Development of Burkholderia mallei and pseudomallei vaccines

Science.gov (United States)

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

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

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

Directory of Open Access Journals (Sweden)

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.

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.

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.

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.

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.

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

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

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.

The effect of environmental conditions on biofilm formation of Burkholderia pseudomallei clinical isolates.

Directory of Open Access Journals (Sweden)

Nur Siti K Ramli

Full Text Available Burkholderia pseudomallei, a Gram-negative saprophytic bacterium, is the causative agent of the potentially fatal melioidosis disease in humans. In this study, environmental parameters including temperature, nutrient content, pH and the presence of glucose were shown to play a role in in vitro biofilm formation by 28 B. pseudomallei clinical isolates, including four isolates with large colony variants (LCVs and small colony variants (SCVs morphotypes. Enhanced biofilm formation was observed when the isolates were tested in LB medium, at 30 °C, at pH 7.2, and in the presence of as little as 2 mM glucose respectively. It was also shown that all SVCs displayed significantly greater capacity to form biofilms than the corresponding LCVs when cultured in LB at 37 °C. In addition, octanoyl-homoserine lactone (C(8-HSL, a quorum sensing molecule, was identified by mass spectrometry analysis in bacterial isolates referred to as LCV CTH, LCV VIT, SCV TOM, SCV CTH, 1 and 3, and the presence of other AHL's with higher masses; decanoyl-homoserine lactone (C(10-HSL and dodecanoyl-homoserine lactone (C(12-HSL were also found in all tested strain in this study. Last but not least, we had successfully acquired two Bacillus sp. soil isolates, termed KW and SA respectively, which possessed strong AHLs degradation activity. Biofilm formation of B. pseudomallei isolates was significantly decreased after treated with culture supernatants of KW and SA strains, demonstrating that AHLs may play a role in B. pseudomallei biofilm formation.

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

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...

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.

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

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...

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.

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.

The In Vitro Antibiotic Susceptibility of Malaysian Isolates of Burkholderia pseudomallei

Directory of Open Access Journals (Sweden)

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.

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

Directory of Open Access Journals (Sweden)

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.

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

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.

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.

Burkholderia pseudomallei isolates from Sarawak, Malaysian Borneo, are predominantly susceptible to aminoglycosides and macrolides.

Science.gov (United States)

Podin, Yuwana; Sarovich, Derek S; Price, Erin P; Kaestli, Mirjam; Mayo, Mark; Hii, KingChing; Ngian, Hieung; Wong, SeeChang; Wong, IngTien; Wong, JinShyan; Mohan, Anand; Ooi, MongHow; Fam, TemLom; Wong, Jack; Tuanyok, Apichai; Keim, Paul; Giffard, Philip M; Currie, Bart J

2014-01-01

Melioidosis is a potentially fatal disease caused by the saprophytic bacterium Burkholderia pseudomallei. Resistance to gentamicin is generally a hallmark of B. pseudomallei, and gentamicin is a selective agent in media used for diagnosis of melioidosis. In this study, we determined the prevalence and mechanism of gentamicin susceptibility found in B. pseudomallei isolates from Sarawak, Malaysian Borneo. We performed multilocus sequence typing and antibiotic susceptibility testing on 44 B. pseudomallei clinical isolates from melioidosis patients in Sarawak district hospitals. Whole-genome sequencing was used to identify the mechanism of gentamicin susceptibility. A novel allelic-specific PCR was designed to differentiate gentamicin-sensitive isolates from wild-type B. pseudomallei. A reversion assay was performed to confirm the involvement of this mechanism in gentamicin susceptibility. A substantial proportion (86%) of B. pseudomallei clinical isolates in Sarawak, Malaysian Borneo, were found to be susceptible to the aminoglycoside gentamicin, a rare occurrence in other regions where B. pseudomallei is endemic. Gentamicin sensitivity was restricted to genetically related strains belonging to sequence type 881 or its single-locus variant, sequence type 997. Whole-genome sequencing identified a novel nonsynonymous mutation within amrB, encoding an essential component of the AmrAB-OprA multidrug efflux pump. We confirmed the role of this mutation in conferring aminoglycoside and macrolide sensitivity by reversion of this mutation to the wild-type sequence. Our study demonstrates that alternative B. pseudomallei selective media without gentamicin are needed for accurate melioidosis laboratory diagnosis in Sarawak. This finding may also have implications for environmental sampling of other locations to test for B. pseudomallei endemicity.

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

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.

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

Development of ceftazidime resistance in an acute Burkholderia pseudomallei infection

Directory of Open Access Journals (Sweden)

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

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.

Brief communication genotyping of Burkholderia pseudomallei revealed high genetic variability among isolates from a single population group.

Science.gov (United States)

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 Malaysia and were confirmed by In-house TTS1-PCR. Isolates were subjected for multi-locus sequence typing (MLST) to explore their genotypic diversity and to investigate for possible clonal clustering of a certain sequence type. Patient's clinical information was examined to investigate for clinical correlation among the different genotypes. In spite of small sample set, MLST results indicated predictive results; considerable genotypic diversity, predominance and novelty among B. pseudomallei collected over a single geographically-located population in Malaysia. Massive genotypic heterogeneity was observed; 8 different sequence types with predominance of sequence type 54 and discovery of two novel sequence types. However, no clear pathogenomic or organ tropism clonal relationships were predicted.

A Burkholderia pseudomallei colony variant necessary for gastric colonization.

Science.gov (United States)

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

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

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

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

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

What drives the occurrence of the melioidosis bacterium Burkholderia pseudomallei in domestic gardens?

Directory of Open Access Journals (Sweden)

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.

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

Efflux Pump-mediated Drug Resistance in Burkholderia

Directory of Open Access Journals (Sweden)

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.

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.

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

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.

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.

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.

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.

Environmental Free-Living Amoebae Isolated from Soil in Khon Kaen, Thailand, Antagonize Burkholderia pseudomallei.

Directory of Open Access Journals (Sweden)

Parumon Noinarin

Full Text Available Presence of Burkholderia pseudomallei in soil and water is correlated with endemicity of melioidosis in Southeast Asia and northern Australia. Several biological and physico-chemical factors have been shown to influence persistence of B. pseudomallei in the environment of endemic areas. This study was the first to evaluate the interaction of B. pseudomallei with soil amoebae isolated from B. pseudomallei-positive soil site in Khon Kaen, Thailand. Four species of amoebae, Paravahlkampfia ustiana, Acanthamoeba sp., Naegleria pagei, and isolate A-ST39-E1, were isolated, cultured and identified based on morphology, movement and 18S rRNA gene sequence. Co-cultivation combined with a kanamycin-protection assay of B. pseudomallei with these amoebae at MOI 20 at 30°C were evaluated during 0-6 h using the plate count technique on Ashdown's agar. The fate of intracellular B. pseudomallei in these amoebae was also monitored by confocal laser scanning microscopy (CLSM observation of the CellTracker™ Orange-B. pseudomallei stained cells. The results demonstrated the ability of P. ustiana, Acanthamoeba sp. and isolate A-ST39-E1 to graze B. pseudomallei. However, the number of internalized B. pseudomallei substantially decreased and the bacterial cells disappeared during the observation period, suggesting they had been digested. We found that B. pseudomallei promoted the growth of Acanthamoeba sp. and isolate A-ST39-E1 in co-cultures at MOI 100 at 30°C, 24 h. These findings indicated that P. ustiana, Acanthamoeba sp. and isolate A-ST39-E1 may prey upon B. pseudomallei rather than representing potential environmental reservoirs in which the bacteria can persist.

An objective approach for Burkholderia pseudomallei strain selection as challenge material for medical countermeasures efficacy testing

Directory of Open Access Journals (Sweden)

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.

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.

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

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...

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.

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.

The concentrations of ambient Burkholderia pseudomallei during typhoon season in endemic area of melioidosis in Taiwan.

Directory of Open Access Journals (Sweden)

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.

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.

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.

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...

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

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.

Two-Phase Bactericidal Mechanism of Silver Nanoparticles against Burkholderia pseudomallei.

Directory of Open Access Journals (Sweden)

Pawinee Siritongsuk

Full Text Available Silver nanoparticles (AgNPs have a strong antimicrobial activity against a variety of pathogenic bacteria. The killing mechanism of AgNPs involves direct physical membrane destruction and subsequent molecular damage from both AgNPs and released Ag+. Burkholderia pseudomallei is the causative agent of melioidosis, an endemic infectious disease primarily found in northern Australia and Southeast Asia. B. pseudomallei is intrinsically resistant to most common antibiotics. In this study, the antimicrobial activity and mechanism of AgNPs (10-20 nm against B. pseudomallei were investigated. The MIC and MBC for nine B. pseudomallei strains ranged from 32-48 μg/mL and 96-128 μg/mL, respectively. Concentrations of AgNPs less than 256 μg/mL were not toxic to human red blood cells. AgNPs exhibited a two-phase mechanism: cell death induction and ROS induction. The first phase was a rapid killing step within 5 min, causing the direct damage of the cytoplasmic membrane of the bacterial cells, as observed by a time-kill assay and fluorescence microscopy. During the period of 5-30 min, the cell surface charge was rapidly neutralized from -8.73 and -7.74 to 2.85 and 2.94 mV in two isolates of B. pseudomallei, as revealed by zeta potential measurement. Energy-dispersive X-ray (EDX spectroscopy showed the silver element deposited on the bacterial membrane, and TEM micrographs of the AgNP-treated B. pseudomallei cells showed severe membrane damage and cytosolic leakage at 1/5 MIC and cell bursting at MBC. During the killing effect the released Ag+ from AgNPs was only 3.9% from the starting AgNPs concentration as observed with ICP-OES experiment. In the second phase, the ROS induction occurred 1-4 hr after the AgNP treatment. Altogether, we provide direct kinetic evidence of the AgNPs killing mechanism, by which cell death is separable from the ROS induction and AgNPs mainly contributes in the killing action. AgNPs may be considered a potential candidate to

Burkholderia Vaccines: Are We Moving Forward?

Directory of Open Access Journals (Sweden)

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.

Burkholderia vaccines: are we moving forward?

Science.gov (United States)

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

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.

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

Science.gov (United States)

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.

Antimicrobial activity of Tachyplesin 1 against Burkholderia pseudomallei: an in vitro and in silico approach

Directory of Open Access Journals (Sweden)

Lyn-Fay Lee

2016-10-01

Full Text Available Burkholderia pseudomallei, the causative agent of melioidosis, is intrinsically resistant to many conventional antibiotics. Therefore, alternative antimicrobial agents such as antimicrobial peptides (AMPs are extensively studied to combat this issue. Our study aims to identify and understand the mode of action of the potential AMP(s that are effective against B. pseudomallei in both planktonic and biofilm state as well as to predict the possible binding targets on using in vitro and in silico approaches. In the in vitro study, 11 AMPs were tested against 100 B. pseudomallei isolates for planktonic cell susceptibility, where LL-37, and PG1, demonstrated 100.0% susceptibility and TP1 demonstrated 83% susceptibility. Since the B. pseudomallei activity was reported on LL-37 and PG1, TP1 was selected for further investigation. TP1 inhibited B. pseudomallei cells at 61.69 μM, and membrane blebbing was observed using scanning electron microscopy. Moreover, TP1 inhibited B. pseudomallei cell growth, reaching bactericidal endpoint within 2 h post exposure as compared to ceftazidime (CAZ (8 h. Furthermore, TP1 was shown to suppress the growth of B. pseudomallei cells in biofilm state at concentrations above 221 μM. However, TP1 was cytotoxic to the mammalian cell lines tested. In the in silico study, molecular docking revealed that TP1 demonstrated a strong interaction to the common peptide or inhibitor binding targets for lipopolysaccharide of Escherichia coli, as well as autolysin, pneumolysin, and pneumococcal surface protein A (PspA of Streptococcus pneumoniae. Homology modelled B. pseudomallei PspA protein (YDP also showed a favourable binding with a strong electrostatic contribution and nine hydrogen bonds. In conclusion, TP1 demonstrated a good potential as an anti-B. pseudomallei agent.

Molecular phylogeny of Burkholderia pseudomallei from a remote region of Papua New Guinea.

Directory of Open Access Journals (Sweden)

Anthony Baker

Full Text Available BACKGROUND: The island of New Guinea is located midway between the world's two major melioidosis endemic regions of Australia and Southeast Asia. Previous studies in Papua New Guinea have demonstrated autochthonous melioidosis in Balimo, Western province. In contrast to other regions of endemicity, isolates recovered from both environmental and clinical sources demonstrate narrow genetic diversity over large spatial and temporal scales. METHODOLOGY/PRINCIPAL FINDINGS: We employed molecular typing techniques to determine the phylogenetic relationships of these isolates to each other and to others worldwide to aid in understanding the origins of the Papua New Guinean isolates. Multi-locus sequence typing of the 39 isolates resolved three unique sequence types. Phylogenetic reconstruction and Structure analysis determined that all isolates were genetically closer to those from Australia than those from Southeast Asia. Gene cluster analysis however, identified a Yersinia-like fimbrial gene cluster predominantly found among Burkholderia pseudomallei derived from Southeast Asia. Higher resolution VNTR typing and phylogenetic reconstruction of the Balimo isolates resolved 24 genotypes with long branch lengths. These findings are congruent with long term persistence in the region and a high level of environmental stability. CONCLUSIONS/SIGNIFICANCE: Given that anthropogenic influence has been hypothesized as a mechanism for the dispersal of B. pseudomallei, these findings correlate with limited movement of the indigenous people in the region. The palaeogeographical and anthropogenic history of Australasia and the results from this study indicate that New Guinea is an important region for the further study of B. pseudomallei origins and dissemination.

Source-identifying biomarker ions between environmental and clinical Burkholderia pseudomallei using whole-cell matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).

Science.gov (United States)

Niyompanich, Suthamat; Jaresitthikunchai, Janthima; Srisanga, Kitima; Roytrakul, Sittiruk; Tungpradabkul, Sumalee

2014-01-01

Burkholderia pseudomallei is the causative agent of melioidosis, which is an endemic disease in Northeast Thailand and Northern Australia. Environmental reservoirs, including wet soils and muddy water, serve as the major sources for contributing bacterial infection to both humans and animals. The whole-cell matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (whole-cell MALDI-TOF MS) has recently been applied as a rapid, accurate, and high-throughput tool for clinical diagnosis and microbiological research. In this present study, we employed a whole-cell MALDI-TOF MS approach for assessing its potency in clustering a total of 11 different B. pseudomallei isolates (consisting of 5 environmental and 6 clinical isolates) with respect to their origins and to further investigate the source-identifying biomarker ions belonging to each bacterial group. The cluster analysis demonstrated that six out of eleven isolates were grouped correctly to their sources. Our results revealed a total of ten source-identifying biomarker ions, which exhibited statistically significant differences in peak intensity between average environmental and clinical mass spectra using ClinProTools software. Six out of ten mass ions were assigned as environmental-identifying biomarker ions (EIBIs), including, m/z 4,056, 4,214, 5,814, 7,545, 7,895, and 8,112, whereas the remaining four mass ions were defined as clinical-identifying biomarker ions (CIBIs) consisting of m/z 3,658, 6,322, 7,035, and 7,984. Hence, our findings represented, for the first time, the source-specific biomarkers of environmental and clinical B. pseudomallei.

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.

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

Phenotypic and functional characterization of human memory T cell responses to Burkholderia pseudomallei.

Directory of Open Access Journals (Sweden)

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.

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...

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

Science.gov (United States)

Puknun, Aekkalak; Bolscher, Jan G M; Nazmi, Kamran; Veerman, Enno C I; Tungpradabkul, Sumalee; Wongratanacheewin, Surasakdi; Kanthawong, Sakawrat; Taweechaisupapong, Suwimol

2013-07-01

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 are two antimicrobial domains of lactoferrin with a broad spectrum of antimicrobial activity. A hybrid peptide (LFchimera) containing lactoferrampin (LFampin265-284) and a part of lactoferricin (LFcin17-30) has strikingly higher antimicrobial activities compared to the individual peptides. In this study, the antimicrobial activities of this chimeric construct (LFchimera1), as well as of another one containing LFcin17-30 and LFampin268-284, a shorter fragment of LFampin265-284 (LFchimera2), and the constituent peptides were tested against 7 isolates of B. pseudomallei and compared to the preferential antibiotic ceftazidime (CAZ). All isolates including B. pseudomallei 979b shown to be resistant to CAZ, at a density of 10(5) CFU/ml, could be killed by 5-10 μM of LFchimera1 within 2 h, while the other peptides as well as the antibiotic CAZ only inhibited the B. pseudomallei strains resulting in an overgrowth in 24 h. These data indicate that LFchimera1 could be considered for development of therapeutic agents against B. pseudomallei.

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

Science.gov (United States)

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

2017-11-17

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 no licensed vaccine for prevention of melioidosis. Here, we explore the use of rapid plasmid DNA vaccination against B. pseudomallei flagellin for protection against respiratory challenge. We tested three flagellin DNA vaccines with different subcellular targeting designs. C57BL/6 mice were vaccinated via skin tattoo on day 0, 3 and 6 before intranasal challenge with B. pseudomallei on day 21. Next, the most effective construct was used as single vaccination on day 0 by tattoo or intranasal formulation. Mice were sacrificed 72 hours post-challenge to assess bacterial loads, cytokine responses, inflammation and microscopic lesions. A construct encoding a cellular secretion signal resulted in the most effective protection against melioidosis via tattooing, with a 10-fold reduction in bacterial loads in lungs and distant organs compared to the empty vector. Strikingly, a single intranasal administration of the same vaccine resulted in >1000-fold lower bacterial loads and increased survival. Pro-inflammatory cytokine responses were significantly diminished and strong reductions in markers for distant organ damage were observed. A rapid vaccination scheme using flagellin DNA tattoo provides significant protection against intranasal challenge with B. pseudomallei, markedly improved by a single administration via airway mucosa. Hence intranasal vaccination with flagellin-encoding DNA may be applicable when acute mass vaccination is indicated and warrants further testing.

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

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.

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.

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

Directory of Open Access Journals (Sweden)

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.

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.

A preliminary X-ray study of sedoheptulose-7-phosphate isomerase from Burkholderia pseudomallei

International Nuclear Information System (INIS)

Kim, Mi-Sun; Shin, Dong Hae

2009-01-01

Sedoheptulose-7-phosphate isomerase (GmhA) from B. pseudomallei is one of the targets of antibiotic adjuvants for melioidosis. In this study, GmhA has been cloned, expressed, purified and crystallized. Sedoheptulose-7-phosphate isomerase (GmhA) converts d-sedoheptulose 7-phosphate to d,d-heptose 7-phosphate. This is the first step in the biosynthesis pathway of NDP-heptose, which is responsible for the pleiotropic phenotype. This biosynthesis pathway is the target of inhibitors to increase the membrane permeability of Gram-negative pathogens or of adjuvants working synergistically with known antibiotics. Burkholderia pseudomallei is the causative agent of melioidosis, a seriously invasive disease in animals and humans in tropical and subtropical areas. GmhA from B. pseudomallei is one of the targets of antibiotic adjuvants for melioidosis. In this study, GmhA has been cloned, expressed, purified and crystallized. Synchrotron X-ray data were also collected to 1.9 Å resolution. The crystal belonged to the primitive orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 61.3, b = 84.2, c = 142.3 Å. A full structural determination is under way in order to provide insights into the structure–function relationships of this protein

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

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

Tandem repeat regions within the Burkholderia pseudomallei genome and their application for high resolution genotyping

Directory of Open Access Journals (Sweden)

Harvey Steven P

2007-03-01

Full Text Available Abstract Background The facultative, intracellular bacterium Burkholderia pseudomallei is the causative agent of melioidosis, a serious infectious disease of humans and animals. We identified and categorized tandem repeat arrays and their distribution throughout the genome of B. pseudomallei strain K96243 in order to develop a genetic typing method for B. pseudomallei. We then screened 104 of the potentially polymorphic loci across a diverse panel of 31 isolates including B. pseudomallei, B. mallei and B. thailandensis in order to identify loci with varying degrees of polymorphism. A subset of these tandem repeat arrays were subsequently developed into a multiple-locus VNTR analysis to examine 66 B. pseudomallei and 21 B. mallei isolates from around the world, as well as 95 lineages from a serial transfer experiment encompassing ~18,000 generations. Results B. pseudomallei contains a preponderance of tandem repeat loci throughout its genome, many of which are duplicated elsewhere in the genome. The majority of these loci are composed of repeat motif lengths of 6 to 9 bp with 4 to 10 repeat units and are predominately located in intergenic regions of the genome. Across geographically diverse B. pseudomallei and B.mallei isolates, the 32 VNTR loci displayed between 7 and 28 alleles, with Nei's diversity values ranging from 0.47 and 0.94. Mutation rates for these loci are comparable (>10-5 per locus per generation to that of the most diverse tandemly repeated regions found in other less diverse bacteria. Conclusion The frequency, location and duplicate nature of tandemly repeated regions within the B. pseudomallei genome indicate that these tandem repeat regions may play a role in generating and maintaining adaptive genomic variation. Multiple-locus VNTR analysis revealed extensive diversity within the global isolate set containing B. pseudomallei and B. mallei, and it detected genotypic differences within clonal lineages of both species that were

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...

