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Gorringe AR, van Alphen L. 16th International Pathogenic Neisseria Conference: Recent progress towards effective meningococcal disease vaccines. Human Vaccines 2014; 5:53-6. [DOI: 10.4161/hv.5.2.7100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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van Gils EJM, Hak E, Veenhoven RH, Rodenburg GD, Bogaert D, Bruin JP, van Alphen L, Sanders EAM. Effect of seven-valent pneumococcal conjugate vaccine on Staphylococcus aureus colonisation in a randomised controlled trial. PLoS One 2011; 6:e20229. [PMID: 21695210 PMCID: PMC3112202 DOI: 10.1371/journal.pone.0020229] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 04/12/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Heptavalent pneumococcal conjugate vaccine (PCV7) shifts nasopharyngeal colonisation with vaccine serotype pneumococci towards nonvaccine serotypes. Because of the reported negative association of vaccine serotype pneumococci and Staphylococcus aureus in the nasopharynx, we explored the effect of PCV7 on nasopharyngeal colonisation with S. aureus in children and parents. METHODOLOGY/PRINCIPAL FINDINGS This study was part of a randomised controlled trial on the effect of PCV7 on pneumococcal carriage, enrolling healthy newborns who were randomly assigned (1:1:1) to receive PCV7 (1) at 2 and 4 months of age (2) at 2, 4 and 11 months or (3) no PCV7 (controls). Nasopharyngeal colonisation of S. aureus was a planned secondary outcome. Nasopharyngeal swabs were obtained from all children over a 2-year period with 6-months interval and from one parent at the child's age of 12 and 24 months and cultured for Streptococcus pneumoniae and S. aureus. Between July 2005 and February 2006, 1005 children were enrolled and received either 2-doses of PCV7 (n = 336), 2+1-doses (336) or no dose (n = 333) before PCV7 implementation in the Dutch national immunization program. S. aureus colonisation had doubled in children in the 2+1-dose group at 12 months of age compared with unvaccinated controls (10.1% versus 5.0%; p = 0.019). A negative association for co-colonisation of S. pneumoniae and S. aureus was observed for both vaccine serotype (adjusted odds ratio (aOR) 0.53, 95% confidence interval (CI) 0.38-0.74) and nonvaccine serotype pneumococci (aOR 0.67, 95% CI 0.52-0.88). CONCLUSIONS/SIGNIFICANCE PCV7 induces a temporary increase in S. aureus colonisation in children around 12 months of age after a 2+1-dose PCV7 schedule. The potential clinical consequences are unknown and monitoring is warranted. TRIAL REGISTRATION ClinicalTrials.gov NCT00189020.
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Affiliation(s)
- Elske J M van Gils
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands.
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van Gils EJM, Veenhoven RH, Hak E, Rodenburg GD, Keijzers WCM, Bogaert D, Trzcinski K, Bruin JP, van Alphen L, van der Ende A, Sanders EAM. Pneumococcal conjugate vaccination and nasopharyngeal acquisition of pneumococcal serotype 19A strains. JAMA 2010; 304:1099-106. [PMID: 20823436 DOI: 10.1001/jama.2010.1290] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT The rapid increase in multiresistant serotype 19A as a cause of invasive and respiratory pneumococcal disease has been associated in time with the widespread implementation of 7-valent pneumococcal conjugate vaccination (PCV-7) in several countries. Because spontaneous fluctuations in time and antibiotic selective pressure may have induced this serotype 19A increase, controlled studies are needed to assess the role of PCV-7. OBJECTIVE To examine the association of PCV-7 vaccination and nasopharyngeal acquisition of serotype 19A pneumococci, their clonal distribution, and antibiotic susceptibility. DESIGN, SETTING, AND PATIENTS Post hoc per-protocol completer's analysis as part of a randomized controlled trial of nasopharyngeal Streptococcus pneumoniae carriage enrolling 1003 healthy newborns with follow-up to the age of 24 months in The Netherlands, which has low antibiotic resistance rates. The study was conducted before widespread PCV-7 implementation in infants, between July 7, 2005, and February 14, 2008. Nasopharyngeal swabs were obtained at the age of 6 weeks and at 6, 12, 18, and 24 months. INTERVENTION Infants were randomly assigned to receive 2 doses of PCV-7 at 2 and 4 months; 2 + 1 doses of PCV-7 at 2, 4, and 11 months; or no dosage (unvaccinated control group). MAIN OUTCOME MEASURE Cumulative proportion of children with nasopharyngeal acquisition of a new serotype 19A strain from 6 through 24 months of age. RESULTS Nine hundred forty-eight children completed the study. Fifty-four nasopharyngeal serotype 19A carriage isolates from 318 in the 2-dose group, 66 isolates from 327 in the 2 + 1-dose group, and 33 isolates from 303 in the unvaccinated were collected from 6 weeks through 24 months. The cumulative proportion who tested positive for new nasopharyngeal serotype 19A acquisition from 6 through 24 months of age was significantly higher in those having received the 2 + 1-dose PCV-7 schedule (16.2%; 95% confidence interval [CI], 12.6%-20.6%) vs those who were unvaccinated (9.2%; 95% CI, 6.5%-13.0%; relative risk [RR], 1.75; 95% CI, 1.14-2.70) but not after a 2-dose schedule (13.2%; 95% CI, 9.9%-17.4%; RR, 1.43; 95% CI, 0.91-2.25). There were 28 different sequence types identified, including 6 new types. The proportion of children with new 19A acquisition who had used antibiotics in the last 6 months (18.7%) did not differ among groups. Five isolates were penicillin-intermediate susceptible and another 3 were nonsusceptible to erythromycin and azithromycin, all in the vaccine groups. CONCLUSION A 2 + 1-dose PCV-7 schedule was associated with an increase in serotype 19A nasopharyngeal acquisition compared with unvaccinated controls. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00189020.
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Affiliation(s)
- Elske J M van Gils
- University Medical Center Utrecht, Wilhelmina Children's Hospital, Department of Pediatric Immunology and Infectious Diseases, 3508 AB Utrecht, The Netherlands
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Abstract
As a consequence of the increased role of pharmacoeconomics in policy-making, economic evaluations are performed at more and more early stages in the development of a therapeutic. This implies the development of models to assess the future impact of an intervention and to account for the level of uncertainty in the associated parameters. This also applies for economic evaluations of vaccines, where not only progression of disease and associated costs are important, but the transmission of the causing agent in the target population also has to be modelled. In this review, we provide an overview of the models that have been used in recent publications on the pharmacoeconomics of vaccines and go deeper into some of the methodological issues associated with the use of models in the economic evaluation of vaccines.
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Affiliation(s)
- Jasper M Bos
- GUIDE, Dept. of Social Pharmacy, University Groningen, Antonius Deusinghlaan 1, 9713 AV, Groningen, The Netherlands.
