TitleAbstractYear(sorted descending)
the in vivo extracellular life of facultative intracellular bacterial parasites: role in pathogenesis.classically labeled facultative intracellular pathogens are characterized by the ability to have an intracellular phase in the host, which is required for pathogenicity, while capable of extracellular growth in vitro. the ability of these bacteria to replicate in cell-free conditions is usually assessed by culture in artificial bacteriological media. however, the extracellular growth ability of these pathogens may also be expressed by a phase of extracellular infection in the natural setting of ...201322795971
the suhb gene of burkholderia cenocepacia is required for protein secretion, biofilm formation, motility and polymyxin b resistance.burkholderia cenocepacia is a member of the burkholderia cepacia complex (bcc), a group of gram-negative opportunistic pathogens that cause severe lung infections in patients with cystic fibrosis and display extreme intrinsic resistance to antibiotics, including antimicrobial peptides. b. cenocepacia bcal2157 encodes a protein homologous to suhb, an inositol-1-monophosphatase from escherichia coli, which was suggested to participate in post-transcriptional control of gene expression. in this wor ...201222767545
burkholderia cenocepacia lectin a binding to heptoses from the bacterial lipopolysaccharide.bacteria from the burkholderia cepacia complex (bcc) cause highly contagious pneumonia among cystic fibrosis (cf) patients. among them, burkholderia cenocepacia is one of the most dangerous in the bcc and is the most frequent cause of morbidity and mortality in cf patients. indeed, it is responsible of "cepacia syndrome", a deadly exacerbation of infection, that is the main cause of poor outcomes in lung transplantation. burkholderia cenocepacia produces several soluble lectins with specificity ...201222763039
synthesis and evaluation of the quorum sensing inhibitory effect of substituted triazolyldihydrofuranones.acylhomoserine lactone (ahl) analogues in which the amide function is replaced by a triazole group were synthesized and evaluated for their effect on quorum sensing (qs) and biofilm formation in burkholderia cenocepacia and pseudomonas aeruginosa. in addition, the influence of the length of the acyl-mimicking chain was investigated. the compounds showed selectivity between two different ahl qs systems. 3-(1h-1,2,3-triazol-1-yl)dihydrofuran-2(3h)-ones, in which the 4-substituent best resembled th ...201222748377
aminoarabinose is essential for lipopolysaccharide export and intrinsic antimicrobial peptide resistance in burkholderia cenocepacia(†).one common mechanism of resistance against antimicrobial peptides in gram-negative bacteria is the addition of 4-amino-4-deoxy-l-arabinose (l-ara4n) to the lipopolysaccharide (lps) molecule. burkholderia cenocepacia exhibits extraordinary intrinsic resistance to antimicrobial peptides and other antibiotics. we have previously discovered that unlike other bacteria, b. cenocepacia requires l-ara4n for viability. here, we describe the isolation of b. cenocepacia suppressor mutants that remain viabl ...201222742453
interaction of environmental burkholderia cenocepacia strains with cystic fibrosis and non-cystic fibrosis bronchial epithelial cells in vitro.burkholderia cenocepacia is an important human pathogen in patients with cystic fibrosis (cf). non-clinical reservoirs may play a role in the acquisition of infection, so it is important to evaluate the pathogenic potential of environmental b. cenocepacia isolates. in this study, we investigated the interactions of two environmental b. cenocepacia strains (mex1 and mcii-168) with two bronchial epithelial cell lines, 16hbe14o(-) and cfbe41o(-), which have a non-cf and a cf phenotype, respectively ...201222322958
[mutants of burkholderia cenocepacia with a change in synthesis of n-acyl-homoserine lactones--signal molecules of quorum sensing regulation].by means of plasposon mutagenesis, mutants of burkholderia cenocepacia 370 with the change in production of n-acyl-homoserine lactones (ahl), signal molecules of the quorum sensing system of regulation, were obtained. to localize plasposon insertions in mutant strains, fragments of chromosomal dna containing plasposons were cloned, adjacent dna regions sequenced, and a search for homologous nucleotide sequences in the genebank was initiated. it has been shown that the insertion of plasposon into ...201222830256
