Sample records for burkholderia pseudomallei melioidosis

  1. Evolution of Burkholderia pseudomallei in Recurrent Melioidosis

    PubMed Central

    Hayden, Hillary S.; Lim, Regina; Brittnacher, Mitchell J.; Sims, Elizabeth H.; Ramage, Elizabeth R.; Fong, Christine; Wu, Zaining; Crist, Eva; Chang, Jean; Zhou, Yang; Radey, Matthew; Rohmer, Laurence; Haugen, Eric; Gillett, Will; Wuthiekanun, Vanaporn; Peacock, Sharon J.; Kaul, Rajinder; Miller, Samuel I.; Manoil, Colin; Jacobs, Michael A.

    2012-01-01

    Burkholderia pseudomallei, the etiologic agent of human melioidosis, is capable of causing severe acute infection with overwhelming septicemia leading to death. A high rate of recurrent disease occurs in adult patients, most often due to recrudescence of the initial infecting strain. Pathogen persistence and evolution during such relapsing infections are not well understood. Bacterial cells present in the primary inoculum and in late infections may differ greatly, as has been observed in chronic disease, or they may be genetically similar. To test these alternative models, we conducted whole-genome comparisons of clonal primary and relapse B. pseudomallei isolates recovered six months to six years apart from four adult Thai patients. We found differences within each of the four pairs, and some, including a 330 Kb deletion, affected substantial portions of the genome. Many of the changes were associated with increased antibiotic resistance. We also found evidence of positive selection for deleterious mutations in a TetR family transcriptional regulator from a set of 107 additional B. pseudomallei strains. As part of the study, we sequenced to base-pair accuracy the genome of B. pseudomallei strain 1026b, the model used for genetic studies of B. pseudomallei pathogenesis and antibiotic resistance. Our findings provide new insights into pathogen evolution during long-term infections and have important implications for the development of intervention strategies to combat recurrent melioidosis. PMID:22615773

  2. Melioidosis: insights into the pathogenicity of Burkholderia pseudomallei

    Microsoft Academic Search

    Tom van der Poll; Nicholas J. White; Nicholas P. Day; Sharon J. Peacock; W. Joost Wiersinga

    2006-01-01

    Burkholderia pseudomallei is a potential bioterror agent and the causative agent of melioidosis, a severe disease that is endemic in areas of Southeast Asia and Northern Australia. Infection is often associated with bacterial dissemination to distant sites, and there are many possible disease manifestations, with melioidosis septic shock being the most severe. Eradication of the organism following infection is difficult,

  3. Detection of Burkholderia pseudomallei DNA in Patients with Septicemic Melioidosis

    Microsoft Academic Search

    TARARAJ DHARAKUL; SIRIRURG SONGSIVILAI; SIRITHIP VIRIYACHITRA; VORAVICH LUANGWEDCHAKARN; BOONRAT TASSANEETRITAP; ANDWIPADA CHAOWAGUL

    1996-01-01

    Septicemic melioidosis is the most severe form of melioidosis, which is caused byBurkholderia pseudomallei. It is endemic in Southeast Asia and is the leading cause of death from community-acquired septicemia in northeast Thailand. A major factor that contributes to the high mortality is the delay in isolation and identificationofthecausativeorganism.Morethanhalfofthepatientsdiewithinthefirst2daysafterhospital admission, before bacterial cultures become positive. The present study was undertaken

  4. Genomic patterns of pathogen evolution revealed by comparison of Burkholderia pseudomallei, the causative agent of melioidosis, to avirulent Burkholderia thailandensis

    E-print Network

    Yu, Yiting

    Background: The Gram-negative bacterium Burkholderia pseudomallei (Bp) is the causative agent of the human disease melioidosis. To understand the evolutionary mechanisms contributing to Bp virulence, we performed a comparative ...

  5. Burkholderia pseudomallei Known Siderophores and Hemin Uptake Are Dispensable for Lethal Murine Melioidosis

    Microsoft Academic Search

    Brian H. Kvitko; Andrew Goodyear; Katie L. Propst; Steven W. Dow; Herbert P. Schweizer

    2012-01-01

    Burkholderia pseudomallei is a mostly saprophytic bacterium, but can infect humans where it causes the difficult-to-manage disease melioidosis. Even with proper diagnosis and prompt therapeutic interventions mortality rates still range from >20% in Northern Australia to over 40% in Thailand. Surprisingly little is yet known about how B. pseudomallei infects, invades and survives within its hosts, and virtually nothing is

  6. The molecular and cellular basis of pathogenesis in melioidosis: how does Burkholderia pseudomallei cause disease?

    PubMed

    Lazar Adler, Natalie R; Govan, Brenda; Cullinane, Meabh; Harper, Marina; Adler, Ben; Boyce, John D

    2009-11-01

    Melioidosis, a febrile illness with disease states ranging from acute pneumonia or septicaemia to chronic abscesses, was first documented by Whitmore & Krishnaswami (1912). The causative agent, Burkholderia pseudomallei, was subsequently identified as a motile, gram-negative bacillus, which is principally an environmental saprophyte. Melioidosis has become an increasingly important disease in endemic areas such as northern Thailand and Australia (Currie et al., 2000). This health burden, plus the classification of B. pseudomallei as a category B biological agent (Rotz et al., 2002), has resulted in an escalation of research interest. This review focuses on the molecular and cellular basis of pathogenesis in melioidosis, with a comprehensive overview of the current knowledge on how B. pseudomallei can cause disease. The process of B. pseudomallei movement from the environmental reservoir to attachment and invasion of epithelial and macrophage cells and the subsequent intracellular survival and spread is outlined. Furthermore, the diverse assortment of virulence factors that allow B. pseudomallei to become an effective opportunistic pathogen, as well as to avoid or subvert the host immune response, is discussed. With the recent increase in genomic and molecular studies, the current understanding of the infection process of melioidosis has increased substantially, yet, much still remains to be elucidated. PMID:19732156

  7. Mechanisms of antibiotic resistance in Burkholderia pseudomallei: implications for treatment of melioidosis

    PubMed Central

    Schweizer, Herbert P

    2013-01-01

    Burkholderia pseudomallei is the etiologic agent of melioidosis. This multifaceted disease is difficult to treat, resulting in high morbidity and mortality. Treatment of B. pseudomallei infections is lengthy and necessitates an intensive phase (parenteral ceftazidime, amoxicillin–clavulanic acid or meropenem) and an eradication phase (oral trimethoprim–sulfamethoxazole). The main resistance mechanisms affecting these antibiotics include enzymatic inactivation, target deletion and efflux from the cell, and are mediated by chromosomally encoded genes. Overproduction and mutations in the class A PenA ?-lactamase cause ceftazidime and amoxicillin–clavulanic acid resistance. Deletion of the penicillin binding protein 3 results in ceftazidime resistance. BpeEF–OprC efflux pump expression causes trimethoprim and trimethoprim–sulfamethoxazole resistance. Although resistance is still relatively rare, therapeutic efficacies may be compromised by resistance emergence due to increased use of antibiotics in endemic regions. Novel agents and therapeutic strategies are being tested and, in some instances, show promise as anti-B. pseudomallei infectives. PMID:23231488

  8. Burkholderia pseudomallei Known Siderophores and Hemin Uptake Are Dispensable for Lethal Murine Melioidosis

    PubMed Central

    Kvitko, Brian H.; Goodyear, Andrew; Propst, Katie L.; Dow, Steven W.; Schweizer, Herbert P.

    2012-01-01

    Burkholderia pseudomallei is a mostly saprophytic bacterium, but can infect humans where it causes the difficult-to-manage disease melioidosis. Even with proper diagnosis and prompt therapeutic interventions mortality rates still range from >20% in Northern Australia to over 40% in Thailand. Surprisingly little is yet known about how B. pseudomallei infects, invades and survives within its hosts, and virtually nothing is known about the contribution of critical nutrients such as iron to the bacterium's pathogenesis. It was previously assumed that B. pseudomallei used iron-acquisition systems commonly found in other bacteria, for example siderophores. However, our previous discovery of a clinical isolate carrying a large chromosomal deletion missing the entire malleobactin gene cluster encoding the bacterium's major high-affinity siderophore while still being fully virulent in a murine melioidosis model suggested that other iron-acquisition systems might make contributions to virulence. Here, we deleted the major siderophore malleobactin (mba) and pyochelin (pch) gene clusters in strain 1710b and revealed a residual siderophore activity which was unrelated to other known Burkholderia siderophores such as cepabactin and cepaciachelin, and not due to increased secretion of chelators such as citrate. Deletion of the two hemin uptake loci, hmu and hem, showed that Hmu is required for utilization of hemin and hemoglobin and that Hem cannot complement a Hmu deficiency. Prolonged incubation of a hmu hem mutant in hemoglobin-containing minimal medium yielded variants able to utilize hemoglobin and hemin suggesting alternate pathways for utilization of these two host iron sources. Lactoferrin utilization was dependent on malleobactin, but not pyochelin synthesis and/or uptake. A mba pch hmu hem quadruple mutant could use ferritin as an iron source and upon intranasal infection was lethal in an acute murine melioidosis model. These data suggest that B. pseudomallei may employ a novel ferritin-iron acquisition pathway as a means to sustain in vivo growth. PMID:22745846

  9. Genome wide transcriptome profiling of a murine acute melioidosis model reveals new insights into how Burkholderia pseudomallei overcomes host innate immunity

    Microsoft Academic Search

    Chui-Yoke Chin; Denise M Monack; Sheila Nathan

    2010-01-01

    BACKGROUND: At present, very little is known about how Burkholderia pseudomallei (B. pseudomallei) interacts with its host to elicit melioidosis symptoms. We established a murine acute-phase melioidosis model and used DNA microarray technology to investigate the global host\\/pathogen interaction. We compared the transcriptome of infected liver and spleen with uninfected tissues over an infection period of 42 hr to identify

  10. Global Map of Growth-Regulated Gene Expression in Burkholderia pseudomallei, the Causative Agent of Melioidosis?

    PubMed Central

    Rodrigues, Fiona; Sarkar-Tyson, Mitali; Harding, Sarah V.; Sim, Siew Hoon; Chua, Hui Hoon; Lin, Chi Ho; Han, Xu; Karuturi, R. Krishna M.; Sung, Ken; Yu, Kun; Chen, Wei; Atkins, Timothy P.; Titball, Richard W.; Tan, Patrick

    2006-01-01

    Many microbial pathogens express specific virulence traits at distinct growth phases. To understand the molecular pathways linking bacterial growth to pathogenicity, we have characterized the growth transcriptome of Burkholderia pseudomallei, the causative agent of melioidosis. Using a fine-scale sampling approach, we found approximately 17% of all B. pseudomallei genes displaying regulated expression during growth in rich medium, occurring as broad waves of functionally coherent gene expression tightly associated with distinct growth phases and transition points. We observed regulation of virulence genes across all growth phases and identified serC as a potentially new virulence factor by virtue of its coexpression with other early-phase virulence genes. serC-disrupted B. pseudomallei strains were serine auxotrophs and in mouse infection assays exhibited a dramatic attenuation of virulence compared to wild-type B. pseudomallei. Immunization of mice with serC-disrupted B. pseudomallei also conferred protection against subsequent challenges with different wild-type B. pseudomallei strains. At a genomic level, early-phase genes were preferentially localized on chromosome 1, while stationary-phase genes were significantly biased towards chromosome 2. We detected a significant level of chromosomally clustered gene expression, allowing us to predict ?100 potential operons in the B. pseudomallei genome. We computationally and experimentally validated these operons by showing that genes in these regions are preferentially transcribed in the same 5??3? direction, possess significantly shorter intergenic lengths than the overall genome, and are expressed as a common mRNA transcript. The availability of this transcriptome map provides an important resource for understanding the transcriptional architecture of B. pseudomallei. PMID:16997946

  11. Sensitive and Specific Molecular Detection of Burkholderia pseudomallei, the Causative Agent of Melioidosis, in the Soil of Tropical Northern Australia?

    PubMed Central

    Kaestli, Mirjam; Mayo, Mark; Harrington, Glenda; Watt, Felicity; Hill, Jason; Gal, Daniel; Currie, Bart J.

    2007-01-01

    Burkholderia pseudomallei, the cause of the severe disease melioidosis in humans and animals, is a gram-negative saprophyte living in soil and water of areas of endemicity such as tropical northern Australia and Southeast Asia. Infection occurs mainly by contact with wet contaminated soil. The environmental distribution of B. pseudomallei in northern Australia is still unclear. We developed and evaluated a direct soil B. pseudomallei DNA detection method based on the recently published real-time PCR targeting the B. pseudomallei type III secretion system. The method was evaluated by inoculating different soil types with B. pseudomallei dilution series and by comparing B. pseudomallei detection rate with culture-based detection rate for 104 randomly collected soil samples from the Darwin rural area in northern Australia. We found that direct soil B. pseudomallei DNA detection not only was substantially faster than culture but also proved to be more sensitive with no evident false-positive results. This assay provides a new tool to detect B. pseudomallei in soil samples in a fast and highly sensitive and specific manner and is applicable for large-scale B. pseudomallei environmental screening studies or in outbreak situations. Furthermore, analysis of the 104 collected soil samples revealed a significant association between B. pseudomallei-positive sites and the presence of animals at these locations and also with moist, reddish brown-to-reddish gray soils. PMID:17873073

  12. The core and accessory genomes of Burkholderia pseudomallei: implications for human melioidosis.

    PubMed

    Sim, Siew Hoon; Yu, Yiting; Lin, Chi Ho; Karuturi, R Krishna M; Wuthiekanun, Vanaporn; Tuanyok, Apichai; Chua, Hui Hoon; Ong, Catherine; Paramalingam, Sivalingam Suppiah; Tan, Gladys; Tang, Lynn; Lau, Gary; Ooi, Eng Eong; Woods, Donald; Feil, Edward; Peacock, Sharon J; Tan, Patrick

    2008-10-01

    Natural isolates of Burkholderia pseudomallei (Bp), the causative agent of melioidosis, can exhibit significant ecological flexibility that is likely reflective of a dynamic genome. Using whole-genome Bp microarrays, we examined patterns of gene presence and absence across 94 South East Asian strains isolated from a variety of clinical, environmental, or animal sources. 86% of the Bp K96243 reference genome was common to all the strains representing the Bp "core genome", comprising genes largely involved in essential functions (eg amino acid metabolism, protein translation). In contrast, 14% of the K96243 genome was variably present across the isolates. This Bp accessory genome encompassed multiple genomic islands (GIs), paralogous genes, and insertions/deletions, including three distinct lipopolysaccharide (LPS)-related gene clusters. Strikingly, strains recovered from cases of human melioidosis clustered on a tree based on accessory gene content, and were significantly more likely to harbor certain GIs compared to animal and environmental isolates. Consistent with the inference that the GIs may contribute to pathogenesis, experimental mutation of BPSS2053, a GI gene, reduced microbial adherence to human epithelial cells. Our results suggest that the Bp accessory genome is likely to play an important role in microbial adaptation and virulence. PMID:18927621

  13. The Core and Accessory Genomes of Burkholderia pseudomallei: Implications for Human Melioidosis

    PubMed Central

    Lin, Chi Ho; Karuturi, R. Krishna M.; Wuthiekanun, Vanaporn; Tuanyok, Apichai; Chua, Hui Hoon; Ong, Catherine; Paramalingam, Sivalingam Suppiah; Tan, Gladys; Tang, Lynn; Lau, Gary; Ooi, Eng Eong; Woods, Donald; Feil, Edward; Peacock, Sharon J.; Tan, Patrick

    2008-01-01

    Natural isolates of Burkholderia pseudomallei (Bp), the causative agent of melioidosis, can exhibit significant ecological flexibility that is likely reflective of a dynamic genome. Using whole-genome Bp microarrays, we examined patterns of gene presence and absence across 94 South East Asian strains isolated from a variety of clinical, environmental, or animal sources. 86% of the Bp K96243 reference genome was common to all the strains representing the Bp “core genome”, comprising genes largely involved in essential functions (eg amino acid metabolism, protein translation). In contrast, 14% of the K96243 genome was variably present across the isolates. This Bp accessory genome encompassed multiple genomic islands (GIs), paralogous genes, and insertions/deletions, including three distinct lipopolysaccharide (LPS)-related gene clusters. Strikingly, strains recovered from cases of human melioidosis clustered on a tree based on accessory gene content, and were significantly more likely to harbor certain GIs compared to animal and environmental isolates. Consistent with the inference that the GIs may contribute to pathogenesis, experimental mutation of BPSS2053, a GI gene, reduced microbial adherence to human epithelial cells. Our results suggest that the Bp accessory genome is likely to play an important role in microbial adaptation and virulence. PMID:18927621

  14. Pathogenesis of percutaneous infection of goats with Burkholderia pseudomallei: clinical, pathologic, and immunological responses in chronic melioidosis

    PubMed Central

    Soffler, Carl; Bosco-Lauth, Angela M; Aboellail, Tawfik A; Marolf, Angela J; Bowen, Richard A

    2014-01-01

    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 pathogenesis of percutaneous infection despite its presumptive importance in natural disease. Caprine models are useful in the study of melioidosis because goats are susceptible to natural infection by B.?pseudomallei, display similar epizootiology/epidemiology to that of humans within the endemic range and develop similar pathologic lesions. Percutaneous inoculation with 104?CFU of B.?pseudomallei produced disease in all experimental animals with rapid dissemination to the lungs, spleen and kidneys. Initial fever was brief, but temperatures did not return to pre-infection levels until day 18, concurrent with a dramatic lymphocytosis and the transition to chronic disease. Distribution and appearance of gross pathologic and radiographic lesions in goats were similar to caprine aerosol infection and to reported human disease. The similarities seen despite different routes of infection suggest that host or bacterial factors may be more important than the route of infection in disease pathogenesis. The nature of melioidosis in goats makes it amenable for modelling additional risk factors to produce acute clinical disease, which is important to the study of human melioidosis. PMID:24571408

  15. The Burkholderia pseudomallei ?asd Mutant Exhibits Attenuated Intracellular Infectivity and Imparts Protection against Acute Inhalation Melioidosis in Mice ?

    PubMed Central

    Norris, Michael H.; Propst, Katie L.; Kang, Yun; Dow, Steven W.; Schweizer, Herbert P.; Hoang, Tung T.

    2011-01-01

    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 an inability to grow in the absence of exogenous diaminopimelate (DAP); upon single-copy complementation with a wild-type copy of the asd gene, growth was restored to wild-type levels. Further characterization of the B. pseudomallei ?asd mutant revealed a marked decrease in RAW264.7 murine macrophage cytotoxicity compared to the wild type and the complemented ?asd mutant. RAW264.7 cells infected by the ?asd mutant did not exhibit signs of cytopathology or multinucleated giant cell (MNGC) formation, which were observed in wild-type B. pseudomallei cell infections. The ?asd mutant was found to be avirulent in BALB/c mice, and mice vaccinated with the mutant were protected against acute inhalation melioidosis. Thus, the B. pseudomallei ?asd mutant may be a promising live attenuated vaccine strain and a biosafe strain for consideration of exclusion from the select agent list. PMID:21807903

  16. T Cell Immunity to the Alkyl Hydroperoxide Reductase of Burkholderia pseudomallei: A Correlate of Disease Outcome in Acute Melioidosis

    PubMed Central

    Reynolds, Catherine; Goudet, Amélie; Jenjaroen, Kemajittra; Sumonwiriya, Manutsanun; Rinchai, Darawan; Musson, Julie; Overbeek, Saskia; Makinde, Julia; Quigley, Kathryn; Manji, Jiten; Spink, Natasha; Yos, Pagnarith; Wuthiekanun, Vanaporn; Bancroft, Gregory; Robinson, John; Lertmemongkolchai, Ganjana; Dunachie, Susanna; Maillere, Bernard; Holden, Matthew; Altmann, Daniel

    2015-01-01

    There is an urgent need for a better understanding of adaptive immunity to Burkholderia pseudomallei, the causative agent of melioidosis that is frequently associated with sepsis or death in patients in Southeast Asia and Northern Australia. The imperative to identify vaccine targets is driven both by the public health agenda in these regions and biological threat concerns. In several intracellular bacterial pathogens, alkyl hydroperoxidase reductases are upregulated as part of the response to host oxidative stress, and they can stimulate strong adaptive immunity. We show that alkyl hydroperoxidase reductase (AhpC) of B. pseudomallei is strongly immunogenic for T cells of ‘humanized’ HLA transgenic mice and seropositive human donors. Some T cell epitopes, such as p6, are able to bind diverse HLA class II heterodimers and stimulate strong T cell immunity in mice and humans. Importantly, patients with acute melioidosis who survive infection show stronger T cell responses to AhpC relative to those who do not. Although the sequence of AhpC is virtually invariant among global B. pseudomallei clinical isolates, a Cambodian isolate varies only in C-terminal truncation of the p6 T cell epitope, raising the possibility of selection by host immunity. This variant peptide is virtually unable to stimulate T cell immunity. For an infection in which there has been debate about centrality of T cell immunity in defense, these observations support a role for T cell immunity to AhpC in disease protection. PMID:25862821

  17. Burkholderia pseudomallei Penetrates the Brain via Destruction of the Olfactory and Trigeminal Nerves: Implications for the Pathogenesis of Neurological Melioidosis

    PubMed Central

    St. John, James A.; Ekberg, Jenny A. K.; Dando, Samantha J.; Meedeniya, Adrian C. B.; Horton, Rachel E.; Batzloff, Michael; Owen, Suzzanne J.; Holt, Stephanie; Peak, Ian R.; Ulett, Glen C.; Mackay-Sim, Alan; Beacham, Ifor R.

    2014-01-01

    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 colonize this nerve in mice. We have now investigated in detail the mechanism by which the bacteria penetrate the olfactory and trigeminal nerves within the nasal cavity and infect the brain. We found that the olfactory epithelium responded to intranasal B. pseudomallei infection by widespread crenellation followed by disintegration of the neuronal layer to expose the underlying basal layer, which the bacteria then colonized. With the loss of the neuronal cell bodies, olfactory axons also degenerated, and the bacteria then migrated through the now-open conduit of the olfactory nerves. Using immunohistochemistry, we demonstrated that B. pseudomallei migrated through the cribriform plate via the olfactory nerves to enter the outer layer of the olfactory bulb in the brain within 24 h. We also found that the bacteria colonized the thin respiratory epithelium in the nasal cavity and then rapidly migrated along the underlying trigeminal nerve to penetrate the cranial cavity. These results demonstrate that B. pseudomallei invasion of the nerves of the nasal cavity leads to direct infection of the brain and bypasses the blood-brain barrier. PMID:24736221

  18. Burkholderia pseudomallei virulence: definition, stability and association with clonality

    Microsoft Academic Search

    Glen C. Ulett; Bart J. Currie; Timothy W. Clair; Mark Mayo; Natkunam Ketheesan; Justin Labrooy; Daniel Gal; Robert Norton; Chris Ashhurst Smith; Jodie Barnes; Jeffrey Warner; Robert G. Hirst

    2001-01-01

    Clinical presentations of melioidosis, caused by Burkholderia pseudomallei are protean, but the mechanisms underlying development of the different forms of disease remain poorly understood. In murine melioidosis, the level of virulence of B. pseudomallei is important in disease pathogenesis and progression. In this study, we used B. pseudomallei-susceptible BALB\\/c mice to determine the virulence of a library of clinical and environmental B. pseudomallei

  19. Immune response to Burkholderia pseudomallei.

    PubMed

    Panomket, Pawana

    2011-11-01

    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 completed The bacteria can activate both innate and adaptive immune responses but B. pseudomallei employ numerous tactics to evade these immune responses. The pathogenesis of melioidosis is poorly understood, especially the interaction between the host and the pathogen that results in acute and chronic infections. The objective of this review was to summarize the current understanding of the immunology of melioidosis. This review presents an overview of host immune response to B. pseudomallei and benefits the development of research into immunology and promotes an understanding of the mechanism and pathology of B. pseudomallei infection. PMID:22256484

  20. Seroepidemiological surveillance of Burkholderia pseudomallei in Bangladesh.

    PubMed

    Maude, Rapeephan R; Maude, Richard J; Ghose, Aniruddha; Amin, Md Robed; Islam, Md Belalul; Ali, Mohammad; Bari, Md Shafiqul; Majumder, Md Ishaque; Wuthiekanan, Vanaporn; Dondorp, Arjen M; Bailey, Robin L; Day, Nicholas P J; Faiz, M Abul

    2012-09-01

    Melioidosis (Burkholderia pseudomallei infection) has yet to be demonstrated systematically in Bangladesh. A prospective, cross-sectional serological survey was conducted in 2010 at six Bangladeshi hospitals. Age, gender, occupation and residential address were recorded. Of 1244 patients, 359 (28.9%) were positive for B. pseudomallei by indirect haemagglutination assay. Farmers had an increased risk of seropositivity (risk ratio=1.4, 95% CI 1.0-1.8; p=0.03). There was no clear geographic clustering of seropositives. Melioidosis should be considered as a possible cause of febrile illness in Bangladesh. Further studies are needed to establish the incidence of clinical disease and distribution of environmental risk. PMID:22795754

  1. Analysis of the Prevalence, Secretion and Function of a Cell Cycle-Inhibiting Factor in the Melioidosis Pathogen Burkholderia pseudomallei

    PubMed Central

    Pumirat, Pornpan; Broek, Charles Vander; Juntawieng, Niramol; Muangsombut, Veerachat; Kiratisin, Pattarachai; Pattanapanyasat, Kovit; Stevens, Joanne M.; Stevens, Mark P.; Korbsrisate, Sunee

    2014-01-01

    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. pseudomallei genome sequences, 33 genomes (76.7%) harbor the gene encoding CHBP. Western blot analysis using antiserum raised to a synthetic CHBP peptide detected CHBP in 46.6% (7/15) of clinical B. pseudomallei isolates from the endemic area. Secretion of CHBP into bacterial culture supernatant could not be detected under conditions where a known effector (BopE) was secreted in a manner dependent on the Bsa T3SS. In contrast, CHBP could be detected in U937 cells infected with B. pseudomallei by immunofluorescence microscopy and Western blotting in a manner dependent on bsaQ. Unlike E. coli Cif, CHBP was localized within the cytoplasm of B. pseudomallei-infected cells. A B. pseudomallei chbP insertion mutant showed a significant reduction in cytotoxicity and plaque formation compared to the wild-type strain that could be restored by plasmid-mediated trans-complementation. However, there was no defect in actin-based motility or multinucleated giant cell formation by the chbP mutant. The data suggest that the level or timing of CHBP secretion differs from a known Bsa-secreted effector and that CHBP is required for selected virulence-associated phenotypes in vitro. PMID:24809950

  2. Quantitative recovery of Burkholderia pseudomallei from soil in Thailand

    Microsoft Academic Search

    Michael D. Smith; Vanaporn Wuthiekanun; Amanda L. Walsh; Nicholas J. White

    1995-01-01

    Melioidosis is common in north-eastern Thailand, but is reported rarely from the adjacent areas of central Thailand, although rice farming is common to both regions. Quantitative soil cultures for Burkholderia pseudomallei were therefore prepared on 12 rice farms in both regions. B. pseudomallei was isolated from a similar proportion of rice fields in the central region (612) and in the

  3. Microevolution of Burkholderia pseudomallei during an acute infection.

    PubMed

    Limmathurotsakul, Direk; Holden, Matthew T G; Coupland, Paul; Price, Erin P; Chantratita, Narisara; Wuthiekanun, Vanaporn; Amornchai, Premjit; Parkhill, Julian; Peacock, Sharon J

    2014-09-01

    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. PMID:24966357

  4. Efflux-Mediated Aminoglycoside and Macrolide Resistance in Burkholderia pseudomallei

    Microsoft Academic Search

    RICHARD A. MOORE; DAVID DESHAZER; SHAUNA RECKSEIDLER; ANIA WEISSMAN; DONALD E. WOODS

    Burkholderia pseudomallei, the causative agent of melioidosis, is intrinsically resistant to a wide range of antimicrobial agents including b-lactams, aminoglycosides, macrolides, and polymyxins. We used Tn5-OT182 to mutagenize B. pseudomallei to identify the genes involved in aminoglycoside resistance. We report here on the identification of AmrAB-OprA, a multidrug efflux system in B. pseudomallei which is specific for both ami- noglycoside

  5. Multilocus Sequence Typing of Historical Burkholderia pseudomallei Isolates Collected in Southeast Asia from 1964 to 1967 Provides Insight into the Epidemiology of Melioidosis

    Microsoft Academic Search

    Roberta L. McCombie; Richard A. Finkelstein; Donald E. Woods

    2006-01-01

    A collection of 207 historically relevant Burkholderia pseudomallei isolates was analyzed by multilocus sequence typing (MLST). The strain collection contains environmental isolates obtained from a geographical distribution survey of B. pseudomallei isolates in Thailand (1964 to 1967), as well as stock cultures and colony variants from the U.S. Army Medical Research Unit (Malaysia), the Walter Reed Army Institute for Research,

  6. Recent Advances in Burkholderia mallei and B. pseudomallei Research

    PubMed Central

    Hatcher, Christopher L.; Muruato, Laura A.

    2015-01-01

    Burkholderia mallei and Burkholderia pseudomallei are Gram-negative organisms, which are etiological agents of glanders and melioidosis, respectively. Although only B. pseudomallei is responsible for a significant number of human cases, both organisms are classified as Tier 1 Select Agents and their diseases lack effective diagnosis and treatment. Despite a recent resurgence in research pertaining to these organisms, there are still a number of knowledge gaps. This article summarizes the latest research progress in the fields of B. mallei and B. pseudomallei pathogenesis, vaccines, and diagnostics. PMID:25932379

  7. Synergistic Interaction between Phenothiazines and Antimicrobial Agents against Burkholderia pseudomallei

    Microsoft Academic Search

    Ying Ying Chan; Yong Mei Ong; Kim Lee Chua

    2007-01-01

    Melioidosis is an infectious disease that is caused by the gram-negative soil bacillus Burkholderia pseudomallei, which is endemic in Southeast Asia and northern Australia. Infection may be acquired through direct skin contact with contaminated soil or surface water or by ingestion of such contaminated water or dust. Clinical symptoms depend upon the route of infection, but four clinical forms are

  8. Genetic Diversity of Burkholderia pseudomallei Isolates in Australia

    Microsoft Academic Search

    Allen C. Cheng; Linda Ward; Daniel Godoy; Robert Norton; Mark Mayo; Daniel Gal; Brian G. Spratt; Bart J. Currie

    2008-01-01

    Melioidosis is caused by the gram-negative saprophytic bacterium Burkholderia pseudomallei, which is endemic to southeast Asia and northern Australia. We have previously found evidence of geographic localiza- tion of strains based on multilocus sequence typing (MLST). In this study, we examined the diversity of 277 isolates from northern Australia, which were resolved into 159 different sequence types. No sequence types

  9. Burkholderia pseudomallei is a Tier 1 Select Agent that causes the often fatal human disease melioidosis. B. pseudomallei and related species invade a variety of cell types, replicate in

    E-print Network

    Chan, Hue Sun

    Burkholderia pseudomallei is a Tier 1 Select Agent that causes the often fatal human disease investigated temporal and spatial requirements for virulence determinants in the Burkholderia intracellular system that functions downstream from T3SS-mediated endosome escape. A remarkable feature of Burkholderia

  10. BALB\\/c and C57Bl\\/6 mice infected with virulent Burkholderia pseudomallei provide contrasting animal models for the acute and chronic forms of human melioidosis

    Microsoft Academic Search

    Alison K Leakey; Glen C Ulett; Robert G Hirst

    1998-01-01

    Burkholderia pseudomalleiis the aetiological agent of melioidosis, a life-threatening bacterial disease occurring in many species of animals, including man. Infection in humans commonly manifests as one of three clinical presentations: acute, subacute or chronic disease. Investigations were undertaken to assess the suitability of BALB\\/c and C57Bl\\/6 mice as animal models for the different forms of human melioidosis. The course of

  11. Nonrandom Distribution of Burkholderia pseudomallei Clones in Relation to Geographical Location and Virulence

    Microsoft Academic Search

    Mongkol Vesaratchavest; Sarinna Tumapa; Nicholas P. J. Day; Vanaporn Wuthiekanun; Wirongrong Chierakul; Matthew T. G. Holden; Nicholas J. White; Bart J. Currie; Brian G. Spratt; Edward J. Feil; Sharon J. Peacock

    2006-01-01

    Burkholderia pseudomallei is a soil-dwelling saprophyte and the causative agent of melioidosis, a life- threatening human infection. Most cases are reported from northeast Thailand and northern Australia. Using multilocus sequence typing (MLST), we have compared (i) soil and invasive isolates from northeast Thailand and (ii) invasive isolates from Thailand and Australia. A total of 266 Thai B. pseudomallei isolates were

  12. Whole-Genome Sequences of 80 Environmental and Clinical Isolates of Burkholderia pseudomallei.

    PubMed

    Johnson, Shannon L; Baker, Anthony L; Chain, Patrick S; Currie, Bart J; Daligault, Hajnalka E; Davenport, Karen W; Davis, Christopher B; Inglis, Timothy J J; Kaestli, Mirjam; Koren, Sergey; Mayo, Mark; Merritt, Adam J; Price, Erin P; Sarovich, Derek S; Warner, Jeffrey; Rosovitz, M J

    2015-01-01

    Here, we present the draft genome sequences of 80 isolates of Burkholderia pseudomallei. The isolates represent clinical cases of melioidosis and environmental isolates from regions in Australia and Papua New Guinea where B. pseudomallei is endemic. The genomes provide further context for the diversity of the pathogen. PMID:25676747

  13. Distribution of type III secretion gene clusters in Burkholderia pseudomallei, B. thailandensis and B. mallei

    Microsoft Academic Search

    LUCILLE RAINBOW; C. ANTHONY HART; CRAIG WINSTANLEY

    Burkholderia pseudomallei, the causative agent of melioidosis, carries a cluster of genes closely related in organisation to the type III secretion (TTS) system gene clusters of the plant pathogens Ralstonia solanacearum and Xanthomonas spp. The TTS gene cluster (TTS1) is present only in B. pseudomallei and not in avirulent B. thailandensis. Adjacent to the gene cluster encoding putative secreton structural

  14. Interaction between Burkholderia pseudomallei and Acanthamoeba Species Results in Coiling Phagocytosis, Endamebic Bacterial Survival, and Escape

    Microsoft Academic Search

    TIMOTHY J. J. INGLIS; PAUL RIGBY; TERRY A. ROBERTSON; NICHOLE S. DUTTON; MANDY HENDERSON; BARBARA J. CHANG

    2000-01-01

    Burkholderia pseudomallei causes melioidosis, a potentially fatal disease whose clinical outcomes include rapid- onset septicemia and relapsing and delayed-onset infections. Like other facultative intracellular bacterial patho- gens, B. pseudomallei is capable of survival in human phagocytic cells, but unlike mycobacteria, Listeria monocytogenes, and Salmonella serovar Typhimurium, the species has not been reported to survive as an endosymbiont in free-living amebae.

  15. Strategies for Intracellular Survival of Burkholderia pseudomallei

    PubMed Central

    Allwood, Elizabeth M.; Devenish, Rodney J.; Prescott, Mark; Adler, Ben; Boyce, John D.

    2011-01-01

    Burkholderia pseudomallei is the causative agent of melioidosis, a disease with high mortality that is prevalent in tropical regions of the world. A key component of the pathogenesis of melioidosis is the ability of B. pseudomallei to enter, survive, and replicate within mammalian host cells. For non-phagocytic cells, bacterial adhesins have been identified both on the bacterial surface and associated with Type 4 pili. Cell invasion involves components of one or more of the three Type 3 Secretion System clusters, which also mediate, at least in part, the escape of bacteria from the endosome into the cytoplasm, where bacteria move by actin-based motility. The mechanism of actin-based motility is not clearly understood, but appears to differ from characterized mechanisms in other bacterial species. A small proportion of intracellular bacteria is targeted by host cell autophagy, involving direct recruitment of LC3 to endosomes rather than through uptake by canonical autophagosomes. However, the majority of bacterial cells are able to circumvent autophagy and other intracellular defense mechanisms such as the induction of inducible nitric oxide synthase, and then replicate in the cytoplasm and spread to adjacent cells via membrane fusion, resulting in the formation of multi-nucleated giant cells. A potential role for host cell ubiquitin in the autophagic response to bacterial infection has recently been proposed. PMID:22007185

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

    PubMed

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

    2015-06-01

    Melioidosis results from an infection with the soil-borne pathogen Burkholderia pseudomallei, and cases of melioidosis usually cluster after rains or a typhoon. In an endemic area of Taiwan, B. pseudomallei is primarily geographically distributed in cropped fields in the northwest of this area, whereas melioidosis cases are distributed in a densely populated district in the southeast. We hypothesized that contaminated cropped fields generated aerosols contaminated with B. pseudomallei, which were carried by a northwesterly wind to the densely populated southeastern district. We collected soil and aerosol samples from a 72 km2 area of land, including the melioidosis-clustered area and its surroundings. Aerosols that contained B. pseudomallei-specific TTSS (type III secretion system) ORF2 DNA were well distributed in the endemic area but were rare in the surrounding areas during the rainy season. The concentration of this specific DNA in aerosols was positively correlated with the incidence of melioidosis and the appearance of a northwesterly wind. Moreover, the isolation rate in the superficial layers of the contaminated cropped field in the northwest was correlated with PCR positivity for aerosols collected from the southeast over a 2-year period. According to pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) analyses, PFGE Type Ia (ST58) was the predominant pattern linking the molecular association among soil, aerosol and human isolates. Thus, the airborne transmission of melioidosis moves from the contaminated soil to aerosols and/or to humans in this endemic area. PMID:26061639

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

    PubMed Central

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

    2015-01-01

    Melioidosis results from an infection with the soil-borne pathogen Burkholderia pseudomallei, and cases of melioidosis usually cluster after rains or a typhoon. In an endemic area of Taiwan, B. pseudomallei is primarily geographically distributed in cropped fields in the northwest of this area, whereas melioidosis cases are distributed in a densely populated district in the southeast. We hypothesized that contaminated cropped fields generated aerosols contaminated with B. pseudomallei, which were carried by a northwesterly wind to the densely populated southeastern district. We collected soil and aerosol samples from a 72 km2 area of land, including the melioidosis-clustered area and its surroundings. Aerosols that contained B. pseudomallei-specific TTSS (type III secretion system) ORF2 DNA were well distributed in the endemic area but were rare in the surrounding areas during the rainy season. The concentration of this specific DNA in aerosols was positively correlated with the incidence of melioidosis and the appearance of a northwesterly wind. Moreover, the isolation rate in the superficial layers of the contaminated cropped field in the northwest was correlated with PCR positivity for aerosols collected from the southeast over a 2-year period. According to pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) analyses, PFGE Type Ia (ST58) was the predominant pattern linking the molecular association among soil, aerosol and human isolates. Thus, the airborne transmission of melioidosis moves from the contaminated soil to aerosols and/or to humans in this endemic area. PMID:26061639

  18. Strategies toward vaccines against Burkholderia mallei and Burkholderia pseudomallei

    PubMed Central

    Bondi, Sara K; Goldberg, Joanna B

    2009-01-01

    Burkholderia mallei and Burkholderia pseudomallei are Gram-negative, rod-shaped bacteria, and are the causative agents of the diseases glanders and melioidosis, respectively. These bacteria have been recognized as important pathogens for over 100 years, yet a relative dearth of available information exists regarding their virulence determinants and immunopathology. Infection with either of these bacteria presents with nonspecific symptoms and can be either acute or chronic, impeding rapid diagnosis. The lack of a vaccine for either bacterium also makes them potential candidates for bioweaponization. Together with their high rate of infectivity via aerosols and resistance to many common antibiotics, both bacteria have been classified as category B priority pathogens by the US NIH and US CDC, which has spurred a dramatic increase in interest in these microorganisms. Attempts have been made to develop vaccines for these infections, which would not only benefit military personnel, a group most likely to be targeted in an intentional release, but also individuals who may come in contact with glanders-infected animals or live in areas where melioidosis is endemic. This review highlights some recent attempts of vaccine development for these infections and the strategies used to improve the efficacy of vaccine approaches. PMID:18980539

  19. RAPID IDENTIFICATION OF BURKHOLDERIA PSEUDOMALLEI IN BLOOD CULTURES BY LATEX AGGLUTINATION USING LIPOPOLYSACCHARIDE-SPECIFIC MONOCLONAL ANTIBODY

    Microsoft Academic Search

    TARARAJ DHARAKUL; SIRIRURG SONGSIVILAI; SAIJAI SMITHIKARN; CHARIN THEPTHAI; AMORNRAT LEELAPORN

    1999-01-01

    Melioidosis, an infection caused by Burkholderia pseudomallei, is endemic in Southeast Asia. The septicemic form of melioidosis is the leading cause of death due to community-acquired bacteremia in the northeastern part of Thailand. The delay in isolation and identification of the causative organism is a major contributing factor to the high mortality. The present study describes the evaluation of a

  20. Type III secretion system cluster 3 is required for maximal virulence of Burkholderia pseudomallei in a hamster infection model

    Microsoft Academic Search

    Jonathan Warawa; Donald E. Woods

    2005-01-01

    Burkholderia pseudomallei, the etiological agent of melioidosis, is an animal pathogen capable of inducing a highly fatal septicemia. B. pseudomallei possesses three type III secretion system (TTSS) clusters, two of which (TTSS1 and TTSS2) are homologous to the TTSS of the plant pathogen Ralstonia solanacearum, and one (TTSS3) is homologous to the Salmonella SPI-1 mammalian pathogenicity island. We have demonstrated

  1. Detection of Bacterial Virulence Genes by Subtractive Hybridization: Identification of Capsular Polysaccharide of Burkholderia pseudomallei as a Major Virulence Determinant

    Microsoft Academic Search

    SHAUNA L. RECKSEIDLER; DAVID DESHAZER; PAMELA A. SOKOL; DONALD E. WOODS

    2001-01-01

    Burkholderia pseudomallei, the etiologic agent of melioidosis, is responsible for a broad spectrum of illnesses in humans and animals particularly in Southeast Asia and northern Australia, where it is endemic. Burkhold- eria thailandensis is a nonpathogenic environmental organism closely related to B. pseudomallei. Subtractive hybridization was carried out between these two species to identify genes encoding virulence determinants in B.

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

    Microsoft Academic Search

    Pornpan Pumirat; Jon Cuccui; Richard A Stabler; Joanne M Stevens; Veerachat Muangsombut; Ekapot Singsuksawat; Mark P Stevens; Brendan W Wren; Sunee Korbsrisate

    2010-01-01

    BACKGROUND: Burkholderia pseudomallei is the causative agent of melioidosis where the highest reported incidence world wide is in the Northeast of Thailand, where saline soil and water are prevalent. Moreover, recent reports indicate a potential pathogenic role for B. pseudomallei in cystic fibrosis lung disease, where an increased sodium chloride (NaCl) concentration in airway surface liquid has been proposed. These

  3. Inflammasome-dependent Pyroptosis and IL18 Protect against Burkholderia pseudomallei Lung Infection while IL1? Is Deleterious

    Microsoft Academic Search

    Ivonne Ceballos-Olvera; Manoranjan Sahoo; Mark A. Miller; Laura del Barrio; Fabio Re

    2011-01-01

    Burkholderia pseudomallei is a Gram-negative bacterium that infects macrophages and other cell types and causes melioidosis. The interaction of B. pseudomallei with the inflammasome and the role of pyroptosis, IL-1?, and IL-18 during melioidosis have not been investigated in detail. Here we show that the Nod-like receptors (NLR) NLRP3 and NLRC4 differentially regulate pyroptosis and production of IL-1? and IL-18

  4. In vitro antimicrobial activity of natural toxins and animal venoms tested against Burkholderia pseudomallei

    Microsoft Academic Search

    R Perumal Samy; A Pachiappan; P Gopalakrishnakone; Maung M Thwin; Yap E Hian; Vincent TK Chow; Ho Bow; Joseph T Weng

    2006-01-01

    BACKGROUND: Burkholderia pseudomallei are the causative agent of melioidosis. Increasing resistance of the disease to antibiotics is a severe problem in treatment regime and has led to intensification of the search for new drugs. Antimicrobial peptides are the most ubiquitous in nature as part of the innate immune system and host defense mechanism. METHODS: Here, we investigated a group of

  5. Clinical Features That Affect Indirect-Hemagglutination-Assay Responses to Burkholderia pseudomallei

    Microsoft Academic Search

    Patrick N. A. Harris; Natkunam Ketheesan; Leigh Owens; Robert E. Norton

    2009-01-01

    Melioidosis, a disease endemic to northern Australia and Southeast Asia, is caused by the soil saprophyte Burkholderia pseudomallei. The indirect hemagglutination assay (IHA) is the most frequently used serological test to help confirm exposure to the causative organism. However, despite culture-confirmed disease, patients often have a negative IHA result at presentation and occasionally fail to seroconvert in serial testing. We

  6. Clinical Features and Laboratory Diagnosis of Infection with the Potential Bioterrorism Agents Burkholderia Mallei and Burkholderia Pseudomallei

    PubMed Central

    Gilad, Jacob; Schwartz, David; Amsalem, Yoram

    2007-01-01

    Burkholderia mallei and Burkholderia pseudomallei are the causative organisms of Glanders and Melioidosis, respectively. Although now rare in Western countries, both organisms have recently gained much interest because of their unique potential as bioterrorism agents. These organisms are less familiar to medical and laboratory personnel than other select bioterrorism bacterial agents and thus heightened awareness of Glanders and Melioidosis is crucial in order to enable adequate emergency preparedness and response to deliberate release of B. mallei and B. pseudomallei. The microbiological diagnosis of both species in the clinical laboratory is complicated. This paper reviews the various challenges and pitfalls associated with the diagnosis of Melioidosis and Glanders in the clinical setting, with emphasis on the role of sentinel laboratories. PMID:23675037

  7. Functional reconstitution, gene isolation and topology modelling of porins from Burkholderia pseudomallei and Burkholderia thailandensis.

    PubMed Central

    Siritapetawee, Jaruwan; Prinz, Heino; Samosornsuk, Worada; Ashley, Richard H; Suginta, Wipa

    2004-01-01

    The sequences for Omp38 from Burkholderia pseudomallei and Burkholderia thailandensis have been deposited in the DDBJ, EMBL, GenBank(R) and GSDB Nucleotide Sequence Databases under the accession numbers AY312416 and AY312417 respectively. The intracellular pathogen Burkholderia pseudomallei is the causative agent of tropical melioidosis, and Burkholderia thailandensis is a closely-related Gram-negative bacterium that does not cause serious disease. Like other bacteria, the major outer membrane (OM) porins of Burkholderia strains, Bps Omp38 and Bth Omp38 may have roles in antibiotic resistance and immunity. We purified both proteins and found them to be immunologically related, SDS-resistant, heat-sensitive trimers with M (r) of approx. 110000. In functional liposome-swelling assays, both proteins showed similar permeabilities for small sugar molecules, compatible with a pore diameter of between 1.2 and 1.6 nm. Secondary structure analysis by FTIR (Fourier-transform infrared) spectroscopy revealed almost identical spectra with predominantly beta-sheet structures, typical of bacterial porins. MALDI-TOF (matrix-assisted laser-desorption ionization-time of flight) MS and ESI/MS (electrospray ionization MS) analysis of each protein showed extensive sequence similarities to the OpcP1 porin from Burkholderia cepacia (later found to be 76.5% identical). Based on information from the incomplete B. pseudomallei genome-sequencing project, the genes encoding Omp38 were identified and amplified by PCR from B. pseudomallei and B. thailandensis genomic DNA. The nucleotide sequences are 99.7% identical, and the predicted processed proteins are 100% identical. Topology prediction and molecular modelling suggest that this newly-isolated and cloned porin is a 16-stranded beta-barrel and the external loops of the protein could be important determinants of the immune response to infection. PMID:14567756

  8. Post-Exposure Therapeutic Efficacy of COX-2 Inhibition against Burkholderia pseudomallei

    PubMed Central

    Asakrah, Saja; Nieves, Wildaliz; Mahdi, Zaid; Agard, Mallory; Zea, Arnold H.; Roy, Chad J.; Morici, Lisa A.

    2013-01-01

    Burkholderia pseudomallei is a Gram-negative, facultative intracellular bacillus and the etiologic agent of melioidosis, a severe disease in Southeast Asia and Northern Australia. Like other multidrug-resistant pathogens, the inherent antibiotic resistance of B. pseudomallei impedes treatment and highlights the need for alternative therapeutic strategies that can circumvent antimicrobial resistance mechanisms. In this work, we demonstrate that host prostaglandin E2 (PGE2) production plays a regulatory role in the pathogenesis of B. pseudomallei. PGE2 promotes B. pseudomallei intracellular survival within macrophages and bacterial virulence in a mouse model of pneumonic melioidosis. PGE2-mediated immunosuppression of macrophage bactericidal effector functions is associated with increased arginase 2 (Arg2) expression and decreased nitric oxide (NO) production. Treatment with a commercially-available COX-2 inhibitor suppresses the growth of B. pseudomallei in macrophages and affords significant protection against rapidly lethal pneumonic melioidosis when administered post-exposure to B. pseudomallei-infected mice. COX-2 inhibition may represent a novel immunotherapeutic strategy to control infection with B. pseudomallei and other intracellular pathogens. PMID:23675544

  9. Post-exposure therapeutic efficacy of COX-2 inhibition against Burkholderia pseudomallei.

    PubMed

    Asakrah, Saja; Nieves, Wildaliz; Mahdi, Zaid; Agard, Mallory; Zea, Arnold H; Roy, Chad J; Morici, Lisa A

    2013-01-01

    Burkholderia pseudomallei is a Gram-negative, facultative intracellular bacillus and the etiologic agent of melioidosis, a severe disease in Southeast Asia and Northern Australia. Like other multidrug-resistant pathogens, the inherent antibiotic resistance of B. pseudomallei impedes treatment and highlights the need for alternative therapeutic strategies that can circumvent antimicrobial resistance mechanisms. In this work, we demonstrate that host prostaglandin E2 (PGE2) production plays a regulatory role in the pathogenesis of B. pseudomallei. PGE2 promotes B. pseudomallei intracellular survival within macrophages and bacterial virulence in a mouse model of pneumonic melioidosis. PGE2-mediated immunosuppression of macrophage bactericidal effector functions is associated with increased arginase 2 (Arg2) expression and decreased nitric oxide (NO) production. Treatment with a commercially-available COX-2 inhibitor suppresses the growth of B. pseudomallei in macrophages and affords significant protection against rapidly lethal pneumonic melioidosis when administered post-exposure to B. pseudomallei-infected mice. COX-2 inhibition may represent a novel immunotherapeutic strategy to control infection with B. pseudomallei and other intracellular pathogens. PMID:23675544

  10. Interrogation of the Burkholderia pseudomallei Genome to Address Differential Virulence among Isolates

    PubMed Central

    Challacombe, Jean F.; Stubben, Chris J.; Klimko, Christopher P.; Welkos, Susan L.; Kern, Steven J.; Bozue, Joel A.; Worsham, Patricia L.; Cote, Christopher K.; Wolfe, Daniel N.

