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identification of burkholderia species and genomovars from cystic fibrosis patients by aflp fingerprinting.aflp is a genomic fingerprinting technique based on the selective amplification of restriction fragments from a total double-digest of genomic dna. the applicability of this method to differentiate between species and genomovars of the genus burkholderia was tested, with particular emphasis on taxa occurring in cystic fibrosis patients. in this study, 78 well-characterized strains and field isolates were investigated by two methods of aflp fingerprinting. in the manual procedure, a radioactively ...199910555347
burkholderia cepacia genomovar iii is a common plant-associated bacterium.a polyphasic taxonomic study involving dna-dna hybridization, whole-cell protein electrophoresis, and 16s ribosomal dna sequence analysis revealed that a group of burkholderia cepacia-like organisms isolated from the rhizosphere or tissues of maize, wheat, and lupine belong to b. cepacia genomovar iii, a genomic species associated with "cepacia syndrome" in cystic fibrosis patients. the present study also revealed considerable protein electrophoretic heterogeneity within this species and demonst ...200111157274
enhanced susceptibility to pulmonary infection with burkholderia cepacia in cftr(-/-) mice.progressive pulmonary infection is the dominant clinical feature of cystic fibrosis (cf), but the molecular basis for this susceptibility remains incompletely understood. to study this problem, we developed a model of chronic pneumonia by repeated instillation of a clinical isolate of burkholderia cepacia (genomovar iii, et12 strain), an opportunistic gram-negative bacterium, from a case of cf into the lungs of cftr (m1unc-/-) (cftr(-/-)) and congenic cftr(+/+) controls. nine days after the last ...200111447196
endemicity and inter-city spread of burkholderia cepacia genomovar iii in cystic fibrosis.we sought to determine whether the same burkholderia cepacia complex strain has persisted as the dominant clonal lineage among patients in a large cystic fibrosis (cf) treatment center during the past 2 decades.200111713440
improved molecular detection of burkholderia cepacia genomovar iii and burkholderia multivorans directly from sputum of patients with cystic fibrosis.optimum detection of the burkholderia cepacia complex (bcc) from sputum of patients with cystic fibrosis (cf) is essential in preventing patient-to-patient transmission of this organism. the aim of this study was to develop an improved pcr assay with reference to sensitivity for the direct detection of bcc organisms from cf sputum employing the reca locus. the sensitivity results of three reca pcr assays were compared using various combinations of previously published primers. these included (i) ...200211830304
comparative assessment of genotyping methods for epidemiologic study of burkholderia cepacia genomovar iii.we analyzed a collection of 97 well-characterized burkholderia cepacia genomovar iii isolates to evaluate multiple genomic typing systems, including pulsed-field gel electrophoresis (pfge), box-pcr fingerprinting and random amplified polymorphic dna (rapd) typing. the typeability, reproducibility, and discriminatory power of these techniques were evaluated, and the results were compared to each other and to data obtained in previous studies by using multilocus restriction typing (mlrt). all meth ...200212202570
population structure analysis of burkholderia cepacia genomovar iii: varying degrees of genetic recombination characterize major clonal complexes.infection with bacterial species belonging to the burkholderia cepacia complex contribute significantly to morbidity and mortality in persons with cystic fibrosis (cf). the majority of isolates recovered from cf patients belong to b. cepacia genomovar iii and several distinct 'epidemic' strains have been described. this study examined the population structure of b. cepacia genomovar iii by using multilocus restriction typing, indexing allelic variation at five chromosomal genes by restriction an ...200312576582
burkholderia cenocepacia sp. nov.--a new twist to an old story.dna-dna hybridisation experiments between isolates representing burkholderia cepacia genomovar iii reca lineages iiia and iiib reinforced the classification of both phylogenetic subgroups as a single genospecies, distinct from b. cepacia (genomovar i). a formal classification of b. cepacia genomovar iii encompassing the reca lineages iiia and iiib, and the new reca lineages iiic and iiid, as b. cenocepacia sp. nov., with lmg 16656 as the type strain, is proposed.200312648723
fatal outcome of lung transplantation in cystic fibrosis patients due to small-colony variants of the burkholderia cepacia complex.the aim of this study was to investigate the possible role of small-colony variant morphotypes of burkholderia cepacia-like organisms in infectious complications in cystic fibrosis patients following lung transplantation. respiratory tract specimens from 470 cystic fibrosis patients were screened over a 22-month period for burkholderia cepacia-like organisms. nineteen patients were positive for these organisms, eight of whom harboured small-colony-variant morphotypes. three patients underwent bi ...200312687415
identification by subtractive hybridization of a novel insertion element specific for two widespread burkholderia cepacia genomovar iii strains.species of the burkholderia cepacia complex cause chronic and life-threatening infections in persons with cystic fibrosis. epidemic strains infect multiple patients, reside primarily in genomovar iii, and have an apparent enhanced capacity for human infection and/or interpatient transmission. by using subtractive hybridization, a novel insertion element, designated is1363, was identified in epidemic strain phdc, known to infect many cystic fibrosis patients in the mid-atlantic region of the unit ...200312791867
polyclonal outbreak of burkholderia cepacia complex bacteraemia in haemodialysis patients.we report a polyclonal outbreak of bacteraemia involving 24 patients at a haemodialysis facility in recife (brazil). during the outbreak period (4 june to 11 july, 2001), three burkholderia cepacia complex strains were isolated from human blood and from various water samples collected at different sites in the haemodialysis unit and from dialysate fluids. out of 14 patients with positive blood cultures, six were infected by burkholderia cepacia complex bacteria: three with burkholderia cepacia g ...200312818585
genomovar diversity amongst burkholderia cepacia complex isolates from an australian adult cystic fibrosis unit.in this study, a combination of reca-based pcr assays and 16s rdna restriction fragment length polymorphism (rflp) analysis was used to determine the genomovar diversity of clinical burkholderia cepacia complex isolates. twenty-eight isolates were prospectively collected from patients attending a large australian adult cystic fibrosis (cf) unit, 22 isolates were referred from other australian cf units and a further eight isolates originated from patients without cf. the 28 prospectively collecte ...200312884074
