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culturable bacterial microbiota of the stomach of helicobacter pylori positive and negative gastric disease patients.human stomach is the only known natural habitat of helicobacter pylori (hp), a major bacterial pathogen that causes different gastroduodenal diseases. despite this, the impact of hp on the diversity and the composition of the gastric microbiota has been poorly studied. in this study, we have analyzed the culturable gastric microbiota of 215 malaysian patients, including 131 hp positive and 84 hp negative individuals that were affected by different gastric diseases. non-hp bacteria isolated from ...201425105162
inactivation of bacterial and viral biothreat agents on metallic copper surfaces.in recent years several studies in laboratory settings and in hospital environments have demonstrated that surfaces of massive metallic copper have intrinsic antibacterial and antiviral properties. microbes are rapidly inactivated by a quick, sharp shock known as contact killing. the underlying mechanism is not yet fully understood; however, in this process the cytoplasmic membrane is severely damaged. pathogenic bacterial and viral high-consequence species able to evade the host immune system a ...201425100640
[melioidosis in a danish tourist returning from north-eastern thailand].melioidosis, an infectious disease caused by burkholderia pseudomallei, is endemic in south east asia and northern australia. it has a wide clinical diversity, spanning from asymptomatic cases to rapid septic shock and death. we present a case of pulmonary melioidosis in a danish tourist returning from north-eastern thailand. the patient was treated with intravenous ceftazidime followed by oral therapy with trimethoprim/sulfamethoxazole and subsequently switched to doxycycline due to abnormal li ...201425096943
fatal burkholderia pseudomallei infection initially reported as a bacillus species, ohio, 2013.a fatal case of melioidosis was diagnosed in ohio one month after culture results were initially reported as a bacillus species. to identify a source of infection and assess risk in patient contacts, we abstracted patient charts; interviewed physicians and contacts; genetically characterized the isolate; performed a burkholderia pseudomallei antibody indirect hemagglutination assay on household contacts and pets to assess seropositivity; and collected household plant, soil, liquid, and insect sa ...201425092821
effect of oral n-acetyl cysteine supplementation in type 2 diabetic patients on intracellular glutathione content and innate immune responses to burkholderia pseudomallei.type 2 diabetic patients have increased susceptibility to melioidosis, an infectious disease caused by burkholderia pseudomallei. we had previously shown that peripheral blood mononuclear cells (pbmcs) from diabetic patients with poor glycemic control had a defective il-12 and ifnγ response to b. pseudomallei infection, resulting in poor intracellular bacterial control. the impaired il-12 response was due to glutathione (gsh) deficiency characterized by a low reduced to oxidized glutathione rati ...201425088507
characterization and analysis of the burkholderia pseudomallei bsan virulence regulon.burkholderia pseudomallei is a facultative intracellular pathogen and the causative agent of melioidosis. a conserved type iii secretion system (t3ss3) and type vi secretion system (t6ss1) are critical for intracellular survival and growth. the t3ss3 and t6ss1 genes are coordinately and hierarchically regulated by a tetr-type regulator, bspr. a central transcriptional regulator of the bspr regulatory cascade, bsan, activates a subset of t3ss3 and t6ss1 loci.201425085508
structural insights into wcbi, a novel polysaccharide-biosynthesis enzyme.capsular polysaccharides (cpss) are protective structures on the surfaces of many gram-negative bacteria. the principal cps of the human pathogen and tier 1 select agent burkholderia pseudomallei consists of a linear repeat of --3)--2-o-acetyl-6-deoxy-β-d-manno-heptopyranose-(1-. this cps is critical to the virulence of this emerging pathogen and represents a key target for the development of novel therapeutics. wcbi is one of several genes in the cps biosynthetic cluster whose deletion leads to ...201325075317
interaction of interferon gamma-induced reactive oxygen species with ceftazidime leads to synergistic killing of intracellular burkholderia pseudomallei.burkholderia pseudomallei, a facultative intracellular pathogen, causes severe infections and is inherently refractory to many antibiotics. previous studies from our group have shown that interferon gamma (ifn-γ) interacts synergistically with the antibiotic ceftazidime to kill bacteria in infected macrophages. the present study aimed to identify the underlying mechanism of that interaction. we first showed that blocking reactive oxygen species (ros) pathways reversed ifn-γ- and ceftazidime-medi ...201425070108
migration of dendritic cells facilitates systemic dissemination of burkholderia pseudomallei.burkholderia pseudomallei, the etiological agent for melioidosis, is an important cause of community-acquired sepsis in northern australia and northeast thailand. due to the rapid dissemination of disease in acute melioidosis, we hypothesized that dendritic cells (dc) could act as a vehicle for dissemination of b. pseudomallei. therefore, this study investigated the effect of b. pseudomallei infection on dc migration capacity and whether migration of dc enabled transportation of b. pseudomallei ...201425069976
rapid burkholderia pseudomallei identification and antibiotic resistance determination by bacteriophage amplification and maldi-tof ms.phage amplification detected by maldi-tof ms was investigated for rapid and simultaneous burkholderia pseudomallei identification and ceftazidime resistance determination. b. pseudomallei ceftazidime susceptible and resistant δpurm mutant strains bp82 and bp82.3 were infected with broadly targeting b. pseudomallei phage ϕx216 and production of the m/z 37.6 kda phage capsid protein observed by maldi-tof ms over the course of 3 h infections. this allowed for repoducible phage-based bacterial id wi ...201425050191
construction and characterization of stable, constitutively expressed, chromosomal green and red fluorescent transcriptional fusions in the select agents, bacillus anthracis, yersinia pestis, burkholderia mallei, and burkholderia pseudomallei.here, we constructed stable, chromosomal, constitutively expressed, green and red fluorescent protein (gfp and rfp) as reporters in the select agents, bacillus anthracis, yersinia pestis, burkholderia mallei, and burkholderia pseudomallei. using bioinformatic approaches and other experimental analyses, we identified p0253 and p1 as potent promoters that drive the optimal expression of fluorescent reporters in single copy in b. anthracis and burkholderia spp. as well as their surrogate strains, r ...201425044501
