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identification of a regulatory cascade controlling type iii secretion system 3 gene expression in burkholderia pseudomallei.a major and critical virulence determinant of many gram-negative bacterial pathogens is the type iii secretion systems (t3ss). t3ss3 in burkholderia pseudomallei is critical for bacterial virulence in mammalian infection models but its regulation is unknown. b. pseudomallei is the causative agent of melioidosis, a potentially fatal disease endemic in southeast asia and northern australia. while screening for bacterial transposon mutants with a defective t3ss function, we discovered a tetr family ...201020345664
spectrum of melioidosis in the suburbs of mangalore, s west coast of india.melioidosis is an emerging infection in india. seventeen cases of culture proven melioidosis are reported in this study. the isolation rate was high during the rainy season. except one case, all the patients had diabetes mellitus as an underlying disease. eleven patients improved with ceftazidime or combination therapy and maintenance therapy with doxycycline and cotrimoxazole. the high prevalence of b. pseudomallei in this region is a matter for serious concern.201020578496
burkholderia thailandensis whole cell antigen cross-reacts with b. pseudomallei antibodies from patients with melioidosis in an immunofluorescent assay.an immunofluorescent assay (ifat) using whole cell antigen derived from burkholderia thailandensis used for detection of total antibodies to burkholderia pseudomallei, was found to compare favorably with a previous published report on a b. pseudomallei ifat assay. at a 1:20 cut-off titer, the assay had high sensitivity (98.9%) and satisfactory specificity (92.3%), when tested against sera from 94 patients suspected of melioidosis. sera from 12 patients with culture proven melioidosis gave absolu ...201020578523
melioidosis in southern india: epidemiological and clinical profile.melioidosis, which is mainly prevalent in thailand and australia, has shown an increasing trend in india in the last few years. we carried out a retrospective study of 25 culture-proven adult cases of melioidosis who were admitted to a tertiary care hospital in southern india during june 2001 to september 2007. there was a six-fold increase in the number of cases in 2006 and 2007 as compared to 2001. diabetes mellitus was the predisposing factor in 68% of cases, followed by alcoholism (28%). the ...201020578524
melioidosis and pulmonary tuberculosis co-infection in a diabetic.burkholderia pseudomallei is the causative agent of melioidosis. it is endemic in south east asian countries and north australia. sporadic cases of melioidosis have been reported from several parts of south india. melioidosis may manifest as chronic pneumonia mimicking tuberculosis and generally be seen as a single entity. we report the first case of melioidosis and pulmonary tuberculosis co-infection in a diabetic patient. the causative agents were identified using standard methods and the pati ...201020582178
escape of intracellular shigella from autophagy requires binding to cholesterol through the type iii effector, icsb.type iii secretion systems are present in many pathogenic bacteria and mediate the translocation of bacterial effectors into host cells. identification of host targets of these effectors is crucial for understanding bacterial virulence. icsb, a type iii secretion effector, helps shigella to evade the host autophagy defense system by binding to the autophagy protein, atg5. here, we show that icsb is able to interact specifically with cholesterol. the cholesterol binding domain (cbd) of icsb is lo ...201020599519
structural characterization of burkholderia pseudomallei adenylate kinase (adk): profound asymmetry in the crystal structure of the 'open' state.in all organisms adenylate kinases (adks) play a vital role in cellular energy metabolism and nucleic acid synthesis. due to differences in catalytic properties between the adks found in prokaryotes and in the cytoplasm of eukaryotes, there is interest in targeting this enzyme for new drug therapies against infectious bacterial agents. here we report the 2.1a resolution crystal structure for the 220-residue adk from burkholderia pseudomallei (bpadk), the etiological agent responsible for the inf ...201020331978
susceptibility of burkholderia pseudomallei to tigecycline and other antimicrobials. 201020356698
the man with the boggy head: cranial melioidosis.melioidosis is known to cause abscesses in various organs, including the cranium, though less commonly. we present a patient with scalp abscess and subdural empyema that was visible on computed tomography of the brain. the neurosurgical drainage grew burkholderia pseudomallei. despite our best effort to treat the patient using parenteral antibiotics and surgical drainage, the patient did not survive.201020358143
genetic and phenotypic diversity in burkholderia: contributions by prophage and phage-like elements.burkholderia species exhibit enormous phenotypic diversity, ranging from the nonpathogenic, soil- and water-inhabiting burkholderia thailandensis to the virulent, host-adapted mammalian pathogen b. mallei. genomic diversity is evident within burkholderia species as well. individual isolates of burkholderia pseudomallei and b. thailandensis, for example, carry a variety of strain-specific genomic islands (gis), including putative pathogenicity and metabolic islands, prophage-like islands, and pro ...201020667135
glutamine deamidation and dysfunction of ubiquitin/nedd8 induced by a bacterial effector family.a family of bacterial effectors including cif homolog from burkholderia pseudomallei (chbp) and cif from enteropathogenic escherichia coli (epec) adopt a functionally important papain-like hydrolytic fold. we show here that chbp was a potent inhibitor of the eukaryotic ubiquitination pathway. chbp acted as a deamidase that specifically and efficiently deamidated gln40 in ubiquitin and ubiquitin-like protein nedd8 both in vitro and during burkholderia infection. deamidated ubiquitin was impaired ...201020688984
melioidosis in an urban-dwelling taiwanese man with splenic abscesses.we report a case of melioidosis with splenic abscesses caused by burkholderia pseudomallei in an urban-dwelling, 54-year-old taiwanese man. the patient presented with prolonged fever and abdominal pain. a splenectomy was performed, followed by successful treatment with ceftazidime and amoxicillin-clavulanate. the patient recovered fully.201020709809