in vitro activity and synergy of bismuth thiols and tobramycin against burkholderia cepacia complex.to determine the susceptibility of burkholderia multivorans and burkholderia cenocepacia to bismuth-thiols (bts), and to examine the synergistic effects of tobramycin and subinhibitory concentrations of bts against these organisms.200314585856
evidence of transmission of burkholderia cepacia, burkholderia multivorans and burkholderia dolosa among persons with cystic fibrosis.previous studies have identified specific burkholderia cepacia complex strains that are common to multiple persons with cystic fibrosis (cf). such so-called epidemic strains have an apparent enhanced capacity for inter-patient spread and reside primarily in burkholderia cenocepacia (formerly b. cepacia complex genomovar iii). we sought to identify strains from b. cepacia complex species other than b. cenocepacia that are similarly shared by multiple cf patients. we performed genotype analysis of ...200314612237
identification and physical organization of the gene cluster involved in the biosynthesis of burkholderia cepacia complex exopolysaccharide.bacteria belonging to the burkholderia cepacia complex (bcc) are important opportunistic pathogens in patients with cystic fibrosis (cf). since approximately 80% of the cf isolates examined produce exopolysaccharide (eps), it was hypothesized that this eps may play a role in the colonization and persistence of these bacteria in the cf lung. the present study describes the identification and physical organization of the eps biosynthetic gene cluster. this bce gene cluster was identified following ...200314637140
adherence and autoaggregation phenotypes of a burkholderia cenocepacia cable pilus mutant.cable pili are unique peritrichous adherence organelles expressed by certain strains of the opportunistic human pathogen burkholderia cenocepacia. cable pili have been proposed to facilitate binding to human epithelial cells and mucin, and may play a role in the ability of b. cenocepacia to colonise the respiratory tract of compromised hosts. in this study, a genetic approach was undertaken to assess the role of cable pili in mediating adherence as well as bacterial cell-cell interactions. the c ...200314638436
improved flagellin genotyping in the burkholderia cepacia complex.oligonucleotide primers designed to n- and c-terminal sequences of burkholderia cepacia complex flic genes were used to amplify and sequence flic genes from a strain of burkholderia vietnamiensis and three isolates of burkholderia multivorans with large flic genes. alignments incorporating the new sequences enabled the design of polymerase chain reaction (pcr) primers for extension of a published pcr/restriction fragment length polymorphism typing method, to include isolates that previously fail ...200314659536
the cepir quorum-sensing system contributes to the virulence of burkholderia cenocepacia respiratory infections.the cepir genes encode an n-acyl homoserine lactone (ahl)-dependent quorum-sensing system consisting of an ahl synthase that directs the synthesis of n-octanoyl-l-homoserine lactone (ohl) and n-hexanoyl-l-homoserine lactone and a transcriptional regulator. the virulence of cepir mutants was examined in two animal models. rats were infected with agar beads containing burkholderia cenocepacia k56-2, k56-i2 (cepi : : tp(r)) or k56-r2 (cepr : : tn5-ot182). at 10 days post-infection, the extent of lu ...200314663096
isolation and characterization of burkholderia cenocepacia mutants deficient in pyochelin production: pyochelin biosynthesis is sensitive to sulfur availability.the opportunistic pathogen burkholderia cenocepacia produces the yellow-green fluorescent siderophore, pyochelin. to isolate mutants which do not produce this siderophore, we mutagenized b. cenocepacia with the transposon mini-tn5tp. two nonfluorescent mutants were identified which were unable to produce pyochelin. in both mutants, the transposon had integrated into a gene encoding an orthologue of cysw, a component of the sulfate/thiosulfate transporter. the cysw gene was located within a putat ...200414702294
salicylate induces an antibiotic efflux pump in burkholderia cepacia complex genomovar iii (b. cenocepacia).an antibiotic efflux gene cluster that confers resistance to chloramphenicol, trimethoprim, and ciprofloxacin has been identified in burkholderia cenocepacia (genomovar iii), an important cystic fibrosis pathogen. five open reading frames have been identified in the cluster. there is apparently a single transcriptional unit, with llpe encoding a lipase-like protein, ceoa encoding a putative periplasmic linker protein, ceob encoding a putative cytoplasmic membrane protein, and opcm encoding a pre ...200414755343
transcriptional and posttranscriptional control of cable pilus gene expression in burkholderia cenocepacia.burkholderia cenocepacia is an important member of the burkholderia cepacia complex, a group of closely related bacteria that inhabits a wide variety of environmental niches in nature and that also colonizes the lungs of compromised humans. certain strains of b. cenocepacia express peritrichous adherence organelles known as cable pili, thought to be important in the colonization of the lower respiratory tract. the genetic locus required for cable pilus biogenesis is comprised of at least five ge ...200414761995
the burkholderia cepacia epidemic strain marker is part of a novel genomic island encoding both virulence and metabolism-associated genes in burkholderia cenocepacia.the burkholderia cepacia epidemic strain marker (bcesm) is a useful epidemiological marker for virulent b. cenocepacia strains that infect patients with cystic fibrosis. however, there was no evidence that the original marker, identified by random amplified polymorphic dna fingerprinting, contributed to pathogenicity. here we demonstrate that the bcesm is part of a novel genomic island encoding genes linked to both virulence and metabolism. the bcesm was present on a 31.7-kb low-gc-content islan ...200414977960
burkholderia cenocepacia lipopolysaccharide, lipid a, and proinflammatory activity.organisms from the burkholderia cepacia complex are important pathogens in cystic fibrosis and are associated with increased rates of sepsis and death. these organisms comprise nine closely related species known as genomovars. b. cenocepacia (genomovar iii) is the most prevalent and appears the most virulent. we investigated the biological activity of a reference panel of strains using whole-cell lysates to induce septic-shock related cytokines from differentiated human monocytic cells. we found ...200415044201
epidemiology and clinical course of burkholderia cepacia complex infections, particularly those caused by different burkholderia cenocepacia strains, among patients attending an italian cystic fibrosis center.in this study, the epidemiology of burkholderia cepacia complex (bcc) recovered from the sputum of 75 patients attending the genoa cystic fibrosis (cf) center at the gaslini children's hospital (genoa, italy) was investigated, and the clinical course of the cf patients infected with the different species and genomovars of bcc was evaluated. all isolates were analyzed for genomovar status by reca gene polymorphism and subsequently random amplified polymorphic dna fingerprinting. burkholderia ceno ...200415070994
