-Straße, 35032, Marburg, Germany
| | - Thomas Dandekar
- Department of Bioinformatics, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Tobias Müller
- Department of Bioinformatics, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Christoph Schoen
- Institute for Hygiene and Microbiology, Joseph-Schneider-Straße 2, University of Würzburg, 97080, Würzburg, Germany.
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8
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Peak IR, Chen A, Jen FEC, Jennings C, Schulz BL, Saunders NJ, Khan A, Seifert HS, Jennings MP. Neisseria meningitidis Lacking the Major Porins PorA and PorB Is Viable and Modulates Apoptosis and the Oxidative Burst of Neutrophils. J Proteome Res 2016; 15:2356-65. [PMID: 26562068 DOI: 10.1021/acs.jproteome.5b00938] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The bacterial pathogen Neisseria meningitidis expresses two major outer-membrane porins. PorA expression is subject to phase-variation (high frequency, random, on-off switching), and both PorA and PorB are antigenically variable between strains. PorA expression is variable and not correlated with meningococcal colonisation or invasive disease, whereas all naturally-occurring strains express PorB suggesting strong selection for expression. We have generated N. meningitidis strains lacking expression of both major porins, demonstrating that they are dispensable for bacterial growth in vitro. The porAB mutant strain has an exponential growth rate similar to the parental strain, as do the single porA or porB mutants, but the porAB mutant strain does not reach the same cell density in stationary phase. Proteomic analysis suggests that the double mutant strain exhibits compensatory expression changes in proteins associated with cellular redox state, energy/nutrient metabolism, and membrane stability. On solid media, there is obvious growth impairment that is rescued by addition of blood or serum from mammalian species, particularly heme. These porin mutants are not impaired in their capacity to inhibit both staurosporine-induced apoptosis and a phorbol 12-myristate 13-acetate-induced oxidative burst in human neutrophils suggesting that the porins are not the only bacterial factors that can modulate these processes in host cells.
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Affiliation(s)
- Ian R Peak
- School of Medical Science, Gold Coast Campus, Griffith University , Southport, QLD 4222, Australia.,Institute for Glycomics, Gold Coast Campus, Griffith University , Southport, QLD 4222, Australia
| | - Adrienne Chen
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University , 303 East Chicago Avenue, Chicago, Illinois 60611, United States
| | - Freda E-C Jen
- Institute for Glycomics, Gold Coast Campus, Griffith University , Southport, QLD 4222, Australia
| | - Courtney Jennings
- Institute for Glycomics, Gold Coast Campus, Griffith University , Southport, QLD 4222, Australia
| | - Benjamin L Schulz
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland , St. Lucia, Brisbane, QLD 4072, Australia
| | - Nigel J Saunders
- Centre for Systems and Synthetic Biology, Brunel University , Uxbridge, Middlesex UB8 3PH, U.K
| | - Arshad Khan
- Centre for Systems and Synthetic Biology, Brunel University , Uxbridge, Middlesex UB8 3PH, U.K
| | - H Steven Seifert
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University , 303 East Chicago Avenue, Chicago, Illinois 60611, United States
| | - Michael P Jennings
- Institute for Glycomics, Gold Coast Campus, Griffith University , Southport, QLD 4222, Australia
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9
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Bacterial Metabolism in the Host Environment: Pathogen Growth and Nutrient Assimilation in the Mammalian Upper Respiratory Tract. Microbiol Spectr 2016; 3. [PMID: 26185081 DOI: 10.1128/microbiolspec.mbp-0007-2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Pathogens evolve in specific host niches and microenvironments that provide the physical and nutritional requirements conducive to their growth. In addition to using the host as a source of food, bacterial pathogens must avoid the immune response to their presence. The mammalian upper respiratory tract is a site that is exposed to the external environment, and is readily colonized by bacteria that live as resident flora or as pathogens. These bacteria can remain localized, descend to the lower respiratory tract, or traverse the epithelium to disseminate throughout the body. By virtue of their successful colonization of the respiratory epithelium, these bacteria obtain the nutrients needed for growth, either directly from host resources or from other microbes. This chapter describes the upper respiratory tract environment, including its tissue and mucosal structure, prokaryotic biota, and biochemical composition that would support microbial life. Neisseria meningitidis and the Bordetella species are discussed as examples of bacteria that have no known external reservoirs but have evolved to obligately colonize the mammalian upper respiratory tract.