[tropical pneumonia: pulmonary melioidosis].melioidosis is a disease that is endemic in north australia and southeast asia, caused by burkholderia pseudomallei. this gram-negative organism can affect all organs, but presents most commonly as severe pneumonia. we report a 58-year-old man who presented with a b. pseudomallei pneumonia on his return from thailand. radiography revealed a complete disappearance of symptoms after a 3-week therapy with ceftazidime and doxycycline followed by 4 months of combined amoxicillin-clavulanic acid and d ...201020413195
within-host evolution of burkholderia pseudomallei in four cases of acute melioidosis.little is currently known about bacterial pathogen evolution and adaptation within the host during acute infection. previous studies of burkholderia pseudomallei, the etiologic agent of melioidosis, have shown that this opportunistic pathogen mutates rapidly both in vitro and in vivo at tandemly repeated loci, making this organism a relevant model for studying short-term evolution. in the current study, b. pseudomallei isolates cultured from multiple body sites from four thai patients with disse ...201020090837
evaluation of azithromycin, trovafloxacin and grepafloxacin as prophylaxis for experimental murine melioidosis.the efficacies of the azalide azithromycin and the fluoroquinolones trovafloxacin and grepafloxacin for pre- and post-exposure prophylaxis of infection with high or low challenge doses of burkholderia pseudomallei strain 576 were assessed in an experimental mouse model. trovafloxacin and grepafloxacin afforded significant levels of protection, whereas azithromycin was ineffective and potentially detrimental. overall, the data suggest that some fluoroquinolones may have potential utility in proph ...201020462743
[immunogenic and protective characteristics of surface antigens 6 and d of burkholderia pseudomallei].extraction of complex of burkholderia pseudomallei antigens 6+d (ag6+d) and study of its immunogenic and protective characteristics.201020734717
effect of acidic ph on the invasion efficiency and the type iii secretion system of burkholderia thailandensis.burkholderia thailandensis is a close relative of burkholderia pseudomallei. these organisms are very similar, but b. thailandensis is far less virulent than b. pseudomallei. nucleotide sequencing and analysis of 14 b. thailandensis isolates revealed variation in the regions coding for the type iii secreted bipd protein. the degree of b. thailandensis bipd sequence variation was greater than that found in b. pseudomallei. western blot analysis indicated that, unlike b. pseudomallei, b. thailande ...201020799096
genomic acquisition of a capsular polysaccharide virulence cluster by non-pathogenic burkholderia isolates.burkholderia thailandensis is a non-pathogenic environmental saprophyte closely related to burkholderia pseudomallei, the causative agent of the often fatal animal and human disease melioidosis. to study b. thailandensis genomic variation, we profiled 50 isolates using a pan-genome microarray comprising genomic elements from 28 burkholderia strains and species.201020799932
spatial analysis of melioidosis distribution in a suburban area.burkholderia pseudomallei, the causative agent of melioidosis is associated with soil. this study used a geographic information system (gis) to determine the spatial distribution of clinical cases of melioidosis in the endemic suburban region of townsville in australia. a total of 65 cases over the period 1996-2008 were plotted using residential address. two distinct groupings were found. one was around the base of a hill in the city centre and the other followed the old course of a major waterw ...201020092666
growing burkholderia pseudomallei in biofilm stimulating conditions significantly induces antimicrobial resistance.burkholderia pseudomallei, a gram-negative bacterium that causes melioidosis, was reported to produce biofilm. as the disease causes high relapse rate when compared to other bacterial infections, it therefore might be due to the reactivation of the biofilm forming bacteria which also provided resistance to antimicrobial agents. however, the mechanism on how biofilm can provide tolerance to antimicrobials is still unclear.201020169199
near-atomic resolution analysis of bipd, a component of the type iii secretion system of burkholderia pseudomallei.burkholderia pseudomallei, the causative agent of melioidosis, possesses a type iii protein secretion apparatus that is similar to those found in salmonella and shigella. a major function of these secretion systems is to inject virulence-associated proteins into target cells of the host organism. the bipd gene of b. pseudomallei encodes a secreted virulence factor that is similar in sequence and is most likely to be functionally analogous to ipad from shigella and sipd from salmonella. proteins ...201020823511
osteopontin impairs host defense during established gram-negative sepsis caused by burkholderia pseudomallei (melioidosis).melioidosis, caused by infection with burkholderia (b.) pseudomallei, is a severe illness that is endemic in southeast asia. osteopontin (opn) is a phosphorylated glycoprotein that is involved in several immune responses including induction of t-helper 1 cytokines and recruitment of inflammatory cells.201020824216
prevalence of burkholderia pseudomallei in guangxi, china.melioidosis, an infectious disease caused by the gram-negative bacterium burkholderia pseudomallei, is now recognized as an important public health problem in southeast asia and tropical northern australia. although b. pseudomallei has been detected in various water and soil samples in southeast china, the enviromental distribution of b. pseudomallei in china is unclear. in the winter months of 2007, 154 and 130 soil and water samples, respectively, were collected from several locations in guang ...201019538822
radiological manifestations of melioidosis.melioidosis is a serious infection that is associated with high mortality. it is due to a gram-negative bacterium, burkholderia pseudomallei which is an environmental saprophyte found in wet soils. melioidosis is endemic to northern australia and the southeast asia. however, there is now increasing number of reports of imported cases to regions where this infection has not been previously encountered. almost any organ can be affected. like many other conditions, radiological imaging is an integr ...201020103424
