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Caracoti VI, Caracoti CȘ, Ancuța DL, Ioniță F, Muntean AA, Bhide M, Popa GL, Popa MI, Coman C. Developing a Novel Murine Meningococcal Meningitis Model Using a Capsule-Null Bacterial Strain. Diagnostics (Basel) 2024; 14:1116. [PMID: 38893642 PMCID: PMC11172168 DOI: 10.3390/diagnostics14111116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 05/22/2024] [Accepted: 05/23/2024] [Indexed: 06/21/2024] Open
Abstract
BACKGROUND Neisseria meningitidis (meningococcus) is a Gram-negative bacterium that colonises the nasopharynx of about 10% of the healthy human population. Under certain conditions, it spreads into the body, causing infections with high morbidity and mortality rates. Although the capsule is the key virulence factor, unencapsulated strains have proved to possess significant clinical implications as well. Meningococcal meningitis is a primarily human infection, with limited animal models that are dependent on a variety of parameters such as bacterial virulence and mouse strain. In this study, we aimed to develop a murine Neisseria meningitidis meningitis model to be used in the study of various antimicrobial compounds. METHOD We used a capsule-deficient Neisseria meningitidis strain that was thoroughly analysed through various methods. The bacterial strain was incubated for 48 h in brain-heart infusion (BHI) broth before being concentrated and injected intracisternally to bypass the blood-brain barrier in CD-1 mice. This prolonged incubation time was a key factor in increasing the virulence of the bacterial strain. A total of three more differently prepared inoculums were tested to further solidify the importance of the protocol (a 24-h incubated inoculum, a diluted inoculum, and an inactivated inoculum). Antibiotic treatment groups were also established. The clinical parameters and number of deaths were recorded over a period of 5 days, and comatose mice with no chance of recovery were euthanised. RESULTS The bacterial strain was confirmed to have no capsule but was found to harbour a total of 56 genes coding virulence factors, and its antibiotic susceptibility was established. Meningitis was confirmed through positive tissue culture and histological evaluation, where specific lesions were observed, such as perivascular sheaths with inflammatory infiltrate. In the treatment groups, survival rates were significantly higher (up to 81.25% in one of the treatment groups compared to 18.75% in the control group). CONCLUSION We managed to successfully develop a cost-efficient murine (using simple CD-1 mice instead of expensive transgenic mice) meningococcal meningitis model using an unencapsulated strain with a novel method of preparation.
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Affiliation(s)
- Viorela-I. Caracoti
- Faculty of Medicine, Microbiology Discipline II, Carol Davila University of Medicine and Pharmacy, 020021 Bucharest, Romania; (V.-I.C.); (C.-Ș.C.); (A.-A.M.); (G.L.P.)
| | - Costin-Ș. Caracoti
- Faculty of Medicine, Microbiology Discipline II, Carol Davila University of Medicine and Pharmacy, 020021 Bucharest, Romania; (V.-I.C.); (C.-Ș.C.); (A.-A.M.); (G.L.P.)
- Cantacuzino National Military Medical Institute for Research and Development, Preclinical Testing Unit, 050096 Bucharest, Romania; (D.L.A.); (F.I.); (C.C.)
| | - Diana L. Ancuța
- Cantacuzino National Military Medical Institute for Research and Development, Preclinical Testing Unit, 050096 Bucharest, Romania; (D.L.A.); (F.I.); (C.C.)
- Faculty of Veterinary Medicine, University of Agronomic Sciences and Veterinary Medicine, 050097 Bucharest, Romania
| | - Fabiola Ioniță
- Cantacuzino National Military Medical Institute for Research and Development, Preclinical Testing Unit, 050096 Bucharest, Romania; (D.L.A.); (F.I.); (C.C.)
- Faculty of Veterinary Medicine, University of Agronomic Sciences and Veterinary Medicine, 050097 Bucharest, Romania
| | - Andrei-A. Muntean
- Faculty of Medicine, Microbiology Discipline II, Carol Davila University of Medicine and Pharmacy, 020021 Bucharest, Romania; (V.-I.C.); (C.-Ș.C.); (A.-A.M.); (G.L.P.)
- Cantacuzino National Military Medical Institute for Research and Development, Preclinical Testing Unit, 050096 Bucharest, Romania; (D.L.A.); (F.I.); (C.C.)
| | - Mangesh Bhide
- Faculty of Veterinary Medicine, University of Veterinary Medicine and Pharmacy in Kosice, Komenskeho 73, 04181 Kosice, Slovakia;
- Institute of Neuroimmunology of Slovak Academy of Sciences, Dubravska Cesta 9, 84510 Bratislava, Slovakia
| | - Gabriela L. Popa
- Faculty of Medicine, Microbiology Discipline II, Carol Davila University of Medicine and Pharmacy, 020021 Bucharest, Romania; (V.-I.C.); (C.-Ș.C.); (A.-A.M.); (G.L.P.)
| | - Mircea I. Popa
- Faculty of Medicine, Microbiology Discipline II, Carol Davila University of Medicine and Pharmacy, 020021 Bucharest, Romania; (V.-I.C.); (C.-Ș.C.); (A.-A.M.); (G.L.P.)
- Cantacuzino National Military Medical Institute for Research and Development, Preclinical Testing Unit, 050096 Bucharest, Romania; (D.L.A.); (F.I.); (C.C.)
| | - Cristin Coman
- Cantacuzino National Military Medical Institute for Research and Development, Preclinical Testing Unit, 050096 Bucharest, Romania; (D.L.A.); (F.I.); (C.C.)
- Faculty of Veterinary Medicine, University of Agronomic Sciences and Veterinary Medicine, 050097 Bucharest, Romania
- Fundeni Clinical Institute Translational Medicine Centre of Excellence, 022328 Bucharest, Romania
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Shevtsov A, Aushakhmetova Z, Amirgazin A, Khegay O, Kamalova D, Sanakulova B, Abdaliyev A, Bayesheva D, Seidullayeva A, Ramankulov Y, Shustov A, Vergnaud G. Whole genome sequence analysis of Neisseria meningitidis strains circulating in Kazakhstan, 2017-2018. PLoS One 2022; 17:e0279536. [PMID: 36576937 PMCID: PMC9797059 DOI: 10.1371/journal.pone.0279536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 12/11/2022] [Indexed: 12/29/2022] Open
Abstract
Neisseria meningitidis (meningococcus) is a cosmopolitan bacterium that is often found in the upper respiratory tract of asymptomatic humans. However, N. meningitidis also causes meningeal inflammation and/or sepsis in humans with a periodic resurgence in incidence and high mortality rates. The pathogen is highly diverse genetically and antigenically, so that genotyping is considered important for vaccine matching to circulating strains. Annual incidence of meningococcal disease in Kazakhstan ranges between 0.2 and 2.5 cases per 100 thousand population. In total, 78 strains of N. meningitidis were isolated from clinical patients and contact persons during the years 2017-2018 in Kazakhstan. Of these, 41 strains including four from the patients and 37 from contacts, were sequenced using Illumina MiSeq. In silico typing was completed using the Neisseria pipeline 1.2 on the Galaxy Workflow Management System and PubMLST. Whole genome SNP (single nucleotide polymorphisms) trees were built using BioNumerics 8. Seven-gene multilocus sequence typing (MLST) identified ten sequence types (ST), two of which have not been previously described (ST-16025; ST-16027). ST-16025 was detected in two patients with invasive meningococcal disease in 2017 and 2018 in Akmola region and 16 contacts in 2017 in Turkistan region. This prevalent type ST-16025 demonstrates considerable intertypic diversity as it consists of three subcomplexes with a distance of more than 2000 SNPs. Invasive and carrier strains belong to different serogroups (MenB and MenC), PorA and FetA_VR. Two invasive strains were MenB, one MenC and one MenW (Hajj lineage). The strains from the contact persons were: MenC (n = 18), cnl (n = 9), MenY (n = 7), MenW (n = 1), MenB (n = 1) and one unidentifiable. Different numbers of alleles were present: 12, 11, 7, and 7 alleles for PorA, FetA, fHbp, and NHBA, respectively. This study is the first report of the genetic diversity of N. meningitidis strains in Kazakhstan. Despite limitations with the studied sample size, important conclusions can be drawn based on data produced. This study provides evidence for regulatory authorities with regard to changing routine diagnostic protocols to increase the collecting of samples for WGS.