Effects of sodium chloride on heat resistance, oxidative susceptibility, motility, biofilm and plaque formation of Burkholderia pseudomallei.

Science.gov (United States)

Pumirat, Pornpan; Vanaporn, Muthita; Boonyuen, Usa; Indrawattana, Nitaya; Rungruengkitkun, Amporn; Chantratita, Narisara

2017-08-01

Burkholderia pseudomallei is an environmental saprophyte and the causative agent of melioidosis, a severe infectious disease prevalent in tropical areas, including southeast Asia and northern Australia. In Thailand, the highest incidence of melioidosis is in the northeast region, where saline soil and water are abundant. We hypothesized that B. pseudomallei develops an ability to thrive in saline conditions and gains a selective ecological advantage over other soil-dwelling microorganisms. However, little is known about how an elevated NaCl concentration affects survival and adaptive changes in this pathogen. In this study, we examined the adaptive changes in six isolates of B. pseudomallei after growth in Luria-Bertani medium containing different concentrations of NaCl at 37°C for 6 hr. The bacteria were then investigated for resistance to heat at 50°C and killing by hydrogen peroxide (H 2 O 2 ). In addition, flagellar production, biofilm formation, and the plaque formation efficiency of B. pseudomallei after culture in saline conditions were observed. In response to exposure to 150 and 300 mmol L -1 NaCl, all B. pseudomallei isolates showed significantly increased thermal tolerance, oxidative resistance, and plaque-forming efficiency. However, NaCl exposure notably decreased the number of B. pseudomallei flagella. Taken together, these results provide insight into the adaptations of B. pseudomallei that might be crucial for survival and persistence in the host and/or endemic environments with high salinity. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

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...

Genomic Diversity of Burkholderia pseudomallei Clinical Isolates: Subtractive Hybridization Reveals a Burkholderia mallei-Specific Propage in B. pseudomallei 1026b

National Research Council Canada - National Science Library

DeShazer, David

2004-01-01

.... pseudomallei, 1026b and K96243. Numerous mobile genetic elements, including a temperate bacteriophage designated phi1026b, were identified among the 1026b-specific suppression subtractive hybridization products...

Phylogenomic Analysis Reveals an Asian Origin for African Burkholderia pseudomallei and Further Supports Melioidosis Endemicity in Africa.

Science.gov (United States)

Sarovich, Derek S; Garin, Benoit; De Smet, Birgit; Kaestli, Mirjam; Mayo, Mark; Vandamme, Peter; Jacobs, Jan; Lompo, Palpouguini; Tahita, Marc C; Tinto, Halidou; Djaomalaza, Innocente; Currie, Bart J; Price, Erin P

2016-01-01

Burkholderia pseudomallei, an environmental bacterium that causes the deadly disease melioidosis, is endemic in northern Australia and Southeast Asia. An increasing number of melioidosis cases are being reported in other tropical regions, including Africa and the Indian Ocean islands. B. pseudomallei first emerged in Australia, with subsequent rare dissemination event(s) to Southeast Asia; however, its dispersal to other regions is not yet well understood. We used large-scale comparative genomics to investigate the origins of three B. pseudomallei isolates from Madagascar and two from Burkina Faso. Phylogenomic reconstruction demonstrates that these African B. pseudomallei isolates group into a single novel clade that resides within the more ancestral Asian clade. Intriguingly, South American strains reside within the African clade, suggesting more recent dissemination from West Africa to the Americas. Anthropogenic factors likely assisted in B. pseudomallei dissemination to Africa, possibly during migration of the Austronesian peoples from Indonesian Borneo to Madagascar ~2,000 years ago, with subsequent genetic diversity driven by mutation and recombination. Our study provides new insights into global patterns of B. pseudomallei dissemination and adds to the growing body of evidence of melioidosis endemicity in Africa. Our findings have important implications for melioidosis diagnosis and management in Africa. IMPORTANCE Sporadic melioidosis cases have been reported in the African mainland and Indian Ocean islands, but until recently, these regions were not considered areas where B. pseudomallei is endemic. Given the high mortality rate of melioidosis, it is crucial that this disease be recognized and suspected in all regions of endemicity. Previous work has shown that B. pseudomallei originated in Australia, with subsequent introduction into Asia; however, the precise origin of B. pseudomallei in other tropical regions remains poorly understood. Using

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

Directory of Open Access Journals (Sweden)

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

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

Global transcriptional profiling of Burkholderia pseudomallei under salt stress reveals differential effects on the Bsa type III secretion system

Directory of Open Access Journals (Sweden)

Singsuksawat Ekapot

2010-06-01

Full Text Available Abstract Background Burkholderia pseudomallei is the causative agent of melioidosis where the highest reported incidence world wide is in the Northeast of Thailand, where saline soil and water are prevalent. Moreover, recent reports indicate a potential pathogenic role for B. pseudomallei in cystic fibrosis lung disease, where an increased sodium chloride (NaCl concentration in airway surface liquid has been proposed. These observations raise the possibility that high salinity may represent a favorable niche for B. pseudomallei. We therefore investigated the global transcriptional response of B. pseudomallei to increased salinity using microarray analysis. Results Transcriptome analysis of B. pseudomallei under salt stress revealed several genes significantly up-regulated in the presence of 320 mM NaCl including genes associated with the bsa-derived Type III secretion system (T3SS. Microarray data were verified by reverse transcriptase-polymerase chain reactions (RT-PCR. Western blot analysis confirmed the increased expression and secretion of the invasion-associated type III secreted proteins BipD and BopE in B. pseudomallei cultures at 170 and 320 mM NaCl relative to salt-free medium. Furthermore, salt-treated B. pseudomallei exhibited greater invasion efficiency into the lung epithelial cell line A549 in a manner partly dependent on a functional Bsa system. Conclusions B. pseudomallei responds to salt stress by modulating the transcription of a relatively small set of genes, among which is the bsa locus associated with invasion and virulence. Expression and secretion of Bsa-secreted proteins was elevated in the presence of exogenous salt and the invasion efficiency was enhanced. Our data indicate that salinity has the potential to influence the virulence of B. pseudomallei.

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.

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.

Diversity of 16S-23S rDNA internal transcribed spacer (ITS reveals phylogenetic relationships in Burkholderia pseudomallei and its near-neighbors.

Directory of Open Access Journals (Sweden)

Andrew P Liguori

Full Text Available Length polymorphisms within the 16S-23S ribosomal DNA internal transcribed spacer (ITS have been described as stable genetic markers for studying bacterial phylogenetics. In this study, we used these genetic markers to investigate phylogenetic relationships in Burkholderia pseudomallei and its near-relative species. B. pseudomallei is known as one of the most genetically recombined bacterial species. In silico analysis of multiple B. pseudomallei genomes revealed approximately four homologous rRNA operons and ITS length polymorphisms therein. We characterized ITS distribution using PCR and analyzed via a high-throughput capillary electrophoresis in 1,191 B. pseudomallei strains. Three major ITS types were identified, two of which were commonly found in most B. pseudomallei strains from the endemic areas, whereas the third one was significantly correlated with worldwide sporadic strains. Interestingly, mixtures of the two common ITS types were observed within the same strains, and at a greater incidence in Thailand than Australia suggesting that genetic recombination causes the ITS variation within species, with greater recombination frequency in Thailand. In addition, the B. mallei ITS type was common to B. pseudomallei, providing further support that B. mallei is a clone of B. pseudomallei. Other B. pseudomallei near-neighbors possessed unique and monomorphic ITS types. Our data shed light on evolutionary patterns of B. pseudomallei and its near relative species.

Paravertebral Abscess Caused by Bukholderia Pseudomallei in

Directory of Open Access Journals (Sweden)

S Ahmad

2009-05-01

Full Text Available A 53-year-old Malay man was admitted with intestinal obstruction, fever and lower limb weakness. Initial clinical impression was myelitis causing paralytic ilues and paraperesis. Blood culture showed Burkholderia pseudomallei infection and subsequent MRI showed paravertebral abscess. This case highlights a rare manifestation of melioidosis involving the spine and difficulties in establishing the diagnosis.

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.

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.

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.

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.

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.

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

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

Crystallization and preliminary X-ray diffraction analysis of BipD, a virulence factor from Burkholderia pseudomallei

Energy Technology Data Exchange (ETDEWEB)

Knight, M. J.; Ruaux, A.; Mikolajek, H.; Erskine, P. T.; Gill, R.; Wood, S. P. [School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX (United Kingdom); Wood, M. [Institute of Animal Health, Division of Environmental Microbiology, Institute for Animal Health, Compton Laboratory, Berkshire RG20 7NN (United Kingdom); Cooper, J. B., E-mail: j.b.cooper@soton.ac.uk [School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX (United Kingdom)

2006-08-01

BipD is likely to be a component of a type-III protein secretion system (TTSS) in B. pseudomallei. Native and selenomethionyl-BipD proteins have been expressed and crystals have been obtained which diffract to 2.1 Å. Burkholderia pseudomallei, the causative agent of melioidosis, possesses a protein-secretion apparatus that is similar to those found in Salmonella and Shigella. A major function of these secretion systems is to secrete virulence-associated proteins into target cells of the host organism. The BipD gene of B. pseudomallei encodes a secreted virulence factor that is similar in sequence and most likely functionally analogous to IpaD from Shigella and SipD from Salmonella. Thus, the BipD protein is likely to be a component of a type III protein-secretion system (TTSS) in B. pseudomallei. Proteins in the same class as BipD, such as IpaD and SipD, are thought to act as extracellular chaperones to help the hydrophobic translocator proteins enter the target cell membrane, where they form a pore and might even link the translocon pore with the secretion needle. There is evidence that the translocator proteins also bind an integrin which stimulates actin-mediated insertion of the bacterium into the host-cell membrane. Native BipD has been crystallized in a monoclinic crystal form that diffracts X-rays to 2.5 Å resolution. BipD protein which incorporates selenomethionine (SeMet-BipD) has also been expressed and forms crystals which diffract to a higher resolution of 2.1 Å.

Crystallization and preliminary X-ray diffraction analysis of BipD, a virulence factor from Burkholderia pseudomallei

International Nuclear Information System (INIS)

Knight, M. J.; Ruaux, A.; Mikolajek, H.; Erskine, P. T.; Gill, R.; Wood, S. P.; Wood, M.; Cooper, J. B.

2006-01-01

BipD is likely to be a component of a type-III protein secretion system (TTSS) in B. pseudomallei. Native and selenomethionyl-BipD proteins have been expressed and crystals have been obtained which diffract to 2.1 Å. Burkholderia pseudomallei, the causative agent of melioidosis, possesses a protein-secretion apparatus that is similar to those found in Salmonella and Shigella. A major function of these secretion systems is to secrete virulence-associated proteins into target cells of the host organism. The BipD gene of B. pseudomallei encodes a secreted virulence factor that is similar in sequence and most likely functionally analogous to IpaD from Shigella and SipD from Salmonella. Thus, the BipD protein is likely to be a component of a type III protein-secretion system (TTSS) in B. pseudomallei. Proteins in the same class as BipD, such as IpaD and SipD, are thought to act as extracellular chaperones to help the hydrophobic translocator proteins enter the target cell membrane, where they form a pore and might even link the translocon pore with the secretion needle. There is evidence that the translocator proteins also bind an integrin which stimulates actin-mediated insertion of the bacterium into the host-cell membrane. Native BipD has been crystallized in a monoclinic crystal form that diffracts X-rays to 2.5 Å resolution. BipD protein which incorporates selenomethionine (SeMet-BipD) has also been expressed and forms crystals which diffract to a higher resolution of 2.1 Å

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

Directory of Open Access Journals (Sweden)

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.

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

Directory of Open Access Journals (Sweden)

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

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.

Crystallization and preliminary X-ray analysis of the receiver domain of a putative response regulator, BPSL0128, from Burkholderia pseudomallei

International Nuclear Information System (INIS)

Abd Aziz, Abd Ghani; Sedelnikova, Svetlana E.; Ruzheinikov, Sergey N.; Thorpe, Simon; Mohamed, Rahmah; Nathan, Sheila; Rafferty, John B.; Baker, Patrick J.; Rice, David W.

2012-01-01

The receiver domain of a putative response regulator from B. pseudomallei, BPSL0128, has been crystallized in a form suitable for X-ray analysis. bpsl0128, a gene encoding a putative response regulator from Burkholderia pseudomallei strain D286, has been cloned into a pETBLUE-1 vector system, overexpressed in Escherichia coli and purified. The full-length protein is degraded during purification to leave a fragment corresponding to the putative receiver domain, and crystals of this protein that diffracted to beyond 1.75 Å resolution have been grown by the hanging-drop vapour-diffusion technique using PEG 6000 as the precipitant. The crystals belonged to one of the enantiomorphic pair of space groups P3 1 21 and P3 2 21, with unit-cell parameters a = b = 65.69, c = 105.01 Å and either one or two molecules in the asymmetric unit

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.

Comparison of DNA extraction kits for detection of Burkholderia pseudomallei in spiked human whole blood using real-time PCR.

Directory of Open Access Journals (Sweden)

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.

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.

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.

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.

Burkholderia pseudomallei Data Gap Analysis

Science.gov (United States)

2015-11-01

Since its discovery , B. pseudomallei has become recognized as a significant public health threat in the tropical regions of the globe where it is...alcoholics, kava users (Australia), chronic drug users, or diabetic. However, HIV does not seem to be a factor. Table 2-1. Published melioidosis...However, the history for these types of vaccines has shown better efficacy in mouse models that in human trials. In addition to the naked-DNA

BurkDiff: a real-time PCR allelic discrimination assay for Burkholderia pseudomallei and B. mallei.

Directory of Open Access Journals (Sweden)

Jolene R Bowers

2010-11-01

Full Text Available A real-time PCR assay, BurkDiff, was designed to target a unique conserved region in the B. pseudomallei and B. mallei genomes containing a SNP that differentiates the two species. Sensitivity and specificity were assessed by screening BurkDiff across 469 isolates of B. pseudomallei, 49 isolates of B. mallei, and 390 isolates of clinically relevant non-target species. Concordance of results with traditional speciation methods and no cross-reactivity to non-target species show BurkDiff is a robust, highly validated assay for the detection and differentiation of B. pseudomallei and B. mallei.

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

Directory of Open Access Journals (Sweden)

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

Tandem Repeat Regions within the Burkholderia pseudomallei Genome and their Application for High-Resolution Genotyping

National Research Council Canada - National Science Library

U'Ren, Jana M; Schupp, James M; Pearson, Talima; Hornstra, Heidie; Friedman, Christine L; Smith, Kimothy L; Daugherty, Rebecca R; Rhoton, Shane D; Leadem, Ben; Georgia, Shalamar

2007-01-01

.... pseudomallei strain K96243 in order to develop a genetic typing method for B. pseudomallei. We then screened 104 of the potentially polymorphic loci across a diverse panel of isolates including B. pseudomallei, B. mallei and B. thailandensis...

Burkholderia humptydooensis sp. nov., A Burkholderia thailandensis-Like Species and the Fifth Member of the pseudomallei Complex

Science.gov (United States)

2016-06-02

biochemical pattern to B. pseudomallei and B. thailandensis were co-64 isolated with B. pseudomallei on Ashdown’s selective agar. To determine the...three B. ubonensis strains) (see SI doc and Fig. S2). 157 Minimum inhibitory concentrations (MICs) were determined by broth microdilution 158...rifampicin (0.0625–8 mg/L), chloramphenicol (0.5–64 mg/L), 162 trimethoprim /sulfamethoxazole (0.25–32/4.75–608 mg/L), streptomycin (0.25–32 mg/L

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

Pyogenic Liver Abscess Caused by Burkhoderia pseudomallei in Taiwan

Directory of Open Access Journals (Sweden)

Yu-Lin Lee

2006-01-01

Full Text Available Pyogenic liver abscess in Taiwan is a well-known disease entity, commonly associated with a single pathogen, Klebsiella pneumoniae. Melioidosis is an endemic disease in Taiwan that can manifest as multiple abscesses in sites including the liver. We report three cases of liver abscesses caused by Burkholderia pseudomallei. The first patient was a 54-year-old diabetic woman, who presented with liver abscess and a left subphrenic abscess resulting from a ruptured splenic abscess, co-infected with K. pneumoniae and B. pseudomallei. The second patient, a 58-year-old diabetic man, developed bacteremic pneumonia over the left lower lung due to B. pseudomallei with acute respiratory distress syndrome, and relapsed 5 months later with bacteremic abscesses of the liver, spleen, prostate and osteomyelitis, due to lack of compliance with prescribed antibiotic therapy. The third patient was a 61-year-old diabetic man with a history of travel to Thailand, who presented with jaundice and fever of unknown origin. Liver and splenic abscesses due to B. pseudomallei were diagnosed. A high clinical alertness to patients' travel history, underlying diseases, and the presence of concomitant splenic abscess is essential to early detection of the great mimicker, melioidosis. The treatment of choice is intravenous ceftazidime for at least 14 days or more. An adequate duration of maintenance oral therapy, with amoxicillin-clavulanate or trimethoprim-sulfamethoxazole for 12-20 weeks, is necessary to prevent relapse. Liver abscess in Taiwan is most commonly due to K. pneumoniae, but clinicians should keep in mind that this may be a presenting feature of melioidosis.

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

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

The Burkholderia pseudomallei Proteins BapA and BapC Are Secreted TTSS3 Effectors and BapB Levels Modulate Expression of BopE.

Directory of Open Access Journals (Sweden)

Puthayalai Treerat

Full Text Available Many Gram-negative pathogens use a type III secretion system (TTSS for the injection of bacterial effector proteins into host cells. The injected effector proteins play direct roles in modulation of host cell pathways for bacterial benefit. Burkholderia pseudomallei, the causative agent of melioidosis, expresses three different TTSSs. One of these systems, the TTSS3, is essential for escape from host endosomes and therefore intracellular survival and replication. Here we have characterized three putative TTSS3 proteins; namely BapA, BapB and BapC. By employing a tetracysteine (TC-FlAsH™ labelling technique to monitor the secretion of TC-tagged fusion proteins, BapA and BapC were shown to be secreted during in vitro growth in a TTSS3-dependant manner, suggesting a role as TTSS3 effectors. Furthermore, we constructed B. pseudomallei bapA, bapB and bapC mutants and used the well-characterized TTSS3 effector BopE as a marker of secretion to show that BapA, BapB and BapC are not essential for the secretion process. However, BopE transcription and secretion were significantly increased in the bapB mutant, suggesting that BapB levels modulate BopE expression. In a BALB/c mouse model of acute melioidosis, the bapA, bapB and bapC mutants showed a minor reduction of in vivo fitness. Thus, this study defines BapA and BapC as novel TTSS3 effectors, BapB as a regulator of BopE production, and all three as necessary for full B. pseudomallei in vivo fitness.

Near-atomic resolution analysis of BipD, a component of the type III secretion system of Burkholderia pseudomallei

International Nuclear Information System (INIS)

Pal, M.; Erskine, P. T.; Gill, R. S.; Wood, S. P.; Cooper, J. B.