identification of tomato plant as a novel host model for burkholderia pseudomallei.burkholderia pseudomallei is the causative agent for melioidosis, a disease with significant mortality and morbidity in endemic regions. its versatility as a pathogen is reflected in its relatively huge 7.24 mb genome and the presence of many virulence factors including three type three secretion systems known as t3ss1, t3ss2 and t3ss3. besides being a human pathogen, it is able to infect and cause disease in many different animals and alternative hosts such as c. elegans.201020109238
innate immune detection of the type iii secretion apparatus through the nlrc4 inflammasome.the mammalian innate immune system uses toll-like receptors (tlrs) and nod-lrrs (nlrs) to detect microbial components during infection. often these molecules work in concert; for example, the tlrs can stimulate the production of the proforms of the cytokines il-1beta and il-18, whereas certain nlrs trigger their subsequent proteolytic processing via caspase 1. gram-negative bacteria use type iii secretion systems (t3ss) to deliver virulence factors to the cytosol of host cells, where they modula ...201020133635
growth-related changes in intracellular spermidine and its effect on efflux pump expression and quorum sensing in burkholderia pseudomallei.the burkholderia pseudomallei bpeab-oprb resistance-nodulation-division (rnd) family pump effluxes aminoglycoside and macrolide antibiotics as well as acylhomoserine lactones (ahls) involved in quorum sensing. expression of bpea-lacz was cell density-dependent and was inducible in the presence of these compounds. intracellular levels of spermidine and n-acetylspermidine increased with cell density in wild-type b. pseudomallei khw, but were always lower in the bpeab pump mutant at all growth phas ...201020035006
identification of burkholderia cepacia complex bacteria with a lipopolysaccharide-specific monoclonal antibody.the genus burkholderia includes many bacteria that cause serious human infections. as is the case with other gram-negative bacteria, burkholderia species produce lps, which is an abundant component of the bacterial cell surface. burkholderia cepacia complex (bcc) bacteria (which include at least 17 separate species) produce lps structures that are quite different. in an attempt to determine the degree of lps epitope variation among bcc species, a mab was produced, designated 5d8, specific for th ...201019729457
inactivation of burkholderia cepacia complex phage ks9 gp41 identifies the phage repressor and generates lytic virions.the burkholderia cepacia complex (bcc) is made up of at least 17 species of gram-negative opportunistic bacterial pathogens that cause fatal infections in patients with cystic fibrosis and chronic granulomatous disease. ks9 (vb_bcens_ks9), one of a number of temperate phages isolated from bcc species, is a prophage of burkholderia pyrrocinia lmg 21824. transmission electron micrographs indicate that ks9 belongs to the family siphoviridae and exhibits the b1 morphotype. the 39,896-bp ks9 genome, ...201019939932
continuing evolution of burkholderia mallei through genome reduction and large-scale rearrangements.burkholderia mallei (bm), the causative agent of the predominately equine disease glanders, is a genetically uniform species that is very closely related to the much more diverse species burkholderia pseudomallei (bp), an opportunistic human pathogen and the primary cause of melioidosis. to gain insight into the relative lack of genetic diversity within bm, we performed whole-genome comparative analysis of seven bm strains and contrasted these with eight bp strains. the bm core genome (shared by ...201020333227
differential susceptibility of inbred mouse strains to burkholderia thailandensis aerosol infection.burkholderia pseudomallei is the causative agent of melioidosis, an emerging bacterial disease that accounts for high rates of septicaemia and death in parts of southeast asia and northern australia. the closely related species burkholderia thailandensis is considered avirulent in humans and has been used as a surrogate for b. pseudomallei in several studies. the pathogenesis of b. pseudomallei and the role of toll-like receptors (tlrs) in host immunity to infection are not well-defined. in this ...201019853031
development and evaluation of polymerase chain reaction assay to detect burkholderia genus and to differentiate the species in clinical specimens.molecular-based techniques are becoming desirable as tools for identification of infectious diseases. amongst the burkholderia spp., there is a need to differentiate burkholderia pseudomallei from burkholderia cepacia, as misidentification could lead to false treatment of patients. in this study, conventional pcr assay targeting three genes was developed. primers were designed for the amplification of burkholderia genus-specific groel gene, b. pseudomallei-specific mpra gene and b. cepacia-speci ...201020345378
mycotic iliac aneurysm associated with burkholderia pseudomallei. 201019897393
pathema: a clade-specific bioinformatics resource center for pathogen research.pathema (http://pathema.jcvi.org) is one of the eight bioinformatics resource centers (brcs) funded by the national institute of allergy and infectious disease (niaid) designed to serve as a core resource for the bio-defense and infectious disease research community. pathema strives to support basic research and accelerate scientific progress for understanding, detecting, diagnosing and treating an established set of six target niaid category a-c pathogens: category a priority pathogens; bacillu ...201019843611
identifying translation initiation sites in prokaryotes using support vector machine.motivation: gene identification in genomes has been a fundamental and long-standing task in bioinformatics and computational biology. many computational methods have been developed to predict genes in prokaryote genomes by identifying translation initiation site (tis) in transcript data. however, the pseudo-tiss at the genome level make these methods suffer from a high number of false positive predictions. in addition, most of the existing tools use an unsupervised learning framework, whose pred ...201019840808
cpg oligodeoxyribonucleotides protect mice from burkholderia pseudomallei but not francisella tularensis schu s4 aerosols.abstract: studies have shown that cpg oligodeoxyribonucleotides (odn) protect mice from various bacterial pathogens, including burkholderia pseudomallei and francisella tularensis live vaccine strain (lvs), when administered before parenteral challenge. given the potential to develop cpg odn as a pre-treatment for multiple bacterial biological warfare agents, we examined survival, histopathology, and cytokine data from cpg odn-treated c57bl/6 mice to determine whether previously-reported protect ...201020181102
