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contribution of the bact/alert mb mycobacterium bottle to bloodstream infection surveillance in thailand: added yield for burkholderia pseudomallei.community-acquired bloodstream infections cause substantial morbidity and mortality worldwide, but microbiology capacity and surveillance limitations have challenged good descriptions of pathogen distribution in many regions, including southeast asia. active surveillance for bloodstream infections has been conducted in two rural thailand provinces for >7 years. blood specimens were divided into two culture bottles, one optimized for aerobic growth (f bottle) and a second for enhanced growth of m ...201525588650
volatile-sulfur-compound profile distinguishes burkholderia pseudomallei from burkholderia thailandensis.solid-phase microextraction gas chromatography-mass spectrometry (spme-gcms) was used to show that dimethyl sulfide produced by burkholderia pseudomallei is responsible for its unusual truffle-like smell and distinguishes the species from burkholderia thailandensis. spme-gcms can be safely used to detect dimethyl sulfide produced by agar-grown b. pseudomallei.201525568444
susceptibility of select agents to predation by predatory bacteria.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 bdello ...201527682124
uncovering major genomic features of essential genes in bacteria and a methanogenic archaea.identification of essential genes is critical to understanding the physiology of a species, proposing novel drug targets and uncovering minimal gene sets required for life. although essential gene sets of several organisms have been determined using large-scale mutagenesis techniques, systematic studies addressing their conservation, genomic context and functions remain scant. here we integrate 17 essential gene sets from genome-wide in vitro screenings and three gene collections required for gr ...201526084810
identification of highly pathogenic microorganisms by matrix-assisted laser desorption ionization-time of flight mass spectrometry: results of an interlaboratory ring trial.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 to complement classical microbiology, pcr, and genotyping of hpb. in the present study, the results of a joint exercise with 11 partner institutions from nine european countries are presented. in this exercise ...201526063856
characterization of burkholderia pseudomallei strains using a murine intraperitoneal infection model and in vitro macrophage assays.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 occurr ...201525909629
recombinant salmonella expressing burkholderia mallei lps o antigen provides protection in a murine model of melioidosis and glanders.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 ...201526148026
identification of burkholderia pseudomallei near-neighbor species in the northern territory of australia.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 hum ...201526121041
altered proteome of burkholderia pseudomallei colony variants induced by exposure to human lung epithelial cells.burkholderia pseudomallei primary diagnostic cultures demonstrate colony morphology variation associated with expression of virulence and adaptation proteins. this study aims to examine the ability of b. pseudomallei colony variants (wild type [wt] and small colony variant [scv]) to survive and replicate intracellularly in a549 cells and to identify the alterations in the protein expression of these variants, post-exposure to the a549 cells. intracellular survival and cytotoxicity assays were pe ...201525996927
complete genome sequences for 59 burkholderia isolates, both pathogenic and near neighbor.the genus burkholderia encompasses both pathogenic (including burkholderia mallei and burkholderia pseudomallei, u.s. centers for disease control and prevention category b listed), and nonpathogenic gram-negative bacilli. here we present full genome sequences for a panel of 59 burkholderia strains, selected to aid in detection assay development.201525931592
concordance and discordance of sequence survey methods for molecular epidemiology.the post-genomic era is characterized by the direct acquisition and analysis of genomic data with many applications, including the enhancement of the understanding of microbial epidemiology and pathology. however, there are a number of molecular approaches to survey pathogen diversity, and the impact of these different approaches on parameter estimation and inference are not entirely clear. we sequenced whole genomes of bacterial pathogens, burkholderia pseudomallei, yersinia pestis, and brucell ...201525737810
differential toll-like receptor-signalling of burkholderia pseudomallei lipopolysaccharide in murine and human models.the gram-negative bacterium burkholderia pseudomallei causes melioidosis and is a cdc category b bioterrorism agent. toll-like receptor (tlr)-2 impairs host defense during pulmonary b.pseudomallei infection while tlr4 only has limited impact. we investigated the role of tlrs in b.pseudomallei-lipopolysaccharide (lps) induced inflammation. purified b.pseudomallei-lps activated only tlr2-transfected-hek-cells during short stimulation but both hek-tlr2 and hek-tlr4-cells after 24 h. in human blood, ...201526689559
clear distinction between burkholderia mallei and burkholderia pseudomallei using fluorescent motb primers.a frame-shift mutation in the flagellum motor gene motb coding for the chemotaxis motb protein of burkholderia mallei has been utilized to design a conventional duplex pcr assay with fluorescent labelled primers.201525887130
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.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: virulen ...201525830295
global transcriptional analysis of burkholderia pseudomallei high and low biofilm producers reveals insights into biofilm production and virulence.chronic bacterial infections occur as a result of the infecting pathogen's ability to live within a biofilm, hence escaping the detrimental effects of antibiotics and the immune defense system. burkholderia pseudomallei, a gram-negative facultative pathogen, is distinctive in its ability to survive within phagocytic and non-phagocytic cells, to persist in vivo for many years and subsequently leading to relapse as well as the development of chronic disease. the capacity to persist has been attrib ...201526092034