conservation of the opcl gene encoding the peptidoglycan-associated outer-membrane lipoprotein among representatives of the burkholderia cepacia complex.members of the burkholderia cepacia complex are gram-negative beta-proteobacteria that are classified into nine genomic species or genomovars. some representatives of this group of bacteria, such as burkholderia multivorans (genomovar ii) and burkholderia cenocepacia (genomovar iii), are considered to be dangerous pathogens for cystic fibrosis (cf) patients because of their capacity to colonize cf lungs. the opcl gene, which encodes the peptidoglycan-associated outer-membrane lipoprotein (pal), ...200415096547
importance of the ornibactin and pyochelin siderophore transport systems in burkholderia cenocepacia lung infections.previously, orba, the gene encoding the outer membrane receptor for ferric-ornibactin, was identified in burkholderia cenocepacia k56-2, a strain which produces ornibactin, salicylic acid, and negligible amounts of pyochelin. a k56-2 orba mutant was less virulent than the parent strain in a rat agar bead infection model. in this study, an orba mutant of b. cenocepacia pc715j which produces pyochelin in addition to ornibactin and salicylic acid was constructed. the gene encoding the outer membran ...200415102796
virulence associated with outbreak-related strains of burkholderia cepacia complex among a cohort of patients with bacteremia.the burkholderia cepacia complex includes 9 genomovars. the relative virulence of each is unknown. host and pathogen features associated with mortality were evaluated among patients with b. cepacia complex bacteremia. cases were ascertained through review of blood culture results for the period of may 1996 through may 2002. isolates were identified to species level with 16s rdna and reca-based species-specific polymerase chain reaction analyses and reca restriction fragment-length polymorphism. ...200415127335
prevalence and clonality of burkholderia cepacia complex genomovars in uk patients with cystic fibrosis referred for lung transplantation.it has previously been reported that patients infected with burkholderia cenocepacia (genomovar iii) before lung transplantation have a poorer outcome than those with other b. cepacia complex infections.200415170040
infection control and the significance of sputum and other respiratory secretions from adult patients with cystic fibrosis.there is limited data available on the environmental and public health impact of the microbiological hazards associated with sputa from patients with cystic fibrosis [cf]. pseudomonas aeruginosa, burkholderia cenocepacia (formerly burkholderia cepacia genomovar iii), staphylococcus aureus and stenotrophomonas maltophilia are bacterial pathogens which are commonly found in the sputum of cf patients. a study was performed to ascertain the amount of sputum produced relating to microbial loading, as ...200415175107
genetic characterization of a multicomponent signal transduction system controlling the expression of cable pili in burkholderia cenocepacia.cable pili are peritrichous organelles expressed by certain strains of burkholderia cenocepacia, believed to facilitate colonization of the lower respiratory tract in cystic fibrosis patients. the b. cenocepacia cblbacds operon encodes the structural and accessory proteins required for the assembly of cable pili, as well as a gene designated cbls, predicted to encode a hybrid sensor kinase protein of bacterial two-component signal transduction systems. in this study we report the identification ...200415175296
burkholderia cenocepacia phage bcepmu and a family of mu-like phages encoding potential pathogenesis factors.we have isolated bcepmu, a mu-like bacteriophage whose host range includes human pathogenic burkholderia cenocepacia (formally b. cepacia genomovar iii) isolates, and determined its complete 36748 bp genomic sequence. like enteric bacteriophage mu, the bcepmu genomic dna is flanked by variable host sequences, a result of transposon-mediated replication. the bcepmu genome encodes 53 proteins, including capsid assembly components related to those of mu, and tail sheath and tube proteins related to ...200415184022
epidemiology of burkholderia cepacia complex species recovered from cystic fibrosis patients: issues related to patient segregation.studies of the prevalence of burkholderia cepacia complex species amongst cystic fibrosis (cf) patients in different geographical regions, and the association between cross-infection and putative transmissibility markers, will further our understanding of these organisms and help to address infection-control issues. in this study, b. cepacia complex isolates from cf patients in different regions of europe were analysed. isolates were examined for b. cepacia complex species and putative transmiss ...200415184539
identification of burkholderia cenocepacia genes required for bacterial survival in vivo.burkholderia cenocepacia (formerly burkholderia cepacia complex genomovar iii) causes chronic lung infections in patients with cystic fibrosis. in this work, we used a modified signature-tagged mutagenesis (stm) strategy for the isolation of b. cenocepacia mutants that cannot survive in vivo. thirty-seven specialized plasposons, each carrying a unique oligonucleotide tag signature, were constructed and used to examine the survival of 2,627 b. cenocepacia transposon mutants, arranged in pools of ...200415213146
responses of well-differentiated airway epithelial cell cultures from healthy donors and patients with cystic fibrosis to burkholderia cenocepacia infection.well-differentiated cultures established from airway epithelia of patients with cystic fibrosis (cf cultures) exhibited goblet cell hyperplasia, increased secretion of mucus, and higher basal levels of interleukin-8 than similarly cultured cells from healthy donors. upon apical infection with low doses (10(4) to 10(5) cfu) of burkholderia cenocepacia isolate bc7, the two cultures gave different responses. while normal cultures trapped the added bacteria in the mucus layer, killed and/or inhibite ...200415213163
epidemiology of burkholderia cepacia complex colonisation in cystic fibrosis patients.in belgian cystic fibrosis (cf) clinics, sputum samples are evaluated on selective mast medium routinely every 3 months. in this study, in 1993 and 1999, isolates were further examined by reca restriction fragment length polymorphism analysis and pulsed-field gel electrophoresis of genomic dna restricted with spei. in 1993, 12 patients were colonised with burkholderia cepacia complex (bcc): b. cenocepacia (n=6), b. multivorans (n=3), b. stabilis (n=3). four patients were colonised with the same ...200415218997
production of exopolysaccharide by burkholderia cenocepacia results in altered cell-surface interactions and altered bacterial clearance in mice.despite the characterization of some burkholderia cepacia complex exopolysaccharides (epss), little is known about the role of epss in the pathogenicity of b. cepacia complex organisms. we describe 2 burkholderia cenocepacia (genomovar iii) isolates obtained from a patient with cystic fibrosis (cf): the nonmucoid isolate c8963 and the mucoid isolate c9343. both isolates had identical random amplified polymorphic dna patterns. c9343 produced a capsule composed of the epss ps-i and ps-ii, as well ...200415295701
