| outer membrane vesicles of neisseria lactamica as a potential mucosal adjuvant. | the muscosal delivery of vaccines has many advantages including ease of administration and the induction of a mucosal immune response at the natural site of infection for many pathogens. mice were immunised with outer membrane vesicles (omv) prepared from neisseria lactamica or neisseria meningitidis by subcutaneous (sc) or intranasal (in) routes, or live cells of n. lactamica given in or by sc injection. a systemic igg and mucosal iga response was demonstrated and n. lactamica omv induced antib ... | 2006 | 16115701 |
| cross-linking analysis of antigenic outer membrane protein complexes of neisseria meningitidis. | polysaccharide-based approaches have not enabled the development of effective vaccines against meningococci of serogroup b, and the most promising current research is focused on the use of outer membrane vesicles. due to the toxicity of the outer membrane oligosaccharides, new vaccines based on purified proteins are being sought, but despite the application of advanced techniques, they remain elusive, perhaps due to the fact that standard techniques for analysis of antigens overlook conformation ... | 2006 | 16135405 |
| a gonococcal homologue of meningococcal gamma-glutamyl transpeptidase gene is a new type of bacterial pseudogene that is transcriptionally active but phenotypically silent. | it has been speculated that the gamma-glutamyl transpeptidase (ggt) gene is present only in neisseria meningitidis and not among related species such as neisseria gonorrhoeae and neisseria lactamica, because n. meningitidis is the only bacterium with ggt activity. however, nucleotide sequences highly homologous to the meningococcal ggt gene were found in the genomes of n. gonorrhoeae isolates. | 2005 | 16202144 |
| evaluation of a rapid direct assay for identification of bacteria and the mec a and van genes from positive-testing blood cultures. | we performed the first evaluation of a dna strip assay (genotype blood culture; hain lifescience, nehren, germany) for the detection of the most relevant bacterial sepsis pathogens directly from positive bactec blood culture bottles (becton dickinson, heidelberg, germany). the test comprises two panels, one for the direct species identification of important gram-positive cocci and the other for gram-negative rods. additionally, detection of the mec a and the van genes are implemented. the genoty ... | 2005 | 16207992 |
| prospective comparison of cell cultures and nucleic acid amplification tests for laboratory diagnosis of chlamydia trachomatis infections. | specimens submitted in m5 medium for cell culture detection of chlamydia trachomatis were tested by nucleic acid amplification testing (naat) and in cell cultures. of 35 (genital) and 26 (nongenital) specimens positive for c. trachomatis, 21 and 14 specimens, respectively, were detected exclusively by naat. naat is significantly (p<0.0001) more sensitive than cell culture and should be considered the new "gold standard" for the laboratory diagnosis of c. trachomatis infections. | 2005 | 16208009 |
| comparative phylogenomics of the food-borne pathogen campylobacter jejuni reveals genetic markers predictive of infection source. | campylobacter jejuni is the predominant cause of bacterial gastroenteritis worldwide, but traditional typing methods are unable to discriminate strains from different sources that cause disease in humans. we report the use of genomotyping (whole-genome comparisons of microbes using dna microarrays) combined with bayesian-based algorithms to model the phylogeny of this major food-borne pathogen. in this study 111 c. jejuni strains were examined by genomotyping isolates from humans with a spectrum ... | 2005 | 16230626 |
| the natural history of meningococcal carriage and disease. | the prevalence of neisseria meningitidis carriage is highest in teenagers and lowest in young children. in contrast, invasive meningococcal disease is most common in young children with a smaller secondary peak in teenagers. data on carriage and disease were analysed to quantify the risks of infection and disease by age and serogroup. the forces of infection for serogroups b, c, other meningococci and neisseria lactamica were modelled together with the risk of disease given infection for serogro ... | 2006 | 16238823 |
| specific and sensitive detection of neisseria gonorrhoeae in clinical specimens by real-time pcr. | early diagnosis of neisseria gonorrhoeae infections is important with regard to patients' health and infectivity. we report the development of a specific and sensitive taqman assay for the detection of n. gonorrhoeae in clinical samples. the target sequence is a 76-bp fragment of the 5' untranslated region of the opa genes that encode opacity proteins. a panel of 448 well-defined n. gonorrhoeae isolates was used to evaluate and optimize the assay. the method employs two minor-groove binding prob ... | 2005 | 16272500 |
| detection and serotyping of streptococcus pneumoniae from nasopharyngeal samples by pcr-based multiplex assay. | we developed a multiplex pcr-based methodology for nasopharyngeal samples maintained in egg thioglycolate antibiotic and skim milk-tryptone-glucose-glycerol media to identify and serotype the most important serotypes of streptococcus pneumoniae that cause invasive disease in children. this technique can be used to study the epidemiology of pneumococcal colonization and the effect of conjugate vaccines. | 2005 | 16333118 |
| nucleic acid amplification testing for neisseria gonorrhoeae: an ongoing challenge. | nucleic acid amplification tests (naats) for the detection of neisseria gonorrhoeae became available in the early 1990s. although offering several advantages over traditional detection methods, n. gonorrhoeae naats do have some limitations. these include cost, risk of carryover contamination, inhibition, and inability to provide antibiotic resistance data. in addition, there are sequence-related limitations that are unique to n. gonorrhoeae naats. in particular, false-positive results are a majo ... | 2006 | 16436629 |
| a novel surface protein of trichomonas vaginalis is regulated independently by low iron and contact with vaginal epithelial cells. | trichomonosis caused by trichomonas vaginalis is the number one, non-viral sexually transmitted disease (std) that affects more than 250 million people worldwide. immunoglobulin a (iga) has been implicated in resistance to mucosal infections by pathogens. no reports are available of iga-reactive proteins and the role, if any, of this class of antibody in the control of this std. the availability of an iga monoclonal antibody (mab) immunoreactive to trichomonads by whole cell (wc)-elisa prompted ... | 2006 | 16448556 |
| identification of a meningococcal l-glutamate abc transporter operon essential for growth in low-sodium environments. | gdhr is a meningococcal transcriptional regulator that was previously shown to positively control the expression of gdha, encoding the nadp-specific l-glutamate dehydrogenase (nadp-gdh), in response to the growth phase and/or to the carbon source. in this study we used reverse transcriptase-pcr-differential display (to identify additional gdhr-regulated genes. the results indicated that gdhr, in addition to nadp-gdh, controls the expression of a number of genes involved in glucose catabolism by ... | 2006 | 16495545 |