genetic analysis of the cdi pathway from burkholderia pseudomallei 1026b.contact-dependent growth inhibition (cdi) is a mode of inter-bacterial competition mediated by the cdib/cdia family of two-partner secretion systems. cdia binds to receptors on susceptible target bacteria, then delivers a toxin domain derived from its c-terminus. studies with escherichia coli suggest the existence of multiple cdi growth-inhibition pathways, whereby different systems exploit distinct target-cell proteins to deliver and activate toxins. here, we explore the cdi pathway in burkhold ...201525786241
tn5/7-lux: a versatile tool for the identification and capture of promoters in gram-negative bacteria.the combination of imaging technologies and luciferase-based bioluminescent bacterial reporter strains provide a sensitive and simple non-invasive detection method (photonic bioimaging) for the study of diverse biological processes, as well as efficacy of therapeutic interventions, in live animal models of disease. the engineering of bioluminescent bacteria required for photonic bioimaging is frequently hampered by lack of promoters suitable for strong, yet stable luciferase gene expression.201525648327
burkholderia stagnalis sp. nov. and burkholderia territorii sp. nov., two novel burkholderia cepacia complex species from environmental and human sources.nine burkholderia cepacia complex (bcc) bacteria were isolated during environmental surveys for the ecological niche of burkholderia pseudomallei, the aetiological agent of melioidosis, in the northern territory of australia. they represented two multi-locus sequence analysis-based clusters, referred to as bcc b and bcc l. three additional environmental and clinical bcc b isolates were identified upon deposition of the sequences in the pubmlst database. analysis of the concatenated nucleotide se ...201525872960
characterization of the murine macrophage response to infection with virulent and avirulent burkholderia species.burkholderia pseudomallei (bp) and burkholderia mallei (bm) are gram-negative facultative intracellular pathogens, which are the causative agents of melioidosis and glanders, respectively. depending on the route of exposure, aerosol or transcutaneous, infection by bp or bm can result in an extensive range of disease - from acute to chronic, relapsing illness to fatal septicemia. both diseases are associated with difficult diagnosis and high fatality rates. about ninety five percent of patients s ...201526545875
a reverse-phase protein microarray-based screen identifies host signaling dynamics upon burkholderia spp. infection.burkholderia is a diverse genus of gram-negative bacteria that causes high mortality rate in humans, equines and cattle. the lack of effective therapeutic treatments poses serious public health threats. developing insights toward host-burkholderia spp. interaction is critical for understanding the pathogenesis of infection as well as identifying therapeutic targets for drug development. reverse-phase protein microarray technology was previously proven to identify and characterize novel biomarker ...201526284031
serum biomarkers of burkholderia mallei infection elucidated by proteomic imaging of skin and lung abscesses.the bacterium burkholderia mallei is the etiological agent of glanders, a highly contagious, often fatal zoonotic infectious disease that is also a biodefense concern. clinical laboratory assays that analyze blood or other biological fluids are the highest priority because these specimens can be collected with minimal risk to the patient. however, progress in developing sensitive assays for monitoring b. mallei infection is hampered by a shortage of useful biomarkers.201526034464
recent advances in burkholderia mallei and b. pseudomallei research.burkholderia mallei and burkholderia pseudomallei are gram-negative organisms, which are etiological agents of glanders and melioidosis, respectively. although only b. pseudomallei is responsible for a significant number of human cases, both organisms are classified as tier 1 select agents and their diseases lack effective diagnosis and treatment. despite a recent resurgence in research pertaining to these organisms, there are still a number of knowledge gaps. this article summarizes the latest ...201525932379
plasticity of the malleobactin pathway and its impact on siderophore action in human pathogenic bacteria.the human pathogenic bacteria burkholderia mallei, burkholderia pseudomallei, and burkholderia thailandensis harbor a highly conserved gene cluster coding for the biosynthesis of the long sought-after malleobactins. four new, unexpected congeners of the malleobactin family that were isolated and fully characterized in this study feature unusual deviations from the parent, ornibactin-like architecture. thus, the malleobactin non-ribosomal peptide synthetase (nrps) has a rare flexibility that yiel ...201525873483
intracellular bacteria find the right motion.benanti et al. report that burkholderia pseudomallei and burkholderia mallei bacteria express proteins that mimic ena/vasp family proteins to polymerize actin, thereby inducing actin-based motility. thus, bacteria can use the various cellular actin polymerization mechanisms for intra- and inter-cellular dissemination.201525860603
use of the phytopathogenic effect for studies of burkholderia virulence.the phytopathogenic effect of the pseudomallei group burkholderia is demonstrated on the peireskia aculeata model. a method for evaluation of the effect is suggested. the effect correlates with the levels of burkholderia pseudomallei, burkholderia mallei, and burkholderia thailandensis virulence for laboratory animals. p. aculeata can be used as a model for preliminary studies of the virulence of the above species.201525705037
characterization of cellular immune response and innate immune signaling in human and nonhuman primate primary mononuclear cells exposed to burkholderia mallei.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 (cynomolg ...201525450887