antimicrobial susceptibility patterns of burkholderia pseudomallei among melioidosis cases in kedah, malaysia.burkholderia pseudomallei, the causative agent of melioidosis is an important cause of morbidity and mortality particularly among diabetics. we evaluated 228 isolates of b. pseudomallei for antimicrobial sensitivity during 2005-2010 using the disc diffusion technique, of which 144 were obtained from blood culture. more than 90% of the strains were susceptible to cefoperazone, ceftazidime, chloramphenicol and imipenem. eighty-two percent of the isolates were susceptible to tetracycline and amoxic ...201424974653
intracerebral coinfection with burkholderia pseudomallei and cryptococcus neoformans in a patient with systemic lupus erythematosus.infections are a serious complication in patients with systemic lupus erythematosus (sle), and are an important cause of morbidity and mortality. sle patients are particularly susceptible to infection due to immune suppression from underlying disease or treatment. most infections are due to common bacterial organisms. clinicians also need to be aware of the possibility of polymicrobial infections as these may cause diagnostic delay and affect outcomes. we report the case of an intra-cerebral coi ...201424968675
comparison of stress adaptation and survival rate between burkholderia pseudomallei with mutant and wild type bfmr.burkholderia pseudomallei (bp) is highly adaptable to a wide range of environmental changes for survival and pathogenesis. however, the underlying mechanisms of such adaptability are still unclear. two-component system (tcs) is a common signal transduction used by bacteria in response to environmental changes. a gene designated as bfmr (locus tag of bpsl2024) has been proposed to encode a response regulator, a member of the tcs, and was studied by mutagenesis and comparison of its phenotypic cha ...201424968674
microevolution of burkholderia pseudomallei during an acute infection.we used whole-genome sequencing to evaluate 69 independent colonies of burkholderia pseudomallei isolated from seven body sites of a patient with acute disseminated melioidosis. fourteen closely related genotypes were found, providing evidence for the rapid in vivo diversification of b. pseudomallei after inoculation and systemic spread.201424966357
the coagulation system in melioidosis: from pathogenesis to new treatment strategies.melioidosis, caused by the gram-negative bacterium burkholderia pseudomallei, is a dreadful disease common in south-east asia and northern australia and is characterized by chronic suppurative lesions and pneumonia. melioidosis may evolve into severe sepsis with multi-organ failure with high mortalities, despite proper antibiotic therapy. besides activation of a strong pro-inflammatory host response, the coagulation system plays an important role during melioidosis, which is thought to be host-p ...201424962103
new insights from the 7th world melioidosis congress 2013. 201424961743
membrane-active mechanism of lfchimera against burkholderia pseudomallei and burkholderia thailandensis.lfchimera, a construct combining two antimicrobial domains of bovine lactoferrin, lactoferrampin265-284 and lactoferricin17-30, possesses strong bactericidal activity. as yet, no experimental evidence was presented to evaluate the mechanisms of lfchimera against burkholderia isolates. in this study we analyzed the killing activity of lfchimera on the category b pathogen burkholderia pseudomallei in comparison to the lesser virulent burkholderia thailandensis often used as a model for the highly ...201424961697
a data-driven approach to modeling the tripartite structure of multidrug resistance efflux pumps.many bacterial pathogens are becoming increasingly resistant to antibiotic treatments, and a detailed understanding of the molecular basis of antibiotic resistance is critical for the development of next-generation approaches for combating bacterial infections. studies focusing on pathogens have revealed the profile of resistance in these organisms to be due primarily to the presence of multidrug resistance efflux pumps: tripartite protein complexes which span the periplasm bridging the inner an ...201524957790
melioidosis presenting as lymphadenitis: a case report.melioidosis is an infection caused by the facultative intracellular gram-negative bacterium; burkholderia pseudomallei. it gives rise to protean clinical manifestations and has a varied prognosis. although it was rare in sri lanka increasing numbers of cases are being reported with high morbidity and mortality. here we report a case of melioidosis presenting with lymphadenitis which was diagnosed early and treated promptly with a good outcome.201424927768
the multiple roles of hypothetical gene bpss1356 in burkholderia pseudomallei.burkholderia pseudomallei is an opportunistic pathogen and the causative agent of melioidosis. it is able to adapt to harsh environments and can live intracellularly in its infected hosts. in this study, identification of transcriptional factors that associate with the β' subunit (rpoc) of rna polymerase was performed. the n-terminal region of this subunit is known to trigger promoter melting when associated with a sigma factor. a pull-down assay using histidine-tagged b. pseudomallei rpoc n-ter ...201424927285
current antimicrobial susceptibility of first-episode melioidosis burkholderia pseudomallei isolates from the northern territory, australia.burkholderia pseudomallei is a saprophytic gram-negative bacterium responsible for the tropical infectious disease melioidosis. melioidosis is endemic to northern australia and southeast asia. in this study, 234 isolates of b. pseudomallei obtained from the first positive clinical specimen from 234 consecutive patients diagnosed with melioidosis between october 2009 and september 2012 were reviewed. all isolates were susceptible to meropenem and ceftazidime. in total, 226 isolates (96.6%) were s ...201424924662
accidental exposure to burkholderia pseudomallei in the laboratory in the era of matrix-assisted laser desorption ionization-time of flight mass spectrometry. 201424920780
source-identifying biomarker ions between environmental and clinical burkholderia pseudomallei using whole-cell matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (maldi-tof ms).burkholderia pseudomallei is the causative agent of melioidosis, which is an endemic disease in northeast thailand and northern australia. environmental reservoirs, including wet soils and muddy water, serve as the major sources for contributing bacterial infection to both humans and animals. the whole-cell matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (whole-cell maldi-tof ms) has recently been applied as a rapid, accurate, and high-throughput tool for clinical di ...201424914956
protection against experimental melioidosis following immunisation with a lipopolysaccharide-protein conjugate.melioidosis is a severe infectious disease caused by burkholderia pseudomallei. it is refractory to antibiotic treatment and there is currently no licensed vaccine. in this report we detail the construction and protective efficacy of a polysaccharide-protein conjugate composed of b. pseudomallei lipopolysaccharide and the hc fragment of tetanus toxin. immunisation of mice with the lipopolysaccharide-conjugate led to significantly reduced bacterial burdens in the spleen 48 hours after challenge a ...201424892035
