scholarly journals Distribution and genomic location of active insertion sequences in the Burkholderia cepacia complex

2006 ◽  
Vol 55 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Dervla T. Kenna ◽  
Hasan Yesilkaya ◽  
Ken J. Forbes ◽  
Victoria A. Barcus ◽  
Peter Vandamme ◽  
...  
Keyword(s):  
Burkholderia Cepacia ◽  
Insertion Site ◽  
Gene Activation ◽  
Burkholderia Cenocepacia ◽  
Burkholderia Cepacia Complex ◽  
Inverse Pcr ◽  
Insertion Sequences ◽  
Complex Species ◽  
Burkholderia Vietnamiensis ◽  
Abundance And Distribution

This study aimed firstly to establish the distribution and copy number within the Burkholderia cepacia complex of three insertion sequences (IS402, IS407 and IS1416) that possess the ability to activate transcription and hence influence gene expression. A second aim was to map the genomic insertion sites of one of the active insertion sequences (IS407) to establish putative links between insertion site and downstream gene activation. The resulting data revealed that all three insertion sequences were present in one-third of the 66 isolates tested. The three insertion sequences were prevalent across the nine B. cepacia complex species, although IS402 was absent from the 16 Burkholderia anthina strains tested and IS407 was absent from all 10 Burkholderia pyrrocinia strains. IS407 copies from six strains (two Burkholderia cenocepacia strains and one strain each of Burkholderia multivorans, Burkholderia stabilis, Burkholderia vietnamiensis and B. anthina) were mapped to the genome using hemi-nested inverse PCR. Insertions were found upstream of genes with wide-ranging functions. This study suggests that the abundance and distribution of these active insertion sequences is likely to affect genomic plasticity, and potentially gene transcription and pathogenicity.

Epidemiology of Burkholderia cepacia complex species recovered from cystic fibrosis patients: issues related to patient segregation

2004 ◽  
Vol 53 (7) ◽  
pp. 663-668 ◽  
Author(s):  
Andrew McDowell ◽  
Eshwar Mahenthiralingam ◽  
Kerstin E.A. Dunbar ◽  
John E. Moore ◽  
Mary Crowe ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Burkholderia Cepacia ◽  
Cross Infection ◽  
Burkholderia Cenocepacia ◽  
Burkholderia Cepacia Complex ◽  
Complex Species ◽  
Burkholderia Multivorans ◽  
Burkholderia Vietnamiensis ◽  
Random Amplification ◽  
Geographical Regions

Studies of the prevalence of Burkholderia cepacia complex species amongst cystic fibrosis (CF) patients in different geographical regions, and the association between cross-infection and putative transmissibility markers, will further our understanding of these organisms and help to address infection-control issues. In this study, B. cepacia complex isolates from CF patients in different regions of Europe were analysed. Isolates were examined for B. cepacia complex species and putative transmissibility markers [cable pilin subunit gene (cblA) and the B. cepacia epidemic strain marker (BCESM)]. Sporadic and cross-infective strains were identified by random amplification of polymorphic DNA (RAPD). In total, 79 % of patients were infected with Burkholderia cenocepacia (genomovar III), 18 % with Burkholderia multivorans (genomovar II) and less than 5 % of patients with B. cepacia (genomovar I), Burkholderia stabilis (genomovar IV) or Burkholderia vietnamiensis (genomovar V). The cblA and BCESM transmissibility markers were only detected in strains of B. cenocepacia. The BCESM was a more sensitive marker for transmissible B. cenocepacia strains than cblA, although sporadic B. cenocepacia strains containing the BCESM, but lacking cblA, were also observed. Furthermore, clusters of cross-infection with transmissibility marker-negative strains of B. multivorans were identified. In conclusion, B. cenocepacia was the greatest cause of cross-infection, and the most widely distributed B. cepacia complex species, within these CF populations. However, cross-infection was not exclusive to B. cenocepacia and cblA and the BCESM were not absolute markers for transmissible B. cenocepacia, or other B. cepacia complex strains. It is therefore suggested that CF centres cohort patients based on the presence or absence of B. cepacia complex infection and not on the basis of transmissibility marker-positive B. cenocepacia as previously suggested.