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10
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Mulley G, Beeton ML, Wilkinson P, Vlisidou I, Ockendon-Powell N, Hapeshi A, Tobias NJ, Nollmann FI, Bode HB, van den Elsen J, ffrench-Constant RH, Waterfield NR. From Insect to Man: Photorhabdus Sheds Light on the Emergence of Human Pathogenicity. PLoS One 2015; 10:e0144937. [PMID: 26681201 PMCID: PMC4683029 DOI: 10.1371/journal.pone.0144937] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 11/25/2015] [Indexed: 12/27/2022] Open
Abstract
Photorhabdus are highly effective insect pathogenic bacteria that exist in a mutualistic relationship with Heterorhabditid nematodes. Unlike other members of the genus, Photorhabdus asymbiotica can also infect humans. Most Photorhabdus cannot replicate above 34°C, limiting their host-range to poikilothermic invertebrates. In contrast, P. asymbiotica must necessarily be able to replicate at 37°C or above. Many well-studied mammalian pathogens use the elevated temperature of their host as a signal to regulate the necessary changes in gene expression required for infection. Here we use RNA-seq, proteomics and phenotype microarrays to examine temperature dependent differences in transcription, translation and phenotype of P. asymbiotica at 28°C versus 37°C, relevant to the insect or human hosts respectively. Our findings reveal relatively few temperature dependant differences in gene expression. There is however a striking difference in metabolism at 37°C, with a significant reduction in the range of carbon and nitrogen sources that otherwise support respiration at 28°C. We propose that the key adaptation that enables P. asymbiotica to infect humans is to aggressively acquire amino acids, peptides and other nutrients from the human host, employing a so called “nutritional virulence” strategy. This would simultaneously cripple the host immune response while providing nutrients sufficient for reproduction. This might explain the severity of ulcerated lesions observed in clinical cases of Photorhabdosis. Furthermore, while P. asymbiotica can invade mammalian cells they must also resist immediate killing by humoral immunity components in serum. We observed an increase in the production of the insect Phenol-oxidase inhibitor Rhabduscin normally deployed to inhibit the melanisation immune cascade. Crucially we demonstrated this molecule also facilitates protection against killing by the alternative human complement pathway.
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Affiliation(s)
- Geraldine Mulley
- School of Biological Sciences, University of Reading, Whiteknights, Reading, RG6 6AJ, United Kingdom
| | - Michael L Beeton
- Cardiff School of Health Sciences, Cardiff Metropolitan University, Llandaff Campus, Western Avenue, Cardiff, CF5 2YB, United Kingdom
| | - Paul Wilkinson
- Life Sciences Building, Bristol University, 24 Tyndall Avenue, Bristol, BS8 1TQ, United Kingdom
| | - Isabella Vlisidou
- Life Sciences Building, Bristol University, 24 Tyndall Avenue, Bristol, BS8 1TQ, United Kingdom
| | - Nina Ockendon-Powell
- Primary Care Unit, Microbiology Department, Public Health England, Gloucester Royal Hospital, Great Western Road, Gloucester, GL1 3NN, United Kingdom
| | - Alexia Hapeshi
- Division of Biomedical Sciences, Warwick Medical School, Medical School Building, The University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| | - Nick J Tobias
- Buchmann Center for Life Sciences (BMLS), Fachbereich Biowissenschaften, Goethe Universität Frankfurt, 60438, Frankfurt, Germany
| | - Friederike I Nollmann
- Buchmann Center for Life Sciences (BMLS), Fachbereich Biowissenschaften, Goethe Universität Frankfurt, 60438, Frankfurt, Germany
| | - Helge B Bode
- Buchmann Center for Life Sciences (BMLS), Fachbereich Biowissenschaften, Goethe Universität Frankfurt, 60438, Frankfurt, Germany
| | - Jean van den Elsen
- Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, United Kingdom
| | | | - Nicholas R Waterfield
- Division of Biomedical Sciences, Warwick Medical School, Medical School Building, The University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
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11
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Colicchio R, Pagliuca C, Pastore G, Cicatiello AG, Pagliarulo C, Talà A, Scaglione E, Sammartino JC, Bucci C, Alifano P, Salvatore P. Fitness Cost of Rifampin Resistance in Neisseria meningitidis: In Vitro Study of Mechanisms Associated with rpoB H553Y Mutation. Antimicrob Agents Chemother 2015; 59:7637-49. [PMID: 26416867 PMCID: PMC4649176 DOI: 10.1128/aac.01746-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 09/23/2015] [Indexed: 12/14/2022] Open
Abstract