2010-01-01

The type III secretion system needle-tip protein BipD has been crystallized in a form that diffracts X-rays to 1.5 Å resolution and the structure has been refined to an R factor of 16.1% and an R free of 19.8% at this resolution. The putative antiparallel dimer interface that was observed in earlier structures is conserved. Burkholderia pseudomallei, the causative agent of melioidosis, possesses a type III protein secretion apparatus that is similar to those found in Salmonella and Shigella. A major function of these secretion systems is to inject virulence-associated proteins into target cells of the host organism. The bipD gene of B. pseudomallei encodes a secreted virulence factor that is similar in sequence and is most likely to be functionally analogous to IpaD from Shigella and SipD from Salmonella. Proteins in this family are thought to act as extracellular chaperones at the tip of the secretion needle to help the hydrophobic translocator proteins enter the target cell membrane, where they form a pore and may also link the translocon pore with the secretion needle. BipD has been crystallized in a monoclinic crystal form that diffracted X-rays to 1.5 Å resolution and the structure was refined to an R factor of 16.1% and an R free of 19.8% at this resolution. The putative dimer interface that was observed in previous crystal structures was retained and a larger surface area was buried in the new crystal form

Environmental Survival, Military Relevance, and Persistence of Burkholderia Pseudomallei

Science.gov (United States)

2007-04-01

products used for disinfection and decontamination (Sagripanti and Bonifacino, 1996, 1999, 2000). 20 Preliminary results indicate that chloramine may be...CONTENTS 1. IN T R O D U C T IO N ............................................................................................. 9 2. IMPACT OF THE...pseudomallei. Moreover, the intracellular nature of melioidosis makes stimulation of T cell immunity difficult. Therefore, a vaccine to provide complete

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.

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

Survey of innate immune responses to Burkholderia pseudomallei in human blood identifies a central role for lipopolysaccharide.

Directory of Open Access Journals (Sweden)

Narisara Chantratita

Full Text Available B. pseudomallei is a gram-negative bacterium that causes the tropical infection melioidosis. In northeast Thailand, mortality from melioidosis approaches 40%. As exemplified by the lipopolysaccharide-Toll-like receptor 4 interaction, innate immune responses to invading bacteria are precipitated by activation of host pathogen recognition receptors by pathogen associated molecular patterns. Human melioidosis is characterized by up-regulation of pathogen recognition receptors and pro-inflammatory cytokine release. In contrast to many gram-negative pathogens, however, the lipopolysaccharide of B. pseudomallei is considered only weakly inflammatory. We conducted a study in 300 healthy Thai subjects to investigate the ex vivo human blood response to various bacterial pathogen associated molecular patterns, including lipopolysaccharide from several bacteria, and to two heat-killed B. pseudomallei isolates. We measured cytokine levels after stimulation of fresh whole blood with a panel of stimuli. We found that age, sex, and white blood cell count modulate the innate immune response to B. pseudomallei. We further observed that, in comparison to other stimuli, the innate immune response to B. pseudomallei is most highly correlated with the response to lipopolysaccharide. The magnitude of cytokine responses induced by B. pseudomallei lipopolysaccharide was significantly greater than those induced by lipopolysaccharide from Escherichia coli and comparable to many responses induced by lipopolysaccharide from Salmonella minnesota despite lower amounts of lipid A in the B. pseudomallei lipopolysaccharide preparation. In human monocytes stimulated with B. pseudomallei, addition of polymyxin B or a TLR4/MD-2 neutralizing antibody inhibited the majority of TNF-α production. Challenging existing views, our data indicate that the innate immune response to B. pseudomallei in human blood is largely driven by lipopolysaccharide, and that the response to B

Redefining the PF06864 Pfam family based on Burkholderia pseudomallei PilO2(Bp S-SAD crystal structure.

Directory of Open Access Journals (Sweden)

Patricia Lassaux

Full Text Available Type IV pili are surface-exposed filaments and bacterial virulence factors, represented by the Tfpa and Tfpb types, which assemble via specific machineries. The Tfpb group is further divided into seven variants, linked to heterogeneity in the assembly machineries. Here we focus on PilO2(Bp, a protein component of the Tfpb R64 thin pilus variant assembly machinery from the pathogen Burkholderia pseudomallei. PilO2(Bp belongs to the PF06864 Pfam family, for which an improved definition is presented based on newly derived Hidden Markov Model (HMM profiles. The 3D structure of the N-terminal domain of PilO2(Bp (N-PilO2(Bp, here reported, is the first structural representative of the PF06864 family. N-PilO2(Bp presents an actin-like ATPase fold that is shown to be present in BfpC, a different variant assembly protein; the new HMM profiles classify BfpC as a PF06864 member. Our results provide structural insight into the PF06864 family and on the Type IV pili assembly machinery.

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.

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

Leveraging structure determination with fragment screening for infectious disease drug targets: MECP synthase from Burkholderia pseudomallei

Energy Technology Data Exchange (ETDEWEB)

Begley, Darren W.; Hartley, Robert C.; Davies, Douglas R.; Edwards, Thomas E.; Leonard, Jess T.; Abendroth, Jan; Burris, Courtney A.; Bhandari, Janhavi; Myler, Peter J.; Staker, Bart L.; Stewart, Lance J. (UWASH); (Emerald)

2011-09-28

As part of the Seattle Structural Genomics Center for Infectious Disease, we seek to enhance structural genomics with ligand-bound structure data which can serve as a blueprint for structure-based drug design. We have adapted fragment-based screening methods to our structural genomics pipeline to generate multiple ligand-bound structures of high priority drug targets from pathogenic organisms. In this study, we report fragment screening methods and structure determination results for 2C-methyl-D-erythritol-2,4-cyclo-diphosphate (MECP) synthase from Burkholderia pseudomallei, the gram-negative bacterium which causes melioidosis. Screening by nuclear magnetic resonance spectroscopy as well as crystal soaking followed by X-ray diffraction led to the identification of several small molecules which bind this enzyme in a critical metabolic pathway. A series of complex structures obtained with screening hits reveal distinct binding pockets and a range of small molecules which form complexes with the target. Additional soaks with these compounds further demonstrate a subset of fragments to only bind the protein when present in specific combinations. This ensemble of fragment-bound complexes illuminates several characteristics of MECP synthase, including a previously unknown binding surface external to the catalytic active site. These ligand-bound structures now serve to guide medicinal chemists and structural biologists in rational design of novel inhibitors for this enzyme.

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

Directory of Open Access Journals (Sweden)

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.

Expression, purification, crystallization and preliminary crystallographic analysis of BipD, a component of the Burkholderia pseudomallei type III secretion system

International Nuclear Information System (INIS)

Roversi, Pietro; Johnson, Steven; Field, Terry; Deane, Janet E.; Galyov, Edouard E.; Lea, Susan M.

2006-01-01

A construct consisting of residues 10–310 of mature BipD, a component of the B. pseudomallei type III secretion system, has been crystallized. Native BipD crystals and SeMet and K 2 PtCl 4 derivative crystals have undergone preliminary crystallographic analysis. A construct consisting of residues 10–310 of BipD, a component of the Burkholderia pseudomallei type III secretion system (T3SS), has been overexpressed as a GST fusion, cleaved from the GST tag and purified. Crystals were grown of native and selenomethionine-labelled BipD. The crystals grow in two different polymorphs from the same condition. The first polymorph belongs to space group C222, with unit-cell parameters a = 103.98, b = 122.79, c = 49.17 Å, a calculated Matthews coefficient of 2.4 Å 3 Da −1 (47% solvent content) and one molecule per asymmetric unit. The second polymorph belongs to space group P2 1 2 1 2, with unit-cell parameters a = 136.47, b = 89.84, c = 50.15 Å, and a calculated Matthews coefficient of 2.3 Å 3 Da −1 (45% solvent content) for two molecules per asymmetric unit (analysis of the self-rotation function indicates the presence of a weak twofold non-crystallographic symmetry axis in this P2 1 2 1 2 form). The native crystals of both forms give diffraction data to 2.7 Å resolution, while the SeMet-labelled P2 1 2 1 2 crystals diffract to 3.3 Å resolution. A K 2 PtCl 4 derivative of the P2 1 2 1 2 form was also obtained and data were collected to 2.7 Å with radiation of wavelength λ = 0.933 Å. The Pt-derivative anomalous difference Patterson map revealed two self-peaks on the Harker sections

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.

Expression, purification, crystallization and preliminary crystallographic analysis of BipD, a component of the Burkholderia pseudomallei type III secretion system

Energy Technology Data Exchange (ETDEWEB)

Roversi, Pietro; Johnson, Steven [Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU (United Kingdom); Field, Terry [Division of Microbiology, Institute for Animal Health, Compton Laboratory, Berkshire RG20 7NN (United Kingdom); Deane, Janet E. [Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU (United Kingdom); Galyov, Edouard E. [Division of Microbiology, Institute for Animal Health, Compton Laboratory, Berkshire RG20 7NN (United Kingdom); Lea, Susan M., E-mail: susan.lea@biop.ox.ac.uk [Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU (United Kingdom); Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE (United Kingdom)

2006-09-01

A construct consisting of residues 10–310 of mature BipD, a component of the B. pseudomallei type III secretion system, has been crystallized. Native BipD crystals and SeMet and K{sub 2}PtCl{sub 4} derivative crystals have undergone preliminary crystallographic analysis. A construct consisting of residues 10–310 of BipD, a component of the Burkholderia pseudomallei type III secretion system (T3SS), has been overexpressed as a GST fusion, cleaved from the GST tag and purified. Crystals were grown of native and selenomethionine-labelled BipD. The crystals grow in two different polymorphs from the same condition. The first polymorph belongs to space group C222, with unit-cell parameters a = 103.98, b = 122.79, c = 49.17 Å, a calculated Matthews coefficient of 2.4 Å{sup 3} Da{sup −1} (47% solvent content) and one molecule per asymmetric unit. The second polymorph belongs to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 136.47, b = 89.84, c = 50.15 Å, and a calculated Matthews coefficient of 2.3 Å{sup 3} Da{sup −1} (45% solvent content) for two molecules per asymmetric unit (analysis of the self-rotation function indicates the presence of a weak twofold non-crystallographic symmetry axis in this P2{sub 1}2{sub 1}2 form). The native crystals of both forms give diffraction data to 2.7 Å resolution, while the SeMet-labelled P2{sub 1}2{sub 1}2 crystals diffract to 3.3 Å resolution. A K{sub 2}PtCl{sub 4} derivative of the P2{sub 1}2{sub 1}2 form was also obtained and data were collected to 2.7 Å with radiation of wavelength λ = 0.933 Å. The Pt-derivative anomalous difference Patterson map revealed two self-peaks on the Harker sections.

Seroprevalence of Burkholderia pseudomallei among Adults in Coastal Areas in Southwestern India.

Directory of Open Access Journals (Sweden)

Kalwaje Eshwara Vandana

2016-04-01

Full Text Available Although melioidosis, is an important disease in many Southeast Asian countries and Australia, there is limited data on its prevalence and disease burden in India. However, an increase in case reports of melioidosis in recent years indicates its endemicity in India.A population-based cross-sectional seroprevalence study was undertaken to determine the seroprevalence of B. pseudomallei by indirect haemagglutination assay and to investigate the associated risk determinants. Subjects were 711 adults aged 18 to 65 years residing in Udupi district, located in south-western coast of India.Overall, 29% of the study subjects were seropositive (titer ≥20. Females were twice as likely to be seropositive compared to males. Rates of seroprevalence were similar in farmers and non-farmers. Besides gardening, other factors including socio-demographic, occupational and environmental factors did not show any relationship with seropositive status.There is a serological evidence of exposure to B. pseudomallei among adults in India. While the bacterium inhabits soil, exposure to the agent is not limited to farmers. Non-occupational exposure might play an important role in eliciting antibody response to the bacterium and may also be an important factor in disease causation.

Airborne Transmission of Melioidosis to Humans from Environmental Aerosols Contaminated with B. pseudomallei.

Science.gov (United States)

Chen, Pei-Shih; Chen, Yao-Shen; Lin, Hsi-Hsun; Liu, Pei-Ju; Ni, Wei-Fan; Hsueh, Pei-Tan; Liang, Shih-Hsiung; Chen, Chialin; Chen, Ya-Lei

2015-06-01

Melioidosis results from an infection with the soil-borne pathogen Burkholderia pseudomallei, and cases of melioidosis usually cluster after rains or a typhoon. In an endemic area of Taiwan, B. pseudomallei is primarily geographically distributed in cropped fields in the northwest of this area, whereas melioidosis cases are distributed in a densely populated district in the southeast. We hypothesized that contaminated cropped fields generated aerosols contaminated with B. pseudomallei, which were carried by a northwesterly wind to the densely populated southeastern district. We collected soil and aerosol samples from a 72 km2 area of land, including the melioidosis-clustered area and its surroundings. Aerosols that contained B. pseudomallei-specific TTSS (type III secretion system) ORF2 DNA were well distributed in the endemic area but were rare in the surrounding areas during the rainy season. The concentration of this specific DNA in aerosols was positively correlated with the incidence of melioidosis and the appearance of a northwesterly wind. Moreover, the isolation rate in the superficial layers of the contaminated cropped field in the northwest was correlated with PCR positivity for aerosols collected from the southeast over a 2-year period. According to pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) analyses, PFGE Type Ia (ST58) was the predominant pattern linking the molecular association among soil, aerosol and human isolates. Thus, the airborne transmission of melioidosis moves from the contaminated soil to aerosols and/or to humans in this endemic area.

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.

Systematic mutagenesis of genes encoding predicted autotransported proteins of Burkholderia pseudomallei identifies factors mediating virulence in mice, net intracellular replication and a novel protein conferring serum resistance.

Directory of Open Access Journals (Sweden)

Natalie R Lazar Adler

Full Text Available Burkholderia pseudomallei is the causative agent of the severe tropical disease melioidosis, which commonly presents as sepsis. The B. pseudomallei K96243 genome encodes eleven predicted autotransporters, a diverse family of secreted and outer membrane proteins often associated with virulence. In a systematic study of these autotransporters, we constructed insertion mutants in each gene predicted to encode an autotransporter and assessed them for three pathogenesis-associated phenotypes: virulence in the BALB/c intra-peritoneal mouse melioidosis model, net intracellular replication in J774.2 murine macrophage-like cells and survival in 45% (v/v normal human serum. From the complete repertoire of eleven autotransporter mutants, we identified eight mutants which exhibited an increase in median lethal dose of 1 to 2-log10 compared to the isogenic parent strain (bcaA, boaA, boaB, bpaA, bpaC, bpaE, bpaF and bimA. Four mutants, all demonstrating attenuation for virulence, exhibited reduced net intracellular replication in J774.2 macrophage-like cells (bimA, boaB, bpaC and bpaE. A single mutant (bpaC was identified that exhibited significantly reduced serum survival compared to wild-type. The bpaC mutant, which demonstrated attenuation for virulence and net intracellular replication, was sensitive to complement-mediated killing via the classical and/or lectin pathway. Serum resistance was rescued by in trans complementation. Subsequently, we expressed recombinant proteins of the passenger domain of four predicted autotransporters representing each of the phenotypic groups identified: those attenuated for virulence (BcaA, those attenuated for virulence and net intracellular replication (BpaE, the BpaC mutant with defects in virulence, net intracellular replication and serum resistance and those displaying wild-type phenotypes (BatA. Only BcaA and BpaE elicited a strong IFN-γ response in a restimulation assay using whole blood from seropositive donors

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

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.

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

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.

Science.gov (United States)

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

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.

Clinical guideline for diagnosis and management of melioidosis

Directory of Open Access Journals (Sweden)

Inglis Timothy J.J.

2006-01-01

Full Text Available Melioidosis is an emerging infection in Brazil and neighbouring South American countries. The wide range of clinical presentations include severe community-acquired pneumonia, septicaemia, central nervous system infection and less severe soft tissue infection. Diagnosis depends heavily on the clinical microbiology laboratory for culture. Burkholderia pseudomallei, the bacterial cause of melioidosis, is easily cultured from blood, sputum and other clinical samples. However, B. pseudomallei can be difficult to identify reliably, and can be confused with closely related bacteria, some of which may be dismissed as insignificant culture contaminants. Serological tests can help to support a diagnosis of melioidosis, but by themselves do not provide a definitive diagnosis. The use of a laboratory discovery pathway can help reduce the risk of missing atypical B. pseudomallei isolates. Recommended antibiotic treatment for severe infection is either intravenous Ceftazidime or Meropenem for several weeks, followed by up to 20 weeks oral treatment with a combination of trimethoprim-sulphamethoxazole and doxycycline. Consistent use of diagnostic microbiology to confirm the diagnosis, and rigorous treatment of severe infection with the correct antibiotics in two stages; acute and eradication, will contribute to a reduction in mortality from melioidosis.

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

Pediatric melioidosis in Sarawak, Malaysia: Epidemiological, clinical and microbiological characteristics.

Science.gov (United States)

Mohan, Anand; Podin, Yuwana; Tai, Nickson; Chieng, Chae-Hee; Rigas, Vanessa; Machunter, Barbara; Mayo, Mark; Wong, Desiree; Chien, Su-Lin; Tan, Lee-See; Goh, Charles; Bantin, Reginal; Mijen, Alexander; Chua, Wen-Yi; Hii, King-Ching; Wong, See-Chang; Ngian, Hie-Ung; Wong, Jin-Shyan; Hashim, Jamilah; Currie, Bart J; Ooi, Mong-How

2017-06-01

Melioidosis is a serious, and potentially fatal community-acquired infection endemic to northern Australia and Southeast Asia, including Sarawak, Malaysia. The disease, caused by the usually intrinsically aminoglycoside-resistant Burkholderia pseudomallei, most commonly affects adults with predisposing risk factors. There are limited data on pediatric melioidosis in Sarawak. A part prospective, part retrospective study of children aged Sarawak between 2009 and 2014. We examined epidemiological, clinical and microbiological characteristics. Forty-two patients were recruited during the 6-year study period. The overall annual incidence was estimated to be 4.1 per 100,000 children Sarawak has a very high incidence of pediatric melioidosis, caused predominantly by gentamicin-susceptible B. pseudomallei strains. Children frequently presented with disseminated disease and had an alarmingly high death rate, despite the absence of any apparent predisposing risk factor.

Macrophage and Galleria mellonella infection models reflect the virulence of naturally occurring isolates of B. pseudomallei, B. thailandensis and B. oklahomensis

Directory of Open Access Journals (Sweden)

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.

ORF Alignment: NC_006351 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available NC_006351 gi|53722258 >1kolA 2 388 1 341 4e-33 ... ref|YP_111243.1| putative zinc-binding xylitol... ... zinc-binding xylitol/sorbitol dehydrogenase ... [Burkholderia pseudomallei K96243] ... .../sorbitol dehydrogenase [Burkholderia ... pseudomallei K96243] emb|CAH38702.1| putative ...

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.

Clinical and microbiological features of melioidosis in northern Vietnam.

Science.gov (United States)

Phuong, Doan Mai; Trung, Trinh Thanh; Breitbach, Katrin; Tuan, Nguyen Quang; Nübel, Ulrich; Flunker, Gisela; Khang, Dinh Duy; Quang, Nguyen Xuan; Steinmetz, Ivo

2008-12-01

Sporadic cases of melioidosis have been reported from Vietnam for decades, but clinical and epidemiological data for the indigenous population are still scarce. In this study, we reviewed clinical and demographic data of patients with culture-proven melioidosis diagnosed at a single large referral hospital in Hanoi between November 1997 and December 2005. We found that the clinical manifestations of melioidosis (with fatal septicaemia as the most common presentation), a high rate of underlying diseases, and a peak of cases admitted during the wet season, were similar to studies from other endemic areas. The geographical origin of patients with melioidosis showed that melioidosis existed in at least 18 northern provinces. The characterization of clinical Burkholderia pseudomallei strains by multilocus sequence typing identified 17 different sequence types (STs), 11 of which have (as yet) not been found outside Vietnam. Several of these STs presumably were generated through recent evolutionary events in this rapidly diversifying bacterial species, and thus, restricted geographic distribution may be a consequence of limited time passed since emergence. To our knowledge, this is the first report on a series of cases describing clinical and epidemiological features of melioidosis and corresponding B. pseudomallei strains from northern Vietnam.

Population-Sequencing as a Biomarker of Burkholderia mallei and Burkholderia pseudomallei Evolution through Microbial Forensic Analysis

Directory of Open Access Journals (Sweden)

John P. Jakupciak

2013-01-01

Full Text Available Large-scale genomics projects are identifying biomarkers to detect human disease. B. pseudomallei and B. mallei are two closely related select agents that cause melioidosis and glanders. Accurate characterization of metagenomic samples is dependent on accurate measurements of genetic variation between isolates with resolution down to strain level. Often single biomarker sensitivity is augmented by use of multiple or panels of biomarkers. In parallel with single biomarker validation, advances in DNA sequencing enable analysis of entire genomes in a single run: population-sequencing. Potentially, direct sequencing could be used to analyze an entire genome to serve as the biomarker for genome identification. However, genome variation and population diversity complicate use of direct sequencing, as well as differences caused by sample preparation protocols including sequencing artifacts and mistakes. As part of a Department of Homeland Security program in bacterial forensics, we examined how to implement whole genome sequencing (WGS analysis as a judicially defensible forensic method for attributing microbial sample relatedness; and also to determine the strengths and limitations of whole genome sequence analysis in a forensics context. Herein, we demonstrate use of sequencing to provide genetic characterization of populations: direct sequencing of populations.

