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Earle SG, Lobanovska M, Lavender H, Tang C, Exley RM, Ramos-Sevillano E, Browning DF, Kostiou V, Harrison OB, Bratcher HB, Varani G, Tang CM, Wilson DJ, Maiden MCJ. Genome-wide association studies reveal the role of polymorphisms affecting factor H binding protein expression in host invasion by Neisseria meningitidis. PLoS Pathog 2021; 17:e1009992. [PMID: 34662348 PMCID: PMC8553145 DOI: 10.1371/journal.ppat.1009992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 10/28/2021] [Accepted: 09/29/2021] [Indexed: 11/18/2022] Open
Abstract
Many invasive bacterial diseases are caused by organisms that are ordinarily harmless components of the human microbiome. Effective interventions against these microbes require an understanding of the processes whereby symbiotic or commensal relationships transition into pathology. Here, we describe bacterial genome-wide association studies (GWAS) of Neisseria meningitidis, a common commensal of the human respiratory tract that is nevertheless a leading cause of meningitis and sepsis. An initial GWAS discovered bacterial genetic variants, including single nucleotide polymorphisms (SNPs), associated with invasive meningococcal disease (IMD) versus carriage in several loci across the meningococcal genome, encoding antigens and other extracellular components, confirming the polygenic nature of the invasive phenotype. In particular, there was a significant peak of association around the fHbp locus, encoding factor H binding protein (fHbp), which promotes bacterial immune evasion of human complement by recruiting complement factor H (CFH) to the meningococcal surface. The association around fHbp with IMD was confirmed by a validation GWAS, and we found that the SNPs identified in the validation affected the 5' region of fHbp mRNA, altering secondary RNA structures, thereby increasing fHbp expression and enhancing bacterial escape from complement-mediated killing. This finding is consistent with the known link between complement deficiencies and CFH variation with human susceptibility to IMD. These observations demonstrate the importance of human and bacterial genetic variation across the fHbp:CFH interface in determining IMD susceptibility, the transition from carriage to disease.
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Affiliation(s)
- Sarah G. Earle
- Big Data Institute, Nuffield Department of Population Health, University of Oxford, Li Ka Shing Centre for Health Information and Discovery, Oxford, United Kingdom
| | - Mariya Lobanovska
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Hayley Lavender
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Changyan Tang
- Department of Chemistry, University of Washington, Seattle, Washington United States of America
| | - Rachel M. Exley
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | | | - Douglas F. Browning
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Vasiliki Kostiou
- Nuffield Department of Clinical Medicine, Experimental Medicine Division, John Radcliffe Hospital, Oxford, United Kingdom
| | | | | | - Gabriele Varani
- Department of Chemistry, University of Washington, Seattle, Washington United States of America
- * E-mail: (GV); (CMT); (DJW); (MCJM)
| | - Christoph M. Tang
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- * E-mail: (GV); (CMT); (DJW); (MCJM)
| | - Daniel J. Wilson
- Big Data Institute, Nuffield Department of Population Health, University of Oxford, Li Ka Shing Centre for Health Information and Discovery, Oxford, United Kingdom
- Department for Continuing Education, University of Oxford, Oxford, United Kingdom
- * E-mail: (GV); (CMT); (DJW); (MCJM)
| | - Martin C. J. Maiden
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- * E-mail: (GV); (CMT); (DJW); (MCJM)
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X-ray crystallographic structure of a bacterial polysialyltransferase provides insight into the biosynthesis of capsular polysialic acid. Sci Rep 2017; 7:5842. [PMID: 28724897 PMCID: PMC5517516 DOI: 10.1038/s41598-017-05627-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 05/31/2017] [Indexed: 12/21/2022] Open
Abstract
Polysialic acid (polySia) is a homopolymeric saccharide that is associated with some neuroinvasive pathogens and is found on selective cell types in their eukaryotic host. The presence of a polySia capsule on these bacterial pathogens helps with resistance to phagocytosis, cationic microbial peptides and bactericidal antibody production. The biosynthesis of bacterial polySia is catalysed by a single polysialyltransferase (PST) transferring sialic acid from a nucleotide-activated donor to a lipid-linked acceptor oligosaccharide. Here we present the X-ray structure of the bacterial PST from Mannheimia haemolytica serotype A2, thereby defining the architecture of this class of enzymes representing the GT38 family. The structure reveals a prominent electropositive groove between the two Rossmann-like domains forming the GT-B fold that is suitable for binding of polySia chain products. Complex structures of PST with a sugar donor analogue and an acceptor mimetic combined with kinetic studies of PST active site mutants provide insight into the principles of substrate binding and catalysis. Our results are the basis for a molecular understanding of polySia biosynthesis in bacteria and might assist the production of polysialylated therapeutic reagents and the development of novel antibiotics.
