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potential of recombinant flagellin fragment from burkholderia thailandensis as an antigen for melioidosis antibody detection by indirect elisa.non-pathogenic burkholderia thailandensis may be used as a model for burkholderia pseudomallei due to the genetic similarity of these species. moreover, the experimental manipulation of b. thailandensis is safer. in this study, we constructed recombinant flagellin protein fragments of b. thailandensis e264 (flag300, flag600, flag900, and flagfl fragments) and used fragments as the antigen to detect melioidosis antibodies by an indirect enzyme-linked immunosorbent assay (indirect elisa). the seru ...201323159530
a structure-based strategy for epitope discovery in burkholderia pseudomallei oppa antigen.we present an approach integrating structural and computational biology with immunological tests to identify epitopes in the oppa antigen from the gram-negative pathogen burkholderia pseudomallei, the etiological agent of melioidosis. the crystal structure of oppa(bp), reported here at 2.1 å resolution, was the basis for a computational analysis that identified three potential epitopes. in parallel, antigen proteolysis and immunocapturing allowed us to identify three additional peptides. all six ...201323159127
first genome sequence of a burkholderia pseudomallei isolate in china, strain bpc006, obtained from a melioidosis patient in hainan.melioidosis, caused by burkholderia pseudomallei, is considered to be endemic to northern australia and southeast asia, with high mortality and relapse rates, regardless of powerful antibiotic therapy. here we report the first genome sequence of burkholderia pseudomallei strain bpc006, obtained from a melioidosis patient in hainan, china. the genome sizes of the 2 chromosomes were determined to be 4,001,777 bp and 3,153,284 bp.201223144371
murine pulmonary infection and inflammation induced by inhalation of burkholderia pseudomallei.melioidosis is a tropical disease caused by ingestion, percutaneous inoculation or inhalation of the gram-negative soil saprophyte burkholderia pseudomallei. we developed a reproducible experimental murine model of pneumonic melioidosis induced by inhalation of aerosolized b. pseudomallei 1026b. in a series of experiments performed to bracket the lethal dose, we found that c57bl/6 mice were modestly more resistant than balb/c mice (median lethal dose 334 cfu/lung vs 204 cfu/lung). we further cha ...201223136994
detection of burkholderia pseudomallei o-antigen serotypes in near-neighbor species.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 ...201223126230
beclin 1 is required for starvation-enhanced, but not rapamycin-enhanced, lc3-associated phagocytosis of burkholderia pseudomallei in raw 264.7 cells.lc3-associated phagocytosis (lap) of burkholderia pseudomallei by murine macrophage (raw 264.7) cells is an intracellular innate defense mechanism. beclin 1, a protein with several roles in autophagic processes, is known to be recruited to phagosomal membranes as a very early event in lap. we sought to determine whether knockdown of beclin 1 by small interfering rna (sirna) would affect recruitment of lc3 and subsequent lap of infecting b. pseudomallei. both starvation and rapamycin treatment ca ...201323115045
identification of type ii toxin-antitoxin modules in burkholderia pseudomallei.type ii toxin-antitoxin (ta) systems are believed to be widely distributed amongst bacteria although their biological functions are not clear. we have identified eight candidate ta systems in the genome of the human pathogen burkholderia pseudomallei. five of these were located in genome islands. of the candidate toxins, bpsl0175 (rele1) or bpss1060 (rele2) caused growth to cease when expressed in escherichia coli, whereas expression of bpss0390 (hica) or bpss1584 (hipa) (in an e. coli δhipba ba ...201323082999
tn5-ot182 should not be used to identify genes involved in biofilm formation in burkholderia pseudomallei.burkholderia pseudomallei, a gram-negative bacterium, is the causative agent of melioidosis. one of the important virulence properties of this bacteria is its ability to form a biofilm. genes involved in biofilm formation in b. pseudomallei have not been thoroughly studied. in this study, tn5-ot182 mutagenesis was used to isolate of b. pseudomallei strain a2 mutants unable to produce biofilm. ten biofilm-defective transposon mutants were isolated and analyzed. flanking dna from each transposon m ...201223082562
outbreak of melioidosis and leptospirosis co-infection following a rescue operation.we analyzed the epidemiological data of all people who were involved in the search and rescue operation in lubuk yu, a natural recreational forest with waterfall and stream. the hospital admission records of the cases who fulfilled the case definition and the environmental samples result taken at lubuk yu recreational area were studied. 153 people were exposed to this outbreak, 85 (55.5%) were professional rescuers from various government agencies and 68 (44.5%) were villagers. 21 fulfilled the ...201223082420
burkholderia pseudomallei kills caenorhabditis elegans through virulence mechanisms distinct from intestinal lumen colonization.the nematode caenorhabditis elegans is hypersusceptible to burkholderia pseudomallei infection. however, the virulence mechanisms underlying rapid lethality of c. elegans upon b. pseudomallei infection remain poorly defined. to probe the host-pathogen interaction, we constructed gfp-tagged b. pseudomallei and followed bacterial accumulation within the c. elegans intestinal lumen. contrary to slow-killing by most bacterial pathogens, b. pseudomallei caused fairly limited intestinal lumen coloniza ...201223076282
construction and characterization of a burkholderia pseudomallei wzm deletion mutant.in burkholderia pseudomallei, the pathogen that causes melioidosis, the gene cluster encoding the capsular polysaccharide, is located on chromosome 1. among the 19 capsular genes in this cluster, wzm has not been thoroughly studied. to study the function of wzm, we generated a deletion mutant and compared it with the wild-type strain. the mutant produced less biofilm in minimal media and was more sensitive to desiccation and oxidative stress compared with the wild-type strain, indicating that wz ...201223075783
an objective approach for burkholderia pseudomallei strain selection as challenge material for medical countermeasures efficacy testing.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 a ...201223057010