| variations in gene organization and dna uptake signal sequence in the folp region between commensal and pathogenic neisseria species. | horizontal gene transfer is an important source of genetic variation among neisseria species and has contributed to the spread of resistance to penicillin and sulfonamide drugs in the pathogen neisseria meningitidis. sulfonamide resistance in neisseria meningitidis is mediated by altered chromosomal folp genes. at least some folp alleles conferring resistance have been horizontally acquired from other species, presumably from commensal neisseriae. in this work, the dna sequence surrounding folp ... | 2006 | 16503987 |
| crystallization and preliminary crystallographic analysis of the (cytosine-5)-dna methyltransferase nlax from neisseria lactamica. | crystals of the (cytosine-5)-dna methyltransferase nlax from neisseria lactamica (molecular weight 36.5 kda) have been grown at 291 k using 2.5 m nacl as precipitant. the crystals diffract to 3.0 a resolution at 100 k. the crystals belong to space group p321, with unit-cell parameters a = 121.98, b = 121.98, c = 56.71 a. there is one molecule in the asymmetric unit and the solvent content is estimated to be 62.1% by volume. | 2005 | 16511177 |
| partial reassociation between the deoxyribonucleic acids of neisseria lactamicus and neisseria meningitidis. | the similarity in polynucleotide sequence of seven strains of neisseria lactamicus to n. meningitidis and to each other was investigated. the per cent reassociation between single-stranded n. lactamicus deoxyribonucleic acid (dna), immobilized on membrane filters, with labeled single-stranded dna fragments derived from strain sd-6 (group c) of n. meningitidis varied from 75 to 56. with strain atcc 23972 of n. lactamicus furnishing the labeled dna fragments, reassociation was 72% with n. meningit ... | 1971 | 16557965 |
| characterization of mspa, an immunogenic autotransporter protein that mediates adhesion to epithelial and endothelial cells in neisseria meningitidis. | a novel putative autotransporter protein (nmb1998) was identified in the available genomic sequence of meningococcal strain mc58 (et-5; st-32). the mspa gene is absent from the genomic sequences of meningococcal strain z2491 (et-iv; st-4) and the gonococcal strain fa1090. an orthologue is present in the meningococcal strain fam18 (et-37; st-11), but the sequence contains a premature stop codon, suggesting that the protein may not be expressed in this strain. mspa is predicted to be a 157-kda pro ... | 2006 | 16622234 |
| rapid detection of brucella spp. in blood cultures by fluorescence in situ hybridization. | brucellosis is a severe systemic disease in humans. we describe a new 16s rrna-based fluorescence in situ hybridization assay that facilitates rapid and specific detection of all human pathogenic species of brucella and that can be applied directly to positive blood cultures. | 2006 | 16672413 |
| proteomic analysis of neisseria lactamica and n eisseria meningitidis outer membrane vesicle vaccine antigens. | vaccines to prevent meningococcal disease have been developed from the outer membrane vesicles (omvs) of neisseria meningitidis and the related commensal organism neisseria lactamica. in addition to lipopolysaccharide and the major porins, these vaccines contain a large number of proteins that are incompletely characterised. here we describe comparative proteomic analyses of the n. lactamica omv vaccine and omvs from a serogroup b strain of n. meningitidis. tandem mass-spectrometry data for tryp ... | 2006 | 16682101 |
| cellular and molecular aspects of gastric cancer. | gastric cancer remains a global killer with a shifting burden from the developed to the developing world. the cancer develops along a multistage process that is defined by distinct histological and pathophysiological phases. several genetic and epigenetic alterations mediate the transition from one stage to another and these include mutations in oncogenes, tumour suppressor genes and cell cycle and mismatch repair genes. the most significant advance in the fight against gastric cancer came with ... | 2006 | 16718776 |
| the obligate human pathogen, neisseria gonorrhoeae, is polyploid. | we show using several methodologies that the gram-negative, diplococcal-bacterium neisseria gonorrhoeae has more than one complete genome copy per cell. gene dosage measurements demonstrated that only a single replication initiation event per chromosome occurs per round of cell division, and that there is a single origin of replication. the region containing the origin does not encode any genes previously associated with bacterial origins of replication. quantitative pcr results showed that ther ... | 2006 | 16719561 |
| the majority of genes in the pathogenic neisseria species are present in non-pathogenic neisseria lactamica, including those designated as 'virulence genes'. | neisseria meningitidis causes the life-threatening diseases meningococcal meningitis and meningococcal septicemia. neisseria gonorrhoeae is closely related to the meningococcus, but is the cause of the very different infection, gonorrhea. a number of genes have been implicated in the virulence of these related yet distinct pathogens, but the genes that define and differentiate the species and their behaviours have not been established. further, a related species, neisseria lactamica is not assoc ... | 2006 | 16734888 |
| the majority of genes in the pathogenic neisseria species are present in non-pathogenic neisseria lactamica, including those designated as virulence genes: response. | | 2006 | 16734889 |
| low-phosphate-dependent invasion resembles a general way for neisseria gonorrhoeae to enter host cells. | obligate human-pathogenic neisseria gonorrhoeae expresses numerous variant surface proteins mediating adherence to and invasion of target cells. the invariant major outer membrane porin porb of serotype a (p.ia) gonococci triggers invasion into chang cells only if the medium is devoid of phosphate. since gonococci expressing porb(ia) are frequently isolated from patients with severe disseminating infections, the interaction initiated by the porin may be of major relevance for the development of ... | 2006 | 16790801 |
| survival of meningococci outside of the host: implications for acquisition. | meningococci are regarded as being unlikely to survive outside of their human host although this has possibly been more assumed than demonstrated. seven strains of meningococci were tested for their ability to survive on glass or plastic while retaining expression of their capsule and important outer membrane proteins. a known number of colony-forming units of each strain were dried onto glass and onto plastic and tested for viability over time. survival on glass was significantly better than on ... | 2007 | 16817988 |
| survival of meningococci outside of the host: implications for acquisition. | meningococci are regarded as being unlikely to survive outside of their human host although this has possibly been more assumed than demonstrated. seven strains of meningococci were tested for their ability to survive on glass or plastic while retaining expression of their capsule and important outer membrane proteins. a known number of colony-forming units of each strain were dried onto glass and onto plastic and tested for viability over time. survival on glass was significantly better than on ... | 2007 | 16817988 |
| first case report of neisseria lactamica causing cavitary lung disease in an adult organ transplant recipient. | we describe a case of an adult organ recipient patient with a pulmonary cavitary lesion due to neisseria lactamica, a harmless commensal organism that rarely causes human infection. to our knowledge, this is the first report of pulmonary disease caused by this organism and the second case of n. lactamica infection in an adult patient. | 2006 | 16825411 |