rhodococcus sp. strain cr-53 lipr, the first member of a new bacterial lipase family (family x) displaying an unusual y-type oxyanion hole, similar to the candida antarctica lipase clan.bacterial lipases constitute the most important group of biocatalysts for synthetic organic chemistry. accordingly, there is substantial interest in developing new valuable lipases. considering the lack of information concerning the lipases of the genus rhodococcus and taking into account the interest raised by the enzymes produced by actinomycetes, a search for putative lipase-encoding genes from rhodococcus sp. strain cr-53 was performed. we isolated, cloned, purified, and characterized lipr, ...201222226953
extracellular glutathione decreases the ability of burkholderia cenocepacia to penetrate into epithelial cells and to induce an inflammatory response.the airway surface liquid (asl) of cystic fibrosis (cf) patients contains a lower concentration of reduced glutathione (gsh) with respect to healthy people. it is not known whether this defect may favor lung colonization by opportunistic pathogens.201223094061
occurrence and antibiotic susceptibility profiles of burkholderia cepacia complex in coastal marine environment.during an environmental study of bacterial resistance to antibiotics in coastal waters of the kaštela bay, adriatic sea, croatia, 47 burkholderia cepacia complex (bcc) isolates were recovered from seawater and mussel (mytilus galloprovincialis) samples. all isolates showed multiple antibiotic resistance. among the isolates, two burkholderia cenocepacia isolates produced chromosomally encoded tem-116 extended-spectrum β-lactamase (esbl). analysis of outer membrane proteins revealed that decreased ...201222428949
inhibition of bacterial biofilm formation and swarming motility by a small synthetic cationic peptide.biofilms cause up to 80% of infections and are difficult to treat due to their substantial multidrug resistance compared to their planktonic counterparts. based on the observation that human peptide ll-37 is able to block biofilm formation at concentrations below its mic, we screened for small peptides with antibiofilm activity and identified novel synthetic cationic peptide 1037 of only 9 amino acids in length. peptide 1037 had very weak antimicrobial activity, but at 1/30th the mic the peptide ...201222354291
pcr detection of burkholderia cepacia complex as one of key factors to handle a long-term outbreak.once the outbreak with burkholderia cenocepacia st32 was identified in the prague cystic fibrosis (cf) centre, molecular tools were implemented into diagnostic routine in order to complement infection control measures with as accurate as possible microbiological service. in addition, genotyping techniques were applied as part of an infection surveillance program to assign species and strain status in samples positive for burkholderia cepacia complex (bcc). we sought to evaluate a usefulness of b ...201222622026
successful treatment of cepacia syndrome with a combination of intravenous cyclosporin, antibiotics and oral corticosteroids.burkholderia cepacia complex (bcc) is a group of 17 closely related bacterial species that can cause pulmonary infection in patients with cystic fibrosis (cf). the clinical manifestations of bcc infection are varied but can include cepacia syndrome, which is a rapidly progressing necrotising pneumonia with an almost universally fatal outcome. we report the case of a 38 year old man, known to have chronic infection with the et12 strain of burkholderia cenocepacia who developed cepacia syndrome 26 ...201222551926
quorum sensing systems influence burkholderia cenocepacia virulence.burkholderia cepacia complex strains communicate using n-acyl homoserine lactones and bdsf-dependent quorum sensing (qs) systems. burkholderia cenocepacia qs systems include cepir, cciir, cepr2 and bdsf. analysis of cepr, cciir, cepr2 and rpff (bdsf synthase) qs regulons revealed that these qs systems both independently regulate and coregulate many target genes, often in an opposing manner. the role of qs and several qs-regulated genes in virulence has been determined using vertebrate, invertebr ...201223231487
structural-functional studies of burkholderia cenocepacia d-glycero-β-d-manno-heptose 7-phosphate kinase (hlda) and characterization of inhibitors with antibiotic adjuvant and antivirulence an essential constituent of the outer membrane of gram-negative bacteria, lipopolysaccharide contributes significantly to virulence and antibiotic resistance. the lipopolysaccharide biosynthetic pathway therefore serves as a promising therapeutic target for antivirulence drugs and antibiotic adjuvants. here we report the structural-functional studies of d-glycero-β-d-manno-heptose 7-phosphate kinase (hlda), an absolutely conserved enzyme in this pathway, from burkholderia cenocepacia. hlda is ...201223256532
