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sigma factor rpon (σ54) regulates pile transcription in commensal neisseria elongata.human-adapted neisseria includes two pathogens, neisseria gonorrhoeae and neisseria meningitidis, and at least 13 species of commensals that colonize many of the same niches as the pathogens. the type iv pilus plays an important role in the biology of pathogenic neisseria. in these species, sigma factor rpod (σ(70)), integration host factor, and repressors regf and crga regulate transcription of pile, the gene encoding the pilus structural subunit. the type iv pilus is also a strictly conserved ...201323899162
homologous recombination drives both sequence diversity and gene content variation in neisseria meningitidis.the study of genetic and phenotypic variation is fundamental for understanding the dynamics of bacterial genome evolution and untangling the evolution and epidemiology of bacterial pathogens. neisseria meningitidis (nm) is among the most intriguing bacterial pathogens in genomic studies due to its dynamic population structure and complex forms of pathogenicity. extensive genomic variation within identical clonal complexes (ccs) in nm has been recently reported and suggested to be the result of h ...201323902748
processing-independent crispr rnas limit natural transformation in neisseria meningitidis.crispr interference confers adaptive, sequence-based immunity against viruses and plasmids and is specified by crispr rnas (crrnas) that are transcribed and processed from spacer-repeat units. pre-crrna processing is essential for crispr interference in all systems studied thus far. here, our studies of crrna biogenesis and crispr interference in naturally competent neisseria spp. reveal a unique crrna maturation pathway in which crrnas are transcribed from promoters that are embedded within eac ...201323706818
fuzzy species revisited. 201323587266
neisseria oralis sp. nov., isolated from healthy gingival plaque and clinical samples.a polyphasic analysis was undertaken of seven independent isolates of gram-negative cocci collected from pathological clinical samples from new york, louisiana, florida and illinois and healthy subgingival plaque from a patient in virginia, usa. the 16s rrna gene sequence similarity among these isolates was 99.7-100 %, and the closest species with a validly published name was neisseria lactamica (96.9 % similarity to the type strain). dna-dna hybridization confirmed that these isolates are of th ...201322798652
protein interactions in genome maintenance as novel antibacterial targets.antibacterial compounds typically act by directly inhibiting essential bacterial enzyme activities. although this general mechanism of action has fueled traditional antibiotic discovery efforts for decades, new antibiotic development has not kept pace with the emergence of drug resistant bacterial strains. these limitations have severely restricted the therapeutic tools available for treating bacterial infections. here we test an alternative antibacterial lead-compound identification strategy in ...201323536821
neisseria infection of rhesus macaques as a model to study colonization, transmission, persistence, and horizontal gene transfer.the strict tropism of many pathogens for man hampers the development of animal models that recapitulate important microbe-host interactions. we developed a rhesus macaque model for studying neisseria-host interactions using neisseria species indigenous to the animal. we report that neisseria are common inhabitants of the rhesus macaque. neisseria isolated from the rhesus macaque recolonize animals after laboratory passage, persist in the animals for at least 72 d, and are transmitted between ani ...201323382234
genome sequence analyses show that neisseria oralis is the same species as 'neisseria mucosa var. heidelbergensis'.phylogenies generated from whole genome sequence (wgs) data provide definitive means of bacterial isolate characterization for typing and taxonomy. the species status of strains recently defined with conventional taxonomic approaches as representing neisseria oralis was examined by the analysis of sequences derived from wgs data, specifically: (i) 53 neisseria ribosomal protein subunit (rps) genes (ribosomal multi-locus sequence typing, rmlst); and (ii) 246 neisseria core genes (core genome mlst ...201324097834
role of transition metal exporters in virulence: the example of neisseria meningitidis.transition metals such as iron, manganese, and zinc are essential micronutrients for bacteria. however, at high concentration, they can generate non-functional proteins or toxic compounds. metal metabolism is therefore regulated to prevent shortage or overload, both of which can impair cell survival. in addition, equilibrium among these metals has to be tightly controlled to avoid molecular replacement in the active site of enzymes. bacteria must actively maintain intracellular metal concentrati ...201324392357
genetic distribution of noncapsular meningococcal group b vaccine antigens in neisseria lactamica.the poor immunogenicity of the meningococcal serogroup b (menb) capsule has led to the development of vaccines targeting subcapsular antigens, in particular the immunodominant and diverse outer membrane porin, pora. these vaccines are largely strain specific; however, they offer limited protection against the diverse menb-associated diseases observed in many industrialized nations. to broaden the scope of its protection, the multicomponent vaccine (4cmenb) incorporates a pora-containing outer me ...201323803905
distribution and diversity of the haemoglobin-haptoglobin iron-acquisition systems in pathogenic and non-pathogenic neisseria.a new generation of vaccines containing multiple protein components that aim to provide broad protection against serogroup b meningococci has been developed. one candidate, 4cmenb (4 component menb), has been approved by the european medicines agency, but is predicted to provide at most 70-80 % strain coverage; hence there is a need for second-generation vaccines that achieve higher levels of coverage. prior knowledge of the diversity of potential protein vaccine components is a key step in vacc ...201323813677
genetic characteristics of neisseria meningitidis serogroup b strains carried by adolescents living in milan, italy: implications for vaccine efficacy.before a protein vaccine is introduced into a country, it is essential to evaluate its potential impact and estimate its benefits and costs. the aim of this study was to determine the genetic characteristics of neisseria meningitidis b (nmb) in the pharyngeal secretions of 1375 healthy adolescents aged 13-19 y living in milan, italy, in september 2012, and the possible protection offered by the two currently available nmb protein vaccines. ninety-one subjects were nm carriers (6.6%), 29 (31.9%) ...201323880917
pseudomonas aeruginosa outer membrane vesicles modulate host immune responses by targeting the toll-like receptor 4 signaling pathway.bacteria can naturally secrete outer membrane vesicles (omvs) as pathogenic factors, while these vesicles may also serve as immunologic regulators if appropriately prepared. however, it is largely unknown whether pseudomonas aeruginosa omvs can activate inflammatory responses and whether immunization with omvs can provide immune protection against subsequent infection. we purified and identified omvs, which were then used to infect lung epithelial cells in vitro as well as c57bl/6j mice to inves ...201324082079