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Abstract
Neisseria meningitidis, a devastating pathogen exclusive to humans, expresses capsular polysaccharides that are the major meningococcal virulence determinants and the basis for successful meningococcal vaccines. With rare exceptions, the expression of capsule (serogroups A, B, C, W, X, Y) is required for systemic invasive meningococcal disease. Changes in capsule expression or structure (e.g. hypo- or hyper-encapsulation, capsule "switching", acetylation) can influence immunologic diagnostic assays or lead to immune escape. The loss or down-regulation of capsule is also critical in meningococcal biology facilitating meningococcal attachment, microcolony formation and the carriage state at human mucosal surfaces. Encapsulated meningococci contain a cps locus with promoters located in an intergenic region between the biosynthesis and the conserved capsule transport operons. The cps intergenic region is transcriptionally regulated (and thus the amount of capsule expressed) by IS element insertion, by a two-component system, MisR/MisS and through sequence changes that result in post-transcriptional RNA thermoregulation. Reversible on-off phase variation of capsule expression is controlled by slipped strand mispairing of homo-polymeric tracts and by precise insertion and excision of IS elements (e.g. IS1301) in the biosynthesis operon. Capsule structure can be altered by phase-variable expression of capsular polymer modification enzymes or "switched" through transformation and homologous recombination of different polymerases. Understanding the complex regulation of meningococcal capsule has important implications for meningococcal biology, pathogenesis, diagnostics, current and future vaccine development and vaccine strategies.
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Affiliation(s)
- Yih-Ling Tzeng
- a Department of Medicine , Emory University School of Medicine, Woodruff Health Sciences Center , Atlanta , GA , USA
| | - Jennifer Thomas
- a Department of Medicine , Emory University School of Medicine, Woodruff Health Sciences Center , Atlanta , GA , USA
| | - David S Stephens
- a Department of Medicine , Emory University School of Medicine, Woodruff Health Sciences Center , Atlanta , GA , USA
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Xia C, He J, Yuan G, Li Y, Li Q, Yu C. A switched catalysis qualified sealers capped one-step synthesis biocompatibility bimetallic scaffold film for Neu5Acα(2-6)Gal β MP Glycoside specific detection. Biosens Bioelectron 2016; 77:853-9. [PMID: 26516685 DOI: 10.1016/j.bios.2015.10.060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 10/16/2015] [Accepted: 10/21/2015] [Indexed: 11/15/2022]
Abstract
In this work, a novel label-free biosensor was designed for the sensitive and selective determination of Neu5Acα(2-6)Gal β MP Glycoside using AuPt-PPy(polypyrrole) conductive nanocomposite film as the sensor platform. The introduced AuPt-PPy nanocomposite provided a large surface area for the immobilization of Sambucus nigra agglutinis (SNA) through a coupling agent for specifically recognizing analytes and exhibited high electrocatalytic activity toward the reduction of hydrogen peroxide (H2O2) as an analytical signal. Subsequently, to block the non-specific sites of the modified electrode, GOx was employed instead of the usual sealers. Most importantly, in the presence of glucose, these localized GOx further enhanced the electrochemical signal, which was achieved by the efficient catalysis of glucose. This study is the first that demonstrates the specific detection of Neu5Acα(2-6)Gal β MP Glycoside using AuPt-PPy as the electrocatalytic. Under optimal conditions, the electrochemical biosensor exhibited a wide linear range of 0.01 pgmL(-1)-800 ngmL(-1) with a low detection limit of 0.003 pgmL(-1) (S/N=3), due to the affinity between SNA and Neu5Acα(2-6)Gal β MP Glycoside. Therefore, the co-catalysis signal amplification approach has considerable potential in clinical applications and is suitable for the quantification of other biomarkers.