    2014-01-01

    Infection by the Gram-negative pathogen Burkholderia pseudomallei results in the disease melioidosis, acquired from the environment in parts of southeast Asia and northern Australia. Clinical symptoms of melioidosis range from acute (fever, pneumonia, septicemia, and localized infection) to chronic (abscesses in various organs and tissues, most commonly occurring in the lungs, liver, spleen, kidney, prostate and skeletal muscle), and persistent infections in humans are difficult to cure. Understanding the basic biology and genomics of B. pseudomallei is imperative for the development of new vaccines and therapeutic interventions. This formidable task is becoming more tractable due to the increasing number of B. pseudomallei genomes that are being sequenced and compared. Here, we compared three B. pseudomallei genomes, from strains MSHR668, K96243 and 1106a, to identify features that might explain why MSHR668 is more virulent than K96243 and 1106a in a mouse model of B. pseudomallei infection. Our analyses focused on metabolic, virulence and regulatory genes that were present in MSHR668 but absent from both K96243 and 1106a. We also noted features present in K96243 and 1106a but absent from MSHR668, and identified genomic differences that may contribute to variations in virulence noted among the three B. pseudomallei isolates. While this work contributes to our understanding of B. pseudomallei genomics, more detailed experiments are necessary to characterize the relevance of specific genomic features to B. pseudomallei metabolism and virulence. Functional analyses of metabolic networks, virulence and regulation shows promise for examining the effects of B. pseudomallei on host cell metabolism and will lay a foundation for future prediction of the virulence of emerging strains. Continued emphasis in this area will be critical for protection against melioidosis, as a better understanding of what constitutes a fully virulent Burkholderia isolate may provide for better diagnostic and medical countermeasure strategies. PMID:25536074

  11. Molecular Characterization of Putative Virulence Determinants in Burkholderia pseudomallei

    PubMed Central

    Puah, Suat Moi; Puthucheary, S. D.; Wang, Jin Town; Pan, Yi Jiun; Chua, Kek Heng

    2014-01-01

    The Gram-negative saprophyte Burkholderia pseudomallei is the causative agent of melioidosis, an infectious disease which is endemic in Southeast Asia and northern Australia. This bacterium possesses many virulence factors which are thought to contribute to its survival and pathogenicity. Using a virulent clinical isolate of B. pseudomallei and an attenuated strain of the same B. pseudomallei isolate, 6 genes BPSL2033, BP1026B_I2784, BP1026B_I2780, BURPS1106A_A0094, BURPS1106A_1131, and BURPS1710A_1419 were identified earlier by PCR-based subtractive hybridization. These genes were extensively characterized at the molecular level, together with an additional gene BPSL3147 that had been identified by other investigators. Through a reverse genetic approach, single-gene knockout mutants were successfully constructed by using site-specific insertion mutagenesis and were confirmed by PCR. BPSL2033::Km and BURPS1710A_1419::Km mutants showed reduced rates of survival inside macrophage RAW 264.7 cells and also low levels of virulence in the nematode infection model. BPSL2033::Km demonstrated weak statistical significance (P = 0.049) at 8 hours after infection in macrophage infection study but this was not seen in BURPS1710A_1419::Km. Nevertheless, complemented strains of both genes were able to partially restore the gene defects in both in vitro and in vivo studies, thus suggesting that they individually play a minor role in the virulence of B. pseudomallei. PMID:25215325

  12. Evaluating Burkholderia pseudomallei Bip proteins as vaccines and Bip antibodies as detection agents.

    PubMed

    Druar, Chris; Yu, Fei; Barnes, Jodie L; Okinaka, Richard T; Chantratita, Narisara; Beg, Steve; Stratilo, Chad W; Olive, Andrew J; Soltes, Glenn; Russell, Michelle L; Limmathurotsakul, Direk; Norton, Robert E; Ni, Sally X; Picking, William D; Jackson, Paul J; Stewart, Don I H; Tsvetnitsky, Vadim; Picking, Wendy L; Cherwonogrodzky, John W; Ketheesan, Natkunam; Peacock, Sharon J; Wiersma, Erik J

    2008-01-01

    Burkholderia pseudomallei is a biothreat agent and an important natural pathogen, causing melioidosis in humans and animals. A type III secretion system (TTSS-3) has been shown to be critical for virulence. Because TTSS components from other pathogens have been used successfully as diagnostic agents and as experimental vaccines, it was investigated whether this was the case for BipB, BipC and BipD, components of B. pseudomallei's TTSS-3. The sequences of BipB, BipC and BipD were found to be highly conserved among B. pseudomallei and B. mallei isolates. A collection of monoclonal antibodies (mAbs) specific for each Bip protein was obtained. Most recognized both native and denatured Bip protein. Burkholderia pseudomallei or B. mallei did not express detectable BipB or BipD under the growth conditions used. However, anti-BipD mAbs did recognize the TTSS needle structures of a Shigella strain engineered to express BipD. The authors did not find that BipB, BipC or BipD are protective antigens because vaccination of mice with any single protein did not result in protection against experimental melioidosis. Enzyme-linked immunosorbent assay (ELISA) studies showed that human melioidosis patients had antibodies to BipB and BipD. However, these ELISAs had low diagnostic accuracy in endemic regions, possibly due to previous patient exposure to B. pseudomallei. PMID:17995960

  13. Recombinant Salmonella Expressing Burkholderia mallei LPS O Antigen Provides Protection in a Murine Model of Melioidosis and Glanders

    PubMed Central

    Moustafa, Dina A.; Scarff, Jennifer M.; Garcia, Preston P.; Cassidy, Sara K. B.; DiGiandomenico, Antonio; Waag, David M.; Inzana, Thomas J.; Goldberg, Joanna B.

    2015-01-01

    Burkholderia pseudomallei and Burkholderia mallei are the etiologic agents of melioidosis and glanders, respectively. These bacteria are highly infectious via the respiratory route and can cause severe and often fatal diseases in humans and animals. Both species are considered potential agents of biological warfare; they are classified as category B priority pathogens. Currently there are no human or veterinary vaccines available against these pathogens. Consequently efforts are directed towards the development of an efficacious and safe vaccine. Lipopolysaccharide (LPS) is an immunodominant antigen and potent stimulator of host immune responses. B. mallei express LPS that is structurally similar to that expressed by B. pseudomallei, suggesting the possibility of constructing a single protective vaccine against melioidosis and glanders. Previous studies of others have shown that antibodies against B. mallei or B. pseudomallei LPS partially protect mice against subsequent lethal virulent Burkholderia challenge. In this study, we evaluated the protective efficacy of recombinant Salmonella enterica serovar Typhimurium SL3261 expressing B. mallei O antigen against lethal intranasal infection with Burkholderia thailandensis, a surrogate for biothreat Burkholderia spp. in a murine model that mimics melioidosis and glanders. All vaccine-immunized mice developed a specific antibody response to B. mallei and B. pseudomallei O antigen and to B. thailandensis and were significantly protected against challenge with a lethal dose of B. thailandensis. These results suggest that live-attenuated SL3261 expressing B. mallei O antigen is a promising platform for developing a safe and effective vaccine. PMID:26148026

  14. The toxin/immunity network of Burkholderia pseudomallei contact-dependent growth inhibition (CDI) systems

    PubMed Central

    Nikolakakis, Kiel; Amber, Saba; Wilbur, J. Scott; Diner, Elie J.; Aoki, Stephanie K.; Poole, Stephen J.; Tuanyok, Apichai; Keim, Paul S.; Peacock, Sharon; Hayes, Christopher S.; Low, David A.

    2012-01-01

    Summary Burkholderia pseudomallei is a Category B pathogen and the causative agent of melioidosis – a serious infectious disease that is typically acquired directly from environmental reservoirs. Nearly all B. pseudomallei strains sequenced to date (>85 isolates) contain gene clusters that are related to the contact-dependent growth inhibition (CDI) systems of ?-proteobacteria. CDI systems from Escherichia coli and Dickeya dadantii play significant roles in bacterial competition, suggesting these systems may also contribute to the competitive fitness of B. pseudomallei. Here, we identify ten distinct CDI systems in B. pseudomallei based on polymorphisms within the cdiA-CT/cdiI coding regions, which are predicted to encode CdiA-CT/CdiI toxin/immunity protein pairs. Biochemical analysis of three B. pseudomallei CdiA-CTs revealed that each protein possesses a distinct tRNase activity capable of inhibiting cell growth. These toxin activities are blocked by cognate CdiI immunity proteins, which specifically bind the CdiA-CT and protect cells from growth inhibition. Using Burkholderia thailandensis E264 as a model, we show that a CDI system from B. pseudomallei 1026b mediates contact-dependent growth inhibition and is capable of delivering CdiA-CT toxins derived from other B. pseudomallei strains. These results demonstrate that Burkholderia species contain functional CDI systems, which may confer a competitive advantage to these bacteria. PMID:22435733

  15. Evidence for the presence in Burkholderia pseudomallei of a type III secretion system-associated gene cluster

    Microsoft Academic Search

    C. WINSTANLEY; B. A. HALES; C. A. HART

    1999-01-01

    Burkholderia pseudomallei, the causative agent of melioidosis, contains a cluster of putative genes homologous to those encoding HpaP, HrcQ, HrcR, HrcS and HrpV in the plant pathogen Ralstonia solanacearum. In R. solanacearum, these genes form part of a type I11 secretion-associated pathogenicity island. The order of the genes in B. pseudomallei is directly equivalent to that found in R. solanacearum.

  16. Burkholderia pseudomallei Induces Cell Fusion and Actin-Associated Membrane Protrusion: a Possible Mechanism for Cell-to-Cell Spreading

    Microsoft Academic Search

    W. Kespichayawattana; S. Rattanachetkul; T. Wanun; P. Utaisincharoen; S. Sirisinha

    2000-01-01

    Burkholderia pseudomallei, a facultative intracellular bacterium, is the causative agent of a broad spectrum of diseases collectively known as melioidosis. Its ability to survive inside phagocytic and nonphagocytic cells and to induce multinucleated giant cell (MNGC) formation has been demonstrated. This study was designed to assess a possible mechanism(s) leading to this cellular change, using virulent and nonvirulent strains of

  17. Use of 16S rRNA Gene Sequencing for Rapid Identification and Differentiation of Burkholderia pseudomallei and B. mallei

    Microsoft Academic Search

    Jay E. Gee; Claudio T. Sacchi; Mindy B. Glass; Barun K. De; Robbin S. Weyant; Paul N. Levett; Anne M. Whitney; Alex R. Hoffmaster; Tanja Popovic

    2003-01-01

    Burkholderia pseudomallei and B. mallei, the causative agents of melioidosis and glanders, respectively, are designated category B biothreat agents. Current methods for identifying these organisms rely on their phe- notypic characteristics and an extensive set of biochemical reactions. We evaluated the use of 16S rRNA gene sequencing to rapidly identify these two species and differentiate them from each other as

  18. Lipopolysaccharide from Nonvirulent Ara1 Burkholderia pseudomallei Isolates Is Immunologically Indistinguishable from Lipopolysaccharide from Virulent Ara2 Clinical Isolates

    Microsoft Academic Search

    NARISARA ANUNTAGOOL; PAKAMAS INTACHOTE; VANAPORN WUTHIEKANUN; NICHOLAS J. WHITE; STITAYA SIRISINHA

    Different lines of evidence suggest that a discrepancy between the distribution of Burkholderia (Pseudomonas) pseudomallei in the environment and the distribution of the disease melioidosis is attributable, at least in part, to phenotypic differences between clinical and some environmental isolates. Two antigenically and biochemi- cally distinct biotypes have been described, only one of which is virulent. In this study, lipopolysaccharides

  19. Macroautophagy is essential for killing of intracellular Burkholderia pseudomallei in human neutrophils.

    PubMed

    Rinchai, Darawan; Riyapa, Donporn; Buddhisa, Surachat; Utispan, Kusumawadee; Titball, Richard W; Stevens, Mark P; Stevens, Joanne M; Ogawa, Michinaga; Tanida, Isei; Koike, Masato; Uchiyama, Yasuo; Ato, Manabu; Lertmemongkolchai, Ganjana

    2015-05-01

    Neutrophils play a key role in the control of Burkholderia pseudomallei, the pathogen that causes melioidosis. Here, we show that survival of intracellular B. pseudomallei was significantly increased in the presence of 3-methyladenine or lysosomal cathepsin inhibitors. The LC3-flux was increased in B. pseudomallei-infected neutrophils. Concordant with this result, confocal microscopy analyses using anti-LC3 antibodies revealed that B. pseudomallei-containing phagosomes partially overlapped with LC3-positive signal at 3 and 6 h postinfection. Electron microscopic analyses of B. pseudomallei-infected neutrophils at 3 h revealed B. pseudomallei-containing phagosomes that occasionally fused with phagophores or autophagosomes. Following infection with a B. pseudomallei mutant lacking the Burkholderia secretion apparatus Bsa Type III secretion system, neither this characteristic structure nor bacterial escape into the cytosol were observed. These findings indicate that human neutrophils are able to recruit autophagic machinery adjacent to B. pseudomallei-containing phagosomes in a Type III secretion system-dependent manner. PMID:25996656

  20. Detection of Burkholderia pseudomallei in Sputum using Selective Enrichment Broth and Ashdown's Medium at Kampong Cham Provincial Hospital, Cambodia.

    PubMed

    Nhem, Somary; Letchford, Joanne; Meas, Chea; Thann, Sovanndeth; McLaughlin, James C; Baron, Ellen Jo; West, T Eoin

    2014-01-01

    Melioidosis infection, caused by Burkholderia pseudomallei, is increasingly reported in Cambodia. We hypothesized that implementation of an enhanced sputum testing protocol in a provincial hospital diagnostic microbiology laboratory would increase detection of B. pseudomallei. We tested 241 sputum specimens that were deemed acceptable for culture, comparing culture in selective enrichment broth followed by sub-culture on Ashdown's medium to standard culture methods. Two specimens (0.8%) were positive for B. pseudomallei using the enhanced protocol whereas one specimen (0.4%) was positive using standard methods. These findings demonstrate that B. pseudomallei is rarely detected in sputum at this hospital. The low frequency of B. pseudomallei in sputum specimens precludes drawing any conclusions about the relative benefits of an enhanced sputum testing protocol at this site. Promoting clinician awareness of the infection and encouraging utilization of diagnostic microbiology services are likely to be important factors in facilitating identification of melioidosis. PMID:25717370

  1. Correspondence Activity of five fluoroquinolones against 71 isolates of Burkholderia pseudomallei

    Microsoft Academic Search

    P. L. Ho; Terence K. M. Cheung; R. Kinoshita; Cindy W. S. Tse; K. Y. Yuen; P. Y. Chau

    Sir, Newer fluoroquinolones have gained popularity for use as monotherapy for community-acquired pneumonia in many parts of the world. This practice deserves caution from clinic- ians in South East Asia, where melioidosis is endemic and Burkholderia pseudomallei is a major cause of community- acquired pneumonia; in north-east Thailand, 18% of com- munity-acquired bacteraemia is caused by the bacterium. One report

  2. The Chemical Arsenal of Burkholderia pseudomallei Is Essential for Pathogenicity

    PubMed Central

    2015-01-01

    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 within its genome has been largely unexplored for its importance to virulence. Herein we demonstrate that BP-encoded small-molecule biosynthesis is indispensible for in vivo BP pathogenicity. Promoter exchange experiments were used to induce high-level molecule production from two gene clusters (MPN and SYR) found to be essential for in vivo virulence. NMR structural characterization of these metabolites identified a new class of lipopeptide biosurfactants/biofilm modulators (the malleipeptins) and syrbactin-type proteasome inhibitors, both of which represent overlooked small-molecule virulence factors for BP. Disruption of Burkholderia virulence by inhibiting the biosynthesis of these small-molecule biosynthetic pathways may prove to be an effective strategy for developing novel melioidosis-specific therapeutics. PMID:24884988

  3. Comparative Burkholderia pseudomallei natural history virulence studies using an aerosol murine model of infection

    PubMed Central

    Massey, Shane; Yeager, Linsey A.; Blumentritt, Carla A.; Vijayakumar, Sudhamathi; Sbrana, Elena; Peterson, Johnny W.; Brasel, Trevor; LeDuc, James W.; Endsley, Janice J.; Torres, Alfredo G.

    2014-01-01

    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 comparative studies. Further, the impact of strain variation on virulence, disease presentation, and mortality is not well understood. Therefore, this study evaluate and compare the virulence and disease progression of B. pseudomallei strains K96243 and HBPUB10303a, following aerosol challenge in a standardized BALB/c mouse model of infection. The natural history analysis of disease progression monitored conditions such as weight, body temperature, appearance, activity, bacteremia, organ and tissue colonization (pathological and histological analysis) and immunological responses. This study provides a detailed, direct comparison of infection with different B. pseudomallei strains and set up the basis for a standardized model useful to test different medical countermeasures against Burkholderia species. Further, this protocol serves as a guideline to standardize other bacterial aerosol models of infection or to define biomarkers of infectious processes caused by other intracellular pathogens. PMID:24603493

  4. ?X216, a P2-like bacteriophage with broad Burkholderia pseudomallei and B. mallei strain infectivity

    PubMed Central

    2012-01-01

    Background Burkholderia pseudomallei and B. mallei are closely related Category B Select Agents of bioterrorism and the causative agents of the diseases melioidosis and glanders, respectively. Rapid phage-based diagnostic tools would greatly benefit early recognition and treatment of these diseases. There is extensive strain-to-strain variation in B. pseudomallei genome content due in part to the presence or absence of integrated prophages. Several phages have previously been isolated from B. pseudomallei lysogens, for example ?K96243, ?1026b and ?52237. Results We have isolated a P2-like bacteriophage, ?X216, which infects 78% of all B. pseudomallei strains tested. ?X216 also infects B. mallei, but not other Burkholderia species, including the closely related B. thailandensis and B. oklahomensis. The nature of the ?X216 host receptor remains unclear but evidence indicates that in B. mallei ?X216 uses lipopolysaccharide O-antigen but a different receptor in B. pseudomallei. The 37,637 bp genome of ?X216 encodes 47 predicted open reading frames and shares 99.8% pairwise identity and an identical strain host range with bacteriophage ?52237. Closely related P2-like prophages appear to be widely distributed among B. pseudomallei strains but both ?X216 and ?52237 readily infect prophage carrying strains. Conclusions The broad strain infectivity and high specificity for B. pseudomallei and B. mallei indicate that ?X216 will provide a good platform for the development of phage-based diagnostics for these bacteria. PMID:23217012

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

    PubMed Central

    Ginther, Jennifer L.; Mayo, Mark; Warrington, Stephanie D.; Kaestli, Mirjam; Mullins, Travis; Wagner, David M.; Currie, Bart J.; Tuanyok, Apichai; Keim, Paul

    2015-01-01

    Identification and characterization of near-neighbor species are critical to the development of robust molecular diagnostic tools for biothreat agents. One such agent, Burkholderia pseudomallei, a soil bacterium and the causative agent of melioidosis, is lacking in this area because of its genomic diversity and widespread geographic distribution. The Burkholderia genus contains over 60 species and occupies a large range of environments including soil, plants, rhizospheres, water, animals and humans. The identification of novel species in new locations necessitates the need to identify the true global distribution of Burkholderia species, especially the members that are closely related to B. pseudomallei. In our current study, we used the Burkholderia-specific recA sequencing assay to analyze environmental samples from the Darwin region in the Northern Territory of Australia where melioidosis is endemic. Burkholderia recA PCR negative samples were further characterized using 16s rRNA sequencing for species identification. Phylogenetic analysis demonstrated that over 70% of the bacterial isolates were identified as B. ubonensis indicating that this species is common in the soil where B. pseudomallei is endemic. Bayesian phylogenetic analysis reveals many novel branches within the B. cepacia complex, one novel B. oklahomensis-like species, and one novel branch containing one isolate that is distinct from all other samples on the phylogenetic tree. During the analysis with recA sequencing, we discovered 2 single nucleotide polymorphisms in the reverse priming region of B. oklahomensis. A degenerate primer was developed and is proposed for future use. We conclude that the recA sequencing technique is an effective tool to classify Burkholderia and identify soil organisms in a melioidosis endemic area. PMID:26121041

  6. Application of carbohydrate microarray technology for the detection of Burkholderia pseudomallei, Bacillus anthracis and Francisella tularensis antibodies.

    PubMed

    Parthasarathy, N; Saksena, R; Ková?, P; Deshazer, D; Peacock, S J; Wuthiekanun, V; Heine, H S; Friedlander, A M; Cote, C K; Welkos, S L; Adamovicz, J J; Bavari, S; Waag, D M

    2008-11-01

    We developed a microarray platform by immobilizing bacterial 'signature' carbohydrates onto epoxide modified glass slides. The carbohydrate microarray platform was probed with sera from non-melioidosis and melioidosis (Burkholderia pseudomallei) individuals. The platform was also probed with sera from rabbits vaccinated with Bacillus anthracis spores and Francisella tularensis bacteria. By employing this microarray platform, we were able to detect and differentiate B. pseudomallei, B. anthracis and F. tularensis antibodies in infected patients, and infected or vaccinated animals. These antibodies were absent in the sera of naïve test subjects. The advantages of the carbohydrate microarray technology over the traditional indirect hemagglutination and microagglutination tests for the serodiagnosis of melioidosis and tularemia are discussed. Furthermore, this array is a multiplex carbohydrate microarray for the detection of all three biothreat bacterial infections including melioidosis, anthrax and tularemia with one, multivalent device. The implication is that this technology could be expanded to include a wide array of infectious and biothreat agents. PMID:18558401

  7. Dictyostelium discoideum as a Model System for Identification of Burkholderia pseudomallei Virulence Factors?§

    PubMed Central

    Hasselbring, Benjamin M.; Patel, Maharsh K.; Schell, Mark A.

    2011-01-01

    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-pathogen interactions. Two assays, one high-throughput and one quantitative, were developed to monitor levels of resistance of B. pseudomallei and the closely related nearly avirulent species Burkholderia thailandensis to predation by the phagocytic amoeba Dictyostelium discoideum. The quantitative assay showed that levels of resistance to, and survival within, amoeba by these bacteria and their known virulence mutants correlate well with their published levels of virulence in animals. Using the high-throughput assay, we screened a 1,500-member B. thailandensis transposon mutant library and identified 13 genes involved in resistance to predation by D. discoideum. Orthologs of these genes were disrupted in B. pseudomallei, and nearly all mutants had similarly decreased resistance to predation by D. discoideum. For some mutants, decreased resistance also correlated with reduced survival in and cytotoxicity toward macrophages, as well as attenuated virulence in mice. These observations suggest that some factors required by B. pseudomallei for resistance to environmental phagocytes also aid in resistance to phagocytic immune cells and contribute to disease in animals. Thus, D. discoideum provides a novel, high-throughput model system for facilitating inquiry into B. pseudomallei virulence. PMID:21402765

  8. Structure of a Burkholderia pseudomallei Trimeric Autotransporter Adhesin Head

    PubMed Central

    Edwards, Thomas E.; Phan, Isabelle; Abendroth, Jan; Dieterich, Shellie H.; Masoudi, Amir; Guo, Wenjin; Hewitt, Stephen N.; Kelley, Angela; Leibly, David; Brittnacher, Mitch J.; Staker, Bart L.; Miller, Samuel I.; Van Voorhis, Wesley C.; Myler, Peter J.; Stewart, Lance J.

    2010-01-01

    Background Pathogenic bacteria adhere to the host cell surface using a family of outer membrane proteins called Trimeric Autotransporter Adhesins (TAAs). Although TAAs are highly divergent in sequence and domain structure, they are all conceptually comprised of a C-terminal membrane anchoring domain and an N-terminal passenger domain. Passenger domains consist of a secretion sequence, a head region that facilitates binding to the host cell surface, and a stalk region. Methodology/Principal Findings Pathogenic species of Burkholderia contain an overabundance of TAAs, some of which have been shown to elicit an immune response in the host. To understand the structural basis for host cell adhesion, we solved a 1.35 Å resolution crystal structure of a BpaA TAA head domain from Burkholderia pseudomallei, the pathogen that causes melioidosis. The structure reveals a novel fold of an intricately intertwined trimer. The BpaA head is composed of structural elements that have been observed in other TAA head structures as well as several elements of previously unknown structure predicted from low sequence homology between TAAs. These elements are typically up to 40 amino acids long and are not domains, but rather modular structural elements that may be duplicated or omitted through evolution, creating molecular diversity among TAAs. Conclusions/Significance The modular nature of BpaA, as demonstrated by its head domain crystal structure, and of TAAs in general provides insights into evolution of pathogen-host adhesion and may provide an avenue for diagnostics. PMID:20862217

  9. Randomized Soil Survey of the Distribution of Burkholderia pseudomallei in Rice Fields in Laos ? †

    PubMed Central

    Rattanavong, Sayaphet; Wuthiekanun, Vanaporn; Langla, Sayan; Amornchai, Premjit; Sirisouk, Joy; Phetsouvanh, Rattanaphone; Moore, Catrin E.; Peacock, Sharon J.; Buisson, Yves; Newton, Paul N.

    2011-01-01

    Melioidosis is a major cause of morbidity and mortality in Southeast Asia, where the causative organism (Burkholderia pseudomallei) is present in the soil. In the Lao People's Democratic Republic (Laos), B. pseudomallei is a significant cause of sepsis around the capital, Vientiane, and has been isolated in soil near the city, adjacent to the Mekong River. We explored whether B. pseudomallei occurs in Lao soil distant from the Mekong River, drawing three axes across northwest, northeast, and southern Laos to create nine sampling areas in six provinces. Within each sampling area, a random rice field site containing a grid of 100 sampling points each 5 m apart was selected. Soil was obtained from a depth of 30 cm and cultured for B. pseudomallei. Four of nine sites (44%) were positive for B. pseudomallei, including all three sites in Saravane Province, southern Laos. The highest isolation frequency was in east Saravane, where 94% of soil samples were B. pseudomallei positive with a geometric mean concentration of 464 CFU/g soil (95% confidence interval, 372 to 579 CFU/g soil; range, 25 to 10,850 CFU/g soil). At one site in northwest Laos (Luangnamtha), only one sample (1%) was positive for B. pseudomallei, at a concentration of 80 CFU/g soil. Therefore, B. pseudomallei occurs in Lao soils beyond the immediate vicinity of the Mekong River, alerting physicians to the likelihood of melioidosis in these areas. Further studies are needed to investigate potential climatic, soil, and biological determinants of this heterogeneity. PMID:21075883

  10. Liver abscess caused by Burkholderia pseudomallei in a young man: A case report and review of literature

    PubMed Central

    Pal, Partha; Ray, Sayantan; Moulick, Avijit; Dey, Subhasis; Jana, Anirban; Banerjee, Kokila

    2014-01-01

    Pyogenic liver abscess is a common entity in Indian subcontinent and is mostly caused by gram negative bacteria. Melioidosis is not commonly seen in India and only a few cases are reported. It can give rise to multiple abscesses at different sites including liver. We report a case of isolated liver abscess caused by Burkholderia pseudomallei (B. pseudomallei) in a 29-year-old recently diagnosed diabetic, immunocompetent male. Diagnosis was made by imaging and culture of pus aspirated from the abscess and he was treated with percutaneous pigtail catheter drainage followed by antibiotics (meropenem and trimethoprim-sulphmethoxazole). Melioidosis is an emerging infection in India and has high mortality rate, so early diagnosis and prompt management is warranted which requires clinical vigilance and an intensive microbiological workup. Clinicians should be aware of isolated liver abscess caused by B. pseudomallei in appropriate clinical settings. PMID:25325075

  11. RHEUMATOLOGICAL MANIFESTATIONS IN PATIENTS WITH MELIOIDOSIS

    Microsoft Academic Search

    P Teparrakkul; JJ Tsai; W Chierakul; T Wacharaprechasgu; W Chaowagul

    Melioidosis, an infection caused by the bacterium Burkholderia pseudomallei, has a wide range of clinical manifestations. Here, we describe rheumatological melioidosis (involving one or more of joint, bone or muscle), and compare features and outcome with patients with- out rheumatological involvement. A retrospective study of patients with culture-confirmed melioidosis admitted to Sappasithiprasong Hospital, Ubon Ratchathani during 2002 and 2005 identified

  12. Detection of Burkholderia pseudomallei in Sputum using Selective Enrichment Broth and Ashdown’s Medium at Kampong Cham Provincial Hospital, Cambodia

    PubMed Central

    Nhem, Somary; Letchford, Joanne; Meas, Chea; Thann, Sovanndeth; McLaughlin, James C.; Baron, Ellen Jo; West, T. Eoin

    2014-01-01

    Melioidosis infection, caused by Burkholderia pseudomallei, is increasingly reported in Cambodia. We hypothesized that implementation of an enhanced sputum testing protocol in a provincial hospital diagnostic microbiology laboratory would increase detection of B. pseudomallei. We tested 241 sputum specimens that were deemed acceptable for culture, comparing culture in selective enrichment broth followed by sub-culture on Ashdown’s medium to standard culture methods. Two specimens (0.8%) were positive for B. pseudomallei using the enhanced protocol whereas one specimen (0.4%) was positive using standard methods. These findings demonstrate that B. pseudomallei is rarely detected in sputum at this hospital. The low frequency of B. pseudomallei in sputum specimens precludes drawing any conclusions about the relative benefits of an enhanced sputum testing protocol at this site. Promoting clinician awareness of the infection and encouraging utilization of diagnostic microbiology services are likely to be important factors in facilitating identification of melioidosis. PMID:25717370

  13. Within-Host Evolution of Burkholderia pseudomallei over a Twelve-Year Chronic Carriage Infection

    PubMed Central

    Price, Erin P.; Sarovich, Derek S.; Mayo, Mark; Tuanyok, Apichai; Drees, Kevin P.; Kaestli, Mirjam; Beckstrom-Sternberg, Stephen M.; Babic-Sternberg, James S.; Kidd, Timothy J.; Bell, Scott C.; Keim, Paul; Pearson, Talima; Currie, Bart J.

    2013-01-01

    ABSTRACT Burkholderia pseudomallei causes the potentially fatal disease melioidosis. It is generally accepted that B. pseudomallei is a noncommensal bacterium and that any culture-positive clinical specimen denotes disease requiring treatment. Over a 23-year study of melioidosis cases in Darwin, Australia, just one patient from 707 survivors has developed persistent asymptomatic B. pseudomallei carriage. To better understand the mechanisms behind this unique scenario, we performed whole-genome analysis of two strains isolated 139 months apart. During this period, B. pseudomallei underwent several adaptive changes. Of 23 point mutations, 78% were nonsynonymous and 43% were predicted to be deleterious to gene function, demonstrating a strong propensity for positive selection. Notably, a nonsense mutation inactivated the universal stress response sigma factor RpoS, with pleiotropic implications. The genome underwent substantial reduction, with four deletions in chromosome 2 resulting in the loss of 221 genes. The deleted loci included genes involved in secondary metabolism, environmental survival, and pathogenesis. Of 14 indels, 11 occurred in coding regions and 9 resulted in frameshift mutations that dramatically affected predicted gene products. Disproportionately, four indels affected lipopolysaccharide biosynthesis and modification. Finally, we identified a frameshift mutation in both P314 isolates within wcbR, an important component of the capsular polysaccharide I locus, suggesting virulence attenuation early in infection. Our study illustrates a unique clinical case that contrasts a high-consequence infectious agent with a long-term commensal infection and provides further insights into bacterial evolution within the human host. PMID:23860767

  14. Characterization of the capsular polysaccharide of Burkholderia (Pseudomonas) pseudomallei 304b.

    PubMed Central

    Masoud, H; Ho, M; Schollaardt, T; Perry, M B

    1997-01-01

    Burkholderia (Pseudomonas) pseudomallei is the causative agent of melioidosis, a bacterial infection of considerable morbidity in areas of endemicity of Southeast Asia and northern Australia. Clinical isolates of B. pseudomallei have been demonstrated to produce a lipopolysaccharide (LPS) containing two separate and chemically distinct antigenic O polysaccharides against which infected patients produced antibodies. A putative capsular polysaccharide (CPS) has also been reported and is thought to be antigenically conserved based on results of serological studies with clinical B. pseudomallei isolates. In the present study, the CPS isolated from B. pseudomallei 304b from northeastern Thailand was found to have an [alpha]D of +99 degrees (water), was composed of D-galactose (D-Gal), 3-deoxy-D-manno-2-octulosonic acid (KDO), and O-acetyl 3:1:1), and was a linear unbranched polymer of repeating tetrasaccharide units having the following structure: -3)-2-O-Ac-beta-D-Galp-(1-4)-alpha-D-Galp-(1-3)-beta-D -Galp-(1-5)-beta-D-KDOp-(2-. Sera from 13 of 15 patients with different clinical manifestations of melioidosis but not normal controls recognize the CPS, which suggests that it is immunogenic and raises the possibility that it may have a role as a vaccine candidate and/or diagnostic agent. PMID:9294419

  15. An ensemble of structures of Burkholderia pseudomallei 2,3-bisphosphoglycerate-dependent phosphoglycerate mutase

    SciTech Connect

    Davies, Douglas R.; Staker, Bart L.; Abendroth, Jan A.; Edwards, Thomas E.; Hartley, Robert; Leonard, Jess; Kim, Hidong; Rychel, Amanda L.; Hewitt, Stephen N.; Myler, Peter J.; Stewart, Lance J. (UWASH); (Emerald)

    2011-12-07

    Burkholderia pseudomallei is a soil-dwelling bacterium endemic to Southeast Asia and Northern Australia. Burkholderia is responsible for melioidosis, a serious infection of the skin. The enzyme 2,3-bisphosphoglycerate-dependent phosphoglycerate mutase (PGAM) catalyzes the interconversion of 3-phosphoglycerate and 2-phosphoglycerate, a key step in the glycolytic pathway. As such it is an extensively studied enzyme and X-ray crystal structures of PGAM enzymes from multiple species have been elucidated. Vanadate is a phosphate mimic that is a powerful tool for studying enzymatic mechanisms in phosphoryl-transfer enzymes such as phosphoglycerate mutase. However, to date no X-ray crystal structures of phosphoglycerate mutase have been solved with vanadate acting as a substrate mimic. Here, two vanadate complexes together with an ensemble of substrate and fragment-bound structures that provide a comprehensive picture of the function of the Burkholderia enzyme are reported.

  16. The Condition-Dependent Transcriptional Landscape of Burkholderia pseudomallei

    PubMed Central

    Nandi, Tannistha; Kreisberg, Jason F.; Chua, Hui Hoon; Sun, Guangwen; Chen, Yahua; Mueller, Claudia; Conejero, Laura; Eshaghi, Majid; Ang, Roy Moh Lik; Liu, Jianhua; Sobral, Bruno W.; Korbsrisate, Sunee; Gan, Yunn Hwen; Titball, Richard W.; Bancroft, Gregory J.; Valade, Eric; Tan, Patrick

    2013-01-01

    Burkholderia pseudomallei (Bp), the causative agent of the often-deadly infectious disease melioidosis, contains one of the largest prokaryotic genomes sequenced to date, at 7.2 Mb with two large circular chromosomes (1 and 2). To comprehensively delineate the Bp transcriptome, we integrated whole-genome tiling array expression data of Bp exposed to >80 diverse physical, chemical, and biological conditions. Our results provide direct experimental support for the strand-specific expression of 5,467 Sanger protein-coding genes, 1,041 operons, and 766 non-coding RNAs. A large proportion of these transcripts displayed condition-dependent expression, consistent with them playing functional roles. The two Bp chromosomes exhibited dramatically different transcriptional landscapes — Chr 1 genes were highly and constitutively expressed, while Chr 2 genes exhibited mosaic expression where distinct subsets were expressed in a strongly condition-dependent manner. We identified dozens of cis-regulatory motifs associated with specific condition-dependent expression programs, and used the condition compendium to elucidate key biological processes associated with two complex pathogen phenotypes — quorum sensing and in vivo infection. Our results demonstrate the utility of a Bp condition-compendium as a community resource for biological discovery. Moreover, the observation that significant portions of the Bp virulence machinery can be activated by specific in vitro cues provides insights into Bp's capacity as an “accidental pathogen”, where genetic pathways used by the bacterium to survive in environmental niches may have also facilitated its ability to colonize human hosts. PMID:24068961

  17. Size distribution and buoyant density of Burkholderia pseudomallei

    Microsoft Academic Search

    Jose-Luis Sagripanti; Monica Carrera; Jeannie Robertson; Avram Levy; Timothy J. J. Inglis

    2011-01-01

    The size and density of microbial cells determine the time that pathogens can remain airborne and thus, their potential to\\u000a infect by the respiratory route. We determined the density and size distribution of Burkholderia pseudomallei cells in comparison with other Burkholderia species, including B. mallei and B. thailandensis, all prepared and analyzed under similar conditions. The observed size distribution and

  18. Characterization of Ceftazidime Resistance Mechanisms in Clinical Isolates of Burkholderia pseudomallei from Australia

    PubMed Central

    Sarovich, Derek S.; Price, Erin P.; Von Schulze, Alex T.; Cook, James M.; Mayo, Mark; Watson, Lindsey M.; Richardson, Leisha; Seymour, Meagan L.; Tuanyok, Apichai; Engelthaler, David M.; Pearson, Talima; Peacock, Sharon J.; Currie, Bart J.; Keim, Paul; Wagner, David M.

    2012-01-01

    Burkholderia pseudomallei is a Gram-negative bacterium that causes the serious human disease, melioidosis. There is no vaccine against melioidosis and it can be fatal if not treated with a specific antibiotic regimen, which typically includes the third-generation cephalosporin, ceftazidime (CAZ). There have been several resistance mechanisms described for B. pseudomallei, of which the best described are amino acid changes that alter substrate specificity in the highly conserved class A ?-lactamase, PenA. In the current study, we sequenced penA from isolates sequentially derived from two melioidosis patients with wild-type (1.5 µg/mL) and, subsequently, resistant (16 or ?256 µg/mL) CAZ phenotypes. We identified two single-nucleotide polymorphisms (SNPs) that directly increased CAZ hydrolysis. One SNP caused an amino acid substitution (C69Y) near the active site of PenA, whereas a second novel SNP was found within the penA promoter region. In both instances, the CAZ resistance phenotype corresponded directly with the SNP genotype. Interestingly, these SNPs appeared after infection and under selection from CAZ chemotherapy. Through heterologous cloning and expression, and subsequent allelic exchange in the native bacterium, we confirmed the role of penA in generating both low-level and high-level CAZ resistance in these clinical isolates. Similar to previous studies, the amino acid substitution altered substrate specificity to other ?-lactams, suggesting a potential fitness cost associated with this mutation, a finding that could be exploited to improve therapeutic outcomes in patients harboring CAZ resistant B. pseudomallei. Our study is the first to functionally characterize CAZ resistance in clinical isolates of B. pseudomallei and to provide proven and clinically relevant signatures for monitoring the development of antibiotic resistance in this important pathogen. PMID:22363490

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

    PubMed Central

    Welkos, Susan L.; Klimko, Christopher P.; Kern, Steven J.; Bearss, Jeremy J.; Bozue, Joel A.; Bernhards, Robert C.; Trevino, Sylvia R.; Waag, David M.; Amemiya, Kei; Worsham, Patricia L.; Cote, Christopher K.

    2015-01-01

    Burkholderia pseudomallei, the etiologic agent of melioidosis, is a gram-negative facultative intracellular bacterium. This bacterium is endemic in Southeast Asia and Northern Australia and can infect humans and animals by several routes. It has also been estimated to present a considerable risk as a potential biothreat agent. There are currently no effective vaccines for B. pseudomallei, and antibiotic treatment can be hampered by nonspecific symptomology, the high incidence of naturally occurring antibiotic resistant strains, and disease chronicity. Accordingly, there is a concerted effort to better characterize B. pseudomallei and its associated disease. Before novel vaccines and therapeutics can be tested in vivo, a well characterized animal model is essential. Previous work has indicated that mice may be a useful animal model. In order to develop standardized animal models of melioidosis, different strains of bacteria must be isolated, propagated, and characterized. Using a murine intraperitoneal (IP) infection model, we tested the virulence of 11 B. pseudomallei strains. The IP route offers a reproducible way to rank virulence that can be readily reproduced by other laboratories. This infection route is also useful in distinguishing significant differences in strain virulence that may be masked by the exquisite susceptibility associated with other routes of infection (e.g., inhalational). Additionally, there were several pathologic lesions observed in mice following IP infection. These included varisized abscesses in the spleen, liver, and haired skin. This model indicated that commonly used laboratory strains of B. pseudomallei (i.e., K96243 and 1026b) were significantly less virulent as compared to more recently acquired clinical isolates. Additionally, we characterized in vitro strain-associated differences in virulence for macrophages and described a potential inverse relationship between virulence in the IP mouse model of some strains and in the macrophage phagocytosis assay. Strains which were more virulent for mice (e.g., HBPU10304a) were often less virulent in the macrophage assays, as determined by several parameters such as intracellular bacterial replication and host cell cytotoxicity. PMID:25909629

  20. Neurologic Melioidosis

    PubMed Central

    Deuble, Martin; Aquilina, Chloe; Norton, Robert

    2013-01-01

    Melioidosis is an important cause of morbidity and mortality in northern Australia and Southeast Asia. Diagnosis is best made by isolation of Burkholderia pseudomallei from clinical specimens. A variety of clinical presentations are described, including neurologic disease. The aim of this study was to review admissions with confirmed neurologic melioidosis to a regional hospital in a region to which melioidosis is endemic during 1995–2011. There were 12 culture-confirmed cases of neurologic melioidosis, of which two were detected by analysis of cerebrospinal fluid. Four of these cases were in children. Significant clinical features were fever, headache, and ataxia. Common changes on magnetic resonance imaging T2-weighted scans included ring-enhancing lesions and leptomeningeal enhancement. There were four deaths and an additional four patients had significant long-term neurologic sequelae. When considering the etiology of undifferentiated neurologic disease, an awareness of the possibility of neurologic melioidosis is important in disease-endemic regions. PMID:23836574

  1. Role for the Burkholderia pseudomallei Type Three Secretion System Cluster 1 bpscN Gene in Virulence ?

    PubMed Central

    D'Cruze, Tanya; Gong, Lan; Treerat, Puthayalai; Ramm, Georg; Boyce, John D.; Prescott, Mark; Adler, Ben; Devenish, Rodney J.

    2011-01-01

    Burkholderia pseudomallei, the causal agent of melioidosis, employs a number of virulence factors during its infection of mammalian cells. One such factor is the type three secretion system (TTSS), which is proposed to mediate the transport and secretion of bacterial effector molecules directly into host cells. The B. pseudomallei genome contains three TTSS gene clusters (designated TTSS1, TTSS2, and TTSS3). Previous research has indicated that neither TTSS1 nor TTSS2 is involved in B. pseudomallei virulence in a hamster infection model. We have characterized a B. pseudomallei mutant lacking expression of the predicted TTSS1 ATPase encoded by bpscN. This mutant was significantly attenuated for virulence in a respiratory melioidosis mouse model of infection. In addition, analyses in vitro showed diminished survival and replication in RAW264.7 cells and an increased level of colocalization with the autophagy marker protein LC3 but an unhindered ability to escape from phagosomes. Taken together, these data provide evidence that the TTSS1 bpscN gene product plays an important role in the intracellular survival of B. pseudomallei and the pathogenesis of murine infection. PMID:21768285

  2. Screening for potential anti-infective agents towards Burkholderia pseudomallei infection

    NASA Astrophysics Data System (ADS)

    Eng, Su Anne; Nathan, Sheila

    2014-09-01

    The established treatment for melioidosis is antibiotic therapy. However, a constant threat to this form of treatment is resistance development of the causative agent, Burkholderia pseudomallei, towards antibiotics. One option to circumvent this threat of antibiotic resistance is to search for new alternative anti-infectives which target the host innate immune system and/or bacterial virulence. In this study, 29 synthetic compounds were evaluated for their potential to increase the lifespan of an infected host. The nematode Caenorhabditis elegans was adopted as the infection model as its innate immune pathways are homologous to humans. Screens were performed in a liquid-based survival assay containing infected worms exposed to individual compounds and survival of untreated and compound-treated worms were compared. A primary screen identified nine synthetic compounds that extended the lifespan of B. pseudomallei-infected worms. Subsequently, a disc diffusion test was performed on these selected compounds to delineate compounds into those that enhanced the survival of worms via antimicrobial activity i.e. reducing the number of infecting bacteria, or into those that did not target pathogen viability. Out of the nine hits selected, two demonstrated antimicrobial effects on B. pseudomallei. Therefore, the findings from this study suggest that the other seven identified compounds are potential anti-infectives which could protect a host against B. pseudomallei infection without developing the risk of drug resistance.

  3. Identification of a Predicted Trimeric Autotransporter Adhesin Required for Biofilm Formation of Burkholderia pseudomallei

    PubMed Central

    Lazar Adler, Natalie R.; Dean, Rachel E.; Saint, Richard J.; Stevens, Mark P.; Prior, Joann L.; Atkins, Timothy P.; Galyov, Edouard E.

    2013-01-01

    The autotransporters are a large and diverse family of bacterial secreted and outer membrane proteins, which are present in many Gram-negative bacterial pathogens and play a role in numerous environmental and virulence-associated interactions. As part of a larger systematic study on the autotransporters of Burkholderia pseudomallei, the causative agent of the severe tropical disease melioidosis, we have constructed an insertion mutant in the bpss1439 gene encoding an unstudied predicted trimeric autotransporter adhesin. The bpss1439 mutant demonstrated a significant reduction in biofilm formation at 48 hours in comparison to its parent 10276 wild-type strain. This phenotype was complemented to wild-type levels by the introduction of a full-length copy of the bpss1439 gene in trans. Examination of the wild-type and bpss1439 mutant strains under biofilm-inducing conditions by microscopy after 48 hours confirmed that the bpss1439 mutant produced less biofilm compared to wild-type. Additionally, it was observed that this phenotype was due to low levels of bacterial adhesion to the abiotic surface as well as reduced microcolony formation. In a murine melioidosis model, the bpss1439 mutant strain demonstrated a moderate attenuation for virulence compared to the wild-type strain. This attenuation was abrogated by in trans complementation, suggesting that bpss1439 plays a subtle role in the pathogenesis of B. pseudomallei. Taken together, these studies indicate that BPSS1439 is a novel predicted autotransporter involved in biofilm formation of B. pseudomallei; hence, this factor was named BbfA, Burkholderia biofilm factor A. PMID:24223950

  4. Porin Involvement in Cephalosporin and Carbapenem Resistance of Burkholderia pseudomallei

    PubMed Central

    Aunkham, Anuwat; Schulte, Albert; Winterhalter, Mathias; Suginta, Wipa

    2014-01-01

    Background 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. Principal Findings Microbiological assays showed that the clinical Bps strain was resistant to most antimicrobial agents and sensitive only to ceftazidime and meropenem. An E. coli strain defective in most porins, but expressing BpsOmp38, exhibited considerably lower antimicrobial susceptibility than the control strain. In addition, mutation of Tyr119, the most prominent pore-lining residue in BpsOmp38, markedly altered membrane permeability, substitution with Ala (mutant BpsOmp38Y119A) enhanced uptake of the antimicrobial agents, while substitution with Phe (mutant BpsOmp38Y119F) inhibited uptake. Channel recordings of BpsOmp38 reconstituted in a planar black lipid membrane (BLM) suggested that the higher permeability of BpsOmp38Y119A was caused by widening of the pore interior through removal of the bulky side chain. In contrast, the lower permeability of BpsOmp38Y119F was caused by introduction of the hydrophobic side chain (Phe), increasing the ‘greasiness’ of the pore lumen. Significantly, liposome swelling assays showed no permeation through the BpsOmp38 channel by antimicrobial agents to which Bps is resistant (cefoxitin, cefepime, and doripenem). In contrast, high permeability to ceftazidime and meropenem was observed, these being agents to which Bps is sensitive. Conclusion/Significance Our results, from both in vivo and in vitro studies, demonstrate that membrane permeability associated with BpsOmp38 expression correlates well with the antimicrobial susceptibility of the virulent bacterium B. pseudomallei, especially to carbapenems and cephalosporins. In addition, substitution of the residue Tyr119 affects the permeability of the BpsOmp38 channel to neutral sugars and antimicrobial agents. PMID:24788109

  5. In Vitro Activity of Doripenem against Burkholderia pseudomallei

    Microsoft Academic Search

    Visanu Thamlikitkul; Suwanna Trakulsomboon

    2009-01-01

    The MIC50 and MIC90 values of doripenem, determined by Etest, for 110 isolates of Burkholderia pseudoma- llei were 0.5 and 0.75 g\\/ml, respectively. There were significant correlations between MICs determined by Etest and MICs determined by agar dilution, MICs determined by Etest and inhibition zone size, and MICs determined by agar dilution and inhibition zone size. Burkholderia pseudomallei, a gram-negative

  6. Persistent Gastric Colonization with Burkholderia pseudomallei and Dissemination from the Gastrointestinal Tract following Mucosal Inoculation of Mice

    PubMed Central

    Goodyear, Andrew; Bielefeldt-Ohmann, Helle; Schweizer, Herbert; Dow, Steven

    2012-01-01

    Melioidosis is a disease of humans caused by opportunistic infection with the soil and water bacterium Burkholderia pseudomallei. Melioidosis can manifest as an acute, overwhelming infection or as a chronic, recurrent infection. At present, it is not clear where B. pseudomallei resides in the mammalian host during the chronic, recurrent phase of infection. To address this question, we developed a mouse low-dose mucosal challenge model of chronic B. pseudomallei infection and investigated sites of bacterial persistence over 60 days. Sensitive culture techniques and selective media were used to quantitate bacterial burden in major organs, including the gastrointestinal (GI) tract. We found that the GI tract was the primary site of bacterial persistence during the chronic infection phase, and was the only site from which the organism could be consistently cultured during a 60-day infection period. The organism could be repeatedly recovered from all levels of the GI tract, and chronic infection was accompanied by sustained low-level fecal shedding. The stomach was identified as the primary site of GI colonization as determined by fluorescent in situ hybridization. Organisms in the stomach were associated with the gastric mucosal surface, and the propensity to colonize the gastric mucosa was observed with 4 different B. pseudomallei isolates. In contrast, B. pseudomallei organisms were present at low numbers within luminal contents in the small and large intestine and cecum relative to the stomach. Notably, inflammatory lesions were not detected in any GI tissue examined in chronically-infected mice. Only low-dose oral or intranasal inoculation led to GI colonization and development of chronic infection of the spleen and liver. Thus, we concluded that in a mouse model of melioidosis B. pseudomallei preferentially colonizes the stomach following oral inoculation, and that the chronically colonized GI tract likely serves as a reservoir for dissemination of infection to extra-intestinal sites. PMID:22624016

  7. Genomic acquisition of a capsular polysaccharide virulence cluster by non-pathogenic Burkholderia isolates

    E-print Network

    Sim, Bernice Meng Qi; Chantratita, Narisara; Ooi, Wen Fong; Nandi, Tannistha; Tewhey, Ryan; Wuthiekanun, Vanaporn; Thaipadungpanit, Janjira; Tumapa, Sarinna; Ariyaratne, Pramila; Sung, Wing-Kin; Sem, Xiao Hui; Chua, Hui Hoon; Ramnarayanan, Kalpana; Lin, Chi Ho; Liu, Yichun; Feil, Edward J; Glass, Mindy B; Tan, Gladys; Peacock, Sharon J; Tan, Patrick

    2010-08-27

    Abstract Background 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...

  8. Antimicrobial resistance to ceftazidime involving loss of penicillin-binding protein 3 in Burkholderia pseudomallei

    PubMed Central

    Chantratita, Narisara; Rholl, Drew A.; Sim, Bernice; Wuthiekanun, Vanaporn; Limmathurotsakul, Direk; Amornchai, Premjit; Thanwisai, Aunchalee; Chua, Hui Hoon; Ooi, Wen Fong; Holden, Matthew T. G.; Day, Nicholas P.; Tan, Patrick; Schweizer, Herbert P.; Peacock, Sharon J.

    2011-01-01

    Known mechanisms of resistance to ?-lactam antibiotics include ?-lactamase expression, altered drug target, decreased bacterial permeability, and increased drug efflux. Here, we describe a unique mechanism of ?-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 ceftazidime-resistant variants from six patients led us to identify a common, large-scale genomic loss involving a minimum of 49 genes in all six resistant strains. Mutational analysis of wild-type B. pseudomallei demonstrated that ceftazidime resistance was due to deletion of a gene encoding a penicillin-binding protein 3 (BPSS1219) present within the region of genomic loss. The clinical ceftazidime-resistant variants failed to grow using commonly used laboratory culture media, including commercial blood cultures, rendering the variants almost undetectable in the diagnostic laboratory. Melioidosis is notoriously difficult to cure and clinical treatment failure is common in patients treated with ceftazidime, the drug of first choice across most of Southeast Asia where the majority of cases are reported. The mechanism described here represents an explanation for ceftazidime treatment failure, and may be a frequent but undetected resistance event. PMID:21969582

  9. Use of a Safe, Reproducible, and Rapid Aerosol Delivery Method to Study Infection by Burkholderia pseudomallei and Burkholderia mallei in Mice

    PubMed Central

    Lafontaine, Eric R.; Zimmerman, Shawn M.; Shaffer, Teresa L.; Michel, Frank; Gao, Xiudan; Hogan, Robert J.