cranial melioidosis with extradural extension after a fall in the bathroom.a 32-year-old diabetic male, with a past history of head injury and seizures, presented with a painful swelling over his forehead present for the past three months. cranial mri demonstrated the presence of a scalp collection with extradural extension through a bony defect. biopsy from the area showed caseating necrosis suggestive of tuberculosis. although the patient failed to return for initiation of anti-tubercular therapy for the next 11 months, the swelling did not progress, and there were n ...201223024720
evaluation of six commercial dna extraction kits for recovery of burkholderia pseudomallei dna.six commercially available dna extraction kits, as well as thermal lysis and proteinase k dna extraction were evaluated regarding bacterial inactivation, dna yield and purity, and their use in a burkholderia pseudomallei real-time pcr. while all methods successfully inactivated the bacteria, by measuring dna purity and the level of detection by real-time pcr, the proteinase k method was the most sensitive.201223022447
transverse myelitis secondary to melioidosis: a case report.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.201223020820
thoracic radiologic manifestations of melioidosis.melioidosis (burkholderia pseudomallei) is a gram-negative bacterial infection that is highly endemic in southeast asia and oceania. pulmonary disease is the most common form of involvement. the clinical-radiologic thoracic manifestations of melioidosis can be classified as acute, subacute, subclinical, and chronic forms. radiographic findings include nodular, alveolar, or mixed infiltration/consolidation with or without cavities. pleural effusion, pneumothorax, and pericardial involvement can b ...201623009770
involvement of signal regulatory protein α, a negative regulator of toll-like receptor signaling, in impairing the myd88-independent pathway and intracellular killing of burkholderia pseudomallei-infected mouse macrophages.the facultative intracellular gram-negative bacterium burkholderia pseudomallei is the causative agent of melioidosis and is known for its ability to evade the toll-like receptor (tlr)-mediated innate immune response. previously it has been demonstrated that this bacterium was able to suppress the myd88-independent pathway and can survive macrophage intracellular killing. however, the underlying mechanisms responsible for the suppression of this pathway are not fully understood. in the present s ...201222988019
development of ceftazidime resistance in an acute burkholderia pseudomallei infection.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 i ...201222977307
neutrophil extracellular traps exhibit antibacterial activity against burkholderia pseudomallei and are influenced by bacterial and host factors.burkholderia pseudomallei is the causative pathogen of melioidosis, of which a major predisposing factor is diabetes mellitus. polymorphonuclear neutrophils (pmns) kill microbes extracellularly by the release of neutrophil extracellular traps (nets). pmns play a key role in the control of melioidosis, but the involvement of nets in killing of b. pseudomallei remains obscure. here, we showed that bactericidal nets were released from human pmns in response to b. pseudomallei in a dose- and time-de ...201222927051
development and characterization of a caprine aerosol infection model of melioidosis.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 ...201222916225
burkholderia pseudomallei osteomyelitis: an unusual cause of fever in a returned traveller.a 52-year-old diabetic man presented to the emergency department with a history of fevers and pain in his right thigh. he had recently returned from a 10-month trip to vietnam. a suspected bacterial abscess in the right thigh did not respond to empirical antibiotics. subsequent investigations revealed melioidotic osteomyelitis of the femur. this case emphasises the need to consider the diagnosis of melioidosis in patients presenting with fever following travel in endemic areas.201222905056
crystallization and preliminary x-ray analysis of the receiver domain of a putative response regulator, bpsl0128, from burkholderia pseudomallei.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 crysta ...201222869122
molecular investigation of virulence determinants between a virulent clinical strain and an attenuated strain of burkholderia pseudomallei.burkholderia pseudomallei is the causative agent of melioidosis. we initiated this investigation with a virulent and an attenuated strain of b. pseudomallei. pulsed-field gel electrophoresis was carried out initially for macrogenomic comparison of both strains of b. pseudomallei. however, the pulsotypes obtained were identical and therefore we applied a subtractive hybridization technique to distinguish and determine the possible differences between the two strains. six virulence strain-specific ...201222846664
blf1, the first burkholderia pseudomallei toxin, connects inhibition of host protein synthesis with melioidosis.melioidosis is a disease caused by infection with burkholderia pseudomallei. the molecular basis for the pathogenicity of b. pseudomallei is poorly understood. however, recent work has identified the first toxin from this bacterium and shown that it inhibits host protein synthesis. here, we review the illness that is potentially associated with biological warfare, the pathogen and its deadly molecular mechanism of action, as well as therapeutic developments that may follow.201222817745
case cluster shifting and contaminant source as determinants of melioidosis in taiwan.to assess the geographical distribution of melioidosis contamination sources and the association between the location of melioidosis cases and positive sampling sites for burkholderia pseudomallei in taiwan.201222809327
development of a diagnostic system for burkholderia pseudomallei infections.monoclonal antibodies were generated against whole cell lysate of burkholderia pseudomallei. two out of 6 monoclonal antibodies were found specific and exhibited high affinity against b. pseudomallei, one of which, was utilized to develop sandwich elisa for detection of specific b. pseudomallei antigen. immunoassays were found to be specific as no reaction was observed with closely related burkholderia and pseudomonas species. blood samples from experimentally infected mice were found positive f ...201222806151
