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Mapping the Laminin Receptor Binding Domains of Neisseria meningitidis PorA and Haemophilus influenzae OmpP2  [PDF]
Noha M. Abouseada, Mahde Saleh A. Assafi, Jafar Mahdavi, Neil J. Oldfield, Lee M. Wheldon, Karl G. Wooldridge, Dlawer A. A. Ala'Aldeen
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0046233
Abstract: Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae are major bacterial agents of meningitis. They each bind the 37/67-kDa laminin receptor (LamR) via the surface protein adhesins: meningococcal PilQ and PorA, H. influenzae OmpP2 and pneumococcal CbpA. We have previously reported that a surface-exposed loop of the R2 domain of CbpA mediates LamR-binding. Here we have identified the LamR-binding regions of PorA and OmpP2. Using truncated recombinant proteins we show that binding is dependent on amino acids 171–240 and 91–99 of PorA and OmpP2, respectively, which are predicted to localize to the fourth and second surface-exposed loops, respectively, of these proteins. Synthetic peptides corresponding to the loops bound LamR and could block LamR-binding to bacterial ligands in a dose dependant manner. Meningococci expressing PorA lacking the apex of loop 4 and H. influenzae expressing OmpP2 lacking the apex of loop 2 showed significantly reduced LamR binding. Since both loops are hyper-variable, our data may suggest a molecular basis for the range of LamR-binding capabilities previously reported among different meningococcal and H. influenzae strains.
Portadores nasofaríngeos de Neisseria meningitidis en trabajadores con riesgo ocupacional
Martínez,Isabel; Sierra,Gustavo; Pardo,Georgina; álvarez,Niurka; Armesto,Marlene; Mirabal,Mayelín;
Vaccimonitor , 2010,
Abstract: neisseria meningitidis carriers are the main infection and transmission source of the meningococcal disease. to know their prevalence, the characteristics of isolated strains and the risk factors associated to carrier status, provide important information for epidemiological surveillance and control. a descriptive-transversal study on n. meningitidis carriers was performed. it involved 112 workers from a biopharmaceutical production center in havana, from 18 to 60 years old. bioethical requirements were complied before starting the study. a nasopharyngeal swab was performed to all subjects and they were surveyed to find out on risk factors (age, sex, overcrowding, smoking and drinking habit, amygdalectomy and background of respiratory infection) that may favor the condition of the carrier. the identification of n. meningitidis strains was carried out using conventional methods, the classification of the serogroups by slide agglutination with commercial antisera and the identification of serotypes and subtypes by an immunoenzymatic assay (elisa) of whole cells with monoclonal antibodies. eight percent of n. meningitidis carriers was detected, serogroup b (77.8%) was predominant and b:4:p1.4 (33.3%) was the most frequently observed phenotype. when analyzing the carrier status and its association to risk factors, statistically significant difference was only observed in age (p=0.05) and sex (p= 0.013). the possibility of occupational risk was demonstrated in those subjects, who due to their profession are involved with pathogenic microorganisms.
Improved Production Process for Native Outer Membrane Vesicle Vaccine against Neisseria meningitidis  [PDF]
Bas van de Waterbeemd, Gijsbert Zomer, Patricia Kaaijk, Nicole Ruiterkamp, René H. Wijffels, Germie P. J. M. van den Dobbelsteen, Leo A. van der Pol
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0065157
Abstract: An improved detergent-free process has been developed to produce vaccine based on native outer membrane vesicles (NOMV) against Neisseria meningitidis serogroup B. Performance was evaluated with the NonaMen vaccine concept, which provides broad coverage based on nine distinct PorA antigens. Scalable aseptic equipment was implemented, replacing undesirable steps like ultracentrifugation, inactivation with phenol, and the use of preservatives. The resulting process is more consistent and gives a higher yield than published reference processes, enabling NOMV production at commercial scale. Product quality met preliminary specifications for 9 consecutive batches, and an ongoing study confirmed real-time stability up to 12 months after production. As the NOMV had low endotoxic activity and induced high bactericidal titres in mice, they are expected to be safe and effective in humans. The production process is not limited to NonaMen and may be applicable for other N. meningitidis serogroups and other gram-negative pathogens. The current results therefore facilitate the late-stage development and clinical evaluation of NOMV vaccines.
