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Arenas J, Szabo Z, van der Wal J, Maas C, Riaz T, Tønjum T, Tommassen J. Serum proteases prevent bacterial biofilm formation: role of kallikrein and plasmin. Virulence 2021; 12:2902-2917. [PMID: 34903146 PMCID: PMC8677018 DOI: 10.1080/21505594.2021.2003115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Biofilm formation is a general strategy for bacterial pathogens to withstand host defense mechanisms. In this study, we found that serum proteases inhibit biofilm formation by Neisseria meningitidis, Neisseria gonorrhoeae, Haemophilus influenzae, and Bordetella pertussis. Confocal laser-scanning microscopy analysis revealed that these proteins reduce the biomass and alter the architecture of meningococcal biofilms. To understand the underlying mechanism, the serum was fractionated through size-exclusion chromatography and anion-exchange chromatography, and the composition of the fractions that retained anti-biofilm activity against N. meningitidis was analyzed by intensity-based absolute quantification mass spectrometry. Among the identified serum proteins, plasma kallikrein (PKLK), FXIIa, and plasmin were found to cleave neisserial heparin-binding antigen and the α-peptide of IgA protease on the meningococcal cell surface, resulting in the release of positively charged polypeptides implicated in biofilm formation by binding extracellular DNA. Further experiments also revealed that plasmin and PKLK inhibited biofilm formation of B. pertussis by cleaving filamentous hemagglutinin. We conclude that the proteolytic activity of serum proteases toward bacterial adhesins involved in biofilm formation could constitute a defense mechanism for the clearance of pathogens.
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Affiliation(s)
- Jesús Arenas
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University, Utrecht, The Netherlands.,Unit of Microbiology and Immunology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
| | - Zalan Szabo
- Research and Development Department, U-Protein Express BV, Utrecht, The Netherlands
| | - Jelle van der Wal
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University, Utrecht, The Netherlands
| | - Coen Maas
- Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Tahira Riaz
- Department of Microbiology, University of Oslo, Oslo, Norway
| | - Tone Tønjum
- Department of Microbiology, University of Oslo, Oslo, Norway
| | - Jan Tommassen
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University, Utrecht, The Netherlands
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2
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The serogroup B meningococcal outer membrane vesicle-based vaccine 4CMenB induces cross-species protection against Neisseria gonorrhoeae. PLoS Pathog 2020; 16:e1008602. [PMID: 33290434 PMCID: PMC7748408 DOI: 10.1371/journal.ppat.1008602] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 12/18/2020] [Accepted: 10/08/2020] [Indexed: 12/15/2022] Open
Abstract
There is a pressing need for a gonorrhea vaccine due to the high disease burden associated with gonococcal infections globally and the rapid evolution of antibiotic resistance in Neisseria gonorrhoeae (Ng). Current gonorrhea vaccine research is in the stages of antigen discovery and the identification of protective immune responses, and no vaccine has been tested in clinical trials in over 30 years. Recently, however, it was reported in a retrospective case-control study that vaccination of humans with a serogroup B Neisseria meningitidis (Nm) outer membrane vesicle (OMV) vaccine (MeNZB) was associated with reduced rates of gonorrhea. Here we directly tested the hypothesis that Nm OMVs induce cross-protection against gonorrhea in a well-characterized female mouse model of Ng genital tract infection. We found that immunization with the licensed Nm OMV-based vaccine 4CMenB (Bexsero) significantly accelerated clearance and reduced the Ng bacterial burden compared to administration of alum or PBS. Serum IgG and vaginal IgA and IgG that cross-reacted with Ng OMVs were induced by 4CMenB vaccination by either the subcutaneous or intraperitoneal routes. Antibodies from vaccinated mice recognized several Ng surface proteins, including PilQ, BamA, MtrE, NHBA (known to be recognized by humans), PorB, and Opa. Immune sera from both mice and humans recognized Ng PilQ and several proteins of similar apparent molecular weight, but MtrE was only recognized by mouse serum. Pooled sera from 4CMenB-immunized mice showed a 4-fold increase in serum bactericidal50 titers against the challenge strain; in contrast, no significant difference in bactericidal activity was detected when sera from 4CMenB-immunized and unimmunized subjects were compared. Our findings directly support epidemiological evidence that Nm OMVs confer cross-species protection against gonorrhea, and implicate several Ng surface antigens as potentially protective targets. Additionally, this study further defines the usefulness of murine infection model as a relevant experimental system for gonorrhea vaccine development.
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Kombarova SY, Bichucher AM, Soldatsky YL, Yunusova RY, Skirda TA, Martynenko IG, Golovina LI, Edgem SR, Severin TV, Melnikov VG. Detection of meningococcus, pneumococcus, Haemophilus influenzae, and group A streptococcus DNA in pediatric adenoid bioptats. ACTA ACUST UNITED AC 2020. [DOI: 10.15789/2220-7619-dom-1163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Meningococcal, pneumococcal, streptococcal A and Haemophilus influenzae infections are manifested in different clinical forms, ranging from bacterial carriage to generalized life-threatening conditions. However, a connection between bacterial carriage and disease development has not been fully explored. A PCR assay was performed with adenoid biopsy samples collected from 112 children after planned adenotomy to detect Neisseria meningitidis, Streptococcus pneumoniae, Streptococcus pyogenes, H. influenzae carriage. A DNA specific to at least one of the four studied microbial species was found in 104 samples (92.86%) so that: meningococcal DNA was detected in one sample (0.9%), pneumococcal — in 98 (87.5%), H. influenzae — in 19 (16.96%), and streptococcal A — in 42 (37.5%) samples. However, none of these species was found in 8 children (7.14%). A sole S. pneumoniae was detected in 54 samples (48.2%), whereas S. pyogenes — in 5 samples (4.5%). Moreover, two bacterial species were simultaneously as follows: N. meningitidis and S. pneumoniae — in 1 sample (0.9%), S. pneumoniae and H. influenzae — in 7 samples (6.3%); H. influenzae and S. pyogenes — in 1 sample (0.9%); S. pneumoniae and S. pyogenes — in 25 samples (22.3%). A triple combination consisting of S. pneumoniae, H. influenzae and S. pyogenes bacteria were detected together in 11 patients (9.8%). Meningococcal serogrouping revealed no connection with any of the 6 most common global serogroups responsible for epidemic incidence rise (A, B, C, W-135, X, Y). A clear tendency for prevalence of S. pyogenes DNA in adenoid pediatric biopsies in children diagnosed with “Adenoids and tonsils hypertrophy” vs. “Adenoids hypertrophy” was observed. It is noteworthy, a high relative prevalence of pneumococcal carriage (87.5%), found by us was of special importance. Pediatric carriers serving as a reservoir for virulent pneumococcal species pose a threat both for themselves and surrounding people. Thus, PCR-based data of adenoid biopsies may be a promising approach for future studies, as a potential to identify live viable but nonculturable bacteria in clinical specimens will contribute to a more accurate assessment of carriage rate of meningococci, pneumococci, H. influenzae and group A streptococci.
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Affiliation(s)
- S. Yu. Kombarova
- G.N. Gabrichevsky Research Institute for Epidemiology and Microbiology
| | - A. M. Bichucher
- G.N. Gabrichevsky Research Institute for Epidemiology and Microbiology
| | | | - R. Yu. Yunusova
- G.N. Gabrichevsky Research Institute for Epidemiology and Microbiology
| | - T. A. Skirda
- G.N. Gabrichevsky Research Institute for Epidemiology and Microbiology
| | - I. G. Martynenko
- G.N. Gabrichevsky Research Institute for Epidemiology and Microbiology
| | - L. I. Golovina
- G.N. Gabrichevsky Research Institute for Epidemiology and Microbiology
| | - S. R. Edgem
- Morozovskaya Children’s City Clinical Hospital
| | | | - V. G. Melnikov
- G.N. Gabrichevsky Research Institute for Epidemiology and Microbiology
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4
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Sigurlásdóttir S, Wassing GM, Zuo F, Arts M, Jonsson AB. Deletion of D-Lactate Dehydrogenase A in Neisseria meningitidis Promotes Biofilm Formation Through Increased Autolysis and Extracellular DNA Release. Front Microbiol 2019; 10:422. [PMID: 30891026 PMCID: PMC6411758 DOI: 10.3389/fmicb.2019.00422] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/18/2019] [Indexed: 11/23/2022] Open
Abstract
Neisseria meningitidis is a Gram-negative bacterium that asymptomatically colonizes the human nasopharyngeal mucosa. Pilus-mediated initial adherence of N. meningitidis to the epithelial mucosa is followed by the formation of three-dimensional aggregates, called microcolonies. Dispersal from microcolonies contributes to the transmission of N. meningitidis across the epithelial mucosa. We have recently discovered that environmental concentrations of host cell-derived lactate influences N. meningitidis microcolony dispersal. Here, we examined the ability of N. meningitidis mutants deficient in lactate metabolism to form biofilms. A lactate dehydrogenease A (ldhA) mutant had an increased level of biofilm formation. Deletion of ldhA increased the N. meningitidis cell surface hydrophobicity and aggregation. In this study, we used FAM20, which belongs to clonal complex ST-11 that forms biofilms independently of extracellular DNA (eDNA). However, treatment with DNase I abolished the increased biofilm formation and aggregation of the ldhA-deficient mutant, suggesting a critical role for eDNA. Compared to wild-type, the ldhA-deficient mutant exhibited an increased autolytic rate, with significant increases in the eDNA concentrations in the culture supernatants and in biofilms. Within the ldhA mutant biofilm, the transcription levels of the capsule, pilus, and bacterial lysis genes were downregulated, while norB, which is associated with anaerobic respiration, was upregulated. These findings suggest that the absence of ldhA in N. meningitidis promotes biofilm formation and aggregation through autolysis-mediated DNA release.