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

A preliminary X-ray study of d,d-heptose-1,7-bisphosphate phosphatase from Burkholderia thailandensis E264

International Nuclear Information System (INIS)

Kim, Mi-Sun; Shin, Dong Hae

2010-01-01

In this study, d,d-heptose-1,7-bisphosphate phosphatase has been cloned, expressed, purified and crystallized. d,d-Heptose-1,7-bisphosphate phosphatase (GmhB), which is involved in the third step of the NDP-heptose biosynthesis pathway, converts d,d-heptose-1,7-bisphosphate to d,d-heptose-1-phosphate. This biosynthesis pathway is a target for new antibiotics or antibiotic adjuvants for Gram-negative pathogens. Burkholderia thailandensis is a useful surrogate organism for studying the pathogenicity of melioidosis owing to its extensive genomic similarity to B. pseudomallei. Melioidosis caused by B. pseudomallei is a serious invasive disease of animals and humans in tropical and subtropical areas. In this study, GmhB has been cloned, expressed, purified and crystallized. X-ray data have also been collected to 2.50 Å resolution using synchrotron radiation. The crystal belonged to space group P6, with unit-cell parameters a = 243.2, b = 243.2, c = 41.1 Å

Characterization of integrons in Burkholderia cepacia clinical isolates

Directory of Open Access Journals (Sweden)

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.

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

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

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

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.

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

Clinical, Bacteriologic, and Geographic Stratification of Melioidosis Emerges from the Sri Lankan National Surveillance Program.

Science.gov (United States)

Sathkumara, Harindra D; Merritt, Adam J; Corea, Enoka M; Krishnananthasivam, Shivankari; Natesan, Mohan; Inglis, Timothy J J; De Silva, Aruna Dharshan

2018-02-01

Melioidosis, a potentially fatal tropical infection, is said to be underdiagnosed in low-income countries. An increase in melioidosis cases in Sri Lanka allowed us to analyze the relationship among clinical outcome, bacteriology, epidemiology, and geography in the first 108 laboratory-confirmed cases of melioidosis from a nationwide surveillance program. The additional 76 cases of laboratory-confirmed melioidosis confirmed further associations between Burkholderia pseudomallei multilocus sequence typing (MLST) and infection phenotype; ST1137/unifocal bacteremic infection (χ 2 = 3.86, P national genotyping-supported melioidosis registry will improve melioidosis diagnosis, treatment, and prevention where underdiagnosis and mortality rates remain high.

Changes in the repertoire of natural antibodies caused by immunization with bacterial antigens

DEFF Research Database (Denmark)

Shilova, N V; Navakouski, M J; Huflejt, M

2011-01-01

The repertoire of natural anti-glycan antibodies in naïve chickens and in chickens immunized with bacteria Burkholderia mallei, Burkholderia pseudomallei, and Francisella tularensis as well as with peptides from an outer membrane protein of B. pseudomallei was studied. A relatively restricted pat...... pattern of natural antibodies (first of all IgY against bacterial cell wall peptidoglycan fragments, L-Rha, and core N-acetyllactosamine) shrank and, moreover, the level of detectable antibodies decreased as a result of immunization....

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

Science.gov (United States)

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

Clinically lesser known entity in India: A Report of two cases of Melioidosis.

Science.gov (United States)

Barman, Purabi; Kaur, Ravneet; Kumar, Kamlesh

2013-01-01

Melioidosis is endemic in the South Asian regions, like Thailand, Singapore Malaysia and Australia. The disease is more pronounced in the southern part of the country. It is caused by Burkholderia pseudomallei which causes systemic involvement, morbidity and mortality associated with the disease is high. Due to highly varied clinical presentation, and low general awareness this infection is largely underdiagnosed and under reported in our country. Most laboratories in the country still rely on conventional culturing methods with their low sensitivity, adding to the under reporting. To enhance physician awareness we describe here two cases who presented to our institute after months of misdiagnosis.

CHLORINE INACTIVATION OF CATEGORY "A" BIO-TERRORISM AGENTS

Science.gov (United States)

This poster presents information on the inactivation of select bioterrorist agents. Information will be presented on chlorine disinfection of vegetative cells of Brucella suis, Brucella melitensis, Burkholderia mallei, Burkholderia pseudomallei, Francisella tularensis and endos...

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.

Development of a Threat Assessment Framework Applicable to Dual Use Biotechnology: Results of a Study to Determine the Feasibility, Applicability and Potential Design of a Threat Assessment Framework Concept

Science.gov (United States)

2007-04-01

Escherichia coli, pathogenic Vibrio spp., Shigella spp., Salmonella spp., Listeria monocytogenes, Campylobacter jejuni and Yersinia enterocolitica...Marburg virus V12. Monkey pox virus V13. Rift Valley fever virus V14. Tick-borne...Burkholderia pseudomallei (Pseudomonas pseudomallei) B10. Salmonella typhi B11. Shigella dysenteriae B12

Pediatric melioidosis in Sarawak, Malaysia: Epidemiological, clinical and microbiological characteristics.

Directory of Open Access Journals (Sweden)

Anand Mohan

2017-06-01

Full Text Available Melioidosis is a serious, and potentially fatal community-acquired infection endemic to northern Australia and Southeast Asia, including Sarawak, Malaysia. The disease, caused by the usually intrinsically aminoglycoside-resistant Burkholderia pseudomallei, most commonly affects adults with predisposing risk factors. There are limited data on pediatric melioidosis in Sarawak.A part prospective, part retrospective study of children aged <15 years with culture-confirmed melioidosis was conducted in the 3 major public hospitals in Central Sarawak between 2009 and 2014. We examined epidemiological, clinical and microbiological characteristics.Forty-two patients were recruited during the 6-year study period. The overall annual incidence was estimated to be 4.1 per 100,000 children <15 years, with marked variation between districts. No children had pre-existing medical conditions. Twenty-three (55% had disseminated disease, 10 (43% of whom died. The commonest site of infection was the lungs, which occurred in 21 (50% children. Other important sites of infection included lymph nodes, spleen, joints and lacrimal glands. Seven (17% children had bacteremia with no overt focus of infection. Delays in diagnosis and in melioidosis-appropriate antibiotic treatment were observed in nearly 90% of children. Of the clinical isolates tested, 35/36 (97% were susceptible to gentamicin. Of these, all 11 isolates that were genotyped were of a single multi-locus sequence type, ST881, and possessed the putative B. pseudomallei virulence determinants bimABp, fhaB3, and the YLF gene cluster.Central Sarawak has a very high incidence of pediatric melioidosis, caused predominantly by gentamicin-susceptible B. pseudomallei strains. Children frequently presented with disseminated disease and had an alarmingly high death rate, despite the absence of any apparent predisposing risk factor.

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.

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.

ORF Alignment: NC_006351 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... [Burkholderia pseudomallei K96243] ... Length = 171 ... Query: 20 ... KSVLRSAHTSTGRAESTAEHSWRLCLMA...ITLADELPGLDMLKVLKMCVIHDLGEALRGDV 79 ... KSVLRSAHTSTGRAESTAEHSWRLCLMAITLADE...LPGLDMLKVLKMCVIHDLGEALRGDV Sbjct: 15 ... KSVLRSAHTSTGRAESTAEHSWRLCLMAITLADELPGLDMLKVLKMCVIHDLGEALRGDV 74 ... Query

ORF Alignment: NC_006349 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... [Burkholderia pseudomallei K96243] ... Length = 171 ... Query: 58 ... KSVLRSAHTSTGRAESTAEHSWRLCLMA...ITLADELPGLDMLKVLKMCVIHDLGEALRGDV 117 ... KSVLRSAHTSTGRAESTAEHSWRLCLMAITLAD...ELPGLDMLKVLKMCVIHDLGEALRGDV Sbjct: 15 ... KSVLRSAHTSTGRAESTAEHSWRLCLMAITLADELPGLDMLKVLKMCVIHDLGEALRGDV 74 ... Quer

Pseudomona pseudomallei community acquired pneumonia

International Nuclear Information System (INIS)

Severiche, Diego

1998-01-01

This is the first published case report en Colombia about pseudomona pseudomallei community acquired pneumonia. This uncommon pathogen is from the epidemiological standpoint a very important one and medical community should be aware to look after it in those patients where no other etiological pathogen is recovered. A brief summary about epidemiology is showed, emphasizing those regions where it can be found. Likewise, comments about the differential diagnosis are important since it should be considered in those patients where tuberculosis is suspected. This is particularly representative for countries with high tuberculosis rates. Furthermore, a microbiological review is shown, emphasizing on isolation techniques, descriptions about therapeutics and other regarding treatment issues according international standards. Finally; a description about the clinical picture, laboratory findings, treatment and evolution of the case reported are shown for discussion

Expression and function of macrophage migration inhibitory factor (MIF in melioidosis.

Directory of Open Access Journals (Sweden)

W Joost Wiersinga

2010-02-01

Full Text Available Macrophage migration inhibitory factor (MIF has emerged as a pivotal mediator of innate immunity and has been shown to be an important effector molecule in severe sepsis. Melioidosis, caused by Burkholderia pseudomallei, is an important cause of community-acquired sepsis in Southeast-Asia. We aimed to characterize the expression and function of MIF in melioidosis.MIF expression was determined in leukocytes and plasma from 34 melioidosis patients and 32 controls, and in mice infected with B. pseudomallei. MIF function was investigated in experimental murine melioidosis using anti-MIF antibodies and recombinant MIF. Patients demonstrated markedly increased MIF mRNA leukocyte and MIF plasma concentrations. Elevated MIF concentrations were associated with mortality. Mice inoculated intranasally with B. pseudomallei displayed a robust increase in pulmonary and systemic MIF expression. Anti-MIF treated mice showed lower bacterial loads in their lungs upon infection with a low inoculum. Conversely, mice treated with recombinant MIF displayed a modestly impaired clearance of B. pseudomallei. MIF exerted no direct effects on bacterial outgrowth or phagocytosis of B. pseudomallei.MIF concentrations are markedly elevated during clinical melioidosis and correlate with patients' outcomes. In experimental melioidosis MIF impaired antibacterial defense.

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.

A Case of Constrictive Pericarditis Associated with Melioidosis in an Immunocompetent Patient Treated by Pericardiectomy

Science.gov (United States)

Lu, Hou Tee; Ramsamy, Gunasekaran; Lee, Chuey Yan; Syed Hamid, Syed Rasul G.; Kan, Foong Kee; Nordin, Rusli Bin

2018-01-01

Patient: Male, 38 Final Diagnosis: Constrictive pericarditis Symptoms: Shortness of breath Medication: — Clinical Procedure: Pericardiocentesis • pericardiectomy Specialty: Cardiology Objective: Unusual clinical course Background: Melioidosis is a rare tropical bacterial infection caused by the Gram-negative soil saprophyte, Burkholderia pseudomallei. Melioidosis can mimic a variety of diseases due to its varied presentation, and unless it is treated rapidly, it can be fatal. A rare case of melioidosis, with pericarditis and pericardial effusion, is described, which demonstrates the value of early diagnosis with echocardiography and pericardiocentesis. Case Report: A 38-year-old native (Iban) East Malaysian man presented with shortness of breath and tachycardia. Transthoracic echocardiography (TTE) showed cardiac tamponade. Urgent pericardiocentesis drained a large amount of purulent pericardial fluid that grew Burkholderia pseudomallei. Despite appropriate dose and duration of intravenous treatment with ceftazidime followed by meropenem, the patient developed recurrent pericardial effusion and right heart failure due to constrictive pericarditis. The diagnosis of constrictive pericarditis was confirmed by computed tomography (CT) and surgical exploration. Following pericardiectomy, his symptoms resolved, but patient follow-up was recommended for possible sequelae of constrictive pericarditis. Conclusions: After the onset of melioidosis pericarditis, the authors recommend follow-up and surveillance for possible complication of constrictive pericarditis. PMID:29551765

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.

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...

Melioidosis Presenting with Isolated Splenic Abscesses: A Case Report

Directory of Open Access Journals (Sweden)

Chun-Yu Lin

2007-08-01

Full Text Available Splenic abscesses caused by Burkholderia pseudomallei are rarely reported in Taiwan. Here we report a middle-aged man who presented with fever, chills, and general malaise for several days. Abdominal echo revealed isolated splenic abscesses and he received antibiotics treatment according to the initial blood culture result, Serratia marcescens. However, fever did not subside. Then he was referred to our hospital and meropenem was prescribed. Fever subsided 5 days after the beginning of meropenem administration. Repeated fine-needle aspiration of splenic abscesses drained out the pus, which was cultured as B. pseudomallei. He was finally diagnosed as a case of melioidosis based on microbiological evidence. Physicians must take melioidosis into consideration when splenic abscesses are encountered clinically.

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

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.

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.

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...

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/.

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

Two fatal cases of melioidosis on the Thai-Myanmar border [v1; ref status: indexed, http://f1000r.es/2os

Directory of Open Access Journals (Sweden)

Cindy S. Chu

2014-01-01

Full Text Available Melioidosis is endemic in areas of Southeast Asia, however, there are no published reports from the Thai-Myanmar border.  We report the first two cases of fatal melioidosis in this region. This is of great public health importance and highlights the need to increase clinical awareness of melioidosis on the Thai-Myanmar border and to assess the true burden of disease in the area through improved case detection and Burkholderia pseudomallei prevalence studies.

Two fatal cases of melioidosis on the Thai-Myanmar border [v2; ref status: indexed, http://f1000r.es/373

Directory of Open Access Journals (Sweden)

Cindy S. Chu

2014-03-01

Full Text Available Melioidosis is endemic in areas of Southeast Asia, however, there are no published reports from the Thai-Myanmar border. We report the first two documented cases of fatal melioidosis in this region. This is of great public health importance and highlights the need to both increase clinical awareness of melioidosis on the Thai-Myanmar border, and to assess the true burden of disease in the area through improved case detection and Burkholderia pseudomallei prevalence studies.

Development of a prototype lateral flow immunoassay (LFI for the rapid diagnosis of melioidosis.

Directory of Open Access Journals (Sweden)

Raymond L Houghton

2014-03-01

Full Text Available Burkholderia pseudomallei is a soil-dwelling bacterium and the causative agent of melioidosis. Isolation of B. pseudomallei from clinical samples is the "gold standard" for the diagnosis of melioidosis; results can take 3-7 days to produce. Alternatively, antibody-based tests have low specificity due to a high percentage of seropositive individuals in endemic areas. There is a clear need to develop a rapid point-of-care antigen detection assay for the diagnosis of melioidosis. Previously, we employed In vivo Microbial Antigen Discovery (InMAD to identify potential B. pseudomallei diagnostic biomarkers. The B. pseudomallei capsular polysaccharide (CPS and numerous protein antigens were identified as potential candidates. Here, we describe the development of a diagnostic immunoassay based on the detection of CPS. Following production of a CPS-specific monoclonal antibody (mAb, an antigen-capture immunoassay was developed to determine the concentration of CPS within a panel of melioidosis patient serum and urine samples. The same mAb was used to produce a prototype Active Melioidosis Detect Lateral Flow Immunoassay (AMD LFI; the limit of detection of the LFI for CPS is comparable to the antigen-capture immunoassay (∼0.2 ng/ml. The analytical reactivity (inclusivity of the AMD LFI was 98.7% (76/77 when tested against a large panel of B. pseudomallei isolates. Analytical specificity (cross-reactivity testing determined that 97.2% of B. pseudomallei near neighbor species (35/36 were not reactive. The non-reactive B. pseudomallei strain and the reactive near neighbor strain can be explained through genetic sequence analysis. Importantly, we show the AMD LFI is capable of detecting CPS in a variety of patient samples. The LFI is currently being evaluated in Thailand and Australia; the focus is to optimize and validate testing procedures on melioidosis patient samples prior to initiation of a large, multisite pre-clinical evaluation.

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...

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

regulation of these components can help us understand both the evolution of these systems and the potential roles these pathways have in the biology of each bacterium. Here, we describe the transcriptome response of Burkholderia thailandensis to the eukaryote-enriched molecule choline, identify the regulatory pathway governing choline catabolism, and compare the pathway to that previously described for Pseudomonas aeruginosa These data support a multitiered regulatory network in B. thailandensis, with conserved orthologs in the select agents Burkholderia pseudomallei and Burkholderia mallei, as well as the opportunistic lung pathogens in the Burkholderia cepacia clade. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

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

VX

Science.gov (United States)

... Marburg virus hemorrhagic fever Melioidosis ( Burkholderia pseudomallei ) Plague ( Yersinia pestis ) FAQ About Plague (as a bioweapon) Facts About ... Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo]) Yersinia pestis (plague) Fact Sheets Case Definitions Training Surveillance Preparation & ...

Abrin

Science.gov (United States)

... Marburg virus hemorrhagic fever Melioidosis ( Burkholderia pseudomallei ) Plague ( Yersinia pestis ) FAQ About Plague (as a bioweapon) Facts About ... Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo]) Yersinia pestis (plague) Fact Sheets Case Definitions Training Surveillance Preparation & ...

Arsine

Science.gov (United States)

... Marburg virus hemorrhagic fever Melioidosis ( Burkholderia pseudomallei ) Plague ( Yersinia pestis ) FAQ About Plague (as a bioweapon) Facts About ... Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo]) Yersinia pestis (plague) Fact Sheets Case Definitions Training Surveillance Preparation & ...

Soman

Science.gov (United States)

... Marburg virus hemorrhagic fever Melioidosis ( Burkholderia pseudomallei ) Plague ( Yersinia pestis ) FAQ About Plague (as a bioweapon) Facts About ... Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo]) Yersinia pestis (plague) Fact Sheets Case Definitions Training Surveillance Preparation & ...

Tabun

Science.gov (United States)

... Marburg virus hemorrhagic fever Melioidosis ( Burkholderia pseudomallei ) Plague ( Yersinia pestis ) FAQ About Plague (as a bioweapon) Facts About ... Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo]) Yersinia pestis (plague) Fact Sheets Case Definitions Training Surveillance Preparation & ...

Ricin

Science.gov (United States)

... Marburg virus hemorrhagic fever Melioidosis ( Burkholderia pseudomallei ) Plague ( Yersinia pestis ) FAQ About Plague (as a bioweapon) Facts About ... Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo]) Yersinia pestis (plague) Fact Sheets Case Definitions Training Surveillance Preparation & ...

Lewisite

Science.gov (United States)

... Marburg virus hemorrhagic fever Melioidosis ( Burkholderia pseudomallei ) Plague ( Yersinia pestis ) FAQ About Plague (as a bioweapon) Facts About ... Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo]) Yersinia pestis (plague) Fact Sheets Case Definitions Training Surveillance Preparation & ...

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.

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.

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...

Establishment of a novel whole animal HTS technology platform for melioidosis drug discovery.

Science.gov (United States)

Lakshmanan, Umayal; Yap, Amelia; Fulwood, Justina; Yichun, Li; Hoon, Sim Siew; Lim, Jolander; Ting, Audrey; Sem, Xiao Hui; Kreisberg, Jason F; Tan, Patrick; Tan, Gladys; Flotow, Horst

2014-01-01

Melioidosis is a serious emerging endemic infectious disease caused by Burkholderia pseudomallei, a gram-negative pathogen. Septicemic melioidosis has a mortality rate of 50% even with treatment. Like other gram-negative bacteria, B. pseudomallei is resistant to a number of antibiotics and multi-drug resistant B. pseudomallei is beginning to be encountered in hospitals. There is a clear medical need to develop new treatment options to manage this disease. We used Burkholderia thailandensis (a BSL-2 class organism) to infect Caenorhabditis elegans and set up a surrogate whole animal infection model of melioidosis that we could run in a 384 microtitre plate and establish a whole animal HTS assay. We have optimized and validated this assay in a fluorescence-based format that can be run on our automated screening platforms. This assay has now been used to screen over 300,000 compounds from our small molecule library and we are in the process of characterizing the hits obtained and select compounds for further studies. We have thus established a biologically relevant assay technology platform to screen for antibacterial compounds and used this platform to identify new compounds that may find application in treating melioidosis infections.

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

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.

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

Transverse myelitis secondary to Melioidosis; A case report

Directory of Open Access Journals (Sweden)

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

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.

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...

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.

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

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

Liver Abscess Caused by Tuberculosis and Melioidosis

OpenAIRE

Azali, Hafiz Yafee Amar; Norly, Salleh; Wong, Leh Meng; Tan, Kia Sin; Safian, Naim Muhammad

2007-01-01

We report an unusual co-existence of Burkholderia pseudomallei and acid fast bacilli in a young Malay gentleman with liver abscess. He was treated with antibiotics and surgical drainage. This phenomenon has not been reported in previous literature and the dilemma of its management is discussed.