scholarly journals Activity of Tobramycin against Cystic Fibrosis Isolates of Burkholderia cepacia Complex Grown as Biofilms

2015 ◽  
Vol 60 (1) ◽  
pp. 348-355 ◽  
Author(s):  
Sarah Kennedy ◽  
Trevor Beaudoin ◽  
Yvonne C. W. Yau ◽  
Emma Caraher ◽  
James E. A. Zlosnik ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Burkholderia Cepacia ◽  
Burkholderia Cenocepacia ◽  
Burkholderia Cepacia Complex ◽  
Suppressive Therapy ◽  
High Dose ◽  
Lung Function Decline ◽  
Complex Species ◽  
Content Type ◽  
Biofilm Thickness

ABSTRACTPulmonary infection withBurkholderia cepaciacomplex in cystic fibrosis (CF) patients is associated with more-rapid lung function decline and earlier death than in CF patients without this infection. In this study, we used confocal microscopy to visualize the effects of various concentrations of tobramycin, achievable with systemic and aerosolized drug administration, on matureB. cepaciacomplex biofilms, both in the presence and absence of CF sputum. After 24 h of growth, biofilm thickness was significantly reduced by exposure to 2,000 μg/ml of tobramycin forBurkholderia cepacia,Burkholderia multivorans, andBurkholderia vietnamiensis; 200 μg/ml of tobramycin was sufficient to reduce the thickness ofBurkholderia dolosabiofilm. With a more mature 48-h biofilm, significant reductions in thickness were seen with tobramycin at concentrations of ≥100 μg/ml for allBurkholderiaspecies. In addition, an increased ratio of dead to live cells was observed in comparison to control with tobramycin concentrations of ≥200 μg/ml forB. cepaciaandB. dolosa(24 h) and ≥100 μg/ml forBurkholderia cenocepaciaandB. dolosa(48 h). Although sputum significantly increased biofilm thickness, tobramycin concentrations of 1,000 μg/ml were still able to significantly reduce biofilm thickness of allB. cepaciacomplex species with the exception ofB. vietnamiensis. In the presence of sputum, 1,000 μg/ml of tobramycin significantly increased the dead-to-live ratio only forB. multivoranscompared to control. In summary, although killing is attenuated, high-dose tobramycin can effectively decrease the thickness ofB. cepaciacomplex biofilms, even in the presence of sputum, suggesting a possible role as a suppressive therapy in CF.

scholarly journals Evaluation of the electron transfer flavoprotein as an antibacterial target in Burkholderia cenocepacia

2017 ◽  
Vol 63 (10) ◽  
pp. 857-863 ◽  
Author(s):  
Maria S. Stietz ◽  
Christina Lopez ◽  
Osasumwen Osifo ◽  
Marcelo E. Tolmasky ◽  
Silvia T. Cardona
Keyword(s):  
Electron Transfer ◽  
Burkholderia Cepacia ◽  
Multidrug Resistant ◽  
Burkholderia Cenocepacia ◽  
Burkholderia Cepacia Complex ◽  
Infection Model ◽  
Electron Transfer Flavoprotein ◽  
C Elegans