| bacteraemic pneumonia caused by neisseria lactamica with reduced susceptibility to penicillin and ciprofloxacin in an adult with liver cirrhosis. | this report presents a case of bacteraemic pneumonia caused by neisseria lactamica in an adult patient with liver cirrhosis who was successfully treated with ceftriaxone. the isolate was confirmed as n. lactamica by analysis of a partial sequence of the 16s rrna gene; it had reduced susceptibilities to penicillin (mic 0.75 microg ml(-1)) and ciprofloxacin (mic > or =0.5 mg l(-1)). | 2006 | 16849737 |
| plasmid diversity in neisseriae. | horizontal gene transfer constitutes an important force in prokaryotic genome evolution, and it is well-known that plasmids are vehicles for dna transfer. chromosomal dna is frequently exchanged between pathogenic and commensal neisseriae, but relatively little is known about plasmid diversity and prevalence among these nasopharyngeal inhabitants. we investigated the plasmid contents of 18 neisseria lactamica isolates and 20 nasopharyngeal neisseria meningitidis isolates. of 18 n. lactamica stra ... | 2006 | 16861678 |
| identification of acquired dna in neisseria lactamica. | anomalous dna (adna) in prokaryotic genomes, identified by its aberrant nucleotide composition, generally represents horizontally acquired dna. previous studies showed that frequent dna transfer occurs between commensal neisseriae and neisseria meningitidis. currently, it is unknown whether adna regions are also transferred between these species. the genome of neisseria lactamica strain 892586 was assessed by a strategy that enables the selective isolation of adna, using endonucleases with recog ... | 2006 | 16907742 |
| comparison of the inflammatory responses of human meningeal cells following challenge with neisseria lactamica and with neisseria meningitidis. | the rationale for the present study was to determine how different species of bacteria interact with cells of the human meninges in order to gain information that would have broad relevance to understanding aspects of the innate immune response in the brain. neisseria lactamica is an occasional cause of meningitis in humans, and in this study we investigated the in vitro interactions between n. lactamica and cells derived from the leptomeninges in comparison with the closely related organism nei ... | 2006 | 16954390 |
| t-cell stimulating protein a (tspa) of neisseria meningitidis is required for optimal adhesion to human cells. | t-cell stimulating protein a (tspa) is an immunogenic, t-cell and b-cell stimulating protein of neisseria meningitidis. sequence similarity between tspa and fimv, a pseudomonas aeruginosa protein involved in twitching motility, suggested a link between tspa and type iv pili (tfp). to determine the role of tspa an isogenic deletion mutant was created. loss of tspa did not affect twitching motility or piliation indicating that there are functional differences between tspa and fimv. mutation of tsp ... | 2007 | 16965515 |
| immunization with live neisseria lactamica protects mice against meningococcal challenge and can elicit serum bactericidal antibodies. | natural immunity against neisseria meningitidis is thought to develop following nasopharyngeal colonization with this bacterium or other microbes expressing cross-reactive antigens. neisseria lactamica is a commensal of the upper respiratory tract which is often carried by infants and young children; epidemiological evidence indicates that colonization with this bacterium can elicit serum bactericidal activity (sba) against neisseria meningitidis, the most validated correlate of protective immun ... | 2006 | 16966413 |
| a fast real-time polymerase chain reaction method for sensitive and specific detection of the neisseria gonorrhoeae pora pseudogene. | ever since the advent of molecular methods, the diagnostics of neisseria gonorrhoeae has been troubled by false negative and false positive results compared with culture. commensal neisseria species and neisseria meningitidis are closely related to n. gonorrhoeae and may cross-react when using molecular tests comprising too-low specificity. we have devised a real-time polymerase chain reaction (pcr), including an internal amplification control, that targets the n. gonorrhoeae pora pseudogene. dn ... | 2006 | 17065426 |
| rapid detection and identification of metallo-beta-lactamase-encoding genes by multiplex real-time pcr assay and melt curve analysis. | metallo-beta-lactamase enzymes (mbetal) are encoded by transferable genes, which appear to spread rapidly among gram-negative bacteria. the objective of this study was to develop a multiplex real-time pcr assay followed by a melt curve step for rapid detection and identification of genes encoding mbetal-type enzymes based on the amplicon melting peak. the reference sequences of all genes encoding imp and vim types, spm-1, gim-1, and sim-1 were downloaded from genbank, and primers were designed t ... | 2007 | 17093019 |
| rapid detection and identification of metallo-beta-lactamase-encoding genes by multiplex real-time pcr assay and melt curve analysis. | metallo-beta-lactamase enzymes (mbetal) are encoded by transferable genes, which appear to spread rapidly among gram-negative bacteria. the objective of this study was to develop a multiplex real-time pcr assay followed by a melt curve step for rapid detection and identification of genes encoding mbetal-type enzymes based on the amplicon melting peak. the reference sequences of all genes encoding imp and vim types, spm-1, gim-1, and sim-1 were downloaded from genbank, and primers were designed t ... | 2007 | 17093019 |
| proteomic analysis of outer membranes and vesicles from wild-type serogroup b neisseria meningitidis and a lipopolysaccharide-deficient mutant. | current experimental vaccines against serogroup b neisseria meningitidis are based on meningococcal outer membrane (om) proteins present in outer membrane vesicles (omv) in which toxic lipopolysaccharide is depleted by detergent extraction. knowledge of the composition of om and omv is essential for developing new meningococcal vaccines based on defined antigens. in the current study, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and nanocapillary liquid chromatography-tandem mass sp ... | 2007 | 17158897 |
| proteomic analysis of outer membranes and vesicles from wild-type serogroup b neisseria meningitidis and a lipopolysaccharide-deficient mutant. | current experimental vaccines against serogroup b neisseria meningitidis are based on meningococcal outer membrane (om) proteins present in outer membrane vesicles (omv) in which toxic lipopolysaccharide is depleted by detergent extraction. knowledge of the composition of om and omv is essential for developing new meningococcal vaccines based on defined antigens. in the current study, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and nanocapillary liquid chromatography-tandem mass sp ... | 2007 | 17158897 |
| comparative genomics of neisseria meningitidis: core genome, islands of horizontal transfer and pathogen-specific genes. | to better understand neisseria meningitidis genomes and virulence, microarray comparative genome hybridization (mcgh) data were collected from one neisseria cinerea, two neisseria lactamica, two neisseria gonorrhoeae and 48 neisseria meningitidis isolates. for n. meningitidis, these isolates are from diverse clonal complexes, invasive and carriage strains, and all major serogroups. the microarray platform represented n. meningitidis strains mc58, z2491 and fam18, and n. gonorrhoeae fa1090. by co ... | 2006 | 17159225 |