the chemical arsenal of burkholderia pseudomallei is essential for pathogenicity.increasing evidence has shown that small-molecule chemistry in microbes (i.e., secondary metabolism) can modulate the microbe-host response in infection and pathogenicity. the bacterial disease melioidosis is conferred by the highly virulent, antibiotic-resistant pathogen burkholderia pseudomallei (bp). whereas some macromolecular structures have been shown to influence bp virulence (e.g., secretion systems, cellular capsule, pili), the role of the large cryptic secondary metabolome encoded with ...201424884988
type three secretion system-mediated escape of burkholderia pseudomallei into the host cytosol is critical for the activation of nfκb.burkholderia pseudomallei is the causative agent of melioidosis, a potentially fatal disease endemic in southeast asia and northern australia. this gram-negative pathogen possesses numerous virulence factors including three "injection type" type three secretion systems (t3sss). b. pseudomallei has been shown to activate nfκb in hek293t cells in a toll-like receptor and myd88 independent manner that requires t3ss gene cluster 3 (t3ss3 or t3ssbsa). however, the mechanism of how t3ss3 contributes t ...201424884837
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
the concentrations of ambient burkholderia pseudomallei during typhoon season in endemic area of melioidosis in taiwan.melioidosis is a severe bacterial infection caused by burkholderia pseudomallei with a high case-fatality rate. epidemiological and animal studies show the possibility of inhalation transmission. however, no b. pseudomallei concentrations in ambient air have been researched. here, we developed a method to quantify ambient b. pseudomallei and then measured concentrations of ambient b. pseudomallei during the typhoon season and the non-typhoon season to determine the factors influencing ambient b. ...201424874950
burkholderia pseudomallei capsular polysaccharide conjugates provide protection against acute melioidosis.burkholderia pseudomallei, the etiologic agent of melioidosis, is a cdc tier 1 select agent that causes severe disease in both humans and animals. diagnosis and treatment of melioidosis can be challenging, and in the absence of optimal chemotherapeutic intervention, acute disease is frequently fatal. melioidosis is an emerging infectious disease for which there are currently no licensed vaccines. due to the potential malicious use of b. pseudomallei as well as its impact on public health in regi ...201424866807
proteomic analysis of the burkholderia pseudomallei type ii secretome reveals hydrolytic enzymes, novel proteins, and the deubiquitinase tssm.burkholderia pseudomallei, the etiologic agent of melioidosis, is an opportunistic pathogen that harbors a wide array of secretion systems, including a type ii secretion system (t2ss), three type iii secretion systems (t3ss), and six type vi secretion systems (t6ss). the proteins exported by these systems provide b. pseudomallei with a growth advantage in vitro and in vivo, but relatively little is known about the full repertoire of exoproducts associated with each system. in this study, we cons ...201424866793
analysis of the prevalence, secretion and function of a cell cycle-inhibiting factor in the melioidosis pathogen burkholderia pseudomallei.enteropathogenic and enterohaemorrhagic escherichia coli express a cell cycle-inhibiting factor (cif), that is injected into host cells via a type iii secretion system (t3ss) leading to arrest of cell division, delayed apoptosis and cytoskeletal rearrangements. a homologue of cif has been identified in burkholderia pseudomallei (chbp; cif homologue in b. pseudomallei; bpss1385), which shares catalytic activity, but its prevalence, secretion and function are ill-defined. among 43 available b. pse ...201424809950
porin involvement in cephalosporin and carbapenem resistance of burkholderia pseudomallei.burkholderia pseudomallei (bps) is a gram-negative bacterium that causes frequently lethal melioidosis, with a particularly high prevalence in the north and northeast of thailand. bps is highly resistant to many antimicrobial agents and this resistance may result from the low drug permeability of outer membrane proteins, known as porins.201424788109
intramolecular aglycon delivery enables the synthesis of 6-deoxy-β-d-manno-heptosides as fragments of burkholderia pseudomallei and burkholderia mallei capsular polysaccharide.burkholderia pseudomallei and burkholderia mallei are potential bioterrorism agents. they express the same capsular polysaccharide (cps), a homopolymer featuring an unusual [→3)-2-o-acetyl-6-deoxy-β-d-manno-heptopyranosyl-(1→] as the repeating unit. this cps is known to be one of the main targets of the adaptive immune response in humans and therefore represents a crucial subunit candidate for vaccine development. herein, the stereoselective synthesis of mono- and disaccharidic fragments of the ...201424786555
clinical features of diabetes mellitus cases complicated by burkholderia pseudomallei septicemia.the aim of this study was to analyze the clinical characteristics of diabetes mellitus patients with burkholderia pseudomallei septicemia and evaluate strategies of diagnosis and treatment. the clinical characteristics, diagnosis, treatment, and prognosis of 39 diabetes mellitus patients with b. pseudomallei septicemia were retrospectively analyzed. farmers, fishermen and workers were found to be high-risk groups. the clinical manifestations of patients were diverse without specific features, bu ...201424782168
the bacterial aetiology of adult community-acquired pneumonia in asia: a systematic review.community-acquired pneumonia (cap) is a major cause of adult mortality in asia. appropriate empirical treatment depends on knowledge of the pathogens commonly responsible. however, assessing the aetiological significance of identified organisms is often difficult, particularly with sputum isolates that might represent contamination with oropharyngeal flora.201424781376
melioidosis :an emerging infection in india.melioidosis caused by the gram-negative bacterium burkholderia pseudomallei is endemic in southeast asia but may be under-diagnosed and under-reported in the indian subcontinent. this study was undertaken to analyse the clinical presentation and epidemiological risk factors for melioidosis in india.201324772696
sulphonylurea usage in melioidosis is associated with severe disease and suppressed immune response.melioidosis is a problem in the developing tropical regions of southeast asia and northern australia where the the gram negative saprophytic bacillus burkholderia pseudomallei is endemic with the risk of fulminant septicaemia. while diabetes mellitus is a well-established risk factor for melioidiosis, little is known if specific hypoglycemic agents may differentially influence the susceptibility and clinical course of infection with b. pseudomallei (bp).201424762472
