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Sample records for burkholderia infection depends

  1. Characterization of in vitro phenotypes of Burkholderia pseudomallei and Burkholderia mallei strains potentially associated with persistent infection in mice.

    Science.gov (United States)

    Bernhards, R C; Cote, C K; Amemiya, K; Waag, D M; Klimko, C P; Worsham, P L; Welkos, S L

    2017-03-01

    Burkholderia pseudomallei (Bp) and Burkholderia mallei (Bm), the agents of melioidosis and glanders, respectively, are Tier 1 biothreats. They infect humans and animals, causing disease ranging from acute and fatal to protracted and chronic. Chronic infections are especially challenging to treat, and the identification of in vitro phenotypic markers which signal progression from acute to persistent infection would be extremely valuable. First, a phenotyping strategy was developed employing colony morphotyping, chemical sensitivity testing, macrophage infection, and lipopolysaccharide fingerprint analyses to distinguish Burkholderia strains. Then mouse spleen isolates collected 3-180 days after infection were characterized phenotypically. Isolates from long-term infections often exhibited increased colony morphology differences and altered patterns of antimicrobial sensitivity and macrophage infection. Some of the Bp and Bm persistent infection isolates clearly displayed enhanced virulence in mice. Future studies will evaluate the potential role and significance of these phenotypic markers in signaling the establishment of a chronic infection.

  2. Burkholderia species infections in patients with cystic fibrosis in British Columbia, Canada. 30 years' experience.

    Science.gov (United States)

    Zlosnik, James E A; Zhou, Guohai; Brant, Rollin; Henry, Deborah A; Hird, Trevor J; Mahenthiralingam, Eshwar; Chilvers, Mark A; Wilcox, Pearce; Speert, David P

    2015-01-01

    We have been collecting Burkholderia species bacteria from patients with cystic fibrosis (CF) for the last 30 years. During this time, our understanding of their multispecies taxonomy and infection control has evolved substantially. To evaluate the long-term (30 year) epidemiology and clinical outcome of Burkholderia infection in CF, and fully define the risks associated with infection by each species. Isolates from Burkholderia-positive patients (n=107) were speciated and typed annually for each infected patient. Microbiological and clinical data were evaluated by thorough review of patient charts, and statistical analyses performed to define significant epidemiological factors. Before 1995, the majority of new Burkholderia infections were caused by epidemic clones of Burkholderia cenocepacia. After implementation of new infection control measures in 1995, Burkholderia multivorans became the most prevalent species. Survival analysis showed that patients with CF infected with B. cenocepacia had a significantly worse outcome than those with B. multivorans, and a novel finding was that, after Burkholderia infection, the prognosis for females was significantly worse than for males. B. multivorans and B. cenocepacia have been the predominant Burkholderia species infecting people with CF in Vancouver. The implementation of infection control measures were successful in preventing new acquisition of epidemic strains of B. cenocepacia, leaving nonclonal B. multivorans as the most prevalent species. Historically, survival after infection with B. cenocepacia has been significantly worse than B. multivorans infection, and, of new significance, we show that females tend toward worse clinical outcomes.

  3. Human Infection with Burkholderia thailandensis, China, 2013.

    Science.gov (United States)

    Chang, Kai; Luo, Jie; Xu, Huan; Li, Min; Zhang, Fengling; Li, Jin; Gu, Dayong; Deng, Shaoli; Chen, Ming; Lu, Weiping

    2017-08-01

    Burkholderia thailandensis infection in humans is uncommon. We describe a case of B. thailandensis infection in a person in China, a location heretofore unknown for B. thailandensis. We identified the specific virulence factors of B. thailandensis, which may indicate a transition to a new virulent form.

  4. Recurrent urinary tract infection by burkholderia cepacia in a live related renal transplant recipient

    International Nuclear Information System (INIS)

    Zeshan, M.

    2012-01-01

    Burkholderia cepacia is high virulent organism usually causing lower respiratory tract infections especially in Cystic fibrosis (CF) patients and post lung transplant. Urinary tract infections with Burkholderia cepacia have been associated after bladder irrigation or use of contaminated hospital objects. Post renal transplant urinary tract infection (UTI) is the most common infectious complications. Recurrent urinary tract infection with Burkholderia cepacia is a rare finding. Complete anatomical evaluation is essential in case recurrent urinary tract infections (UTI) after renal transplant. Vesico-ureteric reflux (VUR) and neurogenic urinary bladder was found to be important risk factors. (author)

  5. An ensemble of structures of Burkholderia pseudomallei 2,3-bisphosphoglycerate-dependent phosphoglycerate mutase

    Energy Technology Data Exchange (ETDEWEB)

    Davies, Douglas R.; Staker, Bart L.; Abendroth, Jan A.; Edwards, Thomas E.; Hartley, Robert; Leonard, Jess; Kim, Hidong; Rychel, Amanda L.; Hewitt, Stephen N.; Myler, Peter J.; Stewart, Lance J. (UWASH); (Emerald)

    2011-12-07

    Burkholderia pseudomallei is a soil-dwelling bacterium endemic to Southeast Asia and Northern Australia. Burkholderia is responsible for melioidosis, a serious infection of the skin. The enzyme 2,3-bisphosphoglycerate-dependent phosphoglycerate mutase (PGAM) catalyzes the interconversion of 3-phosphoglycerate and 2-phosphoglycerate, a key step in the glycolytic pathway. As such it is an extensively studied enzyme and X-ray crystal structures of PGAM enzymes from multiple species have been elucidated. Vanadate is a phosphate mimic that is a powerful tool for studying enzymatic mechanisms in phosphoryl-transfer enzymes such as phosphoglycerate mutase. However, to date no X-ray crystal structures of phosphoglycerate mutase have been solved with vanadate acting as a substrate mimic. Here, two vanadate complexes together with an ensemble of substrate and fragment-bound structures that provide a comprehensive picture of the function of the Burkholderia enzyme are reported.

  6. Caspase-1-dependent and -independent cell death pathways in Burkholderia pseudomallei infection of macrophages.

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    Antje Bast

    2014-03-01

    Full Text Available The cytosolic pathogen Burkholderia pseudomallei and causative agent of melioidosis has been shown to regulate IL-1β and IL-18 production through NOD-like receptor NLRP3 and pyroptosis via NLRC4. Downstream signalling pathways of those receptors and other cell death mechanisms induced during B. pseudomallei infection have not been addressed so far in detail. Furthermore, the role of B. pseudomallei factors in inflammasome activation is still ill defined. In the present study we show that caspase-1 processing and pyroptosis is exclusively dependent on NLRC4, but not on NLRP3 in the early phase of macrophage infection, whereas at later time points caspase-1 activation and cell death is NLRC4- independent. In the early phase we identified an activation pathway involving caspases-9, -7 and PARP downstream of NLRC4 and caspase-1. Analyses of caspase-1/11-deficient infected macrophages revealed a strong induction of apoptosis, which is dependent on activation of apoptotic initiator and effector caspases. The early activation pathway of caspase-1 in macrophages was markedly reduced or completely abolished after infection with a B. pseudomallei flagellin FliC or a T3SS3 BsaU mutant. Studies using cells transfected with the wild-type and mutated T3SS3 effector protein BopE indicated also a role of this protein in caspase-1 processing. A T3SS3 inner rod protein BsaK mutant failed to activate caspase-1, revealed higher intracellular counts, reduced cell death and IL-1β secretion during early but not during late macrophage infection compared to the wild-type. Intranasal infection of BALB/c mice with the BsaK mutant displayed a strongly decreased mortality, lower bacterial loads in organs, and reduced levels of IL-1β, myeloperoxidase and neutrophils in bronchoalveolar lavage fluid. In conclusion, our results indicate a major role for a functional T3SS3 in early NLRC4-mediated caspase-1 activation and pyroptosis and a contribution of late caspase-1

  7. Designing Probes for Immunodiagnostics: Structural Insights into an Epitope Targeting Burkholderia Infections.

    Science.gov (United States)

    Capelli, Riccardo; Matterazzo, Elena; Amabili, Marco; Peri, Claudio; Gori, Alessandro; Gagni, Paola; Chiari, Marcella; Lertmemongkolchai, Ganjana; Cretich, Marina; Bolognesi, Martino; Colombo, Giorgio; Gourlay, Louise J

    2017-10-13

    Structure-based epitope prediction drives the design of diagnostic peptidic probes to reveal specific antibodies elicited in response to infections. We previously identified a highly immunoreactive epitope from the peptidoglycan-associated lipoprotein (Pal) antigen from Burkholderia pseudomallei, which could also diagnose Burkholderia cepacia infections. Here, considering the high phylogenetic conservation within Burkholderia species, we ask whether cross-reactivity can be reciprocally displayed by the synthetic epitope from B. cenocepacia. We perform comparative analyses of the conformational preferences and diagnostic performances of the corresponding epitopes from the two Burkholderia species when presented in the context of the full-length proteins or as isolated peptides. The effects of conformation on the diagnostic potential and cross-reactivity of Pal peptide epitopes are rationalized on the basis of the 1.8 Å crystal structure of B. cenocepacia Pal and through computational analyses. Our results are discussed in the context of designing new diagnostic molecules for the early detection of infectious diseases.

  8. Antibiotic resistance in Burkholderia species.

    Science.gov (United States)

    Rhodes, Katherine A; Schweizer, Herbert P

    2016-09-01

    The genus Burkholderia comprises metabolically diverse and adaptable Gram-negative bacteria, which thrive in often adversarial environments. A few members of the genus are prominent opportunistic pathogens. These include Burkholderia mallei and Burkholderia pseudomallei of the B. pseudomallei complex, which cause glanders and melioidosis, respectively. Burkholderia cenocepacia, Burkholderia multivorans, and Burkholderia vietnamiensis belong to the Burkholderia cepacia complex and affect mostly cystic fibrosis patients. Infections caused by these bacteria are difficult to treat because of significant antibiotic resistance. The first line of defense against antimicrobials in Burkholderia species is the outer membrane penetration barrier. Most Burkholderia contain a modified lipopolysaccharide that causes intrinsic polymyxin resistance. Contributing to reduced drug penetration are restrictive porin proteins. Efflux pumps of the resistance nodulation cell division family are major players in Burkholderia multidrug resistance. Third and fourth generation β-lactam antibiotics are seminal for treatment of Burkholderia infections, but therapeutic efficacy is compromised by expression of several β-lactamases and ceftazidime target mutations. Altered DNA gyrase and dihydrofolate reductase targets cause fluoroquinolone and trimethoprim resistance, respectively. Although antibiotic resistance hampers therapy of Burkholderia infections, the characterization of resistance mechanisms lags behind other non-enteric Gram-negative pathogens, especially ESKAPE bacteria such as Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. A reverse-phase protein microarray-based screen identifies host signaling dynamics upon Burkholderia spp. infection

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    Chih-Yuan eChiang

    2015-07-01

    Full Text Available Burkholderia is a diverse genus of Gram-negative bacteria that cause high mortality rate in humans and cattle. The lack of effective therapeutic treatments poses serious public health threats. Insights toward host-Burkholderia spp. interaction are critical in understanding the pathogenesis of the infection as well as identifying therapeutic targets for drug development. Reverse-phase protein microarray (RPMA technology was previously proven to characterize novel biomarkers and molecular signatures associated with infectious diseases and cancers. In the present study, this technology was utilized to interrogate changes in host protein expression and post-translational phosphorylation events in macrophages infected with a collection of geographically diverse strains of Burkholderia spp. The expression or phosphorylation state of 25 proteins was altered during Burkholderia spp. infections and of which eight proteins were selected for further validation by immunoblotting. Kinetic expression patterns of phosphorylated AMPK-α1, Src, and GSK3β suggested the importance of their roles in regulating Burkholderia spp. mediated innate immune responses. Modulating inflammatory responses by perturbing AMPK-α1, Src, and GSK3β activities may provide novel therapeutic targets for future treatments.

  10. Workshop on treatment of and postexposure prophylaxis for Burkholderia pseudomallei and B. mallei Infection, 2010

    NARCIS (Netherlands)

    Lipsitz, Rebecca; Garges, Susan; Aurigemma, Rosemarie; Baccam, Prasith; Blaney, David D.; Cheng, Allen C.; Currie, Bart J.; Dance, David; Gee, Jay E.; Larsen, Joseph; Limmathurotsakul, Direk; Morrow, Meredith G.; Norton, Robert; O'Mara, Elizabeth; Peacock, Sharon J.; Pesik, Nicki; Rogers, L. Paige; Schweizer, Herbert P.; Steinmetz, Ivo; Tan, Gladys; Tan, Patrick; Wiersinga, W. Joost; Wuthiekanun, Vanaporn; Smith, Theresa L.

    2012-01-01

    The US Public Health Emergency Medical Countermeasures Enterprise convened subject matter experts at the 2010 HHS Burkholderia Workshop to develop consensus recommendations for postexposure prophylaxis against and treatment for Burkholderia pseudomallei and B. mallei infections, which cause

  11. Burkholderia cenocepacia Vaginal Infection in Patient with Smoldering Myeloma and Chronic Hepatitis C

    OpenAIRE

    Petrucca, Andrea; Cipriani, Paola; Sessa, Rosa; Teggi, Antonella; Pustorino, Rosalia; Santapaola, Daniela; Nicoletti, Mauro

    2004-01-01

    We report a case of a vaginal infection caused by a strain of Burkholderia cenocepacia. The strain was isolated from vaginal swab specimens from a 68-year-old woman with smoldering myeloma and chronic hepatitis C virus infection who was hospitalized for abdominal abscess. Treatment with piperacillin/tazobactam eliminated B. cenocepacia infection and vaginal symptoms.

  12. Polysaccharide microarray technology for the detection of Burkholderia pseudomallei and Burkholderia mallei antibodies.

    Science.gov (United States)

    Parthasarathy, Narayanan; DeShazer, David; England, Marilyn; Waag, David M

    2006-11-01

    A polysaccharide microarray platform was prepared by immobilizing Burkholderia pseudomallei and Burkholderia mallei polysaccharides. This polysaccharide array was tested with success for detecting B. pseudomallei and B. mallei serum (human and animal) antibodies. The advantages of this microarray technology over the current serodiagnosis of the above bacterial infections were discussed.

  13. Screening for potential anti-infective agents towards Burkholderia pseudomallei infection

    Science.gov (United States)

    Eng, Su Anne; Nathan, Sheila

    2014-09-01

    The established treatment for melioidosis is antibiotic therapy. However, a constant threat to this form of treatment is resistance development of the causative agent, Burkholderia pseudomallei, towards antibiotics. One option to circumvent this threat of antibiotic resistance is to search for new alternative anti-infectives which target the host innate immune system and/or bacterial virulence. In this study, 29 synthetic compounds were evaluated for their potential to increase the lifespan of an infected host. The nematode Caenorhabditis elegans was adopted as the infection model as its innate immune pathways are homologous to humans. Screens were performed in a liquid-based survival assay containing infected worms exposed to individual compounds and survival of untreated and compound-treated worms were compared. A primary screen identified nine synthetic compounds that extended the lifespan of B. pseudomallei-infected worms. Subsequently, a disc diffusion test was performed on these selected compounds to delineate compounds into those that enhanced the survival of worms via antimicrobial activity i.e. reducing the number of infecting bacteria, or into those that did not target pathogen viability. Out of the nine hits selected, two demonstrated antimicrobial effects on B. pseudomallei. Therefore, the findings from this study suggest that the other seven identified compounds are potential anti-infectives which could protect a host against B. pseudomallei infection without developing the risk of drug resistance.

  14. A Possible Link between Infection with Burkholderia Bacteria and Systemic Lupus Erythematosus Based on Epitope Mimicry

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    Wei Zhang

    2008-01-01

    Full Text Available We previously demonstrated that purified polyclonal and monoclonal anti-dsDNA antibodies bind a 15-mer peptide ASPVTARVLWKASHV in ELISA and Dot blot. This 15-mer peptide partial sequence ARVLWKASH shares similarity with burkholderia bacterial cytochrome B 561 partial sequence ARVLWRATH. In this study, we show that purified anti-dsDNA antibodies react with burkholderia fungorum bacterial cell lysates in Western blot. We used anti-dsDNA antibodies to make an anti-dsDNA antibodies affinity column and used this column to purify the burkholderia fungorum bacterial protein. Purified anti-dsDNA antibodies bind specifically to purified bacterial antigen and purified bacterial antigen blocked the anti-dsDNA antibodies binding to dsDNA antigen. Sera with anti-dsDNA antibodies bind specifically to purified bacterial antigen. We obtained protein partial sequence of RAGTDEGFG which is shared with burkholderia bacterial transcription regulator protein sequence. Sera with anti-dsDNA antibodies bind to RAGTDEGFG peptide better than control groups. These data support our hypothesis that the origin of anti-dsDNA antibodies in SLE may be associated with burkholderia bacterial infection.

  15. Mining Host-Pathogen Protein Interactions to Characterize Burkholderia mallei Infectivity Mechanisms

    Science.gov (United States)

    2015-03-04

    the cytoskeleton, in lysosomes , and in the nuclear lumen. These results were consistent with the experimentally observed pathogen interference with...RESEARCH ARTICLE Mining Host- Pathogen Protein Interactions to Characterize Burkholderia mallei Infectivity Mechanisms Vesna Memišević1, Nela...Bacteriology Division, U.S. Army Medical Research Institute of Infectious Diseases , Fort Detrick, Maryland, United States of America * jaques.reifman.civ

  16. Immune Recognition of the Epidemic Cystic Fibrosis Pathogen Burkholderia dolosa.

    Science.gov (United States)

    Roux, Damien; Weatherholt, Molly; Clark, Bradley; Gadjeva, Mihaela; Renaud, Diane; Scott, David; Skurnik, David; Priebe, Gregory P; Pier, Gerald; Gerard, Craig; Yoder-Himes, Deborah R

    2017-06-01

    Burkholderia dolosa caused an outbreak in the cystic fibrosis (CF) clinic at Boston Children's Hospital from 1998 to 2005 and led to the infection of over 40 patients, many of whom died due to complications from infection by this organism. To assess whether B. dolosa significantly contributes to disease or is recognized by the host immune response, mice were infected with a sequenced outbreak B. dolosa strain, AU0158, and responses were compared to those to the well-studied CF pathogen Pseudomonas aeruginosa In parallel, mice were also infected with a polar flagellin mutant of B. dolosa to examine the role of flagella in B. dolosa lung colonization. The results showed a higher persistence in the host by B. dolosa strains, and yet, neutrophil recruitment and cytokine production were lower than those with P. aeruginosa The ability of host immune cells to recognize B. dolosa was then assessed, B. dolosa induced a robust cytokine response in cultured cells, and this effect was dependent on the flagella only when bacteria were dead. Together, these results suggest that B. dolosa can be recognized by host cells in vitro but may avoid or suppress the host immune response in vivo through unknown mechanisms. B. dolosa was then compared to other Burkholderia species and found to induce similar levels of cytokine production despite being internalized by macrophages more than Burkholderia cenocepacia strains. These data suggest that B. dolosa AU0158 may act differently with host cells and is recognized differently by immune systems than are other Burkholderia strains or species. Copyright © 2017 American Society for Microbiology.

  17. Use of the common marmoset to study Burkholderia mallei infection.

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    Tomislav Jelesijevic

    Full Text Available Burkholderia mallei is a host-adapted bacterium that does not persist outside of its equine reservoir. The organism causes the zoonosis glanders, which is endemic in Asia, Africa, the Middle East and South America. Infection by B. mallei typically occurs via the respiratory or percutaneous route, and the most common manifestations are life-threatening pneumonia and bacteremia. Glanders is difficult to diagnose and requires prolonged antibiotic therapy with low success rates. There is no vaccine to protect against B. mallei and there is concern regarding its use as a biothreat agent. Thus, experiments were performed to establish a non-human primate model of intranasal infection to study the organism and develop countermeasures. Groups of marmosets (Callithrix jacchus were inoculated intranasally with B. mallei strain ATCC 23344 and monitored for clinical signs of illness for up to 13 days. We discovered that 83% of marmosets inoculated with doses of 2.5 X 10(4 to 2.5 X 10(5 bacteria developed acute lethal infection within 3-4 days. Signs of disease were severe and included lethargy, inappetence, conjunctivitis, mucopurulent and hemorrhagic nasal discharges, and increased respiratory effort with abdominal lifts. Burkholderia mallei was cultured from the lungs, spleen and liver of these animals, and pathologic examination of tissues revealed lesions characteristic of glanders. Challenge experiments also revealed that 91% of animals infected with doses ranging from 25 to 2.5 X 10(3 bacteria exhibited mild non-specific signs of illness and were culture negative. One marmoset inoculated with 2.5 X 10(3 organisms developed moderate signs of disease and reached humane end-points 8 days post-infection. The liver and spleen of this animal were colonized with the agent and pathological analysis of tissues showed nasal, splenic and hepatic lesions. Taken together, these data indicate that the marmoset is a suitable model to study respiratory infection by B

  18. Burkholderia Vaccines: Are We Moving Forward?

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    Leang-Chung eChoh

    2013-02-01

    Full Text Available The genus Burkholderia consists of diverse species which includes both ‘friends’ and ‘foes’. Some of the ‘friendly’ Burkholderia spp. are extensively used in the biotechnological and agricultural industry for bioremediation and biocontrol. However, several members of the genus including B. pseudomallei, B. mallei and B. cepacia, are known to cause fatal disease in both humans and animals. B. pseudomallei and B. mallei are the causative agents of melioidosis and glanders, respectively, while B. cepacia infection is lethal to cystic fibrosis patients. Due to the high rate of infectivity and intrinsic resistance to many commonly used antibiotics, together with high mortality rate, B. mallei and B. pseudomallei are considered to be potential biological warfare agents. Treatments of the infections caused by these bacteria are often unsuccessful with frequent relapse of the infection. Thus, we are at a crucial stage of the need for Burkholderia vaccines. Although the search for a prophylactic therapy candidate continues, to date development of vaccines has not advanced beyond research to human clinical trials. In this article, we review the current research on development of safe vaccines with high efficacy against B. pseudomallei, B. mallei and B. cepacia. It can be concluded that further research will enable elucidation of the potential benefits and risks of Burkholderia vaccines.

  19. Burkholderia vaccines: are we moving forward?

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    Choh, Leang-Chung; Ong, Guang-Han; Vellasamy, Kumutha M.; Kalaiselvam, Kaveena; Kang, Wen-Tyng; Al-Maleki, Anis R.; Mariappan, Vanitha; Vadivelu, Jamuna

    2013-01-01

    The genus Burkholderia consists of diverse species which includes both “friends” and “foes.” Some of the “friendly” Burkholderia spp. are extensively used in the biotechnological and agricultural industry for bioremediation and biocontrol. However, several members of the genus including B. pseudomallei, B. mallei, and B. cepacia, are known to cause fatal disease in both humans and animals. B. pseudomallei and B. mallei are the causative agents of melioidosis and glanders, respectively, while B. cepacia infection is lethal to cystic fibrosis (CF) patients. Due to the high rate of infectivity and intrinsic resistance to many commonly used antibiotics, together with high mortality rate, B. mallei and B. pseudomallei are considered to be potential biological warfare agents. Treatments of the infections caused by these bacteria are often unsuccessful with frequent relapse of the infection. Thus, we are at a crucial stage of the need for Burkholderia vaccines. Although the search for a prophylactic therapy candidate continues, to date development of vaccines has not advanced beyond research to human clinical trials. In this article, we review the current research on development of safe vaccines with high efficacy against B. pseudomallei, B. mallei, and B. cepacia. It can be concluded that further research will enable elucidation of the potential benefits and risks of Burkholderia vaccines. PMID:23386999

  20. Phylogenomic Study of Burkholderia glathei-like Organisms, Proposal of 13 Novel Burkholderia Species and Emended Descriptions of Burkholderia sordidicola, Burkholderia zhejiangensis, and Burkholderia grimmiae

    Science.gov (United States)

    Peeters, Charlotte; Meier-Kolthoff, Jan P.; Verheyde, Bart; De Brandt, Evie; Cooper, Vaughn S.; Vandamme, Peter

    2016-01-01

    Partial gyrB gene sequence analysis of 17 isolates from human and environmental sources revealed 13 clusters of strains and identified them as Burkholderia glathei clade (BGC) bacteria. The taxonomic status of these clusters was examined by whole-genome sequence analysis, determination of the G+C content, whole-cell fatty acid analysis and biochemical characterization. The whole-genome sequence-based phylogeny was assessed using the Genome Blast Distance Phylogeny (GBDP) method and an extended multilocus sequence analysis (MLSA) approach. The results demonstrated that these 17 BGC isolates represented 13 novel Burkholderia species that could be distinguished by both genotypic and phenotypic characteristics. BGC strains exhibited a broad metabolic versatility and developed beneficial, symbiotic, and pathogenic interactions with different hosts. Our data also confirmed that there is no phylogenetic subdivision in the genus Burkholderia that distinguishes beneficial from pathogenic strains. We therefore propose to formally classify the 13 novel BGC Burkholderia species as Burkholderia arvi sp. nov. (type strain LMG 29317T = CCUG 68412T), Burkholderia hypogeia sp. nov. (type strain LMG 29322T = CCUG 68407T), Burkholderia ptereochthonis sp. nov. (type strain LMG 29326T = CCUG 68403T), Burkholderia glebae sp. nov. (type strain LMG 29325T = CCUG 68404T), Burkholderia pedi sp. nov. (type strain LMG 29323T = CCUG 68406T), Burkholderia arationis sp. nov. (type strain LMG 29324T = CCUG 68405T), Burkholderia fortuita sp. nov. (type strain LMG 29320T = CCUG 68409T), Burkholderia temeraria sp. nov. (type strain LMG 29319T = CCUG 68410T), Burkholderia calidae sp. nov. (type strain LMG 29321T = CCUG 68408T), Burkholderia concitans sp. nov. (type strain LMG 29315T = CCUG 68414T), Burkholderia turbans sp. nov. (type strain LMG 29316T = CCUG 68413T), Burkholderia catudaia sp. nov. (type strain LMG 29318T = CCUG 68411T) and Burkholderia peredens sp. nov. (type strain LMG 29314T = CCUG

  1. Development of Burkholderia mallei and pseudomallei vaccines

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    Silva, Ediane B.; Dow, Steven W.

    2013-01-01

    Burkholderia mallei and Burkholderia pseudomallei are Gram-negative bacteria that cause glanders and melioidosis, respectively. Inhalational infection with either organism can result in severe and rapidly fatal pneumonia. Inoculation by the oral and cutaneous routes can also produce infection. Chronic infection may develop after recovery from acute infection with both agents, and control of infection with antibiotics requires prolonged treatment. Symptoms for both meliodosis and glanders are non-specific, making diagnosis difficult. B. pseudomallei can be located in the environment, but in the host, B. mallei and B. psedomallei are intracellular organisms, and infection results in similar immune responses to both agents. Effective early innate immune responses are critical to controlling the early phase of the infection. Innate immune signaling molecules such as TLR, NOD, MyD88, and pro-inflammatory cytokines such as IFN-γ and TNF-α play key roles in regulating control of infection. Neutrophils and monocytes are critical cells in the early infection for both microorganisms. Both monocytes and macrophages are necessary for limiting dissemination of B. pseudomallei. In contrast, the role of adaptive immune responses in controlling Burkholderia infection is less well understood. However, T cell responses are critical for vaccine protection from Burkholderia infection. At present, effective vaccines for prevention of glanders or meliodosis have not been developed, although recently development of Burkholderia vaccines has received renewed attention. This review will summarize current and past approaches to develop B. mallei and B. pseudomalllei vaccines, with emphasis on immune mechanisms of protection and the challenges facing the field. At present, immunization with live attenuated bacteria provides the most effective and durable immunity, and it is important therefore to understand the immune correlates of protection induced by live attenuated vaccines. Subunit

  2. The promise of bacteriophage therapy for Burkholderia cepacia complex respiratory infections.

    Directory of Open Access Journals (Sweden)

    Diana Dawn Semler

    2012-01-01

    Full Text Available In recent times, increased attention has been given to evaluating the efficacy of phage therapy, especially in scenarios where the bacterial infectious agent of interest is highly antibiotic resistant. In this regard, phage therapy is especially applicable to infections caused by the Burkholderia cepacia complex (BCC since members of the BCC are antibiotic pan-resistant. Current studies in BCC phage therapy are unique from many other avenues of phage therapy research in that the research is not only comprised of phage isolation, in vitro phage characterization and in vivo infection model efficacy, but also adapting aerosol drug delivery techniques to aerosol phage formulation delivery and storage.

  3. Biochemical Characterization of Glutamate Racemase-A New Candidate Drug Target against Burkholderia cenocepacia Infections.

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    Aygun Israyilova

    Full Text Available The greatest obstacle for the treatment of cystic fibrosis patients infected with the Burkholderia species is their intrinsic antibiotic resistance. For this reason, there is a need to develop new effective compounds. Glutamate racemase, an essential enzyme for the biosynthesis of the bacterial cell wall, is an excellent candidate target for the design of new antibacterial drugs. To this aim, we recombinantly produced and characterized glutamate racemase from Burkholderia cenocepacia J2315. From the screening of an in-house library of compounds, two Zn (II and Mn (III 1,3,5-triazapentadienate complexes were found to efficiently inhibit the glutamate racemase activity with IC50 values of 35.3 and 10.0 μM, respectively. Using multiple biochemical approaches, the metal complexes have been shown to affect the enzyme activity by binding to the enzyme-substrate complex and promoting the formation of an inhibited dimeric form of the enzyme. Our results corroborate the value of glutamate racemase as a good target for the development of novel inhibitors against Burkholderia.

  4. Nasal Acai Polysaccharides Potentiate Innate Immunity to Protect against Pulmonary Francisella tularensis and Burkholderia pseudomallei Infections

    OpenAIRE

    Skyberg, Jerod A.; Rollins, MaryClare F.; Holderness, Jeff S.; Marlenee, Nicole L.; Schepetkin, Igor A.; Goodyear, Andrew; Dow, Steven W.; Jutila, Mark A.; Pascual, David W.

    2012-01-01

    Pulmonary Francisella tularensis and Burkholderia pseudomallei infections are highly lethal in untreated patients, and current antibiotic regimens are not always effective. Activating the innate immune system provides an alternative means of treating infection and can also complement antibiotic therapies. Several natural agonists were screened for their ability to enhance host resistance to infection, and polysaccharides derived from the Acai berry (Acai PS) were found to have potent abilitie...

  5. Fatal Burkholderia pseudomallei Infection Initially Reported as a Bacillus Species, Ohio, 2013

    OpenAIRE

    Doker, Thomas J.; Quinn, Celia L.; Salehi, Ellen D.; Sherwood, Joshua J.; Benoit, Tina J.; Elrod, Mindy Glass; Gee, Jay E.; Shadomy, Sean V.; Bower, William A.; Hoffmaster, Alex R.; Walke, Henry T.; Blaney, David D.; DiOrio, Mary S.

    2014-01-01

    A fatal case of melioidosis was diagnosed in Ohio one month after culture results were initially reported as a Bacillus species. To identify a source of infection and assess risk in patient contacts, we abstracted patient charts; interviewed physicians and contacts; genetically characterized the isolate; performed a Burkholderia pseudomallei antibody indirect hemagglutination assay on household contacts and pets to assess seropositivity; and collected household plant, soil, liquid, and insect...

  6. Direct detection of the plant pathogens Burkholderia glumae, Burkholderia gladioli pv. gladioli, and Erwinia chrysanthemi pv. zeae in infected rice seedlings using matrix assisted laser desorption/ionization time-of-flight mass spectrometry.

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    Kajiwara, Hideyuki

    2016-01-01

    The plant pathogens Burkholderia glumae, Burkholderia gladioli pv. gladioli, and Erwinia chrysanthemi pv. zeae were directly detected in extracts from infected rice seedlings by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). This method did not require culturing of the pathogens on artificial medium. In the MALDI-TOF MS analysis, peaks originating from bacteria were found in extracts from infected rice seedlings. The spectral peaks showed significantly high scores, in spite of minor differences in spectra. The spectral peaks originating from host plant tissues did not affect this direct MALDI-TOF MS analysis for the rapid identification of plant pathogens. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. A Unique Set of the Burkholderia Collagen-Like Proteins Provides Insight into Pathogenesis, Genome Evolution and Niche Adaptation, and Infection Detection.

    Science.gov (United States)

    Bachert, Beth A; Choi, Soo J; Snyder, Anna K; Rio, Rita V M; Durney, Brandon C; Holland, Lisa A; Amemiya, Kei; Welkos, Susan L; Bozue, Joel A; Cote, Christopher K; Berisio, Rita; Lukomski, Slawomir

    2015-01-01

    Burkholderia pseudomallei and Burkholderia mallei, classified as category B priority pathogens, are significant human and animal pathogens that are highly infectious and broad-spectrum antibiotic resistant. Currently, the pathogenicity mechanisms utilized by Burkholderia are not fully understood, and correct diagnosis of B. pseudomallei and B. mallei infection remains a challenge due to limited detection methods. Here, we provide a comprehensive analysis of a set of 13 novel Burkholderia collagen-like proteins (Bucl) that were identified among B. pseudomallei and B. mallei select agents. We infer that several Bucl proteins participate in pathogenesis based on their noncollagenous domains that are associated with the components of a type III secretion apparatus and membrane transport systems. Homology modeling of the outer membrane efflux domain of Bucl8 points to a role in multi-drug resistance. We determined that bucl genes are widespread in B. pseudomallei and B. mallei; Fischer's exact test and Cramer's V2 values indicate that the majority of bucl genes are highly associated with these pathogenic species versus nonpathogenic B. thailandensis. We designed a bucl-based quantitative PCR assay which was able to detect B. pseudomallei infection in a mouse with a detection limit of 50 CFU. Finally, chromosomal mapping and phylogenetic analysis of bucl loci revealed considerable genomic plasticity and adaptation of Burkholderia spp. to host and environmental niches. In this study, we identified a large set of phylogenetically unrelated bucl genes commonly found in Burkholderia select agents, encoding predicted pathogenicity factors, detection targets, and vaccine candidates.

  8. PKC-η-MARCKS Signaling Promotes Intracellular Survival of Unopsonized Burkholderia thailandensis.

    Science.gov (United States)

    Micheva-Viteva, Sofiya N; Shou, Yulin; Ganguly, Kumkum; Wu, Terry H; Hong-Geller, Elizabeth

    2017-01-01

    Pathogenic Burkholderia rely on host factors for efficient intracellular replication and are highly refractory to antibiotic treatment. To identify host genes that are required by Burkholderia spp. during infection, we performed a RNA interference (RNAi) screen of the human kinome and identified 35 host kinases that facilitated Burkholderia thailandensis intracellular survival in human monocytic THP-1 cells. We validated a selection of host kinases using imaging flow cytometry to assess efficiency of B. thailandensis survival in the host upon siRNA-mediated knockdown. We focused on the role of the novel protein kinase C isoform, PKC-η, in Burkholderia infection and characterized PKC-η/MARCKS signaling as a key event that promotes the survival of unopsonized B. thailandensis CDC2721121 within host cells. While infection of lung epithelial cells with unopsonized Gram-negative bacteria stimulated phosphorylation of Ser175/160 in the MARCKS effector domain, siRNA-mediated knockdown of PKC-η expression reduced the levels of phosphorylated MARCKS by >3-fold in response to infection with Bt CDC2721121. We compared the effect of the conventional PKC-α and novel PKC-η isoforms on the growth of B. thailandensis CDC2721121 within monocytic THP-1 cells and found that ≥75% knock-down of PRKCH transcript levels reduced intracellular bacterial load 100% more efficiently when compared to growth in cells siRNA-depleted of the classical PKC-α, suggesting that the PKC-η isoform can specifically mediate Burkholderia intracellular survival. Based on imaging studies of intracellular B. thailandensis , we found that PKC-η function stimulates phagocytic pathways that promote B. thailandensis escape into the cytoplasm leading to activation of autophagosome flux. Identification of host kinases that are targeted by Burkholderia during infection provides valuable molecular insights in understanding Burkholderia pathogenesis, and ultimately, in designing effective host

  9. Members of the genus Burkholderia: good and bad guys

    Science.gov (United States)

    Eberl, Leo; Vandamme, Peter

    2016-01-01

    In the 1990s several biocontrol agents on that contained Burkholderia strains were registered by the United States Environmental Protection Agency (EPA). After risk assessment these products were withdrawn from the market and a moratorium was placed on the registration of Burkholderia-containing products, as these strains may pose a risk to human health. However, over the past few years the number of novel Burkholderia species that exhibit plant-beneficial properties and are normally not isolated from infected patients has increased tremendously. In this commentary we wish to summarize recent efforts that aim at discerning pathogenic from beneficial Burkholderia strains. PMID:27303639

  10. Development of ceftazidime resistance in an acute Burkholderia pseudomallei infection

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    Sarovich DS

    2012-08-01

    Full Text Available Derek S Sarovich,1,2,* Erin P Price,1,2,* Direk Limmathurotsakul,3 James M Cook,1 Alex T Von Schulze,1 Spenser R Wolken,1 Paul Keim,1 Sharon J Peacock,3,4 Talima Pearson1 1Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, USA; 2Tropical and Emerging Infectious Diseases Division, Menzies School of Health Research, Darwin, Australia; 3Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; 4Department of Medicine, University of Cambridge, Cambridge, United Kingdom*These authors contributed equally to this workAbstract: Burkholderia pseudomallei, a bacterium that causes the disease melioidosis, is intrinsically resistant to many antibiotics. First-line antibiotic therapy for treating melioidosis is usually the synthetic β-lactam, ceftazidime (CAZ, as almost all B. pseudomallei strains are susceptible to this drug. However, acquired CAZ resistance can develop in vivo during treatment with CAZ, which can lead to mortality if therapy is not switched to a different drug in a timely manner. Serial B. pseudomallei isolates obtained from an acute Thai melioidosis patient infected by a CAZ susceptible strain, who ultimately succumbed to infection despite being on CAZ therapy for the duration of their infection, were analyzed. Isolates that developed CAZ resistance due to a proline to serine change at position 167 in the β-lactamase PenA were identified. Importantly, these CAZ resistant isolates remained sensitive to the alternative melioidosis treatments; namely, amoxicillin-clavulanate, imipenem, and meropenem. Lastly, real-time polymerase chain reaction-based assays capable of rapidly identifying CAZ resistance in B. pseudomallei isolates at the position 167 mutation site were developed. The ability to rapidly identify the emergence of CAZ resistant B. pseudomallei populations in melioidosis patients will allow timely alterations in treatment strategies

  11. Efflux Pump-mediated Drug Resistance in Burkholderia

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    Nicole L Podnecky

    2015-04-01

    Full Text Available Several members of the genus Burkholderia are prominent pathogens. Infections caused by these bacteria are difficult to treat because of significant antibiotic resistance. Virtually all Burkholderia species are also resistant to polymyxin, prohibiting use of drugs like colistin that are available for treatment of infections caused by most other drug resistant Gram-negative bacteria. Despite clinical significance and antibiotic resistance of Burkholderia species, characterization of efflux pumps lags behind other non-enteric Gram-negative pathogens such as Acinetobacter baumannii and Pseudomonas aeruginosa. Although efflux pumps have been described in several Burkholderia species, they have been best studied in B. cenocepacia and B. pseudomallei. As in other non-enteric Gram-negatives, efflux pumps of the resistance nodulation cell division (RND family are the clinically most significant efflux systems in these two species. Several efflux pumps were described in B. cenocepacia, which when expressed confer resistance to clinically significant antibiotics, including aminoglycosides, chloramphenicol, fluoroquinolones, and tetracyclines. Three RND pumps have been characterized in B. pseudomallei, two of which confer either intrinsic or acquired resistance to aminoglycosides, macrolides, chloramphenicol, fluoroquinolones, tetracyclines, trimethoprim, and in some instances trimethoprim+sulfamethoxazole. Several strains of the host-adapted B. mallei, a clone of B. pseudomallei, lack AmrAB-OprA and are therefore aminoglycoside and macrolide susceptible. B. thailandensis is closely related to B. pseudomallei, but non-pathogenic to humans. Its pump repertoire and ensuing drug resistance profile parallels that of B. pseudomallei. An efflux pump in B. vietnamiensis plays a significant role in acquired aminoglycoside resistance. Summarily, efflux pumps are significant players in Burkholderia drug resistance.

  12. A case of native valve endocarditis caused by Burkholderia cepacia without predisposing factors

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    Han Seong

    2011-05-01

    Full Text Available Abstract Background Infective endocarditis is rarely caused by Burkholderia cepacia. This infection is known to occur particularly in immunocompromised hosts, intravenous heroin users, and in patients with prosthetic valve replacement. Most patients with Burkholderia cepacia endocarditis usually need surgical treatment in addition to antimicrobial treatment. Case Presentation Here, we report the case of a patient who developed Burkholderia cepacia-induced native valve endocarditis with consequent cerebral involvement without any predisposing factors; she was successfully treated by antimicrobial agents only. Conclusion In this report, we also present literature review of relevant cases.

  13. Mechanisms of Disease: Host-Pathogen Interactions between Burkholderia Species and Lung Epithelial Cells

    Science.gov (United States)

    David, Jonathan; Bell, Rachel E.; Clark, Graeme C.

    2015-01-01

    Members of the Burkholderia species can cause a range of severe, often fatal, respiratory diseases. A variety of in vitro models of infection have been developed in an attempt to elucidate the mechanism by which Burkholderia spp. gain entry to and interact with the body. The majority of studies have tended to focus on the interaction of bacteria with phagocytic cells with a paucity of information available with regard to the lung epithelium. However, the lung epithelium is becoming more widely recognized as an important player in innate immunity and the early response to infections. Here we review the complex relationship between Burkholderia species and epithelial cells with an emphasis on the most pathogenic species, Burkholderia pseudomallei and Burkholderia mallei. The current gaps in knowledge in our understanding are highlighted along with the epithelial host-pathogen interactions that offer potential opportunities for therapeutic intervention. PMID:26636042

  14. Development of a multiplex PCR assay for the detection and differentiation of Burkholderia pseudomallei, Burkholderia mallei, Burkholderia thailandensis, and Burkholderia cepacia complex.

    Science.gov (United States)

    Zakharova, Irina; Teteryatnikova, Natalya; Toporkov, Andrey; Viktorov, Dmitry

    2017-10-01

    Two species of Burkholderia pseudomallei complex (Bpc), B. pseudomallei and B. mallei, can cause severe life-threatening infections. Rapidly discerning individual species within the group and separating them from other opportunistic pathogens of the Burkholderia cepacia complex (Bcc) is essential to establish a correct diagnosis and for epidemiological surveillance. In this study, a multiplex PCR assay based on the detection of an individual set of chromosomal beta-lactamase genes for single-step identification and differentiation of B. pseudomallei, B. mallei, B. thailandensis, and Bcc was developed. Two pairs of primers specific to a distinct class of B metallo-beta-lactamase genes and a pair of primers specific to the oxacillin-hydrolyzing class D beta-lactamase gene were demonstrated to successfully discriminate species within Bpc and from Bcc. The assay sensitivity was 9561 genomic equivalents (GE) for B. pseudomallei, 7827 GE for B. mallei, 8749 GE for B. thailandensis and 6023 GE for B. cepacia. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Host evasion by Burkholderia cenocepacia

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    Shyamala eGanesan

    2012-01-01

    Full Text Available Burkholderia cenocepacia is an opportunistic respiratory pathogen of individuals with cystic fibrosis (CF. It is one of the highly transmissible species of Burkholderia cepacia complex and very resistant to almost all the antibiotics. Approximately 1/3rd 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 has capacity to survive and replicate intracellularly in both airway epithelial cells and macrophages, which are primary centennials of the lung and play a pivotal role in clearance of infecting bacteria. Some strains of B. cenocepaica, which express cable pili and the associated 22kDa adhesin are also capable of transmigrating across airway epithelium and persist in mouse models of infection. In this review, we will discuss how this type of interaction between B. cenocepacia and host may lead to persistence of bacteria and contribute to lung inflammation in CF patients.

  16. Brain abscess caused by Burkholderia pseudomallei

    International Nuclear Information System (INIS)

    Padigione, A.; Spelman, D.; Ferris, N.

    1997-01-01

    Full text: Melioidosis, or infection with Burkholderia pseudomallei, is an important human disease in South East Asia and Northern Australia. Neurological manifestations are well recognized amongst its protean presentations, but direct focal central nervous system infection is infrequently described with only 9 adult and 5 paediatric cases reported in the English language literature. A case of brain abscess due to Burkholderia pseudomallei occurring in a 20 year old Dutch visitor to Australia which progressed despite antibiotic treatment is described. A review of the clinical manifestations, Magnetic Resonance (MR) appearance, diagnosis and treatment of melioidosis is presented, highlighting that: (i) physicians outside endernic areas should consider melioidosis in any patient with an appropriate travel history, (ii) MR imaging is more sensitive then CT in diagnosing early brain infection, especially of the brainstem; (iii) Bacterial culture, the mainstay of diagnosis, has many shortcomings; (iv)In vitro antibiotic sensitivity testing may not translate into clinical efficacy; and (v) Steroids appear to have little role, even in severe disease

  17. Iron Acquisition Mechanisms and Their Role in the Virulence of Burkholderia Species

    Science.gov (United States)

    Butt, Aaron T.; Thomas, Mark S.

    2017-01-01

    Burkholderia is a genus within the β-Proteobacteriaceae that contains at least 90 validly named species which can be found in a diverse range of environments. A number of pathogenic species occur within the genus. These include Burkholderia cenocepacia and Burkholderia multivorans, opportunistic pathogens that can infect the lungs of patients with cystic fibrosis, and are members of the Burkholderia cepacia complex (Bcc). Burkholderia pseudomallei is also an opportunistic pathogen, but in contrast to Bcc species it causes the tropical human disease melioidosis, while its close relative Burkholderia mallei is the causative agent of glanders in horses. For these pathogens to survive within a host and cause disease they must be able to acquire iron. This chemical element is essential for nearly all living organisms due to its important role in many enzymes and metabolic processes. In the mammalian host, the amount of accessible free iron is negligible due to the low solubility of the metal ion in its higher oxidation state and the tight binding of this element by host proteins such as ferritin and lactoferrin. As with other pathogenic bacteria, Burkholderia species have evolved an array of iron acquisition mechanisms with which to capture iron from the host environment. These mechanisms include the production and utilization of siderophores and the possession of a haem uptake system. Here, we summarize the known mechanisms of iron acquisition in pathogenic Burkholderia species and discuss the evidence for their importance in the context of virulence and the establishment of infection in the host. We have also carried out an extensive bioinformatic analysis to identify which siderophores are produced by each Burkholderia species that is pathogenic to humans. PMID:29164069

  18. Plant-Associated Symbiotic Burkholderia Species Lack Hallmark Strategies Required in Mammalian Pathogenesis

    Science.gov (United States)

    Fong, Stephanie; Yerrapragada, Shailaja; Estrada-de los Santos, Paulina; Yang, Paul; Song, Nannie; Kano, Stephanie; de Faria, Sergio M.; Dakora, Felix D.; Weinstock, George; Hirsch, Ann M.

    2014-01-01

    Burkholderia is a diverse and dynamic genus, containing pathogenic species as well as species that form complex interactions with plants. Pathogenic strains, such as B. pseudomallei and B. mallei, can cause serious disease in mammals, while other Burkholderia strains are opportunistic pathogens, infecting humans or animals with a compromised immune system. Although some of the opportunistic Burkholderia pathogens are known to promote plant growth and even fix nitrogen, the risk of infection to infants, the elderly, and people who are immunocompromised has not only resulted in a restriction on their use, but has also limited the application of non-pathogenic, symbiotic species, several of which nodulate legume roots or have positive effects on plant growth. However, recent phylogenetic analyses have demonstrated that Burkholderia species separate into distinct lineages, suggesting the possibility for safe use of certain symbiotic species in agricultural contexts. A number of environmental strains that promote plant growth or degrade xenobiotics are also included in the symbiotic lineage. Many of these species have the potential to enhance agriculture in areas where fertilizers are not readily available and may serve in the future as inocula for crops growing in soils impacted by climate change. Here we address the pathogenic potential of several of the symbiotic Burkholderia strains using bioinformatics and functional tests. A series of infection experiments using Caenorhabditis elegans and HeLa cells, as well as genomic characterization of pathogenic loci, show that the risk of opportunistic infection by symbiotic strains such as B. tuberum is extremely low. PMID:24416172

  19. Characterization of integrons in Burkholderia cepacia clinical isolates

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    Linda Furlanis

    2010-03-01

    Full Text Available Burkholderia cepacia is an opportunistic pathogen able to colonize the airways of Cystic Fibrosis (CF patients, frequently developing chronic infections. In 20% of cases these infections cause severe and poorly controlled pathological situations because of the intrinsic antibiotic resistance expressed by the microorganism. CF patients are often subjected to antibiotic therapy: this facilitates the acquisition of antibiotic resistance determinants by the infecting bacteria. Integrons are mobile genetic elements that are widespread in bacterial populations and favor the acquisition of gene cassettes coding for these determinants.The presence of class 1 integrons was investigated by PCR with primers specific for the 5’ and 3’ ends in Burkholderia isolates recovered from patients in treatment at the CF center of Friuli Venezia Giulia. The same integron, carrying an uncommon allelic form (Ib of the aacA4 gene in its cassette array and conferring resistance to some aminoglycosides, was found in two independent isolates (different RAPD profiles infecting two different patients. In both isolates the integron was carried by plasmids and was still present 3 and 6 years later the first finding. Despite the exchange of integrons between bacterial pathogens is fully described, these items were not frequently found in Burkholderia isolates. Although the clinical relevance of the integron we identified is low (a single gene cassette encoding a widespread resistance,we feel concerned that these genetic elements begin to circulate in this bacterial species, as this could make more and more troublesome the treatment of infections notoriously difficult to eradicate.

  20. Identification of Burkholderia cenocepacia strain H111 virulence factors using nonmammalian infection hosts

    DEFF Research Database (Denmark)

    Schwager, Stephan; Agnoli, Kirsty; Köthe, Manuela

    2013-01-01

    Burkholderia cenocepacia H111, a strain isolated from a cystic fibrosis patient, has been shown to effectively kill the nematode Caenorhabditis elegans. We used the C. elegans model of infection to screen a mini-Tn5 mutant library of B. cenocepacia H111 for attenuated virulence....... Of the approximately 5,500 B. cenocepacia H111 random mini-Tn5 insertion mutants that were screened, 22 showed attenuated virulence in C. elegans. Except for the quorum-sensing regulator cepR, none of the mutated genes coded for the biosynthesis of classical virulence factors such as extracellular proteases...... or siderophores. Instead, the mutants contained insertions in metabolic and regulatory genes. Mutants attenuated in virulence in the C. elegans infection model were also tested in the Drosophila melanogaster pricking model, and those also attenuated in this model were further tested in Galleria mellonella. Six...

  1. Membrane-active mechanism of LFchimera against Burkholderia pseudomallei and Burkholderia thailandensis.

    Science.gov (United States)

    Kanthawong, Sakawrat; Puknun, Aekkalak; Bolscher, Jan G M; Nazmi, Kamran; van Marle, Jan; de Soet, Johannes J; Veerman, Enno C I; Wongratanacheewin, Surasakdi; Taweechaisupapong, Suwimol

    2014-10-01

    LFchimera, a construct combining two antimicrobial domains of bovine lactoferrin, lactoferrampin265-284 and lactoferricin17-30, possesses strong bactericidal activity. As yet, no experimental evidence was presented to evaluate the mechanisms of LFchimera against Burkholderia isolates. In this study we analyzed the killing activity of LFchimera on the category B pathogen Burkholderia pseudomallei in comparison to the lesser virulent Burkholderia thailandensis often used as a model for the highly virulent B. pseudomallei. Killing kinetics showed that B. thailandensis E264 was more susceptible for LFchimera than B. pseudomallei 1026b. Interestingly the bactericidal activity of LFchimera appeared highly pH dependent; B. thailandensis killing was completely abolished at and below pH 6.4. FITC-labeled LFchimera caused a rapid accumulation within 15 min in the cytoplasm of both bacterial species. Moreover, freeze-fracture electron microscopy demonstrated extreme effects on the membrane morphology of both bacterial species within 1 h of incubation, accompanied by altered membrane permeability monitored as leakage of nucleotides. These data indicate that the mechanism of action of LFchimera is similar for both species and encompasses disruption of the plasma membrane and subsequently leakage of intracellular nucleotides leading to cell dead.

  2. Live imaging of symbiosis: spatiotemporal infection dynamics of a GFP-labelled Burkholderia symbiont in the bean bug Riptortus pedestris

    Science.gov (United States)

    Kikuchi, Yoshitomo; Fukatsu, Takema

    2014-01-01

    Many insects possess endosymbiotic bacteria inside their body, wherein intimate interactions occur between the partners. While recent technological advancements have deepened our understanding of metabolic and evolutionary features of the symbiont genomes, molecular mechanisms underpinning the intimate interactions remain difficult to approach because the insect symbionts are generally uncultivable. The bean bug Riptortus pedestris is associated with the betaproteobacterial Burkholderia symbiont in a posterior region of the midgut, which develops numerous crypts harbouring the symbiont extracellularly. Distinct from other insect symbiotic systems, R. pedestris acquires the Burkholderia symbiont not by vertical transmission but from the environment every generation. By making use of the cultivability and the genetic tractability of the symbiont, we constructed a transgenic Burkholderia strain labelled with green fluorescent protein (GFP), which enabled detailed observation of spatiotemporal dynamics and the colonization process of the symbiont in freshly prepared specimens. The symbiont live imaging revealed that, at the second instar, colonization of the symbiotic midgut M4 region started around 6 h after inoculation (hai). By 24 hai, the symbiont cells appeared in the main tract and also in several crypts of the M4. By 48 hai, most of the crypts were colonized by the symbiont cells. By 72 hai, all the crypts were filled up with the symbiont cells and the symbiont localization pattern continued during the subsequent nymphal development. Quantitative PCR of the symbiont confirmed the infection dynamics quantitatively. These results highlight the stinkbug-Burkholderia gut symbiosis as an unprecedented model for comprehensive understanding of molecular mechanisms underpinning insect symbiosis. PMID:24103110

  3. Burkholderia pseudomallei septicaemia - A case report

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    Dias M

    2004-01-01

    Full Text Available Burkholderia pseudomallei, a natural saprophyte widely distributed in soil, stagnant waters of endemic areas, is said to infect humans through breaks in the skin or through inhalation causing protean clinical manifestations including fatal septicaemia. A case of septicaemia in a elderly female diabetic due to B. pseudomallei following a history of fall is being reported with complete details.

  4. Distinct human antibody response to the biological warfare agent Burkholderia mallei.

    Science.gov (United States)

    Varga, John J; Vigil, Adam; DeShazer, David; Waag, David M; Felgner, Philip; Goldberg, Joanna B

    2012-10-01

    The genetic similarity between Burkholderia mallei (glanders) and Burkholderia pseudomallei (melioidosis) had led to the general assumption that pathogenesis of each bacterium would be similar. In 2000, the first human case of glanders in North America since 1945 was reported in a microbiology laboratory worker. Leveraging the availability of pre-exposure sera for this individual and employing the same well-characterized protein array platform that has been previously used to study a large cohort of melioidosis patients in southeast Asia, we describe the antibody response in a human with glanders. Analysis of 156 peptides present on the array revealed antibodies against 17 peptides with a > 2-fold increase in this infection. Unexpectedly, when the glanders data were compared with a previous data set from B. pseudomallei infections, there were only two highly increased antibodies shared between these two infections. These findings have implications in the diagnosis and treatment of B. mallei and B. pseudomallei infections.

  5. Nematode Peptides with host-directed anti-inflammatory activity rescue Caenorhabditis elegans from a Burkholderia pseudomallei infection

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    Mei-Perng Lim

    2016-09-01

    Full Text Available Burkholderia pseudomallei, the causative agent of melioidosis, is among a growing number of bacterial pathogens that are increasingly antibiotic resistant. Antimicrobial peptides (AMPs have been investigated as an alternative approach to treat microbial infections, as generally, there is a lower likelihood that a pathogen will develop resistance to AMPs. In this study, 36 candidate Caenorhabditis elegans genes that encode secreted peptides of <150 amino acids and previously shown to be overexpressed during infection by B. pseudomallei were identified from the expression profile of infected nematodes. RNA interference (RNAi-based knockdown of 12/34 peptide-encoding genes resulted in enhanced nematode susceptibility to B. pseudomallei without affecting worm fitness. A microdilution test demonstrated that two peptides, NLP-31 and Y43C5A.3, exhibited anti-B. pseudomallei activity in a dose dependent manner on different pathogens. Time kill analysis proposed that these peptides were bacteriostatic against B. pseudomallei at concentrations up to 8× MIC90. The SYTOX green assay demonstrated that NLP-31 and Y43C5A.3 did not disrupt the B. pseudomallei membrane. Instead, gel retardation assays revealed that both peptides were able to bind to DNA and interfere with bacterial viability. In parallel, microscopic examination showed induction of cellular filamentation, a hallmark of DNA synthesis inhibition, of NLP-31 and Y43C5A.3 treated cells. In addition, the peptides also regulated the expression of inflammatory cytokines in B. pseudomallei infected macrophage cells. Collectively, these findings demonstrate the potential of NLP-31 and Y43C5A.3 as anti-B. pseudomallei peptides based on their function as immune modulators.

  6. Activity of Tobramycin against Cystic Fibrosis Isolates of Burkholderia cepacia Complex Grown as Biofilms.

    Science.gov (United States)

    Kennedy, Sarah; Beaudoin, Trevor; Yau, Yvonne C W; Caraher, Emma; Zlosnik, James E A; Speert, David P; LiPuma, John J; Tullis, Elizabeth; Waters, Valerie

    2016-01-01

    Pulmonary infection with Burkholderia cepacia complex 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 mature B. cepacia complex 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 for Burkholderia cepacia, Burkholderia multivorans, and Burkholderia vietnamiensis; 200 μg/ml of tobramycin was sufficient to reduce the thickness of Burkholderia dolosa biofilm. With a more mature 48-h biofilm, significant reductions in thickness were seen with tobramycin at concentrations of ≥100 μg/ml for all Burkholderia species. In addition, an increased ratio of dead to live cells was observed in comparison to control with tobramycin concentrations of ≥200 μg/ml for B. cepacia and B. dolosa (24 h) and ≥100 μg/ml for Burkholderia cenocepacia and B. 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 all B. cepacia complex species with the exception of B. vietnamiensis. In the presence of sputum, 1,000 μg/ml of tobramycin significantly increased the dead-to-live ratio only for B. multivorans compared to control. In summary, although killing is attenuated, high-dose tobramycin can effectively decrease the thickness of B. cepacia complex biofilms, even in the presence of sputum, suggesting a possible role as a suppressive therapy in CF. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. Combining Functional and Structural Genomics to Sample the Essential Burkholderia Structome

    Science.gov (United States)

    Baugh, Loren; Gallagher, Larry A.; Patrapuvich, Rapatbhorn; Clifton, Matthew C.; Gardberg, Anna S.; Edwards, Thomas E.; Armour, Brianna; Begley, Darren W.; Dieterich, Shellie H.; Dranow, David M.; Abendroth, Jan; Fairman, James W.; Fox, David; Staker, Bart L.; Phan, Isabelle; Gillespie, Angela; Choi, Ryan; Nakazawa-Hewitt, Steve; Nguyen, Mary Trang; Napuli, Alberto; Barrett, Lynn; Buchko, Garry W.; Stacy, Robin; Myler, Peter J.; Stewart, Lance J.; Manoil, Colin; Van Voorhis, Wesley C.

    2013-01-01

    Background The genus Burkholderia includes pathogenic gram-negative bacteria that cause melioidosis, glanders, and pulmonary infections of patients with cancer and cystic fibrosis. Drug resistance has made development of new antimicrobials critical. Many approaches to discovering new antimicrobials, such as structure-based drug design and whole cell phenotypic screens followed by lead refinement, require high-resolution structures of proteins essential to the parasite. Methodology/Principal Findings We experimentally identified 406 putative essential genes in B. thailandensis, a low-virulence species phylogenetically similar to B. pseudomallei, the causative agent of melioidosis, using saturation-level transposon mutagenesis and next-generation sequencing (Tn-seq). We selected 315 protein products of these genes based on structure-determination criteria, such as excluding very large and/or integral membrane proteins, and entered them into the Seattle Structural Genomics Center for Infection Disease (SSGCID) structure determination pipeline. To maximize structural coverage of these targets, we applied an “ortholog rescue” strategy for those producing insoluble or difficult to crystallize proteins, resulting in the addition of 387 orthologs (or paralogs) from seven other Burkholderia species into the SSGCID pipeline. This structural genomics approach yielded structures from 31 putative essential targets from B. thailandensis, and 25 orthologs from other Burkholderia species, yielding an overall structural coverage for 49 of the 406 essential gene families, with a total of 88 depositions into the Protein Data Bank. Of these, 25 proteins have properties of a potential antimicrobial drug target i.e., no close human homolog, part of an essential metabolic pathway, and a deep binding pocket. We describe the structures of several potential drug targets in detail. Conclusions/Significance This collection of structures, solubility and experimental essentiality data

  8. Combining functional and structural genomics to sample the essential Burkholderia structome.

    Directory of Open Access Journals (Sweden)

    Loren Baugh

    Full Text Available The genus Burkholderia includes pathogenic gram-negative bacteria that cause melioidosis, glanders, and pulmonary infections of patients with cancer and cystic fibrosis. Drug resistance has made development of new antimicrobials critical. Many approaches to discovering new antimicrobials, such as structure-based drug design and whole cell phenotypic screens followed by lead refinement, require high-resolution structures of proteins essential to the parasite.We experimentally identified 406 putative essential genes in B. thailandensis, a low-virulence species phylogenetically similar to B. pseudomallei, the causative agent of melioidosis, using saturation-level transposon mutagenesis and next-generation sequencing (Tn-seq. We selected 315 protein products of these genes based on structure-determination criteria, such as excluding very large and/or integral membrane proteins, and entered them into the Seattle Structural Genomics Center for Infection Disease (SSGCID structure determination pipeline. To maximize structural coverage of these targets, we applied an "ortholog rescue" strategy for those producing insoluble or difficult to crystallize proteins, resulting in the addition of 387 orthologs (or paralogs from seven other Burkholderia species into the SSGCID pipeline. This structural genomics approach yielded structures from 31 putative essential targets from B. thailandensis, and 25 orthologs from other Burkholderia species, yielding an overall structural coverage for 49 of the 406 essential gene families, with a total of 88 depositions into the Protein Data Bank. Of these, 25 proteins have properties of a potential antimicrobial drug target i.e., no close human homolog, part of an essential metabolic pathway, and a deep binding pocket. We describe the structures of several potential drug targets in detail.This collection of structures, solubility and experimental essentiality data provides a resource for development of drugs against

  9. Combining functional and structural genomics to sample the essential Burkholderia structome.

    Science.gov (United States)

    Baugh, Loren; Gallagher, Larry A; Patrapuvich, Rapatbhorn; Clifton, Matthew C; Gardberg, Anna S; Edwards, Thomas E; Armour, Brianna; Begley, Darren W; Dieterich, Shellie H; Dranow, David M; Abendroth, Jan; Fairman, James W; Fox, David; Staker, Bart L; Phan, Isabelle; Gillespie, Angela; Choi, Ryan; Nakazawa-Hewitt, Steve; Nguyen, Mary Trang; Napuli, Alberto; Barrett, Lynn; Buchko, Garry W; Stacy, Robin; Myler, Peter J; Stewart, Lance J; Manoil, Colin; Van Voorhis, Wesley C

    2013-01-01

    The genus Burkholderia includes pathogenic gram-negative bacteria that cause melioidosis, glanders, and pulmonary infections of patients with cancer and cystic fibrosis. Drug resistance has made development of new antimicrobials critical. Many approaches to discovering new antimicrobials, such as structure-based drug design and whole cell phenotypic screens followed by lead refinement, require high-resolution structures of proteins essential to the parasite. We experimentally identified 406 putative essential genes in B. thailandensis, a low-virulence species phylogenetically similar to B. pseudomallei, the causative agent of melioidosis, using saturation-level transposon mutagenesis and next-generation sequencing (Tn-seq). We selected 315 protein products of these genes based on structure-determination criteria, such as excluding very large and/or integral membrane proteins, and entered them into the Seattle Structural Genomics Center for Infection Disease (SSGCID) structure determination pipeline. To maximize structural coverage of these targets, we applied an "ortholog rescue" strategy for those producing insoluble or difficult to crystallize proteins, resulting in the addition of 387 orthologs (or paralogs) from seven other Burkholderia species into the SSGCID pipeline. This structural genomics approach yielded structures from 31 putative essential targets from B. thailandensis, and 25 orthologs from other Burkholderia species, yielding an overall structural coverage for 49 of the 406 essential gene families, with a total of 88 depositions into the Protein Data Bank. Of these, 25 proteins have properties of a potential antimicrobial drug target i.e., no close human homolog, part of an essential metabolic pathway, and a deep binding pocket. We describe the structures of several potential drug targets in detail. This collection of structures, solubility and experimental essentiality data provides a resource for development of drugs against infections and diseases

  10. Unusual distribution of Burkholderia cepacia complex species in Danish cystic fibrosis clinics may stem from restricted transmission between patients

    DEFF Research Database (Denmark)

    Nørskov-Lauritsen, Niels; Johansen, Helle Krogh; Fenger, Mette G

    2010-01-01

    Forty-four of 48 Burkholderia cepacia complex strains cultured from Danish cystic fibrosis patients were Burkholderia multivorans, a distribution of species that has not been reported before. Although cases of cross infections were demonstrated, no major epidemic clone was found. The species...

  11. Burkholderia humisilvae sp. nov., Burkholderia solisilvae sp. nov. and Burkholderia rhizosphaerae sp. nov., isolated from forest soil and rhizosphere soil.

    Science.gov (United States)

    Lee, Jae-Chan; Whang, Kyung-Sook

    2015-09-01

    Strains Y-12(T) and Y-47(T) were isolated from mountain forest soil and strain WR43(T) was isolated from rhizosphere soil, at Daejeon, Korea. The three strains grew at 10-55 °C (optimal growth at 28-30 °C), at pH 3.0-8.0 (optimal growth at pH 6.0) and in the presence of 0-4.0% (w/v) NaCl, growing optimally in the absence of added NaCl. On the basis of 16S rRNA gene sequence analysis, the three strains were found to belong to the genus Burkholderia, showing the closest phylogenetic similarity to Burkholderia diazotrophica JPY461(T) (97.2-97.7%); the similarity between the three sequences ranged from 98.3 to 98.7%. Additionally, the three strains formed a distinct group in phylogenetic trees based on the housekeeping genes recA and gyrB. The predominant ubiquinone was Q-8, the major fatty acids were C16 : 0 and C17  : 0 cyclo and the DNA G+C content of the novel isolates was 61.6-64.4 mol%. DNA-DNA relatedness among the three strains and the type strains of the closest species of the genus Burkholderia was less than 50%. On the basis of 16S rRNA, recA and gyrB gene sequence similarities, chemotaxonomic and phenotypic data, the three strains represent three novel species within the genus Burkholderia, for which the names Burkholderia humisilvae sp. nov. (type strain Y-12(T)= KACC 17601(T) = NBRC 109933(T) = NCAIM B 02543(T)), Burkholderia solisilvae sp. nov. (type strain Y-47(T) = KACC 17602(T)= NBRC 109934(T) = NCAIM B 02539(T)) and Burkholderia rhizosphaerae sp. nov. (type strain WR43(T) = KACC 17603(T) = NBRC 109935(T) = NCAIM B 02541(T)) are proposed.

  12. Burkholderia pseudomallei isolates in 2 pet iguanas, California, USA.

    Science.gov (United States)

    Zehnder, Ashley M; Hawkins, Michelle G; Koski, Marilyn A; Lifland, Barry; Byrne, Barbara A; Swanson, Alexandra A; Rood, Michael P; Gee, Jay E; Elrod, Mindy Glass; Beesley, Cari A; Blaney, David D; Ventura, Jean; Hoffmaster, Alex R; Beeler, Emily S

    2014-02-01

    Burkholderia pseudomallei, the causative agent of melioidosis, was isolated from abscesses of 2 pet green iguanas in California, USA. The international trade in iguanas may contribute to importation of this pathogen into countries where it is not endemic and put persons exposed to these animals at risk for infection.

  13. Burkholderia pseudomallei Isolates in 2 Pet Iguanas, California, USA

    OpenAIRE

    Zehnder, Ashley M.; Hawkins, Michelle G.; Koski, Marilyn A.; Lifland, Barry; Byrne, Barbara A.; Swanson, Alexandra A.; Rood, Michael P.; Gee, Jay E.; Elrod, Mindy Glass; Beesley, Cari A.; Blaney, David D.; Ventura, Jean; Hoffmaster, Alex R.; Beeler, Emily S.

    2014-01-01

    Burkholderia pseudomallei, the causative agent of melioidosis, was isolated from abscesses of 2 pet green iguanas in California, USA. The international trade in iguanas may contribute to importation of this pathogen into countries where it is not endemic and put persons exposed to these animals at risk for infection.

  14. Burkholderia sp. KCTC 11096BP modulates pepper growth and resistance against Phytophthora capsici

    International Nuclear Information System (INIS)

    Kang, S.M.; Hamayun, M.; Shinwari, Z.K.

    2016-01-01

    Biological control of crop diseases is desirable for sustainable agriculture as it minimizes chemical inputs in the agricultural system and promotes eco-friendly environment. We analyzed the favorable role of Burkholderia sp. KCTC 11096BP against the pathogen Phytophthora capsici in pepper. We screen thirty rhizobateria for their anti-pathogen activity, and found that Burkholderia sp. KCTC 11096BP exhibits maximum growth inhibition of the pathogen P. capsici. The bacterium inoculation to pepper plants significantly enhanced growth attributes of pepper in infected and control treatments. The total proteins (10.9%), and the amino acids viz. glycine (4.08 ug/g), leucine (3.3 ug/g), and alanine (3.26 ug/g) were preset in considerably higher quantities in Burkholderia sp. applied treatments as compare to control. The systemic acquired resistance (SAR) of the host plant was up-regulated by Burkholderia sp. KCTC, as endogenous salicylic acid (235.5 ng/g) and jasmonic acid (22.8 ng/g) levels were found higher in such treatments. It was concluded that Burkholderia sp. KCTC 11096BP mitigates the adverse effects of P. capsici on pepper crop and can improve crop productivity at the field level. (author)

  15. Cross-species comparison of the Burkholderia pseudomallei, Burkholderia thailandensis, and Burkholderia mallei quorum-sensing regulons.

    Science.gov (United States)

    Majerczyk, Charlotte D; Brittnacher, Mitchell J; Jacobs, Michael A; Armour, Christopher D; Radey, Matthew C; Bunt, Richard; Hayden, Hillary S; Bydalek, Ryland; Greenberg, E Peter

    2014-11-01

    Burkholderia pseudomallei, Burkholderia thailandensis, and Burkholderia mallei (the Bptm group) are close relatives with very different lifestyles: B. pseudomallei is an opportunistic pathogen, B. thailandensis is a nonpathogenic saprophyte, and B. mallei is a host-restricted pathogen. The acyl-homoserine lactone quorum-sensing (QS) systems of these three species show a high level of conservation. We used transcriptome sequencing (RNA-seq) to define the quorum-sensing regulon in each species, and we performed a cross-species analysis of the QS-controlled orthologs. Our analysis revealed a core set of QS-regulated genes in all three species, as well as QS-controlled factors shared by only two species or unique to a given species. This global survey of the QS regulons of B. pseudomallei, B. thailandensis, and B. mallei serves as a platform for predicting which QS-controlled processes might be important in different bacterial niches and contribute to the pathogenesis of B. pseudomallei and B. mallei. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  16. Cross-Species Comparison of the Burkholderia pseudomallei, Burkholderia thailandensis, and Burkholderia mallei Quorum-Sensing Regulons

    Science.gov (United States)

    Majerczyk, Charlotte D.; Brittnacher, Mitchell J.; Jacobs, Michael A.; Armour, Christopher D.; Radey, Matthew C.; Bunt, Richard; Hayden, Hillary S.; Bydalek, Ryland

    2014-01-01

    Burkholderia pseudomallei, Burkholderia thailandensis, and Burkholderia mallei (the Bptm group) are close relatives with very different lifestyles: B. pseudomallei is an opportunistic pathogen, B. thailandensis is a nonpathogenic saprophyte, and B. mallei is a host-restricted pathogen. The acyl-homoserine lactone quorum-sensing (QS) systems of these three species show a high level of conservation. We used transcriptome sequencing (RNA-seq) to define the quorum-sensing regulon in each species, and we performed a cross-species analysis of the QS-controlled orthologs. Our analysis revealed a core set of QS-regulated genes in all three species, as well as QS-controlled factors shared by only two species or unique to a given species. This global survey of the QS regulons of B. pseudomallei, B. thailandensis, and B. mallei serves as a platform for predicting which QS-controlled processes might be important in different bacterial niches and contribute to the pathogenesis of B. pseudomallei and B. mallei. PMID:25182491

  17. Detection of misidentifications of species from the Burkholderia cepacia complex and description of a new member, the soil bacterium Burkholderia catarinensis sp. nov.

    Science.gov (United States)

    Bach, Evelise; Sant'Anna, Fernando Hayashi; Magrich Dos Passos, João Frederico; Balsanelli, Eduardo; de Baura, Valter Antonio; Pedrosa, Fábio de Oliveira; de Souza, Emanuel Maltempi; Passaglia, Luciane Maria Pereira

    2017-08-31

    The correct identification of bacteria from the Burkholderia cepacia complex (Bcc) is crucial for epidemiological studies and treatment of cystic fibrosis infections. However, genome-based identification tools are revealing many controversial Bcc species assignments. The aim of this work is to re-examine the taxonomic position of the soil bacterium B. cepacia 89 through polyphasic and genomic approaches. recA and 16S rRNA gene sequence analysis positioned strain 89 inside the Bcc group. However, based on the divergence score of seven concatenated allele sequences, and values of average nucleotide identity, and digital DNA:DNA hybridization, our results suggest that strain 89 is different from other Bcc species formerly described. Thus, we propose to classify Burkholderia sp. 89 as the novel species Burkholderia catarinensis sp. nov. with strain 89T (=DSM 103188T = BR 10601T) as the type strain. Moreover, our results call the attention to some probable misidentifications of Bcc genomes at the National Center for Biotechnology Information database. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Burkholderia thailandensis: Genetic Manipulation.

    Science.gov (United States)

    Garcia, Erin C

    2017-05-16

    Burkholderia thailandensis is a Gram-negative bacterium endemic to Southeast Asian and northern Australian soils. It is non-pathogenic; therefore, it is commonly used as a model organism for the related human pathogens Burkholderia mallei and Burkholderia pseudomallei. B. thailandensis is relatively easily genetically manipulated and a variety of robust genetic tools can be used in this organism. This unit describes protocols for conjugation, natural transformation, mini-Tn7 insertion, and allelic exchange in B. thailandensis. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  19. Effect of gamma irradiation on Burkholderia thailandensis (Burkholderia pseudomallei surrogate) survival under combinations of pH and NaCl

    International Nuclear Information System (INIS)

    Yoon, Yohan; Kim, Jae-Hun; Byun, Myung-Woo; Choi, Kyoung-Hee; Lee, Ju-Woon

    2010-01-01

    This study evaluated the effect of gamma irradiation on Burkholderia thailandensis (Burkholderia pseudomallei surrogate; potential bioterrorism agent) survival under different levels of NaCl and pH. B. thailandensis in Luria Bertani broth supplemented with NaCl (0-3%), and pH-adjusted to 4-7 was treated with gamma irradiation (0-0.5 kGy). Surviving cell counts of bacteria were then enumerated on tryptic soy agar. Data for the cell counts were also used to calculate D 10 values (the dose required to reduce 1 log CFU/mL of B. thailandensis). Cell counts of B. thailandensis were decreased (P 10 values ranged from 0.04 to 0.07 kGy, regardless of NaCl and pH level. These results indicate that low doses of gamma irradiation should be a useful treatment in decreasing the potential bioterrorism bacteria, which may possibly infect humans through foods.

  20. Burkholderia monticola sp. nov., isolated from mountain soil.

    Science.gov (United States)

    Baek, Inwoo; Seo, Boram; Lee, Imchang; Yi, Hana; Chun, Jongsik

    2015-02-01

    An ivory/yellow, Gram-stain-negative, short-rod-shaped, aerobic bacterial strain, designated JC2948(T), was isolated from a soil sample taken from Gwanak Mountain, Republic of Korea. 16S rRNA gene sequence analysis indicated that strain JC2948(T) belongs to the genus Burkholderia. The test strain showed highest sequence similarities to Burkholderia tropica LMG 22274(T) (97.6 %), Burkholderia acidipaludis NBRC 101816(T) (97.5 %), Burkholderia tuberum LMG 21444(T) (97.5 %), Burkholderia sprentiae LMG 27175(T) (97.4 %), Burkholderia terricola LMG 20594(T) (97.3 %) and Burkholderia diazotrophica LMG 26031(T) (97.1 %). Based on average nucleotide identity (ANI) values, the new isolate represents a novel genomic species as it shows less than 90 % ANI values with other closely related species. Also, other phylosiological and biochemical comparisons allowed the phenotypic differentiation of strain JC2948(T) from other members of the genus Burkholderia. Therefore, we suggest that this strain should be classified as the type strain of a novel species of the genus Burkholderia. The name Burkholderia monticola sp. nov. (type strain, JC2948(T) = JCM 19904(T) = KACC 17924(T)) is proposed. © 2015 IUMS.

  1. Non-obligate predatory bacterium burkholderia casidaeand uses thereof

    OpenAIRE

    1998-01-01

    A novel predator bacterium Burkholderia casidae is disclosed. The invention is directed to the isolation and use of Burkholderia casidae to control microbial diseases of plants. The genetic, biochemical and physiological characteristics of Burkholderia casidae are described. Biocontrol compositions comprising Burkholderia casidae, and antimicrobial compounds and antimicrobial preparations prepared from Burkholderia casidae are also disclosed, as are methods for accomplishing all of the forego...

  2. Global Analysis of the Burkholderia thailandensis Quorum Sensing-Controlled Regulon

    Science.gov (United States)

    Majerczyk, Charlotte; Brittnacher, Mitchell; Jacobs, Michael; Armour, Christopher D.; Radey, Mathew; Schneider, Emily; Phattarasokul, Somsak; Bunt, Richard

    2014-01-01

    Burkholderia thailandensis contains three acyl-homoserine lactone quorum sensing circuits and has two additional LuxR homologs. To identify B. thailandensis quorum sensing-controlled genes, we carried out transcriptome sequencing (RNA-seq) analyses of quorum sensing mutants and their parent. The analyses were grounded in the fact that we identified genes coding for factors shown previously to be regulated by quorum sensing among a larger set of quorum-controlled genes. We also found that genes coding for contact-dependent inhibition were induced by quorum sensing and confirmed that specific quorum sensing mutants had a contact-dependent inhibition defect. Additional quorum-controlled genes included those for the production of numerous secondary metabolites, an uncharacterized exopolysaccharide, and a predicted chitin-binding protein. This study provides insights into the roles of the three quorum sensing circuits in the saprophytic lifestyle of B. thailandensis, and it provides a foundation on which to build an understanding of the roles of quorum sensing in the biology of B. thailandensis and the closely related pathogenic Burkholderia pseudomallei and Burkholderia mallei. PMID:24464461

  3. Global analysis of the Burkholderia thailandensis quorum sensing-controlled regulon.

    Science.gov (United States)

    Majerczyk, Charlotte; Brittnacher, Mitchell; Jacobs, Michael; Armour, Christopher D; Radey, Mathew; Schneider, Emily; Phattarasokul, Somsak; Bunt, Richard; Greenberg, E Peter

    2014-04-01

    Burkholderia thailandensis contains three acyl-homoserine lactone quorum sensing circuits and has two additional LuxR homologs. To identify B. thailandensis quorum sensing-controlled genes, we carried out transcriptome sequencing (RNA-seq) analyses of quorum sensing mutants and their parent. The analyses were grounded in the fact that we identified genes coding for factors shown previously to be regulated by quorum sensing among a larger set of quorum-controlled genes. We also found that genes coding for contact-dependent inhibition were induced by quorum sensing and confirmed that specific quorum sensing mutants had a contact-dependent inhibition defect. Additional quorum-controlled genes included those for the production of numerous secondary metabolites, an uncharacterized exopolysaccharide, and a predicted chitin-binding protein. This study provides insights into the roles of the three quorum sensing circuits in the saprophytic lifestyle of B. thailandensis, and it provides a foundation on which to build an understanding of the roles of quorum sensing in the biology of B. thailandensis and the closely related pathogenic Burkholderia pseudomallei and Burkholderia mallei.

  4. Burkholderia cenocepacia type VI secretion system mediates escape of type II secreted proteins into the cytoplasm of infected macrophages.

    Directory of Open Access Journals (Sweden)

    Roberto Rosales-Reyes

    Full Text Available 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 onto the BcCV membrane. A Type 6 secretion system (T6SS is required for these phenotypes but surprisingly it is not required for the maturation arrest of the BcCV. Here, we show that macrophages infected with B. cenocepacia employ the NLRP3 inflammasome to induce IL-1β secretion and pyroptosis. Moreover, IL-1β secretion by B. cenocepacia-infected macrophages is suppressed in deletion mutants unable to produce functional Type VI, Type IV, and Type 2 secretion systems (SS. We provide evidence that the T6SS mediates the disruption of the BcCV membrane, which allows the escape of proteins secreted by the T2SS into the macrophage cytoplasm. This was demonstrated by the activity of fusion derivatives of the T2SS-secreted metalloproteases ZmpA and ZmpB with adenylcyclase. Supporting this notion, ZmpA and ZmpB are required for efficient IL-1β secretion in a T6SS dependent manner. ZmpA and ZmpB are also required for the maturation arrest of the BcCVs and bacterial intra-macrophage survival in a T6SS-independent fashion. Our results uncover a novel mechanism for inflammasome activation that involves cooperation between two bacterial secretory pathways, and an unanticipated role for T2SS-secreted proteins in intracellular bacterial survival.

  5. Use of a Real-Time PCR TaqMan Assay for Rapid Identification and Differentiation of Burkholderia pseudomallei and Burkholderia mallei

    OpenAIRE

    U'Ren, Jana M.; Van Ert, Matthew N.; Schupp, James M.; Easterday, W. Ryan; Simonson, Tatum S.; Okinaka, Richard T.; Pearson, Talima; Keim, Paul

    2005-01-01

    A TaqMan allelic-discrimination assay designed around a synonymous single-nucleotide polymorphism was used to genotype Burkholderia pseudomallei and Burkholderia mallei isolates. The assay rapidly identifies and discriminates between these two highly pathogenic bacteria and does not cross-react with genetic near neighbors, such as Burkholderia thailandensis and Burkholderia cepacia.