raman spectroscopic detection and identification of burkholderia mallei and burkholderia pseudomallei in feedstuff.burkholderia mallei (the etiologic agent of glanders in equines and rarely humans) and burkholderia pseudomallei, causing melioidosis in humans and animals, are designated category b biothreat agents. the intrinsically high resistance of both agents to many antibiotics, their potential use as bioweapons, and their low infectious dose, necessitate the need for rapid and accurate detection methods. current methods to identify these organisms may require up to 1 week, as they rely on phenotypic cha ...201524880875
characterization of lesion formation in marmosets following inhalational challenge with different strains of burkholderia pseudomallei.the marmoset model of melioidosis was used to explore whether there was any difference in the disease presentation and/or the lesion formation following inhalational challenge with one of four strains of burkholderia pseudomallei (k96243, 1026b, hbpub10303a and hbpub10134a). marmosets were challenged with a range of bacterial doses and bacterial load, histological and physiological features were determined temporally following lethal disease. melioidosis presented as an acute, febrile disease wi ...201526852689
imported melioidosis in south korea: a case series with a literature review.melioidosis is a potentially fatal infectious disease caused by the environmental anaerobic gram-negative bacillus burkholderia pseudomallei. melioidosis is endemic to areas of northern australia and southeast asia. with increasing international travel and migration, imported cases of melioidosis are being reported regularly. here, we summarize the 11 cases of melioidosis reported in south korea from 2003 to 2014.201526835246
neurological melioidosis in norway presenting with a cerebral abscess.neurological melioidosis is a rare condition, as less than 30 cases have been reported in the last 50 years. we present a case of neurological melioidosis, presenting with a cerebral abscess in a returning traveler from an endemic area. while traveling in cambodia on holiday, the patient was admitted to local hospital for pneumonia. her condition improved after antimicrobial treatment, and she returned to norway when discharged. the patient had several contacts with the health care system after ...201526793441
viperatoxin-ii: a novel viper venom protein as an effective bactericidal agent.infections caused by methicillin-resistant staphylococcus aureus (mrsa) have become a rising threat to public health. there is an urgent need for development of promising new therapeutic agents against drug resistant bacteria like s. aureus. this report discusses purification and characterization of proteins from indian russell's viper snake venom. novel 15-kda proteins called "viperatoxin" (viptx-i and viptx-ii) were extracted from the whole venom and evaluated using in vitro antimicrobial expe ...201526793432
genome sequence of a burkholderia pseudomallei clinical isolate from a patient with community-acquired pneumonia and septicemia.here, we report the draft genome sequence of burkholderia pseudomallei cm_manipal, the causative agent of melioidosis isolated from a diabetic patient in manipal, southern india. the draft genome consists of 107 contigs and is 7,209,157 bp long. a total of 5,600 coding sequences (cdss), 60 trnas, 12 rrnas, and one noncoding rna (ncrna) were predicted from this assembly.201526294629
melioidosis in hainan, china: a restrospective study.melioidosis is a tropical disease caused by infection with burkholderia pseudomallei. here, we report an 11 year (2002-2013) retrospective study of melioidosis cases in china.201526276499
a review of melioidosis cases in the americas.melioidosis is a bacterial infection caused by burkholderia pseudomallei, a gram-negative saprophytic bacillus. cases occur sporadically in the americas with an increasing number of cases observed among people with no travel history to endemic countries. to better understand the incidence of the disease in the americas, we reviewed the literature, including unpublished cases reported to the centers for disease control and prevention. of 120 identified human cases, occurring between 1947 and june ...201526458779
emergence of melioidosis in indonesia.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 ...201526458777
evaluation of a biodegradable microparticulate polymer as a carrier for burkholderia pseudomallei subunit vaccines in a mouse model of melioidosis.melioidosis, a potentially lethal disease of humans and animals, is caused by the soil-dwelling bacterium burkholderia pseudomallei. due to b. pseudomallei's classification as a tier 1 select agent, there is substantial interest in the development of an effective vaccine. yet, despite decades of research, no effective target, adjuvant or delivery vehicle capable of inducing protective immunity against b. pseudomallei infection has been identified. we propose a microparticulate delivery vehicle c ...201526428631
selecting soluble/foldable protein domains through single-gene or genomic orf filtering: structure of the head domain of burkholderia pseudomallei antigen bpsl2063.the 1.8 å resolution crystal structure of a conserved domain of the potential burkholderia pseudomallei antigen and trimeric autotransporter bpsl2063 is presented as a structural vaccinology target for melioidosis vaccine development. since bpsl2063 (1090 amino acids) hosts only one conserved domain, and the expression/purification of the full-length protein proved to be problematic, a domain-filtering library was generated using β-lactamase as a reporter gene to select further bpsl2063 domains. ...201526527140
neurologic melioidosis presented as encephalomyelitis and subdural collection in two male labourers in india.two distinct and potentially deceitful cases of neurologic melioidosis are reported. case 1: a 39-year-old alcoholic and uncontrolled diabetic male presented with cough, fever, and left focal seizures with secondary generalization. an magnetic resonance imaging (mri) brain scan revealed a small peripherally enhancing subdural collection along the interhemispheric fissure suggestive of minimal subdural empyema. blood culture grew burkholderia pseudomallei. patient was diagnosed with disseminated ...201526623640