    2013-01-01

    Burkholderia pseudomallei, the etiologic agent of melioidosis, is a saprophytic bacterium readily isolated from wet soils of countries bordering the equator. Burkholderia mallei is a host-adapted clone of B. pseudomallei that does not persist outside of its equine reservoir and causes the zoonosis glanders, which is endemic in Asia, Africa, the Middle East and South America. Infection by these organisms typically occurs via percutaneous inoculation or inhalation of aerosols, and the most common manifestation is severe pneumonia leading to fatal bacteremia. Glanders and melioidosis are difficult to diagnose and require prolonged antibiotic therapy with low success rates. There are no vaccines available to protect against either Burkholderia species, and there is concern regarding their use as biological warfare agents given that B. mallei has previously been utilized in this manner. Hence, experiments were performed to establish a mouse model of aerosol infection to study the organisms and develop countermeasures. Using a hand-held aerosolizer, BALB/c mice were inoculated intratracheally with strains B. pseudomallei 1026b and B. mallei ATCC23344 and growth of the agents in the lungs, as well as dissemination to the spleen, were examined. Mice infected with 102, 103 and 104 organisms were unable to control growth of B. mallei in the lungs and bacteria rapidly disseminated to the spleen. Though similar results were observed in mice inoculated with 103 and 104 B. pseudomallei cells, animals infected with 102 organisms controlled bacterial replication in the lungs, dissemination to the spleen, and the extent of bacteremia. Analysis of sera from mice surviving acute infection revealed that animals produced antibodies against antigens known to be targets of the immune response in humans. Taken together, these data show that small volume aerosol inoculation of mice results in acute disease, dose-dependent chronic infection, and immune responses that correlate with those seen in human infections. PMID:24098563

  10. Burkholderia pseudomallei in soil samples from an oceanarium in Hong Kong detected using a sensitive PCR assay

    PubMed Central

    Lau, Susanna KP; Chan, San-Yuen; Curreem, Shirly OT; Hui, Suk-Wai; Lau, Candy CY; Lee, Paul; Ho, Chi-Chun; Martelli, Paolo; Woo, Patrick CY

    2014-01-01

    Melioidosis, caused by Burkholderia pseudomallei, is an emerging infectious disease with an expanding geographical distribution. Although assessment of the environmental load of B. pseudomallei is important for risk assessment in humans or animals in endemic areas, traditional methods of bacterial culture for isolation have low sensitivities and are labor-intensive. Using a specific polymerase chain reaction (PCR) assay targeting a Tat domain protein in comparison with a bacterial culture method, we examined the prevalence of B. pseudomallei in soil samples from an oceanarium in Hong Kong where captive marine mammals and birds have contracted melioidosis. Among 1420 soil samples collected from various sites in the oceanarium over a 15-month period, B. pseudomallei was detected in nine (0.6%) soil samples using bacterial culture, whereas it was detected in 96 (6.8%) soil samples using the specific PCR assay confirmed by sequencing. The PCR-positive samples were detected during various months, with higher detection rates observed during summer months. Positive PCR detection was significantly correlated with ambient temperature (P<0.0001) and relative humidity (P=0.011) but not with daily rainfall (P=0.241) or a recent typhoon (P=0.787). PCR-positive samples were obtained from all sampling locations, with the highest detection rate in the valley. Our results suggest that B. pseudomallei is prevalent and endemic in the oceanarium. The present PCR assay is more sensitive than the bacterial culture method, and it may be used to help better assess the transmission of melioidosis and to design infection control measures for captive animals in this unique and understudied environment.

  11. Burkholderia pseudomallei in soil samples from an oceanarium in Hong Kong detected using a sensitive PCR assay.

    PubMed

    Lau, Susanna Kp; Chan, San-Yuen; Curreem, Shirly Ot; Hui, Suk-Wai; Lau, Candy Cy; Lee, Paul; Ho, Chi-Chun; Martelli, Paolo; Woo, Patrick Cy

    2014-10-01

    Melioidosis, caused by Burkholderia pseudomallei, is an emerging infectious disease with an expanding geographical distribution. Although assessment of the environmental load of B. pseudomallei is important for risk assessment in humans or animals in endemic areas, traditional methods of bacterial culture for isolation have low sensitivities and are labor-intensive. Using a specific polymerase chain reaction (PCR) assay targeting a Tat domain protein in comparison with a bacterial culture method, we examined the prevalence of B. pseudomallei in soil samples from an oceanarium in Hong Kong where captive marine mammals and birds have contracted melioidosis. Among 1420 soil samples collected from various sites in the oceanarium over a 15-month period, B. pseudomallei was detected in nine (0.6%) soil samples using bacterial culture, whereas it was detected in 96 (6.8%) soil samples using the specific PCR assay confirmed by sequencing. The PCR-positive samples were detected during various months, with higher detection rates observed during summer months. Positive PCR detection was significantly correlated with ambient temperature (P<0.0001) and relative humidity (P=0.011) but not with daily rainfall (P=0.241) or a recent typhoon (P=0.787). PCR-positive samples were obtained from all sampling locations, with the highest detection rate in the valley. Our results suggest that B. pseudomallei is prevalent and endemic in the oceanarium. The present PCR assay is more sensitive than the bacterial culture method, and it may be used to help better assess the transmission of melioidosis and to design infection control measures for captive animals in this unique and understudied environment. PMID:26038496

  12. Imported Melioidosis, Israel, 2008

    PubMed Central

    Cahn, Avivit; Koslowsky, Benjamin; Nir-Paz, Ran; Temper, Violeta; Hiller, Nurit; Karlinsky, Alla; Gur, Itzhak; Hidalgo-Grass, Carlos; Heyman, Samuel N.; Moses, Allon E.

    2009-01-01

    In 2008, melioidosis was diagnosed in an agricultural worker from Thailand in the southern Jordan Valley in Israel. He had newly diagnosed diabetes mellitus, fever, multiple abscesses, and osteomyelitis. Burkholderia pseudomallei was isolated from urine and blood. Four of 10 laboratory staff members exposed to the organism received chemoprophylaxis, 3 of whom had adverse events. PMID:19891871

  13. Molecular Investigations of PenA-mediated ?-lactam Resistance in Burkholderia pseudomallei

    PubMed Central

    Rholl, Drew A.; Papp-Wallace, Krisztina M.; Tomaras, Andrew P.; Vasil, Michael L.; Bonomo, Robert A.; Schweizer, Herbert P.

    2011-01-01

    Burkholderia pseudomallei is the etiological agent of melioidosis. Because of the bacterium’s intrinsic resistance and propensity to establish latent infections, melioidosis therapy is complicated and prolonged. Newer generation ?-lactams, specifically ceftazidime, are used for acute phase therapy, but resistance to this cephalosporin has been observed. The chromosomally encoded penA gene encodes a putative twin arginine translocase (TAT)-secreted ?-lactamase, and penA mutations have been implicated in ceftazidime resistance in clinical isolates. However, the role of PenA in resistance has not yet been systematically studied in isogenetic B. pseudomallei mutant backgrounds. We investigated the effects of penA deletion, point mutations, and up-regulation, as well as tat operon deletion and PenA TAT-signal sequence mutations. These experiments were made possible by employing a B. pseudomallei strain that is excluded from Select Agent regulations. Deletion of penA significantly (>4-fold) reduced the susceptibility to six of the nine ?-lactams tested and ?16-fold for ampicillin, amoxicillin, and carbenicillin. Overexpression of penA by single-copy, chromosomal expression of the gene under control of the inducible Ptac promoter, increased resistance levels for all ?-lactams tested 2- to 10-fold. Recreation of the C69Y and P167S PenA amino acid substitutions previously observed in resistant clinical isolates increased resistance to ceftazidime by ?85- and 5- to 8-fold, respectively. Similarly, a S72F substitution resulted in a 4-fold increase in resistance to amoxicillin and clavulanic acid. Susceptibility assays with PenA TAT-signal sequence and ?tatABC mutants, as well as Western blot analysis, confirmed that PenA is a TAT secreted enzyme and not periplasmic but associated with the spheroplastic cell fraction. Lastly, we determined that two LysR-family regulators encoded by genes adjacent to penA do not play a role in transcriptional regulation of penA expression. PMID:21747814

  14. Characterization of BcaA, a putative classical autotransporter protein in Burkholderia pseudomallei.

    PubMed

    Campos, Cristine G; Borst, Luke; Cotter, Peggy A

    2013-04-01

    Burkholderia pseudomallei is a tier 1 select agent, and the causative agent of melioidosis, a disease with effects ranging from chronic abscesses to fulminant pneumonia and septic shock, which can be rapidly fatal. Autotransporters (ATs) are outer membrane proteins belonging to the type V secretion system family, and many have been shown to play crucial roles in pathogenesis. The open reading frame Bp1026b_II1054 (bcaA) in B. pseudomallei strain 1026b is predicted to encode a classical autotransporter protein with an approximately 80-kDa passenger domain that contains a subtilisin-related domain. Immediately 3' to bcaA is Bp11026_II1055 (bcaB), which encodes a putative prolyl 4-hydroxylase. To investigate the role of these genes in pathogenesis, large in-frame deletion mutations of bcaA and bcaB were constructed in strain Bp340, an efflux pump mutant derivative of the melioidosis clinical isolate 1026b. Comparison of Bp340?bcaA and Bp340?bcaB mutants to wild-type B. pseudomallei in vitro demonstrated similar levels of adherence to A549 lung epithelial cells, but the mutant strains were defective in their ability to invade these cells and to form plaques. In a BALB/c mouse model of intranasal infection, similar bacterial burdens were observed after 48 h in the lungs and liver of mice infected with Bp340?bcaA, Bp340?bcaB, and wild-type bacteria. However, significantly fewer bacteria were recovered from the spleen of Bp340?bcaA-infected mice, supporting the idea of a role for this AT in dissemination or in survival in the passage from the site of infection to the spleen. PMID:23340315

  15. Clinical Evaluation of a Type III Secretion System Real-Time PCR Assay for Diagnosing Melioidosis

    Microsoft Academic Search

    Ella M. Meumann; Ryan T. Novak; Daniel Gal; Mirjam E. Kaestli; Mark Mayo; Joshua P. Hanson; Emma Spencer; Mindy B. Glass; Jay E. Gee; Patricia P. Wilkins; Bart J. Currie; Bacterial Zoonoses; Enteric Diseases

    2006-01-01

    Melioidosis is the disease caused by infection with the envi- ronmental bacterium Burkholderia pseudomallei. In Southeast Asia and northern Australia, melioidosis is an important cause of community-acquired sepsis (1, 8). The clinical manifestations of melioidosis vary widely in terms of time course, severity, and organ system involvement, and it is difficult to differentiate from other causes of sepsis. In its

  16. Altered Proteome of Burkholderia pseudomallei Colony Variants Induced by Exposure to Human Lung Epithelial Cells.

    PubMed

    Al-Maleki, Anis Rageh; Mariappan, Vanitha; Vellasamy, Kumutha Malar; Tay, Sun Tee; Vadivelu, Jamuna

    2015-01-01

    Burkholderia pseudomallei primary diagnostic cultures demonstrate colony morphology variation associated with expression of virulence and adaptation proteins. This study aims to examine the ability of B. pseudomallei colony variants (wild type [WT] and small colony variant [SCV]) to survive and replicate intracellularly in A549 cells and to identify the alterations in the protein expression of these variants, post-exposure to the A549 cells. Intracellular survival and cytotoxicity assays were performed followed by proteomics analysis using two-dimensional gel electrophoresis. B. pseudomallei SCV survive longer than the WT. During post-exposure, among 259 and 260 protein spots of SCV and WT, respectively, 19 were differentially expressed. Among SCV post-exposure up-regulated proteins, glyceraldehyde 3-phosphate dehydrogenase, fructose-bisphosphate aldolase (CbbA) and betaine aldehyde dehydrogenase were associated with adhesion and virulence. Among the down-regulated proteins, enolase (Eno) is implicated in adhesion and virulence. Additionally, post-exposure expression profiles of both variants were compared with pre-exposure. In WT pre- vs post-exposure, 36 proteins were differentially expressed. Of the up-regulated proteins, translocator protein, Eno, nucleoside diphosphate kinase (Ndk), ferritin Dps-family DNA binding protein and peptidyl-prolyl cis-trans isomerase B were implicated in invasion and virulence. In SCV pre- vs post-exposure, 27 proteins were differentially expressed. Among the up-regulated proteins, flagellin, Eno, CbbA, Ndk and phenylacetate-coenzyme A ligase have similarly been implicated in adhesion, invasion. Protein profiles differences post-exposure provide insights into association between morphotypic and phenotypic characteristics of colony variants, strengthening the role of B. pseudomallei morphotypes in pathogenesis of melioidosis. PMID:25996927

  17. The Effect of Environmental Conditions on Biofilm Formation of Burkholderia pseudomallei Clinical Isolates

    PubMed Central

    Ramli, Nur Siti K.; Eng Guan, Chua; Nathan, Sheila; Vadivelu, Jamuna

    2012-01-01

    Burkholderia pseudomallei, a Gram-negative saprophytic bacterium, is the causative agent of the potentially fatal melioidosis disease in humans. In this study, environmental parameters including temperature, nutrient content, pH and the presence of glucose were shown to play a role in in vitro biofilm formation by 28 B. pseudomallei clinical isolates, including four isolates with large colony variants (LCVs) and small colony variants (SCVs) morphotypes. Enhanced biofilm formation was observed when the isolates were tested in LB medium, at 30°C, at pH 7.2, and in the presence of as little as 2 mM glucose respectively. It was also shown that all SVCs displayed significantly greater capacity to form biofilms than the corresponding LCVs when cultured in LB at 37°C. In addition, octanoyl-homoserine lactone (C8-HSL), a quorum sensing molecule, was identified by mass spectrometry analysis in bacterial isolates referred to as LCV CTH, LCV VIT, SCV TOM, SCV CTH, 1 and 3, and the presence of other AHL's with higher masses; decanoyl-homoserine lactone (C10-HSL) and dodecanoyl-homoserine lactone (C12-HSL) were also found in all tested strain in this study. Last but not least, we had successfully acquired two Bacillus sp. soil isolates, termed KW and SA respectively, which possessed strong AHLs degradation activity. Biofilm formation of B. pseudomallei isolates was significantly decreased after treated with culture supernatants of KW and SA strains, demonstrating that AHLs may play a role in B. pseudomallei biofilm formation. PMID:22970167

  18. Application of Polymerase Chain Reaction to Detect Burkholderia Pseudomallei and Brucella Species in Buffy Coat from Patients with Febrile Illness Among Rural and Peri-Urban Population

    PubMed Central

    Nandagopal, Balaji; Sankar, Sathish; Lingesan, Karthikeyan; Appu, KC; Sridharan, Gopalan; Gopinathan, Anilkumar

    2012-01-01

    Context: Melioidosis and Brucellosis are important endemic infections among people in India, especially in rural settings. Conventional detection techniques have several limitations. Only a few studies exist on the prevalence of Melioidosis and Brucellosis in rural area especially in India. Aim: We sought to evaluate detection of Burkholderia pseudomallei and Brucella spp. among patients presenting febrile illness. Material and Methods: Previously described polymerase chain reaction (PCR) assays for both pathogens were evaluated with Deoxyribonucleic acid extracts of buffy coat samples collected from 301 patients recruited prospectively. Data was not amenable to statistical analysis. Results: The PCR showed specific amplification and no non-specific amplification with heterologous Gram-negative bacilli. The lower limit of detection of the assay for B. pseudomallei was determined to be 1 colony-forming unit /mL and for Brucella it was 1.95 × 103 plasmids per microliter. Blood culture in automated blood culture system was negative for all the samples. This prospective study carried out in southern India for the first time. PCR for Brucella was positive in 1% of the patient samples whereas 0.3% was positive for B. pseudomallei. Conclusion: The finding of Brucella and Burkholderia infections in our populations leads us to suggest that tests for Brucella and B. pseudomallei should also form part of a diagnostic platform for patients with Pyrexia of unknown origin in tropical developing countries. PMID:22529625

  19. Nonrandom Distribution of Burkholderia pseudomallei Clones in Relation to Geographical Location and Virulence

    PubMed Central

    Vesaratchavest, Mongkol; Tumapa, Sarinna; Day, Nicholas P. J.; Wuthiekanun, Vanaporn; Chierakul, Wirongrong; Holden, Matthew T. G.; White, Nicholas J.; Currie, Bart J.; Spratt, Brian G.; Feil, Edward J.; Peacock, Sharon J.

    2006-01-01

    Burkholderia pseudomallei is a soil-dwelling saprophyte and the causative agent of melioidosis, a life-threatening human infection. Most cases are reported from northeast Thailand and northern Australia. Using multilocus sequence typing (MLST), we have compared (i) soil and invasive isolates from northeast Thailand and (ii) invasive isolates from Thailand and Australia. A total of 266 Thai B. pseudomallei isolates were characterized (83 soil and 183 invasive). These corresponded to 123 sequence types (STs), the most abundant being ST70 (n = 21), ST167 (n = 15), ST54 (n = 12), and ST58 (n = 11). Two clusters of related STs (clonal complexes) were identified; the larger clonal complex (CC48) did not conform to a simple pattern of radial expansion from an assumed ancestor, while a second (CC70) corresponded to a simple radial expansion from ST70. Despite the large number of STs, overall nucleotide diversity was low. Of the Thai isolates, those isolated from patients with melioidosis were overrepresented in the 10 largest clones (P < 0.0001). There was a significant difference in the classification index between environmental and disease isolates (P < 0.001), confirming that genotypes were not distributed randomly between the two samples. MLST profiles for 158 isolates from Australia (mainly disease associated) contained a number of STs (96) similar to that seen with the Thai invasive isolates, but no ST was found in both populations. There were also differences in diversity and allele frequency distribution between the two populations. This analysis reveals strong genetic differentiation on the basis of geographical isolation and a significant differentiation on the basis of virulence potential. PMID:16825379

  20. A proposed scoring system for predicting mortality in melioidosis

    Microsoft Academic Search

    Allen C. Cheng; Susan P. Jacups; Nicholas M. Anstey; Bart J. Curries

    2003-01-01

    Melioidosis, due to infection with the environmental organism Burkholderia pseudomallei, continues to beassociated with high mortality despite improvements in antibiotic therapy. Using simple clinical findings and baseline laboratory tests available at the time of admission, we attempted to define those patients with acute melioidosis who were at higher risk of death. Using data, collected prospectively from the period October 1989

  1. Effects of Colonization of the Roots of Domestic Rice (Oryza sativa L. cv. Amaroo) by Burkholderia pseudomallei.

    PubMed

    Prasertsincharoen, Noppadol; Constantinoiu, Constantin; Gardiner, Christopher; Warner, Jeffrey; Elliman, Jennifer

    2015-07-01

    Burkholderia pseudomallei is a saprophytic bacterium that causes melioidosis and is often isolated from rice fields in Southeast Asia, where the infection incidence is high among rice field workers. The aim of this study was to investigate the relationship between this bacterium and rice through growth experiments where the effect of colonization of domestic rice (Oryza sativa L. cv Amaroo) roots by B. pseudomallei could be observed. When B. pseudomallei was exposed to surface-sterilized seeds, the growth of both the root and the aerosphere was retarded compared to that in controls. The organism was found to localize in the root hairs and endodermis of the plant. A biofilm formed around the root and root structures that were colonized. Growth experiments with a wild rice species (Oryza meridionalis) produced similar retardation of growth, while another domestic cultivar (O. sativa L. cv Koshihikari) did not show retarded growth. Here we report B. pseudomallei infection and inhibition of O. sativa L. cv Amaroo, which might provide insights into plant interactions with this important human pathogen. PMID:25911477

  2. Characterization and analysis of the Burkholderia pseudomallei BsaN virulence regulon

    PubMed Central

    2014-01-01

    Background 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. Results To elucidate the scope of the BsaN regulon, we used RNAseq analysis to compare the transcriptomes of wild-type B. pseudomallei KHW and a bsaN deletion mutant. The 60 genes positively-regulated by BsaN include those that we had previously identified in addition to a polyketide biosynthesis locus and genes involved in amino acid biosynthesis. BsaN was also found to repress the transcription of 51 genes including flagellar motility loci and those encoding components of the T3SS3 apparatus. Using a promoter-lacZ fusion assay in E. coli, we show that BsaN together with the chaperone BicA directly control the expression of the T3SS3 translocon, effector and associated regulatory genes that are organized into at least five operons (BPSS1516-BPSS1552). Using a mutagenesis approach, a consensus regulatory motif in the promoter regions of BsaN-regulated genes was shown to be essential for transcriptional activation. Conclusions BsaN/BicA functions as a central regulator of key virulence clusters in B. pseudomallei within a more extensive network of genetic regulation. We propose that BsaN/BicA controls a gene expression program that facilitates the adaption and intracellular survival of the pathogen within eukaryotic hosts. PMID:25085508

  3. Curcumin rescues Caenorhabditis elegans from a Burkholderia pseudomallei infection

    PubMed Central

    Eng, Su-Anne; Nathan, Sheila

    2015-01-01

    The tropical pathogen Burkholderia pseudomallei requires long-term parenteral antimicrobial treatment to eradicate the pathogen from an infected patient. However, the development of antibiotic resistance is emerging as a threat to this form of treatment. To meet the need for alternative therapeutics, we proposed a screen of natural products for compounds that do not kill the pathogen, but in turn, abrogate bacterial virulence. We suggest that the use of molecules or compounds that are non-bactericidal (bacteriostatic) will reduce or abolish the development of resistance by the pathogen. In this study, we adopted the established Caenorhabditis elegans-B. pseudomallei infection model to screen a collection of natural products for any that are able to extend the survival of B. pseudomallei infected worms. Of the 42 natural products screened, only curcumin significantly improved worm survival following infection whilst not affecting bacterial growth. This suggested that curcumin promoted B. pseudomallei-infected worm survival independent of pathogen killing. To validate that the protective effect of curcumin was directed toward the pathogen, bacteria were treated with curcumin prior to infection. Worms fed with curcumin-treated bacteria survived with a significantly extended mean-time-to-death (p < 0.0001) compared to the untreated control. In in vitro assays, curcumin reduced the activity of known virulence factors (lipase and protease) and biofilm formation. To determine if other bacterial genes were also regulated in the presence of curcumin, a genome-wide transcriptome analysis was performed on curcumin-treated pathogen. A number of genes involved in iron acquisition and transport as well as genes encoding hypothetical proteins were induced in the presence of curcumin. Thus, we propose that curcumin may attenuate B. pseudomallei by modulating the expression of a number of bacterial proteins including lipase and protease as well as biofilm formation whilst concomitantly regulating iron transport and other proteins of unknown function. PMID:25914690

  4. BPSS1504, a Cluster 1 Type VI Secretion Gene, Is Involved in Intracellular Survival and Virulence of Burkholderia pseudomallei

    PubMed Central

    Hopf, Verena; Göhler, André; Eske-Pogodda, Kristin; Bast, Antje; Steinmetz, Ivo

    2014-01-01

    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 T6SS cluster 1 (T6SS1), which is known to be involved in the pathogenesis of B. pseudomallei in mammalian hosts. For further analysis, a B. pseudomallei BPSS1504 deletion (Bp?BPSS1504) mutant and complemented mutant strain were constructed. B. pseudomallei lacking the BPSS1504 gene was highly attenuated in BALB/c mice, whereas the in vivo virulence of the complemented mutant strain was fully restored to the wild-type level. The Bp?BPSS1504 mutant showed impaired intracellular replication and formation of multinucleated giant cells in macrophages compared with wild-type bacteria, whereas the induction of actin tail formation within host cells was not affected. These observations resembled the phenotype of a mutant lacking hcp1, which is an integral component of the T6SS1 apparatus and is associated with full functionality of the T6SS1. Transcriptional expression of the T6SS components vgrG, tssA, and hcp1, as well as the T6SS regulators virAG, bprC, and bsaN, was not dependent on BPSS1504 expression. However, secretion of Hcp1 was not detectable in the absence of BPSS1504. Thus, BPSS1504 seems to serve as a T6SS component that affects Hcp1 secretion and is therefore involved in the integrity of the T6SS1 apparatus. PMID:24595140

  5. Cross-species comparison of the Burkholderia pseudomallei, Burkholderia thailandensis, and Burkholderia mallei quorum-sensing regulons.

    PubMed

    Majerczyk, Charlotte D; Brittnacher, Mitchell J; Jacobs, Michael A; Armour, Christopher D; Radey, Matthew C; Bunt, Richard; Hayden, Hillary S; Bydalek, Ryland; Greenberg, E Peter

    2014-11-01

    Burkholderia pseudomallei, Burkholderia thailandensis, and Burkholderia mallei (the Bptm group) are close relatives with very different lifestyles: B. pseudomallei is an opportunistic pathogen, B. thailandensis is a nonpathogenic saprophyte, and B. mallei is a host-restricted pathogen. The acyl-homoserine lactone quorum-sensing (QS) systems of these three species show a high level of conservation. We used transcriptome sequencing (RNA-seq) to define the quorum-sensing regulon in each species, and we performed a cross-species analysis of the QS-controlled orthologs. Our analysis revealed a core set of QS-regulated genes in all three species, as well as QS-controlled factors shared by only two species or unique to a given species. This global survey of the QS regulons of B. pseudomallei, B. thailandensis, and B. mallei serves as a platform for predicting which QS-controlled processes might be important in different bacterial niches and contribute to the pathogenesis of B. pseudomallei and B. mallei. PMID:25182491

  6. Kinetic studies of bioactive products nitric oxide and 8-iso-PGF(2alpha) in Burkholderia pseudomallei infected human macrophages, and their role in the intracellular survival of these organisms.

    PubMed

    Nathan, Sakthi A; Qvist, Rajes; Puthucheary, Savithri D

    2005-02-01

    The oxidative response of Burkholderia pseudomallei and Escherichia coli infected macrophages from normal and melioidosis subjects was determined by measuring the production of nitric oxide which is one of the reactive nitrogen intermediates, and the activation state of these macrophages was determined by measuring the generation of 8-iso-PGF(2alpha), a bioactive product of free radical induced lipid peroxidation. Macrophages obtained from the melioidosis patients generated significantly lower levels of nitric oxide and 8-iso-PGF(2alpha) compared to macrophages obtained from the normal subjects (P<0.001). The reduced efficiency of the oxygen dependent microbicidal mechanism in macrophages of melioidosis patients may be one of the survival strategies developed by B. pseudomallei to remain viable intracellularly. PMID:15681148

  7. Identification of Motifs of Burkholderia pseudomallei BimA Required for Intracellular Motility, Actin Binding, and Actin Polymerization?

    PubMed Central

    Sitthidet, Chayada; Korbsrisate, Sunee; Layton, Abigail N.; Field, Terence R.; Stevens, Mark P.; Stevens, Joanne M.

    2011-01-01

    Actin-based motility of the melioidosis pathogen Burkholderia pseudomallei requires BimA (Burkholderia intracellular motility A). The mechanism by which BimA mediates actin assembly at the bacterial pole is ill-defined. Toward an understanding of the regions of B. pseudomallei BimA required for intracellular motility and the binding and polymerization of actin, we constructed plasmid-borne bimA variants and glutathione-S-transferase fusion proteins with in-frame deletions of specific motifs. A 13-amino-acid direct repeat and IP7 proline-rich motif were dispensable for actin binding and assembly in vitro, and expression of the mutated proteins in a B. pseudomallei bimA mutant restored actin-based motility in J774.2 murine macrophage-like cells. However, two WASP homology 2 (WH2) domains were found to be required for actin binding, actin assembly, and plaque formation. A tract of five PDASX direct repeats influenced the polymerization of pyrene-actin monomers in vitro and was required for actin-based motility and intercellular spread, but not actin binding. None of the mutations impaired surface expression or polar targeting of BimA. The number of PDASX repeats varied in natural isolates from two to seven. Such repeats acted additively to promote pyrene-actin polymerization in vitro, with stepwise increases in the rate of polymerization as the number of repeats was increased. No differences in the efficiency of actin tail formation could be discerned between strains expressing BimA variants with two, five, or seven PDASX repeats. The data provide valuable new insights into the role of conserved and variable motifs of BimA in actin-based motility and intercellular spread of B. pseudomallei. PMID:21335455

  8. Thoracic radiologic manifestations of melioidosis.

    PubMed

    Burivong, Wanaporn; Wu, Xiaohua; Saenkote, Wipawadee; Stern, Eric J

    2012-01-01

    Melioidosis (Burkholderia pseudomallei) is a gram-negative bacterial infection that is highly endemic in Southeast Asia and Oceania. Pulmonary disease is the most common form of involvement. The clinical-radiologic thoracic manifestations of melioidosis can be classified as acute, subacute, subclinical, and chronic forms. Radiographic findings include nodular, alveolar, or mixed infiltration/consolidation with or without cavities. Pleural effusion, pneumothorax, and pericardial involvement can be seen. Melioidosis can easily be confused with other infections, especially tuberculosis. Suspicion of this disease in the proper clinical radiologic setting is important for early diagnosis and treatment. In this article, we provide a broad clinical overview of melioidosis, review the radiologic thoracic manifestations of melioidosis with appropriate clinical correlation, as well as compare and contrast the imaging findings of thoracic melioidosis with other similar pulmonary infections. PMID:23009770

  9. The BpeEF-OprC Efflux Pump Is Responsible for Widespread Trimethoprim Resistance in Clinical and Environmental Burkholderia pseudomallei Isolates

    PubMed Central

    Podnecky, Nicole L.; Wuthiekanun, Vanaporn; Peacock, Sharon J.

    2013-01-01

    Trimethoprim-sulfamethoxazole (co-trimoxazole) is the primary drug used for oral eradication therapy of Burkholderia pseudomallei infections (melioidosis). Here, we demonstrate that trimethoprim resistance is widespread in clinical and environmental isolates from northeast Thailand and northern Australia. This resistance was shown to be due to BpeEF-OprC efflux pump expression. No dihydrofolate reductase target mutations were involved, although frequent insertion of ISBma2 was noted within the putative folA transcriptional terminator. All isolates tested remained susceptible to trimethoprim-sulfamethoxazole, suggesting that resistance to trimethoprim alone in these strains probably does not affect the efficacy of co-trimoxazole therapy. PMID:23817379

  10. Whole-Genome Sequences of Five Burkholderia pseudomallei Isolates from Australian Cystic Fibrosis Patients

    PubMed Central

    Kidd, Timothy J.; Bell, Scott C.; Currie, Bart J.

    2015-01-01

    We report here five improved high-quality draft genomes of Burkholderia pseudomallei isolated from Australian cystic fibrosis (CF) patients. This pathogen is rarely seen in CF patients. These genomes will be used to better understand chronic carriage of B. pseudomallei in the CF lung and the within-host evolution of longitudinal isolates from these patients. PMID:25883282

  11. Structural characterization of Burkholderia pseudomallei adenylate kinase (Adk): Profound asymmetry in the crystal structure of the 'open' state

    SciTech Connect

    Buchko, G.W.; Robinson, H.; Abendroth, J.; Staker, B. L.; Myler, P. J.

    2010-04-16

    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 2.1 {angstrom} resolution crystal structure for the 220-residue Adk from Burkholderia pseudomallei (BpAdk), the etiological agent responsible for the infectious disease melioidosis. The general structure of apo BpAdk is similar to other Adk structures, composed of a CORE subdomain with peripheral ATP-binding (ATP{sub bd}) and LID subdomains. The two molecules in the asymmetric unit have significantly different conformations, with a backbone RMSD of 1.46 {angstrom}. These two BpAdk conformations may represent 'open' Adk sub-states along the preferential pathway to the 'closed' substrate-bound state.

  12. Clinical, environmental, and serologic surveillance studies of melioidosis in Gabon, 2012-2013.

    PubMed

    Wiersinga, W Joost; Birnie, Emma; Weehuizen, Tassili A F; Alabi, Abraham S; Huson, Michaëla A M; Huis in 't Veld, Robert A G; Mabala, Harry K; Adzoda, Gregoire K; Raczynski-Henk, Yannick; Esen, Meral; Lell, Bertrand; Kremsner, Peter G; Visser, Caroline E; Wuthiekanun, Vanaporn; Peacock, Sharon J; van der Ende, Arie; Limmathurotsakul, Direk; Grobusch, Martin P

    2015-01-01

    Burkholderia pseudomallei, an environmental gram-negative bacillus, is the causative agent of melioidosis and a bio-threat agent. Reports of B. pseudomallei isolation from soil and animals in East and West Africa suggest that melioidosis might be more widely distributed than previously thought. Because it has been found in equatorial areas with tropical climates, we hypothesized that B. pseudomallei could exist in Gabon. During 2012-2013, we conducted a seroprevalance study in which we set up microbiology facilities at a large clinical referral center and prospectively screened all febrile patients by conducting blood cultures and testing for B. pseudomallei and related species; we also determined whether B. pseudomallei could be isolated from soil. We discovered a novel B. pseudomallei sequence type that caused lethal septic shock and identified B. pseudomallei and B. thailandensis in the environment. Our data suggest that melioidosis is emerging in Central Africa but is unrecognized because of the lack of diagnostic microbiology facilities. PMID:25530077

  13. Burkholderia pseudomallei sequencing identifies genomic clades with distinct recombination, accessory, and epigenetic profiles

    PubMed Central

    Nandi, Tannistha; Holden, Matthew T.G.; Didelot, Xavier; Mehershahi, Kurosh; Boddey, Justin A.; Beacham, Ifor; Peak, Ian; Harting, John; Baybayan, Primo; Guo, Yan; Wang, Susana; How, Lee Chee; Sim, Bernice; Essex-Lopresti, Angela; Sarkar-Tyson, Mitali; Nelson, Michelle; Smither, Sophie; Ong, Catherine; Aw, Lay Tin; Hoon, Chua Hui; Michell, Stephen; Studholme, David J.; Titball, Richard; Chen, Swaine L.; Parkhill, Julian

    2015-01-01

    Burkholderia pseudomallei (Bp) is the causative agent of the infectious disease melioidosis. To investigate population diversity, recombination, and horizontal gene transfer in closely related Bp isolates, we performed whole-genome sequencing (WGS) on 106 clinical, animal, and environmental strains from a restricted Asian locale. Whole-genome phylogenies resolved multiple genomic clades of Bp, largely congruent with multilocus sequence typing (MLST). We discovered widespread recombination in the Bp core genome, involving hundreds of regions associated with multiple haplotypes. Highly recombinant regions exhibited functional enrichments that may contribute to virulence. We observed clade-specific patterns of recombination and accessory gene exchange, and provide evidence that this is likely due to ongoing recombination between clade members. Reciprocally, interclade exchanges were rarely observed, suggesting mechanisms restricting gene flow between clades. Interrogation of accessory elements revealed that each clade harbored a distinct complement of restriction-modification (RM) systems, predicted to cause clade-specific patterns of DNA methylation. Using methylome sequencing, we confirmed that representative strains from separate clades indeed exhibit distinct methylation profiles. Finally, using an E. coli system, we demonstrate that Bp RM systems can inhibit uptake of non-self DNA. Our data suggest that RM systems borne on mobile elements, besides preventing foreign DNA invasion, may also contribute to limiting exchanges of genetic material between individuals of the same species. Genomic clades may thus represent functional units of genetic isolation in Bp, modulating intraspecies genetic diversity. PMID:25236617

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

    SciTech Connect

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

    2011-09-28

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

  15. Association of melioidosis incidence with rainfall and humidity, Singapore, 2003-2012.

    PubMed

    Liu, Xiang; Pang, Long; Sim, Siew Hoon; Goh, Kee Tai; Ravikumar, Sharada; Win, Mar Soe; Tan, Gladys; Cook, Alex Richard; Fisher, Dale; Chai, Louis Yi Ann

    2015-01-01

    Soil has been considered the natural reservoir for the bacterium Burkholderia pseudomallei, which causes melioidosis. We examined 550 melioidosis cases that occurred during a 10-year period in the highly urbanized city of Singapore, where soil exposure is rare, and found that rainfall and humidity levels were associated with disease incidence. PMID:25531547

  16. A rare cause of septic arthritis: melioidosis.

    PubMed

    Caldera, Aruna Sanjeewa; Kumanan, Thirunavukarasu; Corea, Enoka

    2013-10-01

    Melioidosis is a pyogenic infection with high mortality caused by the bacterium Burkholderia pseudomallei. As the clinical presentation is not distinctive, a high index of clinical suspicion is required for diagnosis. We present a case of a 50-year-old farmer who was diabetic and a chronic alcoholic, who presented to us with pneumonia, followed by septic arthritis. He was ultimately diagnosed as having melioidosis. PMID:24067292

  17. Induction of Mouse Melioidosis with Meningitis by CD11b+ Phagocytic Cells Harboring Intracellular B. pseudomallei as a Trojan Horse

    PubMed Central

    Liu, Pei-Ju; Chen, Yao-Shen; Lin, Hsi-Hsu; Ni, Wei-Feng; Hsieh, Tsung-Han; Chen, Hsu-Tzu; Chen, Ya-Lei

    2013-01-01

    Background Approximately 3–5% of patients with melioidosis manifest CNS symptoms; however, the clinical data regarding neurological melioidosis are limited. Methods and Findings We established a mouse model of melioidosis with meningitis characterized by neutrophil infiltration into the meninges histologically and B. pseudomallei in the cerebrospinal fluid (CSF) by bacteriological culturing methods. As the disease progresses, the bacteria successively colonize the spleen, liver, bone marrow (BM) and brain and invade splenic and BM cells by days 2 and 6 post-infection, respectively. The predominant cell types intracellularly infected with B. pseudomallei were splenic and BM CD11b+ populations. The CD11b+Ly6Chigh inflamed monocytes, CD11b+Ly6Clow resident monocytes, CD11b+Ly6G+ neutrophils, CD11b+F4/80+ macrophages and CD11b+CD19+ B cells were expanded in the spleen and BM during the progression of melioidosis. After adoptive transfer of CD11b populations harboring B. pseudomallei, the infected CD11b+ cells induced bacterial colonization in the brain, whereas CD11b? cells only partially induced colonization; extracellular (free) B. pseudomallei were unable to colonize the brain. CD62L (selectin) was absent on splenic CD11b+ cells on day 4 but was expressed on day 10 post-infection. Adoptive transfer of CD11b+ cells expressing CD62L (harvested on day 10 post-infection) resulted in meningitis in the recipients, but transfer of CD11b+ CD62L-negative cells did not. Conclusions/Significance We suggest that B. pseudomallei-infected CD11b+ selectin-expressing cells act as a Trojan horse and are able to transmigrate across endothelial cells, resulting in melioidosis with meningitis. PMID:23951382

  18. Actin-binding proteins from Burkholderia mallei and Burkholderia thailandensis can functionally compensate for the actin-based motility defect of a Burkholderia pseudomallei bimA mutant.

    PubMed

    Stevens, Joanne M; Ulrich, Ricky L; Taylor, Lowrie A; Wood, Michael W; Deshazer, David; Stevens, Mark P; Galyov, Edouard E

    2005-11-01

    Recently we identified a bacterial factor (BimA) required for actin-based motility of Burkholderia pseudomallei. Here we report that Burkholderia mallei and Burkholderia thailandensis are capable of actin-based motility in J774.2 cells and that BimA homologs of these bacteria can restore the actin-based motility defect of a B. pseudomallei bimA mutant. While the BimA homologs differ in their amino-terminal sequence, they interact directly with actin in vitro and vary in their ability to bind Arp3. PMID:16267310

  19. Actin-Binding Proteins from Burkholderia mallei and Burkholderia thailandensis Can Functionally Compensate for the Actin-Based Motility Defect of a Burkholderia pseudomallei bimA Mutant

    PubMed Central

    Stevens, Joanne M.; Ulrich, Ricky L.; Taylor, Lowrie A.; Wood, Michael W.; DeShazer, David; Stevens, Mark P.; Galyov, Edouard E.

    2005-01-01

    Recently we identified a bacterial factor (BimA) required for actin-based motility of Burkholderia pseudomallei. Here we report that Burkholderia mallei and Burkholderia thailandensis are capable of actin-based motility in J774.2 cells and that BimA homologs of these bacteria can restore the actin-based motility defect of a B. pseudomallei bimA mutant. While the BimA homologs differ in their amino-terminal sequence, they interact directly with actin in vitro and vary in their ability to bind Arp3. PMID:16267310

  20. Characterization of an autotransporter adhesin protein shared by Burkholderia mallei and Burkholderia pseudomallei

    PubMed Central

    2014-01-01

    Background 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). Results Database searches identified the gene in at least seven B. mallei isolates and the encoded proteins were found to be 84% identical. Inactivation of the gene encoding the autotransporter in the genome of strain ATCC 23344 substantially reduces adherence to monolayers of HEp-2 laryngeal cells and A549 type II pneumocytes, as well as to cultures of normal human bronchial epithelium (NHBE). Consistent with these findings, expression of the autotransporter on the surface of recombinant E. coli bacteria increases adherence to these cell types by 5–7 fold. The gene specifying the autotransporter was identified in the genome of 29 B. pseudomallei isolates and disruption of the gene in strain DD503 reduced adherence to NHBE cultures by 61%. Unlike B. mallei, the mutation did not impair binding of B. pseudomallei to A549 or HEp-2 cells. Analysis of sera from mice infected via the aerosol route with B. mallei and B. pseudomallei revealed that animals inoculated with as few as 10 organisms produce antibodies against the autotransporter, therefore indicating expression in vivo. Conclusions Our data demonstrate that we have identified an autotransporter protein common to the pathogenic species B. mallei and B. pseudomallei which mediates adherence to respiratory epithelial cells and is expressed in vivo during the course of aerosol infection. PMID:24731253

  1. Pahang melioidosis registry.

    PubMed

    How, S H; Ng, T H; Jamalludin, A R; Tee, H P; Kuan, Y C; Alex, F; Sc, M; Aminudin, C A; Sapari, S; Quazi, M H

    2009-03-01

    Melioidosis has a high annual incidence and mortality rate in Pahang, Malaysia. We initiated the first melioidosis registry in the country on 1st July 2005 to improve the management of melioidosis in the state. Continuous medical education on melioidosis was carried out in all hospitals in the state to highlight the magnitude of the disease and to educate the doctors on the treatment of the disease. All culture confirmed cases were registered and analysed. During the one-year study period from 1st July 2005 till 30th June 2006, a total of 63 patients had positive culture for Burkholderia pseudomallei. The calculated annual incidence of melioidosis in Pahang state was 4.3 per 100,000 population per year (Adult, 6.0 per 100, 000 population per year and paediatric, 1.6 per 100,000 population per year). There were 55 Malays (87.3%), three Chinese (4.8%), four aborigines (6.3%) and one Indonesian. Nine (14.3%) were less than 18 years old. The median age was 49 years (range: 1-68 years). Only one patient (1.6%) had a previous history of confirmed melioidosis. With this programme, we had observed a decline in adult mortality from 54% to 44%, although this was not statistically significant. However, culture-confirmed relapses had dropped from 19% to nil. Several measures need to be taken to decrease mortality from melioidosis in endemic countries. PMID:19852316

  2. Nasal Acai Polysaccharides Potentiate Innate Immunity to Protect against Pulmonary Francisella tularensis and Burkholderia pseudomallei Infections

    Microsoft Academic Search

    Jerod A. Skyberg; MaryClare F. Rollins; Jeff S. Holderness; Nicole L. Marlenee; Igor A. Schepetkin; Andrew Goodyear; Steven W. Dow; Mark A. Jutila; David W. Pascual

    2012-01-01

    Pulmonary Francisella tularensis and Burkholderia pseudomallei infections are highly lethal in untreated patients, and current antibiotic regimens are not always effective. Activating the innate immune system provides an alternative means of treating infection and can also complement antibiotic therapies. Several natural agonists were screened for their ability to enhance host resistance to infection, and polysaccharides derived from the Acai berry

  3. Extended loop region of Hcp1 is critical for the assembly and function of type VI secretion system in Burkholderia pseudomallei.

    PubMed

    Lim, Yan Ting; Jobichen, Chacko; Wong, Jocelyn; Limmathurotsakul, Direk; Li, Shaowei; Chen, Yahua; Raida, Manfred; Srinivasan, Nalini; MacAry, Paul Anthony; Sivaraman, J; Gan, Yunn-Hwen

    2015-01-01

    The Type VI Secretion System cluster 1 (T6SS1) is essential for the pathogenesis of Burkholderia pseudomallei, the causative agent of melioidosis, a disease endemic in the tropics. Inside host cells, B. pseudomallei escapes into the cytosol and through T6SS1, induces multinucleated giant cell (MNGC) formation that is thought to be important for bacterial cell to cell spread. The hemolysin-coregulated protein (Hcp) is both a T6SS substrate, as well as postulated to form part of the T6SS secretion tube. Our structural study reveals that Hcp1 forms hexameric rings similar to the other Hcp homologs but has an extended loop (Asp40-Arg56) that deviates significantly in position compared to other Hcp structures and may act as a key contact point between adjacent hexameric rings. When two residues within the loop were mutated, the mutant proteins were unable to stack as dodecamers, suggesting defective tube assembly. Moreover, infection with a bacterial mutant containing in situ substitution of these hcp1 residues abolishes Hcp1 secretion inside infected cells and MNGC formation. We further show that Hcp has the ability to preferentially bind to the surface of antigen-presenting cells, which may contribute to its immunogenicity in inducing high titers of antibodies seen in melioidosis patients. PMID:25648885

  4. Development and evaluation of a real-time PCR assay targeting the type III secretion system of Burkholderia pseudomallei

    Microsoft Academic Search

    Ryan T. Novak; Mindy B. Glass; Jay E. Gee; Daniel Gal; Mark J. Mayo; Bart J. Currie; Patricia P. Wilkins

    2006-01-01

    Here we report on the development of a discriminatory real-time assay for the rapid identification of Burkholderia pseudomallei isolates and the evaluation of this assay for sensitivity against related species and detection in spiked human blood samples. The assay targets a 115-base-pair region within orf2 of the B. pseudomallei type III secretion system gene cluster and distinguishes B. pseudomallei from

  5. A preliminary X-ray study of 3-deoxy-D-manno-oct-2-ulosonic acid 8-phosphate phosphatase (YrbI) from Burkholderia pseudomallei.

    PubMed

    Park, Jimin; Lee, Daeun; Kim, Mi Sun; Kim, Dae Yong; Shin, Dong Hae

    2015-06-01

    3-Deoxy-D-manno-oct-2-ulosonic acid 8-phosphate phosphatase (YrbI), the third enzyme in the pathway for the biosynthesis of 3-deoxy-D-manno-oct-2-ulosonic acid (KDO), hydrolyzes KDO 8-phosphate to KDO and inorganic phosphate. YrbI belongs to the haloacid dehalogenase (HAD) superfamily, which is a large family of magnesium-dependent phosphatase/phosphotransferase enzymes. In this study, YrbI from Burkholderia pseudomallei, the causative agent of melioidosis, has been cloned, expressed, purified and crystallized. Synchrotron X-ray data were also collected to 2.25?Å resolution. The crystal belonged to the primitive orthorhombic space group P212121, with unit-cell parameters a = 63.7, b = 97.5, c = 98.0?Å. A full structural determination is in progress to elucidate the structure-function relationship of this protein. PMID:26057814

  6. Development of Signature-Tagged Mutagenesis in Burkholderia pseudomallei To Identify Genes Important in Survival and Pathogenesis?

    PubMed Central

    Cuccui, J.; Easton, A.; Chu, K. K.; Bancroft, G. J.; Oyston, P. C. F.; Titball, R. W.; Wren, B. W.

    2007-01-01

    Burkholderia pseudomallei, the causative agent of melioidosis, is an important human pathogen in Southeast Asia and northern Australia for which a vaccine is unavailable. A panel of 892 double signature-tagged mutants was screened for virulence using an intranasal BALB/c mouse model of infection. A novel DNA tag microarray identified 33 mutants as being attenuated in spleens, while 6 were attenuated in both lungs and spleens. The transposon insertion sites in spleen-attenuated mutants revealed genes involved in several stages of capsular polysaccharide biosynthesis and DNA replication and repair, a putative oxidoreductase, ABC transporters, and a lipoprotein that may be important in intercellular spreading. The six mutants identified as missing in both lungs and spleens were found to have insertions in recA involved in the SOS response and DNA repair; putative auxotrophs of leucine, threonine, p-aminobenzoic acid, and a mutant with an insertion in aroB causing auxotrophy for aromatic compounds were also found. Murine challenge studies revealed partial protection in BALB/c mice vaccinated with the aroB mutant. The refined signature-tagged mutagenesis approach developed in this study was used to efficiently identify attenuating mutants from this highly pathogenic species and could be applied to other organisms. PMID:17189432

  7. Interim report on updated microarray probes for the LLNL Burkholderia pseudomallei SNP array

    SciTech Connect

    Gardner, S; Jaing, C

    2012-03-27

    The overall goal of this project is to forensically characterize 100 unknown Burkholderia isolates in the US-Australia collaboration. We will identify genome-wide single nucleotide polymorphisms (SNPs) from B. pseudomallei and near neighbor species including B. mallei, B. thailandensis and B. oklahomensis. We will design microarray probes to detect these SNP markers and analyze 100 Burkholderia genomic DNAs extracted from environmental, clinical and near neighbor isolates from Australian collaborators on the Burkholderia SNP microarray. We will analyze the microarray genotyping results to characterize the genetic diversity of these new isolates and triage the samples for whole genome sequencing. In this interim report, we described the SNP analysis and the microarray probe design for the Burkholderia SNP microarray.

  8. Survival, Sublethal Injury, and Recovery of Environmental Burkholderia pseudomallei in Soil Subjected to Desiccation

    PubMed Central

    Larsen, Eloise; Smith, James J.; Norton, Robert

    2013-01-01

    Environmental Burkholderia pseudomallei isolated from sandy soil at Castle Hill, Townsville, in the dry tropic region of Queensland, Australia, was inoculated into sterile-soil laboratory microcosms subjected to variable soil moisture. Survival and sublethal injury of the B. pseudomallei strain were monitored by recovery using culture-based methods. Soil extraction buffer yielded higher recoveries as an extraction agent than sterile distilled water. B. pseudomallei was not recoverable when inoculated into desiccated soil but remained recoverable from moist soil subjected to 91 days' desiccation and showed a growth response to increased soil moisture over at least 113 days. Results indicate that endemic dry tropic soil may act as a reservoir during the dry season, with an increase in cell number and potential for mobilization from soil into water in the wet season. PMID:23377947

  9. Melioidosis Presenting as Fever and Jaundice: A Rare Presentation

    PubMed Central

    Tyagi, Pankaj; Shah, Vinit; Sharma, Praveen; Bansal, Naresh; Singla, Vikas; Kumar, Ashish; Arora, Anil

    2013-01-01

    Melioidosis caused by the environmental Gram-negative bacillus Burkholderia pseudomallei is endemic in northern Australia and Southeast Asia and is being described increasingly from south and west coastal regions of India. Melioidosis is known to have high mortality (14–50%) and the risk factors associated with it are diabetes mellitus and heavy alcohol abuse. Melioidosis primarily presents as pneumonia, genitourinary infection and bacteremia. We present a case of Melioidosis from North India, a 56-year-old diabetic male, presenting with fever and jaundice. His blood culture was positive for the B. pseudomallei. The hepatic involvement was in the form of jaundice with serum bilirubin value of more than 12 mg/dL, hepatic enzymes more than ten times high and without hepatic abscess. He improved with intravenous antibiotics with complete normalization of liver function tests. PMID:25755553

  10. Melioidosis presenting as Fever and jaundice: a rare presentation.

    PubMed

    Tyagi, Pankaj; Shah, Vinit; Sharma, Praveen; Bansal, Naresh; Singla, Vikas; Kumar, Ashish; Arora, Anil

    2014-06-01

    Melioidosis caused by the environmental Gram-negative bacillus Burkholderia pseudomallei is endemic in northern Australia and Southeast Asia and is being described increasingly from south and west coastal regions of India. Melioidosis is known to have high mortality (14-50%) and the risk factors associated with it are diabetes mellitus and heavy alcohol abuse. Melioidosis primarily presents as pneumonia, genitourinary infection and bacteremia. We present a case of Melioidosis from North India, a 56-year-old diabetic male, presenting with fever and jaundice. His blood culture was positive for the B. pseudomallei. The hepatic involvement was in the form of jaundice with serum bilirubin value of more than 12 mg/dL, hepatic enzymes more than ten times high and without hepatic abscess. He improved with intravenous antibiotics with complete normalization of liver function tests. PMID:25755553

  11. Alanine Racemase Mutants of Burkholderia pseudomallei and Burkholderia mallei and Use of Alanine Racemase as a Non-Antibiotic-Based Selectable Marker

    PubMed Central

    Zajdowicz, Sheryl L. W.; Jones-Carson, Jessica; Vazquez-Torres, Andres; Jobling, Michael G.; Gill, Ronald E.; Holmes, Randall K.