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Affiliation(s)
- Chunyong Xia
- Institute of Life Science and School of Public Health, Chongqing Medical University, Box 174#, No. 1 Yixueyuan Road, Chongqing 400016, PR China
| | - Junlin He
- Institute of Life Science and School of Public Health, Chongqing Medical University, Box 174#, No. 1 Yixueyuan Road, Chongqing 400016, PR China
| | - Guolin Yuan
- Institute of Life Science and School of Public Health, Chongqing Medical University, Box 174#, No. 1 Yixueyuan Road, Chongqing 400016, PR China
| | - Yuliang Li
- Institute of Life Science and School of Public Health, Chongqing Medical University, Box 174#, No. 1 Yixueyuan Road, Chongqing 400016, PR China
| | - Qingying Li
- Institute of Life Science and School of Public Health, Chongqing Medical University, Box 174#, No. 1 Yixueyuan Road, Chongqing 400016, PR China
| | - Chao Yu
- Institute of Life Science and School of Public Health, Chongqing Medical University, Box 174#, No. 1 Yixueyuan Road, Chongqing 400016, PR China.
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Ultrasensitive electrochemical biosensor based on graphite oxide, Prussian blue, and PTC-NH2 for the detection of α2,6-sialylated glycans in human serum. Biosens Bioelectron 2014; 62:79-83. [DOI: 10.1016/j.bios.2014.06.031] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 06/11/2014] [Accepted: 06/12/2014] [Indexed: 01/26/2023]
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Purushotham S, Deivanayagam C. The calcium-induced conformation and glycosylation of scavenger-rich cysteine repeat (SRCR) domains of glycoprotein 340 influence the high affinity interaction with antigen I/II homologs. J Biol Chem 2014; 289:21877-87. [PMID: 24923446 PMCID: PMC4139206 DOI: 10.1074/jbc.m114.565507] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 06/10/2014] [Indexed: 01/17/2023] Open
Abstract
Oral streptococci adhere to tooth-immobilized glycoprotein 340 (GP340) via the surface protein antigen I/II (AgI/II) and its homologs as the first step in pathogenesis. Studying this interaction using recombinant proteins, we observed that calcium increases the conformational stability of the scavenger-rich cysteine repeat (SRCRs) domains of GP340. Our results also show that AgI/II adheres specifically with nanomolar affinity to the calcium-induced SRCR conformation in an immobilized state and not in solution. This interaction is significantly dependent on the O-linked carbohydrates present on the SRCRs. This study also establishes that a single SRCR domain of GP340 contains the two surfaces to which the apical and C-terminal regions of AgI/II noncompetitively adhere. Compared with the single SRCR domain, the three tandem SRCR domains displayed a collective/cooperative increase in their bacterial adherence and aggregation. The previously described SRCRP2 peptide that was shown to aggregate several oral streptococci displayed limited aggregation and also nonspecific adherence compared to SRCR domains. Finally, we show distinct species-specific adherence/aggregation between Streptococcus mutans AgI/II and Streptococcus gordonii SspB in their interaction with the SRCRs. This study concludes that identification of the metal ion and carbohydrate adherence motifs on both SRCRs and AgI/II homologs could lead to the development of anti-adhesive inhibitors that could deter the adherence of pathogenic oral streptococci and thereby prevent the onset of infections.
