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reca gene sequence and multilocus sequence typing for species-level resolution of burkholderia cepacia complex isolates.to identify, by means of reca sequencing and multilocus sequence typing (mlst), burkholderia cepacia complex (bcc) isolates of environmental and clinical origin, which failed to be identified by reca rflp and species-specific pcr.200919732325
eurocarecf quality assessment of diagnostic microbiology of cystic fibrosis isolates.the identification of microbial species from respiratory specimens and their susceptibility to antimicrobial agents are among the most important diagnostic measures of care for patients with cystic fibrosis (cf). under the umbrella of eurocarecf, two quality assurance trials of cf microbiology were performed in 2007 and 2008. nine formulations with cf bacterial isolates were dispatched. a total of 31/37 laboratories from 18/21 european countries participated in the 2007 and 2008 trials. the comm ...200919741077
two type iv secretion systems with different functions in burkholderia cenocepacia k56-2.bacterial type iv secretion systems (t4ss) perform two fundamental functions related to pathogenesis: the delivery of effector molecules to eukaryotic target cells, and genetic exchange. two t4sss have been identified in burkholderia cenocepacia k56-2, a representative of the et12 lineage of the b. cepacia complex (bcc). the plant tissue watersoaking (ptw) t4ss encoded on a resident 92 kb plasmid is a chimera composed of virb/d4 and f-specific subunits, and is responsible for the translocation o ...200919744991
assessment of three resistance-nodulation-cell division drug efflux transporters of burkholderia cenocepacia in intrinsic antibiotic resistance.burkholderia cenocepacia are opportunistic gram-negative bacteria that can cause chronic pulmonary infections in patients with cystic fibrosis. these bacteria demonstrate a high-level of intrinsic antibiotic resistance to most clinically useful antibiotics complicating treatment. we previously identified 14 genes encoding putative resistance-nodulation-cell division (rnd) efflux pumps in the genome of b. cenocepacia j2315, but the contribution of these pumps to the intrinsic drug resistance of t ...200919761586
reciprocal regulation by the cepir and cciir quorum sensing systems in burkholderia cenocepacia.burkholderia cenocepacia belongs to a group of closely related organisms called the b. cepacia complex (bcc) which are important opportunistic human pathogens. b. cenocepacia utilizes a mechanism of cell-cell communication called quorum sensing to control gene expression including genes involved in virulence. the b. cenocepacia quorum sensing network includes the cepir and cciir regulatory systems.200919761612
structural basis of the affinity for oligomannosides and analogs displayed by bc2l-a, a burkholderia cenocepacia soluble lectin.the opportunistic pathogen burkholderia cenocepacia contains three soluble carbohydrate-binding proteins, related to the fucose-binding lectin pa-iil from pseudomonas aeruginosa. all contain a pa-iil-like domain and two of them have an additional n-terminal domain that displays no sequence similarities with known proteins. printed arrays screening performed on the shortest one, b. cenocepacia lectin a (bc2l-a), demonstrated the strict specificity for oligomannose-type n-glycan structures (lameig ...201019770128
differential modulation of burkholderia cenocepacia virulence and energy metabolism by the quorum-sensing signal bdsf and its synthase.burkholderia cenocepacia produces the molecule cis-2-dodecenoic acid (bdsf), which was previously shown to play a role in antagonism against the fungal pathogen candida albicans by interfering with its morphological transition. in this study, we show that production of bdsf is under stringent transcriptional control and the molecule accumulates in a cell density-dependent manner, typically found with quorum-sensing (qs) signals. b. cenocepacia mutant strain j2315 with a deleted bcam0581 gene, wh ...200919801414
regulation of phenylacetic acid degradation genes of burkholderia cenocepacia k56-2.metabolically versatile soil bacteria burkholderia cepacia complex (bcc) have emerged as opportunistic pathogens, especially of cystic fibrosis (cf). previously, we initiated the characterization of the phenylacetic acid (pa) degradation pathway in b. cenocepacia, a member of the bcc, and demonstrated the necessity of a functional pa catabolic pathway for full virulence in caenorhabditis elegans. in this study, we aimed to characterize regulatory elements and nutritional requirements that contro ...200919835630
the lipid a of burkholderia multivorans c1576 smooth-type lipopolysaccharide and its pro-inflammatory activity in a cystic fibrosis airways model.cystic fibrosis is an autosomal recessive disorder and it is characterised by chronic bacterial airway infection which leads to progressive lung deterioration, sometimes with fatal outcome. burkholderia multivorans and burkholderia cenocepacia are the species responsible for most of the infections of cystic fibrosis patients. lipopolysaccharide endotoxins (lpss) are among the foremost factors of pathogenesis of gram-negative infection and, in particular, lipid a is the endotoxic portion of lps r ...201019880661
oxidative stress of burkholderia cenocepacia induces insertion sequence-mediated genomic rearrangements that interfere with macrorestriction-based genotyping.burkholderia cenocepacia can cause serious infections and epidemics in patients with cystic fibrosis (cf). a cf population in the czech republic experienced an epidemic outbreak caused by a b. cenocepacia st-32 strain. the clonality of the isolates was evident by multilocus sequence typing; however, fingerprinting profiles obtained by pulsed-field gel electrophoresis (pfge) showed substantial band variability. we investigated whether the pfge pattern diversity resulted from genomic rearrangement ...201019889907
expression and characterization of penicillin-binding proteins in burkholderia cenocepacia.putative penicillin-binding proteins (pbps) were identified in the genome of the burkholderia cenocepacia strain j2315 based on homology to e. coli pbps. the three sequences identified as homologs of e. coli pbp1a, bcal2021, bcal0274, and bcam2632, were cloned and expressed as his(6)-tagged fusion proteins in e. coli. the fusion proteins were isolated and shown to bind beta-lactams, indicating these putative pbps have penicillin-binding activity.201019924480
induction of immune response to the 17 kda ompa burkholderia cenocepacia polypeptide and protection against pulmonary infection in mice after nasal vaccination with an omp nanoemulsion-based vaccine.burkholderia cepacia complex (bcc) are opportunistic bacteria associated with life-threatening illness in persons with cystic fibrosis. once bcc colonization is established, these antimicrobial-resistant and biofilm-forming bacteria are difficult to eradicate and are associated with increased rates of morbidity and mortality. at present, no vaccines are available to prevent the bcc infection. there is currently a paucity of published information regarding the development of vaccines designed to ...201019967396
efficacy of bacteriophage therapy in a model of burkholderia cenocepacia pulmonary infection.the therapeutic potential of bacteriophages (phages) in a mouse model of acute burkholderia cenocepacia pulmonary infection was assessed. phage treatment was administered by either intranasal inhalation or intraperitoneal injection. bacterial density, macrophage inflammatory protein 2 (mip-2), and tumor necrosis factor alpha (tnf-alpha) levels were significantly reduced in lungs of mice treated with intraperitoneal phages (p < .05). no significant differences in lung bacterial density or mip-2 l ...201020001604