Portadores nasofaríngeos de Neisseria meningitidis en trabajadores con riesgo ocupacional  [PDF]
Isabel Martínez,Gustavo Sierra,Georgina Pardo,Niurka álvarez
Vaccimonitor , 2010,
Abstract: Los portadores de Neisseria meningitidis constituyen la principal fuente de infección y transmisión de la enfermedad meningocócica. Conocer su prevalencia, las características de las cepas aisladas y los factores de riesgos asociados con el estado de portador, aportan datos valiosos al control y vigilancia epidemiológica de esta entidad clínica. Para cumplimentar los objetivos propuestos se realizó un estudio transversal descriptivo de portadores de N. meningitidis en 112 trabajadores de un centro de producción de biofarmacéuticos de La Habana,con edades comprendidas entre 18–60 a os. Previo a su realización se cumplió con las exigencias bioéticasrequeridas para este tipo de estudio. A todos se les realizó un exudado nasofaríngeo y una encuesta, donde se indagó sobre factores de riesgo (edad, sexo, hacinamiento, hábito de fumar, consumo de bebidas alcohólicas,amigdalectomía y antecedentes de infección respiratoria) que favorecen la condición del portador. La identificación de las cepas de N. meningitidis se realizó según métodos convencionales, la clasificación de los serogrupos sehizo por aglutinación en láminas portaobjetos con antisueros comerciales y para la identificación de los serotipos y subtipos se empleó un ensayo inmunoenzimático (ELISA) de células enteras con anticuerpos monoclonales.Se detectó un 8% de portadores de N. meningitidis con predominio del serogrupo B (77,8%) y el fenotipo másfrecuente fue el B:4:P1.4 (33,3%). Al analizar el estado de portador y su asociación con los factores de riesgo,la edad (p = 0,05) y el sexo (p = 0,013) mostraron diferencias significativas. Se demostró la posibilidad del riesgo ocupacional en aquellos individuos que por su profesión están en contacto con microorganismos patógenos.
March GA,Tavárez JJ,Benito JI,Bratos MA
Electronic Journal of Biomedicine , 2012,
Abstract: SUMMARY: PERITONSILLAR ABSCESS CAUSED BY NEISSERIA MENINGITIDIS Neisseria meningitidis is a higly virulent microorganism that can cause meningitis and sepsis. This microorganism can be cultivated from the throats of asymptomatic carriers and it likely enters the circulation through the upper respiratory tract but it is infrequent that N. meningitidis causes simple infections of the upper respiratory tract. Here we present a case report of peritonsillar abscess caused by N. meningitidis.
Geotemporal Analysis of Neisseria meningitidis Clones in the United States: 2000–2005  [PDF]
Ann E. Wiringa, Kathleen A. Shutt, Jane W. Marsh, Amanda C. Cohn, Nancy E. Messonnier, Shelley M. Zansky, Susan Petit, Monica M. Farley, Ken Gershman, Ruth Lynfield, Arthur Reingold, William Schaffner, Jamie Thompson, Shawn T. Brown, Bruce Y. Lee, Lee H. Harrison
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0082048
Abstract: Background The detection of meningococcal outbreaks relies on serogrouping and epidemiologic definitions. Advances in molecular epidemiology have improved the ability to distinguish unique Neisseria meningitidis strains, enabling the classification of isolates into clones. Around 98% of meningococcal cases in the United States are believed to be sporadic. Methods Meningococcal isolates from 9 Active Bacterial Core surveillance sites throughout the United States from 2000 through 2005 were classified according to serogroup, multilocus sequence typing, and outer membrane protein (porA, porB, and fetA) genotyping. Clones were defined as isolates that were indistinguishable according to this characterization. Case data were aggregated to the census tract level and all non-singleton clones were assessed for non-random spatial and temporal clustering using retrospective space-time analyses with a discrete Poisson probability model. Results Among 1,062 geocoded cases with available isolates, 438 unique clones were identified, 78 of which had ≥2 isolates. 702 cases were attributable to non-singleton clones, accounting for 66.0% of all geocoded cases. 32 statistically significant clusters comprised of 107 cases (10.1% of all geocoded cases) were identified. Clusters had the following attributes: included 2 to 11 cases; 1 day to 33 months duration; radius of 0 to 61.7 km; and attack rate of 0.7 to 57.8 cases per 100,000 population. Serogroups represented among the clusters were: B (n = 12 clusters, 45 cases), C (n = 11 clusters, 27 cases), and Y (n = 9 clusters, 35 cases); 20 clusters (62.5%) were caused by serogroups represented in meningococcal vaccines that are commercially available in the United States. Conclusions Around 10% of meningococcal disease cases in the U.S. could be assigned to a geotemporal cluster. Molecular characterization of isolates, combined with geotemporal analysis, is a useful tool for understanding the spread of virulent meningococcal clones and patterns of transmission in populations.