brief communication genotyping of burkholderia pseudomallei revealed high genetic variability among isolates from a single population group.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 malays ...201526417404
burkholderia pseudomallei infection in us traveler returning from mexico, 2014. 201526401597
environmental attributes influencing the distribution of burkholderia pseudomallei in northern australia.factors responsible for the spatial and temporal clustering of burkholderia pseudomallei in the environment remain to be elucidated. whilst laboratory based experiments have been performed to analyse survival of the organism in various soil types, such approaches are strongly influenced by alterations to the soil micro ecology during soil sanitisation and translocation. during the monsoonal season in townsville, australia, b. pseudomallei is discharged from castle hill (an area with a very high ...201526398904
melioidosis as a travel-associated infection: case report and review of the literature.increasing numbers of sporadic cases of melioidosis in returning travelers have been reported from non-endemic regions.201526385170
unusual presentation of melioidosis in a case of pseudoaneurysm of descending thoracic aorta: review of two case reports.melioidosis is a rapidly fatal infectious disease caused by burkholderia pseudomallei, an agent of potential biothreat, endemic in several parts of india. most melioidosis-induced infected aneurysms are located in the abdominal or thoracic aorta.201526380820
synthesis of the tetrasaccharide repeating unit of the β-kdo-containing exopolysaccharide from burkholderia pseudomallei and b. cepacia complex.the synthesis of the repeating unit of the immunogenic β-kdo-containing exopolysaccharide produced by burkholderia pseudomallei and bacteria of the b. cepacia complex is described. the target tetrasaccharide was synthesized via stereoselective 1,2-cis- and 1,2-trans-galactosylations and β-kdosylation. a [3 + 1] coupling reaction between a trigalactosyl n-phenyl-2,2,2-trifluoroacetimidate donor and a kdo acceptor has been successfully achieved for the assembly of the tetrasaccharide skeleton.201526375291
evaluating the role of phage-shock protein a in burkholderia pseudomallei.the phage-shock protein (psp) response is an extracytoplasmic response system that is vital for maintenance of the cytoplasmic membrane when the cell encounters stressful conditions. the paradigm of the psp response has been established in escherichia coli. the response has been shown to be important for survival during the stationary phase, maintenance of the proton motive force across membranes and implicated in virulence. in this study, we identified a putative pspa homologue in burkholderia ...201526374246
immune profiling of the progression of a balb/c mouse aerosol infection by burkholderia pseudomallei and the therapeutic implications of targeting hmgb1.the role of damage-associated molecular pattern hmgb1 signalling in a murine balb/c model of severe respiratory melioidosis (burkholderia pseudomallei infection) was explored in this study.201526358857
inactivation of burkholderia pseudomallei on environmental surfaces using spray-applied, common liquid disinfectants.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 ...201526331308
morphological alteration and survival of burkholderia pseudomallei in soil microcosms.the resilience of burkholderia pseudomallei, the causative agent of melioidosis, was evaluated in control soil microcosms and in soil microcosms containing nacl or feso4 at 30°c. iron (fe(ii)) promoted the growth of b. pseudomallei during the 30-day observation, contrary to the presence of 1.5% and 3% nacl. scanning electron micrographs of b. pseudomallei in soil revealed their morphological alteration from rod to coccoid and the formation of microcolonies. the smallest b. pseudomallei cells wer ...201526324731
the blood transcriptome of experimental melioidosis reflects disease severity and shows considerable similarity with the human disease.melioidosis, a severe human disease caused by the bacterium burkholderia pseudomallei, has a wide spectrum of clinical manifestations ranging from acute septicemia to chronic localized illness or latent infection. murine models have been widely used to study the pathogenesis of infection and to evaluate novel therapies or vaccines, but how faithfully they recapitulate the biology of human melioidosis at a molecular level is not known. in this study, mice were intranasally infected with either hi ...201526311902
burkholderia pseudomallei capsular polysaccharide recognition by a monoclonal antibody reveals key details toward a biodefense vaccine and diagnostics against melioidosis.burkholderia pseudomallei is the bacterium responsible for melioidosis, an infectious disease with high mortality rates. since melioidosis is a significant public health concern in endemic regions and the organism is currently classified as a potential biothreat agent, the development of effective vaccines and rapid diagnostics is a priority. the capsular polysaccharide (cps) expressed by b. pseudomallei is a highly conserved virulence factor and a protective antigen. because of this, cps is con ...201526198038
comparison of the early host immune response to two widely diverse virulent strains of burkholderia pseudomallei that cause acute or chronic infections in balb/c mice.burkholderia pseudomallei is the etiologic agent of melioidosis, which is endemic in southeast asia and northern australia. we previously found by the intraperitoneal (ip) route that we could discern differences in virulence in mice amongst different strains of b. pseudomallei. we report an early immune response study comparing two strains in our collection which represent the least, b. pseudomallei 1106a, and one of the most, hbpub10134a, virulent strains in balb/c mice. b. pseudomallei hbpub10 ...201526162294
bacterial reductionism: host thiols enhance virulence.intracellular bacteria exploit host cytosolic signals to upregulate virulence genes. in this issue of cell host & microbe, wong et al. (2015) show that burkholderia pseudomallei senses host cytosolic glutathione, a low-molecular-weight thiol, through the membrane-bound histidine sensor kinase vira, highlighting the importance of inter-kingdom signaling in bacterial pathogenesis.201526159714