genome-wide analysis of dna repeats in burkholderia cenocepacia j2315 identifies a novel adhesin-like gene unique to epidemic-associated strains of the et-12 lineage.members of the burkholderia cepacia complex (bcc) are respiratory pathogens in patients with cystic fibrosis (cf). close repetitive dna sequences often associate with surface antigens to promote genetic variability in pathogenic bacteria. the genome of burkholderia cenocepacia j2315, a cf isolate belonging to the epidemic lineage edinburgh-toronto (et-12), was analysed for the presence of close repetitive dna sequences. among the 422 dna close repeats, 45 genes potentially involved in virulence ...201020019083
improved electrotransformation and decreased antibiotic resistance of the cystic fibrosis pathogen burkholderia cenocepacia strain j2315.the bacterium burkholderia cenocepacia is pathogenic for sufferers from cystic fibrosis (cf) and certain immunocompromised conditions. the b. cenocepacia strain most frequently isolated from cf patients, and which serves as the reference for cf epidemiology, is j2315. the j2315 genome is split into three chromosomes and one plasmid. the strain was sequenced several years ago, and its annotation has been released recently. this information should allow genetic experimentation with j2315, but two ...201020023084
pseudomonas aeruginosa alginate promotes burkholderia cenocepacia persistence in cystic fibrosis transmembrane conductance regulator knockout mice.pseudomonas aeruginosa, a major respiratory pathogen in cystic fibrosis (cf) patients, facilitates infection by other opportunistic pathogens. burkholderia cenocepacia, which normally infects adolescent patients, encounters alginate elaborated by mucoid p. aeruginosa. to determine whether p. aeruginosa alginate facilitates b. cenocepacia infection in mice, cystic fibrosis transmembrane conductance regulator knockout mice were infected with b. cenocepacia strain bc7 suspended in either phosphate- ...201020048042
subdivision of the bacterioferritin comigratory protein family of bacterial peroxiredoxins based on catalytic activity.peroxiredoxins are ubiquitous proteins that catalyze the reduction of hydroperoxides, thus conferring resistance to oxidative stress. using high-resolution mass spectrometry, we recently reclassified one such peroxiredoxin, bacterioferritin comigratory protein (bcp) of escherichia coli, as an atypical 2-cys peroxiredoxin that functions through the formation of an intramolecular disulfide bond between the active and resolving cysteine. an engineered e. coli bcp, which lacked the resolving cystein ...201020078128
potential mechanisms underlying the acute lung dysfunction and bacterial extrapulmonary dissemination during burkholderia cenocepacia respiratory infection.burkholderia cenocepacia, an opportunistic pathogen that causes lung infections in cystic fibrosis (cf) patients, is associated with rapid and usually fatal lung deterioration due to necrotizing pneumonia and sepsis, a condition known as cepacia syndrome. the key bacterial determinants associated with this poor clinical outcome in cf patients are not clear. in this study, the cytotoxicity and procoagulant activity of b. cenocepacia from the et-12 lineage, that has been linked to the cepacia synd ...201020082687
burkholderia cenocepacia creates an intramacrophage replication niche in zebrafish embryos, followed by bacterial dissemination and establishment of systemic infection.bacteria belonging to the "burkholderia cepacia complex" (bcc) often cause fatal pulmonary infections in cystic fibrosis patients, yet little is know about the underlying molecular mechanisms. these gram-negative bacteria can adopt an intracellular lifestyle, although their ability to replicate intracellularly has been difficult to demonstrate. here we show that bcc bacteria survive and multiply in macrophages of zebrafish embryos. local dissemination by nonlytic release from infected cells was ...201020086083
identification of potential therapeutic targets for burkholderia cenocepacia by comparative transcriptomics.burkholderia cenocepacia is an endemic soil dweller and emerging opportunistic pathogen in patients with cystic fibrosis (cf). the identification of virulence factors and potential therapeutic targets has been hampered by the genomic diversity within the species as many factors are not shared among the pathogenic members of the species.201020090946
transcriptional response of burkholderia cenocepacia j2315 sessile cells to treatments with high doses of hydrogen peroxide and sodium hypochlorite.burkholderia cepacia complex bacteria are opportunistic pathogens, which can cause severe respiratory tract infections in patients with cystic fibrosis (cf). as treatment of infected cf patients is problematic, multiple preventive measures are taken to reduce the infection risk. besides a stringent segregation policy to prevent patient-to-patient transmission, clinicians also advise patients to clean and disinfect their respiratory equipment on a regular basis. however, problems regarding the ef ...201020137066
a tnf-like trimeric lectin domain from burkholderia cenocepacia with specificity for fucosylated human histo-blood group antigens.the opportunistic pathogen burkholderia cenocepacia expresses several soluble lectins, among them bc2l-c. this lectin exhibits two domains: a c-terminal domain with high sequence similarity to the recently described calcium-dependent mannose-binding lectin bc2l-a, and an n-terminal domain of 156 amino acids without similarity to any known protein. the recombinant n-terminal bc2l-c domain is a new lectin with specificity for fucosylated human histo-blood group epitopes h-type 1, lewis b, and lewi ...201020152153
experimental adaptation of burkholderia cenocepacia to onion medium reduces host range.it is unclear whether adaptation to a new host typically broadens or compromises host range, yet the answer bears on the fate of emergent pathogens and symbionts. we investigated this dynamic using a soil isolate of burkholderia cenocepacia, a species that normally inhabits the rhizosphere, is related to the onion pathogen b. cepacia, and can infect the lungs of cystic fibrosis patients. we hypothesized that adaptation of b. cenocepacia to a novel host would compromise fitness and virulence in a ...201020154121
the burkholderia cenocepacia k56-2 pleiotropic regulator pbr, is required for stress resistance and virulence.burkholderia cenocepacia is one of the most virulent species of the burkholderia cepacia complex, a group of bacteria that emerged as important pathogens, especially to cystic fibrosis (cf) patients. in this study, we report the identification and characterization of a mutant strain derived form the cf isolate burkholderia cenocepacia k56-2, carrying a plasposon insertion in a gene, located in a 3516 bp chromosomal region with an atypical g+c content, encoding a 80 amino acid putative regulatory ...201020206249
development and evaluation of polymerase chain reaction assay to detect burkholderia genus and to differentiate the species in clinical specimens.molecular-based techniques are becoming desirable as tools for identification of infectious diseases. amongst the burkholderia spp., there is a need to differentiate burkholderia pseudomallei from burkholderia cepacia, as misidentification could lead to false treatment of patients. in this study, conventional pcr assay targeting three genes was developed. primers were designed for the amplification of burkholderia genus-specific groel gene, b. pseudomallei-specific mpra gene and b. cepacia-speci ...201020345378