Rifampin chemoprophylaxis against Neisseria meningitidis infections led to the onset of rifampin resistance in clinical isolates harboring point mutations in the rpoB gene, coding for the RNA polymerase β chain. These resistant strains are rare in medical practice, suggesting their decreased fitness in the human host. In this study, we isolated rifampin-resistant rpoB mutants from hypervirulent serogroup C strain 93/4286 and analyzed their different properties, including the ability to grow/survive in different culture media and in differentiated THP-1 human monocytes and to compete with the wild-type strain in vitro. Our results demonstrate that different rpoB mutations (H553Y, H553R, and S549F) may have different effects, ranging from low- to high-cost effects, on bacterial fitness in vitro. Moreover, we found that the S549F mutation confers temperature sensitivity, possibly explaining why it is observed very rarely in clinical isolates. Comparative high-throughput RNA sequencing analysis of bacteria grown in chemically defined medium demonstrated that the low-cost H553Y substitution resulted in global transcriptional changes that functionally mimic the stringent response. Interestingly, many virulence-associated genes, including those coding for meningococcal type IV pili, porin A, adhesins/invasins, IgA protease, two-partner secretion system HrpA/HrpB, enzymes involved in resistance to oxidative injury, lipooligosaccharide sialylation, and capsular polysaccharide biosynthesis, were downregulated in the H553Y mutant compared to their level of expression in the wild-type strain. These data might account for the reduced capacity of this mutant to grow/survive in differentiated THP-1 cells and explain the rarity of H553Y mutants among clinical isolates.
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Affiliation(s)
- Roberta Colicchio
- Department of Molecular Medicine and Medical Biotechnology, Federico II University Medical School, Naples, Italy SDN-Foundation, Naples, Italy
| | - Chiara Pagliuca
- Department of Molecular Medicine and Medical Biotechnology, Federico II University Medical School, Naples, Italy Ceinge Advanced Biotechnologies, Naples, Italy
| | - Gabiria Pastore
- Department of Sciences and Technologies, University of Sannio, Benevento, Italy
| | | | - Caterina Pagliarulo
- Department of Sciences and Technologies, University of Sannio, Benevento, Italy
| | - Adelfia Talà
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Elena Scaglione
- Department of Molecular Medicine and Medical Biotechnology, Federico II University Medical School, Naples, Italy
| | - Josè Camilla Sammartino
- Department of Molecular Medicine and Medical Biotechnology, Federico II University Medical School, Naples, Italy
| | - Cecilia Bucci
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Pietro Alifano
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy
| | - Paola Salvatore
- Department of Molecular Medicine and Medical Biotechnology, Federico II University Medical School, Naples, Italy Ceinge Advanced Biotechnologies, Naples, Italy
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12
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Gasparini R, Panatto D, Bragazzi NL, Lai PL, Bechini A, Levi M, Durando P, Amicizia D. How the Knowledge of Interactions between Meningococcus and the Human Immune System Has Been Used to Prepare Effective Neisseria meningitidis Vaccines. J Immunol Res 2015; 2015:189153. [PMID: 26351643 PMCID: PMC4553322 DOI: 10.1155/2015/189153] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 06/09/2015] [Indexed: 01/17/2023] Open
Abstract
In the last decades, tremendous advancement in dissecting the mechanisms of pathogenicity of Neisseria meningitidis at a molecular level has been achieved, exploiting converging approaches of different disciplines, ranging from pathology to microbiology, immunology, and omics sciences (such as genomics and proteomics). Here, we review the molecular biology of the infectious agent and, in particular, its interactions with the immune system, focusing on both the innate and the adaptive responses. Meningococci exploit different mechanisms and complex machineries in order to subvert the immune system and to avoid being killed. Capsular polysaccharide and lipooligosaccharide glycan composition, in particular, play a major role in circumventing immune response. The understanding of these mechanisms has opened new horizons in the field of vaccinology. Nowadays different licensed meningococcal vaccines are available and used: conjugate meningococcal C vaccines, tetravalent conjugate vaccines, an affordable conjugate vaccine against the N. menigitidis serogroup A, and universal vaccines based on multiple antigens each one with a different and peculiar function against meningococcal group B strains.