common oligosaccharide moieties inhibit the adherence of typical and atypical respiratory pathogens.intervention in bacterial adhesion to host cells is a novel method of overcoming current problems associated with antibiotic resistance. antibiotic-resistant strains of bacteria that cause respiratory tract infections are a problem in hospitals and could be used in bioterrorist attacks. a range of bacterial species was demonstrated to attach to an alveolar epithelial (a549) cell line. in all cases, cell surface oligosaccharides were important in attachment, demonstrated by reduced adhesion when ...200415314189
contribution of burkholderia cenocepacia flagella to infectivity and inflammation.burkholderia cenocepacia is an opportunistic pathogen that can cause severe lung infections in cystic fibrosis patients. to understand the contribution of b. cenocepacia flagella to infection, a strain mutated in the major flagellin subunit, flicii, was constructed in b. cenocepacia k56-2 and tested in a murine agar bead model of lung infection. c57/bl6 mice infected with approximately 10(8) wild-type k56-2 bacteria exhibited 40% mortality after 3 days, whereas no mortality was noted in mice inf ...200415322006
involvement of a plasmid-encoded type iv secretion system in the plant tissue watersoaking phenotype of burkholderia cenocepacia.burkholderia cenocepacia strain k56-2, a representative of the burkholderia cepacia complex, is part of the epidemic and clinically problematic et12 lineage. the strain produced plant tissue watersoaking (ptw) on onion tissue, which is a plant disease-associated trait. using plasposon mutagenesis, mutants in the ptw phenotype were generated. the translated sequence of a disrupted gene (ptwd4) from a ptw-negative mutant showed homology to vird4-like proteins. analysis of the region proximal to th ...200415342570
persistence of burkholderia multivorans within the pulmonary macrophage in the murine lung.differences in infection kinetics and host response between burkholderia multivorans and burkholderia cenocepacia were demonstrated in a pulmonary infection model in balb/c mice. b. multivorans persisted in the lung, while b. cenocepacia was cleared. indirect immunofluorescence and electron microscopy of b. multivorans-infected lungs localized bacteria to macrophages. clearance of b. cenocepacia was associated with greater interleukin-1beta and neutrophil responses than the responses induced by ...200415385520
burkholderia cepacia genomovar iii and burkholderia vietnamiensis double infection in a cystic fibrosis child.herein we report a case of a cystic fibrosis child who was simultaneously infected with burkholderia cepacia genomovar iii and burkholderia vietnamiensis. after antimicrobial therapy only b. cepacia genomovar iii persisted.200215463830
clinical outcome of burkholderia cepacia complex infection in cystic fibrosis adults.the burkholderia cepacia complex (bcc) is one of the most important groups of organisms infecting cystic fibrosis (cf) patients. the aim of the study was to examine how infection with bcc affects clinical outcome.200415463892
exopolysaccharides produced by burkholderia cenocepacia reca lineages iiia and iiib.clinical and environmental strains of burkholderia cenocepacia belonging to the reca lineages iiia and iiib were examined for exopolysaccharide (eps) production. the exopolysaccharides structure was determined using mainly gas chromatography coupled to mass spectrometry and nmr spectroscopy. all the strains produced cepacian, a highly branched polysaccharide constituted of a heptasaccharide repeating unit, composed of one rhamnose, one glucose, one glucuronic acid, one mannose and three galactos ...200415463903
species distribution and ribotype diversity of burkholderia cepacia complex isolates from french patients with cystic fibrosis.a total of 153 burkholderia cepacia strains obtained from 153 french patients with cystic fibrosis were identified as burkholderia multivorans (51.6%) or burkholderia cenocepacia (45.1%). eighty-two genotypes were identified using pvuii and ecori ribotyping. b. multivorans genotype a (found in 32 french patients) and two other genotypes were also identified among isolates from austrian, german, italian, and canadian patients.200415472352
pcr-based identification and characterization of burkholderia cepacia complex bacteria from clinical and environmental sources.to study the genotypic identification and characterization of the 119 burkholderia cepacia complex (bcc) strains recovered from clinical and environmental sources in japan and thailand.200415482431
burkholderia cenocepacia and burkholderia multivorans: influence on survival in cystic fibrosis.burkholderia cepacia infection has been associated with a poor prognosis for patients with cystic fibrosis (cf). it is now recognised that organisms classified as b cepacia comprise a number of distinct genomic species each known as a genomovar of the b cepacia complex (bcc). the outcome of infection for cf patients with individual genomovars is unknown. the clinical outcome of infection with the two most commonly isolated genomovars (b cenocepacia and b multivorans) was studied at a specialist ...200415516469
recovery of burkholderia cenocepacia strain phdc from cystic fibrosis patients in europe.burkholderia cenocepacia can cause life threatening respiratory tract infections in patients with cystic fibrosis (cf) and has a significant impact on survival. there is extensive evidence for patient to patient spread and nosocomial transmission of this organism, and several widespread b cenocepacia strains have been described including the transatlantic et12 clone. a study was performed to compare b cenocepacia isolates recovered from cf patients receiving care in several european countries an ...200415516470
burkholderia cenocepacia vaginal infection in patient with smoldering myeloma and chronic hepatitis c.we report a case of a vaginal infection caused by a strain of burkholderia cenocepacia. the strain was isolated from vaginal swab specimens from a 68-year-old woman with smoldering myeloma and chronic hepatitis c virus infection who was hospitalized for abdominal abscess. treatment with piperacillin/tazobactam eliminated b. cenocepacia infection and vaginal symptoms.200415550207
identification of a novel virulence factor in burkholderia cenocepacia h111 required for efficient slow killing of caenorhabditis elegans.burkholderia cenocepacia h111, which was isolated from a cystic fibrosis patient, employs a quorum-sensing (qs) system, encoded by cep, to control the expression of virulence factors as well as the formation of biofilms. the qs system is thought to ensure that pathogenic traits are expressed only when the bacterial population density is high enough to overwhelm the host before it is able to mount an efficient response. while the wild-type strain effectively kills the nematode caenorhabditis eleg ...200415557647
effect of cystic fibrosis exacerbations on neutrophil function.in cystic fibrosis (cf), inflammation is caused by persistent bacterial infection from pseudomonas aeruginosa and burkholderia cenocepacia in the lung and is characterised by the persistent infiltration of massive numbers of neutrophils which leads to lung injury. the aim of this present study was to investigate the effects of cf exacerbations on the reactivity of peripheral blood neutrophils compared to data from a normal healthy control population. peripheral blood neutrophils were isolated fr ...200515683855