construction of aminoglycoside-sensitive burkholderia cenocepacia strains for use in studies of intracellular bacteria with the gentamicin protection assay.burkholderia cenocepacia is a multidrug-resistant opportunistic pathogen that infects the airways of patients with cystic fibrosis (cf) and can survive intracellularly in macrophages and epithelial cells. the gentamicin protection assay, which relies on the poor ability of gentamicin or other aminoglycosides to permeate eukaryotic cell membranes, is traditionally employed to quantify intracellular bacteria. however, the high resistance of these bacteria to aminoglycosides hampers the use of the ...201020348312
an outbreak of burkholderia cenocepacia bacteremia in immunocompromised oncology patients.burkholderia cepacia is a common environmental bacterium that is resistant to disinfectants, and therefore is often encountered as a hospital-acquired pathogen. we describe an outbreak of b. cenocepacia bacteremia among hospitalized oncology patients.201020358245
bovine lactoferrin interacts with cable pili of burkholderia cenocepacia.in this study we evaluated the ability of lactoferrin, the most abundant antimicrobial protein in airway secretions, to bind the surface structures of a burkholderia strain cystic fibrosis-isolated. burkholderia cenocepacia is a gram-negative bacterium involved as respiratory pathogen in cystic fibrosis patient infections. this bacterium possesses filamentous structures, named cable pili that have been proposed as virulence factors because of their ability to bind to respiratory epithelia and mu ...201020364433
response of sessile cells to stress: from changes in gene expression to phenotypic adaptation.a better understanding of the genotypic and phenotypic adaptation of sessile (biofilm-associated) microorganisms to various forms of stress is required in order to develop more effective antibiofilm strategies. this review presents an overview of what high-throughput transcriptomic analyses have taught us concerning the response of various clinically relevant microorganisms (including pseudomonas aeruginosa, burkholderia cenocepacia and candida albicans) to treatment with antibiotics or disinfec ...201020482621
structural and functional characterization of diffusible signal factor family quorum-sensing signals produced by members of the burkholderia cepacia complex.previous work has shown that burkholderia cenocepacia produces the diffusible signal factor (dsf) family signal cis-2-dodecenoic acid (c(12):delta(2), also known as bdsf), which is involved in the regulation of virulence. in this study, we determined whether c(12):delta(2) production is conserved in other members of the burkholderia cepacia complex (bcc) by using a combination of high-performance liquid chromatography, mass spectrometry, and bioassays. our results show that five bcc species are ...201020511428
survival of burkholderia cepacia sepsis following lung transplantation in recipients with cystic fibrosis.cystic fibrosis (cf) lung transplant recipients infected with burkholderia cenocepacia have a worse survival rate after lung transplantation than those who are not infected with this organism. the decreased survival is predominantly due to recurrent b. cenocepacia infection, with the majority of affected recipients succumbing within 3 months after transplant. b. cepacia complex (bcc) sepsis is one of the defining criteria for cepacia syndrome, an almost universally fatal necrotizing pneumonic il ...201020553438
a sensor kinase recognizing the cell-cell signal bdsf (cis-2-dodecenoic acid) regulates virulence in burkholderia cenocepacia.burkholderia cenocepacia is an opportunistic human pathogen that uses cis-2-dodecenoic acid (bdsf) as a quorum-sensing signal to control expression of virulence factors. bdsf is a signal molecule of the diffusible signal factor (dsf) family that was first described in the plant pathogen xanthomonas campestris. the mechanism of perception of this signal and the range of functions regulated in b. cenocepacia are, however, unknown. a screen for transposon mutants unable to respond to exogenous sign ...201020624216
investigation of burkholderia cepacia complex in septicaemic patients in a tertiary care hospital, india.burkholderia cepacia complex (bcc) is being increasingly recognized as an important pathogen of humans. during the year 2007-8, 39 putative bcc isolates were obtained from 21 cases and subjected to reca pcr rflp. twenty-four isolates were confirmed as burkholderia cenocepacia iiia (nineteen isolates, reca pcr rflp type g and five isolates, reca pcr rflp type i), six were confirmed as b. cepacia (reca pcr rflp type e). bcc were isolated from inpatients of different wards of postgraduate institute ...200920635597
a decade of burkholderia cenocepacia virulence determinant research.the burkholderia cepacia complex (bcc) is a group of genetically related environmental bacteria that can cause chronic opportunistic infections in patients with cystic fibrosis (cf) and other underlying diseases. these infections are difficult to treat due to the inherent resistance of the bacteria to antibiotics. bacteria can spread between cf patients through social contact and sometimes cause cepacia syndrome, a fatal pneumonia accompanied by septicemia. burkholderia cenocepacia has been the ...201020643851
the type 2 secretion pseudopilin, gspj, is required for multihost pathogenicity of burkholderia cenocepacia au1054.burkholderia cenocepacia au1054 is an opportunistic pathogen isolated from the blood of a person with cystic fibrosis. au1054 is a multihost pathogen causing rapid pathogenicity to caenorhabditis elegans nematodes. within 24 h, au1054 causes greater than 50% mortality, reduced growth, emaciated body, distended intestinal lumen, rectal swelling, and prolific infection of the nematode intestine. to determine virulence mechanisms, 3,000 transposon mutants were screened for attenuated virulence in n ...201020660607
bcskc is an essential protein for the type vi secretion system activity in burkholderia cenocepacia that forms an outer membrane complex with bcslb.the type vi secretion system (t6ss) contributes to the virulence of burkholderia cenocepacia, an opportunistic pathogen causing serious chronic infections in patients with cystic fibrosis. bcsk(c) is a highly conserved protein among the t6sss in gram-negative bacteria. here, we show that bcsk(c) is required for hcp secretion and cytoskeletal redistribution in macrophages upon bacterial infection. these two phenotypes are associated with a functional t6ss in b. cenocepacia. experiments employing ...201020729192
specific resistance to pseudomonas aeruginosa infection in zebrafish is mediated by the cystic fibrosis transmembrane conductance regulator.cystic fibrosis (cf) is a genetic disease caused by recessive mutations in the cystic fibrosis transmembrane conductance regulator (cftr) gene and is associated with prevalent and chronic pseudomonas aeruginosa lung infections. despite numerous studies that have sought to elucidate the role of cftr in the innate immune response, the links between cftr, innate immunity, and p. aeruginosa infection remain unclear. the present work highlights the zebrafish as a powerful model organism for human inf ...201020732993
lung transplantation for patients with cystic fibrosis and burkholderia cepacia complex infection: a single-center experience.pre-operative infection with organisms from the burkholderia cepacia complex (bcc), particularly b cenocepacia, has been linked with a poorer prognosis after transplantation compared to patients with cystic fibrosis (cf) without this infection. therefore, many transplant centers do not list these patients for transplantation.201020810293