in vitro activity of biapenem against burkholderia pseudomallei. 201020188524
present and future therapeutic strategies for melioidosis and glanders.burkholderia pseudomallei and burkholderia mallei are the causative agents of melioidosis and glanders, respectively. both gram-negative pathogens are endemic in many parts of the world. although natural acquisition of these pathogens is rare in the majority of countries, these bacteria have recently gained much interest because of their potential as bioterrorism agents. in modern times, their potential destructive impact on public health has escalated owing to the ability of these pathogens to ...201020192686
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
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
perasafe, virkon and bleach are bactericidal for burkholderia pseudomallei, a select agent and the cause of melioidosis. 201120832143
autophagy targeting of listeria monocytogenes and the bacterial countermeasure.autophagy acts as an intrinsic defense system against intracellular bacterial survival. recently, multiple cellular pathways that target intracellular bacterial pathogens to autophagy have been described. these include the atg5/lc3 pathway, which targets shigella, the ubiquitin (ub)-ndp52-lc3 pathway, which targets group a streptococcus (gas) and salmonella typhimurium, the ub-p62-lc3 pathway, which targets mycobacterium tuberculosis, listeria monocytogenes and s. typhimurium, and the diacylglyc ...201121193840
burkholderia pseudomallei antibodies in individuals living in endemic regions in northeastern brazil.a seroepidemiological investigation was conducted among the population of two municipalities in northeastern brazil. immunoglobulin m (igm) and igg antibodies to burkholderia pseudomallei were positive in 51.27% (161 in 317 samples) and 58.49% (186), respectively. igm titers were higher in children than in adults. on the contrary, igg increased progressively with age. we observed a significant association between agricultural occupation and raised igm titers (p < 0.005) and igg titers (p < 0.001 ...201121292903
fatal acute melioidosis in a tourist returning from martinique island, november 2010.we report the fatal case of acute melioidosis in a patient returning from martinique with fever in november 2010. gram-negative rods were isolated from a blood culture and burkholderia pseudomallei identified within 24 hours after first medical contact. the patient died two days after admission to hospital despite intravenous therapy with high doses of imipenem/cilastatin and intensive care. clinicians seeing travellers returning from the subtropics or tropics with severe pneumonia or septicaemi ...201121223835
elucidation of the regulon and cis-acting regulatory element of hrpb, the arac-type regulator of a plant pathogen-like type iii secretion system in burkholderia pseudomallei.the human pathogen burkholderia pseudomallei possesses multiple type iii secretion system (t3ss) gene clusters. one of these, the b. pseudomallei t3ss2 (t3ss2(bp)) gene cluster, which apparently plays no role in animal virulence, is also found in six additional burkholderia spp. and is very similar to t3sss found in phytopathogenic xanthomonas spp. and ralstonia solanacearum. the t3ss2(bp) gene cluster also encodes an arac-type regulatory protein (hrpb(bp)) that is an ortholog of hrpb, the maste ...201121335458
human immune responses to burkholderia pseudomallei characterized by protein microarray analysis.we aimed to determine the antibody and t cell responses to burkholderia pseudomallei of humans to select candidate vaccine antigens.201121300673
glyburide is anti-inflammatory and associated with reduced mortality in melioidosis.patients with diabetes mellitus are more prone to bacterial sepsis, but there are conflicting data on whether outcomes are worse in diabetics after presentation with sepsis. glyburide is an oral hypoglycemic agent used to treat diabetes mellitus. this k(atp)-channel blocker and broad-spectrum atp-binding cassette (abc) transporter inhibitor has broad-ranging effects on the immune system, including inhibition of inflammasome assembly and would be predicted to influence the host response to infect ...201121293047
production and characterization of chimeric monoclonal antibodies against burkholderia pseudomallei and b. mallei using the dhfr expression system.burkholderia pseudomallei (bp) and b. mallei (bm) are closely related gram-negative, facultative anaerobic bacteria which cause life-threatening melioidosis in human and glanders in horse, respectively. our laboratory has previously generated and characterized more than 100 mouse monoclonal antibodies (mabs) against bp and bm, according to in vitro and in vivo assay. in this study, 3 mabs (bp7 10b11, bp7 2c6, and bp1 7f7) were selected to develop into chimeric mouse-human monoclonal antibodies ( ...201121573027
impact of streptozotocin-induced diabetes on functional responses of dendritic cells and macrophages towards burkholderia pseudomallei.diabetes mellitus is a documented risk factor for melioidosis, a tropical infection caused by burkholderia pseudomallei. the increased susceptibility of diabetic individuals to infections with other pathogens has been associated with immune dysregulation. however, the impact of diabetes on the functional responses of dendritic cells (dc) and macrophages during b. pseudomallei infection has not been investigated. this study compared the responses of macrophages and dc towards b. pseudomallei usin ...201121204999
macrophage and galleria mellonella infection models reflect the virulence of naturally occurring isolates of b. pseudomallei, b. thailandensis and b. oklahomensis.burkholderia pseudomallei is the causative agent of melioidosis, a tropical disease of humans with a variable and often fatal outcome. in murine models of infection, different strains exhibit varying degrees of virulence. in contrast, two related species, b. thailandensis and b. oklahomensis, are highly attenuated in mice. our aim was to determine whether virulence in mice is reflected in macrophage or wax moth larvae (galleria mellonella) infection models.201121241461
mucosal immunization with liposome-nucleic acid adjuvants generates effective humoral and cellular immunity.development of effective new mucosal vaccine adjuvants has become a priority with the increase in emerging viral and bacterial pathogens. we previously reported that cationic liposomes complexed with non-coding plasmid dna (cldc) were effective parenteral vaccine adjuvants. however, little is known regarding the ability of liposome-nucleic acid complexes to function as mucosal vaccine adjuvants, or the nature of the mucosal immune responses elicited by mucosal liposome-nucleic acid adjuvants. to ...201121600950