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Affiliation(s)
- Sara Sigurlásdóttir
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Gabriela M Wassing
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Fanglei Zuo
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Melanie Arts
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Ann-Beth Jonsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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Koutangni T, Crépey P, Woringer M, Porgho S, Bicaba BW, Tall H, Mueller JE. Compartmental models for seasonal hyperendemic bacterial meningitis in the African meningitis belt. Epidemiol Infect 2018; 147:e14. [PMID: 30264686 PMCID: PMC6520558 DOI: 10.1017/s0950268818002625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 07/03/2018] [Accepted: 08/22/2018] [Indexed: 11/29/2022] Open
Abstract
The pathophysiological mechanisms underlying the seasonal dynamic and epidemic occurrence of bacterial meningitis in the African meningitis belt remain unknown. Regular seasonality (seasonal hyperendemicity) is observed for both meningococcal and pneumococcal meningitis and understanding this is critical for better prevention and modelling. The two principal hypotheses for hyperendemicity during the dry season imply (1) an increased risk of invasive disease given asymptomatic carriage of meningococci and pneumococci; or (2) an increased transmission of these bacteria from carriers and ill individuals. In this study, we formulated three compartmental deterministic models of seasonal hyperendemicity, featuring one (model1-'inv' or model2-'transm'), or a combination (model3-'inv-transm') of the two hypotheses. We parameterised the models based on current knowledge on meningococcal and pneumococcal biology and pathophysiology. We compared the three models' performance in reproducing weekly incidences of suspected cases of acute bacterial meningitis reported by health centres in Burkina Faso during 2004-2010, through the meningitis surveillance system. The three models performed well (coefficient of determination R2, 0.72, 0.86 and 0.87, respectively). Model2-'transm' and model3-'inv-transm' better captured the amplitude of the seasonal incidence. However, model2-'transm' required a higher constant invasion rate for a similar average baseline transmission rate. The results suggest that a combination of seasonal changes of the risk of invasive disease and carriage transmission is involved in the hyperendemic seasonality of bacterial meningitis in the African meningitis belt. Consequently, both interventions reducing the risk of nasopharyngeal invasion and the bacteria transmission, especially during the dry season are believed to be needed to limit the recurrent seasonality of bacterial meningitis in the meningitis belt.
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Affiliation(s)
- T. Koutangni
- Université Pierre et Marie Curie, 4 Place Jussieu, 75005 Paris, France
- Unité de l'Epidémiologie des Maladies Emergentes, Institut Pasteur, 25-28 Rue du Dr Roux, 75015 Paris, France
- EHESP French School of Public Health, Sorbonne Paris Cité, 20 avenue George Sand, 93210 La Plaine St Denis, France
| | - P. Crépey
- UMR Emergence des Pathologies Virales, Université Aix-Marseille – IRD 190 – Inserm 1207 – EHESP, 27 Boulevard Jean-Moulin 13385 Marseille Cedex 5, France
- Univ Rennes, EHESP, REPERES (Recherche en pharmaco-épidémiologie et recours aux soins) – EA 7449, F-35000 Rennes, France
| | - M. Woringer
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), PSL Research University, 45 Rue dʼUlm, 75005 Paris, France
| | - S. Porgho
- Direction de la Lutte contre la Maladie, Ministère de la Santé, 03 BP 7035 Ouagadougou 03, Burkina Faso
| | - B. W. Bicaba
- Direction de la Lutte contre la Maladie, Ministère de la Santé, 03 BP 7035 Ouagadougou 03, Burkina Faso
| | - H. Tall
- Agence de Médecine Préventive, 10 BP 638. Ouagadougou, Burkina Faso
| | - J. E. Mueller
- Unité de l'Epidémiologie des Maladies Emergentes, Institut Pasteur, 25-28 Rue du Dr Roux, 75015 Paris, France
- EHESP French School of Public Health, Sorbonne Paris Cité, 20 avenue George Sand, 93210 La Plaine St Denis, France
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Di Fede M, Biagini M, Cartocci E, Parillo C, Greco A, Martinelli M, Marchi S, Pezzicoli A, Delany I, Rossi Paccani S. Neisseria Heparin Binding Antigen is targeted by the human alternative pathway C3-convertase. PLoS One 2018; 13:e0194662. [PMID: 29579105 PMCID: PMC5868813 DOI: 10.1371/journal.pone.0194662] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 03/07/2018] [Indexed: 11/18/2022] Open
Abstract
Neisserial Heparin Binding Antigen (NHBA) is a surface-exposed lipoprotein specific for Neisseria and constitutes one of the three main protein antigens of the Bexsero vaccine. Meningococcal and human proteases, cleave NHBA protein upstream or downstream of a conserved Arg-rich region, respectively. The cleavage results in the release of the C-terminal portion of the protein. The C-terminal fragment originating from the processing of meningococcal proteases, referred to as C2 fragment, exerts a toxic effect on endothelial cells altering the endothelial permeability. In this work, we reported that recombinant C2 fragment has no influence on the integrity of human airway epithelial cell monolayers, consistent with previous findings showing that Neisseria meningitidis traverses the epithelial barrier without disrupting the junctional structures. We showed that epithelial cells constantly secrete proteases responsible for a rapid processing of C2 fragment, generating a new fragment that does not contain the Arg-rich region, a putative docking domain reported to be essential for C2-mediated toxic effect. Moreover, we found that the C3-convertase of the alternative complement pathway is one of the proteases responsible for this processing. Overall, our data provide new insights on the cleavage of NHBA protein during meningococcal infection. NHBA cleavage may occur at different stages of the infection, and it likely has a different role depending on the environment the bacterium is interacting with.
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7
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Zhang A, Zhao P, Zhu B, Shi F, Xu L, Gao Y, Xie N, Shao Z. Characterization and Distribution of the autB Gene in Neisseria meningitidis. Front Cell Infect Microbiol 2017; 7:436. [PMID: 29057217 PMCID: PMC5635059 DOI: 10.3389/fcimb.2017.00436] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 09/21/2017] [Indexed: 11/16/2022] Open
Abstract
We aimed to investigate and understand the characterization and distribution of the autB gene in Neisseria meningitidis in China. autB is flanked by two conservative genes, smpB and glcD, and it can be present in the majority of meningococcal isolates, but not in 053442 of clonal complex 4821 (CC4821) which contains a 968 bp sequence. In this study, we sequenced the intervenient region between smpB and glcD in 178 Chinese N. meningitidis strains isolated from both patients and carriers. There were 110 serogroupable strains, other 68 were non-groupable (NG). Ninety nine of the 178 strains were clustered into 13 CCs, the remaining 79 were unassigned (UA). CC4821 is one of the dominant CCs in China. Forty of the 42 CC4821 strains and 26 of the 79 UA strains were autB-null, while the remaining 12 CCs were autB-positive. According to the N-terminal sequence, most (97/112) of the autB-positive strains were clustered into AutB1 and the remaining 15 were AutB2. The autB gene and its flanking intergenic sequences was superseded by a perfectly conservative sequence of an identical 968 bp in all of the autB-null N. meningitidis strains which had no identity with the relatively conservative intergenic sequences that flanked the autB gene in autB-positive strains. There was a 10 bp DNA uptake sequence (DUS) at the beginning of the interval 968 bp sequence in the autB-null strains while there was a 9 bp Haemophilus-specific uptake sequence (hUS) at the beginning of the partial holB gene and at the end of the partial tmk gene in autB-positive strains, holB and tmk gene were flanking the autB gene in Haemophilus. In conclusion, not all pathogenic N. meningitidis strains especially CC4821 possess the autB gene in China and the corresponding spacer region of the autB-null strains was not homologous to that found in autB-positive strains. There's a hypothesis that the DUS and hUS are likely to play a key part in the mechanism of uptake or loss of the autB gene.