reconstitution of o-specific lipopolysaccharide expression in burkholderia cenocepacia strain j2315, which is associated with transmissible infections in patients with cystic fibrosis.burkholderia cenocepacia is an opportunistic bacterium that infects patients with cystic fibrosis. b. cenocepacia strains j2315, k56-2, c5424, and bc7 belong to the et12 epidemic clone, which is transmissible among patients. we have previously shown that transposon mutants with insertions within the o antigen cluster of strain k56-2 are attenuated for survival in a rat model of lung infection. from the genomic dna sequence of the o antigen-deficient strain j2315, we have identified an o antigen ...200515687196
down-regulation of il-8 expression in human airway epithelial cells through helper-dependent adenoviral-mediated rna interference.interleukin (il)-8 is a potent neutrophil chemotactic factor and a crucial mediator in neutrophil-dependent inflammation. various cell types produce il-8, either in response to external stimuli such as cytokines or bacterial infection, or after malignant transformation. anti-il-8 strategies have been considered for anti-inflammatory therapy. in this paper we demonstrate that the rna interference technique can be used to efficiently down-regulate il-8 protein expression in airway epithelial cells ...200515740640
infection-induced kinin b1 receptors in human pulmonary fibroblasts: role of intact pathogens and p38 mitogen-activated protein kinase-dependent signaling.kinin b(1) receptors (b(1)r) are involved in many pathophysiological processes, and its expression is up-regulated in inflammatory pulmonary disease. although bacteria can generate kinin peptides, the molecular signaling mechanisms regulating b(1)r during infection by intact pathogens is unknown. the serious opportunistic clinical isolate burkholderia cenocepacia (b. cen.) belongs to the important b. cepacia complex (bcc) of gram-negative pathogens that rapidly causes fatal pulmonary disease in ...200515743925
burkholderia cenocepacia induces neutrophil necrosis in chronic granulomatous disease.burkholderia cepacia complex is a life-threatening group of pathogens for patients with chronic granulomatous disease (cgd), whose phagocytes are unable to produce reactive oxygen species (ros). unlike other cgd pathogens, b. cepacia complex is particularly virulent, characteristically causing septicemia, and is the bacterial species responsible for most fatalities in these patients. we found that a nonmucoid burkholderia cenocepacia (a predominant species in the b. cepacia complex) isolate was ...200515749893
genotypic characterization of burkholderia cenocepacia strains by rep-pcr and pcr-rflp of the flic gene.thirty-five strains of burkholderia cenocepacia from clinical and environmental sources were characterized genotypically by repetitive sequence pcr (eric- and box-pcr) and polymerase chain reaction-restriction fragment length polymorphism (pcr-rflp) analysis of the flagellin gene (flic). in cluster analysis based on the repetitive pcr profiles the strains were composed of five clusters, of which clusters 1, 2 and 3 were more closely related to each other than to clusters 4 and 5. it has been rep ...200515796974
conservation of a novel protein associated with an antibiotic efflux operon in burkholderia cenocepacia.burkholderia cenocepacia is a significant problem in individuals with cystic fibrosis and is a member of the b. cepacia complex of closely related antibiotic resistant bacteria. a salicylate-regulated antibiotic efflux operon has been identified in b. cenocepacia and one of its four genes, llpe, is without parallel in previously reported efflux operons. pcr amplification and sequencing of llpe from b. cepacia complex isolates demonstrated the highest prevalence in b. cenocepacia with a high degr ...200515837391
an expression vector containing a rhamnose-inducible promoter provides tightly regulated gene expression in burkholderia cenocepacia.infection of the respiratory tract caused by burkholderia cepacia complex poses a serious risk for cystic fibrosis (cf) patients due to the high morbidity and mortality associated with the chronic infection and the lack of efficacious antimicrobial treatments. a detailed understanding of the pathogenicity of b. cepacia complex infections is hampered in part by the limited availability of genetic tools and the inherent resistance of these isolates to the most common antibiotics used for genetic s ...200515925406
a minor catalase/peroxidase from burkholderia cenocepacia is required for normal aconitase activity.the opportunistic bacterium burkholderia cenocepacia c5424 contains two catalase/peroxidase genes, kata and katb. to investigate the functions of these genes, kata and katb mutants were generated by targeted integration of suicide plasmids into the kata and katb genes. the catalase/peroxidase activity of the kata mutant was not affected as compared with that of the parental strain, while no catalase/peroxidase activity was detected in the katb mutant. however, the kata mutant displayed reduced r ...200515942004
widespread clone of burkholderia cenocepacia in cystic fibrosis patients in the czech republic.the morbidity and mortality rates in patients with cystic fibrosis (cf) are significantly affected by infections with burkholderia cepacia complex. in a czech cf centre, the prevalence of the infection reached up to 30 %, with the majority of patients found to be infected with burkholderia cenocepacia (formerly genomovar iii of the burkholderia cepacia complex). since b. cenocepacia is associated with patient-to-patient transmission and epidemic outbreaks among cf patients, this study sought to ...200515947430
functional analysis of the burkholderia cenocepacia zmpa metalloprotease.burkholderia cenocepacia zmpa is expressed as a preproenzyme typical of thermolysin-like proteases such as pseudomonas aeruginosa lasb and bacillus thermoproteolyticus thermolysin. the zmpa gene was expressed using the ppro-exhta his(6) tag expression system, which incorporates a six-his tag at the n-terminal end of the protein, and recombinant zmpa was purified using ni-nitrilotriacetic acid affinity chromatography. upon refolding of the recombinant his(6)-pre-pro-zmpa (62 kda), the fusion prot ...200515968051
direct binding of the quorum sensing regulator cepr of burkholderia cenocepacia to two target promoters in vitro.burkholderia cenocepacia is an opportunistic human pathogen that can aggressively colonize the cystic fibrosis lung. this organism has a luxr/luxi-type quorum sensing system that enables cell-cell communication via exchange of acyl homoserine lactones (ahls). the cepr and cepi proteins constitute a global regulatory system, controlling expression of at least 40 genes, including those controlling swarming motility and biofilm formation. in this study, we isolated seven lacz fusions in a clinical ...200515978077