identification of potential diagnostic markers among burkholderia cenocepacia and b. multivorans supernatants.patients with cystic fibrosis (cf) are susceptible to chronic respiratory infections with a number of bacterial pathogens. among them, the burkholderia cepacia complex (bcc) bacteria, consisting of nine related species, have emerged as problematic cf pathogens due to their antibiotic resistance, incidence of nosocomial infection, and person-to-person transmission. bcc organisms present the clinical microbiologist with a diagnostic dilemma due to the lack of phenotypic biochemical or growth-relat ...201020810766
ecological succession in long-term experimentally evolved biofilms produces synergistic communities.many biofilm populations are known for their exceptional biodiversity, but the relative contributions of the forces that could produce this diversity are poorly understood. this uncertainty grows in the old, well-established communities found on many natural surfaces and in long-term, chronic infections. if the prevailing interactions among species within biofilms are positive, productivity should increase with diversity, but if they tend towards competition or antagonism, productivity should de ...201120811470
invasion of burkholderia cepacia complex isolates into lung epithelial cells involves glycolipid receptors.burkholderia cepacia complex (bcc) is a group of opportunistic cystic fibrosis (cf) pathogens that invade lung epithelial cells. the mechanisms of invasion are poorly understood, in particular, the receptors utilised by this bacterium in the invasion process have not been identified. the aim of this study was to investigate the epithelial receptors involved in the invasion of bcc isolates. we confirmed that invasion into two lung epithelial cell lines (16hbe14o- and cfbe41o-) which have a non-cf ...201020826205
bactericidal effects of non-thermal argon plasma in vitro, in biofilms and in the animal model of infected wounds.non-thermal (low-temperature) physical plasma is under intensive study as an alternative approach to control superficial wound and skin infections when the effectiveness of chemical agents is weak due to natural pathogen or biofilm resistance. the purpose of this study was to test the individual susceptibility of pathogenic bacteria to non-thermal argon plasma and to measure the effectiveness of plasma treatments against bacteria in biofilms and on wound surfaces. overall, gram-negative bacteria ...201120829396
inactivation of macrophage rab7 by burkholderia cenocepacia.strains of the burkholderia cepacia complex can survive within macrophages by arresting the maturation of phagocytic vacuoles. the bacteria preclude fusion of the phagosome with lysosomes by a process that is poorly understood. using murine macrophages, we investigated the stage at which maturation is arrested and analyzed the underlying mechanism. vacuoles containing b. cenocepacia strain j2315, an isolate of the transmissible et12 clone, recruited rab5 and synthesized phosphatidylinositol-3-ph ...201020829607
characterization of liposomes formed by lipopolysaccharides from burkholderia cenocepacia, burkholderia multivorans and agrobacterium tumefaciens: from the molecular structure to the aggregate architecture.the microstructure of liposomes formed by the lipopolysaccharides (lps) derived from burkholderia cenocepacia et-12 type strain lmg 16656, burkholderia multivorans strain c1576 and agrobacterium tumefaciens strain tt111 has been investigated by a combined experimental strategy, including dynamic light scattering (dls), small-angle neutron scattering (sans) and electron paramagnetic resonance (epr). the results highlight that the lps molecular structure determines, through a complex interplay of ...201020852798
increased electrical output when a bacterial abts oxidizer is used in a microbial fuel cell.microbial fuel cells (mfcs) are a technology that provides electrical energy from the microbial oxidation of organic compounds. most mfcs use oxygen as the oxidant in the cathode chamber. this study examined the formation in culture of an unidentified bacterial oxidant and investigated the performance of this oxidant in a two-chambered mfc with a proton exchange membrane and an uncoated carbon cathode. dna, fame profile and characterization studies identified the microorganism that produced the ...201120853166
taxonomic parsing of bacteriophages using core genes and in silico proteome-based cgug and applications to small bacterial genomes.a combined genomics and in situ proteomics approach can be used to determine and classify the relatedness of organisms. the common set of proteins shared within a group of genomes is encoded by the "core" set of genes, which is increasingly recognized as a metric for parsing viral and bacterial species. these can be described by the concept of a "pan-genome", which consists of this "core" set and a "dispensable" set, i.e., genes found in one or more but not all organisms in the grouping. "corege ...201020865522
burkholderia cenocepacia in cystic fibrosis: epidemiology and molecular mechanisms of virulence.burkholderia cepacia complex (bcc) bacteria have gained notoriety as pathogens in cystic fibrosis (cf) because they are difficult to identify and treat, and also have the ability to spread between cf individuals. of the 17 formally named species within the complex, burkholderia multivorans and burkholderia cenocepacia dominate in cf. multilocus sequence typing has proven to be a very useful tool for tracing the global epidemiology of bcc bacteria and has shown that b. cenocepacia strains with hi ...201020880411
murine models of acute and chronic lung infection with cystic fibrosis pathogens.animal models of acute and chronic infection, along with mice genetically modified for the cftr gene, are a key asset in cystic fibrosis (cf) research. despite some limitations, these models provide valuable resources to mimic the initial and progressive bronchopulmonary infection typical of cf patients. the following review summarizes the strengths and weaknesses of different types of animal models with a major emphasis placed on the significant species differences between mice and humans. muri ...201020951086
the poba gene of burkholderia cenocepacia encodes a group i sfp-type phosphopantetheinyltransferase required for biosynthesis of the siderophores ornibactin and pyochelin.the opportunistic pathogen burkholderia cenocepacia produces the siderophores ornibactin and pyochelin under iron-restricted conditions. biosynthesis of both siderophores requires the involvement of non-ribosomal peptide synthetases (nrpss). using a transposon containing the lacz reporter gene, two b. cenocepacia mutants were isolated which were deficient in siderophore production. mutant iw10 was shown to produce normal amounts of ornibactin but only trace amounts of pyochelin, whereas synthesi ...201020966087
the burkholderia cenocepacia lysr-type transcriptional regulator shvr influences expression of quorum-sensing, protease, type ii secretion, and afc genes.burkholderia cenocepacia is a significant opportunistic pathogen in individuals with cystic fibrosis. shvr, a lysr-type transcriptional regulator, has previously been shown to influence colony morphology, biofilm formation, virulence in plant and animal infection models, and some quorum-sensing-dependent phenotypes. in the present study, it was shown that shvr negatively regulates its own expression, as is typical for lysr-type regulators. the production of quorum-sensing signal molecules was de ...201020971902