the use of nanoscale visible light-responsive photocatalyst tio2-pt for the elimination of soil-borne pathogens.exposure to the soil-borne pathogens burkholderia pseudomallei and burkholderia cenocepacia can lead to severe infections and even mortality. these pathogens exhibit a high resistance to antibiotic treatments. in addition, no licensed vaccine is currently available. a nanoscale platinum-containing titania photocatalyst (tio(2)-pt) has been shown to have a superior visible light-responsive photocatalytic ability to degrade chemical contaminants like nitrogen oxides. the antibacterial activity of ...201222384003
global changes in gene expression by the opportunistic pathogen burkholderia cenocepacia in response to internalization by murine macrophages.burkholderia cenocepacia is an opportunistic pathogen causing life-threatening infections in patients with cystic fibrosis. the bacterium survives within macrophages by interfering with endocytic trafficking and delaying the maturation of the b. cenocepacia-containing phagosome. we hypothesize that b. cenocepacia undergoes changes in gene expression after internalization by macrophages, inducing genes involved in intracellular survival and host adaptation.201222321740
the ahl- and bdsf-dependent quorum sensing systems control specific and overlapping sets of genes in burkholderia cenocepacia h111.quorum sensing in burkholderia cenocepacia h111 involves two signalling systems that depend on different signal molecules, namely n-acyl homoserine lactones (ahls) and the diffusible signal factor cis-2-dodecenoic acid (bdsf). previous studies have shown that ahls and bdsf control similar phenotypic traits, including biofilm formation, proteolytic activity and pathogenicity. in this study we mapped the bdsf stimulon by rna-seq and shotgun proteomics analysis. we demonstrate that a set of the ide ...201223185499
the genetic basis of cadmium resistance of burkholderia cenocepacia.burkholderia species are highly resistant to heavy metals (hms), yet their resistance mechanisms are largely unknown. in this study we screened 5000 mini-tn5 transposon insertion mutants of burkholderia cenocepacia h111 for loss of cadmium tolerance. of the four genes identified three affected outer membrane biogenesis and integrity or dna repair. the fourth gene, bcae0587, encoded a p1-type atpase belonging to the cada family of hm exporters. cada-deficient strains lost the ability to grow in t ...201223760902
a luxr-type repressor of burkholderia cenocepacia inhibits transcription via antiactivation and is inactivated by its cognate acylhomoserine lactone.burkholderia cenocepacia is an opportunistic human pathogen that encodes two luxi-type acylhomoserine lactone (ahl) synthases and three luxr-type ahl receptors. of these, cepi and cepr form a cognate synthase/receptor pair, as do ccii and ccir, while cepr2 lacks a genetically linked ahl synthase gene. another group showed that a cepr2 mutant overexpressed a cluster of linked genes that appear to direct the production of a secondary metabolite. we found that these same genes were upregulated by o ...201223136852
burkholderia cenocepacia bacteremia without respiratory colonization in an adult intensive care unit: epidemiological and molecular investigation of an investigate an outbreak of burkholderia cenocepacia bacteremia. observational study and chart review in a multidisciplinary adult intensive care unit (icu) at a tertiary care hospital.201223935310
burkholderia cenocepacia type vi secretion system mediates escape of type ii secreted proteins into the cytoplasm of infected macrophages.burkholderia cenocepacia is an opportunistic pathogen that survives intracellularly in macrophages and causes serious respiratory infections in patients with cystic fibrosis. we have previously shown that bacterial survival occurs in bacteria-containing membrane vacuoles (bccvs) resembling arrested autophagosomes. intracellular bacteria stimulate il-1β secretion in a caspase-1-dependent manner and induce dramatic changes to the actin cytoskeleton and the assembly of the nadph oxidase complex ont ...201222848580