burkholderia pseudomallei survival in lung epithelial cells benefits from mirna-mediated suppression of atg10.burkholderia pseudomallei is the causative agent of melioidosis, a disease with high mortality, which is prevalent in tropical regions of the world. a recent study shows that b. pseudomallei can survive inside mammalian cells because of its ability to actively evade cell autophagy. however, the underlying mechanisms remain unclear. in the present study, based on microarray screening, we found that atg10 was downregulated following b. pseudomallei infection in a549 human lung epithelial cells. fo ...201526151773
melioidosis cases and selected reports of occupational exposures to burkholderia pseudomallei--united states, 2008-2013.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 hou ...201526135734
evaluation of polysaccharide-based latex agglutination assays for the rapid detection of antibodies to burkholderia pseudomallei.melioidosis is a severe disease caused by the gram-negative bacterium burkholderia pseudomallei. diagnosis of melioidosis currently relies on the isolation of b. pseudomallei from clinical samples, which can take several days. an indirect hemagglutination assay (iha) is widely used for serodiagnosis, but it has a short shelf life, is poorly standardized, and requires a viable bacteria culture performed in a biosafety level 3 (bsl-3) laboratory. to improve the diagnostic methods, we have develope ...201526123956
metabolomic profiling of burkholderia pseudomallei using uhplc-esi-q-tof-ms reveals specific biomarkers including 4-methyl-5-thiazoleethanol and unique thiamine degradation pathway.burkholderia pseudomallei is an emerging pathogen that causes melioidosis, a serious and potentially fatal disease which requires prolonged antibiotics to prevent relapse. however, diagnosis of melioidosis can be difficult, especially in culture-negative cases. while metabolomics represents an uprising tool for studying infectious diseases, there were no reports on its applications to b. pseudomallei. to search for potential specific biomarkers, we compared the metabolomics profiles of culture s ...201526097677
host cytosolic glutathione sensing by a membrane histidine kinase activates the type vi secretion system in an intracellular bacterium.type vi secretion systems (t6sss) are major virulence mechanisms in many gram-negative bacteria, but the physiological signals that activate them are not well understood. the t6ss1 of burkholderia pseudomallei is essential for pathogenesis in mammalian hosts and is only expressed when the bacterium is intracellular. we found that signals for t6ss1 activation reside in the host cytosol. through site-directed mutagenesis and biochemical studies, we identified low molecular weight thiols, particula ...201526094804
[development and systematical evaluation of an up-converting phosphor technology based lateral flow assay for quantitative detection of burkholderia pseudomallei].to develop an up-converting phosphor technology-based lateral-flow (upt-lf) assay for rapid quantitative detection of burkholderia pseudomallei on site.201526081404
control of bacterial metabolism by quorum sensing.bacterial quorum sensing (qs)-dependent gene expression is a dynamic response to cell density. bacteria produce costly public goods for the benefit of the population as a whole. as an example, qs rewires cellular metabolism to produce oxalate (a public good) to enable survival during the stationary phase in burkholderia glumae, burkholderia thailandensis, and burkholderia pseudomallei. recent reports showed that qs serves as a metabolic brake to maintain homeostatic primary metabolism in b. glum ...201526072043
airborne transmission of melioidosis to humans from environmental aerosols contaminated with b. pseudomallei.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 wer ...201526061639
a preliminary x-ray study of 3-deoxy-d-manno-oct-2-ulosonic acid 8-phosphate phosphatase (yrbi) from burkholderia pseudomallei.3-deoxy-d-manno-oct-2-ulosonic acid 8-phosphate phosphatase (yrbi), the third enzyme in the pathway for the biosynthesis of 3-deoxy-d-manno-oct-2-ulosonic acid (kdo), hydrolyzes kdo 8-phosphate to kdo and inorganic phosphate. yrbi belongs to the haloacid dehalogenase (had) superfamily, which is a large family of magnesium-dependent phosphatase/phosphotransferase enzymes. in this study, yrbi from burkholderia pseudomallei, the causative agent of melioidosis, has been cloned, expressed, purified a ...201526057814
rapid diagnostics for melioidosis: a comparative study of a novel lateral flow antigen detection assay.the rapid diagnosis of septicaemic melioidosis will have an impact on reduction of mortality. currently, this relies almost exclusively upon culture of the causative agent burkholderia pseudomallei from clinical samples. in acute sepsis, blood is the preferred specimen for culture and therefore should be the target for a rapid diagnostic tool. a lateral flow immunoassay (lfi) for the detection of b. pseudomallei antigen has been developed. this was compared with molecular detection using the tar ...201526055557
"melioidosis in antioquia, colombia: an emerging or endemic disease? a cases series".melioidosis is endemic in malaysia, the southwest of thailand, and northern australia. the incidence in thailand is 4.4/1000000 inhabitants, where it causes 19% of community-acquired pneumonia (cap) and 20% of bacteremic pneumonia, and the mortality is 50%. sporadic cases have been described in central and south america. the objective of this study was to describe the clinical and epidemiological features and ecological characteristics of melioidosis in antioquia, colombia.201526051974
direct detection of burkholderia pseudomallei and biological factors in soil.burkholderia pseudomallei, a gram-negative saprophytic bacillus, is a severe infectious agent that causes melioidosis and soil is the most important reservoir.201526048871