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Affiliation(s)
- Aiyu Zhang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Pan Zhao
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Bingqing Zhu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Fenglin Shi
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Li Xu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yuan Gao
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Na Xie
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Zhujun Shao
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
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8
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Mirzakhani K, Gargari SLM, Rasooli I, Rasoulinejad S. Development of a DNA Aptamer for Screening Neisseria meningitidis Serogroup B by Cell SELEX. IRANIAN BIOMEDICAL JOURNAL 2017; 22:193-201. [PMID: 28941453 PMCID: PMC5889504 DOI: 10.22034/ibj.22.3.193] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 07/26/2017] [Accepted: 07/30/2017] [Indexed: 02/07/2023]
Abstract
Background Artificial oligonucleotides like DNA or RNA aptamers can be used as biodiagnostic alternatives for antibodies to detect pathogens. Comparing to antibodies, artificial oligonucleotides are produced easily at lower costs and are more stable. Neisseria meningitidis, the causative agent of meningitis, is responsible for about 1% of infections in an epidemic period. Specific DNA aptamers that bind to N. meningitidis serogroup B were identified by whole-cell Systemic Evolution of Ligands by EXponential Enrichment (SELEX). Methods The SELEX begins with a library of labeled ssDNA molecules. After six rounds of selection and two rounds of counter-selection, 60 clones were obtained, of which the binding efficiency of 21 aptamers to the aforementioned bacterium was tested by flow cytometry. Results The aptamers K3 and K4 showed the highest affinity to N. meningitidis serogroup B and no affinity to N. meningitidis serogroups Y, A, and C, or to other meningitis causing bacteria. The dissociation constant (Kd value) for K3 and K4 were calculated as 28.3±8.9 pM and 39.1±8.6 pM, respectively. K3 aptamer with the lowest Kd was chosen as the main aptamer. K3 could detect N. meningitidis in patients’ cerebrospinal fluid (CSF) samples and in CSF from healthy volunteers inoculated with N. meningitidis serogroup B (ATCC 13090) at 200 and 100 CFU ml-1, respectively. Conclusion The findings suggest the application of the developed aptamer in specific detection of N. meningitidis serogroup B amongst a group of meningitis causing bacteria.
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Affiliation(s)
- Kimia Mirzakhani
- Faculty of Medicine, Institute of Human Genetics, Friedrich-Schiller University, Jena, Germany
| | | | - Iraj Rasooli
- Department of Biology, Shahed University, Tehran, Iran
- Molecular Microbiology Research Center, Shahed University, Tehran, Iran
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Tommassen J, Arenas J. Biological Functions of the Secretome of Neisseria meningitidis. Front Cell Infect Microbiol 2017; 7:256. [PMID: 28670572 PMCID: PMC5472700 DOI: 10.3389/fcimb.2017.00256] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 05/29/2017] [Indexed: 11/13/2022] Open
Abstract
Neisseria meningitidis is a Gram-negative bacterial pathogen that normally resides as a commensal in the human nasopharynx but occasionally causes disease with high mortality and morbidity. To interact with its environment, it transports many proteins across the outer membrane to the bacterial cell surface and into the extracellular medium for which it deploys the common and well-characterized autotransporter, two-partner and type I secretion mechanisms, as well as a recently discovered pathway for the surface exposure of lipoproteins. The surface-exposed and secreted proteins serve roles in host-pathogen interactions, including adhesion to host cells and extracellular matrix proteins, evasion of nutritional immunity imposed by iron-binding proteins of the host, prevention of complement activation, neutralization of antimicrobial peptides, degradation of immunoglobulins, and permeabilization of epithelial layers. Furthermore, they have roles in interbacterial interactions, including the formation and dispersal of biofilms and the suppression of the growth of bacteria competing for the same niche. Here, we will review the protein secretion systems of N. meningitidis and focus on the functions of the secreted proteins.
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Affiliation(s)
- Jan Tommassen
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht UniversityUtrecht, Netherlands
| | - Jesús Arenas
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht UniversityUtrecht, Netherlands
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10
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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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11
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Weyand NJ. Neisseria models of infection and persistence in the upper respiratory tract. Pathog Dis 2017; 75:3078547. [DOI: 10.1093/femspd/ftx031] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 03/15/2017] [Indexed: 12/15/2022] Open
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Pérez-Ortega J, Rodríguez A, Ribes E, Tommassen J, Arenas J. Interstrain Cooperation in Meningococcal Biofilms: Role of Autotransporters NalP and AutA. Front Microbiol 2017; 8:434. [PMID: 28382026 PMCID: PMC5360712 DOI: 10.3389/fmicb.2017.00434] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 03/02/2017] [Indexed: 12/18/2022] Open
Abstract
Neisseria meningitidis (Nm) and Neisseria lactamica (Nl) are commensal bacteria that live in the human nasopharynx, where they form microcolonies. In contrast to Nl, Nm occasionally causes blood and/or meningitis infection with often fatal consequences. Here, we studied interactions between neisserial strains during biofilm formation. Fluorescent strains were engineered and analyzed for growth in single- and dual-strain biofilms with confocal laser-scanning microscopy. Different strains of diverse Neisseria species formed microcolonies of different sizes and morphologies. Pair-wise combinations of two invasive Nm strains and one Nm carrier isolate showed that these strains can coexist in spite of the fact that they produce toxins to combat congeners. This lack of competition was even observed when the biofilms were formed under nutrient limitation and can be explained by the observation that the separate microcolonies within mixed biofilms are mostly lineage specific. However, these microcolonies showed different levels of interaction. The coexistence of two strains was also observed in mixed biofilms of Nm and Nl strains. Inactivation of the autotransporter NalP, which prevents the release of the heparin-binding antigen NHBA and the α-peptide of IgA protease from the cell surface, and/or the production of autotransporter AutA increased interactions between microcolonies, as evidenced by close contacts between microcolonies on the substratum. Qualitative and quantitative analysis revealed an altered spatial distribution of each strain in mixed biofilms with consequences for the biomass, biofilm architecture and bacterial viability depending on the synthesis of NalP and AutA, the expression of which is prone to phase variation. Being in a consortium resulted in some cases in commensalism and cooperative behavior, which promoted attachment to the substratum or increased survival, possibly as result of the shared use of the biofilm matrix. We hypothesize that Nm strains can cooperate during host colonization, but, possibly, the different capacities of the microcolonies of each strain to resist the host's defenses limits the long-term coexistence of strains in the host.
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Affiliation(s)
- Jesús Pérez-Ortega
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
| | - Antonio Rodríguez
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
| | - Eduardo Ribes
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
| | - Jan Tommassen
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
| | - Jesús Arenas
- Section Molecular Microbiology, Department of Biology, Utrecht University Utrecht, Netherlands
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13
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Arenas J, Tommassen J. Meningococcal Biofilm Formation: Let's Stick Together. Trends Microbiol 2017; 25:113-124. [DOI: 10.1016/j.tim.2016.09.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 09/13/2016] [Accepted: 09/16/2016] [Indexed: 11/26/2022]
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15
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Arenas J, Paganelli FL, Rodríguez-Castaño P, Cano-Crespo S, van der Ende A, van Putten JPM, Tommassen J. Expression of the Gene for Autotransporter AutB of Neisseria meningitidis Affects Biofilm Formation and Epithelial Transmigration. Front Cell Infect Microbiol 2016; 6:162. [PMID: 27921012 PMCID: PMC5118866 DOI: 10.3389/fcimb.2016.00162] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/07/2016] [Indexed: 11/15/2022] Open
Abstract
Neisseria meningitidis is a Gram-negative bacterium that resides as a commensal in the upper respiratory tract of humans, but occasionally, it invades the host and causes sepsis and/or meningitis. The bacterium can produce eight autotransporters, seven of which have been studied to some detail. The remaining one, AutB, has not been characterized yet. Here, we show that the autB gene is broadly distributed among pathogenic Neisseria spp. The gene is intact in most meningococcal strains. However, its expression is prone to phase variation due to slipped-strand mispairing at AAGC repeats located within the DNA encoding the signal sequence and is switched off in the vast majority of these strains. Moreover, various genetic disruptions prevent autB expression in most of the strains in which the gene is in phase indicating a strong selection against AutB synthesis. We observed that autB is expressed in two of the strains examined and that AutB is secreted and exposed at the cell surface. Functionality assays revealed that AutB synthesis promotes biofilm formation and delays the passage of epithelial cell layers in vitro. We hypothesize that this autotransporter is produced during the colonization process only in specific niches to facilitate microcolony formation, but its synthesis is switched off probably to evade the immune system and facilitate human tissue invasion.
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Affiliation(s)
- Jesús Arenas
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University Utrecht, Netherlands
| | - Fernanda L Paganelli
- Department of Medical Microbiology, University Medical Center Utrecht Utrecht, Netherlands
| | - Patricia Rodríguez-Castaño
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University Utrecht, Netherlands
| | - Sara Cano-Crespo
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University Utrecht, Netherlands
| | - Arie van der Ende
- Department of Medical Microbiology, Academic Medical Center Amsterdam, Netherlands
| | - Jos P M van Putten
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University Utrecht, Netherlands
| | - Jan Tommassen
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University Utrecht, Netherlands
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Agier L, Martiny N, Thiongane O, Mueller JE, Paireau J, Watkins ER, Irving TJ, Koutangni T, Broutin H. Towards understanding the epidemiology of Neisseria meningitidis in the African meningitis belt: a multi-disciplinary overview. Int J Infect Dis 2016; 54:103-112. [PMID: 27826113 DOI: 10.1016/j.ijid.2016.10.032] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/21/2016] [Accepted: 10/29/2016] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVES Neisseria meningitidis is the major cause of seasonal meningitis epidemics in the African meningitis belt. In the changing context of a reduction in incidence of serogroup A and an increase in incidence of serogroups W and C and of Streptococcus pneumoniae, a better understanding of the determinants driving the disease transmission dynamics remains crucial to improving bacterial meningitis control. METHODS The literature was searched to provide a multi-disciplinary overview of the determinants of meningitis transmission dynamics in the African meningitis belt. RESULTS Seasonal hyperendemicity is likely predominantly caused by increased invasion rates, sporadic localized epidemics by increased transmission rates, and larger pluri-annual epidemic waves by changing population immunity. Carriage likely involves competition for colonization and cross-immunity. The duration of immunity likely depends on the acquisition type. Major risk factors include dust and low humidity, and presumably human contact rates and co-infections; social studies highlighted environmental and dietary factors, with supernatural explanations. CONCLUSIONS Efforts should focus on implementing multi-country, longitudinal seroprevalence and epidemiological studies, validating immune markers of protection, and improving surveillance, including more systematic molecular characterizations of the bacteria. Integrating climate and social factors into disease control strategies represents a high priority for optimizing the public health response and anticipating the geographic evolution of the African meningitis belt.