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van Alphen L. Portrait of a leading vaccinologist: dedicated to meningitis and respiratory tract infections. Hum Vaccin 2009; 5:722-6. [PMID: 19855175 DOI: 10.4161/hv.5.11.10278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Since the early days of Jenner, vaccination against infectious agents appeared a very efficacious way for preventing millions of deaths and patients with serious sequelae. However, only limited success has been obtained in eradicating infectious diseases. Smallpox is the only human infectious disease that has been eradicated so far by vaccination, and eradication of polio is in its endgame. Data from the WHO in 2003 show that 2.5 million children under five still die from vaccine preventable diseases, but many more die from the major microbial killers in the world, i.e. HIV/AIDS, malaria and tuberculosis for which there are no effective vaccines. Very serious morbidity is the consequence of many infectious diseases often leading to disablement for a lifetime. As a junior post-doc with a position in the department of Medical Microbiology at the University of Amsterdam, I was touched by the seriousness of bacterial meningitis. This laboratory is the National Reference Center for Bacterial Meningitis in the Netherlands. It receives more than 80% of all isolates from meningitis patients in the country and has access to patient information for epidemiological research. This environment triggered me to use my experience as a biochemist with a PhD on composition, structure and functioning of the outer membrane of Escherichia coli to move from basic microbiology research to research on pathogenic bacteria, and ultimately prevention of serious bacterial infections.
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Jansen AGSC, Rodenburg GD, van der Ende A, van Alphen L, Veenhoven RH, Spanjaard L, Sanders EAM, Hak E. Invasive pneumococcal disease among adults: associations among serotypes, disease characteristics, and outcome. Clin Infect Dis 2009; 49:e23-9. [PMID: 19522653 DOI: 10.1086/600045] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND The Streptococcus pneumoniae polysaccharide capsule may be related to invasive pneumococcal disease (IPD) course. METHODS We performed a retrospective cohort study with nationally representative surveillance data from 1075 hospitalized patients with IPD from the Netherlands from 1 June 2004 through 31 May 2006 in the prevaccination era. Serotypes were grouped according to invasive disease potential, rate of the most serious clinical syndromes of meningitis and bacteremia without focus, and case-fatality rates. Multivariable logistic regression analysis was performed to obtain odds ratios adjusted for baseline confounders for the association of serotypes and these outcomes, using the serotypes with the lowest rates as reference. RESULTS IPD caused by serogroups with low invasive disease potential concerned meningitis or bacteremia without focus in 22% of cases, and 74% of patients had an underlying comorbidity. For highly invasive serogroups these figures were 10% (P < .01) and 56% (P < .01). Individual serotypes varied in the relative rate by which they caused meningitis or bacteremia without focus. Compared with the reference group composed of serotypes 1, 5, 7F, 15B, 20, and 33F, the group of serotypes 3, 19F, 23A, 16F, 6B, 9N, and 18C was associated with increased case-fatality rates (group adjusted odds ratio, 2.6; 95% confidence interval, 1.5-4.7). CONCLUSIONS The serotype appeared to be independently associated with IPD severity in adults, which indicates that careful monitoring of IPD after implementation of conjugate vaccines is necessary.
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Affiliation(s)
- Angelique G S C Jansen
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands
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van Gils EJM, Veenhoven RH, Hak E, Rodenburg GD, Bogaert D, Ijzerman EPF, Bruin JP, van Alphen L, Sanders EAM. Effect of reduced-dose schedules with 7-valent pneumococcal conjugate vaccine on nasopharyngeal pneumococcal carriage in children: a randomized controlled trial. JAMA 2009; 302:159-67. [PMID: 19584345 DOI: 10.1001/jama.2009.975] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT The effects of reduced-dose schedules of 7-valent pneumococcal conjugate vaccine (PCV-7) on pneumococcal carriage in children are largely unknown, although highly relevant in the context of subsequent herd effects. OBJECTIVE To examine the effects of a 2-dose and 2 + 1-dose PCV-7 schedule on nasopharyngeal pneumococcal carriage in young children compared with controls. DESIGN, SETTING, AND PATIENTS A randomized controlled trial of nasopharyngeal carriage of Streptococcus pneumoniae enrolling 1003 healthy newborns and 1 of their parents in a general community in The Netherlands, with follow-up to age 24 months and conducted between July 7, 2005, and February 14, 2008. INTERVENTION Infants were randomly assigned to receive 2 doses of PCV-7 at 2 and 4 months; 2 + 1 doses of PCV-7 at 2, 4, and 11 months; or no dosage (control group). MAIN OUTCOME MEASURE Vaccine serotype pneumococcal carriage rates in infants in the second year of life. RESULTS At 12 months, vaccine serotype pneumococcal carriage was significantly decreased after both PCV-7 schedules, with vaccine serotype pneumococcal carriage rates of 25% (95% confidence interval [CI], 20%-30%) and 20% (95% CI, 16%-25%) in the 2-dose and 2 + 1-dose schedule groups, respectively, vs 38% (95% CI, 33%-44%) in the control group (both P < .001). At 18 months, in the 2 + 1-dose schedule group, vaccine serotype pneumococcal carriage had further decreased to 16% (95% CI, 12%-20%) and, at 24 months, to 14% (95% CI, 11%-18%; both P < .001); whereas in the 2-dose schedule group, vaccine serotype pneumococcal carriage had remained stable at 18 months (24%; 95% CI, 20%-29%), but at 24 months had further decreased to 15% (95% CI, 11%-19%; both P < .001). In the control group, vaccine serotype pneumococcal carriage remained around 36% to 38% until 24 months. CONCLUSION Compared with no pneumococcal vaccination, a 2 + 1-dose and 2-dose schedule of PCV-7 resulted in significant reductions of vaccine serotype pneumococcal carriage in the second year of life. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00189020.
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Affiliation(s)
- Elske J M van Gils
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, PO Box 85090, 3508 AB Utrecht, The Netherlands
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8
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Abstract
In this commentary we stress that serum bactericidal activity is now internationally accepted as correlate of protection for evaluating new vaccines for epidemic and endemic meningococcal B control, and that the standardization of the assay and the choice of representative strains for each of the vaccine candidates are critical.