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Affiliation(s)
- R. Gasparini
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - D. Panatto
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - N. L. Bragazzi
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - P. L. Lai
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - A. Bechini
- Department of Health Sciences, University of Florence, Viale G.B. Morgagni 48, 50134 Florence, Italy
| | - M. Levi
- Department of Health Sciences, University of Florence, Viale G.B. Morgagni 48, 50134 Florence, Italy
| | - P. Durando
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - D. Amicizia
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
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13
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Multiple Functions of Glutamate Uptake via Meningococcal GltT-GltM L-Glutamate ABC Transporter in Neisseria meningitidis Internalization into Human Brain Microvascular Endothelial Cells. Infect Immun 2015; 83:3555-67. [PMID: 26099588 DOI: 10.1128/iai.00654-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 06/17/2015] [Indexed: 12/30/2022] Open
Abstract
We previously reported that Neisseria meningitidis internalization into human brain microvasocular endothelial cells (HBMEC) was triggered by the influx of extracellular L-glutamate via the GltT-GltM L-glutamate ABC transporter, but the underlying mechanism remained unclear. We found that the ΔgltT ΔgltM invasion defect in assay medium (AM) was alleviated in AM without 10% fetal bovine serum (FBS) [AM(-S)]. The alleviation disappeared again in AM(-S) supplemented with 500 μM glutamate. Glutamate uptake by the ΔgltT ΔgltM mutant was less efficient than that by the wild-type strain, but only upon HBMEC infection. We also observed that both GltT-GltM-dependent invasion and accumulation of ezrin, a key membrane-cytoskeleton linker, were more pronounced when N. meningitidis formed larger colonies on HBMEC under physiological glutamate conditions. These results suggested that GltT-GltM-dependent meningococcal internalization into HBMEC might be induced by the reduced environmental glutamate concentration upon infection. Furthermore, we found that the amount of glutathione within the ΔgltT ΔgltM mutant was much lower than that within the wild-type N. meningitidis strain only upon HBMEC infection and was correlated with intracellular survival. Considering that the L-glutamate obtained via GltT-GltM is utilized as a nutrient in host cells, l-glutamate uptake via GltT-GltM plays multiple roles in N. meningitidis internalization into HBMEC.