seroepidemiological surveillance of burkholderia pseudomallei in bangladesh.melioidosis (burkholderia pseudomallei infection) has yet to be demonstrated systematically in bangladesh. a prospective, cross-sectional serological survey was conducted in 2010 at six bangladeshi hospitals. age, gender, occupation and residential address were recorded. of 1244 patients, 359 (28.9%) were positive for b. pseudomallei by indirect haemagglutination assay. farmers had an increased risk of seropositivity (risk ratio=1.4, 95% ci 1.0-1.8; p=0.03). there was no clear geographic cluster ...201222795754
imaging spectrum of thoracic melioidosis.melioidosis is predominantly a tropical disease caused by burkholderia pseudomallei, a soil-dwelling gram-negative, aerobic bacillus that is distributed primarily in southeast asia and northern australia. in this pictorial essay, we provide an illustrated review and conceptual framework of the protean imaging features of this infection, along with a brief description of its clinical manifestations and demographic features.201322781630
malleilactone, a polyketide synthase-derived virulence factor encoded by the cryptic secondary metabolome of burkholderia pseudomallei group pathogens.sequenced bacterial genomes are routinely found to contain gene clusters that are predicted to encode metabolites not seen in fermentation-based studies. pseudomallei group burkholderia are emerging pathogens whose genomes are particularly rich in cryptic natural product biosynthetic gene clusters. we systematically probed the influence of the cryptic secondary metabolome on the virulence of these bacteria and found that disruption of the mal gene cluster, which is natively silent in laboratory ...201222765305
neonatal melioidosis: systematic review of the literature.twenty-two cases of neonatal melioidosis were identified with the primary outcome from a systematic review, and the clinical presentations were either bacteremia and/or meningitis with burkholderia pseudomallei isolated in all cases. ten cases reported the mode of transmission: infections that occurred from mother-to-child transmission (20%), and infections that were probably healthcare-associated (40%) and community-acquired (40%). the crude mortality was 73% (16/22).201222739573
matrix-assisted laser desorption ionization-time of flight mass spectrometry for rapid identification of burkholderia pseudomallei: importance of expanding databases with pathogens endemic to different localities. 201222718946
differential host response to burkholderia pseudomallei: tissue plasminogen activator*. 201222710226
genomic islands as a marker to differentiate between clinical and environmental burkholderia pseudomallei.burkholderia pseudomallei, as a saprophytic bacterium that can cause a severe sepsis disease named melioidosis, has preserved several extra genes in its genome for survival. the sequenced genome of the organism showed high diversity contributed mainly from genomic islands (gis). comparative genome hybridization (cgh) of 3 clinical and 2 environmental isolates, using whole genome microarrays based on b. pseudomallei k96243 genes, revealed a difference in the presence of genomic islands between cl ...201222675491
use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis for rapid confirmation of burkholderia pseudomallei in septicemic melioidosis.burkholderia pseudomallei was quickly identified from blood cultures collected from septicemic patients by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis using an in-house reference library. this procedure reduced the time to definitive identification by more than 24 hours. this analysis is a useful addition to laboratory methods for early recognition of septicemic melioidosis in non-endemic settings.201222665614
development and validation of burkholderia pseudomallei-specific real-time pcr assays for clinical, environmental or forensic detection applications.the bacterium burkholderia pseudomallei causes melioidosis, a rare but serious illness that can be fatal if untreated or misdiagnosed. species-specific pcr assays provide a technically simple method for differentiating b. pseudomallei from near-neighbor species. however, substantial genetic diversity and high levels of recombination within this species reduce the likelihood that molecular signatures will differentiate all b. pseudomallei from other burkholderiaceae. currently available molecular ...201222624061
persistent gastric colonization with burkholderia pseudomallei and dissemination from the gastrointestinal tract following mucosal inoculation of mice.melioidosis is a disease of humans caused by opportunistic infection with the soil and water bacterium burkholderia pseudomallei. melioidosis can manifest as an acute, overwhelming infection or as a chronic, recurrent infection. at present, it is not clear where b. pseudomallei resides in the mammalian host during the chronic, recurrent phase of infection. to address this question, we developed a mouse low-dose mucosal challenge model of chronic b. pseudomallei infection and investigated sites o ...201222624016
endogenous tissue-type plasminogen activator impairs host defense during severe experimental gram-negative sepsis (melioidosis)*.melioidosis is a frequent cause of severe sepsis in southeast asia caused by the gram-negative bacterium burkholderia pseudomallei. patients with melioidosis have elevated circulating levels of tissue-type plasminogen activator, an important regulator of fibrinolysis. in this study, we aimed to investigate the role of tissue-type plasminogen activator during melioidosis.201222564963
burkholderia pseudomallei detection in surface water in southern laos using moore's swabs.the causal agent of melioidosis, burkholderia pseudomallei, has been cultured from paddy fields in the lao pdr. we carried out a pilot study to examine the relationship between bacterial soil contamination and that of nearby surface waters in saravane province. soil sampling was conducted at a depth of 30 cm (100 holes in a 45 × 45 m grid) at two sites, east and west saravane. moore's swabs were used for water sampling of paddy fields, lakes, rivers, boreholes, and storage tanks within 2 km of t ...201222556090
glutathione deficiency in type 2 diabetes impairs cytokine responses and control of intracellular bacteria.individuals with type 2 diabetes are at increased risk of acquiring melioidosis, a disease caused by burkholderia pseudomallei infection. although up to half of melioidosis patients have underlying diabetes, the mechanisms involved in this increased susceptibility are unknown. we found that b. pseudomallei-infected pbmcs from diabetic patients were impaired in il-12p70 production, which resulted in decreased ifn-γ induction and poor bacterial killing. the defect was specific to the il-12-ifn-γ a ...201222546856