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van den Dobbelsteen GPJM, van Dijken HH, Pillai S, van Alphen L. Immunogenicity of a combination vaccine containing pneumococcal conjugates and meningococcal PorA OMVs. Vaccine 2006; 25:2491-6. [PMID: 17023098 DOI: 10.1016/j.vaccine.2006.09.025] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The pre-clinical immunogenicity of a combination vaccine containing 13-valent pneumococcal conjugate (13vPnC) vaccine (serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F conjugated to CRM197) and nine-valent meningococcal B PorA vaccine (NonaMen; serosubtypes P1.7,16; P1.5-1,2-2; P1.19,15-1; P1.5-2,10; P1.12-1,13; P1.7-2,4; P1.22,14; P1.7-1,1 and P1.18-1,3,6), and any potential immunological interference between pneumococcal and MenB components of the vaccine were evaluated. NIH mice were immunized twice subcutaneously with the vaccines combined in one syringe, or given individually. Combining 13vPnC vaccine with NonaMen vaccine in one syringe had no negative effect on the induced antibody response against any MenB serosubtypes compared to separate injection of the vaccines, and the anti-pneumococcal antibody responses were enhanced. Furthermore, co-administration of the combination vaccine with a combined diphtheria/tetanus/acellular pertussis/inactivated poliomyelitis vaccine/Haemophilus influenzae type b-TT conjugate (DTaP/IPV-Hib) vaccine to New Zealand white rabbits at a different injection site did not affect the anti-pneumococcal polysaccharide and anti-PorA antibody titres. We conclude that no immunological interference was observed by combined administration of pneumococcal conjugate and meningococcal B vaccines in one syringe.
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van Ulsen P, Adler B, Fassler P, Gilbert M, van Schilfgaarde M, van der Ley P, van Alphen L, Tommassen J. A novel phase-variable autotransporter serine protease, AusI, of Neisseria meningitidis. Microbes Infect 2006; 8:2088-97. [PMID: 16824779 DOI: 10.1016/j.micinf.2006.03.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 03/23/2006] [Accepted: 03/23/2006] [Indexed: 11/29/2022]
Abstract
The sequenced genomes of pathogenic Neisseria meningitidis strains contain up to eight genes putatively encoding autotransporters, which are secreted proteins implicated in virulence. Here, we have characterized one of these genes, designated ausI, which encodes an autotransporter of the serine protease family. It was found to be specific for N. meningitidis and present in 14 out of 20 isolates, although only six of them expressed the gene. We show that expression of the gene is subject to phase variation as a result of a variable number of cytosines in a poly-C tract in the coding region. The open reading frame went out-of-phase at the poly-C tract in seven strains that did not express AusI. In the eighth strain, the open reading frame remained in frame at the poly-C tract, but it was disrupted by a premature stop codon further downstream. In accordance with its assignment as an autotransporter, a secreted AusI passenger domain was released into the extracellular milieu. This release was influenced by another autotransporter, NalP, as different forms of AusI were produced in the presence or absence of NalP. In silico sequence analysis suggested several putative functions for AusI, which, however, could not be confirmed experimentally.
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Affiliation(s)
- Peter van Ulsen
- Department of Molecular Microbiology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
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11
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Bos JM, Rümke HC, Welte R, Spanjaard L, van Alphen L, Postma MJ. Combination vaccine against invasive meningococcal B and pneumococcal infections: potential epidemiological and economic impact in the Netherlands. Pharmacoeconomics 2006; 24:141-53. [PMID: 16460135 DOI: 10.2165/00019053-200624020-00004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
BACKGROUND Streptococcus pneumoniae and Neisseria meningitidis group B are among the main causes of invasive bacterial meningitis infections in infants. Worldwide, these diseases lead to significant mortality, morbidity and costs. The societal impact is especially severe since the majority of cases occur in very young infants. A combination vaccine consisting of 9-valent conjugated pneumococcal and meningococcal B components is currently being developed. The aim of this study was to estimate the potential impact and cost effectiveness from the societal perspective of vaccinating infants in The Netherlands with this combination pneumococcal and meningococcal B vaccine versus no vaccination. METHODS A Markov cycle model was developed using epidemiological and healthcare resource use data from 1996 to 2001. This model was used to project the annual costs, benefits and health gains associated with vaccinating all newborns. The base year for the costing was 2003 and all costs and health effects were discounted at 4%. The results of the analysis are expressed in costs per QALY and both probabilistic and univariate sensitivity analyses were used to identify the robustness of the results. RESULTS Annually, an average of 755 cases of invasive pneumococcal and meningococcal B infection occurred in infants aged 0-10 years in The Netherlands. Introduction of the combination vaccine would prevent 201 cases of meningococcal B meningitis and 165 cases of invasive pneumococcal disease per year. Additionally, 3410 cases of pneumococcal pneumonia and 46,350 cases of otitis media would be prevented. Vaccination would save 35 lives per year and prevent 71 cases of severe sequelae. This translates into 860 life-years gained, or 1128 QALYs gained. Alongside these health gains, vaccination would prevent euro 17,681,370 of direct medical and indirect costs attributable to meningococcal and pneumococcal infections in The Netherlands. Depending on vaccine price, cost effectiveness varied from euro 3160 (vaccine price per dose euro 20) to euro 32,170 (vaccine price euro 60 per dose) per QALY. Base-case cost effectiveness (vaccine price euro 40) was euro 17,700 per QALY. The model was most sensitive to changes in incidence, vaccine price and duration of protective efficacy. CONCLUSION Our results suggest that the introduction of a combination meningococcal B and pneumococcal vaccine into the Dutch infant vaccination programme is potentially cost effective compared with no vaccination.
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Affiliation(s)
- Jasper M Bos
- Department of Social Pharmacy, Pharmaco-Epidemiology and Pharmacotherapy, Groningen University Institute for Drug Exploration/University of Groningen Research Institute of Pharmacy (GUIDE/GRIP), Groningen, The Netherlands.
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Erwin AL, Nelson KL, Mhlanga-Mutangadura T, Bonthuis PJ, Geelhood JL, Morlin G, Unrath WCT, Campos J, Crook DW, Farley MM, Henderson FW, Jacobs RF, Mühlemann K, Satola SW, van Alphen L, Golomb M, Smith AL. Characterization of genetic and phenotypic diversity of invasive nontypeable Haemophilus influenzae. Infect Immun 2005; 73:5853-63. [PMID: 16113304 PMCID: PMC1231076 DOI: 10.1128/iai.73.9.5853-5863.2005] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ability of unencapsulated (nontypeable) Haemophilus influenzae (NTHi) to cause systemic disease in healthy children has been recognized only in the past decade. To determine the extent of similarity among invasive nontypeable isolates, we compared strain R2866 with 16 additional NTHi isolates from blood and spinal fluid, 17 nasopharyngeal or throat isolates from healthy children, and 19 isolates from middle ear aspirates. The strains were evaluated for the presence of several genetic loci that affect bacterial surface structures and for biochemical reactions that are known to differ among H. influenzae strains. Eight strains, including four blood isolates, shared several properties with R2866: they were biotype V (indole and ornithine decarboxylase positive, urease negative), contained sequence from the adhesin gene hia, and lacked a genetic island flanked by the infA and ksgA genes. Multilocus sequence typing showed that most biotype V isolates belonged to the same phylogenetic cluster as strain R2866. When present, the infA-ksgA island contains lipopolysaccharide biosynthetic genes, either lic2B and lic2C or homologs of the losA and losB genes described for Haemophilus ducreyi. The island was found in most nasopharyngeal and otitis isolates but was absent from 40% of invasive isolates. Overall, the 33 hmw-negative isolates were much more likely than hmw-containing isolates to have tryptophanase, ornithine decarboxylase, or lysine decarboxylase activity or to contain the hif genes. We conclude (i) that invasive isolates are genetically and phenotypically diverse and (ii) that certain genetic loci of NTHi are frequently found in association among NTHi strains.