a bcam0223 mutant of burkholderia cenocepacia is deficient in hemagglutination, serum resistance, adhesion to epithelial cells and virulence.burkholderia cepacia complex (bcc) bacteria are a problematic group of microorganisms causing severe infections in patients with cystic fibrosis. in early stages of infection, bcc bacteria must be able to adhere to and colonize the respiratory epithelium. although this is not fully understood, this primary stage of infection is believed to be in part mediated by a specific type of adhesins, named trimeric autotransporter adhesins (taas). these homotrimeric proteins exist on the surface of many g ...201222848588
identification of functions linking quorum sensing with biofilm formation in burkholderia cenocepacia h111.burkholderia cenocepacia has emerged as an important pathogen for patients suffering from cystic fibrosis (cf). previous work has shown that this organism employs the cepir quorum-sensing (qs) system to control the expression of virulence factors as well as the formation of biofilms. to date, however, very little is known about the qs-regulated virulence factors and virtually nothing about the factors that link qs and biofilm formation. here, we have employed a combined transcriptomic and proteo ...201222950027
a unique regulator contributes to quorum sensing and virulence in burkholderia cenocepacia.burkholderia cenocepacia causes chronic and life-threatening respiratory infections in immunocompromized people. the b. cenocepacia n-acyl-homoserine lactone (ahl)-dependent quorum sensing system relies on the production of ahls by the synthases cepi and ccii while cepr, ccir and cepr2 control expression of many genes important for pathogenesis. downstream from, and co-transcribed with cepi, lies bcam1871 encoding a hypothetical protein that was uncharacterized prior to this study. orthologs of ...201222624054
tangled bank of experimentally evolved burkholderia biofilms reflects selection during chronic diversity evolves and persists in biofilms is essential for understanding much of microbial life, including the uncertain dynamics of chronic infections. we developed a biofilm model enabling long-term selection for daily adherence to and dispersal from a plastic bead in a test tube. focusing on a pathogen of the cystic fibrosis lung, burkholderia cenocepacia, we sequenced clones and metagenomes to unravel the mutations and evolutionary forces responsible for adaptation and diversification o ...201223271804
the exopolysaccharide gene cluster bcam1330-bcam1341 is involved in burkholderia cenocepacia biofilm formation, and its expression is regulated by c-di-gmp and burkholderia cenocepacia, the second messenger cyclic diguanosine monophosphate (c-di-gmp) has previously been shown to positively regulate biofilm formation and the expression of cellulose and type-i fimbriae genes through binding to the transcriptional regulator bcam1349. here, we provide evidence that cellulose and type-i fimbriae are not involved in b. cenocepacia biofilm formation in flow chambers, and we identify a novel bcam1349/c-di-gmp-regulated exopolysaccharide gene cluster which i ...201223281338
high confidence prediction of essential genes in burkholderia cenocepacia.essential genes are absolutely required for the survival of an organism. the identification of essential genes, besides being one of the most fundamental questions in biology, is also of interest for the emerging science of synthetic biology and for the development of novel antimicrobials. new antimicrobial therapies are desperately needed to treat multidrug-resistant pathogens, such as members of the burkholderia cepacia complex.201222768221
exaggerated inflammatory responses mediated by burkholderia cenocepacia in human macrophages derived from cystic fibrosis patients.cystic fibrosis (cf) is accompanied with heightened inflammation worsened by drug resistant burkholderia cenocepacia. human cf macrophage responses to b. cenocepacia are poorly characterized and variable in the literature. therefore, we examined human macrophage responses to the epidemic b. cenocepacia j2315 strain in order to identify novel anti-inflammatory targets. peripheral blood monocyte derived macrophages were obtained from 23 cf and 27 non-cf donors. macrophages were infected with b. ce ...201222728038
modelling co-infection of the cystic fibrosis lung by pseudomonas aeruginosa and burkholderia cenocepacia reveals influences on biofilm formation and host response.the gram-negative bacteria pseudomonas aeruginosa and burkholderia cenocepacia are opportunistic human pathogens that are responsible for severe nosocomial infections in immunocompromised patients and those suffering from cystic fibrosis (cf). these two bacteria have been shown to form biofilms in the airways of cf patients that make such infections more difficult to treat. only recently have scientists begun to appreciate the complicated interplay between microorganisms during polymicrobial inf ...201223284990