There are hundreds of essential genes in multidrug-resistant bacterial genomes, but only a few of their products are exploited as antibacterial targets. An example is the electron transfer flavoprotein (ETF), which is required for growth and viability in Burkholderia cenocepacia. Here, we evaluated ETF as an antibiotic target for Burkholderia cepacia complex (Bcc). Depletion of the bacterial ETF during infection of Caenorhabditis elegans significantly extended survival of the nematodes, proving that ETF is essential for survival of B. cenocepacia in this host model. In spite of the arrest in respiration in ETF mutants, the inhibition of etf expression did not increase the formation of persister cells, when treated with high doses of ciprofloxacin or meropenem. To test if etf translation could be inhibited by RNA interference, antisense oligonucleotides that target the etfBA operon were synthesized. One antisense oligonucleotide was effective in inhibiting etfB translation in vitro but not in vivo, highlighting the challenge of reduced membrane permeability for the design of drugs against B. cenocepacia. This work contributes to the validation of ETF of B. cenocepacia as a target for antibacterial therapy and demonstrates the utility of a C. elegans liquid killing assay to validate gene essentiality in an in vivo infection model.

scholarly journals Conservation of resistance nodulation cell division efflux pump mediated antibiotic resistance in Burkholderia cepacia complex and Burkholderia pseudomallei complex species

2021 ◽  
Author(s):  
Nawarat Somprasong ◽  
Jinhee Yi ◽  
Carina M. Hall ◽  
Jessica R. Webb ◽  
Jason W. Sahl ◽  
...  
Keyword(s):  
Cell Division ◽  
Burkholderia Cepacia ◽  
Burkholderia Pseudomallei ◽  
Efflux Pump ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Burkholderia Cepacia Complex ◽  
Complex Species ◽  
Functional Studies ◽  
Rnd Efflux Pump

Burkholderia cepacia complex (Bcc) and Burkholderia pseudomallei complex (Bpc) species include pathogens that are typically multidrug resistant. Dominant intrinsic and acquired multidrug resistance mechanisms are efflux mediated by pumps of the resistance nodulation cell division (RND) family. From comparative bioinformatic and, in many instances, functional studies we infer that RND pump-based resistance mechanisms are conserved in Burkholderia . We propose to use these findings as a foundation for adoption of a uniform RND efflux pump nomenclature.

scholarly journals Intracellular survival ofBurkholderia cepaciacomplex in phagocytic cells

2015 ◽  
Vol 61 (9) ◽  
pp. 607-615 ◽  
Author(s):  
Miguel A. Valvano
Keyword(s):  
Burkholderia Cepacia ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Genetic Manipulation ◽  
Intracellular Survival ◽  
Burkholderia Cenocepacia ◽  
Burkholderia Cepacia Complex ◽  
Host Responses ◽  
Current View ◽  
Phagocytic Cells

Burkholderia cepacia complex (Bcc) species are a group of Gram-negative opportunistic pathogens that infect the airways of cystic fibrosis patients, and occasionally they infect other immunocompromised patients. Bcc bacteria display high-level multidrug resistance and chronically persist in the infected host while eliciting robust inflammatory responses. Studies using macrophages, neutrophils, and dendritic cells, combined with advances in the genetic manipulation of these bacteria, have increased our understanding of the molecular mechanisms of virulence in these pathogens and the molecular details of cell-host responses triggering inflammation. This article discusses our current view of the intracellular survival of Burkholderia cenocepacia within macrophages.

scholarly journals In Vitro Activity of a Novel Glycopolymer against Biofilms of Burkholderia cepacia Complex Cystic Fibrosis Clinical Isolates

2019 ◽  
Vol 63 (6) ◽  
Author(s):  
Vidya P. Narayanaswamy ◽  
Andrew P. Duncan ◽  
John J. LiPuma ◽  
William P. Wiesmann ◽  
Shenda M. Baker ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Burkholderia Cepacia ◽  
Laser Scanning Microscopy ◽  
Burkholderia Cenocepacia ◽  
Burkholderia Cepacia Complex ◽  
Confocal Laser ◽  
Content Type ◽  
Biofilm Removal ◽  
Increased Risk