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Affiliation(s)
- Sangeetha Purushotham
- From the Department of Vision Sciences/Center for Structural Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294-4400
| | - Champion Deivanayagam
- From the Department of Vision Sciences/Center for Structural Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294-4400
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Cress BF, Englaender JA, He W, Kasper D, Linhardt RJ, Koffas MAG. Masquerading microbial pathogens: capsular polysaccharides mimic host-tissue molecules. FEMS Microbiol Rev 2014; 38:660-97. [PMID: 24372337 PMCID: PMC4120193 DOI: 10.1111/1574-6976.12056] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 10/16/2013] [Accepted: 12/19/2013] [Indexed: 11/27/2022] Open
Abstract
The increasing prevalence of antibiotic-resistant bacteria portends an impending postantibiotic age, characterized by diminishing efficacy of common antibiotics and routine application of multifaceted, complementary therapeutic approaches to treat bacterial infections, particularly multidrug-resistant organisms. The first line of defense for most bacterial pathogens consists of a physical and immunologic barrier known as the capsule, commonly composed of a viscous layer of carbohydrates that are covalently bound to the cell wall in Gram-positive bacteria or often to lipids of the outer membrane in many Gram-negative bacteria. Bacterial capsular polysaccharides are a diverse class of high molecular weight polysaccharides contributing to virulence of many human pathogens in the gut, respiratory tree, urinary tract, and other host tissues, by hiding cell surface components that might otherwise elicit host immune response. This review highlights capsular polysaccharides that are structurally identical or similar to polysaccharides found in mammalian tissues, including polysialic acid and glycosaminoglycan capsules hyaluronan, heparosan, and chondroitin. Such nonimmunogenic coatings render pathogens insensitive to certain immune responses, effectively increasing residence time in host tissues and enabling pathologically relevant population densities to be reached. Biosynthetic pathways and capsular involvement in immune system evasion are described, providing a basis for potential therapies aimed at supplementing or replacing antibiotic treatment.
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Affiliation(s)
- Brady F Cress
- Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
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Khatua B, Roy S, Mandal C. Sialic acids siglec interaction: a unique strategy to circumvent innate immune response by pathogens. Indian J Med Res 2013; 138:648-62. [PMID: 24434319 PMCID: PMC3928697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Sialic acids (Sias) are nine-carbon keto sugars primarily present on the terminal residue of cell surface glycans. Sialic acid binding immunoglobulins (Ig)-like lectins (siglecs) are generally expressed on various immune cells. They selectively recognize different linkage-specific sialic acids and undertake a variety of cellular functions. Many pathogens either synthesize or acquire sialic acids from the host. Sialylated pathogens generally use siglecs to manipulate the host immune response. The present review mainly deals with the newly developed information regarding mechanism of acquisition of sialic acids by pathogens and their biological relevance especially in the establishment of successful infection by impairing host innate immunity. The pathogens which are unable to synthesize sialic acids might adsorb these from the host as a way to engage the inhibitory siglecs. They promote association with the immune cells through sialic acids-siglec dependent manner. Such an association plays an important role to subvert host's immunity. Detailed investigation of these pathways has been discussed in this review. Particular attention has been focused on Pseudomonas aeruginosa (PA) and Leishmania donovani.