enzymatic profiling of clinical and environmental isolates of burkholderia pseudomallei.melioidosis has been recognized as an important cause of sepsis in the tropics. the disease caused by an environmental saprophyte burkholderia pseudomallei, affects mostly adults with underlying immunocompromised conditions. in this study, the enzymatic profiles of 91 clinical and 9 environmental isolates of b. pseudomallei were evaluated using the apizym system, in addition to assessment of protease, phospholipase c and sialidase activities using agar plate methods and other assays. the activit ...201222543616
pediatric suppurative parotitis in cambodia between 2007 and 2011.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.201222531239
polysaccharide specific monoclonal antibodies provide passive protection against intranasal challenge with burkholderia pseudomallei.burkholderia pseudomallei is a gram-negative bacillus that is the causative agent of melioidosis. the bacterium is inherently resistant to many antibiotics and mortality rates remain high in endemic areas. the lipopolysaccharide (lps) and capsular polysaccharide (cps) are two surface-associated antigens that contribute to pathogenesis. we previously developed two monoclonal antibodies (mabs) specific to the cps and lps; the cps mab was shown to identify antigen in serum and urine from melioidosi ...201222530013
dna binding site analysis of burkholderia thailandensis response regulators.bacterial response regulators (rr) that function as transcription factors in two component signaling pathways are crucial for ensuring tight regulation and coordinated expression of the genome. currently, consensus dna binding sites in the promoter for very few bacterial rrs have been identified. a systematic method to characterize these dna binding sites for rrs would enable prediction of specific gene expression patterns in response to extracellular stimuli. to identify rr dna binding sites, w ...201222521922
nitric oxide-dependent killing of aerobic, anaerobic and persistent burkholderia pseudomallei.burkholderia pseudomallei infections are fastidious to treat with conventional antibiotic therapy, often involving a combination of drugs and long-term regimes. bacterial genetic determinants contribute to the resistance of b. pseudomallei to many classes of antibiotics. in addition, anaerobiosis and hypoxia in abscesses typical of melioidosis select for persistent populations of b. pseudomallei refractory to a broad spectrum of antibacterials. we tested the susceptibility of b. pseudomallei to ...201222521523
emerging clinico-epidemiological trends in melioidosis: analysis of 95 cases from western coastal india.to study the clinico-epidemiological trends in melioidosis, an emerging disease in the western coastal region of india.201222512851
a melioidosis patient presenting with brainstem signs in the emergency department.neurological abnormalities in melioidosis are rare but may manifest as an acute stroke, and in the emergency department (ed), an inappropriate stroke treatment may threaten a patient's life.201322494598
comparison of the efficiency of sampling devices for aerosolized burkholderia pseudomallei.previous studies have demonstrated that aerosol sampling devices can have deleterious effects on bacteria due to stresses intrinsic to the sampling processes. although a significant amount of work has been carried out to develop animal models of inhalational melioidosis, little information has been reported on the effects of the aerosol sampling devices on the causative bacterium, burkholderia pseudomallei. the aim of this study was to compare the efficiencies for collection of aerosolized bacte ...201222486343
[characterisation of burkholderia pseudomallei lethal factor 1 (blf1). a breakthrough against melioidosis]. 201222480647
burkholderia pseudomallei triggers altered inflammatory profiles in a whole-blood model of type 2 diabetes-melioidosis comorbidity.melioidosis is a potentially fatal disease caused by the bacterium burkholderia pseudomallei. type 2 diabetes (t2d) is the most common comorbidity associated with melioidosis. b. pseudomallei isolates from melioidosis patients with t2d are less virulent in animal models than those from patients with melioidosis and no identifiable risk factors. we developed an ex vivo whole-blood assay as a tool for comparison of early inflammatory profiles generated by t2d and nondiabetic (nd) individuals in re ...201222473609
ceftazidime resistance in burkholderia pseudomallei: first report from india.melioidosis, a disease of public health importance in southeast asia and northern australia, of late has shown an increasing trend in india, particularly southern india. we describe a case of a 39-year-old diabetic patient with left elbow septic arthritis, multiple liver, splenic abscesses, pneumonia, pleural effusion, followed by sepsis syndrome. blood cultures and culture of the joint aspirate yielded pure growth of burkholderia pseudomallei (b. pesudomallei), sensitive to carbapenem, co-trimo ...201222449529
[study of extracellular antigens by immunodiffusion methods in differentiation of pathogenic burkholderiae].isolation and composition comparison of extracellular antigens (eca) of pathogenic burkholderiae in sds-page electrophoresis and their use for differentiation of these microorganisms by immunodiffusion methods.201222442972
comparison of taqman pcr assays for detection of the melioidosis agent burkholderia pseudomallei in clinical specimens.melioidosis is an emerging infectious disease caused by the soil bacterium burkholderia pseudomallei. in diagnostic and forensic settings, molecular detection assays need not only high sensitivity with low limits of detection but also high specificity. in a direct comparison of published and newly developed taqman pcr assays, we found the tts1-orf2 assay to be superior in detecting b. pseudomallei directly from clinical specimens. the ylf/btfc multiplex assay (targeting the yersinia-like fimbria ...201222442327
reduced susceptibility of malaysian clinical isolates of burkholderia pseudomallei to ciprofloxacin.ciprofloxacin, a quinolone with good intracellular penetration may possibly be used for treatment of melioidosis caused by burkholderia pseudomallei, but problems with resistance may be encountered. amino acid substitutions in gyra/gyrb have given rise to fluoroquinolone resistance in various microorganisms. using published primers for gyra and gyrb, pcr was performed on 11 isolates of b. pseudomallei with varying degrees of sensitivity to ciprofloxacin, followed by dna sequencing to detect poss ...201122433895