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Affiliation(s)
| | | | | | - Olga Khegay
- National Centre of expertise CSEC MN RK, Astana, Kazakhstan
| | | | | | | | - Dinagul Bayesheva
- Medical University Astana, Astana, Kazakhstan
- Multidisciplinary City Children’s Hospital №3, Astana, Kazakhstan
| | - Aliya Seidullayeva
- Medical University Astana, Astana, Kazakhstan
- Multidisciplinary City Children’s Hospital №3, Astana, Kazakhstan
| | - Yerlan Ramankulov
- National Center for Biotechnology, Astana, Kazakhstan
- School of Science and Humanities Nazarbayev University, Astana, Kazakhstan
| | | | - Gilles Vergnaud
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, Gif-sur-Yvette, France
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Hurst JR, Shannon BA, Craig HC, Rishi A, Tuffs SW, McCormick JK. The Streptococcus pyogenes hyaluronic acid capsule promotes experimental nasal and skin infection by preventing neutrophil-mediated clearance. PLoS Pathog 2022; 18:e1011013. [PMID: 36449535 PMCID: PMC9744330 DOI: 10.1371/journal.ppat.1011013] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 12/12/2022] [Accepted: 11/18/2022] [Indexed: 12/05/2022] Open
Abstract
Streptococcus pyogenes is a globally prominent human-specific pathogen responsible for an enormous burden of human illnesses, including >600 million pharyngeal and >100 million skin infections each year. Despite intensive efforts that focus on invasive indications, much remains unknown about this bacterium in its natural state during colonization of the nasopharynx and skin. Using acute experimental infection models in HLA-transgenic mice, we evaluated how the hyaluronic acid (HA) capsule contributes to S. pyogenes MGAS8232 infection within these limited biological niches. Herein, we demonstrate that HA capsule expression promotes bacterial burden in murine nasal turbinates and skin lesions by resisting neutrophil-mediated killing. HA capsule production is encoded by the hasABC operon and compared to wildtype S. pyogenes infections, mice infected with a ΔhasA mutant exhibited over a 1000-fold CFU reduction at 48-hours post-nasal challenge, and a 10,000-fold CFU reduction from skin lesions 72-hours post-skin challenge. HA capsule expression contributed substantially to skin lesion size development following subdermal inoculations. In the absence of capsule expression, S. pyogenes revealed drastically impeded growth in whole human blood and increased susceptibility to killing by isolated neutrophils ex vivo, highlighting its important role in resisting phagocytosis. Furthermore, we establish that neutrophil depletion in mice recovered the reduced burden by the ΔhasA mutant in both the nasopharynx and skin. Together, this work confirms that the HA capsule is a key virulence determinant during acute infections by S. pyogenes and demonstrates that its predominant function is to protect S. pyogenes against neutrophil-mediated killing.
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Affiliation(s)
- Jacklyn R. Hurst
- Department of Microbiology and Immunology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Blake A. Shannon
- Department of Microbiology and Immunology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Heather C. Craig
- Department of Microbiology and Immunology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Aanchal Rishi
- Department of Microbiology and Immunology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Stephen W. Tuffs
- Department of Microbiology and Immunology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - John K. McCormick
- Department of Microbiology and Immunology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
- * E-mail:
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Limitation of
ctrA
as a Target for Neisseria meningitidis Identification and Potential Alternative Targets. J Clin Microbiol 2022; 60:e0015222. [DOI: 10.1128/jcm.00152-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Sun C. A rhizobial non-coding RNA has an effect on symbiotic nodulation by regulating an ABC transporter. Biochem Biophys Res Commun 2022; 603:82-87. [DOI: 10.1016/j.bbrc.2022.03.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 03/03/2022] [Indexed: 11/02/2022]
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Meiring S, Cohen C, de Gouveia L, du Plessis M, Ganesh K, Kleynhans J, Quan V, Tempia S, von Gottberg A. Human Immunodeficiency Virus Infection Is Associated With Increased Meningococcal Carriage Acquisition Among First-year Students in 2 South African Universities. Clin Infect Dis 2021; 73:e28-e38. [PMID: 32369560 PMCID: PMC8246797 DOI: 10.1093/cid/ciaa521] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 04/30/2020] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Invasive meningococcal disease clusters occur among university students and may reflect higher carriage prevalence among this population. We aimed to measure meningococcal carriage prevalence, acquisition, and risk factors among first-year university students in South Africa. METHODS In summer-autumn 2017, after consenting to participate, we collected oropharyngeal swabs and questionnaires on carriage risk factors and tested students for HIV at 2 universities, during registration week (survey 1) and 6-8 weeks later (survey 2). Meningococci were detected by culture and polymerase chain reaction. RESULTS We enrolled 2120 students at registration. Mean age was 18.5 years, 59% (1252/2120) were female and 0.8% (16/1984) had HIV. Seventy-eight percent of students returned for survey 2 (1655/2120). Among the cohort, carriage prevalence was 4.7% (77/1655) at registration, increasing to 7.9% (130/1655) at survey 2: 5.0% (83) acquired new carriage, 2.8% (47) had persistent carriage, 1.8% (30) cleared the initial carriage, and 90.3% (1495) remained carriage free. At both surveys, nongenogroupable meningococci predominated, followed by genogroups Y, B, W, and C. On multinomial analysis, risk factors for carriage acquisition included attending nightclubs (adjusted relative risk ratio [aRRR], 2.1; 95% CI, 1.1-4.0), having intimate kissing partners (aRRR, 1.8; 95% CI, 1.1-2.9) and HIV (aRRR, 5.0; 95% CI, 1.1-24.4). CONCLUSIONS Meningococcal carriage among first-year university students increased after 2 months. Sociobehavioral risk factors were associated with increased carriage for all analyses. HIV was associated with carriage acquisition. Until vaccination programs become mandatory in South African universities, data suggest that students with HIV could benefit most from meningococcal vaccination.
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Affiliation(s)
- Susan Meiring
- Division of Public Health Surveillance and Response, National Institute for Communicable Diseases, Division of the National Health Laboratory Service, Johannesburg, South Africa
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
| | - Cheryl Cohen
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Division of the National Health Laboratory Service, Johannesburg, South Africa
| | - Linda de Gouveia
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Division of the National Health Laboratory Service, Johannesburg, South Africa
| | - Mignon du Plessis
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Division of the National Health Laboratory Service, Johannesburg, South Africa
- School of Pathology, University of the Witwatersrand, Johannesburg, South Africa
| | - Karistha Ganesh
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Division of the National Health Laboratory Service, Johannesburg, South Africa
| | - Jackie Kleynhans
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Division of the National Health Laboratory Service, Johannesburg, South Africa
| | - Vanessa Quan
- Division of Public Health Surveillance and Response, National Institute for Communicable Diseases, Division of the National Health Laboratory Service, Johannesburg, South Africa
| | - Stefano Tempia
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
| | - Anne von Gottberg
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Division of the National Health Laboratory Service, Johannesburg, South Africa
- School of Pathology, University of the Witwatersrand, Johannesburg, South Africa
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7
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Tzeng YL, Stephens DS. A Narrative Review of the W, X, Y, E, and NG of Meningococcal Disease: Emerging Capsular Groups, Pathotypes, and Global Control. Microorganisms 2021; 9:microorganisms9030519. [PMID: 33802567 PMCID: PMC7999845 DOI: 10.3390/microorganisms9030519] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 12/21/2022] Open
Abstract
Neisseria meningitidis, carried in the human nasopharynx asymptomatically by ~10% of the population, remains a leading cause of meningitis and rapidly fatal sepsis, usually in otherwise healthy individuals. The epidemiology of invasive meningococcal disease (IMD) varies substantially by geography and over time and is now influenced by meningococcal vaccines and in 2020–2021 by COVID-19 pandemic containment measures. While 12 capsular groups, defined by capsular polysaccharide structures, can be expressed by N. meningitidis, groups A, B, and C historically caused most IMD. However, the use of mono-, bi-, and quadrivalent-polysaccharide-conjugate vaccines, the introduction of protein-based vaccines for group B, natural disease fluctuations, new drugs (e.g., eculizumab) that increase meningococcal susceptibility, changing transmission dynamics and meningococcal evolution are impacting the incidence of the capsular groups causing IMD. While the ability to spread and cause illness vary considerably, capsular groups W, X, and Y now cause significant IMD. In addition, group E and nongroupable meningococci have appeared as a cause of invasive disease, and a nongroupable N. meningitidis pathotype of the hypervirulent clonal complex 11 is causing sexually transmitted urethritis cases and outbreaks. Carriage and IMD of the previously “minor” N. meningitidis are reviewed and the need for polyvalent meningococcal vaccines emphasized.