genomic analysis and relatedness of p2-like phages of the burkholderia cepacia complex.the burkholderia cepacia complex (bcc) is comprised of at least seventeen gram-negative species that cause infections in cystic fibrosis patients. because bcc bacteria are broadly antibiotic resistant, phage therapy is currently being investigated as a possible alternative treatment for these infections. the purpose of our study was to sequence and characterize three novel bcc-specific phages: ks5 (vb_bcem-ks5 or vb_bmuz-atcc 17616), ks14 (vb_bcem-ks14) and kl3 (vb_bamm-kl3 or vb_bcez-cep511).201020973964
chromosome translocation and its consequence in the genome of burkholderia cenocepacia au-1054.most bacterial genomes have one single chromosome. the species burkholderia cenocepacia, a gram-negative β-proteobacterium, is one of the exceptions. genomes of four strains of the species have been sequenced and each has three circular chromosomes. in the genus burkholderia, there are another seven sequenced strains that have three chromosomes. in this paper, the numbers of essential genes and trna genes among the 11 strains of the genus burkholderia are compared. interestingly, it is found tha ...201021078295
pathogen-host interactions in dictyostelium, legionella, mycobacterium and other pathogens.dictyostelium discoideum is a haploid social soil amoeba that is an established host model for several human pathogens. the research areas presently pursued include the use of d. discoideum to identify genetic host factors determining the outcome of infections and the use as screening system for identifying bacterial virulence factors. here we report about the legionella pneumophila directed phagosome biogenesis and the cell-to-cell spread of mycobacterium species. moreover, we highlight recent ...201021109012
virulence of an emerging respiratory pathogen, genus pandoraea, in vivo and its interactions with lung epithelial cells.pandoraea species have emerged as opportunistic pathogens among cystic fibrosis (cf) and non-cf patients. pandoraea pulmonicola is the predominant pandoraea species among irish cf patients. the objective of this study was to investigate the pathogenicity and potential mechanisms of virulence of irish p. pulmonicola isolates and strains from other pandoraea species. three patients from whom the p. pulmonicola isolates were isolated have since died. the in vivo virulence of these and other pandora ...201021127160
burkholderia cenocepacia o polysaccharide chain contributes to caspase-1-dependent il-1beta production in macrophages.burkholderia cenocepacia infections in cf patients involve heightened inflammation, fatal sepsis, and high antibiotic resistance. proinflammatory il-1β secretion is important in airway inflammation and tissue damage. however, little is known about this pathway in macrophages upon b. cenocepacia infection. we report here that murine macrophages infected with b. cenocepacia k56-2 produce proinflammatory cytokine il-1β in a tlr4 and caspase-1-mediated manner. we also determined that the ops (o anti ...201021178113
approaches to measure the fitness of burkholderia cepacia complex isolates.members of the burkholderia cepacia complex (bcc) are highly resistant to many antibacterial agents and infection can be difficult to eradicate. a coordinated approach has been used to measure the fitness of bcc bacteria isolated from cystic fibrosis (cf) patients with chronic bcc infection using methods relevant to bcc growth and survival conditions. significant differences in growth rate were observed among isolates; slower growth rates were associated with isolates that exhibited higher mics ...201020185551
cd4+ t-cell immunity to the burkholderia pseudomallei abc transporter lolc in melioidosis.burkholderia pseudomallei causes melioidosis, a disease with a wide range of possible outcomes, from seroconversion and dormancy to sepsis and death. this spectrum of host-pathogen interactions poses challenging questions about the heterogeneity in immunity to b. pseudomallei. models show protection to be dependent on cd4(+) cells and ifn-γ, but little is known about specific target antigens. having previously implicated the abc transporter, lolc, in protective immunity, we here use epitope pred ...201021182082
requirement for asparagine in the aquaporin npa sequence signature motifs for cation exclusion.two highly conserved npa motifs are a hallmark of the aquaporin (aqp) family. the npa triplets form n-terminal helix capping structures with the asn side chains located in the centre of the water or solute-conducting channel, and are considered to play an important role in aqp selectivity. although another aqp selectivity filter site, the aromatic/arg (ar/r) constriction, has been well characterized by mutational analysis, experimental data concerning the npa region--in particular, the asn posit ...201121205205
functional quorum sensing systems are maintained during chronic burkholderia cepacia complex infections in patients with cystic fibrosis.quorum sensing (qs) contributes to the virulence of pseudomonas aeruginosa and burkholderia cepacia complex lung infections. p. aeruginosa qs mutants are frequently isolated from patients with cystic fibrosis. the objective of this study was to determine whether similar adaptations occur over time in b. cepacia complex isolates. forty-five burkholderia multivorans and burkholderia cenocepacia sequential isolates from patients with cystic fibrosis were analyzed for n-acyl-homoserine lactone activ ...201021208930
communication with a growing family: diffusible signal factor (dsf) signaling in bacteria.many pathogenic bacteria use cell-cell signaling to regulate the expression of factors contributing to virulence. bacteria produce signals of diverse structural classes. the signal molecule known as diffusible signal factor (dsf) is a cis-unsaturated fatty acid that was first described in the plant pathogen xanthomonas campestris. recent work has shown that structurally related molecules produced by the unrelated bacteria burkholderia cenocepacia and pseudomonas aeruginosa regulate virulence, bi ...201121227698
saturation mutagenesis of a cepr binding site as a means to identify new quorum-regulated promoters in burkholderia cenocepacia.burkholderia cenocepacia is an opportunistic pathogen of humans that encodes two genes that resemble the acylhomoserine lactone synthase gene luxi of vibrio fischeri and three genes that resemble the acylhomoserine lactone receptor gene luxr. of these, cepi synthesizes octanoylhomoserine lactone (ohl), while cepr is an ohl-dependent transcription factor. in the current study we developed a strategy to identify genes that are directly regulated by cepr. we systematically altered a cepr binding si ...201121255107
the second rna chaperone, hfq2, is also required for survival under stress and full virulence of burkholderia cenocepacia j2315.burkholderia cenocepacia j2315 is a highly virulent and epidemic clinical isolate of the b. cepacia complex (bcc), a group of bacteria that have emerged as important pathogens to cystic fibrosis patients. this bacterium, together with all bcc strains and a few other prokaryotes, is unusual for encoding in its genome two distinct and functional hfq-like proteins. in this work, we show results indicating that the 188-amino-acid hfq2 protein is required for the full virulence and stress resistance ...201121278292
regulation of sulfur assimilation pathways in burkholderia cenocepacia through control of genes by the ssur transcription factor.the genome of burkholderia cenocepacia contains two genes encoding closely related lysr-type transcriptional regulators, cysb and ssur, involved in control of sulfur assimilation processes. in this study we show that the function of ssur is essential for the utilization of a number of organic sulfur sources of either environmental or human origin. among the genes upregulated by ssur identified here are the tauabc operon encoding a predicted taurine transporter, three taud-type genes encoding put ...201121317335