the contribution of soil physicochemical properties to the presence and genetic diversity of burkholderia pseudomallei.burkholderia pseudomallei (bp), the causative agent of melioidosis, is unevenly distributed in the complex soil environment. physicochemical factors in the soil have been reported to affect microbial communities in the soil. the effect of physicochemical factors on the number and diversity of organisms in the soil has not been reported. twenty-five each b. pseudomallei-positive and -negative soil samples were collected from a melioidosis-endemic area. the amount of bp in each soil sample was mea ...201526513904
a pcr-based detection of burkholderia pseudomallei diversity using myoviridae prophage typing.pcr-based detection of myoviridae lysogenic phages in burkholderia pseudomallei was developed using primers targeting k96243 prophage gi2, phie12-2 and phi52237/phix216. investigation of 50 clinical and 50 environmental (soil) isolates revealed that k96243 prophage gi2 was the most common (48%) among the isolates, followed by phie12-2 (38%) and phi52237/phix216 (35%), with k96243 prophage gi2 being significantly more frequent in soil (64%) than clinical (32%) samples. twenty-four percent of soil ...201526513903
t-cell responses are associated with survival in acute melioidosis patients.melioidosis is an increasingly recognised cause of sepsis and death across south east asia and northern australia, caused by the bacterium burkholderia pseudomallei. risk factors include diabetes, alcoholism and renal disease, and a vaccine targeting at-risk populations is urgently required. a better understanding of the protective immune response in naturally infected patients is essential for vaccine design.201526495852
central and peripheral nervous system involvement in neuromelioidosis.we report a case of a 33-year-old sri lankan man who presented with flaccid quadriparesis with brainstem signs and acute motor axonal polyneuropathy. mri of the brain showed multiple abscesses with ring enhancement seen predominantly in the brainstem and upper cervical cord. the patient was initially treated with intravenous immunoglobulin, considering this to be a form of guillain-barré syndrome. cerebrospinal fluid, however, showed lymphocytic pleocytosis with raised protein. tests for brucell ...201526494715
use of whole-genome sequencing to link burkholderia pseudomallei from air sampling to mediastinal melioidosis, australia.the frequency with which melioidosis results from inhalation rather than percutaneous inoculation or ingestion is unknown. we recovered burkholderia pseudomallei from air samples at the residence of a patient with presumptive inhalational melioidosis and used whole-genome sequencing to link the environmental bacteria to b. pseudomallei recovered from the patient.201526488732
correlation between biofilm production, antibiotic susceptibility and exopolysaccharide composition in burkholderia pseudomallei bpsi, ppk, and rpos mutant strains.burkholderia pseudomallei is the cause of melioidosis, a fatal tropical infectious disease, which has been reported to have a high rate of recurrence, even when an intensive dose of antibiotics is used. biofilm formation is believed to be one of the possible causes of relapse because of its ability to increase drug resistance. eps in biofilms have been reported to be related to the limitation of antibiotic penetration in b. pseudomallei. however, the mechanisms by which biofilms restrict the dif ...201526486518
pangenome analysis of burkholderia pseudomallei: genome evolution preserves gene order despite high recombination rates.the pangenomic diversity in burkholderia pseudomallei is high, with approximately 5.8% of the genome consisting of genomic islands. genomic islands are known hotspots for recombination driven primarily by site-specific recombination associated with trnas. however, recombination rates in other portions of the genome are also high, a feature we expected to disrupt gene order. we analyzed the pangenome of 37 isolates of b. pseudomallei and demonstrate that the pangenome is 'open', with approximatel ...201526484663
comparison of whole-genome sequences from two colony morphovars of burkholderia pseudomallei.the entire genomes of two isogenic morphovars (vgh16w and vgh16r) of burkholderia pseudomallei were sequenced. a comparison of the sequences from both strains indicates that they show 99.99% identity, are composed of 22 tandem repeated sequences with <100 bp of indels, and have 199 single-base variants.201526472836
draft genome sequence of burkholderia pseudomallei strain 350105, isolated in hainan, china, in 1976.burkholderia pseudomallei is the etiological agent of the potentially fatal disease melioidosis. here, we report the draft genome sequence of a virulent water isolate obtained from the hainan province of china in 1976, b. pseudomallei strain 350105.201526472827
gene microarray analyses of daboia russelli russelli daboiatoxin treatment of thp-1 human macrophages infected with burkholderia pseudomallei.burkholderia pseudomallei is the causative agent of melioidosis and represents a potential bioterrorism threat. in this study, the transcriptomic responses of b. pseudomallei infection of a human macrophage cell model were investigated using whole-genome microarrays. gene expression profiles were compared between infected thp-1 human monocytic leukemia cells with or without treatment with daboia russelli russelli daboiatoxin (drrdbtx) or ceftazidime (antibiotic control). microarray analyses of i ...201526592245
comprehensive identification of virulence factors required for respiratory melioidosis using tn-seq mutagenesis.respiratory melioidosis is a disease presentation of the biodefense pathogen, burkholderia pseudomallei, which is frequently associated with a lethal septicemic spread of the bacteria. we have recently developed an improved respiratory melioidosis model to study the pathogenesis of burkholderia pseudomallei in the lung (intubation-mediated intratracheal [imit] inoculation), which more closely models descriptions of human melioidosis, including prominent septicemic spread from the lung and reduce ...201526583079