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Affiliation(s)
- Yih-Ling Tzeng
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA;
| | - David S. Stephens
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA;
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
- Correspondence: ; Tel.: +404-727-8357
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Brynildsrud OB, Eldholm V, Rakhimova A, Kristiansen PA, Caugant DA. Gauging the epidemic potential of a widely circulating non-invasive meningococcal strain in Africa. Microb Genom 2020; 5. [PMID: 31454306 PMCID: PMC6755499 DOI: 10.1099/mgen.0.000290] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Neisseria meningitidis colonizes the human oropharynx and transmits mainly via asymptomatic carriage. Actual outbreaks of meningococcal meningitis are comparatively rare and occur when susceptible populations are exposed to hypervirulent clones, genetically distinct from the main carriage isolates. However, carriage isolates can evolve into pathogens through a limited number of recombination events. The present study examines the potential for the sequence type (ST)-192, by far the dominant clone recovered in recent meningococcal carriage studies in sub-Saharan Africa, to evolve into a pathogen. We used whole-genome sequencing on a collection of 478 meningococcal isolates sampled from 1- to 29- year-old healthy individuals in Arba Minch, southern Ethiopia in 2014. The ST-192 clone was identified in nearly 60 % of the carriers. Using complementary short- and long-read techniques for whole-genome sequencing, we were able to completely resolve genomes and thereby identify genomic differences between the ST-192 carriage strain and known pathogenic clones with the highest possible resolution. We conclude that it is possible, but unlikely, that ST-192 could evolve into a significant pathogen, thus, becoming the major invasive meningococcus clone in the meningitis belt of Africa following upcoming mass vaccination with a polyvalent conjugate vaccine that targets the A, C, W, Y and X capsules.
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Affiliation(s)
- Ola Brønstad Brynildsrud
- Department of Food Safety and Infection Biology, Faculty of Veterinary Science, Norwegian University of Life Science, Oslo, Norway.,Division for Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Vegard Eldholm
- Division for Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Adelina Rakhimova
- Division for Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
| | | | - Dominique A Caugant
- Division for Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway.,WHO Collaborating Centre for Reference and Research on Meningococci, Norwegian Institute of Public Health, Oslo, Norway.,Department of Community Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
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Watle SV, Caugant DA, Tunheim G, Bekkevold T, Laake I, Brynildsrud OB, Næss LM. Meningococcal carriage in Norwegian teenagers: strain characterisation and assessment of risk factors. Epidemiol Infect 2020; 148:e80. [PMID: 32228726 PMCID: PMC7189347 DOI: 10.1017/s0950268820000734] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/06/2020] [Accepted: 03/19/2020] [Indexed: 11/24/2022] Open
Abstract
Teenagers have a higher risk of invasive meningococcal disease (IMD) than the general population. This cross-sectional study aimed to characterise strains of Neisseria meningitidis circulating among Norwegian teenagers and to assess risk factors for meningococcal carriage. Oropharyngeal swabs were collected from secondary-school students in southeastern Norway in 2018-2019. Meningococcal isolates were characterised using whole genome sequencing. Risk factors for meningococcal carriage were assessed from questionnaire data. Samples were obtained from 2296 12-24-year-olds (majority 13-19-year-olds). N. meningitidis was identified in 167 (7.3%) individuals. The highest carriage rate was found among 18-year-olds (16.4%). Most carriage isolates were capsule null (40.1%) or genogroup Y (33.5%). Clonal complexes cc23 (35.9%) and cc198 (32.3%) dominated and 38.9% of carriage strains were similar to invasive strains currently causing IMD in Norway. Use of Swedish snus (smokeless tobacco) (OR 1.56, 95% CI 1.07-2.27), kissing >two persons/month (OR 2.76, 95% CI 1.49-5.10) and partying >10 times/3months (OR 3.50, 95% CI 1.45-8.48) were associated with carriage, while age, cigarette smoking, sharing of drinking bottles and meningococcal vaccination were not. The high meningococcal carriage rate among 18-year-olds is probably due to risk-related behaviour. Use of Swedish snus is possibly a new risk factor for meningococcal carriage. Almost 40% of circulating carriage strains have invasive potential.
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Affiliation(s)
- S. V. Watle
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, P.O. Box 222 Skøyen, 0213 Oslo, Norway
- Faculty of Medicine, Institute of Health and Society, University of Oslo, P.O. Box 1078 Blindern, 0316 Oslo, Norway
| | - D. A. Caugant
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, P.O. Box 222 Skøyen, 0213 Oslo, Norway
- Faculty of Medicine, Institute of Health and Society, University of Oslo, P.O. Box 1078 Blindern, 0316 Oslo, Norway
| | - G. Tunheim
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, P.O. Box 222 Skøyen, 0213 Oslo, Norway
| | - T. Bekkevold
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, P.O. Box 222 Skøyen, 0213 Oslo, Norway
| | - I. Laake
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, P.O. Box 222 Skøyen, 0213 Oslo, Norway
| | - O. B. Brynildsrud
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, P.O. Box 222 Skøyen, 0213 Oslo, Norway
| | - L. M. Næss
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, P.O. Box 222 Skøyen, 0213 Oslo, Norway
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Clemence MEA, Harrison OB, Maiden MCJ. Neisseria meningitidis has acquired sequences within the capsule locus by horizontal genetic transfer. Wellcome Open Res 2019; 4:99. [PMID: 31346553 PMCID: PMC6619384 DOI: 10.12688/wellcomeopenres.15333.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2019] [Indexed: 12/24/2022] Open
Abstract
Background: Expression of a capsule from one of serogroups A, B, C, W, X or Y is usually required for
Neisseria meningitidis (
Nme) to cause invasive meningococcal disease. The capsule is encoded by the capsule locus,
cps, which is proposed to have been acquired by a formerly capsule null organism by horizontal genetic transfer (HGT) from another species. Following identification of putative capsule genes in non-pathogenic
Neisseria species, this hypothesis is re-examined. Methods: Whole genome sequence data from
Neisseria species, including
Nme genomes from a diverse range of clonal complexes and capsule genogroups, and non-
Neisseria species, were obtained from PubMLST and GenBank. Sequence alignments of genes from the meningococcal
cps, and predicted orthologues in other species, were analysed using Neighbor-nets, BOOTSCANing and maximum likelihood phylogenies. Results: The meningococcal
cps was highly mosaic within regions B, C and D. A subset of sequences within regions B and C were phylogenetically nested within homologous sequences belonging to
N. subflava, consistent with HGT event in which
N. subflava was the donor. In the
cps of 23/39 isolates, the two copies of region D were highly divergent, with
rfbABC’ sequences being more closely related to predicted orthologues in the proposed species
N. weixii (GenBank accession number
CP023429.1) than the same genes in
Nme isolates lacking a capsule. There was also evidence of mosaicism in the
rfbABC’ sequences of the remaining 16 isolates, as well as
rfbABC from many isolates. Conclusions: Data are consistent with the
en bloc acquisition of
cps in meningococci from
N. subflava, followed by further recombination events with other
Neisseria species. Nevertheless, the data cannot refute an alternative model, in which native meningococcal capsule existed prior to undergoing HGT with
N. subflava and other species. Within-genus recombination events may have given rise to the diversity of meningococcal capsule serogroups.
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Affiliation(s)
| | - Odile B Harrison
- Department of Zoology, University of Oxford, Oxford, OX1 3SY, UK
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Clemence MEA, Harrison OB, Maiden MCJ. Neisseria meningitidis has acquired sequences within the capsule locus by horizontal genetic transfer. Wellcome Open Res 2019; 4:99. [DOI: 10.12688/wellcomeopenres.15333.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2019] [Indexed: 11/20/2022] Open
Abstract
Background:Expression of a capsule from one of serogroups A, B, C, W, X or Y is usually required forNeisseria meningitidis(Nme) to cause invasive meningococcal disease. The capsule is encoded by the capsule locus,cps, which is proposed to have been acquired by a formerly capsule null organism by horizontal genetic transfer (HGT) from another species. Following identification of putative capsule genes in non-pathogenicNeisseriaspecies, this hypothesis is re-examined.Methods:Whole genome sequence data fromNeisseriaspecies, includingNmegenomes from a diverse range of clonal complexes and capsule genogroups, and non-Neisseriaspecies, were obtained from PubMLST and GenBank. Sequence alignments of genes from the meningococcalcps, and predicted orthologues in other species, were analysed using Neighbor-nets, BOOTSCANing and maximum likelihood phylogenies.Results:The meningococcalcpswas highly mosaic within regions B, C and D. A subset of sequences within regions B and C were phylogenetically nested within homologous sequences belonging toN. subflava, consistent with HGT event in whichN. subflavawas the donor. In thecpsof 23/39 isolates, the two copies of region D were highly divergent, withrfbABC’sequences being more closely related to predicted orthologues in the proposed speciesN. weixii (GenBank accession numberCP023429.1) than the same genes inNmeisolates lacking a capsule. There was also evidence of mosaicism in therfbABC’sequences of the remaining 16 isolates, as well asrfbABCfrom many isolates.Conclusions:Data are consistent with theen blocacquisition ofcpsin meningococci fromN. subflava, followed by further recombination events with otherNeisseriaspecies. Nevertheless, the data cannot refute an alternative model, in which native meningococcal capsule existed prior to undergoing HGT withN. subflavaand other species. Within-genus recombination events may have given rise to the diversity of meningococcal capsule serogroups.