  6. Burkholderia humptydooensis sp. nov., a New Species Related to Burkholderia thailandensis and the Fifth Member of the Burkholderia pseudomallei Complex.

    Science.gov (United States)

    Tuanyok, Apichai; Mayo, Mark; Scholz, Holger; Hall, Carina M; Allender, Christopher J; Kaestli, Mirjam; Ginther, Jennifer; Spring-Pearson, Senanu; Bollig, Molly C; Stone, Joshua K; Settles, Erik W; Busch, Joseph D; Sidak-Loftis, Lindsay; Sahl, Jason W; Thomas, Astrid; Kreutzer, Lisa; Georgi, Enrico; Gee, Jay E; Bowen, Richard A; Ladner, Jason T; Lovett, Sean; Koroleva, Galina; Palacios, Gustavo; Wagner, David M; Currie, Bart J; Keim, Paul

    2017-03-01

    During routine screening for Burkholderia pseudomallei from water wells in northern Australia in areas where it is endemic, Gram-negative bacteria (strains MSMB43 T , MSMB121, and MSMB122) with a similar morphology and biochemical pattern to B. pseudomallei and B. thailandensis were coisolated with B. pseudomallei on Ashdown's selective agar. To determine the exact taxonomic position of these strains and to distinguish them from B. pseudomallei and B. thailandensis , they were subjected to a series of phenotypic and molecular analyses. Biochemical and fatty acid methyl ester analysis was unable to distinguish B. humptydooensis sp. nov. from closely related species. With matrix-assisted laser desorption ionization-time of flight analysis, all isolates grouped together in a cluster separate from other Burkholderia spp. 16S rRNA and recA sequence analyses demonstrated phylogenetic placement for B. humptydooensis sp. nov. in a novel clade within the B. pseudomallei group. Multilocus sequence typing (MLST) analysis of the three isolates in comparison with MLST data from 3,340 B. pseudomallei strains and related taxa revealed a new sequence type (ST318). Genome-to-genome distance calculations and the average nucleotide identity of all isolates to both B. thailandensis and B. pseudomallei , based on whole-genome sequences, also confirmed B. humptydooensis sp. nov. as a novel Burkholderia species within the B. pseudomallei complex. Molecular analyses clearly demonstrated that strains MSMB43 T , MSMB121, and MSMB122 belong to a novel Burkholderia species for which the name Burkholderia humptydooensis sp. nov. is proposed, with the type strain MSMB43 T (American Type Culture Collection BAA-2767; Belgian Co-ordinated Collections of Microorganisms LMG 29471; DDBJ accession numbers CP013380 to CP013382). IMPORTANCE Burkholderia pseudomallei is a soil-dwelling bacterium and the causative agent of melioidosis. The genus Burkholderia consists of a diverse group of species, with

  7. Burkholderia megalochromosomata sp. nov., isolated from grassland soil.

    Science.gov (United States)

    Baek, Inwoo; Seo, Boram; Lee, Imchang; Lee, Kihyun; Park, Sang-Cheol; Yi, Hana; Chun, Jongsik

    2015-03-01

    A Gram-stain negative, rod-shaped, non-spore-forming, obligate aerobic bacterial strain, JC2949(T), was isolated from grassland soil in Gwanak Mountain, Seoul, Republic of Korea. Phylogenetic analysis, based on 16S rRNA sequences, indicated that strain JC2949(T) belongs to the genus Burkholderia, showing highest sequence similarities with Burkholderia grimmiae R27(T) (98.8 %), Burkholderia cordobensis LMG 27620(T) (98.6 %), Burkholderia jiangsuensis MP-1T(T) (98.6 %), Burkholderia zhejiangensis OP-1(T) (98.5 %), Burkholderia humi LMG 22934(T) (97.5 %), Burkholderia terrestris LMG 22937(T) (97.3 %), Burkholderia telluris LMG 22936(T) (97.2 %) and Burkholderia glathei ATCC 29195(T) (97.0 %). The major fatty acids of strain JC2949(T) were C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. Its predominant polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and an unknown amino phospholipid. The dominant isoprenoid quinone was ubiquinone Q-8. The pairwise average nucleotide identity values between strain JC2949(T) and the genomes of 30 other species of the genus Burkholderia ranged from 73.4-90.4 %, indicating that the isolate is a novel genomic species within this genus. Based on phenotypic and chemotaxonomic comparisons, it is clear that strain JC2949(T) represents a novel species of the genus Burkholderia. We propose the name for this novel species to be Burkholderia megalochromosomata sp. nov. The type strain is JC2949(T) ( = KACC 17925(T) = JCM 19905(T)). © 2015 IUMS.

  8. Infection of Burkholderia cepacia induces homeostatic responses in the host for their prolonged survival: the microarray perspective.

    Directory of Open Access Journals (Sweden)

    Vanitha Mariappan

    Full Text Available Burkholderia cepacia is an opportunistic human pathogen associated with life-threatening pulmonary infections in immunocompromised individuals. Pathogenesis of B. cepacia infection involves adherence, colonisation, invasion, survival and persistence in the host. In addition, B. cepacia are also known to secrete factors, which are associated with virulence in the pathogenesis of the infection. In this study, the host factor that may be the cause of the infection was elucidated in human epithelial cell line, A549, that was exposed to live B. cepacia (mid-log phase and its secretory proteins (mid-log and early-stationary phases using the Illumina Human Ref-8 microarray platform. The non-infection A549 cells were used as a control. Expression of the host genes that are related to apoptosis, inflammation and cell cycle as well as metabolic pathways were differentially regulated during the infection. Apoptosis of the host cells and secretion of pro-inflammatory cytokines were found to be inhibited by both live B. cepacia and its secretory proteins. In contrast, the host cell cycle and metabolic processes, particularly glycolysis/glycogenesis and fatty acid metabolism were transcriptionally up-regulated during the infection. Our microarray analysis provided preliminary insights into mechanisms of B. cepacia pathogenesis. The understanding of host response to an infection would provide novel therapeutic targets both for enhancing the host's defences and repressing detrimental responses induced by the invading pathogen.

  9. 40 CFR 725.1075 - Burkholderia cepacia complex.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Burkholderia cepacia complex. 725.1075... Specific Microorganisms § 725.1075 Burkholderia cepacia complex. (a) Microorganism and significant new uses subject to reporting. (1) The microorganisms identified as the Burkholderia cepacia complex defined as...

  10. Non-obligate predatory bacterium Burkholderia casidae and uses thereof

    OpenAIRE

    2001-01-01

    A novel predator bacterium Burkholderia casidae is disclosed. The invention is directed to the isolation and use of Burkholderia casidae to control microbial diseases of plants. The genetic, biochemical and physiological characteristics of Burkholderia casidae are described. Biocontrol compositions comprising Burkholderia casidae, and antimicrobial compounds and antimicrobial preparations prepared from Burkholderia casidae are also disclosed, as are methods for accomplishing all of the forego...

  11. Study of class I integron in a Burkholderia cepacia complex strain isolated from blood colture

    Directory of Open Access Journals (Sweden)

    Linda Furlanis

    2011-06-01

    Full Text Available The Burkholderia cepacia complex (Bcc consists of several species that cause lung infections in patients with cystic fibrosis but are also capable to colonize immunocompromised patients. Once established, the infection is usually difficult to eradicate, as Bcc is intrinsically resistant to many antibiotics. Besides, the acquisition of additional resistance determinants by horizontal gene transfer makes very difficult the therapeutic approach to these infections. Among horizontally acquired DNAs, integrons have been frequently reported in many Gramnegative bacteria that affect human health, but they have not been found frequently in Burkholderia isolates until now. In the present work we report on a Bcc isolate, recovered from the blood of an immunocompromised patient, that carries a 2.3 kb class I integron already described in a Salmonella enterica isolate eight years ago, coding for aacA4, aadA1 and catB2 in its cassette array.

  12. Burkholderia bacteria infectiously induce the proto-farming symbiosis of Dictyostelium amoebae and food bacteria.

    Science.gov (United States)

    DiSalvo, Susanne; Haselkorn, Tamara S; Bashir, Usman; Jimenez, Daniela; Brock, Debra A; Queller, David C; Strassmann, Joan E

    2015-09-08

    Symbiotic associations can allow an organism to acquire novel traits by accessing the genetic repertoire of its partner. In the Dictyostelium discoideum farming symbiosis, certain amoebas (termed "farmers") stably associate with bacterial partners. Farmers can suffer a reproductive cost but also gain beneficial capabilities, such as carriage of bacterial food (proto-farming) and defense against competitors. Farming status previously has been attributed to amoeba genotype, but the role of bacterial partners in its induction has not been examined. Here, we explore the role of bacterial associates in the initiation, maintenance, and phenotypic effects of the farming symbiosis. We demonstrate that two clades of farmer-associated Burkholderia isolates colonize D. discoideum nonfarmers and infectiously endow them with farmer-like characteristics, indicating that Burkholderia symbionts are a major driver of the farming phenomenon. Under food-rich conditions, Burkholderia-colonized amoebas produce fewer spores than uncolonized counterparts, with the severity of this reduction being dependent on the Burkholderia colonizer. However, the induction of food carriage by Burkholderia colonization may be considered a conditionally adaptive trait because it can confer an advantage to the amoeba host when grown in food-limiting conditions. We observed Burkholderia inside and outside colonized D. discoideum spores after fruiting body formation; this observation, together with the ability of Burkholderia to colonize new amoebas, suggests a mixed mode of symbiont transmission. These results change our understanding of the D. discoideum farming symbiosis by establishing that the bacterial partner, Burkholderia, is an important causative agent of the farming phenomenon.

  13. Literature Review of DNA-Based Subspecies Analysis of Bacillus Anthracis Burkholderia Pseudomallel Burkholderia Mallei, and Yersinia Pestis

    National Research Council Canada - National Science Library

    Harvey, Steven

    1999-01-01

    ...; Bacillus anthracis, Burkholderia pseudomallei, Burkholderia mallei, and Yersinia pestis. Considerable research has been accomplished for the identification of polymorphisms from the strains B. anthracis and B. pseudomallei. The B...

  14. Effect of gamma irradiation on Burkholderia thailandensis (Burkholderia pseudomallei surrogate) survival under combinations of pH and NaCl

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yohan; Kim, Jae-Hun; Byun, Myung-Woo [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Jeollabuk 580-185 (Korea, Republic of); Choi, Kyoung-Hee [Department of Oral Microbiology, College of Dentistry, Wonkwang University, Iksan, Jeollabuk 570-749 (Korea, Republic of); Lee, Ju-Woon, E-mail: sjwlee@kaeri.re.k [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Jeollabuk 580-185 (Korea, Republic of)

    2010-04-15

    This study evaluated the effect of gamma irradiation on Burkholderia thailandensis (Burkholderia pseudomallei surrogate; potential bioterrorism agent) survival under different levels of NaCl and pH. B. thailandensis in Luria Bertani broth supplemented with NaCl (0-3%), and pH-adjusted to 4-7 was treated with gamma irradiation (0-0.5 kGy). Surviving cell counts of bacteria were then enumerated on tryptic soy agar. Data for the cell counts were also used to calculate D{sub 10} values (the dose required to reduce 1 log CFU/mL of B. thailandensis). Cell counts of B. thailandensis were decreased (P<0.05) as irradiation dose increased, and no differences (P>=0.05) in cell counts of the bacteria were observed among different levels of NaCl and pH. D{sub 10} values ranged from 0.04 to 0.07 kGy, regardless of NaCl and pH level. These results indicate that low doses of gamma irradiation should be a useful treatment in decreasing the potential bioterrorism bacteria, which may possibly infect humans through foods.

  15. Effect of gamma irradiation on Burkholderia thailandensis ( Burkholderia pseudomallei surrogate) survival under combinations of pH and NaCl

    Science.gov (United States)

    Yoon, Yohan; Kim, Jae-Hun; Byun, Myung-Woo; Choi, Kyoung-Hee; Lee, Ju-Woon

    2010-04-01

    This study evaluated the effect of gamma irradiation on Burkholderia thailandensis ( Burkholderia pseudomallei surrogate; potential bioterrorism agent) survival under different levels of NaCl and pH. B. thailandensis in Luria Bertani broth supplemented with NaCl (0-3%), and pH-adjusted to 4-7 was treated with gamma irradiation (0-0.5 kGy). Surviving cell counts of bacteria were then enumerated on tryptic soy agar. Data for the cell counts were also used to calculate D10 values (the dose required to reduce 1 log CFU/mL of B. thailandensis). Cell counts of B. thailandensis were decreased ( P<0.05) as irradiation dose increased, and no differences ( P≥0.05) in cell counts of the bacteria were observed among different levels of NaCl and pH. D10 values ranged from 0.04 to 0.07 kGy, regardless of NaCl and pH level. These results indicate that low doses of gamma irradiation should be a useful treatment in decreasing the potential bioterrorism bacteria, which may possibly infect humans through foods.

  16. Identification and characterization of Burkholderia multivorans CCA53.

    Science.gov (United States)

    Akita, Hironaga; Kimura, Zen-Ichiro; Yusoff, Mohd Zulkhairi Mohd; Nakashima, Nobutaka; Hoshino, Tamotsu

    2017-07-06

    A lignin-degrading bacterium, Burkholderia sp. CCA53, was previously isolated from leaf soil. The purpose of this study was to determine phenotypic and biochemical features of Burkholderia sp. CCA53. Multilocus sequence typing (MLST) analysis based on fragments of the atpD, gltD, gyrB, lepA, recA and trpB gene sequences was performed to identify Burkholderia sp. CCA53. The MLST analysis revealed that Burkholderia sp. CCA53 was tightly clustered with B. multivorans ATCC BAA-247 T . The quinone and cellular fatty acid profiles, carbon source utilization, growth temperature and pH were consistent with the characteristics of B. multivorans species. Burkholderia sp. CCA53 was therefore identified as B. multivorans CCA53.

  17. Understanding the direction of evolution in Burkholderia glumae through comparative genomics.

    Science.gov (United States)

    Lee, Hyun-Hee; Park, Jungwook; Kim, Jinnyun; Park, Inmyoung; Seo, Young-Su

    2016-02-01

    Members of the genus Burkholderia occupy remarkably diverse niches, with genome sizes ranging from ~3.75 to 11.29 Mbp. The genome of Burkholderia glumae ranges in size from ~5.81 to 7.89 Mbp. Unlike other plant pathogenic bacteria, B. glumae can infect a wide range of monocot and dicot plants. Comparative genome analysis of B. glumae strains can provide insight into genome variation as well as differential features of whole metabolism or pathways between multiple strains of B. glumae infecting the same host. Comparative analysis of complete genomes among B. glumae BGR1, B. glumae LMG 2196, and B. glumae PG1 revealed the largest departmentalization of genes onto separate replicons in B. glumae BGR1 and considerable downsizing of the genome in B. glumae LMG 2196. In addition, the presence of large-scale evolutionary events such as rearrangement and inversion and the development of highly specialized systems were found to be related to virulence-associated features in the three B. glumae strains. This connection may explain why this bacterium broadens its host range and reinforces its interaction with hosts.

  18. Neutrophil extracellular traps in the host defense against sepsis induced by Burkholderia pseudomallei (melioidosis)

    NARCIS (Netherlands)

    de Jong, Hanna K.; Koh, Gavin C. K. W.; Achouiti, Ahmed; van der Meer, Anne J.; Bulder, Ingrid; Stephan, Femke; Roelofs, Joris J. T. H.; Day, Nick P. J.; Peacock, Sharon J.; Zeerleder, Sacha; Wiersinga, W. Joost

    2014-01-01

    Neutrophil extracellular traps (NETs) are a central player in the host response to bacteria: neutrophils release extracellular DNA (nucleosomes) and neutrophil elastase to entrap and kill bacteria. We studied the role of NETs in Burkholderia pseudomallei infection (melioidosis), an important cause

  19. Phylogeographic, genomic, and meropenem susceptibility analysis of Burkholderia ubonensis.

    Science.gov (United States)

    Price, Erin P; Sarovich, Derek S; Webb, Jessica R; Hall, Carina M; Jaramillo, Sierra A; Sahl, Jason W; Kaestli, Mirjam; Mayo, Mark; Harrington, Glenda; Baker, Anthony L; Sidak-Loftis, Lindsay C; Settles, Erik W; Lummis, Madeline; Schupp, James M; Gillece, John D; Tuanyok, Apichai; Warner, Jeffrey; Busch, Joseph D; Keim, Paul; Currie, Bart J; Wagner, David M

    2017-09-01

    The bacterium Burkholderia ubonensis is commonly co-isolated from environmental specimens harbouring the melioidosis pathogen, Burkholderia pseudomallei. B. ubonensis has been reported in northern Australia and Thailand but not North America, suggesting similar geographic distribution to B. pseudomallei. Unlike most other Burkholderia cepacia complex (Bcc) species, B. ubonensis is considered non-pathogenic, although its virulence potential has not been tested. Antibiotic resistance in B. ubonensis, particularly towards drugs used to treat the most severe B. pseudomallei infections, has also been poorly characterised. This study examined the population biology of B. ubonensis, and includes the first reported isolates from the Caribbean. Phylogenomic analysis of 264 B. ubonensis genomes identified distinct clades that corresponded with geographic origin, similar to B. pseudomallei. A small proportion (4%) of strains lacked the 920kb chromosome III replicon, with discordance of presence/absence amongst genetically highly related strains, demonstrating that the third chromosome of B. ubonensis, like other Bcc species, probably encodes for a nonessential pC3 megaplasmid. Multilocus sequence typing using the B. pseudomallei scheme revealed that one-third of strains lack the "housekeeping" narK locus. In comparison, all strains could be genotyped using the Bcc scheme. Several strains possessed high-level meropenem resistance (≥32 μg/mL), a concern due to potential transmission of this phenotype to B. pseudomallei. In silico analysis uncovered a high degree of heterogeneity among the lipopolysaccharide O-antigen cluster loci, with at least 35 different variants identified. Finally, we show that Asian B. ubonensis isolate RF23-BP41 is avirulent in the BALB/c mouse model via a subcutaneous route of infection. Our results provide several new insights into the biology of this understudied species.

  20. Burkholderia cordobensis sp. nov., from agricultural soils.

    Science.gov (United States)

    Draghi, Walter O; Peeters, Charlotte; Cnockaert, Margo; Snauwaert, Cindy; Wall, Luis G; Zorreguieta, Angeles; Vandamme, Peter

    2014-06-01

    Two Gram-negative, rod-shaped bacteria were isolated from agricultural soils in Córdoba province in central Argentina. Their 16S rRNA gene sequences demonstrated that they belong to the genus Burkholderia, with Burkholderia zhejiangensis as most closely related formally named species; this relationship was confirmed through comparative gyrB sequence analysis. Whole-cell fatty acid analysis supported their assignment to the genus Burkholderia. Burkholderia sp. strain YI23, for which a whole-genome sequence is available, represents the same taxon, as demonstrated by its highly similar 16S rRNA (100% similarity) and gyrB (99.1-99.7%) gene sequences. The results of DNA-DNA hybridization experiments and physiological and biochemical characterization further substantiated the genotypic and phenotypic distinctiveness of the Argentinian soil isolates, for which the name Burkholderia cordobensis sp. nov. is proposed, with strain MMP81(T) ( = LMG 27620(T) = CCUG 64368(T)) as the type strain. © 2014 IUMS.

  1. Construction and characterization of stable, constitutively expressed, chromosomal green and red fluorescent transcriptional fusions in the select agents, Bacillus anthracis, Yersinia pestis, Burkholderia mallei, and Burkholderia pseudomallei.

    Science.gov (United States)

    Su, Shengchang; Bangar, Hansraj; Saldanha, Roland; Pemberton, Adin; Aronow, Bruce; Dean, Gary E; Lamkin, Thomas J; Hassett, Daniel J

    2014-10-01

    Here, we constructed stable, chromosomal, constitutively expressed, green and red fluorescent protein (GFP and RFP) as reporters in the select agents, Bacillus anthracis, Yersinia pestis, Burkholderia mallei, and Burkholderia pseudomallei. Using bioinformatic approaches and other experimental analyses, we identified P0253 and P1 as potent promoters that drive the optimal expression of fluorescent reporters in single copy in B. anthracis and Burkholderia spp. as well as their surrogate strains, respectively. In comparison, Y. pestis and its surrogate strain need two chromosomal copies of cysZK promoter (P2cysZK) for optimal fluorescence. The P0253-, P2cysZK-, and P1-driven GFP and RFP fusions were first cloned into the vectors pRP1028, pUC18R6KT-mini-Tn7T-Km, pmini-Tn7-gat, or their derivatives. The resultant constructs were delivered into the respective surrogates and subsequently into the select agent strains. The chromosomal GFP- and RFP-tagged strains exhibited bright fluorescence at an exposure time of less than 200 msec and displayed the same virulence traits as their wild-type parental strains. The utility of the tagged strains was proven by the macrophage infection assays and lactate dehydrogenase release analysis. Such strains will be extremely useful in high-throughput screens for novel compounds that could either kill these organisms, or interfere with critical virulence processes in these important bioweapon agents and during infection of alveolar macrophages. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  2. Evidence of environmental and vertical transmission of Burkholderia symbionts in the oriental chinch bug, Cavelerius saccharivorus (Heteroptera: Blissidae).

    Science.gov (United States)

    Itoh, Hideomi; Aita, Manabu; Nagayama, Atsushi; Meng, Xian-Ying; Kamagata, Yoichi; Navarro, Ronald; Hori, Tomoyuki; Ohgiya, Satoru; Kikuchi, Yoshitomo

    2014-10-01

    The vertical transmission of symbiotic microorganisms is omnipresent in insects, while the evolutionary process remains totally unclear. The oriental chinch bug, Cavelerius saccharivorus (Heteroptera: Blissidae), is a serious sugarcane pest, in which symbiotic bacteria densely populate the lumen of the numerous tubule-like midgut crypts that the chinch bug develops. Cloning and sequence analyses of the 16S rRNA genes revealed that the crypts were dominated by a specific group of bacteria belonging to the genus Burkholderia of the Betaproteobacteria. The Burkholderia sequences were distributed into three distinct clades: the Burkholderia cepacia complex (BCC), the plant-associated beneficial and environmental (PBE) group, and the stinkbug-associated beneficial and environmental group (SBE). Diagnostic PCR revealed that only one of the three groups of Burkholderia was present in ∼89% of the chinch bug field populations tested, while infections with multiple Burkholderia groups within one insect were observed in only ∼10%. Deep sequencing of the 16S rRNA gene confirmed that the Burkholderia bacteria specifically colonized the crypts and were dominated by one of three Burkholderia groups. The lack of phylogenetic congruence between the symbiont and the host population strongly suggested host-symbiont promiscuity, which is probably caused by environmental acquisition of the symbionts by some hosts. Meanwhile, inspections of eggs and hatchlings by diagnostic PCR and egg surface sterilization demonstrated that almost 30% of the hatchlings vertically acquire symbiotic Burkholderia via symbiont-contaminated egg surfaces. The mixed strategy of symbiont transmission found in the oriental chinch bug might be an intermediate stage in evolution from environmental acquisition to strict vertical transmission in insects. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  3. Monoclonal antibodies passively protect BALB/c mice against Burkholderia mallei aerosol challenge.

    Science.gov (United States)

    Treviño, Sylvia R; Permenter, Amy R; England, Marilyn J; Parthasarathy, Narayanan; Gibbs, Paul H; Waag, David M; Chanh, Tran C

    2006-03-01

    Glanders is a debilitating disease with no vaccine available. Murine monoclonal antibodies were produced against Burkholderia mallei, the etiologic agent of glanders, and were shown to be effective in passively protecting mice against a lethal aerosol challenge. The antibodies appeared to target lipopolysaccharide. Humoral antibodies may be important for immune protection against B. mallei infection.

  4. Transfer of 13 species of the genus Burkholderia to the genus Caballeronia and reclassification of Burkholderia jirisanensis as Paraburkholderia jirisanensis comb. nov.

    Science.gov (United States)

    Dobritsa, Anatoly P; Linardopoulou, Elena V; Samadpour, Mansour

    2017-10-01

    A recent study of a group of Burkholderia glathei-like bacteria resulted in the description of 13 novel species of the genus Burkholderia. However, our analysis of phylogenetic positions of these species and their molecular signatures (conserved protein sequence indels) showed that they belong to the genus Caballeronia, and we propose to transfer them to this genus. The reclassified species names are proposed as Caballeroniaarationis comb. nov., Caballeroniaarvi comb. nov., Caballeroniacalidae comb. nov., Caballeroniacatudaia comb. nov., Caballeroniaconcitans comb. nov., Caballeroniafortuita comb. nov., Caballeroniaglebae comb. nov., Caballeroniahypogeia comb. nov., Caballeroniapedi comb. nov., Caballeroniaperedens comb. nov., Caballeroniaptereochthonis comb. nov., Caballeroniatemeraria comb. nov. and Caballeronia turbans comb. nov. It is also proposed to reclassify Burkholderia jirisanensis as Paraburkholderiajirisanensis comb. nov. Based on the results of the polyphasic study, B. jirisanensis had been described as a member of the A-group of the genus Burkholderiaand the most closely related to Burkholderia rhizosphaerae, Burkholderia humisilvae and Burkholderia solisilvae currently classified as belonging to the genus Paraburkholderia.

  5. Burkholderia humi sp nov., Burkholderia choica sp nov., Burkholderia telluris sp nov., Burkholderia terrestris sp nov and Burkholderia udeis sp nov. : Burkholderia glathei-like bacteria from soil and rhizosphere soil

    NARCIS (Netherlands)

    Vandamme, Peter; De Brandt, Evie; Houf, Kurt; Salles, Joana Falcao; van Elsas, Jan Dirk; Spilker, Theodore; LiPuma, John J.

    2013-01-01

    Analysis of partial gyrB gene sequences revealed six taxa in a group of 17 Burkholderia glathei-like isolates which were further examined by (GTG)(5)-PCR fingerprinting, 16S rRNA gene sequence analysis, DNA-DNA hybridizations, determination of the DNA G+C content, whole-cell fatty acid analysis and

  6. A genetic programming approach for Burkholderia Pseudomallei diagnostic pattern discovery

    Science.gov (United States)

    Yang, Zheng Rong; Lertmemongkolchai, Ganjana; Tan, Gladys; Felgner, Philip L.; Titball, Richard

    2009-01-01

    Motivation: Finding diagnostic patterns for fighting diseases like Burkholderia pseudomallei using biomarkers involves two key issues. First, exhausting all subsets of testable biomarkers (antigens in this context) to find a best one is computationally infeasible. Therefore, a proper optimization approach like evolutionary computation should be investigated. Second, a properly selected function of the antigens as the diagnostic pattern which is commonly unknown is a key to the diagnostic accuracy and the diagnostic effectiveness in clinical use. Results: A conversion function is proposed to convert serum tests of antigens on patients to binary values based on which Boolean functions as the diagnostic patterns are developed. A genetic programming approach is designed for optimizing the diagnostic patterns in terms of their accuracy and effectiveness. During optimization, it is aimed to maximize the coverage (the rate of positive response to antigens) in the infected patients and minimize the coverage in the non-infected patients while maintaining the fewest number of testable antigens used in the Boolean functions as possible. The final coverage in the infected patients is 96.55% using 17 of 215 (7.4%) antigens with zero coverage in the non-infected patients. Among these 17 antigens, BPSL2697 is the most frequently selected one for the diagnosis of Burkholderia Pseudomallei. The approach has been evaluated using both the cross-validation and the Jack–knife simulation methods with the prediction accuracy as 93% and 92%, respectively. A novel approach is also proposed in this study to evaluate a model with binary data using ROC analysis. Contact: z.r.yang@ex.ac.uk PMID:19561021

  7. The temperate Burkholderia phage AP3 of the Peduovirinae shows efficient antimicrobial activity against B. cenocepacia of the IIIA lineage.

    Science.gov (United States)

    Roszniowski, Bartosz; Latka, Agnieszka; Maciejewska, Barbara; Vandenheuvel, Dieter; Olszak, Tomasz; Briers, Yves; Holt, Giles S; Valvano, Miguel A; Lavigne, Rob; Smith, Darren L; Drulis-Kawa, Zuzanna

    2017-02-01

    Burkholderia phage AP3 (vB_BceM_AP3) is a temperate virus of the Myoviridae and the Peduovirinae subfamily (P2likevirus genus). This phage specifically infects multidrug-resistant clinical Burkholderia cenocepacia lineage IIIA strains commonly isolated from cystic fibrosis patients. AP3 exhibits high pairwise nucleotide identity (61.7 %) to Burkholderia phage KS5, specific to the same B. cenocepacia host, and has 46.7-49.5 % identity to phages infecting other species of Burkholderia. The lysis cassette of these related phages has a similar organization (putative antiholin, putative holin, endolysin, and spanins) and shows 29-98 % homology between specific lysis genes, in contrast to Enterobacteria phage P2, the hallmark phage of this genus. The AP3 and KS5 lysis genes have conserved locations and high amino acid sequence similarity. The AP3 bacteriophage particles remain infective up to 5 h at pH 4-10 and are stable at 60 °C for 30 min, but are sensitive to chloroform, with no remaining infective particles after 24 h of treatment. AP3 lysogeny can occur by stable genomic integration and by pseudo-lysogeny. The lysogenic bacterial mutants did not exhibit any significant changes in virulence compared to wild-type host strain when tested in the Galleria mellonella moth wax model. Moreover, AP3 treatment of larvae infected with B. cenocepacia revealed a significant increase (P < 0.0001) in larvae survival in comparison to AP3-untreated infected larvae. AP3 showed robust lytic activity, as evidenced by its broad host range, the absence of increased virulence in lysogenic isolates, the lack of bacterial gene disruption conditioned by bacterial tRNA downstream integration site, and the absence of detected toxin sequences. These data suggest that the AP3 phage is a promising potent agent against bacteria belonging to the most common B. cenocepacia IIIA lineage strains.

  8. Environmental Transmission of the Gut Symbiont Burkholderia to Phloem-Feeding Blissus insularis.

    Science.gov (United States)

    Xu, Yao; Buss, Eileen A; Boucias, Drion G

    2016-01-01

    The plant-phloem-feeding Blissus insularis possesses specialized midgut crypts, which harbor a dense population of the exocellular bacterial symbiont Burkholderia. Most individual B. insularis harbor a single Burkholderia ribotype in their midgut crypts; however, a diverse Burkholderia community exists within a host population. To understand the mechanism underlying the consistent occurrence of various Burkholderia in B. insularis and their specific association, we investigated potential gut symbiont transmission routes. PCR amplification detected a low titer of Burkholderia in adult reproductive tracts; however, fluorescence in situ hybridization assays failed to produce detectable signals in these tracts. Furthermore, no Burkholderia-specific PCR signals were detected in eggs and neonates, suggesting that it is unlikely that B. insularis prenatally transmits gut symbionts via ovarioles. In rearing experiments, most nymphs reared on St. Augustinegrass treated with cultured Burkholderia harbored the cultured Burkholderia strains. Burkholderia was detected in the untreated host grass of B. insularis, and most nymphs reared on untreated grass harbored a Burkholderia ribotype that was closely related to a plant-associated Burkholderia strain. These findings revealed that B. insularis neonates acquired Burkholderia primarily from the environment (i.e., plants and soils), even though the possibility of acquisition via egg surface cannot be excluded. In addition, our study explains how the diverse Burkholderia symbiont community in B. insularis populations can be maintained.

  9. Environmental Burkholderia cenocepacia Strain Enhances Fitness by Serial Passages during Long-Term Chronic Airways Infection in Mice

    Directory of Open Access Journals (Sweden)

    Alessandra Bragonzi

    2017-11-01

    Full Text Available Burkholderia cenocepacia is an important opportunistic pathogen in cystic fibrosis (CF patients, and has also been isolated from natural environments. In previous work, we explored the virulence and pathogenic potential of environmental B. cenocepacia strains and demonstrated that they do not differ from clinical strains in some pathogenic traits. Here, we investigated the ability of the environmental B. cenocepacia Mex1 strain, isolated from the maize rhizosphere, to persist and increase its virulence after serial passages in a mouse model of chronic infection. B. cenocepacia Mex1 strain, belonging to the recA lineage IIIA, was embedded in agar beads and challenged into the lung of C57Bl/6 mice. The mice were sacrificed after 28 days from infection and their lungs were tested for bacterial loads. Agar beads containing the pool of B. cenocepacia colonies from the four sequential passages were used to infect the mice. The environmental B. cenocepacia strain showed a low incidence of chronic infection after the first passage; after the second, third and fourth passages in mice, its ability to establish chronic infection increased significantly and progressively up to 100%. Colonial morphology analysis and genetic profiling of the Mex1-derived clones recovered after the fourth passage from infected mice revealed that they were indistinguishable from the challenged strain both at phenotypic and genetic level. By testing the virulence of single clones in the Galleria mellonella infection model, we found that two Mex1-derived clones significantly increased their pathogenicity compared to the parental Mex1 strain and behaved similarly to the clinical and epidemic B. cenocepacia LMG16656T. Our findings suggest that serial passages of the environmental B. cenocepacia Mex1 strain in mice resulted in an increased ability to determine chronic lung infection and the appearance of clonal variants with increased virulence in non-vertebrate hosts.

  10. Alanine racemase mutants of Burkholderia pseudomallei and Burkholderia mallei and use of alanine racemase as a non-antibiotic-based selectable marker.

    Directory of Open Access Journals (Sweden)

    Sheryl L W Zajdowicz

    Full Text Available Burkholderia pseudomallei and Burkholderia mallei are category B select agents and must be studied under BSL3 containment in the United States. They are typically resistant to multiple antibiotics, and the antibiotics used to treat B. pseudomallei or B. mallei infections may not be used as selective agents with the corresponding Burkholderia species. Here, we investigated alanine racemase deficient mutants of B. pseudomallei and B. mallei for development of non-antibiotic-based genetic selection methods and for attenuation of virulence. The genome of B. pseudomallei K96243 has two annotated alanine racemase genes (bpsl2179 and bpss0711, and B. mallei ATCC 23344 has one (bma1575. Each of these genes encodes a functional enzyme that can complement the alanine racemase deficiency of Escherichia coli strain ALA1. Herein, we show that B. pseudomallei with in-frame deletions in both bpsl2179 and bpss0711, or B. mallei with an in-frame deletion in bma1575, requires exogenous D-alanine for growth. Introduction of bpsl2179 on a multicopy plasmid into alanine racemase deficient variants of either Burkholderia species eliminated the requirement for D-alanine. During log phase growth without D-alanine, the viable counts of alanine racemase deficient mutants of B. pseudomallei and B. mallei decreased within 2 hours by about 1000-fold and 10-fold, respectively, and no viable bacteria were present at 24 hours. We constructed several genetic tools with bpsl2179 as a selectable genetic marker, and we used them without any antibiotic selection to construct an in-frame ΔflgK mutant in the alanine racemase deficient variant of B. pseudomallei K96243. In murine peritoneal macrophages, wild type B. mallei ATCC 23344 was killed much more rapidly than wild type B. pseudomallei K96243. In addition, the alanine racemase deficient mutant of B. pseudomallei K96243 exhibited attenuation versus its isogenic parental strain with respect to growth and survival in murine

  11. Alanine Racemase Mutants of Burkholderia pseudomallei and Burkholderia mallei and Use of Alanine Racemase as a Non-Antibiotic-Based Selectable Marker

    Science.gov (United States)

    Zajdowicz, Sheryl L. W.; Jones-Carson, Jessica; Vazquez-Torres, Andres; Jobling, Michael G.; Gill, Ronald E.; Holmes, Randall K.

    2011-01-01

    Burkholderia pseudomallei and Burkholderia mallei are category B select agents and must be studied under BSL3 containment in the United States. They are typically resistant to multiple antibiotics, and the antibiotics used to treat B. pseudomallei or B. mallei infections may not be used as selective agents with the corresponding Burkholderia species. Here, we investigated alanine racemase deficient mutants of B. pseudomallei and B. mallei for development of non-antibiotic-based genetic selection methods and for attenuation of virulence. The genome of B. pseudomallei K96243 has two annotated alanine racemase genes (bpsl2179 and bpss0711), and B. mallei ATCC 23344 has one (bma1575). Each of these genes encodes a functional enzyme that can complement the alanine racemase deficiency of Escherichia coli strain ALA1. Herein, we show that B. pseudomallei with in-frame deletions in both bpsl2179 and bpss0711, or B. mallei with an in-frame deletion in bma1575, requires exogenous d-alanine for growth. Introduction of bpsl2179 on a multicopy plasmid into alanine racemase deficient variants of either Burkholderia species eliminated the requirement for d-alanine. During log phase growth without d-alanine, the viable counts of alanine racemase deficient mutants of B. pseudomallei and B. mallei decreased within 2 hours by about 1000-fold and 10-fold, respectively, and no viable bacteria were present at 24 hours. We constructed several genetic tools with bpsl2179 as a selectable genetic marker, and we used them without any antibiotic selection to construct an in-frame ΔflgK mutant in the alanine racemase deficient variant of B. pseudomallei K96243. In murine peritoneal macrophages, wild type B. mallei ATCC 23344 was killed much more rapidly than wild type B. pseudomallei K96243. In addition, the alanine racemase deficient mutant of B. pseudomallei K96243 exhibited attenuation versus its isogenic parental strain with respect to growth and survival in murine peritoneal macrophages

  12. Systematic review and consensus guidelines for environmental sampling of Burkholderia pseudomallei.

    Directory of Open Access Journals (Sweden)

    Direk Limmathurotsakul

    Full Text Available Burkholderia pseudomallei, a Tier 1 Select Agent and the cause of melioidosis, is a Gram-negative bacillus present in the environment in many tropical countries. Defining the global pattern of B. pseudomallei distribution underpins efforts to prevent infection, and is dependent upon robust environmental sampling methodology. Our objective was to review the literature on the detection of environmental B. pseudomallei, update the risk map for melioidosis, and propose international consensus guidelines for soil sampling.An international working party (Detection of Environmental Burkholderia pseudomallei Working Party (DEBWorP was formed during the VIth World Melioidosis Congress in 2010. PubMed (January 1912 to December 2011 was searched using the following MeSH terms: pseudomallei or melioidosis. Bibliographies were hand-searched for secondary references. The reported geographical distribution of B. pseudomallei in the environment was mapped and categorized as definite, probable, or possible. The methodology used for detecting environmental B. pseudomallei was extracted and collated. We found that global coverage was patchy, with a lack of studies in many areas where melioidosis is suspected to occur. The sampling strategies and bacterial identification methods used were highly variable, and not all were robust. We developed consensus guidelines with the goals of reducing the probability of false-negative results, and the provision of affordable and 'low-tech' methodology that is applicable in both developed and developing countries.The proposed consensus guidelines provide the basis for the development of an accurate and comprehensive global map of environmental B. pseudomallei.

  13. Characterisation of the simultaneous molybdenum reduction and glyphosate degradation by Burkholderia vietnamiensis AQ5-12 and Burkholderia sp. AQ5-13.

    Science.gov (United States)

    Manogaran, Motharasan; Ahmad, Siti Aqlima; Yasid, Nur Adeela; Yakasai, Hafeez Muhammad; Shukor, Mohd Yunus

    2018-02-01

    In this novel study, we report on the use of two molybdenum-reducing bacteria with the ability to utilise the herbicide glyphosate as the phosphorus source. The bacteria reduced sodium molybdate to molybdenum blue (Mo-blue), a colloidal and insoluble product, which is less toxic. The characterisation of the molybdenum-reducing bacteria was carried out using resting cells immersed in low-phosphate molybdenum media. Two glyphosate-degrading bacteria, namely Burkholderia vietnamiensis AQ5-12 and Burkholderia sp. AQ5-13, were able to use glyphosate as a phosphorous source to support molybdenum reduction to Mo-blue. The bacteria optimally reduced molybdenum between the pHs of 6.25 and 8. The optimum concentrations of molybdate for strain Burkholderia vietnamiensis strain AQ5-12 was observed to be between 40 and 60 mM, while for Burkholderia sp. AQ5-13, the optimum molybdate concentration occurred between 40 and 50 mM. Furthermore, 5 mM of phosphate was seen as the optimum concentration supporting molybdenum reduction for both bacteria. The optimum temperature aiding Mo-blue formation ranged from 30 to 40 °C for Burkholderia vietnamiensis strain AQ5-12, whereas for Burkholderia sp. AQ5-13, the range was from 35 to 40 °C. Glucose was the best electron donor for supporting molybdate reduction, followed by sucrose, fructose and galactose for both strains. Ammonium sulphate was the best nitrogen source in supporting molybdenum reduction. Interestingly, increasing the glyphosate concentrations beyond 100 and 300 ppm for Burkholderia vietnamiensis strain AQ5-12 and Burkholderia sp. AQ5-13, respectively, significantly inhibited molybdenum reduction. The ability of these bacteria to reduce molybdenum while degrading glyphosate is a useful process for the bioremediation of both toxicants.

  14. Diverse Burkholderia Species Isolated from Soils in the Southern United States with No Evidence of B. pseudomallei.

    Directory of Open Access Journals (Sweden)

    Carina M Hall

    Full Text Available The global distribution of the soil-dwelling bacterium Burkholderia pseudomallei, causative agent of melioidosis, is poorly understood. We used established culturing methods developed for B. pseudomallei to isolate Burkholderia species from soil collected at 18 sampling sites in three states in the southern United States (Arizona (n = 4, Florida (n = 7, and Louisiana (n = 7. Using multi-locus sequence typing (MLST of seven genes, we identified 35 Burkholderia isolates from these soil samples. All species belonged to the B. cepacia complex (Bcc, including B. cenocepacia, B. cepacia, B. contaminans, B. diffusa, B. metallica, B. seminalis, B. vietnamiensis and two unnamed members of the Bcc. The MLST analysis provided a high level of resolution among and within these species. Despite previous clinical cases within the U.S. involving B. pseudomallei and its close phylogenetic relatives, we did not isolate any of these taxa. The Bcc contains a number of opportunistic pathogens that cause infections in cystic fibrosis patients. Interestingly, we found that B. vietnamiensis was present in soil from all three states, suggesting it may be a common component in southern U.S. soils. Most of the Burkholderia isolates collected in this study were from Florida (30/35; 86%, which may be due to the combination of relatively moist, sandy, and acidic soils found there compared to the other two states. We also investigated one MLST gene, recA, for its ability to identify species within Burkholderia. A 365bp fragment of recA recovered nearly the same species-level identification as MLST, thus demonstrating its cost effective utility when conducting environmental surveys for Burkholderia. Although we did not find B. pseudomallei, our findings document that other diverse Burkholderia species are present in soils in the southern United States.

  15. Diverse Burkholderia Species Isolated from Soils in the Southern United States with No Evidence of B. pseudomallei.

    Science.gov (United States)

    Hall, Carina M; Busch, Joseph D; Shippy, Kenzie; Allender, Christopher J; Kaestli, Mirjam; Mayo, Mark; Sahl, Jason W; Schupp, James M; Colman, Rebecca E; Keim, Paul; Currie, Bart J; Wagner, David M

    2015-01-01

    The global distribution of the soil-dwelling bacterium Burkholderia pseudomallei, causative agent of melioidosis, is poorly understood. We used established culturing methods developed for B. pseudomallei to isolate Burkholderia species from soil collected at 18 sampling sites in three states in the southern United States (Arizona (n = 4), Florida (n = 7), and Louisiana (n = 7)). Using multi-locus sequence typing (MLST) of seven genes, we identified 35 Burkholderia isolates from these soil samples. All species belonged to the B. cepacia complex (Bcc), including B. cenocepacia, B. cepacia, B. contaminans, B. diffusa, B. metallica, B. seminalis, B. vietnamiensis and two unnamed members of the Bcc. The MLST analysis provided a high level of resolution among and within these species. Despite previous clinical cases within the U.S. involving B. pseudomallei and its close phylogenetic relatives, we did not isolate any of these taxa. The Bcc contains a number of opportunistic pathogens that cause infections in cystic fibrosis patients. Interestingly, we found that B. vietnamiensis was present in soil from all three states, suggesting it may be a common component in southern U.S. soils. Most of the Burkholderia isolates collected in this study were from Florida (30/35; 86%), which may be due to the combination of relatively moist, sandy, and acidic soils found there compared to the other two states. We also investigated one MLST gene, recA, for its ability to identify species within Burkholderia. A 365bp fragment of recA recovered nearly the same species-level identification as MLST, thus demonstrating its cost effective utility when conducting environmental surveys for Burkholderia. Although we did not find B. pseudomallei, our findings document that other diverse Burkholderia species are present in soils in the southern United States.

  16. Burkholderia mallei tssM encodes a putative deubiquitinase that is secreted and expressed inside infected RAW 264.7 murine macrophages.

    Science.gov (United States)

    Shanks, John; Burtnick, Mary N; Brett, Paul J; Waag, David M; Spurgers, Kevin B; Ribot, Wilson J; Schell, Mark A; Panchal, Rekha G; Gherardini, Frank C; Wilkinson, Keith D; Deshazer, David

    2009-04-01

    Burkholderia mallei, a category B biothreat agent, is a facultative intracellular pathogen that causes the zoonotic disease glanders. The B. mallei VirAG two-component regulatory system activates the transcription of approximately 60 genes, including a large virulence gene cluster encoding a type VI secretion system (T6SS). The B. mallei tssM gene encodes a putative ubiquitin-specific protease that is physically linked to, and transcriptionally coregulated with, the T6SS gene cluster. Mass spectrometry and immunoblot analysis demonstrated that TssM was secreted in a virAG-dependent manner in vitro. Surprisingly, the T6SS was found to be dispensable for the secretion of TssM. The C-terminal half of TssM, which contains Cys and His box motifs conserved in eukaryotic deubiquitinases, was purified and biochemically characterized. Recombinant TssM hydrolyzed multiple ubiquitinated substrates and the cysteine at position 102 was critical for enzymatic activity. The tssM gene was expressed within 1 h after uptake of B. mallei into RAW 264.7 murine macrophages, suggesting that the TssM deubiquitinase is produced in this intracellular niche. Although the physiological substrate(s) is currently unknown, the TssM deubiquitinase may provide B. mallei a selective advantage in the intracellular environment during infection.

  17. Eradication of Burkholderia cepacia Using Inhaled Aztreonam Lysine in Two Patients with Bronchiectasis

    Directory of Open Access Journals (Sweden)

    A. Iglesias

    2014-01-01

    Full Text Available There are not many articles about the chronic bronchial infection/colonization in patients with underlying lung disease other than cystic fibrosis (CF, especially with non-CF bronchiectasis (NCFBQ. The prevalence of B. cepacia complex is not well known in NCFBQ. The vast majority of published clinical data on Burkholderia infection in individuals with CF is comprised of uncontrolled, anecdotal, and/or single center experiences, and no consensus has emerged regarding treatment. We present two cases diagnosed with bronchiectasis (BQ of different etiology, with early pulmonary infection by B. cepacia complex, which was eradicated with inhaled aztreonam lysine.

  18. Evaluation of combination therapy for Burkholderia cenocepacia lung infection in different in vitro and in vivo models.

    Directory of Open Access Journals (Sweden)

    Freija Van den Driessche

    Full Text Available Burkholderia cenocepacia is an opportunistic pathogen responsible for life-threatening infections in cystic fibrosis patients. B. cenocepacia is extremely resistant towards antibiotics and therapy is complicated by its ability to form biofilms. We investigated the efficacy of an alternative antimicrobial strategy for B. cenocepacia lung infections using in vitro and in vivo models. A screening of the NIH Clinical Collection 1&2 was performed against B. cenocepacia biofilms formed in 96-well microtiter plates in the presence of tobramycin to identify repurposing candidates with potentiator activity. The efficacy of selected hits was evaluated in a three-dimensional (3D organotypic human lung epithelial cell culture model. The in vivo effect was evaluated in the invertebrate Galleria mellonella and in a murine B. cenocepacia lung infection model. The screening resulted in 60 hits that potentiated the activity of tobramycin against B. cenocepacia biofilms, including four imidazoles of which econazole and miconazole were selected for further investigation. However, a potentiator effect was not observed in the 3D organotypic human lung epithelial cell culture model. Combination treatment was also not able to increase survival of infected G. mellonella. Also in mice, there was no added value for the combination treatment. Although potentiators of tobramycin with activity against biofilms of B. cenocepacia were identified in a repurposing screen, the in vitro activity could not be confirmed nor in a more sophisticated in vitro model, neither in vivo. This stresses the importance of validating hits resulting from in vitro studies in physiologically relevant model systems.

  19. Burkholderia pseudomallei Infection in a Cystic Fibrosis Patient from the Caribbean: A Case Report

    Directory of Open Access Journals (Sweden)

    Dimas Mateos Corral

    2008-01-01

    Full Text Available Burkholderia pseudomallei is a pathogen identified with increasing frequency in the respiratory tracts of cystic fibrosis (CF patients from endemic areas such as Southeast Asia and northern Australia. The following report describes the first known reported case in a CF patient from the Caribbean attending a North American CF clinic.

  20. Burkholderia pseudomallei infection in a cystic fibrosis patient from the Caribbean: A case report

    Science.gov (United States)

    Corral, Dimas Mateos; Coates, Allan L; Yau, Yvonne CW; Tellier, Raymond; Glass, Mindy; Jones, Steven M; Waters, Valerie J

    2008-01-01

    Burkholderia pseudomallei is a pathogen identified with increasing frequency in the respiratory tracts of cystic fibrosis (CF) patients from endemic areas such as Southeast Asia and northern Australia. The following report describes the first known reported case in a CF patient from the Caribbean attending a North American CF clinic. PMID:18716683

  1. Efflux-mediated resistance to a benzothiadiazol derivative effective against Burkholderia cenocepacia

    Directory of Open Access Journals (Sweden)

    Viola Camilla eScoffone

    2015-08-01

    Full Text Available Burkholderia cenocepacia is a major concern for people suffering from Cystic Fibrosis as it contributes to serious respiratory tract infections. The lack of drugs effective against this opportunistic pathogen, along with the high level of resistance to multiple antibiotics, render the treatment of these infections particularly difficult.Here a new compound, belonging to the 2,1,3-benzothiadiazol-5-yl family (10126109, with a bactericidal effect and a MIC of 8 µg/ml against B. cenocepacia, is described. The compound is not cytotoxic and effective against B. cenocepacia clinical isolates and members of all the known Burkholderia cepacia complex species.Spontaneous mutants resistant to 10126109 were isolated and mutations in the MerR transcriptional regulator BCAM1948 were identified. In this way, a mechanism of resistance to this new molecule was described, which relies on the overexpression of the RND-9 efflux pump. Indeed, rnd-9 overexpression was confirmed by qRT-PCR, and RND-9 was identified in the membrane fractions of the mutant strains. Moreover, the increase in the MIC values of different drugs in the mutant strains, together with complementation experiments, suggested the involvement of RND-9 in the efflux of 10126109, thus indicating again the central role of efflux transporters in B. cenocepacia drug resistance.

  2. The In Vitro Antibiotic Susceptibility of Malaysian Isolates of Burkholderia pseudomallei

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    Norazah Ahmad

    2013-01-01

    Full Text Available Acute melioidosis may present as localised or septicaemic infections and can be fatal if left untreated. Burkholderia pseudomallei resistant to antibiotics used for the treatment of melioidosis had been reported. The aim of this study was to determine the in vitro antibiotic susceptibility patterns of Burkholderia pseudomallei isolated in Malaysia to a panel of antibiotics used for the treatment of melioidosis and also to potential alternative antibiotics such as tigecycline, ampicillin/sulbactam, and piperacillin/tazobactam. A total of 170 Burkholderia pseudomallei isolates were subjected to minimum inhibitory concentration determination using E-test method to eleven antibiotics. All isolates were sensitive to meropenem and piperacillin/tazobactam. For ceftazidime, imipenem, amoxicillin/clavulanic acid, and doxycycline resistance was observed in 1 isolate (0.6% for each of the antibiotics. Trimethoprim/sulfamethoxazole resistance was observed in 17 (10% isolates. For other antibiotics, ampicillin/sulbactam, chloramphenicol, tigecycline, and ciprofloxacin resistance were observed in 1 (0.6%, 6 (3.5%, 60 (35.3% and 98 (57.7% isolates respectively. One isolate B170/06 exhibited resistance to 4 antibiotics, namely, ciprofloxacin, chloramphenicol, trimethoprim/sulfamethoxazole, and tigecycline. In conclusion, the Malaysian isolates were highly susceptible to the current antibiotics used in the treatment of melioidosis in Malaysia. Multiple resistances to the antibiotics used in the maintenance therapy are the cause for a concern.

  3. Competition Experiments for Legume Infection Identify Burkholderia phymatum as a Highly Competitive β-Rhizobium

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    Martina Lardi

    2017-08-01

    Full Text Available Members of the genus Burkholderia (β-proteobacteria have only recently been shown to be able to establish a nitrogen-fixing symbiosis with several legumes, which is why they are also referred to as β-rhizobia. Therefore, very little is known about the competitiveness of these species to nodulate different legume host plants. In this study, we tested the competitiveness of several Burkholderia type strains (B. diazotrophica, B. mimosarum, B. phymatum, B. sabiae, B. symbiotica and B. tuberum to nodulate four legumes (Phaseolus vulgaris, Macroptilium atropurpureum, Vigna unguiculata and Mimosa pudica under our closely defined growth conditions. The assessment of nodule occupancy of these species on different legume host plants revealed that B. phymatum was the most competitive strain in the three papilionoid legumes (bean, cowpea and siratro, while B. mimosarum outcompeted the other strains in mimosa. The analysis of phenotypes known to play a role in nodulation competitiveness (motility, exopolysaccharide production and additional in vitro competition assays among β-rhizobial strains suggested that B. phymatum has the potential to be a very competitive legume symbiont.

  4. Molecular Signatures and Phylogenomic Analysis of the Genus Burkholderia: Proposal for Division of this Genus into the Emended Genus Burkholderia Containing Pathogenic Organisms and a New Genus Paraburkholderia gen. nov. Harboring Environmental Species

    Directory of Open Access Journals (Sweden)

    Aman eSawana

    2014-12-01

    Full Text Available The genus Burkholderia contains large number of diverse species which are not reliably distinguished by the available biochemical or molecular characteristics. We report here results of detailed phylogenetic and comparative genomic analyses of 45 sequenced species of the genus Burkholderia. In phylogenetic trees based upon concatenated sequences for 21 conserved proteins as well as 16S rRNA gene sequences, Burkholderia species grouped into two major clades. Within these main clades a number of smaller clades were also clearly distinguished. Our comparative analysis of protein sequences from Burkholderia spp. has identified 42 highly specific molecular markers in the form of conserved sequence indels (CSIs that are uniquely found in different clades of Burkholderia spp. Six of these CSIs are specific for a group of Burkholderia spp. (referred to as Clade I which contains all clinically relevant members of the genus as well as the phytopathogenic Burkholderia species. The second main clade (Clade II composed of the environmental Burkholderia species, is also distinguished by 2 of the identified CSIs. Additionally, our work has also identified 3 CSIs that are specific for the Burkholderia cepacia complex, 4 CSIs that are uniquely found in the Burkholderia pseudomallei group, 5 CSIs that are specific for the phytopathogenic Burkholderia spp. and 22 other CSI that distinguish two groups within Clade II. The described molecular markers provide highly specific means for the demarcation of different groups of Burkholderia spp. and for development of novel diagnostic assays for the clinically important members of the group. Based upon the results from different lines of studies, a division of the genus Burkholderia into two genera is proposed. In this new proposal, the emended genus Burkholderia will contain only the clinically relevant and phytopathogenic Burkholderia species, whereas all other Burkholderia spp. are transferred to a new genus

  5. Burkholderia mallei tssM Encodes a Putative Deubiquitinase That Is Secreted and Expressed inside Infected RAW 264.7 Murine Macrophages▿ †

    Science.gov (United States)

    Shanks, John; Burtnick, Mary N.; Brett, Paul J.; Waag, David M.; Spurgers, Kevin B.; Ribot, Wilson J.; Schell, Mark A.; Panchal, Rekha G.; Gherardini, Frank C.; Wilkinson, Keith D.; DeShazer, David

    2009-01-01

    Burkholderia mallei, a category B biothreat agent, is a facultative intracellular pathogen that causes the zoonotic disease glanders. The B. mallei VirAG two-component regulatory system activates the transcription of ∼60 genes, including a large virulence gene cluster encoding a type VI secretion system (T6SS). The B. mallei tssM gene encodes a putative ubiquitin-specific protease that is physically linked to, and transcriptionally coregulated with, the T6SS gene cluster. Mass spectrometry and immunoblot analysis demonstrated that TssM was secreted in a virAG-dependent manner in vitro. Surprisingly, the T6SS was found to be dispensable for the secretion of TssM. The C-terminal half of TssM, which contains Cys and His box motifs conserved in eukaryotic deubiquitinases, was purified and biochemically characterized. Recombinant TssM hydrolyzed multiple ubiquitinated substrates and the cysteine at position 102 was critical for enzymatic activity. The tssM gene was expressed within 1 h after uptake of B. mallei into RAW 264.7 murine macrophages, suggesting that the TssM deubiquitinase is produced in this intracellular niche. Although the physiological substrate(s) is currently unknown, the TssM deubiquitinase may provide B. mallei a selective advantage in the intracellular environment during infection. PMID:19168747

  6. An outbreak of Burkholderia stabilis colonization in a nasal ward.

    Science.gov (United States)

    Wang, Lijun; Wang, Mei; Zhang, Junyi; Wu, Wei; Lu, Yuan; Fan, Yanyan

    2015-04-01

    The aim of this study was to describe an outbreak of Burkholderia stabilis colonization among patients in a nasal ward. Multilocus sequence typing (MLST) was used for the molecular typing of B. stabilis isolates. Microbiological records were reviewed to delineate the colonization outbreak period. One hundred seventy-one cultures of environment and equipment samples from the nasal ward were performed to trace the source of contamination. Infection control measures were taken in order to end the outbreak. All B. stabilis isolates were identified as a new MLST type, ST821. A total of 53 patients carried this B. stabilis in the nasal ward between March and September 2013, which was defined as the outbreak period. The source of the colonization was not determined because all environment cultures were negative for Burkholderia cepacia complex. No further B. stabilis carriers have been found in the ward since the implementation of interventions. Attention must be paid to asymptomatic colonization in order to identify outbreaks early. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Phylogenomic Study of Burkholderia glathei-like Organisms, Proposal of 13 Novel Burkholderia Species and Emended Descriptions of Burkholderia sordidicola, Burkholderia zhejiangensis, and Burkholderia grimmiae

    OpenAIRE

    Peeters, Charlotte; Meier-Kolthoff, Jan P.; Verheyde, Bart; De Brandt, Evie; Cooper, Vaughn S.; Vandamme, Peter

    2016-01-01

    Partial gyrB gene sequence analysis of 17 isolates from human and environmental sources revealed 13 clusters of strains and identified them as Burkholderia glathei Glade (BGC) bacteria. The taxonomic status of these clusters was examined by whole-genome sequence analysis, determination of the G+C content, whole-cell fatty acid analysis and biochemical characterization. The whole-genome sequence-based phylogeny was assessed using the Genome Blast Distance Phylogeny (GBDP) method and an extende...

  8. Burkholderia: an update on taxonomy and biotechnological potential as antibiotic producers.

    Science.gov (United States)

    Depoorter, Eliza; Bull, Matt J; Peeters, Charlotte; Coenye, Tom; Vandamme, Peter; Mahenthiralingam, Eshwar

    2016-06-01

    Burkholderia is an incredibly diverse and versatile Gram-negative genus, within which over 80 species have been formally named and multiple other genotypic groups likely represent new species. Phylogenetic analysis based on the 16S rRNA gene sequence and core genome ribosomal multilocus sequence typing analysis indicates the presence of at least three major clades within the genus. Biotechnologically, Burkholderia are well-known for their bioremediation and biopesticidal properties. Within this review, we explore the ability of Burkholderia to synthesise a wide range of antimicrobial compounds ranging from historically characterised antifungals to recently described antibacterial antibiotics with activity against multiresistant clinical pathogens. The production of multiple Burkholderia antibiotics is controlled by quorum sensing and examples of quorum sensing pathways found across the genus are discussed. The capacity for antibiotic biosynthesis and secondary metabolism encoded within Burkholderia genomes is also evaluated. Overall, Burkholderia demonstrate significant biotechnological potential as a source of novel antibiotics and bioactive secondary metabolites.

  9. Development of a Polymerase Chain Reaction Assay for the Specific Identification of Burkholderia mallei and Differentiation from Burkholderia pseudomallei and Other Closely Related Burkholderiaceae

    National Research Council Canada - National Science Library

    Ulrich, Ricky L; Ulrich, Melanie P; Schell, Mark A; Kim, H. S; DeShazer, David

    2005-01-01

    Burkholderia mallei and Burkholderia pseudomallei, the etiologic agents responsible for glanders and melioidosis, respectively, are genetically and phenotypically similar and are category B biothreat agents...

  10. Recombinant Salmonella Expressing Burkholderia mallei LPS O Antigen Provides Protection in a Murine Model of Melioidosis and Glanders.

    Science.gov (United States)

    Moustafa, Dina A; Scarff, Jennifer M; Garcia, Preston P; Cassidy, Sara K B; DiGiandomenico, Antonio; Waag, David M; Inzana, Thomas J; Goldberg, Joanna B

    2015-01-01

    Burkholderia pseudomallei and Burkholderia mallei are the etiologic agents of melioidosis and glanders, respectively. These bacteria are highly infectious via the respiratory route and can cause severe and often fatal diseases in humans and animals. Both species are considered potential agents of biological warfare; they are classified as category B priority pathogens. Currently there are no human or veterinary vaccines available against these pathogens. Consequently efforts are directed towards the development of an efficacious and safe vaccine. Lipopolysaccharide (LPS) is an immunodominant antigen and potent stimulator of host immune responses. B. mallei express LPS that is structurally similar to that expressed by B. pseudomallei, suggesting the possibility of constructing a single protective vaccine against melioidosis and glanders. Previous studies of others have shown that antibodies against B. mallei or B. pseudomallei LPS partially protect mice against subsequent lethal virulent Burkholderia challenge. In this study, we evaluated the protective efficacy of recombinant Salmonella enterica serovar Typhimurium SL3261 expressing B. mallei O antigen against lethal intranasal infection with Burkholderia thailandensis, a surrogate for biothreat Burkholderia spp. in a murine model that mimics melioidosis and glanders. All vaccine-immunized mice developed a specific antibody response to B. mallei and B. pseudomallei O antigen and to B. thailandensis and were significantly protected against challenge with a lethal dose of B. thailandensis. These results suggest that live-attenuated SL3261 expressing B. mallei O antigen is a promising platform for developing a safe and effective vaccine.

  11. Recombinant Salmonella Expressing Burkholderia mallei LPS O Antigen Provides Protection in a Murine Model of Melioidosis and Glanders.

    Directory of Open Access Journals (Sweden)

    Dina A Moustafa

    Full Text Available Burkholderia pseudomallei and Burkholderia mallei are the etiologic agents of melioidosis and glanders, respectively. These bacteria are highly infectious via the respiratory route and can cause severe and often fatal diseases in humans and animals. Both species are considered potential agents of biological warfare; they are classified as category B priority pathogens. Currently there are no human or veterinary vaccines available against these pathogens. Consequently efforts are directed towards the development of an efficacious and safe vaccine. Lipopolysaccharide (LPS is an immunodominant antigen and potent stimulator of host immune responses. B. mallei express LPS that is structurally similar to that expressed by B. pseudomallei, suggesting the possibility of constructing a single protective vaccine against melioidosis and glanders. Previous studies of others have shown that antibodies against B. mallei or B. pseudomallei LPS partially protect mice against subsequent lethal virulent Burkholderia challenge. In this study, we evaluated the protective efficacy of recombinant Salmonella enterica serovar Typhimurium SL3261 expressing B. mallei O antigen against lethal intranasal infection with Burkholderia thailandensis, a surrogate for biothreat Burkholderia spp. in a murine model that mimics melioidosis and glanders. All vaccine-immunized mice developed a specific antibody response to B. mallei and B. pseudomallei O antigen and to B. thailandensis and were significantly protected against challenge with a lethal dose of B. thailandensis. These results suggest that live-attenuated SL3261 expressing B. mallei O antigen is a promising platform for developing a safe and effective vaccine.

  12. Stress conditions triggering mucoid morphotype variation in Burkholderia species and effect on virulence in Galleria mellonella and biofilm formation in vitro.

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    Inês N Silva

    Full Text Available Burkholderia cepacia complex (Bcc bacteria are opportunistic pathogens causing chronic respiratory infections particularly among cystic fibrosis patients. During these chronic infections, mucoid-to-nonmucoid morphotype variation occurs, with the two morphotypes exhibiting different phenotypic properties. Here we show that in vitro, the mucoid clinical isolate Burkholderia multivorans D2095 gives rise to stable nonmucoid variants in response to prolonged stationary phase, presence of antibiotics, and osmotic and oxidative stresses. Furthermore, in vitro colony morphotype variation within other members of the Burkholderia genus occurred in Bcc and non-Bcc strains, irrespectively of their clinical or environmental origin. Survival to starvation and iron limitation was comparable for the mucoid parental isolate and the respective nonmucoid variant, while susceptibility to antibiotics and to oxidative stress was increased in the nonmucoid variants. Acute infection of Galleria mellonella larvae showed that, in general, the nonmucoid variants were less virulent than the respective parental mucoid isolate, suggesting a role for the exopolysaccharide in virulence. In addition, most of the tested nonmucoid variants produced more biofilm biomass than their respective mucoid parental isolate. As biofilms are often associated with increased persistence of pathogens in the CF lungs and are an indicative of different cell-to-cell interactions, it is possible that the nonmucoid variants are better adapted to persist in this host environment.

  13. Membrane-active mechanism of LFchimera against Burkholderia pseudomallei and Burkholderia thailandensis

    NARCIS (Netherlands)

    Kanthawong, S.; Puknun, A.; Bolscher, J.G.M.; Nazmi, K.; van Marle, J.; de Soet, J.J.; Veerman, E.C.I.; Wongratanacheewin, S.; Taweechaisupapong, S.

    2014-01-01

    LFchimera, a construct combining two antimicrobial domains of bovine lactoferrin, lactoferrampin265-284 and lactoferricin17-30, possesses strong bactericidal activity. As yet, no experimental evidence was presented to evaluate the mechanisms of LFchimera against Burkholderia isolates. In this study

  14. Characterization of Burkholderia pseudomallei Strains Using a Murine Intraperitoneal Infection Model and In Vitro Macrophage Assays.

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    Susan L Welkos

    Full Text Available Burkholderia pseudomallei, the etiologic agent of melioidosis, is a gram-negative facultative intracellular bacterium. This bacterium is endemic in Southeast Asia and Northern Australia and can infect humans and animals by several routes. It has also been estimated to present a considerable risk as a potential biothreat agent. There are currently no effective vaccines for B. pseudomallei, and antibiotic treatment can be hampered by nonspecific symptomology, the high incidence of naturally occurring antibiotic resistant strains, and disease chronicity. Accordingly, there is a concerted effort to better characterize B. pseudomallei and its associated disease. Before novel vaccines and therapeutics can be tested in vivo, a well characterized animal model is essential. Previous work has indicated that mice may be a useful animal model. In order to develop standardized animal models of melioidosis, different strains of bacteria must be isolated, propagated, and characterized. Using a murine intraperitoneal (IP infection model, we tested the virulence of 11 B. pseudomallei strains. The IP route offers a reproducible way to rank virulence that can be readily reproduced by other laboratories. This infection route is also useful in distinguishing significant differences in strain virulence that may be masked by the exquisite susceptibility associated with other routes of infection (e.g., inhalational. Additionally, there were several pathologic lesions observed in mice following IP infection. These included varisized abscesses in the spleen, liver, and haired skin. This model indicated that commonly used laboratory strains of B. pseudomallei (i.e., K96243 and 1026b were significantly less virulent as compared to more recently acquired clinical isolates. Additionally, we characterized in vitro strain-associated differences in virulence for macrophages and described a potential inverse relationship between virulence in the IP mouse model of some strains

  15. Characterization of Burkholderia pseudomallei Strains Using a Murine Intraperitoneal Infection Model and In Vitro Macrophage Assays.

    Science.gov (United States)

    Welkos, Susan L; Klimko, Christopher P; Kern, Steven J; Bearss, Jeremy J; Bozue, Joel A; Bernhards, Robert C; Trevino, Sylvia R; Waag, David M; Amemiya, Kei; Worsham, Patricia L; Cote, Christopher K

    2015-01-01

    Burkholderia pseudomallei, the etiologic agent of melioidosis, is a gram-negative facultative intracellular bacterium. This bacterium is endemic in Southeast Asia and Northern Australia and can infect humans and animals by several routes. It has also been estimated to present a considerable risk as a potential biothreat agent. There are currently no effective vaccines for B. pseudomallei, and antibiotic treatment can be hampered by nonspecific symptomology, the high incidence of naturally occurring antibiotic resistant strains, and disease chronicity. Accordingly, there is a concerted effort to better characterize B. pseudomallei and its associated disease. Before novel vaccines and therapeutics can be tested in vivo, a well characterized animal model is essential. Previous work has indicated that mice may be a useful animal model. In order to develop standardized animal models of melioidosis, different strains of bacteria must be isolated, propagated, and characterized. Using a murine intraperitoneal (IP) infection model, we tested the virulence of 11 B. pseudomallei strains. The IP route offers a reproducible way to rank virulence that can be readily reproduced by other laboratories. This infection route is also useful in distinguishing significant differences in strain virulence that may be masked by the exquisite susceptibility associated with other routes of infection (e.g., inhalational). Additionally, there were several pathologic lesions observed in mice following IP infection. These included varisized abscesses in the spleen, liver, and haired skin. This model indicated that commonly used laboratory strains of B. pseudomallei (i.e., K96243 and 1026b) were significantly less virulent as compared to more recently acquired clinical isolates. Additionally, we characterized in vitro strain-associated differences in virulence for macrophages and described a potential inverse relationship between virulence in the IP mouse model of some strains and in the

  16. Molecular signatures and phylogenomic analysis of the genus Burkholderia: proposal for division of this genus into the emended genus Burkholderia containing pathogenic organisms and a new genus Paraburkholderia gen. nov. harboring environmental species.

    Science.gov (United States)

    Sawana, Amandeep; Adeolu, Mobolaji; Gupta, Radhey S

    2014-01-01

    The genus Burkholderia contains large number of diverse species which include many clinically important organisms, phytopathogens, as well as environmental species. However, currently, there is a paucity of biochemical or molecular characteristics which can reliably distinguish different groups of Burkholderia species. We report here the results of detailed phylogenetic and comparative genomic analyses of 45 sequenced species of the genus Burkholderia. In phylogenetic trees based upon concatenated sequences for 21 conserved proteins as well as 16S rRNA gene sequence based trees, members of the genus Burkholderia grouped into two major clades. Within these main clades a number of smaller clades including those corresponding to the clinically important Burkholderia cepacia complex (BCC) and the Burkholderia pseudomallei groups were also clearly distinguished. Our comparative analysis of protein sequences from Burkholderia spp. has identified 42 highly specific molecular markers in the form of conserved sequence indels (CSIs) that are uniquely found in a number of well-defined groups of Burkholderia spp. Six of these CSIs are specific for a group of Burkholderia spp. (referred to as Clade I in this work) which contains all clinically relevant members of the genus (viz. the BCC and the B. pseudomallei group) as well as the phytopathogenic Burkholderia spp. The second main clade (Clade II), which is composed of environmental Burkholderia species, is also distinguished by 2 identified CSIs that are specific for this group. Additionally, our work has also identified multiple CSIs that serve to clearly demarcate a number of smaller groups of Burkholderia spp. including 3 CSIs that are specific for the B. cepacia complex, 4 CSIs that are uniquely found in the B. pseudomallei group, 5 CSIs that are specific for the phytopathogenic Burkholderia spp. and 22 other CSI that distinguish two groups within Clade II. The described molecular markers provide highly specific means for

  17. Molecular signatures and phylogenomic analysis of the genus Burkholderia: proposal for division of this genus into the emended genus Burkholderia containing pathogenic organisms and a new genus Paraburkholderia gen. nov. harboring environmental species

    Science.gov (United States)

    Sawana, Amandeep; Adeolu, Mobolaji; Gupta, Radhey S.

    2014-01-01

    The genus Burkholderia contains large number of diverse species which include many clinically important organisms, phytopathogens, as well as environmental species. However, currently, there is a paucity of biochemical or molecular characteristics which can reliably distinguish different groups of Burkholderia species. We report here the results of detailed phylogenetic and comparative genomic analyses of 45 sequenced species of the genus Burkholderia. In phylogenetic trees based upon concatenated sequences for 21 conserved proteins as well as 16S rRNA gene sequence based trees, members of the genus Burkholderia grouped into two major clades. Within these main clades a number of smaller clades including those corresponding to the clinically important Burkholderia cepacia complex (BCC) and the Burkholderia pseudomallei groups were also clearly distinguished. Our comparative analysis of protein sequences from Burkholderia spp. has identified 42 highly specific molecular markers in the form of conserved sequence indels (CSIs) that are uniquely found in a number of well-defined groups of Burkholderia spp. Six of these CSIs are specific for a group of Burkholderia spp. (referred to as Clade I in this work) which contains all clinically relevant members of the genus (viz. the BCC and the B. pseudomallei group) as well as the phytopathogenic Burkholderia spp. The second main clade (Clade II), which is composed of environmental Burkholderia species, is also distinguished by 2 identified CSIs that are specific for this group. Additionally, our work has also identified multiple CSIs that serve to clearly demarcate a number of smaller groups of Burkholderia spp. including 3 CSIs that are specific for the B. cepacia complex, 4 CSIs that are uniquely found in the B. pseudomallei group, 5 CSIs that are specific for the phytopathogenic Burkholderia spp. and 22 other CSI that distinguish two groups within Clade II. The described molecular markers provide highly specific means for

  18. Case-crossover study of Burkholderia cepacia complex bloodstream infection associated with contaminated intravenous bromopride.

    Science.gov (United States)

    Martins, Ianick Souto; Pellegrino, Flávia Lúcia Piffano Costa; Freitas, Andrea d'Avila; Santos, Marisa da Silva; Ferraiuoli, Giovanna Ianini d'Alemeida; Vasques, Márcia Regina Guimarães; Amorim, Efigenia Lourdes Teixeira; Oliveira, Sandra; Nouér, Simone Aranha; Cardoso, Fernando Luiz Lopes; Mascarenhas, Luiz Affonso; Magalhães, Ana Cristina Gouveia; Cleinman, Isabella Barbosa; Figueiredo, Agnes Marie Sá; Moreira, Beatriz Meurer

    2010-05-01

    To investigate an outbreak of healthcare-associated Burkholderia cepacia complex (BCC) primary bloodstream infections (BCC-BSI). Case-crossover study in a public hospital, a university hospital and a private hospital in Rio de Janeiro, Brazil, from March 2006 to May 2006. Twenty-five patients with BCC-BSI. After determining the date BCC-BSI symptoms started for each patient, 3 time intervals of data collection were defined, each one with a duration of 3 days: the case period, starting just before BCC-BSI symptoms onset; the control period, starting 6 days before BCC-BSI symptoms onset; and the washout period, comprising the 3 days between the case period and the control period. Exposures evaluated were intravascular solutions and invasive devices and procedures. Potential risk factors were identified by using the McNemar chi(2) adjusted test. Cultures of samples of potentially contaminated solutions were performed. BCC strain typing was performed by pulsed-field gel electrophoresis using SpeI. The statistical analysis revealed that the use of bromopride and dipyrone was associated with BCC-BSI. A total of 21 clinical isolates from 17 (68%) of the 25 patients and an isolate obtained from the bromopride vial were available for strain typing. Six pulsotypes were detected. A predominant pulsotype (A) accounted for 11 isolates obtained from 11 patients (65%) in the 3 study hospitals. Our investigation, using a case-crossover design, of an outbreak of BCC-BSI infections concluded it was polyclonal but likely caused by infusion of contaminated bromopride. The epidemiological finding was validated by microbiological analysis. After recall of contaminated bromopride vials by the manufacturer, the outbreak was controlled.

  19. Burkholderia pseudomallei transcriptional adaptation in macrophages

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    Chieng Sylvia

    2012-07-01

    Full Text Available Abstract Background Burkholderia pseudomallei is a facultative intracellular pathogen of phagocytic and non-phagocytic cells. How the bacterium interacts with host macrophage cells is still not well understood and is critical to appreciate the strategies used by this bacterium to survive and how intracellular survival leads to disease manifestation. Results Here we report the expression profile of intracellular B. pseudomallei following infection of human macrophage-like U937 cells. During intracellular growth over the 6 h infection period, approximately 22 % of the B. pseudomallei genome showed significant transcriptional adaptation. B. pseudomallei adapted rapidly to the intracellular environment by down-regulating numerous genes involved in metabolism, cell envelope, motility, replication, amino acid and ion transport system and regulatory function pathways. Reduced expression in catabolic and housekeeping genes suggested lower energy requirement and growth arrest during macrophage infection, while expression of genes encoding anaerobic metabolism functions were up regulated. However, whilst the type VI secretion system was up regulated, expression of many known virulence factors was not significantly modulated over the 6hours of infection. Conclusions The transcriptome profile described here provides the first comprehensive view of how B. pseudomallei survives within host cells and will help identify potential virulence factors and proteins that are important for the survival and growth of B. pseudomallei within human cells.

  20. Crosstalk between sugarcane and a plant-growth promoting Burkholderia species

    Science.gov (United States)

    Paungfoo-Lonhienne, Chanyarat; Lonhienne, Thierry G. A.; Yeoh, Yun Kit; Donose, Bogdan C.; Webb, Richard I.; Parsons, Jeremy; Liao, Webber; Sagulenko, Evgeny; Lakshmanan, Prakash; Hugenholtz, Philip; Schmidt, Susanne; Ragan, Mark A.

    2016-01-01

    Bacterial species in the plant-beneficial-environmental clade of Burkholderia represent a substantial component of rhizosphere microbes in many plant species. To better understand the molecular mechanisms of the interaction, we combined functional studies with high-resolution dual transcriptome analysis of sugarcane and root-associated diazotrophic Burkholderia strain Q208. We show that Burkholderia Q208 forms a biofilm at the root surface and suppresses the virulence factors that typically trigger immune response in plants. Up-regulation of bd-type cytochromes in Burkholderia Q208 suggests an increased energy production and creates the microaerobic conditions suitable for BNF. In this environment, a series of metabolic pathways are activated in Burkholderia Q208 implicated in oxalotrophy, microaerobic respiration, and formation of PHB granules, enabling energy production under microaerobic conditions. In the plant, genes involved in hypoxia survival are up-regulated and through increased ethylene production, larger aerenchyma is produced in roots which in turn facilitates diffusion of oxygen within the cortex. The detected changes in gene expression, physiology and morphology in the partnership are evidence of a sophisticated interplay between sugarcane and a plant-growth promoting Burkholderia species that advance our understanding of the mutually beneficial processes occurring in the rhizosphere. PMID:27869215

  1. Exploring the HME and HAE1 efflux systems in the genus Burkholderia

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    Pasca Maria

    2010-06-01

    Full Text Available Abstract Background The genus Burkholderia includes a variety of species with opportunistic human pathogenic strains, whose increasing global resistance to antibiotics has become a public health problem. In this context a major role could be played by multidrug efflux pumps belonging to Resistance Nodulation Cell-Division (RND family, which allow bacterial cells to extrude a wide range of different substrates, including antibiotics. This study aims to i identify rnd genes in the 21 available completely sequenced Burkholderia genomes, ii analyze their phylogenetic distribution, iii define the putative function(s that RND proteins perform within the Burkholderia genus and iv try tracing the evolutionary history of some of these genes in Burkholderia. Results BLAST analysis of the 21 Burkholderia sequenced genomes, using experimentally characterized ceoB sequence (one of the RND family counterpart in the genus Burkholderia as probe, allowed the assembly of a dataset comprising 254 putative RND proteins. An extensive phylogenetic analysis revealed the occurrence of several independent events of gene loss and duplication across the different lineages of the genus Burkholderia, leading to notable differences in the number of paralogs between different genomes. A putative substrate [antibiotics (HAE1 proteins/heavy-metal (HME proteins] was also assigned to the majority of these proteins. No correlation was found between the ecological niche and the lifestyle of Burkholderia strains and the number/type of efflux pumps they possessed, while a relation can be found with genome size and taxonomy. Remarkably, we observed that only HAE1 proteins are mainly responsible for the different number of proteins observed in strains of the same species. Data concerning both the distribution and the phylogenetic analysis of the HAE1 and HME in the Burkholderia genus allowed depicting a likely evolutionary model accounting for the evolution and spreading of HME and HAE

  2. Plant growth-promoting Burkholderia species isolated from annual ryegrass in Portuguese soils.

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    Castanheira, N; Dourado, A C; Kruz, S; Alves, P I L; Delgado-Rodríguez, A I; Pais, I; Semedo, J; Scotti-Campos, P; Sánchez, C; Borges, N; Carvalho, G; Barreto Crespo, M T; Fareleira, P

    2016-03-01

    To search for culturable Burkholderia species associated with annual ryegrass in soils from natural pastures in Portugal, with plant growth-promoting effects. Annual ryegrass seedlings were used to trap Burkholderia from two different soils in laboratory conditions. A combined approach using genomic fingerprinting and sequencing of 16S rRNA and recA genes resulted in the identification of Burkholderia strains belonging to the species Burkholderia graminis, Burkholderia fungorum and the Burkholderia cepacia complex. Most strains were able to solubilize mineral phosphate and to synthesize indole acetic acid; some of them could produce siderophores and antagonize the phytopathogenic oomycete, Phytophthora cinnamomi. A strain (G2Bd5) of B. graminis was selected for gnotobiotic plant inoculation experiments. The main effects were the stimulation of root growth and enhancement of leaf lipid synthesis and turnover. Fluorescence in situ hybridization and confocal laser microscopy evidenced that strain G2Bd5 is a rhizospheric and endophytic colonizer of annual ryegrass. This work revealed that annual ryegrass can naturally associate with members of the genus Burkholderia. A novel plant growth promoting strain of B. graminis was obtained. The novel strain belongs to the plant-associated Burkholderia cluster and is a promising candidate for exploitation as plant inoculant in field conditions. © 2015 The Society for Applied Microbiology.

  3. Evaluation of the electron transfer flavoprotein as an antibacterial target in Burkholderia cenocepacia.

    Science.gov (United States)

    Stietz, Maria S; Lopez, Christina; Osifo, Osasumwen; Tolmasky, Marcelo E; Cardona, Silvia T

    2017-10-01

    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.

  4. Involvement of the efflux pumps in chloramphenicol selected strains of Burkholderia thailandensis: proteomic and mechanistic evidence.