methods for identifying neisseria meningitidis carriers: a multi-center study in the african meningitis belt.detection of meningococcal carriers is key to understanding the epidemiology of neisseria meningitidis, yet no gold standard has been established. here, we directly compare two methods for collecting pharyngeal swabs to identify meningococcal carriers.201324194921
routine vaccination against menb: considerations for implementation.effective polysaccharide(conjugate) vaccines against neisseria meningitidis serogroups a, c, w, and y have been widely used, but serogroup b meningococci remain a major cause of severe invasive meningococcal disease (imd) worldwide, especially in infants. recently, a vaccine, 4cmenb (bexsero(®)), containing three recombinant proteins, and outer membrane vesicles (omv) derived from a serogroup b meningococcal strain (menb) has been licensed in europe and australia and is indicated for persons age ...201324141209
routine vaccination against menb: considerations for implementation.effective polysaccharide(conjugate) vaccines against neisseria meningitidis serogroups a, c, w, and y have been widely used, but serogroup b meningococci remain a major cause of severe invasive meningococcal disease (imd) worldwide, especially in infants. recently, a vaccine, 4cmenb (bexsero(®)), containing three recombinant proteins, and outer membrane vesicles (omv) derived from a serogroup b meningococcal strain (menb) has been licensed in europe and australia and is indicated for persons age ...201324141209
molecular cloning, sequence characterization and expression analysis of a cd63 homologue from the coleopteran beetle, tenebrio molitor.cd63, a member of the tetraspanin membrane protein family, plays a pivotal role in cell growth, motility, signal transduction, host-pathogen interactions and cancer. in this work, the cdna encoding cd63 homologue (tmcd63) was cloned from larvae of a coleopteran beetle, tenebrio molitor. the cdna is comprised of an open reading frame of 705 bp, encoding putative protein of 235 amino acid residues. in silico analysis shows that the protein has four putative transmembrane domains and one large extr ...201324132157
the significance of virulence factors in helicobacter pylori.helicobacter pylori (h. pylori) infection is linked to various gastroduodenal diseases; however, only a small fraction of these patients develop associated diseases. despite the high prevalence of h. pylori infection in africa and south asia, the incidence of gastric cancer in these areas is much lower than those in other countries. the incidence of gastric cancer tends to decrease from north to south in east asia. such geographical differences in the pathology can be explained, at least in part ...201323452293
bacterial contact-dependent growth inhibition.bacteria cooperate to form multicellular communities and compete against one another for environmental resources. here, we review recent advances in the understanding of bacterial competition mediated by contact-dependent growth inhibition (cdi) systems. different cdi+ bacteria deploy a variety of toxins to inhibit neighboring cells and protect themselves from autoinhibition by producing specific immunity proteins. the genes encoding cdi toxin-immunity protein pairs appear to be exchanged betwee ...201323473845
letter from the editor. 201323454871
seroprevalence of bactericidal, specific igg antibodies and incidence of meningitis due to group a neisseria meningitidis by age in burkina faso 2008.we investigated serological correlates of protection against neisseria meningitidis serogroup a (nma) in burkina faso before the introduction of nma conjugate vaccine.201323457471
neisseria lactamica antigens complexed with a novel cationic adjuvant.colonization of the nasopharynx by non-pathogenic neisseria species, including n. lactamica, has been suggested to lead to the acquisition of natural immunity against neisseria meningitidis in young children. the aim of this study was to identify a model complex of antigens and adjuvant for immunological preparation against n. meningitidis b, based on cross reactivity with n. lactamica outer membrane vesicles (omv) antigens and the (dda-bf) adjuvant. complexes of 25 µg of omv in 0.1 mm of dda-bf ...201323296384
bacterial flora of conjunctiva after death.to evaluate the frequency of bacterial flora of conjunctiva after death (cadaver eyes) which will give information about the bacterial contamination of donor eyes, and the in-vitro sensitivity of isolated bacteria to the commonly used antibiotics in ophthalmic practice.201324195038
neisseria gonorrhoeae-derived heptose elicits an innate immune response and drives hiv-1 expression.clinical and epidemiological synergy exists between the globally important sexually transmitted infections, gonorrhea and hiv. neisseria gonorrhoeae, which causes gonorrhea, is particularly adept at driving hiv-1 expression, but the molecular determinants of this relationship remain undefined. n. gonorrhoeae liberates a soluble factor that potently induces expression from the hiv-1 ltr in coinfected cluster of differentiation 4-positive (cd4(+)) t lymphocytes, but this factor is not a previously ...201323733950
system specificity of the tpsb transporters of coexpressed two-partner secretion systems of neisseria meningitidis.the two-partner secretion (tps) systems of gram-negative bacteria consist of a large secreted exoprotein (tpsa) and a transporter protein (tpsb) located in the outer membrane. tpsa targets tpsb for transport across the membrane via its ∼30-kda tps domain located at its n terminus, and this domain is also the minimal secretory unit. neisseria meningitidis genomes encode up to five tpsas and two tpsbs. sequence alignments of tps domains suggested that these are organized into three systems, while ...201323222722
diagnostic usefulness of ribosomal protein l7/l12 for pneumococcal pneumonia in a mouse model.the capsular antigen detection (cad) kit is widely used in clinics to detect streptococcus pneumoniae infection from urine, because it is rapid, convenient, and effective. however, there are several disadvantages, including false-positive results in children colonized with s. pneumoniae and prolonged positive readings even after the bacteria have been cleared. rp-l7/l12 is a component of the 50s ribosome that is abundant in all bacteria and is specific for each bacterial species. we investigated ...201323100338
allelic variation in a simple sequence repeat element of neisserial pglb2 and its consequences for protein expression and protein glycosylation.neisseria species express an o-linked glycosylation system in which functionally distinct proteins are elaborated with variable glycans. a major source of glycan diversity in n. meningitidis results from two distinct pglb alleles responsible for the synthesis of either n,n'-diacetylbacillosamine or glyceramido-acetamido trideoxyhexose that occupy the reducing end of the oligosaccharides. alternative modifications at c-4 of the precursor udp-4-amino are attributable to distinct c-terminal domains ...201323729645