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Whole-Genome Sequencing for Characterization of Capsule Locus and Prediction of Serogroup of Invasive Meningococcal Isolates. J Clin Microbiol 2019; 57:JCM.01609-18. [PMID: 30567750 DOI: 10.1128/jcm.01609-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 12/14/2018] [Indexed: 01/07/2023] Open
Abstract
Invasive meningococcal disease is mainly caused by Neisseria meningitidis serogroups A, B, C, X, W, and Y. The serogroup is typically determined by slide agglutination serogrouping (SASG) and real-time PCR (RT-PCR). We describe a whole-genome sequencing (WGS)-based method to characterize the capsule polysaccharide synthesis (cps) locus, classify N. meningitidis serogroups, and identify mechanisms for nongroupability using 453 isolates from a global strain collection. We identified novel genomic organizations within functional cps loci, consisting of insertion sequence (IS) elements in unique positions that did not disrupt the coding sequence. Genetic mutations (partial gene deletion, missing genes, IS insertion, internal stop, and phase-variable off) that led to nongroupability were identified. The results of WGS and SASG were in 91% to 100% agreement for all serogroups, while the results of WGS and RT-PCR showed 99% to 100% agreement. Among isolates determined to be nongroupable by WGS (31 of 453), the results of all three methods agreed 100% for those without a capsule polymerase gene. However, 61% (WGS versus SASG) and 36% (WGS versus RT-PCR) agreements were observed for the isolates, particularly those with phase variations or internal stops in cps loci, which warrant further characterization by additional tests. Our WGS-based serogrouping method provides comprehensive characterization of the N. meningitidis capsule, which is critical for meningococcal surveillance and outbreak investigations.
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A homopolymeric adenosine tract in the promoter region of nspA influences factor H-mediated serum resistance in Neisseria meningitidis. Sci Rep 2019; 9:2736. [PMID: 30804422 PMCID: PMC6389960 DOI: 10.1038/s41598-019-39231-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 01/18/2019] [Indexed: 01/18/2023] Open
Abstract
Although usually asymptomatically colonizing the human nasopharynx, the Gram-negative bacterium Neisseria meningitidis (meningococcus) can spread to the blood stream and cause invasive disease. For survival in blood, N. meningitidis evades the complement system by expression of a polysaccharide capsule and surface proteins sequestering the complement regulator factor H (fH). Meningococcal strains belonging to the sequence type (ST-) 41/44 clonal complex (cc41/44) cause a major proportion of serogroup B meningococcal disease worldwide, but they are also common in asymptomatic carriers. Proteome analysis comparing cc41/44 isolates from invasive disease versus carriage revealed differential expression levels of the outer membrane protein NspA, which binds fH. Deletion of nspA reduced serum resistance and NspA expression correlated with fH sequestration. Expression levels of NspA depended on the length of a homopolymeric tract in the nspA promoter: A 5-adenosine tract dictated low NspA expression, whereas a 6-adenosine motif guided high NspA expression. Screening German cc41/44 strain collections revealed the 6-adenosine motif in 39% of disease isolates, but only in 3.4% of carriage isolates. Thus, high NspA expression is associated with disease, but not strictly required. The 6-adenosine nspA promoter is most common to the cc41/44, but is also found in other hypervirulent clonal complexes.
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14
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Fegan JE, Calmettes C, Islam EA, Ahn SK, Chaudhuri S, Yu RH, Gray-Owen SD, Moraes TF, Schryvers AB. Utility of Hybrid Transferrin Binding Protein Antigens for Protection Against Pathogenic Neisseria Species. Front Immunol 2019; 10:247. [PMID: 30837995 PMCID: PMC6389628 DOI: 10.3389/fimmu.2019.00247] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/29/2019] [Indexed: 01/03/2023] Open
Abstract
The surface transferrin receptor proteins from Neisseria gonorrhoeae have been recognized as ideal vaccine targets due to their critical role in survival in the human male genitourinary tract. Recombinant forms of the surface lipoprotein component of the receptor, transferrin binding protein B (TbpB), can be readily produced at high levels in the Escherichia coli cytoplasm and is suitable for commercial vaccine production. In contrast, the integral outer membrane protein, transferrin binding protein A (TbpA), is produced at relatively low levels in the outer membrane and requires detergents for solubilization and stabilization, processes not favorable for commercial applications. Capitalizing on the core β-barrel structural feature common to the lipoprotein and integral outer membrane protein we engineered the lipoprotein as a scaffold for displaying conserved surface epitopes from TbpA. A stable version of the C-terminal domain of TbpB was prepared by replacing four larger exposed variable loops with short linking peptide regions. Four surface regions from the plug and barrel domains of Neisseria TbpA were transplanted onto this TbpB C-lobe scaffold, generating stable hybrid antigens. Antisera generated in mice and rabbits against the hybrid antigens recognized TbpA at the surface of Neisseria meningitidis and inhibited transferrin-dependent growth at levels comparable or better than antisera directed against the native TbpA protein. Two of the engineered hybrid antigens each elicited a TbpA-specific bactericidal antibody response comparable to that induced by TbpA. A hybrid antigen generated using a foreign scaffold (TbpB from the pig pathogen Haemophilus parasuis) displaying neisserial TbpA loop 10 was evaluated in a model of lower genital tract colonization by N. gonorrhoeae and a model of invasive infection by N. meningitidis. The loop 10 hybrid antigen was as effective as full length TbpA in eliminating N. gonorrhoeae from the lower genital tract of female mice and was protective against the low dose invasive infection by N. meningitidis. These results demonstrate that TbpB or its derivatives can serve as an effective scaffold for displaying surface epitopes of integral outer membrane antigens and these antigens can elicit protection against bacterial challenge.
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Affiliation(s)
- Jamie E Fegan
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Charles Calmettes
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Epshita A Islam
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Sang Kyun Ahn
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Somshukla Chaudhuri
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
| | - Rong-Hua Yu
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
| | - Scott D Gray-Owen
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Trevor F Moraes
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Anthony B Schryvers
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
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15
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Mostowy RJ, Holt KE. Diversity-Generating Machines: Genetics of Bacterial Sugar-Coating. Trends Microbiol 2018; 26:1008-1021. [PMID: 30037568 PMCID: PMC6249986 DOI: 10.1016/j.tim.2018.06.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/08/2018] [Accepted: 06/22/2018] [Indexed: 12/11/2022]
Abstract
Bacterial pathogens and commensals are surrounded by diverse surface polysaccharides which include capsules and lipopolysaccharides. These carbohydrates play a vital role in bacterial ecology and interactions with the environment. Here, we review recent rapid advancements in this field, which have improved our understanding of the roles, structures, and genetics of bacterial polysaccharide antigens. Genetic loci encoding the biosynthesis of these antigens may have evolved as bacterial diversity-generating machines, driven by selection from a variety of forces, including host immunity, bacteriophages, and cell-cell interactions. We argue that the high adaptive potential of polysaccharide antigens should be taken into account in the design of polysaccharide-targeting medical interventions like conjugate vaccines and phage-based therapies.