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    Fabrice V Biot

    Full Text Available Burkholderia is a bacterial genus comprising several pathogenic species, including two species highly pathogenic for humans, B. pseudomallei and B. mallei. B. thailandensis is a weakly pathogenic species closely related to both B. pseudomallei and B. mallei. It is used as a study model. These bacteria are able to exhibit multiple resistance mechanisms towards various families of antibiotics. By sequentially plating B. thailandensis wild type strains on chloramphenicol we obtained several resistant variants. This chloramphenicol-induced resistance was associated with resistance against structurally unrelated antibiotics including quinolones and tetracyclines. We functionally and proteomically demonstrate that this multidrug resistance phenotype, identified in chloramphenicol-resistant variants, is associated with the overexpression of two different efflux pumps. These efflux pumps are able to expel antibiotics from several families, including chloramphenicol, quinolones, tetracyclines, trimethoprim and some β-lactams, and present a partial susceptibility to efflux pump inhibitors. It is thus possible that Burkholderia species can develop such adaptive resistance mechanisms in response to antibiotic pressure resulting in emergence of multidrug resistant strains. Antibiotics known to easily induce overexpression of these efflux pumps should be used with discernment in the treatment of Burkholderia infections.

  5. A Burkholderia pseudomallei colony variant necessary for gastric colonization.

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    Austin, C R; Goodyear, A W; Bartek, I L; Stewart, A; Sutherland, M D; Silva, E B; Zweifel, A; Vitko, N P; Tuanyok, A; Highnam, G; Mittelman, D; Keim, P; Schweizer, H P; Vázquez-Torres, A; Dow, S W C; Voskuil, M I

    2015-02-03

    Diverse colony morphologies are a hallmark of Burkholderia pseudomallei recovered from infected patients. We observed that stresses that inhibit aerobic respiration shifted populations of B. pseudomallei from the canonical white colony morphotype toward two distinct, reversible, yet relatively stable yellow colony variants (YA and YB). As accumulating evidence supports the importance of B. pseudomallei enteric infection and gastric colonization, we tested the response of yellow variants to hypoxia, acidity, and stomach colonization. Yellow variants exhibited a competitive advantage under hypoxic and acidic conditions and alkalized culture media. The YB variant, although highly attenuated in acute virulence, was the only form capable of colonization and persistence in the murine stomach. The accumulation of extracellular DNA (eDNA) was a characteristic of YB as observed by 4',6-diamidino-2-phenylindole (DAPI) staining of gastric tissues, as well as in an in vitro stomach model where large amounts of eDNA were produced without cell lysis. Transposon mutagenesis identified a transcriptional regulator (BPSL1887, designated YelR) that when overexpressed produced the yellow phenotype. Deletion of yelR blocked a shift from white to the yellow forms. These data demonstrate that YB is a unique B. pseudomallei pathovariant controlled by YelR that is specifically adapted to the harsh gastric environment and necessary for persistent stomach colonization. Seemingly uniform populations of bacteria often contain subpopulations that are genetically identical but display unique characteristics which offer advantages when the population is faced with infrequent but predictable stresses. The pathogen Burkholderia pseudomallei is capable of forming several reversible colony types, and it interconverted between one white type and two yellow types under certain environmental stresses. The two yellow forms exhibited distinct advantages in low-oxygen and acidic environments. One yellow

  6. Identification of Burkholderia spp. in the Clinical Microbiology Laboratory: Comparison of Conventional and Molecular Methods

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    van Pelt, Cindy; Verduin, Cees M.; Goessens, Wil H. F.; Vos, Margreet C.; Tümmler, Burkhard; Segonds, Christine; Reubsaet, Frans; Verbrugh, Henri; van Belkum, Alex

    1999-01-01

    Cystic fibrosis (CF) predisposes patients to bacterial colonization and infection of the lower airways. Several species belonging to the genus Burkholderia are potential CF-related pathogens, but microbiological identification may be complicated. This situation is not in the least due to the poorly defined taxonomic status of these bacteria, and further validation of the available diagnostic assays is required. A total of 114 geographically diverse bacterial isolates, previously identified in reference laboratories as Burkholderia cepacia (n = 51), B. gladioli (n = 14), Ralstonia pickettii (n = 6), B. multivorans (n = 2), Stenotrophomonas maltophilia (n = 3), and Pseudomonas aeruginosa (n = 11), were collected from environmental, clinical, and reference sources. In addition, 27 clinical isolates putatively identified as Burkholderia spp. were recovered from the sputum of Dutch CF patients. All isolates were used to evaluate the accuracy of two selective growth media, four systems for biochemical identification (API 20NE, Vitek GNI, Vitek NFC, and MicroScan), and three different PCR-based assays. The PCR assays amplify different parts of the ribosomal DNA operon, either alone or in combination with cleavage by various restriction enzymes (PCR-restriction fragment length polymorphism [RFLP] analysis). The best system for the biochemical identification of B. cepacia appeared to be the API 20NE test. None of the biochemical assays successfully grouped the B. gladioli strains. The PCR-RFLP method appeared to be the optimal method for accurate nucleic acid-mediated identification of the different Burkholderia spp. With this method, B. gladioli was also reliably classified in a separate group. For the laboratory diagnosis of B. cepacia, we recommend parallel cultures on blood agar medium and selective agar plates. Further identification of colonies with a Burkholderia phenotype should be performed with the API 20NE test. For final confirmation of species identities, PCR

  7. Burkholderia ginsengiterrae sp. nov. and Burkholderia panaciterrae sp. nov., antagonistic bacteria against root rot pathogen Cylindrocarpon destructans, isolated from ginseng soil.

    Science.gov (United States)

    Farh, Mohamed El-Agamy; Kim, Yeon-Ju; Van An, Hoang; Sukweenadhi, Johan; Singh, Priyanka; Huq, Md Amdadul; Yang, Deok-Chun

    2015-04-01

    Strain DCY85(T) and DCY85-1(T), isolated from rhizosphere of ginseng, were rod-shaped, Gram-reaction-negative, strictly aerobic, catalase positive and oxidase negative. 16S rRNA gene sequence analysis revealed that strain DCY85(T) as well as DCY85-1(T) belonged to the genus Burkholderia and were closely related to Burkholderia fungorum KACC 12023(T) (98.1 and 98.0 % similarity, respectively). The major polar lipids of strain DCY85(T) and DCY85-1(T) were phosphatidylethanolamine, one unidentified aminolipid and two unidentified phospholipids. The major fatty acids of both strains are C16:0, C18:1 ω7c and summed feature 3 (C16:1 ω6c and/or C16:1 ω7c). The predominant isoprenoid quinone of each strain DCY85(T) and DCY85-1(T) was ubiquinone (Q-8) and the G+C content of their genomic DNA was 66.0 and 59.4 mol%, respectively, which fulfill the characteristic range of the genus Burkholderia. The polyamine content of both DCY85(T) and DCY85-1(T) was putrescine. Although both DCY85(T) and DCY85-1(T) have highly similar 16S rRNA and identical RecA and gyrB sequences, they show differences in phenotypic and chemotaxonomic characteristics. DNA-DNA hybridization results proved the consideration of both strains as two different species. Based on the results from our polyphasic characterization, strain DCY85(T) and DCY85-1(T) are considered novel Burkholderia species for which the name Burkholderia ginsengiterrae sp. nov and Burkholderia panaciterrae sp. nov are, respectively, proposed. An emended description of those strains is also proposed. DCY85(T) and DCY85-1(T) showed antagonistic activity against the common root rot pathogen of ginseng, Cylindrocarpon destructans. The proposed type strains are DCY85(T) (KCTC 42054(T) = JCM 19888(T)) and DCY85-1(T) (KCTC 42055(T) = JCM 19889(T)).

  8. Biochemical Characterization and Structural Basis of Reactivity and Regioselectivity Differences between Burkholderia thailandensis and Burkholderia glumae 1,6-Didesmethyltoxoflavin N-Methyltransferase.

    Science.gov (United States)

    Fenwick, Michael K; Almabruk, Khaled H; Ealick, Steven E; Begley, Tadhg P; Philmus, Benjamin

    2017-08-01

    Burkholderia glumae converts the guanine base of guanosine triphosphate into an azapteridine and methylates both the pyrimidine and triazine rings to make toxoflavin. Strains of Burkholderia thailandensis and Burkholderia pseudomallei have a gene cluster encoding seven putative biosynthetic enzymes that resembles the toxoflavin gene cluster. Four of the enzymes are similar in sequence to BgToxBCDE, which have been proposed to make 1,6-didesmethyltoxoflavin (1,6-DDMT). One of the remaining enzymes, BthII1283 in B. thailandensis E264, is a predicted S-adenosylmethionine (SAM)-dependent N-methyltransferase that shows a low level of sequence identity to BgToxA, which sequentially methylates N6 and N1 of 1,6-DDMT to form toxoflavin. Here we show that, unlike BgToxA, BthII1283 catalyzes a single methyl transfer to N1 of 1,6-DDMT in vitro. In addition, we investigated the differences in reactivity and regioselectivity by determining crystal structures of BthII1283 with bound S-adenosylhomocysteine (SAH) or 1,6-DDMT and SAH. BthII1283 contains a class I methyltransferase fold and three unique extensions used for 1,6-DDMT recognition. The active site structure suggests that 1,6-DDMT is bound in a reduced form. The plane of the azapteridine ring system is orthogonal to its orientation in BgToxA. In BthII1283, the modeled SAM methyl group is directed toward the p orbital of N1, whereas in BgToxA, it is first directed toward an sp 2 orbital of N6 and then toward an sp 2 orbital of N1 after planar rotation of the azapteridine ring system. Furthermore, in BthII1283, N1 is hydrogen bonded to a histidine residue whereas BgToxA does not supply an obvious basic residue for either N6 or N1 methylation.

  9. Burkholderia pseudomallei-derived miR-3473 enhances NF-κB via targeting TRAF3 and is associated with different inflammatory responses compared to Burkholderia thailandensis in murine macrophages.

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    Fang, Yao; Chen, Hai; Hu, Yi; Li, Qian; Hu, Zhiqiang; Ma, Tengfei; Mao, Xuhu

    2016-11-28

    Burkholderia pseudomallei (Bp) is the causative agent of melioidosis, a kind of tropical disease. Burkholderia thailandensis (Bt), with a high sequence similarity to Bp, is thought to be an avirulent organism. Since there are numerous similarities between Bp and Bt, their differences in pathogenesis of host response and related mechanism are still undermined. In recent years, microRNAs have been researched in many diseases, but seldom involved in bacterial infection, bacteria-host interaction or explaining the differences between virulent and avirulent species. We found that Bp and Bt had similar phenotypes in terms of intracellular replication, dissemination (reflected by multinucleated giant cell formation), TNF-α release and apoptosis in RAW264.7 macrophages or TC-1 pulmonary cell but in different level. Especially, at the late infection phases (after 12 h post infection), Bp showed faster intracellular growth, stronger cytotoxicity, and higher TNF-α release. After microRNA array analysis, we found some microRNAs were significantly expressed in macrophages treated by Bp. miR-3473 was one of them specifically induced, but not significantly changed in Bt-treated macrophages. In addition, TargetScan suggested that miR-3473 possibly target TRAF3 (TNF receptor-associated factor 3), a well-known negative regulator of the NF-κB pathway, which was probably involved in the TNF-α induction and apoptosis in cells with Bp infection. In vivo, it was found that miR-3473 expression of total lungs cells from Bp-treated was higher than that from Bt-treated mice. And miR-3473 inhibitor was able to decrease the TNF-α release of mice and prolong the survival of mice with Bp infection. In sum, miR-3473 plays an important role in the differential pathogenicity of Bp and Bt via miR-3473-TRAF3-TNF-α network, and regulates TNF-α release, cell apoptosis and animal survival after Bp treatment. In this study, we have found a specific microRNA is related to bacterial virulence and

  10. Burkholderia susongensis sp. nov., a mineral-weathering bacterium isolated from weathered rock surface.

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    Gu, Jia-Yu; Zang, Sheng-Gang; Sheng, Xia-Fang; He, Lin-Yan; Huang, Zhi; Wang, Qi

    2015-03-01

    A novel type of mineral-weathering bacterium was isolated from the weathered surface of rock (mica schist) collected from Susong (Anhui, China). Cells of strain L226(T) were Gram-stain-negative. The strain grew optimally at 30 °C, with 1 % (w/v) NaCl and at pH 7.0 in trypticase soy broth. On the basis of 16S rRNA gene phylogeny, strain L226(T) was shown to belong to the genus Burkholderia and the closest phylogenetic relatives were Burkholderia sprentiae WSM5005(T) (98.3 %), Burkholderia acidipaludis NBRC 101816(T) (98.2 %), Burkholderia tuberum STM678(T) (97.2 %) and Burkholderia diazotrophica JPY461(T) (97.1 %). The DNA G+C content was 63.5 mol% and the respiratory quinone was Q-8. The major fatty acids were C16 : 0, C17 : 0 cyclo and C19 : 0 cyclo ω8c. The polar lipid profile of strain L226(T) consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, unknown lipids and unidentified aminophospholipids. Based on the low level of DNA-DNA relatedness (ranging from 25.8 % to 34.4 %) to the tested type strains of species of the genus Burkholderia and unique phenotypic characteristics, it is suggested that strain L226(T) represents a novel species of the genus Burkholderia, for which the name Burkholderia susongensis sp. nov., is proposed. The type strain is L226(T) ( = CCTCC AB2014142(T) = JCM 30231(T)). © 2015 IUMS.

  11. Molecular mechanisms underlying the close association between soil Burkholderia and fungi

    Science.gov (United States)

    Stopnisek, Nejc; Zühlke, Daniela; Carlier, Aurélien; Barberán, Albert; Fierer, Noah; Becher, Dörte; Riedel, Katharina; Eberl, Leo; Weisskopf, Laure

    2016-01-01

    Bacterial species belonging to the genus Burkholderia have been repeatedly reported to be associated with fungi but the extent and specificity of these associations in soils remain undetermined. To assess whether associations between Burkholderia and fungi are widespread in soils, we performed a co-occurrence analysis in an intercontinental soil sample collection. This revealed that Burkholderia significantly co-occurred with a wide range of fungi. To analyse the molecular basis of the interaction, we selected two model fungi frequently co-occurring with Burkholderia, Alternaria alternata and Fusarium solani, and analysed the proteome changes caused by cultivation with either fungus in the widespread soil inhabitant B. glathei, whose genome we sequenced. Co-cultivation with both fungi led to very similar changes in the B. glathei proteome. Our results indicate that B. glathei significantly benefits from the interaction, which is exemplified by a lower abundance of several starvation factors that were highly expressed in pure culture. However, co-cultivation also gave rise to stress factors, as indicated by the increased expression of multidrug efflux pumps and proteins involved in oxidative stress response. Our data suggest that the ability of Burkholderia to establish a close association with fungi mainly lies in the capacities to utilize fungal-secreted metabolites and to overcome fungal defense mechanisms. This work indicates that beneficial interactions with fungi might contribute to the survival strategy of Burkholderia species in environments with sub-optimal conditions, including acidic soils. PMID:25989372

  12. Molecular mechanisms underlying the close association between soil Burkholderia and fungi.

    Science.gov (United States)

    Stopnisek, Nejc; Zühlke, Daniela; Carlier, Aurélien; Barberán, Albert; Fierer, Noah; Becher, Dörte; Riedel, Katharina; Eberl, Leo; Weisskopf, Laure

    2016-01-01

    Bacterial species belonging to the genus Burkholderia have been repeatedly reported to be associated with fungi but the extent and specificity of these associations in soils remain undetermined. To assess whether associations between Burkholderia and fungi are widespread in soils, we performed a co-occurrence analysis in an intercontinental soil sample collection. This revealed that Burkholderia significantly co-occurred with a wide range of fungi. To analyse the molecular basis of the interaction, we selected two model fungi frequently co-occurring with Burkholderia, Alternaria alternata and Fusarium solani, and analysed the proteome changes caused by cultivation with either fungus in the widespread soil inhabitant B. glathei, whose genome we sequenced. Co-cultivation with both fungi led to very similar changes in the B. glathei proteome. Our results indicate that B. glathei significantly benefits from the interaction, which is exemplified by a lower abundance of several starvation factors that were highly expressed in pure culture. However, co-cultivation also gave rise to stress factors, as indicated by the increased expression of multidrug efflux pumps and proteins involved in oxidative stress response. Our data suggest that the ability of Burkholderia to establish a close association with fungi mainly lies in the capacities to utilize fungal-secreted metabolites and to overcome fungal defense mechanisms. This work indicates that beneficial interactions with fungi might contribute to the survival strategy of Burkholderia species in environments with sub-optimal conditions, including acidic soils.

  13. Burkholderia glumae: next major pathogen of rice?

    Science.gov (United States)

    Ham, Jong Hyun; Melanson, Rebecca A; Rush, Milton C

    2011-05-01

    Burkholderia glumae causes bacterial panicle blight of rice, which is an increasingly important disease problem in global rice production. Toxoflavin and lipase are known to be major virulence factors of this pathogen, and their production is dependent on the TofI/TofR quorum-sensing system, which is mediated by N-octanoyl homoserine lactone. Flagellar biogenesis and a type III secretion system are also required for full virulence of B. glumae. Bacterial panicle blight is thought to be caused by seed-borne B. glumae; however, its disease cycle is not fully understood. In spite of its economic importance, neither effective control measures for bacterial panicle blight nor rice varieties showing complete resistance to the disease are currently available. A better understanding of the molecular mechanisms underlying B. glumae virulence and of the rice defence mechanisms against the pathogen would lead to the development of better methods of disease control for bacterial panicle blight. Bacteria; Proteobacteria; Betaproteobacteria; Burkholderiales; Burkholderiaceae; Burkholderia. Gram-negative, capsulated, motile, lophotrichous flagella, pectolytic. Aborted seed, empty grains as a result of failure of grain filling, brown spots on panicles, seedling rot. Seed sterilization, planting partially resistant lines (no completely resistant line is available). KNOWN VIRULENCE FACTORS: Toxoflavin, lipase, type III effectors. © 2010 LSU AGCENTER. MOLECULAR PLANT PATHOLOGY © 2010 BSPP AND BLACKWELL PUBLISHING LTD.

  14. Common Duckweed (Lemna minor) Is a Versatile High-Throughput Infection Model For the Burkholderia cepacia Complex and Other Pathogenic Bacteria

    Science.gov (United States)

    Thomson, Euan L. S.; Dennis, Jonathan J.

    2013-01-01

    Members of the Burkholderia cepacia complex (Bcc) have emerged in recent decades as problematic pulmonary pathogens of cystic fibrosis (CF) patients, with severe infections progressing to acute necrotizing pneumonia and sepsis. This study presents evidence that Lemna minor (Common duckweed) is useful as a plant model for the Bcc infectious process, and has potential as a model system for bacterial pathogenesis in general. To investigate the relationship between Bcc virulence in duckweed and Galleria mellonella (Greater wax moth) larvae, a previously established Bcc infection model, a duckweed survival assay was developed and used to determine LD50 values. A strong correlation (R2 = 0.81) was found between the strains’ virulence ranks in the two infection models, suggesting conserved pathways in these vastly different hosts. To broaden the application of the duckweed model, enteropathogenic Escherichia coli (EPEC) and five isogenic mutants with previously established LD50 values in the larval model were tested against duckweed, and a strong correlation (R2 = 0.93) was found between their raw LD50 values. Potential virulence factors in B. cenocepacia K56-2 were identified using a high-throughput screen against single duckweed plants. In addition to the previously characterized antifungal compound (AFC) cluster genes, several uncharacterized genes were discovered including a novel lysR regulator, a histidine biosynthesis gene hisG, and a gene located near the gene encoding the recently characterized virulence factor SuhBBc. Finally, to demonstrate the utility of this model in therapeutic applications, duckweed was rescued from Bcc infection by treating with bacteriophage at 6-h intervals. It was observed that phage application became ineffective at a timepoint that coincided with a sharp increase in bacterial invasion of plant tissue. These results indicate that common duckweed can serve as an effective infection model for the investigation of bacterial virulence

  15. A CpG oligonucleotide can protect mice from a low aerosol challenge dose of Burkholderia mallei.

    Science.gov (United States)

    Waag, David M; McCluskie, Michael J; Zhang, Ningli; Krieg, Arthur M

    2006-03-01

    Treatment with an oligodeoxynucleotide (ODN) containing CPG motifs (CpG ODN 7909) was found to protect BALB/c mice from lung infection or death after aerosol challenge with Burkholderia mallei. Protection was associated with enhanced levels of gamma interferon (IFN-gamma)-inducible protein 10, interleukin-12 (IL-12), IFN-gamma, and IL-6. Preexposure therapy with CpG ODNs may protect victims of a biological attack from glanders.

  16. An Objective Approach for Burkholderia pseudomallei Strain Selection as Challenge Material for Medical Countermeasures Efficacy Testing

    OpenAIRE

    Van Zandt, Kristopher E.; Tuanyok, Apichai; Keim, Paul S.; Warren, Richard L.; Gelhaus, H. Carl

    2012-01-01

    Burkholderia pseudomallei is the causative agent of melioidosis, a rare disease of biodefense concern with high mortality and extreme difficulty in treatment. No human vaccines are available that protect against B. pseudomallei infection, and with the current limitations of antibiotic treatment, the development of new preventative and therapeutic interventions is crucial. Although clinical trials could be used to test the efficacy of new medical countermeasures (MCMs), the high mortality rate...

  17. Burkholderia pseudomallei Evades Nramp1 (Slc11a1- and NADPH Oxidase-Mediated Killing in Macrophages and Exhibits Nramp1-Dependent Virulence Gene Expression

    Directory of Open Access Journals (Sweden)

    Veerachat Muangsombut

    2017-08-01

    Full Text Available Bacterial survival in macrophages can be affected by the natural resistance-associated macrophage protein 1 (Nramp1; also known as solute carrier family 11 member a1 or Slc11a1 which localizes to phagosome membranes and transports divalent cations, including iron. Little is known about the role of Nramp1 in Burkholderia infection, in particular whether this differs for pathogenic species like Burkholderia pseudomallei causing melioidosis or non-pathogenic species like Burkholderia thailandensis. Here we show that transfected macrophages stably expressing wild-type Nramp1 (Nramp1+ control the net replication of B. thailandensis, but not B. pseudomallei. Control of B. thailandensis was associated with increased cytokine responses, and could be abrogated by blocking NADPH oxidase-mediated production of reactive oxygen species but not by blocking generation of reactive nitrogen species. The inability of Nramp1+ macrophages to control B. pseudomallei was associated with rapid escape of bacteria from phagosomes, as indicated by decreased co-localization with LAMP1 compared to B. thailandensis. A B. pseudomallei bipB mutant impaired in escape from phagosomes was controlled to a greater extent than the parent strain in Nramp1+ macrophages, but was also attenuated in Nramp1− cells. Consistent with reduced escape from phagosomes, B. thailandensis formed fewer multinucleated giant cells in Nramp1+ macrophages at later time points compared to B. pseudomallei. B. pseudomallei exhibited elevated transcription of virulence-associated genes of Type VI Secretion System cluster 1 (T6SS-1, the Bsa Type III Secretion System (T3SS-3 and the bimA gene required for actin-based motility in Nramp1+ macrophages. Nramp1+ macrophages were found to contain decreased iron levels that may impact on expression of such genes. Our data show that B. pseudomallei is able to evade Nramp1- and NADPH oxidase-mediated killing in macrophages and that expression of virulence

  18. Burkholderia in gladiool lastige bacterie

    NARCIS (Netherlands)

    Kok, B.J.; Aanholt, van J.T.M.

    2009-01-01

    In de bollen- en bloementeelt van gladiolen komt de laatste jaren de bacterieziekte Burkholderia gladiola voor die onder vochtige warme omstandigheden veel uitval veroorzaken. PPO onderzocht een aantal maatregelen om de ziekte in kralen, pitten en knollen te bestrijden

  19. Inflammation in Achromobacter xylosoxidans infected cystic fibrosis patients

    DEFF Research Database (Denmark)

    Hansen, C. R.; Pressler, T.; Nielsen, K. G.

    2010-01-01

    BACKGROUND: Achromobacter xylosoxidans infection may cause conspicuous chronic pulmonary inflammation in cystic fibrosis (CF) patients similar to Pseudomonas aeruginosa and the Burkholderia cepacia complex (Bcc). Evolution in lung function was compared in chronically infected patients. Cytokine...

  20. Burkholderia contaminans Biofilm Regulating Operon and Its Distribution in Bacterial Genomes.

    Science.gov (United States)

    Voronina, Olga L; Kunda, Marina S; Ryzhova, Natalia N; Aksenova, Ekaterina I; Semenov, Andrey N; Romanova, Yulia M; Gintsburg, Alexandr L

    2016-01-01

    Biofilm formation by Burkholderia spp. is a principal cause of lung chronic infections in cystic fibrosis patients. A "lacking biofilm production" (LBP) strain B. contaminans GIMC4587:Bct370-19 has been obtained by insertion modification of clinical strain with plasposon mutagenesis. It has an interrupted transcriptional response regulator (RR) gene. The focus of our investigation was a two-component signal transduction system determination, including this RR. B. contaminans clinical and LBP strains were analyzed by whole genome sequencing and bioinformatics resources. A four-component operon (BiofilmReg) has a key role in biofilm formation. The relative location (i.e., by being separated by another gene) of RR and histidine kinase genes is unique in BiofilmReg. Orthologs were found in other members of the Burkholderiales order. Phylogenetic analysis of strains containing BiofilmReg operons demonstrated evidence for earlier inheritance of a three-component operon. During further evolution one lineage acquired a fourth gene, whereas others lost the third component of the operon. Mutations in sensor domains have created biodiversity which is advantageous for adaptation to various ecological niches. Different species Burkholderia and Achromobacter strains all demonstrated similar BiofilmReg operon structure. Therefore, there may be an opportunity to develop a common drug which is effective for treating all these causative agents.

  1. Interim report on updated microarray probes for the LLNL Burkholderia pseudomallei SNP array

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, S; Jaing, C

    2012-03-27

    The overall goal of this project is to forensically characterize 100 unknown Burkholderia isolates in the US-Australia collaboration. We will identify genome-wide single nucleotide polymorphisms (SNPs) from B. pseudomallei and near neighbor species including B. mallei, B. thailandensis and B. oklahomensis. We will design microarray probes to detect these SNP markers and analyze 100 Burkholderia genomic DNAs extracted from environmental, clinical and near neighbor isolates from Australian collaborators on the Burkholderia SNP microarray. We will analyze the microarray genotyping results to characterize the genetic diversity of these new isolates and triage the samples for whole genome sequencing. In this interim report, we described the SNP analysis and the microarray probe design for the Burkholderia SNP microarray.

  2. Distinct colicin M-like bacteriocin-immunity pairs in Burkholderia.

    Science.gov (United States)

    Ghequire, Maarten G K; De Mot, René

    2015-11-27

    The Escherichia coli bacteriocin colicin M (ColM) acts via degradation of the cell wall precursor lipid II in target cells. ColM producers avoid self-inhibition by a periplasmic immunity protein anchored in the inner membrane. In this study, we identified colM-like bacteriocin genes in genomes of several β-proteobacterial strains belonging to the Burkholderia cepacia complex (Bcc) and the Burkholderia pseudomallei group. Two selected Burkholderia ambifaria proteins, designated burkhocins M1 and M2, were produced recombinantly and showed antagonistic activity against Bcc strains. In their considerably sequence-diverged catalytic domain, a conserved aspartate residue equally proved pivotal for cytotoxicity. Immunity to M-type burkhocins is conferred upon susceptible strains by heterologous expression of a cognate gene located either upstream or downstream of the toxin gene. These genes lack homology with currently known ColM immunity genes and encode inner membrane-associated proteins of two distinct types, differing in predicted transmembrane topology and moiety exposed to the periplasm. The addition of burkhocins to the bacteriocin complement of Burkholderia reveals a wider phylogenetic distribution of ColM-like bacteriotoxins, beyond the γ-proteobacterial genera Escherichia, Pectobacterium and Pseudomonas, and illuminates the diversified nature of immunity-providing proteins.

  3. Comparative Genomics of Burkholderia singularis sp. nov., a Low G+C Content, Free-Living Bacterium That Defies Taxonomic Dissection of the Genus Burkholderia

    Directory of Open Access Journals (Sweden)

    Peter Vandamme

    2017-09-01

    Full Text Available Four Burkholderia pseudomallei-like isolates of human clinical origin were examined by a polyphasic taxonomic approach that included comparative whole genome analyses. The results demonstrated that these isolates represent a rare and unusual, novel Burkholderia species for which we propose the name B. singularis. The type strain is LMG 28154T (=CCUG 65685T. Its genome sequence has an average mol% G+C content of 64.34%, which is considerably lower than that of other Burkholderia species. The reduced G+C content of strain LMG 28154T was characterized by a genome wide AT bias that was not due to reduced GC-biased gene conversion or reductive genome evolution, but might have been caused by an altered DNA base excision repair pathway. B. singularis can be differentiated from other Burkholderia species by multilocus sequence analysis, MALDI-TOF mass spectrometry and a distinctive biochemical profile that includes the absence of nitrate reduction, a mucoid appearance on Columbia sheep blood agar, and a slowly positive oxidase reaction. Comparisons with publicly available whole genome sequences demonstrated that strain TSV85, an Australian water isolate, also represents the same species and therefore, to date, B. singularis has been recovered from human or environmental samples on three continents.

  4. Comparative Genomics of Burkholderia singularis sp. nov., a Low G+C Content, Free-Living Bacterium That Defies Taxonomic Dissection of the Genus Burkholderia

    Science.gov (United States)

    Vandamme, Peter; Peeters, Charlotte; De Smet, Birgit; Price, Erin P.; Sarovich, Derek S.; Henry, Deborah A.; Hird, Trevor J.; Zlosnik, James E. A.; Mayo, Mark; Warner, Jeffrey; Baker, Anthony; Currie, Bart J.; Carlier, Aurélien

    2017-01-01

    Four Burkholderia pseudomallei-like isolates of human clinical origin were examined by a polyphasic taxonomic approach that included comparative whole genome analyses. The results demonstrated that these isolates represent a rare and unusual, novel Burkholderia species for which we propose the name B. singularis. The type strain is LMG 28154T (=CCUG 65685T). Its genome sequence has an average mol% G+C content of 64.34%, which is considerably lower than that of other Burkholderia species. The reduced G+C content of strain LMG 28154T was characterized by a genome wide AT bias that was not due to reduced GC-biased gene conversion or reductive genome evolution, but might have been caused by an altered DNA base excision repair pathway. B. singularis can be differentiated from other Burkholderia species by multilocus sequence analysis, MALDI-TOF mass spectrometry and a distinctive biochemical profile that includes the absence of nitrate reduction, a mucoid appearance on Columbia sheep blood agar, and a slowly positive oxidase reaction. Comparisons with publicly available whole genome sequences demonstrated that strain TSV85, an Australian water isolate, also represents the same species and therefore, to date, B. singularis has been recovered from human or environmental samples on three continents. PMID:28932212

  5. Burkholderia species associated with legumes of Chiapas, Mexico, exhibit stress tolerance and growth in aromatic compounds.

    Science.gov (United States)

    de León-Martínez, José A; Yañez-Ocampo, Gustavo; Wong-Villarreal, Arnoldo

    Leguminous plants have received special interest for the diversity of β-proteobacteria in their nodules and are promising candidates for biotechnological applications. In this study, 15 bacterial strains were isolated from the nodules of the following legumes: Indigofera thibaudiana, Mimosa diplotricha, Mimosa albida, Mimosa pigra, and Mimosa pudica, collected in 9 areas of Chiapas, Mexico. The strains were grouped into four profiles of genomic fingerprints through BOX-PCR and identified based on their morphology, API 20NE biochemical tests, sequencing of the 16S rRNA, nifH and nodC genes as bacteria of the Burkholderia genus, genetically related to Burkholderia phenoliruptrix, Burkholderia phymatum, Burkholderia sabiae, and Burkholderia tuberum. The Burkholderia strains were grown under stress conditions with 4% NaCl, 45°C, and benzene presence at 0.1% as the sole carbon source. This is the first report on the isolation of these nodulating species of the Burkholderia genus in legumes in Mexico. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. PhaR, a Negative Regulator of PhaP, Modulates the Colonization of a Burkholderia Gut Symbiont in the Midgut of the Host Insect, Riptortus pedestris.

    Science.gov (United States)

    Jang, Seong Han; Jang, Ho Am; Lee, Junbeom; Kim, Jong Uk; Lee, Seung Ah; Park, Kyoung-Eun; Kim, Byung Hyun; Jo, Yong Hun; Lee, Bok Luel

    2017-06-01

    Five genes encoding PhaP family proteins and one phaR gene have been identified in the genome of Burkholderia symbiont strain RPE75. PhaP proteins function as the surface proteins of polyhydroxyalkanoate (PHA) granules, and the PhaR protein acts as a negative regulator of PhaP biosynthesis. Recently, we characterized one phaP gene to understand the molecular cross talk between Riptortus insects and Burkholderia gut symbionts. In this study, we constructed four other phaP gene-depleted mutants (Δ phaP1 , Δ phaP2 , Δ phaP3 , and Δ phaP4 mutants), one phaR gene-depleted mutant, and a phaR -complemented mutant (Δ phaR/phaR mutant). To address the biological roles of four phaP family genes and the phaR gene during insect-gut symbiont interaction, these Burkholderia mutants were fed to the second-instar nymphs, and colonization ability and fitness parameters were examined. In vitro , the Δ phaP3 and Δ phaR mutants cannot make a PHA granule normally in a stressful environment. Furthermore, the Δ phaR mutation decreased the colonization ability in the host midgut and negatively affected the host insect's fitness compared with wild-type Burkholderia -infected insects. However, other phaP family gene-depleted mutants colonized well in the midgut of the fifth-instar nymph insects. However, in the case of females, the colonization rate of the Δ phaP3 mutant was decreased and the host's fitness parameters were decreased compared with the wild-type-infected host, suggesting that the environment of the female midgut may be more hostile than that of the male midgut. These results demonstrate that PhaR plays an important role in the biosynthesis of PHA granules and that it is significantly related to the colonization of the Burkholderia gut symbiont in the host insects' midgut. IMPORTANCE Bacterial polyhydroxyalkanoate (PHA) biosynthesis is a complex process requiring several enzymes. The biological roles of PHA granule synthesis enzymes and the surface proteins of PHA

  7. Isolation and Identification of Burkholderia glumae from Symptomless Rice Seeds

    Directory of Open Access Journals (Sweden)

    Bo Zhu

    2008-06-01

    Full Text Available A survey on isolation and detection of the casual organism of bacterial grain rot of rice was conducted during 1997–2006. In 2006, six pathogenic bacterial strains were isolated from two symptomless seed samples of rice (Oryza sativa L. originally produced in Hainan Province and then planted in Zhejiang Province, China. They were identified as Burkholderia glumae which is the causal organism of bacterial grain rot of rice by physiological characteristics, colony morphology, pathogenicity test, Biolog, fatty acid methyl ester (FAME analysis and RAPD-PCR compared with the four standard reference strains. It is confirmed that there is the infection of B. glumae in so-called ‘health looking seeds’.

  8. Diagnosis of biofilm infections in cystic fibrosis patients

    DEFF Research Database (Denmark)

    Høiby, Niels; Bjarnsholt, Thomas; Moser, Claus

    2017-01-01

    Chronic Pseudomonas aeruginosa biofilm lung infection in cystic fibrosis patients is the best described biofilm infection in medicine. The initial focus can be the paranasal sinuses and then follows repeated colonization and infection of the lungs by aspiration. The matrix of the biofilms is domi...... by other pathogens e.g., Stenotrophomonas, Burkholderia multivorans, Achromobacter xylosoxidans and Mycobacterium abscessus complex....

  9. The Organization of the Quorum Sensing luxI/R Family Genes in Burkholderia

    Directory of Open Access Journals (Sweden)

    Sándor Pongor

    2013-07-01

    Full Text Available Members of the Burkholderia genus of Proteobacteria are capable of living freely in the environment and can also colonize human, animal and plant hosts. Certain members are considered to be clinically important from both medical and veterinary perspectives and furthermore may be important modulators of the rhizosphere. Quorum sensing via N-acyl homoserine lactone signals (AHL QS is present in almost all Burkholderia species and is thought to play important roles in lifestyle changes such as colonization and niche invasion. Here we present a census of AHL QS genes retrieved from public databases and indicate that the local arrangement (topology of QS genes, their location within chromosomes and their gene neighborhoods show characteristic patterns that differ between the known Burkholderia clades. In sequence phylogenies, AHL QS genes seem to cluster according to the local gene topology rather than according to the species, which suggests that the basic topology types were present prior to the appearance of current Burkholderia species. The data are available at http://net.icgeb.org/burkholderia/.

  10. The Organization of the Quorum Sensing luxI/R Family Genes in Burkholderia

    Science.gov (United States)

    Choudhary, Kumari Sonal; Hudaiberdiev, Sanjarbek; Gelencsér, Zsolt; Coutinho, Bruna Gonçalves; Venturi, Vittorio; Pongor, Sándor

    2013-01-01

    Members of the Burkholderia genus of Proteobacteria are capable of living freely in the environment and can also colonize human, animal and plant hosts. Certain members are considered to be clinically important from both medical and veterinary perspectives and furthermore may be important modulators of the rhizosphere. Quorum sensing via N-acyl homoserine lactone signals (AHL QS) is present in almost all Burkholderia species and is thought to play important roles in lifestyle changes such as colonization and niche invasion. Here we present a census of AHL QS genes retrieved from public databases and indicate that the local arrangement (topology) of QS genes, their location within chromosomes and their gene neighborhoods show characteristic patterns that differ between the known Burkholderia clades. In sequence phylogenies, AHL QS genes seem to cluster according to the local gene topology rather than according to the species, which suggests that the basic topology types were present prior to the appearance of current Burkholderia species. The data are available at http://net.icgeb.org/burkholderia/. PMID:23820583

  11. 16S rRNA gene-based phylogenetic microarray for simultaneous identification of members of the genus Burkholderia.

    Science.gov (United States)

    Schönmann, Susan; Loy, Alexander; Wimmersberger, Céline; Sobek, Jens; Aquino, Catharine; Vandamme, Peter; Frey, Beat; Rehrauer, Hubert; Eberl, Leo

    2009-04-01

    For cultivation-independent and highly parallel analysis of members of the genus Burkholderia, an oligonucleotide microarray (phylochip) consisting of 131 hierarchically nested 16S rRNA gene-targeted oligonucleotide probes was developed. A novel primer pair was designed for selective amplification of a 1.3 kb 16S rRNA gene fragment of Burkholderia species prior to microarray analysis. The diagnostic performance of the microarray for identification and differentiation of Burkholderia species was tested with 44 reference strains of the genera Burkholderia, Pandoraea, Ralstonia and Limnobacter. Hybridization patterns based on presence/absence of probe signals were interpreted semi-automatically using the novel likelihood-based strategy of the web-tool Phylo- Detect. Eighty-eight per cent of the reference strains were correctly identified at the species level. The evaluated microarray was applied to investigate shifts in the Burkholderia community structure in acidic forest soil upon addition of cadmium, a condition that selected for Burkholderia species. The microarray results were in agreement with those obtained from phylogenetic analysis of Burkholderia 16S rRNA gene sequences recovered from the same cadmiumcontaminated soil, demonstrating the value of the Burkholderia phylochip for determinative and environmental studies.

  12. HemX is required for production of 2-ketogluconate, the predominant organic anion required for inorganic phosphate solubilization by Burkholderia sp. Ha185.

    Science.gov (United States)

    Hsu, Pei-Chun Lisa; Condron, Leo; O'Callaghan, Maureen; Hurst, Mark R H

    2015-12-01

    The bacterium Burkholderia sp. Ha185 readily solubilizes inorganic phosphate by releasing the low molecular weight organic anion, 2-ketogluconate. Using random transposon mutagenesis and in silico analysis, a mutation that caused almost complete abolition of phosphate solubilization was located within hemX, which is part of the hem operon. Burkholderia sp. Ha185 HemX is a multidomain protein, predicted to encode a bifunctional uroporphyrinogen-III synthetase/uroporphyrin-III C-methyltransferase, which has not previously been implicated in phosphate solubilization. Complementation of hemX restored the ability of the mutant to solubilize phosphate in both plate and liquid cultures. Based on a combination of organic-anion profiling, quantitative polymerase chain reaction and in silico analyses, hemX was confirmed to be solely responsible for hydroxyapatite solubilization in Burkholderia sp. Ha185. It is proposed that the biosynthesis of a yet to be determined redox cofactor by HemX is the main pathway for generating 2-ketogluconate via a haem-dependent gluconate 2-dehydrogenase in Burkholderia sp. Ha185. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  13. Regulator LdhR and d-Lactate Dehydrogenase LdhA of Burkholderia multivorans Play Roles in Carbon Overflow and in Planktonic Cellular Aggregate Formation.

    Science.gov (United States)

    Silva, Inês N; Ramires, Marcelo J; Azevedo, Lisa A; Guerreiro, Ana R; Tavares, Andreia C; Becker, Jörg D; Moreira, Leonilde M

    2017-10-01

    LysR-type transcriptional regulators (LTTRs) are the most commonly found regulators in Burkholderia cepacia complex, comprising opportunistic pathogens causing chronic respiratory infections in cystic fibrosis (CF) patients. Despite LTTRs being global regulators of pathogenicity in several types of bacteria, few have been characterized in Burkholderia Here, we show that gene ldhR of B. multivorans encoding an LTTR is cotranscribed with ldhA encoding a d-lactate dehydrogenase and evaluate their implication in virulence traits such as exopolysaccharide (EPS) synthesis and biofilm formation. A comparison of the wild type (WT) and its isogenic Δ ldhR mutant grown in medium with 2% d-glucose revealed a negative impact on EPS biosynthesis and on cell viability in the presence of LdhR. The loss of viability in WT cells was caused by intracellular acidification as a consequence of the cumulative secretion of organic acids, including d-lactate, which was absent from the Δ ldhR mutant supernatant. Furthermore, LdhR is implicated in the formation of planktonic cellular aggregates. WT cell aggregates reached 1,000 μm in size after 24 h in liquid cultures, in contrast to Δ ldhR mutant aggregates that never grew more than 60 μm. The overexpression of d-lactate dehydrogenase LdhA in the Δ ldhR mutant partially restored the formed aggregate size, suggesting a role for fermentation inside aggregates. Similar results were obtained for surface-attached biofilms, with WT cells producing more biofilm. A systematic evaluation of planktonic aggregates in Burkholderia CF clinical isolates showed aggregates in 40 of 74. As CF patients' lung environments are microaerophilic and bacteria are found as free aggregates/biofilms, LdhR and LdhA might have central roles in adapting to this environment. IMPORTANCE Cystic fibrosis patients often suffer from chronic respiratory infections caused by several types of microorganisms. Among them are the Burkholderia cepacia complex bacteria, which

  14. Burkholderia cenocepacia K56-2 trimeric autotransporter adhesin BcaA binds TNFR1 and contributes to induce airway inflammation.

    Science.gov (United States)

    Mil-Homens, Dalila; Pinto, Sandra N; Matos, Rute G; Arraiano, Cecília; Fialho, Arsenio M

    2017-04-01

    Chronic lung disease caused by persistent bacterial infections is a major cause of morbidity and mortality in patients with cystic fibrosis (CF). CF pathogens acquire antibiotic resistance, overcome host defenses, and impose uncontrolled inflammation that ultimately may cause permanent damage of lungs' airways. Among the multiple CF-associated pathogens, Burkholderia cenocepacia and other Burkholderia cepacia complex bacteria have become prominent contributors of disease progression. Here, we demonstrate that BcaA, a trimeric autotransporter adhesin (TAA) from the epidemic strain B. cenocepacia K56-2, is a tumor necrosis factor receptor 1-interacting protein able to regulate components of the tumor necrosis factor signaling pathway and ultimately leading to a significant production of the proinflammatory cytokine IL-8. Notably, this study is the first to demonstrate that a protein belonging to the TAA family is involved in the induction of the inflammatory response during B. cenocepacia infections, contributing to the success of the pathogen. Moreover, our results reinforce the relevance of the TAA BcaA as a multifunctional protein with a major role in B. cenocepacia virulence. © 2016 John Wiley & Sons Ltd.

  15. CHROMOSOMAL MULTIPLICITY IN BURKHOLDERIA CEPACIA

    Science.gov (United States)

    We have used CHEF gel electrophoresis to screen preparations of large DNA from different Burkholderia cepacia isolates for the presence of DNA species corresponding to the linearized forms of the three chromosomes of 3.4,2.5, and 0.9 Mb identified in B. cepacia strain 17616. DNA ...

  16. Common duckweed (Lemna minor is a versatile high-throughput infection model for the Burkholderia cepacia complex and other pathogenic bacteria.

    Directory of Open Access Journals (Sweden)

    Euan L S Thomson

    Full Text Available Members of the Burkholderia cepacia complex (Bcc have emerged in recent decades as problematic pulmonary pathogens of cystic fibrosis (CF patients, with severe infections progressing to acute necrotizing pneumonia and sepsis. This study presents evidence that Lemna minor (Common duckweed is useful as a plant model for the Bcc infectious process, and has potential as a model system for bacterial pathogenesis in general. To investigate the relationship between Bcc virulence in duckweed and Galleria mellonella (Greater wax moth larvae, a previously established Bcc infection model, a duckweed survival assay was developed and used to determine LD50 values. A strong correlation (R(2 = 0.81 was found between the strains' virulence ranks in the two infection models, suggesting conserved pathways in these vastly different hosts. To broaden the application of the duckweed model, enteropathogenic Escherichia coli (EPEC and five isogenic mutants with previously established LD50 values in the larval model were tested against duckweed, and a strong correlation (R(2 = 0.93 was found between their raw LD50 values. Potential virulence factors in B. cenocepacia K56-2 were identified using a high-throughput screen against single duckweed plants. In addition to the previously characterized antifungal compound (AFC cluster genes, several uncharacterized genes were discovered including a novel lysR regulator, a histidine biosynthesis gene hisG, and a gene located near the gene encoding the recently characterized virulence factor SuhB(Bc. Finally, to demonstrate the utility of this model in therapeutic applications, duckweed was rescued from Bcc infection by treating with bacteriophage at 6-h intervals. It was observed that phage application became ineffective at a timepoint that coincided with a sharp increase in bacterial invasion of plant tissue. These results indicate that common duckweed can serve as an effective infection model for the investigation of bacterial

  17. Prevalence and Identification of Burkholderia pseudomallei and Near-Neighbor Species in the Malabar Coastal Region of India

    Science.gov (United States)

    Peddayelachagiri, Bhavani V.; Paul, Soumya; Nagaraj, Sowmya; Gogoi, Madhurjya; Sripathy, Murali H.; Batra, Harsh V.

    2016-01-01

    Accurate identification of pathogens with biowarfare importance requires detection tools that specifically differentiate them from near-neighbor species. Burkholderia pseudomallei, the causative agent of a fatal disease melioidosis, is one such biothreat agent whose differentiation from its near-neighbor species is always a challenge. This is because of its phenotypic similarity with other Burkholderia species which have a wide spread geographical distribution with shared environmental niches. Melioidosis is a major public health concern in endemic regions including Southeast Asia and northern Australia. In India, the disease is still considered to be emerging. Prevalence surveys of this saprophytic bacterium in environment are under-reported in the country. A major challenge in this case is the specific identification and differentiation of B. pseudomallei from the growing list of species of Burkholderia genus. The objectives of this study included examining the prevalence of B. pseudomallei and near-neighbor species in coastal region of South India and development of a novel detection tool for specific identification and differentiation of Burkholderia species. Briefly, we analyzed soil and water samples collected from Malabar coastal region of Kerala, South India for prevalence of B. pseudomallei. The presumptive Burkholderia isolates were identified using recA PCR assay. The recA PCR assay identified 22 of the total 40 presumptive isolates as Burkholderia strains (22.72% and 77.27% B. pseudomallei and non-pseudomallei Burkholderia respectively). In order to identify each isolate screened, we performed recA and 16S rDNA sequencing. This two genes sequencing revealed that the presumptive isolates included B. pseudomallei, non-pseudomallei Burkholderia as well as non-Burkholderia strains. Furthermore, a gene termed D-beta hydroxybutyrate dehydrogenase (bdha) was studied both in silico and in vitro for accurate detection of Burkholderia genus. The optimized bdha

  18. Novel diagnostic PCR assay for Burkholderia cenocepacia epidemic strain ST32 and its utility in monitoring infection in cystic fibrosis patients

    Czech Academy of Sciences Publication Activity Database

    Dědečková, K.; Kalferstová, L.; Strnad, Hynek; Vávrová, J.; Dřevínek, P.

    2013-01-01

    Roč. 12, č. 5 (2013), s. 475-481 ISSN 1569-1993 Institutional support: RVO:68378050 Keywords : Burkholderia cenocepacia * diagnostic PCR * B. cenocepacia ST32 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.820, year: 2013

  19. Host immunity in the protective response to vaccination with heat-killed Burkholderia mallei

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    Paessler Slobodan

    2008-09-01

    Full Text Available Abstract Background We performed initial cell, cytokine and complement depletion studies to investigate the possible role of these effectors in response to vaccination with heat-killed Burkholderia mallei in a susceptible BALB/c mouse model of infection. Results While protection with heat-killed bacilli did not result in sterilizing immunity, limited protection was afforded against an otherwise lethal infection and provided insight into potential host protective mechanisms. Our results demonstrated that mice depleted of either B cells, TNF-α or IFN-γ exhibited decreased survival rates, indicating a role for these effectors in obtaining partial protection from a lethal challenge by the intraperitoneal route. Additionally, complement depletion had no effect on immunoglobulin production when compared to non-complement depleted controls infected intranasally. Conclusion The data provide a basis for future studies of protection via vaccination using either subunit or whole-organism vaccine preparations from lethal infection in the experimental BALB/c mouse model. The results of this study demonstrate participation of B220+ cells and pro-inflammatory cytokines IFN-γ and TNF-α in protection following HK vaccination.

  20. Proof that Burkholderia Strains Form Effective Symbioses with Legumes: a Study of Novel Mimosa-Nodulating Strains from South America

    Science.gov (United States)

    Chen, Wen-Ming; de Faria, Sergio M.; Straliotto, Rosângela; Pitard, Rosa M.; Simões-Araùjo, Jean L.; Chou, Jui-Hsing; Chou, Yi-Ju; Barrios, Edmundo; Prescott, Alan R.; Elliott, Geoffrey N.; Sprent, Janet I.; Young, J. Peter W.; James, Euan K.

    2005-01-01

    Twenty Mimosa-nodulating bacterial strains from Brazil and Venezuela, together with eight reference Mimosa-nodulating rhizobial strains and two other β-rhizobial strains, were examined by amplified rRNA gene restriction analysis. They fell into 16 patterns and formed a single cluster together with the known β-rhizobia, Burkholderia caribensis, Burkholderia phymatum, and Burkholderia tuberum. The 16S rRNA gene sequences of 15 of the 20 strains were determined, and all were shown to belong to the genus Burkholderia; four distinct clusters could be discerned, with strains isolated from the same host species usually clustering very closely. Five of the strains (MAP3-5, Br3407, Br3454, Br3461, and Br3469) were selected for further studies of the symbiosis-related genes nodA, the NodD-dependent regulatory consensus sequences (nod box), and nifH. The nodA and nifH sequences were very close to each other and to those of B. phymatum STM815, B. caribensis TJ182, and Cupriavidus taiwanensis LMG19424 but were relatively distant from those of B. tuberum STM678. In addition to nodulating their original hosts, all five strains could also nodulate other Mimosa spp., and all produced nodules on Mimosa pudica that had nitrogenase (acetylene reduction) activities and structures typical of effective N2-fixing symbioses. Finally, both wild-type and green fluorescent protein-expressing transconjugant strains of Br3461 and MAP3-5 produced N2-fixing nodules on their original hosts, Mimosa bimucronata (Br3461) and Mimosa pigra (MAP3-5), and hence this confirms strongly that Burkholderia strains can form effective symbioses with legumes. PMID:16269788

  1. The phylogenetic distribution and ecological role of carbon monoxide oxidation in the genus Burkholderia.

    Science.gov (United States)

    Weber, Carolyn F; King, Gary M

    2012-01-01

    Burkholderia is a physiologically and ecologically diverse genus that occurs commonly in assemblages of soil and rhizosphere bacteria. Although Burkholderia is known for its heterotrophic versatility, we demonstrate that 14 distinct environmental isolates oxidized carbon monoxide (CO) and possessed the gene encoding the catalytic subunit of form I CO dehydrogenase (coxL). DNA from a Burkholderia isolate obtained from a passalid beetle also contained coxL as do the genomic sequences of species H160 and Ch1-1. Isolates were able to consume CO at concentrations ranging from 100 ppm (vol/vol) to sub-ambient ( 2.5 mM), but mixotrophic consumption of CO and pyruvate occurred when initial pyruvate concentrations were lower (c. 400 lM). With the exception of an isolate most closely related to Burkholderia cepacia, all CO-oxidizing isolates examined were members of a nonpathogenic clade and were most closely related to Burkholderia species, B. caledonica, B. fungorum, B. oxiphila, B. mimosarum, B. nodosa, B. sacchari, B. bryophila, B. ferrariae, B. ginsengesoli, and B. unamae. However, none of these type strains oxidized CO or contained coxL based on results from PCR analyses. Collectively, these results demonstrate that the presence of CO oxidation within members of the Burkholderia genus is variable but it is most commonly found among rhizosphere inhabitants that are not closely related to B. cepacia.

  2. Burkholderia pseudomallei Antibodies in Children, Cambodia

    Science.gov (United States)

    Pheaktra, Ngoun; Putchhat, Hor; Sin, Lina; Sen, Bun; Kumar, Varun; Langla, Sayan; Peacock, Sharon J.; Day, Nicholas P.

    2008-01-01

    Antibodies to Burkholderia pseudomallei were detected in 16% of children in Siem Reap, Cambodia. This organism was isolated from 30% of rice paddies in the surrounding vicinity. Despite the lack of reported indigenous cases, melioidosis is likely to occur in Cambodia. PMID:18258125

  3. Molecular typing of Burkholderia cepacia complex isolated from patients attending an Italian Cystic Fibrosis Centre.

    Science.gov (United States)

    Teri, Antonio; Sottotetti, Samantha; Biffi, Arianna; Girelli, Daniela; D'Accico, Monica; Arghittu, Milena; Colombo, Carla; Corti, Fabiola; Pizzamiglio, Giovanna; Cariani, Lisa

    2018-04-01

    Bacteria from the Burkholderia cepacia complex (Bcc) are capable of causing severe infections in patients with cystic fibrosis (CF). Bcc infection is often extremely difficult to treat due to its intrinsic resistance to multiple antibiotics. In addition, it seems to speed up the decline of lung function and is considered a contraindication for lung transplantation in CF. This study investigates the species of the Bcc strains recovered from chronically infected CF subjects by means of: isolation, identification methods and complete recA nucleotide sequences of 151 samples. Molecular typing showed that B. cenocepacia III is the dominant strain found in the group of subjects being treated at the Milan CF Centre (Italy) and that the infection is chronically maintained by the same species. Defining species by means of molecular analysis yields important information for the clinician in order to establish the most appropriate therapy and implement correct measures for prevention of transmission among CF subjects.

  4. Determinación de la Infección de Burkholderia glumae en Semillas de Variedades Comerciales Colombianas de Arroz Determination of the Infeccion of Burkholderia glumae in Comercial Colombian Rice Varieties

    Directory of Open Access Journals (Sweden)

    Nathalia María Vanesa Flórez Zapata

    2011-12-01

    Full Text Available El añublo bacterial de la panícula del arroz, ocasionado por Burkholderia glumae, es una enfermedad cada vez más difundida en Colombia. Por tal motivo es importante implementar un sistema de evaluación de la infección de este agente fitopatógeno en semilla, ya que ésta es una de las posibles fuentes de la enfermedad en campo. Semillas previamente desinfectadas, fueron sumergidas en suspensiones bacterianas y colocadas en cámara húmeda por siete días, luego de los cuales fueron evaluadas. Este sistema fue validado a través del análisis de la severidad de la infección en siete variedades de arroz y tres concentraciones del patógeno. El análisis reveló que las variedades F60, Panorama y F174, presentaron la menor severidad de la infección, aunque estadísticamente similar entre sí; mientras que, las variedades F369 y F733 presentaron niveles de severidad significativamente mayores y similares entre sí. Todas las variedades, con excepción de F60, presentaron diferencias entre las concentraciones del patógeno evaluadas, encontrándose una relación positiva entre concentración del inóculo y la severidad, la cual osciló según la variedad en la que fue estimada. Se concluyó que el modelo de evaluación de la infección fue exitoso dado que permitió encontrar diferencias en la severidad de la infección entre las variedades de arroz y las concentraciones de inóculo.The bacterial panicle blight of rice caused by Burkholderia glumae, is a disease that has gained increasing distribution in Colombia. Therefore it is important to implement an assessment system of infection of this phytopathogen in seeds, since this is one of the possible disease sources on the field. Thus, previously disinfected seeds were dipped in the bacterial suspension and placed in a moist chamber for 7 days, after which they were assessed. This assessment system, was validated by analyzing the infection severity level on seven rice varieties and three

  5. CD4+ T cell epitopes of FliC conserved between strains of Burkholderia: implications for vaccines against melioidosis and cepacia complex in cystic fibrosis.

    Science.gov (United States)

    Musson, Julie A; Reynolds, Catherine J; Rinchai, Darawan; Nithichanon, Arnone; Khaenam, Prasong; Favry, Emmanuel; Spink, Natasha; Chu, Karen K Y; De Soyza, Anthony; Bancroft, Gregory J; Lertmemongkolchai, Ganjana; Maillere, Bernard; Boyton, Rosemary J; Altmann, Daniel M; Robinson, John H

    2014-12-15

    Burkholderia pseudomallei is the causative agent of melioidosis characterized by pneumonia and fatal septicemia and prevalent in Southeast Asia. Related Burkholderia species are strong risk factors of mortality in cystic fibrosis (CF). The B. pseudomallei flagellar protein FliC is strongly seroreactive and vaccination protects challenged mice. We assessed B. pseudomallei FliC peptide binding affinity to multiple HLA class II alleles and then assessed CD4 T cell immunity in HLA class II transgenic mice and in seropositive individuals in Thailand. T cell hybridomas were generated to investigate cross-reactivity between B. pseudomallei and the related Burkholderia species associated with Cepacia Complex CF. B. pseudomallei FliC contained several peptide sequences with ability to bind multiple HLA class II alleles. Several peptides were shown to encompass strong CD4 T cell epitopes in B. pseudomallei-exposed individuals and in HLA transgenic mice. In particular, the p38 epitope is robustly recognized by CD4 T cells of seropositive donors across diverse HLA haplotypes. T cell hybridomas against an immunogenic B. pseudomallei FliC epitope also cross-reacted with orthologous FliC sequences from Burkholderia multivorans and Burkholderia cenocepacia, important pathogens in CF. Epitopes within FliC were accessible for processing and presentation from live or heat-killed bacteria, demonstrating that flagellin enters the HLA class II Ag presentation pathway during infection of macrophages with B. cenocepacia. Collectively, the data support the possibility of incorporating FliC T cell epitopes into vaccination programs targeting both at-risk individuals in B. pseudomallei endemic regions as well as CF patients. Copyright © 2014 by The American Association of Immunologists, Inc.

  6. The AHL- and BDSF-dependent quorum sensing systems control specific and overlapping sets of genes in Burkholderia cenocepacia H111.

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    Nadine Schmid

    Full Text Available 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 identified BDSF-regulated genes or proteins are also controlled by AHLs, suggesting that the two regulons partially overlap. The detailed analysis of two mutually regulated operons, one encoding three lectins and the other one encoding the large surface protein BapA and its type I secretion machinery, revealed that both AHLs and BDSF are required for full expression, suggesting that the two signalling systems operate in parallel. In accordance with this, we show that both AHLs and BDSF are required for biofilm formation and protease production.

  7. Comparative genome analysis of rice-pathogenic Burkholderia provides insight into capacity to adapt to different environments and hosts.

    Science.gov (United States)

    Seo, Young-Su; Lim, Jae Yun; Park, Jungwook; Kim, Sunyoung; Lee, Hyun-Hee; Cheong, Hoon; Kim, Sang-Mok; Moon, Jae Sun; Hwang, Ingyu

    2015-05-06

    In addition to human and animal diseases, bacteria of the genus Burkholderia can cause plant diseases. The representative species of rice-pathogenic Burkholderia are Burkholderia glumae, B. gladioli, and B. plantarii, which primarily cause grain rot, sheath rot, and seedling blight, respectively, resulting in severe reductions in rice production. Though Burkholderia rice pathogens cause problems in rice-growing countries, comprehensive studies of these rice-pathogenic species aiming to control Burkholderia-mediated diseases are only in the early stages. We first sequenced the complete genome of B. plantarii ATCC 43733T. Second, we conducted comparative analysis of the newly sequenced B. plantarii ATCC 43733T genome with eleven complete or draft genomes of B. glumae and B. gladioli strains. Furthermore, we compared the genome of three rice Burkholderia pathogens with those of other Burkholderia species such as those found in environmental habitats and those known as animal/human pathogens. These B. glumae, B. gladioli, and B. plantarii strains have unique genes involved in toxoflavin or tropolone toxin production and the clustered regularly interspaced short palindromic repeats (CRISPR)-mediated bacterial immune system. Although the genome of B. plantarii ATCC 43733T has many common features with those of B. glumae and B. gladioli, this B. plantarii strain has several unique features, including quorum sensing and CRISPR/CRISPR-associated protein (Cas) systems. The complete genome sequence of B. plantarii ATCC 43733T and publicly available genomes of B. glumae BGR1 and B. gladioli BSR3 enabled comprehensive comparative genome analyses among three rice-pathogenic Burkholderia species responsible for tissue rotting and seedling blight. Our results suggest that B. glumae has evolved rapidly, or has undergone rapid genome rearrangements or deletions, in response to the hosts. It also, clarifies the unique features of rice pathogenic Burkholderia species relative to other

  8. Identification of Burkholderia pseudomallei Near-Neighbor Species in the Northern Territory of Australia.

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    Jennifer L Ginther

    Full Text Available Identification and characterization of near-neighbor species are critical to the development of robust molecular diagnostic tools for biothreat agents. One such agent, Burkholderia pseudomallei, a soil bacterium and the causative agent of melioidosis, is lacking in this area because of its genomic diversity and widespread geographic distribution. The Burkholderia genus contains over 60 species and occupies a large range of environments including soil, plants, rhizospheres, water, animals and humans. The identification of novel species in new locations necessitates the need to identify the true global distribution of Burkholderia species, especially the members that are closely related to B. pseudomallei. In our current study, we used the Burkholderia-specific recA sequencing assay to analyze environmental samples from the Darwin region in the Northern Territory of Australia where melioidosis is endemic. Burkholderia recA PCR negative samples were further characterized using 16s rRNA sequencing for species identification. Phylogenetic analysis demonstrated that over 70% of the bacterial isolates were identified as B. ubonensis indicating that this species is common in the soil where B. pseudomallei is endemic. Bayesian phylogenetic analysis reveals many novel branches within the B. cepacia complex, one novel B. oklahomensis-like species, and one novel branch containing one isolate that is distinct from all other samples on the phylogenetic tree. During the analysis with recA sequencing, we discovered 2 single nucleotide polymorphisms in the reverse priming region of B. oklahomensis. A degenerate primer was developed and is proposed for future use. We conclude that the recA sequencing technique is an effective tool to classify Burkholderia and identify soil organisms in a melioidosis endemic area.

  9. Identification of Burkholderia pseudomallei Near-Neighbor Species in the Northern Territory of Australia

    Science.gov (United States)

    Ginther, Jennifer L.; Mayo, Mark; Warrington, Stephanie D.; Kaestli, Mirjam; Mullins, Travis; Wagner, David M.; Currie, Bart J.; Tuanyok, Apichai; Keim, Paul

    2015-01-01

    Identification and characterization of near-neighbor species are critical to the development of robust molecular diagnostic tools for biothreat agents. One such agent, Burkholderia pseudomallei, a soil bacterium and the causative agent of melioidosis, is lacking in this area because of its genomic diversity and widespread geographic distribution. The Burkholderia genus contains over 60 species and occupies a large range of environments including soil, plants, rhizospheres, water, animals and humans. The identification of novel species in new locations necessitates the need to identify the true global distribution of Burkholderia species, especially the members that are closely related to B. pseudomallei. In our current study, we used the Burkholderia-specific recA sequencing assay to analyze environmental samples from the Darwin region in the Northern Territory of Australia where melioidosis is endemic. Burkholderia recA PCR negative samples were further characterized using 16s rRNA sequencing for species identification. Phylogenetic analysis demonstrated that over 70% of the bacterial isolates were identified as B. ubonensis indicating that this species is common in the soil where B. pseudomallei is endemic. Bayesian phylogenetic analysis reveals many novel branches within the B. cepacia complex, one novel B. oklahomensis-like species, and one novel branch containing one isolate that is distinct from all other samples on the phylogenetic tree. During the analysis with recA sequencing, we discovered 2 single nucleotide polymorphisms in the reverse priming region of B. oklahomensis. A degenerate primer was developed and is proposed for future use. We conclude that the recA sequencing technique is an effective tool to classify Burkholderia and identify soil organisms in a melioidosis endemic area. PMID:26121041

  10. The Burkholderia cepacia rpoE gene is not involved in exopolysaccharide production and onion pathogenicity.

    Science.gov (United States)

    Devescovi, Giulia; Venturi, Vittorio

    2006-03-01

    Burkholderia cepacia was originally described as the causative agent of bacterial rot of onions, and it has now emerged as an important opportunistic pathogen causing severe chronic lung infections in patients having cystic fibrosis. Burkholderia cepacia is now classified into nine very closely related species (previously designated as genomovars), all of which have been isolated from both environmental and clinical sources and are collectively known as the B. cepacia complex. The alternative extracytoplasmic function sigma factor, sigmaE, has been determined in several bacterial species as making substantial contributions to bacterial survival under stress conditions. Here, we report the identification and characterization of the rpoE gene, encoding sigmaE, of B. cepacia. It is highly similar to sigmaE of other bacteria, including Escherichia coli and Pseudomonas aeruginosa. Studies using an rpoE knockout mutant of B. cepacia revealed that many stress adaptations, including osmotic, oxidative, desiccation, carbon, and nitrogen stress, were independent of sigmaE. Similarly, biofilm formation; production of exopolysaccharides, N-acyl homoserine lactones, and several exoenzymes; and onion pathogenicity were not affected by the absence of sigmaE. In contrast, sigmaE contributed to the adaptation to heat stress and phosphate starvation.

  11. A midgut lysate of the Riptortus pedestris has antibacterial activity against LPS O-antigen-deficient Burkholderia mutants.

    Science.gov (United States)

    Jang, Ho Am; Seo, Eun Sil; Seong, Min Young; Lee, Bok Luel

    2017-02-01

    Riptortus pedestris, a common pest in soybean fields, harbors a symbiont Burkholderia in a specialized posterior midgut region of insects. Every generation of second nymphs acquires new Burkholderia cells from the environment. We compared in vitro cultured Burkholderia with newly in vivo colonized Burkholderia in the host midgut using biochemical approaches. The bacterial cell envelope of in vitro cultured and in vivo Burkholderia differed in structure, as in vivo bacteria lacked lipopolysaccharide (LPS) O-antigen. The LPS O-antigen deficient bacteria had a reduced colonization rate in the host midgut compared with that of the wild-type Burkholderia. To determine why LPS O-antigen-deficient bacteria are less able to colonize the host midgut, we examined in vitro survival rates of three LPS O-antigen-deficient Burkholderia mutants and lysates of five different midgut regions. The LPS O-antigen-deficient mutants were highly susceptible when cultured with the lysate of a specific first midgut region (M1), indicating that the M1 lysate contains unidentified substance(s) capable of killing LPS O-antigen-deficient mutants. We identified a 17 kDa protein from the M1 lysate, which was enriched in the active fractions. The N-terminal sequence of the protein was determined to be a soybean Kunitz-type trypsin inhibitor. These data suggest that the 17 kDa protein, which was originated from a main soybean source of the R. pedestris host, has antibacterial activity against the LPS O-antigen deficient (rough-type) Burkholderia. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Divergent homologs of the predicted small RNA BpCand697 in Burkholderia spp.

    Science.gov (United States)

    Damiri, Nadzirah; Mohd-Padil, Hirzahida; Firdaus-Raih, Mohd

    2015-09-01

    The small RNA (sRNA) gene candidate, BpCand697 was previously reported to be unique to Burkholderia spp. and is encoded at 3' non-coding region of a putative AraC family transcription regulator gene. This study demonstrates the conservation of BpCand697 sequence across 32 Burkholderia spp. including B. pseudomallei, B. mallei, B. thailandensis and Burkholderia sp. by integrating both sequence homology and secondary structural analyses of BpCand697 within the dataset. The divergent sequence of BpCand697 was also used as a discriminatory power in clustering the dataset according to the potential virulence of Burkholderia spp., showing that B. thailandensis was clearly secluded from the virulent cluster of B. pseudomallei and B. mallei. Finally, the differential co-transcript expression of BpCand697 and its flanking gene, bpsl2391 was detected in Burkholderia pseudomallei D286 after grown under two different culture conditions using nutrient-rich and minimal media. It is hypothesized that the differential expression of BpCand697-bpsl2391 co-transcript between the two standard prepared media might correlate with nutrient availability in the culture media, suggesting that the physical co-localization of BpCand697 in B. pseudomallei D286 might be directly or indirectly involved with the transcript regulation of bpsl2391 under the selected in vitro culture conditions.

  13. Phylogenetically Diverse Burkholderia Associated with Midgut Crypts of Spurge Bugs, Dicranocephalus spp. (Heteroptera: Stenocephalidae).

    Science.gov (United States)

    Kuechler, Stefan Martin; Matsuura, Yu; Dettner, Konrad; Kikuchi, Yoshitomo

    2016-06-25

    Diverse phytophagous heteropteran insects, commonly known as stinkbugs, are associated with specific gut symbiotic bacteria, which have been found in midgut cryptic spaces. Recent studies have revealed that members of the stinkbug families Coreidae and Alydidae of the superfamily Coreoidea are consistently associated with a specific group of the betaproteobacterial genus Burkholderia, called the "stinkbug-associated beneficial and environmental (SBE)" group, and horizontally acquire specific symbionts from the environment every generation. However, the symbiotic system of another coreoid family, Stenocephalidae remains undetermined. We herein investigated four species of the stenocephalid genus Dicranocephalus. Examinations via fluorescence in situ hybridization (FISH) and transmission electron microscopy (TEM) revealed the typical arrangement and ultrastructures of midgut crypts and gut symbionts. Cloning and molecular phylogenetic analyses of bacterial genes showed that the midgut crypts of all species are colonized by Burkholderia strains, which were further assigned to different subgroups of the genus Burkholderia. In addition to the SBE-group Burkholderia, a number of stenocephalid symbionts belonged to a novel clade containing B. sordidicola and B. udeis, suggesting a specific symbiont clade for the Stenocephalidae. The symbiotic systems of stenocephalid bugs may provide a unique opportunity to study the ongoing evolution of symbiont associations in the stinkbug-Burkholderia interaction.

  14. Influence of neutrophil defects on Burkholderia cepacia complex pathogenesis

    Directory of Open Access Journals (Sweden)

    Laura A. Porter

    2011-11-01

    Full Text Available The Burkholderia cepacia complex (Bcc is a group of Gram-negative bacteria that are ubiquitous in the environment and have emerged as opportunistic pathogens in immunocompromised patients. The primary patient populations infected with Bcc include individuals with cystic fibrosis (CF, as well as those with chronic granulomatous disease (CGD. While Bcc infection in CF is better characterized than in CGD, these two genetic diseases are not obviously similar and it is currently unknown if there is any commonality in host immune defects that is responsible for the susceptibility to Bcc. CF is caused by mutations in the CF transmembrane conductance regulator, resulting in manifestations in various organ systems, however the major cause of morbidity and mortality is currently due to bacterial respiratory infections. CGD, on the other hand, is a genetic disorder that is caused by defects in phagocyte NADPH oxidase. Because of the defect in CGD, phagocytes in these patients are unable to produce reactive oxygen species, which results in increased susceptibility to bacterial and fungal infections. Despite this significant defect in microbial clearance, the spectrum of pathogens frequently implicated in infections in CGD is relatively narrow and includes some bacterial species that are considered almost pathognomonic for this disorder. Very little is known about the cause of the specific susceptibility to Bcc over other potential pathogens more prevalent in the environment, and a better understanding of specific mechanisms required for bacterial virulence has become a high priority. This review will summarize both the current knowledge and future directions related to Bcc virulence in immunocompromised individuals with a focus on the roles of bacterial factors and neutrophil defects in pathogenesis.

  15. Rapid emergence of a ceftazidime-resistant Burkholderia multivorans strain in a cystic fibrosis patient.

    Science.gov (United States)

    Stokell, Joshua R; Gharaibeh, Raad Z; Steck, Todd R

    2013-12-01

    Burkholderia multivorans poses a serious health threat to cystic fibrosis patients due to innate resistance to multiple antibiotics and acquisition of resistance to a range of antibiotics due to the frequent use of antibiotics to treat chronic infections. Monitoring antibiotic susceptibility is crucial to managing patient care. We identified the rapid emergence of a ceftazidime-resistant strain in a single patient within four days during a hospitalization for treatment of an exacerbation. B. multivorans was isolated from expectorated sputum samples using Burkholderia cepacia selective agar. A macrodilution assay was performed on all isolates to determine the minimum inhibitory concentration of ceftazidime. Approximately 4000 colonies were scored to identify the percent of ceftazidime-resistant colonies. Extracted DNA was used to determine the total bacterial counts and abundance of B. multivorans using quantitative PCR. An increase from no detectable B. multivorans ceftazidime-resistant colonies to over 75% of all colonies tested occurred within a four-day period. The resistant population remained dominant in 6 of the 8 samples in the following 17 months of the study. qPCR revealed an association between change in the percent of resistant colonies and abundance of B. multivorans, but not of total bacteria. No association was found between the acquisition of resistance to ceftazidime and other antibiotics commonly used to treat B. multivorans infections. The rapid emergence of a ceftazidime-resistant by B. multivorans strain occurred during a hospitalization while under selective pressure of antibiotics. The resistant strain maintained dominance in the B. multivorans population which resulted in an overall decline in a patient health and treatment efficacy. Copyright © 2013 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  16. GENOME ANALYSIS OF BURKHOLDERIA CEPACIA AC1100

    Science.gov (United States)

    Burkholderia cepacia is an important organism in bioremediation of environmental pollutants and it is also of increasing interest as a human pathogen. The genomic organization of B. cepacia is being studied in order to better understand its unusual adaptive capacity and genome pl...

  17. A prophage tail-like protein is deployed by Burkholderia bacteria to feed on fungi.

    Science.gov (United States)

    Swain, Durga Madhab; Yadav, Sunil Kumar; Tyagi, Isha; Kumar, Rahul; Kumar, Rajeev; Ghosh, Srayan; Das, Joyati; Jha, Gopaljee

    2017-09-01

    Some bacteria can feed on fungi, a phenomenon known as mycophagy. Here we show that a prophage tail-like protein (Bg_9562) is essential for mycophagy in Burkholderia gladioli strain NGJ1. The purified protein causes hyphal disintegration and inhibits growth of several fungal species. Disruption of the Bg_9562 gene abolishes mycophagy. Bg_9562 is a potential effector secreted by a type III secretion system (T3SS) and is translocated into fungal mycelia during confrontation. Heterologous expression of Bg_9562 in another bacterial species, Ralstonia solanacearum, confers mycophagous ability in a T3SS-dependent manner. We propose that the ability to feed on fungi conferred by Bg_9562 may help the bacteria to survive in certain ecological niches. Furthermore, considering its broad-spectrum antifungal activity, the protein may be potentially useful in biotechnological applications to control fungal diseases.Some bacteria can feed on live fungi through unclear mechanisms. Here, the authors show that a T3SS-secreted protein, which is homologous to phage tail proteins, allows a Burkholderia gladioli strain to kill and feed on various fungal species.

  18. Saturation mutagenesis of a CepR binding site as a means to identify new quorum-regulated promoters in Burkholderia cenocepacia

    Science.gov (United States)

    Burkholderia cenocepacia, an opportunistic pathogen of humans, encodes the CepI and CepR proteins, which resemble the LuxI and LuxR quorum sensing proteins of Vibrio fischeri. CepI directs the synthesis of octanoylhomoserine lactone (OHL), while CepR is an OHL dependent transcription factor. In pr...

  19. Burkholderia insulsa sp. nov., a facultatively chemolithotrophic bacterium isolated from an arsenic-rich shallow marine hydrothermal system.

    Science.gov (United States)

    Rusch, Antje; Islam, Shaer; Savalia, Pratixa; Amend, Jan P

    2015-01-01

    Enrichment cultures inoculated with hydrothermally influenced nearshore sediment from Papua New Guinea led to the isolation of an arsenic-tolerant, acidophilic, facultatively aerobic bacterial strain designated PNG-April(T). Cells of this strain were Gram-stain-negative, rod-shaped, motile and did not form spores. Strain PNG-April(T) grew at temperatures between 4 °C and 40 °C (optimum 30-37 °C), at pH 3.5 to 8.3 (optimum pH 5-6) and in the presence of up to 2.7% NaCl (optimum 0-1.0%). Both arsenate and arsenite were tolerated up to concentrations of at least 0.5 mM. Metabolism in strain PNG-April(T) was strictly respiratory. Heterotrophic growth occurred with O2 or nitrate as electron acceptors, and aerobic lithoautotrophic growth was observed with thiosulfate or nitrite as electron donors. The novel isolate was capable of N2-fixation. The respiratory quinones were Q-8 and Q-7. Phylogenetically, strain PNG-April(T) belongs to the genus Burkholderia and shares the highest 16S rRNA gene sequence similarity with the type strains of Burkholderia fungorum (99.8%), Burkholderia phytofirmans (98.8%), Burkholderia caledonica (98.4%) and Burkholderia sediminicola (98.4%). Differences from these related species in several physiological characteristics (lipid composition, carbohydrate utilization, enzyme profiles) and DNA-DNA hybridization suggested the isolate represents a novel species of the genus Burkholderia, for which we propose the name Burkholderia insulsa sp. nov. The type strain is PNG-April(T) ( = DSM 28142(T) = LMG 28183(T)). © 2015 IUMS.

  20. Burkholderia jiangsuensis sp. nov., a methyl parathion degrading bacterium, isolated from methyl parathion contaminated soil.

    Science.gov (United States)

    Liu, Xu-Yun; Li, Chun-Xiu; Luo, Xiao-Jing; Lai, Qi-Liang; Xu, Jian-He

    2014-09-01

    A methyl parathion (MP) degrading bacterial strain, designated MP-1(T), was isolated from a waste land where pesticides were formerly manufactured in Jiangsu province, China. Polyphasic taxonomic studies showed that MP-1(T) is a Gram-stain-negative, non-spore-forming, rod-shaped and motile bacterium. The bacterium could grow at salinities of 0-1 % (w/v) and temperatures of 15-40 °C. Strain MP-1(T) could reduce nitrate to nitrite, utilize d-glucose and l-arabinose, but not produce indole, or hydrolyse gelatin. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that MP-1(T) belongs to the genus Burkholderia, showing highest sequence similarity to Burkholderia grimmiae DSM 25160(T) (98.5 %), and similar strains including Burkholderia zhejiangensis OP-1(T) (98.2 %), Burkholderia choica LMG 22940(T) (97.5 %), Burkholderia glathei DSM 50014(T) (97.4 %), Burkholderia terrestris LMG 22937(T) (97.2 %) and Burkholderia telluris LMG 22936(T) (97.0 %). In addition, the gyrB and recA gene segments of strain MP-1(T) exhibited less than 89.0 % and 95.1 % similarities with the most highly-related type strains indicated above. The G+C content of strain MP-1(T) was 62.6 mol%. The major isoprenoid quinone was ubiquinone Q-8. The predominant polar lipids comprised phosphatidyl ethanolamine, phosphatidyl glycerol, aminolipid and phospholipid. The principal fatty acids in strain MP-1(T) were C18 : 1ω7c/C18 : 1ω6c (23.3 %), C16 : 0 (16.8 %), cyclo-C17 : 0 (15.0 %), C16 : 1ω7c/C16 : 1ω6 (8.5 %), cyclo-C19 : 0ω8c (8.1 %), C16 : 1 iso I/C14 : 0 3-OH (5.7 %), C16 : 0 3-OH (5.6 %) and C16 : 02-OH (5.1 %). The DNA-DNA relatedness values between strain MP-1(T) and the three type strains (B. grimmiae DSM 25160(T), B. zhejiangensis OP-1(T) and B. glathei DSM 50014(T)) ranged from 24.6 % to 37.4 %. In accordance with phenotypic and genotypic characteristics, strain MP-1(T) represents a novel

  1. Enhanced degradation of haloacid by heterologous expression in related Burkholderia species.

    Science.gov (United States)

    Su, Xianbin; Deng, Liyu; Kong, Ka Fai; Tsang, Jimmy S H

    2013-10-01

    Haloacids are environmental pollutant and can be transformed to non-toxic alkanoic acids by microbial dehalogenase. Bacterium Burkholderia species MBA4 was enriched from soil for its ability to bioremediate haloacids such as mono-chloroacetate (MCA), mono-bromoacetate (MBA), 2-mono-chloropropionate, and 2-mono-bromopropionate. MBA4 produces an inducible dehalogenase Deh4a that catalyzes the dehalogenation process. The growth of MBA4 on haloacid also relies on the presence of a haloacid-uptake system. Similar dehalogenase genes can be found in the genome of many related species. However, wildtype Burkholderia caribensis MWAP64, Burkholderia phymatum STM815, and Burkholderia xenovorans LB400 were not able to grow on MCA. When a plasmid containing the regulatory and structural gene of Deh4a was transformed to these species, they were able to grow on haloacid. The specific enzyme activities in these recombinants ranges from 2- to 30-fold that of MBA4 in similar condition. Reverse transcription-quantitative real-time PCR showed that the relative transcript levels in these recombinant strains ranges from 9 to over 1,600 times that of MBA4 in similar condition. A recombinant has produced nearly five times of dehalogenase that MBA4 could ever achieve. While the expressions of Deh4a were more relaxed in these phylogenetically related species, an MCA-uptake activity was found to be inducible. These metabolically engineered strains are better degraders than the haloacid-enriched MBA4. Copyright © 2013 Wiley Periodicals, Inc.