quantitative proteomics (2-d dige) reveals molecular strategies employed by burkholderia cenocepacia to adapt to the airways of cystic fibrosis patients under antimicrobial therapy.chronic respiratory infections caused by burkholderia cenocepacia in patients with cystic fibrosis (cf) are characterized by low responsiveness to antibiotic therapy and, in general, to a more rapid decline of lung function. to get clues into the molecular mechanisms underlying the adaptive strategies employed to deal with the stressing conditions of the cf lung including antibiotic therapy, quantitative proteomics (2-d dige) was used to compare the expression programs of two clonal isolates ret ...201121337515
molecular mechanisms of chlorhexidine tolerance in burkholderia cenocepacia biofilms.the high tolerance of biofilm-grown burkholderia cepacia complex bacteria against antimicrobial agents presents considerable problems for the treatment of infected cystic fibrosis patients and the implementation of infection control guidelines. in the present study, we analyzed the tolerance of planktonic and sessile burkholderia cenocepacia j2315 cultures and examined the transcriptional response of sessile cells to treatment with chlorhexidine. at low (0.0005%) and high (0.05%) concentrations, ...201121357299
defining a structural and kinetic rationale for paralogous copies of phenylacetate-coa ligases from the cystic fibrosis pathogen burkholderia cenocepacia j2315.the phenylacetic acid (paa) degradation pathway is the sole aerobic route for phenylacetic acid metabolism in bacteria and facilitates degradation of environmental pollutants such as styrene and ethylbenzene. the paa pathway also is implicated in promoting burkholderia cenocepacia infections in cystic fibrosis patients. intriguingly, the first enzyme in the paa pathway is present in two copies (paak1 and paak2), yet each subsequent enzyme is present in only a single copy. furthermore, sequence d ...201121388965
quorum sensing inhibitors increase the susceptibility of bacterial biofilms to antibiotics in vitro and in vivo.although the exact role of quorum sensing (qs) in various stages of biofilm formation, maturation, and dispersal and in biofilm resistance is not entirely clear, the use of qs inhibitors (qsi) has been proposed as a potential antibiofilm strategy. we have investigated whether qsi enhance the susceptibility of bacterial biofilms to treatment with conventional antimicrobial agents. the qsi used in our study target the acyl-homoserine lactone-based qs system present in pseudomonas aeruginosa and bu ...201121422204
differences in strategies to combat osmotic stress in burkholderia cenocepacia elucidated by nmr-based metabolic profiling.to investigate mechanisms of osmotic tolerance in burkholderia cenocepacia, a member of the b. cepacia complex (bcc) of closely related strains, which is of clinical as well as environmental importance.201121446999
phenylalanine induces burkholderia cenocepacia phenylacetic acid catabolism through degradation to phenylacetyl-coa in synthetic cystic fibrosis sputum medium.synthetic cystic fibrosis sputum medium (scfm) is rich in amino acids and supports robust growth of burkholderia cenocepacia, a member of the burkholderia cepacia complex (bcc). previous work demonstrated that b. cenocepacia phenylacetic acid (pa) catabolic genes are up-regulated during growth in scfm and are required for full virulence in a caenorhabditis elegans host model. in this work, we investigated the role of phenylalanine, one of the aromatic amino acids present in scfm, as an inducer o ...201121511027
deciphering the role of rnd efflux transporters in burkholderia cenocepacia.burkholderia cenocepacia j2315 is representative of a highly problematic group of cystic fibrosis (cf) pathogens. eradication of b. cenocepacia is very difficult with the antimicrobial therapy being ineffective due to its high resistance to clinically relevant antimicrobial agents and disinfectants. rnd (resistance-nodulation-cell division) efflux pumps are known to be among the mediators of multidrug resistance in gram-negative bacteria. since the significance of the 16 rnd efflux systems prese ...201121526150
isolation of burkholderia cenocepacia j 2315 from non-cystic fibrosis pediatric patients in india.we report for the first time 2 cases of multidrug-resistant burkholderia cenocepacia j2315 isolated from blood samples of patients without cystic fibrosis from a pediatric unit in a hospital in india. the first patient presented with community-acquired bacteremia, and the second patient was immunocompromised and developed hospital-acquired infection approximately 17 days after admission. the isolates from both patients were multidrug-resistant and strong biofilm producers. surveillance cultures ...201121531270
burkholderia cenocepacia phenotypic clonal variation during three and a half years of residence in the lungs of a cystic fibrosis patient.chronic lung infection is the major cause of morbidity and premature mortality in cystic fibrosis (cf) patients. bacteria of the burkholderia cepacia complex are the most threatening pathogens in cf and a better understanding of how these bacteria adapt to the cf airway environment and resist to the host defense mechanisms and to therapeutically administered antibiotics is crucial. to provide clues on the adaptive strategies adopted by b. cenocepacia during long-term colonization, we carried out ...201121536796
diversity analysis of burkholderia cepacia complex in the water bodies of west lake, hangzhou, china.a survey of burkholderia cepacia complex (bcc) species was conducted in water bodies of west lake in china. a total of 670 bacterial isolates were recovered on selective media. out of them, 39.6% (265 isolates) were assigned to the following species: burkholderia multivorans, burkholderia cenocepacia reca lineage iiia, iiib, burkholderia stabilis, burkholderia vietnamiensis, and burkholderia seminalis while b. cenocepacia is documented as a dominant bcc species in water of west lake. in addition ...201121538256
crystal structures of burkholderia cenocepacia dihydropteroate synthase in the apo-form and complexed with the product 7,8-dihydropteroate.abstract:201121554707
the response of pseudomonas aeruginosa pao1 efflux pump-defective mutants to n-octanoyl-l-homoserine lactone.n-octanoyl-l-homoserine lactone (c8-hsl) is an acyl-homoserine-lactone signal utilized in the quorum-sensing (qs) systems of burkholderia cenocepacia and other bacterial species. although also produced by pseudomonas aeruginosa, its role in this species has not been elucidated. here, we report that c8-hsl modulated antibiotic resistance and pyocyanin production in a p. aeruginosa efflux pump-deficient mutant. the rhl/las quorum-sensing system and qscr gene were both shown to be nonessential in t ...200921566394
exploring the metabolic network of the epidemic pathogen burkholderia cenocepacia j2315 via genome-scale reconstruction.abstract: background: burkholderia cenocepacia is a threatening nosocomial epidemic pathogen in patients with cystic fibrosis (cf) or a compromised immune system. its high level of antibiotic resistance is an increasing concern in treatments against its infection. strain b. cenocepacia j2315 is the most infectious isolate from cf patients. there is a strong demand to reconstruct a genome-scale metabolic network of b. cenocepacia j2315 to systematically analyze its metabolic capabilities and its ...201121609491