regulation of a quorum sensing system by stationary phase sigma factor rpos and their co-regulation of target genes in burkholderia pseudomallei.burkholderia pseudomallei is the causative agent of a fatal disease, melioidosis. however, the mechanisms of pathogenesis and genes involved in its virulence are not understood. in the current study, whether stationary phase and stress response sigma factor rpos and bpsi-mediated quorum sensing (qs) system co-regulate its target genes was investigated. positive regulation of rpos on bpsi expression and autoinducer production in stationary phase, but not on flic and ppk expression, was observed. ...201222385268
severe coinfection of melioidosis and dengue fever in northeastern brazil: first case report.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 detecte ...201222370846
diffusion and activity of antibiotics against burkholderia pseudomallei biofilms.the diffusion and activity of ceftazidime (caz), imipenem (ipm) and trimethoprim/sulfamethoxazole (tmp/smx) against burkholderia pseudomallei biofilms were comparatively tested using the high biofilm-producing strain b. pseudomallei 377 and the biofilm-defective mutant b. pseudomallei m6. biofilms were generated by inoculation of bacteria on polycarbonate membranes placed on the surface of tryptic soy agar plates. the results showed that diffusion of tmp/smx through b. pseudomallei biofilms was ...201222364716
characterization of ceftazidime resistance mechanisms in clinical isolates of burkholderia pseudomallei from australia.burkholderia pseudomallei is a gram-negative bacterium that causes the serious human disease, melioidosis. there is no vaccine against melioidosis and it can be fatal if not treated with a specific antibiotic regimen, which typically includes the third-generation cephalosporin, ceftazidime (caz). there have been several resistance mechanisms described for b. pseudomallei, of which the best described are amino acid changes that alter substrate specificity in the highly conserved class a β-lactama ...201222363490
development of hydrolysis probe-based real-time pcr for identification of virulent gene targets of burkholderia pseudomallei and b. mallei--a retrospective study on archival cases of service members with melioidosis and glanders.burkholderia pseudomallei and b. mallei are two highly pathogenic bacteria responsible for melioidosis and glanders, respectively. our laboratory developed hydrolysis probe-based real-time polymerase chain reaction assays targeting type three secretion system (tts) and transposase family protein (tfp) of b. pseudomallei and b. malli, respectively. the assays were validated for target specificity, amplification sensitivity, and reproducibility. a bacterial dna panel, composed of b. pseudomallei ( ...201222360070
validation of a burkholderia pseudomallei hypothetical protein and determination of its translational start codon using chromosomal integration of his-tag coding sequence.in this post genomic era, there are a great number of in silico annotated hypothetical genes. however, experimental validation of the functionality of these genes remains tentative. two of the major challenges faced by researcher are whether these hypothetical genes are protein-coding genes and whether their corresponding predicted translational start codons are correct. in this report, we demonstrate a convenient procedure to validate the presence of a hypothetical gene product of bpss1356 from ...201222354666
melioidosis vaccines: a systematic review and appraisal of the potential to exploit biodefense vaccines for public health purposes.burkholderia pseudomallei is a category b select agent and the cause of melioidosis. research funding for vaccine development has largely considered protection within the biothreat context, but the resulting vaccines could be applicable to populations who are at risk of naturally acquired melioidosis. here, we discuss target populations for vaccination, consider the cost-benefit of different vaccination strategies and review potential vaccine candidates.201222303489
interaction of burkholderia pseudomallei and burkholderia thailandensis with human monocyte-derived dendritic cells.burkholderia pseudomallei is the causative agent of melioidosis, a disease endemic in areas of south-east asia and northern australia, and is classed as a category b select agent by the centers for disease control and prevention (cdc). factors that determine whether host infection is achieved or if disease is chronic or acute are unknown but the type of host immune response that is mounted is important. b. pseudomallei can replicate within macrophages, causing them to multinucleate. in light of ...201222301613
surface plasmon resonance immunosensor for rapid and specific diagnosis of melioidosis antibody.melioidosis, caused by burkholderia pseudomallei, is a potentially fatal disease, which requires an accurate and rapid diagnosis. this paper reports on the highly sensitive and specific detection of melioidosis antibodies by surface plasmon resonance immunosensor. the sensing surface was immobilized with b. pseudomallei bipd protein via a 11-mercaptoundecanoic acid self-assembled monolayer. under optimum conditions individual sera of melioidosis patients, non-melioidosis patients (negative) and ...201122299443
sesquiterpene farnesol contributes to increased susceptibility to β-lactams in strains of burkholderia pseudomallei.this study aimed to evaluate the in vitro combination of farnesol and β-lactams against burkholderia pseudomallei. a total of 12 β-lactamase-positive strains were tested according to clsi standards. all strains were inhibited by farnesol, with mics ranging from 75 to 150 μm. the combination of this compound with β-lactams resulted in statistically significant β-lactam mic reduction (p ≤ 0.05). this study provides new perspectives for the use of farnesol combined with β-lactam antibiotics against ...201222290941
melioidosis presenting with mediastinal lymphadenopathy masquerading as malignancy: a case report.melioidosis, endemic in thailand and in the northern territory of australia is an emerging infectious disease in india which can present with varied forms. a case of melioidosis, presenting as a rare anterior mediastinal mass which can masquerade as malignancy or tuberculosis, is described here. with treatment, our patient initially showed an increase in the size of mediastinal node and development of new submandibular node.. to the best of our knowledge, this phenomenon has not been documented ...201222269609