  2. Survival and Intra-Nuclear Trafficking of Burkholderia pseudomallei: Strategies of Evasion from Immune Surveillance?

    Directory of Open Access Journals (Sweden)

    Jamuna Vadivelu

    2017-01-01

    Full Text Available During infection, successful bacterial clearance is achieved via the host immune system acting in conjunction with appropriate antibiotic therapy. However, it still remains a tip of the iceberg as to where persistent pathogens namely, Burkholderia pseudomallei (B. pseudomallei reside/hide to escape from host immune sensors and antimicrobial pressure.We used transmission electron microscopy (TEM to investigate post-mortem tissue sections of patients with clinical melioidosis to identify the localisation of a recently identified gut microbiome, B. pseudomallei within host cells. The intranuclear presence of B. pseudomallei was confirmed using transmission electron microscopy (TEM of experimentally infected guinea pig spleen tissues and Live Z-stack, and ImageJ analysis of fluorescence microscopy analysis of in vitro infection of A549 human lung epithelial cells.TEM investigations revealed intranuclear localization of B. pseudomallei in cells of infected human lung and guinea pig spleen tissues. We also found that B. pseudomallei induced actin polymerization following infection of A549 human lung epithelial cells. Infected A549 lung epithelial cells using 3D-Laser scanning confocal microscopy (LSCM and immunofluorescence microscopy confirmed the intranuclear localization of B. pseudomallei.B. pseudomallei was found within the nuclear compartment of host cells. The nucleus may play a role as an occult or transient niche for persistence of intracellular pathogens, potentially leading to recurrrent episodes or recrudescence of infection.

  3. Survival and Intra-Nuclear Trafficking of Burkholderia pseudomallei: Strategies of Evasion from Immune Surveillance?

    Science.gov (United States)

    Vadivelu, Jamuna; Vellasamy, Kumutha Malar; Thimma, Jaikumar; Mariappan, Vanitha; Kang, Wen-Tyng; Choh, Leang-Chung; Wong, Kum Thong

    2017-01-01

    Background During infection, successful bacterial clearance is achieved via the host immune system acting in conjunction with appropriate antibiotic therapy. However, it still remains a tip of the iceberg as to where persistent pathogens namely, Burkholderia pseudomallei (B. pseudomallei) reside/hide to escape from host immune sensors and antimicrobial pressure. Methods We used transmission electron microscopy (TEM) to investigate post-mortem tissue sections of patients with clinical melioidosis to identify the localisation of a recently identified gut microbiome, B. pseudomallei within host cells. The intranuclear presence of B. pseudomallei was confirmed using transmission electron microscopy (TEM) of experimentally infected guinea pig spleen tissues and Live Z-stack, and ImageJ analysis of fluorescence microscopy analysis of in vitro infection of A549 human lung epithelial cells. Results TEM investigations revealed intranuclear localization of B. pseudomallei in cells of infected human lung and guinea pig spleen tissues. We also found that B. pseudomallei induced actin polymerization following infection of A549 human lung epithelial cells. Infected A549 lung epithelial cells using 3D-Laser scanning confocal microscopy (LSCM) and immunofluorescence microscopy confirmed the intranuclear localization of B. pseudomallei. Conclusion B. pseudomallei was found within the nuclear compartment of host cells. The nucleus may play a role as an occult or transient niche for persistence of intracellular pathogens, potentially leading to recurrrent episodes or recrudescence of infection. PMID:28045926

  4. Molecular Characterization of Putative Virulence Determinants in Burkholderia pseudomallei

    Directory of Open Access Journals (Sweden)

    Suat Moi Puah

    2014-01-01

    Full Text Available The Gram-negative saprophyte Burkholderia pseudomallei is the causative agent of melioidosis, an infectious disease which is endemic in Southeast Asia and northern Australia. This bacterium possesses many virulence factors which are thought to contribute to its survival and pathogenicity. Using a virulent clinical isolate of B. pseudomallei and an attenuated strain of the same B. pseudomallei isolate, 6 genes BPSL2033, BP1026B_I2784, BP1026B_I2780, BURPS1106A_A0094, BURPS1106A_1131, and BURPS1710A_1419 were identified earlier by PCR-based subtractive hybridization. These genes were extensively characterized at the molecular level, together with an additional gene BPSL3147 that had been identified by other investigators. Through a reverse genetic approach, single-gene knockout mutants were successfully constructed by using site-specific insertion mutagenesis and were confirmed by PCR. BPSL2033::Km and BURPS1710A_1419::Km mutants showed reduced rates of survival inside macrophage RAW 264.7 cells and also low levels of virulence in the nematode infection model. BPSL2033::Km demonstrated weak statistical significance (P=0.049 at 8 hours after infection in macrophage infection study but this was not seen in BURPS1710A_1419::Km. Nevertheless, complemented strains of both genes were able to partially restore the gene defects in both in vitro and in vivo studies, thus suggesting that they individually play a minor role in the virulence of B. pseudomallei.

  5. Riptortus pedestris and Burkholderia symbiont: an ideal model system for insect-microbe symbiotic associations.

    Science.gov (United States)

    Takeshita, Kazutaka; Kikuchi, Yoshitomo

    2017-04-01

    A number of insects establish symbiotic associations with beneficial microorganisms in various manners. The bean bug Riptortus pedestris and allied stink bugs possess an environmentally acquired Burkholderia symbiont in their midgut crypts. Unlike other insect endosymbionts, the Burkholderia symbiont is easily culturable and genetically manipulatable outside the host. In conjunction with the experimental advantages of the host insect, the Riptortus-Burkholderia symbiosis is an ideal model system for elucidating the molecular bases underpinning insect-microbe symbioses, which opens a new window in the research field of insect symbiosis. This review summarizes current knowledge of this system and discusses future perspectives. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  6. Burkholderia in gladiolen: voortgezet diagnostisch onderzoek 2007

    NARCIS (Netherlands)

    Vink, P.; Hollinger, T.C.

    2008-01-01

    In 2006 is middels een infectieproef bekend geworden dat de bacterie Burkholderia gladioli in staat is een ziekte bij gladiolen te veroorzaken waardoor de sier- en handelswaarde zeer negatief worden beïnvloed. In 2007 is in het kader van het voortgezet diagnostisch onderzoek nagegaan of de bacterie

  7. NtrC-dependent control of exopolysaccharide synthesis and motility in Burkholderia cenocepacia H111.

    Directory of Open Access Journals (Sweden)

    Yilei Liu

    Full Text Available Burkholderia cenocepacia is a versatile opportunistic pathogen that survives in a wide variety of environments, which can be limited in nutrients such as nitrogen. We have previously shown that the sigma factor σ54 is involved in the control of nitrogen assimilation and virulence in B. cenocepacia H111. In this work, we investigated the role of the σ54 enhancer binding protein NtrC in response to nitrogen limitation and in the pathogenicity of H111. Of 95 alternative nitrogen sources tested the ntrC showed defects in the utilisation of nitrate, urea, L-citrulline, acetamide, DL-lactamide, allantoin and parabanic acid. RNA-Seq and phenotypic analyses of an ntrC mutant strain showed that NtrC positively regulates two important phenotypic traits: exopolysaccharide (EPS production and motility. However, the ntrC mutant was not attenuated in C. elegans virulence.

  8. POLYCLONAL OUTBREAK OF BLOODSTREAM INFECTIONS CAUSED BY Burkholderia cepacia COMPLEX IN HEMATOLOGY AND BONE MARROW TRANSPLANT OUTPATIENT UNITS

    Directory of Open Access Journals (Sweden)

    Icaro Boszczowski

    2014-01-01

    Full Text Available Aim: The objective was to describe an outbreak of bloodstream infections by Burkholderia cepacia complex (Bcc in bone marrow transplant and hematology outpatients. Methods: On February 15, 2008 a Bcc outbreak was suspected. 24 cases were identified. Demographic and clinical data were evaluated. Environment and healthcare workers' (HCW hands were cultured. Species were determined and typed. Reinforcement of hand hygiene, central venous catheter (CVC care, infusion therapy, and maintenance of laminar flow cabinet were undertaken. 16 different HCWs had cared for the CVCs. Multi-dose heparin and saline were prepared on counter common to both units. Findings: 14 patients had B. multivorans (one patient had also B. cenopacia, six non-multivorans Bcc and one did not belong to Bcc. Clone A B. multivorans occurred in 12 patients (from Hematology; in 10 their CVC had been used on February 11/12. Environmental and HCW cultures were negative. All patients were treated with meropenem, and ceftazidime lock-therapy. Eight patients (30% were hospitalized. No deaths occurred. After control measures (multidose vial for single patient; CVC lock with ceftazidime; cleaning of laminar flow cabinet; hand hygiene improvement; use of cabinet to store prepared medication, no new cases occurred. Conclusions: This polyclonal outbreak may be explained by a common source containing multiple species of Bcc, maybe the laminar flow cabinet common to both units. There may have been contamination by B. multivorans (clone A of multi-dose vials.

  9. Burkholderia pseudomallei: Challenges for the Clinical Microbiology Laboratory.

    Science.gov (United States)

    Hemarajata, Peera; Baghdadi, Jonathan D; Hoffman, Risa; Humphries, Romney M

    2016-12-01

    Melioidosis is a potentially fatal infection caused by the bacterium Burkholderia pseudomallei Clinical diagnosis of melioidosis can be challenging since there is no pathognomonic clinical syndrome, and the organism is often misidentified by methods used routinely in clinical laboratories. Although the disease is more prevalent in Thailand and northern Australia, sporadic cases may be encountered in areas where it is not endemic, including the United States. Since the organism is considered a tier 1 select agent according to the Centers for Disease Control and Prevention and the U.S. Department of Agriculture Animal and Plant Health Inspection Service, clinical laboratories must be proficient at rapidly recognizing isolates suspicious for B. pseudomallei, be able to safely perform necessary rule-out tests, and to refer suspect isolates to Laboratory Response Network reference laboratories. In this minireview, we report a case of melioidosis encountered at our institution and discuss the laboratory challenges encountered when dealing with clinical isolates suspicious for B. pseudomallei or clinical specimens from suspected melioidosis cases. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  10. Burkholderia of Plant-Beneficial Group are Symbiotically Associated with Bordered Plant Bugs (Heteroptera: Pyrrhocoroidea: Largidae).

    Science.gov (United States)

    Takeshita, Kazutaka; Matsuura, Yu; Itoh, Hideomi; Navarro, Ronald; Hori, Tomoyuki; Sone, Teruo; Kamagata, Yoichi; Mergaert, Peter; Kikuchi, Yoshitomo

    2015-01-01

    A number of phytophagous stinkbugs (order Heteroptera: infraorder Pentatomomorpha) harbor symbiotic bacteria in a specific midgut region composed of numerous crypts. Among the five superfamilies of the infraorder Pentatomomorpha, most members of the Coreoidea and Lygaeoidea are associated with a specific group of the genus Burkholderia, called the "stinkbug-associated beneficial and environmental (SBE)" group, which is not vertically transmitted, but acquired from the environment every host generation. A recent study reported that, in addition to these two stinkbug groups, the family Largidae of the superfamily Pyrrhocoroidea also possesses a Burkholderia symbiont. Despite this recent finding, the phylogenetic position and biological nature of Burkholderia associated with Largidae remains unclear. Based on the combined results of fluorescence in situ hybridization, cloning analysis, Illumina deep sequencing, and egg inspections by diagnostic PCR, we herein demonstrate that the largid species are consistently associated with the "plant-associated beneficial and environmental (PBE)" group of Burkholderia, which are phylogenetically distinct from the SBE group, and that they maintain symbiosis through the environmental acquisition of the bacteria. Since the superfamilies Coreoidea, Lygaeoidea, and Pyrrhocoroidea are monophyletic in the infraorder Pentatomomorpha, it is plausible that the symbiotic association with Burkholderia evolved at the common ancestor of the three superfamilies. However, the results of this study strongly suggest that a dynamic transition from the PBE to SBE group, or vice versa, occurred in the course of stinkbug evolution.

  11. Exploring the Anti-Burkholderia cepacia Complex Activity of Essential Oils: A Preliminary Analysis

    Directory of Open Access Journals (Sweden)

    Isabel Maida

    2014-01-01

    Full Text Available In this work we have checked the ability of the essential oils extracted from six different medicinal plants (Eugenia caryophyllata, Origanum vulgare, Rosmarinus officinalis, Lavandula officinalis, Melaleuca alternifolia, and Thymus vulgaris to inhibit the growth of 18 bacterial type strains belonging to the 18 known species of the Burkholderia cepacia complex (Bcc. These bacteria are opportunistic human pathogens that can cause severe infection in immunocompromised patients, especially those affected by cystic fibrosis (CF, and are often resistant to multiple antibiotics. The analysis of the aromatograms produced by the six oils revealed that, in spite of their different chemical composition, all of them were able to contrast the growth of Bcc members. However, three of them (i.e., Eugenia caryophyllata, Origanum vulgare, and Thymus vulgaris were particularly active versus the Bcc strains, including those exhibiting a high degree or resistance to ciprofloxacin, one of the most used antibiotics to treat Bcc infections. These three oils are also active toward both environmental and clinical strains (isolated from CF patients, suggesting that they might be used in the future to fight B. cepacia complex infections.

  12. Burkholderia Species Are the Most Common and Preferred Nodulating Symbionts of the Piptadenia Group (Tribe Mimoseae)

    Science.gov (United States)

    Bournaud, Caroline; de Faria, Sergio Miana; dos Santos, José Miguel Ferreira; Tisseyre, Pierre; Silva, Michele; Chaintreuil, Clémence; Gross, Eduardo; James, Euan K.; Prin, Yves; Moulin, Lionel

    2013-01-01

    Burkholderia legume symbionts (also called α-rhizobia) are ancient in origin and are the main nitrogen-fixing symbionts of species belonging to the large genus Mimosa in Brazil. We investigated the extent of the affinity between Burkholderia and species in the tribe Mimoseae by studying symbionts of the genera Piptadenia (P.), Parapiptadenia (Pp.), Pseudopiptadenia (Ps.), Pityrocarpa (Py.), Anadenanthera (A.) and Microlobius (Mi.), all of which are native to Brazil and are phylogenetically close to Mimosa, and which together with Mimosa comprise the “Piptadenia group”. We characterized 196 strains sampled from 18 species from 17 locations in Brazil using two neutral markers and two symbiotic genes in order to assess their species affiliations and the evolution of their symbiosis genes. We found that Burkholderia are common and highly diversified symbionts of species in the Piptadenia group, comprising nine Burkholderia species, of which three are new ones and one was never reported as symbiotic (B. phenoliruptrix). However, α-rhizobia were also detected and were occasionally dominant on a few species. A strong sampling site effect on the rhizobial nature of symbionts was detected, with the symbiont pattern of the same legume species changing drastically from location to location, even switching from β to α-rhizobia. Coinoculation assays showed a strong affinity of all the Piptadenia group species towards Burkholderia genotypes, with the exception of Mi. foetidus. Phylogenetic analyses of neutral and symbiotic markers showed that symbiosis genes in Burkholderia from the Piptadenia group have evolved mainly through vertical transfer, but also by horizontal transfer in two species. PMID:23691052

  13. Characterization of cellular immune response and innate immune signaling in human and nonhuman primate primary mononuclear cells exposed to Burkholderia mallei.

    Science.gov (United States)

    Alam, Shahabuddin; Amemiya, Kei; Bernhards, Robert C; Ulrich, Robert G; Waag, David M; Saikh, Kamal U

    2015-01-01

    Burkholderia pseudomallei infection causes melioidosis and is often characterized by severe sepsis. Although rare in humans, Burkholderia mallei has caused infections in laboratory workers, and the early innate cellular response to B. mallei in human and nonhuman primates has not been characterized. In this study, we examined the primary cellular immune response to B. mallei in PBMC cultures of non-human primates (NHPs), Chlorocebus aethiops (African Green Monkeys), Macaca fascicularis (Cynomolgus macaque), and Macaca mulatta (Rhesus macaque) and humans. Our results demonstrated that B. mallei elicited strong primary pro-inflammatory cytokines (IFN-γ, TNF-α, IL-1β, and IL-6) equivalent to the levels of B. pseudomallei in primary PBMC cultures of NHPs and humans. When we examined IL-1β and other cytokine responses by comparison to Escherichia coli LPS, African Green Monkeys appears to be most responsive to B. mallei than Cynomolgus or Rhesus. Characterization of the immune signaling mechanism for cellular response was conducted by using a ligand induced cell-based reporter assay, and our results demonstrated that MyD88 mediated signaling contributed to the B. mallei and B. pseudomallei induced pro-inflammatory responses. Notably, the induced reporter activity with B. mallei, B. pseudomallei, or purified LPS from these pathogens was inhibited and cytokine production was attenuated by a MyD88 inhibitor. Together, these results show that in the scenario of severe hyper-inflammatory responses to B. mallei infection, MyD88 targeted therapeutic intervention may be a successful strategy for therapy. Published by Elsevier Ltd.

  14. Construction of a large-scale Burkholderia cenocepacia J2315 transposon mutant library

    Science.gov (United States)

    Wong, Yee-Chin; Pain, Arnab; Nathan, Sheila

    2014-09-01

    Burkholderia cenocepacia, a pathogenic member of the Burkholderia cepacia complex (Bcc), has emerged as a significant threat towards cystic fibrosis patients, where infection often leads to the fatal clinical manifestation known as cepacia syndrome. Many studies have investigated the pathogenicity of B. cenocepacia as well as its ability to become highly resistant towards many of the antibiotics currently in use. In addition, studies have also been undertaken to understand the pathogen's capacity to adapt and survive in a broad range of environments. Transposon based mutagenesis has been widely used in creating insertional knock-out mutants and coupled with recent advances in sequencing technology, robust tools to study gene function in a genome-wide manner have been developed based on the assembly of saturated transposon mutant libraries. In this study, we describe the construction of a large-scale library of B. cenocepacia transposon mutants. To create transposon mutants of B. cenocepacia strain J2315, electrocompetent bacteria were electrotransformed with the EZ-Tn5 transposome. Tetracyline resistant colonies were harvested off selective agar and pooled. Mutants were generated in multiple batches with each batch consisting of ˜20,000 to 40,000 mutants. Transposon insertion was validated by PCR amplification of the transposon region. In conclusion, a saturated B. cenocepacia J2315 transposon mutant library with an estimated total number of 500,000 mutants was successfully constructed. This mutant library can now be further exploited as a genetic tool to assess the function of every gene in the genome, facilitating the discovery of genes important for bacterial survival and adaptation, as well as virulence.

  15. Bacterial cell motility of Burkholderia gut symbiont is required to colonize the insect gut.

    Science.gov (United States)

    Lee, Jun Beom; Byeon, Jin Hee; Jang, Ho Am; Kim, Jiyeun Kate; Yoo, Jin Wook; Kikuchi, Yoshitomo; Lee, Bok Luel

    2015-09-14

    We generated a Burkholderia mutant, which is deficient of an N-acetylmuramyl-l-alanine amidase, AmiC, involved in peptidoglycan degradation. When non-motile ΔamiC mutant Burkholderia cells harboring chain form were orally administered to Riptortus insects, ΔamiC mutant cells were unable to establish symbiotic association. But, ΔamiC mutant complemented with amiC gene restored in vivo symbiotic association. ΔamiC mutant cultured in minimal medium restored their motility with single-celled morphology. When ΔamiC mutant cells harboring single-celled morphology were administered to the host insect, this mutant established normal symbiotic association, suggesting that bacterial motility is essential for the successful symbiosis between host insect and Burkholderia symbiont. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  16. Burkholderia sp. induces functional nodules on the South African invasive legume Dipogon lignosus (Phaseoleae) in New Zealand soils.

    Science.gov (United States)

    Liu, Wendy Y Y; Ridgway, Hayley J; James, Trevor K; James, Euan K; Chen, Wen-Ming; Sprent, Janet I; Young, J Peter W; Andrews, Mitchell

    2014-10-01

    The South African invasive legume Dipogon lignosus (Phaseoleae) produces nodules with both determinate and indeterminate characteristics in New Zealand (NZ) soils. Ten bacterial isolates produced functional nodules on D. lignosus. The 16S ribosomal RNA (rRNA) gene sequences identified one isolate as Bradyrhizobium sp., one isolate as Rhizobium sp. and eight isolates as Burkholderia sp. The Bradyrhizobium sp. and Rhizobium sp. 16S rRNA sequences were identical to those of strains previously isolated from crop plants and may have originated from inocula used on crops. Both 16S rRNA and DNA recombinase A (recA) gene sequences placed the eight Burkholderia isolates separate from previously described Burkholderia rhizobial species. However, the isolates showed a very close relationship to Burkholderia rhizobial strains isolated from South African plants with respect to their nitrogenase iron protein (nifH), N-acyltransferase nodulation protein A (nodA) and N-acetylglucosaminyl transferase nodulation protein C (nodC) gene sequences. Gene sequences and enterobacterial repetitive intergenic consensus (ERIC) PCR and repetitive element palindromic PCR (rep-PCR) banding patterns indicated that the eight Burkholderia isolates separated into five clones of one strain and three of another. One strain was tested and shown to produce functional nodules on a range of South African plants previously reported to be nodulated by Burkholderia tuberum STM678(T) which was isolated from the Cape Region. Thus, evidence is strong that the Burkholderia strains isolated here originated in South Africa and were somehow transported with the plants from their native habitat to NZ. It is possible that the strains are of a new species capable of nodulating legumes.

  17. Burkholderia kirstenboschensis sp. nov. nodulates papilionoid legumes indigenous to South Africa.

    Science.gov (United States)

    Steenkamp, Emma T; van Zyl, Elritha; Beukes, Chrizelle W; Avontuur, Juanita R; Chan, Wai Yin; Palmer, Marike; Mthombeni, Lunghile S; Phalane, Francina L; Sereme, T Karabo; Venter, Stephanus N

    2015-12-01

    Despite the diversity of Burkholderia species known to nodulate legumes in introduced and native regions, relatively few taxa have been formally described. For example, the Cape Floristic Region of South Africa is thought to represent one of the major centres of diversity for the rhizobial members of Burkholderia, yet only five species have been described from legumes occurring in this region and numerous are still awaiting taxonomic treatment. Here, we investigated the taxonomic status of 12 South African root-nodulating Burkholderia isolates from native papilionoid legumes (Hypocalyptus coluteoides, H. oxalidifolius, H. sophoroides and Virgilia oroboides). Analysis of four gene regions (16S rRNA, recA, atpD and rpoB) revealed that the isolates represent a genealogically unique and exclusive assemblage within the genus. Its distinctness was supported by all other aspects of the polyphasic approach utilized, including the genome-based criteria DNA-DNA hybridization (≥70.9%) and average nucleotide identities (≥96%). We accordingly propose the name B. kirstenboschensis sp. nov. for this taxon with isolate Kb15(T) (=LMG 28727(T); =SARC 695(T)) as its type strain. Our data showed that intraspecific genome size differences (≥0.81 Mb) and the occurrence of large DNA regions that are apparently unique to single individuals (16-23% of an isolate's genome) can significantly limit the value of data obtained from DNA-DNA hybridization experiments. Substitution of DNA-DNA hybridization with whole genome sequencing as a prerequisite for the description of Burkholderia species will undoubtedly speed up the pace at which their diversity are documented, especially in hyperdiverse regions such as the Cape Floristic Region. Copyright © 2015 Elsevier GmbH. All rights reserved.

  18. Burkholderia thailandensis: Growth and Laboratory Maintenance.

    Science.gov (United States)

    Garcia, Erin C; Cotter, Peggy A

    2016-08-12

    Burkholderia thailandensis is a nonpathogenic Gram-negative bacterium found in tropical soils. Closely related to several human pathogens, its ease of genetic manipulation, rapid growth in the laboratory, and low virulence make B. thailandensis a commonly used model organism. This unit describes the fundamental protocols for in vitro growth and maintenance of B. thailandensis in the laboratory. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

  19. Effects of methamphetamine dependence and HIV infection on cerebral morphology

    DEFF Research Database (Denmark)

    Jernigan, Terry Lynne; Gamst, Abthony C; Archibald, Sarah L.

    2005-01-01

    -dependent participants. CONCLUSIONS: These results suggest significant brain structure alterations associated with both HIV infection and methamphetamine dependence. The regional patterns of the changes associated with these factors were distinct but overlapping, and the effects on brain volumes were opposing. Although......OBJECTIVE: The authors examined the separate and combined effects of methamphetamine dependence and HIV infection on brain morphology. METHOD: Morphometric measures obtained from magnetic resonance imaging of methamphetamine-dependent and/or HIV-positive participants and their appropriate age......- and education-matched comparison groups were analyzed. Main effects of age, HIV infection, methamphetamine dependence, and the interactions of these factors were examined in analyses of cerebral gray matter structure volumes. RESULTS: Independent of the effect of age, HIV infection was associated with reduced...

  20. Choline Catabolism in Burkholderia thailandensis Is Regulated by Multiple Glutamine Amidotransferase 1-Containing AraC Family Transcriptional Regulators.

    Science.gov (United States)

    Nock, Adam M; Wargo, Matthew J

    2016-09-15

    Burkholderia thailandensis is a soil-dwelling bacterium that shares many metabolic pathways with the ecologically similar, but evolutionarily distant, Pseudomonas aeruginosa Among the diverse nutrients it can utilize is choline, metabolizable to the osmoprotectant glycine betaine and subsequently catabolized as a source of carbon and nitrogen, similar to P. aeruginosa Orthologs of genes in the choline catabolic pathway in these two bacteria showed distinct differences in gene arrangement as well as an additional orthologous transcriptional regulator in B. thailandensis In this study, we showed that multiple glutamine amidotransferase 1 (GATase 1)-containing AraC family transcription regulators (GATRs) are involved in regulation of the B. thailandensis choline catabolic pathway (gbdR1, gbdR2, and souR). Using genetic analyses and sequencing the transcriptome in the presence and absence of choline, we identified the likely regulons of gbdR1 (BTH_II1869) and gbdR2 (BTH_II0968). We also identified a functional ortholog for P. aeruginosa souR, a GATR that regulates the metabolism of sarcosine to glycine. GbdR1 is absolutely required for expression of the choline catabolic locus, similar to P. aeruginosa GbdR, while GbdR2 is important to increase expression of the catabolic locus. Additionally, the B. thailandensis SouR ortholog (BTH_II0994) is required for catabolism of choline and its metabolites as carbon sources, whereas in P. aeruginosa, SouR function can by bypassed by GbdR. The strategy employed by B. thailandensis represents a distinct regulatory solution to control choline catabolism and thus provides both an evolutionary counterpoint and an experimental system to analyze the acquisition and regulation of this pathway during environmental growth and infection. Many proteobacteria that occupy similar environmental niches have horizontally acquired orthologous genes for metabolism of compounds useful in their shared environment. The arrangement and differential

  1. Lack of MyD88 protects the immunodeficient host against fatal lung inflammation triggered by the opportunistic bacteria Burkholderia cenocepacia.

    Science.gov (United States)

    Ventura, Grasiella M de C; Balloy, Viviane; Ramphal, Reuben; Khun, Huot; Huerre, Michel; Ryffel, Bernhard; Plotkowski, Maria-Cristina M; Chignard, Michel; Si-Tahar, Mustapha

    2009-07-01

    Burkholderia cenocepacia is an opportunistic pathogen of major concern for cystic fibrosis patients as well as immunocompromised cancer patients and transplant recipients. The mechanisms by which B. cenocepacia triggers a rapid health deterioration of the susceptible host have yet to be characterized. TLR and their key signaling intermediate MyD88 play a central role in the detection of microbial molecular patterns and in the initiation of an effective immune response. We performed a study to better understand the role of TLR-MyD88 signaling in B. cenocepacia-induced pathogenesis in the immunocompromised host, using an experimental murine model. The time-course of several dynamic parameters, including animal survival, bacterial load, and secretion of critical inflammatory mediators, was compared in infected and immunosuppressed wild-type and MyD88(-/-) mice. Notably, when compared with wild-type mice, infected MyD88(-/-) animals displayed significantly reduced levels of inflammatory mediators (including KC, TNF-alpha, IL-6, MIP-2, and G-CSF) in blood and lung airspaces. Moreover, despite a higher transient bacterial load in the lungs, immunosuppressed mice deficient in MyD88 had an unexpected survival advantage. Finally, we showed that this B. cenocepacia-induced life-threatening infection of wild-type mice involved the proinflammatory cytokine TNF-alpha and could be prevented by corticosteroids. Altogether, our findings demonstrate that a MyD88-dependent pathway can critically contribute to a detrimental host inflammatory response that leads to fatal pneumonia.

  2. Characterization of the Burkholderia mallei tonB Mutant and Its Potential as a Backbone Strain for Vaccine Development.

    Directory of Open Access Journals (Sweden)

    Tiffany M Mott

    Full Text Available In this study, a Burkholderia mallei tonB mutant (TMM001 deficient in iron acquisition was constructed, characterized, and evaluated for its protective properties in acute inhalational infection models of murine glanders and melioidosis.Compared to the wild-type, TMM001 exhibits slower growth kinetics, siderophore hyper-secretion and the inability to utilize heme-containing proteins as iron sources. A series of animal challenge studies showed an inverse correlation between the percentage of survival in BALB/c mice and iron-dependent TMM001 growth. Upon evaluation of TMM001 as a potential protective strain against infection, we found 100% survival following B. mallei CSM001 challenge of mice previously receiving 1.5 x 10(4 CFU of TMM001. At 21 days post-immunization, TMM001-treated animals showed significantly higher levels of B. mallei-specific IgG1, IgG2a and IgM when compared to PBS-treated controls. At 48 h post-challenge, PBS-treated controls exhibited higher levels of serum inflammatory cytokines and more severe pathological damage to target organs compared to animals receiving TMM001. In a cross-protection study of acute inhalational melioidosis with B. pseudomallei, TMM001-treated mice were significantly protected. While wild type was cleared in all B. mallei challenge studies, mice failed to clear TMM001.Although further work is needed to prevent chronic infection by TMM001 while maintaining immunogenicity, our attenuated strain demonstrates great potential as a backbone strain for future vaccine development against both glanders and melioidosis.

  3. The role of siderophores in metal homeostasis of members of the genus Burkholderia.

    Science.gov (United States)

    Mathew, Anugraha; Jenul, Christian; Carlier, Aurelien L; Eberl, Leo

    2016-02-01

    Although members of the genus Burkholderia can utilize a high-affinity iron uptake system to sustain growth under iron-limiting conditions, many strains also produce siderophores, suggesting that they may serve alternative functions. Here we demonstrate that the two Burkholderia siderophores pyochelin and ornibactin can protect the cells from metal toxicity and thus play an alternative role in metal homeostasis. We also demonstrate that metals such as copper and zinc induce the production of ornibactin. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  4. Burkholderia caballeronis sp. nov., a nitrogen fixing species isolated from tomato (Lycopersicon esculentum) with the ability to effectively nodulate Phaseolus vulgaris.

    Science.gov (United States)

    Martínez-Aguilar, Lourdes; Salazar-Salazar, Corelly; Méndez, Rafael Díaz; Caballero-Mellado, Jesús; Hirsch, Ann M; Vásquez-Murrieta, María Soledad; Estrada-de los Santos, Paulina

    2013-12-01

    During a survey of Burkholderia species with potential use in agrobiotechnology, a group of 12 strains was isolated from the rhizosphere and rhizoplane of tomato plants growing in Mexico (Nepantla, Mexico State). A phylogenetic analysis of 16S rRNA gene sequences showed that the strains are related to Burkholderia kururiensis and Burkholderia mimosarum (97.4 and 97.1 %, respectively). However, they induced effective nitrogen-fixing nodules on roots of Phaseolus vulgaris. Based on polyphasic taxonomy, the group of strains represents a novel species for which the name Burkholderia caballeronis sp. nov. is proposed. The type species is TNe-841(T) (= LMG 26416(T) = CIP 110324(T)).

  5. Effects of methamphetamine dependence and HIV infection on cerebral morphology

    DEFF Research Database (Denmark)

    Jernigan, Terry Lynne; Gamst, Abthony C; Archibald, Sarah L.

    2005-01-01

    OBJECTIVE: The authors examined the separate and combined effects of methamphetamine dependence and HIV infection on brain morphology. METHOD: Morphometric measures obtained from magnetic resonance imaging of methamphetamine-dependent and/or HIV-positive participants and their appropriate age......- and education-matched comparison groups were analyzed. Main effects of age, HIV infection, methamphetamine dependence, and the interactions of these factors were examined in analyses of cerebral gray matter structure volumes. RESULTS: Independent of the effect of age, HIV infection was associated with reduced...... volumes of cortical, limbic, and striatal structures. There was also some evidence of an interaction between age and HIV infection such that older HIV-positive participants suffered disproportionate loss. Methamphetamine dependence was surprisingly associated with basal ganglia and parietal cortex volume...

  6. Competition between Burkholderia pseudomallei and B. thailandensis.

    Science.gov (United States)

    Ngamdee, Wikanda; Tandhavanant, Sarunporn; Wikraiphat, Chanthiwa; Reamtong, Onrapak; Wuthiekanun, Vanaporn; Salje, Jeanne; Low, David A; Peacock, Sharon J; Chantratita, Narisara

    2015-03-03

    Burkholderia pseudomallei is a Gram-negative bacterium that causes melioidosis, an often fatal disease in tropical countries. Burkholderia thailandensis is a non-virulent but closely related species. Both species are soil saprophytes but are almost never isolated together. We identified two mechanisms by which B. pseudomallei affects the growth of B. thailandensis. First, we found that six different isolates of B. pseudomallei inhibited the growth of B. thailandensis on LB agar plates. Second, our results indicated that 55% of isolated strains of B. pseudomallei produced a secreted compound that inhibited the motility but not the viability of B. thailandensis. Analysis showed that the active compound was a pH-sensitive and heat-labile compound, likely a protein, which may affect flagella processing or facilitate their degradation. Analysis of bacterial sequence types (STs) demonstrated an association between this and motility inhibition. The active compound was produced from B. pseudomallei during the stationary growth phase. Taken together, our results indicate that B. pseudomallei inhibits both the growth and motility of its close relative B. thailandensis. The latter phenomenon appears to occur via a previously unreported mechanism involving flagellar processing or degradation.

  7. The multiple roles of hypothetical gene BPSS1356 in Burkholderia pseudomallei.

    Directory of Open Access Journals (Sweden)

    Hokchai Yam

    Full Text Available Burkholderia pseudomallei is an opportunistic pathogen and the causative agent of melioidosis. It is able to adapt to harsh environments and can live intracellularly in its infected hosts. In this study, identification of transcriptional factors that associate with the β' subunit (RpoC of RNA polymerase was performed. The N-terminal region of this subunit is known to trigger promoter melting when associated with a sigma factor. A pull-down assay using histidine-tagged B. pseudomallei RpoC N-terminal region as bait showed that a hypothetical protein BPSS1356 was one of the proteins bound. This hypothetical protein is conserved in all B. pseudomallei strains and present only in the Burkholderia genus. A BPSS1356 deletion mutant was generated to investigate its biological function. The mutant strain exhibited reduced biofilm formation and a lower cell density during the stationary phase of growth in LB medium. Electron microscopic analysis revealed that the ΔBPSS1356 mutant cells had a shrunken cytoplasm indicative of cell plasmolysis and a rougher surface when compared to the wild type. An RNA microarray result showed that a total of 63 genes were transcriptionally affected by the BPSS1356 deletion with fold change values of higher than 4. The expression of a group of genes encoding membrane located transporters was concurrently down-regulated in ΔBPSS1356 mutant. Amongst the affected genes, the putative ion transportation genes were the most severely suppressed. Deprivation of BPSS1356 also down-regulated the transcriptions of genes for the arginine deiminase system, glycerol metabolism, type III secretion system cluster 2, cytochrome bd oxidase and arsenic resistance. It is therefore obvious that BPSS1356 plays a multiple regulatory roles on many genes.

  8. Nitrous oxide emission potentials of Burkholderia species isolated from the leaves of a boreal peat moss Sphagnum fuscum.

    Science.gov (United States)

    Nie, Yanxia; Li, Li; Wang, Mengcen; Tahvanainen, Teemu; Hashidoko, Yasuyuki

    2015-01-01

    Using a culture-based nitrous oxide (N2O) emission assay, three active N2O emitters were isolated from Sphagnum fuscum leaves and all identified as members of Burkholderia. These isolates showed N2O emission in the medium supplemented with [Formula: see text] but not with [Formula: see text], and Burkholderia sp. SF-E2 showed the most efficient N2O emission (0.20 μg·vial(-1)·day(-1)) at 1.0 mM KNO3. In Burkholderia sp. SF-E2, the optimum pH for N2O production was 5.0, close to that of the phyllosphere of Sphagnum mosses, while the optimum temperature was uniquely over 30 °C. The stimulating effect of additional 1.5 mM sucrose on N2O emission was ignorable, but Burkholderia sp. SF-E2 upon exposure to 100 mg·L(-1) E-caffeic acid showed uniquely 67-fold higher N2O emission. All of the three N2O emitters were negative in both acetylene inhibition assay and PCR assay for nosZ-detection, suggesting that N2O reductase or the gene itself is missing in the N2O-emitting Burkholderia.

  9. Understanding regulation of the host-mediated gut symbiont population and the symbiont-mediated host immunity in the Riptortus-Burkholderia symbiosis system.

    Science.gov (United States)

    Kim, Jiyeun Kate; Lee, Jun Beom; Jang, Ho Am; Han, Yeon Soo; Fukatsu, Takema; Lee, Bok Luel

    2016-11-01

    Valuable insect models have tremendously contributed to our understanding of innate immunity and symbiosis. Bean bug, Riptortus pedestris, is a useful insect symbiosis model due to harboring cultivable monospecific gut symbiont, genus Burkholderia. Bean bug is a hemimetabolous insect whose immunity is not well-understood. However, we recently identified three major antimicrobial peptides of Riptortus and examined the relationship between gut symbiosis and host immunity. We found that the presence of Burkholderia gut symbiont positively affects Riptortus immunity. From studying host regulation mechanisms of symbiont population, we revealed that the symbiotic Burkholderia cells are much more susceptible to Riptortus immune responses than the cultured cells. We further elucidated that the immune-susceptibility of the Burkholderia gut symbionts is due to the drastic change of bacterial cell envelope. Finally, we show that the immune-susceptible Burkholderia symbionts are able to prosper in host owing to the suppression of immune responses of the symbiotic midgut. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Genetic Determinants Associated With in Vivo Survival of Burkholderia cenocepacia in the Caenorhabditis elegans Model

    KAUST Repository

    Wong, Yee-Chin

    2018-05-29

    A Burkholderia cenocepacia infection usually leads to reduced survival and fatal cepacia syndrome in cystic fibrosis patients. The identification of B. cenocepacia essential genes for in vivo survival is key to designing new anti-infectives therapies. We used the Transposon-Directed Insertion Sequencing (TraDIS) approach to identify genes required for B. cenocepacia survival in the model infection host, Caenorhabditis elegans. A B. cenocepacia J2315 transposon pool of ∼500,000 mutants was used to infect C. elegans. We identified 178 genes as crucial for B. cenocepacia survival in the infected nematode. The majority of these genes code for proteins of unknown function, many of which are encoded by the genomic island BcenGI13, while other gene products are involved in nutrient acquisition, general stress responses and LPS O-antigen biosynthesis. Deletion of the glycosyltransferase gene wbxB and a histone-like nucleoid structuring (H-NS) protein-encoding gene (BCAL0154) reduced bacterial accumulation and attenuated virulence in C. elegans. Further analysis using quantitative RT-PCR indicated that BCAL0154 modulates B. cenocepacia pathogenesis via transcriptional regulation of motility-associated genes including fliC, fliG, flhD, and cheB1. This screen has successfully identified genes required for B. cenocepacia survival within the host-associated environment, many of which are potential targets for developing new antimicrobials.

  11. Genetic Determinants Associated With in Vivo Survival of Burkholderia cenocepacia in the Caenorhabditis elegans Model

    KAUST Repository

    Wong, Yee-Chin; Abd El Ghany, Moataz; Ghazzali, Raeece N. M.; Yap, Soon-Joo; Hoh, Chee-Choong; Pain, Arnab; Nathan, Sheila

    2018-01-01

    A Burkholderia cenocepacia infection usually leads to reduced survival and fatal cepacia syndrome in cystic fibrosis patients. The identification of B. cenocepacia essential genes for in vivo survival is key to designing new anti-infectives therapies. We used the Transposon-Directed Insertion Sequencing (TraDIS) approach to identify genes required for B. cenocepacia survival in the model infection host, Caenorhabditis elegans. A B. cenocepacia J2315 transposon pool of ∼500,000 mutants was used to infect C. elegans. We identified 178 genes as crucial for B. cenocepacia survival in the infected nematode. The majority of these genes code for proteins of unknown function, many of which are encoded by the genomic island BcenGI13, while other gene products are involved in nutrient acquisition, general stress responses and LPS O-antigen biosynthesis. Deletion of the glycosyltransferase gene wbxB and a histone-like nucleoid structuring (H-NS) protein-encoding gene (BCAL0154) reduced bacterial accumulation and attenuated virulence in C. elegans. Further analysis using quantitative RT-PCR indicated that BCAL0154 modulates B. cenocepacia pathogenesis via transcriptional regulation of motility-associated genes including fliC, fliG, flhD, and cheB1. This screen has successfully identified genes required for B. cenocepacia survival within the host-associated environment, many of which are potential targets for developing new antimicrobials.

  12. Microbiological assessment of Burkholderia cepacia complex (Bcc ...

    African Journals Online (AJOL)

    Nancy Omar

    2014-09-18

    Sep 18, 2014 ... tum 4/35 (11.4%) and urine 1/35 (2.9%). Other studies reported higher rates of isolation of B. cepa- cia complex from specimens other than those in our study. Gales et al. (2005)3 found that out of 176 NFGNB (83/176) belonging to Burkholderia spp.: 52/83 (62.7%) were from blood, 25/83 (30.1%) were from ...

  13. Insecticide applications to soil contribute to the development of Burkholderia mediating insecticide resistance in stinkbugs.

    Science.gov (United States)

    Tago, Kanako; Kikuchi, Yoshitomo; Nakaoka, Sinji; Katsuyama, Chie; Hayatsu, Masahito

    2015-07-01

    Some soil Burkholderia strains are capable of degrading the organophosphorus insecticide, fenitrothion, and establish symbiosis with stinkbugs, making the host insects fenitrothion-resistant. However, the ecology of the symbiotic degrading Burkholderia adapting to fenitrothion in the free-living environment is unknown. We hypothesized that fenitrothion applications affect the dynamics of fenitrothion-degrading Burkholderia, thereby controlling the transmission of symbiotic degrading Burkholderia from the soil to stinkbugs. We investigated changes in the density and diversity of culturable Burkholderia (i.e. symbiotic and nonsymbiotic fenitrothion degraders and nondegraders) in fenitrothion-treated soil using microcosms. During the incubation with five applications of pesticide, the density of the degraders increased from less than the detection limit to around 10(6)/g of soil. The number of dominant species among the degraders declined with the increasing density of degraders; eventually, one species predominated. This process can be explained according to the competitive exclusion principle using V(max) and K(m) values for fenitrothion metabolism by the degraders. We performed a phylogenetic analysis of representative strains isolated from the microcosms and evaluated their ability to establish symbiosis with the stinkbug Riptortus pedestris. The strains that established symbiosis with R. pedestris were assigned to a cluster including symbionts commonly isolated from stinkbugs. The strains outside the cluster could not necessarily associate with the host. The degraders in the cluster predominated during the initial phase of degrader dynamics in the soil. Therefore, only a few applications of fenitrothion could allow symbiotic degraders to associate with their hosts and may cause the emergence of symbiont-mediated insecticide resistance. © 2015 John Wiley & Sons Ltd.

  14. Burkholderia tropica una bacteria con gran potencial parasu uso en la agricultura

    Directory of Open Access Journals (Sweden)

    Hernando José Bolívar-Anillo

    2016-01-01

    Full Text Available El género Burkholderia con más de 90 especies reportadas hasta la fecha, se encuentra dividido en dos grupos mayores filogenéticamente distantes. El primer grupo se encuentra constituido por especies patógenas donde destacan los patógenos oportunistas referidos como el complejo Burkholderia cepacia (Bcc;el otro grupo está conformado por especies no patógenas con habilidades para la promoción del crecimiento vegetal y la rizoremediación. Burkholderia tropica es unabacteria con capacidad de fijar nitrógeno; aislada de la rizósfera, rizoplano, tallo y la raíz de plantas de maíz y caña de azúcar. Además de su capacidad diazotrofa, B. tropica presenta características que permiten catalogarla como una bacteria promotora del crecimiento vegetal, por su capacidad de producir sideróforos, solubilizar fosfatos, producir exo-heteropolisacáridos, además de utilizarse como biocontrol para algunos fitoparásitos, lo que la convierte en una bacteria prometedora para su aplicación en el sector agrícola.

  15. Role of phosphate solubilizing Burkholderia spp. for successful colonization and growth promotion of Lycopodium cernuum L. (Lycopodiaceae) in lateritic belt of Birbhum district of West Bengal, India.

    Science.gov (United States)

    Ghosh, Ranjan; Barman, Soma; Mukherjee, Rajib; Mandal, Narayan C

    2016-02-01

    Profuse growth of Lycpodium cernuum L. was found in phosphate deficient red lateritic soil of West Bengal, India. Interaction of vesicular-arbuscular mycorrhiza (VAM) with Lycopodium rhizoids were described earlier but association of PGPR with their rhizoids were not studied. Three potent phosphate solubilizing bacterial strains (P4, P9 and P10) associated with L. cernuum rhizoids were isolated and identified by 16S rDNA homologies on Ez-Taxon database as Burkholderia tropica, Burkholderia unamae and Burkholderia cepacia respectively. Day wise kinetics of phosphate solubilization against Ca3(PO4)2 suggested P4 (580.56±13.38 μg ml(-1)) as maximum mineral phosphate solubilizer followed by P9 (517.12±17.15 μg ml(-1)) and P10 (485.18±14.23 μg ml(-1)) at 28 °C. Release of bound phosphates by isolated strains from ferric phosphate (FePO4), aluminum phosphate (AlPO4) and four different complex rock phosphates indicated their very good phosphate solubilizng efficacy. Nitrogen independent solubilizition also supports their nitrogen fixing capabilities. Inhibition of P solubilization by calcium salts and induction by EDTA suggested pH dependent chelation of metal cations by all of the isolates. Rhizoidal colonization potentials of Burkholderia spp. were confirmed by in planta experiment and also using scanning electron microscope (SEM). Increases of total phosphate content in Lycopodium plants upon soil treatment with these isolates were also recorded. In addition siderophore production on CAS agar medium, tryptophan dependent IAA production and antifungal activities against pathogenic fungi by rhizospheric isolates deep-rooted that they have definite role in nutrient mobilization for successful colonization of L. cernuum in nutrient deficient lateritic soil. Copyright © 2015 Elsevier GmbH. All rights reserved.

  16. South African Papilionoid Legumes Are Nodulated by Diverse Burkholderia with Unique Nodulation and Nitrogen-Fixation Loci

    Science.gov (United States)

    Beukes, Chrizelle W.; Venter, Stephanus N.; Law, Ian J.; Phalane, Francina L.; Steenkamp, Emma T.

    2013-01-01

    The root-nodule bacteria of legumes endemic to the Cape Floristic Region are largely understudied, even though recent reports suggest the occurrence of nodulating Burkholderia species unique to the region. In this study, we considered the diversity and evolution of nodulating Burkholderia associated with the endemic papilionoid tribes Hypocalypteae and Podalyrieae. We identified distinct groups from verified rhizobial isolates by phylogenetic analyses of the 16S rRNA and recA housekeeping gene regions. In order to gain insight into the evolution of the nodulation and diazotrophy of these rhizobia we analysed the genes encoding NifH and NodA. The majority of these 69 isolates appeared to be unique, potentially representing novel species. Evidence of horizontal gene transfer determining the symbiotic ability of these Cape Floristic Region isolates indicate evolutionary origins distinct from those of nodulating Burkholderia from elsewhere in the world. Overall, our findings suggest that Burkholderia species associated with fynbos legumes are highly diverse and their symbiotic abilities have unique ancestries. It is therefore possible that the evolution of these bacteria is closely linked to the diversification and establishment of legumes characteristic of the Cape Floristic Region. PMID:23874611

  17. Occidiofungin is an important component responsible for the antifungal activity of Burkholderia pyrrocinia strain Lyc2.

    Science.gov (United States)

    Wang, X Q; Liu, A X; Guerrero, A; Liu, J; Yu, X Q; Deng, P; Ma, L; Baird, S M; Smith, L; Li, X D; Lu, S E

    2016-03-01

    To identify the taxonomy of tobacco rhizosphere-isolated strain Lyc2 and investigate the mechanisms of the antifungal activities, focusing on antimicrobials gene clusters identification and function analysis. Multilocus sequence typing and 16S rRNA analyses indicated that strain Lyc2 belongs to Burkholderia pyrrocinia. Bioassay results indicated strain Lyc2 showed significant antifungal activities against a broad range of plant and animal fungal pathogens and control efficacy on seedling damping off disease of cotton. A 55·2-kb gene cluster which was homologous to ocf gene clusters in Burkholderia contaminans MS14 was confirmed to be responsible for antifungal activities by random mutagenesis; HPLC was used to verify the production of antifungal compounds. Multiple antibiotic and secondary metabolized biosynthesis gene clusters predicated by antiSMASH revealed the broad spectrum of antimicrobials activities of the strain. Our results revealed the mechanisms of antifungal activities of strain Lyc2 and expand our knowledge about production of occidiofungin in the bacteria Burkholderia. Understanding the mechanisms of antifungal activities of strain Lyc2 has contributed to discovery of new antibiotics and expand our knowledge of production of occidiofungin in the bacteria Burkholderia. © 2015 The Society for Applied Microbiology.

  18. RsaM: a transcriptional regulator of Burkholderia spp. with novel fold

    Energy Technology Data Exchange (ETDEWEB)

    Michalska, Karolina [Midwest Center for Structural Genomics, Argonne National Laboratory, IL USA; Structural Biology Center, Biosciences Division, Argonne National Laboratory, IL USA; Chhor, Gekleng [Midwest Center for Structural Genomics, Argonne National Laboratory, IL USA; Clancy, Shonda [Midwest Center for Structural Genomics, Argonne National Laboratory, IL USA; Jedrzejczak, Robert [Midwest Center for Structural Genomics, Argonne National Laboratory, IL USA; Babnigg, Gyorgy [Midwest Center for Structural Genomics, Argonne National Laboratory, IL USA; Winans, Stephen C. [Department of Microbiology, Cornell University, Ithaca NY USA; Joachimiak, Andrzej [Midwest Center for Structural Genomics, Argonne National Laboratory, IL USA; Structural Biology Center, Biosciences Division, Argonne National Laboratory, IL USA; Department of Biochemistry and Molecular Biology, University of Chicago, IL USA

    2014-07-04

    Burkholderia cepacia complex (Bcc) is a set of closely related bacterial species that are notorious pathogens of cystic fibrosis patients, responsible for life-threatening lung infections. Expression of several virulence factors of Bcc is controlled by a mechanism known as quorum sensing (QS). QS is a means of bacterial communication used to coordinate gene expression in a cell-density-dependent manner. The system involves the production of diffusible signaling molecules (N-acyl-L-homoserine lactones, AHLs), that bind to cognate transcriptional regulators and influence their ability to regulate gene expression. One such system that is highly conserved in Bcc consists of CepI and CepR. CepI is AHL synthase, while CepR is an AHL-dependent transcription factor. In most members of the Bcc group, the cepI and cepR genes are divergently transcribed and separated by additional genes. One of them, bcam1869, encodes the BcRsaM protein, which was recently postulated to modulate the abundance or activity of CepI or CepR. Here we show the crystal structure of BcRsaM from B. cenocepacia J2315. It is a single-domain protein with unique topology and presents a novel fold. The protein is a dimer in the crystal and in solution. This regulator has no known DNA binding motifs and direct binding of BcRsaM to the cepI promoter could not be detected in in vitro assays. Therefore, we propose that the modulatory action of RsaM might result from interactions with other components of the QS machinery rather than from direct association with the DNA promoter.

  19. A conserved two-component regulatory system, PidS/PidR, globally regulates pigmentation and virulence-related phenotypes of Burkholderia glumae.

    Science.gov (United States)

    Karki, Hari Sharan; Barphagha, Inderjit Kaur; Ham, Jong Hyun

    2012-09-01

    Burkholderia glumae is a rice pathogenic bacterium that causes bacterial panicle blight. Some strains of this pathogen produce dark brown pigments when grown on casamino-acid peptone glucose (CPG) agar medium. A pigment-positive and highly virulent strain of B. glumae, 411gr-6, was randomly mutagenized with mini-Tn5gus, and the resulting mini-Tn5gus derivatives showing altered pigmentation phenotypes were screened on CPG agar plates to identify the genetic elements governing the pigmentation of B. glumae. In this study, a novel two-component regulatory system (TCRS) composed of the PidS sensor histidine kinase and the PidR response regulator was identified as an essential regulatory factor for pigmentation. Notably, the PidS/PidR TCRS was also required for the elicitation of the hypersensitive response on tobacco leaves, indicating the dependence of the hypersensitive response and pathogenicity (Hrp) type III secretion system of B. glumae on this regulatory factor. In addition, B. glumae mutants defective in the PidS/PidR TCRS showed less production of the phytotoxin, toxoflavin, and less virulence on rice panicles and onion bulbs relative to the parental strain, 411gr-6. The presence of highly homologous PidS and PidR orthologues in other Burkholderia species suggests that PidS/PidR-family TCRSs may exert the same or similar functions in different Burkholderia species, including both plant and animal pathogens. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  20. Chronic infection of cystic fibrosis patient airways by a single clone of Burkholderia cepacia: replacement of non-mucoid to mucoid morphotype Infecção pulmonar crônica por um único clone de Burkholderia cepacia: substituição do morfotipo não mucóide por mucóide

    Directory of Open Access Journals (Sweden)

    Ana Paula D'Alincourt Carvalho

    2003-11-01

    Full Text Available Mucoid Burkholderia cepacia morphotype emerged within a nine year follow-up of a cystic fibrosis patient. Clinical data suggested a linkage between the mucoid phenotype isolation and the deterioration of the patient's condition. Despite of the phenotypic variation, molecular typing showed that the patient was chronically infected with B. cepacia complex isolates belonging to a same genetic clone.O presente trabalho descreve a emergência de cepas mucoides do complexo B. cepacia em um paciente com Fibrose Cística dentro de um acompanhamento bacteriológico prospectivo de nove anos. Os dados clínicos sugerem a associação entre o isolamento do morfotipo mucoide e a deterioração clínica do paciente. Apesar da variação fenotípica, os testes moleculares mostraram que o paciente manteve-se cronicamente infectado por cepas de mesma origem clonal.

  1. Burkholderia thailandensis harbors two identical rhl gene clusters responsible for the biosynthesis of rhamnolipids

    Directory of Open Access Journals (Sweden)

    Woods Donald E

    2009-12-01

    Full Text Available Abstract Background Rhamnolipids are surface active molecules composed of rhamnose and β-hydroxydecanoic acid. These biosurfactants are produced mainly by Pseudomonas aeruginosa and have been thoroughly investigated since their early discovery. Recently, they have attracted renewed attention because of their involvement in various multicellular behaviors. Despite this high interest, only very few studies have focused on the production of rhamnolipids by Burkholderia species. Results Orthologs of rhlA, rhlB and rhlC, which are responsible for the biosynthesis of rhamnolipids in P. aeruginosa, have been found in the non-infectious Burkholderia thailandensis, as well as in the genetically similar important pathogen B. pseudomallei. In contrast to P. aeruginosa, both Burkholderia species contain these three genes necessary for rhamnolipid production within a single gene cluster. Furthermore, two identical, paralogous copies of this gene cluster are found on the second chromosome of these bacteria. Both Burkholderia spp. produce rhamnolipids containing 3-hydroxy fatty acid moieties with longer side chains than those described for P. aeruginosa. Additionally, the rhamnolipids produced by B. thailandensis contain a much larger proportion of dirhamnolipids versus monorhamnolipids when compared to P. aeruginosa. The rhamnolipids produced by B. thailandensis reduce the surface tension of water to 42 mN/m while displaying a critical micelle concentration value of 225 mg/L. Separate mutations in both rhlA alleles, which are responsible for the synthesis of the rhamnolipid precursor 3-(3-hydroxyalkanoyloxyalkanoic acid, prove that both copies of the rhl gene cluster are functional, but one contributes more to the total production than the other. Finally, a double ΔrhlA mutant that is completely devoid of rhamnolipid production is incapable of swarming motility, showing that both gene clusters contribute to this phenotype. Conclusions Collectively, these

  2. Understanding the Pathogenicity of Burkholderia contaminans, an Emerging Pathogen in Cystic Fibrosis.

    Science.gov (United States)

    Nunvar, Jaroslav; Kalferstova, Lucie; Bloodworth, Ruhi A M; Kolar, Michal; Degrossi, Jose; Lubovich, Silvina; Cardona, Silvia T; Drevinek, Pavel

    2016-01-01

    Several bacterial species from the Burkholderia cepacia complex (Bcc) are feared opportunistic pathogens that lead to debilitating lung infections with a high risk of developing fatal septicemia in cystic fibrosis (CF) patients. However, the pathogenic potential of other Bcc species is yet unknown. To elucidate clinical relevance of Burkholderia contaminans, a species frequently isolated from CF respiratory samples in Ibero-American countries, we aimed to identify its key virulence factors possibly linked with an unfavorable clinical outcome. We performed a genome-wide comparative analysis of two isolates of B. contaminans ST872 from sputum and blood culture of a female CF patient in Argentina. RNA-seq data showed significant changes in expression for quorum sensing-regulated virulence factors and motility and chemotaxis. Furthermore, we detected expression changes in a recently described low-oxygen-activated (lxa) locus which encodes stress-related proteins, and for two clusters responsible for the biosynthesis of antifungal and hemolytic compounds pyrrolnitrin and occidiofungin. Based on phenotypic assays that confirmed changes in motility and in proteolytic, hemolytic and antifungal activities, we were able to distinguish two phenotypes of B. contaminans that coexisted in the host and entered her bloodstream. Whole genome sequencing revealed that the sputum and bloodstream isolates (each representing a distinct phenotype) differed by over 1,400 mutations as a result of a mismatch repair-deficient hypermutable state of the sputum isolate. The inferred lack of purifying selection against nonsynonymous mutations and the high rate of pseudogenization in the derived isolate indicated limited evolutionary pressure during evolution in the nutrient-rich, stable CF sputum environment. The present study is the first to examine the genomic and transcriptomic differences between longitudinal isolates of B. contaminans. Detected activity of a number of putative virulence

  3. Reassessment of the taxonomic position of Burkholderia andropogonis and description of Robbsia andropogonis gen. nov., comb. nov.

    Science.gov (United States)

    Lopes-Santos, Lucilene; Castro, Daniel Bedo Assumpção; Ferreira-Tonin, Mariana; Corrêa, Daniele Bussioli Alves; Weir, Bevan Simon; Park, Duckchul; Ottoboni, Laura Maria Mariscal; Neto, Júlio Rodrigues; Destéfano, Suzete Aparecida Lanza

    2017-06-01

    The phylogenetic classification of the species Burkholderia andropogonis within the Burkholderia genus was reassessed using 16S rRNA gene phylogenetic analysis and multilocus sequence analysis (MLSA). Both phylogenetic trees revealed two main groups, named A and B, strongly supported by high bootstrap values (100%). Group A encompassed all of the Burkholderia species complex, whi.le Group B only comprised B. andropogonis species, with low percentage similarities with other species of the genus, from 92 to 95% for 16S rRNA gene sequences and 83% for conserved gene sequences. Average nucleotide identity (ANI), tetranucleotide signature frequency, and percentage of conserved proteins POCP analyses were also carried out, and in the three analyses B. andropogonis showed lower values when compared to the other Burkholderia species complex, near 71% for ANI, from 0.484 to 0.724 for tetranucleotide signature frequency, and around 50% for POCP, reinforcing the distance observed in the phylogenetic analyses. Our findings provide an important insight into the taxonomy of B. andropogonis. It is clear from the results that this bacterial species exhibits genotypic differences and represents a new genus described herein as Robbsia andropogonis gen. nov., comb. nov.

  4. Genome-Wide Analysis of Type VI System Clusters and Effectors in Burkholderia Species

    Directory of Open Access Journals (Sweden)

    Thao Thi Nguyen

    2018-02-01

    Full Text Available Type VI secretion system (T6SS has been discovered in a variety of gram-negative bacteria as a versatile weapon to stimulate the killing of eukaryotic cells or prokaryotic competitors. Type VI secretion effectors (T6SEs are well known as key virulence factors for important pathogenic bacteria. In many Burkholderia species, T6SS has evolved as the most complicated secretion pathway with distinguished types to translocate diverse T6SEs, suggesting their essential roles in this genus. Here we attempted to detect and characterize T6SSs and potential T6SEs in target genomes of plant-associated and environmental Burkholderia species based on computational analyses. In total, 66 potential functional T6SS clusters were found in 30 target Burkholderia bacterial genomes, of which 33% possess three or four clusters. The core proteins in each cluster were specified and phylogenetic trees of three components (i.e., TssC, TssD, TssL were constructed to elucidate the relationship among the identified T6SS clusters. Next, we identified 322 potential T6SEs in the target genomes based on homology searches and explored the important domains conserved in effector candidates. In addition, using the screening approach based on the profile hidden Markov model (pHMM of T6SEs that possess markers for type VI effectors (MIX motif (MIX T6SEs, 57 revealed proteins that were not included in training datasets were recognized as novel MIX T6SE candidates from the Burkholderia species. This approach could be useful to identify potential T6SEs from other bacterial genomes.

  5. Toward modern inhalational bacteriophage therapy: nebulization of bacteriophages of Burkholderia cepacia complex.

    Science.gov (United States)

    Golshahi, Laleh; Seed, Kimberley D; Dennis, Jonathan J; Finlay, Warren H

    2008-12-01

    Antibiotic-resistant bacterial infections have renewed interest in finding substitute methods of treatment. The purpose of the present in vitro study was to investigate the possibility of respiratory delivery of a Burkholderia cepacia complex (BCC) bacteriophage by nebulized aerosol administration. Bacteriophages in isotonic saline were aerosolized with Pari LC star and eFlow nebulizers, at titers with mean value (standard deviation) of 2.15 x 10(8) (1.63 x 10(8)) plaque-forming unit (PFU)/mL in 2.5-mL nebulizer fills. The breathing pattern of an adult was simulated using a pulmonary waveform generator. During breath simulation, the size distributions of the nebulized aerosol were measured using phase doppler anemometry (PDA). Efficiency of nebulizer delivery was subsequently determined by collection of aerosol on low resistance filters and measurement of bacteriophage titers. These filter titers were used as input data to a mathematical lung deposition model to predict regional deposition of bacteriophages in the lung and initial bacteriophage titers in the liquid surface layer of each conducting airway generation. The results suggest that BCC bacteriophages can be nebulized successfully within a reasonable delivery time and predicted titers in the lung indicate that this method may hold potential for treatment of bacterial lung infections common among cystic fibrosis patients.

  6. Burkholderia novacaledonica sp. nov. and B. ultramafica sp. nov. isolated from roots of Costularia spp. pioneer plants of ultramafic soils in New Caledonia.

    Science.gov (United States)

    Guentas, Linda; Gensous, Simon; Cavaloc, Yvon; Ducousso, Marc; Amir, Hamid; De Georges de Ledenon, Benjamin; Moulin, Lionel; Jourand, Philippe

    2016-05-01

    The taxonomic status of eleven rhizospheric bacterial strains belonging to the genus Burkholderia and isolated from roots of Costularia (Cyperaceae), tropical herbaceous pioneer plants growing on ultramafic soils in New Caledonia, was investigated using a polyphasic taxonomic approach. The genetic analyses (16S rRNA genes, gyrB, recA, nreB and cnr) confirmed that all strains are Burkholderia and cluster into two separated groups. The DNA hybridization results showed low relatedness values to the closest relatives Burkholderia species. The phenotypic analyses confirmed that the two groups of strains could be differentiated from each other and from other known Burkholderia species. This polyphasic study revealed that these two groups of strains represent each a novel species of Burkholderia, for which the names Burkholderia novacaledonica sp. nov. (type strain STM10272(T)=LMG28615(T)=CIP110887(T)) and B. ultramafica sp. nov. (type strain STM10279(T)=LMG28614(T)=CIP110886(T)) are proposed, respectively. These strains of Burkholderia presented specific ecological traits such as the tolerance to the extreme edaphic constraints of ultramafic soils: they grew at pH between 4 and 8 and tolerate the strong unbalanced Ca/Mg ratio (1/19) and the high concentrations of heavy metals i.e. Co, Cr, Mn and Ni. Noteworthy B. ultramafica tolerated nickel until 10mM and B. novacaledonica up to 5mM. The presence of the nickel (nreB) and cobalt/nickel (cnr) resistance determinants encoding for protein involved in metal tolerance was found in all strains of both groups. Moreover, most of the strains were able to produce plant growth promoting molecules (ACC, IAA, NH3 and siderophores). Such ecological traits suggest that these new species of Burkholderia might be environmentally adaptable plant-associated bacteria and beneficial to plants. Copyright © 2016 Elsevier GmbH. All rights reserved.

  7. Type VI Secretion is a Major Virulence Determinant in Burkholderia Mallei

    National Research Council Canada - National Science Library

    Schell, Mark A; Ulrich, Ricky L; Ribot, Wilson J; Brueggemann, Ernst E; Hines, Harry B; Chen, Dan; Lipscomb, Lyla; Kim, H. S; Mrazek, Jan; Nierman, William C; DeShazer, David

    2007-01-01

    Burkholderia mallei is a host-adapted pathogen and a category B biothreat agent. Although the B. mallei VirAG two-component regulatory system is required for virulence in hamsters, the virulence genes it regulates are unknown...

  8. Recovery of a Burkholderia thailandensis-like isolate from an Australian water source

    Directory of Open Access Journals (Sweden)

    Wilkins Patricia P

    2008-04-01

    Full Text Available Abstract Background Burkholderia thailandensis, a close relative of Burkholderia pseudomallei, has previously been reported only from Southeast Asia and North America. It is biochemically differentiated from B. pseudomallei by the ability to utilize arabinose. During the course of environmental sampling for B. pseudomallei in the Northern Territory of Australia, an isolate, MSMB 43, was recovered that is arabinose positive. Results Genetic analysis using 16S rDNA sequencing and DNA/DNA hybridization indicates that MSMB 43 is most similar to B. thailandensis although multi-locus sequence typing indicates that this isolate is divergent from both B. pseudomallei and other described B. thailandensis. Conclusion We report the isolation and initial characterization of strain MSMB 43, which is a B. thailandensis-like isolate recovered in Australia.

  9. Novel engineered cationic antimicrobial peptides display broad-spectrum activity against Francisella tularensis, Yersinia pestis and Burkholderia pseudomallei.

    Science.gov (United States)

    Abdelbaqi, Suha; Deslouches, Berthony; Steckbeck, Jonathan; Montelaro, Ronald; Reed, Douglas S

    2016-02-01

    Broad-spectrum antimicrobials are needed to effectively treat patients infected in the event of a pandemic or intentional release of a pathogen prior to confirmation of the pathogen's identity. Engineered cationic antimicrobial peptides (eCAPs) display activity against a number of bacterial pathogens including multi-drug-resistant strains. Two lead eCAPs, WLBU2 and WR12, were compared with human cathelicidin (LL-37) against three highly pathogenic bacteria: Francisella tularensis, Yersinia pestis and Burkholderia pseudomallei. Both WLBU2 and WR12 demonstrated bactericidal activity greater than that of LL-37, particularly against F. tularensis and Y. pestis. Only WLBU2 had bactericidal activity against B. pseudomallei. WLBU2, WR12 and LL-37 were all able to inhibit the growth of the three bacteria in vitro. Because these bacteria can be facultative intracellular pathogens, preferentially infecting macrophages and dendritic cells, we evaluated the activity of WLBU2 against F. tularensis in an ex vivo infection model with J774 cells, a mouse macrophage cell line. In that model WLBU2 was able to achieve greater than 50% killing of F. tularensis at a concentration of 12.5 μM. These data show the therapeutic potential of eCAPs, particularly WLBU2, as a broad-spectrum antimicrobial for treating highly pathogenic bacterial infections.

  10. Burkholderia cepacia complex infection in an Adult Cystic Fibrosis unit in Madrid.

    Science.gov (United States)

    Correa-Ruiz, Ana; Girón, Rosa; Buendía, Buenaventura; Medina-Pascual, M José; Valenzuela, Claudia; López-Brea, Manuel; Sáez-Nieto, Juan Antonio

    2013-12-01

    Burkholderia cepacia complex have emerged as significant pathogens in cystic fibrosis (CF) patients due to the risk of cepacia syndrome and the innate multi-resistance of the microorganisms to antibiotics. The aim of this study was to describe the antimicrobial susceptibility profiles, the genotypes and subtypes of BCC, and the clinical evolution of CF patients with BCC. The lung function and Brasfield and Shwachman score were assessed in 12 patients. BCC were identified and susceptibility was studied by MicroScan (Siemens). Species and genospecies of BCC were confirmed by molecular methods in a Reference Centre (Majadahonda). BCC were identified in 12 of 70 patients (17.1%) over a ten year period. The mean age to colonization by BCC was 24.4 years (SD: 7.71). B. cenocepacia was isolated in 4 patients (33.3%), B. contaminans was isolated in 3 patients (25%), both B. vietnamiensis and B. stabilis were isolated in 2 patients (16.7%), and B. cepacia, B. multivorans and B. late were isolated in one patient (8.3%). Among the B. cenocepacia, subtype IIIa was identified in two strains, and subtype IIIb was identified in the other two strains. There was susceptibility to meropenem in 90% of BCC, 80% to cotrimoxazole, 60% to minocycline, 50% to ceftazidime, and 40% to levofloxacin. B. cenocepacia was the most prevalent species among the BCC isolated in CF adult patients, and subtypes IIIa and IIIb were identified in the 50% of the strains. Meropenem and cotrimoxazole showed the best activity. Copyright © 2012 Elsevier España, S.L. All rights reserved.

  11. RNA-dependent RNA polymerases from cowpea mosaic virus-infected cowpea leaves

    NARCIS (Netherlands)

    Dorssers, L.

    1983-01-01

    The aim of the research described in this thesis was the purification and identification of the RNA-dependent RNA polymerase engaged in replicating viral RNA in cowpea mosaic virus (CPMV)- infected cowpea leaves.

    Previously, an RNA-dependent RNA polymerase produced upon infection of

  12. Rhizonin A from Burkholderia sp. KCTC11096 and Its Growth Promoting Role in Lettuce Seed Germination

    Directory of Open Access Journals (Sweden)

    Sang-Mo Kang

    2012-07-01

    Full Text Available We isolated and identified a gibberellin-producing Burkholderia sp. KCTC 11096 from agricultural field soils. The culture filtrate of plant growth promoting rhizobacteria (PGPR significantly increased the germination and growth of lettuce and Chinese cabbage seeds. The ethyl acetate extract of the PGPR culture showed significantly higher rate of lettuce seed germination and growth as compared to the distilled water treated control. The ethyl acetate fraction of the Burkholderia sp. was subjected to bioassay-guided isolation and we obtained for the first time from a Burkholderia sp. the plant growth promoting compound rhizonin A (1, which was characterized through NMR and MS techniques. Application of various concentrations of 1 significantly promoted the lettuce seed germination as compared to control.

  13. Effect of agricultural management regimes on Burkholderia community structure in soil

    NARCIS (Netherlands)

    Salles, Joanna; van Elsas, J.D.; Van Veen, J.A.

    2006-01-01

    The main objective of this study was to determine the Burkholderia community structure associated with areas under different agricultural management and to evaluate to which extent this community structure is affected by changes in agricultural management. Two fields with distinct soil history

  14. Assessing the potential for Burkholderia pseudomallei in the southeastern United States

    Science.gov (United States)

    Burkholderia pseudomallei, the causative agent of melioidosis, is an underreported zoonosis in many countries where environmental conditions may be favorable for B. pseudomallei. This soil saprophyte is most often detected in tropical areas such as Southeast Asia and Northern Australia where the cas...

  15. Effect of agricultural management regime on Burkholderia community structure in soil

    NARCIS (Netherlands)

    Salles, J.F.; Elsas, van J.D.; Veen, van J.A.

    2006-01-01

    The main objective of this study was to determine the Burkholderia community structure associated with areas under different agricultural management and to evaluate to which extent this community structure is affected by changes in agricultural management. Two fields with distinct soil history

  16. Effect of agricultural management regime on Burkholderia community structure in soil

    NARCIS (Netherlands)

    Salles, J. F.; van Elsas, J. D.; van Veen, J. A.

    The main objective of this study was to determine the Burkholderia community structure associated with areas under different agricultural management and to evaluate to which extent this community structure is affected by changes in agricultural management. Two fields with distinct soil history

  17. Draft genome sequence of Burkholderia sordidicola S170, a potential plant growth promoter isolated from coniferous forest soil in the Czech Republic

    DEFF Research Database (Denmark)

    Lladó, Salvador; Xu, Zhuofei; Sørensen, Søren Johannes

    2014-01-01

    Burkholderia species are key players in the accumulation of carbon from cellulose decomposition in coniferous forest ecosystems. We report here the draft genome of Burkholderia sordidicola strain S170, containing features associated with known genes involved in plant growth promotion...

  18. Burkholderia pseudomallei traced to water treatment plant in Australia.

    Science.gov (United States)

    Inglis, T J; Garrow, S C; Henderson, M; Clair, A; Sampson, J; O'Reilly, L; Cameron, B

    2000-01-01

    Burkholderia pseudomallei was isolated from environmental specimens 1 year after an outbreak of acute melioidosis in a remote coastal community in northwestern Australia. B. pseudomallei was isolated from a water storage tank and from spray formed in a pH-raising aerator unit. Pulsed-field gel electrophoresis confirmed the aerator and storage tank isolates were identical to the outbreak strain, WKo97.

  19. Burkholderia xenovorans LB400 harbors a multi-replicon, 9.73-Mbp genome shaped for versatility.

    Science.gov (United States)

    Chain, Patrick S G; Denef, Vincent J; Konstantinidis, Konstantinos T; Vergez, Lisa M; Agulló, Loreine; Reyes, Valeria Latorre; Hauser, Loren; Córdova, Macarena; Gómez, Luis; González, Myriam; Land, Miriam; Lao, Victoria; Larimer, Frank; LiPuma, John J; Mahenthiralingam, Eshwar; Malfatti, Stephanie A; Marx, Christopher J; Parnell, J Jacob; Ramette, Alban; Richardson, Paul; Seeger, Michael; Smith, Daryl; Spilker, Theodore; Sul, Woo Jun; Tsoi, Tamara V; Ulrich, Luke E; Zhulin, Igor B; Tiedje, James M

    2006-10-17

    Burkholderia xenovorans LB400 (LB400), a well studied, effective polychlorinated biphenyl-degrader, has one of the two largest known bacterial genomes and is the first nonpathogenic Burkholderia isolate sequenced. From an evolutionary perspective, we find significant differences in functional specialization between the three replicons of LB400, as well as a more relaxed selective pressure for genes located on the two smaller vs. the largest replicon. High genomic plasticity, diversity, and specialization within the Burkholderia genus are exemplified by the conservation of only 44% of the genes between LB400 and Burkholderia cepacia complex strain 383. Even among four B. xenovorans strains, genome size varies from 7.4 to 9.73 Mbp. The latter is largely explained by our findings that >20% of the LB400 sequence was recently acquired by means of lateral gene transfer. Although a range of genetic factors associated with in vivo survival and intercellular interactions are present, these genetic factors are likely related to niche breadth rather than determinants of pathogenicity. The presence of at least eleven "central aromatic" and twenty "peripheral aromatic" pathways in LB400, among the highest in any sequenced bacterial genome, supports this hypothesis. Finally, in addition to the experimentally observed redundancy in benzoate degradation and formaldehyde oxidation pathways, the fact that 17.6% of proteins have a better LB400 paralog than an ortholog in a different genome highlights the importance of gene duplication and repeated acquirement, which, coupled with their divergence, raises questions regarding the role of paralogs and potential functional redundancies in large-genome microbes.

  20. Burkholderia xernovorans LB400 harbors a multi-replicon, 9.73-Mbp genome shaped for versatility

    Energy Technology Data Exchange (ETDEWEB)

    Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Denef, Vincent [University of California, Berkeley; Konstantinidis, Konstantinos T [Michigan State University, East Lansing; Vergez, Lisa [Lawrence Livermore National Laboratory (LLNL); Agullo, Loreine [Universidad Tecnica Federico Santa Maria, Casilla 110-V; Reyes, Valeria Latorre [Universidad Tecnica Federico Santa Maria, Casilla 110-V; Hauser, Loren John [ORNL; Cordova, Macarena [Universidad Tecnica Federico Santa Maria, Casilla 110-V; Gomez, Luis [Universidad Tecnica Federico Santa Maria, Casilla 110-V; Gonzalez, Myriam [Universidad Tecnica Federico Santa Maria, Casilla 110-V; Land, Miriam L [ORNL; Lao, Victoria [Lawrence Livermore National Laboratory (LLNL); Larimer, Frank W [ORNL; LiPuma, John J [University of Michigan; Mahenthiralingam, Eshwar [Cardiff University, Wales; Malfatti, Stephanie [Lawrence Livermore National Laboratory (LLNL); Marx, Christopher J [Harvard University; Parnell, J Jacob [Michigan State University, East Lansing; Ramette, Alban [Michigan State University, East Lansing; Richardson, P M [U.S. Department of Energy, Joint Genome Institute; Seeger, Michael [Universidad Tecnica Federico Santa Maria, Casilla 110-V; Smith, Daryl [University of British Columbia, Vancouver; Spilker, Theodore [University of Michigan; Sul, Woo Jun [Michigan State University, East Lansing; Tsoi, Tamara V [Michigan State University, East Lansing; Zhulin, Igor B [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Tiedje, James M. [Michigan State University, East Lansing

    2006-01-01

    Burkholderia xenovorans LB400 (LB400), a well studied, effective polychlorinated biphenyl-degrader, has one of the two largest known bacterial genomes and is the first nonpathogenic Burkholderia isolate sequenced. From an evolutionary perspective, we find significant differences in functional specialization between the three replicons of LB400, as well as a more relaxed selective pressure for genes located on the two smaller vs. the largest replicon. High genomic plasticity, diversity, and specialization within the Burkholderia genus are exemplified by the conservation of only 44% of the genes between LB400 and Burkholderia cepacia complex strain 383. Even among four B. xenovorans strains, genome size varies from 7.4 to 9.73 Mbp. The latter is largely explained by our findings that >20% of the LB400 sequence was recently acquired by means of lateral gene transfer. Although a range of genetic factors associated with in vivo survival and intercellular interactions are present, these genetic factors are likely related to niche breadth rather than determinants of pathogenicity. The presence of at least eleven 'central aromatic' and twenty 'peripheral aromatic' pathways in LB400, among the highest in any sequenced bacterial genome, supports this hypothesis. Finally, in addition to the experimentally observed redundancy in benzoate degradation and formaldehyde oxidation pathways, the fact that 17.6% of proteins have a better LB400 paralog than an ortholog in a different genome highlights the importance of gene duplication and repeated acquirement, which, coupled with their divergence, raises questions regarding the role of paralogs and potential functional redundancies in large-genome microbes.

  1. Symbiotic factors in Burkholderia essential for establishing an association with the bean bug, Riptortus pedestris.

    Science.gov (United States)

    Kim, Jiyeun Kate; Lee, Bok Luel

    2015-01-01

    Symbiotic bacteria are common in insects and intimately affect the various aspects of insect host biology. In a number of insect symbiosis models, it has been possible to elucidate the effects of the symbiont on host biology, whereas there is a limited understanding of the impact of the association on the bacterial symbiont, mainly due to the difficulty of cultivating insect symbionts in vitro. Furthermore, the molecular features that determine the establishment and persistence of the symbionts in their host (i.e., symbiotic factors) have remained elusive. However, the recently established model, the bean bug Riptortus pedestris, provides a good opportunity to study bacterial symbiotic factors at a molecular level through their cultivable symbionts. Bean bugs acquire genus Burkholderia cells from the environment and harbor them as gut symbionts in the specialized posterior midgut. The genome of the Burkholderia symbiont was sequenced, and the genomic information was used to generate genetically manipulated Burkholderia symbiont strains. Using mutant symbionts, we identified several novel symbiotic factors necessary for establishing a successful association with the host gut. In this review, these symbiotic factors are classified into three categories based on the colonization dynamics of the mutant symbiont strains: initiation, accommodation, and persistence factors. In addition, the molecular characteristics of the symbiotic factors are described. These newly identified symbiotic factors and on-going studies of the Riptortus-Burkholderia symbiosis are expected to contribute to the understanding of the molecular cross-talk between insects and bacterial symbionts that are of ecological and evolutionary importance. © 2014 Wiley Periodicals, Inc.

  2. The cep quorum-sensing system of Burkholderia cepacia H111 controls biofilm formation and swarming motility

    DEFF Research Database (Denmark)

    Huber, B.; Riedel, K.; Hentzer, Morten

    2001-01-01

    Burkholderia cepacia and Pseudomonas aeruginosa often co-exist as mixed biofilms in the lungs of patients suffering from cystic fibrosis (CF). Here, the isolation of random mini-Tn5 insertion mutants of B. cepacia H111 defective in biofilm formation on an abiotic surface is reported. It is demons......Burkholderia cepacia and Pseudomonas aeruginosa often co-exist as mixed biofilms in the lungs of patients suffering from cystic fibrosis (CF). Here, the isolation of random mini-Tn5 insertion mutants of B. cepacia H111 defective in biofilm formation on an abiotic surface is reported...

  3. Burkholderia glumae EN EL CULTIVO DE ARROZ EN COSTA RICA

    Directory of Open Access Journals (Sweden)

    Andrea Quesada-Gonz\\u00E1lez

    2014-01-01

    Full Text Available Burkholderia glumae en el cultivo de arroz en Costa Rica. El objetivo de este trabajo fue determinar la presencia de Burkholderia glumae en arroz en Costa Rica. La bacteria Burkholderia glumae está asociada al cultivo del arroz en el que provoca la enfermedad llamada añublo bacterial. Bajo condiciones ambientales favorables, la densidad bacteriana aumenta, lo que provoca que, bajo un sistema de regulación denominado quorum sensing, se expresen sus mecanismos de virulencia mediante la activación de genes responsables para la síntesis de la toxoflavina, que bloquea el flujo de nutrientes, para la biogénesis de flagelos y la respuesta quimiotáctica, y la producción de la enzima catalasa. Las plantas desarrollan la sintomatología que finalmente conlleva a un vaneamiento del grano provocando pérdidas económicas importantes. Se investigó la situación referente a la contaminación del grano de arroz causado por esta bacteria en Costa Rica durante los años 2009 y 2010, mediante un convenio entre la Corporación Nacional Arrocera y el Laboratorio de Fitopatología del Centro de Investigación en Protección de Cultivos de la Universidad de Costa Rica. Se usó la metodología de PCR de punto final recomendada por investigadores del Centro Internacional de Agricultura Tropical en Colombia y se reforzó la identificación, por medio de técnicas de microbiología convencional. Se obtuvieron resultados que indican la presencia de la bacteria en Costa Rica, la primera información sobre la prevalencia de un fitopatógeno bacteriano de gran importancia para el sector arrocero.