flagellar glycosylation in burkholderia pseudomallei and burkholderia thailandensis.glycosylation of proteins is known to impart novel physical properties and biological roles to proteins from both eukaryotes and prokaryotes. in this study, gel based glycoproteomics were used to identify glycoproteins of the potential bio-threat agent burkholderia pseudomallei and the closely related but non-pathogenic b. thailandensis. top-down and bottom-up ms analysis identified that the flagellin proteins of both species were post-translationally modified by novel glycans. analysis of prote ...201121602339
burkavidin: a novel secreted biotin-binding protein from the human pathogen burkholderia pseudomallei.the avidin-biotin technology has many applications, including molecular detection; immobilization; protein purification; construction of supramolecular assemblies and artificial metalloenzymes. here we present the recombinant expression of novel biotin-binding proteins from bacteria and the purification and characterization of a secreted burkavidin from the human pathogen burkholderia pseudomallei. expression of the native burkavidin in escherichia coli led to periplasmic secretion and formation ...201121241807
spei restriction enzyme displays greater discriminatory power than xbai enzyme does in a pulsed-field gel electrophoresis study on 146 clinical burkholderia pseudomallei isolates.restriction enzymes spei and xbai were used in a pulsed-field gel electrophoresis (pfge) study for molecular characterization of 146 clinical burkholderia pseudomallei isolates. the pfge parameters were optimized to enable comparable, reproducible, and robust results. the optimized parameters for both spei and xbai restriction enzymes used in this study were 200 v and a pulse time of 5 to 65 s for a 28-h runtime. using spei, 9 different clusters were identified, whereas 6 clusters were identifie ...201121617308
chlorine dioxide inactivation of bacterial threat agents.aims:  to evaluate the efficacy of chlorine dioxide (clo(2) ) against seven species of bacterial threat (bt) agents in water. methods and results:  two strains of bacillus anthracis spores, yersinia pestis, francisella tularensis, burkholderia pseudomallei, burkholderia mallei, and brucella species were each inoculated into a clo(2) solution with an initial concentration of 2·0 mg l(-1) (spores only) and 0·25 mg l(-1) (all other bacteria) at ph 7 or 8, 5°c or 25°c. at 0·25 mg l(-1) in potable wa ...201121623848
the aftermath of the western australian melioidosis outbreak.abstract. melioidosis became a notifiable disease in western australia (wa) 2 years after the west kimberley melioidosis outbreak. two cases of melioidosis caused by the outbreak genotype of burkholderia pseudomallei (national collection of type cultures [nctc] 13177) occurred in 1998 and 1999 in persons who visited the outbreak location at the time. no other infections caused by the outbreak strain have been recorded in wa since that time, despite an average of four culture-positive cases per y ...201121633018
repeat blood culture positive for b. pseudomallei indicates an increased risk of death from melioidosis.abstract. melioidosis, a bacterial infection caused by burkholderia pseudomallei, is notoriously difficult to cure despite appropriate antimicrobial therapy and has a mortality rate of up to 40%. we demonstrate that a blood culture positive for b. pseudomallei taken at the end of the first and/or second week after hospitalization for melioidosis is a strong prognostic factor for death (adjusted odds ratio = 4.2, 95% confidence interval = 2.1-8.7, p < 0.001 and adjusted odds ratio = 2.6, 95% conf ...201121633019
the use of positive serological tests as evidence of exposure to burkholderia pseudomallei. 201121633045
metabolites from the induced expression of cryptic single operons found in the genome of burkholderia pseudomallei.bacterial genome sequencing projects routinely uncover gene clusters that are predicted to encode the biosynthesis of uncharacterized small molecules. a subset of these cryptic genetic elements appears as individual operons. here we investigate potential single-operon biosynthetic systems found in the genome of the pathogenic bacterium burkholderia pseudomallei . placing these operons under the control of an inducible promoter led to the production of seven new metabolites. among the molecules w ...201121247113
mycotic aneurysm caused by burkholderia pseudomallei: report of a brazilian strain genetically related to thai strains.clin microbiol infect 2011; 17: 719-721 abstract: melioidosis, a severe infectious disease caused by burkholderia pseudomallei that is prevalent in southeast asia and northern australia, has been sporadically reported in brazil since 2003. we report a case of aortic aneurysm with blood culture positive for b. pseudomallei. the phylogenetic analysis of 16s ribosomal dna showed this isolate to be evolutionarily grouped with the mshr346 strains from thailand.201121521412
comparative in vitro susceptibility of burkholderia pseudomallei to doripenem, ertapenem, tigecycline and moxifloxacin.burkholderia pseudomallei, the causative agent of melioidosis, continues to present therapeutic challenges in endemic areas. a number of clinical issues have prompted consideration of alternative antimicrobial therapies. these include stability in 24-h infusion pumps, broad-spectrum coverage in the empirical treatment of community-acquired pneumonia, cost, the need for effective oral agents and rare reports of emerging resistance. this study aimed to examine the in vitro susceptibility of b. pse ...201121481571
the burkholderia pseudomallei type iii secretion system and bopa are required for evasion of lc3-associated phagocytosis.burkholderia pseudomallei is the causative agent of melioidosis, a fatal infectious disease endemic in tropical regions worldwide, and especially prevalent in southeast asia and northern australia. this intracellular pathogen can escape from phagosomes into the host cytoplasm, where it replicates and infects adjacent cells. we previously demonstrated that, in response to b. pseudomallei infection of macrophage cell line raw 264.7, a subset of bacteria co-localized with the autophagy marker prote ...201121412437