activation of the pyrin inflammasome by intracellular burkholderia cenocepacia.burkholderia cenocepacia is an opportunistic pathogen that causes chronic infection and induces progressive respiratory inflammation in cystic fibrosis patients. recognition of bacteria by mononuclear cells generally results in the activation of caspase-1 and processing of il-1β, a major proinflammatory cytokine. in this study, we report that human pyrin is required to detect intracellular b. cenocepacia leading to il-1β processing and release. this inflammatory response involves the host adapte ...201222368275
cis-2-dodecenoic acid receptor rpfr links quorum-sensing signal perception with regulation of virulence through cyclic dimeric guanosine monophosphate turnover.many bacterial pathogens produce diffusible signal factor (dsf)-type quorum sensing (qs) signals in modulation of virulence and biofilm formation. previous work on xanthomonas campestris showed that the rpfc/rpfg two-component system is involved in sensing and responding to dsf signals, but little is known in other microorganisms. here we show that in burkholderia cenocepacia the dsf-family signal cis-2-dodecenoic acid (bdsf) negatively controls the intracellular cyclic dimeric guanosine monopho ...201222949660
genome-scale ncrna homology search using a hamming distance-based filtration strategy.ncrnas (noncoding rnas) play important roles in many biological processes. existing genome-scale ncrna search tools identify ncrnas in local sequence alignments generated by conventional sequence comparison methods. however, some types of ncrna lack strong sequence conservation and tend to be missed or mis-aligned by conventional sequence comparison.201222536896
the novel cis-encoded small rna h2cr is a negative regulator of hfq2 in burkholderia cenocepacia.small non-coding regulatory rnas (srnas) post-transcriptionally affect multiple phenotypes in prokaryotes and eukaryotes, yet most of the underlying regulatory mechanisms and the nature of the target mrnas remain unclear. here we report the identification and functional analysis of the novel cis-encoded srna h2cr, from the human opportunistic pathogen burkholderia cenocepacia j2315. the srna was found to negatively regulate the hfq2 mrna, through binding to part of the 5'-utr region of the hfq2 ...201223082228
the burkholderia cenocepacia bdsf quorum sensing fatty acid is synthesized by a bifunctional crotonase homologue having both dehydratase and thioesterase activities.signal molecules of the diffusible signal factor (dsf) family have been shown recently to be involved in regulation of pathogenesis and biofilm formation in diverse gram-negative bacteria. dsf signals are reported to be active not only on their cognate bacteria, but also on unrelated bacteria and the pathogenic yeast, candida albicans. dsfs are monounsaturated fatty acids of medium chain length containing an unusual cis-2 double bond. although genetic analyses had identified genes involved in ds ...201222221091
comparative analysis of two phenotypically-similar but genomically-distinct burkholderia cenocepacia-specific bacteriophages.genomic analysis of bacteriophages infecting the burkholderia cepacia complex (bcc) is an important preliminary step in the development of a phage therapy protocol for these opportunistic pathogens. the objective of this study was to characterize kl1 (vb_bces_kl1) and ah2 (vb_bces_ah2), two novel burkholderia cenocepacia-specific siphoviruses isolated from environmental samples.201222676492
expression of phenazine biosynthetic genes during the arbuscular mycorrhizal symbiosis of glomus explore the molecular mechanisms that prevail during the establishment of the arbuscular mycorrhiza symbiosis involving the genus glomus, we transcriptionally analysed spores of glomus intraradices be3 during early hyphal growth. among 458 transcripts initially identified as being expressed at presymbiotic stages, 20% of sequences had homology to previously characterized eukaryotic genes, 30% were homologous to fungal coding sequences, and 9% showed homology to previously characterized bacter ...201224031884