    2011-01-01

    Burkholderia pseudomallei and Burkholderia mallei are category B select agents and must be studied under BSL3 containment in the United States. They are typically resistant to multiple antibiotics, and the antibiotics used to treat B. pseudomallei or B. mallei infections may not be used as selective agents with the corresponding Burkholderia species. Here, we investigated alanine racemase deficient mutants of B. pseudomallei and B. mallei for development of non-antibiotic-based genetic selection methods and for attenuation of virulence. The genome of B. pseudomallei K96243 has two annotated alanine racemase genes (bpsl2179 and bpss0711), and B. mallei ATCC 23344 has one (bma1575). Each of these genes encodes a functional enzyme that can complement the alanine racemase deficiency of Escherichia coli strain ALA1. Herein, we show that B. pseudomallei with in-frame deletions in both bpsl2179 and bpss0711, or B. mallei with an in-frame deletion in bma1575, requires exogenous d-alanine for growth. Introduction of bpsl2179 on a multicopy plasmid into alanine racemase deficient variants of either Burkholderia species eliminated the requirement for d-alanine. During log phase growth without d-alanine, the viable counts of alanine racemase deficient mutants of B. pseudomallei and B. mallei decreased within 2 hours by about 1000-fold and 10-fold, respectively, and no viable bacteria were present at 24 hours. We constructed several genetic tools with bpsl2179 as a selectable genetic marker, and we used them without any antibiotic selection to construct an in-frame ?flgK mutant in the alanine racemase deficient variant of B. pseudomallei K96243. In murine peritoneal macrophages, wild type B. mallei ATCC 23344 was killed much more rapidly than wild type B. pseudomallei K96243. In addition, the alanine racemase deficient mutant of B. pseudomallei K96243 exhibited attenuation versus its isogenic parental strain with respect to growth and survival in murine peritoneal macrophages. PMID:21720554

  12. In Vitro and In Vivo Studies of Monoclonal Antibodies with Prominent Bactericidal Activity against Burkholderia pseudomallei and Burkholderia mallei?

    PubMed Central

    Zhang, Shimin; Feng, Shaw-Huey; Li, Bingjie; Kim, Hyung-Yong; Rodriguez, Joe; Tsai, Shien; Lo, Shyh-Ching

    2011-01-01

    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 challenged intranasally with a lethal dose of the bacteria. The opsonic assay using dimethyl sulfoxide-treated human HL-60 cells as phagocytes revealed that 19 out of 47 tested MAbs (40%) have prominent bactericidal activities against B. pseudomallei and/or B. mallei. Interestingly, all MAbs with strong opsonic activities are those with specificity against either the capsular polysaccharides (PS) or the lipopolysaccharides (LPS) of the bacteria. On the other hand, none of the MAbs reacting to bacterial proteins or glycoproteins showed prominent bactericidal activity. Further study revealed that the antigenic epitopes on either the capsular PS or LPS molecules were readily available for binding in intact bacteria, while the epitopes on proteins/glycoproteins were less accessible to the MAbs. Our in vivo study showed that four MAbs reactive to either the capsular PS or LPS were highly effective in protecting mice against lethal bacterial challenge. The result is compatible with that of our in vitro study. The MAbs with the highest protective efficacy are those reactive to either the capsular PS or LPS of the Burkholderia bacteria. PMID:21450976

  13. Further Evaluation of a Rapid Diagnostic Test for Melioidosis in an Area of Endemicity

    Microsoft Academic Search

    Mathew O'Brien; Kevin Freeman; Gary Lum; Allen C. Cheng; Susan P. Jacups; Bart J. Currie

    2004-01-01

    Immunochromatographic test (ICT) kits for the rapid detection of immunoglobulin G (IgG) and IgM antibodies to Burkholderia pseudomallei were compared to the indirect hemagglutination (IHA) assay. In 138 culture-confirmed melioidosis cases, sensitivities were 80, 77, and 88% for IHA, ICT IgG, and ICT IgM, respectively. In a prospective study of 160 consecutive sera samples sent for melioidosis serology, respective specificities

  14. Pulmonary melioidosis in Cambodia: A prospective study

    Microsoft Academic Search

    Blandine Rammaert; Julien Beauté; Laurence Borand; Sopheak Hem; Philippe Buchy; Sophie Goyet; Rob Overtoom; Cécile Angebault; Vantha Te; Patrich Lorn Try; Charles Mayaud; Sirenda Vong; Bertrand Guillard

    2011-01-01

    Background  Melioidosis is a disease caused by Burkholderia pseudomallei and considered endemic in South-East Asia but remains poorly documented in Cambodia. We report the first series of hospitalized\\u000a pulmonary melioidosis cases identified in Cambodia describing clinical characteristics and outcomes.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  We characterized cases of acute lower respiratory infections (ALRI) that were identified through surveillance in two provincial\\u000a hospitals. Severity was defined by

  15. Endemic melioidosis in residents of desert region after atypically intense rainfall in central Australia, 2011.

    PubMed

    Yip, Teem-Wing; Hewagama, Saliya; Mayo, Mark; Price, Erin P; Sarovich, Derek S; Bastian, Ivan; Baird, Robert W; Spratt, Brian G; Currie, Bart J

    2015-06-01

    After heavy rains and flooding during early 2011 in the normally arid interior of Australia, melioidosis was diagnosed in 6 persons over a 4-month period. Although the precise global distribution of the causal bacterium Burkholderia pseudomallei remains to be determined, this organism can clearly survive in harsh and even desert environments outside the wet tropics. PMID:25988301

  16. Endemic Melioidosis in Residents of Desert Region after Atypically Intense Rainfall in Central Australia, 2011

    PubMed Central

    Yip, Teem-Wing; Hewagama, Saliya; Mayo, Mark; Price, Erin P.; Sarovich, Derek S.; Bastian, Ivan; Baird, Robert W.; Spratt, Brian G.

    2015-01-01

    After heavy rains and flooding during early 2011 in the normally arid interior of Australia, melioidosis was diagnosed in 6 persons over a 4-month period. Although the precise global distribution of the causal bacterium Burkholderia pseudomallei remains to be determined, this organism can clearly survive in harsh and even desert environments outside the wet tropics. PMID:25988301

  17. Type three secretion system-mediated escape of Burkholderia pseudomallei into the host cytosol is critical for the activation of NF?B

    PubMed Central

    2014-01-01

    Background 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 NF?B 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 to NF?B activation is unknown. Results Known T3SS3 effectors are not responsible for NF?B activation. Furthermore, T3SS3-null mutants are able to activate NF?B almost to the same extent as wildtype bacteria at late time points of infection, corresponding to delayed escape into the cytosol. NF?B activation also occurs when bacteria are delivered directly into the cytosol by photothermal nanoblade injection. Conclusions T3SS3 does not directly activate NF?B but facilitates bacterial escape into the cytosol where the host is able to sense the presence of the pathogen through cytosolic sensors leading to NF?B activation. PMID:24884837

  18. Nasal Acai Polysaccharides Potentiate Innate Immunity to Protect against Pulmonary Francisella tularensis and Burkholderia pseudomallei Infections

    PubMed Central

    Skyberg, Jerod A.; Rollins, MaryClare F.; Holderness, Jeff S.; Marlenee, Nicole L.; Schepetkin, Igor A.; Goodyear, Andrew; Dow, Steven W.; Jutila, Mark A.; Pascual, David W.

    2012-01-01

    Pulmonary Francisella tularensis and Burkholderia pseudomallei infections are highly lethal in untreated patients, and current antibiotic regimens are not always effective. Activating the innate immune system provides an alternative means of treating infection and can also complement antibiotic therapies. Several natural agonists were screened for their ability to enhance host resistance to infection, and polysaccharides derived from the Acai berry (Acai PS) were found to have potent abilities as an immunotherapeutic to treat F. tularensis and B. pseudomallei infections. In vitro, Acai PS impaired replication of Francisella in primary human macrophages co-cultured with autologous NK cells via augmentation of NK cell IFN-?. Furthermore, Acai PS administered nasally before or after infection protected mice against type A F. tularensis aerosol challenge with survival rates up to 80%, and protection was still observed, albeit reduced, when mice were treated two days post-infection. Nasal Acai PS administration augmented intracellular expression of IFN-? by NK cells in the lungs of F. tularensis-infected mice, and neutralization of IFN-? ablated the protective effect of Acai PS. Likewise, nasal Acai PS treatment conferred protection against pulmonary infection with B. pseudomallei strain 1026b. Acai PS dramatically reduced the replication of B. pseudomallei in the lung and blocked bacterial dissemination to the spleen and liver. Nasal administration of Acai PS enhanced IFN-? responses by NK and ?? T cells in the lungs, while neutralization of IFN-? totally abrogated the protective effect of Acai PS against pulmonary B. pseudomallei infection. Collectively, these results demonstrate Acai PS is a potent innate immune agonist that can resolve F. tularensis and B. pseudomallei infections, suggesting this innate immune agonist has broad-spectrum activity against virulent intracellular pathogens. PMID:22438809

  19. Laboratory diagnosis of melioidosis: Past, present and future.

    PubMed

    Lau, Susanna Kp; Sridhar, Siddharth; Ho, Chi-Chun; Chow, Wang-Ngai; Lee, Kim-Chung; Lam, Ching-Wan; Yuen, Kwok-Yung; Woo, Patrick Cy

    2015-06-01

    Melioidosis is an emerging, potentially fatal disease caused by Burkholderia pseudomallei, which requires prolonged antibiotic treatment to prevent disease relapse. However, difficulties in laboratory diagnosis of melioidosis may delay treatment and affect disease outcomes. Isolation of B. pseudomallei from clinical specimens has been improved with the use of selective media. However, even with positive cultures, identification of B. pseudomallei can be difficult in clinical microbiology laboratories, especially in non-endemic areas where clinical suspicion is low. Commercial identification systems may fail to distinguish between B. pseudomallei and closely related species such as Burkholderia thailandensis. Genotypic identification of suspected isolates can be achieved by sequencing of gene targets such as groEL which offer higher discriminative power than 16S rRNA. Specific PCR-based identification of B. pseudomallei has also been developed using B. pseudomallei-specific gene targets such as Type III secretion system and Tat-domain protein. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry, a revolutionary technique for pathogen identification, has been shown to be potentially useful for rapid identification of B. pseudomallei, although existing databases require optimization by adding reference spectra for B. pseudomallei. Despite these advances in bacterial identification, diagnostic problems encountered in culture-negative cases remain largely unresolved. Although various serological tests have been developed, they are generally unstandardized "in house" assays and have low sensitivities and specificities. Although specific PCR assays have been applied to direct clinical and environmental specimens, the sensitivities for diagnosis remain to be evaluated. Metabolomics is an uprising tool for studying infectious diseases and may offer a novel approach for exploring potential diagnostic biomarkers. The metabolomics profiles of B. pseudomallei culture supernatants can be potentially distinguished from those of related bacterial species including B. thailandensis . Further studies using bacterial cultures and direct patient samples are required to evaluate the potential of metabolomics for improving diagnosis of melioidosis. PMID:25908634

  20. Use of Various Common Isolation Media To Evaluate the New VITEK 2 Colorimetric GN Card for Identification of Burkholderia pseudomallei

    Microsoft Academic Search

    Peter Lowe; Helen Haswell; Kirsty Lewis

    2006-01-01

    The use of automated systems in the modern microbiology laboratory is becoming commonplace as the pressure of cost containment impacts on staff resources. With increased international travel and threats of bioterrorism, recognition and accurate identification of organisms such as Burkholderia pseudomallei is im- portant. In areas where this organism is endemic, identification is not usually problematic. This study evaluates the

  1. Production of a recombinant vaccine candidate against Burkholderia pseudomallei exploiting the bacterial N-glycosylation machinery

    PubMed Central

    Garcia-Quintanilla, Fatima; Iwashkiw, Jeremy A.; Price, Nancy L.; Stratilo, Chad; Feldman, Mario F.

    2014-01-01

    Vaccines developing immune responses toward surface carbohydrates conjugated to proteins are effective in preventing infection and death by bacterial pathogens. Traditional production of these vaccines utilizes complex synthetic chemistry to acquire and conjugate the glycan to a protein. However, glycoproteins produced by bacterial protein glycosylation systems are significantly easier to produce, and could possible be used as vaccine candidates. In this work, we functionally expressed the Burkholderia pseudomallei O polysaccharide (OPS II), the Campylobacter jejuni oligosaccharyltransferase (OTase), and a suitable glycoprotein (AcrA) in a designer E. coli strain with a higher efficiency for production of glycoconjugates. We were able to produce and purify the OPS II-AcrA glycoconjugate, and MS analysis confirmed correct glycan was produced and attached. We observed the attachment of the O-acetylated deoxyhexose directly to the acceptor protein, which expands the range of substrates utilized by the OTase PglB. Injection of the glycoprotein into mice generated an IgG immune response against B. pseudomallei, and this response was partially protective against an intranasal challenge. Our experiments show that bacterial engineered glycoconjugates can be utilized as vaccine candidates against B. pseudomallei. Additionally, our new E. coli strain SDB1 is more efficient in glycoprotein production, and could have additional applications in the future. PMID:25120536

  2. Spectra of central nervous system melioidosis.

    PubMed

    Muthusamy, Kalai Arasu; Waran, Vicknes; Puthucheary, Savithri D

    2007-12-01

    Burkholderia pseudomallei infection of the central nervous system (CNS) is rare with less than 50 cases reported over the last 30 years. The retrospective melioidosis study at University Malaya Medical Centre has documented three cases of CNS melioidosis out of more than 160 cases of melioidosis since 1978. There were two patients with brain abscess and one with spinal epidural abscess. The predisposing factors were: one patient was an aboriginal farmer and the other two were diabetic. Their age ranged from 17 to 45 years. Prominent neurological features were limb weakness, cranial nerve palsy (6th and 7th) and visual disturbance. CT brain scan and MRI spine showed abscess formation, subdural collection, and spinal epidural collection, osteomyelitis of vertebra and occipital bone and also sagital sinus thrombosis. All these patients underwent surgical drainage leading to bacteriological diagnosis as well as appropriate long-term antibiotic therapy. All had good recovery at 6 months after completion of treatment. PMID:17964168

  3. Knock-out and pull-out recombineering protocols for naturally transformable Burkholderia thailandensis and Burkholderia pseudomallei

    PubMed Central

    Kang, Yun; Norris, Michael H.; Wilcox, Bruce A.; Tuanyok, Apichai; Keim, Paul S.; Hoang, Tung T.

    2013-01-01

    Summary 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 counter-selectable and selectable markers (sacB, pheS, gat, and the arabinose utilization operon) and ? Red mutant proteins. pheS-gat (KO) or oriT-ColE1ori-gat-ori1600-rep (PO) PCR fragments are generated with flanking 40–45 bp homologies to targeted regions incorporated on PCR primers. One-step recombination is achieved by incubating the PCR product with cells expressing ? Red proteins and subsequent selection on glyphosate-containing medium. This procedure takes approximately 10 days and is advantageous over previously published protocols: i) smaller PCR products reduce primer numbers and amplification steps, ii) PO fragments for downstream manipulation in E. coli, and iii) chromosomal KO increases flexibility for downstream processing. PMID:21738123

  4. Development of a Prototype Lateral Flow Immunoassay (LFI) for the Rapid Diagnosis of Melioidosis

    PubMed Central

    Houghton, Raymond L.; Reed, Dana E.; Hubbard, Mark A.; Dillon, Michael J.; Chen, Hongjing; Currie, Bart J.; Mayo, Mark; Sarovich, Derek S.; Theobald, Vanessa; Limmathurotsakul, Direk; Wongsuvan, Gumphol; Chantratita, Narisara; Peacock, Sharon J.; Hoffmaster, Alex R.; Duval, Brea; Brett, Paul J.; Burtnick, Mary N.; AuCoin, David P.

    2014-01-01

    Burkholderia pseudomallei is a soil-dwelling bacterium and the causative agent of melioidosis. Isolation of B. pseudomallei from clinical samples is the “gold standard” for the diagnosis of melioidosis; results can take 3–7 days to produce. Alternatively, antibody-based tests have low specificity due to a high percentage of seropositive individuals in endemic areas. There is a clear need to develop a rapid point-of-care antigen detection assay for the diagnosis of melioidosis. Previously, we employed In vivo Microbial Antigen Discovery (InMAD) to identify potential B. pseudomallei diagnostic biomarkers. The B. pseudomallei capsular polysaccharide (CPS) and numerous protein antigens were identified as potential candidates. Here, we describe the development of a diagnostic immunoassay based on the detection of CPS. Following production of a CPS-specific monoclonal antibody (mAb), an antigen-capture immunoassay was developed to determine the concentration of CPS within a panel of melioidosis patient serum and urine samples. The same mAb was used to produce a prototype Active Melioidosis Detect Lateral Flow Immunoassay (AMD LFI); the limit of detection of the LFI for CPS is comparable to the antigen-capture immunoassay (?0.2 ng/ml). The analytical reactivity (inclusivity) of the AMD LFI was 98.7% (76/77) when tested against a large panel of B. pseudomallei isolates. Analytical specificity (cross-reactivity) testing determined that 97.2% of B. pseudomallei near neighbor species (35/36) were not reactive. The non-reactive B. pseudomallei strain and the reactive near neighbor strain can be explained through genetic sequence analysis. Importantly, we show the AMD LFI is capable of detecting CPS in a variety of patient samples. The LFI is currently being evaluated in Thailand and Australia; the focus is to optimize and validate testing procedures on melioidosis patient samples prior to initiation of a large, multisite pre-clinical evaluation. PMID:24651568

  5. Delineating the Importance of Serum Opsonins and the Bacterial Capsule in Affecting the Uptake and Killing of Burkholderia pseudomallei by Murine Neutrophils and Macrophages

    PubMed Central

    Mulye, Minal; Bechill, Michael P.; Grose, William; Ferreira, Viviana P.; Lafontaine, Eric R.; Wooten, R. Mark

    2014-01-01

    Infection of susceptible hosts by the encapsulated Gram-negative bacterium Burkholderia pseudomallei (Bp) causes melioidosis, with septic patients attaining mortality rates ?40%. Due to its high infectivity through inhalation and limited effective therapies, Bp is considered a potential bioweapon. Thus, there is great interest in identifying immune effectors that effectively kill Bp. Our goal is to compare the relative abilities of murine macrophages and neutrophils to clear Bp, as well as determine the importance of serum opsonins and bacterial capsule. Our findings indicate that murine macrophages and neutrophils are inherently unable to clear either unopsonized Bp or the relatively-avirulent acapsular bacterium B. thailandensis (Bt). Opsonization of Bp and Bt with complement or pathogen-specific antibodies increases macrophage-uptake, but does not promote clearance, although antibody-binding enhances complement deposition. In contrast, complement opsonization of Bp and Bt causes enhanced uptake and killing by neutrophils, which is linked with rapid ROS induction against bacteria exhibiting a threshold level of complement deposition. Addition of bacteria-specific antibodies enhances complement deposition, but antibody-binding alone cannot elicit neutrophil clearance. Bp capsule provides some resistance to complement deposition, but is not anti-phagocytic or protective against reactive oxygen species (ROS)-killing. Macrophages were observed to efficiently clear Bp only after pre-activation with IFN?, which is independent of serum- and/or antibody-opsonization. These studies indicate that antibody-enhanced complement activation is sufficient for neutrophil-clearance of Bp, whereas macrophages are ineffective at clearing serum-opsonized Bp unless pre-activated with IFN?. This suggests that effective immune therapies would need to elicit both antibodies and Th1-adaptive responses for successful prevention/eradication of melioidosis. PMID:25144195

  6. The structure of a Burkholderia pseudomallei immunophilin–inhibitor complex reveals new approaches to antimicrobial development

    PubMed Central

    Norville, Isobel H.; O'Shea, Katherine; Sarkar-Tyson, Mitali; Zheng, Suxin; Titball, Richard W.; Varani, Gabriele; Harmer, Nicholas J.

    2014-01-01

    Mips (macrophage infectivity potentiators) are a subset of immunophilins associated with virulence in a range of micro-organisms. These proteins possess peptidylprolyl isomerase activity and are inhibited by drugs including rapamycin and tacrolimus. We determined the structure of the Mip homologue [BpML1 (Burkholderia pseudomallei Mip-like protein 1)] from the human pathogen and biowarfare threat B. pseudomallei by NMR and X-ray crystallography. The crystal structure suggests that key catalytic residues in the BpML1 active site have unexpected conformational flexibility consistent with a role in catalysis. The structure further revealed BpML1 binding to a helical peptide, in a manner resembling the physiological interaction of human TGF?RI (transforming growth factor ? receptor I) with the human immunophilin FKBP12 (FK506-binding protein 12). Furthermore, the structure of BpML1 bound to the class inhibitor cycloheximide N-ethylethanoate showed that this inhibitor mimics such a helical peptide, in contrast with the extended prolyl-peptide mimicking shown by inhibitors such as tacrolimus. We suggest that Mips, and potentially other bacterial immunophilins, participate in protein–protein interactions in addition to their peptidylprolyl isomerase activity, and that some roles of Mip proteins in virulence are independent of their peptidylprolyl isomerase activity. PMID:21574961

  7. The HicA toxin from Burkholderia pseudomallei has a role in persister cell formation.

    PubMed

    Butt, Aaron; Higman, Victoria A; Williams, Christopher; Crump, Matthew P; Hemsley, Claudia M; Harmer, Nicholas; Titball, Richard W

    2014-04-15

    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 depending on the level of induction of HicA expression. Deleting the hicAB locus from B. pseudomallei K96243 significantly reduced persister cell frequencies following exposure to ciprofloxacin, but not ceftazidime. The structure of HicA(H24A) was solved by NMR and forms a dsRBD-like (dsRNA-binding domain-like) fold, composed of a triple-stranded ?-sheet, with two helices packed against one face. The surface of the protein is highly positively charged indicative of an RNA-binding protein and His24 and Gly22 were functionality important residues. This is the first study demonstrating a role for the HicAB system in bacterial persistence and the first structure of a HicA protein that has been experimentally characterized. PMID:24502667

  8. Regulatory role of GSK3? in the activation of NF-?B and modulation of cytokine levels in Burkholderia pseudomallei-infected PBMC isolated from streptozotocin-induced diabetic animals.

    PubMed

    Maniam, P; Nurul Aiezzah, Z; Mohamed, R; Embi, N; Hasidah, M S

    2015-03-01

    Increased susceptibility of diabetics to melioidosis, a disease caused by the Burkholderia pseudomallei bacterium is believed to be attributed to dysfunction of the innate immune system. However, the underlying mechanism of the innate susceptibility is not well-understood. Glycogen synthase kinase-3? (GSK3?) plays an important role in the innate inflammatory response caused by bacterial pathogens. The present study was conducted to investigate the effects of GSK3? inhibition by LiCl on levels of pro- and anti-inflammatory cytokines; and the activity of transcription factor NF-?B in B. pseudomallei-infected peripheral blood mononuclear cells (PBMC) derived from diabetic-induced and normal Sprague Dawley rats. In addition, the effects of LiCl on intracellular bacterial counts were also investigated. Infection of PBMC from diabetic and normal rats with B. pseudomallei resulted in elevated levels of cytokines (TNF-?, IL-12 and IL-10) and phosphorylation of NF-?B in both cell types. Intracellular bacterial counts decreased with time in both cell types during infection. However bacterial clearance was less prominent in diabetic PBMC. Burkholderia pseudomallei infection also caused inactivation (Ser9 phosphorylation) of GSK3? in normal PBMC, an effect absent in infected diabetic PBMC. Inhibition of GSK3? by LiCl lowered the levels of pro-inflammatory cytokines (TNF-? and IL-12) in both normal and diabetic PBMC. Similarly, phosphorylated NF- ?B (pNF-?B) levels in both cell types were decreased with LiCl treatment. Also, LiCl was able to significantly decrease the intracellular bacterial count in normal as well as diabetic PBMC. Interestingly, the levels of anti-inflammatory cytokine IL-10 in both normal and diabetic PBMC were further elevated with GSK3? inhibition. More importantly, GSK3? in infected diabetic PBMC was inactivated as in their non-diabetic counterparts upon LiCl treatment. Taken together, our results suggest that inhibition of dysregulated GSK3? in diabetic PBMC resulted in the inactivation of NF-?B and modulation of inflammatory cytokine levels. This is evidence that dysregulation of GSK3? is a contributing factor in the molecular basis of innate dysfunction and susceptibility of diabetic host to melioidosis infection. PMID:25801253

  9. Novel Pan-Genomic Analysis Approach in Target Selection for Multiplex PCR Identification and Detection of Burkholderia pseudomallei, Burkholderia thailandensis, and Burkholderia cepacia Complex Species: a Proof-of-Concept Study?

    PubMed Central

    Ho, Chi-Chun; Lau, Candy C. Y.; Martelli, Paolo; Chan, San-Yuen; Tse, Cindy W. S.; Wu, Alan K. L.; Yuen, Kwok-Yung; Lau, Susanna K. P.; Woo, Patrick C. Y.

    2011-01-01

    Burkholderia pseudomallei, Burkholderia thailandensis, and the Burkholderia cepacia complex differ greatly in pathogenicity and epidemiology. Yet, they are occasionally misidentified by biochemical profiling, and even 16S rRNA gene sequencing may not offer adequate discrimination between certain species groups. Using the 23 B. pseudomallei, four B. thailandensis, and 16 B. cepacia complex genome sequences available, we identified gene targets specific to each of them (a Tat domain protein, a 70-kDa protein, and a 12-kDa protein for B. pseudomallei, B. thailandensis, and the B. cepacia complex, respectively), with an in-house developed algorithm. Using these targets, we designed a robust multiplex PCR assay useful for their identification and detection from soil and simulated sputum samples. For all 43 B. pseudomallei, seven B. thailandensis, and 20 B. cepacia complex (B. multivorans, n = 6; B. cenocepacia, n = 3; B. cepacia, n = 4; B. arboris, n = 2; B. contaminans, B. anthina, and B. pyrrocinia, n = 1 each; other unnamed members, n = 2) isolates, the assay produced specific products of predicted size without false positives or negatives. Of the 60 soil samples screened, 19 (31.6%) and 29 (48.3%) were positive for B. pseudomallei and the B. cepacia complex, respectively, and in four (6.7%) soil samples, the organisms were codetected. DNA sequencing confirmed that all PCR products originated from their targeted loci. This novel pan-genomic analysis approach in target selection is simple, computationally efficient, and potentially applicable to any species that harbors species-specific genes. A multiplex PCR assay for rapid and accurate identification and detection of B. pseudomallei, B. thailandensis, and the B. cepacia complex was developed and verified. PMID:21177905

  10. Multiple-antigen ELISA for melioidosis - a novel approach to the improved serodiagnosis of melioidosis

    PubMed Central

    2013-01-01

    Background Burkholderia pseudomallei, the causative agent of melioidosis, is endemic to Southeast Asia and northern Australia. Clinical manifestations of disease are diverse, ranging from chronic infection to acute septicaemia. The current gold standard of diagnosis involves bacterial culture and identification which is time consuming and often too late for early medical intervention. Hence, rapid diagnosis of melioidosis is crucial for the successful management of melioidosis. Methods The study evaluated 4 purified B. pseudomallei recombinant proteins (TssD-5, Omp3, smBpF4 and Omp85) as potential diagnostic agents for melioidosis. A total of 68 sera samples from Malaysian melioidosis patients were screened for the presence of specific antibodies towards these proteins using enzyme-linked immunosorbent assay (ELISA). Sera from patients with various bacterial and viral infections but negative for B. pseudomallei, as well as sera from healthy individuals, were also included as non-melioidosis controls. The Mann Whitney test was performed to compare the statistical differences between melioidosis patients and the non-melioidosis controls. Results TssD-5 demonstrated the highest sensitivity of 71% followed by Omp3 (59%), smBpF4 (41%) and Omp85 (19%). All 4 antigens showed equally high specificity (89-96%). A cocktail of all 4 antigens resulted in slightly reduced sensitivity of 65% but improved specificity (99%). Multiple-antigen ELISA provided improved sensitivity of 88.2% whilst retaining good specificity (96%). There was minimal reactivity with sera from healthy individuals proposing the utility of these antigens to demarcate diseased from non-symptomatic individuals in an endemic country. Conclusions TssD-5 demonstrated high detection sensitivity and specificity and the results were obtained within a few hours compared to time consuming culture and IFAT methods commonly used in a clinical setting. The use of multiple-antigens resulted in improved sensitivity (88.2%) whilst maintaining superior specificity. These data highlight the use of TssD-5 and other recombinant antigens tested in this study as potential serodiagnostic agents for melioidosis. PMID:23556548

  11. Fatal acute melioidosis in a tourist returning from Martinique Island, November 2010.

    PubMed

    Gétaz, L; Abbas, M; Loutan, L; Schrenzel, J; Iten, A; Simon, F; Decosterd, A; Studer, R; Sudre, P; Michel, Y; Merlani, P; Emonet, S

    2011-01-01

    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 septicaemia should consider the possibility of acute melioidosis. PMID:21223835

  12. Diversity of 16S-23S rDNA Internal Transcribed Spacer (ITS) Reveals Phylogenetic Relationships in Burkholderia pseudomallei and Its Near-Neighbors

    PubMed Central

    Liguori, Andrew P.; Warrington, Stephanie D.; Ginther, Jennifer L.; Pearson, Talima; Bowers, Jolene; Glass, Mindy B.; Mayo, Mark; Wuthiekanun, Vanaporn; Engelthaler, David; Peacock, Sharon J.; Currie, Bart J.; Wagner, David M.; Keim, Paul; Tuanyok, Apichai

    2011-01-01

    Length polymorphisms within the 16S-23S ribosomal DNA internal transcribed spacer (ITS) have been described as stable genetic markers for studying bacterial phylogenetics. In this study, we used these genetic markers to investigate phylogenetic relationships in Burkholderia pseudomallei and its near-relative species. B. pseudomallei is known as one of the most genetically recombined bacterial species. In silico analysis of multiple B. pseudomallei genomes revealed approximately four homologous rRNA operons and ITS length polymorphisms therein. We characterized ITS distribution using PCR and analyzed via a high-throughput capillary electrophoresis in 1,191 B. pseudomallei strains. Three major ITS types were identified, two of which were commonly found in most B. pseudomallei strains from the endemic areas, whereas the third one was significantly correlated with worldwide sporadic strains. Interestingly, mixtures of the two common ITS types were observed within the same strains, and at a greater incidence in Thailand than Australia suggesting that genetic recombination causes the ITS variation within species, with greater recombination frequency in Thailand. In addition, the B. mallei ITS type was common to B. pseudomallei, providing further support that B. mallei is a clone of B. pseudomallei. Other B. pseudomallei near-neighbors possessed unique and monomorphic ITS types. Our data shed light on evolutionary patterns of B. pseudomallei and its near relative species. PMID:22195045

  13. The coagulation system in melioidosis: from pathogenesis to new treatment strategies.

    PubMed

    Kager, Liesbeth Martine; van der Poll, Tom; Wiersinga, Willem Joost

    2014-08-01

    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-protective. In particular, a procoagulant state together with downregulation of anticoagulant pathways and activation of fibrinolysis are present, all closely interrelated with parameters of inflammation. This review presents an overview of recent studies in which the role of coagulation, anti-coagulation and fibrinolysis during melioidosis was investigated both in patients and in experimental settings. PMID:24962103

  14. Acute melioidosis outbreak in Western Australia.

    PubMed Central

    Inglis, T. J.; Garrow, S. C.; Adams, C.; Henderson, M.; Mayo, M.; Currie, B. J.

    1999-01-01

    A cluster of acute melioidosis cases occurred in a remote, coastal community in tropical Western Australia. Molecular typing of Burkholderia pseudomallei isolates from culture-confirmed cases and suspected environmental sources by pulsed-field gel electrophoresis (PFGE) of XbaI chromosomal DNA digests showed that a single PFGE type was responsible for five cases of acute infection in a community of around 300 during a 5 week period. This temporal and geographical clustering of acute melioidosis cases provided a unique opportunity to investigate the environmental factors contributing to this disease. B. pseudomallei isolated from a domestic tap at the home of an asymptomatic seroconverter was indistinguishable by PFGE. Possible contributing environmental factors included an unusually acid communal water supply, unrecordable chlorine levels during the probable exposure period, a nearby earth tremor, and gusting winds during the installation of new water and electricity supplies. The possible role of the potable water supply as a source of B. pseudomallei was investigated further. PMID:10694154

  15. Melioidosis: Epidemiology, Pathophysiology, and Management

    PubMed Central

    Cheng, Allen C.; Currie, Bart J.

    2005-01-01

    Melioidosis, caused by the gram-negative saprophyte Burkholderia pseudomallei, is a disease of public health importance in southeast Asia and northern Australia that is associated with high case-fatality rates in animals and humans. It has the potential for epidemic spread to areas where it is not endemic, and sporadic case reports elsewhere in the world suggest that as-yet-unrecognized foci of infection may exist. Environmental determinants of this infection, apart from a close association with rainfall, are yet to be elucidated. The sequencing of the genome of a strain of B. pseudomallei has recently been completed and will help in the further identification of virulence factors. The presence of specific risk factors for infection, such as diabetes, suggests that functional neutrophil defects are important in the pathogenesis of melioidosis; other studies have defined virulence factors (including a type III secretion system) that allow evasion of killing mechanisms by phagocytes. There is a possible role for cell-mediated immunity, but repeated environmental exposure does not elicit protective humoral or cellular immunity. A vaccine is under development, but economic constraints may make vaccination an unrealistic option for many regions of endemicity. Disease manifestations are protean, and no inexpensive, practical, and accurate rapid diagnostic tests are commercially available; diagnosis relies on culture of the organism. Despite the introduction of ceftazidime- and carbapenem-based intravenous treatments, melioidosis is still associated with a significant mortality attributable to severe sepsis and its complications. A long course of oral eradication therapy is required to prevent relapse. Studies exploring the role of preventative measures, earlier clinical identification, and better management of severe sepsis are required to reduce the burden of this disease. PMID:15831829

  16. Natural Infection of Burkholderia pseudomallei in an Imported Pigtail Macaque (Macaca nemestrina) and Management of the Exposed Colony

    PubMed Central

    Johnson, Crystal H; Skinner, Brianna L; Dietz, Sharon M; Blaney, David; Engel, Robyn M; Lathrop, George W; Hoffmaster, Alex R; Gee, Jay E; Elrod, Mindy G; Powell, Nathaniel; Walke, Henry

    2013-01-01

    Identification of the select agent Burkholderia pseudomallei in macaques imported into the United States is rare. A purpose-bred, 4.5-y-old pigtail macaque (Macaca nemestrina) imported from Southeast Asia was received from a commercial vendor at our facility in March 2012. After the initial acclimation period of 5 to 7 d, physical examination of the macaque revealed a subcutaneous abscess that surrounded the right stifle joint. The wound was treated and resolved over 3 mo. In August 2012, 2 mo after the stifle joint wound resolved, the macaque exhibited neurologic clinical signs. Postmortem microbiologic analysis revealed that the macaque was infected with B. pseudomallei. This case report describes the clinical evaluation of a B. pseudomallei-infected macaque, management and care of the potentially exposed colony of animals, and protocols established for the animal care staff that worked with the infected macaque and potentially exposed colony. This article also provides relevant information on addressing matters related to regulatory issues and risk management of potentially exposed animals and animal care staff. PMID:24326230

  17. 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

    PubMed Central

    Su, Shengchang; Bangar, Hansraj; Saldanha, Roland; Pemberton, Adin; Aronow, Bruce; Dean, Gary E; Lamkin, Thomas J; Hassett, Daniel J

    2014-01-01

    Here, we constructed stable, chromosomal, constitutively expressed, green and red fluorescent protein (GFP and RFP) as reporters in the select agents, Bacillus anthracis, Yersinia pestis, Burkholderia mallei, and Burkholderia pseudomallei. Using bioinformatic approaches and other experimental analyses, we identified P0253 and P1 as potent promoters that drive the optimal expression of fluorescent reporters in single copy in B. anthracis and Burkholderia spp. as well as their surrogate strains, respectively. In comparison, Y. pestis and its surrogate strain need two chromosomal copies of cysZK promoter (P2cysZK) for optimal fluorescence. The P0253-, P2cysZK-, and P1-driven GFP and RFP fusions were first cloned into the vectors pRP1028, pUC18R6KT-mini-Tn7T-Km, pmini-Tn7-gat, or their derivatives. The resultant constructs were delivered into the respective surrogates and subsequently into the select agent strains. The chromosomal GFP- and RFP-tagged strains exhibited bright fluorescence at an exposure time of less than 200 msec and displayed the same virulence traits as their wild-type parental strains. The utility of the tagged strains was proven by the macrophage infection assays and lactate dehydrogenase release analysis. Such strains will be extremely useful in high-throughput screens for novel compounds that could either kill these organisms, or interfere with critical virulence processes in these important bioweapon agents and during infection of alveolar macrophages. PMID:25044501

  18. Development and Characterization of a Caprine Aerosol Infection Model of Melioidosis

    PubMed Central

    Soffler, Carl; Bosco-Lauth, Angela M.; Aboellail, Tawfik A.; Marolf, Angela J.; Bowen, Richard A.

    2012-01-01

    Infection with Burkholderia pseudomallei causes the disease melioidosis, which often presents as a serious suppurative infection that is typically fatal without intensive treatment and is a significant emerging infectious disease in Southeast Asia. Despite intensive research there is still much that remains unknown about melioidosis pathogenesis. New animal models of melioidosis are needed to examine novel aspects of pathogenesis as well as for the evaluation of novel therapeutics. The objective of the work presented here was to develop a subacute to chronic caprine model of melioidosis and to characterize the progression of disease with respect to clinical presentation, hematology, clinical microbiology, thoracic radiography, and gross and microscopic pathology. Disease was produced in all animals following an intratracheal aerosol of 104 CFU delivered, with variable clinical manifestations indicative of subacute and chronic disease. Bronchointerstitial pneumonia was apparent microscopically by day 2 and radiographically and grossly apparent by day 7 post infection (PI). Early lesions of bronchopneumonia soon progressed to more severe bronchointerstitial pneumonia with pyogranuloma formation. Extrapulmonary dissemination appeared to be a function of pyogranuloma invasion of pulmonary vasculature, which peaked around day 7 PI. Histopathology indicated that leukocytoclastic vasculitis was the central step in dissemination of B. pseudomallei from the lungs as well as in the establishment of new lesions. While higher doses of organism in goats can produce acute fatal disease, the dose investigated and resulting disease had many similarities to human melioidosis and may warrant further development to provide a model for the study of both natural and bioterrorism associated disease. PMID:22916225

  19. Interaction of Interferon Gamma-Induced Reactive Oxygen Species with Ceftazidime Leads to Synergistic Killing of Intracellular Burkholderia pseudomallei

    PubMed Central

    Mosovsky, Kara; Silva, Ediane; Troyer, Ryan; Propst-Graham, Katie

    2014-01-01

    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-?) 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-?- and ceftazidime-mediated killing, which led to our hypothesis that IFN-?-induced ROS interacted with ceftazidime to synergistically kill Burkholderia bacteria. Consistent with this hypothesis, we also observed that buthionine sulfoximine (BSO), another inducer of ROS, could substitute for IFN-? to similarly potentiate the effect of ceftazidime on intracellular killing. Next, we observed that IFN-? induced ROS-mediated killing of intracellular but not extracellular bacteria. On the other hand, ceftazidime effectively reduced extracellular bacteria but was not capable of intracellular killing when applied at 10 ?g/ml. We investigated the exact role of IFN-?-induced ROS responses on intracellular bacteria and notably observed a lack of actin polymerization associated with Burkholderia bacteria in IFN-?-treated macrophages, which led to our finding that IFN-?-induced ROS blocks vacuolar escape. Based on these results, we propose a model in which synergistically reduced bacterial burden is achieved primarily through separate and compartmentalized killing: intracellular killing by IFN-?-induced ROS responses and extracellular killing by ceftazidime. Our findings suggest a means of enhancing antibiotic activity against Burkholderia bacteria through combination with drugs that induce ROS pathways or otherwise target intracellular spread and/or replication of bacteria. PMID:25070108

  20. Structural characterization of Burkholderia pseudomallei adenylate kinase (Adk): Profound asymmetry in the crystal structure of the ‘open’ state

    PubMed Central

    Buchko, Garry W.; Robinson, Howard; Abendroth, Jan; Staker, Bart L.; Myler, Peter J.

    2010-01-01

    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 drugs therapies against infectious bacterial agents. Here we report the 2.1 Å resolution crystal structure for the 220-residue Adk from Burkholderia pseudomallei (BpAdk), the etiological agent responsible for the infectious disease meliodosis. The general structure of apo BpAdk is similar to other Adk structures, composed of a CORE subdomain with peripheral ATP-binding (ATPbd) and LID subdomains. The two molecules in the asymmetric unit have significantly different conformations, with a backbone RMSD of 1.46 Å. These two BpAdk conformations may represent ‘open’ Adk sub-states along the preferential pathway to the ‘closed’ substrate-bound state. PMID:20331978

  1. Consensus on the Development of Vaccines against Naturally Acquired Melioidosis

    PubMed Central

    Funnell, Simon G.P.; Torres, Alfredo G.; Morici, Lisa A.; Brett, Paul J.; Dunachie, Susanna; Atkins, Timothy; Altmann, Daniel M.; Bancroft, Gregory; Peacock, Sharon J.

    2015-01-01

    Several candidates for a vaccine against Burkholderia pseudomallei, the causal bacterium of melioidosis, have been developed, and a rational approach is now needed to select and advance candidates for testing in relevant nonhuman primate models and in human clinical trials. Development of such a vaccine was the topic of a meeting in the United Kingdom in March 2014 attended by international candidate vaccine developers, researchers, and government health officials. The focus of the meeting was advancement of vaccines for prevention of natural infection, rather than for protection from the organism’s known potential for use as a biological weapon. A direct comparison of candidate vaccines in well-characterized mouse models was proposed. Knowledge gaps requiring further research were identified. Recommendations were made to accelerate the development of an effective vaccine against melioidosis. PMID:25992835

  2. The Type VI Secretion System Spike Protein VgrG5 Mediates Membrane Fusion during Intercellular Spread by Pseudomallei Group Burkholderia Species

    PubMed Central

    Toesca, Isabelle J.; French, Christopher T.

    2014-01-01

    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 B. thailandensis. We also demonstrate that the integrity of the VgrG5 C-terminal domain is required for fusogenic activity, and we identify sequence motifs, including two hydrophobic segments, that are important for fusion. Mutagenesis and secretion experiments using B. pseudomallei strains engineered to express T6SS-5 in vitro show that the VgrG5 C-terminal domain is dispensable for T6SS-mediated secretion of Hcp5, demonstrating that the ability of VgrG5 to mediate membrane fusion can be uncoupled from its essential role in type VI secretion. We propose a model in which a unique fusogenic activity at the C terminus of VgrG5 facilitates intercellular spread by B. pseudomallei and related species following injection across the plasma membranes of infected cells. PMID:24421040

  3. The role of short-chain dehydrogenase/oxidoreductase, induced by salt stress, on host interaction of B. pseudomallei

    PubMed Central

    2014-01-01

    Background 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 interactions between B. pseudomallei and host cells. Results Bioinformatics analysis of B. pseudomallei SDO structure, based on homology modeling, revealed a NAD+ cofactor domain and a catalytic triad containing Ser149, Tyr162, and Lys166. This is similar to Bacillus megaterium glucose 1-dehydrogenase. To investigate the role of this protein, we constructed a B. pseudomallei SDO defective mutant, measured glucose dehydrogenase (GDH) activity, and tested the interactions with host cells. The B. pseudomallei K96243 wild type exhibited potent GDH activity under condition containing 300 mM NaCl, while the mutant showed activity levels 15 times lower. Both invasion into the A549 cell line and early intracellular survival within the J774A.1 macrophage cell were impaired in the mutant. Complementation of SDO was able to restore the mutant ability to produce GDH activity, invade epithelial cells, and survive in macrophages. Conclusions Our data suggest that induced SDO activity during salt stress may facilitate B. pseudomallei invasion and affect initiation of successful intracellular infection. Identifying the role of B. pseudomallei SDO provides a better understanding of the association between bacterial adaptation and pathogenesis in melioidosis. PMID:24382268

  4. Treatment and prophylaxis of melioidosis.

    PubMed

    Dance, David

    2014-04-01

    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 given, usually to complete a total of 20 weeks, with the aim of preventing relapse. Specific treatment for individual patients needs to be tailored according to clinical manifestations and response, and there remain many unanswered questions. Some patients with very mild infections can probably be cured by oral agents alone. Ceftazidime is the mainstay of acute-phase treatment, with carbapenems reserved for severe infections or treatment failures and amoxicillin/clavulanic acid (co-amoxiclav) as second-line therapy. Trimethoprim/sulfamethoxazole (co-trimoxazole) is preferred for the eradication phase, with the alternative of co-amoxiclav. In addition, the best available supportive care is needed, along with drainage of abscesses whenever possible. Treatment for melioidosis is unaffordable for many in endemic areas of the developing world, but the relative costs have reduced over the past decade. Unfortunately there is no likelihood of any new or cheaper options becoming available in the immediate future. Recommendations for prophylaxis following exposure to B. pseudomallei have been made, but the evidence suggests that they would probably only delay rather than prevent the development of infection. PMID:24613038

  5. Surface plasmon resonance immunosensor for rapid and specific diagnosis of melioidosis antibody.

    PubMed

    Dawan, Supaporn; Kanatharana, Proespichaya; Chotigeat, Wilaiwan; Jitsurong, Siroj; Thavarungkul, Panote

    2011-09-01

    Melioidosis, caused by Burkholderia pseudomallei, is a potentially fatal disease, which requires an accurate and rapid diagnosis. This paper reports on the highly sensitive and specific detection of melioidosis antibodies by surface plasmon resonance immunosensor. The sensing surface was immobilized with B. pseudomallei BipD protein via a 11-mercaptoundecanoic acid self-assembled monolayer. Under optimum conditions individual sera of melioidosis patients, non-melioidosis patients (negative) and blood donors (control) were analyzed at a dilution of 1:6,000 in 10 mM phosphate buffered saline pH 7.50. The cut-off value determined from the mean +/- 2SD of 20 control and 20 negative sera was 3.3 m degrees. At this cut-off both sensitivity and specificity were 100%. The system required only a short analysis (20 minutes) and regeneration time (12 minutes). In addition, one immobilization of the sensing surface could be reused more than 30 times. The advantages of the proposed method are savings in both time and cost of analysis, while at the same time providing excellent sensitivity and specificity. PMID:22299443

  6. Characterization of a Murine Model of Melioidosis: Comparison of Different Strains of Mice

    PubMed Central

    Hoppe, I.; Brenneke, B.; Rohde, M.; Kreft, A.; Häußler, S.; Reganzerowski, A.; Steinmetz, I.

    1999-01-01

    Melioidosis is an infectious disease caused by the saprophytic gram-negative rod Burkholderia pseudomallei. The aim of this study was to establish and characterize a murine model of melioidosis to provide a basis for further investigations on the pathogenesis of the disease. After intravenous infection with B. pseudomallei, C57BL/6 mice were found to be significantly more resistant than BALB/c mice. There was a marked organotropism of B. pseudomallei for the spleen and liver in both strains of mice, with the highest bacterial load in the spleen. Electron microscopic investigations of the spleen clearly demonstrated intracellular replication within membrane-bound phagosomes. Electron micrographs of the liver provided evidence that B. pseudomallei-containing phagosomes in hepatocytes fuse with lysosomes, leading to degradation of bacteria. In both strains of mice, the course of infection was highly dependent on the infective dose and the bacterial strain used, ranging from death within a few days to death after several weeks. In comparison with BALB/c mice, the bacterial counts in C57BL/6 mice were decreased 12 h after infection, which is suggestive of an innate immune mechanism against B. pseudomallei in this early phase of infection contributing to the lower susceptibility of C57BL/6 mice. BALB/c mice developed a more pronounced lymphopenia, granulocytosis, and splenomegaly at a lower infective dose compared to C57BL/6 mice. Analysis of the antibody response against B. pseudomallei 11 days after infection revealed a significantly higher immunoglobulin G2A (IgG2a)/IgG1 ratio in C57BL/6 mice than in BALB/c mice, indicating that a T helper type 1 immune response is associated with resistance to infection with B. pseudomallei. PMID:10338496

  7. Comparative experimental subcutaneous glanders and melioidosis in the common marmoset (Callithrix jacchus).

    PubMed

    Nelson, Michelle; Salguero, Francisco J; Dean, Rachel E; Ngugi, Sarah A; Smither, Sophie J; Atkins, Timothy P; Lever, Mark S

    2014-12-01

    Glanders and melioidosis are caused by two distinct Burkholderia species and have generally been considered to have similar disease progression. While both of these pathogens are HHS/CDC Tier 1 agents, natural infection with both these pathogens is primarily through skin inoculation. The common marmoset (Callithrix jacchus) was used to compare disease following experimental subcutaneous challenge. Acute, lethal disease was observed in marmosets following challenge with between 26 and 1.2 × 10(8) cfu Burkholderia pseudomallei within 22-85 h. The reproducibility and progression of the disease were assessed following a challenge of 1 × 10(2) cfu of B. pseudomallei. Melioidosis was characterised by high levels of bacteraemia, focal microgranuloma progressing to non-necrotic multifocal solid lesions in the livers and spleens and multi-organ failure. Lethal disease was observed in 93% of animals challenged with Burkholderia mallei, occurring between 5 and 10.6 days. Following challenge with 1 × 10(2) cfu of B. mallei, glanders was characterised with lymphatic spread of the bacteria and non-necrotic, multifocal solid lesions progressing to a multifocal lesion with severe necrosis and pneumonia. The experimental results confirmed that the disease pathology and presentation is strikingly different between the two pathogens. The marmoset provides a model of the human syndrome for both diseases facilitating the development of medical countermeasures. PMID:25477002

  8. Efficient Inactivation of Burkholderia pseudomallei or Francisella tularensis in infected Cells for Safe Removal from Biosafety Level 3 Containment Laboratories

    PubMed Central

    Emery, Felicia D.; Stabenow, Jennifer M.; Miller, Mark A.