Liver abscess caused by tuberculosis and melioidosis.

Science.gov (United States)

Azali, Hafiz Yafee Amar; Norly, Salleh; Wong, Leh Meng; Tan, Kia Sin; Safian, Naim Muhammad

2007-04-01

We report an unusual co-existence of Burkholderia pseudomallei and acid fast bacilli in a young Malay gentleman with liver abscess. He was treated with antibiotics and surgical drainage. This phenomenon has not been reported in previous literature and the dilemma of its management is discussed.

Using BOX-PCR to exclude a clonal outbreak of melioidosis

Directory of Open Access Journals (Sweden)

Ward Linda

2007-06-01

Full Text Available Abstract Background Although melioidosis in endemic regions is usually caused by a diverse range of Burkholderia pseudomallei strains, clonal outbreaks from contaminated potable water have been described. Furthermore B. pseudomallei is classified as a CDC Group B bioterrorism agent. Ribotyping, pulsed-field gel electrophoresis (PFGE and multilocus sequence typing (MLST have been used to identify genetically related B. pseudomallei isolates, but they are time consuming and technically challenging for many laboratories. Methods We have adapted repetitive sequence typing using a BOX A1R primer for typing B. pseudomallei and compared BOX-PCR fingerprinting results on a wide range of well-characterized B. pseudomallei isolates with MLST and PFGE performed on the same isolates. Results BOX-PCR typing compared favourably with MLST and PFGE performed on the same isolates, both discriminating between the majority of multilocus sequence types and showing relatedness between epidemiologically linked isolates from various outbreak clusters. Conclusion Our results suggest that BOX-PCR can be used to exclude a clonal outbreak of melioidosis within 10 hours of receiving the bacterial strains.

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.

Liver Abscess Caused by Tuberculosis and Melioidosis

Directory of Open Access Journals (Sweden)

Hafiz Yafee Amar Azali

2007-04-01

Full Text Available We report an unusual co-existence of Burkholderia pseudomallei and acid fast bacilli in a young Malay gentleman with liver abscess. He was treated with antibiotics and surgical drainage. This phenomenon has not been reported in previous literature and the dilemma of its management is discussed.

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...

The potential of TaqMan Array Cards for detection of multiple biological agents by real-time PCR.

Directory of Open Access Journals (Sweden)

Phillip A Rachwal

Full Text Available The TaqMan Array Card architecture, normally used for gene expression studies, was evaluated for its potential to detect multiple bacterial agents by real-time PCR. Ten PCR assays targeting five biological agents (Bacillus anthracis, Burkholderia mallei, Burkholderia pseudomallei, Francisella tularensis, and Yersinia pestis were incorporated onto Array Cards. A comparison of PCR performance of each PCR in Array Card and singleplex format was conducted using DNA extracted from pure bacterial cultures. When 100 fg of agent DNA was added to Array Card channels the following levels of agent detection (where at least one agent PCR replicate returned a positive result were observed: Y. pestis 100%, B. mallei & F. tularensis 93%; B. anthracis 71%; B. pseudomallei 43%. For B. mallei & pseudomallei detection the BPM2 PCR, which detects both species, outperformed PCR assays specific to each organism indicating identification of the respective species would not be reproducible at the 100 fg level. Near 100% levels of detection were observed when 100 fg of DNA was added to each PCR in singleplex format with singleplex PCRs also returning sporadic positives at the 10 fg per PCR level. Before evaluating the use of Array Cards for the testing of environmental and clinical sample types, with potential levels of background DNA and PCR inhibitors, users would therefore have to accept a 10-fold reduction in sensitivity of PCR assays on the Array Card format, in order to benefit for the capacity to test multiple samples for multiple agents. A two PCR per agent strategy would allow the testing of 7 samples for the presence of 11 biological agents or 3 samples for 23 biological agents per card (with negative control channels.

Download this PDF file

African Journals Online (AJOL)

hanumantp

Melioidosis is a zoonotic disease caused by an accidental pathogen Burkholderia pseudomallei. The organism is endemic in Southeast Asia and northern Australia. The mortality of melioidosis is 20-50% even with treatment.[1] Melioidosis has been called the “Great Imitator” because the disease does not show any specific ...

GIPSy

DEFF Research Database (Denmark)

Soares, Siomar C; Geyik, Hakan; Ramos, Rommel T J

2016-01-01

in Escherichia coli CFT073; 1 MI for Burkholderia pseudomallei K96243, which seems to be a miscellaneous island; 1 RI of Acinetobacter baumannii AYE, named AbaR1; and, 1 SI of Mesorhizobium loti MAFF303099 presenting a mosaic structure. GIPSy is the first life-style-specific genomic island prediction software...

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

Exploring the HME and HAE1 efflux systems in the genus Burkholderia

Directory of Open Access Journals (Sweden)

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

Severe coinfection of melioidosis and dengue fever in northeastern Brazil: first case report

Directory of Open Access Journals (Sweden)

Rafael Nogueira Macedo

2012-02-01

Full Text Available This report focuses on a fatality involving severe dengue fever and melioidosis in a 28-year-old truck driver residing in Pacoti in northeastern Brazil. He exhibited long-term respiratory symptoms (48 days and went through a wide-ranging clinical investigation at three hospitals, after initial clinical diagnoses of pneumonia, visceral leishmaniasis, tuberculosis, and fungal sepsis. After death, Burkholderia pseudomallei was isolated in a culture of ascitic fluid. Dengue virus type 1 was detected by polymerase chain reaction in cerebrospinal fluid (CSF; this infection was the cause of death. This description reinforces the need to consider melioidosis among the reported differential diagnoses of community-acquired infections where both melioidosis and dengue fever are endemic.

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

Science.gov (United States)

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.

Tracing melioidosis back to the source: using whole-genome sequencing to investigate an outbreak originating from a contaminated domestic water supply.

Science.gov (United States)

McRobb, Evan; Sarovich, Derek S; Price, Erin P; Kaestli, Mirjam; Mayo, Mark; Keim, Paul; Currie, Bart J

2015-04-01

Melioidosis, a disease of public health importance in Southeast Asia and northern Australia, is caused by the Gram-negative soil bacillus Burkholderia pseudomallei. Melioidosis is typically acquired through environmental exposure, and case clusters are rare, even in regions where the disease is endemic. B. pseudomallei is classed as a tier 1 select agent by the Centers for Disease Control and Prevention; from a biodefense perspective, source attribution is vital in an outbreak scenario to rule out a deliberate release. Two cases of melioidosis within a 3-month period at a residence in rural northern Australia prompted an investigation to determine the source of exposure. B. pseudomallei isolates from the property's groundwater supply matched the multilocus sequence type of the clinical isolates. Whole-genome sequencing confirmed the water supply as the probable source of infection in both cases, with the clinical isolates differing from the likely infecting environmental strain by just one single nucleotide polymorphism (SNP) each. For the first time, we report a phylogenetic analysis of genomewide insertion/deletion (indel) data, an approach conventionally viewed as problematic due to high mutation rates and homoplasy. Our whole-genome indel analysis was concordant with the SNP phylogeny, and these two combined data sets provided greater resolution and a better fit with our epidemiological chronology of events. Collectively, this investigation represents a highly accurate account of source attribution in a melioidosis outbreak and gives further insight into a frequently overlooked reservoir of B. pseudomallei. Our methods and findings have important implications for outbreak source tracing of this bacterium and other highly recombinogenic pathogens. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

MALDI-TOF MS contribution to diagnosis of melioidosis in a nonendemic country in three French travellers

Directory of Open Access Journals (Sweden)

V. Walewski

2016-07-01

Full Text Available Melioidosis is an endemic disease in Southeast Asia and northern Australia. An increasing number of cases are being reported in nonendemic countries, making the diagnosis less obvious. We discuss the identification of Burkholderia pseudomallei using matrix-assisted desorption ionization–time of flight mass spectrometry on the occasion of recent cases of imported melioidosis in French travellers.

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)).

A Report from the Cambodia Training Event for Awareness of Melioidosis (C-TEAM, October 2017

Directory of Open Access Journals (Sweden)

Sotharith Bory

2018-02-01

Full Text Available Melioidosis is an endemic infection in Cambodia, a lower middle income SE Asian country. Despite more laboratories isolating and identifying Burkholderia pseudomallei in recent years, the infection remains under-recognised and under-diagnosed, particularly in the adult population. Lack of knowledge about the disease and lack of utilization of microbiology laboratories contributes to this, along with laboratory capacity issues. Treatment costs often hamper optimal management. In response to these issues, a national one-health training event was held in October 2017 to raise awareness of the disease amongst clinical, laboratory, and public health professionals. The meeting format, findings, and outcomes are described here.

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

Science.gov (United States)

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.

Pediatric suppurative parotitis in Cambodia between 2007 and 2011.

Science.gov (United States)

Stoesser, Nicole; Pocock, Joanna; Moore, Catrin E; Soeng, Sona; Chhat, Hor P; Sar, Poda; Limmathurotsakul, Direk; Day, Nicholas; Thy, Vann; Sar, Vuthy; Parry, Christopher M

2012-08-01

The causes of suppurative parotitis in Cambodian children are not known. We describe 39 cases at the Angkor Hospital for Children, Siem Reap, between January 2007 and July 2011 (0.07/1000 hospital attendances). The median age was 5.7 years with no neonates affected. Burkholderia pseudomallei was cultured in 29 (74%) cases. No deaths occurred; 1 child developed facial nerve palsy.

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

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

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.

Fatal Septicemic Melioidosis in a Young Military Person Possibly Co-Infected With Leptospira Interrogans and Orientia Tsutsugamushi

Directory of Open Access Journals (Sweden)

Po-Liang Lu

2005-04-01

Full Text Available Concurrent melioidosis, leptospirosis, and scrub typhus after rural activities is rarely reported. A 19-year-old previously healthy man had fever onset after 2 weeks of military training. Pneumonia became evident on the fifth day of fever under intravenous penicillin and oral minocycline therapy. Acute respiratory failure developed the next day with shock and acute renal and liver function deterioration, which resulted in death. Blood cultures on the third and fifth days grew Burkholderia pseudomallei. Serology revealed leptospirosis and scrub typhus. The emergence of melioidosis in Taiwan and this death without antibiotic treatment for melioidosis alert us that B. pseudomallei should be included as a possible pathogen of pneumonia and sepsis, especially after rural activities.

Pulmonary melioidosis presenting with pleural effusion: A case report and review of literature

Directory of Open Access Journals (Sweden)

Chun Ian Soo

2015-01-01

Full Text Available Melioidosis is a serious infection, which can involve multiple systems. We report a case of pulmonary melioidosis with the initial presentation mimicking a partially treated pneumonia complicated by right-sided pleural effusion. The patient is a 49-year old man who did not respond to parenteral ceftriaxone and tazobactam/piperacillin therapy. However, upon culture and sensitivity results from blood and pleural samples isolated Burkholderia pseudomallei; antimicrobial therapy was de-escalated to parenteral ceftazidime. Within 72 h duration, his fever subsided and other respiratory symptoms improved tremendously. This case highlights the importance of early recognition of B. pseudomallei in pulmonary infection in order for prompt institution of appropriate antibiotics treatment; thus reducing morbidity and mortality.

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

Imported melioidosis in Japan: a review of cases

Directory of Open Access Journals (Sweden)

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 

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.

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

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.

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.

Development of capsular polysaccharide-based glycoconjugates for immunization against melioidosis and glanders

Directory of Open Access Journals (Sweden)

Mary N Burtnick

2012-08-01

Full Text Available Burkholderia pseudomallei and Burkholderia mallei, the etiologic agents of melioidosis and glanders respectively, cause severe disease in humans and animals and are considered potential agents of biological warfare and terrorism. Diagnosis and treatment of infections caused by these pathogens can be challenging and, in the absence of chemotherapeutic intervention, acute disease is frequently fatal. At present, there are no human or veterinary vaccines available for immunization against these emerging/re-emerging infectious diseases. One of the long term objectives of our research, therefore, is to identify and characterize protective antigens expressed by B. pseudomallei and B. mallei and use them to develop efficacious vaccine candidates. Previous studies have demonstrated that the 6-deoxy-heptan capsular polysaccharide (CPS expressed by these bacterial pathogens is both a virulence determinant and a protective antigen. Consequently, this carbohydrate moiety has become an important component of the various subunit vaccines that we are currently developing in our laboratory. In the present study, we describe a reliable method for isolating CPS antigens from O-polysaccharide deficient strains of B. pseudomallei; including a derivative of the select agent excluded strain Bp82. Utilizing these purified CPS samples, we also describe a simple procedure for covalently linking these T-cell independent antigens to carrier proteins. In addition, we demonstrate that high titer IgG responses can be raised against the CPS component of such constructs. Collectively, these approaches provide a tangible starting point for the development of novel CPS-based glycoconjugates for immunization against melioidosis and glanders.

The use of nanoscale visible light-responsive photocatalyst TiO2-Pt for the elimination of soil-borne pathogens.

Directory of Open Access Journals (Sweden)

Ya-Lei Chen

Full Text Available Exposure to the soil-borne pathogens Burkholderia pseudomallei and Burkholderia cenocepacia can lead to severe infections and even mortality. These pathogens exhibit a high resistance to antibiotic treatments. In addition, no licensed vaccine is currently available. A nanoscale platinum-containing titania photocatalyst (TiO(2-Pt has been shown to have a superior visible light-responsive photocatalytic ability to degrade chemical contaminants like nitrogen oxides. The antibacterial activity of the catalyst and its potential use in soil pathogen control were evaluated. Using the plating method, we found that TiO(2-Pt exerts superior antibacterial performance against Escherichia coli compared to other commercially available and laboratory prepared ultraviolet/visible light-responsive titania photocatalysts. TiO(2-Pt-mediated photocatalysis also affectively eliminates the soil-borne bacteria B. pseudomallei and B. cenocepacia. An air pouch infection mouse model further revealed that TiO(2-Pt-mediated photocatalysis could reduce the pathogenicity of both strains of bacteria. Unexpectedly, water containing up to 10% w/v dissolved soil particles did not reduce the antibacterial potency of TiO(2-Pt, suggesting that the TiO(2-Pt photocatalyst is suitable for use in soil-contaminated environments. The TiO(2-Pt photocatalyst exerted superior antibacterial activity against a broad spectrum of human pathogens, including B. pseudomallei and B. cenocepacia. Soil particles (<10% w/v did not significantly reduce the antibacterial activity of TiO(2-Pt in water. These findings suggest that the TiO(2-Pt photocatalyst may have potential applications in the development of bactericides for soil-borne pathogens.

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.

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 ...

Prevalence and distribution of soil-borne zoonotic pathogens in Lahore district of Pakistan

OpenAIRE

Shabbir, Muhammad Z.; Jamil, Tariq; Ali, Asad A.; Ahmad, Arfan; Naeem, Muhammad; Chaudhary, Muhammad H.; Bilal, Muhammad; Ali, Muhammad A.; Muhammad, Khushi; Yaqub, Tahir; Bano, Asghari; Mirza, Ali I.; Shabbir, Muhammad A. B.; McVey, Walter R.; Patel, Ketan

2015-01-01

A multidisciplinary, collaborative project was conducted to determine the prevalence and distribution of soil-borne zoonotic pathogens in Lahore district of Pakistan and ascertain its Public Health Significance. Using a grid-based sampling strategy, soil samples (n = 145) were collected from villages (n = 29, 5 samples/village) and examined for Bacillus anthracis, Burkholderia mallei/pseudomallei, Coxiella burnetii, Francisella tularensis, and Yersinia pestis using real time PCR assays. Chemi...

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)

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

Directory of Open Access Journals (Sweden)

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.

Comparison of in-house IgM and IgG ELISAs for the serodiagnosis of melioidosis in Malaysia.

Science.gov (United States)

Hii, Shirley Yi Fen; Ali, Noor Azila; Ahmad, Norazah; Amran, Fairuz

2017-11-01

Melioidosis is an endemic infectious disease in Southeast Asia and northern Australia, caused by Burkholderia pseudomallei. However, the incidence rate in Malaysia is not well documented. The high mortality rate and broad range of clinical presentations require rapid and accurate diagnosis for appropriate treatment. This study compared the efficacy of in-house IgM and IgG ELISA methods using a local B. pseudomallei strain. The diagnostic accuracy of the in-house IgG ELISA was better than that of the IgM ELISA: sensitivity (IgG: 84.71 %, IgM: 76.14 %) and specificity (IgG: 93.64 %, IgM: 90.17 %); positive predictive value (IgG: 86.75 %, IgM: 79.76 %) and negative predictive value (IgG: 92.57 %, IgM: 89.66 %); likelihood ratio (LR) [IgG: 13.32, IgM: 7.75 (LR+); IgG: 0.16, IgM: 0.26 (LR-)], and was supported by the observation of the absorbance value in comparisons between culture and serology sampling. In-house IgG ELISA was shown to be useful as an early diagnostic tool for melioidosis.

Environmental management procedures following fatal melioidosis in a captive chimpanzee (Pan troglodytes).

Science.gov (United States)

Sommanustweechai, Angkana; Kasantikul, Tanit; Somsa, Wachirawit; Wongratanacheewin, Surasakdi; Sermswan, Rasana W; Kongmakee, Piyaporn; Thomas, Warissara; Kamolnorranath, Sumate; Siriaroonrat, Boripat; Bush, Mitchell; Banlunara, Wijit

2013-06-01

A 40-yr-old male captive chimpanzee (Pan troglodytes) presented with depression and anorexia for 7 days. The tentative diagnosis, following a physical examination under anesthesia, was pneumonia with sepsis. Despite antibiotic treatment and supportive care the chimpanzee died a week following presentation. Gross pathology confirmed severe purulent pneumonia and diffuse hepatosplenic abscesses. Detected in serum at the time of the initial examination, the melioidosis serum antibody titer was elevated (> 1:512). Soil samples were collected from three sites in the exhibit at three depths of 5, 15, and 30 cm. By direct and enrichment culture, positive cultures for Burkholderia pseudomallei were found at 5 and 15 cm in one site. The other two sites were positive by enrichment culture at the depth of 5 cm. To prevent disease in the remaining seven troop members, they were relocated to permit a soil treatment with calcium oxide. The exhibit remained empty for approximately 1 yr before the chimpanzees were returned. During that period, the soil in the exhibit area was again cultured as before and all samples were negative for B. pseudomallei. Following the soil treatment in the exhibit, all chimpanzees have remained free of clinical signs consistent with melioidosis.

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.

Peritoneal Dialysis-Related Peritonitis Due to Melioidosis: A Potentially Devastating Condition.