functional and structural characterization of a heparanase.we report the structural and functional characterization of a novel heparanase (bphep) from the invasive pathogenic bacterium burkholderia pseudomallei (bp), showing ∼24% sequence identity with human heparanase (hhep). site-directed mutagenesis studies confirmed the active site resi-dues essential for activity, and we found that bphep has specificity for heparan sulfate. finally, we describe the first heparanase x-ray crystal structure, which provides new insight into both substrate recognition ...201526565989
diverse burkholderia species isolated from soils in the southern united states with no evidence of b. pseudomallei.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 sample ...201526600238
characterization of burkholderia pseudomallei protein bpsl1375 validates the putative hemolytic activity of the cog3176 n-acyltransferase family.there are still numerous protein subfamilies within families and superfamilies that do not yet have conclusive empirical experimental evidence providing a specific function. these proteins persist in databases with the annotation of a specific 'putative' function made by association with discernible features in the protein sequence.201526597807
pulmonary melioidosis presenting with pleural effusion: a case report and review of literature.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 ...201526744655
membrane-bound pena β-lactamase of burkholderia pseudomallei.burkholderia pseudomallei is the etiologic agent of melioidosis, a difficult-to-treat disease with diverse clinical manifestations. β-lactam antibiotics such as ceftazidime are crucial to the success of melioidosis therapy. ceftazidime-resistant clinical isolates have been described, and the most common mechanism is point mutations affecting expression or critical amino acid residues of the chromosomally encoded class a pena β-lactamase. we previously showed that pena was exported via the twin a ...201526711764
atypical presentations of melioidosis in north india: report of two cases.melioidosis is an infection caused by gram-negative bacterium, burkholderia pseudomallei. this is a rare disease in india, more so in north india. we present two cases of melioidosis with unusual sites of infection. the first patient was a young diabetic male presenting to us with history of prolonged fever and upper abdominal discomfort, subsequently diagnosed as a case of pyogenic liver abscess. the second patient was a middle aged diabetic complaining of prolonged fever and headache and found ...201526710411
anti-malarial and anti-inflammatory effects of gleichenia truncata mediated through inhibition of gsk3β.gleichenia truncata is a highland fern from the gleicheniaceae family known for its traditional use among indigenous communities in asia to treat fever. the scientific basis of its effect has yet to be documented. a yeast-based kinase assay conducted in our laboratory revealed that crude methanolic extract (cme) of g. truncata exhibited glycogen synthase kinase-3 (gsk3)-inhibitory activity. gsk3β is now recognized to have a pivotal role in the regulation of inflammatory response during bacterial ...201526695202
drug susceptibility and biofilm formation of burkholderia pseudomallei in nutrient-limited condition.burkholderia pseudomallei is the causative agent of melioidosis, which can form biofilms and microcolonies in vivo and in vitro. one of the hallmark characteristics of the biofilm-forming bacteria is that they can be up to 1,000 times more resistant to antibiotics than their free-living counterpart. bacteria also become highly tolerant to antibiotics when nutrients are limited. one of the most important causes of starvation induced tolerance in vivo is biofilm growth. however, the effect of nutr ...201526691259
finished annotated genome sequence of burkholderia pseudomallei strain bp1651, a multidrug-resistant clinical isolate.burkholderia pseudomallei strain bp1651, a human isolate, is resistant to all clinically relevant antibiotics. we report here on the finished genome sequence assembly and annotation of the two chromosomes of this strain. this genome sequence may assist in understanding the mechanisms of antimicrobial resistance for this pathogenic species.201526634765
an intriguing case of locked jaw secondary to melioidosis.a 56-year-old woman presented with fever, pain and restriction of movement of the right temporomandibular joint. she was premorbidly diagnosed to have type 2 diabetes mellitus and rheumatoid arthritis. local examination revealed a poorly demarcated severely tender, erythematous swelling in the right preauricular region. all haematological and biochemical investigations were within normal limits. mri of the neck revealed the presence of a masticator space infection with intramuscular abscess invo ...201526628312
utilization of whole-cell maldi-tof mass spectrometry to differentiate burkholderia pseudomallei wild-type and constructed mutants.whole-cell matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (whole-cell maldi-tof ms) has been widely adopted as a useful technology in the identification and typing of microorganisms. this study employed the whole-cell maldi-tof ms to identify and differentiate wild-type and mutants containing constructed single gene mutations of burkholderia pseudomallei, a pathogenic bacterium causing melioidosis disease in both humans and animals. candidate biomarkers for the b. p ...201526656930
novel phospholipase a2 inhibitors from python serum are potent peptide antibiotics.antimicrobial peptides (amps) play a vital role in defense against resistant bacteria. in this study, eight different amps synthesized from python reticulatus serum protein were tested for bactericidal activity against various gram-positive and gram-negative bacteria (staphylococcus aureus, burkholderia pseudomallei (khw and tes strains), and proteus vulgaris) using a disc-diffusion method (20 μg/disc). among the tested peptides, phospholipase a2 inhibitory peptide (pip)-18[59-76], β-asp65-pip[5 ...201525583073
type 3 secretion system cluster 3 is a critical virulence determinant for lung-specific melioidosis.burkholderia pseudomallei, the bacterial agent of melioidosis, causes disease through inhalation of infectious particles, and is classified as a tier 1 select agent. optical diagnostic imaging has demonstrated that murine respiratory disease models are subject to significant upper respiratory tract (urt) colonization. because human melioidosis is not associated with urt colonization as a prominent presentation, we hypothesized that lung-specific delivery of b. pseudomallei may enhance our abilit ...201525569630