rapid pcr detection of mycoplasma hominis, ureaplasma urealyticum, and ureaplasma parvum.objective. we compared laboratory developed real-time pcr assays for detection of mycoplasma hominis and for detection and differentiation of ureaplasma urealyticum and parvum to culture using genitourinary specimens submitted for m. hominis and ureaplasma culture. methods. 283 genitourinary specimens received in the clinical bacteriology laboratory for m. hominis and ureaplasma species culture were evaluated. nucleic acids were extracted using the total nucleic acid kit on the magna pure 2.0. 5 ...201326904723
description of an unusual neisseria meningitidis isolate containing and expressing neisseria gonorrhoeae-specific 16s rrna gene sequences.an apparently rare neisseria meningitidis isolate containing one copy of a neisseria gonorrhoeae 16s rrna gene is described herein. this isolate was identified as n. meningitidis by biochemical identification methods but generated a positive signal with gen-probe aptima assays for the detection of neisseria gonorrhoeae. direct 16s rrna gene sequencing of the purified isolate revealed mixed bases in signature regions that allow for discrimination between n. meningitidis and n. gonorrhoeae. the mi ...201323863567
where does neisseria acquire foreign dna from: an examination of the source of genomic and pathogenic islands and the evolution of the neisseria genus.pathogenicity islands (pais) or genomic islands (geis) are considered to be the result of a recent horizontal transfer. detecting pais/geis as well as their putative source can provide insight into the organism's pathogenicity within its host. previously we introduced a tool called s-plot which provides a visual representation of the variation in compositional properties across and between genomic sequences. utilizing s-plot and new functionality developed here, we examined 18 publicly available ...201324007216
patient-specific analysis of periodontal and peri-implant microbiomes.periodontally involved teeth have been implicated as 'microbial reservoirs' in the etiology of peri-implant diseases. therefore, the purpose of this investigation was to use a deep-sequencing approach to identify the degree of congruence between adjacent peri-implant and periodontal microbiomes in states of health and disease. subgingival and peri-implant biofilm samples were collected from 81 partially edentulous individuals with periodontal and peri-implant health and disease. bacterial dna wa ...201324158341
molecular mapping to species level of the tonsillar crypt microbiota associated with health and recurrent tonsillitis.the human palatine tonsils, which belong to the central antigen handling sites of the mucosal immune system, are frequently affected by acute and recurrent infections. this study compared the microbiota of the tonsillar crypts in children and adults affected by recurrent tonsillitis with that of healthy adults and children with tonsillar hyperplasia. an in-depth 16s rrna gene based pyrosequencing approach combined with a novel strategy that included phylogenetic analysis and detection of species ...201323437130
functional genes to assess nitrogen cycling and aromatic hydrocarbon degradation: primers and processing matter.targeting sequencing to genes involved in key environmental processes, i.e., ecofunctional genes, provides an opportunity to sample nature's gene guilds to greater depth and help link community structure to process-level outcomes. vastly different approaches have been implemented for sequence processing and, ultimately, for taxonomic placement of these gene reads. the overall quality of next generation sequence analysis of functional genes is dependent on multiple steps and assumptions of unknow ...201324062736
evolution and comparative genomics of campylobacter jejuni st-677 clonal complex.campylobacter is the most common bacterial cause of gastroenteritis in the european union with over 200,000 laboratory-confirmed cases reported annually. this is the first study to describe findings related to comparative genomics analyses of the sequence type (st)-677 clonal complex (cc), a campylobacter jejuni lineage associated with bacteremia cases in humans. we performed whole-genome sequencing, using illumina hiseq sequencing technology, on five related st-677 cc isolates from two chicken ...201425193305
exploring preterm birth as a polymicrobial disease: an overview of the uterine microbiome.infection is a leading cause of preterm birth (ptb). a focus of many studies over the past decade has been to characterize microorganisms present in the uterine cavity and document any association with negative pregnancy outcome. a range of techniques have been used to achieve this, including microbiological culture and targeted polymerase chain reaction assays, and more recently, microbiome-level analyses involving either conserved, phylogenetically informative genes such as the bacterial 16s r ...201425505898
the dam replacing gene product enhances neisseria gonorrhoeae fa1090 viability and biofilm formation.many neisseriaceae do not exhibit dam methyltransferase activity and, instead of the dam gene, possess drg (dam replacing gene) inserted in the leus/dam locus. the drg locus in neisseria gonorrhoeae fa1090 has a lower gc-pairs content (40.5%) compared to the whole genome of n. gonorrhoeae fa1090 (52%). the gonococcal drg gene encodes a dna endonuclease drg, with gmeatc specificity. disruption of drg or insertion of the dam gene in gonococcal genome changes the level of expression of genes as sho ...201425566225
cas9-based tools for targeted genome editing and transcriptional control.development of tools for targeted genome editing and regulation of gene expression has significantly expanded our ability to elucidate the mechanisms of interesting biological phenomena and to engineer desirable biological systems. recent rapid progress in the study of a clustered, regularly interspaced short palindromic repeat (crispr)/crispr-associated (cas) protein system in bacteria has facilitated the development of newly facile and programmable platforms for genome editing and transcriptio ...201424389925
sterilizing immunity elicited by neisseria meningitidis carriage shows broader protection than predicted by serum antibody cross-reactivity in ceacam1-humanized mice.neisseria meningitidis asymptomatically colonizes the human upper respiratory tract but is also the cause of meningitis and severe septicemia. carriage or disease evokes an immune response against the infecting strain. hitherto, we have known little about the breadth of immunity induced by natural carriage of a single strain or its implications for subsequent infectious challenge. in this study, we establish that transgenic mice expressing human ceacam1 support nasal colonization by a variety of ...201425368118
sterilizing immunity elicited by neisseria meningitidis carriage shows broader protection than predicted by serum antibody cross-reactivity in ceacam1-humanized mice.neisseria meningitidis asymptomatically colonizes the human upper respiratory tract but is also the cause of meningitis and severe septicemia. carriage or disease evokes an immune response against the infecting strain. hitherto, we have known little about the breadth of immunity induced by natural carriage of a single strain or its implications for subsequent infectious challenge. in this study, we establish that transgenic mice expressing human ceacam1 support nasal colonization by a variety of ...201425368118