  4. Characterization of BcaA, a putative classical autotransporter protein in Burkholderia pseudomallei.

    Science.gov (United States)

    Campos, Cristine G; Borst, Luke; Cotter, Peggy A

    2013-04-01

    Burkholderia pseudomallei is a tier 1 select agent, and the causative agent of melioidosis, a disease with effects ranging from chronic abscesses to fulminant pneumonia and septic shock, which can be rapidly fatal. Autotransporters (ATs) are outer membrane proteins belonging to the type V secretion system family, and many have been shown to play crucial roles in pathogenesis. The open reading frame Bp1026b_II1054 (bcaA) in B. pseudomallei strain 1026b is predicted to encode a classical autotransporter protein with an approximately 80-kDa passenger domain that contains a subtilisin-related domain. Immediately 3' to bcaA is Bp11026_II1055 (bcaB), which encodes a putative prolyl 4-hydroxylase. To investigate the role of these genes in pathogenesis, large in-frame deletion mutations of bcaA and bcaB were constructed in strain Bp340, an efflux pump mutant derivative of the melioidosis clinical isolate 1026b. Comparison of Bp340ΔbcaA and Bp340ΔbcaB mutants to wild-type B. pseudomallei in vitro demonstrated similar levels of adherence to A549 lung epithelial cells, but the mutant strains were defective in their ability to invade these cells and to form plaques. In a BALB/c mouse model of intranasal infection, similar bacterial burdens were observed after 48 h in the lungs and liver of mice infected with Bp340ΔbcaA, Bp340ΔbcaB, and wild-type bacteria. However, significantly fewer bacteria were recovered from the spleen of Bp340ΔbcaA-infected mice, supporting the idea of a role for this AT in dissemination or in survival in the passage from the site of infection to the spleen.

  5. Antimicrobial Properties of an Oxidizer Produced by Burkholderia cenocepacia P525

    Science.gov (United States)

    A compound with both oxidizing properties and antibiotic properties was extracted and purified from broth cultures of Burkholderia cenocepacia strain P525. A four step purification procedure was used to increase its specific activity ~ 400 fold and to yield a HPLC- UV chromatogram containing a sing...

  6. Adaptation and Antibiotic Tolerance of Anaerobic Burkholderia pseudomallei ▿ †

    Science.gov (United States)

    Hamad, Mohamad A.; Austin, Chad R.; Stewart, Amanda L.; Higgins, Mike; Vázquez-Torres, Andrés; Voskuil, Martin I.

    2011-01-01

    The Gram-negative bacterium Burkholderia pseudomallei is the etiological agent of melioidosis and is remarkably resistant to most classes of antibacterials. Even after months of treatment with antibacterials that are relatively effective in vitro, there is a high rate of treatment failure, indicating that this pathogen alters its patterns of antibacterial susceptibility in response to cues encountered in the host. The pathology of melioidosis indicates that B. pseudomallei encounters host microenvironments that limit aerobic respiration, including the lack of oxygen found in abscesses and in the presence of nitric oxide produced by macrophages. We investigated whether B. pseudomallei could survive in a nonreplicating, oxygen-deprived state and determined if this physiological state was tolerant of conventional antibacterials. B. pseudomallei survived initial anaerobiosis, especially under moderately acidic conditions similar to those found in abscesses. Microarray expression profiling indicated a major shift in the physiological state of hypoxic B. pseudomallei, including induction of a variety of typical anaerobic-environment-responsive genes and genes that appear specific to anaerobic B. pseudomallei. Interestingly, anaerobic B. pseudomallei was unaffected by antibacterials typically used in therapy. However, it was exquisitely sensitive to drugs used against anaerobic pathogens. After several weeks of anaerobic culture, a significant loss of viability was observed. However, a stable subpopulation that maintained complete viability for at least 1 year was established. Thus, during the course of human infection, if a minor subpopulation of bacteria inhabited an oxygen-restricted environment, it might be indifferent to traditional therapy but susceptible to antibiotics frequently used to treat anaerobic infections. PMID:21537012

  7. Degradación de Fenantreno por bacterias del género Burkholderia y Rhizobium aisladas de nódulos de mimosas

    Directory of Open Access Journals (Sweden)

    Arnoldo Wong-Villarreal

    2017-01-01

    Full Text Available El presente trabajo tuvo como objetivo identificar y evaluar la capacidad de degradación de microorganismos aislados de nódulos de mimosas, que puedan ser utilizados en procesos de biorremediación de suelos contaminados con fenantreno . Método . Se realizó el aislamiento de 122 cepas bacterianas de nódulos de mimosas; fueron crecidas en el medio de cultivo Maconkey para descartar enterobacterias. L as cepas bacterianas que dieron resultado negativo a esta prueba, fueron inoculadas en el medio de cultivo que contenía como úni ca fuente de carbono fenantreno; tres aislados tuvieron la capacidad de crecer en este medio. Las tres cepas fueron identificadas por secuencia del gen 1 6s ribosomal, se evaluó su capacidad de crecimiento en presencia de fenantreno mediante curvas de crecimiento microbiano; la capacidad para degradar fenantreno de las tres cepas fue cuantificada por cromatografía de gases acoplado a masas. Resultados . La s secuencias obtenidas del gen 16s ribosomal tienen relación genética con las especies de Burkholderia phenoliruptrix , Burkholderia phymatum y Rhizobium paknamense. El crecimiento microbiano de las tres cepas, suministradas con fenantreno, tuvieron un comp ortamiento similar al control , el cual contenía succinato como fuente de carbono. La cepa de Burkholderia sp. BB26 degradó 78.5 % , Burkholderia sp. BB24 68.5 % y Rhizobium sp. BY8 99%. Discusión . Los resultados de degradación de fenantreno por las cepas de Burkholderia sp. BB26 , Burkholderia sp. BB24 y Rhizobium sp. BY8 sugieren que las tres cepas tienen p otencial para utilizarse en procesos de biorremediación de suelos contaminados con fenantreno.

  8. Complete genome sequence of Burkholderia sp. strain PAMC28687, a potential octopine-utilizing bacterium isolated from Antarctica lichen.

    Science.gov (United States)

    Han, So-Ra; Yu, Sang-Cheol; Ahn, Do-Hwan; Park, Hyun; Oh, Tae-Jin

    2016-05-20

    We report the complete genome sequence of Burkholderia sp. PAMC28687, which was isolated from the Antarctica lichen Useea sp., for better understanding of its catabolic traits in utilizing octopine as a source of carbon/nitrogen between Burkholderia and lichen. The genome consists of three circular chromosomes with five circular plasmids for the total 6,881,273bp sized genome with a G+C content of 58.14%. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Detection of Burkholderia pseudomallei O-antigen serotypes in near-neighbor species

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    Stone Joshua K

    2012-11-01

    Full Text Available Abstract Background Burkholderia pseudomallei is the etiological agent of melioidosis and a CDC category B select agent with no available effective vaccine. Previous immunizations in mice have utilized the lipopolysaccharide (LPS as a potential vaccine target because it is known as one of the most important antigenic epitopes in B. pseudomallei. Complicating this strategy are the four different B. pseudomallei LPS O-antigen types: A, B, B2, and rough. Sero-crossreactivity is common among O-antigens of Burkholderia species. Here, we identified the presence of multiple B. pseudomallei O-antigen types and sero-crossreactivity in its near-neighbor species. Results PCR screening of O-antigen biosynthesis genes, phenotypic characterization using SDS-PAGE, and immunoblot analysis showed that majority of B. mallei and B. thailandensis strains contained the typical O-antigen type A. In contrast, most of B. ubonensis and B. thailandensis-like strains expressed the atypical O-antigen types B and B2, respectively. Most B. oklahomensis strains expressed a distinct and non-seroreactive O-antigen type, except strain E0147 which expressed O-antigen type A. O-antigen type B2 was also detected in B. thailandensis 82172, B. ubonensis MSMB108, and Burkholderia sp. MSMB175. Interestingly, B. thailandensis-like MSMB43 contained a novel serotype B positive O-antigen. Conclusions This study expands the number of species which express B. pseudomallei O-antigen types. Further work is required to elucidate the full structures and how closely these are to the B. pseudomallei O-antigens, which will ultimately determine the efficacy of the near-neighbor B serotypes for vaccine development.

  10. Investigation into the susceptibility of Burkholderia cepacia complex isolates to photodynamic antimicrobial chemotherapy (PACT)

    Science.gov (United States)

    Cassidy, C. M.; Watters, A. L.; Donnelly, R. F.; Tunney, M. M.

    2009-06-01

    The main cause of morbidity and mortality in cystic fibrosis (CF) sufferers is progressive pulmonary damage caused by recurrent and often unremitting respiratory tract infection. Causative organisms include Pseudomonas aeruginosa and Haemophilus influenzae, but in recent years the Burkholderia cepacia complex has come to the fore. This group of highly drug-resistant Gram-negative bacteria are associated with a rapid decline in lung function and the often fatal cepacia syndrome, with treatment limited to patient segregation and marginally effective antibacterial regimens. Thus, development of an effective treatment is of the upmost importance. PACT, a non-target specific therapy, has proven successful in killing both Gram-positive and Gram-negative bacteria. In this study, planktonic cultures of six strains of the B. cepacia complex were irradiated (635 nm, 200 J cm-2,10 minutes irradiation) following 30 seconds incubation with methylene blue (MB) or meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate (TMP). Rates of kill of > 99 % were achieved with MB- and TMP-PACT. A MB concentration of 50 μg ml-1 and TMP concentration of 500 μg ml-1 were associated with highest percentage kills for each photosensitizer. PACT is an attractive option for treatment of B.cepacia complex infection. Further study, involving biofilm culture susceptibility, delivery of light to the target and in vivo testing will be necessary before it PACT becomes a viable treatment option for CF patients who are colonised or infected with B. cepacia complex.

  11. Genome-wide analysis reveals loci encoding anti-macrophage factors in the human pathogen Burkholderia pseudomallei K96243.

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    Andrea J Dowling

    2010-12-01

    Full Text Available Burkholderia pseudomallei is an important human pathogen whose infection biology is still poorly understood. The bacterium is endemic to tropical regions, including South East Asia and Northern Australia, where it causes melioidosis, a serious disease associated with both high mortality and antibiotic resistance. B. pseudomallei is a Gram-negative facultative intracellular pathogen that is able to replicate in macrophages. However despite the critical nature of its interaction with macrophages, few anti-macrophage factors have been characterized to date. Here we perform a genome-wide gain of function screen of B. pseudomallei strain K96243 to identify loci encoding factors with anti-macrophage activity. We identify a total of 113 such loci scattered across both chromosomes, with positive gene clusters encoding transporters and secretion systems, enzymes/toxins, secondary metabolite, biofilm, adhesion and signal response related factors. Further phenotypic analysis of four of these regions shows that the encoded factors cause striking cellular phenotypes relevant to infection biology, including apoptosis, formation of actin 'tails' and multi-nucleation within treated macrophages. The detailed analysis of the remaining host of loci will facilitate genetic dissection of the interaction of this important pathogen with host macrophages and thus further elucidate this critical part of its infection cycle.

  12. CpG oligodeoxyribonucleotides protect mice from Burkholderia pseudomallei but not Francisella tularensis Schu S4 aerosols.

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    Rozak, David A; Gelhaus, Herbert C; Smith, Mark; Zadeh, Mojgan; Huzella, Louis; Waag, David; Adamovicz, Jeffrey J

    2010-02-05

    Studies have shown that CpG oligodeoxyribonucleotides (ODN) protect mice from various bacterial pathogens, including Burkholderia pseudomallei and Francisella tularensis live vaccine strain (LVS), when administered before parenteral challenge. Given the potential to develop CpG ODN as a pre-treatment for multiple bacterial biological warfare agents, we examined survival, histopathology, and cytokine data from CpG ODN-treated C57BL/6 mice to determine whether previously-reported protection extended to aerosolized B. pseudomallei 1026b and highly virulent F. tularensis Schu S4 infections. We found that, although CpG ODN protected mice from aerosolized B. pseudomallei challenges, the immunostimulant failed to benefit the animals exposed to F. tularensis Schu S4 aerosols. Our results, which contrast with earlier F. tularensis LVS studies, highlight potential differences in Francisella species pathogenesis and underscore the need to evaluate immunotherapies against human pathogenic species.

  13. Aerogenic vaccination with a Burkholderia mallei auxotroph protects against aerosol-initiated glanders in mice.

    Science.gov (United States)

    Ulrich, Ricky L; Amemiya, Kei; Waag, David M; Roy, Chad J; DeShazer, David

    2005-03-14

    Burkholderia mallei is an obligate mammalian pathogen that causes the zoonotic disease glanders. Two live attenuated B. mallei strains, a capsule mutant and a branched-chain amino acid auxotroph, were evaluated for use as vaccines against aerosol-initiated glanders in mice. Animals were aerogenically vaccinated and serum samples were obtained before aerosol challenge with a high-dose (>300 times the LD50) of B. mallei ATCC 23344. Mice vaccinated with the capsule mutant developed a Th2-like Ig subclass antibody response and none survived beyond 5 days. In comparison, the auxotrophic mutant elicited a Th1-like Ig subclass antibody response and 25% of the animals survived for 1 month postchallenge. After a low-dose (5 times the LD50) aerosol challenge, the survival rates of auxotroph-vaccinated and unvaccinated animals were 50 and 0%, respectively. Thus, live attenuated strains that promote a Th1-like Ig response may serve as promising vaccine candidates against aerosol infection with B. mallei.

  14. Brucella infection inhibits macrophages apoptosis via Nedd4-dependent degradation of calpain2.

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    Cui, Guimei; Wei, Pan; Zhao, Yuxi; Guan, Zhenhong; Yang, Li; Sun, Wanchun; Wang, Shuangxi; Peng, Qisheng

    2014-11-07

    The calcium-dependent protease calpain2 is involved in macrophages apoptosis. Brucella infection-induced up-regulation of intracellular calcium level is an essential factor for the intracellular survival of Brucella within macrophages. Here, we hypothesize that calcium-dependent E3 ubiquitin ligase Nedd4 ubiquitinates calpain2 and inhibits Brucella infection-induced macrophage apoptosis via degradation of calpain2.Our results reveal that Brucella infection induces increases in Nedd4 activity in an intracellular calcium dependent manner. Furthermore, Brucella infection-induced degradation of calpain2 is mediated by Nedd4 ubiquitination of calpain2. Brucella infection-induced calpain2 degradation inhibited macrophages apoptosis. Treatment of Brucella infected macrophages with calcium chelator BAPTA or Nedd4 knock-down decreased Nedd4 activity, prevented calpain2 degradation, and resulted in macrophages apoptosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Burkholderia dipogonis sp. nov., isolated from root nodules of Dipogon lignosus in New Zealand and Western Australia.

    Science.gov (United States)

    Sheu, Shih-Yi; Chen, Ming-Hui; Liu, Wendy Y Y; Andrews, Mitchell; James, Euan K; Ardley, Julie K; De Meyer, Sofie E; James, Trevor K; Howieson, John G; Coutinho, Bruna G; Chen, Wen-Ming

    2015-12-01

    Seven strains, ICMP 19430T, ICMP 19429, ICMP 19431, WSM4637, WSM4638, WSM4639 and WSM4640, were isolated from nitrogen-fixing nodules on roots of the invasive South African legume Dipogon lignosus (subfamily Papilionoideae, tribe Phaseoleae) in New Zealand and Western Australia, and their taxonomic positions were investigated by using a polyphasic approach. All seven strains grew at 10-37 °C (optimum, 25-30 °C), at pH 4.0-9.0 (optimum, pH 6.0-7.0) and with 0-2 % (w/v) NaCl (optimum growth in the absence of NaCl). On the basis of 16S rRNA gene sequence analysis, the strains showed 99.0-99.5 % sequence similarity to the closest type strain, Burkholderia phytofirmans PsJNT, and 98.4-99.7 % sequence similarity to Burkholderia caledonica LMG 19076T. The predominant fatty acids were C18 : 1ω7c (21.0 % of the total fatty acids in strain ICMP 19430T), C16 : 0 (19.1 %), C17 : 0 cyclo (18.9 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 10.7 %) and C19 : 0 cyclov ω8c (7.5 %). The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several uncharacterized aminophospholipids and phospholipids. The major isoprenoid quinone was Q-8 and the DNA G+C content of strain ICMP 19430T was 63.2 mol%. The DNA–DNA relatedness of the novel strains with respect to the closest neighbouring members of the genus Burkholderia was 55 % or less. On the basis of 16S rRNA and recA gene sequence similarities and chemotaxonomic and phenotypic data,these strains represent a novel symbiotic species in the genus Burkholderia, for which the name Burkholderia dipogonis sp. nov. is proposed, with the type strain ICMP 19430T (=LMG28415T=HAMBI 3637T).

  16. Rapid DNA vaccination against Burkholderia pseudomallei flagellin by tattoo or intranasal application

    NARCIS (Netherlands)

    Lankelma, Jacqueline M.; Wagemakers, Alex; Birnie, Emma; Haak, Bastiaan W.; Trentelman, Jos J. A.; Weehuizen, Tassili A. F.; Ersöz, Jasmin; Roelofs, Joris J. T. H.; Hovius, Joppe W.; Wiersinga, W. Joost; Bins, Adriaan D.

    2017-01-01

    Melioidosis is a severe infectious disease with a high mortality that is endemic in South-East Asia and Northern Australia. The causative pathogen, Burkholderia pseudomallei, is listed as potential bioterror weapon due to its high virulence and potential for easy dissemination. Currently, there is

  17. Characterization of the Burkholderia thailandensis SOS response by using whole-transcriptome shotgun sequencing.

    Science.gov (United States)

    Ulrich, Ricky L; Deshazer, David; Kenny, Tara A; Ulrich, Melanie P; Moravusova, Anna; Opperman, Timothy; Bavari, Sina; Bowlin, Terry L; Moir, Donald T; Panchal, Rekha G

    2013-10-01

    The bacterial SOS response is a well-characterized regulatory network encoded by most prokaryotic bacterial species and is involved in DNA repair. In addition to nucleic acid repair, the SOS response is involved in pathogenicity, stress-induced mutagenesis, and the emergence and dissemination of antibiotic resistance. Using high-throughput sequencing technology (SOLiD RNA-Seq), we analyzed the Burkholderia thailandensis global SOS response to the fluoroquinolone antibiotic, ciprofloxacin (CIP), and the DNA-damaging chemical, mitomycin C (MMC). We demonstrate that a B. thailandensis recA mutant (RU0643) is ∼4-fold more sensitive to CIP in contrast to the parental strain B. thailandensis DW503. Our RNA-Seq results show that CIP and MMC treatment (P SOS response were induced and include lexA, uvrA, dnaE, dinB, recX, and recA. At the genome-wide level, we found an overall decrease in gene expression, especially for genes involved in amino acid and carbohydrate transport and metabolism, following both CIP and MMC exposure. Interestingly, we observed the upregulation of several genes involved in bacterial motility and enhanced transcription of a B. thailandensis genomic island encoding a Siphoviridae bacteriophage designated E264. Using B. thailandensis plaque assays and PCR with B. mallei ATCC 23344 as the host, we demonstrate that CIP and MMC exposure in B. thailandensis DW503 induces the transcription and translation of viable bacteriophage in a RecA-dependent manner. This is the first report of the SOS response in Burkholderia spp. to DNA-damaging agents. We have identified both common and unique adaptive responses of B. thailandensis to chemical stress and DNA damage.

  18. The lipopolysaccharide core oligosaccharide of Burkholderia plays a critical role in maintaining a proper gut symbiosis with the bean bug Riptortus pedestris.

    Science.gov (United States)

    Kim, Jiyeun Kate; Jang, Ho Am; Kim, Min Seon; Cho, Jae Hyun; Lee, Junbeom; Di Lorenzo, Flaviana; Sturiale, Luisa; Silipo, Alba; Molinaro, Antonio; Lee, Bok Luel

    2017-11-24

    Lipopolysaccharide, the outer cell-wall component of Gram-negative bacteria, has been shown to be important for symbiotic associations. We recently reported that the lipopolysaccharide O-antigen of Burkholderia enhances the initial colonization of the midgut of the bean bug, Riptortus pedestris However, the midgut-colonizing Burkholderia symbionts lack the O-antigen but display the core oligosaccharide on the cell surface. In this study, we investigated the role of the core oligosaccharide, which directly interacts with the host midgut, in the Riptortus-Burkholderia symbiosis. To this end, we generated the core oligosaccharide mutant strains, Δ wabS , Δ wabO , Δ waaF, and Δ waaC, and determined the chemical structures of their oligosaccharides, which exhibited different compositions. The symbiotic properties of these mutant strains were compared with those of the wild-type and O-antigen-deficient Δ wbiG strains. Upon introduction into Riptortus via the oral route, the core oligosaccharide mutant strains exhibited different rates of colonization of the insect midgut. The symbiont titers in fifth-instar insects revealed significantly reduced population sizes of the inner core oligosaccharide mutant strains Δ waaF and Δ waaC These two strains also negatively affected host growth rate and fitness. Furthermore, R. pedestris individuals colonized with the Δ waaF and Δ waaC strains were vulnerable to septic bacterial challenge, similar to insects without a Burkholderia symbiont. Taken together, these results suggest that the core oligosaccharide from Burkholderia symbionts plays a critical role in maintaining a proper symbiont population and in supporting the beneficial effects of the symbiont on its host in the Riptortus-Burkholderia symbiosis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Characterization of the papilionoid-Burkholderia interaction in the Fynbos biome: The diversity and distribution of beta-rhizobia nodulating Podalyria calyptrata (Fabaceae, Podalyrieae).

    Science.gov (United States)

    Lemaire, Benny; Van Cauwenberghe, Jannick; Verstraete, Brecht; Chimphango, Samson; Stirton, Charles; Honnay, Olivier; Smets, Erik; Sprent, Janet; James, Euan K; Muasya, A Muthama

    2016-02-01

    The South African Fynbos soils are renowned for nitrogen-fixing Burkholderia associated with diverse papilionoid legumes of the tribes Crotalarieae, Hypocalypteae, Indigofereae, Phaseoleae and Podalyrieae. However, despite numerous rhizobial studies in the region, the symbiotic diversity of Burkholderia has not been investigated in relation to a specific host legume and its geographical provenance. This study analyzed the diversity of nodulating strains of Burkholderia from the legume species Podalyria calyptrata. Diverse lineages were detected that proved to be closely related to Burkholderia taxa, originating from hosts in other legume tribes. By analyzing the genetic variation of chromosomal (recA) and nodulation (nodA) sequence data in relation to the sampling sites we assessed the geographical distribution patterns of the P. calyptrata symbionts. Although we found a degree of genetically differentiated rhizobial populations, a correlation between genetic (recA and nodA) and geographic distances among populations was not observed, suggesting high rates of dispersal and rhizobial colonization within Fynbos soils. Copyright © 2015 Elsevier GmbH. All rights reserved.

  20. PCR detection of Burkholderia multivorans in water and soil samples.

    Science.gov (United States)

    Peeters, Charlotte; Daenekindt, Stijn; Vandamme, Peter

    2016-08-12

    Although semi-selective growth media have been developed for the isolation of Burkholderia cepacia complex bacteria from the environment, thus far Burkholderia multivorans has rarely been isolated from such samples. Because environmental B. multivorans isolates mainly originate from water samples, we hypothesized that water rather than soil is its most likely environmental niche. The aim of the present study was to assess the occurrence of B. multivorans in water samples from Flanders (Belgium) using a fast, culture-independent PCR assay. A nested PCR approach was used to achieve high sensitivity, and specificity was confirmed by sequencing the resulting amplicons. B. multivorans was detected in 11 % of the water samples (n = 112) and 92 % of the soil samples (n = 25) tested. The percentage of false positives was higher for water samples compared to soil samples, showing that the presently available B. multivorans recA primers lack specificity when applied to the analysis of water samples. The results of the present study demonstrate that B. multivorans DNA is commonly present in soil samples and to a lesser extent in water samples in Flanders (Belgium).

  1. An efficient system for the generation of marked genetic mutants in members of the genus Burkholderia.

    Science.gov (United States)

    Shastri, Sravanthi; Spiewak, Helena L; Sofoluwe, Aderonke; Eidsvaag, Vigdis A; Asghar, Atif H; Pereira, Tyrone; Bull, Edward H; Butt, Aaron T; Thomas, Mark S

    2017-01-01

    To elucidate the function of a gene in bacteria it is vital that targeted gene inactivation (allelic replacement) can be achieved. Allelic replacement is often carried out by disruption of the gene of interest by insertion of an antibiotic-resistance marker followed by subsequent transfer of the mutant allele to the genome of the host organism in place of the wild-type gene. However, due to their intrinsic resistance to many antibiotics only selected antibiotic-resistance markers can be used in members of the genus Burkholderia, including the Burkholderia cepacia complex (Bcc). Here we describe the construction of improved antibiotic-resistance cassettes that specify resistance to kanamycin, chloramphenicol or trimethoprim effectively in the Bcc and related species. These were then used in combination with and/or to construct a series enhanced suicide vectors, pSHAFT2, pSHAFT3 and pSHAFT-GFP to facilitate effective allelic replacement in the Bcc. Validation of these improved suicide vectors was demonstrated by the genetic inactivation of selected genes in the Bcc species Burkholderia cenocepacia and B. lata, and in the non-Bcc species, B. thailandensis. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  2. A potent human neutralizing antibody Fc-dependently reduces established HBV infections.

    Science.gov (United States)

    Li, Dan; He, Wenhui; Liu, Ximing; Zheng, Sanduo; Qi, Yonghe; Li, Huiyu; Mao, Fengfeng; Liu, Juan; Sun, Yinyan; Pan, Lijing; Du, Kaixin; Ye, Keqiong; Li, Wenhui; Sui, Jianhua

    2017-09-26

    Hepatitis B virus (HBV) infection is a major global health problem. Currently-available therapies are ineffective in curing chronic HBV infection. HBV and its satellite hepatitis D virus (HDV) infect hepatocytes via binding of the preS1 domain of its large envelope protein to sodium taurocholate cotransporting polypeptide (NTCP). Here, we developed novel human monoclonal antibodies that block the engagement of preS1 with NTCP and neutralize HBV and HDV with high potency. One antibody, 2H5-A14, functions at picomolar level and exhibited neutralization-activity-mediated prophylactic effects. It also acts therapeutically by eliciting antibody-Fc-dependent immunological effector functions that impose durable suppression of viral infection in HBV-infected mice, resulting in reductions in the levels of the small envelope antigen and viral DNA, with no emergence of escape mutants. Our results illustrate a novel antibody-Fc-dependent approach for HBV treatment and suggest 2H5-A14 as a novel clinical candidate for HBV prevention and treatment of chronic HBV infection.

  3. The relationship of biofilm production to biocontrol activity of Burkholderia pyrrocinia FP62

    Science.gov (United States)

    Foliar biocontrol agent (BCA) efficacy is often inconsistent due to poor colonization and survival on plant surfaces. Burkholderia pyrrocinia FP62, a superior leaf colonist and BCA of Botrytis cinerea, forms unsaturated biofilms on plant surfaces. To determine the relationship between biocontrol act...

  4. NOVEL ORGANIZATION OF THE GENES FOR PHTHALATE DEGRADATION FROM BURKHOLDERIA CEPACIA DBO1

    Science.gov (United States)

    Burkholderia cepacia DBO1 is able to utilize phthalate as the sole source of carbon and energy for growth. Two overlapping cosmid clones containing the genes for phthalate degradation were isolated from this strain. Subcloning and activity analysis localized the genes for phthala...

  5. Molecular method to assess the diversity of Burkholderia species in environmental samples

    NARCIS (Netherlands)

    Salles, J.; Souza, de F.A.; Elsas, van J.D.

    2002-01-01

    In spite of the importance of many members of the genus Burkholderia in the soil microbial community, no direct method to assess the diversity of this genus has been developed so far. The aim of this work was the development of soil DNA-based PCR-denaturing gradient gel electrophoresis (DGGE), a

  6. Molecular method to assess the diversity of Burkholderia species in environmental samples

    NARCIS (Netherlands)

    Salles, Joanna; De Souza, F.A.; Van Elsas, J.D.

    2002-01-01

    In spite of the importance of many members of the genus Burkholderia in the soil microbial community, no direct method to assess the diversity of this genus has been developed so far. The aim of this work was the development of soil DNA-based PCR-denaturing gradient get electrophoresis (DGGE), a

  7. Adaptive Significance of Quorum Sensing-Dependent Regulation of Rhamnolipids by Integration of Growth Rate in Burkholderia glumae: A Trade-Off between Survival and Efficiency.

    Science.gov (United States)

    Nickzad, Arvin; Déziel, Eric

    2016-01-01

    Quorum sensing (QS) is a cell density-dependent mechanism which enables a population of bacteria to coordinate cooperative behaviors in response to the accumulation of self-produced autoinducer signals in their local environment. An emerging framework is that the adaptive significance of QS in the regulation of production of costly extracellular metabolites ("public goods") is to maintain the homeostasis of cooperation. We investigated this model using the phytopathogenic bacterium Burkholderia glumae, which we have previously demonstrated uses QS to regulate the production of rhamnolipids, extracellular surface-active glycolipids promoting the social behavior called "swarming motility." Using mass spectrometric quantification and chromosomal lux-based gene expression, we made the unexpected finding that when unrestricted nutrient resources are provided, production of rhamnolipids is carried out completely independently of QS regulation. This is a unique observation among known QS-controlled factors in bacteria. On the other hand, under nutrient-limited conditions, QS then becomes the main regulating mechanism, significantly enhancing the specific rhamnolipids yield. Accordingly, decreasing nutrient concentrations amplifies rhamnolipid biosynthesis gene expression, revealing a system where QS-dependent regulation is specifically triggered by the growth rate of the population, rather than by its cell density. Furthermore, a gradual increase in QS signal specific concentration upon decrease of specific growth rate suggests a reduction in quorum threshold, which reflects an increase in cellular demand for production of QS-dependent target gene product at low density populations. Integration of growth rate with QS as a decision-making mechanism for biosynthesis of costly metabolites, such as rhamnolipids, could serve to assess the demand and timing for expanding the carrying capacity of a population through spatial expansion mechanisms, such as swarming motility, thus

  8. Investigating the Role of the Host Multidrug Resistance Associated Protein Transporter Family in Burkholderia cepacia Complex Pathogenicity Using a Caenorhabditis elegans Infection Model.

    Science.gov (United States)

    Tedesco, Pietro; Visone, Marco; Parrilli, Ermenegilda; Tutino, Maria Luisa; Perrin, Elena; Maida, Isabel; Fani, Renato; Ballestriero, Francesco; Santos, Radleigh; Pinilla, Clemencia; Di Schiavi, Elia; Tegos, George; de Pascale, Donatella

    2015-01-01

    This study investigated the relationship between host efflux system of the non-vertebrate nematode Caenorhabditis elegans and Burkholderia cepacia complex (Bcc) strain virulence. This is the first comprehensive effort to profile host-transporters within the context of Bcc infection. With this aim, two different toxicity tests were performed: a slow killing assay that monitors mortality of the host by intestinal colonization and a fast killing assay that assesses production of toxins. A Virulence Ranking scheme was defined, that expressed the toxicity of the Bcc panel members, based on the percentage of surviving worms. According to this ranking the 18 Bcc strains were divided in 4 distinct groups. Only the Cystic Fibrosis isolated strains possessed profound nematode killing ability to accumulate in worms' intestines. For the transporter analysis a complete set of isogenic nematode single Multidrug Resistance associated Protein (MRP) efflux mutants and a number of efflux inhibitors were interrogated in the host toxicity assays. The Bcc pathogenicity profile of the 7 isogenic C. elegans MRP knock-out strains functionality was classified in two distinct groups. Disabling host transporters enhanced nematode mortality more than 50% in 5 out of 7 mutants when compared to wild type. In particular mrp-2 was the most susceptible phenotype with increased mortality for 13 out 18 Bcc strains, whereas mrp-3 and mrp-4 knock-outs had lower mortality rates, suggesting a different role in toxin-substrate recognition. The use of MRP efflux inhibitors in the assays resulted in substantially increased (>40% on average) mortality of wild-type worms.

  9. Identification of Burkholderia mallei and Burkholderia pseudomallei adhesins for human respiratory epithelial cells

    Directory of Open Access Journals (Sweden)

    Hogan Robert J

    2010-09-01

    Full Text Available Abstract Background Burkholderia pseudomallei and Burkholderia mallei cause the diseases melioidosis and glanders, respectively. A well-studied aspect of pathogenesis by these closely-related bacteria is their ability to invade and multiply within eukaryotic cells. In contrast, the means by which B. pseudomallei and B. mallei adhere to cells are poorly defined. The purpose of this study was to identify adherence factors expressed by these organisms. Results Comparative sequence analyses identified a gene product in the published genome of B. mallei strain ATCC23344 (locus # BMAA0649 that resembles the well-characterized Yersinia enterocolitica autotransporter adhesin YadA. The gene encoding this B. mallei protein, designated boaA, was expressed in Escherichia coli and shown to significantly increase adherence to human epithelial cell lines, specifically HEp2 (laryngeal cells and A549 (type II pneumocytes, as well as to cultures of normal human bronchial epithelium (NHBE. Consistent with these findings, disruption of the boaA gene in B. mallei ATCC23344 reduced adherence to all three cell types by ~50%. The genomes of the B. pseudomallei strains K96243 and DD503 were also found to contain boaA and inactivation of the gene in DD503 considerably decreased binding to monolayers of HEp2 and A549 cells and to NHBE cultures. A second YadA-like gene product highly similar to BoaA (65% identity was identified in the published genomic sequence of B. pseudomallei strain K96243 (locus # BPSL1705. The gene specifying this protein, termed boaB, appears to be B. pseudomallei-specific. Quantitative attachment assays demonstrated that recombinant E. coli expressing BoaB displayed greater binding to A549 pneumocytes, HEp2 cells and NHBE cultures. Moreover, a boaB mutant of B. pseudomallei DD503 showed decreased adherence to these respiratory cells. Additionally, a B. pseudomallei strain lacking expression of both boaA and boaB was impaired in its ability to

  10. Burkholderia metalliresistens sp. nov., a multiple metal-resistant and phosphate-solubilising species isolated from heavy metal-polluted soil in Southeast China.

    Science.gov (United States)

    Guo, Jun Kang; Ding, Yong Zhen; Feng, Ren Wei; Wang, Rui Gang; Xu, Ying Ming; Chen, Chun; Wei, Xiu Li; Chen, Wei Min

    2015-06-01

    A metal-resistant and phosphate-solubilising bacterium, designated as strain D414(T), was isolated from heavy metal (Pb, Cd, Cu and Zn)-polluted paddy soils at the surrounding area of Dabao Mountain Mine in Southeast China. The minimum inhibitory concentrations of heavy metals for strain D414(T) were 2000 mg L(-1) (Cd), 800 mg L(-1) (Pb), 150 mg L(-1) (Cu) and 2500 mg L(-1) (Zn). The strain possessed plant growth-promoting properties, such as 1-aminocyclopropane-1-carboxylate assimilation, indole production and phosphate solubilisation. Analysis of 16S rRNA gene sequence indicated that the isolate is a member of the genus Burkholderia where strain D414(T) formed a distinct phyletic line with validly described Burkholderia species. Strain D414(T) is closely related to Burkholderia tropica DSM 15359(T), B. bannensis NBRC E25(T) and B. unamae DSM 17197(T), with 98.5, 98.3 and 98.3 % sequence similarities, respectively. Furthermore, less than 34 % DNA-DNA relatedness was detected between strain D414(T) and the type strains of the phylogenetically closest species of Burkholderia. The dominant fatty acids of strain D414(T) were C14:0, C16:0, C17:0 cyclo and C18:1 ω7c. The DNA G+C content was 62.3 ± 0.5 mol%. On the basis of genotypic, phenotypic and phylogenetic data, strain D414(T) represents a novel species, for which the name Burkholderia metalliresistens sp. nov. is proposed, with D414(T) (=CICC 10561(T) = DSM 26823(T)) as the type strain.

  11. Cell-bound lipases from Burkholderia sp. ZYB002: gene sequence analysis, expression, enzymatic characterization, and 3D structural model.

    Science.gov (United States)

    Shu, Zhengyu; Lin, Hong; Shi, Shaolei; Mu, Xiangduo; Liu, Yanru; Huang, Jianzhong

    2016-05-03

    The whole-cell lipase from Burkholderia cepacia has been used as a biocatalyst in organic synthesis. However, there is no report in the literature on the component or the gene sequence of the cell-bound lipase from this species. Qualitative analysis of the cell-bound lipase would help to illuminate the regulation mechanism of gene expression and further improve the yield of the cell-bound lipase by gene engineering. Three predictive cell-bound lipases, lipA, lipC21 and lipC24, from Burkholderia sp. ZYB002 were cloned and expressed in E. coli. Both LipA and LipC24 displayed the lipase activity. LipC24 was a novel mesophilic enzyme and displayed preference for medium-chain-length acyl groups (C10-C14). The 3D structural model of LipC24 revealed the open Y-type active site. LipA displayed 96 % amino acid sequence identity with the known extracellular lipase. lipA-inactivation and lipC24-inactivation decreased the total cell-bound lipase activity of Burkholderia sp. ZYB002 by 42 % and 14 %, respectively. The cell-bound lipase activity from Burkholderia sp. ZYB002 originated from a multi-enzyme mixture with LipA as the main component. LipC24 was a novel lipase and displayed different enzymatic characteristics and structural model with LipA. Besides LipA and LipC24, other type of the cell-bound lipases (or esterases) should exist.

  12. Context-dependent medicinal effects of anabasine and infection-dependent toxicity in bumble bees.

    Directory of Open Access Journals (Sweden)

    Evan C Palmer-Young

    Full Text Available Floral phytochemicals are ubiquitous in nature, and can function both as antimicrobials and as insecticides. Although many phytochemicals act as toxins and deterrents to consumers, the same chemicals may counteract disease and be preferred by infected individuals. The roles of nectar and pollen phytochemicals in pollinator ecology and conservation are complex, with evidence for both toxicity and medicinal effects against parasites. However, it remains unclear how consistent the effects of phytochemicals are across different parasite lineages and environmental conditions, and whether pollinators actively self-medicate with these compounds when infected.Here, we test effects of the nectar alkaloid anabasine, found in Nicotiana, on infection intensity, dietary preference, and survival and performance of bumble bees (Bombus impatiens. We examined variation in the effects of anabasine on infection with different lineages of the intestinal parasite Crithidia under pollen-fed and pollen-starved conditions.We found that anabasine did not reduce infection intensity in individual bees infected with any of four Crithidia lineages that were tested in parallel, nor did anabasine reduce infection intensity in microcolonies of queenless workers. In addition, neither anabasine nor its isomer, nicotine, was preferred by infected bees in choice experiments, and infected bees consumed less anabasine than did uninfected bees under no-choice conditions. Furthermore, anabasine exacerbated the negative effects of infection on bee survival and microcolony performance. Anabasine reduced infection in only one experiment, in which bees were deprived of pollen and post-pupal contact with nestmates. In this experiment, anabasine had antiparasitic effects in bees from only two of four colonies, and infected bees exhibited reduced-rather than increased-phytochemical consumption relative to uninfected bees.Variation in the effect of anabasine on infection suggests potential

  13. Context-dependent medicinal effects of anabasine and infection-dependent toxicity in bumble bees.

    Science.gov (United States)

    Palmer-Young, Evan C; Hogeboom, Alison; Kaye, Alexander J; Donnelly, Dash; Andicoechea, Jonathan; Connon, Sara June; Weston, Ian; Skyrm, Kimberly; Irwin, Rebecca E; Adler, Lynn S

    2017-01-01

    Floral phytochemicals are ubiquitous in nature, and can function both as antimicrobials and as insecticides. Although many phytochemicals act as toxins and deterrents to consumers, the same chemicals may counteract disease and be preferred by infected individuals. The roles of nectar and pollen phytochemicals in pollinator ecology and conservation are complex, with evidence for both toxicity and medicinal effects against parasites. However, it remains unclear how consistent the effects of phytochemicals are across different parasite lineages and environmental conditions, and whether pollinators actively self-medicate with these compounds when infected. Here, we test effects of the nectar alkaloid anabasine, found in Nicotiana, on infection intensity, dietary preference, and survival and performance of bumble bees (Bombus impatiens). We examined variation in the effects of anabasine on infection with different lineages of the intestinal parasite Crithidia under pollen-fed and pollen-starved conditions. We found that anabasine did not reduce infection intensity in individual bees infected with any of four Crithidia lineages that were tested in parallel, nor did anabasine reduce infection intensity in microcolonies of queenless workers. In addition, neither anabasine nor its isomer, nicotine, was preferred by infected bees in choice experiments, and infected bees consumed less anabasine than did uninfected bees under no-choice conditions. Furthermore, anabasine exacerbated the negative effects of infection on bee survival and microcolony performance. Anabasine reduced infection in only one experiment, in which bees were deprived of pollen and post-pupal contact with nestmates. In this experiment, anabasine had antiparasitic effects in bees from only two of four colonies, and infected bees exhibited reduced-rather than increased-phytochemical consumption relative to uninfected bees. Variation in the effect of anabasine on infection suggests potential modulation of

  14. Study of the mode of action of a polygalacturonase from the phytopathogen Burkholderia cepacia

    DEFF Research Database (Denmark)

    Massa, C.; Clausen, Mads Hartvig; Stojan, J.

    2007-01-01

    We have recently isolated and heterologously expressed BcPeh28A, an endopolygalacturonase from the phytopathogenic Gram-negative bacterium Burkholderia cepacia. Endopolygalacturonases belong to glycoside hydrolase family 28 and are responsible for the hydrolysis of the non-esterified regions...

  15. Chronic suppurative joint effusion due to burkholderia pseudomallei: A case report

    Directory of Open Access Journals (Sweden)

    Madhavi Deshmukh

    2013-01-01

    Full Text Available Burkholderia pseudomallei, a Gram-negative bacillus is the causative agent of Melioidosis, a glanders-like disease, primarily a disease of animals. Melioidosis has been only a rare and sporadic disease in humans outside its endemic region. Currently, diagnosis of B. pseudomallei in the clinical laboratory is very difficult, owing to low awareness of physicians to the nonspecific clinical manifestations, lack of responsiveness among microbiologists outside endemic areas, identification systems in the average sentinel laboratory, and the biosafety conditions necessary to process these organisms. We report a case of chronic left hip joint effusion in a known case of diabetes mellitus. Gram stain of computed tomography (CT-guided aspirate from the joint revealed Gram-negative bacilli along with pus cells. Culture was confirmed as Burkholderia pseudomallei on Vitek2C, which was sensitive to ceftazidime and trimethoprim/sulfmethoxazole. Unfortunately, patient could not be started on appropriate antibiotics due to delay in detection and patient succumbed to severe septicemia. This case is reported to highlight importance of automated identification and sensitivity especially in nonendemic areas and unusual antibiogram of this organism for which disc diffusion method is not standardized.

  16. More than skin deep: moisturizing body milk and Burkholderia cepacia.

    Science.gov (United States)

    Irwin, Amy E; Price, Connie Savor

    2008-01-01

    Alvarez-Lerma and colleagues observed over an 18-day period that five critically ill patients admitted to a multidisciplinary 18-bed intensive care unit contracted Burkholderia cepacia from unopened containers of moisturizing body milk, calling into question the use in critical care settings of cosmetic products that do not guarantee sterilization during the manufacturing process. Is this the answer to the problem, however, or should the use of lotions in such settings be re-examined?

  17. More than skin deep: moisturizing body milk and Burkholderia cepacia

    OpenAIRE

    Irwin, Amy E; Price, Connie Savor

    2008-01-01

    Alvarez-Lerma and colleagues observed over an 18-day period that five critically ill patients admitted to a multidisciplinary 18-bed intensive care unit contracted Burkholderia cepacia from unopened containers of moisturizing body milk, calling into question the use in critical care settings of cosmetic products that do not guarantee sterilization during the manufacturing process. Is this the answer to the problem, however, or should the use of lotions in such settings be re-examined?

  18. Global Analysis of the Burkholderia thailandensis Quorum Sensing-Controlled Regulon

    OpenAIRE

    Majerczyk, Charlotte; Brittnacher, Mitchell; Jacobs, Michael; Armour, Christopher D.; Radey, Mathew; Schneider, Emily; Phattarasokul, Somsak; Bunt, Richard; Greenberg, E. Peter

    2014-01-01

    Burkholderia thailandensis contains three acyl-homoserine lactone quorum sensing circuits and has two additional LuxR homologs. To identify B. thailandensis quorum sensing-controlled genes, we carried out transcriptome sequencing (RNA-seq) analyses of quorum sensing mutants and their parent. The analyses were grounded in the fact that we identified genes coding for factors shown previously to be regulated by quorum sensing among a larger set of quorum-controlled genes. We also found that gene...

  19. Identification of putative noncoding RNA genes in the Burkholderia cenocepacia J2315 genome

    DEFF Research Database (Denmark)

    Coenye, T.; Drevinek, P.; Mahenthiralingam, E.

    2007-01-01

    Noncoding RNA (ncRNA) genes are not involved in the production of mRNA and proteins, but produce transcripts that function directly as structural or regulatory RNAs. In the present study, the presence of ncRNA genes in the genome of Burkholderia cenocepacia J2315 was evaluated by combining...

  20. N-acylhomoserine-lactone-mediated communication between Pseudomonas aeruginosa and Burkholderia cepacia in mixed biofilms

    DEFF Research Database (Denmark)

    Riedel, K.; Hentzer, Morten; Geisenberger, O.

    2001-01-01

    Pseudomonas aeruginosa and Burkholderia cepacia are capable of forming mixed biofilms in the lungs of cystic fibrosis patients. Both bacteria employ quorum-sensing systems, which rely on N-acylhomoserine lactone (AHL) signal molecules, to co- ordinate expression of virulence factors with the form...

  1. Genotyping of Burkholderia mallei from an outbreak of glanders in Bahrain suggests multiple introduction events.

    Directory of Open Access Journals (Sweden)

    Holger C Scholz

    2014-09-01

    Full Text Available Glanders, caused by the gram-negative bacterium Burkholderia mallei, is a highly infectious zoonotic disease of solipeds causing severe disease in animals and men. Although eradicated from many Western countries, it recently emerged in Asia, the Middle-East, Africa, and South America. Due to its rareness, little is known about outbreak dynamics of the disease and its epidemiology.We investigated a recent outbreak of glanders in Bahrain by applying high resolution genotyping (multiple locus variable number of tandem repeats, MLVA and comparative whole genome sequencing to B. mallei isolated from infected horses and a camel. These results were compared to samples obtained from an outbreak in the United Arab Emirates in 2004, and further placed into a broader phylogeographic context based on previously published B. mallei data. The samples from the outbreak in Bahrain separated into two distinct clusters, suggesting a complex epidemiological background and evidence for the involvement of multiple B. mallei strains. Additionally, the samples from Bahrain were more closely related to B. mallei isolated from horses in the United Arab Emirates in 2004 than other B. mallei which is suggestive of repeated importation to the region from similar geographic sources.High-resolution genotyping and comparative whole genome analysis revealed the same phylogenetic patterns among our samples. The close relationship of the Dubai/UAE B. mallei populations to each other may be indicative of a similar geographic origin that has yet to be identified for the infecting strains. The recent emergence of glanders in combination with worldwide horse trading might pose a new risk for human infections.

  2. Extensive cultivation of soil and water samples yields various pathogens in patients with cystic fibrosis but not Burkholderia multivorans.

    Science.gov (United States)

    Peeters, Charlotte; Depoorter, Eliza; Praet, Jessy; Vandamme, Peter

    2016-11-01

    While the epidemiology of Burkholderia cepacia complex (Bcc) bacteria in cystic fibrosis (CF) patients suggests that Burkholderia multivorans is acquired from environmental sources, this species has rarely been isolated from soil and water samples. Multiple isolation strategies were applied to water and soil samples that were previously shown to be B. multivorans PCR positive. These included direct plating and liquid enrichment procedures and the use of selective media, acclimatizing recovery and co-cultivation with CF sputum. MALDI-TOF mass spectrometry and sequence analysis of 16S rRNA and housekeeping genes were used to identify all isolates. None of the approaches yielded B. multivorans isolates. Other Burkholderia species, several Gram-negative non-fermenting bacteria (including Cupriavidus, Inquilinus, Pandoraea, Pseudomonas and Stenotrophomonas) and rapidly growing mycobacteria (including Mycobacterium chelonae) were all isolated from water and soil samples. The use of Bcc isolation media yielded a surprisingly wide array of rare but often clinically relevant CF pathogens, confirming that soil and water are reservoirs of these infectious agents. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  3. Reclassification of the Specialized Metabolite Producer Pseudomonas mesoacidophila ATCC 31433 as a Member of the Burkholderia cepacia Complex.

    Science.gov (United States)

    Loveridge, E Joel; Jones, Cerith; Bull, Matthew J; Moody, Suzy C; Kahl, Małgorzata W; Khan, Zainab; Neilson, Louis; Tomeva, Marina; Adams, Sarah E; Wood, Andrew C; Rodriguez-Martin, Daniel; Pinel, Ingrid; Parkhill, Julian; Mahenthiralingam, Eshwar; Crosby, John

    2017-07-01

    Pseudomonas mesoacidophila ATCC 31433 is a Gram-negative bacterium, first isolated from Japanese soil samples, that produces the monobactam isosulfazecin and the β-lactam-potentiating bulgecins. To characterize the biosynthetic potential of P. mesoacidophila ATCC 31433, its complete genome was determined using single-molecule real-time DNA sequence analysis. The 7.8-Mb genome comprised four replicons, three chromosomal (each encoding rRNA) and one plasmid. Phylogenetic analysis demonstrated that P. mesoacidophila ATCC 31433 was misclassified at the time of its deposition and is a member of the Burkholderia cepacia complex, most closely related to Burkholderia ubonensis The sequenced genome shows considerable additional biosynthetic potential; known gene clusters for malleilactone, ornibactin, isosulfazecin, alkylhydroxyquinoline, and pyrrolnitrin biosynthesis and several uncharacterized biosynthetic gene clusters for polyketides, nonribosomal peptides, and other metabolites were identified. Furthermore, P. mesoacidophila ATCC 31433 harbors many genes associated with environmental resilience and antibiotic resistance and was resistant to a range of antibiotics and metal ions. In summary, this bioactive strain should be designated B. cepacia complex strain ATCC 31433, pending further detailed taxonomic characterization. IMPORTANCE This work reports the complete genome sequence of Pseudomonas mesoacidophila ATCC 31433, a known producer of bioactive compounds. Large numbers of both known and novel biosynthetic gene clusters were identified, indicating that P. mesoacidophila ATCC 31433 is an untapped resource for discovery of novel bioactive compounds. Phylogenetic analysis demonstrated that P. mesoacidophila ATCC 31433 is in fact a member of the Burkholderia cepacia complex, most closely related to the species Burkholderia ubonensis Further investigation of the classification and biosynthetic potential of P. mesoacidophila ATCC 31433 is warranted. Copyright © 2017

  4. The type IV pilin of Burkholderia mallei is highly immunogenic but fails to protect against lethal aerosol challenge in a murine model.

    Science.gov (United States)

    Fernandes, Paula J; Guo, Qin; Waag, David M; Donnenberg, Michael S

    2007-06-01

    Burkholderia mallei is the cause of glanders and a proven biological weapon. We identified and purified the type IV pilin protein of this organism to study its potential as a subunit vaccine. We found that purified pilin was highly immunogenic. Furthermore, mice infected via sublethal aerosol challenge developed significant increases in titers of antibody against the pilin, suggesting that it is expressed in vivo. Nevertheless, we found no evidence that high-titer antipilin antisera provided passive protection against a sublethal or lethal aerosol challenge and no evidence of protection afforded by active immunization with purified pilin. These results contrast with the utility of type IV pilin subunit vaccines against other infectious diseases and highlight the need for further efforts to identify protective responses against this pathogen.

  5. Multivariate analyses of Burkholderia species in soil: effect of crop and land use history

    NARCIS (Netherlands)

    Salles, Joanna; Van Veen, J.A.; van Elsas, J.D.

    2004-01-01

    The assessment of Burkholderia diversity in agricultural areas is important considering the potential use of this genus for agronomic and environmental applications. Therefore, the aim of this work was to ascertain how plant species and land use management drive the diversity of the genus

  6. Multivariate analyses of Burkholderia species in soil : Effect of crop and land use history

    NARCIS (Netherlands)

    Salles, JF; van Veen, JA; van Elsas, JD

    The assessment of Burkholderia diversity in agricultural areas is important considering the potential use of this genus for agronomic and environmental applications. Therefore, the aim of this work was to ascertain how plant species and land use management drive the diversity of the genus

  7. Multivariate Analyses of Burkholderia species in soil: effect of crop and land use history.

    NARCIS (Netherlands)

    Salles, J.F.; Veen, van J.A.; Elsas, van J.D.

    2004-01-01

    The assessment of Burkholderia diversity in agricultural areas is important considering the potential use of this genus for agronomic and environmental applications. Therefore, the aim of this work was to ascertain how plant species and land use management drive the diversity of the genus

  8. Inactivation of Toluene 2-Monooxygenase in Burkholderia cepacia G4 by Alkynes

    Science.gov (United States)

    Yeager, Chris M.; Bottomley, Peter J.; Arp, Daniel J.; Hyman, Michael R.

    1999-01-01

    High concentrations of acetylene (10 to 50% [vol/vol] gas phase) were required to inhibit the growth of Burkholderia cepacia G4 on toluene, while 1% (vol/vol) (gas phase) propyne or 1-butyne completely inhibited growth. Low concentrations of longer-chain alkynes (C5 to C10) were also effective inhibitors of toluene-dependent growth, and 2- and 3-alkynes were more potent inhibitors than their 1-alkyne counterparts. Exposure of toluene-grown B. cepacia G4 to alkynes resulted in the irreversible loss of toluene- and o-cresol-dependent O2 uptake activities, while acetate- and 3-methylcatechol-dependent O2 uptake activities were unaffected. Toluene-dependent O2 uptake decreased upon the addition of 1-butyne in a concentration- and time-dependent manner. The loss of activity followed first-order kinetics, with apparent rate constants ranging from 0.25 min−1 to 2.45 min−1. Increasing concentrations of toluene afforded protection from the inhibitory effects of 1-butyne. Furthermore, oxygen, supplied as H2O2, was required for inhibition by 1-butyne. These results suggest that alkynes are specific, mechanism-based inactivators of toluene 2-monooxygenase in B. cepacia G4, although the simplest alkyne, acetylene, was relatively ineffective compared to longer alkynes. Alkene analogs of acetylene and propyne—ethylene and propylene—were not inactivators of toluene 2-monooxygenase activity in B. cepacia G4 but were oxidized to their respective epoxides, with apparent Ks and Vmax values of 39.7 μM and 112.3 nmol min−1 mg of protein−1 for ethylene and 32.3 μM and 89.2 nmol min−1 mg of protein−1 for propylene. PMID:9925593

  9. Activation of MAPK/ERK signaling by Burkholderia pseudomallei cycle inhibiting factor (Cif.

    Directory of Open Access Journals (Sweden)

    Mei Ying Ng

    Full Text Available Cycle inhibiting factors (Cifs are virulence proteins secreted by the type III secretion system of some Gram-negative pathogenic bacteria including Burkholderia pseudomallei. Cif is known to function to deamidate Nedd8, leading to inhibition of Cullin E3 ubiquitin ligases (CRL and consequently induction of cell cycle arrest. Here we show that Cif can function as a potent activator of MAPK/ERK signaling without significant activation of other signaling pathways downstream of receptor tyrosine kinases. Importantly, we found that the ability of Cif to activate ERK is dependent on its deamidase activity, but independent of Cullin E3 ligase inhibition. This suggests that apart from Nedd8, other cellular targets of Cif-dependent deamidation exist. We provide evidence that the mechanism involved in Cif-mediated ERK activation is dependent on recruitment of the Grb2-SOS1 complex to the plasma membrane. Further investigation revealed that Cif appears to modify the phosphorylation status of SOS1 in a region containing the CDC25-H and proline-rich domains. It is known that prolonged Cullin E3 ligase inhibition leads to cellular apoptosis. Therefore, we hypothesize that ERK activation is an important mechanism to counter the pro-apoptotic effects of Cif. Indeed, we show that Cif dependent ERK activation promotes phosphorylation of the proapoptotic protein Bim, thereby potentially conferring a pro-survival signal. In summary, we identified a novel deamidation-dependent mechanism of action of the B. pseudomallei virulence factor Cif/CHBP to activate MAPK/ERK signaling. Our study demonstrates that bacterial proteins such as Cif can serve as useful molecular tools to uncover novel aspects of mammalian signaling pathways.

  10. Determining the biochemical properties of the Oxalate Biosynthetic Component (Obc)1 from Burkholderia mallei

    Science.gov (United States)

    Oxalic acid is produced by a variety of organisms ranging from simple microbes to complex animals. This acid has been proposed to fulfill various physiological and pathological functions which vary between organisms. In bacteria from the Burkholderia genus, oxalate secretion has been shown to be quo...

  11. Isolation and Characterization of Burkholderia rinojensis sp. nov., a Non-Burkholderia cepacia Complex Soil Bacterium with Insecticidal and Miticidal Activities

    Science.gov (United States)

    Fernandez, Lorena E.; Koivunen, Marja; Yang, April; Flor-Weiler, Lina; Marrone, Pamela G.

    2013-01-01

    Isolate A396, a bacterium isolated from a Japanese soil sample demonstrated strong insecticidal and miticidal activities in laboratory bioassays. The isolate was characterized through biochemical methods, fatty acid methyl ester (FAME) analysis, sequencing of 16S rRNA, multilocus sequence typing and analysis, and DNA-DNA hybridization. FAME analysis matched A396 to Burkholderia cenocepacia, but this result was not confirmed by 16S rRNA or DNA-DNA hybridization. 16S rRNA sequencing indicated closest matches with B. glumae and B. plantarii. DNA-DNA hybridization experiments with B. plantarii, B. glumae, B. multivorans, and B. cenocepacia confirmed the low genetic similarity (11.5 to 37.4%) with known members of the genus. PCR-based screening showed that A396 lacks markers associated with members of the B. cepacia complex. Bioassay results indicated two mechanisms of action: through ingestion and contact. The isolate effectively controlled beet armyworms (Spodoptera exigua; BAW) and two-spotted spider mites (Tetranychus urticae; TSSM). In diet overlay bioassays with BAW, 1% to 4% (vol/vol) dilution of the whole-cell broth caused 97% to 100% mortality 4 days postexposure, and leaf disc treatment bioassays attained 75% ± 22% mortality 3 days postexposure. Contact bioassays led to 50% larval mortality, as well as discoloration, stunting, and failure to molt. TSSM mortality reached 93% in treated leaf discs. Activity was maintained in cell-free supernatants and after heat treatment (60°C for 2 h), indicating that a secondary metabolite or excreted thermostable enzyme might be responsible for the activity. Based on these results, we describe the novel species Burkholderia rinojensis, a good candidate for the development of a biocontrol product against insect and mite pests. PMID:24096416

  12. Insecticide-degrading Burkholderia symbionts of the stinkbug naturally occupy various environments of sugarcane fields in a Southeast island of Japan.

    Science.gov (United States)

    Tago, Kanako; Okubo, Takashi; Itoh, Hideomi; Kikuchi, Yoshitomo; Hori, Tomoyuki; Sato, Yuya; Nagayama, Atsushi; Hayashi, Kentaro; Ikeda, Seishi; Hayatsu, Masahito

    2015-01-01

    The stinkbug Cavelerius saccharivorus, which harbors Burkholderia species capable of degrading the organophosphorus insecticide, fenitrothion, has been identified on a Japanese island in farmers' sugarcane fields that have been exposed to fenitrothion. A clearer understanding of the ecology of the symbiotic fenitrothion degraders of Burkholderia species in a free-living environment is vital for advancing our knowledge on the establishment of degrader-stinkbug symbiosis. In the present study, we analyzed the composition and abundance of degraders in sugarcane fields on the island. Degraders were recovered from field samples without an enrichment culture procedure. Degrader densities in the furrow soil in fields varied due to differences in insecticide treatment histories. Over 99% of the 659 isolated degraders belonged to the genus Burkholderia. The strains related to the stinkbug symbiotic group predominated among the degraders, indicating a selection for this group in response to fenitrothion. Degraders were also isolated from sugarcane stems, leaves, and rhizosphere in fields that were continuously exposed to fenitrothion. Their density was lower in the plant sections than in the rhizosphere. A phylogenetic analysis of 16S rRNA gene sequences demonstrated that most of the degraders from the plants and rhizosphere clustered with the stinkbug symbiotic group, and some were identical to the midgut symbionts of C. saccharivorus collected from the same field. Our results confirmed that plants and the rhizosphere constituted environmental reservoirs for stinkbug symbiotic degraders. To the best of our knowledge, this is the first study to investigate the composition and abundance of the symbiotic fenitrothion degraders of Burkholderia species in farmers' fields.

  13. BIOAUGMENTATION WITH BURKHOLDERIA CEPACIA PR1301 FOR IN SITU BIOREMEDIATION OF TRICHLOROETHYLENE CONTAMINATED GROUNDWATER (RESEARCH BRIEF)

    Science.gov (United States)

    A pilot field study was conducted at the Moffett Federal Airfield, Mountain View, California, to determine whether effective in-situ aerobic cometabolic biodegradation of TCE could be accomplished through bioaugmentation with a genetically modified strain of Burkholderia cepacia ...

  14. In Vitro Activity of Ceftolozane-Tazobactam against Burkholderia pseudomallei.

    Science.gov (United States)

    Slack, Andrew; Parsonson, Fiona; Cronin, Katie; Engler, Kathy; Norton, Robert

    2018-06-25

    We investigated the in vitro activity of a novel fifth-generation cephalosporin-tazobactam combination, ceftolozane-tazobactam against Burkholderia pseudomallei , the etiological agent of melioidosis. Using both disc diffusion and minimum inhibitory concentration (MIC) strip techniques against 56 clinical isolates and an NCTC strain, the MIC to ceftolozane-tazobactam was found to be between 0.75 and 4 mcg/mL. The MIC50 was found to be 1.5 mcg/mL and MIC90 was 2.0 mcg/mL. This study provides initial evidence of ceftolozane-tazobactam as a novel agent in the management of melioidosis.

  15. AQUIFER PROTIST RESPONSE AND THE POTENTIAL FOR TCE BIOREMEDIATION WITH BURKHOLDERIA CEPACIA G4 PR1

    Science.gov (United States)

    The introduction of bacteria into the environment for bioremediation purposes (bioaugmentation) requires analysis and monitoring of the persistence and activity of microbial population for efficacy and risk assessment purposes. Burkholderia cepacia G4 PR123 and PR131 constitutive...

  16. A heterodimer comprised of two bovine lactoferrin antimicrobial peptides exhibits powerful bactericidal activity against Burkholderia pseudomallei

    NARCIS (Netherlands)

    Puknun, A.; Bolscher, J.G.M.; Nazmi, K.; Veerman, E.C.I.; Tungpradabkul, S.; Wongratanacheewin, S.; Kanthawong, S.; Taweechaisupapong, S.

    2013-01-01

    Melioidosis is a severe infectious disease that is endemic in Southeast Asia and Northern Australia. Burkholderia pseudomallei, the causative agent of this disease, has developed resistance to an increasing list of antibiotics, demanding a search for novel agents. Lactoferricin and lactoferrampin

  17. Changes in agricultural management drive the diversity of Burkholderia species isolated from soil on PLAT medium

    NARCIS (Netherlands)

    Salles, JF; Samyn, E; Vandamme, P; van Veen, JA; van Elsas, JD

    In order to assess the diversity of culturable Burkholderia populations in rhizosphere and bulk soil and to evaluate how different agricultural management regimes and land use history affect this diversity, four treatments were evaluated: permanent grassland; grassland converted into maize

  18. Changes in agricultural management drive the diversity of Burkholderia species isolated from soil on PCAT medium

    NARCIS (Netherlands)

    Salles, J.F.; Samyn, E.; Vandamme, P.A.; Veen, van J.A.; Elsas, van J.D.

    2006-01-01

    In order to assess the diversity of culturable Burkholderia populations in rhizosphere and bulk soil and to evaluate how different agricultural management regimes and land use history affect this diversity, four treatments were evaluated: permanent grassland; grassland converted into maize

  19. Changes in agricultural management drive the diversity of Burkholderia species isolated from soil on PCAT medium

    NARCIS (Netherlands)

    Salles, Joanna; Samyn, E.; Vandamme, P.; Van Veen, J.A.; van Elsas, J.D.

    2006-01-01

    Abstract In order to assess the diversity of culturable Burkholderia populations in rhizosphere and bulk soil and to evaluate how different agricultural management regimes and land use history affect this diversity, four treatments were evaluated: permanent grassland; grassland converted into maize

  20. Symbiotic Burkholderia Species Show Diverse Arrangements of nif/fix and nod Genes and Lack Typical High-Affinity Cytochrome cbb3 Oxidase Genes.

    Science.gov (United States)

    De Meyer, Sofie E; Briscoe, Leah; Martínez-Hidalgo, Pilar; Agapakis, Christina M; de-Los Santos, Paulina Estrada; Seshadri, Rekha; Reeve, Wayne; Weinstock, George; O'Hara, Graham; Howieson, John G; Hirsch, Ann M

    2016-08-01

    Genome analysis of fourteen mimosoid and four papilionoid beta-rhizobia together with fourteen reference alpha-rhizobia for both nodulation (nod) and nitrogen-fixing (nif/fix) genes has shown phylogenetic congruence between 16S rRNA/MLSA (combined 16S rRNA gene sequencing and multilocus sequence analysis) and nif/fix genes, indicating a free-living diazotrophic ancestry of the beta-rhizobia. However, deeper genomic analysis revealed a complex symbiosis acquisition history in the beta-rhizobia that clearly separates the mimosoid and papilionoid nodulating groups. Mimosoid-nodulating beta-rhizobia have nod genes tightly clustered in the nodBCIJHASU operon, whereas papilionoid-nodulating Burkholderia have nodUSDABC and nodIJ genes, although their arrangement is not canonical because the nod genes are subdivided by the insertion of nif and other genes. Furthermore, the papilionoid Burkholderia spp. contain duplications of several nod and nif genes. The Burkholderia nifHDKEN and fixABC genes are very closely related to those found in free-living diazotrophs. In contrast, nifA is highly divergent between both groups, but the papilionoid species nifA is more similar to alpha-rhizobia nifA than to other groups. Surprisingly, for all Burkholderia, the fixNOQP and fixGHIS genes required for cbb3 cytochrome oxidase production and assembly are missing. In contrast, symbiotic Cupriavidus strains have fixNOQPGHIS genes, revealing a divergence in the evolution of two distinct electron transport chains required for nitrogen fixation within the beta-rhizobia.

  1. Comparison of four urease-dependent tests of detecting HP infection

    International Nuclear Information System (INIS)

    Han Yuan; Huang Gang; Zhu Cuiying; Ling Liqun

    2001-01-01

    Objective: The aim of this study is to compare the four urease-dependent tests of detecting Hp infection. The authors used following method: 1) rapid urease test (RUT), 2) 14 C urea breath test ( 14 C-UBT), 3) 13 C urea breath test which is measured by with infrared spectrometry ( 13 C-UBT1), 4) 13 C urea breath test with mass spectrometry ( 13 C-UBT). Methods: 54 patients underwent RUT, 14 C-UBT, 13 C-UBT1, 13 C-UBT2 respectively. Results: Sensitivity and specificity, accurate rate, positive predictive value (PPV), negative predictive value (NPV), respectively, were as follows: RUT (82.1%, 80%, 81.5%, 91.4%, 63.2%), 14 C-UBT (97.4%, 100%, 98.1%, 100%, 93.8%), 13 C-UBT1 (100%, 93.3%, 98.1%, 97.5%, 100%), 13 C-UBT2 (100%, 86.7%, 96.3%, 95.1%, 100%), PPV of four tests are not significantly different (P>0.05). Conclusion: Four urease-dependent tests are high sensitive and accurate methods for detecting Hp infection. UBT is an ideal tool for diagnosis, screen and follow-up of Hp infection

  2. Alteration in cell surface properties of Burkholderia spp. during surfactant-aided biodegradation of petroleum hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, Sagarika; Mukherji, Suparna [Indian Institute of Technology Bombay, Mumbai (India). Centre for Environmental Science and Engineering (CESE)

    2012-04-15

    Chemical surfactants may impact microbial cell surface properties, i.e., cell surface hydrophobicity (CSH) and cell surface charge, and may thus affect the uptake of components from non-aqueous phase liquids (NAPLs). This work explored the impact of Triton X-100, Igepal CA 630, and Tween 80 (at twice the critical micelle concentration, CMC) on the cell surface characteristics of Burkholderia cultures, Burkholderia cepacia (ES1, aliphatic degrader) and Burkholderia multivorans (NG1, aromatic degrader), when grown on a six-component model NAPL. In the presence of Triton X-100, NAPL biodegradation was enhanced from 21% to 60% in B. cepacia and from 18% to 53% in B. multivorans. CSH based on water contact angle (50-52 ) was in the same range for both strains while zeta potential at neutral pH was -38 and -31 mV for B. cepacia and B. multivorans, respectively. In the presence of Triton X-100, their CSH increased to greater than 75 and the zeta potential decreased. This induced a change in the mode of uptake and initiated aliphatic hydrocarbon degradation by B. multivorans and increased the rate of aliphatic hydrocarbon degradation in B. cepacia. Igepal CA 630 and Tween 80 also altered the cell surface properties. For B. cepacia grown in the presence of Triton X-100 at two and five times its CMC, CSH increased significantly in the log growth phase. Growth in the presence of the chemical surfactants also affected the abundance of chemical functional groups on the cell surface. Cell surface changes had maximum impact on NAPL degradation in the presence of emulsifying surfactants, Triton X-100 and Igepal CA630.

  3. Differential roles of RND efflux pumps in antimicrobial drug resistance of sessile and planktonic Burkholderia cenocepacia cells.

    Science.gov (United States)

    Buroni, Silvia; Matthijs, Nele; Spadaro, Francesca; Van Acker, Heleen; Scoffone, Viola C; Pasca, Maria Rosalia; Riccardi, Giovanna; Coenye, Tom

    2014-12-01

    Burkholderia cenocepacia is notorious for causing respiratory tract infections in people with cystic fibrosis. Infections with this organism are particularly difficult to treat due to its high level of intrinsic resistance to most antibiotics. Multidrug resistance in B. cenocepacia can be ascribed to different mechanisms, including the activity of efflux pumps and biofilm formation. In the present study, the effects of deletion of the 16 operons encoding resistance-nodulation-cell division (RND)-type efflux pumps in B. cenocepacia strain J2315 were investigated by determining the MICs of various antibiotics and by investigating the antibiofilm effect of these antibiotics. Finally, the expression levels of selected RND genes in treated and untreated cultures were investigated using reverse transcriptase quantitative PCR (RT-qPCR). Our data indicate that the RND-3 and RND-4 efflux pumps are important for resistance to various antimicrobial drugs (including tobramycin and ciprofloxacin) in planktonic B. cenocepacia J2315 populations, while the RND-3, RND-8, and RND-9 efflux systems protect biofilm-grown cells against tobramycin. The RND-8 and RND-9 efflux pumps are not involved in ciprofloxacin resistance. Results from the RT-qPCR experiments on the wild-type strain B. cenocepacia J2315 suggest that there is little regulation at the level of mRNA expression for these efflux pumps under the conditions tested. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  4. Epidemiological tracking and population assignment of the non-clonal bacterium, Burkholderia pseudomallei.

    Science.gov (United States)

    Dale, Julia; Price, Erin P; Hornstra, Heidie; Busch, Joseph D; Mayo, Mark; Godoy, Daniel; Wuthiekanun, Vanaporn; Baker, Anthony; Foster, Jeffrey T; Wagner, David M; Tuanyok, Apichai; Warner, Jeffrey; Spratt, Brian G; Peacock, Sharon J; Currie, Bart J; Keim, Paul; Pearson, Talima

    2011-12-01

    Rapid assignment of bacterial pathogens into predefined populations is an important first step for epidemiological tracking. For clonal species, a single allele can theoretically define a population. For non-clonal species such as Burkholderia pseudomallei, however, shared allelic states between distantly related isolates make it more difficult to identify population defining characteristics. Two distinct B. pseudomallei populations have been previously identified using multilocus sequence typing (MLST). These populations correlate with the major foci of endemicity (Australia and Southeast Asia). Here, we use multiple Bayesian approaches to evaluate the compositional robustness of these populations, and provide assignment results for MLST sequence types (STs). Our goal was to provide a reference for assigning STs to an established population without the need for further computational analyses. We also provide allele frequency results for each population to enable estimation of population assignment even when novel STs are discovered. The ability for humans and potentially contaminated goods to move rapidly across the globe complicates the task of identifying the source of an infection or outbreak. Population genetic dynamics of B. pseudomallei are particularly complicated relative to other bacterial pathogens, but the work here provides the ability for broad scale population assignment. As there is currently no independent empirical measure of successful population assignment, we provide comprehensive analytical details of our comparisons to enable the reader to evaluate the robustness of population designations and assignments as they pertain to individual research questions. Finer scale subdivision and verification of current population compositions will likely be possible with genotyping data that more comprehensively samples the genome. The approach used here may be valuable for other non-clonal pathogens that lack simple group-defining genetic characteristics

  5. Epidemiological tracking and population assignment of the non-clonal bacterium, Burkholderia pseudomallei.

    Directory of Open Access Journals (Sweden)

    Julia Dale

    2011-12-01

    Full Text Available Rapid assignment of bacterial pathogens into predefined populations is an important first step for epidemiological tracking. For clonal species, a single allele can theoretically define a population. For non-clonal species such as Burkholderia pseudomallei, however, shared allelic states between distantly related isolates make it more difficult to identify population defining characteristics. Two distinct B. pseudomallei populations have been previously identified using multilocus sequence typing (MLST. These populations correlate with the major foci of endemicity (Australia and Southeast Asia. Here, we use multiple Bayesian approaches to evaluate the compositional robustness of these populations, and provide assignment results for MLST sequence types (STs. Our goal was to provide a reference for assigning STs to an established population without the need for further computational analyses. We also provide allele frequency results for each population to enable estimation of population assignment even when novel STs are discovered. The ability for humans and potentially contaminated goods to move rapidly across the globe complicates the task of identifying the source of an infection or outbreak. Population genetic dynamics of B. pseudomallei are particularly complicated relative to other bacterial pathogens, but the work here provides the ability for broad scale population assignment. As there is currently no independent empirical measure of successful population assignment, we provide comprehensive analytical details of our comparisons to enable the reader to evaluate the robustness of population designations and assignments as they pertain to individual research questions. Finer scale subdivision and verification of current population compositions will likely be possible with genotyping data that more comprehensively samples the genome. The approach used here may be valuable for other non-clonal pathogens that lack simple group-defining genetic

  6. Octanoyl-Homoserine Lactone Is the Cognate Signal for Burkholderia mallei BmaR1-BmaI1 Quorum Sensing

    National Research Council Canada - National Science Library

    Duerkop, Breck A; Ulrich, Ricky L; Greenberg, E. P

    2007-01-01

    .... The obligate animal pathogen Burkholderia mallei produces several acyl-HSLs, and the B. mallei genome has four luxR and two luxI homologs, each of which has been established as a virulence factor...

  7. Degradation of toluene and trichloroethylene by Burkholderia cepacia G4 in growth-limited fed-batch culture

    NARCIS (Netherlands)

    Mars, Astrid E.; Houwing, Joukje; Dolfing, Jan; Janssen, Dick B.

    Burkholderia (Pseudomonas) cepacia G4 was cultivated in a fed-batch bioreactor on either toluene or toluene plus trichloroethylene (TCE), The culture was allowed to reach a constant cell density under conditions in which the amount of toluene supplied equals the maintenance energy demand of the

  8. Recovery efficiencies for Burkholderia thailandensis from various aerosol sampling media

    Directory of Open Access Journals (Sweden)

    Paul eDabisch

    2012-06-01

    Full Text Available Burkholderia thailandensis is used in the laboratory as a surrogate of the more virulent B. pseudomallei. Since inhalation is believed to be a natural route of infection for B. pseudomallei, many animal studies with B. pseudomallei and B. thailandensis utilize the inhalation route of exposure. The aim of the present study was to quantify the recovery efficiency of culturable B. thailandensis from several common aerosol sampling devices to ensure that collected microorganisms could be reliably recovered post-collection. The sampling devices tested included 25-mm gelatin filters, 25-mm stainless steel disks used in Mercer cascade impactors, and two types of glass impingers. The results demonstrate that while several processing methods tested resulted in significantly lower physical recovery efficiencies than other methods, it was possible to obtain culturable recovery efficiencies for B. thailandensis and physical recovery efficiencies for 1 μm fluorescent spheres of at least 0.95 from all of the sampling media tested given an appropriate sample processing procedure. The results of the present study also demonstrated that the bubbling action of liquid media in all-glass impingers (AGIs can result in physical loss of material from the collection medium, although additional studies are needed to verify the exact mechanisms involved. Overall, the results of this study demonstrate that the collection mechanism as well as the post-collection processing method can significantly affect the recovery from and retention of culturable microorganisms in sampling media, potentially affecting the calculated airborne concentration and any subsequent estimations of risk or dose derived from such data.

  9. Endophytic bacterial community living in roots of healthy and 'Candidatus Phytoplasma mali'-infected apple (Malus domestica, Borkh.) trees.

    Science.gov (United States)

    Bulgari, Daniela; Bozkurt, Adem I; Casati, Paola; Cağlayan, Kadriye; Quaglino, Fabio; Bianco, Piero A

    2012-11-01

    'Candidatus Phytoplasma mali', the causal agent of apple proliferation (AP) disease, is a quarantine pathogen controlled by chemical treatments against insect vectors and eradication of diseased plants. In accordance with the European Community guidelines, novel strategies should be developed for sustainable management of plant diseases by using resistance inducers (e.g. endophytes). A basic point for the success of this approach is the study of endophytic bacteria associated with plants. In the present work, endophytic bacteria living in healthy and 'Ca. Phytoplasma mali'-infected apple trees were described by cultivation-dependent and independent methods. 16S rDNA sequence analysis showed the presence of the groups Proteobacteria, Acidobacteria, Bacteroidetes, Actinobacteria, Chlamydiae, and Firmicutes. In detail, library analyses underscored 24 and 17 operational taxonomic units (OTUs) in healthy and infected roots, respectively, with a dominance of Betaproteobacteria. Moreover, differences in OTUs number and in CFU/g suggested that phytoplasmas could modify the composition of endophytic bacterial communities associated with infected plants. Intriguingly, the combination of culturing methods and cloning analysis allowed the identification of endophytic bacteria (e.g. Bacillus, Pseudomonas, and Burkholderia) that have been reported as biocontrol agents. Future research will investigate the capability of these bacteria to control 'Ca. Phytoplasma mali' in order to develop sustainable approaches for managing AP.

  10. Isolation of the highly pathogenic and zoonotic agent Burkholderia pseudomallei from a pet green Iguana in Prague, Czech Republic.

    Science.gov (United States)

    Elschner, Mandy C; Hnizdo, Jan; Stamm, Ivonne; El-Adawy, Hosny; Mertens, Katja; Melzer, Falk

    2014-11-28

    Melioidosis caused by Burkholderia (B.) pseudomallei is an endemic zoonotic disease mainly reported from northern Australia and Southeast Asia. In Europe, cases of human melioidosis have been reported only from patients travelling to endemic regions. Besides humans, B. pseudomallei has a very broad host range in domestic and wild animals. There are some reports about importation of B. pseudomallei-infected animals from endemic areas into Europe. The present report describes the first case of B. pseudomallei infection of a pet iguana in Europe. In a 5-year-old pet Iguana iguana living in a private household in Prague, Czech Republic, B. pseudomallei was isolated from pus of an abscess. The isolate VB976100 was identified by Vitek®2, MALDI-TOF mass spectrometry and polymerase chain reaction as B. pseudomallei. The molecular typing resulted in multi-locus sequence type 436 hitherto, which has been found only once worldwide in a B. pseudomallei strain isolated in the USA and originating from Guatemala. The identification as internal transcribed spacer type G indicates a close relatedness to strains mainly isolated in the Western Hemisphere. These findings support the hypothesis that the iguana became infected in this region or in a breeding facility through contact to other infected animals. The present case highlights the risk of importation of the highly pathogenic and zoonotic B. pseudomallei into non-endemic regions through animal trade. Therefore, veterinarians treating animals from these areas and physicians examining patients owning such animals should include melioidosis in differential diagnosis whenever specific symptoms appear. Furthermore, veterinary authorities responsible for supervision of traders and pet shops should be aware of this risk of zoonotic transmission.