functional and topological analysis of the burkholderia cenocepacia priming glucosyltransferase bceb, involved in the biosynthesis of the cepacian exopolysaccharide.the bceb protein of the cystic fibrosis mucoid isolate burkholderia cenocepacia ist432 is proposed to catalyze the first step of the exopolysaccharide repeat unit assembly. extracts of escherichia coli cells overexpressing bceb were shown to contain glycosyltransferase activity and mediate incorporation of glucose-1-phosphate into membrane lipids. the amino acid sequence of bceb exhibits two conserved regions, one comprising two invariant aspartic acid residues (asp339 and asp355) that are essen ...200515995219
temperate bacteriophages dk4 and bcepmu from burkholderia cenocepacia j2315 are identical. 200516009540
use of suppression-subtractive hybridization to identify genes in the burkholderia cepacia complex that are unique to burkholderia cenocepacia.we have previously shown differences in virulence between species of the burkholderia cepacia complex using the alfalfa infection model and the rat agar bead chronic infection model. burkholderia cenocepacia strains were more virulent in these two infection models than burkholderia multivorans and burkholderia stabilis strains. in order to identify genes that may account for the increased virulence of b. cenocepacia, suppression-subtractive hybridization was performed between b. cenocepacia k56- ...200516030222
characterization of the cciir quorum-sensing system in burkholderia cenocepacia.several transmissible burkholderia cenocepacia strains that infect multiple cystic fibrosis patients contain a genomic island designated as the cenocepacia island (cci). the cci contains a predicted n-acylhomoserine lactone (ahl) synthase gene, ccii, and a predicted response regulator gene, ccir. ahl production profiles indicated that ccii catalyzes the synthesis of n-hexanoyl-l-homoserine lactone and minor amounts of n-octanoyl-l-homoserine lactone. the ccii and ccir genes were found to be cotr ...200516041013
in vitro evaluation of efficacy of 5 methods of disinfection on mouthpieces and facemasks contaminated by strains of cystic fibrosis patients.home-nebulizers are a potential source of bacterial infection of the respiratory tract in patients suffering from cystic fibrosis. recommendations for disinfecting this equipment are often arbitrary and sometimes contradictory.200516046195
neutrophil cell death, activation and bacterial infection in cystic fibrosis.cystic fibrosis (cf) is characterised by chronic endobronchial bacterial infection and neutrophil mediated inflammation. neutrophil apoptosis is essential for the resolution of inflammation. this study assessed the relationship between levels of neutrophil apoptosis and sputum microbiology in matched clinically stable patients with cf.200516061707
effect of fusarium verticillioides on maize-root-associated burkholderia cenocepacia populations.burkholderia cepacia complex (bcc) bacteria are naturally present in the rhizosphere of several crop plants and have been found to antagonize a wide range of important plant pathogens. in this study, we evaluated the effect of the pathogenic fungus fusarium verticillioides on bcc populations recovered from the roots of zea mays plants. maize plants were cultivated under greenhouse conditions and bacterial colonies were randomly isolated from distinct root portions of fusarium-treated and control ...200516085398
cable pili and the 22-kilodalton adhesin are required for burkholderia cenocepacia binding to and transmigration across the squamous epithelium.burkholderia cenocepacia strains expressing both cable (cbl) pili and the 22-kda adhesin bind to cytokeratin 13 (ck13) strongly and invade squamous epithelium efficiently. it has not been established, however, whether the gene encoding the adhesin is located in the cbl operon or what specific contribution the adhesin and cbl pili lend to binding and transmigration or invasion capacity of b. cenocepacia. by immunoscreening an expression library of b. cenocepacia isolate bc7, we identified a large ...200516113259
quorum-sensing mutations affect attachment and stability of burkholderia cenocepacia biofilms.biofilm formation in burkholderia cenocepacia has been shown to rely in part on acylhomoserine lactone-based quorum sensing. for many other bacterial species, it appears that both the initial adherence and the later stages of biofilm maturation are affected when quorum sensing pathways are inhibited. in this study, we examined the effects of mutations in the cepir and cciir quorum-sensing systems of burkholderia cenocepacia k56-2 with respect to biofilm attachment and antibiotic resistance. we a ...200516151106
class 2 integron with a novel cassette array in a burkholderia cenocepacia isolate. 200516189138
transmission of burkholderia cepacia complex: evidence for new epidemic clones infecting cystic fibrosis patients in italy.to analyze national prevalence, genomovar distribution, and epidemiology of the burkholderia cepacia complex in italy, 225 putative b. cepacia complex isolates were obtained from 225 cystic fibrosis (cf) patients attending 18 cf centers. the genomovar status of these isolates was determined by a polyphasic approach, which included whole-cell protein electrophoresis and reca restriction fragment length polymorphism (rflp) analysis. two approaches were used to genotype b. cepacia complex isolates: ...200516207975
update on the burkholderia cepacia complex.the burkholderia cepacia complex is comprised of a group of related bacterial species that are capable of causing life-threatening respiratory tract infection in persons with cystic fibrosis. this article reviews advances in our understanding of burkholderia cepacia complex infection in cystic fibrosis, focusing on the taxonomy, clinical microbiology, and epidemiology, as well as the natural history and clinical outcomes associated with burkholderia cepacia complex infection.200516217180
detection of cultured and uncultured burkholderia cepacia complex bacteria naturally occurring in the maize rhizosphere.the species composition of a burkholderia cepacia complex population naturally occurring in the maize rhizosphere was investigated by using both culture-dependent and culture-independent methods. b. cepacia complex isolates were recovered from maize root slurry on the two selective media pseudomonas cepacia azelaic acid tryptamine (pcat) and trypan blue tetracycline (tb-t) and subjected to identification by a combination of restriction fragment length polymorphism (rflp) analysis and species-spe ...200516232288
disruption of tight junctions during traversal of the respiratory epithelium by burkholderia cenocepacia.burkholderia cenocepacia is an opportunistic bacterial species capable of causing life-threatening respiratory tract infection in persons with cystic fibrosis (cf). unlike most other pathogens in cf, which typically remain confined to the endobronchial spaces, b. cenocepacia can traverse airway epithelium to cause bacteremia and sepsis. the mechanisms by which this occurs, however, are unknown. we examined the transmigration of b. cenocepacia through polarized respiratory epithelium. representat ...200516239504