activity of aristolochia bracteolata against moraxella catarrhalis.a bioassay-guided fractionation of methanol extract of aristolochia bracteolata whole plant was carried out in order to evaluate its antimicrobial activity and to identify the active compounds in this extract. antibacterial and antifungal activities of methanol extract against gram-positive, gram-negative, and fungal strains were investigated by the agar disk diffusion method. among the strains tested, moraxella catarrhalis and sea urchin-derived bacillus sp. showed the highest sensitivity towar ...201426904734
recommendations for the laboratory-based detection of chlamydia trachomatis and neisseria gonorrhoeae--2014.this report updates cdc's 2002 recommendations regarding screening tests to detect chlamydia trachomatis and neisseria gonorrhoeae infections (cdc. screening tests to detect chlamydia trachomatis and neisseria gonorrhoeae infections-2002. mmwr 2002;51[no. rr-15]) and provides new recommendations regarding optimal specimen types, the use of tests to detect rectal and oropharyngeal c. trachomatis and n. gonorrhoeae infections, and circumstances when supplemental testing is indicated. the recommend ...201424622331
placental microbiome and its role in preterm birth.despite the well-known fact that the placenta has long-term effects on maternal and fetal health, the placenta remains a poorly understood and understudied organ. not only is the placenta a site of exchange of nutrients and blood and gases between the fetal and maternal systems, but it also performs critical metabolic functions for supporting fetal development and maintaining maternal-fetal tolerance. it is also abundantly clear that impairment of placental function leads to severe pregnancy com ...201425635174
disease-associated neisseria meningitidis isolates inhibit wound repair in respiratory epithelial cells in a type iv pilus-independent manner.neisseria meningitidis is the causative agent of meningococcal disease. onset of meningococcal disease can be extremely rapid and can kill within a matter of hours. however, although a much-feared pathogen, neisseria meningitidis is frequently found in the nasopharyngeal mucosae of healthy carriers. the bacterial factors that distinguish disease- from carriage-associated meningococci are incompletely understood. evidence suggesting that disruptions to the nasopharynx may increase the risk of acq ...201425225250
emergence of a new epidemic neisseria meningitidis serogroup a clone in the african meningitis belt: high-resolution picture of genomic changes that mediate immune evasion.in the african "meningitis belt," outbreaks of meningococcal meningitis occur in cycles, representing a model for the role of host-pathogen interactions in epidemic processes. the periodicity of the epidemics is not well understood, nor is it currently possible to predict them. in our longitudinal colonization and disease surveys, we have observed waves of clonal replacement with the same serogroup, suggesting that immunity to noncapsular antigens plays a significant role in natural herd immunit ...201425336458
draft genome assembly of neisseria lactamica type strain a7515.we present the scaffolded genome assembly of neisseria lactamica type strain a7515 (atcc 23970) as submitted to ncbi under accession no. jovi00000000. this type strain of the lactose-fermenting neisseria species is often used in quality control testing and intra-genus phylogenetic analyses. the assembly includes four contigs placed into a single scaffold.201425291770
implications of differential age distribution of disease-associated meningococcal lineages for vaccine development.new vaccines targeting meningococci expressing serogroup b polysaccharide have been developed, with some being licensed in europe. coverage depends on the distribution of disease-associated genotypes, which may vary by age. it is well established that a small number of hyperinvasive lineages account for most disease, and these lineages are associated with particular antigens, including vaccine candidates. a collection of 4,048 representative meningococcal disease isolates from 18 european countr ...201424695776
the polypeptide transport-associated (potra) domains of tpsb transporters determine the system specificity of two-partner secretion systems.the two-partner secretion (tps) systems of gram-negative bacteria secrete large tpsa exoproteins by a dedicated tpsb transporter in the outer membrane. tpsbs contain an n-terminal module located in the periplasm that includes two polypeptide transport-associated (potra) domains. these are thought to initiate secretion of a tpsa by binding its n-terminal secretion signal, called the tps domain. neisseria meningitidis encodes up to five tpsa proteins that are secreted via only two tpsb transporter ...201424872418
virulence factors of helicobacter pylori: a review.helicobacter pylori is a spiral-shaped gram-negative bacterium that colonizes the human stomach and can establish a long-term infection of the gastric mucosa, a condition that affects the relative risk of developing various clinical disorders of the upper gastrointestinal tract, such as chronic gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue (malt) lymphoma, and gastric adenocarcinoma. h. pylori presents a high-level of genetic diversity, which can be an important factor in it ...201424833944
genotypic analysis of meningococcal factor h-binding protein from non-culture clinical specimens.factor h-binding protein (fhbp) is an outer membrane protein antigen included in two novel meningococcal group b vaccines and, as such, is an important typing target. approximately 50% of meningococcal disease cases in england and wales are confirmed using real-time pcr on non-culture clinical specimens only. protocols for typing fhbp from this subset of cases have not yet been established. here we present a nested pcr-based assay designed to amplify and sequence fhbp from non-culture clinical s ...201424587125
serogroup-specific interaction of neisseria meningitidis capsular polysaccharide with host cell microtubules and effects on tubulin polymerization.we have previously shown that during late stages of the infectious process, serogroup b meningococci (menb) are able to escape the phagosome of in vitro-infected human epithelial cells. they then multiply in the cytosolic environment and spread intracellularly and to surrounding cells by exploiting the microtubule cytoskeleton, as suggested by results of infections in the presence of microtubule inhibitors and evidence of nanotubes connecting neighboring cells. in this study, by using microtubul ...201424166951
identifying neisseria species by use of the 50s ribosomal protein l6 (rplf) gene.the comparison of 16s rrna gene sequences is widely used to differentiate bacteria; however, this gene can lack resolution among closely related but distinct members of the same genus. this is a problem in clinical situations in those genera, such as neisseria, where some species are associated with disease while others are not. here, we identified and validated an alternative genetic target common to all neisseria species which can be readily sequenced to provide an assay that rapidly and accur ...201424523465