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Affiliation(s)
- Lydiane Agier
- Combining Health Information, Computation and Statistics, Lancaster Medical School, Lancaster University, Lancaster, UK.
| | - Nadège Martiny
- Centre de Recherches de Climatologie (CRC), UMR 6282 CNRS Biogeosciences, Université de Bourgogne, Dijon, France
| | - Oumy Thiongane
- Institut de Recherche pour le Développement, UMR INTERTRYP IRD-CIRAD, Antenne IRD Bobo Dioulasso, Bobo, Burkina Faso
| | - Judith E Mueller
- EHESP French School of Public Health, Sorbonne Paris Cité, Rennes, France; Unité de l'Epidémiologie des Maladies Emergentes, Institut Pasteur, Paris, France
| | - Juliette Paireau
- Unité de l'Epidémiologie des Maladies Emergentes, Institut Pasteur, Paris, France; Department of Ecology and Evolutionary Biology, Princeton Environmental Institute, Princeton University, Princeton, New Jersey, USA
| | | | - Tom J Irving
- School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - Thibaut Koutangni
- EHESP French School of Public Health, Sorbonne Paris Cité, Rennes, France; Unité de l'Epidémiologie des Maladies Emergentes, Institut Pasteur, Paris, France
| | - Hélène Broutin
- MIVEGEC, UMR 590CNRS/224IRD/UM, Montpellier, France; Service de Parasitologie-Mycologie, Faculté de Médecine, Université Cheikh Anta Diop, Fann, Dakar, Senegal
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Loh E, Lavender H, Tan F, Tracy A, Tang CM. Thermoregulation of Meningococcal fHbp, an Important Virulence Factor and Vaccine Antigen, Is Mediated by Anti-ribosomal Binding Site Sequences in the Open Reading Frame. PLoS Pathog 2016; 12:e1005794. [PMID: 27560142 PMCID: PMC4999090 DOI: 10.1371/journal.ppat.1005794] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 07/07/2016] [Indexed: 12/13/2022] Open
Abstract
During colonisation of the upper respiratory tract, bacteria are exposed to gradients of temperatures. Neisseria meningitidis is often present in the nasopharynx of healthy individuals, yet can occasionally cause severe disseminated disease. The meningococcus can evade the human complement system using a range of strategies that include recruitment of the negative complement regulator, factor H (CFH) via factor H binding protein (fHbp). We have shown previously that fHbp levels are influenced by the ambient temperature, with more fHbp produced at higher temperatures (i.e. at 37°C compared with 30°C). Here we further characterise the mechanisms underlying thermoregulation of fHbp, which occurs gradually over a physiologically relevant range of temperatures. We show that fHbp thermoregulation is not dependent on the promoters governing transcription of the bi- or mono-cistronic fHbp mRNA, or on meningococcal specific transcription factors. Instead, fHbp thermoregulation requires sequences located in the translated region of the mono-cistronic fHbp mRNA. Site-directed mutagenesis demonstrated that two anti-ribosomal binding sequences within the coding region of the fHbp transcript are involved in fHbp thermoregulation. Our results shed further light on mechanisms underlying the control of the production of this important virulence factor and vaccine antigen. The bacterium Neisseria meningitidis is exquisitely adapted to survive in the human host, and possesses several mechanisms to interact with host cells in the upper airway and to circumvent immune responses. However, the mechanisms that govern the expression of factors that contribute to colonisation and disease are incompletely understood. In this work, we further characterise how temperature influences the production of factor H binding protein (fHbp) by the meningococcus; fHbp recruits human complement proteins to the surface of the bacterium, and is an important vaccine antigen. We show that thermoregulation of fHbp occurs gradually over a physiological range of temperatures found in the upper airway, the site of colonisation. This regulation does not require specific meningococcal transcription factors, and sequence analysis indicates that fHbp mRNA forms a secondary structure which could act as an RNA thermosensor. Additional studies demonstrate that there are two specific sequences within the coding region of fHbp mRNA are important for thermosensing and could base-pair to the ribosome binding site, thus blocking translation of this protein. As fHbp is thermoregulated, vaccines that target this antigen might not impose a high level of selective pressure on the bacterium at the mucosal surface, thereby limiting herd immunity induce by fHbp containing vaccines.
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Affiliation(s)
- Edmund Loh
- 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
| | - Felicia Tan
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Alexander Tracy
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Christoph M. Tang
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- * E-mail:
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18
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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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Cleary PR, Calvert N, Gee S, Graham C, Gray S, Kaczmarski E, Morphet J, Murphy L, Verlander N, Wood T, Borrow R. Variations in Neisseria meningitidis carriage by socioeconomic status: a cross-sectional study. J Public Health (Oxf) 2015; 38:61-70. [PMID: 25742719 DOI: 10.1093/pubmed/fdv015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Deprivation is associated with an increased risk of invasive Neisseria meningitidis disease, but little is known about the relationship between deprivation and asymptomatic carriage of N. meningitidis. This analysis was conducted to examine the relationship between meningococcal carriage and deprivation. METHODS As part of a rapid meningococcal carriage prevalence study conducted in West Cumbria to investigate an apparent cluster of invasive meningococcal disease, data were collected on lifestyle and social factors, including area-level indicators of socioeconomic status, to identify factors associated with meningococcal carriage. RESULTS In a multivariable log binomial regression model adjusted for age, lower socioeconomic status was significantly associated with higher prevalence of meningococcal carriage. A 1-unit increase in Index of Multiple Deprivation (2010) score was associated with a 1.7% increase in meningococcal carriage prevalence (95% confidence interval 0.3-3.0%). Age was the only significant predictor of carriage of Neisseria lactamica. CONCLUSIONS Living in a deprived area is associated with increased carriage of Group B meningococcus. Deprivation is an important factor to consider in the evaluation of the effectiveness and cost-effectiveness of the introduction of new meningococcal B vaccines and the development and implementation of immunization policies. Further work is required to understand whether deprivation has an effect on meningococcal carriage through other factors such as smoking.
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Affiliation(s)
- P R Cleary
- PHE Field Epidemiology Service, Liverpool L1 1JF, UK
| | - N Calvert
- NHS Cumbria, Penrith, Cumbria CA11 8HX, UK
| | - S Gee
- Cumbria and Lancashire Public Health England Centre, Chorley PR7 1NY, UK
| | - C Graham
- North Cumbria University Hospitals Whitehaven, Cumbria CA28 8JG, UK
| | - S Gray
- PHE Meningococcal Reference Unit, Public Health England (PHE), Manchester M13 9WL, UK
| | - E Kaczmarski
- PHE Meningococcal Reference Unit, Public Health England (PHE), Manchester M13 9WL, UK
| | - J Morphet
- NHS Cumbria, Penrith, Cumbria CA11 8HX, UK
| | - L Murphy
- NHS Cumbria, Penrith, Cumbria CA11 8HX, UK
| | - N Verlander
- Public Health England Centre for Infection Disease Surveillance and Control, London NW9 5EQ, UK
| | - T Wood
- Cumbria and Lancashire Public Health England Centre, Chorley PR7 1NY, UK
| | - R Borrow
- PHE Meningococcal Reference Unit, Public Health England (PHE), Manchester M13 9WL, UK
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20
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Abstract
The exclusive reservoir of the genus Neisseria is the human. Of the broad range of species that comprise the Neisseria, only two are frequently pathogenic, and only one of those is a resident of the nasopharynx. Although Neisseria meningitidis can cause severe disease if it invades the bloodstream, the vast majority of interactions between humans and Neisseria are benign, with the bacteria inhabiting its mucosal niche as a non-invasive commensal. Understandably, with the exception of Neisseria gonorrhoeae, which preferentially colonises the urogenital tract, the neisseriae are extremely well adapted to survival in the human nasopharynx, their sole biological niche. The purpose of this review is to provide an overview of the molecular mechanisms evolved by Neisseria to facilitate colonisation and survival within the nasopharynx, focussing on N. meningitidis. The organism has adapted to survive in aerosolised transmission and to attach to mucosal surfaces. It then has to replicate in a nutrition-poor environment and resist immune and competitive pressure within a polymicrobial complex. Temperature and relative gas concentrations (nitric oxide and oxygen) are likely to be potent initial signals of arrival within the nasopharyngeal environment, and this review will focus on how N. meningitidis responds to these to increase the likelihood of its survival.