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14
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Rifampicin-resistance, rpoB polymorphism and RNA polymerase genetic engineering. J Biotechnol 2015; 202:60-77. [DOI: 10.1016/j.jbiotec.2014.11.024] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 11/22/2014] [Accepted: 11/26/2014] [Indexed: 01/22/2023]
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15
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Chen WJ, Hsieh FC, Hsu FC, Tasy YF, Liu JR, Shih MC. Characterization of an insecticidal toxin and pathogenicity of Pseudomonas taiwanensis against insects. PLoS Pathog 2014; 10:e1004288. [PMID: 25144637 PMCID: PMC4140846 DOI: 10.1371/journal.ppat.1004288] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 06/17/2014] [Indexed: 01/28/2023] Open
Abstract
Pseudomonas taiwanensis is a broad-host-range entomopathogenic bacterium that exhibits insecticidal activity toward agricultural pests Plutella xylostella, Spodoptera exigua, Spodoptera litura, Trichoplusia ni and Drosophila melanogaster. Oral infection with different concentrations (OD = 0.5 to 2) of wild-type P. taiwanensis resulted in insect mortality rates that were not significantly different (92.7%, 96.4% and 94.5%). The TccC protein, a component of the toxin complex (Tc), plays an essential role in the insecticidal activity of P. taiwanensis. The ΔtccC mutant strain of P. taiwanensis, which has a knockout mutation in the tccC gene, only induced 42.2% mortality in P. xylostella, even at a high bacterial dose (OD = 2.0). TccC protein was cleaved into two fragments, an N-terminal fragment containing an Rhs-like domain and a C-terminal fragment containing a Glt symporter domain and a TraT domain, which might contribute to antioxidative stress activity and defense against macrophagosis, respectively. Interestingly, the primary structure of the C-terminal region of TccC in P. taiwanensis is unique among pathogens. Membrane localization of the C-terminal fragment of TccC was proven by flow cytometry. Sonicated pellets of P. taiwanensis ΔtccC strain had lower toxicity against the Sf9 insect cell line and P. xylostella larvae than the wild type. We also found that infection of Sf9 and LD652Y-5d cell lines with P. taiwanensis induced apoptotic cell death. Further, natural oral infection by P. taiwanensis triggered expression of host programmed cell death-related genes JNK-2 and caspase-3.
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Affiliation(s)
- Wen-Jen Chen
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan; Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Feng-Chia Hsieh
- Biopesticide Division, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Taichung, Taiwan
| | - Fu-Chiun Hsu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yi-Fang Tasy
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Je-Ruei Liu
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan; Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Ming-Che Shih
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan; Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
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16
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Schoen C, Kischkies L, Elias J, Ampattu BJ. Metabolism and virulence in Neisseria meningitidis. Front Cell Infect Microbiol 2014; 4:114. [PMID: 25191646 PMCID: PMC4138514 DOI: 10.3389/fcimb.2014.00114] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 07/31/2014] [Indexed: 01/14/2023] Open
Abstract
A longstanding question in infection biology addresses the genetic basis for invasive behavior in commensal pathogens. A prime example for such a pathogen is Neisseria meningitidis. On the one hand it is a harmless commensal bacterium exquisitely adapted to humans, and on the other hand it sometimes behaves like a ferocious pathogen causing potentially lethal disease such as sepsis and acute bacterial meningitis. Despite the lack of a classical repertoire of virulence genes in N. meningitidis separating commensal from invasive strains, molecular epidemiology suggests that carriage and invasive strains belong to genetically distinct populations. In recent years, it has become increasingly clear that metabolic adaptation enables meningococci to exploit host resources, supporting the concept of nutritional virulence as a crucial determinant of invasive capability. Here, we discuss the contribution of core metabolic pathways in the context of colonization and invasion with special emphasis on results from genome-wide surveys. The metabolism of lactate, the oxidative stress response, and, in particular, glutathione metabolism as well as the denitrification pathway provide examples of how meningococcal metabolism is intimately linked to pathogenesis. We further discuss evidence from genome-wide approaches regarding potential metabolic differences between strains from hyperinvasive and carriage lineages and present new data assessing in vitro growth differences of strains from these two populations. We hypothesize that strains from carriage and hyperinvasive lineages differ in the expression of regulatory genes involved particularly in stress responses and amino acid metabolism under infection conditions.