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Affiliation(s)
- Rafał J Mostowy
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK.
| | - Kathryn E Holt
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia; The London School of Hygiene and Tropical Medicine, London, United Kingdom
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16
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Kurose S, Onozawa K, Yoshikawa H, Yaita K, Takahashi H, Shimono N, Nagasaki Y. Invasive meningococcal disease due to a non-capsulated Neisseria meningitidis strain in a patient with IgG4-related disease. BMC Infect Dis 2018; 18:146. [PMID: 29606119 PMCID: PMC5879769 DOI: 10.1186/s12879-018-3064-2] [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: 12/12/2017] [Accepted: 03/26/2018] [Indexed: 12/13/2022] Open
Abstract
Background Invasive Meningococcal Disease (IMD) is a rare and critical disease in Japan. Most of these cases are caused by capsulated Neisseria meningitidis strains. Non-capsulated (non-typable) strains are considered relatively low-pathogenic and can colonize in the nasopharynx of healthy children and young adults. As far as could be ascertained, only twelve IMD cases due to non-capsulated strains have been reported in the literature. No clear risk factors could be identified in a literature review (unknown or immunocompetent, seven cases; C6 deficiency, three cases). Case presentation We report a Japanese male taxi driver with bacteremia and meningitis due to non-capsulated N. meningitidis. He had a fever and shaking chills. Ceftriaxone was administered, and the patient finally recovered. During the clinical course, relative adrenal insufficiency occurred and was treated with hydrocortisone. A hidden co-morbidity, immunoglobulin G4 (IgG4)-related disease, was revealed in the past surgical history (a resection of bilateral orbital tumors), which included symptoms (swelling lachrymal glands and lymph nodes), elevated IgG4, immunoglobulin E, and hypocomplementemia. He recovered finally and no recurrence was observed. Conclusions Our IMD case is the first reported in Japan, where IMD is not considered pandemic. The patient had a history of IgG4-related disease, although we could not establish a clear relationship between the patient’s IMD and co-morbidity. A collection of further clinical cases might establish the risk factors and characteristics of IMD that could be caused by this neglected pathogen, non-capsulated N. meningitidis.
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Affiliation(s)
- Shun Kurose
- Division of Infectious Diseases, Fukuoka City Hospital, 13-1 Yoshizuka-Honmachi, Hakata-ku, Fukuoka, 812-0046, Japan
| | - Kyoko Onozawa
- Division of Infectious Diseases, Fukuoka City Hospital, 13-1 Yoshizuka-Honmachi, Hakata-ku, Fukuoka, 812-0046, Japan.
| | - Hiroshi Yoshikawa
- Department of Ophthalmology, Graduate School of Medical Science at Kyushu University, Fukuoka, Japan
| | - Kenichiro Yaita
- Division of Infection Control and Prevention, Kurume University Hospital, Kurume, Japan
| | - Hideyuki Takahashi
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Nobuyuki Shimono
- Center for the Study of Global Infection, Kyushu University Hospital, Fukuoka, Japan
| | - Yoji Nagasaki
- Division of Infectious Diseases, Fukuoka City Hospital, 13-1 Yoshizuka-Honmachi, Hakata-ku, Fukuoka, 812-0046, Japan
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17
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Buckwalter CM, Currie EG, Tsang RSW, Gray-Owen SD. Discordant Effects of Licensed Meningococcal Serogroup B Vaccination on Invasive Disease and Nasal Colonization in a Humanized Mouse Model. J Infect Dis 2017; 215:1590-1598. [PMID: 28368526 DOI: 10.1093/infdis/jix162] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 03/23/2017] [Indexed: 11/12/2022] Open
Abstract
Background The multicomponent meningococcal serogroup B vaccine (4CMenB) is an outer membrane vesicle and recombinant protein-based vaccine licensed to protect against serogroup B meningococcal disease. It remains unknown whether this vaccine will prevent carriage or transmission, key aspects in long-term vaccine success and disease eradication. Methods Using a "humanized" transgenic mouse model of nasal colonization, we took a systematic approach to estimate the potential for carriage prevention against antigenically diverse Neisseria meningitidis strains and to compare this protection to an invasive meningococcal disease challenge model. Results The 4CMenB vaccine prevented morbidity and mortality after lethal invasive doses of all meningococcal strains tested. Immunization effectively prevented carriage with only 1 of 4 single antigen-matched strains but reduced or prevented nasal colonization by all 4 isolates with multiple cross-reacting antigens. Each immunized mouse had substantial immunoglobulin G targeting the challenge strains, indicating that antibody correlates with protection against sepsis but not nasal carriage. Conclusions Immunization with the 4CMenB vaccine elicits a robust humoral response that correlates with protection against invasive challenge but not with prevention of asymptomatic colonization. This suggests that widespread use of this vaccine will reduce morbidity and mortality rates in immunized individuals, with the potential to contribute to herd protection against a subset of strains.
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Affiliation(s)
| | - Elissa G Currie
- Department of Molecular Genetics, University of Toronto, Ontario and
| | - Raymond S W Tsang
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba
| | - Scott D Gray-Owen
- Department of Molecular Genetics, University of Toronto, Ontario and
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18
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Ganesh K, Allam M, Wolter N, Bratcher HB, Harrison OB, Lucidarme J, Borrow R, de Gouveia L, Meiring S, Birkhead M, Maiden MCJ, von Gottberg A, du Plessis M. Molecular characterization of invasive capsule null Neisseria meningitidis in South Africa. BMC Microbiol 2017; 17:40. [PMID: 28222677 PMCID: PMC5320719 DOI: 10.1186/s12866-017-0942-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 01/31/2017] [Indexed: 12/15/2022] Open
Abstract
Background The meningococcal capsule is an important virulence determinant. Unencapsulated meningococci lacking capsule biosynthesis genes and containing the capsule null locus (cnl) are predominantly non-pathogenic. Rare cases of invasive meningococcal disease caused by cnl isolates belonging to sequence types (ST) and clonal complexes (cc) ST-845 (cc845), ST-198 (cc198), ST-192 (cc192) and ST-53 (cc53) have been documented. The clinical significance of these isolates however remains unclear. We identified four invasive cnl meningococci through laboratory-based surveillance in South Africa from 2003 through 2013, which we aimed to characterize using whole genome data. Results One isolate [NG: P1.7-2,30: F1-2: ST-53 (cc53)] contained cnl allele 12, and caused empyema in an adult male with bronchiectasis from tuberculosis, diabetes mellitus and a smoking history. Three isolates were NG: P1.18-11,42-2: FΔ: ST-192 (cc192) and contained cnl allele 2. One patient was an adolescent male with meningitis. The remaining two isolates were from recurrent disease episodes (8 months apart) in a male child with deficiency of the sixth complement component, and with the exception of two single nucleotide polymorphisms, contained identical core genomes. The ST-53 (cc53) isolate possessed alleles for NHBA peptide 191 and fHbp variant 2; whilst the ST-192 (cc192) isolates contained NHBA peptide 704 and fHbp variant 3. All four isolates lacked nadA. Comparison of the South African genomes to 61 additional cnl genomes on the PubMLST Neisseria database (http://pubmlst.org/neisseria/), determined that most putative virulence genes could be found in both invasive and carriage phenotypes. Conclusions Although rare, invasive disease by cnl meningococci may be associated with host immunodeficiency and such patients may benefit from protein-based meningococcal vaccines. Electronic supplementary material The online version of this article (doi:10.1186/s12866-017-0942-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Karistha Ganesh
- National Institute for Communicable Diseases (NICD), A division of the National Health Laboratory Service (NHLS), Johannesburg, South Africa. .,School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - Mushal Allam
- National Institute for Communicable Diseases (NICD), A division of the National Health Laboratory Service (NHLS), Johannesburg, South Africa
| | - Nicole Wolter
- National Institute for Communicable Diseases (NICD), A division of the National Health Laboratory Service (NHLS), Johannesburg, South Africa.,School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | | | - Jay Lucidarme
- Meningococcal Reference Unit, Public Health England, Manchester Medical Microbiology Partnership, Manchester Royal Infirmary, Manchester, UK
| | - Ray Borrow
- Meningococcal Reference Unit, Public Health England, Manchester Medical Microbiology Partnership, Manchester Royal Infirmary, Manchester, UK
| | - Linda de Gouveia
- National Institute for Communicable Diseases (NICD), A division of the National Health Laboratory Service (NHLS), Johannesburg, South Africa
| | - Susan Meiring
- National Institute for Communicable Diseases (NICD), A division of the National Health Laboratory Service (NHLS), Johannesburg, South Africa
| | - Monica Birkhead
- National Institute for Communicable Diseases (NICD), A division of the National Health Laboratory Service (NHLS), Johannesburg, South Africa
| | | | - Anne von Gottberg
- National Institute for Communicable Diseases (NICD), A division of the National Health Laboratory Service (NHLS), Johannesburg, South Africa.,School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Mignon du Plessis
- National Institute for Communicable Diseases (NICD), A division of the National Health Laboratory Service (NHLS), Johannesburg, South Africa.,School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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19
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Abstract
Antigenic variation is a strategy used by a broad diversity of microbial pathogens to persist within the mammalian host. Whereas viruses make use of a minimal proofreading capacity combined with large amounts of progeny to use random mutation for variant generation, antigenically variant bacteria have evolved mechanisms which use a stable genome, which aids in protecting the fitness of the progeny. Here, three well-characterized and highly antigenically variant bacterial pathogens are discussed: Anaplasma, Borrelia, and Neisseria. These three pathogens display a variety of mechanisms used to create the structural and antigenic variation needed for immune escape and long-term persistence. Intrahost antigenic variation is the focus; however, the role of these immune escape mechanisms at the population level is also presented.