agrobacteria lacking ornithine lipids induce more rapid tumour formation.ornithine lipids (ols) are phosphorus-free membrane lipids that are widespread among gram-negative bacteria. their basic structure consists of a 3-hydroxy fatty acyl group attached in amide linkage to the α-amino group of ornithine and a second fatty acyl group ester-linked to the 3-hydroxy position of the first fatty acid. it has been shown that ols can be hydroxylated within the amide-linked fatty acyl moiety, the secondary fatty acyl moiety or within the ornithine moiety. these modifications ...201222958119
centromere binding and evolution of chromosomal partition systems in the split genomes arise and evolve in bacteria is poorly understood. since each replicon of such genomes encodes a specific partition (par) system, the evolution of par systems could shed light on their evolution. the cystic fibrosis pathogen burkholderia cenocepacia has three chromosomes (c1, c2, and c3) and one plasmid (pbc), whose compatibility depends on strictly specific interactions of the centromere sequences (pars) with their cognate binding proteins (parb). however, the par systems of b ...201222522899
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
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
can early burkholderia cepacia complex infection in cystic fibrosis be eradicated with antibiotic therapy?organisms of the burkholderia cepacia complex (bcc) are important pathogens in cystic fibrosis (cf). the majority of those who acquire bcc develop chronic infection but it can also result in rapid decline in a significant minority. in addition, chronic infection with burkholderia cenocepacia in particular is regarded as a contraindication to lung transplantation in many units. whilst aggressive antibiotic therapy is employed in cf to eradicate pseudomonas aeruginosa before infection becomes irre ...201122919584
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
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
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
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
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
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
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
genetic relationships among italian and mexican maize-rhizosphere burkholderia cepacia complex (bcc) populations belonging to burkholderia cenocepacia iiib and bcc6 group.abstract:201121995705
differences in strategies to combat osmotic stress in burkholderia cenocepacia elucidated by nmr-based metabolic 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
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
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
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
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
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
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
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 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
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
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
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
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
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
crystal structures of burkholderia cenocepacia dihydropteroate synthase in the apo-form and complexed with the product 7,8-dihydropteroate.abstract:201121554707
the quorum-sensing molecules farnesol/homoserine lactone and dodecanol operate via distinct modes of action in candida 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
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
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
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
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
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
hopanoid production is required for low-ph tolerance, antimicrobial resistance, and motility in burkholderia cenocepacia.hopanoids are pentacyclic triterpenoids that are thought to be bacterial surrogates for eukaryotic sterols, such as cholesterol, acting to stabilize membranes and to regulate their fluidity and permeability. to date, very few studies have evaluated the role of hopanoids in bacterial physiology. the synthesis of hopanoids depends on the enzyme squalene-hopene cyclase (shc), which converts the linear squalene into the basic hopene structure. deletion of the 2 genes encoding shc enzymes in burkhold ...201121965564