neisseria meningitidis elicits a pro-inflammatory response involving iκbζ in a human blood-cerebrospinal fluid barrier model.the human-specific, gram-negative bacterium neisseria meningitidis (nm) is a leading cause of bacterial meningitis worldwide. the blood-cerebrospinal fluid barrier (bcsfb), which is constituted by the epithelial cells of the choroid plexus (cp), has been suggested as one of the potential entry sites of nm into the csf and can contribute to the inflammatory response during infectious diseases of the brain. toll-like receptors (tlrs) are involved in mediating signal transduction caused by the path ...201425347003
mp3: a software tool for the prediction of pathogenic proteins in genomic and metagenomic data.the identification of virulent proteins in any de-novo sequenced genome is useful in estimating its pathogenic ability and understanding the mechanism of pathogenesis. similarly, the identification of such proteins could be valuable in comparing the metagenome of healthy and diseased individuals and estimating the proportion of pathogenic species. however, the common challenge in both the above tasks is the identification of virulent proteins since a significant proportion of genomic and metagen ...201424736651
restriction endonucleases from invasive neisseria gonorrhoeae cause double-strand breaks and distort mitosis in epithelial cells during infection.the host epithelium is both a barrier against, and the target for microbial infections. maintaining regulated cell growth ensures an intact protective layer towards microbial-induced cellular damage. neisseria gonorrhoeae infections disrupt host cell cycle regulation machinery and the infection causes dna double strand breaks that delay progression through the g2/m phase. we show that intracellular gonococci upregulate and release restriction endonucleases that enter the nucleus and damage human ...201425460012
identification of srnas expressed by the human pathogen neisseria gonorrhoeae under disparate growth conditions.in the last several years, bacterial gene regulation via small rnas (srnas) has been recognized as an important mechanism controlling expression of essential proteins that are critical to bacterial growth and metabolism. technologies such as rna-seq are rapidly expanding the field of srnas and are enabling a global view of the "srnaome" of several bacterial species. while numerous srnas have been identified in a variety of both gram-negative and gram-positive bacteria, only a very small number h ...201425221548
a genome-wide identification of genes undergoing recombination and positive selection in neisseria.currently, there is particular interest in the molecular mechanisms of adaptive evolution in bacteria. neisseria is a genus of gram negative bacteria, and there has recently been considerable focus on its two human pathogenic species n. meningitidis and n. gonorrhoeae. until now, no genome-wide studies have attempted to scan for the genes related to adaptive evolution. for this reason, we selected 18 neisseria genomes (14 n. meningitidis, 3 n. gonorrhoeae and 1 commensal n. lactamics) to conduct ...201425180194
a large genomic island allows neisseria meningitidis to utilize propionic acid, with implications for colonization of the human nasopharynx.neisseria meningitidis is an important human pathogen that is capable of killing within hours of infection. its normal habitat is the nasopharynx of adult humans. here we identify a genomic island (the prp gene cluster) in n. meningitidis that enables this species to utilize propionic acid as a supplementary carbon source during growth, particularly under nutrient poor growth conditions. the prp gene cluster encodes enzymes for a methylcitrate cycle. novel aspects of the methylcitrate cycle in n ...201424910087
sequence, distribution and chromosomal context of class i and class ii pilin genes of neisseria meningitidis identified in whole genome sequences.neisseria meningitidis expresses type four pili (tfp) which are important for colonisation and virulence. tfp have been considered as one of the most variable structures on the bacterial surface due to high frequency gene conversion, resulting in amino acid sequence variation of the major pilin subunit (pile). meningococci express either a class i or a class ii pile gene and recent work has indicated that class ii pilins do not undergo antigenic variation, as class ii pile genes encode conserved ...201424690385
neisseria proteomics for antigen discovery and vaccine development.neisseria meningitidis (meningococcus) is a major causative organism of meningitis and sepsis and neisseria gonorrhoeae (gonococcus) is the causative organism of the sexually transmitted disease gonorrhea. infections caused by meningococci are vaccine-preventable, whereas gonococcal vaccine research and development has languished for decades and the correlates of protection are still largely unknown. in the past two decades, complementary 'omic' platforms have been developed to interrogate neiss ...201425017717
on-line sers detection of single bacterium using novel sers nanoprobes and a microfluidic dielectrophoresis device.the integration of novel surface-enhanced raman scattering (sers) nanoprobes and a microfluidic dielectrophoresis (dep) device is developed for rapid on-line sers detection of salmonella enterica serotype choleraesuis and neisseria lactamica. the sers nanoprobes are prepared by immobilization of specific antibody onto the surface of nanoaggregate-embedded beads (naebs), which are silica-coated, dye-induced aggregates of a small number of gold nanoparticles (aunps). each naeb gives highly enhance ...201425115777
role of pena polymorphisms for penicillin susceptibility in neisseria lactamica and neisseria meningitidis.in meningococci, reduced penicillin susceptibility is associated with five specific mutations in the transpeptidase region of penicillin binding protein 2 (pbp2). we showed that the same set of mutations was present in 64 of 123 neisseria lactamica strains obtained from a carriage study (mic range: 0.125-2.0mg/l). the pbp2 encoding pena alleles in these strains were genetically similar to those found in intermediate resistant meningococci suggesting frequent interspecies genetic exchange. fifty- ...201526321007
nasal inoculation of the commensal neisseria lactamica inhibits carriage of neisseria meningitidis by young adults: a controlled human infection study.herd protection by meningococcal vaccines is conferred by population-level reduction of meningococcal nasopharyngeal colonization. given the inverse epidemiological association between colonization by commensal neisseria lactamica and meningococcal disease, we investigated whether controlled infection of human volunteers with n. lactamica prevents colonization by neisseria meningitidis.201525814628
structural analysis of haemoglobin binding by hpua from the neisseriaceae family.the neisseriaceae family of bacteria causes a range of diseases including meningitis, septicaemia, gonorrhoea and endocarditis, and extracts haem from haemoglobin as an important iron source within the iron-limited environment of its human host. herein we report crystal structures of apo- and haemoglobin-bound hpua, an essential component of this haem import system. the interface involves long loops on the bacterial receptor that present hydrophobic side chains for packing against the surface of ...201526671256