| new functional identity for the dna uptake sequence in transformation and its presence in transcriptional terminators. | the frequently occurring dna uptake sequence (dus), recognized as a 10-bp repeat, is required for efficient genetic transformation in the human pathogens neisseria meningitidis and neisseria gonorrhoeae. genome scanning for dus occurrences in three different species of neisseria demonstrated that 76% of the nearly 2,000 neisserial dus were found to have two semiconserved base pairs extending from the 5' end of dus to constitute a 12-mer repeat. plasmids containing sequential variants of the neis ... | 2007 | 17194793 |
| new functional identity for the dna uptake sequence in transformation and its presence in transcriptional terminators. | the frequently occurring dna uptake sequence (dus), recognized as a 10-bp repeat, is required for efficient genetic transformation in the human pathogens neisseria meningitidis and neisseria gonorrhoeae. genome scanning for dus occurrences in three different species of neisseria demonstrated that 76% of the nearly 2,000 neisserial dus were found to have two semiconserved base pairs extending from the 5' end of dus to constitute a 12-mer repeat. plasmids containing sequential variants of the neis ... | 2007 | 17194793 |
| characteristics of the m2000 automated sample preparation and multiplex real-time pcr system for detection of chlamydia trachomatis and neisseria gonorrhoeae. | we evaluated a new real-time pcr-based prototype assay for the detection of chlamydia trachomatis and neisseria gonorrhoeae developed by abbott molecular inc. this assay is designed to be performed on an abbott m2000 real-time instrument system, which consists of an m2000sp instrument for sample preparation and an m2000rt instrument for real-time pcr amplification and detection. the limit of detection of this prototype assay was determined to be 20 copies of target dna for both c. trachomatis an ... | 2007 | 17202273 |
| the small fnr regulon of neisseria gonorrhoeae: comparison with the larger escherichia coli fnr regulon and interaction with the narq-narp regulon. | neisseria gonorrhoeae can survive during oxygen starvation by reducing nitrite to nitrous oxide catalysed by the nitrite and nitric oxide reductases, ania and norb. the oxygen-sensing transcription factor, fnr, is essential for transcription activation at the ania promoter, and full activation also requires the two-component regulatory system, narq-narp, and the presence of nitrite. the only other gene known to be activated by the gonococcal fnr is ccp encoding a cytochrome c peroxidase, and no ... | 2007 | 17261178 |
| meningococcal genetic variation mechanisms viewed through comparative analysis of serogroup c strain fam18. | the bacterium neisseria meningitidis is commonly found harmlessly colonising the mucosal surfaces of the human nasopharynx. occasionally strains can invade host tissues causing septicaemia and meningitis, making the bacterium a major cause of morbidity and mortality in both the developed and developing world. the species is known to be diverse in many ways, as a product of its natural transformability and of a range of recombination and mutation-based systems. previous work on pathogenic neisser ... | 2007 | 17305430 |
| neisseria species identification assay for the confirmation of neisseria gonorrhoeae-positive results of the cobas amplicor pcr. | screening assays for neisseria gonorrhoeae exhibit low positive predictive values, particularly in low-prevalence populations. a new real-time pcr assay that detects and identifies individual neisseria spp. using melt curve analysis was compared to two previously published supplementary assays. nsppid, a 16s rrna real-time pcr/melt curve assay developed to distinguish n. gonorrhoeae from other neisseria spp., was compared to real-time pcr assays targeting genes reportedly specific for n. gonorrh ... | 2007 | 17360838 |
| clonal waves of neisseria colonisation and disease in the african meningitis belt: eight- year longitudinal study in northern ghana. | the kassena-nankana district of northern ghana lies in the african "meningitis belt" where epidemics of meningococcal meningitis have been reoccurring every eight to 12 years for the last 100 years. the dynamics of meningococcal colonisation and disease are incompletely understood, and hence we embarked on a long-term study to determine how levels of colonisation with different bacterial serogroups change over time, and how the patterns of disease relate to such changes. | 2007 | 17388665 |
| a detailed analysis of 16s ribosomal rna gene segments for the diagnosis of pathogenic bacteria. | bacterial 16s ribosomal rna (rrna) genes contain nine "hypervariable regions" (v1-v9) that demonstrate considerable sequence diversity among different bacteria. species-specific sequences within a given hypervariable region constitute useful targets for diagnostic assays and other scientific investigations. no single region can differentiate among all bacteria; therefore, systematic studies that compare the relative advantage of each region for specific diagnostic goals are needed. we characteri ... | 2007 | 17391789 |
| bioinformatic analysis of outer membrane proteome of neisseria meningitidis and neisseria lactamica. | two-dimensional electrophoresis (isoelectric focusing/sds-page) and western-blotting techniques were used to analyze and compare common and/or specific outer-membrane proteins and antigens from neisseria meningitidis and neisseria lactamica. bioinformatic image analyses of proteome and immunoproteome maps indicated the presence of numerous proteins and several antigens shared by n. meningitidis and n. lactamica, although the inter-strain variation in the maps was of similar magnitude to the inte ... | 2007 | 17407055 |
| patterns of antigenic diversity and the mechanisms that maintain them. | many of the remaining challenges in infectious disease control involve pathogens that fail to elicit long-lasting immunity in their hosts. antigenic variation is a common reason for this failure and a contributor to the complexity of vaccine design. diversifying selection by the host immune system is commonly, and often correctly, invoked to explain antigenic variability in pathogens. however, there is a wide variety of patterns of antigenic variation across space and time, and within and betwee ... | 2007 | 17426010 |
| seroprevalence of bactericidal and anti-outer membrane vesicle antibodies to neisseria meningitidis group b in england. | outer membrane vesicle (omv) and recombinant protein-based vaccines targeted against multiple strains of group b meningococci are under development. the serum bactericidal antibody (sba) assay has been designated the surrogate of protection, but the exact cutoff has not been determined. we measured the sba titers in 2,415 serum samples and the anti-omv igg antibody concentrations in 2,672 serum samples representative of the english population to establish a baseline of natural immunity. sba and ... | 2007 | 17494636 |
| molecular characteristics and epidemiology of meningococcal carriage, burkina faso, 2003. | to describe neisseria meningitidis strains in the african meningitis belt in 2003, we obtained 2,389 oropharyngeal swabs at 5 monthly visits a representative population sample (age range 4-29 years) in bobo-dioulasso, burkina faso. a total of 152 carriage isolates were grouped, serotyped, and genotyped. most isolates were ng:nt:nst sequence type (st) 192 (63% of all n. meningitidis), followed by w135:2a:p1.5,2 of st-11 (16%) and ng:15:p1.6 of st-198 (12%). we also found st-2881 (w135:nt:p1.5,2), ... | 2007 | 17553222 |