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20
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van de Beek D, Brouwer M, Hasbun R, Koedel U, Whitney CG, Wijdicks E. Community-acquired bacterial meningitis. Nat Rev Dis Primers 2016; 2:16074. [PMID: 27808261 DOI: 10.1038/nrdp.2016.74] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Meningitis is an inflammation of the meninges and subarachnoid space that can also involve the brain cortex and parenchyma. It can be acquired spontaneously in the community - community-acquired bacterial meningitis - or in the hospital as a complication of invasive procedures or head trauma (nosocomial bacterial meningitis). Despite advances in treatment and vaccinations, community-acquired bacterial meningitis remains one of the most important infectious diseases worldwide. Streptococcus pneumoniae and Neisseria meningitidis are the most common causative bacteria and are associated with high mortality and morbidity; vaccines targeting these organisms, which have designs similar to the successful vaccine that targets Haemophilus influenzae type b meningitis, are now being used in many routine vaccination programmes. Experimental and genetic association studies have increased our knowledge about the pathogenesis of bacterial meningitis. Early antibiotic treatment improves the outcome, but the growing emergence of drug resistance as well as shifts in the distribution of serotypes and groups are fuelling further development of new vaccines and treatment strategies. Corticosteroids were found to be beneficial in high-income countries depending on the bacterial species. Further improvements in the outcome are likely to come from dampening the host inflammatory response and implementing preventive measures, especially the development of new vaccines.
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Affiliation(s)
- Diederik van de Beek
- Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, P.O. BOX 22660, 1100DD Amsterdam, The Netherlands
| | - Matthijs Brouwer
- Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, P.O. BOX 22660, 1100DD Amsterdam, The Netherlands
| | - Rodrigo Hasbun
- Department of Internal Medicine, UT Health McGovern Medical School, Houston, Texas, USA
| | - Uwe Koedel
- Department of Neurology, Clinic Grosshadern of the Ludwig-Maximilians University of Munich, Munich, Germany
| | - Cynthia G Whitney
- Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Eelco Wijdicks
- Division of Critical Care Neurology, Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
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21
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Hooda Y, Lai CCL, Judd A, Buckwalter CM, Shin HE, Gray-Owen SD, Moraes TF. Slam is an outer membrane protein that is required for the surface display of lipidated virulence factors in Neisseria. Nat Microbiol 2016; 1:16009. [DOI: 10.1038/nmicrobiol.2016.9] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 01/19/2016] [Indexed: 11/09/2022]
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22
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Comparison of Phenotypic and Genotypic Approaches to Capsule Typing of Neisseria meningitidis by Use of Invasive and Carriage Isolate Collections. J Clin Microbiol 2015; 54:25-34. [PMID: 26311858 DOI: 10.1128/jcm.01447-15] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/20/2015] [Indexed: 12/17/2022] Open
Abstract
Neisseria meningitidis serogroup B (MnB) is a leading cause of bacterial meningitis; however, MnB is most commonly associated with asymptomatic carriage in the nasopharyngeal cavity, as opposed to the disease state. Two vaccines are now licensed for the prevention of MnB disease; a possible additional benefit of these vaccines could be to protect against disease indirectly by disrupting nasopharyngeal carriage (e.g., herd protection). To investigate this possibility, accurate diagnostic approaches to characterize MnB carriage isolates are required. In contrast to invasive meningococcal disease (IMD) isolates, which can be readily serogrouped, carriage isolates often lack capsule expression, making standard phenotypic assays unsuitable for strain characterization. Several antibody-based methods were evaluated for their abilities to serogroup isolates and were compared with two genotyping methods (real-time PCR [rt-PCR] and whole-genome sequencing [WGS]) to identify which approach would most accurately ascertain the polysaccharide groups associated with carriage isolates. WGS and rt-PCR were in agreement for 99% of IMD isolates, including those with coding sequences for MnB, MnC, MnW, and MnY, and the phenotypic methods correctly identified serogroups for 69 to 98% of IMD isolates. In contrast, only 47% of carriage isolates were groupable by genotypic methods, due to mutations within the capsule operon; of the isolates identified by genotypic methods, ≤43% were serogroupable with any of the phenotypic methods tested. These observations highlight the difficulties in the serogrouping and capsular genogrouping of meningococcal carriage isolates. Based on our findings, WGS is the most suitable approach for the characterization of meningococcal carriage isolates.
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23
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Gasparini R, Panatto D, Bragazzi NL, Lai PL, Bechini A, Levi M, Durando P, Amicizia D. How the Knowledge of Interactions between Meningococcus and the Human Immune System Has Been Used to Prepare Effective Neisseria meningitidis Vaccines. J Immunol Res 2015; 2015:189153. [PMID: 26351643 PMCID: PMC4553322 DOI: 10.1155/2015/189153] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 06/09/2015] [Indexed: 01/17/2023] Open
Abstract
In the last decades, tremendous advancement in dissecting the mechanisms of pathogenicity of Neisseria meningitidis at a molecular level has been achieved, exploiting converging approaches of different disciplines, ranging from pathology to microbiology, immunology, and omics sciences (such as genomics and proteomics). Here, we review the molecular biology of the infectious agent and, in particular, its interactions with the immune system, focusing on both the innate and the adaptive responses. Meningococci exploit different mechanisms and complex machineries in order to subvert the immune system and to avoid being killed. Capsular polysaccharide and lipooligosaccharide glycan composition, in particular, play a major role in circumventing immune response. The understanding of these mechanisms has opened new horizons in the field of vaccinology. Nowadays different licensed meningococcal vaccines are available and used: conjugate meningococcal C vaccines, tetravalent conjugate vaccines, an affordable conjugate vaccine against the N. menigitidis serogroup A, and universal vaccines based on multiple antigens each one with a different and peculiar function against meningococcal group B strains.
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Affiliation(s)
- R. Gasparini
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - D. Panatto
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - N. L. Bragazzi
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - P. L. Lai
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - A. Bechini
- Department of Health Sciences, University of Florence, Viale G.B. Morgagni 48, 50134 Florence, Italy
| | - M. Levi
- Department of Health Sciences, University of Florence, Viale G.B. Morgagni 48, 50134 Florence, Italy
| | - P. Durando
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - D. Amicizia
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
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Xu Z, Du P, Zhu B, Xu L, Wang H, Gao Y, Zhou H, Zhang W, Chen C, Shao Z. Phylogenetic study of clonal complex (CC)198 capsule null locus (cnl) genomes: A distinctive group within the species Neisseria meningitidis. INFECTION GENETICS AND EVOLUTION 2015; 34:372-7. [PMID: 26171575 DOI: 10.1016/j.meegid.2015.07.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 07/07/2015] [Accepted: 07/11/2015] [Indexed: 10/23/2022]
Abstract
Capsule null locus (cnl) strains, one type of specific unencapsulated Neisseria spp., only have regions D and E of the capsule gene cluster which encodes the genes for capsule biosynthesis, modification, and transportation. Compared with encapsulated strains, regions A and C of cnl strains have been replaced by 113 or 114 bp conserved non-coding sequences. Cnl strains include multiple clonal complexes (CC). According to previous studies, CC198 is the major clonal lineage in both cnl patients and healthy cnl carriers. We hypothesized that CC198 possesses different genome characteristics compared with other cnl strains. In this study, we obtained the draft genomes of two CC198 strains from healthy carriers. Using 75071 single nucleotide polymorphisms located in 1163 core genes, we constructed the phylogenetic relationships between a batch of representative Neisseria meningitidis genomes. CC198 and CC1136 clustered together, but apart from other N. meningitidis strains including CC53. We also aligned the sequences of genes located in regions D and E of the capsule gene locus from encapsulated and unencapsulated strains. A number of possible recombination events were identified in the galE and tex genes between different serogroups of encapsulated N. meningitidis and CC53 strains, especially in tex. In contrast, there is almost no recombination in N. meningitidis CC198 strains. These results showed that CC198 belongs to a phylogenetically distinct group within the species N. meningitidis, which may be directly derived from the cnl-type ancestor of N. meningitidis. The encapsulated strains may acquire other necessary genes for capsule formation by horizontal transfer.