how clonal are neisseria species? the epidemic clonality model revisited.the three species neisseria meningitidis, neisseria gonorrheae, and neisseria lactamica are often regarded as highly recombining bacteria. n. meningitidis has been considered a paradigmatic case of the "semiclonal model" or of "epidemic clonality," demonstrating occasional bouts of clonal propagation in an otherwise recombining species. in this model, occasional clonality generates linkage disequilibrium in the short term. in the long run, however, the effects of clonality are countered by recom ...201526195766
the neisseria gonorrhoeae obg protein is an essential ribosome-associated gtpase and a potential drug target.neisseria gonorrhoeae (gc) is a gram-negative pathogen that most commonly infects mucosal surfaces, causing sexually transmitted urethritis in men and endocervicitis in women. serious complications associated with these infections are frequent and include pelvic inflammatory disease, ectopic pregnancy, and infertility. the incidence of gonorrhea cases remains high globally while antibiotic treatment options, the sole counter measures against gonorrhea, are declining due to the remarkable ability ...201526122105
map-based comparative genomic analysis of virulent haemophilus parasuis serovars 4 and 5.haemophilus parasuis is a commensal bacterium of the upper respiratory tract of healthy pigs. however, in conjunction with viral infections in immunocompromised animals h. parasuis can transform into a pathogen that is responsible for causing glasser's disease which is typically characterized by fibrinous polyserositis, polyarthritis, meningitis and sometimes acute pneumonia and septicemia in pigs. haemophilus parasuis serovar 5 is highly virulent and more frequently isolated from respiratory an ...201525874016
mobile dna in the pathogenic neisseria.the genus neisseria contains two pathogenic species of notable public health concern: neisseria gonorrhoeae and neisseria meningitidis. these pathogens display a notable ability to undergo frequent programmed recombination events. the recombination mediated pathways of transformation and pilin antigenic variation in the neisseria are well studied systems that are critical for pathogenesis. here we will detail the conserved and unique aspects of transformation and antigenic variation in the neiss ...201525866700
comparative proteomics analysis of two strains of neisseria meningitidis serogroup b and neisseria lactamica.antigenic similarities between neisseria lactamica as a commensal species and n. meningitidis serogroup b (nmb) as an important cause of meningitis infection have been considered for the development of an effective vaccine based on their common proteins to prevent life-threatening bacterial meningitis.201526855742
impact of vaccination on meningococcal epidemiology.neisseria meningitidis may cause invasive disease (meningitis and sepsis), leading to considerable disease burden and mortality. however, effective vaccines are available against most pathogenic serogroups. large-scale vaccination campaigns with the mcc vaccine conducted in uk and with menafrivac in the sahel have clearly demonstrated the direct and indirect effect of immunization programmes on disease and carriage. moreover, the introduction of novel subcapsular vaccines against serogroup b, wh ...201526512927
impact of vaccination on meningococcal epidemiology.neisseria meningitidis may cause invasive disease (meningitis and sepsis), leading to considerable disease burden and mortality. however, effective vaccines are available against most pathogenic serogroups. large-scale vaccination campaigns with the mcc vaccine conducted in uk and with menafrivac in the sahel have clearly demonstrated the direct and indirect effect of immunization programmes on disease and carriage. moreover, the introduction of novel subcapsular vaccines against serogroup b, wh ...201526512927
diversification of β-augmentation interactions between cdi toxin/immunity proteins.contact-dependent growth inhibition (cdi) is a widespread mechanism of inter-bacterial competition mediated by the cdib/cdia family of two-partner secretion proteins. cdia effectors carry diverse c-terminal toxin domains (cdia-ct), which are delivered into neighboring target cells to inhibit growth. cdi(+) bacteria also produce cdii immunity proteins that bind specifically to cognate cdia-ct toxins and protect the cell from auto-inhibition. here, we compare the structures of homologous cdia-ct/c ...201526449640
what exists beyond caga and vaca? helicobacter pylori genes in gastric diseases.helicobacter pylori (h. pylori) infection is present in more than half the world's population and has been associated with several gastric disorders, such as gastritis, peptic ulceration, and gastric adenocarcinoma. the clinical outcome of this infection depends on host and bacterial factors where h. pylori virulence genes seem to play a relevant role. studies of caga and vaca genes established that they were determining factors in gastric pathogenesis. however, there are gastric cancer cases th ...201526457016
infected cardiac myxoma: an updated review.this study aims to present an updated clinical picture of the infected cardiac myxoma. revankar & clark made a systematic review of infected cardiac myxoma based on the literature before 1998. since then, there has not been any updated information describing its recent changing trends.201526735605
exploring the population-level impact of menb vaccination via modeling: potential for serogroup replacement.various meningococcal conjugate vaccines exist against serogroups a, c, w and y. a new protein-based vaccine targeting serogroup b (menb) is also now available. the potential of such vaccines to drive serogroup replacement is considered a possible public health concern when implementing nationwide routine immunization programmes. the aim of this work was to investigate if and how serogroup replacement may occur following widespread vaccination with a menb vaccine that may protect against carriag ...201526308796
exploring the population-level impact of menb vaccination via modeling: potential for serogroup replacement.various meningococcal conjugate vaccines exist against serogroups a, c, w and y. a new protein-based vaccine targeting serogroup b (menb) is also now available. the potential of such vaccines to drive serogroup replacement is considered a possible public health concern when implementing nationwide routine immunization programmes. the aim of this work was to investigate if and how serogroup replacement may occur following widespread vaccination with a menb vaccine that may protect against carriag ...201526308796
population-based surveillance of neisseria meningitidis antimicrobial resistance in the united states.background.  antimicrobial treatment and chemoprophylaxis of patients and their close contacts is critical to reduce the morbidity and mortality and prevent secondary cases of meningococcal disease. through the 1990's, the prevalence of antimicrobial resistance to commonly used antimicrobials among neisseria meningitidis was low in the united states. susceptibility testing was performed to ascertain whether the proportions of isolates with reduced susceptibility to antimicrobials commonly used f ...201526357666