    2014-01-01

    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 labs for these types of studies is necessary, and methods for complete and dependable inactivation of the samples are required. In this report we have done a thorough characterization of the effectiveness of paraformaldehyde fixation for inactivation of cell samples infected with the intracellular bacterial agents Burkholderia pseudomallei (Bp) and Francisella tularensis (Ft), both of which are Tier 1 select agent pathogens that require BSL-3 containment. We have demonstrated that cells infected with these pathogens are completely inactivated via 5-minute treatment with 4% paraformaldehyde. Moreover, a 15-minute treatment with 2% paraformaldehyde completely sterilized both Bp- and Ft-infected cells. These studies also revealed that Bp is significantly more sensitive to paraformaldehyde treatment than Ft. Our findings have clearly demonstrated that a 15-minute treatment of Bp- or Ft-infected cells with 4% paraformaldehyde solution will allow for safe removal of the cell samples from BSL-3 labs for downstream studies. PMID:24449562

  9. Redefining the PF06864 Pfam Family Based on Burkholderia pseudomallei PilO2Bp S-SAD Crystal Structure

    PubMed Central

    Manjasetty, Babu A.; Yero, Daniel; Perletti, Lucia; Belrhali, Hassan; Daura, Xavier; Gourlay, Louise J.; Bolognesi, Martino

    2014-01-01

    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 PilO2Bp, a protein component of the Tfpb R64 thin pilus variant assembly machinery from the pathogen Burkholderia pseudomallei. PilO2Bp belongs to the PF06864 Pfam family, for which an improved definition is presented based on newly derived Hidden Markov Model (HMM) profiles. The 3D structure of the N-terminal domain of PilO2Bp (N-PilO2Bp), here reported, is the first structural representative of the PF06864 family. N-PilO2Bp presents an actin-like ATPase fold that is shown to be present in BfpC, a different variant assembly protein; the new HMM profiles classify BfpC as a PF06864 member. Our results provide structural insight into the PF06864 family and on the Type IV pili assembly machinery. PMID:24728008

  10. Molecular Investigations of a Locally Acquired Case of Melioidosis in Southern AZ, USA

    PubMed Central

    Engelthaler, David M.; Bowers, Jolene; Schupp, James A.; Pearson, Talima; Ginther, Jennifer; Hornstra, Heidie M.; Dale, Julia; Stewart, Tasha; Sunenshine, Rebecca; Waddell, Victor; Levy, Craig; Gillece, John; Price, Lance B.; Contente, Tania; Beckstrom-Sternberg, Stephen M.; Blaney, David D.; Wagner, David M.; Mayo, Mark; Currie, Bart J.; Keim, Paul; Tuanyok, Apichai

    2011-01-01

    Melioidosis is caused by Burkholderia pseudomallei, a Gram-negative bacillus, primarily found in soils in Southeast Asia and northern Australia. A recent case of melioidosis in non-endemic Arizona was determined to be the result of locally acquired infection, as the patient had no travel history to endemic regions and no previous history of disease. Diagnosis of the case was confirmed through multiple microbiologic and molecular techniques. To enhance the epidemiological analysis, we conducted several molecular genotyping procedures, including multi-locus sequence typing, SNP-profiling, and whole genome sequence typing. Each technique has different molecular epidemiologic advantages, all of which provided evidence that the infecting strain was most similar to those found in Southeast Asia, possibly originating in, or around, Malaysia. Advancements in new typing technologies provide genotyping resolution not previously available to public health investigators, allowing for more accurate source identification. PMID:22028940

  11. A non-invasive intratracheal inoculation method for the study of pulmonary melioidosis

    PubMed Central

    Revelli, David A.; Boylan, Julie A.; Gherardini, Frank C.

    2012-01-01

    Pulmonary melioidosis, a disease manifestation caused by the bacterium Burkholderia pseudomallei, has been studied using aerosols or intranasal (IN) inoculation in small animal models. Both have inherent disadvantages which may not accurately model primary pulmonary melioidosis in humans. Intratracheal inoculation (IT) by direct visualization of the tracheal opening offers an alternative technique for infection that overcomes the disadvantages of aerosol and IN challenge. In this study, we describe a method which requires relatively inexpensive equipment, little training, and is compliant with the operational constraints of a BSL3 laboratory. Results obtained using trypan blue demonstrated that an inoculum can be accurately delivered into the lungs of mice within a biosafety cabinet (BSC). Whole body imaging and histopathology confirmed that mice inoculated intratracheally with B. pseudomallei develop the primary focus of infection in the lungs, and not the nasal passages which can lead to invasion of the central nervous system and potential neurologic complications. Further, based on colony counts and bioluminescent imaging, dissemination to secondary organs occurred as expected. Taken together, this intratracheal method of inoculation fulfills four goals: (1) to accurately deliver B. pseudomallei into the lungs of the animal model, (2) to avoid potentially confounding complications due to primary infections at sites other than the lung, (3) to maintain normal organ dissemination, and (4) to be BSL3 compliant. PMID:23267442

  12. Protection against experimental melioidosis following immunisation with a lipopolysaccharide-protein conjugate.

    PubMed

    Scott, Andrew E; Ngugi, Sarah A; Laws, Thomas R; Corser, David; Lonsdale, Claire L; D'Elia, Riccardo V; Titball, Richard W; Williamson, E Diane; Atkins, Timothy P; Prior, Joann L

    2014-01-01

    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 and afforded significant protection against a lethal challenge with B. pseudomallei. The conjugate generated significantly higher levels of antigen-specific IgG1 and IgG2a than in lipopolysaccharide-immunised mice. Immunisation with the conjugate also demonstrated a bias towards Th1 type responses, evidenced by high levels of IgG2a. In contrast, immunisation with unconjugated lipopolysaccharide evoked almost no IgG2a demonstrating a bias towards Th2 type responses. This study demonstrates the effectiveness of this approach in the development of an efficacious and protective vaccine against melioidosis. PMID:24892035

  13. Spectroscopic and kinetic investigation of the reactions of peroxyacetic acid with Burkholderia pseudomallei catalase-peroxidase, KatG.

    PubMed

    Ivancich, Anabella; Donald, Lynda J; Villanueva, Jacylyn; Wiseman, Ben; Fita, Ignacio; Loewen, Peter C

    2013-10-15

    Catalase-peroxidases or KatGs can utilize organic peroxyacids and peroxides instead of hydrogen peroxide to generate the high-valent ferryl-oxo intermediates involved in the catalase and peroxidase reactions. In the absence of peroxidatic one-electron donors, the ferryl intermediates generated with a low excess (10-fold) of peroxyacetic acid (PAA) slowly decay to the ferric resting state after several minutes, a reaction that is demonstrated in this work by both stopped-flow UV-vis absorption measurements and EPR spectroscopic characterization of Burkholderia pseudomallei KatG (BpKatG). EPR spectroscopy showed that the [Fe(IV)?O Trp330(•+)], [Fe(IV)?O Trp139(•)], and [Fe(IV)?O Trp153(•)] intermediates of the peroxidase-like cycle of BpKatG ( Colin, J. Wiseman, B. Switala, J. Loewen, P. C. Ivancich, A. ( 2009 ) J. Am. Chem. Soc. 131 , 8557 - 8563 ), formed with a low excess of PAA at low temperature, are also generated with a high excess (1000-fold) of PAA at room temperature. However, under high excess conditions, there is a rapid conversion to a persistent [Fe(IV)?O] intermediate. Analysis of tryptic peptides of BpKatG by mass spectrometry before and after treatment with PAA showed that specific tryptophan (including W330, W139, and W153), methionine (including Met264 of the M-Y-W adduct), and cysteine residues are either modified with one, two, or three oxygen atoms or could not be identified in the spectrum because of other undetermined modifications. It was concluded that these oxidized residues were the source of electrons used to reduce the excess of PAA to acetic acid and return the enzyme to the ferric state. Treatment of BpKatG with PAA also caused a loss of catalase activity towards certain substrates, consistent with oxidative disruption of the M-Y-W adduct, and a loss of peroxidase activity, consistent with accumulation of the [Fe(IV)?O] intermediate and the oxidative modification of the W330, W139, and W153. PAA, but not H2O2 or tert-butyl hydroperoxide, also caused subunit cross-linking. PMID:24044787

  14. Glyphosate Resistance as a Novel Select-Agent-Compliant, Non-Antibiotic-Selectable Marker in Chromosomal Mutagenesis of the Essential Genes asd and dapB of Burkholderia pseudomallei?

    PubMed Central

    Norris, Michael H.; Kang, Yun; Lu, Diana; Wilcox, Bruce A.; Hoang, Tung T.

    2009-01-01

    Genetic manipulation of the category B select agents Burkholderia pseudomallei and Burkholderia mallei has been stifled due to the lack of compliant selectable markers. Hence, there is a need for additional select-agent-compliant selectable markers. We engineered a selectable marker based on the gat gene (encoding glyphosate acetyltransferase), which confers resistance to the common herbicide glyphosate (GS). To show the ability of GS to inhibit bacterial growth, we determined the effective concentrations of GS against Escherichia coli and several Burkholderia species. Plasmids based on gat, flanked by unique flip recombination target (FRT) sequences, were constructed for allelic-replacement. Both allelic-replacement approaches, one using the counterselectable marker pheS and the gat-FRT cassette and one using the DNA incubation method with the gat-FRT cassette, were successfully utilized to create deletions in the asd and dapB genes of wild-type B. pseudomallei strains. The asd and dapB genes encode an aspartate-semialdehyde dehydrogenase (BPSS1704, chromosome 2) and dihydrodipicolinate reductase (BPSL2941, chromosome 1), respectively. Mutants unable to grow on media without diaminopimelate (DAP) and other amino acids of this pathway were PCR verified. These mutants displayed cellular morphologies consistent with the inability to cross-link peptidoglycan in the absence of DAP. The B. pseudomallei 1026b ?asd::gat-FRT mutant was complemented with the B. pseudomallei asd gene on a site-specific transposon, mini-Tn7-bar, by selecting for the bar gene (encoding bialaphos/PPT resistance) with PPT. We conclude that the gat gene is one of very few appropriate, effective, and beneficial compliant markers available for Burkholderia select-agent species. Together with the bar gene, the gat cassette will facilitate various genetic manipulations of Burkholderia select-agent species. PMID:19648360

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

    PubMed Central

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

    2012-01-01

    bpsl0128, a gene encoding a putative response regulator from Burkholderia pseudomallei strain D286, has been cloned into a pETBLUE-1 vector system, overexpressed in Escherichia coli and purified. The full-length protein is degraded during purification to leave a fragment corresponding to the putative receiver domain, and crystals of this protein that diffracted to beyond 1.75?Å resolution have been grown by the hanging-drop vapour-diffusion technique using PEG 6000 as the precipitant. The crystals belonged to one of the enantiomorphic pair of space groups P3121 and P3221, with unit-cell parameters a = b = 65.69, c = 105.01?Å and either one or two molecules in the asymmetric unit. PMID:22869122

  16. Melioidosis Vaccines: A Systematic Review and Appraisal of the Potential to Exploit Biodefense Vaccines for Public Health Purposes

    PubMed Central

    Lubell, Yoel; Koh, Gavin C. K. W.; White, Lisa J.; Day, Nicholas P. J.; Titball, Richard W.

    2012-01-01

    Background Burkholderia pseudomallei is a Category B select agent and the cause of melioidosis. Research funding for vaccine development has largely considered protection within the biothreat context, but the resulting vaccines could be applicable to populations who are at risk of naturally acquired melioidosis. Here, we discuss target populations for vaccination, consider the cost-benefit of different vaccination strategies and review potential vaccine candidates. Methods and Findings Melioidosis is highly endemic in Thailand and northern Australia, where a biodefense vaccine might be adopted for public health purposes. A cost-effectiveness analysis model was developed, which showed that a vaccine could be a cost-effective intervention in Thailand, particularly if used in high-risk populations such as diabetics. Cost-effectiveness was observed in a model in which only partial immunity was assumed. The review systematically summarized all melioidosis vaccine candidates and studies in animal models that had evaluated their protectiveness. Possible candidates included live attenuated, whole cell killed, sub-unit, plasmid DNA and dendritic cell vaccines. Live attenuated vaccines were not considered favorably because of possible reversion to virulence and hypothetical risk of latent infection, while the other candidates need further development and evaluation. Melioidosis is acquired by skin inoculation, inhalation and ingestion, but routes of animal inoculation in most published studies to date do not reflect all of this. We found a lack of studies using diabetic models, which will be central to any evaluation of a melioidosis vaccine for natural infection since diabetes is the most important risk factor. Conclusion Vaccines could represent one strand of a public health initiative to reduce the global incidence of melioidosis. PMID:22303489

  17. Influence of the molybdenum cofactor biosynthesis on anaerobic respiration, biofilm formation and motility in Burkholderia thailandensis.

    PubMed

    Andreae, Clio A; Titball, Richard W; Butler, Clive S

    2014-01-01

    Burkholderia thailandensis is closely related to Burkholderia pseudomallei, a bacterial pathogen and the causative agent of melioidosis. B. pseudomallei can survive and persist within a hypoxic environment for up to one year and has been shown to grow anaerobically in the presence of nitrate. Currently, little is known about the role of anaerobic respiration in pathogenesis of melioidosis. Using B. thailandensis as a model, a library of 1344 transposon mutants was created to identify genes required for anaerobic nitrate respiration. One transposon mutant (CA01) was identified with an insertion in BTH_I1704 (moeA), a gene required for the molybdopterin biosynthetic pathway. This pathway is involved in the synthesis of a molybdopterin cofactor required for a variety of molybdoenzymes, including nitrate reductase. Disruption of molybdopterin biosynthesis prevented growth under anaerobic conditions, when using nitrate as the sole terminal electron acceptor. Defects in anaerobic respiration, nitrate reduction, motility and biofilm formation were observed for CA01. Mutant complementation with pDA-17:BTH_I1704 was able to restore anaerobic growth on nitrate, nitrate reductase activity and biofilm formation, but did not restore motility. This study highlights the potential importance of molybdoenzyme-dependent anaerobic respiration in the survival and virulence of B. thailandensis. PMID:24239959

  18. Neutrophil Elastase Causes Tissue Damage That Decreases Host Tolerance to Lung Infection with Burkholderia Species

    PubMed Central

    Miller, Mark A.; Re, Fabio

    2014-01-01

    Two distinct defense strategies can protect the host from infection: resistance is the ability to destroy the infectious agent, and tolerance is the ability to withstand infection by minimizing the negative impact it has on the host's health without directly affecting pathogen burden. Burkholderia pseudomallei is a Gram-negative bacterium that infects macrophages and causes melioidosis. We have recently shown that inflammasome-triggered pyroptosis and IL-18 are equally important for resistance to B. pseudomallei, whereas IL-1? is deleterious. Here we show that the detrimental role of IL-1? during infection with B. pseudomallei (and closely related B. thailandensis) is due to excessive recruitment of neutrophils to the lung and consequent tissue damage. Mice deficient in the potentially damaging enzyme neutrophil elastase were less susceptible than the wild type C57BL/6J mice to infection, although the bacterial burdens in organs and the extent of inflammation were comparable between C57BL/6J and elastase-deficient mice. In contrast, lung tissue damage and vascular leakage were drastically reduced in elastase-deficient mice compared to controls. Bradykinin levels were higher in C57BL/6 than in elastase-deficient mice; administration of a bradykinin antagonist protected mice from infection, suggesting that increased vascular permeability mediated by bradykinin is one of the mechanisms through which elastase decreases host tolerance to melioidosis. Collectively, these results demonstrate that absence of neutrophil elastase increases host tolerance, rather than resistance, to infection by minimizing host tissue damage. PMID:25166912

  19. Sulphonylurea Usage in Melioidosis Is Associated with Severe Disease and Suppressed Immune Response

    PubMed Central

    Liu, Xiang; Foo, Geraldine; Lim, Wan Peng; Ravikumar, Sharada; Sim, Siew Hoon; Win, Mar Soe; Goh, Jessamine Geraldine; Lim, Joan Hui Juan; Ng, Ying Hui; Fisher, Dale; Khoo, Chin Meng

    2014-01-01

    Background Melioidosis is a problem in the developing tropical regions of Southeast Asia and Northern Australia where the the Gram negative saprophytic bacillus Burkholderia pseudomallei is endemic with the risk of fulminant septicaemia. While diabetes mellitus is a well-established risk factor for melioidiosis, little is known if specific hypoglycemic agents may differentially influence the susceptibility and clinical course of infection with B. pseudomallei (Bp). Methodology/Principal Findings In this cohort study, patients with pre-existing diabetes and melioidosis were retrospectively studied. Outcome measures: mortality, length of stay and development of complications (namely hypotension, intubation, renal failure and septicaemia) were studied in relation to prior diabetic treatment regimen. Peripheral blood mononuclear cells (PBMC) from diabetic patients and healthy PBMC primed with metformin, glyburide and insulin were stimulated with purified Bp antigens in vitro. Immune response and specific immune pathway mediators were studied to relate to the clinical findings mechanistically. Of 74 subjects, 44 (57.9%) had sulphonylurea-containing diabetic regimens. Patient receiving sulphonylureas had more severe septic complications (47.7% versus 16.7% p?=?0.006), in particular, hypotension requiring intropes (p?=?0.005). There was also a trend towards increased mortality in sulphonylurea-users (15.9% versus 3.3% p?=?0.08). In-vitro, glyburide suppressed inflammatory cytokine production in a dose-dependent manner. An effect of the drug was the induction of IL-1R-associated kinase-M at the level of mRNA transcription. Conclusion/Significance Sulphonylurea treatment results in suppression of host inflammatory response and may put patients at higher risk for adverse outcomes in melioidosis. PMID:24762472

  20. In Vivo Manipulation of ?9+ T Cells in the Common Marmoset (Callithrix Jacchus) with Phosphoantigen and Effect on the Progression of Respiratory Melioidosis

    PubMed Central

    Laws, Thomas R.; Nelson, Michelle; Bonnafous, Cecile; Sicard, Helene; Taylor, Christopher; Salguero, Francisco Javier; Atkins, Timothy P.; Oyston, Petra C. F.; Rowland, Caroline A.

    2013-01-01

    Burkholderia pseudomallei is a dangerous human pathogen. Phosphoantigens specifically the target primate specific ?9+?2+ T cells subset and some have been developed as potential immunotherapeutics. Previously, we demonstrated that, when stimulated with the phosphoantigen CHDMAPP, ?9+?2+ T cells aid in the killing of intracellular B. pseudomallei bacteria. Moreover, we found that common marmoset (Callithrix Jacchus) ?9+ T cells increase in frequency and respond to the phosphoantigen CHDMAPP and/or B. pseudomallei, in combination with IL-2, in a similar manner to human ?9+?2+ T cells. Here we evaluate the efficacy of the phosphoantigen CHDMAPP, in combination with IL-2, as a therapy against B. pseudomallei infection, in vivo. We found that the previous studies predicted the in vivo responsiveness of ?9+ T cells to the CHDMAPP+IL-2 treatment and significant expansion of the numbers of peripheral and splenic ?9+ T cells were observed. This effect was similar to those reported in other primate species treated with phosphoantigen. Furthermore, splenocytes were retrieved 7 days post onset of treatment, restimulated with CHDMAPP or heat-killed B. pseudomallei and the cultured ?9+ T cells demonstrated no reduction in IFN-? response when CHDMAPP+IL-2 animals were compared to IL-2 only treated animals. Using an established model of B. pseudomallei infection in the marmoset, we assessed the potential for using phosphoantigen as a novel immunotherapy. The CHDMAPP treatment regime had no effect on the progression of respiratory melioidosis and this was despite the presence of elevated numbers of ?9+ T cells in the spleen, liver and lung and an increased proportion of IFN-?+ cells in response to infection. We therefore report that the common marmoset has proven a good model for studying the effect in vivo of ?9+ T cell stimulation; however, ?9+ T cells have little or no effect on the progression of lethal, respiratory B. pseudomallei infection. PMID:24098670

  1. Outbreak of melioidosis and leptospirosis co-infection following a rescue operation.

    PubMed

    Sapian, M; Khair, M T; How, S H; Rajalingam, R; Sahhir, K; Norazah, A; Khebir, V; Jamalludin, A R

    2012-06-01

    We analyzed the epidemiological data of all people who were involved in the search and rescue operation in Lubuk Yu, a natural recreational forest with waterfall and stream. The hospital admission records of the cases who fulfilled the case definition and the environmental samples result taken at Lubuk Yu recreational area were studied. 153 people were exposed to this outbreak, 85 (55.5%) were professional rescuers from various government agencies and 68 (44.5%) were villagers. 21 fulfilled the case definition. Ten cases were confirmed melioidosis, six melioidosis alone and four coinfected with leptospirosis. There were eight deaths in this outbreak, seven were villagers and one professional rescuer. Overall case fatality was 70%. All confirmed melioidosis cases and seven who died had diabetes mellitus. The morbidity rate were higher among the villagers, 23.5% compared to professional rescuers, 5.9%. The case fatality rate were also higher in this group which was 100% compared to 33.3% in professional rescuers. The soil and water samples in Lubuk Yu recreational area were positive for leptospira and Burkholderia pseudomallei. The presence of co-infection and co-morbidities especially diabetes mellitus among the exposed led to the high mortality in this outbreak hence a high index of suspicion is important among the healthcare professionals in the management of melioidosis cases. To avoid similar incident in future, search and rescue operation should be only conducted by professional rescuers with appropriate personal protective equipment. A register of rescuers should be maintained for surveillance and follow up if necessary. PMID:23082420

  2. Burkholderia pseudomallei, B. thailandensis, and B. ambifaria Produce 4-Hydroxy-2-Alkylquinoline Analogues with a Methyl Group at the 3 Position That Is Required for Quorum-Sensing Regulation ?

    PubMed Central

    Vial, Ludovic; Lépine, François; Milot, Sylvain; Groleau, Marie-Christine; Dekimpe, Valérie; Woods, Donald E.; Déziel, Eric

    2008-01-01

    4-Hydroxy-2-alkylquinolines (HAQs), especially 3,4-dihydroxy-2-heptylquinoline (Pseudomonas quinolone signal) and its precursor, 4-hydroxy-2-heptylquinoline, are attracting much attention, mainly because of their role as signaling molecules in Pseudomonas aeruginosa. The pqsABCDE operon is centrally involved in their biosynthesis. The presence of a homologous operon in Burkholderia pseudomallei and B. thailandensis was recently reported. Thus, we have investigated the abilities of 11 Burkholderia species to produce HAQ-like molecules by liquid chromatography/mass spectrometry. We have identified 29 different HAQ derivatives produced by the only three Burkholderia species where a pqsABCDE homologue was found among available sequenced Burkholderia species genomes, including B. ambifaria, a member of the Burkholderia cepacia complex. In contrast with those of P. aeruginosa, Burkholderia HAQs typically bear a methyl group, hence their designation as 4-hydroxy-3-methyl-2-alkylquinolines (HMAQs). We identified three families of HMAQs with a saturated or unsaturated alkyl chain at the 2? position, in contrast with the 1? position of P. aeruginosa, including one with an N-oxide group. Furthermore, the operon in these species contains two more genes downstream of the pqsE homologue, resulting in the hmqABCDEFG operon. While the inactivation of hmqA inhibits the production of HMAQs, the methylation of the quinoline ring requires a putative methyltransferase encoded by hmqG. Interestingly, hmqA or hmqG mutations increase the production of acyl homoserine lactones and, consequently, phenotypes under the control of quorum sensing in B. ambifaria: antifungal activity, siderophore production, and proteolytic activity. These results indicate that only HAQs bearing a methyl group (HMAQs) are involved in quorum-sensing regulation. PMID:18539738

  3. Development of an acute model of inhalational melioidosis in the common marmoset (Callithrix jacchus)

    PubMed Central

    Nelson, Michelle; Dean, Rachel E; Salguero, Francisco J; Taylor, Christopher; Pearce, Peter C; Simpson, Andrew J H; Lever, Mark S

    2011-01-01

    Studies of inhalational melioidosis were undertaken in the common marmoset (Callithrix jacchus). Following exposure to an inhaled challenge with aerosolized Burkholderia pseudomallei, lethal infection was observed in marmosets challenged with doses below 10 cfu; a precise LD50 determination was not possible. The model was further characterized using a target challenge dose of approximately 102 cfu. A separate pathogenesis time-course experiment was also conducted. All animals succumbed, between 27 and 78 h postchallenge. The challenge dose received and the time to the humane endpoint (1 °C below normal body temperature postfever) were correlated. The first indicator of disease was an increased core body temperature (Tc), at 22 h postchallenge. This coincided with bacteraemia and bacterial dissemination. Overt clinical signs were first observed 3–5 h later. A sharp decrease (typically within 3–6 h) in the Tc was observed prior to humanely culling the animals in the lethality study. Pathology was noted in the lung, liver and spleen. Disease progression in the common marmoset appears to be consistent with human infection in terms of bacterial spread, pathology and physiology. The common marmoset can therefore be considered a suitable animal model for further studies of inhalational melioidosis. PMID:22122591

  4. Siderophore production by Pseudomonas pseudomallei.

    PubMed

    Yang, H M; Chaowagul, W; Sokol, P A

    1991-03-01

    Eighty-four strains of Pseudomonas pseudomallei isolated from patients with melioidosis were examined for siderophore production. All the strains were shown to produce siderophore both on chrome azurol S agar plates and in liquid medium under iron-deficient conditions. Chemical assays indicated that the siderophore belongs to the hydroxamate class. Addition of iron to the culture medium resulted in increased culture growth with markedly decreased yield of siderophore. Siderophore produced by strain U7 was purified by gel filtration chromatography, and the molecular weight was estimated to be 1,000. When this partially purified siderophore was added to culture medium, it promoted iron uptake by P. pseudomallei in the presence of EDTA and enhanced growth of the organism in the presence of transferrin. We have given this siderophore the trivial name malleobactin. PMID:1825486

  5. Melioidosis: the tip of the iceberg?

    PubMed Central

    Dance, D A

    1991-01-01

    For nearly 80 years clinical melioidosis has been considered a rare disease. This bacterial infection is caused by Pseudomonas pseudomallei, a saprophyte found in soil and surface water of endemic areas. Consequently, those who have most contact with soil, the rural poor, are likely to be at greatest risk of infection. Since the diversity of clinical manifestations necessitates the isolation and identification of the causative organism for a definitive diagnosis of melioidosis and the population at greatest risk within endemic areas rarely have access to an appropriate level of health care, the disease has probably been underrecognized. Melioidosis is now known to be an important cause of human morbidity and mortality in Thailand, and this may be true throughout Southeast Asia, which is usually regarded as the main endemic area for the disease. In Australia, melioidosis causes a smaller number of human infections, while disease among livestock has important economic and possible public health implications. Sporadic reports of the infection indicate its presence in several other tropical regions: in the Indian subcontinent, Africa, and Central and South America. Clinical melioidosis may be highly prevalent in these areas, but underdiagnosed as a result of a lack of awareness of the clinical and microbiological features of the disease, or simply because of a lack of health care facilities. Furthermore, during the last two decades the importation and transmission of melioidosis within nontropical zones have been documented. The causative organism is not difficult to grow, and modern antibiotics have improved disease prognosis. Further studies are needed to determine the true worldwide distribution and prevalence of melioidosis so that improved therapeutic and preventive measures can be developed and applied. PMID:2004347

  6. Sequence-Defined Transposon Mutant Library of Burkholderia thailandensis

    PubMed Central

    Gallagher, Larry A.; Ramage, Elizabeth; Patrapuvich, Rapatbhorn; Weiss, Eli; Brittnacher, Mitch; Manoil, Colin

    2013-01-01

    ABSTRACT We constructed a near-saturation transposon mutant library for Burkholderia thailandensis, a low-virulence surrogate for the causative agent of melioidosis (Burkholderia pseudomallei). A primary set of nearly 42,000 unique mutants (~7.5 mutants/gene) was generated using transposon Tn5 derivatives. The strains carry insertions in 87% of the predicted protein-coding genes of the organism, corresponding to nearly all of those nonessential for growth on nutrient agar. To achieve high genome coverage, we developed procedures for efficient sequence identification of insertions in extremely GC-rich regions of DNA. To facilitate strain distribution, we created a secondary library with two mutants per gene for which most transposon locations had been confirmed by resequencing. A map of mutations in the two-allele library and procedures for obtaining strains can be found at http://tools.nwrce.org/tn_mutants/ and http://www.gs.washington.edu/labs/manoil/. The library should facilitate comprehensive mutant screens and serve as a source of strains to test predicted genotype-phenotype associations. PMID:24194535

  7. The BpeAB-OprB Efflux Pump of Burkholderia pseudomallei 1026b Does Not Play a Role in Quorum Sensing, Virulence Factor Production, or Extrusion of Aminoglycosides but Is a Broad-Spectrum Drug Efflux System ?

    PubMed Central

    Mima, Takehiko; Schweizer, Herbert P.

    2010-01-01

    Most Burkholderia pseudomallei strains are intrinsically aminoglycoside resistant, mainly due to AmrAB-OprA-mediated efflux. Rare naturally occurring or genetically engineered mutants lacking this pump are aminoglycoside susceptible despite the fact that they also encode and express BpeAB-OprB, which was reported to mediate efflux of aminoglycosides in the Singapore strain KHW. To reassess the role of BpeAB-OprB in B. pseudomallei aminoglycoside resistance, we used mutants overexpressing or lacking this pump in either AmrAB-OprA-proficient or -deficient strain 1026b backgrounds. Our data show that BpeAB-OprB does not mediate efflux of aminoglycosides but is a multidrug efflux system which extrudes macrolides, fluoroquinolones, tetracyclines, acriflavine, and, to a lesser extent, chloramphenicol. Phylogenetically, BpeAB-OprB is closely related to Pseudomonas aeruginosa MexAB-OprM, which has a similar substrate spectrum. AmrAB-OprA is most closely related to MexXY, the only P. aeruginosa efflux pump known to extrude aminoglycosides. Since BpeAB-OprB in strain KHW was also implicated in playing a major role in export of acylated homoserine lactone (AHL) quorum-sensing molecules and in expression of diverse virulence factors, we explored whether this was also true in the strain 1026b background. The results showed that BpeAB-OprB was not required for AHL export, and mutants lacking this efflux system exhibited normal swimming motility and siderophore production, which were severely impaired in KHW bpeAB-oprB mutants. Biofilm formation was impaired in 1026b ?(amrRAB-oprA) and ?(amrRAB-oprA) ?(bpeAB-oprB) mutants. At present, we do not know why our BpeAB-OprB susceptibility and virulence factor expression results with 1026b and its derivatives are different from those previously published for Singapore strain KHW. PMID:20498323

  8. COMPLEMENT FIXATION TEST IN EXPERIMENTAL CLINICAL AND SUBCLINICAL MELIOIDOSIS

    PubMed Central

    Nigg, Clara; Johnston, Margaret M.

    1961-01-01

    Nigg, Clara (University of California, Berkeley), and Margaret M. Johnston. Complement fixation test in experimental clinical and subclinical melioidosis. J. Bacteriol. 82:159–168. 1961.—Soluble stable antigens prepared from Pseudomonas pseudomallei gave 4+ complement fixation reactions in a dilution of 1 to 8,000 when tested with specific rabbit antiserum diluted 1 to 10,000. The complement fixation reaction was positive in 100% of experimentally infected rabbits 9 to 11 days postinfection. Infected guinea pigs and monkeys showed similar results. Monkeys inoculated with very small infecting doses of P. pseudomallei developed positive complement fixation reactions in the absence of clinical manifestation of infection. An anamnestic complement-fixing antibody response could be induced in such monkeys, after the titer had dropped to approximately the preinfection level, by inoculating very small doses of viable P. pseudomallei or larger doses of killed melioidosis vaccine. The complement fixation test described appeared to be both sensitive and specific, and should be of value in human melioidosis which cannot be diagnosed on the basis of clinical manifestations alone. It is suggested that subclinical infections may play a role in the epidemiology of human meliodosis. The potential application of the complement fixation test to serological surveys in areas where melioidosis occurs endemically is discussed. PMID:13729013

  9. Complete Genome Sequences for 59 Burkholderia Isolates, Both Pathogenic and Near Neighbor

    PubMed Central

    Bishop-Lilly, Kimberly A.; Ladner, Jason T.; Daligault, Hajnalka E.; Davenport, Karen W.; Jaissle, James; Frey, Kenneth G.; Koroleva, Galina I.; Bruce, David C.; Coyne, Susan R.; Broomall, Stacey M.; Li, Po-E; Teshima, Hazuki; Gibbons, Henry S.; Palacios, Gustavo F.; Rosenzweig, C. Nicole; Redden, Cassie L.; Xu, Yan; Minogue, Timothy D.; Chain, Patrick S.

    2015-01-01

    The genus Burkholderia encompasses both pathogenic (including Burkholderia mallei and Burkholderia pseudomallei, U.S. Centers for Disease Control and Prevention Category B listed), and nonpathogenic Gram-negative bacilli. Here we present full genome sequences for a panel of 59 Burkholderia strains, selected to aid in detection assay development. PMID:25931592

  10. Virulent burkholderia species mimic host actin polymerases to drive actin-based motility.

    PubMed

    Benanti, Erin L; Nguyen, Catherine M; Welch, Matthew D

    2015-04-01

    Burkholderia pseudomallei and B. mallei are bacterial pathogens that cause melioidosis and glanders, whereas their close relative B. thailandensis is non-pathogenic. All use the trimeric autotransporter BimA to facilitate actin-based motility, host cell fusion, and dissemination. Here, we show that BimA orthologs mimic different host actin-polymerizing proteins. B. thailandensis BimA activates the host Arp2/3 complex. In contrast, B. pseudomallei and B. mallei BimA mimic host Ena/VASP actin polymerases in their ability to nucleate, elongate, and bundle filaments by associating with barbed ends, as well as in their use of WH2 motifs and oligomerization for activity. Mechanistic differences among BimA orthologs resulted in distinct actin filament organization and motility parameters, which affected the efficiency of cell fusion during infection. Our results identify bacterial Ena/VASP mimics and reveal that pathogens imitate the full spectrum of host actin-polymerizing pathways, suggesting that mimicry of different polymerization mechanisms influences key parameters of infection. PMID:25860613

  11. Common TLR1 genetic variation is not associated with death from melioidosis, a common cause of sepsis in rural Thailand.

    PubMed

    Chantratita, Narisara; Tandhavanant, Sarunporn; Myers, Nicolle D; Chierakul, Wirongrong; Wuthiekanun, Vanaporn; Mahavanakul, Weera; Limmathurotsakul, Direk; Peacock, Sharon J; West, T Eoin

    2014-01-01

    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), rs4833095 (742A/G), and rs5743618 (1804G/T). We noted a reversal of the minor allele from white North American subjects to Asian populations that was particularly pronounced for rs5743618. In the Utah residents of European ancestry, the frequency of the rs5743618 T allele was 17% whereas in Vietnamese subjects the frequency was >99%. We conducted a genetic association study in 427 patients with melioidosis to determine the association of TLR1 variation with organ failure or death. We genotyped rs5743551 and rs4833095. The variants were in high linkage disequilibrium but neither variant was associated with organ failure or in-hospital death. In 300 healthy Thai individuals we further tested the association of TLR1 variation with ex vivo blood responses to Pam3CSK4, a TLR1 agonist. Neither variant was robustly associated with blood cytokine responses induced by Pam3CSK4. We identified additional common variation in TLR1 by searching public databases and the published literature and screened three additional TLR1 variants for associations with Pam3CSK4-induced responses but found none. We conclude that the genetic architecture of TLR1 variation differs substantially in southeast Asians compared to other populations and common variation in TLR1 in Thais is not associated with outcome from melioidosis or with altered blood responses to Pam3CSK4. Our findings highlight the need for additional studies of TLR1 and other innate immune genetic modulators of the inflammatory host response and determinants of sepsis in southeast Asian populations. PMID:24392083

  12. Characterization of the Burkholderia mallei tonB Mutant and Its Potential as a Backbone Strain for Vaccine Development

    PubMed Central

    Mott, Tiffany M.; Vijayakumar, Sudhamathi; Sbrana, Elena; Endsley, Janice J.; Torres, Alfredo G.

    2015-01-01

    Background In this study, a Burkholderia mallei tonB mutant (TMM001) deficient in iron acquisition was constructed, characterized, and evaluated for its protective properties in acute inhalational infection models of murine glanders and melioidosis. Methodology/Principal Findings Compared to the wild-type, TMM001 exhibits slower growth kinetics, siderophore hyper-secretion and the inability to utilize heme-containing proteins as iron sources. A series of animal challenge studies showed an inverse correlation between the percentage of survival in BALB/c mice and iron-dependent TMM001 growth. Upon evaluation of TMM001 as a potential protective strain against infection, we found 100% survival following B. mallei CSM001 challenge of mice previously receiving 1.5 x 104 CFU of TMM001. At 21 days post-immunization, TMM001-treated animals showed significantly higher levels of B. mallei-specific IgG1, IgG2a and IgM when compared to PBS-treated controls. At 48 h post-challenge, PBS-treated controls exhibited higher levels of serum inflammatory cytokines and more severe pathological damage to target organs compared to animals receiving TMM001. In a cross-protection study of acute inhalational melioidosis with B. pseudomallei, TMM001-treated mice were significantly protected. While wild type was cleared in all B. mallei challenge studies, mice failed to clear TMM001. Conclusions/Significance Although further work is needed to prevent chronic infection by TMM001 while maintaining immunogenicity, our attenuated strain demonstrates great potential as a backbone strain for future vaccine development against both glanders and melioidosis. PMID:26114445

  13. Bacterial genome adaptation to niches: Divergence of the potential virulence genes in three Burkholderia species of different survival strategies

    Microsoft Academic Search

    H Stanley Kim; Mark A Schell; Yan Yu; Ricky L Ulrich; Saul H Sarria; William C Nierman; David DeShazer

    2005-01-01

    BACKGROUND: Two closely related species Burkholderia mallei (Bm) and Burkholderia pseudomallei (Bp) are serious human health hazards and are potential bio-warfare agents, whereas another closely related species Burkholderia thailandensis (Bt) is a non-pathogenic saprophyte. To investigate the genomic factors resulting in such a dramatic difference, we first identified the Bm genes responsive to the mouse environment, and then examined the

  14. Snake Cathelicidin NA-CATH and Smaller Helical Antimicrobial Peptides Are Effective against Burkholderia thailandensis

    PubMed Central

    Blower, Ryan J.; Barksdale, Stephanie M.; van Hoek, Monique L.

    2015-01-01

    Burkholderia thailandensis is a Gram-negative soil bacterium used as a model organism for B. pseudomallei, the causative agent of melioidosis and an organism classified category B priority pathogen and a Tier 1 select agent for its potential use as a biological weapon. Burkholderia species are reportedly “highly resistant” to antimicrobial agents, including cyclic peptide antibiotics, due to multiple resistance systems, a hypothesis we decided to test using antimicrobial (host defense) peptides. In this study, a number of cationic antimicrobial peptides (CAMPs) were tested in vitro against B. thailandensis for both antimicrobial activity and inhibition of biofilm formation. Here, we report that the Chinese cobra (Naja atra) cathelicidin NA-CATH was significantly antimicrobial against B. thailandensis. Additional cathelicidins, including the human cathelicidin LL-37, a sheep cathelicidin SMAP-29, and some smaller ATRA peptide derivatives of NA-CATH were also effective. The D-enantiomer of one small peptide (ATRA-1A) was found to be antimicrobial as well, with EC50 in the range of the L-enantiomer. Our results also demonstrate that human alpha-defensins (HNP-1 & -2) and a short beta-defensin-derived peptide (Peptide 4 of hBD-3) were not bactericidal against B. thailandensis. We also found that the cathelicidin peptides, including LL-37, NA-CATH, and SMAP-29, possessed significant ability to prevent biofilm formation of B. thailandensis. Additionally, we show that LL-37 and its D-enantiomer D-LL-37 can disperse pre-formed biofilms. These results demonstrate that although B. thailandensis is highly resistant to many antibiotics, cyclic peptide antibiotics such as polymyxin B, and defensing peptides, some antimicrobial peptides including the elapid snake cathelicidin NA-CATH exert significant antimicrobial and antibiofilm activity towards B. thailandensis. PMID:26196513

  15. Mediastinal Lymphadenopathy: Melioidosis Mimicking Tuberculosis

    PubMed Central

    Chan, Hiang Ping; Yip, Hwee Seng

    2015-01-01

    Melioidosis has protean manifestations and often mimics other disease processes. We present a case of a gentleman presenting with chronic cough whose initial radiographic findings of a cavitatory lung lesion and mediastinal lymphadenopathy were suggestive of tuberculosis. This case highlights the important role that bronchoscopy and endobronchial ultrasound can play in the diagnosis of melioidosis in patients presenting with mediastinal lymphadenopathy whose initial microbiological findings from sputum are negative for tuberculosis.

  16. Mediastinal Lymphadenopathy: Melioidosis Mimicking Tuberculosis.

    PubMed

    Chan, Hiang Ping; Yip, Hwee Seng

    2015-06-01

    Melioidosis has protean manifestations and often mimics other disease processes. We present a case of a gentleman presenting with chronic cough whose initial radiographic findings of a cavitatory lung lesion and mediastinal lymphadenopathy were suggestive of tuberculosis. This case highlights the important role that bronchoscopy and endobronchial ultrasound can play in the diagnosis of melioidosis in patients presenting with mediastinal lymphadenopathy whose initial microbiological findings from sputum are negative for tuberculosis. PMID:26060421

  17. MELIOIDOSIS: PATHOGENESIS AND IMMUNITY IN MICE AND HAMSTERS

    PubMed Central

    Dannenberg, Arthur M.; Scott, Eva M.

    1958-01-01

    The pathogenesis of acute respiratory melioidosis mice and hamsters is described. Inhaled organisms giving rise to lesions seemed to be first engulfed by the mononuclear alveolar phagocytes, but in less than 1 day polymorphonuclear cells made their appearance. In spite of this defense reaction, the bacteria continued to multiply and their products caused focal necrosis. These foci enlarged and gave rise to septicemia, toxemia, and eventually death, which usually occurred in 3 to 10 days depending on the dose. Melioidosis, is, therefore, an acute septicotoxemic disease resembling plague and anthrax in this respect. In hamsters the disease process developed more rapidly than in mice and death occurred sooner. The course of the disease in hamsters was sometimes complicated by intraglomerular deposits resembling "fibrinoid," which were similar to those of the generalized Shwartzman phenomenon. This phenomenon may have been an indirect cause of both the perifocal hemorrhage and the extremely large number of bacteria in some of the hamster lesions. When low infecting doses of organisms were employed, mice, but not hamsters, developed a chronic type of disease, lasting 2 to 8 weeks. This was characterized by large abscesses in the spleen or lung, marked proliferation of mononuclear phagocytes and plasma cells, and increased immunity against reinfection (about 40-fold against respiratory challenge). When mice and hamsters inhaled high infecting doses of organisms, a peracute disease resulted with death in 1 to 3 days. Increased numbers of bacteria were observed in the lesions, and the histological changes in the spleen resembled those following the intravenous injection of Malleomyces pseudomallei toxin or the intramuscular injection of large doses of cortisone. These changes were characterized by a swelling of the phagocytes of the white pulp with nuclear debris. The peracute, the acute, and the chronic forms of melioidosis in mice are similar to analogous clinical forms found in man. PMID:13481262

  18. Melioidotic septic arthritis: a case report and literature review

    Microsoft Academic Search

    Nadeem Sajjad Raja

    Burkholderia pseudomallei, the causative agent of melioidosis, is endemic in southeast Asia and northern Australia. In recent years, the incidence of melioidosis has increased worldwide. Septic arthritis is a rare but well-recognized manifestation of melioidosis. Patients with underlying medical conditions, such as diabetes mellitus, renal impairment, cirrhosis, and malignancy are at greater risk. The presentations of melioidotic septic arthritis often

  19. Autophagy and burkholderia.

    PubMed

    Devenish, Rodney J; Lai, Shu-chin

    2015-01-01

    Autophagy has become increasingly viewed as an important component of the eukaryotic innate immune system. The elimination of intracellular pathogens by autophagy in mammalian cells (xenophagy) results not only in the degradation of invading bacteria, viruses, fungi and parasites, but also liberation of metabolites that may have been utilized during pathogen infection, thus promoting cell survival. After gaining entry into the cell, intracellular bacterial pathogens attempt to escape from phagosomes (or endosomes) into the cytosol where they endeavour to continue the infection cycle unhindered by host cell protective mechanisms. Bacterial recognition resulting from either their cytosolic location, the secretion of bacterial products, or phagosomal membrane damage, can induce autophagy. In this context, induction of autophagy results in the clearance of some bacterial pathogens, whereas other bacteria are able to manipulate autophagy for their own benefit and appear to effectively replicate within autophagosome-like vesicles. Some bacteria are seemingly able to evade autophagy and Burkholderia pseudomallei is one of them. This review will discuss the autophagic processes that may be activated by host cells to provide protection against infection by this bacterial pathogen. PMID:25331551

  20. Acute Septicemic Melioidosis Presenting with Acute Cholangitis

    Microsoft Academic Search

    C.-H. Lai; C.-K. Huang; C. Chin; W.-F. Chen; Y.-T. Yang; Y.-L. Chen; H.-H. Lin

    2007-01-01

    Melioidosis is a disease prevalent in the tropics, especially in Southeast Asia. The most common clinical presentations are\\u000a bacteremic pneumonia and abscess formation in various organs. Although a wide variety of disease presentations are reported\\u000a for melioidosis, acute cholangitis has not been previously reported. Herein, we report a 54-year-old woman who had fever,\\u000a right upper abdominal pain and jaundice 1

  1. Melioidosis

    MedlinePLUS

    ... and soil. It is spread to humans and animals through direct contact with the contaminated source. Specimens Submission of Laboratory Specimens. Classification Learn About the Four Types of Meliodosis. Lab Exposure Management of Accidental Laboratory Exposure. Transmission How do people ...

  2. Molecular typing of Pseudomonas pseudomallei: restriction fragment length polymorphisms of rRNA genes.

    PubMed Central

    Lew, A E; Desmarchelier, P M

    1993-01-01

    The aim of this study was to develop a typing scheme for Pseudomonas pseudomallei by comparison of patterns of restriction fragment length polymorphisms in rRNA genes (ribotyping). BamHI restriction digests of 100 isolates from various animal (34), human (58), and environmental (6) sources, including six reference strains, were hybridized to Escherichia coli 16S and 23S rRNAs. A chemiluminescent labelling and detection system was used to visualize bands. On the basis of patterns, the strains were classified into 22 different groups, with the largest containing 29 isolates. While most of the ribotypes were not exclusive to a particular source, some ribotypes were restricted to a particular geographic area or to either a human or a particular animal species. Application of the typing scheme to isolates of four independent outbreaks among animals showed that certain ribotypes predominated. The study demonstrated ribotyping to be a useful tool in epidemiological investigations of melioidosis. Images PMID:7681436

  3. Genetic tools for allelic replacement in Burkholderia species.

    PubMed

    Barrett, Ashley R; Kang, Yun; Inamasu, Ken S; Son, Mike S; Vukovich, Joseph M; Hoang, Tung T

    2008-07-01

    Allelic replacement in the Burkholderia genus has been problematic due to the lack of appropriate counter-selectable and selectable markers. The counter-selectable marker sacB, commonly used in gram-negative bacteria, is nonselective on sucrose in many Burkholderia species. In addition, the use of antibiotic resistance markers of clinical importance for the selection of desirable genetic traits is prohibited in the United States for two potential bioterrorism agents, Burkholderia mallei and Burkholderia pseudomallei. Here, we engineered a mutated counter-selectable marker based on the B. pseudomallei PheS (the alpha-subunit of phenylalanyl tRNA synthase) protein and tested its effectiveness in three different Burkholderia species. The mutant PheS protein effectively killed 100% of the bacteria in the presence of 0.1% p-chlorophenylalanine. We assembled the mutant pheS on several allelic replacement vectors, in addition to constructing selectable markers based on tellurite (Tel(r)) and trimethoprim (Tp(r)) resistance that are excisable by flanking unique FLP recombination target (FRT) sequences. As a proof of concept, we utilized one of these gene replacement vectors (pBAKA) and the Tel(r)-FRT cassette to produce a chromosomal mutation in the Burkholderia thailandensis betBA operon, which codes for betaine aldehyde dehydrogenase and choline dehydrogenase. Chromosomal resistance markers could be excised by the introduction of pFLP-AB5 (Tp(r)), which is one of two constructed flp-containing plasmids, pFLP-AB4 (Tel(r)) and pFLP-AB5 (Tp(r)). These flp-containing plasmids harbor the mutant pheS gene and allow self curing on media that contain p-chlorophenylalanine after Flp-FRT excision. The characterization of the Delta betBA::Tel(r)-FRT and Delta betBA::FRT mutants indicated a defect in growth with choline as a sole carbon source, while these mutants grew as well as the wild type with succinate and glucose as alternative carbon sources. PMID:18502918

  4. Subcutaneous Surprise

    PubMed Central

    Jakribettu, RP; Boloor, R; D’Souza, R; Aithala, S

    2014-01-01

    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 lymphadenitis. Hence, we report a case of unilateral suppurative inguinal lymphadenitis caused by B. pseudomallei in a 48-year-old lady who presented with groin swelling of 2 months duration. PMID:24669344

  5. DNA-Based Diagnostic Approaches for Identification of Burkholderia cepacia Complex, Burkholderia vietnamiensis, Burkholderia multivorans, Burkholderia stabilis, and Burkholderia cepacia Genomovars I and III

    Microsoft Academic Search

    ESHWAR MAHENTHIRALINGAM; JOCELYN BISCHOF; SEAN K. BYRNE; CHRISTOPHER RADOMSKI; JULIAN E. DAVIES; YOSSEF AV-GAY

    Bacteria of the Burkholderia cepacia complex consist of five discrete genomic species, including genomovars I and III and three new species: Burkholderia multivorans (formerly genomovar II), Burkholderia stabilis (formerly genomovar IV), and Burkholderia vietnamiensis (formerly genomovar V). Strains of all five genomo- vars are capable of causing opportunistic human infection, and microbiological identification of these closely related species is difficult.

  6. Plant-Associated Symbiotic Burkholderia Species Lack Hallmark Strategies Required in Mammalian Pathogenesis

    PubMed Central

    Fong, Stephanie; Yerrapragada, Shailaja; Estrada-de los Santos, Paulina; Yang, Paul; Song, Nannie; Kano, Stephanie; de Faria, Sergio M.; Dakora, Felix D.; Weinstock, George; Hirsch, Ann M.

    2014-01-01

    Burkholderia is a diverse and dynamic genus, containing pathogenic species as well as species that form complex interactions with plants. Pathogenic strains, such as B. pseudomallei and B. mallei, can cause serious disease in mammals, while other Burkholderia strains are opportunistic pathogens, infecting humans or animals with a compromised immune system. Although some of the opportunistic Burkholderia pathogens are known to promote plant growth and even fix nitrogen, the risk of infection to infants, the elderly, and people who are immunocompromised has not only resulted in a restriction on their use, but has also limited the application of non-pathogenic, symbiotic species, several of which nodulate legume roots or have positive effects on plant growth. However, recent phylogenetic analyses have demonstrated that Burkholderia species separate into distinct lineages, suggesting the possibility for safe use of certain symbiotic species in agricultural contexts. A number of environmental strains that promote plant growth or degrade xenobiotics are also included in the symbiotic lineage. Many of these species have the potential to enhance agriculture in areas where fertilizers are not readily available and may serve in the future as inocula for crops growing in soils impacted by climate change. Here we address the pathogenic potential of several of the symbiotic Burkholderia strains using bioinformatics and functional tests. A series of infection experiments using Caenorhabditis elegans and HeLa cells, as well as genomic characterization of pathogenic loci, show that the risk of opportunistic infection by symbiotic strains such as B. tuberum is extremely low. PMID:24416172

  7. RESEARCH ARTICLE Open Access Pulmonary melioidosis in Cambodia

    E-print Network

    Paris-Sud XI, Université de

    and outcomes. Methods: We characterized cases of acute lower respiratory infections (ALRI) that were identified from acute septicemia to chronic localized abscess while most infections with B. pseudomallei frequency, respiratory rate, oxygen saturation and body temperature. B. pseudomallei was detected in sputum

  8. Engineering of Tellurite-Resistant Genetic Tools for Single-Copy Chromosomal Analysis of Burkholderia spp. and Characterization of the Burkholderia thailandensis betBA Operon? †

    PubMed Central

    Kang, Yun; Norris, Michael H.; Barrett, Ashley R.; Wilcox, Bruce A.; Hoang, Tung T.