the quorum-sensing molecules farnesol/homoserine lactone and dodecanol operate via distinct modes of action in candida albicans.living as a commensal, candida albicans must adapt and respond to environmental cues generated by the mammalian host and by microbes comprising the natural flora. these signals have opposing effects on c. albicans, with host cues promoting the yeast-to-hyphal transition and bacteria-derived quorum-sensing molecules inhibiting hyphal development. hyphal development is regulated through modulation of the cyclic amp (camp)/protein kinase a (pka) signaling pathway, and it has been postulated that qu ...201121666074
cable pili and the associated 22 kda adhesin contribute to burkholderia cenocepacia persistence in vivo.infection by burkholderia cenocepacia in cystic fibrosis (cf) patients is associated with poor clinical prognosis. previously, we demonstrated that one of the highly transmissible strains, bc7, expresses cable pili and the associated 22 kda adhesin, both of which contribute to bc7 binding to airway epithelial cells. however, the contribution of these factors to induce inflammation and bacterial persistence in vivo is not known.201121811611
genome and characterization of phages bcep22 and bcepil02, founders of a novel phage type in burkholderia cenocepacia.within the burkholderia cepacia complex (bcc), b. cenocepacia is the most common species associated with aggressive infections in the lungs of cystic fibrosis patients, causing disease that is often refractive to treatment by antibiotics. phage therapy may be a potential alternative form of treatment for these infections. here we describe the genome of the previously described therapeutic b. cenocepacia podophage bcepil02 and its close relative, bcep22. phage bcep22 was found to contain a circul ...201121804006
spontaneous and evolutionary changes in the antibiotic resistance of burkholderia cenocepacia observed by global gene expression analysis.abstract: background: burkholderia cenocepacia is a member of the burkholderia cepacia complex group of bacteria that cause infections in individuals with cystic fibrosis. b. cenocepacia isolate j2315 has been genome sequenced and is representative of a virulent, epidemic cf strain (et12). its genome encodes multiple antimicrobial resistance pathways and it is not known which of these is important for intrinsic or spontaneous resistance. to map these pathways, transcriptomic analysis was perform ...201121781329
blocking candida albicans biofilm formation by bdsf and trans-bdsf.candida is an important opportunistic human fungal pathogen. infections caused by c. albicans are related to the formation of a biofilm. the biofilm enhances the resistance of the c. albicans defense system, increases its resistance to antifungal drugs, and induces increased drug tolerance and makes clinical care more challenging. the in vitro activity of bdsf (cis-2-dodecenoic acid) and trans-bdsf (trans-2-dodecenoic acid) against candida albicans growth, germ tube germination and biofilm forma ...201121778264
activation of mmp-9 by human lung epithelial cells in response to cystic fibrosis associated pathogen burkholderia cenocepacia reduced wound healing in vitro.burkholderia cepacia complex is a group of bacterial pathogens which cause opportunistic infections in cystic fibrosis (cf). the most virulent of these is burkholderia cenocepacia. matrix metalloproteases (mmps) are upregulated in cf patients. the aim of this work was to examine the role of mmps in the pathogenesis of b. cepacia complex, which has not been explored to date. real-time pcr analysis showed that b. cenocepacia infection up-regulated mmp-2 and mmp-9 genes in cf lung cell line, cfbe41 ...201121743026
the dioxygenase-encoding olsd gene from burkholderia cenocepacia causes the hydroxylation of the amide-linked fatty acyl moiety of ornithine-containing membrane lipids.burkholderia cenocepacia is an important opportunistic pathogen, and one of the most striking features of the burkholderia genus is the collection of polar lipids present in its membrane, including phosphatidylethanolamine (pe) and ornithine-containing lipids (ols), as well as the 2-hydroxylated derivatives of pe and ols (2-oh-pe and 2-oh-ols, respectively), which differ from the standard versions by virtue of the presence of a hydroxyl group at c2 (2-oh) of an esterified fatty acyl residue. sim ...201121707055
akt-mediated proinflammatory response of mononuclear phagocytes infected with burkholderia cenocepacia occurs by a novel gsk3+¦-dependent, i+¦b kinase-independent mechanism.the environmental bacterium burkholderia cenocepacia causes opportunistic lung infections in immunocompromised individuals, particularly in patients with cystic fibrosis. infections in these patients are associated with exacerbated inflammation leading to rapid decay of lung function, and in some cases resulting in cepacia syndrome, which is characterized by a fatal acute necrotizing pneumonia and sepsis. b. cenocepacia can survive intracellularly in macrophages by altering the maturation of the ...201121697459
burkholderia cenocepacia shvr-regulated genes that influence colony morphology, biofilm formation, and virulence.burkholderia cenocepacia is an opportunistic pathogen that primarily infects cystic fibrosis (cf) patients. previously, we reported that shvr, a lysr regulator, influences colony morphology, virulence, and biofilm formation and regulates the expression of an adjacent 24-kb genomic region encoding 24 genes. in this study, we report the functional characterization of selected genes in this region. a tn5 mutant with shiny colony morphology was identified with a polar mutation in bcas0208, predicted ...201121690240
the type vi secretion system of burkholderia cenocepacia affects multiple rho family gtpases disrupting the actin cytoskeleton and the assembly of nadph oxidase complex in macrophages.burkholderia cenocepacia is a gram-negative opportunistic pathogen of patients with cystic fibrosis and chronic granulomatous disease. the bacterium survives intracellularly in macrophages within a membrane-bound vacuole (bccv) that precludes the fusion with lysosomes. the underlying cellular mechanisms and bacterial molecules mediating these phenotypes are unknown. here, we show that intracellular b. cenocepacia expressing a type vi secretion system (t6ss) affects the activation of the rac1 and ...201122023353
insertion sequences evolutionary patterns highlight convergent genetic inactivations and recent genomic islands acquisitions among epidemic burkholderia cenocepacia.the burkholderia cenocepacia b&b clone was previously found responsible of an epidemic outbreak within an intensive care unit in france. this clone belongs to the st32 clonal complex which is one of the most prevalent among french cystic fibrosis patients, and is known to be related to the highly virulent et12 clonal complex. genomic repartition biases of insertion sequences (is) were investigated to improve our understanding of the evolutionary events leading to b. cenocepacia diversification a ...201121980044
molecular approaches to pathogenesis study of burkholderia cenocepacia, an important cystic fibrosis opportunistic bacterium.burkholderia cenocepacia is a gram-negative opportunistic pathogen belonging to the burkholderia cepacia complex (bcc). it is spread in a wide range of ecological niches, and in cystic fibrosis patients, it is responsible for serious infections. its eradication is very difficult due to the high level of intrinsic resistance to clinically relevant antibiotics. one of the main resistance mechanisms in clinical isolates is represented by efflux systems that are able to extrude a variety of molecule ...201121997606