growth, motility and resistance to oxidative stress of the melioidosis pathogen burkholderia pseudomallei are enhanced by epinephrine.burkholderia pseudomallei causes melioidosis, a severe invasive disease endemic in south-east asia and northern australia. bacterial pathogens of several genera have been reported to be able to sense and respond to the stress-related catecholamine hormone epinephrine. here, we report that epinephrine induces growth of b. pseudomallei in minimal serum-rich medium and heat-inactivated whole human serum and enhances bacterial motility, transcription of flagellar genes and flagellin synthesis. the e ...201424753312
a high-content imaging assay for the quantification of the burkholderia pseudomallei induced multinucleated giant cell (mngc) phenotype in murine macrophages.burkholderia pseudomallei (bp), a gram-negative, motile, facultative intracellular bacterium is the causative agent of melioidosis in humans and animals. the bp genome encodes a repertoire of virulence factors, including the cluster 3 type iii secretion system (t3ss-3), the cluster 1 type vi secretion system (t6ss-1), and the intracellular motility protein bima, that enable the pathogen to invade both phagocytic and non-phagocytic cells. a unique hallmark of bp infection both in vitro and in viv ...201424750902
enhanced intracellular survival and epithelial cell adherence abilities of burkholderia pseudomallei morphotypes are dependent on differential expression of virulence-associated proteins during mid-logarithmic growth phase.colony morphology variation is a characteristic of burkholderia pseudomallei primary clinical isolates, associated with variations in expression of virulence factors. here, we performed comparative investigations on adhesion, invasion, plaque-forming abilities and protein profiles of b. pseudomallei wild-type (wt) and a small colony variant (scv). the percentage of scv adherence to a549 cells was significantly higher (2.73%) than wt (1.91%). in contrast, wt was significantly more efficient (0.63 ...201424742602
burkholderia pseudomallei penetrates the brain via destruction of the olfactory and trigeminal nerves: implications for the pathogenesis of neurological melioidosis.abstract melioidosis is a potentially fatal disease that is endemic to tropical northern australia and southeast asia, with a mortality rate of 14 to 50%. the bacterium burkholderia pseudomallei is the causative agent which infects numerous parts of the human body, including the brain, which results in the neurological manifestation of melioidosis. the olfactory nerve constitutes a direct conduit from the nasal cavity into the brain, and we have previously reported that b. pseudomallei can colon ...201424736221
characterization of an autotransporter adhesin protein shared by burkholderia mallei and burkholderia pseudomallei.autotransporters form a large family of outer membrane proteins specifying diverse biological traits of gram-negative bacteria. in this study, we report the identification and characterization of a novel autotransporter gene product of burkholderia mallei (locus tag bma1027 in strain atcc 23344).201424731253
redefining the pf06864 pfam family based on burkholderia pseudomallei pilo2(bp) s-sad crystal structure.type iv pili are surface-exposed filaments and bacterial virulence factors, represented by the tfpa and tfpb types, which assemble via specific machineries. the tfpb group is further divided into seven variants, linked to heterogeneity in the assembly machineries. here we focus on pilo2(bp), a protein component of the tfpb r64 thin pilus variant assembly machinery from the pathogen burkholderia pseudomallei. pilo2(bp) belongs to the pf06864 pfam family, for which an improved definition is presen ...201424728008
two fatal cases of melioidosis on the thai-myanmar border.melioidosis is endemic in areas of southeast asia, however, there are no published reports from the thai-myanmar border. we report the first two documented cases of fatal melioidosis in this region. this is of great public health importance and highlights the need to both increase clinical awareness of melioidosis on the thai-myanmar border, and to assess the true burden of disease in the area through improved case detection and burkholderia pseudomallei prevalence studies.201424715973
splenic abscess due to chronic melioidosis in a patient previously misdiagnosed as tuberculosis.melioidosis is endemic in southeast asia and northern australia. sporadic cases have been reported from many parts of the world where it has an epidemic potential with high-rate fatality cases. in non-endemic areas, melioidosis may be misdiagnosed with common diseases and this may prove fatal. sporadic cases of melioidosis are mistaken for tuberculosis in india. we report a case of splenic abscess due to chronic melioidosis who was earlier misdiagnosed as tuberculosis and underwent anti-tubercul ...201324714690
evaluation of a latex agglutination assay for the identification of burkholderia pseudomallei and burkholderia mallei.cases of melioidosis and glanders are rare in the united states, but the etiologic agents of each disease (burkholderia pseudomallei and burkholderia mallei, respectively) are classified as tier 1 select agents because of concerns about their potential use as bioterrorism agents. a rapid, highly sensitive, and portable assay for clinical laboratories and field use is required. our laboratory has further evaluated a latex agglutination assay for its ability to identify b. pseudomallei and b. mall ...201424710616
bone marrow-derived macrophages from balb/c and c57bl/6 mice fundamentally differ in their respiratory chain complex proteins, lysosomal enzymes and components of antioxidant stress systems.macrophages are essential components of the innate immune system and crucial for pathogen elimination in early stages of infection. we previously observed that bone marrow-derived macrophages (bmms) from c57bl/6 mice exhibited increased killing activity against burkholderia pseudomallei compared to bmms from balb/c mice. this effect was particularly pronounced when cells were treated with ifn-γ. to unravel mechanisms that could explain these distinct bactericidal effects, a comparative combined ...201424704164
genetic control of weight loss during pneumonic burkholderia pseudomallei infection.burkholderia pseudomallei (bp) is the causal agent of a high-morbidity/mortality disease syndrome known as melioidosis. this syndrome can range from acute fulminate disease to chronic, local, and disseminated infections that are often difficult to treat because bp exhibits resistance to many antibiotics. bp is a prime candidate for use in biologic warfare/terrorism and is classified as a tier-1 select agent by hhs and aphis. it is known that inbred mouse strains display a range of susceptibility ...201424687986