    2009-01-01

    There are few appropriate single-copy genetic tools for most Burkholderia species, and the high level of antibiotic resistance in this genus further complicates the development of genetic tools. In addition, the utilization of resistance genes for clinically important antibiotics is prohibited for the bioterrorism agents Burkholderia pseudomallei and Burkholderia mallei, necessitating the development of additional nonantibiotic-based genetic tools. Three single-copy systems devoid of antibiotic selection based on two nonantibiotic selectable markers, tellurite resistance (Telr) and Escherichia coli aspartate-semialdehyde dehydrogenase (asdEc), were developed to facilitate genetic manipulation in Burkholderia species. These systems include one mariner transposon, a mini-Tn7-derived site-specific transposon, and six FRT reporter fusion vectors based on the lacZ, gfp, and luxCDABE reporter genes. Initially, we showed that the random mariner transposon pBT20-?bla-Telr-FRT efficiently transposed within Burkholderia cenocepacia, Burkholderia thailandensis, B. pseudomallei, and B. mallei. We then utilized the mini-Tn7-Telr-based transposon vector (mini-Tn7-Telr-betBA) and a transposase-containing helper plasmid (pTNS3-asdEc) to complement the B. thailandensis ?betBA mutation. Next, one of the FRT-lacZ fusion vectors (pFRT1-lacZ-Telr) was integrated by Flp (encoded on a helper plasmid, pCD13SK-Flp-oriT-asdEc) to construct the B. thailandensis ?betBA::FRT-lacZ-Telr reporter fusion strain. The betBA operon was shown to be induced in the presence of choline and under osmotic stress conditions by performing ?-galactosidase assays on the B. thailandensis ?betBA::FRT-lacZ-Telr fusion strain. Finally, we engineered B. thailandensis ?betBA::FRT-gfp-Telr and ?betBA::FRT-lux-Telr fusion strains by utilizing fusion vectors pFRT1-gfp-Telr and pFRT1-lux-Telr, respectively. The induction of the betBA operon by choline and osmotic stress was confirmed by performing fluorescent microscopy and bioluminescent imaging analyses. PMID:19376905

  9. Engineering of tellurite-resistant genetic tools for single-copy chromosomal analysis of Burkholderia spp. and characterization of the Burkholderia thailandensis betBA operon.

    PubMed

    Kang, Yun; Norris, Michael H; Barrett, Ashley R; Wilcox, Bruce A; Hoang, Tung T

    2009-06-01

    There are few appropriate single-copy genetic tools for most Burkholderia species, and the high level of antibiotic resistance in this genus further complicates the development of genetic tools. In addition, the utilization of resistance genes for clinically important antibiotics is prohibited for the bioterrorism agents Burkholderia pseudomallei and Burkholderia mallei, necessitating the development of additional nonantibiotic-based genetic tools. Three single-copy systems devoid of antibiotic selection based on two nonantibiotic selectable markers, tellurite resistance (Tel(r)) and Escherichia coli aspartate-semialdehyde dehydrogenase (asd(Ec)), were developed to facilitate genetic manipulation in Burkholderia species. These systems include one mariner transposon, a mini-Tn7-derived site-specific transposon, and six FRT reporter fusion vectors based on the lacZ, gfp, and luxCDABE reporter genes. Initially, we showed that the random mariner transposon pBT20-Deltabla-Tel(r)-FRT efficiently transposed within Burkholderia cenocepacia, Burkholderia thailandensis, B. pseudomallei, and B. mallei. We then utilized the mini-Tn7-Tel(r)-based transposon vector (mini-Tn7-Tel(r)-betBA) and a transposase-containing helper plasmid (pTNS3-asd(Ec)) to complement the B. thailandensis DeltabetBA mutation. Next, one of the FRT-lacZ fusion vectors (pFRT1-lacZ-Tel(r)) was integrated by Flp (encoded on a helper plasmid, pCD13SK-Flp-oriT-asd(Ec)) to construct the B. thailandensis DeltabetBA::FRT-lacZ-Tel(r) reporter fusion strain. The betBA operon was shown to be induced in the presence of choline and under osmotic stress conditions by performing beta-galactosidase assays on the B. thailandensis DeltabetBA::FRT-lacZ-Tel(r) fusion strain. Finally, we engineered B. thailandensis DeltabetBA::FRT-gfp-Tel(r) and DeltabetBA::FRT-lux-Tel(r) fusion strains by utilizing fusion vectors pFRT1-gfp-Tel(r) and pFRT1-lux-Tel(r), respectively. The induction of the betBA operon by choline and osmotic stress was confirmed by performing fluorescent microscopy and bioluminescent imaging analyses. PMID:19376905

  10. Dissection of the Burkholderia intracellular life cycle using a photothermal nanoblade

    PubMed Central

    French, Christopher T.; Toesca, Isabelle J.; Wu, Ting-Hsiang; Teslaa, Tara; Beaty, Shannon M.; Wong, Wayne; Liu, Minghsun; Schröder, Imke; Chiou, Pei-Yu; Teitell, Michael A.; Miller, Jeff F.

    2011-01-01

    Burkholderia pseudomallei and Burkholderia thailandensis are related pathogens that invade a variety of cell types, replicate in the cytoplasm, and spread to nearby cells. We have investigated temporal and spatial requirements for virulence determinants in the intracellular life cycle, using genetic dissection and photothermal nanoblade delivery, which allows efficient placement of bacterium-sized cargo into the cytoplasm of mammalian cells. The conserved Bsa type III secretion system (T3SSBsa) is dispensable for invasion, but is essential for escape from primary endosomes. By nanoblade delivery of B. thailandensis we demonstrate that all subsequent events in intercellular spread occur independently of T3SSBsa activity. Although intracellular movement was essential for cell–cell spread by B. pseudomallei and B. thailandensis, neither BimA-mediated actin polymerization nor the formation of membrane protrusions containing bacteria was required for B. thailandensis. Surprisingly, the cryptic (fla2) flagellar system encoded on chromosome 2 of B. thailandensis supported rapid intracellular motility and efficient cell–cell spread. Plaque formation by both pathogens was dependent on the activity of a type VI secretion system (T6SS-1) that functions downstream from T3SSBsa-mediated endosome escape. A remarkable feature of Burkholderia is their ability to induce the formation of multinucleate giant cells (MNGCs) in multiple cell types. By infection and nanoblade delivery, we observed complete correspondence between mutant phenotypes in assays for cell fusion and plaque formation, and time-course studies showed that plaque formation represents MNGC death. Our data suggest that the primary means for intercellular spread involves cell fusion, as opposed to pseudopod engulfment and bacterial escape from double-membrane vacuoles. PMID:21730143

  11. Global Analysis of the Burkholderia thailandensis Quorum Sensing-Controlled Regulon

    PubMed Central

    Majerczyk, Charlotte; Brittnacher, Mitchell; Jacobs, Michael; Armour, Christopher D.; Radey, Mathew; Schneider, Emily; Phattarasokul, Somsak; Bunt, Richard

    2014-01-01

    Burkholderia thailandensis contains three acyl-homoserine lactone quorum sensing circuits and has two additional LuxR homologs. To identify B. thailandensis quorum sensing-controlled genes, we carried out transcriptome sequencing (RNA-seq) analyses of quorum sensing mutants and their parent. The analyses were grounded in the fact that we identified genes coding for factors shown previously to be regulated by quorum sensing among a larger set of quorum-controlled genes. We also found that genes coding for contact-dependent inhibition were induced by quorum sensing and confirmed that specific quorum sensing mutants had a contact-dependent inhibition defect. Additional quorum-controlled genes included those for the production of numerous secondary metabolites, an uncharacterized exopolysaccharide, and a predicted chitin-binding protein. This study provides insights into the roles of the three quorum sensing circuits in the saprophytic lifestyle of B. thailandensis, and it provides a foundation on which to build an understanding of the roles of quorum sensing in the biology of B. thailandensis and the closely related pathogenic Burkholderia pseudomallei and Burkholderia mallei. PMID:24464461

  12. Detection of Pseudomonas pseudomallei by PCR and hybridization.

    PubMed Central

    Lew, A E; Desmarchelier, P M

    1994-01-01

    A molecular method for the detection of Pseudomonas pseudomallei was developed on the basis of the differences in the 23S rRNA sequences of related species of the genus Pseudomonas. An 18-base oligonucleotide probe, designed following partial sequencing of 23s ribosomal DNA (rDNA), was used for the identification and detection of P. pseudomallei either by hybridization or by direct PCR. Optimal detection was obtained by hybridization of the probe with PCR-amplified rDNA rather than with total genomic DNA or colony blots. One nanogram of template DNA amplified in a PCR mixture containing 14% glycerol could be detected in slot blots hybridized with the digoxigenin-labelled probe and the lumigen PPD detection system. Amplified rDNA sequences from 41 P. pseudomallei strains of various origins hybridized with the probe. The probe also hybridized with three Pseudomonas mallei reference strains under conditions of high stringency but failed to hybridize with amplified rDNA sequences from other closely related Pseudomonas spp. PCR with a conserved primer and the 18-base oligonucleotide probe (direct PCR) specifically amplified P. pseudomallei and P. mallei. By using these methods, approximately 10(4) P. pseudomallei cells per ml could be detected in artificially inoculated blood samples and in blood dried on filter paper following Chelex extraction. The detection limit in blood was increased to 10(2) cells per ml by concentration of bacteria from 0.5 ml of blood or by a 24-h blood culture enrichment prior to PCR. Approximately 10(3) cells per ml were detected in seeded sputum samples. The detection times by direct PCR and indirect PCR and then probe hybridization were approximately 5 h and 24 h, respectively. These results indicate that amplification of conserved rDNA sequences by PCR directly or by hybridization with a probe to PCR fragments offers promise for the detection of P. pseudomallei and P. mallei. Images PMID:7519629

  13. Multiple formaldehyde oxidation/detoxification pathways in Burkholderia fungorum LB400.

    PubMed

    Marx, Christopher J; Miller, Jonathan A; Chistoserdova, Ludmila; Lidstrom, Mary E

    2004-04-01

    Burkholderia species are free-living bacteria with a versatile metabolic lifestyle. The genome of B. fungorum LB400 is predicted to encode three different pathways for formaldehyde oxidation: an NAD-linked, glutathione (GSH)-independent formaldehyde dehydrogenase; an NAD-linked, GSH-dependent formaldehyde oxidation system; and a tetrahydromethanopterin-methanofuran-dependent formaldehyde oxidation system. The other Burkholderia species for which genome sequences are available, B. mallei, B. pseudomallei, and B. cepacia, are predicted to contain only the first two of these pathways. The roles of the three putative formaldehyde oxidation pathways in B. fungorum LB400 have been assessed via knockout mutations in each of these pathways, as well as in all combinations of knockouts. The resulting mutants have the expected loss of enzyme activities and exhibit defects of varying degrees of severity during growth on choline, a formaldehyde-producing substrate. Our data suggest that all three pathways are involved in formaldehyde detoxification and are functionally redundant under the tested conditions. PMID:15028703

  14. Commonalities and Differences in Regulation of N-Acyl Homoserine Lactone Quorum Sensing in the Beneficial Plant-Associated Burkholderia Species Cluster? †

    PubMed Central

    Suárez-Moreno, Zulma Rocío; Devescovi, Giulia; Myers, Mike; Hallack, Letícia; Mendonça-Previato, Lucia; Caballero-Mellado, Jesús; Venturi, Vittorio

    2010-01-01

    The genus Burkholderia includes over 60 species isolated from a wide range of environmental niches and can be tentatively divided into two major species clusters. The first cluster includes pathogens such as Burkholderia glumae, B. pseudomallei, and B. mallei and 17 well-studied species of the Burkholderia cepacia complex. The other recently established cluster comprises at least 29 nonpathogenic species, which in most cases have been found to be associated with plants. It was previously established that Burkholderia kururiensis, a member of the latter cluster, possesses an N-acyl homoserine lactone (AHL) quorum-sensing (QS) system designated “BraI/R,” which is found in all species of the plant-associated cluster. In the present study, two other BraI/R-like systems were characterized in B. xenovorans and B. unamae and were designated the BraI/RXEN and BraI/RUNA systems, respectively. Several phenotypes were analyzed, and it was determined that exopolysaccharide was positively regulated by the BraIR-like system in the species B. kururiensis, B. unamae, and B. xenovorans, highlighting commonality in targets. However, the three BraIR-like systems also revealed differences in targets since biofilm formation and plant colonization were differentially regulated. In addition, a second AHL QS system designated XenI2/R2 and an unpaired LuxR solo protein designated BxeR solo were also identified and characterized in B. xenovorans LB400T. The two AHL QS systems of B. xenovorans are not transcriptionally regulating each other, whereas BxeR solo negatively regulated xenI2. The XenI2/R2 and BxeR solo proteins are not widespread in the Burkholderia species cluster. In conclusion, the present study represents an extensive analysis of AHL QS in the Burkholderia plant-associated cluster demonstrating both commonalities and differences, probably reflecting environmental adaptations of the various species. PMID:20435760

  15. Melioidosis-induced septic arthritis of the knee joint after total knee arthroplasty

    Microsoft Academic Search

    Sung-Chun Lin; Hsin-Pai Lee; Chih-Ju Chen; Zhi-Hong Wen; Yen-Hsuan Jean

    2011-01-01

    Melioidosis-induced septic arthritis of the knee joint is a rare condition. To date, no study has reported a case of melioidosis-induced septic arthritis of the knee joint after a total knee arthroplasty (TKA). We report a case of a 68-year-old man who presented with pain and swelling in the right knee for 1 week. He had undergone a TKA because

  16. The Epidemiology and Clinical Spectrum of Melioidosis: 540 Cases from the 20 Year Darwin Prospective Study

    Microsoft Academic Search

    Bart J. Currie; Linda Ward; Allen C. Cheng

    2010-01-01

    BackgroundOver 20 years, from October 1989, the Darwin prospective melioidosis study has documented 540 cases from tropical Australia, providing new insights into epidemiology and the clinical spectrum.Principal FindingsThe principal presentation was pneumonia in 278 (51%), genitourinary infection in 76 (14%), skin infection in 68 (13%), bacteremia without evident focus in 59 (11%), septic arthritis\\/osteomyelitis in 20 (4%) and neurological melioidosis

  17. Use of Suppression-Subtractive Hybridization To Identify Genes in the Burkholderia cepacia Complex That Are Unique to Burkholderia cenocepacia

    Microsoft Academic Search

    Steve P. Bernier; Pamela A. Sokol

    2005-01-01

    We have previously shown differences in virulence between species of the Burkholderia cepacia complex using the alfalfa infection model and the rat agar bead chronic infection model. Burkholderia cenocepacia strains were more virulent in these two infection models than Burkholderia multivorans and Burkholderia stabilis strains. In order to identify genes that may account for the increased virulence of B. cenocepacia,

  18. Evaluation of Recombinant Proteins of Burkholderia mallei for Serodiagnosis of Glanders

    PubMed Central

    Kumar, Subodh; Malik, Praveen

    2012-01-01

    Glanders is a contagious disease caused by the Gram-negative bacillus Burkholderia mallei. The number of equine glanders outbreaks has increased steadily during the last decade. The disease must be reported to the Office International des Epizooties, Paris, France. Glanders serodiagnosis is hampered by the considerable number of false positives and negatives of the internationally prescribed tests. The major problem leading to the low sensitivity and specificity of the complement fixation test (CFT) and enzyme-linked immunosorbent assay (ELISA) has been linked to the test antigens currently used, i.e., crude preparations of whole cells. False-positive results obtained from other diagnostic tests utilizing crude antigens lead to financial losses to animal owners, and false-negative results can turn a risk into a possible threat. In this study, we report on the identification of diagnostic targets using bioinformatics tools for serodiagnosis of glanders. The identified gene sequences were cloned and expressed as recombinant proteins. The purified recombinant proteins of B. mallei were used in an indirect ELISA format for serodiagnosis of glanders. Two recombinant proteins, 0375H and 0375TH, exhibited 100% sensitivity and specificity for glanders diagnosis. The proteins also did not cross-react with sera from patients with the closely related disease melioidosis. The results of this investigation highlight the potential of recombinant 0375H and 0375TH proteins in specific and sensitive diagnosis of glanders. PMID:22695165

  19. The Twin Arginine Translocation System Is Essential for Aerobic Growth and Full Virulence of Burkholderia thailandensis

    PubMed Central

    Wagley, Sariqa; Hemsley, Claudia; Thomas, Rachael; Moule, Madeleine G.; Vanaporn, Muthita; Andreae, Clio; Robinson, Matthew; Goldman, Stan; Wren, Brendan W.; Butler, Clive S.

    2014-01-01

    The twin arginine translocation (Tat) system in bacteria is responsible for transporting folded proteins across the cytoplasmic membrane, and in some bacteria, Tat-exported substrates have been linked to virulence. We report here that the Tat machinery is present in Burkholderia pseudomallei, B. mallei, and B. thailandensis, and we show that the system is essential for aerobic but not anaerobic growth. Switching off of the Tat system in B. thailandensis grown anaerobically resulted in filamentous bacteria, and bacteria showed increased sensitivity to some ?-lactam antibiotics. In Galleria mellonella and zebrafish infection models, the Tat conditional mutant was attenuated. The aerobic growth-restricted phenotype indicates that Tat substrates may play a functional role in oxygen-dependent energy conservation. In other bacteria, aerobic growth restriction in Tat mutants has been attributed to the inability to translocate PetA, the Rieske iron-sulfur protein which forms part of the quinol-cytochrome c oxidoreductase complex. Here, we show that PetA is not responsible for aerobic growth restriction in B. thailandensis. However, we have identified an operon encoding 2 proteins of unknown function (BTH_I2176 and BTH_I2175) that play a role in aerobic growth restriction, and we present evidence that BTH_I2176 is Tat translocated. PMID:24214943

  20. Gene and Protein Expression in Response to Different Growth Temperatures and Oxygen Availability in Burkholderia thailandensis

    PubMed Central

    Peano, Clelia; Chiaramonte, Fabrizio; Motta, Sara; Pietrelli, Alessandro; Jaillon, Sebastien; Rossi, Elio; Consolandi, Clarissa; Champion, Olivia L.; Michell, Stephen L.; Freddi, Luca; Falciola, Luigi; Basilico, Fabrizio; Garlanda, Cecilia; Mauri, Pierluigi; De Bellis, Gianluca; Landini, Paolo

    2014-01-01

    Burkholderia thailandensis, although normally avirulent for mammals, can infect macrophages in vitro and has occasionally been reported to cause pneumonia in humans. It is therefore used as a model organism for the human pathogen B. pseudomallei, to which it is closely related phylogenetically. We characterized the B. thailandensis clinical isolate CDC2721121 (BtCDC272) at the genome level and studied its response to environmental cues associated with human host colonization, namely, temperature and oxygen limitation. Effects of the different growth conditions on BtCDC272 were studied through whole genome transcription studies and analysis of proteins associated with the bacterial cell surface. We found that growth at 37°C, compared to 28°C, negatively affected cell motility and flagella production through a mechanism involving regulation of the flagellin-encoding fliC gene at the mRNA stability level. Growth in oxygen-limiting conditions, in contrast, stimulated various processes linked to virulence, such as lipopolysaccharide production and expression of genes encoding protein secretion systems. Consistent with these observations, BtCDC272 grown in oxygen limitation was more resistant to phagocytosis and strongly induced the production of inflammatory cytokines from murine macrophages. Our results suggest that, while temperature sensing is important for regulation of B. thailandensis cell motility, oxygen limitation has a deeper impact on its physiology and constitutes a crucial environmental signal for the production of virulence factors. PMID:24671187

  1. Occurrence of Multiple Genomovars of Burkholderia cepacia in Cystic Fibrosis Patients and Proposal of Burkholderia multivorans sp. nov

    Microsoft Academic Search

    P. VANDAMME; B. HOLMES; M. VANCANNEYT; T. COENYE; B. HOSTE; R. COOPMAN; H. REVETS; S. LAUWERS; M. GILLIS; K. KERSTERS; J. R. W. GOVAN

    We performed an integrated genotypic and phenotypic analysis of 128 strains of the genera Burkholderia, Rabtonia, and Pseudomonas in order to study the taxonomic structure of Burkholderia cepacia and its relation- ships with other Burkholderia species. Our data show that presumed B. cepacia strains isolated from cystic fibrosis patients belong to at least five distinct genomic species, one of which

  2. Burkholderia cepacia genomovar VI, a new member of the Burkholderia cepacia complex isolated from cystic fibrosis patients

    Microsoft Academic Search

    Tom Coenye; John J. LiPuma; Deborah Henry; Bart Hoste; Katrien Vandemeulebroecke; Monique Gillis; David P. Speert; Peter Vandamme

    A polyphasic taxonomic study was performed on 23 strains isolated from cystic fibrosis (CF) patients in the USA. These strains were tentatively identified as Burkholderia cepacia, Burkholderia vietnamiensis and Burkholderia or Ralstonia sp. using biochemical tests and 16S rDNA-based PCR assays. Visual comparison of protein profiles indicated that they belonged to a single new group ('group 13'). The polyphasic taxonomic

  3. Host Evasion by Burkholderia cenocepacia

    PubMed Central

    Ganesan, Shyamala; Sajjan, Umadevi S.

    2012-01-01

    Burkholderia cenocepacia is an opportunistic respiratory pathogen of individuals with cystic fibrosis (CF). Some strains of B. cenocepacia are highly transmissible and resistant to almost all antibiotics. Approximately one-third of B. cenocepacia infected CF patients go on to develop fatal “cepacia syndrome.” During the last two decades, substantial progress has been made with regards to evasion of host innate defense mechanisms by B. cenocepacia. Almost all strains of B. cenocepacia have the capacity to survive and replicate intracellularly in both airway epithelial cells and macrophages, which are primary sentinels of the lung and play a pivotal role in clearance of infecting bacteria. Those strains of B. cenocepacia, which express both cable pili and the associated 22?kDa adhesin are also capable of transmigrating across airway epithelium and persist in mouse models of infection. In this review, we will discuss how this type of interaction between B. cenocepacia and host may lead to persistence of bacteria as well as lung inflammation in CF patients. PMID:22919590

  4. Mapping the Burkholderia cenocepacia niche response via high-throughput sequencing

    E-print Network

    Sorek, Rotem

    Mapping the Burkholderia cenocepacia niche response via high-throughput sequencing D. R. Yoder and endemic soil dweller, Burkholderia cenocepacia, in conditions mimicking these 2 environments different environments, we took advantage of the uniquely disparate natural ecologies of Burkholderia

  5. Burkholderia monticola sp. nov., isolated from mountain soil.

    PubMed

    Baek, Inwoo; Seo, Boram; Lee, Imchang; Yi, Hana; Chun, Jongsik

    2015-02-01

    An ivory/yellow, Gram-stain-negative, short-rod-shaped, aerobic bacterial strain, designated JC2948(T), was isolated from a soil sample taken from Gwanak Mountain, Republic of Korea. 16S rRNA gene sequence analysis indicated that strain JC2948(T) belongs to the genus Burkholderia. The test strain showed highest sequence similarities to Burkholderia tropica LMG 22274(T) (97.6 %), Burkholderia acidipaludis NBRC 101816(T) (97.5 %), Burkholderia tuberum LMG 21444(T) (97.5 %), Burkholderia sprentiae LMG 27175(T) (97.4 %), Burkholderia terricola LMG 20594(T) (97.3 %) and Burkholderia diazotrophica LMG 26031(T) (97.1 %). Based on average nucleotide identity (ANI) values, the new isolate represents a novel genomic species as it shows less than 90 % ANI values with other closely related species. Also, other phylosiological and biochemical comparisons allowed the phenotypic differentiation of strain JC2948(T) from other members of the genus Burkholderia. Therefore, we suggest that this strain should be classified as the type strain of a novel species of the genus Burkholderia. The name Burkholderia monticola sp. nov. (type strain, JC2948(T)?= JCM 19904(T)?= KACC 17924(T)) is proposed. PMID:25472981

  6. Biological activity of Burkholderia (Pseudomonas) cepacia lipopolysaccharide

    Microsoft Academic Search

    Deborah Shaw; Ian R. Poxton; John R. W. Govan

    1995-01-01

    Burkholderia cepacia has emerged as an important multiresistant pathogen in cystic fibrosis (CF), associated in 20% of colonised patients with a rapid and fatal decline in lung function. Although knowledge of B. cepacia epidemiology has improved, the mechanisms involved in pathogenesis remain obscure. In this study, B. cepacia lipopolysaccharide (LPS) was assessed for endotoxic potential and the capacity to induce

  7. The multifarious, multireplicon Burkholderia cepacia complex

    Microsoft Academic Search

    Eshwar Mahenthiralingam; Teresa A. Urban; Joanna B. Goldberg

    2005-01-01

    The Burkholderia cepacia complex (Bcc) is a collection of genetically distinct but phenotypically similar bacteria that are divided into at least nine species. Bcc bacteria are found throughout the environment, where they can have both beneficial and detrimental effects on plants and some members can also degrade natural and man-made pollutants. Bcc bacteria are now recognized as important opportunistic pathogens

  8. Invasion and Intracellular Survival of Burkholderia cepacia

    Microsoft Academic Search

    DANIEL W. MARTIN; CHRISTIAN D. MOHR

    2000-01-01

    Burkholderia cepacia has emerged as an important pulmonary pathogen in immunocompromised patients and in patients with cystic fibrosis (CF). Little is known about the virulence factors and pathogenesis of B. cepacia, although the persistent and sometimes invasive infections caused by B. cepacia suggest that the organism possesses mechanisms for both cellular invasion and evasion of the host immune response. In

  9. Genomic complexity and plasticity of Burkholderia cepacia

    Microsoft Academic Search

    Thomas G. Lessie; William Hendrickson; Brendan D. Manning; Richard Devereux

    1996-01-01

    Burkholderia cepacia has attracted attention because of its extraordinary degradative abilities and its potential as a pathogen for plants and for humans. This bacterium was formerly considered to belong to the genus Pseudomonas in the ?-subclass of the Proteobacteria, but recently has been assigned to the ?-subclass based on rrn gene sequence analyses and other key phenotypic characteristics. The B.

  10. Burkholderia cepacia: medical, taxonomic and ecological issues

    Microsoft Academic Search

    J. R. W. Govan; JAYNE E. HUGHES; P. Vandamme

    1996-01-01

    The increasing challenge posed by multiresistant saprophytes in medical microbiology is strikingly demonstrated by the emergence of Burkholderia (formerly Pseudomonas) cepacia as an opportunist pathogen in immunocompromised patients, particularly individuals with chronic granulomatous disease and cystic fibrosis (CF). Best known previously as a phytopathogen and the cause of soft rot of onions, B. cepacia presents three major problems for the

  11. Expanded Multilocus Sequence Typing for Burkholderia Species

    Microsoft Academic Search

    Theodore Spilker; Adam Baldwin; Amy Bumford; Chris G. Dowson; Eshwar Mahenthiralingam; John J. LiPuma

    2009-01-01

    The multilocus sequence typing (MLST) scheme for the Burkholderia cepacia complex has provided important insights into the population dynamics, diversity, and recombination events in this group of opportunistic pathogens (1-3, 7). It has also been effective in identifying previously misclassified strains and has proved useful in the recent identification of seven novel species in the B. cepacia complex (9, 10).

  12. Burkholderia anthina sp. nov. and Burkholderia pyrrocinia, two additional Burkholderia cepacia complex bacteria, may confound results of new molecular diagnostic tools

    Microsoft Academic Search

    Peter Vandamme; Deborah Henry; Tom Coenye; Sazini Nzula; Marc Vancanneyt; John J. LiPuma; David P. Speert; John R. W. Govan; Eshwar Mahenthiralingam

    2002-01-01

    Nineteen Burkholderia cepacia-like isolates of human and environmental origin could not be assigned to one of the seven currently established genomovars using recently developed molecular diagnostic tools for B. cepacia complex bacteria. Various genotypic and phenotypic characteristics were examined. The results of this polyphasic study allowed classification of the 19 isolates as an eighth B. cepacia complex genomovar (Burkholderia anthina

  13. Splenic Abscesses in a Returning Traveler

    PubMed Central

    Guo, Richard F.; Wong, Frances L.; Perez, Mario L.

    2015-01-01

    Burkholderia, an aerobic gram-negative rod, is the causative organism behind melioidosis and is a common soil and water organism found predominantly in South-East Asia. We report the case of a 68 year-old man returning from an extended trip to the Philippines, with splenic hypodense lesions on abdominal computer tomography scan, later confirmed to be culture-positive for Burkholderia pseudomallei. The patient was treated with a course of intravenous ceftazidime followed by eradication therapy with oral doxycycline and trimethoprim-sulfamethoxazole. He recovered with complete resolution of symptoms at follow up. In a returning traveler from an endemic area, melioidosis should be considered as part of the differential for any febrile illness with abscesses. PMID:25874071

  14. Burkholderia graminis sp. nov., a rhizospheric Burkholderia species, and reassessment of [Pseudomonas] phenazinium, [Pseudomonas] pyrrocinia and [Pseudomonas] glathei as Burkholderia

    Microsoft Academic Search

    Vkronique Viallard; Isabelle Poirier; Benoit Cournoyer; Jacqueline Haurat; Sue Wiebkin; Kathy Ophel-Keller; J. Balandreau

    1998-01-01

    In a survey of soil and wheat or maize rhizoplane bacteria isolated using a medium containing azelaic acid and tryptamine as sole carbon and nitrogen sources, respectively, a large proportion of Burkholderia-l i ke bacteria were found. Among them, a homogeneous group of strains was identifiable based on phenotypic properties, fatty acid composition, DNA-DNA hybridizations and 16s rDNA sequences. According

  15. Diagnostically and Experimentally Useful Panel of Strains from the Burkholderia cepacia Complex

    Microsoft Academic Search

    ESHWAR MAHENTHIRALINGAM; TOM COENYE; JACQUELINE W. CHUNG; DAVID P. SPEERT

    Two new species, Burkholderia multivorans and Burkholderia vietnamiensis, and three genomovars (genomo- vars I, III, and IV) currently constitute the Burkholderia cepacia complex. A panel of 30 well-characterized strains representative of each genomovar and new species was assembled to assist with identification, epide- miological analysis, and virulence studies on this important group of opportunistic pathogens. The gram-negative bacterium Burkholderia cepacia

  16. Genomic Analysis of Burkholderia And Rhodococcus equi Bacteriophages

    E-print Network

    Orchard II, Robert C.

    2011-08-04

    GENOMIC ANALYSIS OF Burkholderia AND Rhodococcus equi BACTERIOPHAGES Major: Microbiology April 2008 Submitted to the Office of Undergraduate Research Texas A&M University in partial fulfillment of the requirements... for the designation as UNDERGRADUATE RESEARCH SCHOLAR A Senior Scholars Thesis by ROBERT CHARLES ORCHARD II GENOMIC ANALYSIS OF Burkholderia AND Rhodococcus equi BACTERIOPHAGES Approved by: Research Advisor: Elizabeth Summer Associate Dean...

  17. Identification and Population Structure of Burkholderia stabilis sp. nov. (formerly Burkholderia cepacia Genomovar IV)

    Microsoft Academic Search

    P. VANDAMME; E. MAHENTHIRALINGAM; B. HOLMES; T. COENYE; B. HOSTE; P. DE VOS; D. HENRY; D. P. SPEERT

    The Burkholderia cepacia complex currently comprises five genomic species, i.e., B. cepacia genomovar I, B. multivorans (formerly known as B. cepacia genomovar II), B. cepacia genomovar III, B. cepacia genomovar IV, and B. vietnamiensis (also known as B. cepacia genomovar V). In the absence of straightforward diagnostic tests for the identification of B. cepacia genomovars I, III, and IV, the

  18. Glutathione deficiency in type 2 diabetes impairs cytokine responses and control of intracellular bacteria.

    PubMed

    Tan, Kai Soo; Lee, Kok Onn; Low, Kee Chung; Gamage, Akshamal Mihiranga; Liu, Yichun; Tan, Gek-Yen Gladys; Koh, Hui Qi Vanessa; Alonso, Sylvie; Gan, Yunn-Hwen

    2012-06-01

    Individuals with type 2 diabetes are at increased risk of acquiring melioidosis, a disease caused by Burkholderia pseudomallei infection. Although up to half of melioidosis patients have underlying diabetes, the mechanisms involved in this increased susceptibility are unknown. We found that B. pseudomallei-infected PBMCs from diabetic patients were impaired in IL-12p70 production, which resulted in decreased IFN-? induction and poor bacterial killing. The defect was specific to the IL-12-IFN-? axis. Defective IL-12 production was also observed during Mycobacterium tuberculosis infection, in which diabetes is likewise known to be a strong risk factor. In contrast, IL-12 production in diabetic cells was not affected upon Salmonella enterica infection or in response to TLR2, -3, -4, and -5 ligands. Poor IL-12 production correlated with a deficiency in intracellular reduced glutathione (GSH) concentrations in diabetic patients. Addition of GSH or N-acetylcysteine to PBMCs selectively restored IL-12 and IFN-? production and improved bacterial killing. Furthermore, the depletion of GSH in mice led to increased susceptibility to melioidosis, reduced production of IL-12p70, and poorer disease outcome. Our data thus establish a link between GSH deficiency in diabetes and increased susceptibility to melioidosis that may open up new therapeutic avenues to protect diabetic patients against some intracellular bacterial pathogens. PMID:22546856

  19. Biocide susceptibility of the Burkholderia cepacia complex

    PubMed Central

    Rose, Helen; Baldwin, Adam; Dowson, Christopher G.; Mahenthiralingam, Eshwar

    2009-01-01

    Objectives The Burkholderia cepacia complex (Bcc) species are important opportunistic pathogens with intrinsic antibiotic resistance. They are also well known as contaminants of disinfectants, yet their biocide susceptibility has not been studied in detail. We investigated Bcc biocide susceptibility and correlated it to their taxonomy, antibiotic susceptibility and ability to form biofilms. Methods Genetically distinct Bcc strains belonging to 12 of the defined species were examined. Biocide susceptibility was assessed by (i) broth dilution MIC assays, (ii) agar growth-based MBC screens and (iii) suspension tests. Antibiotic MIC was determined by Etest® strips, and the ability to form biofilms was examined in a 96-well plate assay. Results Biocide susceptibility varied across the Bcc complex with high MIC recorded for chlorhexidine (>100 mg/L), cetylpyridinium chloride (>200 mg/L), triclosan (>500 mg/L), benzalkonium chloride (>400 mg/L) and povidone (>50?000 mg/L). Species-dependent differences were apparent only for cetylpyridinium chloride. There was no correlation between biocide susceptibility and (i) antibiotic susceptibility or (ii) the ability to form biofilms. Biocide MBC was considerably higher than the MIC (chlorhexidine, 6-fold greater; cetylpyridinium chloride, 20-fold greater). Cystic fibrosis outbreak strains (Burkholderia multivorans Glasgow strain and Burkholderia cenocepacia ET12) possessed elevated chlorhexidine resistance, and Bcc bacteria were also shown to remain viable in current commercial biocide formulations. Conclusions Bcc bacteria are resistant to a wide range of biocides and further representatives of this group should be included as reference strains in the development of new anti-infectives and commercial formulations. PMID:19153076

  20. Genomic Analysis of Burkholderia And Rhodococcus equi Bacteriophages 

    E-print Network

    Orchard II, Robert C.

    2011-08-04

    ). Rhodococcus equi is an intracellular pathogen which invades the macrophages of immunocompromised individuals such as young foals. While phylogenetically R. equi, a Gram-positive bacterium, and Burkholderia, Gram-negative bacteria, are unrelated, they both...

  1. Clonally related Burkholderia contaminans among ventilated patients without cystic fibrosis.

    PubMed

    Peterson, Amy E; Chitnis, Amit S; Xiang, Nan; Scaletta, Joseph M; Geist, Robert; Schwartz, Jennifer; Dement, Jamie; Lawlor, Elizabeth; Lipuma, John J; O'Connell, Heather; Noble-Wang, Judith; Kallen, Alexander J; Hunt, D Charles

    2013-12-01

    We investigated a cluster of 10 Burkholderia cepacia complex-positive cultures among ventilated patients and those with a tracheostomy in an acute care hospital. Isolates from 5 patients had outbreak-strain-related Burkholderia contaminans. Isolates of B. cepacia complex unrelated to the outbreak strain were cultured from a sink drain. The investigation identified practices that might have led to contamination of patient respiratory care supplies with tap water, which might have contributed to the cluster. PMID:23973426

  2. Burkholderia cepacia: current clinical issues, environmental controversies and ethical dilemmas

    Microsoft Academic Search

    A. M. Jones; M. E. Dodd; A. K. Webb

    2001-01-01

    Burkholderia cepacia: current clinical issues, environmental controversies and ethical dilemmas. A.M. Jones, M.E. Dodd, A.K. Webb. #ERS Journals Ltd 2001. ABSTRACT: Burkholderia cepacia is a plant phytogen and is known as a hardy and versatile organism. Over the past two decades it has emerged as a pathogen in the cystic fibrosis (CF) community, with devastating effects. Pulmonary colonisation can lead

  3. VgrG-5 Is a Burkholderia Type VI Secretion System-Exported Protein Required for Multinucleated Giant Cell Formation and Virulence

    PubMed Central

    Singh, Pragya; Robertson, Johanna D.; LeRoux, Michele; Skerrett, Shawn J.; Goodlett, David R.; West, T. Eoin; Mougous, Joseph D.

    2014-01-01

    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 group, the effector repertoire of T6SS-5 has remained elusive. Here we used quantitative mass spectrometry to compare the secretome of wild-type B. thailandensis to that of a mutant harboring a nonfunctional T6SS-5. This analysis identified VgrG-5 as a novel secreted protein whose export depends on T6SS-5 function. Bioinformatics analysis revealed that VgrG-5 is a specialized VgrG protein that harbors a C-terminal domain (CTD) conserved among Bptm group species. We found that a vgrG-5 ?CTD mutant is avirulent in mice and is unable to stimulate the fusion of host cells, a hallmark of the Bptm group previously shown to require T6SS-5 function. The singularity of VgrG-5 as a detected T6SS-5 substrate, taken together with the essentiality of its CTD for virulence, suggests that the protein is critical for the effector activity of T6SS-5. Intriguingly, we show that unlike the bacterial-cell-targeting T6SSs characterized so far, T6SS-5 localizes to the bacterial cell pole. We propose a model whereby the CTD of VgrG-5—, propelled by T6SS-5—, plays a key role in inducing membrane fusion, either by the recruitment of other factors or by direct participation. PMID:24452686

  4. Burkholderia Type VI Secretion Systems Have Distinct Roles in Eukaryotic and Bacterial Cell Interactions

    PubMed Central

    Schwarz, Sandra; West, T. Eoin; Boyer, Frédéric; Chiang, Wen-Chi; Carl, Mike A.; Hood, Rachel D.; Rohmer, Laurence; Tolker-Nielsen, Tim; Skerrett, Shawn J.; Mougous, Joseph D.

    2010-01-01

    Bacteria that live in the environment have evolved pathways specialized to defend against eukaryotic organisms or other bacteria. In this manuscript, we systematically examined the role of the five type VI secretion systems (T6SSs) of Burkholderia thailandensis (B. thai) in eukaryotic and bacterial cell interactions. Consistent with phylogenetic analyses comparing the distribution of the B. thai T6SSs with well-characterized bacterial and eukaryotic cell-targeting T6SSs, we found that T6SS-5 plays a critical role in the virulence of the organism in a murine melioidosis model, while a strain lacking the other four T6SSs remained as virulent as the wild-type. The function of T6SS-5 appeared to be specialized to the host and not related to an in vivo growth defect, as ?T6SS-5 was fully virulent in mice lacking MyD88. Next we probed the role of the five systems in interbacterial interactions. From a group of 31 diverse bacteria, we identified several organisms that competed less effectively against wild-type B. thai than a strain lacking T6SS-1 function. Inactivation of T6SS-1 renders B. thai greatly more susceptible to cell contact-induced stasis by Pseudomonas putida, Pseudomonas fluorescens and Serratia proteamaculans—leaving it 100- to 1000-fold less fit than the wild-type in competition experiments with these organisms. Flow cell biofilm assays showed that T6S-dependent interbacterial interactions are likely relevant in the environment. B. thai cells lacking T6SS-1 were rapidly displaced in mixed biofilms with P. putida, whereas wild-type cells persisted and overran the competitor. Our data show that T6SSs within a single organism can have distinct functions in eukaryotic versus bacterial cell interactions. These systems are likely to be a decisive factor in the survival of bacterial cells of one species in intimate association with those of another, such as in polymicrobial communities present both in the environment and in many infections. PMID:20865170

  5. Evaluation of Immunoglobulin M (IgM) and IgG Rapid Cassette Test Kits for Diagnosis of Melioidosis in an Area of Endemicity

    Microsoft Academic Search

    Vanaporn Wuthiekanun; Premjit Amornchai; Wirongrong Chierakul; Allen C. Cheng; Nicholas J. White; Sharon J. Peacock; Nicholas P. J. Day

    2004-01-01

    An enzyme-linked immunosorbent assay-based rapid cassette immunoglobulin G (IgG) and IgM immuno- chromogenic test kit was compared to the indirect hemagglutination test (IHA) for the diagnosis of acute melioidosis in northeastern Thailand. Admission sera from 70 culture-confirmed septicemic melioidosis patients and 30 patients with localized infections were tested. As a control group, 80 patients with other acute febrile illnesses (other

  6. 9 CFR 121.9 - Responsible official.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...email: African horse sickness virus, African swine fever virus, avian influenza virus (highly pathogenic), Bacillus anthracis, Burkholderia mallei, Burkholderia pseudomallei, classical swine fever virus, foot-and-mouth...

  7. 9 CFR 121.9 - Responsible official.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...email: African horse sickness virus, African swine fever virus, avian influenza virus (highly pathogenic), Bacillus anthracis, Burkholderia mallei, Burkholderia pseudomallei, classical swine fever virus, foot-and-mouth...

  8. Wayne State University Office of Environmental Health & Safety

    E-print Network

    Finley Jr., Russell L.

    melitensis (cultures only) · Brucella suis (cultures only) · Burkholderia mallei - Pseudomonas mallei - Glanders (cultures only) · Burkholderia pseudomalli - Pseudomonas pseudomallei (cultures only) · Chlamydia

  9. 42 CFR 73.9 - Responsible Official.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...neurotoxin producing species of Clostridium, Burkholderia mallei, Burkholderia pseudomallei, Francisella tularensis, Ebola viruses, Marburg virus, Variola major virus (Smallpox virus), Variola minor (Alastrim), or Yersinia pestis....

  10. 42 CFR 73.9 - Responsible Official.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...neurotoxin producing species of Clostridium, Burkholderia mallei, Burkholderia pseudomallei Francisella tularensis, Ebola viruses, , Marburg virus, Variola major virus (Smallpox virus), Variola minor (Alastrim), or Yersinia pestis....

  11. Title : Liquid C. elegans culture for the study of Burkholderia pathogenesis Authors : Vaughn Cooper1

    E-print Network

    Title : Liquid C. elegans culture for the study of Burkholderia pathogenesis Authors : Vaughn and allows the study of Burkholderia infection in pure liquid C. elegans cultures, in which each competitor

  12. Conservation of a novel protein associated with an antibiotic efflux operon in Burkholderia cenocepacia

    E-print Network

    Chattopadhyay, Sujay

    Conservation of a novel protein associated with an antibiotic efflux operon in Burkholderia Burkholderia cenocepacia is a significant problem in individuals with cystic fibrosis and is a member of the B Microbiological Societies. Published by Elsevier B.V. All rights reserved. Keywords: Burkholderia cenocepacia

  13. Saturation Mutagenesis of 2,4-DNT Dioxygenase of Burkholderia sp. Strain DNT

    E-print Network

    Wood, Thomas K.

    Saturation Mutagenesis of 2,4-DNT Dioxygenase of Burkholderia sp. Strain DNT for Enhanced this study indicated that the 2,4-DNT dioxygenases of Burkholderia sp. strain DNT and B. cepacia R34 are more). Burkholderia sp. strain DNT was isolated from water samples from Waconda Bay near the Volunteer Army Ammunition

  14. South African Papilionoid Legumes Are Nodulated by Diverse Burkholderia with Unique Nodulation and

    E-print Network

    South African Papilionoid Legumes Are Nodulated by Diverse Burkholderia with Unique Nodulation reports suggest the occurrence of nodulating Burkholderia species unique to the region. In this study, we considered the diversity and evolution of nodulating Burkholderia associated with the endemic papilionoid

  15. DNA binding site analysis of Burkholderia thailandensis response regulators Kristy L. Nowak-Lovato a

    E-print Network

    Bulyk, Martha L.

    DNA binding site analysis of Burkholderia thailandensis response regulators Kristy L. Nowak Keywords: Response regulator Protein-binding microarray Promoter binding site Burkholderia Two component (PBM) to discover DNA binding motifs for RRs expressed in Burkholderia, a Gram-negative bacterial genus

  16. 21 CFR 866.3415 - Pseudomonas spp. serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...abscesses, and meningitis (inflammation of brain membranes). Pseudomonas pseudomallei causes melioidosis, a chronic pneumonia. (b) Classification. Class II (special controls). The device is exempt from the premarket notification...

  17. 21 CFR 866.3415 - Pseudomonas spp. serological reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...abscesses, and meningitis (inflammation of brain membranes). Pseudomonas pseudomallei causes melioidosis, a chronic pneumonia. (b) Classification. Class II (special controls). The device is exempt from the premarket notification...

  18. Identification and Population Structure of Burkholderia stabilis sp. nov. (formerly Burkholderia cepacia Genomovar IV)

    PubMed Central

    Vandamme, P.; Mahenthiralingam, E.; Holmes, B.; Coenye, T.; Hoste, B.; De Vos, P.; Henry, D.; Speert, D. P.

    2000-01-01

    The Burkholderia cepacia complex currently comprises five genomic species, i.e., B. cepacia genomovar I, B. multivorans (formerly known as B. cepacia genomovar II), B. cepacia genomovar III, B. cepacia genomovar IV, and B. vietnamiensis (also known as B. cepacia genomovar V). In the absence of straightforward diagnostic tests for the identification of B. cepacia genomovars I, III, and IV, the last two genomic species were not formally classified as novel Burkholderia species (genomovar I contains the type strain and therefore retains the name B. cepacia). In the present study, we describe differential biochemical tests and a recA gene-based PCR assay for the routine identification of strains currently known as B. cepacia genomovar IV and propose formal classification of this organism as Burkholderia stabilis sp. nov. B. stabilis can indeed be differentiated from all other B. cepacia complex strains by the absence of beta-galactosidase activity, from strains of B. cepacia genomovars I and III and B. vietnamiensis by the inability to oxidize sucrose, and from B. multivorans by the lack of growth at 42°C. In addition, analysis with the recA gene-derived primers BCRG41 (5?-ACCGGCGAGCAGGCGCTT-3?) and BCRG42 (5?-ACGCCATCGGGCATGGCA-3?) specifically allows the detection of B. stabilis strains in a conventional PCR assay. Examination of a set of 21 B. stabilis strains by means of random amplified polymorphic DNA analysis and pulsed-field gel electrophoresis typing suggested that the genome of this organism is highly conserved, which is in sharp contrast to the generally accepted genomic diversity, variability, and plasticity among B. cepacia strains. PMID:10698993

  19. Bacterial gene loss as a mechanism for gain of antimicrobial resistance

    PubMed Central

    Török, ME; Chantratita, N; Peacock, SJ

    2012-01-01

    Acquisition of exogenous DNA by pathogenic bacteria represents the basis for much of the acquired antimicrobial resistance in pathogenic bacteria. A more extreme mechanism to avoid the effect of an antibiotic is to delete the drug target, although this would be predicted to be rare since drug targets are often essential genes. Here, we review and discuss the description of a novel mechanism of resistance to the cephalosporin drug ceftazidime caused by loss of a penicillin-binding protein (PBP) in a Gram-negative bacillus (Burkholderia pseudomallei). This organism causes melioidosis across south-east Asia and northern Australia, and is usually treated with two or more weeks of ceftazidime followed by oral antibiotics for three to six months. Comparison of clinical isolates from six patients with melioidosis found initial ceftazidime-susceptible isolates and subsequent ceftazidime-resistant variants. The latter failed to grow on commonly used culture media, rendering these isolates difficult to detect in the diagnostic laboratory. Genomic analysis using pulsed-field gel electrophoresis and array based genomic hybridisation revealed a large-scale genomic deletion comprising 49 genes in the ceftazidime-resistant strains. Mutational analysis of wild-type B. pseudomallei demonstrated that ceftazidime resistance was due to deletion of a gene encoding a PBP 3 present within the region of genomic loss. This provides one explanation for ceftazidime treatment failure, and may be a frequent but undetected event in patients with melioidosis. PMID:23022568

  20. Cytokine Gene Expression in Innately Susceptible BALB\\/c Mice and Relatively Resistant C57BL\\/6 Mice during Infection with Virulent Burkholderia pseudomallei

    Microsoft Academic Search

    GLEN C. ULETT; NATKUNAM KETHEESAN; ROBERT G. HIRST

    2000-01-01

    Production of cytokines including gamma interferon (IFN-g) and tumor necrosis factor alpha (TNF-a )i s an important early-stage host response following infection with intracellular pathogens. Development of immunity to these pathogens is determined to a large extent by the timing and relative level of expression of the cytokines. Numerous studies have shown that early cytokine responses involving interleukin-12 (IL-12) and

  1. Symbiotic ß-Proteobacteria beyond Legumes: Burkholderia in Rubiaceae

    PubMed Central

    Verstraete, Brecht; Janssens, Steven; Smets, Erik; Dessein, Steven

    2013-01-01

    Symbiotic ß-proteobacteria not only occur in root nodules of legumes but are also found in leaves of certain Rubiaceae. The discovery of bacteria in plants formerly not implicated in endosymbiosis suggests a wider occurrence of plant-microbe interactions. Several ß-proteobacteria of the genus Burkholderia are detected in close association with tropical plants. This interaction has occurred three times independently, which suggest a recent and open plant-bacteria association. The presence or absence of Burkholderia endophytes is consistent on genus level and therefore implies a predictive value for the discovery of bacteria. Only a single Burkholderia species is found in association with a given plant species. However, the endophyte species are promiscuous and can be found in association with several plant species. Most of the endophytes are part of the plant-associated beneficial and environmental group, but others are closely related to B. glathei. This soil bacteria, together with related nodulating and non-nodulating endophytes, is therefore transferred to a newly defined and larger PBE group within the genus Burkholderia. PMID:23372845

  2. Symbiotic ß-proteobacteria beyond legumes: Burkholderia in Rubiaceae.

    PubMed

    Verstraete, Brecht; Janssens, Steven; Smets, Erik; Dessein, Steven

    2013-01-01

    Symbiotic ß-proteobacteria not only occur in root nodules of legumes but are also found in leaves of certain Rubiaceae. The discovery of bacteria in plants formerly not implicated in endosymbiosis suggests a wider occurrence of plant-microbe interactions. Several ß-proteobacteria of the genus Burkholderia are detected in close association with tropical plants. This interaction has occurred three times independently, which suggest a recent and open plant-bacteria association. The presence or absence of Burkholderia endophytes is consistent on genus level and therefore implies a predictive value for the discovery of bacteria. Only a single Burkholderia species is found in association with a given plant species. However, the endophyte species are promiscuous and can be found in association with several plant species. Most of the endophytes are part of the plant-associated beneficial and environmental group, but others are closely related to B. glathei. This soil bacteria, together with related nodulating and non-nodulating endophytes, is therefore transferred to a newly defined and larger PBE group within the genus Burkholderia. PMID:23372845

  3. Siderophore Production by Cystic Fibrosis Isolates of Burkholderia cepacia

    Microsoft Academic Search

    PATRICIA DARLING; MARIA CHAN; ANDREW D. COX; PAMELA A. SOKOL

    Sixty-one Burkholderia cepacia isolates from patients with cystic fibrosis (CF) and four plant isolates were screened for production of the siderophores salicylic acid (SA), pyochelin, cepabactin, and ornibactins and fingerprinted by a PCR-based randomly amplified polymorphic DNA (RAPD) method. Of the 24 RAPD types determined, 22 (92%) were associated with isolates that produced SA, 21 (87%) were associated with isolates

  4. Burkholderia cepacia complex infection in patients with cystic fibrosis

    Microsoft Academic Search

    ESHWAR MAHENTHIRALINGAM; ADAM BALDWIN; PETER VANDAMME

    2002-01-01

    The word 'complex' has several meanings and synonyms such as composite, obsession, heterogeneous, mixed and network, can all be used in its place. Our obsession with bacteria from the Burkholderia cepacia complex started in the early 1990s. In less than 10 years, we have seen the status of this bacterium move from: (i) a lesser known pseudomonad opportunist pathogen, (ii)

  5. Genetic structure of a lotic population of Burkholderia (Pseudomonas) cepacia

    Microsoft Academic Search

    M. G. Wise; L. J. Shimkets; J. V. McArthur

    1995-01-01

    The genetic structure of a population of Burkholderia (Pseudomonas) cepacia isolated from a southeastern blackwater stream was investigated by using multilocus enzyme electrophoresis to examine the allelic variation in eight structural gene loci. Overall, 213 isolates were collected at transect points along the stream continuum, from both the sediments along the bank and the water column. Multilocus enzyme electrophoresis analysis

  6. Complete Genome Sequence of Burkholderia cepacia Strain LO6.

    PubMed

    Belcaid, Mahdi; Kang, Yun; Tuanyok, Apichai; Hoang, Tung T

    2015-01-01

    Burkholderia cepacia strain LO6 is a betaproteobacterium that was isolated from a cystic fibrosis patient. Here we report the 6.4 Mb draft genome sequence assembled into 2 contigs. This genome sequence will aid the transcriptomic profiling of this bacterium and help us to better understand the mechanisms specific to pulmonary infections. PMID:26067955

  7. Complete Genome Sequence of Burkholderia cepacia Strain LO6

    PubMed Central

    Belcaid, Mahdi; Kang, Yun; Tuanyok, Apichai

    2015-01-01

    Burkholderia cepacia strain LO6 is a betaproteobacterium that was isolated from a cystic fibrosis patient. Here we report the 6.4 Mb draft genome sequence assembled into 2 contigs. This genome sequence will aid the transcriptomic profiling of this bacterium and help us to better understand the mechanisms specific to pulmonary infections. PMID:26067955

  8. Burkholderia thailandensis oacA Mutants Facilitate the Expression of Burkholderia mallei-Like O Polysaccharides?

    PubMed Central

    Brett, Paul J.; Burtnick, Mary N.; Heiss, Christian; Azadi, Parastoo; DeShazer, David; Woods, Donald E.; Gherardini, Frank C.