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Asmat TM, Tenenbaum T, Jonsson AB, Schwerk C, Schroten H. Impact of calcium signaling during infection of Neisseria meningitidis to human brain microvascular endothelial cells. PLoS One 2014; 9:e114474. [PMID: 25464500 PMCID: PMC4252121 DOI: 10.1371/journal.pone.0114474] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 11/10/2014] [Indexed: 01/08/2023] Open
Abstract
The pili and outer membrane proteins of Neisseria meningitidis (meningococci) facilitate bacterial adhesion and invasion into host cells. In this context expression of meningococcal PilC1 protein has been reported to play a crucial role. Intracellular calcium mobilization has been implicated as an important signaling event during internalization of several bacterial pathogens. Here we employed time lapse calcium-imaging and demonstrated that PilC1 of meningococci triggered a significant increase in cytoplasmic calcium in human brain microvascular endothelial cells, whereas PilC1-deficient meningococci could not initiate this signaling process. The increase in cytosolic calcium in response to PilC1-expressing meningococci was due to efflux of calcium from host intracellular stores as demonstrated by using 2-APB, which inhibits the release of calcium from the endoplasmic reticulum. Moreover, pre-treatment of host cells with U73122 (phospholipase C inhibitor) abolished the cytosolic calcium increase caused by PilC1-expressing meningococci demonstrating that active phospholipase C (PLC) is required to induce calcium transients in host cells. Furthermore, the role of cytosolic calcium on meningococcal adherence and internalization was documented by gentamicin protection assay and double immunofluorescence (DIF) staining. Results indicated that chelation of intracellular calcium by using BAPTA-AM significantly impaired PilC1-mediated meningococcal adherence to and invasion into host endothelial cells. However, buffering of extracellular calcium by BAPTA or EGTA demonstrated no significant effect on meningococcal adherence to and invasion into host cells. Taken together, these results indicate that meningococci induce calcium release from intracellular stores of host endothelial cells via PilC1 and cytoplasmic calcium concentrations play a critical role during PilC1 mediated meningococcal adherence to and subsequent invasion into host endothelial cells.
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Affiliation(s)
- Tauseef M. Asmat
- Department of Pediatrics, Pediatric Infectious Diseases, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- * E-mail:
| | - Tobias Tenenbaum
- Department of Pediatrics, Pediatric Infectious Diseases, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Ann-Beth Jonsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Christian Schwerk
- Department of Pediatrics, Pediatric Infectious Diseases, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Horst Schroten
- Department of Pediatrics, Pediatric Infectious Diseases, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Arenas J, Cano S, Nijland R, van Dongen V, Rutten L, van der Ende A, Tommassen J. The meningococcal autotransporter AutA is implicated in autoaggregation and biofilm formation. Environ Microbiol 2014; 17:1321-37. [PMID: 25059714 DOI: 10.1111/1462-2920.12581] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 07/22/2014] [Indexed: 11/29/2022]
Abstract
Autotransporters (ATs) are proteins secreted by Gram-negative bacteria that often play a role in virulence. Eight different ATs have been identified in Neisseria meningitidis, but only six of them have been characterized. AutA is one of the remaining ATs. Its expression remains controversial. Here, we show that the autA gene is present in many neisserial species, but its expression is often disrupted by various genetic features; however, it is expressed in certain strains of N. meningitidis. By sequencing the autA gene in large panels of disease isolates and Western blot analysis, we demonstrated that AutA expression is prone to phase variation at AAGC nucleotide repeats located within the DNA encoding the signal sequence. AutA is not secreted into the extracellular medium, but remains associated with the bacterial cell surface. We further demonstrate that AutA expression induces autoaggregation in a process that, dependent on the particular strain, may require extracellular DNA (eDNA). This property influences the organization of bacterial communities like lattices and biofilms. In vitro assays evidenced that AutA is a self-associating AT that binds DNA. We suggest that AutA-mediated autoaggregation might be particularly important for colonization and persistence of the pathogen in the nasopharynx of the host.
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Affiliation(s)
- Jesús Arenas
- Department of Molecular Microbiology and Institute of Biomembranes, Utrecht University, Paudalaan 8, Utrecht, 3584 CH, The Netherlands
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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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Catenazzi MCE, Jones H, Wallace I, Clifton J, Chong JPJ, Jackson MA, Macdonald S, Edwards J, Moir JWB. A large genomic island allows Neisseria meningitidis to utilize propionic acid, with implications for colonization of the human nasopharynx. Mol Microbiol 2014; 93:346-55. [PMID: 24910087 PMCID: PMC4441257 DOI: 10.1111/mmi.12664] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2014] [Indexed: 01/01/2023]
Abstract
Neisseria meningitidis is an important human pathogen that is capable of killing within hours of infection. Its normal habitat is the nasopharynx of adult humans. Here we identify a genomic island (the prp gene cluster) in N. meningitidis that enables this species to utilize propionic acid as a supplementary carbon source during growth, particularly under nutrient poor growth conditions. The prp gene cluster encodes enzymes for a methylcitrate cycle. Novel aspects of the methylcitrate cycle in N. meningitidis include a propionate kinase which was purified and characterized, and a putative propionate transporter. This genomic island is absent from the close relative of N. meningitidis, the commensal Neisseria lactamica, which chiefly colonizes infants not adults. We reason that the possession of the prp genes provides a metabolic advantage to N. meningitidis in the adult oral cavity, which is rich in propionic acid-generating bacteria. Data from classical microbiological and sequence-based microbiome studies provide several lines of supporting evidence that N. meningitidis colonization is correlated with propionic acid generating bacteria, with a strong correlation between prp-containing Neisseria and propionic acid generating bacteria from the genus Porphyromonas, and that this may explain adolescent/adult colonization by N. meningitidis.
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Soriano-Gabarró M, Wolter J, Hogea C, Vyse A. Carriage ofNeisseria meningitidisin Europe: a review of studies undertaken in the region. Expert Rev Anti Infect Ther 2014; 9:761-74. [DOI: 10.1586/eri.11.89] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Basta NE, Stuart JM, Nascimento MC, Manigart O, Trotter C, Hassan-King M, Chandramohan D, Sow SO, Berthe A, Bedru A, Tekletsion YK, Collard JM, Jusot JF, Diallo A, Basséne H, Daugla DM, Gamougam K, Hodgson A, Forgor AA, Omotara BA, Gadzama GB, Watkins ER, Rebbetts LS, Diallo K, Weiss NS, Halloran ME, Maiden MCJ, Greenwood B. Methods for identifying Neisseria meningitidis carriers: a multi-center study in the African meningitis belt. PLoS One 2013; 8:e78336. [PMID: 24194921 PMCID: PMC3806823 DOI: 10.1371/journal.pone.0078336] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 09/19/2013] [Indexed: 11/21/2022] Open
Abstract
Objective Detection of meningococcal carriers is key to understanding the epidemiology of Neisseria meningitidis, yet no gold standard has been established. Here, we directly compare two methods for collecting pharyngeal swabs to identify meningococcal carriers. Methods We conducted cross-sectional surveys of schoolchildren at multiple sites in Africa to compare swabbing the posterior pharynx behind the uvula (U) to swabbing the posterior pharynx behind the uvula plus one tonsil (T). Swabs were cultured immediately and analyzed using molecular methods. Results One thousand and six paired swab samples collected from schoolchildren in four countries were analyzed. Prevalence of meningococcal carriage was 6.9% (95% CI: 5.4-8.6%) based on the results from both swabs, but the observed prevalence was lower based on one swab type alone. Prevalence based on the T swab or the U swab alone was similar (5.2% (95% CI: 3.8-6.7%) versus 4.9% (95% CI: 3.6-6.4%) respectively (p=0.6)). The concordance between the two methods was 96.3% and the kappa was 0.61 (95% CI: 0.50-0.73), indicating good agreement. Conclusions These two commonly used methods for collecting pharyngeal swabs provide consistent estimates of the prevalence of carriage, but both methods misclassified carriers to some degree, leading to underestimates of the prevalence.