  11. Diversidade de bactérias diazotróficas endofíticas dos gêneros Herbaspirillum e Burkholderia na cultura do arroz inundado Diversity of endophytic diazotrophic bacteria of the genus Herbaspirillum and Burkholderia in wetland rice

    Directory of Open Access Journals (Sweden)

    Luciana da Silva Rodrigues

    2006-02-01

    Full Text Available O objetivo deste trabalho foi avaliar a diversidade de bactérias diazotróficas endofíticas, dos gêneros Herbaspirillum e Burkholderia, em duas variedades de arroz, consideradas de alta (IR 42 e baixa (IAC 4440 eficiência de fixação biológica de nitrogênio. Foram realizados dois experimentos em casa de vegetação, em vasos com dois tipos de solos, provenientes dos Estados de Goiás e do Rio de Janeiro. Foi feita a contagem do número de bactérias e o isolamento em diferentes partes e estágios de desenvolvimento das plantas, mediante o uso de meios de cultivo JNFb e JMV. Os isolados bacterianos foram caracterizados a partir de aspectos morfológicos das colônias, com o crescimento em meios de cultivo, e de testes fisiológicos (uso de fontes de carbono e atividade de redução de acetileno. A contagem revelou grande número de bactérias diazotróficas (10(6 células g-1 matéria fresca, presentes em ambas as variedades de arroz, principalmente nas amostras radiculares. Os dados, obtidos na matriz de similaridade, mostram a presença de representantes da espécie Herbaspirillum seropedicae, bem como a diversidade entre isolados pertencentes ao gênero Burkholderia.The objective of this work was to evaluate the diversity of endophytic diazotrophic bacteria of the genera Herbaspirillum and Burkholderia, in two rice varieties, considered of high (IR 42 and low (IAC 4440 contribution on BNF. Two experiments were conducted in greenhouse conditions, in order to study the association of endophytic diazotrophic bacteria with wetland rice varieties, which were planted in two types of soil: one from Rio de Janeiro State and another from Goiás State, Brazil. Bacterial population (in different parts and physiological stages of the plants were evaluated, followed by the both genera strains isolation using culture media. The isolated bacteria were characterized based on morphological and physiological aspects. High bacterial counts were detected

  12. Genome wide transcriptome profiling of a murine acute melioidosis model reveals new insights into how Burkholderia pseudomallei overcomes host innate immunity

    Directory of Open Access Journals (Sweden)

    Nathan Sheila

    2010-11-01

    Full Text Available Abstract Background At present, very little is known about how Burkholderia pseudomallei (B. pseudomallei interacts with its host to elicit melioidosis symptoms. We established a murine acute-phase melioidosis model and used DNA microarray technology to investigate the global host/pathogen interaction. We compared the transcriptome of infected liver and spleen with uninfected tissues over an infection period of 42 hr to identify genes whose expression is altered in response to an acute infection. Results Viable B. pseudomallei cells were consistently detected in the blood, liver and spleen during the 42 hr course of infection. Microarray analysis of the liver and spleen over this time course demonstrated that genes involved in immune response, stress response, cell cycle regulation, proteasomal degradation, cellular metabolism and signal transduction pathways were differentially regulated. Up regulation of toll-like receptor 2 (TLR2 gene expression suggested that a TLR2-mediated signalling pathway is responsible for recognition and initiation of an inflammatory response to the acute B. pseudomallei infection. Most of the highly elevated inflammatory genes are a cohort of "core host immune response" genes commonly seen in general inflammation infections. Concomitant to this initial inflammatory response, we observed an increase in transcripts associated with cell-death, caspase activation and peptidoglysis that ultimately promote tissue injury in the host. The complement system responsible for restoring host cellular homeostasis and eliminating intracellular bacteria was activated only after 24 hr post-infection. However, at this time point, diverse host nutrient metabolic and cellular pathways including glycolysis, fatty acid metabolism and tricarboxylic acid (TCA cycle were repressed. Conclusions This detailed picture of the host transcriptional response during acute melioidosis highlights a broad range of innate immune mechanisms that are

  13. Cedecea davisae’s Role in a Polymicrobial Lung Infection in a Cystic Fibrosis Patient

    Directory of Open Access Journals (Sweden)

    Thayer G. Ismaael

    2012-01-01

    Full Text Available Chronic airway colonization and infection are the hallmark of cystic fibrosis (CF. Staphylococcus aureus, Pseudomonas aeruginosa, and Burkholderia cepacia are well-documented bacterial culprits in this chronic suppurative airway disease. Advanced molecular diagnostics have uncovered a possible role of a larger group of microorganisms in CF. Cedecea is a member of the family Enterobacteriaceae and is an emerging pathogen. We present a case of a polymicrobial healthcare-associated pneumonia in a CF patient caused by Cedecea davisae, among other bacteria.

  14. Candidate Essential Genes in Burkholderia cenocepacia J2315 Identified by Genome-Wide TraDIS

    KAUST Repository

    Wong, Yee-Chin

    2016-08-22

    Burkholderia cenocepacia infection often leads to fatal cepacia syndrome in cystic fibrosis patients. However, antibiotic therapy rarely results in complete eradication of the pathogen due to its intrinsic resistance to many clinically available antibiotics. Recent attention has turned to the identification of essential genes as the proteins encoded by these genes may serve as potential targets for development of novel antimicrobials. In this study, we utilized TraDIS (Transposon Directed Insertion-site Sequencing) as a genome-wide screening tool to facilitate the identification of B. cenocepacia genes essential for its growth and viability. A transposon mutant pool consisting of approximately 500,000 mutants was successfully constructed, with more than 400,000 unique transposon insertion sites identified by computational analysis of TraDIS datasets. The saturated library allowed for the identification of 383 genes that were predicted to be essential in B. cenocepacia. We extended the application of TraDIS to identify conditionally essential genes required for in vitro growth and revealed an additional repertoire of 439 genes to be crucial for B. cenocepacia growth under nutrient-depleted conditions. The library of B. cenocepacia mutants can subsequently be subjected to various biologically related conditions to facilitate the discovery of genes involved in niche adaptation as well as pathogenicity and virulence.

  15. Candidate Essential Genes in Burkholderia cenocepacia J2315 Identified by Genome-Wide TraDIS

    KAUST Repository

    Wong, Yee-Chin; Abd El Ghany, Moataz; Naeem, Raeece; Lee, Kok-Wei; Tan, Yung-Chie; Pain, Arnab; Nathan, Sheila

    2016-01-01

    Burkholderia cenocepacia infection often leads to fatal cepacia syndrome in cystic fibrosis patients. However, antibiotic therapy rarely results in complete eradication of the pathogen due to its intrinsic resistance to many clinically available antibiotics. Recent attention has turned to the identification of essential genes as the proteins encoded by these genes may serve as potential targets for development of novel antimicrobials. In this study, we utilized TraDIS (Transposon Directed Insertion-site Sequencing) as a genome-wide screening tool to facilitate the identification of B. cenocepacia genes essential for its growth and viability. A transposon mutant pool consisting of approximately 500,000 mutants was successfully constructed, with more than 400,000 unique transposon insertion sites identified by computational analysis of TraDIS datasets. The saturated library allowed for the identification of 383 genes that were predicted to be essential in B. cenocepacia. We extended the application of TraDIS to identify conditionally essential genes required for in vitro growth and revealed an additional repertoire of 439 genes to be crucial for B. cenocepacia growth under nutrient-depleted conditions. The library of B. cenocepacia mutants can subsequently be subjected to various biologically related conditions to facilitate the discovery of genes involved in niche adaptation as well as pathogenicity and virulence.

  16. Candidate essential genes in Burkholderia cenocepacia J2315 identified by genome-wide TraDIS

    Directory of Open Access Journals (Sweden)

    Yee-Chin Wong

    2016-08-01

    Full Text Available Burkholderia cenocepacia infection often leads to fatal cepacia syndrome in cystic fibrosis patients. However, antibiotic therapy rarely results in complete eradication of the pathogen due to its intrinsic resistance to many clinically available antibiotics. Recent attention has turned to the identification of essential genes as the proteins encoded by these genes may serve as potential targets for development of novel antimicrobials. In this study, we utilized TraDIS (Transposon Directed Insertion-site Sequencing as a genome-wide screening tool to facilitate the identification of B. cenocepacia genes essential for its growth and viability. A transposon mutant pool consisting of approximately 500,000 mutants was successfully constructed, with more than 400,000 unique transposon insertion sites identified by computational analysis of TraDIS datasets. The saturated library allowed for the identification of 383 genes that were predicted to be essential in B. cenocepacia. We extended the application of TraDIS to identify conditionally essential genes required for in vitro growth and revealed an additional repertoire of 439 genes to be crucial for B. cenocepacia growth under nutrient-depleted conditions. The library of B. cenocepacia mutants can subsequently be subjected to various biologically related conditions to facilitate the discovery of genes involved in niche adaptation as well as pathogenicity and virulence.

  17. Cyanide toxicity to Burkholderia cenocepacia is modulated by polymicrobial communities and environmental factors

    Directory of Open Access Journals (Sweden)

    Steve P. Bernier

    2016-05-01

    Full Text Available Microbes within polymicrobial communities can establish positive and negative interactions that have the potential to influence the overall behaviour of the community. Pseudomonas aeruginosa and species of the Burkholderia cepacia complex (Bcc can co-exist in the lower airways, however several studies have shown that P. aeruginosa can effectively kill the Bcc in vitro, for which hydrogen cyanide was recently proposed to play a critical role. Here we show that modification of the environment (i.e. culture medium, long-term genetic adaptation of P. aeruginosa to the cystic fibrosis (CF lung, or the addition of another bacterial species to the community can alter the sensitivity of Burkholderia cenocepacia to P. aeruginosa toxins. We specifically demonstrate that undefined rich media leads to higher susceptibility of B. cenocepacia to P. aeruginosa toxins like cyanide as compared to a synthetic medium (SCFM, that mimics the CF lung nutritional content. Overall, our study shows that the polymicrobial environment can have profound effects on negative interactions mediated by P. aeruginosa against B. cenocepacia. In fact, evolved P. aeruginosa or the presence of other species such as Staphylococcus aureus can directly abolish the direct competition mediated by cyanide and consequently maintaining a higher level of species diversity within the community.

  18. The CRP/FNR family protein Bcam1349 is a c-di-GMP effector that regulates biofilm formation in the respiratory pathogen Burkholderia cenocepacia

    DEFF Research Database (Denmark)

    Fazli, Mustafa; O'Connell, Aileen; Nilsson, Martin

    2011-01-01

    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 formation and virulence in B. cenocepacia. Elevated intracellular levels of c-di-GMP promoted wrinkly...... colony, pellicle and biofilm formation in B. cenocepacia. A screen for transposon mutants unable to respond to elevated levels of c-di-GMP led to the identification of the mutant bcam1349 that did not display increased biofilm and pellicle formation with excessive c-di-GMP levels, and displayed a biofilm...

  19. Complete Genome Sequence of a Burkholderia pseudomallei Strain Isolated from a Pet Green Iguana in Prague, Czech Republic

    Science.gov (United States)

    Thomas, Prasad; El-Adawy, Hosny; Mertens, Katja; Melzer, Falk; Hnizdo, Jan; Stamm, Ivonne

    2017-01-01

    ABSTRACT Burkholderia pseudomallei was isolated from pus from an abscess of a pet iguana living in a private household in Prague, Czech Republic. This paper presents the complete genome sequence of B. pseudomallei strain VB976100. PMID:28280033

  20. Unusual Multiple Production of N-Acylhomoserine Lactones a by Burkholderia sp. Strain C10B Isolated from Dentine Caries

    Directory of Open Access Journals (Sweden)

    Share Yuan Goh

    2014-05-01

    Full Text Available Bacteria realize the ability to communicate by production of quorum sensing (QS molecules called autoinducers, which regulate the physiological activities in their ecological niches. The oral cavity could be a potential area for the presence of QS bacteria. In this study, we report the isolation of a QS bacterial isolate C10B from dentine caries. Preliminary screening using Chromobacterium violaceum CV026 biosensor showed that isolate C10B was able to produce N-acylhomoserine lactones (AHLs. This bacterium was further identified as a member of Burkholderia, an opportunistic pathogen. The isolated Burkholderia sp. was confirmed to produce N-hexanoyl-L-homoserine lactone (C6-HSL, N-octanoyl-L-homoserine lactone (C8-HSL, N-decanoyl-L-homoserine lactone (C10-HSL and N-dodecanoyl-L-homoserine lactone (C12-HSL.

  1. Does human bocavirus infection depend on helper viruses? A challenging case report

    Directory of Open Access Journals (Sweden)

    Brockmann Michael

    2011-08-01

    Full Text Available Abstract A case of severe diarrhoea associated with synergistic human bocavirus type 1 (HBoV and human herpes virus type 6 (HHV6 is reported. The case supports the hypotheses that HBoV infection under clinical conditions may depend on helper viruses, or that HBoV replicates by a mechanism that is atypical for parvoviruses, or that HBoV infection can be specifically treated with cidofovir.

  2. Polymorphisms within the prnD and pltC genes from pyrrolnitrin and pyoluteorin-producing Pseudomonas and Burkholderia spp

    NARCIS (Netherlands)

    Souza, J.T.; Raaijmakers, J.M.

    2003-01-01

    Pyrrolnitrin (PRN) and pyoluteorin (PLT) are broad-spectrum antibiotics produced by several strains of Pseudomonas and Burkholderia species. Both antibiotics play an important role in the suppression of multiple plant pathogenic fungi. Primers were developed from conserved sequences and amplified

  3. In-Frame and Unmarked Gene Deletions in Burkholderia cenocepacia via an Allelic Exchange System Compatible with Gateway Technology.

    Science.gov (United States)

    Fazli, Mustafa; Harrison, Joe J; Gambino, Michela; Givskov, Michael; Tolker-Nielsen, Tim

    2015-06-01

    Burkholderia cenocepacia is an emerging opportunistic pathogen causing life-threatening infections in immunocompromised individuals and in patients with cystic fibrosis, which are often difficult, if not impossible, to treat. Understanding the genetic basis of virulence in this emerging pathogen is important for the development of novel treatment regimes. Generation of deletion mutations in genes predicted to encode virulence determinants is fundamental to investigating the mechanisms of pathogenesis. However, there is a lack of appropriate selectable and counterselectable markers for use in B. cenocepacia, making its genetic manipulation problematic. Here we describe a Gateway-compatible allelic exchange system based on the counterselectable pheS gene and the I-SceI homing endonuclease. This system provides efficiency in cloning homology regions of target genes and allows the generation of precise and unmarked gene deletions in B. cenocepacia. As a proof of concept, we demonstrate its utility by deleting the Bcam1349 gene, encoding a cyclic di-GMP (c-di-GMP)-responsive regulator protein important for biofilm formation. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  4. Proteogenomic Characterization of Monocyclic Aromatic Hydrocarbon Degradation Pathways in the Aniline-Degrading Bacterium Burkholderia sp. K24.

    Directory of Open Access Journals (Sweden)

    Sang-Yeop Lee

    Full Text Available Burkholderia sp. K24, formerly known as Acinetobacter lwoffii K24, is a soil bacterium capable of utilizing aniline as its sole carbon and nitrogen source. Genomic sequence analysis revealed that this bacterium possesses putative gene clusters for biodegradation of various monocyclic aromatic hydrocarbons (MAHs, including benzene, toluene, and xylene (BTX, as well as aniline. We verified the proposed MAH biodegradation pathways by dioxygenase activity assays, RT-PCR, and LC/MS-based quantitative proteomic analyses. This proteogenomic approach revealed four independent degradation pathways, all converging into the citric acid cycle. Aniline and p-hydroxybenzoate degradation pathways converged into the β-ketoadipate pathway. Benzoate and toluene were degraded through the benzoyl-CoA degradation pathway. The xylene isomers, i.e., o-, m-, and p-xylene, were degraded via the extradiol cleavage pathways. Salicylate was degraded through the gentisate degradation pathway. Our results show that Burkholderia sp. K24 possesses versatile biodegradation pathways, which may be employed for efficient bioremediation of aniline and BTX.

  5. Proteogenomic Characterization of Monocyclic Aromatic Hydrocarbon Degradation Pathways in the Aniline-Degrading Bacterium Burkholderia sp. K24

    Science.gov (United States)

    Yun, Sung Ho; Choi, Chi-Won; Yi, Yoon-Sun; Kim, Jonghyun; Chung, Young-Ho; Park, Edmond Changkyun; Kim, Seung Il

    2016-01-01

    Burkholderia sp. K24, formerly known as Acinetobacter lwoffii K24, is a soil bacterium capable of utilizing aniline as its sole carbon and nitrogen source. Genomic sequence analysis revealed that this bacterium possesses putative gene clusters for biodegradation of various monocyclic aromatic hydrocarbons (MAHs), including benzene, toluene, and xylene (BTX), as well as aniline. We verified the proposed MAH biodegradation pathways by dioxygenase activity assays, RT-PCR, and LC/MS-based quantitative proteomic analyses. This proteogenomic approach revealed four independent degradation pathways, all converging into the citric acid cycle. Aniline and p-hydroxybenzoate degradation pathways converged into the β-ketoadipate pathway. Benzoate and toluene were degraded through the benzoyl-CoA degradation pathway. The xylene isomers, i.e., o-, m-, and p-xylene, were degraded via the extradiol cleavage pathways. Salicylate was degraded through the gentisate degradation pathway. Our results show that Burkholderia sp. K24 possesses versatile biodegradation pathways, which may be employed for efficient bioremediation of aniline and BTX. PMID:27124467

  6. Pediatric mortality due to nosocomial infection: a critical approach

    Directory of Open Access Journals (Sweden)

    Julia Marcia Maluf Lopes

    Full Text Available Nosocomial infection is a frequent event with potentially lethal consequences. We reviewed the literature on the predictive factors for mortality related to nosocomial infection in pediatric medicine. Electronic searches in English, Spanish and Portuguese of the PubMed/MEDLINE, LILACS and Cochrane Collaboration Databases was performed, focusing on studies that had been published from 1996 to 2006. The key words were: nosocomial infection and mortality and pediatrics/neonate/ newborn/child/infant/adolescent. The risk factors found to be associated with mortality were: nosocomial infection itself, leukemia, lymphopenia, neutropenia, corticosteroid therapy, multiple organ failure, previous antimicrobial therapy, catheter use duration, candidemia, cancer, bacteremia, age over 60, invasive procedures, mechanical ventilation, transport out of the pediatric intensive care unit, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Burkholderia cepacia infections, acute physiology and chronic health evaluation (APACHE II scores over 15. Among these factors, the only one that can be minimized is inadequate antimicrobial treatment, which has proven to be an important contributor to hospital mortality in critically-ill patients. There is room for further prognosis research on this matter to determine local differences. Such research requires appropriate epidemiological design and statistical analysis so that pediatric death due to nosocomial infection can be reduced and health care quality improved in pediatric hospitals.

  7. AN IMPORTED CASE OF ACUTE MELIOIDOSIS CAUSED BY ST881 BURKHOLDERIA PSEUDOMALLEI.

    Science.gov (United States)

    Zong, Zhiyong; Wang, Xiaohui; Deng, Yiyun

    2016-03-01

    A previously healthy Chinese male working in Malaysia returned to China with high fever. A blood culture showed Burkholderia pseudomallei strain WCBP1. This isolate was sequenced, showing type, ST881, which appears to be present in Malaysia. WCP1 had unusual susceptibility to aminoglycosides and habored the Yersinia-like fimbrial gene cluster for virulence. The patient's condition deteriorated rapidly but he recovered after receiving meropenem and intensive care support. Melioidosis is a potential problem among Chinese imigrant workers with strains new to China being identified.

  8. Caracterização fenotípica e molecular de amostras de Burkholderia mallei isoladas na Região Nordeste do Brasil Phenotypic and molecular characterization of Burkholderia mallei isolated in northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Karla P.C. Silva

    2009-05-01

    Full Text Available Objetivou-se com este trabalho realizar o estudo bioquímico e molecular de amostras de Burkholderia mallei isoladas de eqüídeos com diagnóstico clínico e sorológico para o mormo e provenientes da Região Metropolitana do Recife-PE e Zona da Mata dos Estados de Alagoas e Pernambuco. Foram realizadas as técnicas microbiológicas para o isolamento e identificação fenotípica de B. mallei e as técnicas moleculares de ribotipagem-PCR e RAPD-PCR. Das oito amostras estudadas, quatro apresentaram pequenas variações fenotípicas. Nas técnicas moleculares, as amostras formaram quatro grupos de diferentes perfis ribotípicos, demonstrando também quatro perfis genotípicos. Houve associação nos resultados da Ribotipagem-PCR e RAPD-PCR. As variações nos perfis ribotípicos e genotípicos foram associadas às diferentes regiões estudadas. De acordo com os resultados obtidos, conclui-se que as pequenas variações bioquímicas não estão associadas aos diferentes perfis moleculares e que essas diferenças demonstram uma heterogeneidade que está associada à procedência das amostras, indicando que a infecção nos animais ocorre por clones diferentes das amostras analisadas.The objective of this paper was to study the molecular performance and phenotypic characterization of Burkholderia mallei isolated from horses with clinical and serological diagnosis of glanders, originating from the Metropolitan District of Recife and Zona da Mata of Pernambuco and Alagoas. The isolation and biochemical identification of B. mallei was carried out by microbiological and molecular techniques of PCR-fingerprinting and RAPD-PCR. From the eight samples studied, four showed little phenotype variations. In the molecular tests, the samples formed 4 groups of different ribotype profiles and 4 genotype profiles. There was some association of PCR-fingerprinting with RAPD-PCR results. It was concluded that the slight biochemical variations were not associated with

  9. Characterization of the Phthalate Permease OphD from Burkholderia cepacia ATCC 17616†

    OpenAIRE

    Chang, Hung-Kuang; Zylstra, Gerben J.

    1999-01-01

    The ophD gene, encoding a permease for phthalate transport, was cloned from Burkholderia cepacia ATCC 17616. Expression of the gene in Escherichia coli results in the ability to transport phthalate rapidly into the cell. Uptake inhibition experiments show that 4-hydroxyphthalate, 4-chlorophthalate, 4-methylphthalate, and cinchomeronate compete for the phthalate permease. An ophD knockout mutant of 17616 grows slightly more slowly on phthalate but is still able to take up phthalate at rates eq...

  10. Phosphorus uptake of an arbuscular mycorrhizal fungus is not effected by the biocontrol bacterium ¤Burkholderia cepacia¤

    DEFF Research Database (Denmark)

    Ravnskov, S.; Larsen, J.; Jakobsen, I.

    2002-01-01

    The biocontrol bacterium Burkholderia cepacia is known to suppress a broad range of root pathogenic fungi, while its impact on other beneficial non-target organisms such as arbuscular mycorrhizal (AM) fungi is unknown. Direct interactions between five B. cepacia strains and the AM fungus, Glomus ...

  11. Draft Genome Sequence of the Soil Bacterium Burkholderia terrae Strain BS001, Which Interacts with Fungal Surface Structures

    DEFF Research Database (Denmark)

    Nazir, Rashid; Hansen, Martin A.; Sorensen, Soren

    2012-01-01

    Burkholderia terrae BS001 is a soil bacterium which was originally isolated from the mycosphere of the ectomycorrhizal fungus Laccaria proxima. It exhibits a range of fungus-interacting traits which reveal its propensity to actively interact at fungal interfaces. Here, we present the approximately...

  12. T-cell-dependent control of acute Giardia lamblia infections in mice.

    Science.gov (United States)

    Singer, S M; Nash, T E

    2000-01-01

    We have studied immune mechanisms responsible for control of acute Giardia lamblia and Giardia muris infections in adult mice. Association of chronic G. lamblia infection with hypogammaglobulinemia and experimental infections of mice with G. muris have led to the hypothesis that antibodies are required to control these infections. We directly tested this hypothesis by infecting B-cell-deficient mice with either G. lamblia or G. muris. Both wild-type mice and B-cell-deficient mice eliminated the vast majority of parasites between 1 and 2 weeks postinfection with G. lamblia. G. muris was also eliminated in both wild-type and B-cell-deficient mice. In contrast, T-cell-deficient and scid mice failed to control G. lamblia infections, as has been shown previously for G. muris. Treatment of wild-type or B-cell-deficient mice with antibodies to CD4 also prevented elimination of G. lamblia, confirming a role for T cells in controlling infections. By infecting mice deficient in either alphabeta- or gammadelta-T-cell receptor (TCR)-expressing T cells, we show that the alphabeta-TCR-expressing T cells are required to control parasites but that the gammadelta-TCR-expressing T cells are not. Finally, infections in mice deficient in production of gamma interferon or interleukin 4 (IL-4) and mice deficient in responding to IL-4 and IL-13 revealed that neither the Th1 nor the Th2 subset is absolutely required for protection from G. lamblia. We conclude that a T-cell-dependent mechanism is essential for controlling acute Giardia infections and that this mechanism is independent of antibody and B cells.

  13. Inactivation of Burkholderia pseudomallei on environmental surfaces using spray-applied, common liquid disinfectants.

    Science.gov (United States)

    Calfee, M W; Wendling, M

    2015-11-01

    Five commercially available liquid antimicrobials were evaluated for their ability to decontaminate common environmental surface materials, contaminated with Burkholderia pseudomallei, using a spray-based disinfectant delivery procedure. Tests were conducted at both an ambient temperature (c. 20°C) and a lower temperature (c. 12°C) condition. Nonporous materials (glass and aluminium) were more easily decontaminated than porous materials (wood, concrete and carpet). Citric acid (1%) demonstrated poor efficacy in all test conditions. Bleach (pH-adjusted), ethanol (70%), quaternary ammonium and PineSol®, demonstrated high (>6 log10 reduction) efficacies on glass and aluminium at both temperatures, but achieved varying results for wood, carpet and concrete. Temperature had minimal effect on decontamination efficacy during these tests. Much of the antimicrobial efficacy data for pathogenic micro-organisms are generated with testing that utilizes hard nonporous surface materials. These data are not directly translatable for decontaminant selection following an incident whereby complex and porous environmental surfaces are contaminated. This study presents efficacy data for spray-applied antimicrobial liquids, when used to decontaminate common environmental surfaces contaminated with Burkholderia pseudomallei. These data can help responders develop effective remediation strategies following an environmental contamination incident involving B. pseudomallei. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  14. Bacteria of the Burkholderia cepacia complex are cyanogenic under biofilm and colonial growth conditions

    Directory of Open Access Journals (Sweden)

    Hoshino Saiko

    2008-06-01

    Full Text Available Abstract Background The Burkholderia cepacia complex (Bcc is a collection of nine genotypically distinct but phenotypically similar species. They show wide ecological diversity and include species that are used for promoting plant growth and bio-control as well species that are opportunistic pathogens of vulnerable patients. Over recent years the Bcc have emerged as problematic pathogens of the CF lung. Pseudomonas aeruginosa is another important CF pathogen. It is able to synthesise hydrogen cyanide (HCN, a potent inhibitor of cellular respiration. We have recently shown that HCN production by P. aeruginosa may have a role in CF pathogenesis. This paper describes an investigation of the ability of bacteria of the Bcc to make HCN. Results The genome of Burkholderia cenocepacia has 3 putative HCN synthase encoding (hcnABC gene clusters. B. cenocepacia and all 9 species of the Bcc complex tested were able to make cyanide at comparable levels to P. aeruginosa, but only when grown surface attached as colonies or during biofilm growth on glass beads. In contrast to P. aeruginosa and other cyanogenic bacteria, cyanide was not detected during planktonic growth of Bcc strains. Conclusion All species in the Bcc are cyanogenic when grown as surface attached colonies or as biofilms.

  15. Identification and cloning of four riboswitches from Burkholderia pseudomallei strain K96243

    Science.gov (United States)

    Munyati-Othman, Noor; Fatah, Ahmad Luqman Abdul; Piji, Mohd Al Akmarul Fizree Bin Md; Ramlan, Effirul Ikhwan; Raih, Mohd Firdaus

    2015-09-01

    Structured RNAs referred as riboswitches have been predicted to be present in the genome sequence of Burkholderia pseudomallei strain K96243. Four of the riboswitches were identified and analyzed through BLASTN, Rfam search and multiple sequence alignment. The RNA aptamers belong to the following riboswitch classifications: glycine riboswitch, cobalamin riboswitch, S-adenosyl-(L)-homocysteine (SAH) riboswitch and flavin mononucleotide (FMN) riboswitch. The conserved nucleotides for each aptamer were identified and were marked on the secondary structure generated by RNAfold. These riboswitches were successfully amplified and cloned for further study.

  16. Outbreak of Burkholderia cepacia complex bacteremia in a chemotherapy day care unit due to intrinsic contamination of an antiemetic drug

    Directory of Open Access Journals (Sweden)

    T Singhal

    2015-01-01

    Full Text Available Background: In the end of 2009, a large number of patients with cancer undergoing chemotherapy at the day care unit of a private hospital in Mumbai, India developed Burkholderia cepacia complex (BCC blood stream infection (BSI. Objective: The objectives were to identify the source of the outbreak and terminate the outbreak as rapidly as possible. Materials and Methods: All infection control protocols and processes were reviewed. Intensive training was started for all nursing staff involved in patient care. Cultures were sent from the environment (surfaces, water, air, intravenous fluids, disinfectants and antiseptics and opened/unopened medication. Results: A total of 13 patients with cancer with tunneled catheters were affected with BCC BSI. The isolates were of similar antimicrobial sensitivity. No significant breach of infection control protocols could be identified. Cultures from the prepared intravenous medication bags grew BCC. Subsequently, culture from unused vials of the antiemetic granisetron grew BCC, whereas those from the unopened IV fluid bag and chemotherapy medication were negative. On review, it was discovered that the outbreak started when a new brand of granisetron was introduced. The result was communicated to the manufacturer and the brand was withdrawn. There were no further cases. Conclusions: This outbreak was thus linked to intrinsic contamination of medication vials. We acknowledge a delay in identifying the source as we were concentrating more on human errors in medication preparation and less on intrinsic contamination. We recommend that in an event of an outbreak, unopened vials be cultured at the outset.

  17. A genomic survey of positive selection in Burkholderia pseudomallei provides insights into the evolution of accidental virulence.

    Directory of Open Access Journals (Sweden)

    Tannistha Nandi

    2010-04-01

    Full Text Available Certain environmental microorganisms can cause severe human infections, even in the absence of an obvious requirement for transition through an animal host for replication ("accidental virulence". To understand this process, we compared eleven isolate genomes of Burkholderia pseudomallei (Bp, a tropical soil microbe and causative agent of the human and animal disease melioidosis. We found evidence for the existence of several new genes in the Bp reference genome, identifying 282 novel genes supported by at least two independent lines of supporting evidence (mRNA transcripts, database homologs, and presence of ribosomal binding sites and 81 novel genes supported by all three lines. Within the Bp core genome, 211 genes exhibited significant levels of positive selection (4.5%, distributed across many cellular pathways including carbohydrate and secondary metabolism. Functional experiments revealed that certain positively selected genes might enhance mammalian virulence by interacting with host cellular pathways or utilizing host nutrients. Evolutionary modifications improving Bp environmental fitness may thus have indirectly facilitated the ability of Bp to colonize and survive in mammalian hosts. These findings improve our understanding of the pathogenesis of melioidosis, and establish Bp as a model system for studying the genetics of accidental virulence.

  18. Molecular characterization of a novel family VIII esterase from burkholderia multivorans UWC10

    CSIR Research Space (South Africa)

    Rashamuse, KJ

    2007-02-01

    Full Text Available et al., 1992). Here we report the cloning, purification, and 3D model of a novel family VIII esterase from Burkholderia multivorans UWC10. To our knowledge no report of esterolytic activity from B. multivorans is currently available. METHODOLOGY... stream_source_info Rashamuse1_2007_d.pdf.txt stream_content_type text/plain stream_size 9884 Content-Encoding UTF-8 stream_name Rashamuse1_2007_d.pdf.txt Content-Type text/plain; charset=UTF-8 Molecular Characterization...

  19. Regulation of Burkholderia cenocepacia biofilm formation by RpoN and the c-di-GMP effector BerB

    DEFF Research Database (Denmark)

    Fazli, Mustafa; Rybtke, Morten Levin; Steiner, Elisabeth

    2017-01-01

    Knowledge about the molecular mechanisms that are involved in the regulation of biofilm formation is essential for the development of biofilm-control measures. It is well established that the nucleotide second messenger cyclic diguanosine monophosphate (c-di-GMP) is a positive regulator of biofilm...... formation in many bacteria, but more knowledge about c-di-GMP effectors is needed. We provide evidence that c-di-GMP, the alternative sigma factor RpoN (σ54), and the enhancer-binding protein BerB play a role in biofilm formation of Burkholderia cenocepacia by regulating the production of a biofilm......-stabilizing exopolysaccharide. Our findings suggest that BerB binds c-di-GMP, and activates RpoN-dependent transcription of the berA gene coding for a c-di-GMP-responsive transcriptional regulator. An increased level of the BerA protein in turn induces the production of biofilm-stabilizing exopolysaccharide in response to high...

  20. HIV-1 Infection of T Cells and Macrophages Are Differentially Modulated by Virion-Associated Hck: A Nef-Dependent Phenomenon

    Directory of Open Access Journals (Sweden)

    Gilda Tachedjian

    2013-09-01

    Full Text Available The proline repeat motif (PxxP of Nef is required for interaction with the SH3 domains of macrophage-specific Src kinase Hck. However, the implication of this interaction for viral replication and infectivity in macrophages and T lymphocytes remains unclear. Experiments in HIV-1 infected macrophages confirmed the presence of a Nef:Hck complex which was dependent on the Nef proline repeat motif. The proline repeat motif of Nef also enhanced both HIV-1 infection and replication in macrophages, and was required for incorporation of Hck into viral particles. Unexpectedly, wild-type Hck inhibited infection of macrophages, but Hck was shown to enhance infection of primary T lymphocytes. These results indicate that the interaction between Nef and Hck is important for Nef-dependent modulation of viral infectivity. Hck-dependent enhancement of HIV-1 infection of T cells suggests that Nef-Hck interaction may contribute to the spread of HIV-1 infection from macrophages to T cells by modulating events in the producer cell, virion and target cell.

  1. Transfer of eleven species of the genus Burkholderia to the genus Paraburkholderia and proposal of Caballeronia gen. nov. to accommodate twelve species of the genera Burkholderia and Paraburkholderia.

    Science.gov (United States)

    Dobritsa, Anatoly P; Samadpour, Mansour

    2016-08-01

    It has been proposed to split the genus Burkholderia into two genera according to phylogenetic clustering: (1) a genus retaining this name and consisting mainly of animal and plant pathogens and (2) the genus Paraburkholderia including so-called environmental bacteria. The latter genus name has been validly published recently. During the period between the effective and valid publications of the genus name Paraburkholderia, 16 novel species of the genus Burkholderiawere described, but only two of them can be classified as members of this genus based on the emended genus description. Analysis of traits and phylogenetic positions of the other 11 species shows that they belong to the genus Paraburkholderia, and we propose to transfer them to this genus. The reclassified species names are proposed as Paraburkholderia dipogonis comb. nov., Paraburkholderia ginsengiterrae comb. nov., Paraburkholderia humisilvae comb. nov., Paraburkholderia insulsa comb. nov., Paraburkholderia kirstenboschensis comb. nov., Paraburkholderia metalliresistens comb. nov., Paraburkholderia monticola comb. nov., Paraburkholderia panaciterrae comb. nov., Paraburkholderia rhizosphaerae comb. nov., Paraburkholderia solisilvae comb. nov. and Paraburkholderia susongensis comb. nov. The remaining three species are transferred to the new genus Caballeronia gen. nov. proposed to accommodate twelve species of the genera Burkholderia and Paraburkholderia forming a distinctive clade in phylogenetic trees. The new genus members are Caballeronia choica comb. nov., Caballeronia cordobensis comb. nov., Caballeronia glathei comb. nov., Caballeronia grimmiae comb. nov., Caballeronia humi comb. nov., Caballeronia megalochromosomata comb. nov., Caballeronia jiangsuensis comb. nov., Caballeronia sordidicola comb. nov., Caballeronia telluris comb. nov., Caballeronia terrestris comb. nov., Caballeronia udeis comb. nov., and Caballeronia zhejiangensis comb. nov.

  2. Development and validation of Burkholderia pseudomallei-specific real-time PCR assays for clinical, environmental or forensic detection applications.

    Directory of Open Access Journals (Sweden)

    Erin P Price

    Full Text Available The bacterium Burkholderia pseudomallei causes melioidosis, a rare but serious illness that can be fatal if untreated or misdiagnosed. Species-specific PCR assays provide a technically simple method for differentiating B. pseudomallei from near-neighbor species. However, substantial genetic diversity and high levels of recombination within this species reduce the likelihood that molecular signatures will differentiate all B. pseudomallei from other Burkholderiaceae. Currently available molecular assays for B. pseudomallei detection lack rigorous validation across large in silico datasets and isolate collections to test for specificity, and none have been subjected to stringent quality control criteria (accuracy, precision, selectivity, limit of quantitation (LoQ, limit of detection (LoD, linearity, ruggedness and robustness to determine their suitability for environmental, clinical or forensic investigations. In this study, we developed two novel B. pseudomallei specific assays, 122018 and 266152, using a dual-probe approach to differentiate B. pseudomallei from B. thailandensis, B. oklahomensis and B. thailandensis-like species; other species failed to amplify. Species specificity was validated across a large DNA panel (>2,300 samples comprising Burkholderia spp. and non-Burkholderia bacterial and fungal species of clinical and environmental relevance. Comparison of assay specificity to two previously published B. pseudomallei-specific assays, BurkDiff and TTS1, demonstrated comparable performance of all assays, providing between 99.7 and 100% specificity against our isolate panel. Last, we subjected 122018 and 266152 to rigorous quality control analyses, thus providing quantitative limits of assay performance. Using B. pseudomallei as a model, our study provides a framework for comprehensive quantitative validation of molecular assays and provides additional, highly validated B. pseudomallei assays for the scientific research community.

  3. Characterization of Burkholderia rhizoxinica and B. endofungorum isolated from clinical specimens.

    Directory of Open Access Journals (Sweden)

    Jay E Gee

    Full Text Available Eight isolates submitted to CDC from 1989 to 2006 from clinical specimens were initially identified as members of the genus Burkholderia based on preliminary cellular fatty acid analysis and/or 16S rRNA gene sequencing. With the recent descriptions of the new species B. rhizoxinica and B. endofungorum, which are considered endosymbiotic bacteria in Rhizopus microsporus fungi, we now identify seven of these clinical isolates as B. rhizoxinica and one as B. endofungorum based on biochemical testing, 16s rRNA, and DNA-DNA hybridization results. We also further characterize these isolates by assessing toxin production and/or by multiple locus sequence typing.

  4. Secondary metabolites from Bacillus amyloliquefaciens isolated from soil can kill Burkholderia pseudomallei.

    Science.gov (United States)

    Boottanun, Patcharaporn; Potisap, Chotima; Hurdle, Julian G; Sermswan, Rasana W

    2017-12-01

    Bacillus species are Gram-positive bacteria found in abundance in nature and their secondary metabolites were found to possess various potential activities, notably antimicrobial. In this study, Bacillus amyloliquefaciens N2-4 and N3-8 were isolated from soil and their metabolites could kill Burkholderia pseudomallei, a Gram-negative pathogenic bacterium also found in soil in its endemic areas. Moreover, the metabolites were able to kill drug resistant isolates of B. pseudomallei and also inhibit other pathogenic bacteria such as Staphylococcus aureus, Escherichia coli and Acinetobacter baumannii but not the non-pathogenic Burkholderia thailandensis, which is closely related to B. pseudomallei. Since the antimicrobial activity of N3-8 was not partially decreased or abolished when treated with proteolytic enzymes or autoclaved, but N2-4 was, these two strains should have produced different compounds. The N3-8 metabolites with antimicrobial activity consisted of both protein and non-protein compounds. The inhibition spectrum of the precipitated proteins compared to the culture supernatant indicated a possible synergistic effect of the non-protein and peptide compounds of N3-8 isolates against other pathogens. When either N2-4 or N3-8 isolates was co-cultured with B. pseudomallei the numbers of the bacteria decreased by 5 log 10 within 72 h. Further purification and characterization of the metabolites is required for future use of the bacteria or their metabolites as biological controls of B. pseudomallei in the environment or for development as new drugs for problematic pathogenic bacteria.

  5. TLR-dependent control of Francisella tularensis infection and host inflammatory responses.

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    Allison L Abplanalp

    2009-11-01

    Full Text Available Francisella tularensis is the causative agent of tularemia and is classified as a Category A select agent. Recent studies have implicated TLR2 as a critical element in the host protective response to F. tularensis infection, but questions remain about whether TLR2 signaling dominates the response in all circumstances and with all species of Francisella and whether F. tularensis PAMPs are predominantly recognized by TLR2/TLR1 or TLR2/TLR6. To address these questions, we have explored the role of Toll-like receptors (TLRs in the host response to infections with F. tularensis Live Vaccine Strain (LVS and F. tularensis subspecies (subsp. novicida in vivo.C57BL/6 (B6 control mice and TLR- or MyD88-deficient mice were infected intranasally (i.n. or intradermally (i.d. with F. tularensis LVS or with F. tularensis subsp. novicida. B6 mice survived >21 days following infection with LVS by both routes and survival of TLR1(-/-, TLR4(-/-, and TLR6(-/- mice infected i.n. with LVS was equivalent to controls. Survival of TLR2(-/- and MyD88(-/- mice, however, was significantly reduced compared to B6 mice, regardless of the route of infection or the subspecies of F. tularensis. TLR2(-/- and MyD88(-/- mice also showed increased bacterial burdens in lungs, liver, and spleen compared to controls following i.n. infection. Primary macrophages from MyD88(-/- and TLR2(-/- mice were significantly impaired in the ability to secrete TNF and other pro-inflammatory cytokines upon ex vivo infection with LVS. TNF expression was also impaired in vivo as demonstrated by analysis of bronchoalveolar lavage fluid and by in situ immunofluorescent staining.We conclude from these studies that TLR2 and MyD88, but not TLR4, play critical roles in the innate immune response to F. tularensis infection regardless of the route of infection or the subspecies. Moreover, signaling through TLR2 does not depend exclusively on TLR1 or TLR6 during F. tularensis LVS infection.

  6. Functional characterisation of Burkholderia pseudomallei biotin protein ligase: A toolkit for anti-melioidosis drug development.

    Science.gov (United States)

    Bond, Thomas E H; Sorenson, Alanna E; Schaeffer, Patrick M

    2017-06-01

    Burkholderia pseudomallei (Bp) is the causative agent of melioidosis. The bacterium is responsible for 20% of community-acquired sepsis cases and 40% of sepsis-related mortalities in northeast Thailand, and is intrinsically resistant to aminoglycosides, macrolides, rifamycins, cephalosporins, and nonureidopenicillins. There is no vaccine and its diagnosis is problematic. Biotin protein ligase (BirA) which is essential for fatty acid synthesis has been proposed as a drug target in bacteria. Very few bacterial BirA have been characterized, and a better understanding of these enzymes is necessary to further assess their value as drug targets. BirA within the Burkholderia genus have not yet been investigated. We present for the first time the cloning, expression, purification and functional characterisation of the putative Bp BirA and orthologous B. thailandensis (Bt) biotin carboxyl carrier protein (BCCP) substrate. A GFP-tagged Bp BirA was produced and applied for the development of a high-throughput (HT) assay based on our differential scanning fluorimetry of GFP-tagged proteins (DSF-GTP) principle as well as an electrophoretic mobility shift assay. Our biochemical data in combination with the new HT DSF-GTP and biotinylation activity assay could facilitate future drug screening efforts against this drug-resistant organism. Copyright © 2017 Elsevier GmbH. All rights reserved.

  7. Prevalence of Burkholderia pseudomallei in Guangxi, China.

    Science.gov (United States)

    Ma, G; Zheng, D; Cai, Q; Yuan, Z

    2010-01-01

    Melioidosis, an infectious disease caused by the Gram-negative bacterium Burkholderia pseudomallei, is now recognized as an important public health problem in Southeast Asia and tropical northern Australia. Although B. pseudomallei has been detected in various water and soil samples in southeast China, the enviromental distribution of B. pseudomallei in China is unclear. In the winter months of 2007, 154 and 130 soil and water samples, respectively, were collected from several locations in Guangxi, China. The samples were screened for B. pseudomallei by bacterial culture and identification and confirmed by PCR for species-specific 16S rDNA and flagellin genes. B. pseudomallei was detected in 8.4% of the soil samples but in none of the water samples. All positive samples were confined to a single low-lying region from rice paddy fields. Counts of B. pseudomallei ranged from 23 to 521 c.f.u./g soil. This is the first geographical distribution survey of B. pseudomallei in soil in Guangxi, China, and the data are of importance for further evaluating the impact of this pathogen on melioidosis in this region.

  8. Manganese scavenging and oxidative stress response mediated by type VI secretion system in Burkholderia thailandensis.

    Science.gov (United States)

    Si, Meiru; Zhao, Chao; Burkinshaw, Brianne; Zhang, Bing; Wei, Dawei; Wang, Yao; Dong, Tao G; Shen, Xihui

    2017-03-14

    Type VI secretion system (T6SS) is a versatile protein export machinery widely distributed in Gram-negative bacteria. Known to translocate protein substrates to eukaryotic and prokaryotic target cells to cause cellular damage, the T6SS has been primarily recognized as a contact-dependent bacterial weapon for microbe-host and microbial interspecies competition. Here we report contact-independent functions of the T6SS for metal acquisition, bacteria competition, and resistance to oxidative stress. We demonstrate that the T6SS-4 in Burkholderia thailandensis is critical for survival under oxidative stress and is regulated by OxyR, a conserved oxidative stress regulator. The T6SS-4 is important for intracellular accumulation of manganese (Mn 2+ ) under oxidative stress. Next, we identified a T6SS-4-dependent Mn 2+ -binding effector TseM, and its interacting partner MnoT, a Mn 2+ -specific TonB-dependent outer membrane transporter. Similar to the T6SS-4 genes, expression of mnoT is regulated by OxyR and is induced under oxidative stress and low Mn 2+ conditions. Both TseM and MnoT are required for efficient uptake of Mn 2+ across the outer membrane under Mn 2+ -limited and -oxidative stress conditions. The TseM-MnoT-mediated active Mn 2+ transport system is also involved in contact-independent bacteria-bacteria competition and bacterial virulence. This finding provides a perspective for understanding the mechanisms of metal ion uptake and the roles of T6SS in bacteria-bacteria competition.

  9. Rapid Antimicrobial Susceptibility Testing of Bacillus anthracis, Yersinia pestis, and Burkholderia pseudomallei by Use of Laser Light Scattering Technology.

    Science.gov (United States)

    Bugrysheva, Julia V; Lascols, Christine; Sue, David; Weigel, Linda M

    2016-06-01

    Rapid methods to determine antimicrobial susceptibility would assist in the timely distribution of effective treatment or postexposure prophylaxis in the aftermath of the release of bacterial biothreat agents such as Bacillus anthracis, Yersinia pestis, or Burkholderia pseudomallei Conventional susceptibility tests require 16 to 48 h of incubation, depending on the bacterial species. We evaluated a method that is based on laser light scattering technology that measures cell density in real time. We determined that it has the ability to rapidly differentiate between growth (resistant) and no growth (susceptible) of several bacterial threat agents in the presence of clinically relevant antimicrobials. Results were available in 10 h of incubation. Use of laser scattering technology decreased the time required to determine antimicrobial susceptibility by 50% to 75% for B. anthracis, Y. pestis, and B. pseudomallei compared to conventional methods. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  10. Relative uptake of technetium 99m stannous colloid by neutrophils and monocytes is altered by gram-negative infection

    International Nuclear Information System (INIS)

    Ramsay, Stuart C.; Maggs, Jacqueline A.; Ketheesan, Natkunam; Norton, Robert; LaBrooy, Justin

    2005-01-01

    Gram-negative infection alters phagocytic cell function; hence, it could affect phagocytic uptake of inorganic colloids by these cells. Neutrophil and monocyte uptake of technetium 99m stannous colloid ( 99m Tc SnC) in whole blood was measured in 10 patients with gram-negative infection (Burkholderia pseudomallei) and 7 controls. Mean uptake per individual neutrophil was reduced in infection. Uptake per monocyte was not significantly different. Blood from six normal individuals was incubated with lysed B. pseudomallei and colloid, which showed reduced neutrophil uptake, but increased monocyte uptake. These results indicate that uptake of 99m Tc SnC stannous colloid can be used to measure alteration in phagocytic cell function. They suggest that infection with B. pseudomallei is associated with reduced phagocytosis by individual neutrophils, possibly through toxic effects of bacterial products. This could have immunopathogenic consequences for this gram-negative infection and may explain why it responds to granulocyte colony-stimulating factor

  11. Detection of Burkholderia pseudomallei in Sputum using Selective Enrichment Broth and Ashdown’s Medium at Kampong Cham Provincial Hospital, Cambodia [v1; ref status: indexed, http://f1000r.es/4w7

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    Somary Nhem

    2014-12-01

    Full Text Available Melioidosis infection, caused by Burkholderia pseudomallei, is increasingly reported in Cambodia. We hypothesized that implementation of an enhanced sputum testing protocol in a provincial hospital diagnostic microbiology laboratory would increase detection of B. pseudomallei. We tested 241 sputum specimens that were deemed acceptable for culture, comparing culture in selective enrichment broth followed by sub-culture on Ashdown’s medium to standard culture methods. Two specimens (0.8% were positive for B. pseudomallei using the enhanced protocol whereas one specimen (0.4% was positive using standard methods. These findings demonstrate that B. pseudomallei is rarely detected in sputum at this hospital. The low frequency of B. pseudomallei in sputum specimens precludes drawing any conclusions about the relative benefits of an enhanced sputum testing protocol at this site. Promoting clinician awareness of the infection and encouraging utilization of diagnostic microbiology services are likely to be important factors in facilitating identification of melioidosis.

  12. Relationships within the Proteobacteria of plant pathogenic Acidovorax species and subspecies, Burkholderia species, and Herbaspirillum rubrisubalbicans by sequence analysis of 16S rDNA, numerical analysis and determinative tests.

    Science.gov (United States)

    Hu, F P; Young, J M; Triggs, C M; Park, D C; Saul, D J

    2001-12-01

    Sequence data for 16S rDNA of the type strains of Acidovorax avenae subsp. avenae, A. avenae subsp. cattleyae, A. avenae subsp. citrulli, A. konjaci and Herbaspirillum rubrisubalbicans were compared with GenBank library accessions of Burkholderia spp., Comamonas sp., Ralstonia solanacearum and Variovorax sp. Maximum Parsimony analysis produced two clusters: 1. Acidovorax spp., Comamonas sp., and Variovorax sp. (all in the Comamonadaceae), and 2. Burkholderia spp., Ralstonia solanacearum, and Herbaspirillum rubrisubalbicans. Maximum Likelihood analysis produced only one cluster (of the Comamonadaceae). Using nutritional and laboratory tests, all Acidovorax spp., Burkholderia spp., and Herbaspirillum rubrisubalbicans were discriminated in distinct clusters at the species level, and could be identified by selected determinative tests. There were no phenotypic tests constituted as a circumscription of the genera and which permitted the allocation of strains to genera. Strain identification as species allowed allocation to genera only by inference. The nomenclatural implications of these data are discussed.

  13. An outbreak of Burkholderia cepacia complex in the paediatric unit of a tertiary care hospital.

    Science.gov (United States)

    Mali, Swapna; Dash, Lona; Gautam, Vikas; Shastri, Jayanthi; Kumar, Sunil

    2017-01-01

    Burkholderia cepacia complex (Bcc) has emerged as a serious nosocomial pathogen worldwide especially in patients with indwelling catheters and cystic fibrosis. Bcc is a common contaminant of pharmaceutical products. We describe an outbreak of Bcc bacteraemia amongst children admitted in Paediatric Intensive Care Unit (PICU) and paediatric ward at a tertiary care hospital, Mumbai, in Western India. Blood culture samples from paediatric patients yielded growth of non-fermenting, oxidase positive, motile, Gram negative bacilli (NFGNB) (76/909) over a period of 8 months. Based on conventional biochemical tests and antimicrobial susceptibility testing, these isolates were provisionally identified as Bcc. The increased, repeated and continued isolation of Bcc alerted the possibility of an outbreak confined to PICU and paediatric ward. Active surveillance was undertaken to trace the source and contain the outbreak. Isolates were subjected to recA polymerase chain reaction (PCR) and Expanded multilocus sequence typing (EMLST). Surveillance revealed the presence of Bcc on the upper surface of rubber stopper of sealed multidose amikacin vials. Isolates from blood culture and rubber stoppers were confirmed as Bcc by recA PCR. EMLST revealed that these isolates shared an identical novel sequence type 824 proving clonality. Timely interventions instituted led to control of the outbreak. This study highlights the importance of identification and molecular characterization of Bcc to establish its role in infection and outbreak.

  14. Carotenoid-dependent coloration of male American kestrels predicts ability to reduce parasitic infections

    Science.gov (United States)

    Dawson, Russell D.; Bortolotti, Gary R.

    2006-12-01

    The signaling function of sexually selected traits, such as carotenoid-dependent avian plumage coloration, has received a great deal of recent attention especially with respect to parasitism and immunocompetence. We argue that parasite-mediated models of sexual selection may have an implicit temporal component that many researchers have ignored. For example, previous studies have demonstrated that carotenoid-dependent traits can signal past parasite exposure, current levels of parasitism, or the ability of individuals to manage parasitic infections in the future. We examined repeated measures of carotenoid-dependent skin color and blood parasitism in American kestrels ( Falco sparverius) to distinguish whether coloration might signal current parasitism or the potential to deal with infections in the future. We found no evidence that coloration was related to current levels of parasitism in either sex. However, coloration of males significantly predicted their response to parasitism; males with bright orange coloration during prelaying, when mate choice is occurring, were more likely than dull yellow males to reduce their levels of infection by the time incubation began. Coloration during prelaying may advertise a male’s health later in the breeding season. For kestrels, the ability to predict future health would be highly beneficial given the male’s role in providing food to his mate and offspring. Coloration of females was not a significant predictor of parasitism in the future, and we provide several possible explanations for this result.

  15. Differentiation-Dependent KLF4 Expression Promotes Lytic Epstein-Barr Virus Infection in Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Dhananjay M Nawandar

    2015-10-01

    Full Text Available Epstein-Barr virus (EBV is a human herpesvirus associated with B-cell and epithelial cell malignancies. EBV lytically infects normal differentiated oral epithelial cells, where it causes a tongue lesion known as oral hairy leukoplakia (OHL in immunosuppressed patients. However, the cellular mechanism(s that enable EBV to establish exclusively lytic infection in normal differentiated oral epithelial cells are not currently understood. Here we show that a cellular transcription factor known to promote epithelial cell differentiation, KLF4, induces differentiation-dependent lytic EBV infection by binding to and activating the two EBV immediate-early gene (BZLF1 and BRLF1 promoters. We demonstrate that latently EBV-infected, telomerase-immortalized normal oral keratinocyte (NOKs cells undergo lytic viral reactivation confined to the more differentiated cell layers in organotypic raft culture. Furthermore, we show that endogenous KLF4 expression is required for efficient lytic viral reactivation in response to phorbol ester and sodium butyrate treatment in several different EBV-infected epithelial cell lines, and that the combination of KLF4 and another differentiation-dependent cellular transcription factor, BLIMP1, is highly synergistic for inducing lytic EBV infection. We confirm that both KLF4 and BLIMP1 are expressed in differentiated, but not undifferentiated, epithelial cells in normal tongue tissue, and show that KLF4 and BLIMP1 are both expressed in a patient-derived OHL lesion. In contrast, KLF4 protein is not detectably expressed in B cells, where EBV normally enters latent infection, although KLF4 over-expression is sufficient to induce lytic EBV reactivation in Burkitt lymphoma cells. Thus, KLF4, together with BLIMP1, plays a critical role in mediating lytic EBV reactivation in epithelial cells.

  16. Games of age-dependent prevention of chronic infections by social distancing.

    Science.gov (United States)

    Reluga, Timothy C; Li, Jing

    2013-06-01

    Epidemiological games combine epidemic modelling with game theory to assess strategic choices in response to risks from infectious diseases. In most epidemiological games studied thus-far, the strategies of an individual are represented with a single choice parameter. There are many natural situations where strategies can not be represented by a single dimension, including situations where individuals can change their behavior as they age. To better understand how age-dependent variations in behavior can help individuals deal with infection risks, we study an epidemiological game in an SI model with two life-history stages where social distancing behaviors that reduce exposure rates are age-dependent. When considering a special case of the general model, we show that there is a unique Nash equilibrium when the infection pressure is a monotone function of aggregate exposure rates, but non-monotone effects can appear even in our special case. The non-monotone effects sometimes result in three Nash equilibria, two of which have local invasion potential simultaneously. Returning to a general case, we also describe a game with continuous age-structure using partial-differential equations, numerically identify some Nash equilibria, and conjecture about uniqueness.

  17. IN SITU BIOREMEDIATION OF TRICHLOROETHYLENE USING BURKHOLDERIA CEPACIA G4 PR1: ANALYSIS OF MICROBIAL ECOLOGY PARAMETERS FOR RISK ASSESSMENT (RESEARCH BRIEF)

    Science.gov (United States)

    The introduction of bacteria into aquifers for bioremediation purposes requires monitoring of the persistence and activity of microbial populations for efficacy and risk assessment purposes. Burkholderia cepacia G4 PR1 constitutively expresses a toluene ortho-monooxygenase (tom) ...

  18. Functional interactions of HIV-infection and methamphetamine dependence during motor programming.

    Science.gov (United States)

    Archibald, Sarah L; Jacobson, Mark W; Fennema-Notestine, Christine; Ogasawara, Miki; Woods, Steven P; Letendre, Scott; Grant, Igor; Jernigan, Terry L

    2012-04-30

    Methamphetamine (METH) dependence is frequently comorbid with HIV infection and both have been linked to alterations of brain structure and function. In a previous study, we showed that the brain volume loss characteristic of HIV infection contrasts with METH-related volume increases in striatum and parietal cortex, suggesting distinct neurobiological responses to HIV and METH (Jernigan et al., 2005). Functional magnetic resonance imaging (fMRI) has the potential to reveal functional interactions between the effects of HIV and METH. In the present study, 50 participants were studied in four groups: an HIV+ group, a recently METH-dependent group, a dually affected group, and a group of unaffected community comparison subjects. An fMRI paradigm consisting of motor sequencing tasks of varying levels of complexity was administered to examine blood oxygenation level dependent (BOLD) changes. Within all groups, activity increased significantly with increasing task complexity in large clusters within sensorimotor and parietal cortex, basal ganglia, cerebellum, and cingulate. The task complexity effect was regressed on HIV status, METH status, and the HIV×METH interaction term in a simultaneous multiple regression. HIV was associated with less complexity-related activation in striatum, whereas METH was associated with less complexity-related activation in parietal regions. Significant interaction effects were observed in both cortical and subcortical regions; and, contrary to expectations, the complexity-related activation was less aberrant in dually affected than in single risk participants, in spite of comparable levels of neurocognitive impairment among the clinical groups. Thus, HIV and METH dependence, perhaps through their effects on dopaminergic systems, may have opposing functional effects on neural circuits involved in motor programming. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  19. Phenotypic characterization of a novel virulence-factor deletion strain of Burkholderia mallei that provides partial protection against inhalational glanders in mice

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    Joel A. Bozue

    2016-02-01

    Full Text Available Burkholderia mallei (Bm is a highly infectious intracellular pathogen classified as a category B biological agent by the Centers for Disease Control and Prevention. After respiratory exposure, Bm establishes itself within host macrophages before spreading into major organ systems, which can lead to chronic infection, sepsis, and death. Previously, we combined computational prediction of host-pathogen interactions with yeast two-hybrid experiments and identified novel virulence factor genes in Bm, including BMAA0553, BMAA0728 (tssN, and BMAA1865. In the present study, we used recombinant allelic exchange to construct deletion mutants of BMAA0553 and tssN (ΔBMAA0553 and ΔTssN, respectively and showed that both deletions completely abrogated virulence at doses of >100 times the LD50 of the wild-type Bm strain. Analysis of ΔBMAA0553- and ΔTssN-infected mice showed starkly reduced bacterial dissemination relative to wild-type Bm, and subsequent in vitro experiments characterized pathogenic phenotypes with respect to intracellular growth, macrophage uptake and phagosomal escape, actin-based motility, and multinucleated giant cell formation. Based on observed in vitro and in vivo phenotypes, we explored the use of ΔTssN as a candidate live-attenuated vaccine. Mice immunized with aerosolized ΔTssN showed a 21-day survival rate of 67% after a high-dose aerosol challenge with the wild-type Bm ATCC 23344 strain, compared to a 0% survival rate for unvaccinated mice. However, analysis of histopathology and bacterial burden showed that while the surviving vaccinated mice were protected from acute infection, Bm was still able to establish a chronic infection. Vaccinated mice showed a modest IgG response, suggesting a limited potential of ΔTssN as a vaccine candidate, but also showed prolonged elevation of pro-inflammatory cytokines, underscoring the role of cellular and innate immunity in mitigating acute infection in inhalational glanders.

  20. Nanolipoprotein Particles (NLPs) as Versatile Vaccine Platforms for Co-delivery of Multiple Adjuvants with Subunit Antigens from Burkholderia spp. and F. tularensis - Annual Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, N. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-04-16

    The goal of this proposal is to demonstrate that co-localization of protein subunit antigens and adjuvants on nanolipoprotein particles (NLPs) can increase the protective efficacy of recombinant subunit antigens from Burkholderia spp. and Francisella tularensis against an aerosol challenge. NLPs are are biocompatible, high-density lipoprotein mimetics that are amenable to the incorporation of multiple, chemically-disparate adjuvant and antigen molecules. We hypothesize that the ability to co-localize optimized adjuvant formulations with subunit antigens within a single particle will enhance the stimulation and activation of key immune effector cells, increasing the protective efficacy of subunit antigen-based vaccines. While Burkholderia spp. and F. tularensis subunit antigens are the focus of this proposal, we anticipate that this approach is applicable to a wide range of DOD-relevant biothreat agents. The F344 rat aerosol challenge model for F. tularensis has been successfully established at Battelle under this contract, and Year 3 efficacy studies performed at Battelle demonstrated that an NLP vaccine formulation was able to enhance survival of female F344 rats relative to naïve animals. In addition, Year 3 focused on the incorporation of multiple Burkholderia antigens (both polysaccharides and proteins) onto adjuvanted NLPs, with immunological analysis poised to begin in the next quarter.

  1. Comparative and bioinformatics analyses of pathogenic bacterial secretomes identified by mass spectrometry in Burkholderia species.

    Science.gov (United States)

    Nguyen, Thao Thi; Chon, Tae-Soo; Kim, Jaehan; Seo, Young-Su; Heo, Muyoung

    2017-07-01

    Secreted proteins (secretomes) play crucial roles during bacterial pathogenesis in both plant and human hosts. The identification and characterization of secretomes in the two plant pathogens Burkholderia glumae BGR1 and B. gladioli BSR3, which cause diseases in rice such as seedling blight, panicle blight, and grain rot, are important steps to not only understand the disease-causing mechanisms but also find remedies for the diseases. Here, we identified two datasets of secretomes in B. glumae BGR1 and B. gladioli BSR3, which consist of 118 and 111 proteins, respectively, using mass spectrometry approach and literature curation. Next, we characterized the functional properties, potential secretion pathways and sequence information properties of secretomes of two plant pathogens in a comparative analysis by various computational approaches. The ratio of potential non-classically secreted proteins (NCSPs) to classically secreted proteins (CSPs) in B. glumae BGR1 was greater than that in B. gladioli BSR3. For CSPs, the putative hydrophobic regions (PHRs) which are essential for secretion process of CSPs were screened in detail at their N-terminal sequences using hidden Markov model (HMM)-based method. Total 31 pairs of homologous proteins in two bacterial secretomes were indicated based on the global alignment (identity ≥ 70%). Our results may facilitate the understanding of the species-specific features of secretomes in two plant pathogenic Burkholderia species.

  2. Burkholderia sacchari DSM 17165: A source of compositionally-tunable block-copolymeric short-chain poly(hydroxyalkanoates) from xylose and levulinic acid

    Science.gov (United States)

    Burkholderia sacchari DSM 17165 was used as a biocatalyst for the production of poly-3-hydroxybutyrate-co-3-hydroxyvalerate block copolymers (Poly-3HB-block-3HV) from xylose and levulinic acid. Among the carbon source mixtures, levulinic acid was preferred and was consumed early in the fermentations...

  3. Procalcitonin levels in bloodstream infections caused by different sources and species of bacteria.

    Science.gov (United States)

    Yan, Sheng Tao; Sun, Li Chao; Jia, Hong Bing; Gao, Wen; Yang, Jian Ping; Zhang, Guo Qiang

    2017-04-01

    The aim of this study was to evaluate procalcitonin (PCT) diagnostic accuracy in discriminating gram-negative (GN) from gram-positive (GP) bloodstream infections and determining the relationship between PCT levels, infection sites, and pathogen types. Clinical and laboratory data were collected from patients with blood culture (BC)-positive sepsis between January 2014 and December 2015. PCT levels at different infection sites were compared, as was the presence of GN and GP bloodstream infection. A receiver operating characteristic (ROC) curve was generated to assess diagnostic accuracy. Of the 486 monomicrobial BCs, 254 (52.26%) were positive for GN bacteria (GNB), and 202 (42.18%) for GP bacteria (GPB). Median PCT levels were higher in BCs positive for GN (2.42ng/ml, IQR: 0.38-15.52) than in those positive for GPB (0.49ng/ml, IQR: 0.13-5.89) (PAcinetobacter baumanni/Burkholderia cepacia, Klebsiella pneumonia and Acinetobacter baumanni. PCT levels caused by GPB differed between Staphylococcus epidermidis/Staphylococcus aureus and Staphylococcus hominis/Staphylococcus haemolyticus, Enterococcus faecium and Enterococcus faecalis/S.hominis/S. haemolyticus. Among patients with known infection sites, there were statistical differences in PCT levels between abdominal infection and pneumonia/infective endocarditis, urinary tract infection and pneumonia/catheter-related infection/infective endocarditis. PCT can distinguish between GNB and GPB infection, as well as between different bacterial species and infection sites. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Transcriptome analysis of Acidovorax avenae subsp. avenae cultivated in vivo and co-culture with Burkholderia seminalis

    OpenAIRE

    Bin Li; Muhammad Ibrahim; Mengyu Ge; Zhouqi Cui; Guochang Sun; Fei Xu; Michael Kube

    2014-01-01

    Response of bacterial pathogen to environmental bacteria and its host is critical for understanding of microbial adaption and pathogenesis. Here, we used RNA-Seq to comprehensively and quantitatively assess the transcriptional response of Acidovorax avenae subsp. avenae strain RS-1 cultivated in vitro, in vivo and in co-culture with rice rhizobacterium Burkholderia seminalis R456. Results revealed a slight response to other bacteria, but a strong response to host. In particular, a large numbe...

  5. Spinal cord injury-induced immune deficiency syndrome enhances infection susceptibility dependent on lesion level.

    Science.gov (United States)

    Brommer, Benedikt; Engel, Odilo; Kopp, Marcel A; Watzlawick, Ralf; Müller, Susanne; Prüss, Harald; Chen, Yuying; DeVivo, Michael J; Finkenstaedt, Felix W; Dirnagl, Ulrich; Liebscher, Thomas; Meisel, Andreas; Schwab, Jan M

    2016-03-01

    Pneumonia is the leading cause of death after acute spinal cord injury and is associated with poor neurological outcome. In contrast to the current understanding, attributing enhanced infection susceptibility solely to the patient's environment and motor dysfunction, we investigate whether a secondary functional neurogenic immune deficiency (spinal cord injury-induced immune deficiency syndrome, SCI-IDS) may account for the enhanced infection susceptibility. We applied a clinically relevant model of experimental induced pneumonia to investigate whether the systemic SCI-IDS is functional sufficient to cause pneumonia dependent on spinal cord injury lesion level and investigated whether findings are mirrored in a large prospective cohort study after human spinal cord injury. In a mouse model of inducible pneumonia, high thoracic lesions that interrupt sympathetic innervation to major immune organs, but not low thoracic lesions, significantly increased bacterial load in lungs. The ability to clear the bacterial load from the lung remained preserved in sham animals. Propagated immune susceptibility depended on injury of central pre-ganglionic but not peripheral postganglionic sympathetic innervation to the spleen. Thoracic spinal cord injury level was confirmed as an independent increased risk factor of pneumonia in patients after motor complete spinal cord injury (odds ratio = 1.35, P spinal cord injury directly causes increased risk for bacterial infection in mice as well as in patients. Besides obvious motor and sensory paralysis, spinal cord injury also induces a functional SCI-IDS ('immune paralysis'), sufficient to propagate clinically relevant infection in an injury level dependent manner. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Macrophage and Galleria mellonella infection models reflect the virulence of naturally occurring isolates of B. pseudomallei, B. thailandensis and B. oklahomensis

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    Michell Stephen L

    2011-01-01

    Full Text Available Abstract Background Burkholderia pseudomallei is the causative agent of melioidosis, a tropical disease of humans with a variable and often fatal outcome. In murine models of infection, different strains exhibit varying degrees of virulence. In contrast, two related species, B. thailandensis and B. oklahomensis, are highly attenuated in mice. Our aim was to determine whether virulence in mice is reflected in macrophage or wax moth larvae (Galleria mellonella infection models. Results B. pseudomallei strains 576 and K96243, which have low median lethal dose (MLD values in mice, were able to replicate and induce cellular damage in macrophages and caused rapid death of G. mellonella. In contrast, B. pseudomallei strain 708a, which is attenuated in mice, showed reduced replication in macrophages, negligible cellular damage and was avirulent in G. mellonella larvae. B. thailandensis isolates were less virulent than B. pseudomallei in all of the models tested. However, we did record strain dependent differences. B. oklahomensis isolates were the least virulent isolates. They showed minimal ability to replicate in macrophages, were unable to evoke actin-based motility or to form multinucleated giant cells and were markedly attenuated in G. mellonella compared to B. thailandensis. Conclusions We have shown that the alternative infection models tested here, namely macrophages and Galleria mellonella, are able to distinguish between strains of B. pseudomallei, B. thailandensis and B. oklahomensis and that these differences reflect the observed virulence in murine infection models. Our results indicate that B. oklahomensis is the least pathogenic of the species investigated. They also show a correlation between isolates of B. thailandensis associated with human infection and virulence in macrophage and Galleria infection models.

  7. An objective approach for Burkholderia pseudomallei strain selection as challenge material for medical countermeasures efficacy testing

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    Kristopher E. Van Zandt

    2012-09-01

    Full Text Available Burkholderia pseudomallei is the causative agent of melioidosis, a rare disease of biodefense concern with high mortality and extreme difficulty in treatment. No human vaccines are available that protect against B. pseudomallei infection, and with the current limitations of antibiotic treatment, the development of new preventative and therapeutic interventions is crucial. Although clinical trials could be used to test the efficacy of new medical countermeasures (MCMs, the high mortality rates associated with melioidosis raises significant ethical issues concerning treating individuals with new compounds with unknown efficacies. The US Food and Drug Administration (FDA has formulated a set of guidelines for the licensure of new MCMs to treat diseases in which it would be unethical to test the efficacy of these drugs in humans. The FDA Animal Rule 21 CFR 314 calls for consistent, well-characterized B. pseudomallei strains to be used as challenge material in animal models. In order to facilitate the efficacy testing of new MCMs for melioidosis using animal models, we intend to develop a well-characterized panel of strains for use. This panel will comprise of strains that were isolated from human cases, have a low passage history, are virulent in animal models, and are well characterized phenotypically and genotypically. We have reviewed published and unpublished data on various B. pseudomallei strains to establish an objective method for selecting the strains to be included in the panel of B. pseudomallei strains with attention to five categories: animal infection models, genetic characterization, clinical and passage history, and availability of the strain to the research community. We identified 109 strains with data in at least one of the five categories, scored each strain based on the gathered data and identified 6 strains as candidate for a B. pseudomallei strain panel.

  8. An objective approach for Burkholderia pseudomallei strain selection as challenge material for medical countermeasures efficacy testing.

    Science.gov (United States)

    Van Zandt, Kristopher E; Tuanyok, Apichai; Keim, Paul S; Warren, Richard L; Gelhaus, H Carl

    2012-01-01

    Burkholderia pseudomallei is the causative agent of melioidosis, a rare disease of biodefense concern with high mortality and extreme difficulty in treatment. No human vaccines are available that protect against B. pseudomallei infection, and with the current limitations of antibiotic treatment, the development of new preventative and therapeutic interventions is crucial. Although clinical trials could be used to test the efficacy of new medical countermeasures (MCMs), the high mortality rates associated with melioidosis raises significant ethical issues concerning treating individuals with new compounds with unknown efficacies. The US Food and Drug Administration (FDA) has formulated a set of guidelines for the licensure of new MCMs to treat diseases in which it would be unethical to test the efficacy of these drugs in humans. The FDA "Animal Rule" 21 CFR 314 calls for consistent, well-characterized B. pseudomallei strains to be used as challenge material in animal models. In order to facilitate the efficacy testing of new MCMs for melioidosis using animal models, we intend to develop a well-characterized panel of strains for use. This panel will comprise of strains that were isolated from human cases, have a low passage history, are virulent in animal models, and are well-characterized phenotypically and genotypically. We have reviewed published and unpublished data on various B. pseudomallei strains to establish an objective method for selecting the strains to be included in the panel of B. pseudomallei strains with attention to five categories: animal infection models, genetic characterization, clinical and passage history, and availability of the strain to the research community. We identified 109 strains with data in at least one of the five categories, scored each strain based on the gathered data and identified six strains as candidate for a B. pseudomallei strain panel.

  9. Mutation of the cyclic di-GMP phosphodiesterase gene in Burkholderia lata SK875 attenuates virulence and enhances biofilm formation.

    Science.gov (United States)

    Jung, Hae-In; Kim, Yun-Jung; Lee, Yun-Jung; Lee, Hee-Soo; Lee, Jung-Kee; Kim, Soo-Ki

    2017-10-01

    Burkholderia sp. is a gram-negative bacterium that commonly exists in the environment, and can cause diseases in plants, animals, and humans. Here, a transposon mutant library of a Burkholderia lata isolate from a pig with swine respiratory disease in Korea was screened for strains showing attenuated virulence in Caenorhabditis elegans. One such mutant was obtained, and the Tn5 insertion junction was mapped to rpfR, a gene encoding a cyclic di-GMP phosphodiesterase that functions as a receptor. Mutation of rpfR caused a reduction in growth on CPG agar and swimming motility as well as a rough colony morphology on Congo red agar. TLC analysis showed reduced AHL secretion, which was in agreement with the results from plate-based and bioluminescence assays. The mutant strain produced significantly more biofilm detected by crystal violet staining than the parent strain. SEM of the mutant strain clearly showed that the overproduced biofilm contained a filamentous structure. These results suggest that the cyclic di-GMP phosphodiesterase RpfR plays an important role in quorum sensing modulation of the bacterial virulence and biofilm formation.

  10. Experimental population dynamics of Rhabdias bufonis (Nematoda) in toads (Bufo bufo): density-dependence in the primary infection

    OpenAIRE

    Goater, C. P.

    2017-01-01

    Density-dependence in worm establishment, numbers, biomass and larval production were examined in primary infections of 0, 10, 40, 80 and 160 larvae of the lung nematode, Rhabdias bufonis in the common toad, Bufo bufo. The infection procedure established 4 non-overlapping levels of infection which persisted until 6 weeks post-infection (p.i.), after which there was an overall decline up to 12 weeks p.i. Worm numbers had no direct effect on adult worm survival but temporal changes in worm weig...

  11. Proteasome Inhibition Suppresses Dengue Virus Egress in Antibody Dependent Infection.

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    Milly M Choy

    2015-11-01

    Full Text Available The mosquito-borne dengue virus (DENV is a cause of significant global health burden, with an estimated 390 million infections occurring annually. However, no licensed vaccine or specific antiviral treatment for dengue is available. DENV interacts with host cell factors to complete its life cycle although this virus-host interplay remains to be fully elucidated. Many studies have identified the ubiquitin proteasome pathway (UPP to be important for successful DENV production, but how the UPP contributes to DENV life cycle as host factors remains ill defined. We show here that proteasome inhibition decouples infectious virus production from viral RNA replication in antibody-dependent infection of THP-1 cells. Molecular and imaging analyses in β-lactone treated THP-1 cells suggest that proteasome function does not prevent virus assembly but rather DENV egress. Intriguingly, the licensed proteasome inhibitor, bortezomib, is able to inhibit DENV titers at low nanomolar drug concentrations for different strains of all four serotypes of DENV in primary monocytes. Furthermore, bortezomib treatment of DENV-infected mice inhibited the spread of DENV in the spleen as well as the overall pathological changes. Our findings suggest that preventing DENV egress through proteasome inhibition could be a suitable therapeutic strategy against dengue.

  12. Temperature dependent RNA metabolism in Xylella fastidiosa during cold stress and grapevine infection

    Science.gov (United States)

    Re-occurrence of Pierce’s disease of grapes, caused by Xylella fastidiosa, is known to be influenced by environmental factors, particularly cold temperatures during overwintering. Grapevines in colder regions are often cured of X. fastidiosa infection over the winter season, depending on cultivar, t...

  13. Brief communication genotyping of Burkholderia pseudomallei revealed high genetic variability among isolates from a single population group

    OpenAIRE

    Zueter, Abdelrahman Mohammad; Rahman, Zaidah Abdul; Yean, Chan Yean; Harun, Azian

    2015-01-01

    Burkholderia pseudomallei is a soil dwelling Gram-negative bacteria predominates in Southeast Asia zone and the tropical part of Australia. Genetic diversity has been explored among various populations and environments worldwide. To date, little data is available on MLST profiling of clinical B. pseudomallei isolates in peninsular Malaysia. In this brief report, thirteen culture positive B. pseudomallei cases collected from a single population of Terengganu state in the Western Peninsular Mal...

  14. Nanolipoprotein Particles (NLPs) as Versatile Vaccine Platforms for Co-delivery of Multiple Adjuvants with Subunit Antigens from Burkholderia spp. and F. tularensis - Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, N. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-01-13

    The goal of this proposal is to demonstrate that colocalization of protein subunit antigens and adjuvants on nanolipoprotein particles (NLPs) can increase the protective efficacy of subunit antigens from Burkholderia spp. and Francisella tularensis against an aerosol challenge. In the third quarter of the third year, F344 rats vaccinated with adjuvanted NLP formulations were challenged with F. tularensis SCHU S4 at Battelle. Preliminary data indicate that up to 65% of females vaccinated intranasally with an NLP-based formulation survived this challenge, compared to only 20% survival of naïve animals. In addition, NLPs were successfully formulated with Burkholderia protein antigens. IACUC approval for immunological assessments in BALB/c mice was received and we anticipate that these assessments will begin by March 2015, pending ACURO approval.

  15. Mobilization of HIV Spread by Diaphanous 2 Dependent Filopodia in Infected Dendritic Cells

    Science.gov (United States)

    Aggarwal, Anupriya; Iemma, Tina L.; Shih, Ivy; Newsome, Timothy P.; McAllery, Samantha; Cunningham, Anthony L.; Turville, Stuart G.

    2012-01-01

    Paramount to the success of persistent viral infection is the ability of viruses to navigate hostile environments en route to future targets. In response to such obstacles, many viruses have developed the ability of establishing actin rich-membrane bridges to aid in future infections. Herein through dynamic imaging of HIV infected dendritic cells, we have observed how viral high-jacking of the actin/membrane network facilitates one of the most efficient forms of HIV spread. Within infected DC, viral egress is coupled to viral filopodia formation, with more than 90% of filopodia bearing immature HIV on their tips at extensions of 10 to 20 µm. Live imaging showed HIV filopodia routinely pivoting at their base, and projecting HIV virions at µm.sec−1 along repetitive arc trajectories. HIV filopodial dynamics lead to up to 800 DC to CD4 T cell contacts per hour, with selection of T cells culminating in multiple filopodia tethering and converging to envelope the CD4 T-cell membrane with budding HIV particles. Long viral filopodial formation was dependent on the formin diaphanous 2 (Diaph2), and not a dominant Arp2/3 filopodial pathway often associated with pathogenic actin polymerization. Manipulation of HIV Nef reduced HIV transfer 25-fold by reducing viral filopodia frequency, supporting the potency of DC HIV transfer was dependent on viral filopodia abundance. Thus our observations show HIV corrupts DC to CD4 T cell interactions by physically embedding at the leading edge contacts of long DC filopodial networks. PMID:22685410

  16. Mobilization of HIV spread by diaphanous 2 dependent filopodia in infected dendritic cells.

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    Anupriya Aggarwal

    Full Text Available Paramount to the success of persistent viral infection is the ability of viruses to navigate hostile environments en route to future targets. In response to such obstacles, many viruses have developed the ability of establishing actin rich-membrane bridges to aid in future infections. Herein through dynamic imaging of HIV infected dendritic cells, we have observed how viral high-jacking of the actin/membrane network facilitates one of the most efficient forms of HIV spread. Within infected DC, viral egress is coupled to viral filopodia formation, with more than 90% of filopodia bearing immature HIV on their tips at extensions of 10 to 20 µm. Live imaging showed HIV filopodia routinely pivoting at their base, and projecting HIV virions at µm.sec⁻¹ along repetitive arc trajectories. HIV filopodial dynamics lead to up to 800 DC to CD4 T cell contacts per hour, with selection of T cells culminating in multiple filopodia tethering and converging to envelope the CD4 T-cell membrane with budding HIV particles. Long viral filopodial formation was dependent on the formin diaphanous 2 (Diaph2, and not a dominant Arp2/3 filopodial pathway often associated with pathogenic actin polymerization. Manipulation of HIV Nef reduced HIV transfer 25-fold by reducing viral filopodia frequency, supporting the potency of DC HIV transfer was dependent on viral filopodia abundance. Thus our observations show HIV corrupts DC to CD4 T cell interactions by physically embedding at the leading edge contacts of long DC filopodial networks.

  17. Global and regional dissemination and evolution of Burkholderia pseudomallei

    Science.gov (United States)

    Chewapreecha, Claire; Holden, Matthew T. G.; Vehkala, Minna; Välimäki, Niko; Yang, Zhirong; Harris, Simon R; Mather, Alison E.; Tuanyok, Apichai; De Smet, Birgit; Le Hello, Simon; Bizet, Chantal; Mayo, Mark; Wuthiekanun, Vanaporn; Limmathurotsakul, Direk; Phetsouvanh, Rattanaphone; Spratt, Brian G; Corander, Jukka; Keim, Paul; Dougan, Gordon; Dance, David A. B.; Currie, Bart J; Parkhill, Julian; Peacock, Sharon J.

    2017-01-01

    The environmental bacterium Burkholderia pseudomallei causes an estimated 165,000 cases of human melioidosis per year worldwide, and is also classified as a biothreat agent. We used whole genome sequences of 469 B. pseudomallei isolates from 30 countries collected over 79 years to explore its geographic transmission. Our data point to Australia as an early reservoir, with transmission to Southeast Asia followed by onward transmission to South Asia, and East Asia. Repeated reintroduction was observed within the Malay Peninsula, and between countries bordered by the Mekong river. Our data support an African origin of the Central and South American isolates with introduction of B. pseudomallei into the Americas between 1650 and 1850, providing a temporal link with the slave trade. We also identified geographically distinct genes/variants in Australasian or Southeast Asian isolates alone, with virulence-associated genes being among those overrepresented. This provides a potential explanation for clinical manifestations of melioidosis that are geographically restricted. PMID:28112723

  18. An outbreak of Burkholderia cepacia complex in the paediatric unit of a tertiary care hospital

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    Swapna Mali

    2017-01-01

    Full Text Available Introduction: Burkholderia cepacia complex (Bcc has emerged as a serious nosocomial pathogen worldwide especially in patients with indwelling catheters and cystic fibrosis. Bcc is a common contaminant of pharmaceutical products. We describe an outbreak of Bcc bacteraemia amongst children admitted in Paediatric Intensive Care Unit (PICU and paediatric ward at a tertiary care hospital, Mumbai, in Western India. Materials and Methods: Blood culture samples from paediatric patients yielded growth of non-fermenting, oxidase positive, motile, Gram negative bacilli (NFGNB (76/909 over a period of 8 months. Based on conventional biochemical tests and antimicrobial susceptibility testing, these isolates were provisionally identified as Bcc. The increased, repeated and continued isolation of Bcc alerted the possibility of an outbreak confined to PICU and paediatric ward. Active surveillance was undertaken to trace the source and contain the outbreak. Isolates were subjected to recA polymerase chain reaction (PCR and Expanded multilocus sequence typing (EMLST. Results: Surveillance revealed the presence of Bcc on the upper surface of rubber stopper of sealed multidose amikacin vials. Isolates from blood culture and rubber stoppers were confirmed as Bcc by recA PCR. EMLST revealed that these isolates shared an identical novel sequence type 824 proving clonality. Timely interventions instituted led to control of the outbreak. Conclusion: This study highlights the importance of identification and molecular characterization of Bcc to establish its role in infection and outbreak.