ABSTRACT Burkholderia cepacia complex (Bcc) lung infections in cystic fibrosis (CF) patients are often associated with a steady decline in lung function and death. The formation of biofilms and inherent multidrug resistance are virulence factors associated with Bcc infection and contribute to increased risk of mortality in CF patients. New therapeutic strategies targeting bacterial biofilms are anticipated to enhance antibiotic penetration and facilitate resolution of infection. Poly (acetyl, arginyl) glucosamine (PAAG) is a cationic glycopolymer therapeutic being developed to directly target biofilm integrity. In this study, 13 isolates from 7 species were examined, including Burkholderia multivorans, Burkholderia cenocepacia, Burkholderia gladioli, Burkholderia dolosa, Burkholderia vietnamiensis, and B. cepacia. These isolates were selected for their resistance to standard clinical antibiotics and their ability to form biofilms in vitro. Biofilm biomass was quantitated using static tissue culture plate (TCP) biofilm methods and a minimum biofilm eradication concentration (MBEC) assay. Confocal laser scanning microscopy (CLSM) visualized biofilm removal by PAAG during treatment. Both TCP and MBEC methods demonstrated a significant dose-dependent relationship with regard to biofilm removal by 50 to 200 μg/ml PAAG following a 1-h treatment (P < 0.01). A significant reduction in biofilm thickness was observed following a 10-min treatment of Bcc biofilms with PAAG compared to that with vehicle control (P < 0.001) in TCP, MBEC, and CLSM analyses. PAAG also rapidly permeabilizes bacteria within the first 10 min of treatment. Glycopolymers, such as PAAG, are a new class of large-molecule therapeutics that support the treatment of recalcitrant Bcc biofilm.

scholarly journals Draft Genome of Burkholderia cenocepacia TAtl-371, a Strain from the Burkholderia cepacia Complex Retains Antagonism in Different Carbon and Nitrogen Sources

2019 ◽  
Vol 76 (5) ◽  
pp. 566-574 ◽  
Author(s):  
Fernando Uriel Rojas-Rojas ◽  
David Sánchez-López ◽  
Erika Yanet Tapia-García ◽  
Ivan Arroyo-Herrera ◽  
Maskit Maymon ◽  
...  
Keyword(s):  
Burkholderia Cepacia ◽  
Draft Genome ◽  
Nitrogen Sources ◽  
Burkholderia Cenocepacia ◽  
Burkholderia Cepacia Complex ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen

scholarly journals Identification of Burkholderia cepacia complex pathogens by rapid-cycle PCR with fluorescent hybridization probes

2006 ◽  
Vol 55 (6) ◽  
pp. 721-727 ◽  
Author(s):  
Ralf-Peter Vonberg ◽  
Susanne Häußler ◽  
Peter Vandamme ◽  
Ivo Steinmetz
Keyword(s):  
Burkholderia Cepacia ◽  
Melting Curve ◽  
Resonance Energy ◽  
Burkholderia Cenocepacia ◽  
Burkholderia Cepacia Complex ◽  
Melting Curve Analysis ◽  
Identification System ◽  
Fluorescence Signal ◽  
Pathogenic Potential ◽  
Specific Fluorescence

Members of the Burkholderia cepacia complex are important bacterial pathogens in cystic fibrosis (CF) patients. The B. cepacia complex currently consists of nine genetic subgroups (genomovars) of different epidemiological relevance and possibly of different pathogenic potential in humans. In this study, a new approach was developed for the rapid identification of B. cepacia genomovar I, Burkholderia multivorans (genomovar II), Burkholderia cenocepacia (lineage III-A and III-B), Burkholderia stabilis (genomovar IV) and Burkholderia vietnamiensis (genomovar V), which cause the large majority of infections in CF patients. The method was based on the detection of differences in the recA gene sequence by using rapid-cycle PCR and genomovar-specific fluorescence resonance energy transfer (FRET) probes. The genomovar status of all 39 B. cepacia complex strains tested (genomovars I–V) was identified by melting-curve analysis. Each FRET probe produced a specific fluorescence signal only with the respective genomovar, and not with other B. cepacia complex strains and Burkholderia spp. The identification system was easy to handle and revealed B. cepacia complex genomovar I–V status from culture isolates within about 1 h.

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