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Affiliation(s)
- Nicole E. Basta
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
- Research and Policy for Infectious Disease Dynamics, Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- * E-mail:
| | - James M. Stuart
- Faculty of Infectious and Tropical Diseases, Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Maria C. Nascimento
- Faculty of Infectious and Tropical Diseases, Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Olivier Manigart
- Faculty of Infectious and Tropical Diseases, Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Caroline Trotter
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Musa Hassan-King
- Faculty of Infectious and Tropical Diseases, Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Daniel Chandramohan
- Faculty of Infectious and Tropical Diseases, Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Samba O. Sow
- Centre pour le Développement des Vaccins, Bamako, Mali
| | | | - Ahmed Bedru
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Yenenesh K. Tekletsion
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | | | | | - Aldiouma Diallo
- Instiutut de Recherche pour le Développement, Dakar, Senegal
| | - Hubert Basséne
- Instiutut de Recherche pour le Développement, Dakar, Senegal
| | | | | | - Abraham Hodgson
- Research and Development Division, Ghana Health Service, Accra, Ghana
| | | | - Babatunji A. Omotara
- Department of Community Medicine, University of Maiduguri, Maiduguri, Borno State, Nigeria
| | - Galadima B. Gadzama
- Department of Medical Microbiology, University of Maiduguri, Maiduguri, Borno State, Nigeria
| | | | - Lisa S. Rebbetts
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Kanny Diallo
- Centre pour le Développement des Vaccins, Bamako, Mali
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Noel S. Weiss
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Epidemiology, School of Public Health, University of Washington, Seattle, Washington, United States of America
| | - M. Elizabeth Halloran
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Biostatistics, School of Public Health, University of Washington, Seattle, Washington, United States of America
| | | | - Brian Greenwood
- Faculty of Infectious and Tropical Diseases, Department of Disease Control, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Arenas J, Schipper K, van Ulsen P, van der Ende A, Tommassen J. Domain exchange at the 3' end of the gene encoding the fratricide meningococcal two-partner secretion protein A. BMC Genomics 2013; 14:622. [PMID: 24034852 PMCID: PMC3848433 DOI: 10.1186/1471-2164-14-622] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 09/13/2013] [Indexed: 02/01/2023] Open
Abstract
Background Two-partner secretion systems in Gram-negative bacteria consist of an outer membrane protein TpsB that mediates the secretion of a cognate TpsA protein into the extracellular milieu. TpsA proteins have diverse, often virulence-related functions, and some of them inhibit the growth of related bacteria. In Neisseria meningitidis, several functions have been attributed to the TpsA proteins. Downstream of the tpsB and tpsA genes, several shorter tpsA-related gene cassettes, called tpsC, are located interspersed with intervening open-reading frames (IORFs). It has been suggested that the tpsC cassettes may recombine with the tpsA gene as a mechanism of antigenic variation. Here, we investigated (i) whether TpsA of N. meningitidis also has growth-inhibitory properties, (ii) whether tpsC cassettes recombine with the tpsA gene, and (iii) what the consequences of such recombination events might be. Results We demonstrate that meningococcal TpsA has growth-inhibitory properties and that the IORF located immediately downstream of tpsA confers immunity to the producing strain. Although bioinformatics analysis suggests that recombination between tpsC cassettes and tpsA occurs, detailed analysis of the tpsA gene in a large collection of disease isolates of three clonal complexes revealed that the frequency is very low and cannot be a mechanism of antigenic variation. However, recombination affected growth inhibition. In vitro experiments revealed that recombination can be mediated through acquirement of tpsC cassettes from the environment and it identified the regions involved in the recombination. Conclusions Meningococcal TpsA has growth-inhibitory properties. Recombination between tpsA and tpsC cassettes occurs in vivo but is rare and has consequences for growth inhibition. A recombination model is proposed and we propose that the main goal of recombination is the collection of new IORFs for protection against a variety of TpsA proteins.
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Affiliation(s)
- Jesús Arenas
- Department of Molecular Microbiology, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands.
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Grijpstra J, Arenas J, Rutten L, Tommassen J. Autotransporter secretion: varying on a theme. Res Microbiol 2013; 164:562-82. [PMID: 23567321 DOI: 10.1016/j.resmic.2013.03.010] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 02/28/2013] [Indexed: 10/27/2022]
Abstract
Autotransporters are widely distributed among Gram-negative bacteria. They can have a large variety of functions and many of them have a role in virulence. They are synthesized as large precursors with an N-terminal signal sequence that mediates transport across the inner membrane via the Sec machinery and a translocator domain that mediates the transport of the connected passenger domain across the outer membrane to the bacterial cell surface. Like integral outer membrane proteins, the translocator domain folds in a β-barrel structure and requires the Bam machinery for its insertion into the outer membrane. After transport across the outer membrane, the passenger may stay connected via the translocator domain to the bacterial cell surface or it is proteolytically released into the extracellular milieu. Based on the size of the translocator domain and its position relative to the passenger in the precursor, autotransporters are divided into four sub-categories. We review here the current knowledge of the biogenesis, structure and function of various autotransporters.
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Affiliation(s)
- Jan Grijpstra
- Section Molecular Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
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Clarke ET, Williams NA, Dull PM, Findlow J, Borrow R, Finn A, Heyderman RS. Polysaccharide-protein conjugate vaccination induces antibody production but not sustained B-cell memory in the human nasopharyngeal mucosa. Mucosal Immunol 2013; 6:288-96. [PMID: 22806100 DOI: 10.1038/mi.2012.70] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Colonization of the nasopharyngeal mucosa by meningococcus and other polysaccharide (PS)-encapsulated bacteria precedes invasion. PS-conjugate vaccines induce PS-specific B-cell memory (B(MEM)) and also prevent colonization, thus blocking person-to-person transmission, generating herd protection. However, in isolation the B(MEM) are unable to sustain immunity. Furthermore, the duration of herd protection the vaccines induce appears limited. We demonstrate that, despite the persistence of PS-specific B(MEM), the population is not maintained within the nasopharynx. Although booster immunization results in the transient appearance of PS-specific B(MEM) within the mucosa, this reflects the re-circulation of systemic B(MEM) through the site rather than the generation of resident mucosal B(MEM). The induction of sustained PS-specific B(MEM) in the nasopharynx would allow the population to be activated by colonization, thus inhibiting subsequent invasion. It would also be expected to boost local mucosal immunity, thus extending herd protection. Strategies to generate PS-specific B(MEM) in the mucosa warrant further investigation.
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Affiliation(s)
- E T Clarke
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK.
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Arenas J, Nijland R, Rodriguez FJ, Bosma TNP, Tommassen J. Involvement of three meningococcal surface-exposed proteins, the heparin-binding protein NhbA, the α-peptide of IgA protease and the autotransporter protease NalP, in initiation of biofilm formation. Mol Microbiol 2012; 87:254-68. [DOI: 10.1111/mmi.12097] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2012] [Indexed: 11/28/2022]
Affiliation(s)
- Jesús Arenas
- Department of Molecular Microbiology and Institute of Biomembranes; Utrecht University; Padualaan 8; 3584 CH; Utrecht; the Netherlands
| | - Reindert Nijland
- Department of Medical Microbiology,; University Medical Center Utrecht; Heidelberglaan 100, G04.614; 3584 CX; Utrecht; the Netherlands
| | - Francisco J. Rodriguez
- Department of Molecular Microbiology and Institute of Biomembranes; Utrecht University; Padualaan 8; 3584 CH; Utrecht; the Netherlands
| | - Tom N. P. Bosma
- Department of Earth Sciences; Utrecht University; 3584 CD; Utrecht; the Netherlands
| | - Jan Tommassen
- Department of Molecular Microbiology and Institute of Biomembranes; Utrecht University; Padualaan 8; 3584 CH; Utrecht; the Netherlands
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Abstract
Microbial adhesion is generally a complex process, involving multiple adhesins on a single microbe and their respective target receptors on host cells. In some situations, various adhesins of a microbe may co-operate in an apparently hierarchical and sequential manner whereby the first adhesive event triggers the target cell to express receptors for additional microbial adhesins. In other instances, adhesins may act in concert leading to high avidity interactions, often a prelude to cellular invasion and tissue penetration. Mechanisms used to target the host include both lectin-like interactions and protein-protein interactions; the latter are often highly specific for the host or a tissue within the host. This reflective chapter aims to offer a point of view on microbial adhesion by presenting some experiences and thoughts especially related to respiratory pathogens and explore if there can be any future hope of controlling bacterial infections via preventing adhesion or invasion stages of microbial pathogenesis.
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Laboratory quality control in a multicentre meningococcal carriage study in Burkina Faso. Trans R Soc Trop Med Hyg 2012; 106:289-97. [DOI: 10.1016/j.trstmh.2011.12.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 09/21/2011] [Accepted: 12/20/2011] [Indexed: 11/20/2022] Open
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Abstract
Neisseria meningitidisis an organism whose environmental niche is limited to the human host. It can frequently colonize the human nasopharynx and has the ability to cause severe systemic infections. These infections can be sporadic, endemic or occur in outbreaks associated with more virulent meningococcal strains. Studies have demonstrated that the meningococcus can form biofilms both in vivo and ex vivo. In this chapter, we discuss methods to establish biofilms in the laboratory for in-depth biochemical, genetic, or microscopic studies.
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Affiliation(s)
- Michael A Apicella
- The Department of Microbiology, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA.
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Trivedi K, Tang CM, Exley RM. Mechanisms of meningococcal colonisation. Trends Microbiol 2011; 19:456-63. [PMID: 21816616 DOI: 10.1016/j.tim.2011.06.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 06/16/2011] [Accepted: 06/28/2011] [Indexed: 01/05/2023]
Abstract
Despite advances against infectious diseases over the past century, Neisseria meningitidis remains a major causative agent of meningitis and septicaemia worldwide. Its adaptation for survival in the human nasopharynx makes the meningococcus a highly successful commensal bacterium. Recent progress has been made in understanding the mechanisms that enable neisserial colonisation, in terms of the role of type IV pili, the impact of other adhesins, biofilm formation, nutrient acquisition and resistance to host immune defences. Refinements in cell-based and in vivo models will lead to improved understanding of the colonisation process, and hopefully to more effective vaccines and therapeutic strategies.