| modeling neisseria meningitidis metabolism: from genome to metabolic fluxes. | neisseria meningitidis is a human pathogen that can infect diverse sites within the human host. the major diseases caused by n. meningitidis are responsible for death and disability, especially in young infants. in general, most of the recent work on n. meningitidis focuses on potential antigens and their functions, immunogenicity, and pathogenicity mechanisms. very little work has been carried out on neisseria primary metabolism over the past 25 years. | 2007 | 17617894 |
| neisserial outer membrane vesicles bind the coinhibitory receptor carcinoembryonic antigen-related cellular adhesion molecule 1 and suppress cd4+ t lymphocyte function. | pathogenic neisseria bacteria naturally liberate outer membrane "blebs," which are presumed to contribute to pathology, and the detergent-extracted outer membrane vesicles (omvs) from neisseria meningitidis are currently employed as meningococcal vaccines in humans. while the composition of these vesicles reflects the bacteria from which they are derived, the functions of many of their constituent proteins remain unexplored. the neisserial colony opacity-associated opa proteins function as adhes ... | 2007 | 17620353 |
| haemophilus influenzae phasevarions have evolved from type iii dna restriction systems into epigenetic regulators of gene expression. | phase variably expressed (randomly switching) methyltransferases associated with type iii restriction-modification (r-m) systems have been identified in a variety of pathogenic bacteria. we have previously shown that a phase variable methyltransferase (mod) associated with a type iii r-m system in haemophilus influenzae strain rd coordinates the random switching of expression of multiple genes, and constitutes a phase variable regulon--'phasevarion'. we have now identified the recognition site f ... | 2007 | 17675301 |
| strategies for development of universal vaccines against meningococcal serogroup b disease: the most promising options and the challenges evaluating them. | a vaccine inducing protection against most of the circulating variants of serogroup b meningococcal strains is not yet available. a number of plausible options are currently under investigation. a conjugate vaccine based on a modified capsular polysaccharide might well work, but has safety concerns from molecular mimicry between group b sialic acid and human tissue. recently, however, the group b capsule has been shown to contain de-n-acetyl sialic acid residues that do not cross react with norm ... | 2007 | 17712231 |
| microbiological evaluation of the new vitek 2 neisseria-haemophilus identification card. | vitek 2 is an automated identification system for diverse bacterial and fungal species. a new card (the neisseria-haemophilus [nh] card) for the identification of neisseria spp., haemophilus spp., and other fastidious gram-negative or gram-variable microorganisms has been developed, but its performance in a routine clinical laboratory has not yet been evaluated. in this study, a total of 188 bacterial strains belonging to the genera actinobacillus, campylobacter, capnocytophaga, cardiobacterium, ... | 2007 | 17728469 |
| species status of neisseria gonorrhoeae: evolutionary and epidemiological inferences from multilocus sequence typing. | various typing methods have been developed for neisseria gonorrhoeae, but none provide the combination of discrimination, reproducibility, portability, and genetic inference that allows the analysis of all aspects of the epidemiology of this pathogen from a single data set. multilocus sequence typing (mlst) has been used successfully to characterize the related organisms neisseria meningitidis and neisseria lactamica. here, the same seven locus neisseria scheme was used to characterize a diverse ... | 2007 | 17825091 |
| a functional two-partner secretion system contributes to adhesion of neisseria meningitidis to epithelial cells. | neisseria meningitidis is a frequent commensal of the human nasopharynx causing severe invasive infections in rare cases. a functional two-partner secretion (tps) system in n. meningitidis, composed of the secreted effector protein hrpa and its cognate transporter hrpb, is identified and characterized in this study. although all meningococcal strains harbor at least one tps system, the hrpa genes display significant c-terminal sequence variation. meningococcal genes encoding the tps effector pro ... | 2007 | 17873034 |
| characterization of the key antigenic components and pre-clinical immune responses to a meningococcal disease vaccine based on neisseria lactamica outer membrane vesicles. | serogroup b strains are now responsible for over 80% of meningococcal disease in the uk and no suitable vaccine is available that confers universal protection against all serogroup b strains. neisseria lactamica shares many antigens with the meningococcus, except capsule and the surface protein pora. many of these antigens are thought to be responsible for providing cross-protective immunity to meningococcal disease. we have developed an n. lactamica vaccine using methods developed for meningoco ... | 2008 | 17921703 |
| the laboratory diagnosis of neisseria gonorrhoeae. | the present article describes the laboratory diagnosis of neisseria gonorrhoeae by culturing of the organism from different types of clinical specimens followed by confirmatory tests. the success of culture methods requires good quality collection and transport of clinical specimens. the present guide describes the media requirements and cultural conditions for n gonorrhoeae growth and the characteristics for a presumptive identification of n gonorrhoeae. confirmatory tests include biochemical t ... | 2005 | 18159523 |
| the porb porin from commensal neisseria lactamica induces th1 and th2 immune responses to ovalbumin in mice and is a potential immune adjuvant. | porins from pathogenic neisseriae are among several bacterial products with immune adjuvant activity. neisseria meningitidis (nme) porb, has been shown to induce immune cells activation in a tlr2-dependent manner and acts as a vaccine immune adjuvant. the porb porin from neisseria lactamica (nlac), a common nasopharyngeal commensal, shares significant structural and functional similarities with nme porb. in this work we ask whether the immune adjuvant ability of porins from pathogenic neisserial ... | 2008 | 18191311 |
| the acute-phase reactant c-reactive protein binds to phosphorylcholine-expressing neisseria meningitidis and increases uptake by human phagocytes. | neisseria meningitidis is a global cause of meningitis and septicemia. immunity to n. meningitidis involves both innate and specific mechanisms with killing by serum bactericidal activity and phagocytic cells. c-reactive protein (crp) is an acute-phase serum protein that has been shown to help protect the host from several bacterial pathogens, which it recognizes by binding to phosphorylcholine (pc) on their surfaces. pathogenic neisseria species can exhibit phase-variable pc modification on typ ... | 2008 | 18195032 |
| vesicle-independent extracellular release of a proinflammatory outer membrane lipoprotein in free-soluble form. | aggregatibacter actinomycetemcomitans is an oral bacterium associated with aggressively progressing periodontitis. extracellular release of bacterial outer membrane proteins has been suggested to mainly occur via outer membrane vesicles. this study investigated the presence and conservation of peptidoglycan-associated lipoprotein (aapal) among a. actinomycetemcomitans strains, the immunostimulatory effect of aapal, and whether live cells release this structural outer membrane lipoprotein in free ... | 2008 | 18226201 |