transient isolation of burkholderia multivorans and burkholderia cenocepacia from a brazilian cystic fibrosis patient chronically colonized with burkholderia vietnamiensis.fifteen serial burkholderia cepacia complex isolates recovered over a period of 4 years from a single cystic fibrosis patient were analysed for genomovar status by means of reca sequence determination, and genetic relatedness by rapd-pcr. twelve isolates were assigned as burkholderia vietnamiensis, two as burkholderia cenocepacia and one as burkholderia multivorans. b. vietnamiensis persisted in the airways during 4 years, except in three occasions when b. cenocepacia or b. multivorans were isol ...200516266831
towards the proteome of burkholderia cenocepacia h111: setting up a 2-de reference map.polyphasic-taxonomic studies of the past decade have shown that the burkholderia cepacia complex (bcc) comprises at least nine species, which share a high degree of 16s rdna (98-100%) sequence similarity but only moderate levels of dna-dna hybridization. members of the bcc are well known as opportunistic pathogens of plants, animals and humans but also as biocontrol and bioremediation agents. in this study intra-, surface-associated and extracellular proteins of b. cenocepacia h111, which was is ...200616294309
exopolysaccharides from burkholderia cenocepacia inhibit neutrophil chemotaxis and scavenge reactive oxygen species.bacteria belonging to the burkholderia cepacia complex are important opportunistic pathogens in compromised hosts, particularly patients with cystic fibrosis or chronic granulomatous disease. isolates of b. cepacia complex may produce large amounts of exopolysaccharides (eps) that endow the bacteria with a mucoid phenotype and appear to facilitate bacterial persistence during infection. we showed that eps from a clinical b. cenocepacia isolate interfered with the function of human neutrophils in ...200616316987
distribution and expression of the zmpa metalloprotease in the burkholderia cepacia complex.the distribution of the metalloprotease gene zmpa was determined among strains of the burkholderia cepacia complex (bcc). the zmpa gene was present in b. cepacia, b. cenocepacia, b. stabilis, b. ambifaria and b. pyrrocinia but absent from b. multivorans, b. vietnamiensis, b. dolosa, and b. anthina. the presence of zmpa generally correlated with extracellular proteolytic activity with the exception of five strains, which had zmpa but had no detectable proteolytic activity when skim milk agar was ...200516321929
metabolic profiling of burkholderia cenocepacia, burkholderia ambifaria, and burkholderia pyrrocinia isolates from maize rhizosphere.burkholderia cenocepacia, burkholderia ambifaria, and burkholderia pyrrocinia are the burkholderia cepacia complex (bcc) species most frequently associated with roots of crop plants. to investigate the ecophysiological diversity of these species, metabolic profiling of maize rhizosphere isolates was carried out by means of the biolog system, using gn2 and sfn2 plates and different parameters related to optical density (od). the metabolic profiles produced by the sfn2 and gn2 plates were identica ...200516328653
computer-aided design of agents that inhibit the cep quorum-sensing system of burkholderia cenocepacia.recent research has provided evidence that interference with bacterial cell-to-cell signaling is a promising strategy for the development of novel antimicrobial agents. here we report on the computer-aided design of novel compounds that specifically inhibit an n-acyl-homoserine lactone-dependent communication system that is widespread among members of the genus burkholderia. this genus comprises more than 30 species, many of which are important pathogens of animals and humans. over the past few ...200616377703
distribution and genomic location of active insertion sequences in the burkholderia cepacia complex.this study aimed firstly to establish the distribution and copy number within the burkholderia cepacia complex of three insertion sequences (is402, is407 and is1416) that possess the ability to activate transcription and hence influence gene expression. a second aim was to map the genomic insertion sites of one of the active insertion sequences (is407) to establish putative links between insertion site and downstream gene activation. the resulting data revealed that all three insertion sequences ...200616388024
identification of an rtx determinant of burkholderia cenocepacia j2315 by subtractive hybridization.this study utilized suppressive subtractive hybridization between the clinical isolate burkholderia cenocepacia j2315 and the closely related environmental isolate burkholderia cepacia atcc 25416(t) to isolate dna fragments specific to b. cenocepacia j2315. analysis of the resulting pools of b. cenocepacia-specific dnas identified several fragments that may be part of putative virulence factors. further in silico analysis of a single fragment indicated that it was internal to a gene of which the ...200616388025
iron availability influences aggregation, biofilm, adhesion and invasion of pseudomonas aeruginosa and burkholderia cenocepacia.pseudomonas aeruginosa and burkholderia cenocepacia are predominant opportunistic pathogens in cystic fibrosis (cf) patients. in healthy humans the lower respiratory tract as well as all mucosa, contains a very low free iron concentration (10(-18) m), while in cf patients sputum iron concentration is very high, showing a median value of 63x10(-6) m. accumulation of catalytic reactive iron heavily contributes to subsequent clinical complications in the lung disorders by the production of reactive ...200516388713
parabs systems of the four replicons of burkholderia cenocepacia: new chromosome centromeres confer partition specificity.most bacterial chromosomes carry an analogue of the parabs systems that govern plasmid partition, but their role in chromosome partition is ambiguous. parabs systems might be particularly important for orderly segregation of multipartite genomes, where their role may thus be easier to evaluate. we have characterized parabs systems in burkholderia cenocepacia, whose genome comprises three chromosomes and one low-copy-number plasmid. a single parab locus and a set of parb-binding (pars) centromere ...200616452432
a complete lipopolysaccharide inner core oligosaccharide is required for resistance of burkholderia cenocepacia to antimicrobial peptides and bacterial survival in vivo.burkholderia cenocepacia is an important opportunistic pathogen of patients with cystic fibrosis. this bacterium is inherently resistant to a wide range of antimicrobial agents, including high concentrations of antimicrobial peptides. we hypothesized that the lipopolysaccharide (lps) of b. cenocepacia is important for both virulence and resistance to antimicrobial peptides. we identified hlda and hldd genes in b. cenocepacia strain k56-2. these two genes encode enzymes involved in the modificati ...200616513737
a comparison of alternative 60-mer probe designs in an in-situ synthesized oligonucleotide microarray.dna microarrays have proven powerful for functional genomics studies. several technologies exist for the generation of whole-genome arrays. it is well documented that 25mer probes directed against different regions of the same gene produce variable signal intensity values. however, the extent to which this is true for probes of greater length (60mers) is not well characterized. moreover, this information has not previously been reported for whole-genome arrays designed against bacteria, whose ge ...200616595014