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Affiliation(s)
- Kaushali Trivedi
- Centre for Molecular Microbiology and Infection, Faculty of Medicine, Flowers Building, Imperial College London, London SW7 2AZ, UK
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35
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Sanders MS, van Well GTJ, Ouburg S, Morré SA, van Furth AM. Genetic variation of innate immune response genes in invasive pneumococcal and meningococcal disease applied to the pathogenesis of meningitis. Genes Immun 2011; 12:321-34. [DOI: 10.1038/gene.2011.20] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Tezera LB, Hampton J, Jackson SK, Davenport V. Neisseria lactamica attenuates TLR-1/2-induced cytokine responses in nasopharyngeal epithelial cells using PPAR-γ. Cell Microbiol 2011; 13:554-68. [DOI: 10.1111/j.1462-5822.2010.01554.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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van Alen T, Claus H, Zahedi RP, Groh J, Blazyca H, Lappann M, Sickmann A, Vogel U. Comparative proteomic analysis of biofilm and planktonic cells of Neisseria meningitidis. Proteomics 2010; 10:4512-21. [PMID: 21136603 DOI: 10.1002/pmic.201000267] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Neisseria meningitidis is a commensal of the human nasopharynx occasionally causing invasive disease. In vitro biofilms have been employed to model meningococcal carriage. A proteomic analysis of meningococcal biofilms was conducted and metabolic changes related to oxygen and nutrient limitation and upregulation of proteins involved in ROS defense were observed. The upregulated MntC which protects against ROS was shown to be required for meningococcal biofilm formation, but not for planktonic growth. ROS-induced proteomic changes might train the biofilm to cope with immune effectors.
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Affiliation(s)
- Tessa van Alen
- Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
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Transcellular passage of Neisseria meningitidis across a polarized respiratory epithelium. Infect Immun 2010; 78:3832-47. [PMID: 20584970 DOI: 10.1128/iai.01377-09] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Neisseria meningitidis is a major cause of sepsis and meningitis but is also a common commensal, present in the nasopharynx of between 8 and 20% of healthy individuals. During carriage, the bacterium is found on the surface of the nasopharyngeal epithelium and in deeper tissues, while to develop disease the meningococcus must spread across the respiratory epithelium and enter the systemic circulation. Therefore, investigating the pathways by which N. meningitidis crosses the epithelial barrier is relevant for understanding carriage and disease but has been hindered by the lack of appropriate models. Here, we have established a physiologically relevant model of the upper respiratory epithelial cell barrier to investigate the mechanisms responsible for traversal of N. meningitidis. Calu-3 human respiratory epithelial cells were grown on permeable cell culture membranes to form polarized monolayers of cells joined by tight junctions. We show that the meningococcus crosses the epithelial cell barrier by a transcellular route; traversal of the layer did not disrupt its integrity, and bacteria were detected within the cells of the monolayer. We demonstrate that successful traversal of the epithelial cell barrier by N. meningitidis requires expression of its type 4 pili (Tfp) and capsule and is dependent on the host cell microtubule network. The Calu-3 model should be suitable for dissecting the pathogenesis of infections caused by other respiratory pathogens, as well as the meningococcus.
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Biofilm formation by the human pathogen Neisseria meningitidis. Med Microbiol Immunol 2010; 199:173-83. [PMID: 20376486 DOI: 10.1007/s00430-010-0149-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Indexed: 10/19/2022]
Abstract
The past decade has seen an increasing interest in biofilm formation by Neisseria meningitidis, a human facultative pathogen causing life-threatening childhood disease commencing from asymptomatic nasopharyngeal colonization. Studying the biology of in vitro biofilm formation improves the understanding of inter-bacterial processes in asymptomatic carriage, of bacterial aggregate formation on host cells, and of meningococcal population biology. This paper reviews publications referring to meningococcal biofilm formation with an emphasis on the role of motility and of extracellular DNA. The theory of sub-dividing the meningococcal population in settler and spreader lineages is discussed, which provides a mechanistic framework for the assumed balance of colonization efficacy and transmission frequency.
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Lappann M, Claus H, van Alen T, Harmsen M, Elias J, Molin S, Vogel U. A dual role of extracellular DNA during biofilm formation ofNeisseria meningitidis. Mol Microbiol 2010; 75:1355-71. [DOI: 10.1111/j.1365-2958.2010.07054.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
The human species is the only natural host of Neisseria meningitidis, an important cause of bacterial meningitis globally, and, despite its association with devastating diseases, N. meningitidis is a commensal organism found frequently in the respiratory tract of healthy individuals. To date, antibiotic resistance is relatively uncommon in N. meningitidis isolates but, due to the rapid onset of disease in susceptible hosts, the mortality rate remains approx. 10%. Additionally, patients who survive meningococcal disease often endure numerous debilitating sequelae. N. meningitidis strains are classified primarily into serogroups based on the type of polysaccharide capsule expressed. In total, 13 serogroups have been described; however, the majority of disease is caused by strains belonging to one of only five serogroups. Although vaccines have been developed against some of these, a universal meningococcal vaccine remains a challenge due to successful immune evasion strategies of the organism, including mimicry of host structures as well as frequent antigenic variation. N. meningitidis express a range of virulence factors including capsular polysaccharide, lipopolysaccharide and a number of surface-expressed adhesive proteins. Variation of these surface structures is necessary for meningococci to evade killing by host defence mechanisms. Nonetheless, adhesion to host cells and tissues needs to be maintained to enable colonization and ensure bacterial survival in the niche. The aims of the present review are to provide a brief outline of meningococcal carriage, disease and burden to society. With this background, we discuss several bacterial strategies that may enable its survival in the human respiratory tract during colonization and in the blood during infection. We also examine several known meningococcal adhesion mechanisms and conclude with a section on the potential processes that may operate in vivo as meningococci progress from the respiratory niche through the blood to reach the central nervous system.
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van Putten J, Tønjum T. Neisseria. Infect Dis (Lond) 2010. [DOI: 10.1016/b978-0-323-04579-7.00168-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Neil RB, Apicella MA. Clinical and laboratory evidence for Neisseria meningitidis biofilms. Future Microbiol 2009; 4:555-63. [PMID: 19492966 DOI: 10.2217/fmb.09.27] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Neisseria meningitidis is the etiologic agent of meningococcal meningitis. Carriage of the organism is approximately 10% while active disease occurs at a rate of 1:100,000. Recent publications demonstrate that N. meningitidis has the ability to form biofilms on glass, plastic or cultured human bronchial epithelial cells. Microcolony-like structures are also observed in histological sections from patients with active meningococcal disease. This review investigates the possible role of meningococcal biofilms in carriage and active disease, based on the laboratory and clinical aspects of the disease.
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Affiliation(s)
- R Brock Neil
- University of Iowa, Hygienic Laboratory, 102 Oakdale Campus, H101 OH, Iowa City, IA 52242-5002, USA
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Phase I safety and immunogenicity study of a candidate meningococcal disease vaccine based on Neisseria lactamica outer membrane vesicles. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2009; 16:1113-20. [PMID: 19553555 DOI: 10.1128/cvi.00118-09] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Natural immunity to meningococcal disease in young children is associated epidemiologically with carriage of commensal Neisseria species, including Neisseria lactamica. We have previously demonstrated that outer membrane vesicles (OMVs) from N. lactamica provide protection against lethal challenge in a mouse model of meningococcal septicemia. We evaluated the safety and immunogenicity of an N. lactamica OMV vaccine in a phase I placebo-controlled, double-blinded clinical trial. Ninety-seven healthy young adult male volunteers were randomized to receive three doses of either an OMV vaccine or an Alhydrogel control. Subsequently, some subjects who had received the OMV vaccine also received a fourth dose of OMV vaccine, 6 months after the third dose. Injection site reactions were more frequent in the OMV-receiving group, but all reactions were mild or moderate in intensity. The OMV vaccine was immunogenic, eliciting rises in titers of immunoglobulin G (IgG) against the vaccine OMVs, together with a significant booster response, as determined by an enzyme-linked immunosorbent assay. Additionally, the vaccine induced modest cross-reactive immunity to six diverse strains of serogroup B Neisseria meningitidis, including IgG against meningococcal OMVs, serum bactericidal antibodies, and opsonophagocytic activity. The percentages of subjects showing > or =4-fold rises in bactericidal antibody titer obtained were similar to those previously reported for the Norwegian meningococcal OMV vaccine against the same heterologous meningococcal strain panel. In conclusion, this N. lactamica OMV vaccine is safe and induces a weak but broad humoral immune response to N. meningitidis.
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Carbonnelle E, Hill DJ, Morand P, Griffiths NJ, Bourdoulous S, Murillo I, Nassif X, Virji M. Meningococcal interactions with the host. Vaccine 2009; 27 Suppl 2:B78-89. [PMID: 19481311 DOI: 10.1016/j.vaccine.2009.04.069] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Neisseria meningitidis interacts with host tissues through hierarchical, concerted and co-ordinated actions of a number of adhesins; many of which undergo antigenic and phase variation, a strategy that helps immune evasion. Three major structures, pili, Opa and Opc predominantly influence bacterial adhesion to host cells. Pili and Opa proteins also determine host and tissue specificity while Opa and Opc facilitate efficient cellular invasion. Recent studies have also implied a role of certain adhesin-receptor pairs in determining increased host susceptibility to infection. This chapter examines our current knowledge of meningococcal adhesion and invasion mechanisms particularly related to human epithelial and endothelial cells which are of primary importance in the disease process.