whole-genome sequencing confirms that burkholderia pseudomallei multilocus sequence types common to both cambodia and australia are due to homoplasy.burkholderia pseudomallei isolates with shared multilocus sequence types (sts) have not been isolated from different continents. we identified two sts shared between australia and cambodia. whole-genome analysis revealed substantial diversity within sts, correctly identified the asian or australian origin, and confirmed that these shared sts were due to homoplasy.201525392354
diabetes-independent increase of factor vii-activating protease activation in patients with gram-negative sepsis (melioidosis).the plasma protease factor vii-activating protease (fsap) can release nucleosomes from late apoptotic cells. nucleosomes are markers of cell death, and extracellular cell-free dna has been suggested to play an important role in inflammation and has been demonstrated to correlate with severity and outcome in sepsis patients.201525370187
whole-genome sequencing of burkholderia pseudomallei isolates from an unusual melioidosis case identifies a polyclonal infection with the same multilocus sequence type.twelve burkholderia pseudomallei isolates collected over a 32-month period from a patient with chronic melioidosis demonstrated identical multilocus sequence types (sts). however, whole-genome sequencing suggests a polyclonal infection. this study is the first to report a mixed infection with the same st.201525339397
autophagy and burkholderia.autophagy has become increasingly viewed as an important component of the eukaryotic innate immune system. the elimination of intracellular pathogens by autophagy in mammalian cells (xenophagy) results not only in the degradation of invading bacteria, viruses, fungi and parasites, but also liberation of metabolites that may have been utilized during pathogen infection, thus promoting cell survival. after gaining entry into the cell, intracellular bacterial pathogens attempt to escape from phagos ...201525331551
a prospective study of melioidosis after environmental exposure of healthy participants to burkholderia pseudomallei during a muddy endurance challenge.in a prospective study of 123 healthy adults competing in a mud-exposing endurance challenge in the melioidosis-endemic tropical north of the northern territory of australia, there were no asymptomatic seroconversions to burkholderia pseudomallei using indirect hemagglutination assay. however, one competitor developed melioidosis attributable to infection acquired during the event.201525624406
transcriptome analysis of burkholderia pseudomallei t6ss identifies hcp1 as a potential serodiagnostic marker.burkholderia pseudomallei, the causative agent of melioidosis, is able to survive extreme environments and utilizes various virulence factors for survival and pathogenicity. to compete and survive within these different ecological niches, b. pseudomallei has evolved specialized pathways, including the type vi secretion systems (t6sss), that have a role in pathogenesis as well as interbacterial interactions. we examined the expression profile of b. pseudomallei t6ss six gene clusters during infec ...201525616255
burkholderia pseudomallei type iii secretion system cluster 3 atpase bsas, a chemotherapeutic target for small-molecule atpase inhibitors.melioidosis is an infectious disease of high mortality for humans and other animal species; it is prevalent in tropical regions worldwide. the pathogenesis of melioidosis depends on the ability of its causative agent, the gram-negative bacterium burkholderia pseudomallei, to enter and survive in host cells. b. pseudomallei can escape from the phagosome into the cytosol of phagocytic cells where it replicates and acquires actin-mediated motility, avoiding killing by the autophagy-dependent proces ...201525605762
the first autochthonous case of human melioidosis in reunion island. 201525596804
cutaneous melioidosis in a healthy danish man after travelling to south-east asia.a healthy danish man presented with infected prepatellar bursitis 8 months after being involved in a car accident in malaysia resulting in exposure of a laceration of his knee to stagnant water. tissue samples grew burkholderia pseudomallei and diagnostic work up revealed no secondary foci. the patient was successfully treated with surgical debridement and 3 months of oral trimethoprim-sulfamethoxazole. at 6 months follow-up the patient was without relapse.201525596295
parietal bone osteomyelitis in melioidosis.we report a case of a 55-year-old man with uncontrolled diabetes who presented with pneumonia. during his hospital stay his clinical status worsened and he had a focal seizure. mri showed central nervous system involvement and parietal bone osteomyelitis. as the patient's blood culture and endotracheal aspirate grew burkholderia pseudomallei, melioidosis was diagnosed. he was treated with meropenem after failure to respond to ceftazidime. he gradually improved over a period of 4 weeks and was di ...201525725029
melioidosis in africa: should we be looking more closely?melioidosis is a life-threatening infection caused by the gram-negative bacterium burkholderia pseudomallei, mainly found in southeast asia. recently, african foci have been identified, although reports remain mostly anecdotal. in africa, multiple febrile diseases have been erroneously attributed to malaria in the past, and many cases of fever remain mis- or undiagnosed. vigilance for previously under-recognized pathogens may enhance our understanding of disease epidemiology and facilitate impro ...201525689538
whole-genome sequences of 80 environmental and clinical isolates of burkholderia pseudomallei.here, we present the draft genome sequences of 80 isolates of burkholderia pseudomallei. the isolates represent clinical cases of melioidosis and environmental isolates from regions in australia and papua new guinea where b. pseudomallei is endemic. the genomes provide further context for the diversity of the pathogen.201525676747
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