| new diagnostic real-time pcr for specific detection of parachlamydia acanthamoebae dna in clinical samples. | given the low sensitivity of amoebal coculture, we developed a specific real-time pcr for the detection of parachlamydia. the analytical sensitivity was high, and the inter- and intrarun variabilities were low. when the pcr was applied to nasopharyngeal aspirates, it was positive for six patients with bronchiolitis. future studies should assess the role of parachlamydia in bronchiolitis. | 2008 | 18234873 |
| protochlamydia naegleriophila as etiologic agent of pneumonia. | using ameba coculture, we grew a naegleria endosymbiont. phenotypic, genetic, and phylogenetic analyses supported its affiliation as protochlamydia naegleriophila sp. nov. we then developed a specific diagnostic pcr for protochlamydia spp. when applied to bronchoalveolar lavages, results of this pcr were positive for 1 patient with pneumonia. further studies are needed to assess the role of protochlamydia spp. in pneumonia. | 2008 | 18258101 |
| whole-genome comparison of disease and carriage strains provides insights into virulence evolution in neisseria meningitidis. | neisseria meningitidis is a leading cause of infectious childhood mortality worldwide. most research efforts have hitherto focused on disease isolates belonging to only a few hypervirulent clonal lineages. however, up to 10% of the healthy human population is temporarily colonized by genetically diverse strains mostly with little or no pathogenic potential. currently, little is known about the biology of carriage strains and their evolutionary relationship with disease isolates. the expression o ... | 2008 | 18305155 |
| the impact of the neisserial dna uptake sequences on genome evolution and stability. | efficient natural transformation in neisseria requires the presence of short dna uptake sequences (duss). doubts remain whether duss propagate by pure selfish molecular drive or are selected for 'safe sex' among conspecifics. | 2008 | 18366792 |
| the effect of immune selection on the structure of the meningococcal opa protein repertoire. | the opa genes of the gram negative bacterium neisseria meningitidis encode opacity-associated outer membrane proteins whose role is to promote adhesion to the human host tissue during colonisation and invasion. each meningococcus contains 3-4 opa loci, each of which may be occupied by one of a large number of alleles. we analysed the opa repertoire structure in a large, well-characterised collection of asymptomatically carried meningococci. our data show an association between opa repertoire and ... | 2008 | 18369470 |
| variation in the neisseria lactamica porin, and its relationship to meningococcal porb. | one potential vaccine strategy in the fight against meningococcal disease involves the exploitation of outer-membrane components of neisseria lactamica, a commensal bacterium closely related to the meningococcus, neisseria meningitidis. although n. lactamica shares many surface structures with the meningococcus, little is known about the antigenic diversity of this commensal bacterium or the antigenic relationships between n. lactamica and n. meningitidis. here, the n. lactamica porin protein (p ... | 2008 | 18451061 |
| the bsahi restriction-modification system: cloning, sequencing and analysis of conserved motifs. | restriction and modification enzymes typically recognise short dna sequences of between two and eight bases in length. understanding the mechanism of this recognition represents a significant challenge that we begin to address for the bsahi restriction-modification system, which recognises the six base sequence grcgyc. | 2008 | 18479503 |
| opa protein repertoires of disease-causing and carried meningococci. | the meningococcal opa proteins play an important role in pathogenesis by mediating invasion of human cells. the aim of this investigation was to determine whether carried and disease-associated meningococci possess different opa repertoires and whether the diversity of these proteins is associated with clinical severity of disease. opa repertoires in 227 disease-associated meningococci, isolated in the united kingdom over a period of 6 years, were compared to the repertoires in 190 asymptomatica ... | 2008 | 18508936 |
| multicenter evaluation of the new vitek 2 neisseria-haemophilus identification card. | the new neisseria-haemophilus identification (nh) card for vitek 2 was compared with 16s rrna gene sequencing (16s) as the reference method for accurate identification of neisseria spp., haemophilus spp., and other fastidious gram-negative bacteria. testing was performed on the vitek 2 xl system with modified software at three clinical trial laboratories. reproducibility was determined with nine atcc quality control strains tested 20 times over a minimum of 10 days at all three sites. a challeng ... | 2008 | 18579712 |
| a prospective study of etiology of childhood acute bacterial meningitis, turkey. | determination of the etiology of bacterial meningitis and estimating cost of disease are important in guiding vaccination policies. to determine the incidence and etiology of meningitis in turkey, cerebrospinal fluid (csf) samples were obtained prospectively from children (1 month-17 years of age) with a clinical diagnosis of acute bacterial meningitis. multiplex pcr was used to detect dna evidence of streptococcus pneumoniae, haemophilus influenzae type b (hib), and neisseria meningitidis. in t ... | 2008 | 18598630 |
| two-partner secretion systems of neisseria meningitidis associated with invasive clonal complexes. | the two-partner secretion (tps) pathway is widespread among gram-negative bacteria and facilitates the secretion of very large and often virulence-related proteins. tps systems consist of a secreted tpsa protein and a tpsb protein involved in tpsa transport across the outer membrane. sequenced neisseria meningitidis genomes contain up to five tpsa- and two tpsb-encoding genes. here, we investigated the distribution of tps-related open reading frames in a collection of disease isolates. three dis ... | 2008 | 18678657 |
| a common gene pool for the neisseria feta antigen. | meningococcal feta is an iron-regulated, immunogenic outer membrane protein and vaccine component. the most diverse region of this protein is a previously defined variable region (vr) that has been shown to be immunodominant. in this analysis, a total of 275 neisseria lactamica isolates, collected during studies of nasopharyngeal bacterial carriage in infants, were examined for the presence of a feta gene. the feta vr nucleotide sequence was determined for 217 of these isolates, with feta appare ... | 2009 | 18718812 |
| african trypanosomes contain 5-methylcytosine in nuclear dna. | it is currently unclear if there are modified dna bases in trypanosoma brucei other than j-base. we identify herein a cytosine-5 dna methyltransferase gene and report the presence and location of 5-methylcytosine in genomic dna. our data demonstrate that african trypanosomes contain a functional cytosine dna methylation pathway. | 2008 | 18791035 |