the impact of aggregating serogroups in dynamic models of neisseria meningitidis transmission.neisseria meningitidis (nm) is a pathogen of multiple serogroups that is highly prevalent in many populations. serogroups associated with invasive meningococcal disease (imd) in canada, for example, include a, b, c, w-135, x and y. imd is a rare but serious outcome of nm infection, and can be prevented with vaccines that target certain serogroups. this has stimulated the development of dynamic models to evaluate vaccine impact. however, these models typically aggregate the various nm serogroups ...201526223223
seroprevalence of antibody-mediated, complement-dependent opsonophagocytic activity against neisseria meningitidis serogroup b in england.the correlate of protection for the licensure of meningococcal vaccines is serum bactericidal activity. however, evidence indicates that a complex situation and other mechanisms, such as antibody-mediated, complement-dependent opsonophagocytosis (op), may play a role in protection and should be investigated in order to understand immunity to this disease. in this study, a high-throughput flow cytometric opsonophagocytic assay (opa) was optimized. the assay measures the presence of killed fluores ...201525739917
the diversity of meningococcal carriage across the african meningitis belt and the impact of vaccination with a group a meningococcal conjugate vaccine.study of meningococcal carriage is essential to understanding the epidemiology of neisseria meningitidis infection.201525858956
population density profiles of nasopharyngeal carriage of 5 bacterial species in pre-school children measured using quantitative pcr offer potential insights into the dynamics of transmission.bacterial vaccines can reduce carriage rates. colonization is usually a binary endpoint. real time quantitative pcr (qpcr) can quantify bacterial dna in mucosal samples over a wide range. using culture and single-gene species-specific qpcrs for streptococcus pneumoniae (lyta), streptococcus pyogenes (ntpc), moraxella catarrhalis (ompj), haemophilus influenzae (hdp) and staphylococcus aureus (nuc) and standard curves against log-phase reference strain broth cultures we described frequency and pea ...201526367344
population density profiles of nasopharyngeal carriage of 5 bacterial species in pre-school children measured using quantitative pcr offer potential insights into the dynamics of transmission.bacterial vaccines can reduce carriage rates. colonization is usually a binary endpoint. real time quantitative pcr (qpcr) can quantify bacterial dna in mucosal samples over a wide range. using culture and single-gene species-specific qpcrs for streptococcus pneumoniae (lyta), streptococcus pyogenes (ntpc), moraxella catarrhalis (ompj), haemophilus influenzae (hdp) and staphylococcus aureus (nuc) and standard curves against log-phase reference strain broth cultures we described frequency and pea ...201526367344
molecular assay for detection of genetic markers associated with decreased susceptibility to cephalosporins in neisseria gonorrhoeae.the incidence of antimicrobial-resistant neisseria gonorrhoeae continues to rise in canada; however, antimicrobial resistance data are lacking for approximately 70% of gonorrhea infections that are diagnosed directly from clinical specimens by nucleic acid amplification tests (naats). we developed a molecular assay for surveillance use to detect mutations in genes associated with decreased susceptibility to cephalosporins that can be applied to both culture isolates and clinical samples. real-ti ...201525878350
oropharyngeal colonization with neisseria lactamica, other nonpathogenic neisseria species and moraxella catarrhalis among young healthy children in ahvaz, iran.neisseria lactamica as one of the main commensal in oropharynx during the childhood is related to the induction of a natural immunity against meningococcal meningitis. also moraxella catarrhalis in oropharynx of children is a predisposing factor for otitis media infection.201525964847
use of 16s rrna gene for identification of a broad range of clinically relevant bacterial pathogens.according to world health organization statistics of 2011, infectious diseases remain in the top five causes of mortality worldwide. however, despite sophisticated research tools for microbial detection, rapid and accurate molecular diagnostics for identification of infection in humans have not been extensively adopted. time-consuming culture-based methods remain to the forefront of clinical microbial detection. the 16s rrna gene, a molecular marker for identification of bacterial species, is ub ...201525658760
development of two real-time multiplex pcr assays for the detection and quantification of eight key bacterial pathogens in lower respiratory tract infections.the frequent lack of a positive and timely microbiological diagnosis in patients with lower respiratory tract infection (lrti) is an important obstacle to antimicrobial stewardship. patients are typically prescribed broad-spectrum empirical antibiotics while microbiology results are awaited, but, because these are often slow, negative, or inconclusive, de-escalation to narrow-spectrum agents rarely occurs in clinical practice. the aim of this study was to develop and evaluate two multiplex real- ...201525980353
commensal streptococcus salivarius modulates pparγ transcriptional activity in human intestinal epithelial cells.the impact of commensal bacteria in eukaryotic transcriptional regulation has increasingly been demonstrated over the last decades. a multitude of studies have shown direct effects of commensal bacteria from local transcriptional activity to systemic impact. the commensal bacterium streptococcus salivarius is one of the early bacteria colonizing the oral and gut mucosal surfaces. it has been shown to down-regulate nuclear transcription factor (nf-кb) in human intestinal cells, a central regulato ...201525946041
association of targeted multiplex pcr with resequencing microarray for the detection of multiple respiratory pathogens.a large number of viral and bacterial organisms are responsible for community-acquired pneumonia (cap) which contributes to substantial burden on health management. a new resequencing microarray (rpm-ivdc1) associated with targeted multiplex pcr was recently developed and validated for multiple respiratory viruses detection and discrimination. in this study, we evaluated the capability of rpm-ivdc1 for simultaneous identification of multiple viral and bacterial organisms. the nasopharyngeal aspi ...201526074910
differential distribution of type ii crispr-cas systems in agricultural and nonagricultural campylobacter coli and campylobacter jejuni isolates correlates with lack of shared environments.crispr (clustered regularly interspaced palindromic repeats)-cas (crispr-associated) systems are sequence-specific adaptive defenses against phages and plasmids which are widespread in prokaryotes. here we have studied whether phylogenetic relatedness or sharing of environmental niches affects the distribution and dissemination of type ii crispr-cas systems, first in 132 bacterial genomes from 15 phylogenetic classes, ranging from proteobacteria to actinobacteria. there was clustering of distinc ...201526338188