immune response to burkholderia pseudomallei.burkholderia pseudomallei are the causative agents of melioidosis, a disease found mostly in people with underlying risk factors. fifty percent of cases are community-acquired septicemias and manifestation can vary from acute septicemia (with or without shock), to chronic, to subclinical infections. there is no vaccine to prevent the condition. it is difficult to eradicate the bacteria. prolonged antibiotic therapy is required. finally, there is a high rate of relapse when therapy is not complet ...201122256484
the bug and the big heart --melioidotic pericardial effusion.melioidosis is an infection caused by gram negative bacterium burkholderia pseudomallei leading to abscesses in lungs, liver, spleen, musculoskeletal system, prostate and sepsis. we present a rare case of purulent pericardial effusion caused by melioidosis with concomitant pneumonia and splenic abscesses. the patient underwent pericardiocentesis and successfully recovered from cardiogenic and septic shock.201123765151
melioidosis: it is not far from here.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 an ...201125191391
melioidosis--an uncommon but also under-recognized cause of pneumonia in papua new guinea.melioidosis is being increasingly recognized as an important cause of severe, acute community-acquired pneumonia in various tropical regions. the chronic form of melioidosis can also mimic tuberculosis. studies have established that, while uncommon in the port moresby region, melioidosis is an important cause of pneumonia and sepsis in the balimo region of western province. phylogenetic analyses of strains of burkholderia pseudomallei from papua new guinea have shown them to be more closely rela ...201223163189
melioidotic pericardial effusion.aim is to present a rare case of purulent pericardial effusion caused by burkholderia pseudomallei. pericardial sample was inoculated into bactec peds plus/f broth of the bactec automated system. after the system flagged positive, the broth was subjected to gram stain, biochemical tests and drug susceptibility. the organism was identified as burkholderia pseudomallei. tuberculosis (tb) is the most common cause of pericarditis in countries where it remains a major public health problem, but in th ...201022466500
atypical morphological characteristics and surface antigen expression of burkholderia pseudomallei in naturally infected human synovial tissues.abstract burkholderia pseudomallei is the causative agent of melioidosis, a disease that frequently runs a protracted course and is very difficult to eradicate. the mechanisms that this organism uses to escape from host defense mechanisms and antibiotics are not well understood. the aim of the study was to compare the morphological characteristics and surface antigen expression of b. pseudomallei in naturally infected human synovial tissues with the characteristics of bacteria grown in culture m ...200024383589
deciphering minimal antigenic epitopes associated with burkholderia pseudomallei and burkholderia mallei lipopolysaccharide o-antigens.burkholderia pseudomallei (bp) and burkholderia mallei (bm), the etiologic agents of melioidosis and glanders, respectively, cause severe disease in both humans and animals. studies have highlighted the importance of bp and bm lipopolysaccharides (lps) as vaccine candidates. here we describe the synthesis of seven oligosaccharides as the minimal structures featuring all of the reported acetylation/methylation patterns associated with bp and bm lps o-antigens (oags). our approach is based on the ...201728740137
development of a real-time loop-mediated isothermal amplification assay for detection of burkholderia mallei.burkholderia mallei is the aetiological agent of glanders, a highly contagious and re-emerging zoonotic disease. early diagnosis of glanders is critically important to ensure timely treatment with appropriate antibiotics in humans, and to prevent spread of infection in animals. molecular detection of b. mallei has always been troublesome because of its genetic similarity with burkholderia pseudomallei, the causative agent of melioidosis. in present investigation, a set of six b. mallei-specific ...201728649808
development of a multiplex pcr assay for the detection and differentiation of burkholderia pseudomallei, burkholderia mallei, burkholderia thailandensis, and burkholderia cepacia complex.two species of burkholderia pseudomallei complex (bpc), b. pseudomallei and b. mallei, can cause severe life-threatening infections. rapidly discerning individual species within the group and separating them from other opportunistic pathogens of the burkholderia cepacia complex (bcc) is essential to establish a correct diagnosis and for epidemiological surveillance. in this study, a multiplex pcr assay based on the detection of an individual set of chromosomal beta-lactamase genes for single-ste ...201728634144
burkholderia thailandensis: genetic manipulation.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 allel ...201728510362
antibodies against in vivo-expressed antigens are sufficient to protect against lethal aerosol infection with burkholderia mallei and burkholderia pseudomallei.burkholderia mallei, a facultative intracellular bacterium and tier 1 biothreat, causes the fatal zoonotic disease glanders. the organism possesses multiple genes encoding autotransporter proteins, which represent important virulence factors and targets for developing countermeasures in pathogenic gram-negative bacteria. in the present study, we investigated one of these autotransporters, bata, and demonstrate that it displays lipolytic activity, aids in intracellular survival, is expressed in v ...201728507073
preparing for biological threats: addressing the needs of pregnant women.intentional release of infectious agents and biological weapons to cause illness and death has the potential to greatly impact pregnant women and their fetuses. we review what is known about the maternal and fetal effects of seven biological threats: bacillus anthracis (anthrax); variola virus (smallpox); clostridium botulinum toxin (botulism); burkholderia mallei (glanders) and burkholderia pseudomallei (melioidosis); yersinia pestis (plague); francisella tularensis (tularemia); and rickettsia ...201728398677
genomics reveals a unique clone of burkholderia cenocepacia harboring an actively excising novel genomic island.burkholderia cenocepacia is a clinically dominant form among the other virulent species of burkholderia cepacia complex (bcc). in the present study, we sequenced and analyzed the genomes of seven nosocomial bcc isolates, five of which were isolated from the bloodstream infections and two isolates were recovered from the hospital setting during the surveillance. genome-based species identification of the bcc isolates using a type strain explicitly identified the species as b. cenocepacia. moreove ...201728428775