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Affiliation(s)
- Alice L Erwin
- Seattle Biomedical Research Institute, 307 Westlake Ave. N., Suite 500, Seattle, WA 98109-5219, USA.
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13
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Oomen CJ, Hoogerhout P, Kuipers B, Vidarsson G, van Alphen L, Gros P. Crystal Structure of an Anti-meningococcal Subtype P1.4 PorA Antibody Provides Basis for Peptide–Vaccine Design. J Mol Biol 2005; 351:1070-80. [PMID: 16038932 DOI: 10.1016/j.jmb.2005.06.061] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2005] [Revised: 06/23/2005] [Accepted: 06/27/2005] [Indexed: 10/25/2022]
Abstract
In various western countries, subtype P1.4 of Neisseria meningitidis serogroup B causes the greatest incidence of meningococcal disease. To investigate the molecular recognition of this subtype, we crystallised a peptide (P1HVVVNNKVATH(P11)), corresponding to the subtype P1.4 epitope sequence of outer membrane protein PorA, in complex with a Fab fragment of the bactericidal antibody MN20B9.34 directed against this epitope. Structure determination at 1.95 A resolution revealed a unique complex of one P1.4 antigen peptide bound to two identical Fab fragments. One Fab recognises the putative epitope residues in a 2:2 type I beta-turn at residues P5NNKV(P8), whereas the other Fab binds the C-terminal residues of the peptide that we consider a crystallisation artefact. Interestingly, recognition of the P1.4 epitope peptide is mediated almost exclusively through the complementarity-determining regions of the heavy chain. We exploited the observed turn conformation for designing conformationally restricted cyclic peptides for use as a peptide vaccine. The conformational stability of the two peptide designs was assessed by molecular dynamics simulations. Unlike the linear peptide, both cyclic peptides, conjugated to tetanus toxoid as a carrier protein, elicited antibody responses in mice that recognised meningococci of subtype P1.7-2,4. Serum bactericidal assays showed that some, but not all, of the sera induced with the cyclic peptide conjugates could activate the complement system with titres that were very high compared to the titres induced by complete PorA protein in its native conformation administered in outer membrane vesicles.
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Affiliation(s)
- Clasien J Oomen
- Department of Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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14
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de Jonge MI, Hamstra HJ, Jiskoot W, Roholl P, Williams NA, Dankert J, van Alphen L, van der Ley P. Intranasal immunisation of mice with liposomes containing recombinant meningococcal OpaB and OpaJ proteins. Vaccine 2004; 22:4021-8. [PMID: 15364452 DOI: 10.1016/j.vaccine.2004.03.047] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2003] [Revised: 03/18/2004] [Accepted: 03/29/2004] [Indexed: 11/27/2022]
Abstract
The opacity (Opa) proteins of Neisseria meningitidis are outer membrane proteins involved in adhesion and invasion of host epithelial cells and are therefore expected to play an important role in colonisation of the nasopharynx. The majority of meningococcal Opa proteins bind to members of the CEACAM receptor family, such as CEA. Blocking of the Opa-CEACAM interaction by mucosal anti-Opa antibodies could thus constitute an important protective mechanism for novel meningococcal vaccines. In this study we analysed the specific anti-Opa antibody responses after intranasal immunisation of mice with liposomes containing purified and native OpaB (recognising the CEA receptor) and OpaJ (no affinity for CEA) proteins. These antigens were combined with or without one of three different adjuvants, i.e. purified meningococcal LPS, monophosphoryl lipid A (MPL) or the B-subunit of Escherichia coli heat-labile enterotoxin (EtxB). After intranasal immunisation with any of these formulations, anti-Opa IgA antibodies were found in nasal lavages and in some cases anti-Opa IgA and IgG antibodies were also found in lung lavages. With OpaJ but not OpaB, significant bactericidal serum titres were obtained. Of the different adjuvants used, meningococcal LPS gave the strongest overall immune response. Non-adjuvated liposomal Opa formulations were poorly immunogenic. No differences were found between the immune response in transgenic mice expressing the CEA-receptor and non-transgenic mice, showing that the CEA-Opa interaction does not influence the antibody response.
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MESH Headings
- Adjuvants, Immunologic
- Administration, Intranasal
- Animals
- Antibodies, Bacterial/analysis
- Antibodies, Bacterial/blood
- Antibodies, Bacterial/immunology
- Antigens, Bacterial/administration & dosage
- Antigens, Bacterial/immunology
- Antigens, Bacterial/isolation & purification
- Bacterial Outer Membrane Proteins/administration & dosage
- Bacterial Outer Membrane Proteins/immunology
- Bacterial Outer Membrane Proteins/isolation & purification
- Bacterial Toxins/pharmacology
- Bronchoalveolar Lavage Fluid/immunology
- Enterotoxins/pharmacology
- Escherichia coli Proteins/pharmacology
- Immunoglobulin A/analysis
- Immunoglobulin A/immunology
- Immunoglobulin G/analysis
- Immunoglobulin G/immunology
- Lipid A/analogs & derivatives
- Lipid A/immunology
- Lipopolysaccharides/immunology
- Liposomes
- Meningitis, Meningococcal/prevention & control
- Meningococcal Vaccines/administration & dosage
- Meningococcal Vaccines/immunology
- Mice
- Mice, Transgenic
- Nasal Lavage Fluid/immunology
- Neisseria meningitidis/immunology
- Vaccination/methods
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Affiliation(s)
- Marien I de Jonge
- Netherlands Vaccine Institute (NVI), 3720 AL Bilthoven, The Netherlands
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van Ulsen P, van Alphen L, ten Hove J, Fransen F, van der Ley P, Tommassen J. A Neisserial autotransporter NalP modulating the processing of other autotransporters. Mol Microbiol 2004; 50:1017-30. [PMID: 14617158 DOI: 10.1046/j.1365-2958.2003.03773.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Autotransporters constitute a relatively simple secretion system in Gram-negative bacteria, depending for their translocation across the outer membrane only on a C-terminal translocator domain. We have studied a novel autotransporter serine protease, designated NalP, from Neisseria meningitidis strain H44/76, featuring a lipoprotein motif at the signal sequence cleavage site. Indeed, lipidation of NalP could be demonstrated, but the secreted 70 kDa domain of NalP lacked the lipid-moiety as a result of additional N-terminal processing. A nalP mutant showed a drastically altered profile of secreted proteins. Mass-spectrometric analysis of tryptic fragments identified the autotransporters IgA protease and App, a homologue of the adhesin Hap of Haemophilus influenzae, as the major secreted proteins. Two forms of both of these proteins were found in the culture supernatant of the wild-type strain, whereas only the lower molecular-weight forms predominated in the culture supernatant of the nalP mutant. The serine-protease active site of NalP was required for the modulation of the processing of these autotransporters. We propose that, apart from the autoproteolytic processing, NalP can process App and IgA protease and hypothesize that this function of NalP could contribute to the virulence of the organism.