| the use of monoclonal antibodies to neisseria lactamica in an antigen selection to neisseria meningitides b vaccine. | abstract neisseria lactamica, a commensal bacterium that is non-pathogenic to humans and is usually found in the upper respiratory tract of children, is closely related to the pathogenic species neisseria meningitidis. colonization by neisseria lactamica can be responsible for the development of natural immunity to meningococcal infection in childhood, when rates of meningococcal carriers are low. these features suggest that n. lactamica components can be key elements in the production of a new ... | 2008 | 18803504 |
| population genomics: diversity and virulence in the neisseria. | advances in high-throughput nucleotide sequencing and bioinformatics make the study of genomes at the population level feasible. preliminary population genomic studies have explored the relationships among three closely related bacteria, neisseria meningitidis, neisseria gonorrhoeae and neisseria lactamica, which exhibit very different phenotypes with respect to human colonisation. the data obtained have been especially valuable in the establishing of the role of horizontal genetic exchange in b ... | 2008 | 18822386 |
| factor h-binding protein is important for meningococcal survival in human whole blood and serum and in the presence of the antimicrobial peptide ll-37. | factor h-binding protein (fhbp; gna1870) is one of the antigens of the recombinant vaccine against serogroup b neisseria meningitidis, which has been developed using reverse vaccinology and is the basis of a meningococcal b vaccine entering phase iii clinical trials. binding of factor h (fh), an inhibitor of the complement alternative pathway, to fhbp enables n. meningitidis to evade killing by the innate immune system. all fhbp null mutant strains analyzed were sensitive to killing in ex vivo h ... | 2009 | 18852235 |
| factor h-binding protein is important for meningococcal survival in human whole blood and serum and in the presence of the antimicrobial peptide ll-37. | factor h-binding protein (fhbp; gna1870) is one of the antigens of the recombinant vaccine against serogroup b neisseria meningitidis, which has been developed using reverse vaccinology and is the basis of a meningococcal b vaccine entering phase iii clinical trials. binding of factor h (fh), an inhibitor of the complement alternative pathway, to fhbp enables n. meningitidis to evade killing by the innate immune system. all fhbp null mutant strains analyzed were sensitive to killing in ex vivo h ... | 2009 | 18852235 |
| identification of meningococcal genes necessary for colonization of human upper airway tissue. | neisseria meningitidis is an exclusively human pathogen that has evolved primarily to colonize the nasopharynx rather than to cause systemic disease. colonization is the most frequent outcome following meningococcal infection and a prerequisite for invasive disease. the mechanism of colonization involves attachment of the organism to epithelial cells via bacterial type iv pili (tfp), but subsequent events during colonization remain largely unknown. we analyzed 576 n. meningitidis mutants for the ... | 2009 | 18936183 |
| identification of meningococcal genes necessary for colonization of human upper airway tissue. | neisseria meningitidis is an exclusively human pathogen that has evolved primarily to colonize the nasopharynx rather than to cause systemic disease. colonization is the most frequent outcome following meningococcal infection and a prerequisite for invasive disease. the mechanism of colonization involves attachment of the organism to epithelial cells via bacterial type iv pili (tfp), but subsequent events during colonization remain largely unknown. we analyzed 576 n. meningitidis mutants for the ... | 2009 | 18936183 |
| association of a bacteriophage with meningococcal disease in young adults. | despite being the agent of life-threatening meningitis, neisseria meningitidis is usually carried asymptomatically in the nasopharynx of humans and only occasionally causes disease. the genetic bases for virulence have not been entirely elucidated and the search for new virulence factors in this species is hampered by the lack of an animal model representative of the human disease. as an alternative strategy we employ a molecular epidemiological approach to establish a statistical association of ... | 2008 | 19065260 |
| relative contributions of recombination and mutation to the diversification of the opa gene repertoire of neisseria gonorrhoeae. | to understand the rates and mechanisms of neisseria gonorrhoeae opa gene variation, the 11 opa genes were amplified independently so that an opa allelic profile could be defined for any isolate from the sequences at each locus. the opa allelic profiles from 14 unrelated isolates were all different, with no opa alleles shared between isolates. examination of very closely related isolates from sexual contacts and sexual networks showed that these typically shared most opa alleles, and the mechanis ... | 2009 | 19114493 |
| relative contributions of recombination and mutation to the diversification of the opa gene repertoire of neisseria gonorrhoeae. | to understand the rates and mechanisms of neisseria gonorrhoeae opa gene variation, the 11 opa genes were amplified independently so that an opa allelic profile could be defined for any isolate from the sequences at each locus. the opa allelic profiles from 14 unrelated isolates were all different, with no opa alleles shared between isolates. examination of very closely related isolates from sexual contacts and sexual networks showed that these typically shared most opa alleles, and the mechanis ... | 2009 | 19114493 |
| characterization of the meningococcal dna glycosylase fpg involved in base excision repair. | neisseria meningitidis, the causative agent of meningococcal disease, is exposed to high levels of reactive oxygen species inside its exclusive human host. the dna glycosylase fpg of the base excision repair pathway (ber) is a central player in the correction of oxidative dna damage. this study aimed at characterizing the meningococcal fpg and its role in dna repair. | 2009 | 19134198 |
| application of atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry for rapid identification of neisseria species. | atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry (ap-maldi ms) was applied to develop a proteomics-based method to detect and identify neisseria species. heat-inactivated clinical isolate cell suspensions of neisseria gonorrhoeae and strains belonging to five serogroups (a, b, c, w135, and y) of neisseria meningitidis were subjected to on-probe protein/peptide extraction and tryptic digestion followed by ap-maldi tandem ms (ms/ms)-based proteomic analysis. amino ... | 2008 | 19137107 |
| absence of mucosal immunity in the human upper respiratory tract to the commensal bacteria neisseria lactamica but not pathogenic neisseria meningitidis during the peak age of nasopharyngeal carriage. | the normal flora that colonizes the mucosal epithelia has evolved diverse strategies to evade, modulate, or suppress the immune system and avoid clearance. neisseria lactamica and neisseria meningitidis are closely related obligate inhabitants of the human upper respiratory tract. n. lactamica is a commensal but n. meningitidis is an opportunistic pathogen that occasionally causes invasive disease such as meningitis and septicemia. we demonstrate that unlike n. meningitidis, n. lactamica does no ... | 2009 | 19201877 |