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Affiliation(s)
- Biswajit Khatua
- Cancer Biology & Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Saptarshi Roy
- Cancer Biology & Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Chitra Mandal
- Cancer Biology & Inflammatory Disorder Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India,Reprint requests: Dr Chitra Mandal, Cancer Biology & Inflammatory Disorders Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India e-mail: or
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9
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Harrison OB, Claus H, Jiang Y, Bennett JS, Bratcher HB, Jolley KA, Corton C, Care R, Poolman JT, Zollinger WD, Frasch CE, Stephens DS, Feavers I, Frosch M, Parkhill J, Vogel U, Quail MA, Bentley SD, Maiden MCJ. Description and nomenclature of Neisseria meningitidis capsule locus. Emerg Infect Dis 2013; 19:566-73. [PMID: 23628376 PMCID: PMC3647402 DOI: 10.3201/eid1904.111799] [Citation(s) in RCA: 213] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Pathogenic Neisseria meningitidis isolates contain a polysaccharide capsule that is the main virulence determinant for this bacterium. Thirteen capsular polysaccharides have been described, and nuclear magnetic resonance spectroscopy has enabled determination of the structure of capsular polysaccharides responsible for serogroup specificity. Molecular mechanisms involved in N. meningitidis capsule biosynthesis have also been identified, and genes involved in this process and in cell surface translocation are clustered at a single chromosomal locus termed cps. The use of multiple names for some of the genes involved in capsule synthesis, combined with the need for rapid diagnosis of serogroups commonly associated with invasive meningococcal disease, prompted a requirement for a consistent approach to the nomenclature of capsule genes. In this report, a comprehensive description of all N. meningitidis serogroups is provided, along with a proposed nomenclature, which was presented at the 2012 XVIIIth International Pathogenic Neisseria Conference.
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10
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Willis LM, Whitfield C. Structure, biosynthesis, and function of bacterial capsular polysaccharides synthesized by ABC transporter-dependent pathways. Carbohydr Res 2013; 378:35-44. [PMID: 23746650 DOI: 10.1016/j.carres.2013.05.007] [Citation(s) in RCA: 150] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/06/2013] [Accepted: 05/11/2013] [Indexed: 12/11/2022]
Abstract
Bacterial capsules are formed primarily from long-chain polysaccharides with repeat-unit structures. A given bacterial species can produce a range of capsular polysaccharides (CPSs) with different structures and these help distinguish isolates by serotyping, as is the case with Escherichia coli K antigens. Capsules are important virulence factors for many pathogens and this review focuses on CPSs synthesized via ATP-binding cassette (ABC) transporter-dependent processes in Gram-negative bacteria. Bacteria utilizing this pathway are often associated with urinary tract infections, septicemia, and meningitis, and E. coli and Neisseria meningitidis provide well-studied examples. CPSs from ABC transporter-dependent pathways are synthesized at the cytoplasmic face of the inner membrane through the concerted action of glycosyltransferases before being exported across the inner membrane and translocated to the cell surface. A hallmark of these CPSs is a conserved reducing terminal glycolipid composed of phosphatidylglycerol and a poly-3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) linker. Recent discovery of the structure of this conserved lipid terminus provides new insights into the early steps in CPS biosynthesis.
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Affiliation(s)
- Lisa M Willis
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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Bartley SN, Tzeng YL, Heel K, Lee CW, Mowlaboccus S, Seemann T, Lu W, Lin YH, Ryan CS, Peacock C, Stephens DS, Davies JK, Kahler CM. Attachment and invasion of Neisseria meningitidis to host cells is related to surface hydrophobicity, bacterial cell size and capsule. PLoS One 2013; 8:e55798. [PMID: 23405216 PMCID: PMC3566031 DOI: 10.1371/journal.pone.0055798] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 01/04/2013] [Indexed: 12/13/2022] Open
Abstract
We compared exemplar strains from two hypervirulent clonal complexes, strain NMB-CDC from ST-8/11 cc and strain MC58 from ST-32/269 cc, in host cell attachment and invasion. Strain NMB-CDC attached to and invaded host cells at a significantly greater frequency than strain MC58. Type IV pili retained the primary role for initial attachment to host cells for both isolates regardless of pilin class and glycosylation pattern. In strain MC58, the serogroup B capsule was the major inhibitory determinant affecting both bacterial attachment to and invasion of host cells. Removal of terminal sialylation of lipooligosaccharide (LOS) in the presence of capsule did not influence rates of attachment or invasion for strain MC58. However, removal of either serogroup B capsule or LOS sialylation in strain NMB-CDC increased bacterial attachment to host cells to the same extent. Although the level of inhibition of attachment by capsule was different between these strains, the regulation of the capsule synthesis locus by the two-component response regulator MisR, and the level of surface capsule determined by flow cytometry were not significantly different. However, the diplococci of strain NMB-CDC were shown to have a 1.89-fold greater surface area than strain MC58 by flow cytometry. It was proposed that the increase in surface area without changing the amount of anchored glycolipid capsule in the outer membrane would result in a sparser capsule and increase surface hydrophobicity. Strain NMB-CDC was shown to be more hydrophobic than strain MC58 using hydrophobicity interaction chromatography and microbial adhesion-to-solvents assays. In conclusion, improved levels of adherence of strain NMB-CDC to cell lines was associated with increased bacterial cell surface and surface hydrophobicity. This study shows that there is diversity in bacterial cell surface area and surface hydrophobicity within N. meningitidis which influence steps in meningococcal pathogenesis.