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Affiliation(s)
- Peter van Ulsen
- Department of Molecular Microbiology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands.
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16
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Abstract
The opacity (Opa) proteins of pathogenic Neisseria spp. are adhesins, which play an important role in adhesion and invasion of host cells. Most members of this highly variable family of outer membrane proteins can bind to the human carcinoembryonic antigen-related cell adhesion molecules (CEACAMs). Several studies have identified the Opa-binding region on the CEACAM receptors; however, not much is known about the binding sites on the Opa proteins for the corresponding CEACAM-receptors. The high degree of sequence variation in the surface-exposed loops of Opa proteins raises the question how the binding sites for the CEACAM receptors are conserved. Neisseria meningitidis strain H44/76 possesses four different Opa proteins, of which OpaA and OpaJ bind to CEACAM1, while OpaB and OpaD bind to CEACAM1 and CEA. A sequence motif involved in binding to CEACAM1 was identified by alanine scanning mutagenesis of those amino acid residues conserved within the hypervariable (HV) regions of all four Opa proteins. Hybrid Opa variants with different combinations of HV-1 and HV-2 derived from OpaB and OpaJ showed a reduced binding to CEACAM1 and CEA, indicating that particular combinations of HV-1 and HV-2 are required for the Opa binding capacity. Homologue scanning mutagenesis was used to generate more refined hybrids containing novel combinations of OpaB and OpaJ sequences within HV-1 and HV-2. They could be used to identify residues determining the specificity for CEA binding. The combined results obtained with mutants and hybrids strongly suggest the existence of a conserved binding site for CEACAM receptors by the interaction of HV-1 and HV-2 regions.
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Affiliation(s)
- Marien I de Jonge
- Laboratory of Vaccine Research, Netherlands Vaccine Institute, Bilthoven, the Netherlands
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17
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Luijkx TA, van Dijken H, Hamstra HJ, Kuipers B, van der Ley P, van Alphen L, van den Dobbelsteen G. Relative immunogenicity of PorA subtypes in a multivalent Neisseria meningitidis vaccine is not dependent on presentation form. Infect Immun 2003; 71:6367-71. [PMID: 14573657 PMCID: PMC219571 DOI: 10.1128/iai.71.11.6367-6371.2003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The hexavalent meningococcal vaccine HexaMen, containing six PorAs on two vesicles, was tested in clinical studies. Although fourfold increases in serum bactericidal activity (SBA) titers against all of the PorAs were observed, there were significant differences between PorA-specific SBA titers. SBA titers were mainly directed against one PorA from each vesicle, P1.5-2,10 and P1.5-1,2-2, and were lower against the other PorAs, especially P1.7-2,4 and P1.19,15-1. We investigated whether these differences were due to immunological interference that resulted in competition between the three PorAs on the same vesicle or whether they were caused by a difference in the immunogenicities of the separate PorAs. Therefore, mice were immunized either with HexaMen, with six monovalent outer membrane vesicles (OMVs) representing the same six PorAs simultaneously (HexaMix), or with only one of the monovalent OMVs. The immunoglobulin G and SBA titers after HexaMen immunization in mice resembled the results obtained in clinical studies. Although immunization with HexaMix gave higher titers than immunization with HexaMen for some PorAs, the pattern of high and low titers was the same. Similar differences in immunogenicity between subtypes were seen after monovalent immunization when interference was eliminated as a cause of the differences. Monovalent immunization resulted in higher titers for P1.5-1,2-2 and P1.7,16 than immunization with HexaMen. However, no significant differences were found for the weakly immunogenic PorAs, P1.7-2,4 and P1.19,15-1. Since immunization with the six PorAs in the trivalent presentation form (HexaMen) and in the mixture of monovalent vesicles (HexaMix) resulted in the same pattern of high and low titers, we concluded that the differences between the PorA-specific responses are due to differences in the immunogenicities of the various PorAs and not due to interference that results in competition between different PorAs.
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Affiliation(s)
- Thomas A Luijkx
- Laboratory for Vaccine Research, Netherlands Vaccine Institute, 3720 AL Bilthoven, The
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18
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de Greeff A, Hamilton A, Sutcliffe IC, Buys H, van Alphen L, Smith HE. Lipoprotein signal peptidase of Streptococcus suis serotype 2. Microbiology (Reading) 2003; 149:1399-1407. [PMID: 12777481 DOI: 10.1099/mic.0.26329-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This paper reports the complete coding sequence for a proliprotein signal peptidase (SP-ase) of Streptococcus suis, Lsp. This is believed to be the first SP-ase described for S. suis. SP-ase II is involved in the removal of the signal peptide from glyceride-modified prolipoproteins. By using in vitro transcription/translation systems, it was shown that the lsp gene was transcribed in vitro. Functionality of Lsp in Escherichia coli was demonstrated by using an in vitro globomycin resistance assay, to show that expression of Lsp in E. coli increased the globomycin resistance. An isogenic mutant of S. suis serotype 2 unable to produce Lsp was constructed and shown to process lipoproteins incorrectly, including an S. suis homologue of the pneumococcal PsaA lipoprotein. Five piglets were inoculated with a mixture of both strains in an experimental infection, to determine the virulence of the mutant strain relative to that of the wild-type strain in a competitive challenge experiment. The data showed that both strains were equally virulent, indicating that the knockout mutant of lsp is not attenuated in vivo.