  19. Humoral immune responses in a human case of glanders.

    Science.gov (United States)

    Waag, David M; England, Marilyn J; DeShazer, David

    2012-05-01

    Within 2 months of acquiring glanders, a patient developed 8-, 16-, and 4-fold increases, respectively, in specific IgA, IgG, and IgM serological titers against Burkholderia mallei. Within 14 months of infection, the titers decreased to the baseline. Serum from this patient was also highly reactive against Burkholderia pseudomallei whole cells. Burkholderia mallei whole cells did not react with sera from patients with other diseases. Therefore, an assay using a B. mallei cellular diagnostic antigen may be useful for the serodiagnosis of glanders.

  20. Quantitative comparison of HTLV-1 and HIV-1 cell-to-cell infection with new replication dependent vectors.

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    Dmitriy Mazurov

    2010-02-01

    Full Text Available We have developed an efficient method to quantify cell-to-cell infection with single-cycle, replication dependent reporter vectors. This system was used to examine the mechanisms of infection with HTLV-1 and HIV-1 vectors in lymphocyte cell lines. Effector cells transfected with reporter vector, packaging vector, and Env expression plasmid produced virus-like particles that transduced reporter gene activity into cocultured target cells with zero background. Reporter gene expression was detected exclusively in target cells and required an Env-expression plasmid and a viral packaging vector, which provided essential structural and enzymatic proteins for virus replication. Cell-cell fusion did not contribute to infection, as reporter protein was rarely detected in syncytia. Coculture of transfected Jurkat T cells and target Raji/CD4 B cells enhanced HIV-1 infection two fold and HTLV-1 infection ten thousand fold in comparison with cell-free infection of Raji/CD4 cells. Agents that interfere with actin and tubulin polymerization strongly inhibited HTLV-1 and modestly decreased HIV-1 cell-to-cell infection, an indication that cytoskeletal remodeling was more important for HTLV-1 transmission. Time course studies showed that HTLV-1 transmission occurred very rapidly after cell mixing, whereas slower kinetics of HIV-1 coculture infection implies a different mechanism of infectious transmission. HTLV-1 Tax was demonstrated to play an important role in altering cell-cell interactions that enhance virus infection and replication. Interestingly, superantigen-induced synapses between Jurkat cells and Raji/CD4 cells did not enhance infection for either HTLV-1 or HIV-1. In general, the dependence on cell-to-cell infection was determined by the virus, the effector and target cell types, and by the nature of the cell-cell interaction.

  1. Efflux pump genes of the resistance-nodulation-division family in Burkholderia cenocepacia genome

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    Manina Giulia

    2006-07-01

    Full Text Available Abstract Background Burkholderia cenocepacia is recognized as opportunistic pathogen that can cause lung infections in cystic fibrosis patients. A hallmark of B. cenocepacia infections is the inability to eradicate the organism because of multiple intrinsic antibiotic resistance. As Resistance-Nodulation-Division (RND efflux systems are responsible for much of the intrinsic multidrug resistance in Gram-negative bacteria, this study aims to identify RND genes in the B. cenocepacia genome and start to investigate their involvement into antimicrobial resistance. Results Genome analysis and homology searches revealed 14 open reading frames encoding putative drug efflux pumps belonging to RND family in B. cenocepacia J2315 strain. By reverse transcription (RT-PCR analysis, it was found that orf3, orf9, orf11, and orf13 were expressed at detectable levels, while orf10 appeared to be weakly expressed in B. cenocepacia. Futhermore, orf3 was strongly induced by chloramphenicol. The orf2 conferred resistance to fluoroquinolones, tetraphenylphosphonium, streptomycin, and ethidium bromide when cloned and expressed in Escherichia coli KAM3, a strain lacking the multidrug efflux pump AcrAB. The orf2-overexpressing E. coli also accumulate low concentrations of ethidium bromide, which was restored to wild type level in the presence of CCCP, an energy uncoupler altering the energy of the drug efflux pump. Conclusion The 14 RND pumps gene we have identified in the genome of B. cenocepacia suggest that active efflux could be a major mechanism underlying antimicrobial resistance in this microorganism. We have characterized the ORF2 pump, one of these 14 potential RND efflux systems. Its overexpression in E. coli conferred resistance to several antibiotics and to ethidium bromide but it remains to be determined if this pump play a significant role in the antimicrobial intrinsic resistance of B. cenocepacia. The characterization of antibiotic efflux pumps in B

  2. The Animal Pathogen-Like Type III Secretion System is Required for the Intracellular Survival of Burkholderia mallei within J774.2 Macrophages

    Science.gov (United States)

    2006-03-30

    for B. mallei are horses, donkeys, and mules (solipeds), but other animals, including mice, hamsters, guinea pigs, monkeys , lions, and dogs, are...Spa/Prg and Shigella Ipa/Mxi/Spa TTS networks, are important for in vitro and in vivo survival of these pathogenic Burkholderia species (9–12, 14, 15

  3. Identification of the conserved hypothetical protein BPSL0317 in Burkholderia pseudomallei K96243

    Science.gov (United States)

    Yusoff, Nur Syamimi; Damiri, Nadzirah; Firdaus-Raih, Mohd

    2014-09-01

    Burkholderia pseudomallei K96243 is the causative agent of melioidosis, a disease which is endemic in Northern Australia and Southeastern Asia. The genome encodes several essential proteins including those currently annotated as hypothetical proteins. We studied the conservation and the essentiality of expressed hypothetical proteins in normal and different stress conditions. Based on the comparative genomics, we identified a hypothetical protein, BPSL0317, a potential essential gene that is being expressed in all normal and stress conditions. BPSL0317 is also phylogenetically conserved in the Burkholderiales order suggesting that this protein is crucial for survival among the order's members. BPSL0317 therefore has a potential to be a candidate antimicrobial drug target for this group of bacteria.

  4. What drives the occurrence of the melioidosis bacterium Burkholderia pseudomallei in domestic gardens?

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    Mirjam Kaestli

    2015-03-01

    Full Text Available Melioidosis is an often fatal infectious disease affecting humans and animals in tropical regions and is caused by the saprophytic environmental bacterium Burkholderia pseudomallei. Domestic gardens are not only a common source of exposure to soil and thus to B. pseudomallei, but they also have been found to contain more B. pseudomallei than other environments. In this study we addressed whether anthropogenic manipulations common to gardens such as irrigation or fertilizers change the occurrence of B. pseudomallei. We conducted a soil microcosm experiment with a range of fertilizers and soil types as well as a longitudinal interventional study over three years on an experimental fertilized field site in an area naturally positive for B. pseudomallei. Irrigation was the only consistent treatment to increase B. pseudomallei occurrence over time. The effects of fertilizers upon these bacteria depended on soil texture, physicochemical soil properties and biotic factors. Nitrates and urea increased B. pseudomallei load in sand while phosphates had a positive effect in clay. The high buffering and cation exchange capacities of organic material found in a commercial potting mix led to a marked increase in soil salinity with no survival of B. pseudomallei after four weeks in the potting mix sampled. Imported grasses were also associated with B. pseudomallei occurrence in a multivariate model. With increasing population density in endemic areas these findings inform the identification of areas in the anthropogenic environment with increased risk of exposure to B. pseudomallei.

  5. Antibody-dependent enhancement of HIV-1 infection in human term syncytiotrophoblast cells cultured in vitro.

    Science.gov (United States)

    Tóth, F D; Mosborg-Petersen, P; Kiss, J; Aboagye-Mathiesen, G; Zdravkovic, M; Hager, H; Aranyosi, J; Lampé, L; Ebbesen, P

    1994-06-01

    We examined if Fc receptor-mediated antibody-dependent enhancement (FcR-ADE) or complement-mediated antibody-dependent enhancement (C'-ADE) of virus infection can contribute to increasing replication of HIV-1 in human syncytiotrophoblast (ST) cells. Here we report that both FcR-ADE and C'-ADE may result in enhanced virus release from HIV-1-infected ST cells. We show that FcR-ADE of HIV-1 infection in ST cells is mediated by FcRIII and other FcR(s) belonging to undetermined Fc classes and does not require CD4 receptors, whereas C'-ADE uses both CD4 and CR2-like receptors. FcR-ADE seems to be more efficient in enhancing HIV-1 replication than C'-ADE. While FcR-ADE leads to increased internalization of HIV-1, C'-ADE does not result in enhanced endocytosis of the virus. In addition, antibodies mediating FcR-ADE are reactive with the gp120 viral envelope antigen, whereas antibodies involved in C'-ADE react with the viral transmembrane glycoprotein gp41. Data suggest that both FcR-ADE and C'-ADE may contribute to the spread of HIV-1 from mother to the fetus.

  6. Transports of acetate and haloacetate in Burkholderia species MBA4 are operated by distinct systems

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    Su Xianbin

    2012-11-01

    Full Text Available Abstract Background Acetate is a commonly used substrate for biosynthesis while monochloroacetate is a structurally similar compound but toxic and inhibits cell metabolism by blocking the citric acid cycle. In Burkholderia species MBA4 haloacetate was utilized as a carbon and energy source for growth. The degradation of haloacid was mediated by the production of an inducible dehalogenase. Recent studies have identified the presence of a concomitantly induced haloacetate-uptake activity in MBA4. This uptake activity has also been found to transport acetate. Since acetate transporters are commonly found in bacteria it is likely that haloacetate was transported by such a system in MBA4. Results The haloacetate-uptake activity of MBA4 was found to be induced by monochloroacetate (MCA and monobromoacetate (MBA. While the acetate-uptake activity was also induced by MCA and MBA, other alkanoates: acetate, propionate and 2-monochloropropionate (2MCPA were also inducers. Competing solute analysis showed that acetate and propionate interrupted the acetate- and MCA- induced acetate-uptake activities. While MCA, MBA, 2MCPA, and butyrate have no effect on acetate uptake they could significantly quenched the MCA-induced MCA-uptake activity. Transmembrane electrochemical potential was shown to be a driving force for both acetate- and MCA- transport systems. Conclusions Here we showed that acetate- and MCA- uptake in Burkholderia species MBA4 are two transport systems that have different induction patterns and substrate specificities. It is envisaged that the shapes and the three dimensional structures of the solutes determine their recognition or exclusion by the two transport systems.

  7. Purification and characterization of vanillin dehydrogenases from alkaliphile Micrococcus sp. TA1 and neutrophile Burkholderia cepacia TM1.

    Science.gov (United States)

    Mitsui, Ryoji; Hirota, Mizuho; Tsuno, Takuo; Tanaka, Mitsuo

    2010-02-01

    Vanillin dehydrogenases (VDHs) were purified and characterized from two bacterial strains that have different pH dependencies for growth. The alkaliphile Micrococcus sp. TA1, isolated from an alkaline spa, can grow on several aromatic compounds such as ferulic acid, vanillin, vanillic acid, and protocatechuic acid under alkaline conditions. The neutrophile Burkholderia cepacia TM1, which was isolated previously, also grew on the above-mentioned compounds because they functioned as the sole carbon source under neutral conditions. Purified VDHs showed activities toward some aromatic aldehydes. These enzymes have the same subunit molecular mass of about 57 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but differed in some of their observed properties. Native molecular masses also differed between the purified enzymes. These were 250 kDa for the enzyme from alkaliphilic strain TA1 and 110 kDa for that from neutrophilic strain TM1, as determined by gel filtration. The enzyme from strain TA1 required NADP(+) as a coenzyme for its activity, but that from strain TM1 required NAD(+). These results are important because this is the first report of an alkaliphilic bacterium consuming lignin monomers.

  8. Phenotypic and functional characterization of human memory T cell responses to Burkholderia pseudomallei.

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    Patcharaporn Tippayawat

    Full Text Available Infection with the Gram-negative bacterium Burkholderia pseudomallei is an important cause of community-acquired lethal sepsis in endemic regions in southeast Asia and northern Australia and is increasingly reported in other tropical areas. In animal models, production of interferon-gamma (IFN-gamma is critical for resistance, but in humans the characteristics of IFN-gamma production and the bacterial antigens that are recognized by the cell-mediated immune response have not been defined.Peripheral blood from 133 healthy individuals who lived in the endemic area and had no history of melioidosis, 60 patients who had recovered from melioidosis, and 31 other patient control subjects were stimulated by whole bacteria or purified bacterial proteins in vitro, and IFN-gamma responses were analyzed by ELISPOT and flow cytometry.B. pseudomallei was a potent activator of human peripheral blood NK cells for innate production of IFN-gamma. In addition, healthy individuals with serological evidence of exposure to B. pseudomallei and patients recovered from active melioidosis developed CD4(+ (and CD8(+ T cells that recognized whole bacteria and purified proteins LolC, OppA, and PotF, members of the B. pseudomallei ABC transporter family. This response was primarily mediated by terminally differentiated T cells of the effector-memory (T(EMRA phenotype and correlated with the titer of anti-B. pseudomallei antibodies in the serum.Individuals living in a melioidosis-endemic region show clear evidence of T cell priming for the ability to make IFN-gamma that correlates with their serological status. The ability to detect T cell responses to defined B. pseudomallei proteins in large numbers of individuals now provides the opportunity to screen candidate antigens for inclusion in protein or polysaccharide-conjugate subunit vaccines against this important but neglected disease.

  9. Antibody-dependent enhancement of dengue virus infection is inhibited by SA-17, a doxorubicin derivative

    NARCIS (Netherlands)

    Ayala Nunez, Vanesa; Jarupathirun, Patsaporn; Kaptein, Suzanne; Neyts, Johan; Smit, Jolanda

    2013-01-01

    Antibody-dependent enhancement (ADE) is thought to play a critical role in the exacerbation of dengue virus (DENV)-induced disease during a heterologous re-infection. Despite ADE's clinical impact, only a few antiviral compounds have been assessed for their anti-ADE activity. We reported earlier

  10. A putative lateral flagella of the cystic fibrosis pathogen Burkholderia dolosa regulates swimming motility and host cytokine production

    Science.gov (United States)

    Clark, Bradley S.; Weatherholt, Molly; Renaud, Diane; Scott, David; LiPuma, John J.; Priebe, Gregory; Gerard, Craig

    2018-01-01

    Burkholderia dolosa caused an outbreak in the cystic fibrosis clinic at Boston Children’s Hospital and was associated with high mortality in these patients. This species is part of a larger complex of opportunistic pathogens known as the Burkholderia cepacia complex (Bcc). Compared to other species in the Bcc, B. dolosa is highly transmissible; thus understanding its virulence mechanisms is important for preventing future outbreaks. The genome of one of the outbreak strains, AU0158, revealed a homolog of the lafA gene encoding a putative lateral flagellin, which, in other non-Bcc species, is used for movement on solid surfaces, attachment to host cells, or movement inside host cells. Here, we analyzed the conservation of the lafA gene and protein sequences, which are distinct from those of the polar flagella, and found lafA homologs to be present in numerous β-proteobacteria but notably absent from most other Bcc species. A lafA deletion mutant in B. dolosa showed a greater swimming motility than wild-type due to an increase in the number of polar flagella, but did not appear to contribute to biofilm formation, host cell invasion, or murine lung colonization or persistence over time. However, the lafA gene was important for cytokine production in human peripheral blood mononuclear cells, suggesting it may have a role in recognition by the human immune response. PMID:29346379

  11. Lectin-dependent enhancement of Ebola virus infection via soluble and transmembrane C-type lectin receptors.

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    Matthew Brudner

    Full Text Available Mannose-binding lectin (MBL is a key soluble effector of the innate immune system that recognizes pathogen-specific surface glycans. Surprisingly, low-producing MBL genetic variants that may predispose children and immunocompromised individuals to infectious diseases are more common than would be expected in human populations. Since certain immune defense molecules, such as immunoglobulins, can be exploited by invasive pathogens, we hypothesized that MBL might also enhance infections in some circumstances. Consequently, the low and intermediate MBL levels commonly found in human populations might be the result of balancing selection. Using model infection systems with pseudotyped and authentic glycosylated viruses, we demonstrated that MBL indeed enhances infection of Ebola, Hendra, Nipah and West Nile viruses in low complement conditions. Mechanistic studies with Ebola virus (EBOV glycoprotein pseudotyped lentiviruses confirmed that MBL binds to N-linked glycan epitopes on viral surfaces in a specific manner via the MBL carbohydrate recognition domain, which is necessary for enhanced infection. MBL mediates lipid-raft-dependent macropinocytosis of EBOV via a pathway that appears to require less actin or early endosomal processing compared with the filovirus canonical endocytic pathway. Using a validated RNA interference screen, we identified C1QBP (gC1qR as a candidate surface receptor that mediates MBL-dependent enhancement of EBOV infection. We also identified dectin-2 (CLEC6A as a potentially novel candidate attachment factor for EBOV. Our findings support the concept of an innate immune haplotype that represents critical interactions between MBL and complement component C4 genes and that may modify susceptibility or resistance to certain glycosylated pathogens. Therefore, higher levels of native or exogenous MBL could be deleterious in the setting of relative hypocomplementemia which can occur genetically or because of immunodepletion

  12. Lectin-dependent enhancement of Ebola virus infection via soluble and transmembrane C-type lectin receptors.

    Science.gov (United States)

    Brudner, Matthew; Karpel, Marshall; Lear, Calli; Chen, Li; Yantosca, L Michael; Scully, Corinne; Sarraju, Ashish; Sokolovska, Anna; Zariffard, M Reza; Eisen, Damon P; Mungall, Bruce A; Kotton, Darrell N; Omari, Amel; Huang, I-Chueh; Farzan, Michael; Takahashi, Kazue; Stuart, Lynda; Stahl, Gregory L; Ezekowitz, Alan B; Spear, Gregory T; Olinger, Gene G; Schmidt, Emmett V; Michelow, Ian C

    2013-01-01

    Mannose-binding lectin (MBL) is a key soluble effector of the innate immune system that recognizes pathogen-specific surface glycans. Surprisingly, low-producing MBL genetic variants that may predispose children and immunocompromised individuals to infectious diseases are more common than would be expected in human populations. Since certain immune defense molecules, such as immunoglobulins, can be exploited by invasive pathogens, we hypothesized that MBL might also enhance infections in some circumstances. Consequently, the low and intermediate MBL levels commonly found in human populations might be the result of balancing selection. Using model infection systems with pseudotyped and authentic glycosylated viruses, we demonstrated that MBL indeed enhances infection of Ebola, Hendra, Nipah and West Nile viruses in low complement conditions. Mechanistic studies with Ebola virus (EBOV) glycoprotein pseudotyped lentiviruses confirmed that MBL binds to N-linked glycan epitopes on viral surfaces in a specific manner via the MBL carbohydrate recognition domain, which is necessary for enhanced infection. MBL mediates lipid-raft-dependent macropinocytosis of EBOV via a pathway that appears to require less actin or early endosomal processing compared with the filovirus canonical endocytic pathway. Using a validated RNA interference screen, we identified C1QBP (gC1qR) as a candidate surface receptor that mediates MBL-dependent enhancement of EBOV infection. We also identified dectin-2 (CLEC6A) as a potentially novel candidate attachment factor for EBOV. Our findings support the concept of an innate immune haplotype that represents critical interactions between MBL and complement component C4 genes and that may modify susceptibility or resistance to certain glycosylated pathogens. Therefore, higher levels of native or exogenous MBL could be deleterious in the setting of relative hypocomplementemia which can occur genetically or because of immunodepletion during active

  13. Fluorescence and NMR spectroscopy together with molecular simulations reveal amphiphilic characteristics of a Burkholderia biofilm exopolysaccharide.

    Science.gov (United States)

    Kuttel, Michelle M; Cescutti, Paola; Distefano, Marco; Rizzo, Roberto

    2017-06-30

    Biofilms are a collective mode of bacterial life in which a self-produced matrix confines cells in close proximity to each other. Biofilms confer many advantages, including protection from chemicals (including antibiotics), entrapment of useful extracellular enzymes and nutrients, as well as opportunities for efficient recycling of molecules from dead cells. Biofilm matrices are aqueous gel-like structures composed of polysaccharides, proteins, and DNA stabilized by intermolecular interactions that may include non-polar connections. Recently, polysaccharides extracted from biofilms produced by species of the Burkholderia cepacia complex were shown to possess clusters of rhamnose, a 6-deoxy sugar with non-polar characteristics. Molecular dynamics simulations are well suited to characterizing the structure and dynamics of polysaccharides, but only relatively few such studies exist of their interaction with non-polar molecules. Here we report an investigation into the hydrophobic properties of the exopolysaccharide produced by Burkholderia multivorans strain C1576. Fluorescence experiments with two hydrophobic fluorescent probes established that this polysaccharide complexes hydrophobic species, and NMR experiments confirmed these interactions. Molecular simulations to model the hydrodynamics of the polysaccharide and the interaction with guest species revealed a very flexible, amphiphilic carbohydrate chain that has frequent dynamic interactions with apolar molecules; both hexane and a long-chain fatty acid belonging to the quorum-sensing system of B. multivorans were tested. A possible role of the non-polar domains of the exopolysaccharide in facilitating the diffusion of aliphatic species toward specific targets within the biofilm aqueous matrix is proposed. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. In Vitro Antibiotic Susceptibilities of Burkholderia mallei (Causative Agent of Glanders) Determined by Broth Microdilution and E-Test

    Science.gov (United States)

    Heine, Henry S.; England, Marilyn J.; Waag, David M.; Byrne, W. Russell

    2001-01-01

    In vitro susceptibilities to 28 antibiotics were determined for 11 strains of Burkholderia mallei by the broth microdilution method. The B. mallei strains demonstrated susceptibility to aminoglycosides, macrolides, quinolones, doxycycline, piperacillin, ceftazidime, and imipenem. For comparison and evaluation, 17 antibiotic susceptibilities were also determined by the E-test. E-test values were always lower than the broth dilution values. Establishing and comparing antibiotic susceptibilities of specific B. mallei strains will provide reference information for assessing new antibiotic agents. PMID:11408233

  15. Investigating early stages of biocorrosion with XPS: AISI 304 stainless steel exposed to Burkholderia species

    Science.gov (United States)

    Johansson, Leena-Sisko; Saastamoinen, Tuomas

    1999-04-01

    We have investigated the interactions of an exopolymer-producing bacteria, Burkholderia sp. with polished AISI 304 stainless steel substrates using X-ray photoelectron spectroscopy (XPS). Steel coupons were exposed to the pure bacteria culture in a specially designed flowcell for 6 h during which the experiment was monitored in situ with an optical microscope. XPS results verified the formation of biofilm containing extracellular polymer on all the samples exposed to bacteria. Sputter results indicated that some ions needed for metabolic processes were trapped within the biofilm. Changes in the relative Fe concentration and Fe 2p peak shape indicated that also iron had accumulated into the biofilm.

  16. A preliminary X-ray study of transketolase from Burkholderia pseudomallei

    International Nuclear Information System (INIS)

    Kim, Mi-Sun; Lim, Areum; Yang, Seung Won; Lee, Daeun; Park, Jimin; Shin, Dong Hae

    2012-01-01

    The transketolase TktA from B. pseudomallei has been cloned, expressed, purified and crystallized. Synchrotron X-ray data were collected to 2.0 Å resolution. TktA is the most critical enzyme in the nonoxidative pentose phosphate pathway. It catalyzes the conversion of xylulose 5-phosphate and ribose 5-phosphate into sedoheptulose 7-phosphate and glyceraldehyde 3-phosphate, and its products are used in the biosynthesis of acetyl-CoA, aromatic amino acids, nucleic acids and ADP-l-glycero-β-d-manno-heptose. TktA also has an unexpected role in chromosome structure that is independent of its metabolic responsibilities. Therefore, it is a new potent antibiotic target. In this study, TktA from Burkholderia pseudomallei has been cloned, expressed, purified and crystallized. Synchrotron X-ray data were also collected to 2.0 Å resolution. The crystal belonged to the monoclinic space group C2, with unit-cell parameters a = 146.2, b = 74.6, c = 61.6 Å, β = 113.0°. A full structural determination is under way in order to provide insight into the structure–function relationship of this protein

  17. In vivo fluorescence imaging of bacteriogenic cyanide in the lungs of live mice infected with cystic fibrosis pathogens.

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    Seong-Won Nam

    Full Text Available BACKGROUND: Pseudomonas aeruginosa (PA and Burkholderia cepacia complex (Bcc, commonly found in the lungs of cystic fibrosis (CF patients, often produce cyanide (CN, which inhibits cellular respiration. CN in sputa is a potential biomarker for lung infection by CF pathogens. However, its actual concentration in the infected lungs is unknown. METHODS AND FINDINGS: This work reports observation of CN in the lungs of mice infected with cyanogenic PA or Bcc strains using a CN fluorescent chemosensor (4',5'-fluorescein dicarboxaldehyde with a whole animal imaging system. When the CN chemosensor was injected into the lungs of mice intratracheally infected with either PA or B. cepacia strains embedded in agar beads, CN was detected in the millimolar range (1.8 to 4 mM in the infected lungs. CN concentration in PA-infected lungs rapidly increased within 24 hours but gradually decreased over the following days, while CN concentration in B. cepacia-infected lungs slowly increased, reaching a maximum at 5 days. CN concentrations correlated with the bacterial loads in the lungs. In vivo efficacy of antimicrobial treatments was tested in live mice by monitoring bacteriogenic CN in the lungs. CONCLUSIONS: The in vivo imaging method was also found suitable for minimally invasive testing the efficacy of antibiotic compounds as well as for aiding the understanding of bacterial cyanogenesis in CF lungs.

  18. Switch from cap- to factorless IRES-dependent 0 and +1 frame translation during cellular stress and dicistrovirus infection.

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    Qing S Wang

    Full Text Available Internal ribosome entry sites (IRES are utilized by a subset of cellular and viral mRNAs to initiate translation during cellular stress and virus infection when canonical cap-dependent translation is compromised. The intergenic region (IGR IRES of the Dicistroviridae uses a streamlined mechanism in which it can directly recruit the ribosome in the absence of initiation factors and initiates translation using a non-AUG codon. A subset of IGR IRESs including that from the honey bee viruses can also direct translation of an overlapping +1 frame gene. In this study, we systematically examined cellular conditions that lead to IGR IRES-mediated 0 and +1 frame translation in Drosophila S2 cells. Towards this, a novel bicistronic reporter that exploits the 2A "stop-go" peptide was developed to allow the detection of IRES-mediated translation in vivo. Both 0 and +1 frame translation by the IGR IRES are stimulated under a number of cellular stresses and in S2 cells infected by cricket paralysis virus, demonstrating a switch from cap-dependent to IRES-dependent translation. The regulation of the IGR IRES mechanism ensures that both 0 frame viral structural proteins and +1 frame ORFx protein are optimally expressed during virus infection.

  19. Fcγ-receptor IIa-mediated Src Signaling Pathway Is Essential for the Antibody-Dependent Enhancement of Ebola Virus Infection.

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    Wakako Furuyama

    2016-12-01

    Full Text Available Antibody-dependent enhancement (ADE of Ebola virus (EBOV infection has been demonstrated in vitro, raising concerns about the detrimental potential of some anti-EBOV antibodies. ADE has been described for many viruses and mostly depends on the cross-linking of virus-antibody complexes to cell surface Fc receptors, leading to enhanced infection. However, little is known about the molecular mechanisms underlying this phenomenon. Here we show that Fcγ-receptor IIa (FcγRIIa-mediated intracellular signaling through Src family protein tyrosine kinases (PTKs is required for ADE of EBOV infection. We found that deletion of the FcγRIIa cytoplasmic tail abolished EBOV ADE due to decreased virus uptake into cellular endosomes. Furthermore, EBOV ADE, but not non-ADE infection, was significantly reduced by inhibition of the Src family protein PTK pathway, which was also found to be important to promote phagocytosis/macropinocytosis for viral uptake into endosomes. We further confirmed a significant increase of the Src phosphorylation mediated by ADE. These data suggest that antibody-EBOV complexes bound to the cell surface FcγRIIa activate the Src signaling pathway that leads to enhanced viral entry into cells, providing a novel perspective for the general understanding of ADE of virus infection.

  20. Genome sequencing and transposon mutagenesis of Burkholderia seminalis TC3.4.2R3 identify genes contributing to suppression of orchid necrosis caused by B. gladioli

    Science.gov (United States)

    Thirty six strains of Burkholderia spp. isolated from sugarcane were evaluated for biological control of leaf and pseudobulb necrosis of orchid caused by B. gladioli. Twenty nine of the sugarcane strains suppressed the disease in greenhouse assays. We generated a draft genomic sequence of one suppr...

  1. MOLECULAR DYNAMICS SIMULATION OF KINETIC RESOLUTION OF RACEMIC ALCOHOL USING BURKHOLDERIA CEPACIA LIPASE IN ORGANIC SOLVENTS

    Directory of Open Access Journals (Sweden)

    A. C. Mathpati

    2018-03-01

    Full Text Available Lipases, a subclass of hydrolases, have gained a lot of importance as they can catalyze esterification, transesterification and hydrolysis reaction in non-aqueous media. Lipases are also widely used for kinetic resolution of racemic alcohols into enantiopure compounds. The lipase activity is affected by organic solvents due to changes in the conformational rigidity of enzymes, the active site, or altering the solvation of the transition state. The activity of lipases strongly depends on the logP value of solvents. Molecular dynamics (MD can help to understand the effect of solvents on lipase conformation as well as protein-ligand complex. In this work, MD simulations of Burkholderia cepacia lipase (BCL and complex between R and S conformation of acetylated form of 1-phenylethanol with BCL using gromacs have been carried in various organic solvents. The RMSD values were within the range of 0.15 to 0.20 nm and radius of gyration was found to be with 1.65 to 1.9 nm. Major changes in the B factor compared to reference structure were observed between residues 60 to 80, 120 to 150 and 240 to 260. Higher unfolding was observed in toluene and diethyl ether compared to hexane and acetonitrile. R acetylated complex was found to favorably bind BCL compared to S form. The predicted enantioselectivity were in good agreement with the experimental data.

  2. Particle-size dependent effects in the Balb/c murine model of inhalational melioidosis

    Directory of Open Access Journals (Sweden)

    Richard eThomas

    2012-07-01

    Full Text Available Deposition of Burkholderia pseudomallei within either the lungs or nasal passages of the Balb/c murine model resulted in different infection kinetics. The infection resulting from the inhalation of B. pseudomallei within a 12 um particle aerosol was prolonged compared to a 1 um particle aerosol with a mean time-to-death (MTD of 73.8 ± 11.3 h and 174.7 ± 14.9 h respectively. Inhalation of B. pseudomallei within 1 um or 12 um particle aerosols resulted in a median lethal dose (MLD of 4 and 12 cfu respectively. The 12 mm particle inhalational infection was characterised by involvement of the respiratory epithelium and inflammation of the neurological path leading from the olfactory epithelium to the olfactory bulb (100%, culminating in abscessation of the brain (33%. Initial involvement of the upper respiratory tract lymphoid tissues (nasal-associated lymphoid tissue and cervical lymph nodes was observed in both the 1 and 12 um particle inhalational infections (80-85%. Necrotising alveolitis and bronchiolitis were evident in both inhalational infections however lung pathology was greater after inhalation of the 1 mm particle aerosol with pronounced involvement of the mediastinal lymph node (50%. Terminal disease was characterised by bacteraemia in both inhalational infections with dissemination to the spleen, liver, kidneys and thymus. Treatment with co-trimoxazole was more effective than treatment with doxycycline irrespective of the size of the particles inhaled. Doxycycline was more effective against the 12 um particle inhalational infection as evidenced by increased time to death. However, both treatment regimes exhibited significant relapse when therapy was discontinued with massive enlargement and abscessation of the lungs, spleen and cervical lymph nodes observed.

  3. IL-4 receptor-alpha-dependent control of Cryptococcus neoformans in the early phase of pulmonary infection.

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    Andreas Grahnert

    Full Text Available Cryptococcus neoformans is an opportunistic fungal pathogen that causes lung inflammation and meningoencephalitis in immunocompromised people. Previously we showed that mice succumb to intranasal infection by induction of pulmonary interleukin (IL-4Rα-dependent type 2 immune responses, whereas IL-12-dependent type 1 responses confer resistance. In the experiments presented here, IL-4Rα⁻/⁻ mice unexpectedly show decreased fungal control early upon infection with C. neoformans, whereas wild-type mice are able to control fungal growth accompanied by enhanced macrophage and dendritic cell recruitment to the site of infection. Lower pulmonary recruitment of macrophages and dendritic cells in IL-4Rα⁻/⁻ mice is associated with reduced pulmonary expression of CCL2 and CCL20 chemokines. Moreover, IFN-γ and nitric oxide production are diminished in IL-4Rα⁻/⁻ mice compared to wild-type mice. To directly study the potential mechanism(s responsible for reduced production of IFN-γ, conventional dendritic cells were stimulated with C. neoformans in the presence of IL-4 which results in increased IL-12 production and reduced IL-10 production. Together, a beneficial role of early IL-4Rα signaling is demonstrated in pulmonary cryptococcosis, which contrasts with the well-known IL-4Rα-mediated detrimental effects in the late phase.

  4. Improved detection of Burkholderia pseudomallei from non-blood clinical specimens using enrichment culture and PCR: narrowing diagnostic gap in resource-constrained settings.

    Science.gov (United States)

    Tellapragada, Chaitanya; Shaw, Tushar; D'Souza, Annet; Eshwara, Vandana Kalwaje; Mukhopadhyay, Chiranjay

    2017-07-01

    To evaluate the diagnostic utility of enrichment culture and PCR for improved case detection rates of non-bacteraemic form of melioidosis in limited resource settings. Clinical specimens (n = 525) obtained from patients presenting at a tertiary care hospital of South India with clinical symptoms suggestive of community-acquired pneumonia, lower respiratory tract infections, superficial or internal abscesses, chronic skin ulcers and bone or joint infections were tested for the presence of Burkholderia pseudomallei using conventional culture (CC), enrichment culture (EC) and PCR. Sensitivity, specificity, positive and negative predictive values of CC and PCR were initially deduced using EC as the gold standard method. Further, diagnostic accuracies of all the three methods were analysed using Bayesian latent class modelling (BLCM). Detection rates of B. pseudomallei using CC, EC and PCR were 3.8%, 5.3% and 6%, respectively. Diagnostic sensitivities and specificities of CC and PCR were 71.4, 98.4% and 100 and 99.4%, respectively in comparison with EC as the gold standard test. With Bayesian latent class modelling, EC and PCR demonstrated sensitivities of 98.7 and 99.3%, respectively, while CC showed a sensitivity of 70.3% for detection of B. pseudomallei. An increase of 1.6% (95% CI: 1.08-4.32%) in the case detection rate of melioidosis was observed in the study population when EC and/or PCR were used in adjunct to the conventional culture technique. Our study findings underscore the diagnostic superiority of enrichment culture and/or PCR over conventional microbiological culture for improved case detection of melioidosis from non-blood clinical specimens. © 2017 John Wiley & Sons Ltd.

  5. Effect of nitrofurans and NO generators on biofilm formation by Pseudomonas aeruginosa PAO1 and Burkholderia cenocepacia 370.

    Science.gov (United States)

    Zaitseva, Julia; Granik, Vladimir; Belik, Alexandr; Koksharova, Olga; Khmel, Inessa

    2009-06-01

    Antibacterial drugs in the nitrofuran series, such as nitrofurazone, furazidin, nitrofurantoin and nifuroxazide, as well as the nitric oxide generators sodium nitroprusside and isosorbide mononitrate in concentrations that do not suppress bacterial growth, were shown to increase the capacity of pathogenic bacteria Pseudomonas aeruginosa PAO1 and Burkholderia cenocepacia 370 to form biofilms. At 25-100microg/ml, nitrofurans 2-2.5-fold enhanced biofilm formation of P. aeruginosa PAO1, and NO donors 3-6-fold. For B. cenocepacia 370, the enhancement was 2-5-fold (nitrofurans) and 4.5-fold (sodium nitroprusside), respectively.

  6. Potential of Burkholderia seminalis TC3.4.2R3 as Biocontrol Agent Against Fusarium oxysporum Evaluated by Mass Spectrometry Imaging

    Science.gov (United States)

    Araújo, Francisca Diana da Silva; Araújo, Welington Luiz; Eberlin, Marcos Nogueira

    2017-05-01

    Species of genus Burkholderia display different interaction profiles in the environment, causing either several diseases in plants and animals or being beneficial to some plants, promoting their growth, and suppressing phytopathogens. Burkholderia spp. also produce many types of biomolecules with antimicrobial activity, which may be commercially used to protect crops of economic interest, mainly against fungal diseases. Herein we have applied matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to investigate secondary metabolites produced by B. seminalis TC3.4.2R3 in monoculture and coculture with plant pathogen Fusarium oxysporum. The siderophore pyochelin and the rhamnolipid Rha-Rha-C15-C14 were detected in wild-type B. seminalis strain, and their productions were found to vary in mutant strains carrying disruptions in gene clusters associated with antimicrobial compounds. Two mycotoxins were detected in F. oxysporum. During coculture with B. seminalis, metabolites probably related to defense mechanisms of these microorganisms were observed in the interspecies interaction zone. Our findings demonstrate the effective application of MALDI-MSI in the detection of bioactive molecules involved in the defense mechanism of B. seminalis, and these findings suggest the potential use of this bacterium in the biocontrol of plant diseases caused by F. oxysporum.

  7. Cometabolic degradation of trichloroethylene by Burkholderia cepacia G4 with poplar leaf homogenate.

    Science.gov (United States)

    Kang, Jun Won; Doty, Sharon Lafferty

    2014-07-01

    Trichloroethylene (TCE), a chlorinated organic solvent, is one of the most common and widespread groundwater contaminants worldwide. Among the group of TCE-degrading aerobic bacteria, Burkholderia cepacia G4 is the best-known representative. This strain requires the addition of specific substrates, including toluene, phenol, and benzene, to induce the enzymes to degrade TCE. However, the substrates are toxic and introducing them into the soil can result in secondary contamination. In this study, poplar leaf homogenate containing natural phenolic compounds was tested for the ability to induce the growth of and TCE degradation by B. cepacia G4. The results showed that the G4 strain could grow and degrade TCE well with the addition of phytochemicals. The poplar leaf homogenate also functioned as an inducer of the toluene-ortho-monooxygenase (TOM) gene in B. cepacia G4.

  8. Hierarchical ZIF-8 toward Immobilizing Burkholderia cepacia Lipase for Application in Biodiesel Preparation

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    Miaad Adnan

    2018-05-01

    Full Text Available A hierarchical mesoporous zeolitic imidazolate framework (ZIF-8 was processed based on cetyltrimethylammonium bromide (CTAB as a morphological regulating agent and amino acid (l-histidine as assisting template agent. Burkholderia cepacia lipase (BCL was successfully immobilized by ZIF-8 as the carrier via an adsorption method (BCL-ZIF-8. The immobilized lipase (BCL showed utmost activity recovery up to 1279%, a 12-fold boost in its free counterpart. BCL-ZIF-8 was used as a biocatalyst in the transesterification reaction for the production of biodiesel with 93.4% yield. There was no significant lowering of conversion yield relative to original activity for BCL-ZIF-8 when continuously reused for eight cycles. This work provides a new outlook for biotechnological importance by immobilizing lipase on the hybrid catalyst (ZIF-8 and opens the door for its uses in the industrial field.

  9. The Capsular Polysaccharide of Burkholderia pseudomallei Contributes to Survival in Serum by Reducing Complement Factor C3b Deposition

    OpenAIRE

    Reckseidler-Zenteno, Shauna L.; DeVinney, Rebekah; Woods, Donald E.

    2005-01-01

    Burkholderia pseudomallei produces an extracellular polysaccharide capsule -3)-2-O-acetyl-6-deoxy-β-d-manno-heptopyranose-(1- which has been shown to be an essential virulence determinant. The addition of purified capsule was shown to increase the virulence of a capsule mutant strain in the Syrian hamster model of acute melioidosis. An increase in the number of wild-type B. pseudomallei cells in the blood was seen by 48 h, while the number of capsule mutant cells in the blood declined by 48 h...

  10. A FRET-based DNA biosensor tracks OmpR-dependent acidification of Salmonella during macrophage infection.

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    Smarajit Chakraborty

    2015-04-01

    Full Text Available In bacteria, one paradigm for signal transduction is the two-component regulatory system, consisting of a sensor kinase (usually a membrane protein and a response regulator (usually a DNA binding protein. The EnvZ/OmpR two-component system responds to osmotic stress and regulates expression of outer membrane proteins. In Salmonella, EnvZ/OmpR also controls expression of another two-component system SsrA/B, which is located on Salmonella Pathogenicity Island (SPI 2. SPI-2 encodes a type III secretion system, which functions as a nanomachine to inject bacterial effector proteins into eukaryotic cells. During the intracellular phase of infection, Salmonella switches from assembling type III secretion system structural components to secreting effectors into the macrophage cytoplasm, enabling Salmonella to replicate in the phagocytic vacuole. Major questions remain regarding how bacteria survive the acidified vacuole and how acidification affects bacterial secretion. We previously reported that EnvZ sensed cytoplasmic signals rather than extracellular ones, as intracellular osmolytes altered the dynamics of a 17-amino-acid region flanking the phosphorylated histidine. We reasoned that the Salmonella cytoplasm might acidify in the macrophage vacuole to activate OmpR-dependent transcription of SPI-2 genes. To address these questions, we employed a DNA-based FRET biosensor ("I-switch" to measure bacterial cytoplasmic pH and immunofluorescence to monitor effector secretion during infection. Surprisingly, we observed a rapid drop in bacterial cytoplasmic pH upon phagocytosis that was not predicted by current models. Cytoplasmic acidification was completely dependent on the OmpR response regulator, but did not require known OmpR-regulated genes such as ompC, ompF, or ssaC (SPI-2. Microarray analysis highlighted the cadC/BA operon, and additional experiments confirmed that it was repressed by OmpR. Acidification was blocked in the ompR null background in a

  11. The concentrations of ambient Burkholderia pseudomallei during typhoon season in endemic area of melioidosis in Taiwan.

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    Ya-Lei Chen

    Full Text Available BACKGROUND: Melioidosis is a severe bacterial infection caused by Burkholderia pseudomallei with a high case-fatality rate. Epidemiological and animal studies show the possibility of inhalation transmission. However, no B. pseudomallei concentrations in ambient air have been researched. Here, we developed a method to quantify ambient B. pseudomallei and then measured concentrations of ambient B. pseudomallei during the typhoon season and the non-typhoon season to determine the factors influencing ambient B. pseudomallei levels. METHODS: We quantified ambient B. pseudomallei by using a filter/real-time qPCR method in the Zoynan Region in Kaohsiung, southern Taiwan. Twenty-four hour samples were collected at a sampling rate of 20 L/min every day from June 11 to December 21, 2012 including during the typhoon season (June to September and reference season (October to December. RESULTS: We successfully developed a filtration/real-time qPCR method to quantify ambient B. pseudomallei. To our knowledge, this is the first report describing concentrations of ambient B. pseudomallei. Ambient B. pseudomallei were only detected during the typhoon season when compared to the reference season. For the typhoons affecting the Zoynan Region, the positive rates of ambient B. pseudomallei were very high at 80% to 100%. During June to December, rainfall was positively correlated with ambient B. pseudomallei with a statistical significance. Sediment at a nearby pond significantly influenced the concentration of ambient B. pseudomallei. During the typhoon month, the typhoon was positively correlated with ambient B. pseudomallei whereas wind speed was reversely correlated with ambient B. pseudomallei. CONCLUSIONS: Our data suggest the possibility of transmission of B. pseudomallei via inhalation during the typhoon season.

  12. The concentrations of ambient Burkholderia pseudomallei during typhoon season in endemic area of melioidosis in Taiwan.

    Science.gov (United States)

    Chen, Ya-Lei; Yen, Yu-Chuan; Yang, Chun-Yuh; Lee, Min Sheng; Ho, Chi-Kung; Mena, Kristina D; Wang, Peng-Yau; Chen, Pei-Shih

    2014-01-01

    Melioidosis is a severe bacterial infection caused by Burkholderia pseudomallei with a high case-fatality rate. Epidemiological and animal studies show the possibility of inhalation transmission. However, no B. pseudomallei concentrations in ambient air have been researched. Here, we developed a method to quantify ambient B. pseudomallei and then measured concentrations of ambient B. pseudomallei during the typhoon season and the non-typhoon season to determine the factors influencing ambient B. pseudomallei levels. We quantified ambient B. pseudomallei by using a filter/real-time qPCR method in the Zoynan Region in Kaohsiung, southern Taiwan. Twenty-four hour samples were collected at a sampling rate of 20 L/min every day from June 11 to December 21, 2012 including during the typhoon season (June to September) and reference season (October to December). We successfully developed a filtration/real-time qPCR method to quantify ambient B. pseudomallei. To our knowledge, this is the first report describing concentrations of ambient B. pseudomallei. Ambient B. pseudomallei were only detected during the typhoon season when compared to the reference season. For the typhoons affecting the Zoynan Region, the positive rates of ambient B. pseudomallei were very high at 80% to 100%. During June to December, rainfall was positively correlated with ambient B. pseudomallei with a statistical significance. Sediment at a nearby pond significantly influenced the concentration of ambient B. pseudomallei. During the typhoon month, the typhoon was positively correlated with ambient B. pseudomallei whereas wind speed was reversely correlated with ambient B. pseudomallei. Our data suggest the possibility of transmission of B. pseudomallei via inhalation during the typhoon season.

  13. Key role for efflux in the preservative susceptibility and adaptive resistance of Burkholderia cepacia complex bacteria.

    Science.gov (United States)

    Rushton, Laura; Sass, Andrea; Baldwin, Adam; Dowson, Christopher G; Donoghue, Denise; Mahenthiralingam, Eshwar

    2013-07-01

    Bacteria from the Burkholderia cepacia complex (Bcc) are encountered as industrial contaminants, and little is known about the species involved or their mechanisms of preservative resistance. Multilocus sequence typing (MLST) revealed that multiple Bcc species may cause contamination, with B. lata (n = 17) and B. cenocepacia (n = 11) dominant within the collection examined. At the strain level, 11 of the 31 industrial sequence types identified had also been recovered from either natural environments or clinical infections. Minimal inhibitory (MIC) and minimum bactericidal (MBC) preservative concentrations varied across 83 selected Bcc strains, with industrial strains demonstrating increased tolerance for dimethylol dimethyl hydantoin (DMDMH). Benzisothiazolinone (BIT), DMDMH, methylisothiazolinone (MIT), a blend of 3:1 methylisothiazolinone-chloromethylisothiazolinone (M-CMIT), methyl paraben (MP), and phenoxyethanol (PH), were all effective anti-Bcc preservatives; benzethonium chloride (BC) and sodium benzoate (SB) were least effective. Since B. lata was the dominant industrial Bcc species, the type strain, 383(T) (LMG 22485(T)), was used to study preservative tolerance. Strain 383 developed stable preservative tolerance for M-CMIT, MIT, BIT, and BC, which resulted in preservative cross-resistance and altered antibiotic susceptibility, motility, and biofilm formation. Transcriptomic analysis of the B. lata 383 M-CMIT-adapted strain demonstrated that efflux played a key role in its M-CMIT tolerance and elevated fluoroquinolone resistance. The role of efflux was corroborated using the inhibitor l-Phe-Arg-β-napthylamide, which reduced the MICs of M-CMIT and ciprofloxacin. In summary, intrinsic preservative tolerance and stable adaptive changes, such as enhanced efflux, play a role in the ability of Bcc bacteria to cause industrial contamination.

  14. Human Papillomavirus 16 Infection Induces VAP-Dependent Endosomal Tubulation.

    Science.gov (United States)

    Siddiqa, Abida; Massimi, Paola; Pim, David; Broniarczyk, Justyna; Banks, Lawrence

    2018-03-15

    Human papillomavirus (HPV) infection involves complex interactions with the endocytic transport machinery, which ultimately facilitates the entry of the incoming viral genomes into the trans -Golgi network (TGN) and their subsequent nuclear entry during mitosis. The endosomal pathway is a highly dynamic intracellular transport system, which consists of vesicular compartments and tubular extensions, although it is currently unclear whether incoming viruses specifically alter the endocytic machinery. In this study, using MICAL-L1 as a marker for tubulating endosomes, we show that incoming HPV-16 virions induce a profound alteration in global levels of endocytic tubulation. In addition, we also show a critical requirement for the endoplasmic reticulum (ER)-anchored protein VAP in this process. VAP plays an essential role in actin nucleation and endosome-to-Golgi transport. Indeed, the loss of VAP results in a dramatic decrease in the level of endosomal tubulation induced by incoming HPV-16 virions. This is also accompanied by a marked reduction in virus infectivity. In VAP knockdown cells, we see that the defect in virus trafficking occurs after capsid disassembly but prior to localization at the trans -Golgi network, with the incoming virion-transduced DNA accumulating in Vps29/TGN46-positive hybrid vesicles. Taken together, these studies demonstrate that infection with HPV-16 virions induces marked alterations of endocytic transport pathways, some of which are VAP dependent and required for the endosome-to-Golgi transport of the incoming viral L2/DNA complex. IMPORTANCE Human papillomavirus infectious entry involves multiple interactions with the endocytic transport machinery. In this study, we show that incoming HPV-16 virions induce a dramatic increase in endocytic tubulation. This tubulation requires ER-associated VAP, which plays a critical role in ensuring the delivery of cargoes from the endocytic compartments to the trans -Golgi network. Indeed, the loss of

  15. Expression, purification, crystallization and preliminary X-ray analysis of a novel N-substituted branched-chain l-amino-acid dioxygenase from Burkholderia ambifaria AMMD

    International Nuclear Information System (INIS)

    Qin, Hui-Min; Miyakawa, Takuya; Nakamura, Akira; Xue, You-Lin; Kawashima, Takashi; Kasahara, Takuya; Hibi, Makoto; Ogawa, Jun; Tanokura, Masaru

    2012-01-01

    Diffraction data were collected to a limiting resolution of 2.4 Å from a crystal of selenomethionyl-labelled SadA, an l-amino-acid dioxygenase. Ferrous ion- and α-ketoglutarate-dependent dioxygenase from Burkholderia ambifaria AMMD (SadA) catalyzes the C3-hydroxylation of N-substituted branched-chain l-amino acids, especially N-succinyl-l-leucine, coupled to the conversion of α-ketoglutarate to succinate and CO 2 . SadA was expressed in Escherichia coli, purified and crystallized using the sitting-drop vapour-diffusion method at 293 K. Crystals of selenomethionine-substituted SadA were obtained using a reservoir solution containing PEG 3000 as the precipitant at pH 9.5 and diffracted X-rays to 2.4 Å resolution. The crystal belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 49.3, b = 70.9, c = 148.2 Å. The calculated Matthews coefficient (V M = 2.1 Å 3 Da −1 , 41% solvent content) suggested that the crystal contains two molecules per asymmetric unit

  16. Human factors related to time-dependent infection control measures: "Scrub the hub" for venous catheters and feeding tubes.

    Science.gov (United States)

    Caspari, Lindsay; Epstein, Elizabeth; Blackman, Amy; Jin, Li; Kaufman, David A

    2017-06-01

    The use of catheter hub decontamination protocols is a common practice to reduce central line-associated bloodstream infections. However, few data exist on the most effective disinfection procedure prior to hub access accounting for human factors and time-dependent practices in real time in the clinical setting. An observational design with a multimodal intervention was used in this study in a neonatal intensive care unit. Direct observations on nurse compliance of scrub times with decontamination when accessing of venous catheter and feeding tube hubs were conducted during 3 phases: (1) baseline period prior to any interventions; (2) during an educational intervention phase; and (3) during a timer intervention period when using a timing device, either an actual timer or music button. Overall, both education and the timing device interventions increased the mean scrub time ± SD of venous catheter hubs. Mean baseline scrub times of 10 ± 5 seconds were lower compared with 23 ± 12 seconds after educational intervention (P music button use (P observed with scrub times of feeding tubes. Time-based infection control measures, such as scrubbing the hub, must be implemented with aids that qualify specific times to account for human factors, to ensure adherence to time-dependent measures aimed at decreasing nosocomial infections. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  17. Crystal structure of a β-aminopeptidase from an Australian Burkholderia sp.

    Science.gov (United States)

    John-White, Marietta; Dumsday, Geoff J; Johanesen, Priscilla; Lyras, Dena; Drinkwater, Nyssa; McGowan, Sheena

    2017-07-01

    β-Aminopeptidases are a unique group of enzymes that have the unusual capability to hydrolyze N-terminal β-amino acids from synthetic β-peptides. β-Peptides can form secondary structures mimicking α-peptide-like structures that are resistant to degradation by most known proteases and peptidases. These characteristics of β-peptides give them great potential as peptidomimetics. Here, the X-ray crystal structure of BcA5-BapA, a β-aminopeptidase from a Gram-negative Burkholderia sp. that was isolated from activated sludge from a wastewater-treatment plant in Australia, is reported. The crystal structure of BcA5-BapA was determined to a resolution of 2.0 Å and showed a tetrameric assembly typical of the β-aminopeptidases. Each monomer consists of an α-subunit (residues 1-238) and a β-subunit (residues 239-367). Comparison of the structure of BcA5-BapA with those of other known β-aminopeptidases shows a highly conserved structure and suggests a similar proteolytic mechanism of action.

  18. Differentiation of pulmonary bacterial pathogens in cystic fibrosis by volatile metabolites emitted by their in vitro cultures: Pseudomonas aeruginosa, Staphylococcus aureus, Stenotrophomonas maltophilia and the Burkholderia cepacia complex

    Czech Academy of Sciences Publication Activity Database

    Dryahina, Kseniya; Sovová, Kristýna; Nemec, A.; Španěl, Patrik

    2016-01-01

    Roč. 10, AUG 2016 (2016), s. 037102 ISSN 1752-7155 R&D Projects: GA ČR(CZ) GA14-14534S Institutional support: RVO:61388955 Keywords : Burkholderia cepacia complex * Pseudomonas aeruginosa * cystic fibrosis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.318, year: 2016

  19. Hepatitis C virus infection induces apoptosis through a Bax-triggered, mitochondrion-mediated, caspase 3-dependent pathway.

    Science.gov (United States)

    Deng, Lin; Adachi, Tetsuya; Kitayama, Kikumi; Bungyoku, Yasuaki; Kitazawa, Sohei; Ishido, Satoshi; Shoji, Ikuo; Hotta, Hak

    2008-11-01

    We previously reported that cells harboring the hepatitis C virus (HCV) RNA replicon as well as those expressing HCV NS3/4A exhibited increased sensitivity to suboptimal doses of apoptotic stimuli to undergo mitochondrion-mediated apoptosis (Y. Nomura-Takigawa, et al., J. Gen. Virol. 87:1935-1945, 2006). Little is known, however, about whether or not HCV infection induces apoptosis of the virus-infected cells. In this study, by using the chimeric J6/JFH1 strain of HCV genotype 2a, we demonstrated that HCV infection induced cell death in Huh7.5 cells. The cell death was associated with activation of caspase 3, nuclear translocation of activated caspase 3, and cleavage of DNA repair enzyme poly(ADP-ribose) polymerase, which is known to be an important substrate for activated caspase 3. These results suggest that HCV-induced cell death is, in fact, apoptosis. Moreover, HCV infection activated Bax, a proapoptotic member of the Bcl-2 family, as revealed by its conformational change and its increased accumulation on mitochondrial membranes. Concomitantly, HCV infection induced disruption of mitochondrial transmembrane potential, followed by mitochondrial swelling and release of cytochrome c from mitochondria. HCV infection also caused oxidative stress via increased production of mitochondrial superoxide. On the other hand, HCV infection did not mediate increased expression of glucose-regulated protein 78 (GRP78) or GRP94, which are known as endoplasmic reticulum (ER) stress-induced proteins; this result suggests that ER stress is not primarily involved in HCV-induced apoptosis in our experimental system. Taken together, our present results suggest that HCV infection induces apoptosis of the host cell through a Bax-triggered, mitochondrion-mediated, caspase 3-dependent pathway(s).

  20. Cloning, purification, crystallization and preliminary X-ray analysis of the Burkholderia pseudomallei L1 ribosomal protein

    International Nuclear Information System (INIS)

    Abd Aziz, Abd Ghani; Ruzheinikov, Sergey N.; Sedelnikova, Svetlana E.; Mohamed, Rahmah; Nathan, Sheila; Baker, Patrick J.; Rice, David W.

    2012-01-01

    The L1 ribosomal protein from B. pseudomallei has been overexpressed, purified and crystallized in a form suitable for X-ray analysis. The gene encoding the L1 ribosomal protein from Burkholderia pseudomallei strain D286 has been cloned into the pETBLUE-1 vector system, overexpressed in Escherichia coli and purified. Crystals of the native protein were grown by the hanging-drop vapour-diffusion technique using PEG 3350 as a precipitant and diffracted to beyond 1.65 Å resolution. The crystals belonged to space group P2 1 2 1 2, with unit-cell parameters a = 53.6, b = 127.1, c = 31.8 Å and with a single molecule in the asymmetric unit

  1. Biological Control of White Rot in Garlic Using Burkholderia pyrrocinia CAB08106-4

    Directory of Open Access Journals (Sweden)

    Kwang Seop Han

    2013-03-01

    Full Text Available White rot caused by Sclerotium cepivorum was reported to be severe soil-born disease on garlic. Disease progress of white rot of garlic (Allium sativum L. was investigated during the growing season of 2009 to 2011 at Taean and Seosan areas. The white rot disease on bulb began to occur from late April and peaked in late May. The antifungal bacteria, Burkholderia pyrrocinia CAB08106-4 was tested in field bioassay for suppression of white rot disease. As a result of the nucleotide sequence of the gene 16S rRNA, CAB008106-4 strain used in this study has been identified as B. pyrrocinia. B. pyrrocinia CAB080106-4 isolate suppressed the white rot with 69.6% control efficacy in field test. These results suggested that B. pyrrocinia CAB08106-4 isolate could be an effective biological control agent against white rot of garlic.

  2. Immune Control of Burkholderia pseudomallei––Common, High-Frequency T-Cell Responses to a Broad Repertoire of Immunoprevalent Epitopes

    Directory of Open Access Journals (Sweden)

    Arnone Nithichanon

    2018-03-01

    Full Text Available Burkholderia pseudomallei (Bp is an environmental bacterial pathogen that causes potentially lethal sepsis in susceptible individuals and is considered a Category B, Tier-1 biothreat agent. As such, it is crucial to gain an improved understanding of protective immunity and potential vaccine candidates. The nature of immune correlates dictating why most exposed individuals in endemic regions undergo asymptomatic seroconversion while others succumb to life-threatening sepsis is largely uncharted. Bp seroreactive, immunogenic proteins have previously been identified by antigen microarray. We here set out to conduct an analysis of T-cell recognition of the Bp immunome using serodominant antigens represented in the original antigen microarray, examining immune correlates of disease in healthy seropositive individuals and those with acute disease or in convalescence. By screening a library of 739 overlapping peptides representing the sequences of 20 different Bp antigens, we aimed to define immune correlates of protection at the level of immunoprevalent T-cell epitopes. Responses to a large number of epitopes were common in healthy seropositive individuals: we found remarkably broad responsiveness to Bp epitopes, with 235 of 739 peptides recognized by ≥80% of all tested donors. The cumulative response to Bp epitopes in healthy, seropositive, donors from this endemic region were of the order of thousands of spot forming cells per million cells, making Bp recognition a significant component of the T-cell repertoire. Noteworthy among our findings, analysis revealed 10 highly immunoprevalent T-cell epitopes, able to induce Bp-specific IFNγ responses that were high in responding T-cell frequency within the repertoire, and also common across individuals with different human leukocyte antigen types. Acute melioidosis patients showed poor T-cell responses to the immunoprevalent epitopes, but acquired responsiveness following recovery from infection. Our

  3. Host-pathogen interactions in typhoid fever

    NARCIS (Netherlands)

    de Jong, H.K.

    2015-01-01

    This thesis focuses on host-pathogen interactions in Salmonella Typhi and Burkholderia pseudomallei infections and explores the interplay between these bacteria and the innate immune system. Typhoid fever is one of the most common causes of bacterial infection in low-income countries. With adequate

  4. Uso del sistema E-test per lo studio di combinazioni antibiotiche verso batteri Gram-negativi multiresistenti in Fibrosi Cistica

    Directory of Open Access Journals (Sweden)

    Antonietta Lambiase

    2006-06-01

    Full Text Available Objectives: Cystic Fibrosis patients are prone to infection by Gram-negative bacteria, such as Pseudomonas aeruginosa and Burkholderia cepacia, which become very resistant with recurrent antibiotic treatments.The purpose of this study was to evaluate the susceptibility patterns of 12 isolates of Burkholderia cepacia and 8 isolates of Pseudomonas aeruginosa, isolated from Cystic Fibrosis patients to five individual antibiotics (ceftazidime, ciprofloxacin, piperacillin/tazobactam, levofloxacin and trimethoprim-sulfamethoxazole and to four antibiotic combinations (ceftazidime associated with one of the other antibiotics. Methods: Susceptibility tests were carried out using an agar diffusion method, the E-test (AB Biodisk, Solna, Sweden. Results: Strains were selected because of their resistance to individual antimicrobial agents, tested with automated system (Phoenix, BD, which ranged from 41.6% for ceftazidime to 83.3% for ciprofloxacin for Burkholderia cepacia and from 25% for ceftazidime to 100% for trimethoprim-sulfamethoxazole for Pseudomonas aeruginosa. By using E-test,we were able to demonstrate synergy against 2 strains of Pseudomonas aeruginosa (25% with ceftazidime- piperacillin/tazobactam. No synergy was detected against all strains of Burkholderia cepacia. Conclusions:These results suggest that the E-test offers a simple, labour-efficient and accurate method for MIC determination on agar medium and the susceptibility to antibiotic combinations greatly improves the guide to antibiotic therapy for infections to Gram-negative bacteria in Cystic Fibrosis patients.

  5. Genomic characterization of Burkholderia pseudomallei isolates selected for medical countermeasures testing: comparative genomics associated with differential virulence.

    Directory of Open Access Journals (Sweden)

    Jason W Sahl

    Full Text Available Burkholderia pseudomallei is the causative agent of melioidosis and a potential bioterrorism agent. In the development of medical countermeasures against B. pseudomallei infection, the US Food and Drug Administration (FDA animal Rule recommends using well-characterized strains in animal challenge studies. In this study, whole genome sequence data were generated for 6 B. pseudomallei isolates previously identified as candidates for animal challenge studies; an additional 5 isolates were sequenced that were associated with human inhalational melioidosis. A core genome single nucleotide polymorphism (SNP phylogeny inferred from a concatenated SNP alignment from the 11 isolates sequenced in this study and a diverse global collection of isolates demonstrated the diversity of the proposed Animal Rule isolates. To understand the genomic composition of each isolate, a large-scale blast score ratio (LS-BSR analysis was performed on the entire pan-genome; this demonstrated the variable composition of genes across the panel and also helped to identify genes unique to individual isolates. In addition, a set of ~550 genes associated with pathogenesis in B. pseudomallei were screened against the 11 sequenced genomes with LS-BSR. Differential gene distribution for 54 virulence-associated genes was observed between genomes and three of these genes were correlated with differential virulence observed in animal challenge studies using BALB/c mice. Differentially conserved genes and SNPs associated with disease severity were identified and could be the basis for future studies investigating the pathogenesis of B. pseudomallei. Overall, the genetic characterization of the 11 proposed Animal Rule isolates provides context for future studies involving B. pseudomallei pathogenesis, differential virulence, and efficacy to therapeutics.

  6. Biochemical and Functional Studies on the Burkholderia cepacia Complex bceN Gene, Encoding a GDP-D-Mannose 4,6-Dehydratase

    Science.gov (United States)

    Pinheiro, Pedro F.; Leitão, Jorge H.

    2013-01-01

    This work reports the biochemical and functional analysis of the Burkholderia cenocepacia J2315 bceN gene, encoding a protein with GDP-D-mannose 4,6-dehydratase enzyme activity (E.C.4.2.1.47). Data presented indicate that the protein is active when in the tetrameric form, catalyzing the conversion of GDP-D-mannose into GDP-4-keto-6-deoxy-D-mannose. This sugar nucleotide is the intermediary necessary for the biosynthesis of GDP-D-rhamnose, one of the sugar residues of cepacian, the major exopolysaccharide produced by environmental and human, animal and plant pathogenic isolates of the Burkholderia cepacia complex species. Vmax and Km values of 1.5±0.2 µmol.min−1.mg−1 and 1024±123 µM, respectively, were obtained from the kinetic characterization of the B. cenocepacia J2315 BceN protein by NMR spectroscopy, at 25°C and in the presence of 1 mol MgCl2 per mol of protein. The enzyme activity was strongly inhibited by the substrate, with an estimated Ki of 2913±350 µM. The lack of a functional bceN gene in a mutant derived from B. cepacia IST408 slightly reduced cepacian production. However, in the B. multivorans ATCC17616 with bceN as the single gene in its genome with predicted GMD activity, a bceN mutant did not produce cepacian, indicating that this gene product is required for cepacian biosynthesis. PMID:23460819

  7. Biochemical and functional studies on the Burkholderia cepacia complex bceN gene, encoding a GDP-D-mannose 4,6-dehydratase.

    Directory of Open Access Journals (Sweden)

    Sílvia A Sousa

    Full Text Available This work reports the biochemical and functional analysis of the Burkholderia cenocepacia J2315 bceN gene, encoding a protein with GDP-D-mannose 4,6-dehydratase enzyme activity (E.C.4.2.1.47. Data presented indicate that the protein is active when in the tetrameric form, catalyzing the conversion of GDP-D-mannose into GDP-4-keto-6-deoxy-D-mannose. This sugar nucleotide is the intermediary necessary for the biosynthesis of GDP-D-rhamnose, one of the sugar residues of cepacian, the major exopolysaccharide produced by environmental and human, animal and plant pathogenic isolates of the Burkholderia cepacia complex species. Vmax and Km values of 1.5±0.2 µmol.min(-1.mg(-1 and 1024±123 µM, respectively, were obtained from the kinetic characterization of the B. cenocepacia J2315 BceN protein by NMR spectroscopy, at 25°C and in the presence of 1 mol MgCl2 per mol of protein. The enzyme activity was strongly inhibited by the substrate, with an estimated Ki of 2913±350 µM. The lack of a functional bceN gene in a mutant derived from B. cepacia IST408 slightly reduced cepacian production. However, in the B. multivorans ATCC17616 with bceN as the single gene in its genome with predicted GMD activity, a bceN mutant did not produce cepacian, indicating that this gene product is required for cepacian biosynthesis.

  8. Proteasome- and Ethanol-Dependent Regulation of HCV-Infection Pathogenesis

    Directory of Open Access Journals (Sweden)

    Natalia A. Osna

    2014-09-01

    Full Text Available This paper reviews the role of the catabolism of HCV and signaling proteins in HCV protection and the involvement of ethanol in HCV-proteasome interactions. HCV specifically infects hepatocytes, and intracellularly expressed HCV proteins generate oxidative stress, which is further exacerbated by heavy drinking. The proteasome is the principal proteolytic system in cells, and its activity is sensitive to the level of cellular oxidative stress. Not only host proteins, but some HCV proteins are degraded by the proteasome, which, in turn, controls HCV propagation and is crucial for the elimination of the virus. Ubiquitylation of HCV proteins usually leads to the prevention of HCV propagation, while accumulation of undegraded viral proteins in the nuclear compartment exacerbates infection pathogenesis. Proteasome activity also regulates both innate and adaptive immunity in HCV-infected cells. In addition, the proteasome/immunoproteasome is activated by interferons, which also induce “early” and “late” interferon-sensitive genes (ISGs with anti-viral properties. Cleaving viral proteins to peptides in professional immune antigen presenting cells and infected (“target” hepatocytes that express the MHC class I-antigenic peptide complex, the proteasome regulates the clearance of infected hepatocytes by the immune system. Alcohol exposure prevents peptide cleavage by generating metabolites that impair proteasome activity, thereby providing escape mechanisms that interfere with efficient viral clearance to promote the persistence of HCV-infection.

  9. Life cycle-dependent cytoskeletal modifications in Plasmodium falciparum infected erythrocytes.

    Directory of Open Access Journals (Sweden)

    Hui Shi

    Full Text Available Plasmodium falciparum infection of human erythrocytes is known to result in the modification of the host cell cytoskeleton by parasite-coded proteins. However, such modifications and corresponding implications in malaria pathogenesis have not been fully explored. Here, we probed the gradual modification of infected erythrocyte cytoskeleton with advancing stages of infection using atomic force microscopy (AFM. We reported a novel strategy to derive accurate and quantitative information on the knob structures and their connections with the spectrin network by performing AFM-based imaging analysis of the cytoplasmic surface of infected erythrocytes. Significant changes on the red cell cytoskeleton were observed from the expansion of spectrin network mesh size, extension of spectrin tetramers and the decrease of spectrin abundance with advancing stages of infection. The spectrin network appeared to aggregate around knobs but also appeared sparser at non-knob areas as the parasite matured. This dramatic modification of the erythrocyte skeleton during the advancing stage of malaria infection could contribute to the loss of deformability of the infected erythrocyte.

  10. Life cycle-dependent cytoskeletal modifications in Plasmodium falciparum infected erythrocytes.

    Science.gov (United States)

    Shi, Hui; Liu, Zhuo; Li, Ang; Yin, Jing; Chong, Alvin G L; Tan, Kevin S W; Zhang, Yong; Lim, Chwee Teck

    2013-01-01

    Plasmodium falciparum infection of human erythrocytes is known to result in the modification of the host cell cytoskeleton by parasite-coded proteins. However, such modifications and corresponding implications in malaria pathogenesis have not been fully explored. Here, we probed the gradual modification of infected erythrocyte cytoskeleton with advancing stages of infection using atomic force microscopy (AFM). We reported a novel strategy to derive accurate and quantitative information on the knob structures and their connections with the spectrin network by performing AFM-based imaging analysis of the cytoplasmic surface of infected erythrocytes. Significant changes on the red cell cytoskeleton were observed from the expansion of spectrin network mesh size, extension of spectrin tetramers and the decrease of spectrin abundance with advancing stages of infection. The spectrin network appeared to aggregate around knobs but also appeared sparser at non-knob areas as the parasite matured. This dramatic modification of the erythrocyte skeleton during the advancing stage of malaria infection could contribute to the loss of deformability of the infected erythrocyte.

  11. A ROS-dependent and Caspase-3-mediated apoptosis in sheep bronchial epithelial cells in response to Mycoplasma Ovipneumoniae infections.

    Science.gov (United States)

    Xue, Di; Li, Yanan; Jiang, Zhongjia; Deng, Guangcun; Li, Min; Liu, Xiaoming; Wang, Yujiong

    2017-05-01

    Mycoplasma Ovipneumoniae (M. ovipneumoniae) is a primary etiological agent of enzootic pneumonia in sheep and goats. It can enter and colonize ovine respiratory epithelial cells to establish an infection, which leads a serious cell death of epithelial cells. However, the nature of the interaction between pathogen of M. ovipneumoniae and host cells in the cell injury is currently not well understood. In this study, we investigated the epithelial cell apoptosis caused by an infection of M. ovipneumoniae in sheep primary air-liquid interface (ALI) epithelial cultures. The results showed that M. ovipneumoniae could specifically bind to ciliated cells at early stage of infection. Flow cytometric analysis demonstrated that an infection of M. ovipneumoniae induced a time-dependent cell apoptotic cell death, accompanied with an increased production of extracellular nitric oxide (NO), intracellular reactive oxygen species (ROS) production and activation of caspase-3 signaling in sheep bronchial epithelial cells. The induced cell apoptosis was further confirmed by a transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL) assay. Interestingly, the M. ovipneumoniae-induced apoptosis and activation of caspase-3 were correlated with the production of ROS but not NO. Mechanistically, M. ovipneumoniae-induced cell apoptosis was mediated by a mechanism by increasing the expression of phosphorylation of p38 and pro-apoptotic proteins, and activating caspase-3, caspase-8 and poly ADP-ribose polymerase (PARP) cleavage. These results suggest a ROS-dependent and caspase-3-mediated cell apoptosis in sheep bronchial epithelial cells in response to M. ovipneumoniae infections. Copyright © 2017. Published by Elsevier B.V.

  12. Biosurfactant Production by Pseudomonas aeruginosa and Burkholderia gladioli Isolated from Mangrove Sediments Using Alternative Substrates

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    Karla Maria Catter

    2016-10-01

    Full Text Available Biosurfactants are surface-active agents produced by a variety of microorganisms. To make biosurfactant production economically feasible, several alternative carbon sources have been proposed. This study describes biosurfactant production by strains of Pseudomonas aeruginosa and Burkholderia gladioli isolated from mangrove sediments in Northeastern Brazil and cultured in mineral media enriched with waste cooking oil. The biosurfactants were tested for drop collapse, emulsion formation and stability and surface tension. P. aeruginosa performed better both at lowering the surface tension (from 69 to 28 mN/m and at forming stable emulsions (approximately 80% at 48 hours of culture. The strains tested in this study were found to be efficient biosurfactant producers when cultured on substrates enriched with vegetable oil. DOI: http://dx.doi.org/10.17807/orbital.v8i5.771

  13. Multilocus Sequence Typing of Historical Burkholderia pseudomallei Isolates Collected in Southeast Asia from 1964 to 1967 Provides Insight into the Epidemiology of Melioidosis

    OpenAIRE

    McCombie, Roberta L.; Finkelstein, Richard A.; Woods, Donald E.

    2006-01-01

    A collection of 207 historically relevant Burkholderia pseudomallei isolates was analyzed by multilocus sequence typing (MLST). The strain collection contains environmental isolates obtained from a geographical distribution survey of B. pseudomallei isolates in Thailand (1964 to 1967), as well as stock cultures and colony variants from the U.S. Army Medical Research Unit (Malaysia), the Walter Reed Army Institute for Research, and the Pasteur Institute (Vietnam). The 207 isolates of the colle...

  14. Dependency Traits, Relationship Power, and Health Risks in Women Receiving Sexually-Transmitted Infection Clinic Services.

    Science.gov (United States)

    Benotsch, Eric G; Sawyer, Ashlee N; Martin, Aaron M; Allen, Elizabeth S; Nettles, Christopher D; Richardson, Doug; Rietmeijer, Cornelis A

    2017-01-01

    In prior research, having traits consistent with a personality disorder has been shown to be related to substance use and high-risk sexual activity; however, few studies have examined relationships between dependency traits and health-jeopardizing behaviors. Individuals with traits consistent with dependent personality disorder may be more likely to be in a primary relationship characterized by unhealthy conditions, including physical abuse from a partner, low assertiveness in sexual situations, and partner infidelity. In addition, dependency traits may be associated with unhealthy coping (e.g., through substance use). To examine associations between dependent personality traits and these types of health-related behaviors, 198 women seeking sexually transmitted infection clinic services completed a computer-assisted assessment of dependent personality traits, substance use, unhealthy conditions in primary relationships, perceived sexual and relationship power, and sexual risk related to condom use. Dependency trait scores were correlated with the use of cocaine, heroin, and methamphetamine. Participants high in dependency traits reported low perceived power within their relationships and less say in sexual behaviors, including condom use. In a series of multivariate analyses, dependency traits significantly predicted having been hit by a partner, staying with a partner after he cheated, having sex because of threats, and fear of asking a partner to use a condom. Dependency traits were also associated with lower past condom use and lower future condom use intentions. Results suggest that dependent personality traits may place women at higher risk for physical abuse and harmful health behaviors.

  15. Effects of the inoculation of Burkholderia vietnamensis and related endophytic diazotrophic bacteria on grain yield of rice.

    Science.gov (United States)

    Govindarajan, Munusamy; Balandreau, Jacques; Kwon, Soon-Wo; Weon, Hang-Yeon; Lakshminarasimhan, Cunthipuram

    2008-01-01

    During a survey of endophytic diazotrophic bacteria associated with different rice varieties in Tamilnadu, some "endophytes" were obtained. Thirteen bacterial isolates from surface-sterilized roots and shoots were obtained in pure culture, which produced indole acetic acid (IAA) and reduced acetylene to ethylene. Polymerase chain reaction (PCR) amplification confirmed the presence of nif-H gene in all the isolates. Morphological, biochemical, and molecular characteristics indicated that all of them belonged to the genus Burkholderia One of them, MGK3, was consistently more active in reducing acetylene, and 16S rDNA sequences of isolate MGK3 confirmed its identification as Burkholderia vietnamiensis. Colonization of rice root was confirmed by strain MGK3 marked with gusA gene. The inoculated roots showed a blue color, which was most intense at the points of lateral root emergence and at the root tip. Transverse sections of roots, 15 days after inoculation, revealed beta-glucuronidase (GUS) activity within many of the cortical intercellular spaces next to the stele and within the aerenchyma. Nitrogen fixation was quantified by using (15)N isotope dilution method with two different cultivars grown in pot and field experiments. Higher nitrogen fixation was observed in variety Ponni than in ADT-43, where nearly 42% (field) and 40% (pot) of the nitrogen was derived from the atmosphere (% Ndfa). Isolate MGK3 was used to inoculate rice seedlings in a comparison with four other diazotrophs, viz., Gluconacetobacter diazotrophicus LMG7603, Herbaspirillum seropedicae LMG6513, Azospirillum lipoferum 4B LMG4348, and B. vietnamiensis LMG10929. They were used to conduct two pot and four field inoculation experiments. MGK3 alone, and combined with other diazotrophs, performed best under both pot and field conditions: combined inoculation produced yield increases between 9.5 and 23.6%, while MGK3 alone increased yield by 5.6 to 12.16% over the uninoculated control treatment.

  16. Growth promotion of pineapple 'vitória' by humic acids and burkholderia spp. during acclimatization Promoção do crescimento do abacaxizeiro 'vitória' por ácidos húmicos e Burkholderia spp. durante a aclimatização

    Directory of Open Access Journals (Sweden)

    Lílian Estrela Borges Baldotto

    2010-10-01

    Full Text Available In vitro propagation of pineapple produces uniform and disease-free plantlets, but requires a long period of acclimatization before transplanting to the field. Quicker adaptation to the ex vitro environment and growth acceleration of pineapple plantlets are prerequisites for the production of a greater amount of vigorous, well-rooted planting material. The combination of humic acids and endophytic bacteria could be a useful technological approach to reduce the critical period of acclimatization. The aim of this study was to evaluate the initial performance of tissue-cultured pineapple variety Vitória in response to application of humic acids isolated from vermicompost and plant growth-promoting bacteria (Burkholderia spp. during greenhouse acclimatization. The basal leaf axils were treated with humic acids while roots were immersed in bacterial medium. Humic acids and bacteria application improved shoot growth (14 and 102 %, respectively, compared with the control; the effect of the combined treatment was most pronounced (147 %. Likewise, humic acids increased root growth by 50 %, bacteria by 81 % and the combined treatment by 105 %. Inoculation was found to significantly increase the accumulation of N (115 %, P (112 % and K (69 % in pineapple leaves. Pineapple growth was influenced by inoculation with Burkholderia spp., and further improved in combination with humic acids, resulting in higher shoot and root biomass as well as nutrient contents (N 132 %, P 131 %, K 80 % than in uninoculated plantlets. The stability and increased consistency of the host plant response to bacterization in the presence of humic substances indicate a promising biotechnological tool to improve growth and adaptation of pineapple plantlets to the ex vitro environment.A propagação in vitro de abacaxizeiro produz mudas uniformes e sadias, mas exige longo período de aclimatização antes da transferência para o campo. A adaptação ao ambiente ex vitro seguida da

  17. Unravelling the Molecular Epidemiology and Genetic Diversity among Burkholderia pseudomallei Isolates from South India Using Multi-Locus Sequence Typing.

    Science.gov (United States)

    Tellapragada, Chaitanya; Kamthan, Aayushi; Shaw, Tushar; Ke, Vandana; Kumar, Subodh; Bhat, Vinod; Mukhopadhyay, Chiranjay

    2016-01-01

    There is a slow but steady rise in the case detection rates of melioidosis from various parts of the Indian sub-continent in the past two decades. However, the epidemiology of the disease in India and the surrounding South Asian countries remains far from well elucidated. Multi-locus sequence typing (MLST) is a useful epidemiological tool to study the genetic relatedness of bacterial isolates both with-in and across the countries. With this background, we studied the molecular epidemiology of 32 Burkholderia pseudomallei isolates (31 clinical and 1 soil isolate) obtained during 2006-2015 from various parts of south India using multi-locus sequencing typing and analysis. Of the 32 isolates included in the analysis, 30 (93.7%) had novel allelic profiles that were not reported previously. Sequence type (ST) 1368 (n = 15, 46.8%) with allelic profile (1, 4, 6, 4, 1, 1, 3) was the most common genotype observed. We did not observe a genotypic association of STs with geographical location, type of infection and year of isolation in the present study. Measure of genetic differentiation (FST) between Indian and the rest of world isolates was 0.14413. Occurrence of the same ST across three adjacent states of south India suggest the dispersion of B.pseudomallei across the south western coastal part of India with limited geographical clustering. However, majority of the STs reported from the present study remained as "outliers" on the eBURST "Population snapshot", suggesting the genetic diversity of Indian isolates from the Australasian and Southeast Asian isolates.

  18. Unravelling the Molecular Epidemiology and Genetic Diversity among Burkholderia pseudomallei Isolates from South India Using Multi-Locus Sequence Typing.

    Directory of Open Access Journals (Sweden)

    Chaitanya Tellapragada

    Full Text Available There is a slow but steady rise in the case detection rates of melioidosis from various parts of the Indian sub-continent in the past two decades. However, the epidemiology of the disease in India and the surrounding South Asian countries remains far from well elucidated. Multi-locus sequence typing (MLST is a useful epidemiological tool to study the genetic relatedness of bacterial isolates both with-in and across the countries. With this background, we studied the molecular epidemiology of 32 Burkholderia pseudomallei isolates (31 clinical and 1 soil isolate obtained during 2006-2015 from various parts of south India using multi-locus sequencing typing and analysis. Of the 32 isolates included in the analysis, 30 (93.7% had novel allelic profiles that were not reported previously. Sequence type (ST 1368 (n = 15, 46.8% with allelic profile (1, 4, 6, 4, 1, 1, 3 was the most common genotype observed. We did not observe a genotypic association of STs with geographical location, type of infection and year of isolation in the present study. Measure of genetic differentiation (FST between Indian and the rest of world isolates was 0.14413. Occurrence of the same ST across three adjacent states of south India suggest the dispersion of B.pseudomallei across the south western coastal part of India with limited geographical clustering. However, majority of the STs reported from the present study remained as "outliers" on the eBURST "Population snapshot", suggesting the genetic diversity of Indian isolates from the Australasian and Southeast Asian isolates.