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Affiliation(s)
- Stephanie N. Bartley
- School of Pathology and Laboratory Medicine, The University of Western Australia, Perth, Western Australia, Australia
| | - Yih-Ling Tzeng
- Veterans Affairs Medical Center, Atlanta, Georgia, United States of America
- Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Kathryn Heel
- Centre for Microscopy, Characterisation and Analysis, and Translational Cancer Pathology Laboratory, School of Pathology and Laboratory Medicine, The University of Western Australia, Perth, Western Australia, Australia
| | - Chiang W. Lee
- School of Pathology and Laboratory Medicine, The University of Western Australia, Perth, Western Australia, Australia
| | - Shakeel Mowlaboccus
- School of Pathology and Laboratory Medicine, The University of Western Australia, Perth, Western Australia, Australia
| | - Torsten Seemann
- Victorian Bioinformatics Consortium, Monash University, Melbourne, Victoria, Australia
| | - Wei Lu
- School of Pathology and Laboratory Medicine, The University of Western Australia, Perth, Western Australia, Australia
| | - Ya-Hsun Lin
- Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Catherine S. Ryan
- Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Christopher Peacock
- School of Pathology and Laboratory Medicine, The University of Western Australia, Perth, Western Australia, Australia
| | - David S. Stephens
- Veterans Affairs Medical Center, Atlanta, Georgia, United States of America
- Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - John K. Davies
- Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Charlene M. Kahler
- School of Pathology and Laboratory Medicine, The University of Western Australia, Perth, Western Australia, Australia
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Abstract
Neisseria meningitidis (the meningococcus) causes significant morbidity and mortality in children and young adults worldwide through epidemic or sporadic meningitis and/or septicemia. In this review, we describe the biology, microbiology, and epidemiology of this exclusive human pathogen. N.meningitidis is a fastidious, encapsulated, aerobic gram-negative diplococcus. Colonies are positive by the oxidase test and most strains utilize maltose. The phenotypic classification of meningococci, based on structural differences in capsular polysaccharide, lipooligosaccharide (LOS) and outer membrane proteins, is now complemented by genome sequence typing (ST). The epidemiological profile of N. meningitidis is variable in different populations and over time and virulence of the meningococcus is based on a transformable/plastic genome and expression of certain capsular polysaccharides (serogroups A, B, C, W-135, Y and X) and non-capsular antigens. N. meningitidis colonizes mucosal surfaces using a multifactorial process involving pili, twitching motility, LOS, opacity associated, and other surface proteins. Certain clonal groups have an increased capacity to gain access to the blood, evade innate immune responses, multiply, and cause systemic disease. Although new vaccines hold great promise, meningococcal infection continues to be reported in both developed and developing countries, where universal vaccine coverage is absent and antibiotic resistance increasingly more common.
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Affiliation(s)
- Nadine G Rouphael
- Department of Medicine, Division of Infectious Diseases, Emory University School of Medicine, Atlanta, GA, USA
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