distinct roles for nitric oxide in resistant c57bl/6 and susceptible balb/c mice to control burkholderia pseudomallei infection.burkholderia pseudomallei is the causative agent of melioidosis, an emerging bacterial infectious disease in tropical and subtropical areas. we recently showed that nadph oxidase but not nitric oxide (no) contributes to resistance in innately resistant c57bl/6 mice in a b. pseudomallei respiratory infection model. however, the function of no for resistance was shown to differ among distinct strains of mice and proved also to be stage dependent in various infection models. the present study there ...201121410970
vith world melioidosis congress report: celebrating a century of research. 201121449838
systemic melioidiosis. 201121378433
[a case of melioidosis in argentina].we describe a case of 17-year- old man native of dominican republic, with hodgkin's lymphoma, who presented soft espontaneous draining nodules. in the clinical samples grew burkholderia pseudomallei; the etiological agent of melioidosis. he received antimicrobial treatment with imipenem and amoxicillin/clavulanic with very good clinical evolution of the infectious process. melioidosis diagnosis could be underestimated due to the low incidence of burkholderia pseudomallei in our continent. the de ...201121296719
mechanism and inhibition of the fabi enoyl-acp reductase from burkholderia pseudomallei.as an initial step in developing novel antibacterials against burkholderia pseudomallei, we have characterized the fabi enoyl-acp reductase homologues in the type ii fatty acid biosynthesis pathway from this organism and performed an initial enzyme inhibition study.201121393229
a conference report from "down under": talking autophagy at ozbio2010.ozbio2010 was held at the melbourne convention and exhibition centre, september 26 to october 1, 2010. this international conference catered to researchers in several fields having complementary interests including biochemistry, molecular biology, cell biology, plant physiology and health-related research. it was held under the auspices of two major international scientific societies, iubmb and faobmb, and the combio2010 collective (representing nine professional societies and groupings from aus ...201121116128
complete killing of caenorhabditis elegans by burkholderia pseudomallei is dependent on prolonged direct association with the viable pathogen.burkholderia pseudomallei is the causative agent of melioidosis, a disease of significant morbidity and mortality in both human and animals in endemic areas. much remains to be known about the contributions of genotypic variations within the bacteria and the host, and environmental factors that lead to the manifestation of the clinical symptoms of melioidosis.201121408228
rapid identification of burkholderia pseudomallei and burkholderia mallei by fluorescence in situ hybridization (fish) from culture and paraffin-embedded tissue samples.we evaluated newly developed probes for rapid identification of burkholderia (b.) pseudomallei and b. mallei and differentiation from b. thailandensis by fluorescence in situ hybridization (fish). fish correctly identified 100% of the tested b. pseudomallei (11), b. mallei (11), and b. thailandensis (1) strains, excluded 100% of all tested negative controls (61), and allowed demonstration of b. pseudomallei infection in a paraffin-embedded spleen tissue sample of an experimentally infected mouse ...201121658996
knockout and pullout recombineering for naturally transformable burkholderia thailandensis and burkholderia pseudomallei.phage ++-red proteins are powerful tools for pulling and knocking out chromosomal fragments but have been limited to the +¦-proteobacteria. procedures are described here to easily knock out (ko) and pull out (po) chromosomal dna fragments from naturally transformable burkholderia thailandensis and burkholderia pseudomallei. this system takes advantage of published compliant counterselectable and selectable markers (sacb, phes, gat and the arabinose-utilization operon) and ++-red mutant proteins. ...201121738123
superoxide dismutase c is required for intracellular survival and virulence of burkholderia pseudomallei.burkholderia pseudomallei is an intracellular pathogen and the causative agent of melioidosis, a life-threatening disease of humans. within host cells, superoxide is an important mediator of pathogen killing. in this study, we have identified the b. pseudomallei k96243 sodc gene, shown that it has superoxide dismutase activity, and constructed an allelic deletion mutant of this gene. compared with the wild-type, the mutant was more sensitive to killing by extracellular superoxide, but not to sup ...201121659326
autotransporters and their role in the virulence of burkholderia pseudomallei and burkholderia mallei.burkholderia pseudomallei and burkholderia mallei are closely related gram-negative bacteria responsible for the infectious diseases melioidosis and glanders, respectively. autotransporters (ats) comprise a large and diverse family of secreted and outer membrane proteins that includes virulence-associated invasins, adhesins, proteases, and actin-nucleating factors. the b. pseudomallei k96243 genome contains 11 predicted ats, eight of which share homologs in the b. mallei atcc 23344 genome. this ...201121811486
the burkholderia pseudomallei {delta}asd mutant exhibits attenuated intracellular infectivity and imparts protection against acute inhalation melioidosis in mice.burkholderia pseudomallei, the cause of serious and life threatening diseases in humans, is of national biodefense concern because of its potential use as a bioterrorism agent. this microbe is listed as a select agent by the cdc, therefore, development of vaccines is of significant importance. here, we further investigated the growth characteristics of a recently created b. pseudomallei 1026b ?asd mutant in vitro, in a cell model, and in an animal model of infection. the mutant was typified by a ...201121807903
alanine racemase mutants of burkholderia pseudomallei and burkholderia mallei and use of alanine racemase as a non-antibiotic-based selectable marker.burkholderia pseudomallei and burkholderia mallei are category b select agents and must be studied under bsl3 containment in the united states. they are typically resistant to multiple antibiotics, and the antibiotics used to treat b. pseudomallei or b. mallei infections may not be used as selective agents with the corresponding burkholderia species. here, we investigated alanine racemase deficient mutants of b. pseudomallei and b. mallei for development of non-antibiotic-based genetic selection ...201121720554