reactivation of latent melioidosis presenting with acute pyelonephritis and bacteremia.we report an interesting case involving an 81-year-old male patient who presented to our hospital with sepsis secondary to pyelonephritis and bacteremia. blood cultures were positive for a gram-negative bacillus, burkholderia pseudomallei. his risk factors were diabetes, chronic obstructive pulmonary disease including travel to an endemic area. the patient received antibiotic therapy in accordance with the national guidelines. this is the first report of reactivation of latent melioidosis in the ...201424678468
evaluation of the remel rapid nf plus rapid biochemical method for identification of burkholderia pseudomallei.typical methods for the identification of burkholderia pseudomallei colonies produce results in 18 h. the remel rapid nf plus kit produces results in 4 h. we used the kit for 190 stored b. pseudomallei isolates and correctly identified 189 of them. this kit produces consistent results for known b. pseudomallei isolates.201424671779
a burkholderia pseudomallei outer membrane vesicle vaccine provides protection against lethal sepsis.the environmental gram-negative encapsulated bacillus burkholderia pseudomallei is the causative agent of melioidosis, a disease associated with high morbidity and mortality rates in areas of southeast asia and northern australia in which the disease is endemic. b. pseudomallei is also classified as a tier i select agent due to the high level of lethality of the bacterium and its innate resistance to antibiotics, as well as the lack of an effective vaccine. gram-negative bacteria, including b. p ...201424671550
subcutaneous surprise.melioidosis is a zoonosis caused by the accidental pathogen burkholderia pseudomallei, which is endemic in southeast asia and northern australia. the mortality of melioidosis is 20-50% even with treatment. suppurative lymphadenitis caused by melioidosis has been rarely encountered by clinicians practicing in endemic areas. in the majority of previously described patients, the infected lymph nodes were in the head and neck region, except for four patients who presented with unilateral, inguinal l ...201424669344
distribution of burkholderia pseudomallei in northern australia, a land of diversity.burkholderia pseudomallei is a gram-negative soil bacillus that is the etiological agent of melioidosis and a biothreat agent. little is known about the biogeography of this bacterium in australia, despite its hyperendemicity in the northern region of this continent. the population structure of 953 australian b. pseudomallei strains representing 779 and 174 isolates of clinical and environmental origins, respectively, was analyzed using multilocus sequence typing (mlst). bayesian population stru ...201424657869
burkholderia pseudomallei type g in western hemisphere.burkholderia pseudomallei isolates from the western hemisphere are difficult to differentiate from those from regions in which melioidosis is traditionally endemic. we used internal transcribed spacer typing to determine that b. pseudomallei isolates from the western hemisphere are consistently type g. knowledge of this relationship might be useful for epidemiologic investigations.201424655932
development of a prototype lateral flow immunoassay (lfi) for the rapid diagnosis of melioidosis.burkholderia pseudomallei is a soil-dwelling bacterium and the causative agent of melioidosis. isolation of b. pseudomallei from clinical samples is the "gold standard" for the diagnosis of melioidosis; results can take 3-7 days to produce. alternatively, antibody-based tests have low specificity due to a high percentage of seropositive individuals in endemic areas. there is a clear need to develop a rapid point-of-care antigen detection assay for the diagnosis of melioidosis. previously, we emp ...201424651568
[melioidosis, first four cases in iceland].we report the first four cases of melioidosis treated in iceland and review the literature. melioidosis is caused by the saprophytic gram negative bacteria burkholderia pseudomallei. most disease occurs in residents of southeast-asia and north-australia. the most common presentation of melioidosis is pneumonia but as these cases demonstrate the infection has protean manifestations and b. pseudomallei can infect nearly every organ. it is important to notify the laboratory of the possibilty of mel ...201424639431
caspase-1-dependent and -independent cell death pathways in burkholderia pseudomallei infection of macrophages.the cytosolic pathogen burkholderia pseudomallei and causative agent of melioidosis has been shown to regulate il-1β and il-18 production through nod-like receptor nlrp3 and pyroptosis via nlrc4. downstream signalling pathways of those receptors and other cell death mechanisms induced during b. pseudomallei infection have not been addressed so far in detail. furthermore, the role of b. pseudomallei factors in inflammasome activation is still ill defined. in the present study we show that caspase ...201424626296
etiologies and resistance profiles of bacterial community-acquired pneumonia in cambodian and neighboring countries' health care settings: a systematic review (1995 to 2012).community-acquired pneumonia (cap) is one of the most important causes of morbidity and mortality worldwide. etiological data for cambodia is scarce. we aimed to describe the main etiological agents causing cap, and their resistance patterns in cambodia and the greater mekong region.201424626053
variable virulence factors in burkholderia pseudomallei (melioidosis) associated with human disease.burkholderia pseudomallei is a gram-negative environmental bacterium that causes melioidosis, a potentially life-threatening infectious disease affecting mammals, including humans. melioidosis symptoms are both protean and diverse, ranging from mild, localized skin infections to more severe and often fatal presentations including pneumonia, septic shock with multiple internal abscesses and occasionally neurological involvement. several ubiquitous virulence determinants in b. pseudomallei have al ...201424618705
functional characterization and evaluation of in vitro protective efficacy of murine monoclonal antibodies burk24 and burk37 against burkholderia pseudomallei.burkholderia pseudomallei, the causative agent of melioidosis has been recognized by cdc as a category b select agent. although substantial efforts have been made for development of vaccine molecules against the pathogen, significant hurdles still remain. with no licensed vaccines available and high relapse rate of the disease, there is a pressing need for development of alternate protection strategies. antibody-mediated passive protection is promising in this regard and our primary interest was ...201424614539
treatment and prophylaxis of melioidosis.melioidosis, infection with burkholderia pseudomallei, is being recognised with increasing frequency and is probably more common than currently appreciated. treatment recommendations are based on a series of clinical trials conducted in thailand over the past 25 years. treatment is usually divided into two phases: in the first, or acute phase, parenteral drugs are given for ≥10 days with the aim of preventing death from overwhelming sepsis; in the second, or eradication phase, oral drugs are giv ...201424613038