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Affiliation(s)
- Christoph Schoen
- Institute for Hygiene and Microbiology, University of Würzburg Würzburg, Germany ; Research Center for Infectious Diseases (ZINF), University of Würzburg Würzburg, Germany
| | - Laura Kischkies
- Institute for Hygiene and Microbiology, University of Würzburg Würzburg, Germany
| | - Johannes Elias
- Institute for Hygiene and Microbiology, University of Würzburg Würzburg, Germany ; National Reference Centre for Meningococci and Haemophilus influenzae (NRZMHi), University of Würzburg Würzburg, Germany
| | - Biju Joseph Ampattu
- Institute for Hygiene and Microbiology, University of Würzburg Würzburg, Germany
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17
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Inhibition of the alternative pathway of nonhuman infant complement by porin B2 contributes to virulence of Neisseria meningitidis in the infant rat model. Infect Immun 2014; 82:2574-84. [PMID: 24686052 DOI: 10.1128/iai.01517-14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Neisseria meningitidis utilizes capsular polysaccharide, lipooligosaccharide (LOS) sialic acid, factor H binding protein (fHbp), and neisserial surface protein A (NspA) to regulate the alternative pathway (AP) of complement. Using meningococcal mutants that lacked all four of the above-mentioned molecules (quadruple mutants), we recently identified a role for PorB2 in attenuating the human AP; inhibition was mediated by human fH, a key downregulatory protein of the AP. Previous studies showed that fH downregulation of the AP via fHbp or NspA is specific for human fH. Here, we report that PorB2-expressing quadruple mutants also regulate the AP of baby rabbit and infant rat complement. Blocking a human fH binding region on PorB2 of the quadruple mutant of strain 4243 with a chimeric protein that comprised human fH domains 6 and 7 fused to murine IgG Fc enhanced AP-mediated baby rabbit C3 deposition, which provided evidence for an fH-dependent mechanism of nonhuman AP regulation by PorB2. Using isogenic mutants of strain H44/76 that differed only in their PorB molecules, we confirmed a role for PorB2 in resistance to killing by infant rat serum. The PorB2-expressing strain also caused higher levels of bacteremia in infant rats than its isogenic PorB3-expressing counterpart, thus providing a molecular basis for increased survival of PorB2 isolates in this model. These studies link PorB2 expression with infection of infant rats, which could inform the choice of meningococcal strains for use in animal models, and reveals, for the first time, that PorB2-expressing strains of N. meningitidis regulate the AP of baby rabbits and rats.
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18
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Coureuil M, Join-Lambert O, Lécuyer H, Bourdoulous S, Marullo S, Nassif X. Pathogenesis of meningococcemia. Cold Spring Harb Perspect Med 2013; 3:3/6/a012393. [PMID: 23732856 DOI: 10.1101/cshperspect.a012393] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Neisseria meningitidis is responsible for two major diseases: cerebrospinal meningitis and/or septicemia. The latter can lead to a purpura fulminans, an often-fatal condition owing to the associated septic shock. These two clinical aspects of the meningococcal infection are consequences of a tight interaction of meningococci with host endothelial cells. This interaction, mediated by the type IV pili, is responsible for the formation of microcolonies on the apical surface of the cells. This interaction is followed by the activation of signaling pathways in the host cells leading to the formation of a microbiological synapse. A low level of bacteremia is likely to favor the colonization of brain vessels, leading to bacterial meningitis, whereas the colonization of a large number of vessels by a high number of bacteria is responsible for one of the most severe forms of septic shock observed.
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Hedman AK, Li MS, Langford PR, Kroll JS. Transcriptional profiling of serogroup B Neisseria meningitidis growing in human blood: an approach to vaccine antigen discovery. PLoS One 2012; 7:e39718. [PMID: 22745818 PMCID: PMC3382141 DOI: 10.1371/journal.pone.0039718] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 05/25/2012] [Indexed: 12/14/2022] Open
Abstract
Neisseria meningitidis is a nasopharyngeal commensal of humans which occasionally invades the blood to cause septicaemia. The transcriptome of N. meningitidis strain MC58 grown in human blood for up to 4 hours was determined and around 10% of the genome was found to be differentially regulated. The nuo, pet and atp operons, involved in energy metabolism, were up-regulated, while many house-keeping genes were down-regulated. Genes encoding protein chaperones and proteases, involved in the stress response; complement resistant genes encoding enzymes for LOS sialylation and biosynthesis; and fHbp (NMB1870) and nspA (NMB0663), encoding vaccine candidates, were all up-regulated. Genes for glutamate uptake and metabolism, and biosynthesis of purine and pyrimidine were also up-regulated. Blood grown meningococci are under stress and undergo a metabolic adaptation and energy conservation strategy. The localisation of four putative outer membrane proteins encoded by genes found to be up-regulated in blood was assessed by FACS using polyclonal mouse antisera, and one (NMB0390) showed evidence of surface expression, supporting its vaccine candidacy.