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Affiliation(s)
- Astrid de Greeff
- Department of Medical Microbiology, University of Amsterdam, 1100 DD Amsterdam, The Netherlands
- Division of Infectious Diseases and Food Chain Quality, Cluster of Endemic Diseases, Institute of Animal Science and Health, 8200 AB Lelystad, The Netherlands
| | - Andrea Hamilton
- Institute of Pharmacy, Chemistry and Biomedical Sciences, University of Sunderland, UK
| | - Iain C Sutcliffe
- Institute of Pharmacy, Chemistry and Biomedical Sciences, University of Sunderland, UK
| | - Herma Buys
- Division of Infectious Diseases and Food Chain Quality, Cluster of Endemic Diseases, Institute of Animal Science and Health, 8200 AB Lelystad, The Netherlands
| | - Loek van Alphen
- Laboratory for Vaccine Research, RIVM, National Institute of Public Health and the Environment, 3720 BA Bilthoven, The Netherlands
- Department of Medical Microbiology, University of Amsterdam, 1100 DD Amsterdam, The Netherlands
| | - Hilde E Smith
- Division of Infectious Diseases and Food Chain Quality, Cluster of Endemic Diseases, Institute of Animal Science and Health, 8200 AB Lelystad, The Netherlands
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19
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Oomen CJ, Hoogerhout P, Bonvin AMJJ, Kuipers B, Brugghe H, Timmermans H, Haseley SR, van Alphen L, Gros P. Immunogenicity of peptide-vaccine candidates predicted by molecular dynamics simulations. J Mol Biol 2003; 328:1083-9. [PMID: 12729743 DOI: 10.1016/s0022-2836(03)00377-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We present an in silico, structure-based approach for design and evaluation of conformationally restricted peptide-vaccines. In particular, we designed four cyclic peptides of ten or 11 residues mimicking the crystallographically observed beta-turn conformation of a predicted immunodominant loop of PorA from Neisseria meningitidis. Conformational correctness and stability of the peptide designs, as evaluated by molecular dynamics simulations, correctly predicted the immunogenicity of the peptides. We observed a peptide-induced functional antibody response that, remarkably, exceeded the response induced by the native protein in outer membrane vesicles, without losing specificity for related strains. The presented approach offers tools for a priori design and selection of peptide-vaccine candidates with full biological activity. This approach could be widely applicable: to outer membrane proteins of Gram-negative bacteria, and to other epitopes in a large range of pathogens.
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Affiliation(s)
- Clasien J Oomen
- Department of Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, NL-3584 CH Utrecht, The Netherlands
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20
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van Belkum A, van Alphen L. Diagnosis of infection. Methods Mol Med 2003; 71:71-92. [PMID: 12374032 DOI: 10.1385/1-59259-321-6:71] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Affiliation(s)
- Alex van Belkum
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center Rotterdam EMCR, Department of Medical Microbiology and Infectious Diseases, Rotterdam, The Netherlands
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21
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Gorter AD, Oostrik J, van der Ley P, Hiemstra PS, Dankert J, van Alphen L. Involvement of lipooligosaccharides of Haemophilus influenzae and Neisseria meningitidis in defensin-enhanced bacterial adherence to epithelial cells. Microb Pathog 2003; 34:121-30. [PMID: 12631473 DOI: 10.1016/s0882-4010(02)00193-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Stimulated neutrophils release a variety of antimicrobial peptides, including neutrophil defensins (HNP1-4). We have previously reported that neutrophil defensins enhanced the adherence of Haemophilus influenzae and Neisseria meningitidis to cultured respiratory epithelial cells. In this study, the effect of defensins on the adherence of H. influenzae and N. meningitidis lipooligosaccharide (LOS) mutants to epithelial cells was tested. Neutrophil defensins enhanced the adherence of the oligosaccharide mutants of H. influenzae and N. meningitidis, whilst the adherence of the lipid A mutants B29 of H. influenzae and lpxL1 and lpxL2 of N. meningitidis was not or only moderately stimulated by neutrophil defensins. The adherence of the N. meningitidis LOS negative mutant lpxA was not enhanced by defensins. These findings suggested that the secondary fatty acids of lipid A were involved in the defensin-enhanced adherence. LOS from strain H44/76 or HNP-LOS complexes did not affect or stimulate the adherence of N. meningitidis, although the defensin-enhanced adherence is specific for certain bacterial species having LOS in their outer membrane. These results indicated that LOS is involved in the defensin-enhanced adherence. However, the mechanism by which defensins and LOS interact with epithelial cells to promote bacterial adherence remains to be resolved.
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Affiliation(s)
- Annelies D Gorter
- Department of Medical Microbiology, Academic Medical Center, Amsterdam, The Netherlands
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22
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Solzbacher D, Hanisch FG, van Alphen L, Gilsdorf JR, Schroten H. Mucin in middle ear effusions inhibits attachment of Haemophilus influenzae to mucosal epithelial cells. Eur Arch Otorhinolaryngol 2003; 260:141-7. [PMID: 12687386 DOI: 10.1007/s00405-002-0535-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2002] [Accepted: 08/09/2002] [Indexed: 10/25/2022]
Abstract
Although otitis media with effusion is often preceded by an infection of the tympanic cavity, when cultured, many effusions show no culturable bacteria. Based on the hypothesis that the effusion might play a protective role in the course of infection, the influence of this fluid on adhesion of H. influenzae (Hi) type-b strain 770235 and nontypeable H. influenzae (NTHi) strains to buccal epithelial cells was investigated. Effusions were classified as mucoid, seromucoid and serous. Mucoid secretions inhibited adhesion to a significantly greater extent (62%) than did seromucous (52%) and serous effusions (47%) ( P<0.001). The glycoprotein and high-molecular-weight fractions showed similar levels of inhibition. Sialic acid concentration, and, to a lesser extent, protein concentration, correlated with the level of inhibition. Desialylated effusions lost their ability to block bacterial attachment. Thus, middle ear effusion fluid exhibits an inhibitory effect that is due to mucins, which determine viscosity and represent the sialylated high-molecular-weight glycoprotein fraction of the effusion.
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23
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Bresser P, van Alphen L, Lutter R. New strains of bacteria and exacerbations of COPD. N Engl J Med 2002; 347:2077-9; author reply 2077-9; discussion 2077-9. [PMID: 12494936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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24
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de Jonge MI, Bos MP, Hamstra HJ, Jiskoot W, van Ulsen P, Tommassen J, van Alphen L, van der Ley P. Conformational analysis of opacity proteins from Neisseria meningitidis. Eur J Biochem 2002; 269:5215-23. [PMID: 12392553 DOI: 10.1046/j.1432-1033.2002.03228.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Opacity-associated (Opa) proteins are outer membrane proteins which play a critical role in the adhesion of pathogenic Neisseria spp. to epithelial and endothelial cells and polymorphonuclear neutrophils. The adherence is mainly mediated by the CD66-epitope-containing members of the carcinoembryonic-antigen family of human cell-adhesion molecules (CEACAM). For the analysis of the specific interactions of individual Opa proteins with their receptors, pure protein is needed in its native conformation. In this study, we describe the isolation and structural analysis of opacity proteins OpaJ129 and OpaB128 derived from Neisseria meningitidis strain H44/76. When the Opa proteins were produced with the phoE signal sequence in Escherichia coli, they were localized at the cell surface and the recombinant bacteria were found to specifically interact with CEACAM1. For refolding and purification, the proteins were overproduced without their signal sequences in E. coli, resulting in its cytoplasmic accumulation in the form of inclusion bodies. After solubilization of the inclusion bodies in urea, the proteins could be folded efficiently in vitro, under alkaline conditions by dilution in ethanolamine and the detergent n-dodecyl-N,N-dimethyl-1-ammonio-3-propanesulfonate (SB12). The structure of the refolded and purified proteins, determined by circular dichroism, indicated a high content of beta-sheet conformation, which is consistent with previously proposed topology models for Opa proteins. A clear difference was found between the binding of refolded vs. denatured OpaJ protein to the N-A1 domain of CEACAM1. Almost no binding was found with the denatured Opa protein, showing that the Opa-receptor interaction is conformation-dependent.