septicemic melioidosis: a case report and literature review.this report was about a 22-year-old male patient who died from acute and severe septicemic melioidosis. he was initially misdiagnosed as having pneumonia in a local hospital in hainan but transferred to guangzhou red cross hospital after ineffective treatment and detection of burkholderia pseudomallei in his blood sample. unfortunately, right diagnosis and antibiotic treatment of melioidosis had been delayed so that his condition deteriorated rapidly out of control. the victim's death highlights ...201424605237
acute pulmonary melioidosis in a child: a case report and review of literature.melioidosis is a rare potentially fatal infection caused by the bacterium burkholderia pseudomallei, which is endemic in southeast asia and northern australia and an emerging pathogen in india. it is a largely under-diagnosed disease and an imitator of tuberculosis, both clinically and radiologically.201324604934
comparative burkholderia pseudomallei natural history virulence studies using an aerosol murine model of infection.melioidosis is an endemic disease caused by the bacterium burkholderia pseudomallei. concerns exist regarding b. pseudomallei use as a potential bio-threat agent causing persistent infections and typically manifesting as severe pneumonia capable of causing fatal bacteremia. development of suitable therapeutics against melioidosis is complicated due to high degree of genetic and phenotypic variability among b. pseudomallei isolates and lack of data establishing commonly accepted strains for compa ...201424603493
role of burkholderia pseudomallei biofilm formation and lipopolysaccharide in relapse of melioidosis.we examined whether quantitative biofilm formation and/or lipopolysaccharide type of burkholderia pseudomallei was associated with relapsing melioidosis. we devised a 1:4 nested case-control study in which both cases and controls were drawn from a cohort of patients with primary melioidosis. paired isolates from 80 patients with relapse and single isolates from 184 patients without relapse were tested. relapse was associated with biofilm formation of the primary infecting isolate (conditional or ...201424602145
bpss1504, a cluster 1 type vi secretion gene, is involved in intracellular survival and virulence of burkholderia pseudomallei.burkholderia pseudomallei is a gram-negative rod and the causative agent of melioidosis, an emerging infectious disease of tropical and subtropical areas worldwide. b. pseudomallei harbors a remarkable number of virulence factors, including six type vi secretion systems (t6ss). using our previously described plaque assay screening system, we identified a b. pseudomallei transposon mutant defective in the bpss1504 gene that showed reduced plaque formation. the bpss1504 locus is encoded within t6s ...201424595140
thoracic melioidosis: a diagnostic dilemma.the diagnosis of melioidosis can be difficult, and it is frequently described as "the great mimicker". we report a case of thoracic melioidosis presenting as a mediastinal mass with impending superior vena cava obstruction. with the presumptive diagnosis of mediastinal tumor, the patient underwent surgery for tissue sampling, and a purulent collection was found. the clinical syndromes of melioidosis and the diagnostic dilemma are discussed.201524585290
pathogenesis of percutaneous infection of goats with burkholderia pseudomallei: clinical, pathologic, and immunological responses in chronic melioidosis.melioidosis is a severe suppurative to granulomatous infection caused by burkholderia pseudomallei. the disease is endemic to south-east asia and northern australasia and is also of interest as a potential biological weapon. natural infection can occur by percutaneous inoculation, inhalation or ingestion, but the relative importance of each route is unknown. experimental infection models using mice have shown inhalation to be the most lethal route of exposure, but few studies have examined the p ...201424571408
wound healing activity and mechanisms of action of an antibacterial protein from the venom of the eastern diamondback rattlesnake (crotalus adamanteus).basic phospholipase a2 was identified from the venom of the eastern diamondback rattlesnake. the crotalus adamanteus toxin-ii (catx-ii) induced bactericidal effects (7.8 µg/ml) on staphylococcus aureus, while on burkholderia pseudomallei (khw), and enterobacter aerogenes were killed at 15.6 µg/ml. catx-ii caused pore formation and membrane damaging effects on the bacterial cell wall. catx-ii was not cytotoxic on lung (mrc-5), skin fibroblast (hepk) cells and in mice. catx-ii-treated mice showed ...201424551028
genome-wide saturation mutagenesis of burkholderia pseudomallei k96243 predicts essential genes and novel targets for antimicrobial development.burkholderia pseudomallei is the causative agent of melioidosis, an often fatal infectious disease for which there is no vaccine. b. pseudomallei is listed as a tier 1 select agent, and as current therapeutic options are limited due to its natural resistance to most antibiotics, the development of new antimicrobial therapies is imperative. to identify drug targets and better understand the complex b. pseudomallei genome, we sought a genome-wide approach to identify lethal gene targets. as b. pse ...201424520057
whitmore's disease: an uncommon urological presentation.the incidence of prostatic abscesses has much decreased in the antibiotic era. we present an uncommon cause of prostatic abscess secondary to melioidosis, also known as whitmore's disease or pseudoglanders. the disease is endemic in south east asia and australia. although india is considered endemic for burkholderia pseudomallei, the causative organism of melioidosis, not many cases have been reported. most of the reported cases from india are from the south-west coastal regions of kerala and ka ...201424518392
colonization or spontaneous resolution: expanding the role for burkholderia pseudomallei.a 19-year-old asian indian female presented with productive cough since the past one month and low grade fever since the past two weeks. she was diagnosed with pulmonary tuberculosis and treated with antitubercular drugs. subsequently, delayed cultures of bronchoalveolar lavage fluid grew burkholderia pseudomallei (b. pseudomallei). on follow up the patient reported significant subjective improvement and esr progressively returned to normal. in summary, this case report raises two distinct and e ...201424507650
in vitro activity of ceftaroline against burkholderia pseudomallei. 201424505090
the hica toxin from burkholderia pseudomallei has a role in persister cell formation.ta (toxin-antitoxin) systems are widely distributed amongst bacteria and are associated with the formation of antibiotic tolerant (persister) cells that may have involvement in chronic and recurrent disease. we show that overexpression of the burkholderia pseudomallei hica toxin causes growth arrest and increases the number of persister cells tolerant to ciprofloxacin or ceftazidime. furthermore, our data show that persistence towards ciprofloxacin or ceftazidime can be differentially modulated ...201424502667