Burkholderia cenocepacia BC2L-C is a super lectin with dual specificity and proinflammatory activity.Lectins and adhesins are involved in bacterial adhesion to host tissues and mucus during early steps of infection. We report the characterization of BC2L-C, a soluble lectin from the opportunistic pathogen Burkholderia cenocepacia, which has two distinct domains with unique specificities and biological activities. The N-terminal domain is a novel TNF-a-like fucose-binding lectin, while the C-terminal part is similar to a superfamily of calcium-dependent bacterial lectins. The C-terminal domain d ...201121909279
Screening microorganisms for insulin binding reveals binding by Burkholderia multivorans and Burkholderia cenocepacia and novel attachment of insulin to Aeromonas salmonicida via the A-layer.Exposure to microorganisms is considered an environmental factor which can contribute to Type 1 diabetes. Insulin binding proteins on microorganisms may induce production of antibodies which can react with the human insulin receptor (HIR) with possible consequences in developing a diabetic autoimmune response against HIR and insulin. The interaction of insulin with microorganisms was studied by screening forty-five microbial species for their ability to bind insulin. Binding assays were performe ...201122171975
reflectron maldi tof and maldi tof/tof mass spectrometry reveal novel structural details of native lipooligosaccharides.lipooligosaccharides (los) are powerful gram-negative glycolipids that evade the immune system and invade host animal and vegetal cells. the structural elucidation of los is pivotal to understanding the mechanisms of infection at the molecular level. the amphiphilic nature of los has been the main obstacle for structural analysis by matrix-assisted laser desorption/ionization (maldi) mass spectrometry (ms). our approach has resolved this important issue and has permitted us to obtain reflectron ...201122124985
Characterization of DC1, a broad host range Bcep22-like podovirus.Bcep22-like phages are a recently described group of podoviruses that infect strains of Burkholderia cenocepacia. We have isolated and characterized a novel member of this group named DC1. This podovirus shows many genomic similarities to BcepIL02 and Bcep22, but infects strains belonging to multiple Burkholderia cepacia complex (BCC) species.201122139000
autophagy stimulation by rapamycin suppresses lung inflammation and infection by burkholderia cenocepacia in a model of cystic fibrosis.cystic fibrosis (cf) is the most common inherited lethal disease of caucasians which results in multi organ dysfunction. however, 85% of the deaths are due to pulmonary infections. infection by burkholderia cenocepacia (b. cepacia) is a particularly lethal threat to cf patients because it causes severe and persistent lung inflammation and is resistant to nearly all available antibiotics. in cftr δf508 mouse macrophages, b. cepacia persists in vacuoles that do not fuse with the lysosomes and medi ...201121997369
the antibacterial properties of docosahexaenoic omega-3 fatty acid against the cystic fibrosis multi-resistant pathogen burkholderia cenocepacia.burkholderia cepacia complex (bcc) bacteria are opportunistic pathogens that cause multiresistant pulmonary infections in cystic fibrosis (cf) patients. in this study we evaluated the in vitro antimicrobial efficacy of eight unsaturated fatty acids against burkholderia cenocepacia k56-2, a cf epidemic strain. docosahexaenoic acid (dha) was the most active compound. its action can be either bacteriostatic or bactericidal, depending upon the concentration used. the effect of dha was also evaluated ...201122150831
Bacterial cis-2-unsaturated fatty acids found in the cystic fibrosis airway modulate virulence and persistence of Pseudomonas aeruginosa.There is an increasing appreciation of the polymicrobial nature of many bacterial infections such as those associated with cystic fibrosis (CF) and of the potentially important role for interspecies interactions in influencing both bacterial virulence and response to therapy. Patients with CF are often co-infected with Pseudomonas aeruginosa and other pathogens including Burkholderia cenocepacia and Stenotrophomonas maltophilia. These latter bacteria produce signal molecules of the diffusible si ...201122134647
The CRP/FNR family protein Bcam1349 is a c-di-GMP effector that regulates biofilm formation in the respiratory pathogen Burkholderia cenocepacia.Burkholderia cenocepacia is an opportunistic respiratory pathogen that can cause severe infections in immune-compromised individuals and is associated with poor prognosis for patients suffering from cystic fibrosis. The second messenger cyclic diguanosine monophosphate (c-di-GMP) has been shown to control a wide range of functions in bacteria, but little is known about these regulatory mechanisms in B. cenocepacia. Here we investigated the role that c-di-GMP plays in the regulation of biofilm fo ...201121883527
transcriptional responses of burkholderia cenocepacia to polymyxin b in isogenic strains with diverse polymyxin b resistance phenotypes.burkholderia cenocepacia is a gram-negative opportunistic pathogen displaying high resistance to antimicrobial peptides and polymyxins. we identified mechanisms of resistance by analyzing transcriptional changes to polymyxin b treatment in three isogenic b. cenocepacia strains with diverse polymyxin b resistance phenotypes: the polymyxin b-resistant parental strain k56-2, a polymyxin b-sensitive k56-2 mutant strain with heptoseless lipopolysaccharide (lps) (rsf34), and a derivative of rsf34 (rsf ...201121955326
should cystic fibrosis patients infected with burkholderia cepacia complex be listed for lung transplantation?a best evidence topic was constructed according to a structured protocol. the question addressed was whether lung transplantation remained a beneficial treatment for cystic fibrosis (cf) patients infected or colonized with burkholderia cepacia complex (bcc) prior to lung transplantation (ltx). of the 25 papers found using a report search, five presented the best evidence to answer the clinical question. the authors, journal, date and country of publication, study type, group studied, relevant ou ...201121920934
characterization of the poly-β-1,6-n-acetylglucosamine polysaccharide component of burkholderia biofilms.we demonstrated the production of poly-β-1,6-n-acetylglucosamine (pnag) polysaccharide in the biofilms of burkholderia multivorans, burkholderia vietnamiensis, burkholderia ambifaria, burkholderia cepacia, and burkholderia cenocepacia using an immunoblot assay for pnag. these results were confirmed by further studies, which showed that the pnag hydrolase, dispersin b, eliminated immunoreactivity of extracts from the species that were tested (b. cenocepacia and b. multivorans). dispersin b also i ...201121984237
Use of 3-hydroxy fatty acid concentrations in a murine air pouch infection model as a surrogate marker for LPS activity: a feasibility study using environmental Burkholderia cenocepacia isolates.Using a murine hypodermic air pouch infection model designed to mimic the release of bacterial products at physiological levels, 3-hydroxy fatty acid (3-OH FA) and endotoxin unit levels from Burkholderia cenocepacia isolates were assessed. The B. cenocepacia environmental isolates (n=35) survived in the hypodermic air pouch but did not invade across the peritoneal epithelial layer during a 72-h infection. For all 35 strains, when the molar ratio of C(14:0) 3-OH FA to C(16:0) 3-OH FA in the air p ...201122008505
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