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Affiliation(s)
- Zheng Xu
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Pengcheng Du
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China
| | - Bingqing Zhu
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Li Xu
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Haiyin Wang
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Yuan Gao
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Haijian Zhou
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Wen Zhang
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Chen Chen
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China
| | - Zhujun Shao
- National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
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25
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Host-like carbohydrates promote bloodstream survival of Vibrio vulnificus in vivo. Infect Immun 2015; 83:3126-36. [PMID: 26015477 PMCID: PMC4496609 DOI: 10.1128/iai.00345-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 05/13/2015] [Indexed: 01/15/2023] Open
Abstract
Sialic acids are found on all vertebrate cell surfaces and are part of a larger class of molecules known as nonulosonic acids. Many bacterial pathogens synthesize related nine-carbon backbone sugars; however, the role(s) of these non-sialic acid molecules in host-pathogen interactions is poorly understood. Vibrio vulnificus is the leading cause of seafood-related death in the United States due to its ability to quickly access the host bloodstream, which it can accomplish through gastrointestinal or wound infection. However, little is known about how this organism persists systemically. Here we demonstrate that sialic acid-like molecules are present on the lipopolysaccharide of V. vulnificus, are required for full motility and biofilm formation, and also contribute to the organism's natural resistance to polymyxin B. Further experiments in a murine model of intravenous V. vulnificus infection demonstrated that expression of nonulosonic acids had a striking benefit for bacterial survival during bloodstream infection and dissemination to other tissues in vivo. In fact, levels of bacterial persistence in the blood corresponded to the overall levels of these molecules expressed by V. vulnificus isolates. Taken together, these results suggest that molecules similar to sialic acids evolved to facilitate the aquatic lifestyle of V. vulnificus but that their emergence also resulted in a gain of function with life-threatening potential in the human host.
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Xu Z, Zhu B, Xu L, Gao Y, Shao Z. First case of Neisseria meningitidis capsule null locus infection in China. Infect Dis (Lond) 2015; 47:591-2. [PMID: 25728375 DOI: 10.3109/00365548.2015.1010228] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Invasive meningococcal diseases are rarely caused by capsule null locus (cnl) strains, which are unencapsulated owing to an absence of capsule synthesis genes. Only a few cases of cnl meningococcemia in severely immunocompromised patients have been reported. Here, we describe and discuss the first case of invasive disease in an immunocompetent patient due to a cnl strain of Neisseria meningitidis in China. We characterize this strain and discuss the special ST-198 complex of cnl.
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Affiliation(s)
- Zheng Xu
- From the 1 National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention , Beijing , PR China
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Law DKS, Zhou J, Deng S, Hoang L, Tyrrell G, Horsman G, Wylie J, Tsang RSW. Determination of serotyping antigens, clonal analysis and genetic characterization of the 4CMenB vaccine antigen genes in invasive Neisseria meningitidis from Western Canada, 2009 to 2013. J Med Microbiol 2014; 63:1490-1499. [PMID: 25165123 DOI: 10.1099/jmm.0.079921-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
This study examined invasive Neisseria meningitidis recovered from invasive meningococcal disease (IMD) cases in Western Canada between 2009 and 2013. A total of 161 isolates from individual IMD cases were analysed for serogroup, serotype, serosubtype, PorA genotype, multi-locus sequence type and nucleotide sequence of their 4CMenB vaccine antigen genes. Sixty-nine isolates were serogroup B (MenB), 47 were serogroup Y (MenY), 22 were serogroup C (MenC), 19 were serogroup W (MenW), three were serogroup E and one was non-encapsulated. MenC, MenY and MenW were mainly clonal, represented primarily by clonal complex (cc) 11, cc23 or cc167, and cc22, respectively. In contrast, MenB were composed of eight different ccs together with 11 isolates not assigned to any known cc. Antigenic analysis and PorA genotyping confirmed the heterogeneity of MenB isolates, while such results supported the clonal nature of most MenC, MenY and MenW isolates. Thirty-four (21.1%) isolates had at least one gene that encoded one matching vaccine protein component of the 4CMenB vaccine (i.e. PorA P1.4; fHbp variant 1.1; NHBA peptide 2; and NadA-1, -2, or -3). An additional 18 isolates had genes that encoded variant 1 or subfamily B factor H binding proteins of this same vaccine.
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Affiliation(s)
- Dennis K S Law
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Jianwei Zhou
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Saul Deng
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Linda Hoang
- Public Health Microbiology and Reference Laboratory, BC Public Health Microbiology and Reference Laboratory, Vancouver, BC, Canada
| | - Gregory Tyrrell
- Provincial Laboratory for Public Health, Edmonton, AB, Canada
| | - Greg Horsman
- Saskatchewan Disease Control Laboratory, Regina, SK, Canada
| | - John Wylie
- Cadham Provincial Public Health Laboratory, Winnipeg, MB, Canada
| | - Raymond S W Tsang
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
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Morgenthau A, Beddek A, Schryvers AB. The negatively charged regions of lactoferrin binding protein B, an adaptation against anti-microbial peptides. PLoS One 2014; 9:e86243. [PMID: 24465982 PMCID: PMC3896470 DOI: 10.1371/journal.pone.0086243] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 12/09/2013] [Indexed: 12/02/2022] Open
Abstract
Lactoferrin binding protein B (LbpB) is a bi-lobed membrane bound lipoprotein that is part of the lactoferrin receptor complex in a variety of Gram-negative pathogens. Despite high sequence diversity among LbpBs from various strains and species, a cluster of negatively charged amino acids is invariably present in the protein’s C-terminal lobe in all species except Moraxella bovis. The function of LbpB in iron acquisition has yet to be experimentally demonstrated, whereas in vitro studies have shown that LbpB confers protection against lactoferricin, a short cationic antimicrobial peptide released from the N- terminus of lactoferrin. In this study we demonstrate that the negatively charged regions can be removed from the Neisseria meningitidis LbpB without compromising stability, and this results in the inability of LbpB to protect against the bactericidal effects of lactoferricin. The release of LbpB from the cell surface by the autotransporter NalP reduces the protection against lactoferricin in the in vitro killing assay, attributed to removal of LbpB during washing steps, but is unlikely to have a similar impact in vivo. The protective effect of the negatively charged polysaccharide capsule in the killing assay was less than the protection conferred by LbpB, suggesting that LbpB plays a major role in protection against cationic antimicrobial peptides in vivo. The selective release of LbpB by NalP has been proposed to be a mechanism for evading the adaptive immune response, by reducing the antibody binding to the cell surface, but may also provide insights into the primary function of LbpB in vivo. Although TbpB and LbpB have been shown to be major targets of the human immune response, the selective release of LbpB suggests that unlike TbpB, LbpB may not be essential for iron acquisition, but important for protection against cationic antimicrobial peptides.