mining locus tags in pubmed central to improve microbial gene annotation.the scientific literature contains millions of microbial gene identifiers within the full text and tables, but these annotations rarely get incorporated into public sequence databases. we propose to utilize the open access (oa) subset of pubmed central (pmc) as a gene annotation database and have developed an r package called pmcxml to automatically mine and extract locus tags from full text, tables and supplements.201424499370
structural characterization of polysaccharides expressed by burkholderia oklahomensis e0147.burkholderia oklahomensis e0147 is a us isolated bacterium believed to express a similar o-antigen to type a structure of the highly pathogenic species, burkholderia pseudomallei. both species are genetically closely related. lipopolysaccharide was collected from e0147 and structurally characterized to test this hypothesis. glycosyl composition and linkage analyses in conjunction with 1d and 2d (1)h and (13)c nmr spectroscopy showed that the o-antigen was a repeating disaccharide with the follow ...201424491843
recurrent melioidosis in the darwin prospective melioidosis study: improving therapies mean that relapse cases are now rare.the darwin prospective melioidosis study has documented 785 melioidosis cases over 23 years. recurrent melioidosis occurred in 39/679 (5.7%) patients surviving initial infection; 29 patients suffered relapse of the original infection, and 10 presented with a new burkholderia pseudomallei infection. with improved therapy, relapse has become rare in recent years.201424478504
global analysis of the burkholderia thailandensis quorum sensing-controlled regulon.burkholderia thailandensis contains three acyl-homoserine lactone quorum sensing circuits and has two additional luxr homologs. to identify b. thailandensis quorum sensing-controlled genes, we carried out transcriptome sequencing (rna-seq) analyses of quorum sensing mutants and their parent. the analyses were grounded in the fact that we identified genes coding for factors shown previously to be regulated by quorum sensing among a larger set of quorum-controlled genes. we also found that genes c ...201424464461
the serine protease inhibitor ecotin is required for full virulence of burkholderia pseudomallei.burkholderia pseudomallei is a gram negative soil saprophyte that causes the disease melioidosis where clinical symptoms can vary from localised infection to pneumonia and septic shock. ecotin is a potent periplasmic serine protease inhibitor first identified in escherichia coli. ecotin, although present in only a small subset of genera, can inhibit a broad range of serine proteases including those typically associated with the innate immune system such as neutrophil elastase and cathepsin g. an ...201424462575
population-sequencing as a biomarker of burkholderia mallei and burkholderia pseudomallei evolution through microbial forensic analysis.large-scale genomics projects are identifying biomarkers to detect human disease. b. pseudomallei and b. mallei are two closely related select agents that cause melioidosis and glanders. accurate characterization of metagenomic samples is dependent on accurate measurements of genetic variation between isolates with resolution down to strain level. often single biomarker sensitivity is augmented by use of multiple or panels of biomarkers. in parallel with single biomarker validation, advances in ...201324455204
melioidosis of salivary glands with coexisting diabetes: management of a difficult case.melioidosis is an infectious disease caused by the gram-negative bacillus burkholderia pseudomallei. melioidosis is endemic in southeast asia and northern australia. an important risk factor for the development of melioidosis is the presence of diabetes mellitus, which may increase the relative risk of infection by as much as 100-fold. we report a rare case of melioidosis of the parotid and submandibular gland with coexisting diabetes. this was successfully managed conservatively with intravenou ...201424452899
vgrg-5 is a burkholderia type vi secretion system-exported protein required for multinucleated giant cell formation and virulence.the type vi secretion system (t6ss) has emerged as a critical virulence factor for the group of closely related burkholderia spp. that includes burkholderia pseudomallei, b. mallei, and b. thailandensis. while the genomes of these bacteria, referred to as the bptm group, appear to encode several t6sss, we and others have shown that one of these, type vi secretion system 5 (t6ss-5), is required for virulence in mammalian infection models. despite its pivotal role in the pathogenesis of the bptm g ...201424452686
efficient inactivation of burkholderia pseudomallei or francisella tularensis in infected cells for safe removal from biosafety level 3 containment laboratories.working with infectious agents that require bsl-3 level containment agents offers many challenges for researchers. bsl-3 containment laboratories are usually not equipped with expensive specialty equipment that is needed for studies such as flow cytometric analysis, microscopy, and proteomic analyses. therefore, for most researchers that are working with bsl-3 level infectious agents, removal of samples from bsl-3 laboratories for these types of studies is necessary, and methods for complete and ...201424449562
melioidosis caused by burkholderia pseudomallei in drinking water, thailand, 2012.we identified 10 patients in thailand with culture-confirmed melioidosis who had burkholderia pseudomallei isolated from their drinking water. the multilocus sequence type of b. pseudomallei from clinical specimens and water samples were identical for 2 patients. this finding suggests that drinking water is a preventable source of b. pseudomallei infection.201424447771
burkholderia pseudomallei isolates in 2 pet iguanas, california, usa.burkholderia pseudomallei, the causative agent of melioidosis, was isolated from abscesses of 2 pet green iguanas in california, usa. the international trade in iguanas may contribute to importation of this pathogen into countries where it is not endemic and put persons exposed to these animals at risk for infection.201424447394
physicochemical factors affecting the growth of burkholderia pseudomallei in soil microcosm.burkholderia pseudomallei causes melioidosis, the third most common cause of death from infectious diseases in northeast thailand. four physicochemical factors were set so that their values covered the range of the northeast, which is an endemic area. the soil ph was set at ph 4-10, soil salinity was 0.0-5.0% nacl, total iron was 50-150 mg/kg soil, and carbon to nitrogen ratio (c/n) was 10:1 to 40:1. the experiments were carried out at 37°c, and soil moisture was maintained for 7 days. the numbe ...201424445210