Science.gov (United States)

Kanjanabuch, Talerngsak; Lumlertgul, Nuttha; Pearson, Lachlan J; Chatsuwan, Tanittha; Pongpirul, Krit; Leelahavanichkul, Asada; Thongbor, Nisa; Nuntawong, Gunticha; Praderm, Laksamon; Wechagama, Pantiwa; Narenpitak, Surapong; Wechpradit, Apinya; Punya, Worauma; Halue, Guttiga; Naka, Phetpailin; Jeenapongsa, Somboon; Eiam-Ong, Somchai

2017-01-01

♦ BACKGROUND: Melioidosis, an infectious disease caused by Burkholderia pseudomallei , is endemic in Southeast Asia and Northern Australia. Although a wide range of clinical manifestations from this organism are known, peritonitis associated with peritoneal dialysis (PD) has rarely been reported. ♦ PATIENTS AND METHODS: Peritoneal dialysis patients from all regions in Thailand were eligible for the study if they had peritonitis and either peritoneal fluid or effluent culture positive for B. pseudomallei . Patient data obtained included baseline characteristics, laboratory investigations, treatments, and clinical outcomes. When possible, PD fluid and removed Tenckhoff (TK) catheters were submitted for analyses of minimal inhibitory concentration (MIC) and microbial biofilm, respectively. ♦ RESULTS: Twenty-six patients were identified who were positive for peritoneal B. pseudomallei infection. The recorded mean age was 50 ± 15 (24 - 75) years, and the majority (58%) were female. Most of the cases were farmers living in Northeastern and Northern Thailand. Almost half of the cases had diabetes. Infections were reported commonly during the monsoon season and winter. The clinical presentations of peritonitis were similar to the manifestations from other microorganisms. Nine patients (41%) died (7 from sepsis), 6 fully recovered, and 7 switched to permanent hemodialysis. The mortality was potentially associated with sepsis ( p = 0.007), infection during the monsoon season ( p = 0.017), high initial dialysate neutrophils ( p = 0.045), and high hematocrit ( p = 0.045). Although no antibiotic resistance to ceftazidime and carbapenems was detected, approximately 50% of patients died with this treatment. Microbial biofilms were identified on the luminal surface of 4 out of 5 TK catheters, but the removal of the catheter did not alter the outcomes. ♦ CONCLUSION: Peritoneal dialysis-related peritonitis due to melioidosis is uncommon but highly fatal. Increased awareness

Sinonasal Melioidosis in a Returned Traveller Presenting with Nasal Cellulitis and Sinusitis

Directory of Open Access Journals (Sweden)

Rebecca Sin Mei Lim

2013-01-01

Full Text Available We illustrate a case involving a 51-year-old man who presented to a tertiary hospital with sepsis secondary to an abscess of the nasal vestibule and pustular eruptions of the nasal mucosa. Associated cellulitis extended across the face to the eye, and mucosal thickening of the sinuses was seen on computed tomography. The patient underwent incision and drainage and endoscopic sinus surgery. Blood cultures and swabs were positive for a gram-negative bacillus, Burkholderia pseudomallei. He had multiple risk factors including travel to an endemic area. The patient received extended antibiotic therapy in keeping with published national guidelines. Melioidosis is caused by Burkholderia pseudomallei, found in the soil in Northern Australia and Asia. It is transmitted via cutaneous or inhaled routes, leading to pneumonia, skin or soft tissue abscesses, and genitourinary infections. Risk factors include diabetes, chronic lung disease, and alcohol abuse. It can exist as a latent, active, or reactivated infection. A high mortality rate has been identified in patients with sepsis. Melioidosis is endemic in tropical Northern Australia and northeastern Thailand where it is the most common cause of severe community-acquired sepsis. There is one other report of melioidosis in the literature involving orbital cellulitis and sinusitis.

Melioidosis: A Rare Cause of Liver Abscess

Directory of Open Access Journals (Sweden)

Peter Franz M. San Martin

2016-01-01

Full Text Available Case Presentation. This is a case of a 44-year-old male, farmer, known to be diabetic, presenting with two-week history of vague abdominal pain associated with high grade fever. Abdominal CT scan showed localized liver abscess at segment 8 measuring 7.5 × 6.8 × 6.1 cm. Patient subsequently underwent laparoscopic ultrasound guided pigtail insertion for drainage of abscess. Culture studies showed moderate growth of Burkholderia pseudomallei in which the patient completed seven days of IV Meropenem. On follow-up after 12 weeks of oral Sulfamethoxazole/Trimethoprim, taken twice a day, the patient remained asymptomatic with no residual findings based on the abdominal ultrasound. Discussion. Diagnosis of melioidosis, a known “great masquerader,” relies heavily on culture studies. Consensus with regard to the management of liver abscess caused by Burkholderia pseudomallei has not yet been established due to the rarity of cases. Surgical intervention through either a percutaneous or open drainage has shown good outcomes compared to IV antibiotics alone. In Philippines, the possibility of underreporting is highly plausible. This write-up serves not only to report a rare presentation of melioidosis but also to add to the number of cases reported in the country, possibly indicative of disease emergence.

Host evasion by Burkholderia cenocepacia

Directory of Open Access Journals (Sweden)

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.

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.

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.

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.

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

Biodefense-driven murine model of pneumonic melioidosis.

Science.gov (United States)

Jeddeloh, J A; Fritz, D L; Waag, D M; Hartings, J M; Andrews, G P

2003-01-01

A whole-body mouse model of pneumonic melioidosis was established for future evaluation of biodefense vaccine candidates. The aerosol 50% lethal doses of Burkholderia pseudomallei strain 1026b for BALB/c and C57BL/6 mice and the times to death, dissemination in organs, and tissue loads after exposure of the mice to low- and high-dose aerosols are reported. In addition, rpsL mutant backgrounds were attenuated in this acute model of disease.

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)

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.

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.

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.

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

Directory of Open Access Journals (Sweden)

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.

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.

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

Directory of Open Access Journals (Sweden)

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.

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...

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

Directory of Open Access Journals (Sweden)

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.

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.

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.

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

Outer Membrane Vesicle Vaccines from Biosafe Surrogates Prevent Acute Lethal Glanders in Mice

Directory of Open Access Journals (Sweden)

Michael H. Norris

2018-01-01

Full Text Available Burkholderia mallei is a host-adapted Gram-negative mammalian pathogen that causes the severe disease glanders. Glanders can manifest as a rapid acute progression or a chronic debilitating syndrome primarily affecting solipeds and humans in close association with infected animals. In USA, B. mallei is classified as one of the most important bacterial biothreat agents. Presently, there is no licensed glanders vaccine available for humans or animals. In this work, outer membrane vesicles (OMVs were isolated from three attenuated biosafe bacterial strains, Burkholderia pseudomallei Bp82, B. thailandensis E555, and B. thailandensis TxDOH and used to vaccinate mice. B. thailandensis OMVs induced significantly higher antibody responses that were investigated. B. mallei specific serum antibody responses were of higher magnitude in mice vaccinated with B. thailandensis OMVs compared to levels in mice vaccinated with B. pseudomallei OMVs. OMVs derived from biosafe strains protected mice from acute lethal glanders with vesicles from the two B. thailandensis strains affording significant protection (>90% up to 35 days post-infection with some up to 60 days. Organ loads from 35-day survivors indicated bacteria colonization of the lungs, liver, and spleen while those from 60 days had high CFUs in the spleens. The highest antibody producing vaccine (B. thailandensis E555 OMVs also protected C57BL/6 mice from acute inhalational glanders with evidence of full protection.

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.

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.

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.

Expression of Caenorhabditis elegans antimicrobial peptide NLP-31 in Escherichia coli

Science.gov (United States)

Lim, Mei-Perng; Nathan, Sheila

2014-09-01

Burkholderia pseudomallei is the causative agent of melioidosis, a fulminant disease endemic in Southeast Asia and Northern Australia. The standardized form of therapy is antibiotics treatment; however, the bacterium has become increasingly resistant to these antibiotics. This has spurred the need to search for alternative therapeutic agents. Antimicrobial peptides (AMPs) are small proteins that possess broad-spectrum antimicrobial activity. In a previous study, the nematode Caenorhabditis elegans was infected by B. pseudomallei and a whole animal transcriptome analysis identified a number of AMP-encoded genes which were induced significantly in the infected worms. One of the AMPs identified is NLP-31 and to date, there are no reports of anti-B. pseudomallei activity demonstrated by NLP-31. To produce NLP-31 protein for future studies, the gene encoding for NLP-31 was cloned into the pET32b expression vector and transformed into Escherichia coli BL21(DE3). Protein expression was induced with 1 mM IPTG for 20 hours at 20°C and recombinant NLP-31 was detected in the soluble fraction. Taken together, a simple optimized heterologous production of AMPs in an E. coli expression system has been successfully developed.

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

Incidence, risk factors and clinical epidemiology of melioidosis: a complex socio-ecological emerging infectious disease in the Alor Setar region of Kedah, Malaysia

Directory of Open Access Journals (Sweden)

Vijayalakshmi Natesan

2010-10-01

Full Text Available Abstract Background Melioidosis, a severe and fatal infectious disease caused by Burkholderia pseudomallei, is believed to an emerging global threat. However, data on the natural history, risk factors, and geographic epidemiology of the disease are still limited. Methods We undertook a retrospective analysis of 145 confirmed cases extracted from a hospital-based Melioidosis Registry set up from 2005 in Hospital Sultanah Bahiyah, Alor Setar, Kedah state, Malaysia, in order to provide a first description of the contemporary incidence, risk factors, and clinical epidemiology of the disease in this putatively high risk region of the country. Results The incidence of melioidosis in Alor Setar is remarkably high at 16.35 per 100,000 population per year. The mean age of patients was 50.40 years, with infection varying nonlinearly with age. Males (75.2%; P 2 = 30.57, P Conclusions Melioidosis represents a complex socio-ecological public health problem in Kedah, being strongly related with age, occupation, rainfall and predisposing chronic diseases, such as diabetes mellitus. Among cases, bacteremic patients were associated with significantly high mortality despite provision of the recommended antibacterial therapy. The burden of this disease is likely to grow in this region unless better informed interventions targeted at high-risk groups and associated diseases are urgently implemented.

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.

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

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.

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.

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.

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.

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.

Pulmonary melioidosis in Cambodia: A prospective study

Directory of Open Access Journals (Sweden)

Te Vantha

2011-05-01

Full Text Available Abstract Background Melioidosis is a disease caused by Burkholderia pseudomallei and considered endemic in South-East Asia but remains poorly documented in Cambodia. We report the first series of hospitalized pulmonary melioidosis cases identified in Cambodia describing clinical characteristics and outcomes. Methods We characterized cases of acute lower respiratory infections (ALRI that were identified through surveillance in two provincial hospitals. Severity was defined by systolic blood pressure, cardiac frequency, respiratory rate, oxygen saturation and body temperature. B. pseudomallei was detected in sputum or blood cultures and confirmed by API20NE gallery. We followed up these cases between 6 months and 2 years after hospital discharge to assess the cost-of-illness and long-term outcome. Results During April 2007 - January 2010, 39 ALRI cases had melioidosis, of which three aged ≤2 years; the median age was 46 years and 56.4% were males. A close contact with soil and water was identified in 30 patients (76.9%. Pneumonia was the main radiological feature (82.3%. Eleven patients were severe cases. Twenty-four (61.5% patients died including 13 who died within 61 days after discharge. Of the deceased, 23 did not receive any antibiotics effective against B. pseudomallei. Effective drugs that were available did not include ceftazidime. Mean total illness-related costs was of US$65 (range $25-$5000. Almost two-thirds (61.5% incurred debt and 28.2% sold land or other belongings to pay illness-related costs. Conclusions The observed high fatality rate is likely explained by the lack or limited access to efficient antibiotics and under-recognition of the disease among clinicians, which led to inappropriate therapy.

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.

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.

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.

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)).

Emergence of Melioidosis in Indonesia.

Science.gov (United States)

Tauran, Patricia M; Sennang, Nurhayana; Rusli, Benny; Wiersinga, W Joost; Dance, David; Arif, Mansyur; Limmathurotsakul, Direk

2015-12-01

Melioidosis is known to be highly endemic in parts of southeast Asia and northern Australia; however, cases are rarely reported in Indonesia. Here we report three cases of melioidosis in Makassar, South Sulawesi, Indonesia occurring between 2013 and 2014. Two patients died and the other was lost to follow-up. Burkholderia pseudomallei isolates from all three cases were identified by the VITEK2 Compact installed in the hospital in 2012. None of the three patients reported received antimicrobials recommended for melioidosis because of the delayed recognition of the organism. We reviewed the literature and found only seven reports of melioidosis in Indonesia. Five were reported before 1960. We suggest that melioidosis is endemic throughout Indonesia but currently under-recognized. Training on how to identify B. pseudomallei accurately and safely in all available microbiological facilities should be provided, and consideration should be given to making melioidosis a notifiable disease in Indonesia. © The American Society of Tropical Medicine and Hygiene.

Probing conformational states of glutaryl-CoA dehydrogenase by fragment screening

Energy Technology Data Exchange (ETDEWEB)

Begley, Darren W.; Davies, Douglas R.; Hartley, Robert C.; Hewitt, Stephen N.; Rychel, Amanda L.; Myler, Peter J.; Van Voorhis, Wesley C.; Staker, Bart L.; Stewart, Lance J. (Emerald)

2014-10-02

Glutaric acidemia type 1 is an inherited metabolic disorder which can cause macrocephaly, muscular rigidity, spastic paralysis and other progressive movement disorders in humans. The defects in glutaryl-CoA dehydrogenase (GCDH) associated with this disease are thought to increase holoenzyme instability and reduce cofactor binding. Here, the first structural analysis of a GCDH enzyme in the absence of the cofactor flavin adenine dinucleotide (FAD) is reported. The apo structure of GCDH from Burkholderia pseudomallei reveals a loss of secondary structure and increased disorder in the FAD-binding pocket relative to the ternary complex of the highly homologous human GCDH. After conducting a fragment-based screen, four small molecules were identified which bind to GCDH from B. pseudomallei. Complex structures were determined for these fragments, which cause backbone and side-chain perturbations to key active-site residues. Structural insights from this investigation highlight differences from apo GCDH and the utility of small-molecular fragments as chemical probes for capturing alternative conformational states of preformed protein crystals.

Dicty_cDB: Contig-U04002-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available 529_3951( CP000529 |pid:none) Polaromonas naphthalenivorans C... 39 0.15 AE009952_2826( AE009952 |pid:none) Yersinia pes.........done Score E Sequences producing significant alignments: (bits) Value N ( AU061399 ) Dictyostelium disc............done Score E Sequences producing significant alignments: (bits) Value EU937995_1( EU937995 |pid:none) Phytophthora sojae cal....022 FM992690_559( FM992690 |pid:none) Candida dubliniensis CD36 chromo... 42 0.0...1688( CP000571 |pid:none) Burkholderia pseudomallei 668 c... 38 0.25 CP000302_2086( CP000302 |pid:none) Shewanella denitrificans

GenBank blastx search result: AK243402 [KOME

Lifescience Database Archive (English)

Full Text Available AK243402 J100064O18 AF110185.1 AF110185 Burkholderia pseudomallei strain 1026b DbhB (dbhB), general... secretory pathway protein D (gspD), general secretory pathway protein E (gspE), general sec...retory pathway protein F (gspF), GspC (gspC), general secretory pathway protein G (gspG), general secretory ...pathway protein H (gspH), general secretory pathway protein I (gspI), general sec...retory pathway protein J (gspJ), general secretory pathway protein K (gspK), general secretory pathway protein L (gspL), general

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.

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.

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 ...

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.

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.

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

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

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.

Novel Burkholderia mallei Virulence Factors Linked to Specific Host-Pathogen Protein Interactions

Science.gov (United States)

2013-06-23

equine hosts. Thus, the genes retained in B. mallei share a high sequence similarity to genes common to B. pseudomallei (3), and many virulence...oppor- tunistic infections in mammalian hosts. Even for the equine - adapted and, thus, more genetically constrained, B. mallei pathogen, we cannot...BioDrugs: Clin. Immunotherapeut., Biopharmaceut. Gene Therapy 17, 413–424 88. Anderson, D. M., and Frank, D. W. (2012) Five mechanisms of manipula

Phylogeographic reconstruction of a bacterial species with high levels of lateral gene transfer

Science.gov (United States)

Pearson, T.; Giffard, P.; Beckstrom-Sternberg, S.; Auerbach, R.; Hornstra, H.; Tuanyok, A.; Price, E.P.; Glass, M.B.; Leadem, B.; Beckstrom-Sternberg, J. S.; Allan, G.J.; Foster, J.T.; Wagner, D.M.; Okinaka, R.T.; Sim, S.H.; Pearson, O.; Wu, Z.; Chang, J.; Kaul, R.; Hoffmaster, A.R.; Brettin, T.S.; Robison, R.A.; Mayo, M.; Gee, J.E.; Tan, P.; Currie, B.J.; Keim, P.

2009-01-01

Background: Phylogeographic reconstruction of some bacterial populations is hindered by low diversity coupled with high levels of lateral gene transfer. A comparison of recombination levels and diversity at seven housekeeping genes for eleven bacterial species, most of which are commonly cited as having high levels of lateral gene transfer shows that the relative contributions of homologous recombination versus mutation for Burkholderia pseudomallei is over two times higher than for Streptococcus pneumoniae and is thus the highest value yet reported in bacteria. Despite the potential for homologous recombination to increase diversity, B. pseudomallei exhibits a relative lack of diversity at these loci. In these situations, whole genome genotyping of orthologous shared single nucleotide polymorphism loci, discovered using next generation sequencing technologies, can provide very large data sets capable of estimating core phylogenetic relationships. We compared and searched 43 whole genome sequences of B. pseudomallei and its closest relatives for single nucleotide polymorphisms in orthologous shared regions to use in phylogenetic reconstruction. Results: Bayesian phylogenetic analyses of >14,000 single nucleotide polymorphisms yielded completely resolved trees for these 43 strains with high levels of statistical support. These results enable a better understanding of a separate analysis of population differentiation among >1,700 B. pseudomallei isolates as defined by sequence data from seven housekeeping genes. We analyzed this larger data set for population structure and allele sharing that can be attributed to lateral gene transfer. Our results suggest that despite an almost panmictic population, we can detect two distinct populations of B. pseudomallei that conform to biogeographic patterns found in many plant and animal species. That is, separation along Wallace's Line, a biogeographic boundary between Southeast Asia and Australia. Conclusion: We describe an

Phylogeographic reconstruction of a bacterial species with high levels of lateral gene transfer

Directory of Open Access Journals (Sweden)

Kaul Rajinder

2009-11-01

Full Text Available Abstract Background Phylogeographic reconstruction of some bacterial populations is hindered by low diversity coupled with high levels of lateral gene transfer. A comparison of recombination levels and diversity at seven housekeeping genes for eleven bacterial species, most of which are commonly cited as having high levels of lateral gene transfer shows that the relative contributions of homologous recombination versus mutation for Burkholderia pseudomallei is over two times higher than for Streptococcus pneumoniae and is thus the highest value yet reported in bacteria. Despite the potential for homologous recombination to increase diversity, B. pseudomallei exhibits a relative lack of diversity at these loci. In these situations, whole genome genotyping of orthologous shared single nucleotide polymorphism loci, discovered using next generation sequencing technologies, can provide very large data sets capable of estimating core phylogenetic relationships. We compared and searched 43 whole genome sequences of B. pseudomallei and its closest relatives for single nucleotide polymorphisms in orthologous shared regions to use in phylogenetic reconstruction. Results Bayesian phylogenetic analyses of >14,000 single nucleotide polymorphisms yielded completely resolved trees for these 43 strains with high levels of statistical support. These results enable a better understanding of a separate analysis of population differentiation among >1,700 B. pseudomallei isolates as defined by sequence data from seven housekeeping genes. We analyzed this larger data set for population structure and allele sharing that can be attributed to lateral gene transfer. Our results suggest that despite an almost panmictic population, we can detect two distinct populations of B. pseudomallei that conform to biogeographic patterns found in many plant and animal species. That is, separation along Wallace's Line, a biogeographic boundary between Southeast Asia and Australia

A retrospective analysis of melioidosis in Cambodian children, 2009–2013

Directory of Open Access Journals (Sweden)

Paul Turner

2016-11-01

Full Text Available Abstract Background Melioidiosis, infection by Burkholderia pseudomallei, is an important but frequently under-recognised cause of morbidity and mortality in Southeast Asia and elsewhere in the tropics. Data on the epidemiology of paediatric melioidosis in Cambodia are extremely limited. Methods Culture-positive melioidosis cases presenting to Angkor Hospital for Children, a non-governmental paediatric hospital located in Siem Reap, Northern Cambodia, between 1st January 2009 and 31st December 2013 were identified by searches of hospital and laboratory databases and logbooks. Results One hundred seventy-three evaluable cases were identified, presenting from eight provinces. For Siem Reap province, the median commune level incidence was estimated to be 28-35 cases per 100,000 children <15 years per year. Most cases presented during the wet season, May to October. The median age at presentation was 5.7 years (range 8 days–15.9 years. Apart from undernutrition, co-morbidities were rare. Three quarters (131/173 of the children had localised infection, most commonly skin/soft tissue infection (60 cases or suppurative parotitis (51 cases. There were 39 children with B. pseudomallei bacteraemia: 29 (74.4% of these had clinical and/or radiological evidence of pneumonia. Overall mortality was 16.8% (29/173 with mortality in bacteraemic cases of 71.8% (28/39. At least seven children did not receive an antimicrobial with activity against B. pseudomallei prior to death. Conclusions This retrospective study demonstrated a considerable burden of melioidosis in Cambodian children. Given the high mortality associated with bacteraemic infection, there is an urgent need for greater awareness amongst healthcare professionals in Cambodia and other countries where melioidosis is known or suspected to be endemic. Empiric treatment guidelines should ensure suspected cases are treated early with appropriate antimicrobials.

A retrospective analysis of melioidosis in Cambodian children, 2009-2013.