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Affiliation(s)
- Marien I de Jonge
- Laboratory of Vaccine Research, National Institute of Public Health and the Environment, RIVM Bilthoven, the Netherlands.
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25
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Abstract
In this study, we describe the first response regulator of Streptococcus suis serotype 2, designated RevS. RevS was cloned and the sequence was determined. No histidine kinase was found in the vicinity ofrevS, therefore RevS was considered to be an orphan response regulator. An isogenic knock-out mutant of RevS was shown to be attenuated in colonising the S. suis specific organs in a competitive assay in four piglets, indicating thatrevS plays a role in the pathogenesis of S. suis infections. We analysed the protein expression profiles of various fractions of the wild-type strain 10 and the mutant strain 10DeltaRevS. The expression of known virulence factors ofS. suis by wild-type and the mutant strain, was not different. However, one protein in the protoplast fraction, with unknown identity was shown to be repressed by revS in the exponential growth phase of the mutant.
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Affiliation(s)
- Astrid de Greeff
- Department of Medical Microbiology, University of Amsterdam, Academical Medical Center, The Netherlands.
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26
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Steeghs L, Berns M, ten Hove J, de Jong A, Roholl P, van Alphen L, Tommassen J, van der Ley P. Expression of foreign LpxA acyltransferases in Neisseria meningitidis results in modified lipid A with reduced toxicity and retained adjuvant activity. Cell Microbiol 2002; 4:599-611. [PMID: 12390352 DOI: 10.1046/j.1462-5822.2002.00214.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A major problem in the development of vaccines against Gram-negative bacteria is the endotoxic -activity of lipopolysaccharide (LPS), which is determined by its lipid A moiety. Nevertheless, LPS would be an interesting vaccine component because of its immune-stimulating properties. In the present study, we have changed the fatty acid composition of Neisseria meningitidis LPS by replacing the lpxA gene of strain H44/76 with the Escherichia coli or Pseudomonas aeruginosa homologue. The majority of the O-linked 3-OH C12 in N. meningitidis lipid A was replaced by 3-OH C14 (strain HA01E) and 3-OH C10 (strain HA25P) respectively. Both strains, but most notably strain HA01E, had reduced amounts of LPS compared with the wild-type strain. In addition, growth was severely impaired for HA01E. The major outer membrane proteins were expressed normally. Outer membrane complexes of both strains normalized on their LPS content showed a 10-fold reduction in their ability to induce tumour necrosis factor (TNF)-alpha. Immunogenicity studies in BALB/c mice revealed that the adjuvant activity of the LPS was not affected. Thus, the replacement of the O-linked fatty acids in meningococcal lipid A results in immunogenic outer membranes with reduced endotoxic activity, more suitable for use in outer membrane vesicle vaccines.
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Affiliation(s)
- Liana Steeghs
- Laboratory of Vaccine Research, National Institute of Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, PO Box 1, 3720 BA Bilthoven, The Netherlands.
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27
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van Ulsen P, van Schilfgaarde M, Dankert J, Jansen H, van Alphen L. Genes of non-typeable Haemophilus influenzae expressed during interaction with human epithelial cell lines. Mol Microbiol 2002; 45:485-500. [PMID: 12123458 DOI: 10.1046/j.1365-2958.2002.03025.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Non-typeable Haemophilus influenzae may infect the lower respiratory airways of chronic obstructive pulmonary disease patients. We characterized genes of non-typeable H. influenzae expressed during interaction with two human respiratory tract-derived epithelial cell lines. A library of 8000 clones was constructed in H. influenzae Rd (rec1) by cloning chromosomal fragments upstream of a promoterless cat gene. Exposure of this library to NCI-H292 epithelial cell layers in the presence of chloramphenicol (Cam) resulted in survival of bacteria expressing cat. A total of 52 clones were selected that were resistant to Cam in the presence of epithelial cells of cell line NCI-H292. These did not (n = 42) or hardly grow (n = 10) on sBHI plates containing Cam and were sensitive to Cam in cell culture medium alone. All clones, moreover, survived Cam in the presence of Hep2 epithelial cell layers. Sequence analysis showed that four clones contained sequences without homology to Rd or any other sequence, and therefore contained promoters and parts of open reading frames (ORFs) of novel genes. The other 48 clones were homologous to Rd, and characterization was based upon this genome. Six different functional classes were distinguished: (i) metabolic processes; (ii) stress response; (iii) gene expression; (iv) cell envelope biosynthesis; (v) DNA-related processes and cell division; and (vi) ORFs encoding proteins of unknown function. The contribution of identified genes to non-typeable H. influenzae adaptation to the epithelial cell environment is discussed.
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Affiliation(s)
- Peter van Ulsen
- Laboratory for Vaccine Research, National Institute of Public Health and the Environment, 3720 BA Bilthoven, The Netherlands.
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28
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de Greeff A, Buys H, Verhaar R, Dijkstra J, van Alphen L, Smith HE. Contribution of fibronectin-binding protein to pathogenesis of Streptococcus suis serotype 2. Infect Immun 2002; 70:1319-25. [PMID: 11854216 PMCID: PMC127759 DOI: 10.1128/iai.70.3.1319-1325.2002] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the present study we investigated the role of the fibronectin (FN)- and fibrinogen (FGN)-binding protein (FBPS) in the pathogenesis of Streptococcus suis serotype 2 in piglets. The complete gene encoding FBPS from S. suis serotype 2 was cloned in Escherichia coli and sequenced. The occurrence of the gene in various serotypes was analyzed by hybridization studies. The FBPS protein was expressed in E. coli and purified, and binding to human FN and FGN was demonstrated. The induction of antibodies in piglets was studied upon infection. An isogenic mutant unable to produce FBPS was constructed, and the levels of virulence of the wild-type and mutant strains were compared in a competitive infection model in young piglets. Organ cultures showed that FBPS was not required for colonization of the tonsils but that FBPS played a role in the colonization of the specific organs involved in an S. suis infection. Therefore, the FBPS mutant was considered as an attenuated mutant.
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Affiliation(s)
- Astrid de Greeff
- Department of Medical Microbiology, University of Amsterdam, The Netherlands.