alteration of the phenotypic and pathogenic patterns of burkholderia pseudomallei that persist in a soil environment.melioidosis is caused by the soil-borne pathogen burkholderia pseudomallei. to investigate whether the distinct phenotypic and virulent characteristics result from environmental adaptations in the soil or from the host body, two pairs of isogenic strains were generated by passages in soil or mice. after cultivation in soil, the levels of 3-hydroxytetradecanoic acid, biofilm formation, flagellar expression, and ultrastructure were altered in the bacteria. uniformly fatal melioidosis developed as ...201424445207
chronic suppurative joint effusion due to burkholderia pseudomallei: a case report.burkholderia pseudomallei, a gram-negative bacillus is the causative agent of melioidosis, a glanders-like disease, primarily a disease of animals. melioidosis has been only a rare and sporadic disease in humans outside its endemic region. currently, diagnosis of b. pseudomallei in the clinical laboratory is very difficult, owing to low awareness of physicians to the nonspecific clinical manifestations, lack of responsiveness among microbiologists outside endemic areas, identification systems in ...201424441249
uncommon clinical presentations of melioidosis in children: 2 cases with sore throat and 1 case with urticarial rash.common clinical presentations of melioidosis in children include suppurative parotitis, lymphadenitis, skin infection and septicemia with pneumonia. here we describe three cases with uncommon presentations of melioidosis seen among children attending a university hospital in northeastern thailand. two patients presented with pharyngitis and subsequently developed cervical lymphadenitis. another patient presented with high fever and generalized urticarial rash. a pharyngeal culture in each of the ...201324437321
reverse line blot macroarray for simultaneous detection and characterization of four biological warfare agents.the need for a rapid detection and characterization of biowarfare (bw) agents cannot be over emphasized. with diverse array of potential bw pathogen available presently, rapid identification of the pathogen is crucial, so that specific therapy and control measures can be initiated. we have developed a multiplex polymerase chain reaction based reverse line blot macroarray to simultaneously detect four pathogens of bw importance viz. bacillus anthracis, yersinia pestis, brucella melitensis and bur ...201324426077
the type vi secretion system spike protein vgrg5 mediates membrane fusion during intercellular spread by pseudomallei group burkholderia species.pseudomallei group burkholderia species are facultative intracellular parasites that spread efficiently from cell to cell by a mechanism involving the fusion of adjacent cell membranes. intercellular fusion requires the function of the cluster 5 type vi secretion system (t6ss-5) and its associated valine-glycine repeat protein, vgrg5. here we show that vgrg5 alleles are conserved and functionally interchangeable between burkholderia pseudomallei and its relatives b. mallei, b. oklahomensis, and ...201424421040
osteomyelitis and septic arthritis from infection with burkholderia pseudomallei: a 20-year prospective melioidosis study from northern australia.the gram-negative organism, burkholderia pseudomallei, is responsible for the disease melioidosis. septic arthritis and osteomyelitis due to b. pseudomallei are rare but recognised presentations of the disease.201324403756
mice lacking the lectin-like domain of thrombomodulin are protected against melioidosis.thrombomodulin is a multidomain receptor primarily expressed by vascular endothelium. the lectin-like domain of thrombomodulin has anti-inflammatory properties. in this study, we investigated the role of the thrombomodulin lectin-like domain in the host response to gram-negative sepsis caused by burkholderia pseudomallei, a "tier 1" biothreat agent and the causative agent of melioidosis, a common form of community-acquired sepsis in southeast asia.201424399241
common tlr1 genetic variation is not associated with death from melioidosis, a common cause of sepsis in rural thailand.melioidosis, infection caused by the gram-negative bacterium burkholderia pseudomallei, is a common cause of sepsis in northeast thailand. in white north americans, common functional genetic variation in tlr1 is associated with organ failure and death from sepsis. we hypothesized that tlr1 variants would be associated with outcomes in thais with melioidosis. we collated the global frequencies of three tlr1 variants that are common in white north american populations: rs5743551 (-7202a/g), rs4833 ...201424392083
a multiplex nested pcr for the simultaneous detection of salmonella typhi, mycobacterium tuberculosis, and burkholderia pseudomallei in patients with pyrexia of unknown origin (puo) in vellore, south india.salmonella typhi, mycobacterium tuberculosis, and burkholderia pseudomallei are among the most important monocyte-tropic bacterial agents causing pyrexia of unknown origin (puo), with a significant number of endemic infections in both south and southeast asian regions. these infections pose a major risk to travelers to these regions as well.201424385404
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
the role of short-chain dehydrogenase/oxidoreductase, induced by salt stress, on host interaction of b. pseudomallei.burkholderia pseudomallei is the causative agent of melioidosis, a frequently occurring disease in northeastern thailand, where soil and water high in salt content are common. using microarray analysis, we previously showed that b. pseudomallei up-regulated a short-chain dehydrogenase/oxidoreductase (sdo) under salt stress. however, the importance of sdo in b. pseudomallei infection is unknown. this study aimed to explore the function of b. pseudomallei sdo, and to investigate its role in intera ...201424382268
substituted diphenyl ethers as a novel chemotherapeutic platform against burkholderia pseudomallei.identification of a novel class of anti-burkholderia compounds is key in addressing antimicrobial resistance to current therapies as well as naturally occurring resistance. the fabi enoyl-acp reductase in burkholderia is an underexploited target that presents an opportunity for development of a new class of inhibitors. a library of substituted diphenyl ethers was used to identify fabi1-specific inhibitors for assessment in burkholderia pseudomallei ex vivo and murine efficacy models. active fabi ...201424379198
discovery of inhibitors of burkholderia pseudomallei methionine aminopeptidase with antibacterial activity.evaluation of a series of metap inhibitors in an in vitro enzyme activity assay led to the first identification of potent molecules that show significant growth inhibition against burkholderia pseudomallei. nitroxoline analogs show excellent inhibition potency in the bpmetap1 enzyme activity assay with the lowest ic50 of 30 nm, and inhibit the growth of b. pseudomallei and b. thailandensis at concentrations ≥ 31 μm.201324376907
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