burkholderia pseudomallei infection in a child with cystic fibrosis: acquisition in the western hemisphere.melioidosis, an infection caused by the bacterium burkholderia pseudomallei, is endemic to southeast asia and northern australia but is only very rarely seen in patients in the united states. we report pulmonary b pseudomallei infection in a young girl with cystic fibrosis (cf) who had never traveled to asia or australia. biochemical and epidemiologic investigation determined aruba as the likely site of disease acquisition. this report highlights the ability of patients with cf to acquire this o ...201121729895
endovascular therapy for infected aortic aneurysms.objective: to determine the outcome of endovascular therapy for an infected aortic aneurysm in patients with or without aorto-aerodigestive/aortocaval fistulas. methods: from september 2005 to may 2010, 21 patients, 17 abdominal and four thoracic infected aortic aneurysms were treated with an endovascular stent graft at songklanagarind hospital, thailand. five patients presented with fistula complications, 1 aortoesophageal, 1 aortobronchial, 1 aortocaval, and 2 aortoenteric fistulas. lifelong a ...201121802238
neutrophils are the predominant cell-type to associate with burkholderia pseudomallei in a balb/c mouse model of respiratory melioidosis.a variety of studies have implicated neutrophils and the rapid induction of cytokine in the host response in melioidosis. here a balb/c mouse model of infection with aerosolised burkholderia pseudomalleik96243 has been used to understand the immune response to infection in this model and verify other infection models that show rapid growth of bacteria, colonisation of tissues and periphery, induction of cytokines and influx of neutrophils. uniquely, this study has also determined the association ...201121798336
a naturally derived outer-membrane vesicle vaccine protects against lethal pulmonary burkholderia pseudomallei infection.burkholderia pseudomallei, and other members of the burkholderia, are among the most antibiotic-resistant bacterial species encountered in human infection. mortality rates associated with severe b. pseudomallei infection approach 50% despite therapeutic treatment. a protective vaccine against b. pseudomallei would dramatically reduce morbidity and mortality in endemic areas and provide a safeguard for the u.s. and other countries against biological attack with this organism. in this study, we in ...201121871517
A Burkholderia pseudomallei toxin inhibits helicase activity of translation factor eIF4A.The structure of BPSL1549, a protein of unknown function from Burkholderia pseudomallei, reveals a similarity to Escherichia coli cytotoxic necrotizing factor 1. We found that BPSL1549 acted as a potent cytotoxin against eukaryotic cells and was lethal when administered to mice. Expression levels of bpsl1549 correlate with conditions expected to promote or suppress pathogenicity. BPSL1549 promotes deamidation of glutamine-339 of the translation initiation factor eIF4A, abolishing its helicase ac ...201122076380
isolation and characterization of a novel virulent podovirus which infects burkholderia pseudomallei.abstract: burkholderia pseudomallei is a saprophytic soil bacterium and the etiological agent that causes melioidosis. it is naturally resistant to many antibiotics and therefore is difficult to treat. bacteriophages may provide an alternative source of treatment. we have isolated and characterised the bacteriophage phi bp-amp1. the phage is a member of the podoviridae family and has a genome size of ~ 45 kb. molecular data based on the gene which encodes for the phage tail tubular protein sugge ...201121791081
Antimicrobial resistance to ceftazidime involving loss of penicillin-binding protein 3 in Burkholderia pseudomallei.Known mechanisms of resistance to ß-lactam antibiotics include ß-lactamase expression, altered drug target, decreased bacterial permeability, and increased drug efflux. Here, we describe a unique mechanism of ß-lactam resistance in the biothreat organism Burkholderia pseudomallei (the cause of melioidosis), associated with treatment failure during prolonged ceftazidime therapy of natural infection. Detailed comparisons of the initial ceftazidime-susceptible infecting isolate and subsequent cefta ...201121969582
Two Norwegian patients with melioidosis presenting with bacteraemia and splenic and prostatic abscesses.Infections caused by Burkholderia pseudomallei are rare in nonendemic areas, such as Scandinavia. We report the first two cases of melioidosis in Norway presenting with bacteraemia and splenic and prostatic abscesses, respectively.201122017720
Structural basis of the substrate specificity of bifunctional isocitrate dehydrogenase kinase/phosphatase.Isocitrate dehydrogenase kinase/phosphatase (AceK) regulates entry into the glyoxylate bypass by reversibly phosphorylating isocitrate dehydrogenase (ICDH). On the basis of the recently determined structure of the AceK-ICDH complex from Escherichia coli, we have classified the structures of homodimeric NADP(+)-ICDHs to rationalize and predict which organisms likely contain substrates for AceK. One example is Burkholderia pseudomallei (Bp). Here we report a crystal structure of Bp-ICDH that exhib ...201121870819
A Burkholderia pseudomallei macrophage infectivity potentiator-like protein has rapamycin-inhibitable peptidylprolyl isomerase activity and pleiotropic effects on virulence.Macrophage infectivity potentiators (Mips) are a group of virulence factors encoded by pathogenic bacteria such as Legionella, Chlamydia, and Neisseria species. Mips are part of the FK506-binding protein (FKBP) family, whose members typically exhibit peptidylprolyl cis-trans isomerase (PPIase) activity which is inhibitable by the immunosuppressants FK506 and rapamycin. Here we describe the identification and characterization of BPSS1823, a Mip-like protein in the intracellular pathogen Burkholde ...201121859853
[Detection and identification of highly pathogenic bacteria within the framework of the EQADeBa project--Part I: Samples containing living pathogens].Bacillus anthracis, Yersinia pestis, Francisella tularensis, Brucella sp., Bulkholderia mallei are B. pseudomallei are highly pathogenic bacteria of potential bioterrorism risk. To support the early warning and rapid response capacity to ensure an effective reaction to bioterrorist attacks the international project "Establishment of Quality Assurances for Detection of Highly Pathogenic Bacteria of Potential Bioterrorism Risk" (EQADeBa) has been established. The aim of the project was establishme ...201122184939