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Affiliation(s)
- Ari Morgenthau
- Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Amanda Beddek
- Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Anthony B. Schryvers
- Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- * E-mail:
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Johswich KO, McCaw SE, Islam E, Sintsova A, Gu A, Shively JE, Gray-Owen SD. In vivo adaptation and persistence of Neisseria meningitidis within the nasopharyngeal mucosa. PLoS Pathog 2013; 9:e1003509. [PMID: 23935487 PMCID: PMC3723569 DOI: 10.1371/journal.ppat.1003509] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Accepted: 06/04/2013] [Indexed: 12/13/2022] Open
Abstract
Neisseria meningitidis (Nme) asymptomatically colonizes the human nasopharynx, yet can initiate rapidly-progressing sepsis and meningitis in rare instances. Understanding the meningococcal lifestyle within the nasopharyngeal mucosa, a phase of infection that is prerequisite for disease, has been hampered by the lack of animal models. Herein, we compare mice expressing the four different human carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) that can bind the neisserial Opa protein adhesins, and find that expression of human CEACAM1 is necessary and sufficient to establish intranasal colonization. During infection, in vivo selection for phase variants expressing CEACAM1-specific Opa proteins occurs, allowing mucosal attachment and entry into the subepithelial space. Consistent with an essential role for Opa proteins in this process, Opa-deficient meningococci were unable to colonize the CEACAM1-humanized mice. While simple Opa-mediated attachment triggered an innate response regardless of meningococcal viability within the inoculum, persistence of viable Opa-expressing bacteria within the CEACAM1-humanized mice was required for a protective memory response to be achieved. Parenteral immunization with a capsule-based conjugate vaccine led to the accumulation of protective levels of Nme-specific IgG within the nasal mucus, yet the sterilizing immunity afforded by natural colonization was instead conferred by Nme-specific IgA without detectable IgG. Considered together, this study establishes that the availability of CEACAM1 helps define the exquisite host specificity of this human-restricted pathogen, displays a striking example of in vivo selection for the expression of desirable Opa variants, and provides a novel model in which to consider meningococcal infection and immunity within the nasopharyngeal mucosa. Neisseria meningitidis (Nme), a common cause of bacterial meningitis, are carried asymptomatically in the nasopharynx by a substantial proportion of healthy individuals. Their strict adaptation to the human as host has so far impeded the development of animal models to study the meningococcal lifestyle in vivo. While several human CEACAMs are recognized by the neisserial Opa protein adhesins, we show here that the expression of human CEACAM1 in transgenic mice is necessary and sufficient to allow nasal colonization by Nme. The dependence on human CEACAM1 is attributable to the Opa proteins, since intranasal infection with Opa-negative colonies of Nme selects for bacteria expressing Opa proteins, and genetically Opa-deficient meningococci are unable to colonize these animals. We use this new mouse model to examine how innate immune factors such as neutrophils and complement limit colonization. Furthermore, we compare how adaptive responses elicited by colonization and those generated by parenteral vaccination differentially confer sterilizing immunity. Together, this work provides the first evidence of the critical nature of Opa-CEACAM1 binding in vivo, demonstrates that this is a major determinant of the host restriction by Nme, and reveals a clear disparity between immune correlates of sterilizing immunity conferred by natural colonization versus parenteral immunization.
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Affiliation(s)
- Kay O Johswich
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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30
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Sorhouet-Pereira C, Efron A, Gagetti P, Faccone D, Regueira M, Corso A, Gabastou JM, Ibarz-Pavón AB. Phenotypic and genotypic characteristics of Neisseria meningitidis disease-causing strains in Argentina, 2010. PLoS One 2013; 8:e58065. [PMID: 23483970 PMCID: PMC3587574 DOI: 10.1371/journal.pone.0058065] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 01/29/2013] [Indexed: 11/19/2022] Open
Abstract
Phenotypic and genotypic characterization of 133 isolates of Neisseria meningitidis obtained from meningococcal disease cases in Argentina during 2010 were performed by the National Reference Laboratory as part of a project coordinated by the PAHO within the SIREVA II network. Serogroup, serotype, serosubtype and MLST characterization were performed. Minimum Inhibitory Concentration to penicillin, ampicillin, ceftriaxone, rifampin, chloramphenicol, tetracycline and ciprofloxacin were determined and interpreted according to CLSI guidelines. Almost 49% of isolates were W135, and two serotype:serosubtype combinations, W135:2a:P1.5,2:ST-11 and W135:2a:P1.2:ST-11 accounted for 78% of all W135 isolates. Serogroup B accounted for 42.1% of isolates, and was both phenotypically and genotypically diverse. Serogroup C isolates represented 5.3% of the dataset, and one isolate belonging to the ST-198 complex was non-groupable. Isolates belonged mainly to the ST-11 complex (48%) and to a lesser extent to the ST-865 (18%), ST-32 (9,8%) and the ST-35 complexes (9%). Intermediate resistance to penicillin and ampicillin was detected in 35.4% and 33.1% of isolates respectively. Two W135:2a:P1.5,2:ST-11:ST-11 isolates presented resistance to ciprofloxacin associated with a mutation in the QRDR of gyrA gene Thr91-Ile. These data show serogroup W135 was the first cause of disease in Argentina in 2010, and was strongly associated with the W135:2a:P1.5,2:ST-11 epidemic clone. Serogroup B was the second cause of disease and isolates belonging to this serogroup were phenotypically and genotypically diverse. The presence of isolates with intermediate resistance to penicillin and the presence of fluorquinolone-resistant isolates highlight the necessity and importance of maintaining and strengthening National Surveillance Programs.
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Affiliation(s)
- Cecilia Sorhouet-Pereira
- Clinical Bacteriology Service, Department of Bacteriology, National Institute for Infectious Diseases (ANLIS-INEI), ‘Dr Carlos G. Malbrán’, Ministry of Health, Buenos Aires, Argentina
| | - Adriana Efron
- Clinical Bacteriology Service, Department of Bacteriology, National Institute for Infectious Diseases (ANLIS-INEI), ‘Dr Carlos G. Malbrán’, Ministry of Health, Buenos Aires, Argentina
| | - Paula Gagetti
- Antimicrobial Resistance Service, Department of Bacteriology, National Institute for Infectious Diseases (ANLIS-INEI), ‘Dr Carlos G. Malbrán’, Ministry of Health, Buenos Aires, Argentina
| | - Diego Faccone
- Antimicrobial Resistance Service, Department of Bacteriology, National Institute for Infectious Diseases (ANLIS-INEI), ‘Dr Carlos G. Malbrán’, Ministry of Health, Buenos Aires, Argentina
| | - Mabel Regueira
- Clinical Bacteriology Service, Department of Bacteriology, National Institute for Infectious Diseases (ANLIS-INEI), ‘Dr Carlos G. Malbrán’, Ministry of Health, Buenos Aires, Argentina
| | - Alejandra Corso
- Antimicrobial Resistance Service, Department of Bacteriology, National Institute for Infectious Diseases (ANLIS-INEI), ‘Dr Carlos G. Malbrán’, Ministry of Health, Buenos Aires, Argentina
| | | | - Jean-Marc Gabastou
- Pan American Health Organization, Washington, DC, United States of America
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Genome sequence of a Neisseria meningitidis capsule null locus strain from the clonal complex of sequence type 198. J Bacteriol 2012; 194:5144-5. [PMID: 22933768 DOI: 10.1128/jb.01099-12] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neisseria meningitidis is a commensal and accidental pathogen exclusively of humans. Although the production of polysaccharide capsules is considered to be essential for meningococcal virulence, there have been reports of constitutively unencapsulated strains causing invasive meningococcal disease (IMD). Here we report the genome sequence of a capsule null locus (cnl) strain of sequence type 198 (ST-198), which is found in half of the reported cases of IMD caused by cnl meningococcal strains.
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32
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Jamieson FB, Rawte P, Deeks SL, Zhou J, Law DKS, Deng S, Tsang RSW. Genetic and antigenic characterization of invasive endemic serogroup B Neisseria meningitidis from Ontario, Canada, in 2001-2010. J Med Microbiol 2012; 62:46-55. [PMID: 23038803 DOI: 10.1099/jmm.0.050369-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
This study examined the antigenic and genetic diversity of serogroup B Neisseria meningitidis (MenB) recovered from invasive meningococcal disease (IMD) cases in Ontario, Canada, over the period 2001-2010 during which no MenB outbreaks had occurred. MenB was found to be responsible for 39 % of all IMD cases, with the remaining cases caused mainly by serogroups Y (28 %), C (23.5 %) and W135 (8 %). One hundred and ninety-three individual MenB case isolates were collected and characterized. Of the 88 sequence types (STs) identified, 75 were grouped into 14 known clonal complexes (CCs), whilst 13 STs were not assigned to any known CC. Fifty-seven different PorA genotypes and 88 STs defined the diversity of invasive MenB in Ontario, which supported the endemic nature of MenB disease in Ontario. Despite the presence of the hypervirulent ST-41/44 and ST-32 CCs, no single ST was predominant and responsible for a large number of IMD cases. Although the Québec outbreak clone of ST-269 was also found in Ontario, the 20 case isolates were genetically diverse: they grouped into seven STs and did not have a predominant PorA genotype. eburst analysis identified a new CC responsible for 14.5 % of the MenB case isolates. The six most common PorA variable region 2 (VR2) genotypes (VR2-9, -4, -14, -16, -13-1 and -16-3) were found in 67 % of invasive MenB isolates.
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Affiliation(s)
- Frances B Jamieson
- Faculty of Medicine, University of Toronto, Ontario, Canada.,Public Health Ontario Laboratory, Public Health Ontario, Ontario, Canada
| | - Prasad Rawte
- Public Health Ontario Laboratory, Public Health Ontario, Ontario, Canada
| | - Shelley L Deeks
- Dalla Lana School of Public Health, University of Toronto, Ontario, Canada.,Surveillance and Epidemiology, Public Health Ontario, Ontario, Canada
| | - Jianwei Zhou
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Dennis K S Law
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Saul Deng
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Raymond S W Tsang
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
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