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Affiliation(s)
- Asa K. Hedman
- Section of Paediatrics, Department of Medicine, Imperial College London, St. Mary’s Campus, London, United Kingdom
| | - Ming-Shi Li
- Section of Paediatrics, Department of Medicine, Imperial College London, St. Mary’s Campus, London, United Kingdom
| | - Paul R. Langford
- Section of Paediatrics, Department of Medicine, Imperial College London, St. Mary’s Campus, London, United Kingdom
| | - J. Simon Kroll
- Section of Paediatrics, Department of Medicine, Imperial College London, St. Mary’s Campus, London, United Kingdom
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20
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Coureuil M, Join-Lambert O, Lécuyer H, Bourdoulous S, Marullo S, Nassif X. Mechanism of meningeal invasion by Neisseria meningitidis. Virulence 2012; 3:164-72. [PMID: 22366962 PMCID: PMC3396695 DOI: 10.4161/viru.18639] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The blood-cerebrospinal fluid barrier physiologically protects the meningeal spaces from blood-borne bacterial pathogens, due to the existence of specialized junctional interendothelial complexes. Few bacterial pathogens are able to reach the subarachnoidal space and among those, Neisseria meningitidis is the one that achieves this task the most constantly when present in the bloodstream. Meningeal invasion is a consequence of a tight interaction of meningococci with brain endothelial cells. This interaction, mediated by the type IV pili, is responsible for the formation of microcolonies on the apical surface of the cells. This interaction is followed by the activation of signaling pathways in the host cells leading to the formation of endothelial docking structures resembling those elicited by the interaction of leukocytes with endothelial cells during extravasation. The consequence of these bacterial-induced signaling events is the recruitment of intercellular junction components in the docking structure and the subsequent opening of the intercellular junctions.
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21
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A bacterial siren song: intimate interactions between Neisseria and neutrophils. Nat Rev Microbiol 2012; 10:178-90. [PMID: 22290508 DOI: 10.1038/nrmicro2713] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Neisseria gonorrhoeae and Neisseria meningitidis are Gram-negative bacterial pathogens that are exquisitely adapted for growth at human mucosal surfaces and for efficient transmission between hosts. One factor that is essential to neisserial pathogenesis is the interaction between the bacteria and neutrophils, which are recruited in high numbers during infection. Although this vigorous host response could simply reflect effective immune recognition of the bacteria, there is mounting evidence that in fact these obligate human pathogens manipulate the innate immune response to promote infectious processes. This Review summarizes the mechanisms used by pathogenic neisseriae to resist and modulate the antimicrobial activities of neutrophils. It also details some of the major outstanding questions about the Neisseria-neutrophil relationship and proposes potential benefits of this relationship for the pathogen.
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Vascular colonization by Neisseria meningitidis. Curr Opin Microbiol 2011; 15:50-6. [PMID: 22185907 DOI: 10.1016/j.mib.2011.10.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 10/13/2011] [Accepted: 10/14/2011] [Indexed: 11/21/2022]
Abstract
Bacterial infection of human vasculature can lead to unregulated systemic activation of coagulation and innate immunity and rapidly becomes life threatening. Neisseria meningitidis is a vascular pathogen that causes fatal sepsis and meningitis. Post-mortem histological analysis of tissues from individuals infected with N. meningitidis show large bacterial aggregates in close association with the vascular wall of small vessels. The ability of this bacterium to colonize blood vessel endothelium is likely to impact its capacity to both multiply in the blood stream and reach the brain. This process will be referred to as vascular colonization. Recent work has described a number of early steps in N. meningitidis vascular colonization, from attachment to proliferation and dissemination, focusing on the bacterial-host interaction.
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