    2011-01-01

    Previous studies have shown that the O polysaccharides (OPS) expressed by Burkholderia mallei are similar to those produced by Burkholderia thailandensis except that they lack the 4-O-acetyl modifications on their 6-deoxy-?-l-talopyranosyl residues. In the present study, we describe the identification and characterization of an open reading frame, designated oacA, expressed by B. thailandensis that accounts for this phenomenon. Utilizing the B. thailandensis and B. mallei lipopolysaccharide (LPS)-specific monoclonal antibodies Pp-PS-W and 3D11, Western immunoblot analyses demonstrated that the LPS antigens expressed by the oacA mutant, B. thailandensis ZT0715, were antigenically similar to those produced by B. mallei ATCC 23344. In addition, immunoblot analyses demonstrated that when B. mallei ATCC 23344 was complemented in trans with oacA, it synthesized B. thailandensis-like LPS antigens. To elucidate the structure of the OPS moieties expressed by ZT0715, purified samples were analyzed via nuclear magnetic resonance spectroscopy. As predicted, these studies demonstrated that the loss of OacA activity influenced the O acetylation phenotype of the OPS moieties. Unexpectedly, however, the results indicated that the O methylation status of the OPS antigens was also affected by the loss of OacA activity. Nonetheless, it was revealed that the LPS moieties expressed by the oacA mutant reacted strongly with the B. mallei LPS-specific protective monoclonal antibody 9C1-2. Based on these findings, it appears that OacA is required for the 4-O acetylation and 2-O methylation of B. thailandensis OPS antigens and that ZT0715 may provide a safe and cost-effective source of B. mallei-like OPS to facilitate the synthesis of glanders subunit vaccine candidates. PMID:21115721

  9. Burkholderia bryophila sp. nov. and Burkholderia megapolitana sp. nov., moss-associated species with antifungal and plant-growth-promoting properties.

    PubMed

    Vandamme, Peter; Opelt, Katja; Knöchel, Nadine; Berg, Christian; Schönmann, Susan; De Brandt, Evie; Eberl, Leo; Falsen, Enevold; Berg, Gabriele

    2007-10-01

    A polyphasic taxonomic study including DNA-DNA reassociation experiments and an extensive biochemical characterization was performed on 14 Burkholderia isolates from moss gametophytes of nutrient-poor plant communities on the southern Baltic Sea coast in northern Germany. The strains were classified within two novel species, for which the names Burkholderia bryophila sp. nov. and Burkholderia megapolitana sp. nov. are proposed. The former species also includes isolates from grassland and agricultural soil collected in previous studies. Strains Burkholderia bryophila 1S18(T) (=LMG 23644(T) =CCUG 52993(T)) and Burkholderia megapolitana A3(T) (=LMG 23650(T) =CCUG 53006(T)) are the proposed type strains. They were isolated from Sphagnum rubellum and Aulacomnium palustre, respectively, growing in the 'Ribnitzer Grosses Moor' nature reserve (Mecklenburg-Pommern, Germany). All moss isolates of both novel species showed antifungal activity against phytopathogens as well as plant-growth-promoting properties. PMID:17911288

  10. Removal of Burkholderia cepacia biofilms with oxidants

    NASA Technical Reports Server (NTRS)

    Koenig, D. W.; Mishra, S. K.; Pierson, D. L.

    1995-01-01

    Iodine is used to disinfect the water system aboard US space shuttles and is the anticipated biocide for the international space station. Water quality on spacecraft must be maintained at the highest possible levels for the safety of the crew. Furthermore, the treatment process used to maintain the quality of water on research must be robust and operate for long periods with minimal crew intervention. Biofilms are recalcitrant and pose a major threat with regard to chronic contamination of spacecraft water systems. We measured the effectiveness of oxidizing biocides on the removal and regrowth of Burkholderia (Pseudomonas) cepacia biofilms. B. cepacia, isolated from the water distribution system of the space shuttle Discovery, was grown in continuous culture to produce a bacterial contamination source for biofilm formation and removal studies. A 10(7) CFU ml-1 B. cepacia suspension, in distilled water, was used to form biofilms on 3000 micrometers2 glass surfaces. Rates of attachment were measured directly with image analysis and were found to be 7.8, 15.2, and 22.8 attachment events h-1 for flow rates of 20.7, 15.2, and 9.8 ml min-1, respectively. After 18 h of formation, the B. cepacia biofilms were challenged with oxidants (ozone, chlorine, and iodine) and the rates of biofilm removal determined by image analysis. Fifty percent of the biofilm material was removed in the first hour of continous treatment with 24 mg l-1 chlorine or 2 mg l-1 ozone. Iodine (48 mg l-1) did not remove any measurable cellular material after 6 h continuous contact. After this first removal of biofilms by the oxidants, the surface was allowed to refoul and was again treated with the biocide. Iodine was the only compound that was unable to remove cellular debris from either primary or secondary biofilms. Moreover, treating primary biofilms with iodine increased the rate of formation of secondary biofilms, from 4.4 to 5.8 attachment events h-1. All the oxidants tested inactivated the B. cepacia associated with both primary and secondary biofilms. The amount of biocide needed to inactivate 50% of planktonic B. cepacia in 10 min at 25 degrees C was 8.4, 0.5, and 0.2 mg l-1 for iodine, chlorine, and ozone, respectively. The data suggest that iodine maynot be the best chemical for treating of biofilms when removal of cellular material is required.

  11. Vertical transmission explains the specific Burkholderia pattern in Sphagnum mosses at multi-geographic scale

    PubMed Central

    Bragina, Anastasia; Cardinale, Massimiliano; Berg, Christian; Berg, Gabriele

    2013-01-01

    The betaproteobacterial genus Burkholderia is known for its versatile interactions with its hosts that can range from beneficial to pathogenic. A plant-beneficial-environmental (PBE) Burkholderia cluster was recently separated from the pathogen cluster, yet still little is known about burkholderial diversity, distribution, colonization, and transmission patterns on plants. In our study, we applied a combination of high-throughput molecular and microscopic methods to examine the aforementioned factors for Burkholderia communities associated with Sphagnum mosses – model plants for long-term associations – in Austrian and Russian bogs. Analysis of 16S rRNA gene amplicons libraries revealed that most of the Burkholderia are part of the PBE group, but a minor fraction was closely related to B. glathei and B. andropogonis from the pathogen cluster. Notably, Burkholderia showed highly similar composition patterns for each moss species independent of the geographic region, and Burkholderia-specific fluorescent in situ hybridization of Sphagnum gametophytes exhibited similar colonization patterns in different Sphagnum species at multi-geographic scales. To explain these patterns, we compared the compositions of the surrounding water, gametophyte-, and sporophyte-associated microbiome at genus level and discovered that Burkholderia were present in the Sphagnum sporophyte and gametophyte, but were absent in the flark water. Therefore, Burkholderia is a part of the core microbiome transmitted from the moss sporophyte to the gametophyte. This suggests a vertical transmission of Burkholderia strains, and thus underlines their importance for the plants themselves. PMID:24391630

  12. Vertical transmission explains the specific Burkholderia pattern in Sphagnum mosses at multi-geographic scale.

    PubMed

    Bragina, Anastasia; Cardinale, Massimiliano; Berg, Christian; Berg, Gabriele

    2013-01-01

    The betaproteobacterial genus Burkholderia is known for its versatile interactions with its hosts that can range from beneficial to pathogenic. A plant-beneficial-environmental (PBE) Burkholderia cluster was recently separated from the pathogen cluster, yet still little is known about burkholderial diversity, distribution, colonization, and transmission patterns on plants. In our study, we applied a combination of high-throughput molecular and microscopic methods to examine the aforementioned factors for Burkholderia communities associated with Sphagnum mosses - model plants for long-term associations - in Austrian and Russian bogs. Analysis of 16S rRNA gene amplicons libraries revealed that most of the Burkholderia are part of the PBE group, but a minor fraction was closely related to B. glathei and B. andropogonis from the pathogen cluster. Notably, Burkholderia showed highly similar composition patterns for each moss species independent of the geographic region, and Burkholderia-specific fluorescent in situ hybridization of Sphagnum gametophytes exhibited similar colonization patterns in different Sphagnum species at multi-geographic scales. To explain these patterns, we compared the compositions of the surrounding water, gametophyte-, and sporophyte-associated microbiome at genus level and discovered that Burkholderia were present in the Sphagnum sporophyte and gametophyte, but were absent in the flark water. Therefore, Burkholderia is a part of the core microbiome transmitted from the moss sporophyte to the gametophyte. This suggests a vertical transmission of Burkholderia strains, and thus underlines their importance for the plants themselves. PMID:24391630

  13. Nodulation of Cyclopia spp. (Leguminosae, Papilionoideae) by Burkholderia tuberum

    PubMed Central

    Elliott, Geoffrey N.; Chen, Wen-Ming; Bontemps, Cyril; Chou, Jui-Hsing; Young, J. Peter W.; Sprent, Janet I.; James, Euan K.

    2007-01-01

    Background and Aims Species of the genus Burkholderia, from the Betaproteobacteria, have been isolated from legume nodules, but so far they have only been shown to form symbioses with species of Mimosa, sub-family Mimosoideae. This work investigates whether Burkholderia tuberum strains STM678 (isolated from Aspalathus carnosa) and DUS833 (from Aspalathus callosa) can nodulate species of the South African endemic papilionoid genera Cyclopia (tribe Podalyrieae) and Aspalathus (Crotalarieae) as well as the promiscuous legume Macroptilium atropurpureum (Phaseoleae). Method Bacterial strains and the phylogeny of their symbiosis-related (nod) genes were examined via 16S rRNA gene sequencing. Seedlings were grown in liquid culture and inoculated with one of the two strains of B. tuberum or with Sinorhizobium strain NGR 234 (from Lablab purpureus), Mesorhizobium strain DUS835 (from Aspalathus linearis) or Methylobacterium nodulans (from Crotalaria podocarpa). Some nodules, inoculated with green fluorescence protein (GFP)-tagged strains, were examined by light and electron microscopy coupled with immunogold labelling with a Burkholderia-specific antibody. The presence of active nitrogenase was checked by immunolabelling of nitrogenase and by the acetylene reduction assay. B. tuberum STM678 was also tested on a wide range of legumes from all three sub-families. Key Results Nodules were not formed on any of the Aspalathus spp. Only B. tuberum nodulated Cyclopia falcata, C. galioides, C. genistoides, C. intermedia and C. pubescens. It also effectively nodulated M. atropurpureum but no other species tested. GFP-expressing inoculant strains were located inside infected cells of C. genistoides, and bacteroids in both Cyclopia spp. and M. atropurpureum were immunogold-labelled with antibodies against Burkholderia and nitrogenase. Nitrogenase activity was also shown using the acetylene reduction assay. This is the first demonstration that a ?-rhizobial strain can effectively nodulate papilioinoid legumes. Conclusions Papilionoid legumes from widely different tribes can be nodulated by ?-rhizobia, forming both indeterminate (Cyclopia) and determinate (Macroptilium) nodules. PMID:17881339

  14. Phenotypic comparison between rhizosphere and clinical isolates of Burkholderia cepacia

    Microsoft Academic Search

    Annamaria Bevivino; Silvia Tabacchioni; Luigi Chiarini; M. Vittoria Carusi; Maddalena Del Gallo; Paolo Visca

    1994-01-01

    The phenotypic characteristics of four Burkholderia cepacia strains isolated from the rhizosphere and the clinical environment were compared. Tests included optimum growth temperature, utilization of carbon sources, production of HCN, indole-3-acetic acid (IAA) and siderophores, proteolytic activity, nitrogen fixation, inhibition of some phytopathogenic fungi, adherence to human mucosal and plant root epithelia, and greenhouse-based plant-growth promotion experiments using cucumber (Cucumis

  15. Identification and enzymatic characterization of acid phosphatase from Burkholderia gladioli

    PubMed Central

    2014-01-01

    Background The genus Burkholderia is widespread in diverse ecological niches, the majority of known species are soil bacteria that exhibit different types of non-pathogenic interactions with plants. Burkholderia species are versatile organisms that solubilize insoluble minerals through the production of organic acids, which increase the availability of nutrients for the plant. Therefore these bacteria are promising candidates for biotechnological applications. Results Burkholderia sp. (R 3.25 isolate) was isolated from agricultural soil in Ponta Grossa-PR-Brazil and identified through analysis of the 16S rDNA as a strain classified as Burkholderia gladioli. The expression of membrane-bound acid phosphatase (MBAcP) was strictly regulated with optimal expression at a concentration of phosphorus 5 mM. The apparent optimum pH for the hydrolysis of p-nitrophenylphosphate (PNPP) was 6.0. The hydrolysis of PNPP by the enzyme exhibited a hyperbolic relationship with increasing concentration of substrate and no inhibition by excess of substrate was observed. Kinetic data revealed that the hydrolysis of PNPP exhibited cooperative kinetics with n?=?1.3, Vm?=?113.5 U/mg and K0.5?=?65 ?M. The PNPPase activity was inhibited by vanadate, p-hydroxymercuribenzoate, arsenate and phosphate, however the activity was not inhibited by calcium, levamisole, sodium tartrate, EDTA, zinc, magnesium, cobalt, ouabain, oligomycin or pantoprazol. Conclusion The synthesis of membrane-bound non-specific acid phosphatase, strictly regulated by phosphate, and its properties suggest that this bacterium has a potential biotechnological application to solubilize phosphate in soils with low levels of this element, for specific crops. PMID:24713147

  16. Genome characterization of a novel Burkholderia cepacia complex genomovar isolated from dieback affected mango orchards.

    PubMed

    Khan, Asifullah; Asif, Huma; Studholme, David J; Khan, Ishtiaq A; Azim, M Kamran

    2013-11-01

    We characterized the genome of the antibiotic resistant, caseinolytic and non-hemolytic Burkholderia sp. strain TJI49, isolated from mango trees (Mangifera indica L.) with dieback disease. This isolate produced severe disease symptoms on the indicator plants. Next generation DNA sequencing and short-read assembly generated the 60X deep 7,631,934 nucleotide draft genome of Burkholderia sp. TJI49 which comprised three chromosomes and at least one mega plasmid. Genome annotation studies revealed a total 8,992 genes, out of which 8,940 were protein coding genes. Comparative genomics and phylogenetics identified Burkholderia sp. TJI49 as a distinct species of Burkholderia cepacia complex (BCC), closely related to B. multivorans ATCC17616. Genome-wide sequence alignment of this isolate with replicons of BCC members showed conservation of core function genes but considerable variations in accessory genes. Subsystem-based gene annotation identified the active presence of wide spread colonization island and type VI secretion system in Burkholderia sp. TJI49. Sequence comparisons revealed (a) 28 novel ORFs that have no database matches and (b) 23 ORFs with orthologues in species other than Burkholderia, indicating horizontal gene transfer events. Fold recognition of novel ORFs identified genes encoding pertactin autotransporter-like proteins (a constituent of type V secretion system) and Hap adhesion-like proteins (involved in cell-cell adhesion) in the genome of Burkholderia sp. TJI49. The genomic characterization of this isolate provided additional information related to the 'pan-genome' of Burkholderia species. PMID:23653265

  17. Microbial degradation of quinoline by immobilized cells of Burkholderia pickettii.

    PubMed

    Jianlong, Wang; Xiangchun, Quan; Liping, Han; Yi, Qian; Hegemann, Werner

    2002-05-01

    A quinoline-biodegrading microorganism was isolated from activated sludge of coke-oven wastewater treatment plant using quinoline as sole carbon and nitrogen source. It is a gram negative, rod-shaped and aerobic strain, which was identified as Burkholderia pickettii. The biodegradation of quinoline was carried out with this isolated strain. Analysis by high performance liquid chromatography and gas chromatography/mass spectrum (GC/MS) revealed that 2-hydroxyquinoline (2-OH-Q) was the first intermediate in the course of quinoline biodegradation. A novel immobilization carrier, that is, polyvinyl alcohol (PVA)-gauze hybrid carrier, was developed. The isolated strain was immobilized by two different immobilizing techniques and used for the quinolinerdegradation. It was found that biodegradation rate of quinoline by the microorganisms immobilized on PVA-gauze hybrid carrier was faster than that by the microorganisms immobilized in PVA gel beads. Kinetics of quinoline biodegradation by cells of Burkholderia pickettii immobilized on PVA-gauze hybrid carrier was investigated. The results demonstrate that quinoline degradation could be described by zero-order reaction rate equation when the initial quinoline concentration was in the range of 50-500 mg l(-1). PMID:12108721

  18. Prognostic value of cytokine concentrations (tumor necrosis factor-alfa, interleukin-6, and interleukin-10) and clinical parameters in severe melioidosis

    Microsoft Academic Search

    Yupin Suputtamongkol; Wipada Chaowagul; Deventer van S. J. H

    2000-01-01

    Raised serum concentrations of tumor necrosis factor (TNF)-a, interleukin (IL)-1b, IL-6, or IL-10 are associated with mortality in patients with sepsis, but it is not known whether elevated cytokine levels are independently predictive of mortality. Cytokine assays (TNF-a, IL-6, and IL-10) were performed on admission plasma samples from 172 adult Thai patients with severe melioidosis. Mortality was 31.4%. APACHE II

  19. The Driskill Graduate Program Northwestern University

    E-print Network

    Engman, David M.

    by Burkholderia pseudomallei Jeffery F. Miller, Ph.D. is the M. Philip Davis Chair in Microbiology and Immunology cycles of Bordetella pertussis, which causes whooping cough, and Burkholderia pseudomallei, which causes and Burkholderia, iv) biofilm formation and the hyper-colonization phenotype of Staphylococcus epidermiditis, and v

  20. Variable Ammonia Production Among Smooth and Rough Strains of Pseudomonas pseudomallei: Resemblance to Bacteriocin Production

    PubMed Central

    Rogul, Marvin; Carr, Susan R.

    1972-01-01

    The colonial morphology of some strains of Pseudomonas pseudomallei was correlated with certain biochemical and physiological traits. After 3 days of growth on Wahba or heart infusion agars, smooth-colony strains generated toxic amounts of ammonia. Under the same conditions, the rough strains simultaneously produced oxalic acid which decreased the inhibitory concentration of ammonia. The ammonia-ammonium concentrations in smooth cultures exhibited certain bacteriocin-like characteristics. An unusually stable, smooth strain (strain 165) was chosen to compare and emphasize any differences with typical, rough strain 7815. Three-day-old smooth cultures grown on Wahba agar containing 3% (w/v) glycerol demonstrated ammonia toxicity. The substitution of glucose for glycerol completely obviated this toxicity. In highly aerated Wahba broth containing glucose, the amount of ammonia found in strain 165 smooth cultures and the amount of oxalic acid found in strain 7815 rough cultures were greatly reduced. In Difco nitrate broth smooth strain 165 did not form gas, and it reduced nitrate to nitrite only. Strain 7815 produced a gas and reduced both nitrate and nitrite. PMID:4562401

  1. DATABASE Open Access DBSecSys: a database of Burkholderia mallei

    E-print Network

    -pathogen interactions, Burkholderia mallei Background Introduction Pathogenic bacteria cause a variety of diseases exposure, consider- able antibiotic resistance, and the lack of a vaccine, B. mallei represents an emerging

  2. BIOAUGMENTATION WITH BURKHOLDERIA CEPACIA PR1301 FOR IN SITU BIOREMEDIATION OF TRICHLOROETHYLENE CONTAMINATED GROUNDWATER (RESEARCH BRIEF)

    EPA Science Inventory

    A pilot field study was conducted at the Moffett Federal Airfield, Mountain View, California, to determine whether effective in-situ aerobic cometabolic biodegradation of TCE could be accomplished through bioaugmentation with a genetically modified strain of Burkholderia cepacia ...

  3. Biosynthesis pathway & transport of endotoxin - promising antibacterial drug targets in the Burkholderia cepacia Complex (BCC) 

    E-print Network

    Bodewits, Karin

    2011-11-23

    Burkholderia cepacia complex (Bcc) species are opportunistic pathogens in patients with cystic fibrosis (CF), which are able to cause lethal infections. The Bcc are inherently resistant to most classes of antibiotics, ...

  4. Common Features of Environmental and Potentially Beneficial Plant-Associated Burkholderia

    Microsoft Academic Search

    Zulma Rocío Suárez-Moreno; Jesús Caballero-Mellado; Bruna G. Coutinho; Lucia Mendonça-Previato; Euan K. James; Vittorio Venturi

    The genus Burkholderia comprises more than 60 species isolated from a wide range of niches. Although they have been shown to be diverse and ubiquitously\\u000a distributed, most studies have thus far focused on the pathogenic species due to their clinical importance. However, the increasing\\u000a number of recently described Burkholderia species associated with plants or with the environment has highlighted the

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

    PubMed

    Gu, Jia-Yu; Zang, Sheng-Gang; Sheng, Xia-Fang; He, Lin-Yan; Huang, Zhi; Wang, Qi

    2015-03-01

    A novel type of mineral-weathering bacterium was isolated from the weathered surface of rock (mica schist) collected from Susong (Anhui, China). Cells of strain L226(T) were Gram-stain-negative. The strain grew optimally at 30 °C, with 1?% (w/v) NaCl and at pH 7.0 in trypticase soy broth. On the basis of 16S rRNA gene phylogeny, strain L226(T) was shown to belong to the genus Burkholderia and the closest phylogenetic relatives were Burkholderia sprentiae WSM5005(T) (98.3?%), Burkholderia acidipaludis NBRC 101816(T) (98.2?%), Burkholderia tuberum STM678(T) (97.2?%) and Burkholderia diazotrophica JPY461(T) (97.1?%). The DNA G+C content was 63.5 mol% and the respiratory quinone was Q-8. The major fatty acids were C16?:?0, C17?:?0 cyclo and C19?:?0 cyclo ?8c. The polar lipid profile of strain L226(T) consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, unknown lipids and unidentified aminophospholipids. Based on the low level of DNA-DNA relatedness (ranging from 25.8?% to 34.4?%) to the tested type strains of species of the genus Burkholderia and unique phenotypic characteristics, it is suggested that strain L226(T) represents a novel species of the genus Burkholderia, for which the name Burkholderia susongensis sp. nov., is proposed. The type strain is L226(T) (?=?CCTCC AB2014142(T)?=?JCM 30231(T)). PMID:25575828

  6. Development of a PCR probe test for identifying Pseudomonas aeruginosa and Pseudomonas (Burkholderia) cepacia

    Microsoft Academic Search

    E M OCallaghan; M S Tanner; G J Boulnois

    1994-01-01

    AIMS--To develop a system of species specific polymerase chain reaction (PCR) and DNA hybridisation based on 16s ribosomal RNA sequences for the identification of Pseudomonas aeruginosa and Pseudomonas (Burkholderia) cepacia in sputum from children with cystic fibrosis. METHODS--Most of the 16s rRNA sequences from strains of Ps aeruginosa, Ps (Burkholderia) cepacia, and Ps putida were determined. PCR primers and DNA

  7. Burkholderia cenocepacia C5424 Produces a Pigment with Antioxidant Properties Using a Homogentisate Intermediate

    Microsoft Academic Search

    Karen E. Keith; Lauren Killip; Panqing He; Graham R. Moran; Miguel A. Valvano

    2007-01-01

    Burkholderia cenocepacia is a gram-negative opportunistic pathogen that belongs to the Burkholderia cepacia complex. B. cenocepacia can survive intracellularly within phagocytic cells, and some epidemic strains produce a brown melanin-like pigment that can scavenge free radicals, resulting in the attenuation of the host cell oxidative burst. In this work, we demonstrate that the brown pigment produced by B. cenocepacia C5424

  8. Aerosol phage therapy efficacy in Burkholderia cepacia complex respiratory infections.

    PubMed

    Semler, Diana D; Goudie, Amanda D; Finlay, Warren H; Dennis, Jonathan J

    2014-07-01

    Phage therapy has been suggested as a potential treatment for highly antibiotic-resistant bacteria, such as the species of the Burkholderia cepacia complex (BCC). To address this hypothesis, experimental B. cenocepacia respiratory infections were established in mice using a nebulizer and a nose-only inhalation device. Following infection, the mice were treated with one of five B. cenocepacia-specific phages delivered as either an aerosol or intraperitoneal injection. The bacterial and phage titers within the lungs were assayed 2 days after treatment, and mice that received the aerosolized phage therapy demonstrated significant decreases in bacterial loads. Differences in phage activity were observed in vivo. Mice that received phage treatment by intraperitoneal injection did not demonstrate significantly reduced bacterial loads, although phage particles were isolated from their lung tissue. Based on these data, aerosol phage therapy appears to be an effective method for treating highly antibiotic-resistant bacterial respiratory infections, including those caused by BCC bacteria. PMID:24798268

  9. Cytotoxic Spliceostatins from Burkholderia sp. and Their Semisynthetic Analogues.

    PubMed

    He, Haiyin; Ratnayake, Anokha S; Janso, Jeffrey E; He, Min; Yang, Hui Y; Loganzo, Frank; Shor, Boris; O'Donnell, Christopher J; Koehn, Frank E

    2014-08-01

    The spliceostatin class of natural products was reported to be potent cytotoxic agents via inhibition of the spliceosome, a key protein complex in the biosynthesis of mature mRNA. As part of an effort to discover novel leads for cancer chemotherapy, we re-examined this class of compounds from several angles, including fermentation of the producing strains, isolation and structure determination of new analogues, and semisynthetic modification. Accordingly, a group of spliceostatins were isolated from a culture broth of Burkholderia sp. FERM BP-3421, and their structures identified by analysis of spectroscopic data. Semisynthesis was performed on the major components 4 and 5 to generate ester and amide derivatives with improved in vitro potency. With their potent activity against tumor cells and unique mode of action, spliceostatins can be considered potential leads for development of cancer drugs. PMID:25098528

  10. Degradation of 2-nitrobenzoate by Burkholderia terrae strain KU-15.

    PubMed

    Iwaki, Hiroaki; Hasegawa, Yoshie

    2007-01-01

    Bacterial strain KU-15, identified as a Burkholderia terrae by 16S rRNA gene sequence analysis, was one of 11 new isolates that grew on 2-nitrobenzoate as sole source of carbon and nitrogen. Strain KU-15 was also found to grow on anthranilate, 4-nitrobenzoate, and 4-aminobenzoate. Whole cells of strain KU-15 were found to accumulate ammonia in the medium, indicating that the degradation of 2-nitrobenzoate proceeds through a reductive route. Metabolite analyses by high-performance liquid chromatography indicated that 3-hydroxyanthranilate, anthranilate, and catechol are intermediates of 2-nitrobenzoate metabolism in strain KU-15. Enzyme studies suggested that 2-nitrobenzoate degradation occurs via the formation of 2-hydroxylaminobenzoate and that the pathway branches at this point to form two different aromatic intermediates: anthranilate and 3-hydroxyanthranilate. PCR amplifications and DNA sequencing revealed DNA fragments encoding a polypeptide homologous to 2-amino-3-carboxymuconate 6-semialdehyde decarboxylase and anthranilate 1,2-dioxygenase. PMID:17213670

  11. Molecular Mechanisms of Chlorhexidine Tolerance in Burkholderia cenocepacia Biofilms?†

    PubMed Central

    Coenye, Tom; Van Acker, Heleen; Peeters, Elke; Sass, Andrea; Buroni, Silvia; Riccardi, Giovanna; Mahenthiralingam, Eshwar

    2011-01-01

    The high tolerance of biofilm-grown Burkholderia cepacia complex bacteria against antimicrobial agents presents considerable problems for the treatment of infected cystic fibrosis patients and the implementation of infection control guidelines. In the present study, we analyzed the tolerance of planktonic and sessile Burkholderia cenocepacia J2315 cultures and examined the transcriptional response of sessile cells to treatment with chlorhexidine. At low (0.0005%) and high (0.05%) concentrations, chlorhexidine had a similar effect on both populations, but at intermediate concentrations (0.015%) the antimicrobial activity was more pronounced in planktonic cultures. The exposure of sessile cells to chlorhexidine resulted in an upregulation of the transcription of 469 (6.56%) and the downregulation of 257 (3.59%) protein-coding genes. A major group of upregulated genes in the treated biofilms encoded membrane-related and regulatory proteins. In addition, several genes coding for drug resistance determinants also were upregulated. The phenotypic analysis of RND (resistance-nodulation-division) efflux pump mutants suggests the presence of lifestyle-specific chlorhexidine tolerance mechanisms; efflux system RND-4 (BCAL2820-BCAL2822) was more responsible for chlorhexidine tolerance in planktonic cells, while other systems (RND-3 [BCAL1672-BCAL1676] and RND-9 [BCAM1945-BCAM1947]) were linked to resistance in sessile cells. After sessile cell exposure, multiple genes encoding chemotaxis and motility-related proteins were upregulated in concert with the downregulation of an adhesin-encoding gene (BCAM2143), suggesting that sessile cells tried to escape the biofilm. We also observed the differential expression of 19 genes carying putative small RNA molecules, indicating a novel role for these regulatory elements in chlorhexidine tolerance. PMID:21357299

  12. Use of the Common Marmoset to Study Burkholderia mallei Infection

    PubMed Central

    Harvey, Stephen B.; Mead, Daniel G.; Shaffer, Teresa L.; Estes, D. Mark; Michel, Frank; Quinn, Frederick D.; Hogan, Robert J.; Lafontaine, Eric R.

    2015-01-01

    Burkholderia mallei is a host-adapted bacterium that does not persist outside of its equine reservoir. The organism causes the zoonosis glanders, which is endemic in Asia, Africa, the Middle East and South America. Infection by B. mallei typically occurs via the respiratory or percutaneous route, and the most common manifestations are life-threatening pneumonia and bacteremia. Glanders is difficult to diagnose and requires prolonged antibiotic therapy with low success rates. There is no vaccine to protect against B. mallei and there is concern regarding its use as a biothreat agent. Thus, experiments were performed to establish a non-human primate model of intranasal infection to study the organism and develop countermeasures. Groups of marmosets (Callithrix jacchus) were inoculated intranasally with B. mallei strain ATCC 23344 and monitored for clinical signs of illness for up to 13 days. We discovered that 83% of marmosets inoculated with doses of 2.5 X 104 to 2.5 X 105 bacteria developed acute lethal infection within 3–4 days. Signs of disease were severe and included lethargy, inappetence, conjunctivitis, mucopurulent and hemorrhagic nasal discharges, and increased respiratory effort with abdominal lifts. Burkholderia mallei was cultured from the lungs, spleen and liver of these animals, and pathologic examination of tissues revealed lesions characteristic of glanders. Challenge experiments also revealed that 91% of animals infected with doses ranging from 25 to 2.5 X 103 bacteria exhibited mild non-specific signs of illness and were culture negative. One marmoset inoculated with 2.5 X 103 organisms developed moderate signs of disease and reached humane end-points 8 days post-infection. The liver and spleen of this animal were colonized with the agent and pathological analysis of tissues showed nasal, splenic and hepatic lesions. Taken together, these data indicate that the marmoset is a suitable model to study respiratory infection by B. mallei. PMID:25860021

  13. A Structural Biology Approach Enables the Development of Antimicrobials Targeting Bacterial Immunophilins

    PubMed Central

    Fox, David; Jenner, Dominic; Juli, Christina; Pierce, Phillip G.; Abendroth, Jan; Muruthi, Muigai; Safford, Kris; Anderson, Vanessa; Atkins, Kateri; Barnes, Steve R.; Moen, Spencer O.; Raymond, Amy C.; Stacy, Robin; Myler, Peter J.; Staker, Bart L.; Harmer, Nicholas J.; Norville, Isobel H.; Holzgrabe, Ulrike; Sarkar-Tyson, Mitali; Edwards, Thomas E.; Lorimer, Donald D.

    2014-01-01

    Macrophage infectivity potentiators (Mips) are immunophilin proteins and essential virulence factors for a range of pathogenic organisms. We applied a structural biology approach to characterize a Mip from Burkholderia pseudomallei (BpML1), the causative agent of melioidosis. Crystal structure and nuclear magnetic resonance analyses of BpML1 in complex with known macrocyclics and other derivatives led to the identification of a key chemical scaffold. This scaffold possesses inhibitory potency for BpML1 without the immunosuppressive components of related macrocyclic agents. Biophysical characterization of a compound series with this scaffold allowed binding site specificity in solution and potency determinations for rank ordering the set. The best compounds in this series possessed a low-micromolar affinity for BpML1, bound at the site of enzymatic activity, and inhibited a panel of homologous Mip proteins from other pathogenic bacteria, without demonstrating toxicity in human macrophages. Importantly, the in vitro activity of BpML1 was reduced by these compounds, leading to decreased macrophage infectivity and intracellular growth of Burkholderia pseudomallei. These compounds offer the potential for activity against a new class of antimicrobial targets and present the utility of a structure-based approach for novel antimicrobial drug discovery. PMID:24366729

  14. Diversity of the parB and repA genes of the Burkholderia cepacia complex and their utility for rapid identification of Burkholderia cenocepacia

    Microsoft Academic Search

    Pavel Drevinek; Adam Baldwin; Christopher G Dowson; Eshwar Mahenthiralingam

    2008-01-01

    BACKGROUND: Burkholderia cenocepacia is the most prominent species of the B. cepacia complex (Bcc), a group of nine closely related and difficult to identify bacteria that cause serious infections in patients with cystic fibrosis. Despite its clinical relevance, identification of B. cenocepacia as a single species is unavailable, as it splits by a widely used recA gene-based PCR identification method

  15. Draft Genome Sequence of Burkholderia sp. MR1, a Methylarsenate-Reducing Bacterial Isolate from Florida Golf Course Soil

    PubMed Central

    Pawitwar, Shashank S.; Utturkar, Sagar M.; Brown, Steven D.; Yoshinaga, Masafumi

    2015-01-01

    To elucidate the environmental organoarsenical biocycle, we isolated a soil organism, Burkholderia sp. MR1, which reduces relatively nontoxic pentavalent methylarsenate to the more toxic trivalent methylarsenite, with the goal of identifying the gene for the reductase. Here, we report the draft genome sequence of Burkholderia sp. MR1. PMID:26044439

  16. 16S rRNA gene-based phylogenetic microarray for simultaneous identification of members of the genus Burkholderia.

    PubMed

    Schönmann, Susan; Loy, Alexander; Wimmersberger, Céline; Sobek, Jens; Aquino, Catharine; Vandamme, Peter; Frey, Beat; Rehrauer, Hubert; Eberl, Leo

    2009-04-01

    For cultivation-independent and highly parallel analysis of members of the genus Burkholderia, an oligonucleotide microarray (phylochip) consisting of 131 hierarchically nested 16S rRNA gene-targeted oligonucleotide probes was developed. A novel primer pair was designed for selective amplification of a 1.3 kb 16S rRNA gene fragment of Burkholderia species prior to microarray analysis. The diagnostic performance of the microarray for identification and differentiation of Burkholderia species was tested with 44 reference strains of the genera Burkholderia, Pandoraea, Ralstonia and Limnobacter. Hybridization patterns based on presence/absence of probe signals were interpreted semi-automatically using the novel likelihood-based strategy of the web-tool Phylo- Detect. Eighty-eight per cent of the reference strains were correctly identified at the species level. The evaluated microarray was applied to investigate shifts in the Burkholderia community structure in acidic forest soil upon addition of cadmium, a condition that selected for Burkholderia species. The microarray results were in agreement with those obtained from phylogenetic analysis of Burkholderia 16S rRNA gene sequences recovered from the same cadmiumcontaminated soil, demonstrating the value of the Burkholderia phylochip for determinative and environmental studies. PMID:19396938

  17. Draft Genome Sequence of Burkholderia pyrrocinia Lyc2, a Biological Control Strain That Can Suppress Multiple Plant Microbial Pathogens

    PubMed Central

    Wang, Xiao-Qiang; Showmaker, Kurt C.; Yu, Xiao-Qing; Bi, Tao; Hsu, Chuan-Yu; Baird, Sonya M.; Peterson, Daniel G.

    2014-01-01

    Burkholderia pyrrocinia strain Lyc2 was isolated from the tobacco rhizosphere in China. This bacterium exhibits a remarkable capacity to inhibit the growth of multiple pathogens and shows strong suppression of cotton seedling damping-off. Here, we present the draft genome sequence of Burkholderia pyrrocinia strain Lyc2. PMID:25278535

  18. Draft Genome Sequence of Burkholderia sp. MR1, a Methylarsenate-Reducing Bacterial Isolate from Florida Golf Course Soil.

    PubMed

    Pawitwar, Shashank S; Utturkar, Sagar M; Brown, Steven D; Yoshinaga, Masafumi; Rosen, Barry P

    2015-01-01

    To elucidate the environmental organoarsenical biocycle, we isolated a soil organism, Burkholderia sp. MR1, which reduces relatively nontoxic pentavalent methylarsenate to the more toxic trivalent methylarsenite, with the goal of identifying the gene for the reductase. Here, we report the draft genome sequence of Burkholderia sp. MR1. PMID:26044439

  19. Development of rRNA-Based PCR Assays for Identification of Burkholderia cepacia Complex Isolates Recovered from Cystic Fibrosis Patients

    Microsoft Academic Search

    JOHN J. LIPUMA; BETTY JO DULANEY; JENNIFER D. MCMENAMIN; PAUL W. WHITBY; TERRENCE L. STULL; TOM COENYE; PETER VANDAMME

    1999-01-01

    PCR assays targeting rRNA genes were developed to identify species (genomovars) within the Burkholderia cepacia complex. Each assay was tested with 177 bacterial isolates that also underwent taxonomic analysis by whole-cell protein profile. These isolates were from clinical and environmental sources and included 107 B. cepacia complex strains, 23 Burkholderia gladioli strains, 20 Ralstonia pickettii strains, 10 Pseudomonas aeruginosa strains,

  20. A Functional Phenylacetic Acid Catabolic Pathway Is Required for Full Pathogenicity of Burkholderia cenocepacia in the Caenorhabditis elegans Host Model

    Microsoft Academic Search

    Robyn J. Law; Jason N. R. Hamlin; Aida Sivro; Stuart J. McCorrister; Georgina A. Cardama; Silvia T. Cardona

    2008-01-01

    Burkholderia cenocepacia is a member of the Burkholderia cepacia complex, a group of metabolically versatile bacteria that have emerged as opportunistic pathogens in cystic fibrosis and immunocompromised patients. Previously a screen of transposon mutants in a rat pulmonary infection model identified an attenuated mutant with an insertion in paaE, a gene related to the phenylacetic acid (PA) catabolic pathway. In

  1. Burkholderia jiangsuensis sp. nov., a methyl parathion degrading bacterium, isolated from methyl parathion contaminated soil.

    PubMed

    Liu, Xu-Yun; Li, Chun-Xiu; Luo, Xiao-Jing; Lai, Qi-Liang; Xu, Jian-He

    2014-09-01

    A methyl parathion (MP) degrading bacterial strain, designated MP-1(T), was isolated from a waste land where pesticides were formerly manufactured in Jiangsu province, China. Polyphasic taxonomic studies showed that MP-1(T) is a Gram-stain-negative, non-spore-forming, rod-shaped and motile bacterium. The bacterium could grow at salinities of 0-1?% (w/v) and temperatures of 15-40 °C. Strain MP-1(T) could reduce nitrate to nitrite, utilize d-glucose and l-arabinose, but not produce indole, or hydrolyse gelatin. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that MP-1(T) belongs to the genus Burkholderia, showing highest sequence similarity to Burkholderia grimmiae DSM 25160(T) (98.5?%), and similar strains including Burkholderia zhejiangensis OP-1(T) (98.2?%), Burkholderia choica LMG 22940(T) (97.5?%), Burkholderia glathei DSM 50014(T) (97.4?%), Burkholderia terrestris LMG 22937(T) (97.2?%) and Burkholderia telluris LMG 22936(T) (97.0?%). In addition, the gyrB and recA gene segments of strain MP-1(T) exhibited less than 89.0?% and 95.1?% similarities with the most highly-related type strains indicated above. The G+C content of strain MP-1(T) was 62.6 mol%. The major isoprenoid quinone was ubiquinone Q-8. The predominant polar lipids comprised phosphatidyl ethanolamine, phosphatidyl glycerol, aminolipid and phospholipid. The principal fatty acids in strain MP-1(T) were C18?:?1?7c/C18?:?1?6c (23.3?%), C16?:?0 (16.8?%), cyclo-C17?:?0 (15.0?%), C16?:?1?7c/C16?:?1?6 (8.5?%), cyclo-C19?:?0?8c (8.1?%), C16?:?1 iso I/C14?:?0 3-OH (5.7?%), C16?:?0 3-OH (5.6?%) and C16?:?02-OH (5.1?%). The DNA-DNA relatedness values between strain MP-1(T) and the three type strains (B. grimmiae DSM 25160(T), B. zhejiangensis OP-1(T) and B. glathei DSM 50014(T)) ranged from 24.6?% to 37.4?%. In accordance with phenotypic and genotypic characteristics, strain MP-1(T) represents a novel species of the genus Burkholderia, for which the name Burkholderia jiangsuensis sp. nov. is proposed, the type strain is MP-1(T) (LMG 27927(T)?=?MCCC 1K00250(T)). PMID:24981326

  2. The Organization of the Quorum Sensing luxI/R Family Genes in Burkholderia

    PubMed Central

    Choudhary, Kumari Sonal; Hudaiberdiev, Sanjarbek; Gelencsér, Zsolt; Coutinho, Bruna Gonçalves; Venturi, Vittorio; Pongor, Sándor

    2013-01-01

    Members of the Burkholderia genus of Proteobacteria are capable of living freely in the environment and can also colonize human, animal and plant hosts. Certain members are considered to be clinically important from both medical and veterinary perspectives and furthermore may be important modulators of the rhizosphere. Quorum sensing via N-acyl homoserine lactone signals (AHL QS) is present in almost all Burkholderia species and is thought to play important roles in lifestyle changes such as colonization and niche invasion. Here we present a census of AHL QS genes retrieved from public databases and indicate that the local arrangement (topology) of QS genes, their location within chromosomes and their gene neighborhoods show characteristic patterns that differ between the known Burkholderia clades. In sequence phylogenies, AHL QS genes seem to cluster according to the local gene topology rather than according to the species, which suggests that the basic topology types were present prior to the appearance of current Burkholderia species. The data are available at http://net.icgeb.org/burkholderia/. PMID:23820583

  3. 61 FR 1482 - Recombinant DNA Research: Actions Under the Guidelines

    Federal Register 2010, 2011, 2012, 2013, 2014

    1996-01-19

    ...burgdorferi --Burkholderia (formerly Pseudomonas species) except those listed in Appendix...Heterophyes --Hymenolepis including H. diminuta, H. nana --Isospora --Leishmania...canis, B. suis --Burkholderia (Pseudomonas) mallei, B. pseudomallei...

  4. 9 CFR 121.6 - Exemptions for overlap select agents and toxins.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...following overlap select agents and toxins must be immediately reported by telephone, facsimile, or e-mail: Bacillus anthracis, Burkholderia mallei, and Burkholderia pseudomallei . This report must be followed by submission of...

  5. 42 CFR 73.6 - Exemptions for overlap select agents and toxins.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...the following overlap select agents or toxins must be immediately reported by telephone, facsimile, or e-mail: Bacillus anthracis, Burkholderia mallei and Burkholderia pseudomallei . This report must be followed by submission of...

  6. CHLORINE INACTIVATION OF CATEGORY "A" BIO-TERRORISM AGENTS

    EPA Science Inventory

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

  7. 42 CFR 73.6 - Exemptions for overlap select agents and toxins.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...the following overlap select agents or toxins must be immediately reported by telephone, facsimile, or e-mail: Bacillus anthracis, Burkholderia mallei and Burkholderia pseudomallei. This report must be followed by submission of...

  8. 9 CFR 121.6 - Exemptions for overlap select agents and toxins.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...following overlap select agents and toxins must be immediately reported by telephone, facsimile, or e-mail: Bacillus anthracis, Burkholderia mallei, and Burkholderia pseudomallei . This report must be followed by submission of...

  9. Rhizonin A from Burkholderia sp. KCTC11096 and its growth promoting role in lettuce seed germination.

    PubMed

    Kang, Sang-Mo; Khan, Abdul Latif; Hussain, Javid; Ali, Liaqat; Kamran, Muhammad; Waqas, Muhammad; Lee, In-Jung

    2012-01-01

    We isolated and identified a gibberellin-producing Burkholderia sp. KCTC 11096 from agricultural field soils. The culture filtrate of plant growth promoting rhizobacteria (PGPR) significantly increased the germination and growth of lettuce and Chinese cabbage seeds. The ethyl acetate extract of the PGPR culture showed significantly higher rate of lettuce seed germination and growth as compared to the distilled water treated control. The ethyl acetate fraction of the Burkholderia sp. was subjected to bioassay-guided isolation and we obtained for the first time from a Burkholderia sp. the plant growth promoting compound rhizonin A (1), which was characterized through NMR and MS techniques. Application of various concentrations of 1 significantly promoted the lettuce seed germination as compared to control. PMID:22759911

  10. Identification of quorum sensing-controlled genes in Burkholderia ambifaria

    PubMed Central

    Chapalain, Annelise; Vial, Ludovic; Laprade, Natacha; Dekimpe, Valérie; Perreault, Jonathan; Déziel, Eric

    2013-01-01

    The Burkholderia cepacia complex (Bcc) comprises strains with a virulence potential toward immunocompromised patients as well as plant growth–promoting rhizobacteria (PGPR). Owing to the link between quorum sensing (QS) and virulence, most studies among Bcc species have been directed toward QS of pathogenic bacteria. We have investigated the QS of B. ambifaria, a PGPR only infrequently recovered from patients. The cepI gene, responsible for the synthesis of the main signaling molecule N-octanoylhomoserine lactone (C8-HSL), was inactivated. Phenotypes of the B. ambifaria cepI mutant we observed, such as increased production of siderophores and decreased proteolytic and antifungal activities, are in agreement with those of other Bcc cepI mutants. The cepI mutant was then used as background strain for a whole-genome transposon-insertion mutagenesis strategy, allowing the identification of 20 QS-controlled genes, corresponding to 17 loci. The main functions identified are linked to antifungal and antimicrobial properties, as we have identified QS-controlled genes implicated in the production of pyrrolnitrin, burkholdines (occidiofungin-like molecules), and enacyloxins. This study provides insights in the QS-regulated functions of a PGPR, which could lead to beneficial potential biotechnological applications. PMID:23382083

  11. Genetic structure of a lotic population of Burkholderia (Pseudomonas) cepacia

    SciTech Connect

    Wise, M.G.; Shimkets, L.J. [Univ. of Georgia, Athens, GA (United States); McArthur, J.V. [Savannah River Ecology Lab., Aiken, SC (United States)

    1995-05-01

    The genetic structure of a population of Burkholderia (Pseudomonas) cepacia isolated from a southeastern blackwater stream was investigated by using multilocus enzyme electrophoresis to examine the allelic variation in eight structural gene loci. Overall, 213 isolates were collected at transect points along the stream continuum, from both the sediments along the bank and the water column. Multilocus enzyme electrophoresis analysis revealed 164 distinct electrophoretic types, and the mean genetic diversity of the entire population was 0.574. Genetic diversity values did not vary spatially along the stream continuum. From a canonical discriminant analysis, Mahalonobis distances (measurements of genetic similarity between populations) revealed significant differences among the subpopulations at the sediment sampling points, suggesting bacterial adaptation to a heterogeneous (or patchy) microgeographical environment. Multilocus linkage disequilibrium analysis of the isolates revealed only limited association between alleles, suggesting frequent recombination, relative to binary fission, in this population. Furthermore, the dendrogram created from the data of this study and the allele mismatch distribution are typical of a population characterized by extensive genetic mixing. We suggest that B. cepacia be added to the growing list of bacteria that are not obligatorily clonal. 41 refs., 5 figs., 3 tabs.

  12. Development of phylogenetic probes specific to Burkholderia cepacia G4

    SciTech Connect

    Zhou, J.; Tiedje, J.M. [Michigan State Univ., East Lansing, MI (United States). Center for Microbial Ecology

    1995-12-31

    Burkholderia (formerly Pseudomonas) cepacia G4 is capable of oxidizing trichloroethylene (TCE) while growing on toluene or phenol and has potential for use in remediating TCE-contaminated groundwater. To track G4 in the environment, polymerase chain reaction (PCR)-based phylogenetic probes were developed. Four sets of specific primers for PCR amplification of 16S ribosomal RNA gene sequences were designed and tested against both closely and distantly related environmental isolates. Two sets of the primers specifically detected the species B. cepacia, and the other two sets specifically detected the strain G4. The sensitivity of these primer sets was evaluated using DNA isolated from the G4 pure culture and form the sterile soils seeded with a known number of G4 and E. coli cells. These primer sets were able to detect 1 fg to 1 pg of template DNA rom the pure culture, and 2.1 {times} 10{sup 2} to 2.1 {times} 10{sup 4} G4 cells per g soil in the presence of 1.56 {times} 10{sup 8} E. coli cells. With such specificity and sensitivity, these probe could be useful in tracking B. cepacia G4 and its relatives in the environment.