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29
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Rijneveld AW, van den Dobbelsteen GP, Florquin S, Standiford TJ, Speelman P, van Alphen L, van der Poll T. Roles of interleukin-6 and macrophage inflammatory protein-2 in pneumolysin-induced lung inflammation in mice. J Infect Dis 2002; 185:123-6. [PMID: 11756992 DOI: 10.1086/338008] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2001] [Revised: 09/18/2001] [Indexed: 11/03/2022] Open
Abstract
Pneumolysin (PLY), a toxin synthesized by Streptococcus pneumoniae, is an important virulence factor in pneumococcal disease. This study evaluated the effects of PLY in lungs of mice. Intranasal inoculation with PLY was associated with a dose-dependent influx of polymorphonuclear leukocytes (PMNL) in bronchoalveolar lavage fluid (BALF) and increased concentrations of interleukin (IL)-6, macrophage inflammatory protein (MIP)-2, and KC in BALF. PLY mutants with either reduced cytolytic activity or reduced cytolytic and complement-activating activities were less potent in inducing PMNL recruitment to the lung (P<.05), which suggests that PLY cytolytic activity is very important for the inflammatory response. IL-6 and MIP-2 also played a role in PLY-induced PMNL recruitment; this response was partially diminished in IL-6 gene-deficient mice and in mice treated with anti-MIP-2 antiserum. PLY may play an important role in the induction of an inflammatory response in the pulmonary compartment in the early phase of pneumococcal pneumonia.
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Affiliation(s)
- Anita W Rijneveld
- Department of Experimental Internal Medicine, Tropical Medicine, and AIDS, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands.
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30
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Sprong T, Stikkelbroeck N, van der Ley P, Steeghs L, van Alphen L, Klein N, Netea MG, van der Meer JWM, van Deuren M. Contributions of
Neisseria meningitidis
LPS and non‐LPS to proinflammatory cytokine response. J Leukoc Biol 2001. [DOI: 10.1189/jlb.70.2.283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Tom Sprong
- Department of Internal Medicine, University Medical Center Nijmegen, Nijmegen, and
| | - Nike Stikkelbroeck
- Department of Internal Medicine, University Medical Center Nijmegen, Nijmegen, and
| | - Peter van der Ley
- National Institute of Public Health and the Environment, Bilthoven, The Netherlands; and
| | - Liana Steeghs
- National Institute of Public Health and the Environment, Bilthoven, The Netherlands; and
| | - Loek van Alphen
- National Institute of Public Health and the Environment, Bilthoven, The Netherlands; and
| | - Nigel Klein
- Institute of Child Health, University College London Medical School, London, United Kingdom
| | - Mihai G. Netea
- Department of Internal Medicine, University Medical Center Nijmegen, Nijmegen, and
| | | | - Marcel van Deuren
- Department of Internal Medicine, University Medical Center Nijmegen, Nijmegen, and
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31
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van der Meulen FW, Ibrahim K, Sterenborg HJ, Alphen LV, Maikoe A, Dankert J. Photodynamic destruction of Haemophilus parainfluenzae by endogenously produced porphyrins. J Photochem Photobiol B 1997; 40:204-8. [PMID: 9372610 DOI: 10.1016/s1011-1344(97)00057-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Bacterial resistance against antibiotic treatment is becoming an increasing problem in medicine. Therefore methods to destroy microorganisms by other means are being investigated, one of which is photodynamic therapy (PDT). It has already been shown that a variety of Gram-positive and Gram-negative bacteria can be killed in vitro by PDT using exogenous sensitizers. An alternative method of photosensitizing cells is to stimulate the production of endogenous sensitizers. The purpose of this study was to investigate the bactericidal efficacy of PDT for Haemophilus parainfluenzae with endogenously produced porphyrins, synthesized in the presence of delta-aminolaevulinic acid (delta-ALA). H. parainfluenzae incubated with increasing amounts of delta-ALA showed decreased survival after illumination with 630 nm light. No photodynamic effect on the bacterial viability was found when H. parainfluenzae was grown without added delta-ALA. H. influenzae, grown in the presence of delta-ALA, but not capable of synthesizing porphyrins from delta-ALA, was not affected by PDT. Of the range of incident wavelengths, 617 nm appeared to be the most efficient in killing the bacteria. Spectrophotometry of the bacterial porphyrins demonstrated that the maximum fluorescence occurred at approximately 617 nm, with a much lower peak around 680 nm. We conclude that a substantial killing of H. parainfluenzae by PDT in vitro after endogenous sensitization with delta-ALA can be achieved.
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van Alphen L, Caugant DA, Duim B, O'Rourke M, Bowler LD. Differences in genetic diversity of nonecapsulated Haemophilus influenzae from various diseases. Microbiology (Reading) 1997; 143 ( Pt 4):1423-1431. [PMID: 9141705 DOI: 10.1099/00221287-143-4-1423] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Genetic relationships among 80 isolates of nonencapsulated Haemophilus influenzae recovered from different disease types were determined by multilocus enzyme electrophoresis (MEE) at 13 enzyme loci in an attempt to assess the association between multilocus genotype and disease. The isolates were obtained from 15 patients with meningitis, 10 with otitis media, 19 with chronic bronchitis, 20 with cystic fibrosis, and 16 were obtained from healthy carriers. The 80 isolates were assigned to 69 electrophoretic types (ETs) falling into 5 groups. Isolates from each disease entity were represented by a variety of genotypes; however, cluster analysis from a matrix of genetic distances between ETs revealed that the ETs of the otitis media and meningitis isolates were all clustered within a genetic distance of 0.55 (group I). In addition, no genotypes were shared between H. influenzae carrier isolates and isolates from cases of disease, H. influenzae isolates from healthy individuals were distributed significantly differently from those from chronic bronchitis meningitis and otitis media patients. The genetic diversity (H) of carrier strains was greatest, although not statistically different from that of isolates from patients with disease. It was concluded that the genetic distribution of acute disease isolates is not random over the five ET groups, although the genetic diversity within the groups is not different. The effect of bacterial persistence in the host on the genetic diversity of H. influenzae is discussed.
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Affiliation(s)
- Loek van Alphen
- Academic Medical Center, Department of Medical Microbiology, Meibergdreef 15, NL-1105 AZ Amsterdam, The Netherlands
| | - Dominique A Caugant
- National Institute of Public Health, Department of Bacteriology, 0462 Oslo, Norway
| | - Birgitta Duim
- Academic Medical Center, Department of Medical Microbiology, Meibergdreef 15, NL-1105 AZ Amsterdam, The Netherlands
| | - Maria O'Rourke
- Dept of Molecular Microbiology, School of Biological Sciences, University of Sussex, Brighton, UK
| | - Lucas D Bowler
- Academic Medical Center, Department of Medical Microbiology, Meibergdreef 15, NL-1105 AZ Amsterdam, The Netherlands
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Duim B, Vogel L, van Alphen L. Response from Dulm, Vogel and van Alphen. Trends Microbiol 1994. [DOI: 10.1016/0966-842x(94)90798-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Terpstra WJ, Groeneveld K, Eijk PP, Geelen LJ, Schoone GJ, Schegget JT, van Nierop JC, Griffioen RW, van Alphen L. Comparison of Two Nonculture Techniques for Detection of Hemophilus influenzae in Sputum. Chest 1988. [DOI: 10.1378/chest.94.2_supplement.126s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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