Science.gov (United States)

Turner, Paul; Kloprogge, Sabine; Miliya, Thyl; Soeng, Sona; Tan, Pisey; Sar, Poda; Yos, Pagnarith; Moore, Catrin E; Wuthiekanun, Vanaporn; Limmathurotsakul, Direk; Turner, Claudia; Day, Nicholas P J; Dance, David A B

2016-11-21

Melioidiosis, infection by Burkholderia pseudomallei, is an important but frequently under-recognised cause of morbidity and mortality in Southeast Asia and elsewhere in the tropics. Data on the epidemiology of paediatric melioidosis in Cambodia are extremely limited. Culture-positive melioidosis cases presenting to Angkor Hospital for Children, a non-governmental paediatric hospital located in Siem Reap, Northern Cambodia, between 1 st January 2009 and 31 st December 2013 were identified by searches of hospital and laboratory databases and logbooks. One hundred seventy-three evaluable cases were identified, presenting from eight provinces. For Siem Reap province, the median commune level incidence was estimated to be 28-35 cases per 100,000 children <15 years per year. Most cases presented during the wet season, May to October. The median age at presentation was 5.7 years (range 8 days-15.9 years). Apart from undernutrition, co-morbidities were rare. Three quarters (131/173) of the children had localised infection, most commonly skin/soft tissue infection (60 cases) or suppurative parotitis (51 cases). There were 39 children with B. pseudomallei bacteraemia: 29 (74.4%) of these had clinical and/or radiological evidence of pneumonia. Overall mortality was 16.8% (29/173) with mortality in bacteraemic cases of 71.8% (28/39). At least seven children did not receive an antimicrobial with activity against B. pseudomallei prior to death. This retrospective study demonstrated a considerable burden of melioidosis in Cambodian children. Given the high mortality associated with bacteraemic infection, there is an urgent need for greater awareness amongst healthcare professionals in Cambodia and other countries where melioidosis is known or suspected to be endemic. Empiric treatment guidelines should ensure suspected cases are treated early with appropriate antimicrobials.

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.

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.

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

Directory of Open Access Journals (Sweden)

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.

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

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.

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...

Susceptibility of Select Agents to Predation by Predatory Bacteria

Directory of Open Access Journals (Sweden)

Riccardo Russo

2015-12-01

Full Text Available Select Agents are microorganisms and toxins considered to be exploitable as biological weapons. Although infections by many Select Agents can be treated by conventional antibiotics, the risk of an emerging or engineered drug resistant strain is of great concern. One group of microorganisms that is showing potential to control drug resistant Gram-negative bacteria are the predatory bacteria from the genera Bdellovibrio spp. and Micavibrio spp. In this study, we have examined the ability of Bdellovibrio bacteriovorus (B. bacteriovorus strain 109J, HD100 and Micavibrio aeruginosavorus (M. aeruginosavorus ARL-13 to prey on a variety of Select Agents. Our findings demonstrate that B. bacteriovorus and M. aeruginosavorus are able to prey efficiently on Yersinia pestis and Burkholderia mallei. Modest predation was also measured in co-cultures of B. bacteriovorus and Francisella tularensis. However, neither of the predators showed predation when Burkholderia pseudomallei and Brucella melitensis were used as prey.

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.

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.

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.

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.

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

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

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

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...

Transmission Modes of Melioidosis in Taiwan

Directory of Open Access Journals (Sweden)

Pei-Tan Hsueh

2018-02-01

Full Text Available In Taiwan, melioidosis is an emerging disease that suddenly increased in the Er-Ren River Basin, beginning in 2005 and in the Zoynan region during 2008–2012, following a typhoon. Additionally, the disease sporadically increased in a geography-dependent manner in 2016. Subcutaneous inoculation, ingestion, and the inhalation of soil or water contaminated with Burkholderia pseudomallei are recognized as the transmission modes of melioidosis. The appearance of environmental B. pseudomallei positivity in northern, central and southern Taiwan is associated with disease prevalence (cases/population: 0.03/100,000 in the northern region, 0.29/100,000 in the central region and 1.98/100,000 in the southern region. However, melioidosis-clustered areas are confined to 5 to 7.5 km2 hot spots containing high-density populations, but B. pseudomallei-contaminated environments are located >5 km northwestern of the periphery of these hot spots. The observation that the concentration of B. pseudomallei-specific DNA in aerosols was positively correlated with the incidence of melioidosis and the appearance of a northwesterly wind in a hot spot indicated that airborne transmission had occurred in Taiwan. Moreover, the isolation rate in the superficial layers of a contaminated crop field in the northwest was correlated with PCR positivity in aerosols collected from the southeast over a two-year period. The genotype ST58 was identified by multilocus sequence typing in human and aerosol isolates. The genotype ST1001 has increased in prevalence but has been sporadically distributed elsewhere since 2016. These data indicate the transmission modes and environmental foci that support the dissemination of melioidosis are changing in Taiwan.

Overexpression of the endothelial protein C receptor is detrimental during pneumonia-derived gram-negative sepsis (Melioidosis.

Directory of Open Access Journals (Sweden)

Liesbeth M Kager

Full Text Available The endothelial protein C receptor (EPCR enhances anticoagulation by accelerating activation of protein C to activated protein C (APC and mediates anti-inflammatory effects by facilitating APC-mediated signaling via protease activated receptor-1. We studied the role of EPCR in the host response during pneumonia-derived sepsis instigated by Burkholderia (B. pseudomallei, the causative agent of melioidosis, a common form of community-acquired Gram-negative (pneumosepsis in South-East Asia.Soluble EPCR was measured in plasma of patients with septic culture-proven melioidosis and healthy controls. Experimental melioidosis was induced by intranasal inoculation of B. pseudomallei in wild-type (WT mice and mice with either EPCR-overexpression (Tie2-EPCR or EPCR-deficiency (EPCR(-/-. Mice were sacrificed after 24, 48 or 72 hours. Organs and plasma were harvested to measure colony forming units, cellular influxes, cytokine levels and coagulation parameters. Plasma EPCR-levels were higher in melioidosis patients than in healthy controls and associated with an increased mortality. Tie2-EPCR mice demonstrated enhanced bacterial growth and dissemination to distant organs during experimental melioidosis, accompanied by increased lung damage, neutrophil influx and cytokine production, and attenuated coagulation activation. EPCR(-/- mice had an unremarkable response to B. pseudomallei infection as compared to WT mice, except for a difference in coagulation activation in plasma.Increased EPCR-levels correlate with accelerated mortality in patients with melioidosis. In mice, transgenic overexpression of EPCR aggravates outcome during Gram-negative pneumonia-derived sepsis caused by B. pseudomallei, while endogenous EPCR does not impact on the host response. These results add to a better understanding of the regulation of coagulation during severe (pneumosepsis.

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.

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.

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.

Case of a lung mass due to melioidosis in Mexico.

Science.gov (United States)

Truong, Kimberly K; Moghaddam, Samer; Al Saghbini, Samer; Saatian, Bahman

2015-05-06

Melioidosis, an infection caused by the gram-negative bacterium Burkholderia pseudomallei, is an important cause of pneumonia, skin infection, sepsis, and death in Southeast Asia and Australia, but is exceedingly rare in North America. Pulmonary melioidosis typically presents as acute bacterial pneumonia or cavitary lung lesions resembling tuberculosis. We report melioidosis in a 70-year-old active smoker from Mexico with no history of travel to disease-endemic areas. The patient presented with a left supraclavicular abscess and a non-cavitary, left lung mass encasing a pulmonary vein. Incision and drainage of the patient's subcutaneous abscess isolated B. pseudomallei, and fine-needle aspiration of enlarged mediastinal lymph nodes revealed the presence of intracellular gram-negative bacilli with no evidence of malignancy. Biochemical tests determined that the strain the patient acquired from Mexico is identical to only 1 other isolate from Thailand. This report highlights the blurring epidemiological borders of this organism, its rare presentation mimicking lung malignancy, and an aggressive antimicrobial treatment that resulted in resolution of the patient's symptoms.

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.

Science.gov (United States)

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.

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...

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.

A Fresh Shine onCystic Fibrosis Inhalation Therapy: Antimicrobial Synergy of Polymyxin B in Combination with Silver Nanoparticles.

Science.gov (United States)

Jasim, Raad; Schneider, Elena K; Han, Meiling; Azad, Mohammad A K; Hussein, Maytham; Nowell, Cameron; Baker, Mark A; Wang, Jiping; Li, Jian; Velkov, Tony

2017-04-01

This in vitro study aimed to investigate the synergistic antibacterial activity of polymyxin B in combination with 2 nm silver nanoparticles (NPs) against Gram-negative pathogens commonly isolated from the cystic fibrosis (CF) lung. The in vitro synergistic activity of polymyxin B with silver NPs was assessed using the checkerboard assay against polymyxinsusceptible and polymyxin-resistant Pseudomonas aeruginosa isolates from the lungs of CF patients. The combination was also examined against the Gram-negative species Haemophilus influenzae, Burkholderia cepacia, Burkholderia pseudomallei, Stenotrophomonas maltophilia, Klebsiella pneumoniae and Acinetobacter baumannii that are less common in the CF lung. The killing kinetics of the polymyxin B-silver NPs combinations was assessed against P. aeruginosa by static time-kill assays over 24 h. Polymyxin B and silver NPs alone were not active against polymyxin-resistant (MIC ≥4 mg/L) P. aeruginosa. Whereas, the combination of a clinically-relevant concentration of polymyxin B (2 mg/L) with silver NPs (4 mg/L) successfully inhibited the growth of polymyxin-resistant P. aeruginosa isolates from CF patients as demonstrated by ≥2 log10 decrease in bacterial count (CFU/mL) after 24 h. Treatment of P. aeruginosa cells with the combination induced cytosolic GFP release and an increase of cellular reactive oxygen species. In the nitrocefin assay, the combination displayed a membrane permeabilizing activity superior to each of the drugs alone. The combination of polymyxin B and silver NPs displays excellent synergistic activity against highly polymyxin-resistant P. aeruginosa and is potentially of considerable clinical utility for the treatment of problematic CF lung infections.

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...

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.

Sulphonylurea usage in melioidosis is associated with severe disease and suppressed immune response.

Directory of Open Access Journals (Sweden)

Xiang Liu

2014-04-01

Full Text Available BACKGROUND: Melioidosis is a problem in the developing tropical regions of Southeast Asia and Northern Australia where the the Gram negative saprophytic bacillus Burkholderia pseudomallei is endemic with the risk of fulminant septicaemia. While diabetes mellitus is a well-established risk factor for melioidiosis, little is known if specific hypoglycemic agents may differentially influence the susceptibility and clinical course of infection with B. pseudomallei (Bp. METHODOLOGY/PRINCIPAL FINDINGS: In this cohort study, patients with pre-existing diabetes and melioidosis were retrospectively studied. OUTCOME MEASURES: mortality, length of stay and development of complications (namely hypotension, intubation, renal failure and septicaemia were studied in relation to prior diabetic treatment regimen. Peripheral blood mononuclear cells (PBMC from diabetic patients and healthy PBMC primed with metformin, glyburide and insulin were stimulated with purified Bp antigens in vitro. Immune response and specific immune pathway mediators were studied to relate to the clinical findings mechanistically. Of 74 subjects, 44 (57.9% had sulphonylurea-containing diabetic regimens. Patient receiving sulphonylureas had more severe septic complications (47.7% versus 16.7% p = 0.006, in particular, hypotension requiring intropes (p = 0.005. There was also a trend towards increased mortality in sulphonylurea-users (15.9% versus 3.3% p = 0.08. In-vitro, glyburide suppressed inflammatory cytokine production in a dose-dependent manner. An effect of the drug was the induction of IL-1R-associated kinase-M at the level of mRNA transcription. CONCLUSION/SIGNIFICANCE: Sulphonylurea treatment results in suppression of host inflammatory response and may put patients at higher risk for adverse outcomes in melioidosis.

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.

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.

Acute Disseminated Melioidosis Presenting with Septic Arthritis and Diffuse Pulmonary Consolidation in an Otherwise Healthy Adult: A Case Report

Directory of Open Access Journals (Sweden)

Hai Sherng Lee

2015-03-01

Full Text Available Background: Melioidosis is an infectious disease caused by Burkholderia pseudomallei. It is most prevalent in South-East Asia, northern Australia, and the Indian subcontinent. Septic arthritis is a rare manifestation of melioidosis. Melioidosis is usually found in patients with diabetes, heavy alcohol use, or chronic lung disease. Results: We report a case of melioidosis in an otherwise healthy 44-year-old male, who presented with acute painful left knee swelling, high-grade fever associated with chills, rigors and night sweats, and a productive cough. Examination revealed active synovitis with effusion involving his left knee, ankle and elbow joints and scattered crackles over both lung fields. Chest X-ray showed diffuse pulmonary consolidation. Abdominal ultrasound showed splenic micro-abscesses. The diagnosis was made based on a positive blood culture for Burkholderia pseudomallei. He was started on appropriate antibiotics and responded well, becoming afebrile after 48 hours, while his joint effusions disappeared after one week. A repeat chest X-ray after two weeks of intensive antibiotic therapy showed marked improvement. At the time of writing, he was under uneventful outpatient follow-up and still had 12 weeks to complete his course of antibiotics. Conclusion: Septic arthritis only occurs in 4% of patients with melioidosis. When there is diffuse pulmonary involvement, melioidosis may mimic disseminated tuberculosis, other acute disseminated or focal sepsis syndromes, and systemic vasculitis syndromes. This case is relevant for medical literature as melioidosis is emerging and is expanding its known territories worldwide. It should be considered early in the differential diagnoses of patients presenting with constitutional symptoms in endemic areas, so that treatment can be started early to reduce its high mortality and morbidity.

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

Use of the common marmoset to study Burkholderia mallei infection.

Directory of Open Access Journals (Sweden)

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

Lymphocytic Pleural Effusion in Acute Melioidosis

Directory of Open Access Journals (Sweden)

Kuo-Mou Chung

2007-10-01

Full Text Available An endemic outbreak of melioidosis developed in southern Taiwan following a flood caused by a typhoon in July 2005. A total of 27 patients were diagnosed with the acute and indigenous form of pulmonary melioidosis. Parapneumonic pleural effusions were noted on chest X-rays in six patients. Thoracentesis was done in three patients and all revealed lymphocyte predominance in differential cell count. Burkholderia pseudomallei was isolated in the pleural effusion in one of them. All three patients survived after antibiotic treatment. Lymphocytic pleural effusion is generally seen in tuberculosis or malignancy. However, our findings suggest that melioidosis should be considered in the differential diagnosis of lymphocytic pleural effusion.

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).

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

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.

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.

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).

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.

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.

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...

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...

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.

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

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

Are brucellosis, Q fever and melioidosis potential causes of febrile illness in Madagascar?

Science.gov (United States)

Boone, Ides; Henning, Klaus; Hilbert, Angela; Neubauer, Heinrich; von Kalckreuth, Vera; Dekker, Denise Myriam; Schwarz, Norbert Georg; Pak, Gi Deok; Krüger, Andreas; Hagen, Ralf Matthias; Frickmann, Hagen; Heriniaina, Jean Noël; Rakotozandrindrainy, Raphael; Rakotondrainiarivelo, Jean Philibert; Razafindrabe, Tsiry; Hogan, Benedikt; May, Jürgen; Marks, Florian; Poppert, Sven; Al Dahouk, Sascha

2017-08-01

Brucellosis, Q fever and melioidosis are zoonoses, which can lead to pyrexia. These diseases are often under-ascertained and underreported because of their unspecific clinical signs and symptoms, insufficient awareness by physicians and public health officers and limited diagnostic capabilities, especially in low-resource countries. Therefore, the presence of Brucella spp., Coxiella burnetii and Burkholderia pseudomallei was investigated in Malagasy patients exhibiting febrile illness. In addition, we analyzed zebu cattle and their ticks as potential reservoirs for Brucella and C. burnetii, respectively. Specific quantitative real-time PCR assays (qPCRs) were performed on 1020 blood samples drawn from febrile patients. In total, 15 samples (1.5%) were Brucella-positive, mainly originating from patients without travel history, while DNA from C. burnetii and Bu. pseudomallei was not detected. Anti-C. burnetii antibodies were found in four out of 201 zebu serum samples (2%), whereas anti-Brucella antibodies could not be detected. Brucella DNA was detected in a single zebu sample. Three out of 330 ticks analyzed (1%) were positively tested for C. burnetii DNA but with high Ct values in the qPCR assay. Our data suggest that zebus as well as Amblyomma and Boophilus ticks have to be considered as a natural reservoir or vector for C. burnetii, but the risk of cattle-to-human transmission is low. Since bovine brucellosis does not seem to contribute to human infections in Madagascar, other transmission routes have to be assumed. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

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.

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

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

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.

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...

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.

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?

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?

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...

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...

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...

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

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

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

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

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

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...

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.

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

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.

Clinical and epidemiologic characteristics of dengue and other etiologic agents among patients with acute febrile illness, Puerto Rico, 2012-2015.

Directory of Open Access Journals (Sweden)

Kay M Tomashek

2017-09-01

Full Text Available Identifying etiologies of acute febrile illnesses (AFI is challenging due to non-specific presentation and limited availability of diagnostics. Prospective AFI studies provide a methodology to describe the syndrome by age and etiology, findings that can be used to develop case definitions and multiplexed diagnostics to optimize management. We conducted a 3-year prospective AFI study in Puerto Rico. Patients with fever ≤7 days were offered enrollment, and clinical data and specimens were collected at enrollment and upon discharge or follow-up. Blood and oro-nasopharyngeal specimens were tested by RT-PCR and immunodiagnostic methods for infection with dengue viruses (DENV 1-4, chikungunya virus (CHIKV, influenza A and B viruses (FLU A/B, 12 other respiratory viruses (ORV, enterovirus, Leptospira spp., and Burkholderia pseudomallei. Clinical presentation and laboratory findings of participants infected with DENV were compared to those infected with CHIKV, FLU A/B, and ORV. Clinical predictors of laboratory-positive dengue compared to all other AFI etiologies were determined by age and day post-illness onset (DPO at presentation. Of 8,996 participants enrolled from May 7, 2012 through May 6, 2015, more than half (54.8%, 4,930 had a pathogen detected. Pathogens most frequently detected were CHIKV (1,635, 18.2%, FLU A/B (1,074, 11.9%, DENV 1-4 (970, 10.8%, and ORV (904, 10.3%. Participants with DENV infection presented later and a higher proportion were hospitalized than those with other diagnoses (46.7% versus 27.3% with ORV, 18.8% with FLU A/B, and 11.2% with CHIKV. Predictors of dengue in participants presenting <3 DPO included leukopenia, thrombocytopenia, headache, eye pain, nausea, and dizziness, while negative predictors were irritability and rhinorrhea. Predictors of dengue in participants presenting 3-5 DPO were leukopenia, thrombocytopenia, facial/neck erythema, nausea, eye pain, signs of poor circulation, and diarrhea; presence of

Clinical and epidemiologic characteristics of dengue and other etiologic agents among patients with acute febrile illness, Puerto Rico, 2012-2015.

Science.gov (United States)

Tomashek, Kay M; Lorenzi, Olga D; Andújar-Pérez, Doris A; Torres-Velásquez, Brenda C; Hunsperger, Elizabeth A; Munoz-Jordan, Jorge Luis; Perez-Padilla, Janice; Rivera, Aidsa; Gonzalez-Zeno, Gladys E; Sharp, Tyler M; Galloway, Renee L; Glass Elrod, Mindy; Mathis, Demetrius L; Oberste, M Steven; Nix, W Allan; Henderson, Elizabeth; McQuiston, Jennifer; Singleton, Joseph; Kato, Cecilia; García Gubern, Carlos; Santiago-Rivera, William; Cruz-Correa, Jesús; Muns-Sosa, Robert; Ortiz-Rivera, Juan D; Jiménez, Gerson; Galarza, Ivonne E; Horiuchi, Kalanthe; Margolis, Harold S; Alvarado, Luisa I

2017-09-01

Identifying etiologies of acute febrile illnesses (AFI) is challenging due to non-specific presentation and limited availability of diagnostics. Prospective AFI studies provide a methodology to describe the syndrome by age and etiology, findings that can be used to develop case definitions and multiplexed diagnostics to optimize management. We conducted a 3-year prospective AFI study in Puerto Rico. Patients with fever ≤7 days were offered enrollment, and clinical data and specimens were collected at enrollment and upon discharge or follow-up. Blood and oro-nasopharyngeal specimens were tested by RT-PCR and immunodiagnostic methods for infection with dengue viruses (DENV) 1-4, chikungunya virus (CHIKV), influenza A and B viruses (FLU A/B), 12 other respiratory viruses (ORV), enterovirus, Leptospira spp., and Burkholderia pseudomallei. Clinical presentation and laboratory findings of participants infected with DENV were compared to those infected with CHIKV, FLU A/B, and ORV. Clinical predictors of laboratory-positive dengue compared to all other AFI etiologies were determined by age and day post-illness onset (DPO) at presentation. Of 8,996 participants enrolled from May 7, 2012 through May 6, 2015, more than half (54.8%, 4,930) had a pathogen detected. Pathogens most frequently detected were CHIKV (1,635, 18.2%), FLU A/B (1,074, 11.9%), DENV 1-4 (970, 10.8%), and ORV (904, 10.3%). Participants with DENV infection presented later and a higher proportion were hospitalized than those with other diagnoses (46.7% versus 27.3% with ORV, 18.8% with FLU A/B, and 11.2% with CHIKV). Predictors of dengue in participants presenting dengue in participants presenting 3-5 DPO were leukopenia, thrombocytopenia, facial/neck erythema, nausea, eye pain, signs of poor circulation, and diarrhea; presence of rhinorrhea, cough, and red conjunctiva predicted non-dengue AFI. By enrolling febrile patients at clinical presentation, we identified unbiased predictors of laboratory

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.