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Affiliation(s)
- Etienne Carbonnelle
- INSERM, unité 570, Université Paris Descartes, 156 rue de Vaugirard, Paris 75015, France
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The tumor necrosis factor polymorphism TNF (-308) is associated with susceptibility to meningococcal sepsis, but not with lethality. Crit Care Med 2009; 37:1237-43. [PMID: 19242354 DOI: 10.1097/ccm.0b013e31819c39bc] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine whether the promoter polymorphism tumor necrosis factor (TNF) (-308) is associated with susceptibility to or death from meningococcal sepsis. DESIGN, SETTING, PATIENTS, AND PARTICIPANTS: Association study involving 1321 patients with microbiologically proven invasive meningococcal disease presenting to hospitals throughout United Kingdom during 1998-2001, among whom 134 died. Controls were derived from 1280 northern English blood donors. MEASUREMENTS DNA from patients and controls was genotyped at TNF (-308). After analysis, DNA was subsequently genotyped at eight other markers in strong linkage disequilibrium with TNF (-308); these markers were IkappaBL (-62), BAT3, LST1, NOTCH4 (+1297), NOTCH4 (+3061), CCHCR1 (+436), CCHCR1 (+2271), and LTalpha. To confirm functional relevance of TNF (-308) in the context of meningococcal disease, TNF secretion by, and TNF messenger RNA expression of macrophages derived from volunteers with known TNF (-308) genotype after exposure to Neisseria meningitidis were measured. MAIN RESULTS Among cases of meningococcal disease, likelihood of death was shown to be influenced by the age of the affected individual and also with the infecting serogroup, but was not influenced by genotype at TNF (-308) or the other linked markers. However, patients with meningococcal disease, irrespective of whether they died, were more likely to be homozygous for the rare allele at TNF (-308) (odds ratio = 1.93, 95% confidence interval 1.08-3.46), and less likely to be heterozygous for this marker (odds ratio = 0.79, 95% confidence interval 0.64-0.97), compared with the control cohort. There was no association of susceptibility to disease with the other markers studied. Macrophages derived from volunteers homozygous for the rare allele at TNF (-308) expressed higher levels of TNF messenger RNA and secreted higher concentrations of TNF compared with common homozygotes after exposure to N. meningitidis. CONCLUSIONS Genotype at TNF (-308) modifies cellular TNF secretion in response to N. meningitidis and may influence susceptibility to meningococcal disease, but does not influence the likelihood of death after infection.
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Impaired maintenance of naturally acquired T-cell memory to the meningococcus in patients with B-cell immunodeficiency. Blood 2009; 113:4206-12. [DOI: 10.1182/blood-2008-08-171587] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
AbstractThe importance of T cells in the generation of antigen-specific B-cell immunity has been extensively described, but the role B cells play in shaping T-cell memory is uncertain. In healthy controls, exposure to Neisseria meningitidis in the upper respiratory tract is associated with the generation of memory T cells in the mucosal and systemic compartments. However, we demonstrate that in B cell–deficient subjects with X-linked agammaglobulinemia (XLA), naturally acquired T-cell memory responses to meningococcal antigens are reduced compared with healthy control patients. This difference is not found in T-cell memory to an obligate respiratory pathogen, influenza virus. Accordingly, we show that meningococcal antigens up-regulate major histocompatibility complex (MHC) class II, CD40, CD86/80 expression on mucosal and systemic associated B cells and that antigen presentation stimulates T-cell proliferation. A similar reduction in N meningitidis but not influenza antigen–specific T-cell memory was observed in subjects with X-linked hyper IgM syndrome (X-HIM), implicating the interaction of CD40-CD40L in this process. Together, these data implicate B cells in the induction and maintenance of T-cell memory to mucosal colonizing bacteria such as N meningitidis and highlight the importance of B cells beyond antibody production but as a target for immune reconstitution.
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Vaughan AT, Gorringe A, Davenport V, Williams NA, Heyderman RS. Absence of mucosal immunity in the human upper respiratory tract to the commensal bacteria Neisseria lactamica but not pathogenic Neisseria meningitidis during the peak age of nasopharyngeal carriage. THE JOURNAL OF IMMUNOLOGY 2009; 182:2231-40. [PMID: 19201877 DOI: 10.4049/jimmunol.0802531] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The normal flora that colonizes the mucosal epithelia has evolved diverse strategies to evade, modulate, or suppress the immune system and avoid clearance. Neisseria lactamica and Neisseria meningitidis are closely related obligate inhabitants of the human upper respiratory tract. N. lactamica is a commensal but N. meningitidis is an opportunistic pathogen that occasionally causes invasive disease such as meningitis and septicemia. We demonstrate that unlike N. meningitidis, N. lactamica does not prime the development of mucosal T or B cell memory during the peak period of colonization. This cannot be explained by the induction of peripheral tolerance or regulatory CD4(+)CD25(+) T cell activity. Instead, N. lactamica mediates a B cell-dependent mitogenic proliferative response that is absent to N. meningitidis. This mitogenic response is associated with the production of T cell-independent polyclonal IgM that we propose functions by shielding colonizing N. lactamica from the adaptive immune system, maintaining immunological ignorance in the host. We conclude that, in contrast to N. meningitidis, N. lactamica maintains a commensal relationship with the host in the absence of an adaptive immune response. This may prolong the period of susceptibility to colonization by both pathogenic and nonpathogenic Neisseria species.
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Affiliation(s)
- Andrew T Vaughan
- Department of Cellular and Molecular Medicine, School of Medical Science, University of Bristol, Bristol, United Kingdom.
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Sa E Cunha C, Griffiths NJ, Murillo I, Virji M. Neisseria meningitidis Opc invasin binds to the cytoskeletal protein alpha-actinin. Cell Microbiol 2009; 11:389-405. [PMID: 19016781 PMCID: PMC2688670 DOI: 10.1111/j.1462-5822.2008.01262.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2008] [Revised: 10/14/2008] [Accepted: 10/28/2008] [Indexed: 12/12/2022]
Abstract
Neisseria meningitidis Opc protein is an effective invasin for human endothelial cells. We have investigated novel human endothelial receptors targeted by Opc and observed that Opc-expressing bacteria interacted with a 100 kDa protein in whole-cell lysates of human endothelial and epithelial cells. The identity of the protein was established as alpha-actinin by mass spectrometry. Opc expression was essential for the recognition of alpha-actinin whether provided in a purified form or in cell extracts. The interaction of the two proteins did not involve intermediate molecules. As there was no demonstrable expression of alpha-actinin on the surfaces of any of the eight cell lines studied, the likelihood of the interactions after meningococcal internalization was examined. Confocal imaging demonstrated considerable colocalization of N. meningitidis with alpha-actinin especially after a prolonged period of internalization. This may imply that bacteria and alpha-actinin initially occur in separate compartments and co-compartmentalization occurs progressively over the 8 h infection period used. In conclusion, these studies have identified a novel and an intracellular target for the N. meningitidis Opc invasin. Since alpha-actinin is a modulator of a variety of signalling pathways and of cytoskeletal functions, its targeting by Opc may enable bacteria to survive/translocate across endothelial barriers.
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Affiliation(s)
- Claudia Sa E Cunha
- Department of Cellular and Molecular Medicine, School of Medical Sciences, University of BristolBristol BS8 1TD, UK
| | - Natalie J Griffiths
- Department of Cellular and Molecular Medicine, School of Medical Sciences, University of BristolBristol BS8 1TD, UK
| | - Isabel Murillo
- Department of Cellular and Molecular Medicine, School of Medical Sciences, University of BristolBristol BS8 1TD, UK
| | - Mumtaz Virji
- Department of Cellular and Molecular Medicine, School of Medical Sciences, University of BristolBristol BS8 1TD, UK
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Roberts J, Greenwood B, Stuart J. Sampling methods to detect carriage of Neisseria meningitidis; literature review. J Infect 2009; 58:103-7. [PMID: 19167762 DOI: 10.1016/j.jinf.2008.12.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Accepted: 12/18/2008] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Studies of meningococcal carriage are important in understanding the epidemiology of meningococcal disease and the impact of vaccination programmes. However, microbiological sampling methods to determine pharyngeal carriage are not consistent between studies and the optimal method is uncertain. METHODS A comprehensive literature search was undertaken using Medline, Embase and the Cochrane Library (Feb 2008) to identify studies comparing isolation rates using different sampling methods. RESULTS Four studies compared isolation of meningococci from different pharyngeal sites. Nasopharyngeal swabs taken through the nose were less likely to yield meningococcal cultures than pharyngeal swabs taken through the mouth. One study investigated different sampling sites using swabs taken through the mouth and found higher yields from the posterior pharyngeal wall compared to the tonsils (32.2% cf 19.4%, p=0.001). Four studies compared the yield obtained using transport medium to direct plating. Loss of yield in transport medium ranged from 5.7% to 16.4% after storage for >5h. CONCLUSIONS The evidence to date suggests that meningococcal carriage should be assessed by swabbing the posterior pharyngeal wall through the mouth, and that swabs should be plated directly on site or placed in transport medium for <5h. SUMMARY The current literature suggests meningococcal carriage is best assessed by swabbing the posterior pharyngeal wall through the mouth with direct plating or keeping transport time to below 5h. Whether a swab taken from both the posterior pharynx and the tonsils improves yield further needs evaluation.
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Affiliation(s)
- Jonathan Roberts
- Health Protection Agency, Local and Regional Services, South West, UK.
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