identification of essential operons with a rhamnose-inducible promoter in burkholderia cenocepacia.scanning of bacterial genomes to identify essential genes is of biological interest, for understanding the basic functions required for life, and of practical interest, for the identification of novel targets for new antimicrobial therapies. in particular, the lack of efficacious antimicrobial treatments for infections caused by the burkholderia cepacia complex is causing high morbidity and mortality of cystic fibrosis patients and of patients with nosocomial infections. here, we present a metho ...200616597956
the ornibactin biosynthesis and transport genes of burkholderia cenocepacia are regulated by an extracytoplasmic function sigma factor which is a part of the fur regulon.burkholderia cenocepacia mutants that fail to produce the siderophore ornibactin were obtained following mutagenesis with mini-tn5tp. these mutants were shown to be growth restricted under conditions of iron depletion. in eight of the mutants, the transposon had integrated into one of two genes, orbi and orbj, encoding nonribosomal peptide synthetases. in the other mutant, the transposon had inserted into an open reading frame, orbs, located upstream from orbi. the polypeptide product of orbs ex ...200616672617
burkholderia cenocepacia utilizes ferritin as an iron source.burkholderia cenocepacia is a member of the burkholderia cepacia complex, a group of genetically similar species that inhabit a number of environmental niches, including the lungs of patients with cystic fibrosis (cf). to colonize the lung, this bacterium requires a source of iron to satisfy its nutritional requirements for this important metal. because of the high potential for damage in lung tissue resulting from oxygen-iron interactions, this metal is sequestered by a number of mechanisms tha ...200616687582
identification of burkholderia cepacia complex pathogens by rapid-cycle pcr with fluorescent hybridization probes.members of the burkholderia cepacia complex are important bacterial pathogens in cystic fibrosis (cf) patients. the b. cepacia complex currently consists of nine genetic subgroups (genomovars) of different epidemiological relevance and possibly of different pathogenic potential in humans. in this study, a new approach was developed for the rapid identification of b. cepacia genomovar i, burkholderia multivorans (genomovar ii), burkholderia cenocepacia (lineage iii-a and iii-b), burkholderia stab ...200616687590
effect of reduced ph on inorganic polyphosphate accumulation by burkholderia cepacia complex isolates.burkholderia cepacia complex (bcc) isolates causing pulmonary infection in cystic fibrosis (cf) patients grow within an acidic environment in the lung. as exposure to acid ph has been shown to increase intracellular inorganic polyphosphate (polyp) formation in some bacteria, we investigated the inter-relationship between acidic ph and polyp accumulation in bcc isolates.200616706902
use of ribosomal promoters from burkholderia cenocepacia and burkholderia cepacia for improved expression of transporter protein in escherichia coli.expression of heterologous protein in escherichia coli usually based on the iptg-inducible expression systems. the use of these systems for membrane protein production, however, usually caused cytotoxic problem that affected the yield and functional characterization of the protein. optimization of these systems for transporter protein production is time-consuming and is usually ineffective. here, we described the use of the ribosomal promoters p(s12) from burkholderia cenocepacia lmg16656 and fr ...200616737826
caenorhabditis elegans killing assay as an infection model to study the role of type iii secretion in burkholderia cenocepacia. 200616772429
invasion and biofilm formation of burkholderia dolosa is comparable with burkholderia cenocepacia and burkholderia multivorans.colonisation with burkholderia cepacia complex pathogens has been associated with accelerated decline in cystic fibrosis (cf) patients. the two most common species among the cf community are burkholderia cenocepacia and burkholderia multivorans. however, burkholderia dolosa has recently been causing concern due to its transmissibility and virulence in cf patients.200716781896
burkholderia cenocepacia zmpb is a broad-specificity zinc metalloprotease involved in virulence.in previous studies we characterized the burkholderia cenocepacia zmpa zinc metalloprotease. in this study, we determined that b. cenocepacia has an additional metalloprotease, which we designated zmpb. the zmpb gene is present in the same species as zmpa and was detected in b. cepacia, b. cenocepacia, b. stabilis, b. ambifaria, and b. pyrrocinia but was absent from b. multivorans, b. vietnamiensis, b. dolosa, and b. anthina. the zmpb gene was expressed, and zmpb was purified from escherichia co ...200616790782
identification of a response regulator gene for catabolite control from a pcb-degrading beta-proteobacteria, acidovorax sp. kks102.acidovorax sp. (formally pseudomonas sp.) strain kks102 carries a bph operon for the degradation of pcb/biphenyl. transcription from the pe promoter for the bph operon was found to be under catabolite control, i.e. the promoter activity was at a lower level when succinate, fumarate or acetate was added to the culture. some mutations in the immediate upstream region of the pe promoter resulted in catabolite-insensitive and constitutively low promoter activity, suggesting that a transcriptional ac ...200616796688
efflux pump genes of the resistance-nodulation-division family in burkholderia cenocepacia genome.burkholderia cenocepacia is recognized as opportunistic pathogen that can cause lung infections in cystic fibrosis patients. a hallmark of b. cenocepacia infections is the inability to eradicate the organism because of multiple intrinsic antibiotic resistance. as resistance-nodulation-division (rnd) efflux systems are responsible for much of the intrinsic multidrug resistance in gram-negative bacteria, this study aims to identify rnd genes in the b. cenocepacia genome and start to investigate th ...200616857052
a napkin-associated outbreak of burkholderia cenocepacia bacteraemia in haemodialysis patients.this article reports a catheter-related outbreak of bacteraemia involving 38 patients in two haemodialysis units in verona. burkholderia cepacia complex strains were isolated from human blood and from an individually wrapped disinfection napkin that was contained in a commercially available, sterile dressing kit used to handle central venous catheters. micro-organisms isolated from blood cultures and from the napkin were identified by standard procedures and confirmed as b. cenocepacia (genomova ...200616859809
exopolysaccharides produced by clinical strains belonging to the burkholderia cepacia complex.in the frame of a research line dedicated to better clarify the role of exopolysaccharides (eps) in bacterial virulence, eps produced by species of the burkholderia cepacia complex (bcc), namely burkholderia multivorans, burkholderia cenocepacia, and a bcc member of undetermined genomovar, all isolated at the cystic fibrosis regional centre of florence (italy), were investigated for they structural properties.200716860003
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