designing probes for immunodiagnostics: structural insights into an epitope targeting burkholderia infections.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 ...201728707874
within-host evolution of burkholderia pseudomallei during chronic infection of seven australasian cystic fibrosis patients.cystic fibrosis (cf) is a genetic disorder characterized by progressive lung function decline. cf patients are at an increased risk of respiratory infections, including those by the environmental bacterium burkholderia pseudomallei, the causative agent of melioidosis. here, we compared the genomes of b. pseudomallei isolates collected between ~4 and 55 months apart from seven chronically infected cf patients. overall, the b. pseudomallei strains showed evolutionary patterns similar to those of o ...201728400528
clinical outcomes in musculoskeletal involvement of burkholderia pseudomallei infection.musculoskeletal involvement in melioidosis is often seen in conjunction with a disseminated illness. recent reports suggest that operative management of musculoskeletal melioidosis has favourable results. the purpose of this study was to review the patient profile and clinical outcomes of burkholderia pseudomallei infection in the musculoskeletal system.201728861207
mitogen-activated protein kinases (mapks) are modulated during in vitro and in vivo infection with the intracellular bacterium burkholderia pseudomallei.burkholderia pseudomallei is a gram-negative intracellular bacterium that causes the disease melioidosis. the disease can be fatal if left untreated or when antibiotic therapy is delayed and total clearance of the pathogen from the host is often not accomplished with current therapies. thus, new therapeutic approaches for the treatment of infections caused by b. pseudomallei are required. to better understand host responses to b. pseudomallei infection, the activation of key proteins involved in ...201728856457
investigation of host-pathogen interaction between burkholderia pseudomallei and autophagy-related protein lc3 using hydrophobic chromatography-based technique.burkholderia pseudomallei is an intracellular bacteria causing melioidosis, the disease widely disseminates in southeast asia and northern australia. b. pseudomallei has ability to invade various types of host cell and to interfere with host defense mechanisms, such as nitric oxide (no). due to the cross-talk among alternative killing mechanisms in host immune response against invading microbes, autophagy is the molecular mechanism belonging to intracellular elimination of eukaryotic cells that ...201728852470
burkholderia pseudomallei evades nramp1 (slc11a1)- and nadph oxidase-mediated killing in macrophages and exhibits nramp1-dependent virulence gene expression.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 ...201728848712
host-adaptation of burkholderia pseudomallei alters metabolism and virulence: a global proteome analysis.little is known about the evolution, adaptation and pathogenesis of burkholderia pseudomallei within host during acute melioidosis infection. melioidosis is a potential life threatening disease contracted through inhalation, ingestion, inoculation or direct entry of the organism into the blood stream via wounds or skin abrasions from contaminated soil and water. environmental b. pseudomallei strain (bp maran ), isolated during a melioidosis outbreak in pahang, malaysia was injected intra-periton ...201728827633
anti-cancer drug hmba acts as an adjuvant during intracellular bacterial infections by inducing type i ifn through sting.the anti-proliferative agent hexamethylene bisacetamide (hmba) belongs to a class of hybrid bipolar compounds developed more than 30 y ago for their ability to induce terminal differentiation of transformed cells. recently, hmba has also been shown to trigger hiv transcription from latently infected cells, via a cdk9/hmba inducible protein-1 dependent process. however, the effect of hmba on the immune response has not been explored. we observed that pretreatment of human peripheral blood mononuc ...201728827286
pacbio but not illumina technology can achieve fast, accurate and complete closure of the high gc, complex burkholderia pseudomallei two-chromosome genome.although pacbio third-generation sequencers have improved the read lengths of genome sequencing which facilitates the assembly of complete genomes, no study has reported success in using pacbio data alone to completely sequence a two-chromosome bacterial genome from a single library in a single run. previous studies using earlier versions of sequencing chemistries have at most been able to finish bacterial genomes containing only one chromosome with de novo assembly. in this study, we compared t ...201728824579
persistent infection due to a small-colony variant of burkholderia pseudomallei leads to pd-1 upregulation on circulating immune cells and mononuclear infiltration in viscera of experimental balb/c mice.melioidosis is a neglected tropical disease endemic across south east asia and northern australia. the etiological agent, burkholderia pseudomallei (b.pseudomallei), is a gram-negative, rod-shaped, motile bacterium residing in the soil and muddy water across endemic regions of the tropical world. the bacterium is known to cause persistent infections by remaining latent within host cells for prolonged duration. reactivation of the recrudescent disease often occurs in elders whose immunity wanes. ...201728820897
differential microrna analyses of burkholderia pseudomallei- and francisella tularensis-exposed hpbmcs reveal potential biomarkers.increasing evidence that micrornas (mirnas) play important roles in the immune response against infectious agents suggests that mirna might be exploitable as signatures of exposure to specific infectious agents. in order to identify potential early mirna biomarkers of bacterial infections, human peripheral blood mononuclear cells (hpbmcs) were exposed to two select agents, burkholderia pseudomallei k96243 and francisella tularensis shu s4, as well as to the nonpathogenic control escherichia coli ...201728791299
nitrate sensing and metabolism inhibit biofilm formation in the opportunistic pathogen burkholderia pseudomallei by reducing the intracellular concentration of c-di-gmp.the opportunistic pathogen burkholderia pseudomallei is a saprophytic bacterium and the causative agent of melioidosis, an emerging infectious disease associated with high morbidity and mortality. although melioidosis is most prevalent during the rainy season in endemic areas, domestic gardens and farms can also serve as a reservoir for b. pseudomallei during the dry season, in part due to irrigation and fertilizer use. in the environment, b. pseudomallei forms biofilms and persists in soil near ...201728790983