burkholderia cenocepacia differential gene expression during host-pathogen interactions and adaptation to the host environment.members of the burkholderia cepacia complex (bcc) are important in medical, biotechnological, and agricultural disciplines. these bacteria naturally occur in soil and water environments and have adapted to survive in association with plants and animals including humans. all bcc species are opportunistic pathogens including burkholderia cenocepacia that causes infections in cystic fibrosis and chronic granulomatous disease patients. the adaptation of b. cenocepacia to the host environment was ass ...201122919581
long-term colonization of the cystic fibrosis lung by burkholderia cepacia complex bacteria: epidemiology, clonal variation, and genome-wide expression alterations.long-term respiratory infections with burkholderia cepacia complex (bcc) bacteria in cystic fibrosis (cf) patients generally lead to a more rapid decline in lung function and, in some cases, to a fatal necrotizing pneumonia known as the "cepacia syndrome." bcc bacteria are ubiquitous in the environment and are recognized as serious opportunistic pathogens that are virtually impossible to eradicate from the cf lung, posing a serious clinical threat. the epidemiological survey of bcc bacteria invo ...201122919578
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
3-hydroxyphenylacetic acid induces the burkholderia cenocepacia phenylacetic acid degradation pathway - toward understanding the contribution of aromatic catabolism to pathogenesis.the phenylacetic acid (pa) degradative pathway is the central pathway by which various aromatic compounds (e.g., styrene) are degraded. upper pathways for different aromatic compounds converge at common intermediate phenylacetyl-coa (pa-coa), which is then metabolized to succinyl-coa and acetyl-coa. we previously made a link in burkholderia cenocepacia between pa degradation and virulence by showing that insertional mutagenesis of paaa and paae genes, that encode part of a multicomponent oxidase ...201122919580
Burkholderia cenocepacia disrupts host cell actin cytoskeleton by inactivating Rac and Cdc42.Burkholderia cenocepacia, a member of the Burkholderia cepacia complex, is an opportunistic pathogen that causes devastating infections in patients with cystic fibrosis. The ability of B. cenocepacia to survive within host cells could contribute significantly to its virulence in immunocompromised patients. In this study, we explored the mechanisms that enable B. cenocepacia to survive inside macrophages. We found that B. cenocepacia disrupts the actin cytoskeleton of infected macrophages, drast ...201122023324
genomic expression analysis reveals strategies of burkholderia cenocepacia to adapt to cystic fibrosis patients' airways and antimicrobial therapy.pulmonary colonization of cystic fibrosis (cf) patients with burkholderia cenocepacia or other bacteria of the burkholderia cepacia complex (bcc) is associated with worse prognosis and increased risk of death. during colonization, the bacteria may evolve under the stressing selection pressures exerted in the cf lung, in particular, those resulting from challenges of the host immune defenses, antimicrobial therapy, nutrient availability and oxygen limitation. understanding the adaptive mechanisms ...201122216120
host evasion by burkholderia cenocepacia.burkholderia cenocepacia is an opportunistic respiratory pathogen of individuals with cystic fibrosis (cf). some strains of b. cenocepacia are highly transmissible and resistant to almost all antibiotics. approximately one-third of b. cenocepacia infected cf patients go on to develop fatal "cepacia syndrome." during the last two decades, substantial progress has been made with regards to evasion of host innate defense mechanisms by b. cenocepacia. almost all strains of b. cenocepacia have the ca ...201122919590
a two-tier model of polymyxin b resistance in burkholderia cenocepacia.burkholderia cenocepacia is an environmental bacterium causing serious human opportunistic infections and is extremely resistant to multiple antibiotics including antimicrobial peptides, such as polymyxin b (pmb). extreme antibiotic resistance is attributed to outer membrane impermeability ('intrinsic' resistance). previous work showed that production of full-length lipopolysaccharide (lps) prevents surface binding of pmb. we hypothesized that two tiers of resistance mechanisms rendering differe ...201123761261
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
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
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
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
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
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
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