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 ...

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

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...

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

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

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

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.

Melioidosis in Myanmar

Directory of Open Access Journals (Sweden)

Mo Mo Win

2018-03-01

Full Text Available Sporadic cases of melioidosis have been diagnosed in Myanmar since the disease was first described in Yangon in 1911. Published and unpublished cases are summarized here, along with results from environmental and serosurveys. A total of 298 cases have been reported from seven states or regions between 1911 and 2018, with the majority of these occurring before 1949. Findings from soil surveys confirm the presence of Burkholderia pseudomallei in the environment in all three regions examined. The true epidemiology of the disease in Myanmar is unknown. Important factors contributing to the current gaps in knowledge are lack of awareness among clinicians and insufficient laboratory diagnostic capacity in many parts of the country. This is likely to have led to substantial under-reporting.

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

Directory of Open Access Journals (Sweden)

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.

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.

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.

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.

Studies on the sensitivity of guinea pigs and golden hamsters irradiated with different doses of gamma rays to infections with R and S forms of Pseudomonas pseudomallei

International Nuclear Information System (INIS)

Najdenski, Kh.M.; Velyanov, D.K.

1989-01-01

Whole-body gamma irradiation was carried out on guinea pigs of both sexes with 2 Gy (sublethal dose), 2 Gy fractionated (4 x 0.5 Gy a day) and 0.5 Gy, and on golden hamsters with 6 Gy (sublethal dose) and 0.5 Gy. The animals were injected i.p. 24 h after irradiation with bacterial suspensions of P. pseudomallei R 7 and R 15 . The results showed a great increase of sensitivity to infection in the animals irradiated with sublethal dose, both as regards the R and S forms. Susceptibility rose appreciably also in guinea pigs irradiated fractionally with a dose of 2 Gy and to a relatively lower degree upon irradiation with 0.5 Gy. For the golden hamsters the sensitivity toward both investigated strains was extremely high and it remained unchanged upon irradiation with 6 Gy and 0.5 Gy. The data obtained provided grounds for the existence of a certain correlation between the different radioresistance of guinea pigs and golden hamsters and the changes established in their sensitivity to infections with R and S forms of Ps. pseudomallei after whole-body gamma irradiation

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...

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

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

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.

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.

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.

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

Identification of Highly Pathogenic Microorganisms by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry: Results of an Interlaboratory Ring Trial

DEFF Research Database (Denmark)

Lasch, Peter; Wahab, Tara; Weil, Sandra

2015-01-01

In the case of a release of highly pathogenic bacteria (HPB), there is an urgent need for rapid, accurate, and reliable diagnostics. MALDI-TOF mass spectrometry is a rapid, accurate, and relatively inexpensive technique that is becoming increasingly important in microbiological diagnostics...... mallei, Burkholderia pseudomallei, and Yersinia pestis, were characterized under blinded conditions. Microbial strains were inactivated by high-dose gamma irradiation before shipment. Preparatory investigations ensured that this type of inactivation induced only subtle spectral changes with negligible...... by the individual laboratories on the basis of spectral libraries available on site. All mass spectra were also tested against an in-house HPB library at the Robert Koch Institute (RKI). The averaged identification accuracy was 77% in the first case and improved to >93% when the spectral diagnoses were obtained...

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.

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

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...

Stimulate The Growth of Rice Using Endophytic Bacteria from Lowland Rice Plant Tissue

Directory of Open Access Journals (Sweden)

Nuni Gofar

2015-07-01

Full Text Available Exploration and selection of endophytic bacteria from healthy food crops grown in lowland ecosystem is important to be conducted in order to get growth-stimulating endophytic bacteria at soil with low fertility level so that capable to optimize initial growth of food crops and subsequently can increase productivity level of lowland soil.The research objective was to isolate and to test the IAA-producing endophytic bacteria isolate in stimulating the rice crop growth at lowland area. Endophytic bacteria are isolated from tissues of rice, corn and peanut crops which grown at shallow swamp land in Ogan Ilir and Ogan Komering Ilir Districts, South Sumatra, Indonesia. There was nine isolates of nitrogen-fixer endophytic bacteria that capable to contribute IAA phytohormone into their growth media. The P31 isolate from rice crop tisssue of 2 months old produce the best rice sprouts than other isolates. This isolate can contribute of about 10 mg kg-1 IAA to its growth medium and increase the crowns dry weight and the roots dry weight respectively with magnitudes of 133% and 225% compared to control treatment. Concentration and absorbtion of N for rice crops innoculated with P31 isolates had increased by 169% and 400%, recpectively. The P31 isolates had been identified as Burkholderia pseudomallei (also known as Pseudomonas pseudomallei.

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 ...

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...

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.

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.

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...

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’.

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.

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.

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.

Melioidosis in the Lao People’s Democratic Republic

Directory of Open Access Journals (Sweden)

David A.B. Dance

2018-02-01

Full Text Available Melioidosis is clearly highly endemic in Laos, although the disease has only been diagnosed regularly in humans (1359 cases since 1999, and only a single animal case has been microbiologically confirmed. Burkholderia pseudomallei is extensively and abundantly present in soil and surface water in central and southern Laos, but the true distribution of the disease across the country remains to be determined. Surveillance is almost non-existent and diagnostic microbiology services are not yet well established, whilst awareness of melioidosis is low amongst policy-makers, healthcare providers, and the public. It is hoped that this situation will improve over the next decade as the country rapidly develops, especially as this is likely to be accompanied by a further increase in the prevalence of diabetes, meaning that more people in this predominantly agricultural population will be at risk of contracting melioidosis.

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

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.

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.

Dynamics of the changes in the number and phagocytic activity of leucocytes from whole-body gamma-irradiated guinea pigs with respect to R and S forms of Pseudomonas pseudomallei

International Nuclear Information System (INIS)

Najdenski, Kh.M.; Velyanov, D.K.

1987-01-01

Guinea pigs of both sexes received whole-body gamma irradiation (0.5 Gy, 4 x 0.5 Gy and 2 Gy; 92.5 rad/min). Two bacterial strains were used: Ps. pseudomallei R 1 5 and S 7 . The measurments were carried out on days 1, 3, 7, 15 and 30 after treatment. The changes observed were directly dependent on the dose applied: for sublethally (2 Gy) irradiated animals - an abrupt decrease of leukocytes and strongly expressed leukopenia lasting throughout the whole investigation; for fractiionally irradiated (4 x 0.5 Gy) -the number of leukocytes P<0.001 and leukopenia being observed to day 7 after irradiation; for 0.5 Gy irradiated -the leucocytes number equal to that of the controls on day 15 and significantly higher on day 30; less strongly expressed leukopenia. The alterations in phagocytic activity in relation to R and S forms of Ps. pseudomallei were similar: leukocytes from 2 Gy irradiated guinea pigs showed on day 1 a markedly raised phagocytic activity and phagocytized the R and S forms to a similar degree, while at later intervals of the study the phagocytic activity decreased and they began to phagocytize the R forms more actively. Leukocytes from 0.5 Gy treated animals phagocytized the R forms more actively than the S forms throughout the whole investigation

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) ...

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.

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.

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...

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...

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...

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.

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

Rapid and high-throughput detection of highly pathogenic bacteria by Ibis PLEX-ID technology.

Directory of Open Access Journals (Sweden)

Daniela Jacob

Full Text Available In this manuscript, we describe the identification of highly pathogenic bacteria using an assay coupling biothreat group-specific PCR with electrospray ionization mass spectrometry (PCR/ESI-MS run on an Ibis PLEX-ID high-throughput platform. The biothreat cluster assay identifies most of the potential bioterrorism-relevant microorganisms including Bacillus anthracis, Francisella tularensis, Yersinia pestis, Burkholderia mallei and pseudomallei, Brucella species, and Coxiella burnetii. DNA from 45 different reference materials with different formulations and different concentrations were chosen and sent to a service screening laboratory that uses the PCR/ESI-MS platform to provide a microbial identification service. The standard reference materials were produced out of a repository built up in the framework of the EU funded project "Establishment of Quality Assurances for Detection of Highly Pathogenic Bacteria of Potential Bioterrorism Risk" (EQADeBa. All samples were correctly identified at least to the genus level.

Molecular investigations of a locally acquired case of melioidosis in Southern AZ, USA.

Directory of Open Access Journals (Sweden)

David M Engelthaler

2011-10-01

Full Text Available Melioidosis is caused by Burkholderia pseudomallei, a Gram-negative bacillus, primarily found in soils in Southeast Asia and northern Australia. A recent case of melioidosis in non-endemic Arizona was determined to be the result of locally acquired infection, as the patient had no travel history to endemic regions and no previous history of disease. Diagnosis of the case was confirmed through multiple microbiologic and molecular techniques. To enhance the epidemiological analysis, we conducted several molecular genotyping procedures, including multi-locus sequence typing, SNP-profiling, and whole genome sequence typing. Each technique has different molecular epidemiologic advantages, all of which provided evidence that the infecting strain was most similar to those found in Southeast Asia, possibly originating in, or around, Malaysia. Advancements in new typing technologies provide genotyping resolution not previously available to public health investigators, allowing for more accurate source identification.

Melioidosis: It is not Far from here.

Science.gov (United States)

Darazam, Ilad Alavi; Kiani, Arda; Ghasemi, Shahin; Sadeghi, Hosein; Alavi, Farhad; Moosavi, Mohammad Jafar; Akbari, Asghar; Shahidi, Mojtaba; Jalali, Mehran; Pourfarziani, Vahid; Saba, Hossein; Nazari, Shahram; Mohammadi, Forozan; Mansouri, Seyed Davood

2011-01-01

In the modern world, with developed traveling facilities, tourism is an important factor in emerging new infectious diseases in non-endemic areas. Therefore, the epidemiology of infections is a considerable issue for physicians and should be taken into account. We report a case of melioidosis in a 69-year-old Iranian man during his trip to Southeast Asia. On admission, he was febrile with tachycardia and tachypnea and had diabetes mellitus and hypertension since eleven years ago. Bronchoscopy and bronchoalveolar lavage (BAL) were performed. Blood and BAL cultures revealed heavy growth of Burkholderia pseudomallei. According to the aforementioned culture results, the patient was treated with meropenem and TMP-SMX, while other antibiotics were discontinued. After 3 weeks, the patient was discharged with stable status and normal pulmonary function; and eradication therapy with TMP-SMX continued for about 3 months. The control lung CT scan after one month demonstrated significant improvement.

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.

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.

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.

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.

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.

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.

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.

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

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.

Imported melioidosis in Japan: a review of cases.

Science.gov (United States)

Hadano, Yoshiro

2018-01-01

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.

Pangenomic Definition of Prokaryotic Species and the Phylogenetic Structure of Prochlorococcus spp.

Directory of Open Access Journals (Sweden)

Mikhail A. Moldovan

2018-03-01

Full Text Available The pangenome is the collection of all groups of orthologous genes (OGGs from a set of genomes. We apply the pangenome analysis to propose a definition of prokaryotic species based on identification of lineage-specific gene sets. While being similar to the classical biological definition based on allele flow, it does not rely on DNA similarity levels and does not require analysis of homologous recombination. Hence this definition is relatively objective and independent of arbitrary thresholds. A systematic analysis of 110 accepted species with the largest numbers of sequenced strains yields results largely consistent with the existing nomenclature. However, it has revealed that abundant marine cyanobacteria Prochlorococcus marinus should be divided into two species. As a control we have confirmed the paraphyletic origin of Yersinia pseudotuberculosis (with embedded, monophyletic Y. pestis and Burkholderia pseudomallei (with B. mallei. We also demonstrate that by our definition and in accordance with recent studies Escherichia coli and Shigella spp. are one species.

Radiological manifestations of melioidosis

International Nuclear Information System (INIS)

Lim, K.S.; Chong, V.H.

2010-01-01

Melioidosis is a serious infection that is associated with high mortality. It is due to a Gram-negative bacterium, Burkholderia pseudomallei which is an environmental saprophyte found in wet soils. Melioidosis is endemic to northern Australia and the Southeast Asia. However, there is now increasing number of reports of imported cases to regions where this infection has not been previously encountered. Almost any organ can be affected. Like many other conditions, radiological imaging is an integral part of the diagnostic workup of melioidosis. Awareness of the various radiological manifestations can help direct appropriate investigations to achieve early diagnosis and the initiation of appropriate treatment. Generally, there are no known characteristic features on imaging that can specifically differentiate melioidosis from other infections. However, the 'honeycomb' appearance has been described to be characteristic for large melioidosis liver abscesses. Simultaneous involvement of various organs is also characteristics. To date, there are few data available on the radiological manifestations of melioidosis. The present pictorial essay describes melioidosis affecting the various organs.

Transports of acetate and haloacetate in Burkholderia species MBA4 are operated by distinct systems

Directory of Open Access Journals (Sweden)

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.

Seroepidemiology of melioidosis in children from a remote region of Papua New Guinea.

Science.gov (United States)

Diefenbach-Elstob, Tanya R; Graves, Patricia M; Burgess, Graham W; Pelowa, Daniel B; Warner, Jeffrey M

2015-09-01

The Balimo region in Papua New Guinea has previously been identified as melioidosis-endemic with a predilection for children. Where health resources are scarce, seroepidemiology can be used to assess exposure to Burkholderia pseudomallei and therefore risk of acquiring melioidosis. Logistic regression was used to determine associations between indirect haemagglutination assay (IHA) seroreactivity with environmental and demographic/cultural factors to aid in determining risk factors associated with exposure to B. pseudomallei in children. Of the 968 participants, 92.9% (899/968) were children, representing the majority of the community school population in the immediate Balimo region. Of these, 24.6% (221/899) were seropositive. Bathing in the lagoon (OR=2.679), drinking from the well or lagoon (OR=1.474), and being a member of the Siboko (OR=1.914) or Wagumisi (OR=1.942) clans were significantly associated with seropositivity. In the multivariate analysis, drinking from a well or lagoon (OR=1.713), and the Siboko (OR=2.341) and Wabadala (OR=2.022) clans were associated with seropositivity. This study in children supports observations that interactions with groundwater in this region are risk factors in acquiring melioidosis. Public health measures intended to limit this exposure may help reduce the risk of acquiring melioidosis in this remote community. Associations with clan structure may provide more cultural specific insights, however this requires further elucidation. © The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Deciphering the role of RND efflux transporters in Burkholderia cenocepacia.

Directory of Open Access Journals (Sweden)

Silvia Bazzini

Full Text Available Burkholderia cenocepacia J2315 is representative of a highly problematic group of cystic fibrosis (CF pathogens. Eradication of B. cenocepacia is very difficult with the antimicrobial therapy being ineffective due to its high resistance to clinically relevant antimicrobial agents and disinfectants. RND (Resistance-Nodulation-Cell Division efflux pumps are known to be among the mediators of multidrug resistance in gram-negative bacteria. Since the significance of the 16 RND efflux systems present in B. cenocepacia (named RND-1 to -16 has been only partially determined, the aim of this work was to analyze mutants of B. cenocepacia strain J2315 impaired in RND-4 and RND-9 efflux systems, and assess their role in the efflux of toxic compounds. The transcriptomes of mutants deleted individually in RND-4 and RND-9 (named D4 and D9, and a double-mutant in both efflux pumps (named D4-D9, were compared to that of the wild-type B. cenocepacia using microarray analysis. Microarray data were confirmed by qRT-PCR, phenotypic experiments, and by Phenotype MicroArray analysis. The data revealed that RND-4 made a significant contribution to the antibiotic resistance of B. cenocepacia, whereas RND-9 was only marginally involved in this process. Moreover, the double mutant D4-D9 showed a phenotype and an expression profile similar to D4. The microarray data showed that motility and chemotaxis-related genes appeared to be up-regulated in both D4 and D4-D9 strains. In contrast, these gene sets were down-regulated or expressed at levels similar to J2315 in the D9 mutant. Biofilm production was enhanced in all mutants. Overall, these results indicate that in B. cenocepacia RND pumps play a wider role than just in drug resistance, influencing additional phenotypic traits important for pathogenesis.

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.

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.

Emergence of Melioidosis in Indonesia and Today’s Challenges

Directory of Open Access Journals (Sweden)

Patricia M. Tauran

2018-03-01

Full Text Available A recent modeling study estimated that there could be as many as 20,000 human melioidosis cases per year in Indonesia, with around 10,000 potential deaths annually. Nonetheless, the true burden of melioidosis in Indonesia is still unknown. The Indonesia Melioidosis Network was formed during the first melioidosis workshop in 2017. Here, we reviewed 101 melioidosis cases (99 human and two animal cases previously reported and described an additional 45 human melioidosis cases. All 146 culture-confirmed cases were found in Sumatra (n = 15, Java (n = 104, Kalimantan (n = 15, Sulawesi (n = 11 and Nusa Tenggara (n = 1. Misidentification of Burkholderia pseudomallei was not uncommon, and most cases were only recently identified. We also evaluated clinical manifestations and outcome of recent culture-confirmed cases between 2012 and 2017 (n = 42. Overall, 15 (36% cases were children (age <15 years and 27 (64% were adults (age ≥15 years. The overall mortality was 43% (18/42. We conducted a survey and found that 57% (327/548 of healthcare workers had never heard of melioidosis. In conclusion, melioidosis is endemic throughout Indonesia and associated with high mortality. We propose that top priorities are increasing awareness of melioidosis amongst all healthcare workers, increasing the use of bacterial culture, and ensuring accurate identification of B. pseudomalleiand diagnosis of melioidosis.

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.

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

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.

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...

Activities of daily living associated with acquisition of melioidosis in northeast Thailand: a matched case-control study.

Directory of Open Access Journals (Sweden)

Direk Limmathurotsakul

Full Text Available Melioidosis is a serious infectious disease caused by the Category B select agent and environmental saprophyte, Burkholderia pseudomallei. Most cases of naturally acquired infection are assumed to result from skin inoculation after exposure to soil or water. The aim of this study was to provide evidence for inoculation, inhalation and ingestion as routes of infection, and develop preventive guidelines based on this evidence.A prospective hospital-based 1∶2 matched case-control study was conducted in Northeast Thailand. Cases were patients with culture-confirmed melioidosis, and controls were patients admitted with non-infectious conditions during the same period, matched for gender, age, and diabetes mellitus. Activities of daily living were recorded for the 30-day period before onset of symptoms, and home visits were performed to obtain drinking water and culture this for B. pseudomallei. Multivariable conditional logistic regression analysis based on 286 cases and 512 controls showed that activities associated with a risk of melioidosis included working in a rice field (conditional odds ratio [cOR] = 2.1; 95% confidence interval [CI] 1.4-3.3, other activities associated with exposure to soil or water (cOR = 1.4; 95%CI 0.8-2.6, an open wound (cOR = 2.0; 95%CI 1.2-3.3, eating food contaminated with soil or dust (cOR = 1.5; 95%CI 1.0-2.2, drinking untreated water (cOR = 1.7; 95%CI 1.1-2.6, outdoor exposure to rain (cOR = 2.1; 95%CI 1.4-3.2, water inhalation (cOR = 2.4; 95%CI 1.5-3.9, current smoking (cOR = 1.5; 95%CI 1.0-2.3 and steroid intake (cOR = 3.1; 95%CI 1.4-6.9. B. pseudomallei was detected in water source(s consumed by 7% of cases and 3% of controls (cOR = 2.2; 95%CI 0.8-5.8.We used these findings to develop the first evidence-based guidelines for the prevention of melioidosis. These are suitable for people in melioidosis-endemic areas, travelers and military personnel. Public health campaigns