improvement of anti-burkholderia mouse monoclonal antibody from various phage-displayed single-chain antibody libraries.to improve anti-burkholderia monoclonal antibody (mab) binding affinity, six single chain variable fragments (scfvs) constructed previously were used as scaffolds to construct large highly-diversified phage-displayed mouse scfv random and domain libraries. first, we employed random mutagenesis to introduce random point mutations into entire variable regions, generating six random libraries. additionally, the oligonucleotide-directed mutagenesis was targeted on complementarity-determining region ...201121787781
identification of circulating bacterial antigens by in vivo microbial antigen discovery.detection of microbial antigens in clinical samples can lead to rapid diagnosis of an infection and administration of appropriate therapeutics. a major barrier in diagnostics development is determining which of the potentially hundreds or thousands of antigens produced by a microbe are actually present in patient samples in detectable amounts against a background of innumerable host proteins. in this report, we describe a strategy, termed in vivo microbial antigen discovery (inmad), that we used ...201121846829
burkholderia pseudomallei-induced cell fusion in u937 macrophages can be inhibited by monoclonal antibodies against host cell surface molecules.burkholderia pseudomallei induces the formation of multinucleated giant cells in cell monolayers. after infection of human macrophage-like u937 cells with b. pseudomallei, addition of monoclonal antibodies against integrin-associated protein (cd47), e-selectin (cd62e), a fusion regulatory protein (cd98), and e-cadherin (cd324) suppressed multinucleated giant cells in a concentration-dependent manner while monoclonal antibodies against other surface molecules did not inhibit fusion despite bindin ...201121784167
toll-like receptor 4 region genetic variants are associated with susceptibility to melioidosis.melioidosis is a tropical infection caused by the gram-negative soil saprophyte burkholderia pseudomallei. despite broad exposure of northeastern thais, disease develops in only a small proportion of individuals. although diabetes is a risk factor, the mechanisms of host susceptibility to melioidosis are still poorly understood. we postulated that toll-like receptors (tlrs) regulate host susceptibility to disease, and that genetic variation in tlrs is associated with melioidosis. we analyzed the ...201121776015
Development of vaccines against burkholderia pseudomallei.Burkholderia pseudomallei is a Gram-negative bacterium which is the causative agent of melioidosis, a disease which carries a high mortality and morbidity rate in endemic areas of South East Asia and Northern Australia. At present there is no available human vaccine that protects against B. pseudomallei, and with the current limitations of antibiotic treatment, the development of new preventative and therapeutic interventions is crucial. This review considers the multiple elements of melioidosis ...201121991263
in vitro activity of sitafloxacin against burkholderia pseudomallei. 201121775108
survival of burkholderia pseudomallei in distilled water for 16 years.burkholderia pseudomallei was examined after being maintained in distilled water at 25°c for 16 years. the gram stain was atypical (pale pink cocci or coccobacilli). the estimated number of live and dead b. pseudomallei was 3.8×10(7) cells/ml and 1.4×10(5) cells/ml, respectively. a colony count on agar of 1.0×10(6) cfu/ml suggested that a proportion of cells were in a viable but non-culturable state. colony morphology was different from the parental isolate for 84% of colonies. pulsed-field gel ...201121764093
etymologia: melioidosis.from the greek melis, distemper of asses, oeide-s, resemblance, and osis, a suffix indicating an abnormal condition or disease. alfred whitmore, a british pathologist serving in burma, and his assistant c. s. krishnaswami first described melioidosis in 1912. the infection became known as whitmore's disease. in 1925, ambrose t. stanton and william fletcher, the researchers who identified burkholderia pseudomallei as the infection's causative agent, renamed the infection melioidosis because of its ...201121762621
dictyostelium discoideum as a model system for identification of burkholderia pseudomallei virulence factors.burkholderia pseudomallei is an emerging bacterial pathogen and category b biothreat. human infections with b. pseudomallei (called melioidosis) present as a range of manifestations, including acute septicemia and pneumonia. although melioidosis can be fatal, little is known about the molecular basis of b. pseudomallei pathogenicity, in part because of the lack of simple, genetically tractable eukaryotic models to facilitate en masse identification of virulence determinants or explore host-patho ...201121402765
in vitro and in vivo studies of monoclonal antibodies with prominent bactericidal activity against burkholderia pseudomallei and burkholderia mallei.our laboratory has developed more than a hundred mouse monoclonal antibodies (mabs) against burkholderia pseudomallei and burkholderia mallei. these antibodies have been categorized into different groups based on their specificities and the biochemical natures of their target antigens. the current study first examined the bactericidal activities of a number of these mabs by an in vitro opsonic assay. then, the in vivo protective efficacy of selected mabs was evaluated using balb/c mice challenge ...201121450976
molecular phylogeny of burkholderia pseudomallei from a remote region of papua new guinea.the island of new guinea is located midway between the world's two major melioidosis endemic regions of australia and southeast asia. previous studies in papua new guinea have demonstrated autochthonous melioidosis in balimo, western province. in contrast to other regions of endemicity, isolates recovered from both environmental and clinical sources demonstrate narrow genetic diversity over large spatial and temporal scales.201121483841
adaptation and antibiotic tolerance of anaerobic burkholderia pseudomallei.the gram-negative bacterium, burkholderia pseudomallei, is the etiological agent of melioidosis and is remarkably resistant to most classes of antibacterials. even after months of treatment with antibacterials relatively effective in vitro, there is a high rate of treatment failure, indicating that this pathogen alters its patterns of antibacterial susceptibility in response to cues encountered in the host. the pathology of melioidosis indicates that b. pseudomallei encounter host microenvironme ...201121537012
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