  19. Loss of predator aversion in female rats after Toxoplasma gondii infection is not dependent on ovarian steroids.

    Science.gov (United States)

    Abdulai-Saiku, Samira; Vyas, Ajai

    2017-10-01

    Toxoplasma gondii infection reduces aversion to cat odors in male rats. Relevant proximate mechanisms include interaction of gonadal testosterone and brain nonapeptide arginine-vasopressin. Both of these substrates are sexually dimorphic with preferential expression in males; suggesting either absence of behavioral change in females or mediation by analogous neuroendocrine substrates. Here we demonstrate that Toxoplasma gondii infection reduces aversion to cat odor in female rats. This change is not accompanied by altered steroid hormones; cannot be rescued by gonadal removal; and, does not depend on arginine-vasopressin. Thus behavioral change in males and female occur through non-analogous mechanisms that remain hitherto unknown. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Characterization of N-acylhomoserine lactone-degrading bacteria associated with the Zingiber officinale (ginger rhizosphere: Co-existence of quorum quenching and quorum sensing in Acinetobacter and Burkholderia

    Directory of Open Access Journals (Sweden)

    Chhabra Siri

    2011-03-01

    Full Text Available Abstract Background Cell-to-cell communication (quorum sensing (QS co-ordinates bacterial behaviour at a population level. Consequently the behaviour of a natural multi-species community is likely to depend at least in part on co-existing QS and quorum quenching (QQ activities. Here we sought to discover novel N-acylhomoserine lactone (AHL-dependent QS and QQ strains by investigating a bacterial community associated with the rhizosphere of ginger (Zingiber officinale growing in the Malaysian rainforest. Results By using a basal growth medium containing N-(3-oxohexanoylhomoserine lactone (3-oxo-C6-HSL as the sole source of carbon and nitrogen, the ginger rhizosphere associated bacteria were enriched for strains with AHL-degrading capabilities. Three isolates belonging to the genera Acinetobacter (GG2, Burkholderia (GG4 and Klebsiella (Se14 were identified and selected for further study. Strains GG2 and Se14 exhibited the broadest spectrum of AHL-degrading activities via lactonolysis while GG4 reduced 3-oxo-AHLs to the corresponding 3-hydroxy compounds. In GG2 and GG4, QQ was found to co-exist with AHL-dependent QS and GG2 was shown to inactivate both self-generated and exogenously supplied AHLs. GG2, GG4 and Se14 were each able to attenuate virulence factor production in both human and plant pathogens. Conclusions Collectively our data show that ginger rhizosphere bacteria which make and degrade a wide range of AHLs are likely to play a collective role in determining the QS-dependent phenotype of a polymicrobial community.

  1. Effect of Azospirillum brasilense and Burkholderia unamae Bacteria on Maize Photosynthetic Activity Evaluated Using the Photoacoustic Technique

    Science.gov (United States)

    Gordillo-Delgado, F.; Marín, E.; Calderón, A.

    2016-09-01

    In this work, the photosynthetic process of maize plants ( Zea mays), which were grown using seeds inoculated with plant growth promoting bacteria Azospirillum brasilense and Burkholderia unamae, was monitored. Photothermal and photobaric signals obtained by a time-resolved photoacoustic measurement configuration were used for measuring the oxygen evolution rate in situ. A frequency-resolved configuration of the method was utilized to determine the oxygen diffusion coefficient and the thermal diffusivity of the maize leaves. The latter parameters, which can be used as indicators of the photosynthetic activity of maize, are found to vary according to the plant-microbe interaction. Treatment with plant growth promoting bacteria induced a decrease in the oxygen diffusion coefficient of about 20 %.

  2. Bifurcation analysis of a discrete SIS model with bilinear incidence depending on new infection.

    Science.gov (United States)

    Cao, Hui; Zhou, Yicang; Ma, Zhien

    2013-01-01

    A discrete SIS epidemic model with the bilinear incidence depending on the new infection is formulated and studied. The condition for the global stability of the disease free equilibrium is obtained. The existence of the endemic equilibrium and its stability are investigated. More attention is paid to the existence of the saddle-node bifurcation, the flip bifurcation, and the Hopf bifurcation. Sufficient conditions for those bifurcations have been obtained. Numerical simulations are conducted to demonstrate our theoretical results and the complexity of the model.

  3. Toxoplasma depends on lysosomal consumption of autophagosomes for persistent infection.

    Science.gov (United States)

    Di Cristina, Manlio; Dou, Zhicheng; Lunghi, Matteo; Kannan, Geetha; Huynh, My-Hang; McGovern, Olivia L; Schultz, Tracey L; Schultz, Aric J; Miller, Alyssa J; Hayes, Beth M; van der Linden, Wouter; Emiliani, Carla; Bogyo, Matthew; Besteiro, Sébastien; Coppens, Isabelle; Carruthers, Vern B

    2017-06-19

    Globally, nearly 2 billion people are infected with the intracellular protozoan Toxoplasma gondii 1 . This persistent infection can cause severe disease in immunocompromised people and is epidemiologically linked to major mental illnesses 2 and cognitive impairment 3 . There are currently no options for curing this infection. The lack of effective therapeutics is due partly to a poor understanding of the essential pathways that maintain long-term infection. Although it is known that Toxoplasma replicates slowly within intracellular cysts demarcated with a cyst wall, precisely how it sustains itself and remodels organelles in this niche is unknown. Here, we identify a key role for proteolysis within the parasite lysosomal organelle (the vacuolar compartment or VAC) in turnover of autophagosomes and persistence during neural infection. We found that disrupting a VAC-localized cysteine protease compromised VAC digestive function and markedly reduced chronic infection. Death of parasites lacking the VAC protease was preceded by accumulation of undigested autophagosomes in the parasite cytoplasm. These findings suggest an unanticipated function for parasite lysosomal degradation in chronic infection, and identify an intrinsic role for autophagy in the T. gondii parasite and its close relatives. This work also identifies a key element of Toxoplasma persistence and suggests that VAC proteolysis is a prospective target for pharmacological development.

  4. Trypanosoma Infection Favors Brucella Elimination via IL-12/IFNγ-Dependent Pathways

    Directory of Open Access Journals (Sweden)

    Arnaud Machelart

    2017-07-01

    Full Text Available This study develops an original co-infection model in mice using Brucella melitensis, the most frequent cause of human brucellosis, and Trypanosoma brucei, the agent of African trypanosomiasis. Although the immunosuppressive effects of T. brucei in natural hosts and mice models are well established, we observed that the injection of T. brucei in mice chronically infected with B. melitensis induces a drastic reduction in the number of B. melitensis in the spleen, the main reservoir of the infection. Similar results are obtained with Brucella abortus- and Brucella suis-infected mice and B. melitensis-infected mice co-infected with Trypanosoma cruzi, demonstrating that this phenomenon is not due to antigenic cross-reactivity. Comparison of co-infected wild-type and genetically deficient mice showed that Brucella elimination required functional IL-12p35/IFNγ signaling pathways and the presence of CD4+ T cells. However, the impact of wild type and an attenuated mutant of T. brucei on B. melitensis were similar, suggesting that a chronic intense inflammatory reaction is not required to eliminate B. melitensis. Finally, we also tested the impact of T. brucei infection on the course of Mycobacterium tuberculosis infection. Although T. brucei strongly increases the frequency of IFNγ+CD4+ T cells, it does not ameliorate the control of M. tuberculosis infection, suggesting that it is not controlled by the same effector mechanisms as Brucella. Thus, whereas T. brucei infections are commonly viewed as immunosuppressive and pathogenic, our data suggest that these parasites can specifically affect the immune control of Brucella infection, with benefits for the host.

  5. Anti-Idiotypic Antibodies Specific to prM Monoantibody Prevent Antibody Dependent Enhancement of Dengue Virus Infection

    Directory of Open Access Journals (Sweden)

    Miao Wang

    2017-05-01

    Full Text Available Dengue virus (DENV co-circulates as four serotypes (DENV1-4. Primary infection only leads to self-limited dengue fever. But secondary infection with another serotype carries a higher risk of increased disease severity, causing life-threatening dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS. Serotype cross-reactive antibodies facilitate DENV infection in Fc-receptor-bearing cells by promoting virus entry via Fcγ receptors (FcγR, a process known as antibody dependent enhancement (ADE. Most studies suggested that enhancing antibodies were mainly specific to the structural premembrane protein (prM of DENV. However, there is still no effective drugs or vaccines to prevent ADE. In this study, we firstly confirmed that both DENV-2 infected human sera (anti-DENV-2 and DENV-2 prM monoclonal antibody (prM mAb could significantly enhance DENV-1 infection in K562 cells. Then we developed anti-idiotypic antibodies (prM-AIDs specific to prM mAb by immunizing of Balb/c mice. Results showed that these polyclonal antibodies can dramatically reduce ADE phenomenon of DENV-1 infection in K562 cells. To further confirm the anti-ADE effect of prM-AIDs in vivo, interferon-α and γ receptor-deficient mice (AG6 were used as the mouse model for DENV infection. We found that administration of DENV-2 prM mAb indeed caused a higher DENV-1 titer as well as interleukin-10 (IL-10 and alaninea minotransferase (ALT in mice infected with DENV-1, similar to clinical ADE symptoms. But when we supplemented prM-AIDs to DENV-1 challenged AG6 mice, the viral titer, IL-10 and ALT were obviously decreased to the negative control level. Of note, the number of platelets in peripheral blood of prM-AIDs group were significantly increased at day 3 post infection with DENV-1 compared that of prM-mAb group. These results confirmed that our prM-AIDs could prevent ADE not only in vitro but also in vivo, suggested that anti-idiotypic antibodies might be a new choice to be considered to

  6. Anti-Idiotypic Antibodies Specific to prM Monoantibody Prevent Antibody Dependent Enhancement of Dengue Virus Infection.

    Science.gov (United States)

    Wang, Miao; Yang, Fan; Huang, Dana; Huang, Yalan; Zhang, Xiaomin; Wang, Chao; Zhang, Shaohua; Zhang, Renli

    2017-01-01

    Dengue virus (DENV) co-circulates as four serotypes (DENV1-4). Primary infection only leads to self-limited dengue fever. But secondary infection with another serotype carries a higher risk of increased disease severity, causing life-threatening dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). Serotype cross-reactive antibodies facilitate DENV infection in Fc-receptor-bearing cells by promoting virus entry via Fcγ receptors (FcγR), a process known as antibody dependent enhancement (ADE). Most studies suggested that enhancing antibodies were mainly specific to the structural premembrane protein (prM) of DENV. However, there is still no effective drugs or vaccines to prevent ADE. In this study, we firstly confirmed that both DENV-2 infected human sera (anti-DENV-2) and DENV-2 prM monoclonal antibody (prM mAb) could significantly enhance DENV-1 infection in K562 cells. Then we developed anti-idiotypic antibodies (prM-AIDs) specific to prM mAb by immunizing of Balb/c mice. Results showed that these polyclonal antibodies can dramatically reduce ADE phenomenon of DENV-1 infection in K562 cells. To further confirm the anti-ADE effect of prM-AIDs in vivo , interferon-α and γ receptor-deficient mice (AG6) were used as the mouse model for DENV infection. We found that administration of DENV-2 prM mAb indeed caused a higher DENV-1 titer as well as interleukin-10 (IL-10) and alaninea minotransferase (ALT) in mice infected with DENV-1, similar to clinical ADE symptoms. But when we supplemented prM-AIDs to DENV-1 challenged AG6 mice, the viral titer, IL-10 and ALT were obviously decreased to the negative control level. Of note, the number of platelets in peripheral blood of prM-AIDs group were significantly increased at day 3 post infection with DENV-1 compared that of prM-mAb group. These results confirmed that our prM-AIDs could prevent ADE not only in vitro but also in vivo , suggested that anti-idiotypic antibodies might be a new choice to be considered to treat

  7. The Small Protein HemP Is a Transcriptional Activator for the Hemin Uptake Operon in Burkholderia multivorans ATCC 17616.

    Science.gov (United States)

    Sato, Takuya; Nonoyama, Shouta; Kimura, Akane; Nagata, Yuji; Ohtsubo, Yoshiyuki; Tsuda, Masataka

    2017-08-15

    Iron and heme play very important roles in various metabolic functions in bacteria, and their intracellular homeostasis is maintained because high concentrations of free forms of these molecules greatly facilitate the Fenton reaction-mediated production of large amounts of reactive oxygen species that severely damage various biomolecules. The ferric uptake regulator (Fur) from Burkholderia multivorans ATCC 17616 is an iron-responsive global transcriptional regulator, and its fur deletant exhibits pleiotropic phenotypes. In this study, we found that the phenotypes of the fur deletant were suppressed by an additional mutation in hemP The transcription of hemP was negatively regulated by Fur under iron-replete conditions and was constitutive in the fur deletant. Growth of a hemP deletant was severely impaired in a medium containing hemin as the sole iron source, demonstrating the important role of HemP in hemin utilization. HemP was required as a transcriptional activator that specifically binds the promoter-containing region upstream of a Fur-repressive hmuRSTUV operon, which encodes the proteins for hemin uptake. A hmuR deletant was still able to grow using hemin as the sole iron source, albeit at a rate clearly lower than that of the wild-type strain. These results strongly suggested (i) the involvement of HmuR in hemin uptake and (ii) the presence in ATCC 17616 of at least part of other unknown hemin uptake systems whose expression depends on the HemP function. Our in vitro analysis also indicated high-affinity binding of HemP to hemin, and such a property might modulate transcriptional activation of the hmu operon. IMPORTANCE Although the hmuRSTUV genes for the utilization of hemin as a sole iron source have been identified in a few Burkholderia strains, the regulatory expression of these genes has remained unknown. Our analysis in this study using B. multivorans ATCC 17616 showed that its HemP protein is required for expression of the hmuRSTUV operon, and the

  8. Disease: H00317 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available H00317 Melioidosis Melioidosis is an infection caused by the gram-negative soil-dw...elling bacillus Burkholderia pseudomallei. It predominantly affects people in regular contact with soil and

  9. Human glial chimeric mice reveal astrocytic dependence of JC virus infection

    DEFF Research Database (Denmark)

    Kondo, Yoichi; Windrem, Martha S; Zou, Lisa

    2014-01-01

    with humanized white matter by engrafting human glial progenitor cells (GPCs) into neonatal immunodeficient and myelin-deficient mice. Intracerebral delivery of JCV resulted in infection and subsequent demyelination of these chimeric mice. Human GPCs and astrocytes were infected more readily than...... that was chimeric for human astrocytes and GPCs. JCV effectively propagated in these mice, which indicates that astroglial infection is sufficient for JCV spread. Sequencing revealed progressive mutation of the JCV capsid protein VP1 after infection, suggesting that PML may evolve with active infection...

  10. Melioidosis in acute cholangitis of diabetic patient: a forgotten diagnosis

    Directory of Open Access Journals (Sweden)

    Mohamad N

    2012-08-01

    Full Text Available Nasir Mohamad,1 Suresh Ponnusamy,2 Sunita Devi,3 Rishya Manikam,4 Ilya Irinaz Idrus,1 Nor Hidayah Abu Bakar51Department of Emergency Medicine, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia; 2AIMST University, Bedong, Malaysia; 3Hospital Sultan Abdul Halim, Sungai Petani, Malaysia; 4University Malaya Medical Centre, Kuala Lumpur, Malaysia; 5Department of Pathology, Hospital Raja Perempuan Zainab II, Kota Bharu, MalaysiaAbstract: Melioidosis presents with a wide range of clinical presentations, which include severe community-acquired pneumonia, septicemia, central nervous system infection, and less severe soft tissue infection. Hence, its diagnosis depends heavily on the clinical microbiology laboratory for culture. In this case report, we describe an atypical presentation of melioidosis in a 52-year-old man who had fever, right upper-abdominal pain, and jaundice for 15 days. Melioidosis caused by Burkholderia pseudomallei was subsequently diagnosed from blood culture. As a primary care physician, high suspicion index is of great importance. High suspicion index of melioidosis in a high-risk group patient, such as the patient with diabetes mellitus and diabetic foot, is crucial in view of atypical presentations of pseudomonas sepsis. A correct combination of antibiotic administration in the early phase of therapy will determine its successful outcome.Keywords: Burkholderia pseudomallei, atypical, high suspicion, primary care

  11. Dependency of water concentration on ethanolysis of trioleoylglycerol by lipases

    DEFF Research Database (Denmark)

    Piyatheerawong, W.; Iwasaki, Y; Xu, Xuebing

    2004-01-01

    tested (Rhizomucor miehei lipase, Burkholderia cepacia lipase and Thermomyces lanuginosus lipase) required larger amounts of free water (ca. 7-9 wt.%) for their best performance and exhibited no ethanolysis reaction at low free water concentrations. The CALB's anomalous behavior was also observed...

  12. Stability of a viral infection model with state-dependent delay, CTL and antibody immune responses

    Czech Academy of Sciences Publication Activity Database

    Rezunenko, Oleksandr

    2017-01-01

    Roč. 22, č. 4 (2017), s. 1547-1563 ISSN 1531-3492 R&D Projects: GA ČR(CZ) GA16-06678S Institutional support: RVO:67985556 Keywords : Evolution equations * Lyapunov stability * state-dependent delay * virus infection model Subject RIV: BC - Control Systems Theory OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 0.994, year: 2016 http://library.utia.cas.cz/separaty/2017/AS/rezunenko-0476128.pdf

  13. Mycobacterium tuberculosis-infected human monocytes down-regulate microglial MMP-2 secretion in CNS tuberculosis via TNFα, NFκB, p38 and caspase 8 dependent pathways

    Directory of Open Access Journals (Sweden)

    Elkington Paul T

    2011-05-01

    Full Text Available Abstract Tuberculosis (TB of the central nervous system (CNS is a deadly disease characterized by extensive tissue destruction, driven by molecules such as Matrix Metalloproteinase-2 (MMP-2 which targets CNS-specific substrates. In a simplified cellular model of CNS TB, we demonstrated that conditioned medium from Mycobacterium tuberculosis-infected primary human monocytes (CoMTb, but not direct infection, unexpectedly down-regulates constitutive microglial MMP-2 gene expression and secretion by 72.8% at 24 hours, sustained up to 96 hours (P M.tb-infected monocyte-dependent networks paradoxically involves the pro-inflammatory mediators TNF-α, p38 MAP kinase and NFκB in addition to a novel caspase 8-dependent pathway.

  14. Biorremediation of soil polluted by 75000 ppm of waste motor oil applying biostimulation and phytoremediation with Sorghum vulgare and Bacillus cereus or Burkholderia cepacia

    OpenAIRE

    Balderas-León Iván; Sánchez-Yáñez Juan Manuel

    2015-01-01

    Waste motor oil (WMO) pollutes soil and causing lost soil fertility. An alternative to solve this problem its bioremediation (BR) by double and following biostimulation (BS) with mineral solution (MS) and a legume as green manure (GM) then using phytoremediation (PR) with growth promoting vegetal bacteria (GPVB) like Bacillus cereus and Burkholderia cepacia to minimize remaining WMO. The aims of this research were: a) bioremediation of polluted soil by 75000 ppm of WMO by biostimulation and t...

  15. Integration process of fermentation and liquid biphasic flotation for lipase separation from Burkholderia cepacia.

    Science.gov (United States)

    Sankaran, Revathy; Show, Pau Loke; Lee, Sze Ying; Yap, Yee Jiun; Ling, Tau Chuan

    2018-02-01

    Liquid Biphasic Flotation (LBF) is an advanced recovery method that has been effectively applied for biomolecules extraction. The objective of this investigation is to incorporate the fermentation and extraction process of lipase from Burkholderia cepacia using flotation system. Initial study was conducted to compare the performance of bacteria growth and lipase production using flotation and shaker system. From the results obtained, bacteria shows quicker growth and high lipase yield via flotation system. Integration process for lipase separation was investigated and the result showed high efficiency reaching 92.29% and yield of 95.73%. Upscaling of the flotation system exhibited consistent result with the lab-scale which are 89.53% efficiency and 93.82% yield. The combination of upstream and downstream processes in a single system enables the acceleration of product formation, improves the product yield and facilitates downstream processing. This integration system demonstrated its potential for biomolecules fermentation and separation that possibly open new opportunities for industrial production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Melioidosis Cases and Selected Reports of Occupational Exposures to Burkholderia pseudomallei--United States, 2008-2013.

    Science.gov (United States)

    Benoit, Tina J; Blaney, David D; Gee, Jay E; Elrod, Mindy G; Hoffmaster, Alex R; Doker, Thomas J; Bower, William A; Walke, Henry T

    2015-07-03

    Melioidosis is an infection caused by the Gram-negative bacillus Burkholderia pseudomallei, which is naturally found in water and soil in areas endemic for melioidosis. Infection can be severe and sometimes fatal. The federal select agent program designates B. pseudomallei as a Tier 1 overlap select agent, which can affect both humans and animals. Identification of B. pseudomallei and all occupational exposures must be reported to the Federal Select Agent Program immediately (i.e., within 24 hours), whereas states are not required to notify CDC's Bacterial Special Pathogens Branch (BSPB) of human infections. 2008-2013. The passive surveillance system includes reports of suspected (human and animal) melioidosis cases and reports of incidents of possible occupational exposures. Reporting of suspected cases to BSPB is voluntary. BSPB receives reports of occupational exposure in the context of a request for technical consultation (so that the system does not include the full complement of the mandatory and confidential reporting to the Federal Select Agent Program). Reporting sources include state health departments, medical facilities, microbiologic laboratories, or research facilities. Melioidosis cases are classified using the standard case definition adopted by the Council of State and Territorial Epidemiologists in 2011. In follow up to reports of occupational exposures, CDC often provides technical assistance to state health departments to identify all persons with possible exposures, define level of risk, and provide recommendations for postexposure prophylaxis and health monitoring of exposed persons. During 2008-2013, BSPB provided technical assistance to 20 U.S. states and Puerto Rico involving 37 confirmed cases of melioidosis (34 human cases and three animal cases). Among those with documented travel history, the majority of reported cases (64%) occurred among persons with a documented travel history to areas endemic for melioidosis. Two persons did not

  17. Neurons are MHC class I-dependent targets for CD8 T cells upon neurotropic viral infection.

    Directory of Open Access Journals (Sweden)

    Grégoire Chevalier

    2011-11-01

    Full Text Available Following infection of the central nervous system (CNS, the immune system is faced with the challenge of eliminating the pathogen without causing significant damage to neurons, which have limited capacities of renewal. In particular, it was thought that neurons were protected from direct attack by cytotoxic T lymphocytes (CTL because they do not express major histocompatibility class I (MHC I molecules, at least at steady state. To date, most of our current knowledge on the specifics of neuron-CTL interaction is based on studies artificially inducing MHC I expression on neurons, loading them with exogenous peptide and applying CTL clones or lines often differentiated in culture. Thus, much remains to be uncovered regarding the modalities of the interaction between infected neurons and antiviral CD8 T cells in the course of a natural disease. Here, we used the model of neuroinflammation caused by neurotropic Borna disease virus (BDV, in which virus-specific CTL have been demonstrated as the main immune effectors triggering disease. We tested the pathogenic properties of brain-isolated CD8 T cells against pure neuronal cultures infected with BDV. We observed that BDV infection of cortical neurons triggered a significant up regulation of MHC I molecules, rendering them susceptible to recognition by antiviral CTL, freshly isolated from the brains of acutely infected rats. Using real-time imaging, we analyzed the spatio-temporal relationships between neurons and CTL. Brain-isolated CTL exhibited a reduced mobility and established stable contacts with BDV-infected neurons, in an antigen- and MHC-dependent manner. This interaction induced rapid morphological changes of the neurons, without immediate killing or impairment of electrical activity. Early signs of neuronal apoptosis were detected only hours after this initial contact. Thus, our results show that infected neurons can be recognized efficiently by brain-isolated antiviral CD8 T cells and

  18. Development and characterization of a caprine aerosol infection model of melioidosis.

    Directory of Open Access Journals (Sweden)

    Carl Soffler

    Full Text Available Infection with Burkholderia pseudomallei causes the disease melioidosis, which often presents as a serious suppurative infection that is typically fatal without intensive treatment and is a significant emerging infectious disease in Southeast Asia. Despite intensive research there is still much that remains unknown about melioidosis pathogenesis. New animal models of melioidosis are needed to examine novel aspects of pathogenesis as well as for the evaluation of novel therapeutics. The objective of the work presented here was to develop a subacute to chronic caprine model of melioidosis and to characterize the progression of disease with respect to clinical presentation, hematology, clinical microbiology, thoracic radiography, and gross and microscopic pathology. Disease was produced in all animals following an intratracheal aerosol of 10(4 CFU delivered, with variable clinical manifestations indicative of subacute and chronic disease. Bronchointerstitial pneumonia was apparent microscopically by day 2 and radiographically and grossly apparent by day 7 post infection (PI. Early lesions of bronchopneumonia soon progressed to more severe bronchointerstitial pneumonia with pyogranuloma formation. Extrapulmonary dissemination appeared to be a function of pyogranuloma invasion of pulmonary vasculature, which peaked around day 7 PI. Histopathology indicated that leukocytoclastic vasculitis was the central step in dissemination of B. pseudomallei from the lungs as well as in the establishment of new lesions. While higher doses of organism in goats can produce acute fatal disease, the dose investigated and resulting disease had many similarities to human melioidosis and may warrant further development to provide a model for the study of both natural and bioterrorism associated disease.

  19. Antimicrobial Susceptibility and Genetic Characterisation of Burkholderia pseudomallei Isolated from Malaysian Patients

    Directory of Open Access Journals (Sweden)

    Yalda Khosravi

    2014-01-01

    Full Text Available Burkholderia pseudomallei, the causative agent of melioidosis, is intrinsically resistant to many antibiotics. Ceftazidime (CAZ, the synthetic β-lactam, is normally used as the first-line antibiotic therapy for treatment of melioidosis. However, acquired CAZ resistance can develop in vivo during treatment with CAZ, leading to mortality if therapy is not switched to a different antibiotic(s in a timely manner. In this study, susceptibilities of 81 B. pseudomallei isolates to nine different antimicrobial agents were determined using the disk diffusion method, broth microdilution test and Etest. Highest percentage of susceptibility was demonstrated to CAZ, amoxicillin/clavulanic acid, meropenem, imipenem, and trimethoprim/sulfamethoxazole. Although these drugs demonstrated the highest percentage of susceptibility in B. pseudomallei, the overall results underline the importance of the emergence of resistance in this organism. PCR results showed that, of the 81 B. pseudomallei, six multidrug resistant (MDR isolates carried bpeB, amrB, and BPSS1119 and penA genes. Genotyping of the isolates using random amplified polymorphic DNA analysis showed six different PCR fingerprinting patterns generated from the six MDR isolates clusters (A and eight PCR fingerprinting patterns generated for the remaining 75 non-MDR isolates clusters (B.

  20. Feline leukemia virus infection requires a post-receptor binding envelope-dependent cellular component.

    Science.gov (United States)

    Hussain, Naveen; Thickett, Kelly R; Na, Hong; Leung, Cherry; Tailor, Chetankumar S

    2011-12-01

    Gammaretrovirus receptors have been suggested to contain the necessary determinants to mediate virus binding and entry. Here, we show that murine NIH 3T3 and baby hamster kidney (BHK) cells overexpressing receptors for subgroup A, B, and C feline leukemia viruses (FeLVs) are weakly susceptible (10(1) to 10(2) CFU/ml) to FeLV pseudotype viruses containing murine leukemia virus (MLV) core (Gag-Pol) proteins, whereas FeLV receptor-expressing murine Mus dunni tail fibroblast (MDTF) cells are highly susceptible (10(4) to 10(6) CFU/ml). However, NIH 3T3 cells expressing the FeLV subgroup B receptor PiT1 are highly susceptible to gibbon ape leukemia virus pseudotype virus, which differs from the FeLV pseudotype viruses only in the envelope protein. FeLV resistance is not caused by a defect in envelope binding, low receptor expression levels, or N-linked glycosylation. Resistance is not alleviated by substitution of the MLV core in the FeLV pseudotype virus with FeLV core proteins. Interestingly, FeLV resistance is alleviated by fusion of receptor-expressing NIH 3T3 and BHK cells with MDTF or human TE671 cells, suggesting the absence of an additional cellular component in NIH 3T3 and BHK cells that is required for FeLV infection. The putative FeLV-specific cellular component is not a secreted factor, as MDTF conditioned medium does not alleviate the block to FeLV infection. Together, our findings suggest that FeLV infection requires an additional envelope-dependent cellular component that is absent in NIH 3T3 and BHK cells but that is present in MDTF and TE671 cells.

  1. Risk of cardiac pacemaker pocket infection in a tertiary care hospital

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    Jaswinder Singh Gill

    2017-01-01

    Full Text Available Background: The risk of pacemaker pocket infections (PPIs is rare with good antisepsis techniques and use of advanced antibiotics. However, injudicious antibiotic usage leads to the rise of multidrug-resistant bacteria, which may cause PPI. Few reports exist about the microbial spectrum of the PPI from our country, prompting us to study the same. Methods: We conducted this retrospective observational study for 3 years (January 2013–February 2016 from all the patients with PPI. We collected the relevant clinical samples (blood and pus for the microbial culture using a standard protocol. We included 100 samples collected from the medical staff and the hospital environment as a control sample. The data were analyzed using appropriate statistical methods and a P< 0.05 was considered statistically significant. Results: Our data showed that 17 out of 160 (10.6% patients had PPI. Coagulase negative Staphylococcus sp. was isolated in 7 (41.2% patients, followed by Staphylococcus aureus in 4 patients (23.5%. Other isolated bacteria include multidrug-resistant Burkholderia cepacia (n = 3, Mycobacterium abscessus (n = 2 and polymicrobial infection in a single patient. One out of hundred surveillance samples grew B. cepacia. Conclusion: Our data revealed a high incidence of Gram-positive cocci causing PPI. Every hospital should formulate their antibiotic policy based on the pattern of the hospital flora and their drug sensitivity.

  2. Innate Immune Response to Burkholderia mallei

    Science.gov (United States)

    2017-02-16

    highly contagious and often fatal disease, glanders. With its high rate of infectivity via aerosol and recalcitrance towards antibiotics , this...pathology (1-7). Glanders transmits amongst animals via respiratory secretions and exudates from skin lesions. In human infections, the primary modes of...resulted in the uniform production of cytokines interleukin 1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), and murine keratinocyte-derived

  3. Endosymbiont-dependent host reproduction maintains bacterial-fungal mutualism.

    Science.gov (United States)

    Partida-Martinez, Laila P; Monajembashi, Shamci; Greulich, Karl-Otto; Hertweck, Christian

    2007-05-01

    Bacterial endosymbionts play essential roles for many organisms, and thus specialized mechanisms have evolved during evolution that guarantee the persistence of the symbiosis during or after host reproduction. The rice seedling blight fungus Rhizopus microsporus represents a unique example of a mutualistic life form in which a fungus harbors endobacteria (Burkholderia sp.) for the production of a phytotoxin. Here we report the unexpected observation that in the absence of endosymbionts, the host is not capable of vegetative reproduction. Formation of sporangia and spores is restored only upon reintroduction of endobacteria. To monitor this process, we succeeded in GFP labeling cultured endosymbionts. We also established a laserbeam transformation technique for the first controlled introduction of bacteria into fungi to observe their migration to the tips of the aseptate hyphae. The persistence of this fungal-bacterial mutualism through symbiont-dependent sporulation is intriguing from an evolutionary point of view and implies that the symbiont produces factors that are essential for the fungal life cycle. Reproduction of the host has become totally dependent on endofungal bacteria, which in return provide a highly potent toxin for defending the habitat and accessing nutrients from decaying plants. This scenario clearly highlights the significance for a controlled maintenance of this fungal-bacterial symbiotic relationship.

  4. Insights into selenite reduction and biogenesis of elemental selenium nanoparticles by two environmental isolates of Burkholderia fungorum.

    Science.gov (United States)

    Khoei, Nazanin Seyed; Lampis, Silvia; Zonaro, Emanuele; Yrjälä, Kim; Bernardi, Paolo; Vallini, Giovanni

    2017-01-25

    Microorganisms capable of transforming toxic selenium oxyanions into non-toxic elemental selenium (Se°) may be considered as biocatalysts for the production of selenium nanoparticles (SeNPs), eventually exploitable in different biotechnological applications. Two Burkholderia fungorum strains (B. fungorum DBT1 and B. fungorum 95) were monitored during their growth for both capacity and efficiency of selenite (SeO 3 2- ) reduction and elemental selenium formation. Both strains are environmental isolates in origin: B. fungorum DBT1 was previously isolated from an oil refinery drainage, while B. fungorum 95 has been enriched from inner tissues of hybrid poplars grown in a soil contaminated by polycyclic aromatic hydrocarbons. Our results showed that B. fungorum DBT1 is able to reduce 0.5mM SeO 3 2- to Se° when cultured aerobically in liquid medium at 27°C, while B. fungorum 95 can reduce more than 1mM SeO 3 2- to Se° within 96h under the same growth conditions, with the appearance of SeNPs in cultures of both bacterial strains. Biogenic SeNPs were spherical, with pH-dependent charge and an average hydrodynamic diameter of 170nm and 200nm depending on whether they were produced by B. fungorum 95 or B. fungorum DBT1, respectively. Electron microscopy analyses evidenced that Se nanoparticles occurred intracellularly and extracellularly. The mechanism of SeNPs formation can be tentatively attributed to cytoplasmic enzymatic activation mediated by electron donors. Biogenic nanoparticles were then probably released outside the bacterial cells as a consequence of a secretory process or cell lysis. Nevertheless, formation of elemental selenium nanoparticles under aerobic conditions by B. fungorum DBT1 and B. fungorum 95 is likely due to intracellular reduction mechanisms. Biomedical and other high tech sectors might exploit these biogenic nanoparticles in the near future, once fully characterized and tested for their multiple properties. Copyright © 2016 Elsevier B.V. All

  5. Inoculation of Burkholderia cepacia and Gluconacetobacter diazotrophicus on phenotype and biomass of Triticum aestivum var. Nana-F2007 at 50% of nitrogen fertilizer

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    Jesús Jaime Hernández-Escareño

    2015-03-01

    Full Text Available Wheat (Triticum aestivum L consuming requires of nitrogen fertilizer (NF, as ammonium nitrate (NH4NO3, which one in excess causes lost soil productivity. An alternative to reduce and optimize NF to wheat is to inoculate with endophytic promoting growth bacteria (EPGB, as genus Burkholderia cepacia and Gluconacetobacter diazotrophicus able to improve radical uptake of NF, its suggesting by inducing synthesis of growth promoting vegetal substances (GPVS. The aim of this research was to evaluate the inoculation of Burkholderia cepacia and Gluconacetobacter diazotrophicus on phenology and biomass of T.aestivum at 50% dose of NF. A trial in greenhouse condition wasconducted inoculating seed T.aestivum´s with both EPGB by measuring its phenology: (PH plant height, (RL root length and biomass: total fresh weight (TFW and dry (TDW at seedling and flowering stages. Results showed a positive effect of B. cepacia in wheat on its TDW with 0.61g value statistically significant compared to 0.53g TDW of wheat used as relative control fed with NF 100% dose (RC. B. cepacia and G. diazotrophicus inoculated to wheat had a positive increased on its TDW with 4.23 g value statistically significant compared to 1.13 g TDW of wheat used as RC. Conclusion suggested that B. cepacia and G. diazotrophicus by synthetized GPVS had a positive effect on wheat growth at reduced dose of NF.

  6. Healthcare-associated respiratory tract infection and colonization in an intensive care unit caused by Burkholderia cepacia isolated in mouthwash

    Directory of Open Access Journals (Sweden)

    Jeannete Zurita

    2014-12-01

    Conclusions: Our findings strongly suggest that alcohol-free mouthwash solution intrinsically contaminated with B. cepacia was the source of these colonizations and infections involving adults in the ICU.

  7. Interleukin-12 induces a Th1-like response to Burkholderia mallei and limited protection in BALB/c mice.

    Science.gov (United States)

    Amemiya, Kei; Meyers, Jennifer L; Trevino, Sylvia R; Chanh, Tran C; Norris, Sarah L; Waag, David M

    2006-02-27

    We evaluated the effect of interleukin (IL)-12 on the immune response to Burkholderia mallei in BALB/c mice. Mice were vaccinated with non-viable B. mallei cells with or without IL-12. There was a seven- to nine-fold increase in IgG2a levels, and a significant increase in the proliferative response and interferon (IFN)-gamma production by splenocytes from mice that received B. mallei and IL-12. We saw an increase in survivors in the groups of mice that received B. mallei and IL-12 when challenged, compared to mice that received only B. mallei or IL-12. The results suggest that IL-12 can enhance the Th1-like immune response to B. mallei and mediate limited protection from a lethal challenge.

  8. Transcriptomic profiling of Burkholderia phymatum STM815, Cupriavidus taiwanensis LMG19424 and Rhizobium mesoamericanum STM3625 in response to Mimosa pudica root exudates illuminates the molecular basis of their nodulation competitiveness and symbiotic evolutionary history.

    Science.gov (United States)

    Klonowska, Agnieszka; Melkonian, Rémy; Miché, Lucie; Tisseyre, Pierre; Moulin, Lionel

    2018-01-30

    Rhizobial symbionts belong to the classes Alphaproteobacteria and Betaproteobacteria (called "alpha" and "beta"-rhizobia). Most knowledge on the genetic basis of symbiosis is based on model strains belonging to alpha-rhizobia. Mimosa pudica is a legume that offers an excellent opportunity to study the adaptation toward symbiotic nitrogen fixation in beta-rhizobia compared to alpha-rhizobia. In a previous study (Melkonian et al., Environ Microbiol 16:2099-111, 2014) we described the symbiotic competitiveness of M. pudica symbionts belonging to Burkholderia, Cupriavidus and Rhizobium species. In this article we present a comparative analysis of the transcriptomes (by RNAseq) of B. phymatum STM815 (BP), C. taiwanensis LMG19424 (CT) and R. mesoamericanum STM3625 (RM) in conditions mimicking the early steps of symbiosis (i.e. perception of root exudates). BP exhibited the strongest transcriptome shift both quantitatively and qualitatively, which mirrors its high competitiveness in the early steps of symbiosis and its ancient evolutionary history as a symbiont, while CT had a minimal response which correlates with its status as a younger symbiont (probably via acquisition of symbiotic genes from a Burkholderia ancestor) and RM had a typical response of Alphaproteobacterial rhizospheric bacteria. Interestingly, the upregulation of nodulation genes was the only common response among the three strains; the exception was an up-regulated gene encoding a putative fatty acid hydroxylase, which appears to be a novel symbiotic gene specific to Mimosa symbionts. The transcriptional response to root exudates was correlated to each strain nodulation competitiveness, with Burkholderia phymatum appearing as the best specialised symbiont of Mimosa pudica.

  9. Temperature-Dependent Effects of Cutaneous Bacteria on a Frog’s Tolerance of Fungal Infection

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    Matthew J. Robak

    2018-03-01

    Full Text Available Defense against pathogens is one of many benefits that bacteria provide to animal hosts. A clearer understanding of how changes in the environment affect the interactions between animals and their microbial benefactors is needed in order to predict the impact and dynamics of emerging animal diseases. Due to its dramatic effects on the physiology of animals and their pathogens, temperature may be a key variable modulating the level of protection that beneficial bacteria provide to their animal hosts. Here we investigate how temperature and the makeup of the skin microbial community affect the susceptibility of amphibian hosts to infection by Batrachochytrium dendrobatidis (Bd, one of two fungal pathogens known to cause the disease chytridiomycosis. To do this, we manipulated the skin bacterial communities of susceptible hosts, northern cricket frogs (Acris crepitans, prior to exposing these animals to Bd under two different ecologically relevant temperatures. Our manipulations included one treatment where antibiotics were used to reduce the skin bacterial community, one where the bacterial community was augmented with the antifungal bacterium, Stenotrophomonas maltophilia, and one in which the frog’s skin bacterial community was left intact. We predicted that frogs with reduced skin bacterial communities would be more susceptible (i.e., less resistant to and/or tolerant of Bd infection, and frogs with skin bacterial communities augmented with the known antifungal bacterium would be less susceptible to Bd infection and chytridiomycosis. However, we also predicted that this interaction would be temperature dependent. We found a strong effect of temperature but not of skin microbial treatment on the probability and intensity of infection in Bd-exposed frogs. Whether temperature affected survival; however, it differed among our skin microbial treatment groups, with animals having more S. maltophilia on their skin surviving longer at 14 but not at

  10. Genetic diversity and microevolution of Burkholderia pseudomallei in the environment.

    Directory of Open Access Journals (Sweden)

    Narisara Chantratita

    2008-02-01

    Full Text Available The soil dwelling Gram-negative pathogen Burkholderia pseudomallei is the cause of melioidosis. The diversity and population structure of this organism in the environment is poorly defined.We undertook a study of B. pseudomallei in soil sampled from 100 equally spaced points within 237.5 m(2 of disused land in northeast Thailand. B. pseudomallei was present on direct culture of 77/100 sampling points. Genotyping of 200 primary plate colonies from three independent sampling points was performed using a combination of pulsed field gel electrophoresis (PFGE and multilocus sequence typing (MLST. Twelve PFGE types and nine sequence types (STs were identified, the majority of which were present at only a single sampling point. Two sampling points contained four STs and the third point contained three STs. Although the distance between the three sampling points was low (7.6, 7.9, and 13.3 meters, respectively, only two STs were present in more than one sampling point. Each of the three samples was characterized by the localized expansion of a single B. pseudomallei clone (corresponding to STs 185, 163, and 93. Comparison of PFGE and MLST results demonstrated that two STs contained strains with variable PFGE banding pattern types, indicating geographic structuring even within a single MLST-defined clone.We discuss the implications of this extreme structuring of genotype and genotypic frequency in terms of micro-evolutionary dynamics and ecology, and how our results may inform future sampling strategies.

  11. Comparison of DNA extraction kits for detection of Burkholderia pseudomallei in spiked human whole blood using real-time PCR.

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    Nicole L Podnecky

    Full Text Available Burkholderia pseudomallei, the etiologic agent of melioidosis, is endemic in northern Australia and Southeast Asia and can cause severe septicemia that may lead to death in 20% to 50% of cases. Rapid detection of B. pseudomallei infection is crucial for timely treatment of septic patients. This study evaluated seven commercially available DNA extraction kits to determine the relative recovery of B. pseudomallei DNA from spiked EDTA-containing human whole blood. The evaluation included three manual kits: the QIAamp DNA Mini kit, the QIAamp DNA Blood Mini kit, and the High Pure PCR Template Preparation kit; and four automated systems: the MagNAPure LC using the DNA Isolation Kit I, the MagNAPure Compact using the Nucleic Acid Isolation Kit I, and the QIAcube using the QIAamp DNA Mini kit and the QIAamp DNA Blood Mini kit. Detection of B. pseudomallei DNA extracted by each kit was performed using the B. pseudomallei specific type III secretion real-time PCR (TTS1 assay. Crossing threshold (C T values were used to compare the limit of detection and reproducibility of each kit. This study also compared the DNA concentrations and DNA purity yielded for each kit. The following kits consistently yielded DNA that produced a detectable signal from blood spiked with 5.5×10(4 colony forming units per mL: the High Pure PCR Template Preparation, QIAamp DNA Mini, MagNA Pure Compact, and the QIAcube running the QIAamp DNA Mini and QIAamp DNA Blood Mini kits. The High Pure PCR Template Preparation kit yielded the lowest limit of detection with spiked blood, but when this kit was used with blood from patients with confirmed cases of melioidosis, the bacteria was not reliably detected indicating blood may not be an optimal specimen.

  12. Inhibition of herpes simplex virus infection by lactoferrin is dependent on interference with the virus binding to glycosaminoglycans

    International Nuclear Information System (INIS)

    Marchetti, Magda; Trybala, Edward; Superti, Fabiana; Johansson, Maria; Bergstroem, Tomas

    2004-01-01

    Previous reports have indicated that lactoferrin inhibits herpes simplex virus (HSV) infection during the very early phases of the viral replicative cycle. In the present work we investigated the mechanism of the antiviral activity of lactoferrin in mutant glycosaminoglycan (GAG)-deficient cells. Bovine lactoferrin (BLf) was a strong inhibitor of HSV-1 infection in cells expressing either heparan sulfate (HS) or chondroitin sulfate (CS) or both, but was ineffective or less efficient in GAG-deficient cells or in cells treated with GAG-degrading enzymes. In contrast to wild-type HSV-1, virus mutants devoid of glycoprotein C (gC) were significantly less inhibited by lactoferrin in GAG-expressing cells, indicating that lactoferrin interfered with the binding of viral gC to cell surface HS and/or CS. Finally, we demonstrated that lactoferrin bound directly to both HS and CS isolated from surfaces of the studied cells, as well as to commercial preparations of GAG chains. The results support the hypothesis that the inhibition of HSV-1 infectivity by lactoferrin is dependent on its interaction with cell surface GAG chains of HS and CS

  13. Molecular determinants of dengue virus 2 envelope protein important for virus entry in FcγRIIA-mediated antibody-dependent enhancement of infection

    International Nuclear Information System (INIS)

    Chotiwan, Nunya; Roehrig, John T.; Schlesinger, Jacob J.; Blair, Carol D.; Huang, Claire Y.-H.

    2014-01-01

    Antibody-dependent enhancement (ADE) of infection may cause severe illness in patients suffering a secondary infection by a heterologous dengue virus (DENV) serotype. During ADE of infection, cross-reactive non- or poorly-neutralizing antibodies form infectious virus-Ab complexes with the newly infecting serotype and enhance virus infection by binding to the Fcγ receptors (FcγR) on FcγR-bearing cells. In this study, we determined that molecular determinants of DENV2 envelope protein critical for virus entry during non-ADE infection are also required for ADE infection mediated by FcγRIIA, and binding of virus-Ab complexes with FcγRIIA alone is not sufficient for ADE of infection. The FcγRIIA mainly plays an auxiliary role in concentrating the virus–Ab complex to the cell surface, and other primary cellular receptors are required for virus entry. Understanding the viral entry pathway in ADE of DENV infection will greatly facilitate rational designs of anti-viral therapeutics against severe dengue disease associated with ADE. - Highlights: • KKK305/307/310 in DENV2 E-DIII is critical for virus attachment in ADE and non-ADE infection. • Binding of DENV2–Ab complex with FcγRII alone is not sufficient for virus entry in ADE infection. • Other primary receptors were required for DENV2 internalization during FcγRII–mediated ADE. • G104 and L135 of DENV2 E are critical for virus-mediated membrane fusion. • DENV2 virus-mediated membrane fusion is required for both ADE and non-ADE infection

  14. Molecular determinants of dengue virus 2 envelope protein important for virus entry in FcγRIIA-mediated antibody-dependent enhancement of infection

    Energy Technology Data Exchange (ETDEWEB)

    Chotiwan, Nunya; Roehrig, John T. [Arboviral Diseases Branch, Division of Vector-Borne Disease, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Schlesinger, Jacob J. [Department of Medicine, University of Rochester, Rochester, NY 14642 (United States); Blair, Carol D. [Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523 (United States); Huang, Claire Y.-H., E-mail: yxh0@cdc.gov [Arboviral Diseases Branch, Division of Vector-Borne Disease, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States)

    2014-05-15

    Antibody-dependent enhancement (ADE) of infection may cause severe illness in patients suffering a secondary infection by a heterologous dengue virus (DENV) serotype. During ADE of infection, cross-reactive non- or poorly-neutralizing antibodies form infectious virus-Ab complexes with the newly infecting serotype and enhance virus infection by binding to the Fcγ receptors (FcγR) on FcγR-bearing cells. In this study, we determined that molecular determinants of DENV2 envelope protein critical for virus entry during non-ADE infection are also required for ADE infection mediated by FcγRIIA, and binding of virus-Ab complexes with FcγRIIA alone is not sufficient for ADE of infection. The FcγRIIA mainly plays an auxiliary role in concentrating the virus–Ab complex to the cell surface, and other primary cellular receptors are required for virus entry. Understanding the viral entry pathway in ADE of DENV infection will greatly facilitate rational designs of anti-viral therapeutics against severe dengue disease associated with ADE. - Highlights: • KKK305/307/310 in DENV2 E-DIII is critical for virus attachment in ADE and non-ADE infection. • Binding of DENV2–Ab complex with FcγRII alone is not sufficient for virus entry in ADE infection. • Other primary receptors were required for DENV2 internalization during FcγRII–mediated ADE. • G104 and L135 of DENV2 E are critical for virus-mediated membrane fusion. • DENV2 virus-mediated membrane fusion is required for both ADE and non-ADE infection.

  15. Genotype distribution and treatment response among incarcerated drug-dependent patients with chronic hepatitis C infection.

    Directory of Open Access Journals (Sweden)

    Chun-Han Cheng

    Full Text Available The prevalence of hepatitis C virus (HCV infection is disproportionately high among prisoners, especially among those who are drug-dependent. However, current screening and treatment recommendations are inconsistent for this population, and appropriate care is not reliably provided. To address these problems, the present study aimed to identify unique characteristics and clinical manifestations of incarcerated patients with HCV infection. We included incarcerated patients who received treatment with pegylated-interferon combined with ribavirin at Mackay Memorial Hospital in Taitung and were serving sentences at either the Taiyuan Skill Training Institute or the Yanwan Training Institute. HCV genotypes 1 (41.4%, 3 (25.9%, and 6 (24.1% were the most prevalent in the incarcerated patients. During the study period, we analyzed treatment response among 58 incarcerated patients and compared obtained results with treatment response among 52 patients who were living in the community. Higher sustained virological response rate was observed among patients with incarceration and HCV genotype other than 1. The odds ratios (corresponding 95% confidence intervals for incarceration and genotype 1 were 2.75 (1.06-7.11 and 0.37 (0.14-0.99, respectively. Better treatment compliance among incarcerated patients might partially explain these results. The results of this study suggest that treatment of prisoners with HCV infection is feasible and effective. More appropriate and timely methods are needed to prevent HCV transmission among injection drug users inside prisons.

  16. Bioleaching remediation of heavy metal-contaminated soils using Burkholderia sp. Z-90.

    Science.gov (United States)

    Yang, Zhihui; Zhang, Zhi; Chai, Liyuan; Wang, Yong; Liu, Yi; Xiao, Ruiyang

    2016-01-15

    Bioleaching is an environment-friendly and economical technology to remove heavy metals from contaminated soils. In this study, a biosurfactant-producing strain with capacity of alkaline production was isolated from cafeteria sewer sludge and its capability for removing Zn, Pb, Mn, Cd, Cu, and As was investigated. Phylogenetic analysis using 16S rDNA gene sequences confirmed that the strain belonged to Burkholderia sp. and named as Z-90. The biosurfactant was glycolipid confirmed by thin layer chromatography and Fourier-transform infrared spectroscopy. Z-90 broth was then used for bioleaching remediation of heavy metal-contaminated soils. The removal efficiency was 44.0% for Zn, 32.5% for Pb, 52.2% for Mn, 37.7% for Cd, 24.1% for Cu and 31.6% for As, respectively. Mn, Zn and Cd were more easily removed from soil than Cu, Pb and As, which was attributed to the presence of high acid-soluble fraction of Mn, Zn and Cd and high residual fraction of Cu, Pb and As. The heavy metal removal in soils was contributed to the adhesion of heavy metal-contaminated soil minerals with strain Z-90 and the formation of a metal complex with biosurfactant. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Molecular architecture of the N-type ATPase rotor ring from Burkholderia pseudomallei.

    Science.gov (United States)

    Schulz, Sarah; Wilkes, Martin; Mills, Deryck J; Kühlbrandt, Werner; Meier, Thomas

    2017-04-01

    The genome of the highly infectious bacterium Burkholderia pseudomallei harbors an atp operon that encodes an N-type rotary ATPase, in addition to an operon for a regular F-type rotary ATPase. The molecular architecture of N-type ATPases is unknown and their biochemical properties and cellular functions are largely unexplored. We studied the B. pseudomallei N 1 N o -type ATPase and investigated the structure and ion specificity of its membrane-embedded c-ring rotor by single-particle electron cryo-microscopy. Of several amphiphilic compounds tested for solubilizing the complex, the choice of the low-density, low-CMC detergent LDAO was optimal in terms of map quality and resolution. The cryoEM map of the c-ring at 6.1 Å resolution reveals a heptadecameric oligomer with a molecular mass of ~141 kDa. Biochemical measurements indicate that the c 17 ring is H + specific, demonstrating that the ATPase is proton-coupled. The c 17 ring stoichiometry results in a very high ion-to-ATP ratio of 5.7. We propose that this N-ATPase is a highly efficient proton pump that helps these melioidosis-causing bacteria to survive in the hostile, acidic environment of phagosomes. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

  18. A new species of Burkholderia isolated from sugarcane roots promotes plant growth

    Science.gov (United States)

    Paungfoo-Lonhienne, Chanyarat; Lonhienne, Thierry G A; Yeoh, Yun Kit; Webb, Richard I; Lakshmanan, Prakash; Chan, Cheong Xin; Lim, Phaik-Eem; Ragan, Mark A; Schmidt, Susanne; Hugenholtz, Philip

    2014-01-01

    Sugarcane is a globally important food, biofuel and biomaterials crop. High nitrogen (N) fertilizer rates aimed at increasing yield often result in environmental damage because of excess and inefficient application. Inoculation with diazotrophic bacteria is an attractive option for reducing N fertilizer needs. However, the efficacy of bacterial inoculants is variable, and their effective formulation remains a knowledge frontier. Here, we take a new approach to investigating diazotrophic bacteria associated with roots using culture-independent microbial community profiling of a commercial sugarcane variety (Q208A) in a field setting. We first identified bacteria that were markedly enriched in the rhizosphere to guide isolation and then tested putative diazotrophs for the ability to colonize axenic sugarcane plantlets (Q208A) and promote growth in suboptimal N supply. One isolate readily colonized roots, fixed N2 and stimulated growth of plantlets, and was classified as a new species, Burkholderia australis sp. nov. Draft genome sequencing of the isolate confirmed the presence of nitrogen fixation. We propose that culture-independent identification and isolation of bacteria that are enriched in rhizosphere and roots, followed by systematic testing and confirming their growth-promoting capacity, is a necessary step towards designing effective microbial inoculants. PMID:24350979

  19. Nanolipoprotein Particles (NLPs) as Versatile Vaccine Platforms for Co-delivery of Multiple Adjuvants with Subunit Antigens from Burkholderia spp. and F. tularensis - Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, N. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-01-06

    The goal of this proposal is to demonstrate that colocalization of protein subunit antigens and adjuvants on nanolipoprotein particles (NLPs) can increase the protective efficacy of subunit antigens from Burkholderia spp. and Francisella tularensis against an aerosol challenge. In the second quarter of the third year, LLNL finalized all immunological assessments of NLP vaccine formulations in the F344 model. Battelle has immunized rats with three unique NLP formulations by either intramuscular or intranasal administration. All inoculations have been completed, and protective efficacy against an aerosolized challenge will begin at the end of October, 2014.

  20. Spatio-temporal responses of Arabidopsis leaves in photosynthetic performance and metabolite contents to Burkholderia phytofirmans PsJN

    Directory of Open Access Journals (Sweden)

    Fan eSu

    2016-03-01

    Full Text Available A valuable strategy to improve crop yield consists in the use of plant growth-promoting rhizobacteria (PGPRs. However, the influence of PGPR colonization on plant physiology is largely unknown. PGPR Burkholderia phytofirmans strain PsJN (Bp PsJN colonized only Arabidopsis thaliana roots after seed or soil inoculation. Foliar bacteria were detected only after leaf infiltration. Since different bacterial times of presence and/or locations in host plant could lead to different plant physiological responses, photosynthesis and metabolite profiles in A. thaliana leaves were thus investigated following leaf, root or seed inoculation with Bp PsJN. Only Bp PsJN leaf colonization transiently decreased cyclic electron transport and effective quantum yield of photosystem I (PSI, and prevented a decrease in net photosynthesis and stomatal opening compared to the corresponding control. Metabolomic analysis revealed that soluble sugars, amino acids or their derivatives accumulated differently in all Bp PsJN-inoculated plants. Octanoic acid accumulated only in case of inoculated plants. Modifications in vitamin, organic acid such as tricarboxylic acid intermediates, and hormone amounts were dependent on bacterial time of presence and location. Additionally, a larger array of amino acids and hormones (auxin, cytokinin, abscisic acid were modified by seed inoculation with Bp PsJN. Our work thereby provides evidence that relative short-term inoculation with Bp PsJN altered physiological status of A.thaliana leaves, whereas long-term bacterization triggered modifications on a larger set of metabolites. Our data highlighted the changes displayed during this plant-microbe interaction to trigger physiological and metabolic responses that could explain the increase in plant growth or stress tolerance conferred by the presence of Bp PsJN.

  1. Differential antibiotic-induced endotoxin release in severe melioidosis

    NARCIS (Netherlands)

    Simpson, A. J.; Opal, S. M.; Angus, B. J.; Prins, J. M.; Palardy, J. E.; Parejo, N. A.; Chaowagul, W.; White, N. J.

    2000-01-01

    Severe melioidosis is a life-threatening, systemic bacterial infection caused by Burkholderia pseudomallei. A prospective, randomized treatment trial was conducted in northeast Thailand to compare ceftazidime (a penicillin-binding protein [PBP]-3-specific agent that causes release of large amounts

  2. Dengue Virus-Infected Dendritic Cells, but Not Monocytes, Activate Natural Killer Cells through a Contact-Dependent Mechanism Involving Adhesion Molecules.

    Science.gov (United States)

    Costa, Vivian Vasconcelos; Ye, Weijian; Chen, Qingfeng; Teixeira, Mauro Martins; Preiser, Peter; Ooi, Eng Eong; Chen, Jianzhu

    2017-08-01

    Natural killer (NK) cells play a protective role against dengue virus (DENV) infection, but the cellular and molecular mechanisms are not fully understood. Using an optimized humanized mouse model, we show that human NK cells, through the secretion of gamma interferon (IFN-γ), are critical in the early defense against DENV infection. Depletion of NK cells or neutralization of IFN-γ leads to increased viremia and more severe thrombocytopenia and liver damage in humanized mice. In vitro studies using autologous human NK cells show that DENV-infected monocyte-derived dendritic cells (MDDCs), but not monocytes, activate NK cells in a contact-dependent manner, resulting in upregulation of CD69 and CD25 and secretion of IFN-γ. Blocking adhesion molecules (LFA-1, DNAM-1, CD2, and 2β4) on NK cells abolishes NK cell activation, IFN-γ secretion, and the control of DENV replication. NK cells activated by infected MDDCs also inhibit DENV infection in monocytes. These findings show the essential role of human NK cells in protection against acute DENV infection in vivo , identify adhesion molecules and dendritic cells required for NK cell activation, and delineate the sequence of events for NK cell activation and protection against DENV infection. IMPORTANCE Dengue is a mosquito-transmitted viral disease with a range of symptoms, from mild fever to life-threatening dengue hemorrhagic fever. The diverse disease manifestation is thought to result from a complex interplay between viral and host factors. Using mice engrafted with a human immune system, we show that human NK cells inhibit virus infection through secretion of the cytokine gamma interferon and reduce disease pathogenesis, including depletion of platelets and liver damage. During a natural infection, DENV initially infects dendritic cells in the skin. We find that NK cells interact with infected dendritic cells through physical contact mediated by adhesion molecules and become activated before they can control

  3. Caspase-2-dependent dendritic cell death, maturation, and priming of T cells in response to Brucella abortus infection.

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    Xinna Li

    Full Text Available Smooth virulent Brucella abortus strain 2308 (S2308 causes zoonotic brucellosis in cattle and humans. Rough B. abortus strain RB51, derived from S2308, is a live attenuated cattle vaccine strain licensed in the USA and many other countries. Our previous report indicated that RB51, but not S2308, induces a caspase-2-dependent apoptotic and necrotic macrophage cell death. Dendritic cells (DCs are professional antigen presenting cells critical for bridging innate and adaptive immune responses. In contrast to Brucella-infected macrophages, here we report that S2308 induced higher levels of apoptotic and necrotic cell death in wild type bone marrow-derived DCs (WT BMDCs than RB51. The RB51 and S2308-induced BMDC cell death was regulated by caspase-2, indicated by the minimal cell death in RB51 and S2308-infected BMDCs isolated from caspase-2 knockout mice (Casp2KO BMDCs. More S2308 bacteria were taken up by Casp2KO BMDCs than wild type BMDCs. Higher levels of S2308 and RB51 cells were found in infected Casp2KO BMDCs compared to infected WT BMDCs at different time points. RB51-infected wild type BMDCs were mature and activated as shown by significantly up-regulated expression of CD40, CD80, CD86, MHC-I, and MHC-II. RB51 induced the production of cytokines TNF-α, IL-6, IFN-γ and IL12/IL23p40 in infected BMDCs. RB51-infected WT BMDCs also stimulated the proliferation of CD4(+ and CD8(+ T cells compared to uninfected WT BMDCs. However, the maturation, activation, and cytokine secretion are significantly impaired in Casp2KO BMDCs infected with RB51 or Salmonella (control. S2308-infected WT and Casp2KO BMDCs were not activated and could not induce cytokine production. These results demonstrated that virulent smooth strain S2308 induced more apoptotic and necrotic dendritic cell death than live attenuated rough vaccine strain RB51; however, RB51, but not its parent strain S2308, induced caspase-2-mediated DC maturation, cytokine production, antigen

  4. Identification of potential genetic components involved in the deviant quorum-sensing signaling pathways of Burkholderia glumae through a functional genomics approach

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    Ruoxi eChen

    2015-03-01

    Full Text Available Burkholderia glumae is the chief causal agent for bacterial panicle blight of rice. The acyl-homoserine lactone (AHL-mediated quorum-sensing (QS system dependent on a pair of luxI and luxR homologs, tofI and tofR, is the primary cell-to-cell signaling mechanism determining the virulence of this bacterium. Production of toxoflavin, a major virulence factor of B. glumae, is known to be dependent on the tofI/tofR QS system. In our previous study, however, it was observed that B. glumae mutants defective in tofI or tofR produced toxoflavin if they grew on the surface of a solid medium, suggesting that alternative signaling pathways independent of tofI or tofR are activated in that growth condition for the production of toxoflavin. In this study, potential genetic components involved in the tofI- and tofR-independent signaling pathways for toxoflavin production were sought through screening random mini-Tn5 mutants of B. glumae to better understand the intercellular signaling pathways of this pathogen. Fifteen and three genes were initially identified as the potential genetic elements of the tofI- and tofR-independent pathways, respectively. Especially, the ORF (bglu_2g06320 divergently transcribed from toxJ, which encodes an orphan LuxR protein and controls toxoflavin biosynthesis, was newly identified in this study as a gene required for the tofR-independent toxoflavin production and named as toxK. Among those genes, flhD, dgcB, and wyzB were further studied to validate their functions in the tofI-independent toxoflavin production, and similar studies were also conducted with qsmR and toxK for their functions in the tofR-independent toxoflavin production. This work provides a foundation for future comprehensive studies of the intercellular signaling systems of B. glumae and other related pathogenic bacteria.

  5. Identification of a phenoloxidase- and melanin-dependent defence mechanism in Achatina fulica infected with Angiostrongylus vasorum.

    Science.gov (United States)

    Coaglio, Aytube Lucas; Ferreira, Mônica Alves Neves Diniz; Dos Santos Lima, Walter; de Jesus Pereira, Cíntia Aparecida

    2018-02-27

    illustrates PO activity in a helminth-infected A. fulica and provides the first observation of an L-tyrosine dependent PO activity in molluscs infected with A. vasorum. This work suggests that PO pathway may help to control A. vasorum infection in A. fulica.

  6. Imported melioidosis in Japan: a review of cases

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    Hadano Y

    2018-01-01

    Full Text Available Yoshiro Hadano Department of Infectious Diseases, St. Mary’s Hospital, Kurume, Fukuoka, Japan Abstract: Fourteen cases of reported melioidosis in Japan were reviewed. The mean age was 52.4 years (33–69 years, and all patients were male. All of the presumed exposures originated in Southeast Asia. The most common underlying disease was diabetes mellitus, including those patients with impaired glucose tolerance (n=8. As for mode of onset, 13 patients had acute infections and one had chronic infection. Of these 14 patients, the most common infection site on admission was lung (n=8, followed by bone (n=5, skin (n=4, gastrointestinal abscess formation (n=3, urinary tract (n=3, aorta (n=2, mediastinal lymph node swelling (n=1, and central nervous system (n=1. Bacteremia was observed in nine patients, and Burkholderia pseudomallei isolates were mostly susceptible to ceftazidime and carbapenem. Overall mortality was 14.3%. Melioidosis is a rare infection in Japan, with all known cases to date having been imported from Southeast Asia. Diabetes was a common risk factor. Keywords: melioidosis, Burkholderia pseudomallei, Japan, Southeast Asia 

  7. Modulation of Dengue/Zika Virus Pathogenicity by Antibody-Dependent Enhancement and Strategies to Protect Against Enhancement in Zika Virus Infection

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    Rekha Khandia

    2018-04-01

    Full Text Available Antibody-dependent enhancement (ADE is a phenomenon in which preexisting poorly neutralizing antibodies leads to enhanced infection. It is a serious concern with mosquito-borne flaviviruses such as Dengue virus (DENV and Zika virus (ZIKV. In vitro experimental evidences have indicated the preventive, as well as a pathogenicity-enhancing role, of preexisting DENV antibodies in ZIKV infections. ADE has been confirmed in DENV but not ZIKV infections. Principally, the Fc region of the anti-DENV antibody binds with the fragment crystallizable gamma receptor (FcγR, and subsequent C1q interactions and immune effector functions are responsible for the ADE. In contrast to normal DENV infections, with ADE in DENV infections, inhibition of STAT1 phosphorylation and a reduction in IRF-1 gene expression, NOS2 levels, and RIG-1 and MDA-5 expression levels occurs. FcγRIIA is the most permissive FcγR for DENV-ADE, and under hypoxic conditions, hypoxia-inducible factor-1 alpha transcriptionally enhances expression levels of FcγRIIA, which further enhances ADE. To produce therapeutic antibodies with broad reactivity to different DENV serotypes, as well as to ZIKV, bispecific antibodies, Fc region mutants, modified Fc regions, and anti-idiotypic antibodies may be engineered. An in-depth understanding of the immunological and molecular mechanisms of DENV-ADE of ZIKV pathogenicity will be useful for the design of common and safe therapeutics and prophylactics against both viral pathogens. The present review discusses the role of DENV antibodies in modulating DENV/ZIKV pathogenicity/infection and strategies to counter ADE to protect against Zika infection.

  8. Transverse myelitis secondary to Melioidosis; A case report

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    Nandasiri Shanika

    2012-09-01

    Full Text Available Abstract Background Melioidosis has become an emerging infection in Sri Lanka; a country which is considered non endemic for it. Paraplegia due to Burkholderia pseudomallei is a very rare entity encountered even in countries where the disease is endemic. There are no reported cases of transverse myelitis due to melioidosis in Sri Lankan population thus we report the first case. Case presentation A 21 year old farmer presented with sudden onset bi lateral lower limb weakness, numbness and urine retention. Examination revealed flaccid areflexic lower limbs with a sensory loss of all modalities and a sensory level at T10 together with sphincter involvement. MRI of the thoracolumbar spine showed extensive myelitis of the thoracic spine complicating left psoas abscess without definite extension to the spinal cord or cord compression. Burkholderia pseudomallei was isolated from the psoas abscess pus cultures and the diagnosis of melioidosis was confirmed with high titers of Burkholderia pseudomallei antibodies and positive PCR. He was treated with high doses of IV ceftazidime and oral cotrimoxazole for one month with a plan to continue cotrimoxazole and doxycycline till one year. Patient’s general condition improved but the residual neurological problems persisted. Conclusion The exact pathogenesis of spinal cord melioidosis is not quite certain except in the cases where there is direct microbial invasion, which does not appear to be the case in our patient. We postulate our patient’s presentation could be due to ischemia of the spinal cord following septic embolisation or thrombosis of spinal artery due to the abscess nearby. A neurotrophic exotoxin causing myelitis or post infectious immunological demyelination is yet another possibility. This emphasizes the necessity of further studies to elucidate the exact pathogenesis in this type of presentations. Health care professionals in Sri Lanka, where this is an emerging infection, need to improve

  9. Polar Lipids of Burkholderia pseudomallei Induce Different Host Immune Responses

    Science.gov (United States)

    Gonzalez-Juarrero, Mercedes; Mima, Naoko; Trunck, Lily A.; Schweizer, Herbert P.; Bowen, Richard A.; Dascher, Kyle; Mwangi, Waithaka; Eckstein, Torsten M.

    2013-01-01

    Melioidosis is a disease in tropical and subtropical regions of the world that is caused by Burkholderia pseudomallei. In endemic regions the disease occurs primarily in humans and goats. In the present study, we used the goat as a model to dissect the polar lipids of B. pseudomallei to identify lipid molecules that could be used for adjuvants/vaccines or as diagnostic tools. We showed that the lipidome of B. pseudomallei and its fractions contain several polar lipids with the capacity to elicit different immune responses in goats, namely rhamnolipids and ornithine lipids which induced IFN-γ, whereas phospholipids and an undefined polar lipid induced strong IL-10 secretion in CD4+ T cells. Autologous T cells co-cultured with caprine dendritic cells (cDCs) and polar lipids of B. pseudomallei proliferated and up-regulated the expression of CD25 (IL-2 receptor) molecules. Furthermore, we demonstrated that polar lipids were able to up-regulate CD1w2 antigen expression in cDCs derived from peripheral blood monocytes. Interestingly, the same polar lipids had only little effect on the expression of MHC class II DR antigens in the same caprine dendritic cells. Finally, antibody blocking of the CD1w2 molecules on cDCs resulted in decreased expression for IFN-γ by CD4+ T cells. Altogether, these results showed that polar lipids of B. pseudomallei are recognized by the caprine immune system and that their recognition is primarily mediated by the CD1 antigen cluster. PMID:24260378

  10. Polar lipids of Burkholderia pseudomallei induce different host immune responses.

    Directory of Open Access Journals (Sweden)

    Mercedes Gonzalez-Juarrero

    Full Text Available Melioidosis is a disease in tropical and subtropical regions of the world that is caused by Burkholderia pseudomallei. In endemic regions the disease occurs primarily in humans and goats. In the present study, we used the goat as a model to dissect the polar lipids of B. pseudomallei to identify lipid molecules that could be used for adjuvants/vaccines or as diagnostic tools. We showed that the lipidome of B. pseudomallei and its fractions contain several polar lipids with the capacity to elicit different immune responses in goats, namely rhamnolipids and ornithine lipids which induced IFN-γ, whereas phospholipids and an undefined polar lipid induced strong IL-10 secretion in CD4(+ T cells. Autologous T cells co-cultured with caprine dendritic cells (cDCs and polar lipids of B. pseudomallei proliferated and up-regulated the expression of CD25 (IL-2 receptor molecules. Furthermore, we demonstrated that polar lipids were able to up-regulate CD1w2 antigen expression in cDCs derived from peripheral blood monocytes. Interestingly, the same polar lipids had only little effect on the expression of MHC class II DR antigens in the same caprine dendritic cells. Finally, antibody blocking of the CD1w2 molecules on cDCs resulted in decreased expression for IFN-γ by CD4(+ T cells. Altogether, these results showed that polar lipids of B. pseudomallei are recognized by the caprine immune system and that their recognition is primarily mediated by the CD1 antigen cluster.

  11. NCBI nr-aa BLAST: CBRC-XTRO-01-0737 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0737 ref|YP_772985.1| binding-protein-dependent transport systems inne...r membrane component [Burkholderia cepacia AMMD] gb|ABI86651.1| binding-protein-dependent transport systems

  12. Imported melioidosis in Danish travellers: a diagnostic challenge

    DEFF Research Database (Denmark)

    Badran, Shadia; Pedersen, Thomas Ingemann; Roed, Casper

    2010-01-01

    Infections with Burkholderia pseudomallei (melioidosis) are rare events in Scandinavian countries, but the bacterium may be contracted during travel to endemic areas, i.e. Southeast Asia (especially Thailand) and northern Australia. Here, 5 travel-related cases occurring within the last 3 y...

  13. dsRNA-Dependent Protein Kinase PKR and its Role in Stress, Signaling and HCV Infection

    Directory of Open Access Journals (Sweden)

    Eliane F. Meurs

    2012-10-01

    Full Text Available The double-stranded RNA-dependent protein kinase PKR plays multiple roles in cells, in response to different stress situations. As a member of the interferon (IFN‑Stimulated Genes, PKR was initially recognized as an actor in the antiviral action of IFN, due to its ability to control translation, through phosphorylation, of the alpha subunit of eukaryotic initiation factor 2 (eIF2a. As such, PKR participates in the generation of stress granules, or autophagy and a number of viruses have designed strategies to inhibit its action. However, PKR deficient mice resist most viral infections, indicating that PKR may play other roles in the cell other than just acting as an antiviral agent. Indeed, PKR regulates several signaling pathways, either as an adapter protein and/or using its kinase activity. Here we review the role of PKR as an eIF2a kinase, its participation in the regulation of the NF-kB, p38MAPK and insulin pathways, and we focus on its role during infection with the hepatitis C virus (HCV. PKR binds the HCV IRES RNA, cooperates with some functions of the HCV core protein and may represent a target for NS5A or E2. Novel data points out for a role of PKR as a pro-HCV agent, both as an adapter protein and as an eIF2a-kinase, and in cooperation with the di-ubiquitin-like protein ISG15. Developing pharmaceutical inhibitors of PKR may help in resolving some viral infections as well as stress-related damages.

  14. Expression, purification, crystallization and preliminary X-ray analysis of maleylacetate reductase from Burkholderia sp. strain SJ98

    International Nuclear Information System (INIS)

    Chauhan, Archana; Islam, Zeyaul; Jain, Rakesh Kumar; Karthikeyan, Subramanian

    2009-01-01

    Purification and preliminary X-ray crystallographic analysis of maleylacetate reductase encoded by the pnpD gene is reported. Maleylacetate reductase (EC 1.3.1.32) is an important enzyme that is involved in the degradation pathway of aromatic compounds and catalyzes the reduction of maleylacetate to 3-oxoadipate. The gene pnpD encoding maleylacetate reductase in Burkholderia sp. strain SJ98 was cloned, expressed in Escherichia coli and purified by affinity chromatography. The enzyme was crystallized in both native and SeMet-derivative forms by the sitting-drop vapour-diffusion method using PEG 3350 as a precipitant at 293 K. The crystals belonged to space group P2 1 2 1 2, with unit-cell parameters a = 72.91, b = 85.94, c = 53.07 Å. X-ray diffraction data for the native and SeMet-derivative crystal were collected to 2.7 and 2.9 Å resolution, respectively

  15. Age-dependent effects of oral infection with dengue virus on Aedes aegypti (Diptera: Culicidae) feeding behavior, survival, oviposition success and fecundity.

    Science.gov (United States)

    Sylvestre, Gabriel; Gandini, Mariana; Maciel-de-Freitas, Rafael

    2013-01-01

    Aedes aegypti is the main vector of dengue, a disease that is increasing its geographical range as well as incidence rates. Despite its public health importance, the effect of dengue virus (DENV) on some mosquito traits remains unknown. Here, we investigated the impact of DENV-2 infection on the feeding behavior, survival, oviposition success and fecundity of Ae. aegypti females. After orally-challenging Ae. aegypti females with a DENV-2 strain using a membrane feeder, we monitored the feeding behavior, survival, oviposition success and fecundity throughout the mosquito lifespan. We observed an age-dependent cost of DENV infection on mosquito feeding behavior and fecundity. Infected individuals took more time to ingest blood from anesthetized mice in the 2(nd) and 3(rd) weeks post-infection, and also longer overall blood-feeding times in the 3(rd) week post-infection, when females were around 20 days old. Often, infected Ae. aegypti females did not lay eggs and when they were laid, smaller number of eggs were laid compared to uninfected controls. A reduction in the number of eggs laid per female was evident starting on the 3(rd) week post-infection. DENV-2 negatively affected mosquito lifespan, since overall the longevity of infected females was halved compared to that of the uninfected control group. The DENV-2 strain tested significantly affected Ae. aegypti traits directly correlated with vectorial capacity or mosquito population density, such as feeding behavior, survival, fecundity and oviposition success. Infected mosquitoes spent more time ingesting blood, had reduced lifespan, laid eggs less frequently, and when they did lay eggs, the clutches were smaller than uninfected mosquitoes.

  16. Age-dependent effects of oral infection with dengue virus on Aedes aegypti (Diptera: Culicidae feeding behavior, survival, oviposition success and fecundity.

    Directory of Open Access Journals (Sweden)

    Gabriel Sylvestre

    Full Text Available BACKGROUND: Aedes aegypti is the main vector of dengue, a disease that is increasing its geographical range as well as incidence rates. Despite its public health importance, the effect of dengue virus (DENV on some mosquito traits remains unknown. Here, we investigated the impact of DENV-2 infection on the feeding behavior, survival, oviposition success and fecundity of Ae. aegypti females. METHODS/PRINCIPAL FINDINGS: After orally-challenging Ae. aegypti females with a DENV-2 strain using a membrane feeder, we monitored the feeding behavior, survival, oviposition success and fecundity throughout the mosquito lifespan. We observed an age-dependent cost of DENV infection on mosquito feeding behavior and fecundity. Infected individuals took more time to ingest blood from anesthetized mice in the 2(nd and 3(rd weeks post-infection, and also longer overall blood-feeding times in the 3(rd week post-infection, when females were around 20 days old. Often, infected Ae. aegypti females did not lay eggs and when they were laid, smaller number of eggs were laid compared to uninfected controls. A reduction in the number of eggs laid per female was evident starting on the 3(rd week post-infection. DENV-2 negatively affected mosquito lifespan, since overall the longevity of infected females was halved compared to that of the uninfected control group. CONCLUSIONS: The DENV-2 strain tested significantly affected Ae. aegypti traits directly correlated with vectorial capacity or mosquito population density, such as feeding behavior, survival, fecundity and oviposition success. Infected mosquitoes spent more time ingesting blood, had reduced lifespan, laid eggs less frequently, and when they did lay eggs, the clutches were smaller than uninfected mosquitoes.

  17. Mise au point de l’analyse par séquençage à haut-débit du microbiote fongique et bactérien respiratoire chez les patients atteints de mucoviscidose

    OpenAIRE

    Nguyen , Do Ngoc Linh

    2016-01-01

    Chronic pulmonary infection results in an irreversible decline in lung function in patients with cystic fibrosis (CF). While several bacteria are known as main causes for these infections (for example: Pseudomonas aeruginosa, Staphylococcus aureus, Burkholderia cepacia, Achromobacter xylosoxidans...), more recently some fungal genera including filamentous fungi (such as Aspergillus, Scedosporium...) have also been identified as emerging or re-emerging pathogens able to cause invasive mycosis....

  18. Bacterial superantigens promote acute nasopharyngeal infection by Streptococcus pyogenes in a human MHC Class II-dependent manner.

    Directory of Open Access Journals (Sweden)

    Katherine J Kasper

    2014-05-01

    Full Text Available Establishing the genetic determinants of niche adaptation by microbial pathogens to specific hosts is important for the management and control of infectious disease. Streptococcus pyogenes is a globally prominent human-specific bacterial pathogen that secretes superantigens (SAgs as 'trademark' virulence factors. SAgs function to force the activation of T lymphocytes through direct binding to lateral surfaces of T cell receptors and class II major histocompatibility complex (MHC-II molecules. S. pyogenes invariably encodes multiple SAgs, often within putative mobile genetic elements, and although SAgs are documented virulence factors for diseases such as scarlet fever and the streptococcal toxic shock syndrome (STSS, how these exotoxins contribute to the fitness and evolution of S. pyogenes is unknown. Here we show that acute infection in the nasopharynx is dependent upon both bacterial SAgs and host MHC-II molecules. S. pyogenes was rapidly cleared from the nasal cavity of wild-type C57BL/6 (B6 mice, whereas infection was enhanced up to ∼10,000-fold in B6 mice that express human MHC-II. This phenotype required the SpeA superantigen, and vaccination with an MHC -II binding mutant toxoid of SpeA dramatically inhibited infection. Our findings indicate that streptococcal SAgs are critical for the establishment of nasopharyngeal infection, thus providing an explanation as to why S. pyogenes produces these potent toxins. This work also highlights that SAg redundancy exists to avoid host anti-SAg humoral immune responses and to potentially overcome host MHC-II polymorphisms.

  19. NCBI nr-aa BLAST: CBRC-XTRO-01-0560 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0560 ref|YP_001116518.1| binding-protein-dependent transport systems i...nner membrane component [Burkholderia vietnamiensis G4] gb|ABO57053.1| binding-protein-dependent transport systems

  20. Complete Genome sequence of Burkholderia phymatum STM815, a broad host range and efficient nitrogen-fixing symbiont of Mimosa species

    Energy Technology Data Exchange (ETDEWEB)

    Moulin, Lionel [UMR, France; Klonowska, Agnieszka [UMR, France; Caroline, Bournaud [UMR, France; Booth, Kristina [University of Massachusetts; Vriezen, Jan A.C. [University of Massachusetts; Melkonian, Remy [UMR, France; James, Euan [James Hutton Institute, Dundee, United Kingdom; Young, Peter W. [University of York, United Kingdom; Bena, Gilles [UMR, France; Hauser, Loren John [ORNL; Land, Miriam L [ORNL; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Copeland, A [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Lizotte-Waniewski, Michelle [University of Massachusetts; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Riley, Monica [Woods Hole Oceanographic Institution (WHOI), Woods Hole

    2014-01-01

    Burkholderia phymatum is a soil bacterium able to develop a nitrogen-fixing symbiosis with species of the legume genus Mimosa, and is frequently found associated specifically with Mimosa pudica. The type strain of the species, STM 815T, was isolated from a root nodule in French Guiana in 2000. The strain is an aerobic, motile, non-spore forming, Gram-negative rod, and is a highly competitive strain for nodulation compared to other Mimosa symbionts, as it also nodulates a broad range of other legume genera and species. The 8,676,562 bp genome is composed of two chromosomes (3,479,187 and 2,697,374 bp), a megaplasmid (1,904,893 bp) and a plasmid hosting the symbiotic functions (595,108 bp).