Prediction and characterization of T-cell epitopes for epitope vaccine design from outer membrane protein of Neisseria meningitidis serogroup B  [cached]
Sharat Chandra,Digvijay Singh,Tiratha Raj Singh
Bioinformation , 2010,
Abstract: Neisseria meningitidis serogroup B (MC58) is a leading cause of meningitis and septicaemia, principally infects the infants and adolescents. No vaccine is available for the prevention of these infections because the serogroup B capsular polysaccharide is unable to stimulate an immune response, due to its similarity with polysialic acid. To overcome these obstacles, we proposed to develop a peptide based epitope vaccine from outer membrane protein contained in outer membrane vesicles (OMV) based on our computational analysis. In OMV a total of 236 proteins were identified, only 15 (6.4%) of which were predicted to be located in outer membrane. The major requirement is the identification and selection of T-cell epitopes that act as a vaccine target. We have selected 13 out of 15 outer membrane proteins from OMV proteins. Due to similarity of the fkpA and omp85 with the human FKBP2 and SAMM50 protein, we removed these two sequences from the analysis as their presence in the vaccine is likely to elicit an autoimmune response. ProPred and ProPred1 were used to predict promiscuous helper T Lymphocytes (HTL) and cytotoxic T Lymphocytes (CTL) epitopes and MHCPred for their binding affinity in N. meningitidis serogroup B (MC58), respectively. Binding peptides (epitopes) are distinguished from nonbinding peptides in properties such as amino acid preference on the basis of amino acid composition. By using this dataset, we compared physico-chemical and structural properties at amino acid level through amino acid composition, computed from ProtParam server. Results indicate that porA, porB, opc, rmpM, mtrE and nspA are more suitable vaccine candidates. The predicted peptides are expected to be useful in the design of multi-epitope vaccines without compromising the human population coverage.
Respuesta de anticuerpos inducidos por la vacuna antimeningocócica cubana VA-MENGOC-BC? frente a la cepa de Neisseria meningitidis B:4:P1.19,15 en adolescentes después de 12 a?os de inmunizados
Camaraza,María A; Martínez,Isabel; Ochoa,Rolando; Arnet,Aida; Sotolongo,Franklin; Hernández,Dairis; Cuevas,Iván; Pérez,Antonio E;
Vaccimonitor , 2006,
Abstract: the response of antibodies induced by the cuban meningococcal vaccine va-mengoc-bc? against the strain of neisseria meningitidis b:4:p1.19,15 was studied by the serum bactericidal assay (sba) and indirect elisa, to measure antibodies against outer membrane vesicles (omv) of n. meningitidis b in 184 teenagers of a polytechnical school of ciego de ávila who were immunized in massive campaigns 12 years before. blood extractions were carried out before applying the first dose (t0), 4 weeks after the first dose (t1) and 4 weeks after the second dose (t2). after 12 years of this vaccination, 42% of teenagers presented bactericidal titers ≥ 1:4 against the homologous strain (b:4:p1.19,15) and 98% showed detectable antibodies against the omvs. in the sba, seroconversion percentage t1/t0 was 57% and t2/t0 was 60%. by elisa, seroconversion was 59% and 54%, respectively. it was demonstrated that application of only one dose after 12 years induced an important immune response which can suggest an anamnesic response.
Subclinical infection of the genital tract with Neisseria meningitidis
Louren?o, Maria Cristina S.;Reis, Roberto S.;Andrade, Angela C. V.;Tuyama, Mari;Barroso, David E;
Brazilian Journal of Infectious Diseases , 2006, DOI: 10.1590/S1413-86702006000200015
Abstract: we report the isolation of neisseria meningitidis, characterized as b:nt:p1.7, from a female patient's genital tract in an outpatient clinic for hiv care. the gynecology clinic, as part of the follow up, collects specimens from all patients with hiv infection for routine exams and for early laboratory detection of sexually transmitted diseases . a gram-negative diplococcus was isolated from the cervix of a heterosexual patient with aids. based on this and other reported cases, urogenital infection with n. meningitidis can no longer be considered uncommon. the rising incidence of n. meningitidis isolated from this and similar sites has significant medical and diagnostic implications.
The Development of an Experimental Multiple Serogroups Vaccine for Neisseria meningitidis  [PDF]
Valerian B. Pinto, Robert Burden, Allyn Wagner, Elizabeth E. Moran, Che-Hung Lee
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0079304
Abstract: A native outer membrane vesicles (NOMV) vaccine was developed from three antigenically diverse strains of Neisseria meningitidis that express the L1,8, L2, and L3,7 lipooligosaccharide (LOS) immunotypes, and whose synX, and lpxL1 genes were deleted.. Immunogenicity studies in mice showed that the vaccine induced bactericidal antibody against serogroups B, C, W, Y and X N. meningitidis strains. However, this experimental NOMV vaccine was not effective against serogroup A N. meningitidis strains. N. meningitidis capsular polysaccharide (PS) from serogroups A, C, W and Y were effective at inducing bactericidal antibody when conjugated to either tetanus toxoid or the fHbp1-fHbp2 fusion protein fHbp(1+2). The combination of the NOMV vaccine and the N. meningitidis serogroup A capsular polysaccharide (MAPS) protein conjugate was capable of inducing bactericidal antibodies against a limited number of N. meningitidis strains from serogroups A, B, C, W, Y and X tested in this study.
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