| comparative analysis of two neisseria gonorrhoeae genome sequences reveals evidence of mobilization of correia repeat enclosed elements and their role in regulation. | the correia repeat enclosed element (cree) of the neisseria spp., with its inverted repeat and conserved core structure, can generate a promoter sequence at either or both ends, can bind ihf, and can bind rnase iii and either be cleaved by it or protected by it. as such, the presence of this element can directly control the expression of adjacent genes. previous work has shown differences in regulation of gene expression between neisserial strains and species due to the presence of a cree. these ... | 2009 | 19203353 |
| regulation of the type i protein secretion system by the misr/miss two-component system in neisseria meningitidis. | neisseria meningitidis, an obligate human pathogen, remains a leading cause of meningitis and fatal sepsis. meningococci are known to secrete a family of proteins, such as frpc, with sequence similarity to the repeat-in-toxin (rtx) proteins via the type i secretion system. the meningococcal type i secretion proteins are encoded at two distant genetic loci, nmb1400 (hlyb) and nmb1738/1737 (hlyd/tolc), and are separated from the rtx toxin-like substrates. we have characterized the promoter element ... | 2009 | 19372150 |
| molecular characterization and identification of proteins regulated by hfq in neisseria meningitidis. | hfq is a highly conserved pleiotropically acting prokaryotic rna-binding protein involved in the post-transcriptional regulation of many stress-responsive genes by small rnas. in this study, we show that hfq of the strictly human pathogen neisseria meningitidis is involved in the regulation of expression of components involved in general metabolic pathways, iron metabolism and virulence. a meningococcal hfq deletion strain (h44/76deltahfq) is impaired in growth in nutrient-rich media and does no ... | 2009 | 19374669 |
| mechanisms in neisseria meningitidis for resistance against complement-mediated killing. | bacterial meningitis and septicaemia is a global health problem often caused by neisseria meningitidis. the complement system is the most important aspect of host defence against this pathogen, and the critical interaction between the two is influenced by genetic polymorphisms on both the bacterial and the host side; variations of the meningococcus may lead to increased survival in human sera, whereas humans with complement deficiencies are more susceptible to meningococcal infections. here we d ... | 2008 | 19388162 |
| phasevarions mediate random switching of gene expression in pathogenic neisseria. | many host-adapted bacterial pathogens contain dna methyltransferases (mod genes) that are subject to phase-variable expression (high-frequency reversible on/off switching of gene expression). in haemophilus influenzae, the random switching of the moda gene controls expression of a phase-variable regulon of genes (a "phasevarion"), via differential methylation of the genome in the moda on and off states. phase-variable mod genes are also present in neisseria meningitidis and neisseria gonorrhoeae ... | 2009 | 19390608 |
| biogenesis of bacterial membrane vesicles. | membrane vesicle (mv) release remains undefined, despite its conservation among replicating gram-negative bacteria both in vitro and in vivo. proteins identified in salmonella mvs, derived from the envelope, control mv production via specific defined domains that promote outer membrane protein-peptidoglycan (om-pg) and om protein-inner membrane protein (om-pg-im) interactions within the envelope structure. modulation of om-pg and om-pg-im interactions along the cell body and at division septa, r ... | 2009 | 19432795 |
| global optimal eburst analysis of multilocus typing data using a graphic matroid approach. | multilocus sequence typing (mlst) is a frequently used typing method for the analysis of the clonal relationships among strains of several clinically relevant microbial species. mlst is based on the sequence of housekeeping genes that result in each strain having a distinct numerical allelic profile, which is abbreviated to a unique identifier: the sequence type (st). the relatedness between two strains can then be inferred by the differences between allelic profiles. for a more comprehensive an ... | 2009 | 19450271 |
| evidence for capsule switching between carried and disease-causing neisseria meningitidis strains. | changing antigenic structure such as with capsule polysaccharide is a common strategy for bacterial pathogens to evade a host immune system. the recent emergence of an invasive w:2a:p1.7-2,4 sequence type 11 (st-11) strain of neisseria meningitidis in new zealand, an uncommon serogroup/serotype in new zealand disease cases, was investigated for its genetic origins. molecular typing of 107 meningococcal isolates with similar serotyping characteristics was undertaken to determine genetic relations ... | 2009 | 19451248 |
| homologous prime-boost strategy in neonate mice using neisseria lactamica. | the aim of the present study was to investigate the immune response to native outer membrane vesicles (nomvs) of neisseria lactamica with and without bordetella pertussis (bp) as adjuvant in intranasal (i.n./i.m) immunization. n. lactamica nomvs delivered intranasally (i.n) to balb/c mice in a final volume of 5microl that was gradually introduced with a micropipette, animals received 1, 2, 3, or 4 doses of antigens at 3, 7, 9 and 12 days after birth. on the 35th day, the animals were immunized i ... | 2009 | 19460600 |
| epidemiological evidence for the role of the hemoglobin receptor, hmbr, in meningococcal virulence. | the distribution of the hemoglobin receptor gene (hmbr) was investigated among disease and carriage neisseria meningitidis isolates, revealing that the gene was detected at a significantly higher frequency among disease isolates than among carriage isolates. in isolates without hmbr, the locus was occupied by the cassettes exl2 or exl3 or by a "pseudo hmbr" gene, designated exl4. the hmbr locus exhibited characteristics of a pathogenicity island in published genomes of n. meningitidis, neisseria ... | 2009 | 19476432 |
| genome flexibility in neisseria meningitidis. | neisseria meningitidis usually lives as a commensal bacterium in the upper airways of humans. however, occasionally some strains can also cause life-threatening diseases such as sepsis and bacterial meningitis. comparative genomics demonstrates that only very subtle genetic differences between carriage and disease strains might be responsible for the observed virulence differences and that n. meningitidis is, evolutionarily, a very recent species. comparative genome sequencing also revealed a pa ... | 2009 | 19477564 |
| clinical and laboratory evidence for neisseria meningitidis biofilms. | neisseria meningitidis is the etiologic agent of meningococcal meningitis. carriage of the organism is approximately 10% while active disease occurs at a rate of 1:100,000. recent publications demonstrate that n. meningitidis has the ability to form biofilms on glass, plastic or cultured human bronchial epithelial cells. microcolony-like structures are also observed in histological sections from patients with active meningococcal disease. this review investigates the possible role of meningococc ... | 2009 | 19492966 |
| towards the immunoproteome of neisseria meningitidis. | despite the introduction of conjugated polysaccharide vaccines for many of the neisseria meningitidis serogroups, neisserial infections continue to cause septicaemia and meningitis across the world. this is in part due to the difficulties in developing a, cross-protective vaccine that is effective against all serogroups, including serogroup b meningococci. although convalescent n. meningitidis patients develop a natural long-lasting cross-protective immunity, the antigens that mediate this respo ... | 2009 | 19529772 |