a simple laboratory algorithm for diagnosis of melioidosis in resource-constrained areas: a study from north central vietnam.melioidosis may be endemic in many tropical developing countries but diagnosis of the disease is currently unreliable in resource-limited areas. here we aimed to validate a simple and cheap laboratory algorithm for the identification of burkholderia pseudomallei from clinical specimens in parts of vietnam where the disease has not been reported before.201728780059
bipc, a predicted burkholderia pseudomallei type 3 secretion system translocator protein with actin binding activity.burkholderia pseudomallei is an intracellular bacterial pathogen and the causative agent of melioidosis, a severe disease of humans and animals. like other clinically important gram-negative bacteria, fundamental to b. pseudomallei pathogenesis is the bsa type iii secretion system. the bsa system injects bacterial effector proteins into the cytoplasm of target host cells subverting cellular pathways for the benefit of the bacteria. it is required for invasion of non-phagocytic host cells, escape ...201728770177
a case report of co-infection of melioidosis and cutaneous leishmaniasis.leishmaniasis and melioidosis are frequently reported from the north central province of sri lanka. however, only one case of co-infection of the two diseases has been reported to date over the world. this is a case report of a patient who had co-infection with cutaneous leishmaniasis and melioidosis and was successfully treated and recovered from the illness.201728764662
entry, intracellular survival and multinucleated giant cell-forming activity of burkholderia pseudomallei in human primary phagocytic and non-phagocytic cells.the human pathogen burkholderia pseudomallei and the related species burkholderia thailandensis are facultative intracellular bacteria characterized by the ability to escape into the cytosol of the host cell and to stimulate the formation of multinucleated giant cells (mngcs). mngc formation is induced via an unknown mechanism by the bacterial type vi secretion system 5 (t6ss-5), which is an essential virulence factor in both species. despite the vital role of the intracellular life cycle in the ...201728760929
epidemiological cut-off value of clinical isolates of burkholderia pseudomallei from northern queensland to meropenem, ceftazidime, trimethoprim/sulfamethoxazole and doxycycline by the microbroth dilution method.melioidosis is caused by the bacterium burkholderia pseudomallei. the most common antibiotics used to treat melioidosis in australia are meropenem, ceftazidime, trimethoprim/sulfamethoxazole (sxt) and doxycycline. the european committee on antimicrobial susceptibility testing (eucast) and clinical and laboratory standards institute (clsi) do not provide standards for assessing the susceptibility of b. pseudomallei for these agents. the international standards organisation (iso) microbroth diluti ...201728729203
antimicrobial susceptibility pattern of clinical isolates of burkholderia pseudomallei in bangladesh.melioidosis an infectious disease, caused by a gram negative bacterium called burkholderia pseudomallei, is endemic in bangladesh. this organism is sensitive to limited number of antimicrobial agents and need prolonged treatment. there is no comprehensive data on the antimicrobial susceptibility profile of b. pseudomallei isolated in bangladesh over last several years. the present study aimed to determine the antimicrobial susceptibility pattern of b. pseudomallei isolated in a tertiary care hos ...201728728591
susceptibility of clinical isolates of burkholderia pseudomallei to a lipid a biosynthesis inhibitor.burkholderia pseudomallei is the causative agent of melioidosis, a serious infection associated with high mortality and relapse. current antimicrobial therapy using ceftazidime (caz) is often ineffective. inhibitors of lpxc, the enzyme responsible for lipid a biosynthesis, have potential antimicrobial activity against several gram-negative bacteria in vivo, but their activity against b. pseudomallei is unclear. herein, we investigated the susceptibility of b. pseudomallei clinical isolates to lp ...201728719324
differences in inflammation patterns induced by african and asian burkholderia pseudomallei isolates in mice.abstractburkholderia pseudomallei is the causative agent of melioidosis, an emerging tropical disease of high mortality. sub-saharan africa represents potential melioidosis "hotspots"; however, to date, only a few cases have been reported. here in, we compared the inflammatory patterns induced by a b. pseudomallei strain recently isolated from a fatal gabonese case with the thai reference strain b. pseudomallei-1026b and burkholderia thailandensis-e264. ex vivo, no differences were observed in t ...201728719265
melioidosis: an emerging infection with fatal outcomes.according to the centers for disease control and prevention, from being nonendemic for melioidosis, india has now become endemic for the disease since 2012. until then, melioidosis cases were being reported sporadically from india. there have been isolated case reports from few states across the country for the past few years. most of the times, burkholderia pseudomallei may be misreported as pseudomonas species, especially in resource-poor laboratories. due to its varied clinical presentation, ...201728701847
bacterial bloodstream infections in a tertiary infectious diseases hospital in northern vietnam: aetiology, drug resistance, and treatment outcome.bloodstream infections (bsis) are associated with high morbidity and mortality worldwide. however their aetiology, antimicrobial susceptibilities and associated outcomes differ between developed and developing countries. systematic data from vietnam are scarce. here we present aetiologic data on bsi in adults admitted to a large tertiary referral hospital for infectious diseases in hanoi, vietnam.201728701159
infected abdominal aortic aneurysms treated with extra-anatomic prosthesis bypass in the retroperitoneum.infected abdominal aortic aneurysms (iaaas) are rare but life-threatening diseases. the purpose of the present study was to report our experience of extra-anatomic prosthesis bypass in the retroperitoneum as a treatment for iaaas.201728687504
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