the influence of smoking on the peri-implant microbiome.smokers are at high risk for 2 bacterially driven oral diseases: peri-implant mucositis and peri-implantitis. therefore, the purpose of this investigation was to use a deep-sequencing approach to identify the effect of smoking on the peri-implant microbiome in states of health and disease. peri-implant biofilm samples were collected from 80 partially edentulous subjects with peri-implant health, peri-implant mucositis, and peri-implantitis. bacterial dna was isolated and 16s ribsomal rna gene li ...201526124222
long-term evaluation of the antimicrobial susceptibility and microbial profile of subgingival biofilms in individuals with aggressive periodontitis.this study evaluates the antimicrobial susceptibility and composition of subgingival biofilms in generalized aggressive periodontitis (gap) patients treated using mechanical/antimicrobial therapies, including chlorhexidine (chx), amoxicillin (amx) and metronidazole (met). gap patients allocated to the placebo (c, n = 15) or test group (t, n = 16) received full-mouth disinfection with chx, scaling and root planning, and systemic amx (500 mg)/met (250 mg) or placebos. subgingival plaque samples we ...201526273264
dna microarray characterization of pathogens associated with sexually transmitted diseases.this study established a multiplex pcr-based microarray to detect simultaneously a diverse panel of 17 sexually transmitted diseases (stds)-associated pathogens including neisseria gonorrhoeae, chlamydia trachomatis, mycoplasma genitalium, mycoplasma hominis, ureaplasma, herpes simplex virus (hsv) types 1 and 2, and human papillomavirus (hpv) types 6, 11, 16, 18, 31, 33, 35, 39, 54 and 58. the target genes are 16s rrna gene for n. gonorrhoeae, m. genitalium, m. hominism, and ureaplasma, the majo ...201526208181
outer membrane vesicles as platform vaccine technology.outer membrane vesicles (omvs) are released spontaneously during growth by many gram-negative bacteria. they present a range of surface antigens in a native conformation and have natural properties like immunogenicity, self-adjuvation and uptake by immune cells which make them attractive for application as vaccines against pathogenic bacteria. in particular with neisseria meningitidis, they have been investigated extensively and an omv-containing meningococcal vaccine has recently been approved ...201526912077
evolutionary switches between two serine codon sets are driven by selection.serine is the only amino acid that is encoded by two disjoint codon sets so that a tandem substitution of two nucleotides is required to switch between the two sets. previously published evidence suggests that, for the most evolutionarily conserved serines, the codon set switch occurs by simultaneous substitution of two nucleotides. here we report a genome-wide reconstruction of the evolution of serine codons in triplets of closely related species from diverse prokaryotes and eukaryotes. the res ...201627799560
identification of novel immunogenic proteins of neisseria gonorrhoeae by phage display.neisseria gonorrhoeae is one of the most prevalent sexually transmitted diseases worldwide with more than 100 million new infections per year. a lack of intense research over the last decades and increasing resistances to the recommended antibiotics call for a better understanding of gonococcal infection, fast diagnostics and therapeutic measures against n. gonorrhoeae. therefore, the aim of this work was to identify novel immunogenic proteins as a first step to advance those unresolved problems ...201626859666
antigenic variation in bacterial pathogens.antigenic variation is a strategy used by a broad diversity of microbial pathogens to persist within the mammalian host. whereas viruses make use of a minimal proofreading capacity combined with large amounts of progeny to use random mutation for variant generation, antigenically variant bacteria have evolved mechanisms which use a stable genome, which aids in protecting the fitness of the progeny. here, three well-characterized and highly antigenically variant bacterial pathogens are discussed: ...201626999387
trypanosoma cruzi differentiates and multiplies within chimeric parasitophorous vacuoles in macrophages coinfected with leishmania amazonensis.the trypanosomatids leishmania amazonensis and trypanosoma cruzi are excellent models for the study of the cell biology of intracellular protozoan infections. after their uptake by mammalian cells, the parasitic protozoan flagellates l. amazonensis and t. cruzi lodge within acidified parasitophorous vacuoles (pvs). however, whereas l. amazonensis develops in spacious, phagolysosome-like pvs that may enclose numerous parasites, t. cruzi is transiently hosted within smaller vacuoles from which it ...201626975994
the capricious nature of bacterial pathogens: phasevarions and vaccine development.infectious diseases are a leading cause of morbidity and mortality worldwide, and vaccines are one of the most successful and cost-effective tools for disease prevention. one of the key considerations for rational vaccine development is the selection of appropriate antigens. antigens must induce a protective immune response, and this response should be directed to stably expressed antigens so the target microbe can always be recognized by the immune system. antigens with variable expression, due ...201628018352
multiplex assay for simultaneous detection of mycoplasma genitalium and macrolide resistance using plexzyme and plexprime technology.mycoplasma genitalium is a cause of non-gonoccocal urethritis (ngu) in men and cervicitis and pelvic inflammatory disease in women. recent international data also indicated that the first line treatment, 1 gram stat azithromycin therapy, for m. genitalium is becoming less effective, with the corresponding emergence of macrolide resistant strains. increasing failure rates of azithromycin for m. genitalium has significant implications for the presumptive treatment of ngu and international clinical ...201627271704
comprehensive laboratory evaluation of a highly specific lateral flow assay for the presumptive identification of bacillus anthracis spores in suspicious white powders and environmental samples.we conducted a comprehensive, multiphase laboratory evaluation of the anthrax biothreat alert(®) test strip, a lateral flow immunoassay (lfa) for the rapid detection of bacillus anthracis spores. the study, conducted at 2 sites, evaluated this assay for the detection of spores from the ames and sterne strains of b. anthracis, as well as those from an additional 22 strains. phylogenetic near neighbors, environmental background organisms, white powders, and environmental samples were also tested. ...201627661796
performance of an in-house real-time polymerase chain reaction for identification of mycobacterium tuberculosis isolates in laboratory routine diagnosis from a high burden setting.brazil is one of the high burden countries for tuberculosis, and a rapid diagnosis is essential for effective control of the disease. in the present study, an in-house real-time polymerase chain reaction (pcr) assay targeting the mpt64 gene for identification of mycobacterium tuberculosis complex isolates was evaluated under routine diagnosis conditions in a reference laboratory. from may 2011 to july 2012, 1,520 isolates of mycobacteria were prospectively submitted for phenotypic and/or pra-hsp ...201627598243
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