  13. Mixotrophic metabolism in Burkholderia kururiensis subsp. thiooxydans subsp. nov., a facultative chemolithoautotrophic thiosulfate oxidizing bacterium isolated from rhizosphere soil and proposal for classification of the type strain of Burkholderia kururiensis as Burkholderia kururiensis subsp. kururiensis subsp. nov

    Microsoft Academic Search

    Rangasamy Anandham; Pandiyan Indira Gandhi; Soon Wo Kwon; Tong Min Sa; Yong Ki Kim; Hyeong Jin Jee

    2009-01-01

    A thiosulfate-oxidizing facultative chemolithoautotrophic Burkholderia sp. strain ATSB13T was previously isolated from rhizosphere soil of tobacco plant. Strain ATSB13T was aerobic, Gram-staining-negative, rod shaped and motile by means of sub-terminal flagellum. Strain ATSB13T exhibited mixotrophic growth in a medium containing thiosulfate plus acetate. A phylogenetic study based on 16S rRNA gene\\u000a sequence analysis indicated that strain ATSB13T was most closely

  14. Toluene 2-Monooxygenase-Dependent Growth of Burkholderia cepacia G4/PR1 on Diethyl Ether

    PubMed Central

    Hur, H.; Newman, L. M.; Wackett, L. P.; Sadowsky, M. J.

    1997-01-01

    Aerobic bacterial growth on aromatic hydrocarbons typically requires oxygenase enzymes, which are known to fortuitously oxidize nongrowth substrates. In this study, we found that oxidation of diethyl ether by toluene 2-monooxygenase supported more rapid growth of Burkholderia cepacia G4/PR1 than did the aromatic substrates n-propylbenzene and o-xylene. The wild-type Burkholderia cepacia G4 failed to grow on diethyl ether. Purified toluene 2-monooxygenase protein components oxidized diethyl ether stoichiometrically to ethanol and acetaldehyde. Butyl methyl ether, diethyl sulfide, and 2-chloroethyl ethyl ether were oxidized by B. cepacia G4/PR1. PMID:16535583

  15. Solubilization of insoluble inorganic phosphate by Burkholderia cepacia DA23 isolated from cultivated soil

    PubMed Central

    Song, Ok-Ryul; Lee, Seung-Jin; Lee, Yong-Seok; Lee, Sang-Cheol; Kim, Keun-Ki; Choi, Yong-Lark

    2008-01-01

    A mineral phosphate solubilizing bacterium, Burkholderia cepacia DA23 has been isolated from cultivated soils. Phosphate-solubilizing activities of the strain against three types of insoluble phosphate were quantitatively determined. When 3% of glucose concentration was used for carbon source, the strain had a marked mineral phosphate-solubilizing activity. Mineral phosphate solubilization was directly related to the pH drop by the strain. Analysis of the culture medium by high pressure liquid chromatography identified gluconic acid as the main organic acid released by Burkholderia cepacia DA23. Gluconic acid production was apparently the result of the glucose dehydrogenase activity and glucose dehydrogenase was affected by phosphate regulation. PMID:24031195

  16. Burkholderia ginsengiterrae sp. nov. and Burkholderia panaciterrae sp. nov., antagonistic bacteria against root rot pathogen Cylindrocarpon destructans, isolated from ginseng soil.

    PubMed

    Farh, Mohamed El-Agamy; Kim, Yeon-Ju; Van An, Hoang; Sukweenadhi, Johan; Singh, Priyanka; Huq, Md Amdadul; Yang, Deok-Chun

    2015-04-01

    Strain DCY85(T) and DCY85-1(T), isolated from rhizosphere of ginseng, were rod-shaped, Gram-reaction-negative, strictly aerobic, catalase positive and oxidase negative. 16S rRNA gene sequence analysis revealed that strain DCY85(T) as well as DCY85-1(T) belonged to the genus Burkholderia and were closely related to Burkholderia fungorum KACC 12023(T) (98.1 and 98.0 % similarity, respectively). The major polar lipids of strain DCY85(T) and DCY85-1(T) were phosphatidylethanolamine, one unidentified aminolipid and two unidentified phospholipids. The major fatty acids of both strains are C16:0, C18:1 ?7c and summed feature 3 (C16:1 ?6c and/or C16:1 ?7c). The predominant isoprenoid quinone of each strain DCY85(T) and DCY85-1(T) was ubiquinone (Q-8) and the G+C content of their genomic DNA was 66.0 and 59.4 mol%, respectively, which fulfill the characteristic range of the genus Burkholderia. The polyamine content of both DCY85(T) and DCY85-1(T) was putrescine. Although both DCY85(T) and DCY85-1(T) have highly similar 16S rRNA and identical RecA and gyrB sequences, they show differences in phenotypic and chemotaxonomic characteristics. DNA-DNA hybridization results proved the consideration of both strains as two different species. Based on the results from our polyphasic characterization, strain DCY85(T) and DCY85-1(T) are considered novel Burkholderia species for which the name Burkholderia ginsengiterrae sp. nov and Burkholderia panaciterrae sp. nov are, respectively, proposed. An emended description of those strains is also proposed. DCY85(T) and DCY85-1(T) showed antagonistic activity against the common root rot pathogen of ginseng, Cylindrocarpon destructans. The proposed type strains are DCY85(T) (KCTC 42054(T) = JCM 19888(T)) and DCY85-1(T) (KCTC 42055(T) = JCM 19889(T)). PMID:25537097

  17. Cytotoxicity Associated with Trichloroethylene Oxidation in Burkholderia cepacia G4

    PubMed Central

    Yeager, Chris M.; Bottomley, Peter J.; Arp, Daniel J.

    2001-01-01

    The effects of trichloroethylene (TCE) oxidation on toluene 2-monooxygenase activity, general respiratory activity, and cell culturability were examined in the toluene-oxidizing bacterium Burkholderia cepacia G4. Nonspecific damage outpaced inactivation of toluene 2-monooxygenase in B. cepacia G4 cells. Cells that had degraded approximately 0.5 ?mol of TCE (mg of cells?1) lost 95% of their acetate-dependent O2 uptake activity (a measure of general respiratory activity), yet toluene-dependent O2 uptake activity decreased only 35%. Cell culturability also decreased upon TCE oxidation; however, the extent of loss varied greatly (up to 3 orders of magnitude) with the method of assessment. Addition of catalase or sodium pyruvate to the surfaces of agar plates increased enumeration of TCE-injured cells by as much as 100-fold, indicating that the TCE-injured cells were ultrasensitive to oxidative stress. Cell suspensions that had oxidized TCE recovered the ability to grow in liquid minimal medium containing lactate or phenol, but recovery was delayed substantially when TCE degradation approached 0.5 ?mol (mg of cells?1) or 66% of the cells' transformation capacity for TCE at the cell density utilized. Furthermore, among B. cepacia G4 cells isolated on Luria-Bertani agar plates from cultures that had degraded approximately 0.5 ?mol of TCE (mg of cells?1), up to 90% were Tol? variants, no longer capable of TCE degradation. These results indicate that a toxicity threshold for TCE oxidation exists in B. cepacia G4 and that once a cell suspension has exceeded this toxicity threshold, the likelihood of reestablishing an active, TCE-degrading biomass from the cells will decrease significantly. PMID:11319088

  18. Activation of the pyrin inflammasome by intracellular Burkholderia cenocepacia.

    PubMed

    Gavrilin, Mikhail A; Abdelaziz, Dalia H A; Mostafa, Mahmoud; Abdulrahman, Basant A; Grandhi, Jaykumar; Akhter, Anwari; Abu Khweek, Arwa; Aubert, Daniel F; Valvano, Miguel A; Wewers, Mark D; Amer, Amal O

    2012-04-01

    Burkholderia cenocepacia is an opportunistic pathogen that causes chronic infection and induces progressive respiratory inflammation in cystic fibrosis patients. Recognition of bacteria by mononuclear cells generally results in the activation of caspase-1 and processing of IL-1?, a major proinflammatory cytokine. In this study, we report that human pyrin is required to detect intracellular B. cenocepacia leading to IL-1? processing and release. This inflammatory response involves the host adapter molecule ASC and the bacterial type VI secretion system (T6SS). Human monocytes and THP-1 cells stably expressing either small interfering RNA against pyrin or YFP-pyrin and ASC (YFP-ASC) were infected with B. cenocepacia and analyzed for inflammasome activation. B. cenocepacia efficiently activates the inflammasome and IL-1? release in monocytes and THP-1. Suppression of pyrin levels in monocytes and THP-1 cells reduced caspase-1 activation and IL-1? release in response to B. cenocepacia challenge. In contrast, overexpression of pyrin or ASC induced a robust IL-1? response to B. cenocepacia, which correlated with enhanced host cell death. Inflammasome activation was significantly reduced in cells infected with T6SS-defective mutants of B. cenocepacia, suggesting that the inflammatory reaction is likely induced by an as yet uncharacterized effector(s) of the T6SS. Together, we show for the first time, to our knowledge, that in human mononuclear cells infected with B. cenocepacia, pyrin associates with caspase-1 and ASC forming an inflammasome that upregulates mononuclear cell IL-1? processing and release. PMID:22368275

  19. Quorum Sensing Controls Flagellar Morphogenesis in Burkholderia glumae

    PubMed Central

    Jang, Moon Sun; Goo, Eunhye; An, Jae Hyung; Kim, Jinwoo; Hwang, Ingyu

    2014-01-01

    Burkholderia glumae is a motile plant pathogenic bacterium that has multiple polar flagella and one LuxR/LuxI-type quorum sensing (QS) system, TofR/TofI. A QS-dependent transcriptional regulator, QsmR, activates flagellar master regulator flhDC genes. FlhDC subsequently activates flagellar gene expression in B. glumae at 37°C. Here, we confirm that the interplay between QS and temperature is critical for normal polar flagellar morphogenesis in B. glumae. In the wild-type bacterium, flagellar gene expression and flagellar number were greater at 28°C compared to 37°C. The QS-dependent flhC gene was significantly expressed at 28°C in two QS-defective (tofI::? and qsmR::?) mutants. Thus, flagella were present in both tofI::? and qsmR::? mutants at 28°C, but were absent at 37°C. Most tofI::? and qsmR::? mutant cells possessed polar or nonpolar flagella at 28°C. Nonpolarly flagellated cells processing flagella around cell surface of both tofI::? and qsmR::? mutants exhibited tumbling and spinning movements. The flhF gene encoding GTPase involved in regulating the correct placement of flagella in other bacteria was expressed in QS mutants in a FlhDC-dependent manner at 28°C. However, FlhF was mislocalized in QS mutants, and was associated with nonpolar flagellar formation in QS mutants at 28°C. These results indicate that QS-independent expression of flagellar genes at 28°C allows flagellar biogenesis, but is not sufficient for normal polar flagellar morphogenesis in B. glumae. Our findings demonstrate that QS functions together with temperature to control flagellar morphogenesis in B. glumae. PMID:24416296

  20. Influence of Neutrophil Defects on Burkholderia cepacia Complex Pathogenesis

    PubMed Central

    Porter, Laura A.; Goldberg, Joanna B.

    2011-01-01

    The Burkholderia cepacia complex (Bcc) is a group of Gram-negative bacteria that are ubiquitous in the environment and have emerged as opportunistic pathogens in immunocompromised patients. The primary patient populations infected with Bcc include individuals with cystic fibrosis (CF), as well as those with chronic granulomatous disease (CGD). While Bcc infection in CF is better characterized than in CGD, these two genetic diseases are not obviously similar and it is currently unknown if there is any commonality in host immune defects that is responsible for the susceptibility to Bcc. CF is caused by mutations in the CF transmembrane conductance regulator, resulting in manifestations in various organ systems, however the major cause of morbidity and mortality is currently due to bacterial respiratory infections. CGD, on the other hand, is a genetic disorder that is caused by defects in phagocyte NADPH oxidase. Because of the defect in CGD, phagocytes in these patients are unable to produce reactive oxygen species, which results in increased susceptibility to bacterial and fungal infections. Despite this significant defect in microbial clearance, the spectrum of pathogens frequently implicated in infections in CGD is relatively narrow and includes some bacterial species that are considered almost pathognomonic for this disorder. Very little is known about the cause of the specific susceptibility to Bcc over other potential pathogens more prevalent in the environment, and a better understanding of specific mechanisms required for bacterial virulence has become a high priority. This review will summarize both the current knowledge and future directions related to Bcc virulence in immunocompromised individuals with a focus on the roles of bacterial factors and neutrophil defects in pathogenesis. PMID:22919575

  1. Deciphering the Role of RND Efflux Transporters in Burkholderia cenocepacia

    PubMed Central

    Pasca, Maria Rosalia; Longo, Francesca; Emiliani, Giovanni; Fondi, Marco; Perrin, Elena; Decorosi, Francesca; Viti, Carlo; Giovannetti, Luciana; Leoni, Livia; Fani, Renato; Riccardi, Giovanna; Mahenthiralingam, Eshwar; Buroni, Silvia

    2011-01-01

    Burkholderia cenocepacia J2315 is representative of a highly problematic group of cystic fibrosis (CF) pathogens. Eradication of B. cenocepacia is very difficult with the antimicrobial therapy being ineffective due to its high resistance to clinically relevant antimicrobial agents and disinfectants. RND (Resistance-Nodulation-Cell Division) efflux pumps are known to be among the mediators of multidrug resistance in Gram-negative bacteria. Since the significance of the 16 RND efflux systems present in B. cenocepacia (named RND-1 to -16) has been only partially determined, the aim of this work was to analyze mutants of B. cenocepacia strain J2315 impaired in RND-4 and RND-9 efflux systems, and assess their role in the efflux of toxic compounds. The transcriptomes of mutants deleted individually in RND-4 and RND-9 (named D4 and D9), and a double-mutant in both efflux pumps (named D4-D9), were compared to that of the wild-type B. cenocepacia using microarray analysis. Microarray data were confirmed by qRT-PCR, phenotypic experiments, and by Phenotype MicroArray analysis. The data revealed that RND-4 made a significant contribution to the antibiotic resistance of B. cenocepacia, whereas RND-9 was only marginally involved in this process. Moreover, the double mutant D4-D9 showed a phenotype and an expression profile similar to D4. The microarray data showed that motility and chemotaxis-related genes appeared to be up-regulated in both D4 and D4–D9 strains. In contrast, these gene sets were down-regulated or expressed at levels similar to J2315 in the D9 mutant. Biofilm production was enhanced in all mutants. Overall, these results indicate that in B. cenocepacia RND pumps play a wider role than just in drug resistance, influencing additional phenotypic traits important for pathogenesis. PMID:21526150

  2. Complete genome sequence of the lipase producing strain Burkholderia glumae PG1.

    PubMed

    Voget, Sonja; Knapp, Andreas; Poehlein, Anja; Vollstedt, Christel; Streit, Wolfgang; Daniel, Rolf; Jaeger, Karl-Erich

    2015-06-20

    The Gram-negative proteobacterium Burkholderia glumae PG1 produces a lipase of biotechnological interest, which is used for the production of enantiopure pharmaceuticals. In order to better understand the underlying mechanisms and provide a basis for further studies, we present here the complete genome sequence of B. glumae PG1. PMID:25848987

  3. Draft Genome Sequence of Burkholderia gladioli Strain UCD-UG_CHAPALOTE (Phylum Proteobacteria)

    PubMed Central

    Ettinger, Cassandra L.; Shehata, Hanan R.; Johnston-Monje, David; Raizada, Manish N.

    2015-01-01

    Here, we present the draft genome of Burkholderia gladioli strain UCD-UG_CHAPALOTE. This strain is an endophyte isolated from surface sterilized seeds of an ancient Mexican landrace of corn, Chapalote. The genome contains 8,527,129 bp in 109 scaffolds. PMID:25614570

  4. Susceptibility of Caenorhabditis elegans to Burkholderia Infection Depends on Prior Diet and Secreted Bacterial Attractants

    PubMed Central

    Cooper, Vaughn S.; Carlson, Wendy A.; LiPuma, John J.

    2009-01-01

    The nematode Caenorhabditis elegans may be killed by certain pathogenic bacteria and thus is a model organism for studying interactions between bacteria and animal hosts. However, growing nematodes on prey bacteria may influence their susceptibility to potential pathogens. A method of axenic nematode culture was developed to isolate and quantify interactions between C. elegans and potentially pathogenic strains of the Burkholderia cepacia complex. Studying these dynamics in liquid solution rather than on agar surfaces minimized nematode avoidance behavior and resolved more differences among isolates. Most isolates of B. cenocepacia, B. ambifaria and B. cepacia caused 60–80% mortality of nematodes after 7 days, whereas isolates of B. multivorans caused less mortality (<25%) and supported nematode reproduction. However, some B. cenocepacia isolates recovered from chronic infections were much less virulent (5–28% mortality). As predicted, prior diet altered the outcome of interactions between nematodes and bacteria. When given the choice between Burkholderia and E. coli as prey on agar, axenically raised nematodes initially preferred most lethal Burkholderia isolates to E. coli as a food source, but this was not the case for nematodes fed E. coli, which avoided toxic Burkholderia. This food preference was associated with the cell-free supernatant and thus secreted compounds likely mediated bacterial-nematode interactions. This model, which isolates interactions between bacteria and nematodes from the effects of prior feeding, demonstrates that bacteria can influence nematode behavior and their susceptibility to pathogens. PMID:19956737

  5. Mode of Action of Antimicrobial Substances from Burkholderia multivorans and Microbacterium testaceum Against Schizophyllum commune Fr

    Microsoft Academic Search

    A. DIKIN; KAMARUZAMAN SIJAM; JUGAH KADIR; IDRIS ABU SEMAN

    Supernatant of antimicrobial substances from Burkholderia multivorans and Microbacterium testaceum suppressed S. commune is an important factor to understand the right application for bio-control. The mechanism of inhibition of fungal action by antimicrobial substances was observed under electron microscope. Direct contact of the mycelium, spores and basidia of S. commune with antimicrobial supernatant under scanning electron microscope showed the loss

  6. In vitro activities of antimicrobial agents, alone and in combinations, against Burkholderia cepacia isolated from blood

    Microsoft Academic Search

    Daniel C.-T. Lu; Shan-Chwen Chang; Yee-Chun Chen; Kwen-Tay Luh; Wei-Chuan Hsieh

    1997-01-01

    Burkholderia cepacia is a widespread, environmental gram-negative bacillus that is associated with nosocomial infections. This bacterium is considered to be an important pathogen in immunocompromised patients and is inherently resistant to multiple antimicrobial agents. To compare the activity of different antimicrobial agents and the potential of combinations against invasive strains of B. cepacia, we collected 36 isolates of B. cepacia

  7. Survey of Bartonella spp. in U.S. Bed Bugs Detects Burkholderia multivorans but Not Bartonella

    E-print Network

    Vargo, Ed

    Survey of Bartonella spp. in U.S. Bed Bugs Detects Burkholderia multivorans but Not Bartonella of Agriculture and Consumer Services, Raleigh, North Carolina, United States of America Abstract Bed bugs (Cimex lectularius L.) have resurged in the United States and globally. Bed bugs are hematophagous ectoparasites

  8. Type III Secretion: a Virulence Factor Delivery System Essential for the Pathogenicity of Burkholderia mallei

    Microsoft Academic Search

    Ricky L. Ulrich; David DeShazer

    2004-01-01

    By creating mutations in the Burkholderia mallei ATCC 23344 animal pathogen-like type III secretion system (TTSS), this study analyzes the correlation between type III secretion and the pathogenicity of ATCC 23344 in vivo. Mutagenesis demonstrated that a functional TTSS was required for the full pathogenicity of ATCC 23344 in the BALB\\/c mouse and Syrian hamster models of infection. However, vaccination

  9. Burkholderia aspalathi sp. nov., isolated from root nodules of the South African legume Aspalathus abietina Thunb.

    PubMed

    Mavengere, Natasha R; Ellis, Allan G; Le Roux, Johannes J

    2014-06-01

    During a study to investigate the diversity of rhizobia associated with native legumes in South Africa's Cape Floristic Region, a Gram-negative bacterium designated VG1C(T) was isolated from the root nodules of Aspalathus abietina Thunb. Based on phylogenetic analyses of the 16S rRNA and recA genes, VG1C(T) belongs to the genus Burkholderia, with the highest degree of sequence similarity to the type strain of Burkholderia sediminicola (98.5% and 98%, respectively). The DNA G+C content of strain VG1C(T) was 60.1 mol%, and DNA-DNA relatedness values to the type strain of closely related species were found to be substantially lower than 70%. As evidenced by results of genotypic, phenotypic and chemotaxonomic tests provided here, we conclude that isolate VG1C(T) represents a novel rhizosphere-associated species in the genus Burkholderia, for which the name Burkholderia aspalathi sp. nov. is proposed, with the type strain VG1C(T) (?=?DSM 27239(T)?=?LMG 27731(T)). PMID:24599894

  10. A novel DSF-like signal from Burkholderia cenocepacia interferes with Candida albicans morphological transition

    Microsoft Academic Search

    Calvin Boon; Yinyue Deng; Lian-Hui Wang; Yawen He; Jin-Ling Xu; Yang Fan; Shen Q Pan; Lian-Hui Zhang; L-H Zhang

    2008-01-01

    In addition to producing lethal antibiotics, microorganisms may also use a new form of antagonistic mechanism in which signal molecules are exported to influence the gene expression and hence the ecological competence of their competitors. We report here the isolation and characterization of a novel signaling molecule, cis-2-dodecenoic acid (BDSF), from Burkholderia cenocepacia. BDSF is structurally similar to the diffusible

  11. Effect of Agricultural Management Regime on Burkholderia Community Structure in Soil

    Microsoft Academic Search

    J. F. Salles; J. D. van Elsas; J. A. van Veen

    2006-01-01

    The main objective of this study was to determine the Burkholderia community structure associated with areas under different agricultural management and to evaluate to which extent this community structure is affected by changes in agricultural management. Two fields with distinct soil history (arable land and permanent grassland) were exposed to three agricultural management regimes (crop rotation, maize monoculture, and grassland).

  12. Burkholderia cepacia Complex Infection in Italian Patients with Cystic Fibrosis: Prevalence, Epidemiology, and Genomovar Status

    Microsoft Academic Search

    ANTONELLA AGODI; ESHWAR MAHENTHIRALINGAM; MARTINA BARCHITTA; VIVIANA GIANNINO; AGATA SCIACCA; STEFANIA STEFANI

    2001-01-01

    The prevalence, epidemiology, and genomovar status of Burkholderia cepacia complex strains recovered from Italian cystic fibrosis (CF) patients were investigated using genetic typing and species identification methods. Four CF treatment centers were examined: two in Sicily, one in central Italy, and one in northern Italy. B. cepacia complex bacteria were isolated from 59 out of 683 CF patients attending these

  13. Multiple Combination Bactericidal Antibiotic Testing for Patients with Cystic Fibrosis Infected with Burkholderia cepacia

    Microsoft Academic Search

    SHAWN D. AARON; WENDY FERRIS; DEBORAH A. HENRY; DAVID P. SPEERT; NONI E. M AC

    Most Burkholderia cepacia strains are resistant to many, or all, of the antibacterial agents commonly used in cystic fibrosis (CF), and selec- tion of appropriate antibiotics for treatment of pulmonary exacerba- tions is therefore difficult. We developed a technique for rapid in vitro testing of multiple antibiotic combinations for B. cepacia iso- lates. For each of 119 multi-drug-resistant isolates of

  14. Outcome of Burkholderia (Pseudomonas) cepacia colonisation in children with cystic fibrosis following a hospital outbreak

    Microsoft Academic Search

    M L Whiteford; J D Wilkinson; J H McColl; F M Conlon; J R Michie; T J Evans; J Y Paton

    1995-01-01

    BACKGROUND--While there are reports on the outcome in adults and teenagers with cystic fibrosis of colonisation with Burkholderia (Pseudomonas) cepacia, there is little information in children. METHODS--In December 1991 only one of 115 children with cystic fibrosis attending a paediatric centre was colonised with B cepacia. Over the next 12 months there was a rapid increase with 23 (20%) becoming

  15. Burkholderia cepacia Produces a Hemolysin That Is Capable of Inducing Apoptosis and Degranulation of Mammalian Phagocytes

    Microsoft Academic Search

    MICHAEL L. HUTCHISON; IAN R. POXTON; JOHN R. W. GOVAN

    1998-01-01

    Burkholderia cepacia is an opportunistic pathogen that has become a major threat to individuals with cystic fibrosis (CF). In approximately 20% of patients, pulmonary colonization with B. cepacia leads to cepacia syndrome, a fatal fulminating pneumonia sometimes associated with septicemia. It has been reported that culture filtrates of clinically derived strains of B. cepacia are hemolytic. In this study, we

  16. Endemicity and inter-city spread of Burkholderia cepacia genomovar III in cystic fibrosis

    Microsoft Academic Search

    Janet S. Chen; Kimberly A. Witzmann; Theodore Spilker; Robert J. Fink; John J. LiPuma

    2001-01-01

    Objectives: We sought to determine whether the same Burkholderia cepacia complex strain has persisted as the dominant clonal lineage among patients in a large cystic fibrosis (CF) treatment center during the past 2 decades. Study design: The inter-city spread of B cepacia through transfer of a colonized patient and the impact of infection control measures in containing inter-patient transmission were

  17. NOVEL ORGANIZATION OF THE GENES FOR PHTHALATE DEGRADATION FROM BURKHOLDERIA CEPACIA DBO1

    EPA Science Inventory

    Burkholderia cepacia DBO1 is able to utilize phthalate as the sole source of carbon and energy for growth. Two overlapping cosmid clones containing the genes for phthalate degradation were isolated from this strain. Subcloning and activity analysis localized the genes for phthala...

  18. Antimicrobial Properties of an Oxidizer Produced by Burkholderia cenocepacia P525

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A compound with both oxidizing properties and antibiotic properties was extracted and purified from broth cultures of Burkholderia cenocepacia strain P525. A four step purification procedure was used to increase its specific activity ~ 400 fold and to yield a HPLC- UV chromatogram containing a sing...

  19. Epidemiology of Burkholderia cepacia Complex in Patients with Cystic Fibrosis, Canada

    Microsoft Academic Search

    David P. Speert; Deborah Henry; Peter Vandamme; Mary Corey; Eshwar Mahenthiralingam

    The Burkholderia cepacia complex is an important group of pathogens in patients with cystic fibrosis (CF). Although evidence for patient-to-patient spread is clear, microbial factors facilitating transmission are poorly understood. To identify microbial clones with enhanced transmissibility, we evaluated B. cepacia complex isolates from patients with CF from throughout Canada. A total of 905 isolates from the B. cepacia complex

  20. Genotypic Analysis of Burkholderia cepacia Isolates from 13 French Cystic Fibrosis Centers

    Microsoft Academic Search

    CHRISTINE SEGONDS; EDOUARD BINGEN; GERARD COUETDIC; STEPHANIE MATHY; NAIMA BRAHIMI; NICOLE MARTY; PATRICK PLESIAT; YVON MICHEL-BRIAND; GERARD CHABANON; Hopital Robert Debre; CHU Jean Minjoz

    1997-01-01

    Burkholderia cepacia has been involved in outbreaks of pulmonary infection among patients with cystic fibrosis (CF), and the spread of a highly transmissible clone has been reported throughout the United Kingdom and Canada. These data prompted a DNA-based typing study of the strains recovered in French CF centers. Ninety-five isolates recovered from 71 patients attending 13 CF centers in 9

  1. Energy-Generating Enzymes of Burkholderia cepacia and Their Interactions with Macrophages

    Microsoft Academic Search

    Vasu Punj; Rachna Sharma; Olga Zaborina; A. M. Chakrabarty

    2003-01-01

    We previously demonstrated that several clinical and environmental isolates of Burkholderia cepacia secreted ATP-utilizing enzymes to the medium; the secretion of these enzymes by cystic fibrosis lung isolate strain 38 was shown to be greatly enhanced in the presence of 2-macroglobulin. Fractionation of the growth medium of cystic fibrosis isolate strain 71 belonging to genomovar I demonstrated the presence of

  2. Adherence of Burkholderia cepacia to respiratory tract epithelial cells and inhibition with dextrans

    Microsoft Academic Search

    Cheng-Hsun Chiu; Simon Wong; Robert E. W. Hancock; David P. Speert; Edward Jenner

    Adherence of Burkholderia cepacia to cells of the respiratory tract of patients with cystic fibrosis (CF) appears to be a necessary precondition for colonization and infection. To date, no effective anti-adhesive strategy has been devised for preventing B. cepacia infection in CF patients. It was found in this study that B. cepacia adhered to respiratory epithelial cells both in vitro

  3. Cystic fibrosis adults' perception and management of the risk of infection with Burkholderia cepacia complex

    Microsoft Academic Search

    Karen Lowton; Jonathan Gabe

    2006-01-01

    The risk of infection for cystic fibrosis patients from Burkholderia cepacia complex pathogens is of increasing concern to doctors and scientists. This paper reports on how these patients perceive and manage the risk of cepacia infection using Douglas and Calvez's (1990) typology of four cultures of the community (the central community, dissenting enclaves, isolates, and individualists) and Douglas' works on

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

    PubMed Central

    van Pelt, Cindy; Verduin, Cees M.; Goessens, Wil H. F.; Vos, Margreet C.; Tümmler, Burkhard; Segonds, Christine; Reubsaet, Frans; Verbrugh, Henri; van Belkum, Alex

    1999-01-01

    Cystic fibrosis (CF) predisposes patients to bacterial colonization and infection of the lower airways. Several species belonging to the genus Burkholderia are potential CF-related pathogens, but microbiological identification may be complicated. This situation is not in the least due to the poorly defined taxonomic status of these bacteria, and further validation of the available diagnostic assays is required. A total of 114 geographically diverse bacterial isolates, previously identified in reference laboratories as Burkholderia cepacia (n = 51), B. gladioli (n = 14), Ralstonia pickettii (n = 6), B. multivorans (n = 2), Stenotrophomonas maltophilia (n = 3), and Pseudomonas aeruginosa (n = 11), were collected from environmental, clinical, and reference sources. In addition, 27 clinical isolates putatively identified as Burkholderia spp. were recovered from the sputum of Dutch CF patients. All isolates were used to evaluate the accuracy of two selective growth media, four systems for biochemical identification (API 20NE, Vitek GNI, Vitek NFC, and MicroScan), and three different PCR-based assays. The PCR assays amplify different parts of the ribosomal DNA operon, either alone or in combination with cleavage by various restriction enzymes (PCR-restriction fragment length polymorphism [RFLP] analysis). The best system for the biochemical identification of B. cepacia appeared to be the API 20NE test. None of the biochemical assays successfully grouped the B. gladioli strains. The PCR-RFLP method appeared to be the optimal method for accurate nucleic acid-mediated identification of the different Burkholderia spp. With this method, B. gladioli was also reliably classified in a separate group. For the laboratory diagnosis of B. cepacia, we recommend parallel cultures on blood agar medium and selective agar plates. Further identification of colonies with a Burkholderia phenotype should be performed with the API 20NE test. For final confirmation of species identities, PCR amplification of the small-subunit rRNA gene followed by RFLP analysis with various enzymes is recommended. PMID:10364579

  5. Insecticide applications to soil contribute to the development of Burkholderia mediating insecticide resistance in stinkbugs.

    PubMed

    Tago, Kanako; Kikuchi, Yoshitomo; Nakaoka, Sinji; Katsuyama, Chie; Hayatsu, Masahito

    2015-07-01

    Some soil Burkholderia strains are capable of degrading the organophosphorus insecticide, fenitrothion, and establish symbiosis with stinkbugs, making the host insects fenitrothion-resistant. However, the ecology of the symbiotic degrading Burkholderia adapting to fenitrothion in the free-living environment is unknown. We hypothesized that fenitrothion applications affect the dynamics of fenitrothion-degrading Burkholderia, thereby controlling the transmission of symbiotic degrading Burkholderia from the soil to stinkbugs. We investigated changes in the density and diversity of culturable Burkholderia (i.e. symbiotic and nonsymbiotic fenitrothion degraders and nondegraders) in fenitrothion-treated soil using microcosms. During the incubation with five applications of pesticide, the density of the degraders increased from less than the detection limit to around 10(6) /g of soil. The number of dominant species among the degraders declined with the increasing density of degraders; eventually, one species predominated. This process can be explained according to the competitive exclusion principle using Vmax and Km values for fenitrothion metabolism by the degraders. We performed a phylogenetic analysis of representative strains isolated from the microcosms and evaluated their ability to establish symbiosis with the stinkbug Riptortus pedestris. The strains that established symbiosis with R. pedestris were assigned to a cluster including symbionts commonly isolated from stinkbugs. The strains outside the cluster could not necessarily associate with the host. The degraders in the cluster predominated during the initial phase of degrader dynamics in the soil. Therefore, only a few applications of fenitrothion could allow symbiotic degraders to associate with their hosts and may cause the emergence of symbiont-mediated insecticide resistance. PMID:26059639

  6. Evidence of Environmental and Vertical Transmission of Burkholderia Symbionts in the Oriental Chinch Bug, Cavelerius saccharivorus (Heteroptera: Blissidae)

    PubMed Central

    Itoh, Hideomi; Aita, Manabu; Nagayama, Atsushi; Meng, Xian-Ying; Kamagata, Yoichi; Navarro, Ronald; Hori, Tomoyuki; Ohgiya, Satoru

    2014-01-01

    The vertical transmission of symbiotic microorganisms is omnipresent in insects, while the evolutionary process remains totally unclear. The oriental chinch bug, Cavelerius saccharivorus (Heteroptera: Blissidae), is a serious sugarcane pest, in which symbiotic bacteria densely populate the lumen of the numerous tubule-like midgut crypts that the chinch bug develops. Cloning and sequence analyses of the 16S rRNA genes revealed that the crypts were dominated by a specific group of bacteria belonging to the genus Burkholderia of the Betaproteobacteria. The Burkholderia sequences were distributed into three distinct clades: the Burkholderia cepacia complex (BCC), the plant-associated beneficial and environmental (PBE) group, and the stinkbug-associated beneficial and environmental group (SBE). Diagnostic PCR revealed that only one of the three groups of Burkholderia was present in ?89% of the chinch bug field populations tested, while infections with multiple Burkholderia groups within one insect were observed in only ?10%. Deep sequencing of the 16S rRNA gene confirmed that the Burkholderia bacteria specifically colonized the crypts and were dominated by one of three Burkholderia groups. The lack of phylogenetic congruence between the symbiont and the host population strongly suggested host-symbiont promiscuity, which is probably caused by environmental acquisition of the symbionts by some hosts. Meanwhile, inspections of eggs and hatchlings by diagnostic PCR and egg surface sterilization demonstrated that almost 30% of the hatchlings vertically acquire symbiotic Burkholderia via symbiont-contaminated egg surfaces. The mixed strategy of symbiont transmission found in the oriental chinch bug might be an intermediate stage in evolution from environmental acquisition to strict vertical transmission in insects. PMID:25038101

  7. Fatal Outcome of Lung Transplantation in Cystic Fibrosis Patients due to Small-Colony Variants of the Burkholderia cepacia Complex

    Microsoft Academic Search

    S. Häußler; C. Lehmann; C. Breselge; M. Rohde; M. Claßen; B. Tümmler; P. Vandamme; I. Steinmetz

    2003-01-01

      \\u000a The aim of this study was to investigate the possible role of small-colony variant morphotypes of Burkholderia cepacia-like organisms in infectious complications in cystic fibrosis patients following lung transplantation. Respiratory tract\\u000a specimens from 470 cystic fibrosis patients were screened over a 22-month period for Burkholderia cepacia-like organisms. Nineteen patients were positive for these organisms, eight of whom harboured small-colony-variant

  8. Draft Genome Sequences of Two Burkholderia multivorans Sequential Isolates from a Chronic Lung Infection of a Cystic Fibrosis Patient

    PubMed Central

    Silva, Inês N.; Santos, Pedro M.

    2015-01-01

    Burkholderia multivorans belongs to the Burkholderia cepacia complex, which comprises opportunistic pathogens infecting cystic fibrosis (CF) patients. Here, we report the genome sequences and annotations of two sequential B. multivorans clinical isolates (D2095 and D2214) displaying different traits. The differences in the genomic contents of these isolates may provide clues regarding the evolution of B. multivorans within the airways of a CF patient. PMID:25676757

  9. Revelation of the ability of Burkholderia sp. USM (JCM 15050) PHA synthase to polymerize 4-hydroxybutyrate monomer

    PubMed Central

    2012-01-01

    The nutrition-versatility of Burkholderia sp. strain USM (JCM 15050) has initiated the studies on the use of this bacterium for polyhydroxyalkanoate (PHA) production. To date, the Burkholderia sp. has been reported to synthesize 3-hydroxybutyrate, 3-hydroxyvalerate and 3-hydroxy-4-methylvalerate monomers. In this study, the PHA biosynthetic genes of this strain were successfully cloned and characterized. The PHA biosynthetic cluster of this strain consisted of a PHA synthase (phaC), ?-ketothiolase (phaA), acetoacetyl-CoA reductase (phaB) and PHA synthesis regulator (phaR). The translated products of these genes revealed identities to corresponding proteins of Burkholderia vietnamiensis (99–100?%) and Cupriavidus necator H16 (63–89%). Heterologous expression of phaCBs conferred PHA synthesis to the PHA-negative Cupriavidus necator PHB¯4, confirming that phaCBs encoded functionally active protein. PHA synthase activity measurements revealed that the crude extracts of C. necator PHB¯4 transformant showed higher synthase activity (243 U/g) compared to that of wild-types Burkholderia sp. (151 U/g) and C. necator H16 (180 U/g). Interestingly, the transformant C. necator PHB¯4 harbouring Burkholderia sp. PHA synthase gene accumulated poly(3-hydroxybutyrate-co-4-hydroxybutyrate) with 4-hydroxybutyrate monomer as high as up to 87?mol% from sodium 4-hydroxybutyrate. The wild type Burkholderia sp. did not have the ability to produce this copolymer. PMID:22877240

  10. Revelation of the ability of Burkholderia sp. USM (JCM 15050) PHA synthase to polymerize 4-hydroxybutyrate monomer.

    PubMed

    Lau, Nyok-Sean; Sudesh, Kumar

    2012-01-01

    The nutrition-versatility of Burkholderia sp. strain USM (JCM 15050) has initiated the studies on the use of this bacterium for polyhydroxyalkanoate (PHA) production. To date, the Burkholderia sp. has been reported to synthesize 3-hydroxybutyrate, 3-hydroxyvalerate and 3-hydroxy-4-methylvalerate monomers. In this study, the PHA biosynthetic genes of this strain were successfully cloned and characterized. The PHA biosynthetic cluster of this strain consisted of a PHA synthase (phaC), ?-ketothiolase (phaA), acetoacetyl-CoA reductase (phaB) and PHA synthesis regulator (phaR). The translated products of these genes revealed identities to corresponding proteins of Burkholderia vietnamiensis (99-100?%) and Cupriavidus necator H16 (63-89%). Heterologous expression of phaCBs conferred PHA synthesis to the PHA-negative Cupriavidus necator PHB¯4, confirming that phaCBs encoded functionally active protein. PHA synthase activity measurements revealed that the crude extracts of C. necator PHB¯4 transformant showed higher synthase activity (243 U/g) compared to that of wild-types Burkholderia sp. (151 U/g) and C. necator H16 (180 U/g). Interestingly, the transformant C. necator PHB¯4 harbouring Burkholderia sp. PHA synthase gene accumulated poly(3-hydroxybutyrate-co-4-hydroxybutyrate) with 4-hydroxybutyrate monomer as high as up to 87?mol% from sodium 4-hydroxybutyrate. The wild type Burkholderia sp. did not have the ability to produce this copolymer. PMID:22877240

  11. Soluble granzymes are released during human endotoxemia and in patients with severe infection due to gram-negative bacteria.

    PubMed

    Lauw, F N; Simpson, A J; Hack, C E; Prins, J M; Wolbink, A M; van Deventer, S J; Chaowagul, W; White, N J; van Der Poll, T

    2000-07-01

    Extracellular release of granzymes is considered to reflect the involvement of cytotoxic T lymphocytes and NK cells in various disease states. To obtain insight into granzyme release during bacterial infection, granzyme levels were measured during experimental human endotoxemia and in patients with melioidosis, a severe infection due to gram-negative bacteria. Plasma concentrations of granzyme A (GrA) and GrB increased transiently after endotoxin administration, peaking after 2-6 h. In patients with bacteremic melioidosis, GrA and GrB levels were elevated on admission and remained high during the 72-h study period. In whole blood stimulated with heat-killed Burkholderia pseudomallei, neutralization of tumor necrosis factor, interleukin-12, or interleukin-18 inhibited granzyme secretion, which was independent of interferon-gamma. Stimulation with endotoxin and other gram-negative and gram-positive bacteria also strongly induced the secretion of granzymes, suggesting that granzyme release is a general immune response during bacterial infection. The interaction between the cytokine network and granzymes may play an important immunoregulatory role during bacterial infections. PMID:10882599

  12. ?54-Dependent Response to Nitrogen Limitation and Virulence in Burkholderia cenocepacia Strain H111.

    PubMed

    Lardi, Martina; Aguilar, Claudio; Pedrioli, Alessandro; Omasits, Ulrich; Suppiger, Angela; Cárcamo-Oyarce, Gerardo; Schmid, Nadine; Ahrens, Christian H; Eberl, Leo; Pessi, Gabriella

    2015-06-15

    Members of the genus Burkholderia are versatile bacteria capable of colonizing highly diverse environmental niches. In this study, we investigated the global response of the opportunistic pathogen Burkholderia cenocepacia H111 to nitrogen limitation at the transcript and protein expression levels. In addition to a classical response to nitrogen starvation, including the activation of glutamine synthetase, PII proteins, and the two-component regulatory system NtrBC, B. cenocepacia H111 also upregulated polyhydroxybutyrate (PHB) accumulation and exopolysaccharide (EPS) production in response to nitrogen shortage. A search for consensus sequences in promoter regions of nitrogen-responsive genes identified a ?(54) consensus sequence. The mapping of the ?(54) regulon as well as the characterization of a ?(54) mutant suggests an important role of ?(54) not only in control of nitrogen metabolism but also in the virulence of this organism. PMID:25841012

  13. Genome sequence of the Lebeckia ambigua-nodulating “Burkholderia sprentiae” strain WSM5005T

    PubMed Central

    Reeve, Wayne; De Meyer, Sofie; Terpolilli, Jason; Melino, Vanessa; Ardley, Julie; Rui, Tian; Tiwari, Ravi; Howieson, John; Yates, Ron; O’Hara, Graham; Lu, Megan; Bruce, David; Detter, Chris; Tapia, Roxanne; Han, Cliff; Wei, Chia-Lin; Huntemann, Marcel; Han, James; Chen, I-Min; Mavromatis, Konstantinos; Markowitz, Victor; Szeto, Ernest; Ivanova, Natalia; Mikhailova, Natalia; Ovchinnikova, Galina; Pagani, Ioanna; Pati, Amrita; Goodwin, Lynne; Peters, Lin; Pitluck, Sam; Woyke, Tanja; Kyrpides, Nikos

    2013-01-01

    Burkholderia sprentiae” strain WSM5005T is an aerobic, motile, Gram-negative, non-spore-forming rod that was isolated in Australia from an effective N2-fixing root nodule of Lebeckia ambigua collected in Klawer, Western Cape of South Africa, in October 2007. Here we describe the features of “Burkholderia sprentiae” strain WSM5005T, together with the genome sequence and its annotation. The 7,761,063 bp high-quality-draft genome is arranged in 8 scaffolds of 236 contigs, contains 7,147 protein-coding genes and 76 RNA-only encoding genes, and is one of 20 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Community Sequencing Program. PMID:24976894

  14. Quorum Sensing Controls Swarming Motility of Burkholderia glumae through Regulation of Rhamnolipids

    PubMed Central

    Nickzad, Arvin; Lépine, François; Déziel, Eric

    2015-01-01

    Burkholderia glumae is a plant pathogenic bacterium that uses an acyl-homoserine lactone-mediated quorum sensing system to regulate protein secretion, oxalate production and major virulence determinants such as toxoflavin and flagella. B. glumae also releases surface-active rhamnolipids. In Pseudomonas aeruginosa and Burkholderia thailandensis, rhamnolipids, along with flagella, are required for the social behavior called swarming motility. In the present study, we demonstrate that quorum sensing positively regulates the production of rhamnolipids in B. glumae and that rhamnolipids are necessary for swarming motility also in this species. We show that a rhlA- mutant, which is unable to produce rhamnolipids, loses its ability to swarm, and that this can be complemented by providing exogenous rhamnolipids. Impaired rhamnolipid production in a quorum sensing-deficient B. glumae mutant is the main factor responsible for its defective swarming motility behaviour. PMID:26047513

  15. Enhanced phosphate uptake and polyphosphate accumulation in Burkholderia cepacia grown under low-pH conditions

    Microsoft Academic Search

    A. Mullan; J. P. Quinn; J. W. McGrath

    2002-01-01

    Of bacterial cells in a sample of activated sludge, 34% contained detectable intracellular polyphosphate inclusions following\\u000a Neisser staining when grown on glucose\\/mineral salts medium at pH 5.5; at pH 7.5 only 7% of cells visibly accumulated polyphosphate.\\u000a In a sludge isolate of Burkholderia cepacia chosen for further study, maximal removal of phosphate and accumulation of polyphosphate occurred at pH 5.5;

  16. Pathogenicity, virulence factors, and strategies to fight against Burkholderia cepacia complex pathogens and related species

    Microsoft Academic Search

    Jorge H. Leitão; Sílvia A. Sousa; Ana S. Ferreira; Christian G. Ramos; Inês N. Silva; Leonilde M. Moreira

    2010-01-01

    The Burkholderia cepacia complex (Bcc) is a group of 17 closely related species of the ?-proteobacteria subdivision that emerged in the 1980s as important\\u000a human pathogens, especially to patients suffering from cystic fibrosis. Since then, a remarkable progress has been achieved\\u000a on the taxonomy and molecular identification of these bacteria. Although some progress have been achieved on the knowledge\\u000a of

  17. Photodynamic Antimicrobial Chemotherapy (PACT) in combination with antibiotics for treatment of Burkholderia cepacia complex infection

    Microsoft Academic Search

    Corona M. Cassidy; Ryan F. Donnelly; J. Stuart Elborn; Nicholas D. Magee; Michael M. Tunney

    This study aimed to determine if Photodynamic Antimicrobial Chemotherapy (PACT) was effective in the treatment of Burkholderia cepacia complex infection and whether a synergistic effect was evident if PACT was used in combination with antibiotics. The susceptibility of both planktonic and biofilm cultures of B. cepacia complex strains to methylene blue (MB) and meso-tetra(n-methyl-4-pyridyl)porphine tetra-tosylate (TMP)–mediated PACT was determined alone

  18. Mining host-pathogen protein interactions to characterize Burkholderia mallei infectivity mechanisms.

    PubMed

    Memiševi?, Vesna; Zavaljevski, Nela; Rajagopala, Seesandra V; Kwon, Keehwan; Pieper, Rembert; DeShazer, David; Reifman, Jaques; Wallqvist, Anders

    2015-03-01

    Burkholderia pathogenicity relies on protein virulence factors to control and promote bacterial internalization, survival, and replication within eukaryotic host cells. We recently used yeast two-hybrid (Y2H) screening to identify a small set of novel Burkholderia proteins that were shown to attenuate disease progression in an aerosol infection animal model using the virulent Burkholderia mallei ATCC 23344 strain. Here, we performed an extended analysis of primarily nine B. mallei virulence factors and their interactions with human proteins to map out how the bacteria can influence and alter host processes and pathways. Specifically, we employed topological analyses to assess the connectivity patterns of targeted host proteins, identify modules of pathogen-interacting host proteins linked to processes promoting infectivity, and evaluate the effect of crosstalk among the identified host protein modules. Overall, our analysis showed that the targeted host proteins generally had a large number of interacting partners and interacted with other host proteins that were also targeted by B. mallei proteins. We also introduced a novel Host-Pathogen Interaction Alignment (HPIA) algorithm and used it to explore similarities between host-pathogen interactions of B. mallei, Yersinia pestis, and Salmonella enterica. We inferred putative roles of B. mallei proteins based on the roles of their aligned Y. pestis and S. enterica partners and showed that up to 73% of the predicted roles matched existing annotations. A key insight into Burkholderia pathogenicity derived from these analyses of Y2H host-pathogen interactions is the identification of eukaryotic-specific targeted cellular mechanisms, including the ubiquitination degradation system and the use of the focal adhesion pathway as a fulcrum for transmitting mechanical forces and regulatory signals. This provides the mechanisms to modulate and adapt the host-cell environment for the successful establishment of host infections and intracellular spread. PMID:25738731

  19. Quorum Sensing: a Transcriptional Regulatory System Involved in the Pathogenicity of Burkholderia mallei

    Microsoft Academic Search

    Ricky L. Ulrich; David DeShazer; Harry B. Hines; Jeffrey A. Jeddeloh

    2004-01-01

    Numerous gram-negative bacterial pathogens regulate virulence factor expression by using a cell density mechanism termed quorum sensing (QS). An in silico analysis of the Burkholderia mallei ATCC 23344 genome revealed that it encodes at least two luxI and four luxR homologues. Using mass spectrometry, we showed that wild-type B. mallei produces the signaling molecules N-octanoyl-homoserine lactone and N-decanoyl-homo- serine lactone.

  20. Identification of Burkholderia spp. in the clinical microbiology laboratory: comparison of conventional and molecular methods

    Microsoft Academic Search

    Pelt van C; C. M. Verduin; W. H. F. Goessens; M. C. Vos; B. Tummler; C. Segonds; F. Reubsaet; Belkum van A. F; H. A. Verbrugh

    1999-01-01

    Cystic fibrosis (CF) predisposes patients to bacterial colonization and\\u000a infection of the lower airways. Several species belonging to the genus\\u000a Burkholderia are potential CF-related pathogens, but microbiological\\u000a identification may be complicated. This situation is not in the least due\\u000a to the poorly defined taxonomic status of these bacteria, and further\\u000a validation of the available diagnostic assays is required. A total

  1. Attenuated Virulence of a Burkholderia cepacia Type III Secretion Mutant in a Murine Model of Infection

    Microsoft Academic Search

    Mladen Tomich; Adam Griffith; Christine A. Herfst; Jane L. Burns; Christian D. Mohr

    2003-01-01

    Type III secretion systems are utilized by a number of gram-negative bacterial pathogens to deliver viru- lence-associated proteins into host cells. Using a PCR-based approach, we identified homologs of type III secretion genes in the gram-negative bacterium Burkholderia cepacia, an important pulmonary pathogen in immunocompromised patients and patients with cystic fibrosis. One of the genes, designated bscN, encodes a member

  2. Burkholderia grimmiae sp. nov., isolated from a xerophilous moss (Grimmia montana).

    PubMed

    Tian, Yang; Kong, Bi He; Liu, Su Lin; Li, Chun Li; Yu, Rong; Liu, Lei; Li, Yan Hong

    2013-06-01

    A Gram-staining-negative, rod-shaped, non-spore-forming bacterium, designated strain R27(T), was isolated from the moss Grimmia montana, collected from Beijing Songshan National Nature Reserve, China, and characterized by using a polyphasic taxonomic approach. The predominant fatty acids of strain R27(T) were C18:1?7c (33.6%), C16:0 (16.3%), summed feature 3 (C16:1?7c and/or C16:1?6c; 15.8%) and C17:0 cyclo (8.7%) and its major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, three uncharacterized aminolipids and an unknown phospholipid. Strain R27(T) contained Q-8 as the dominant isoprenoid quinone and the G+C content of its genomic DNA was 64.6 mol%. On the basis of 16S rRNA gene sequence comparison, strain R27(T) showed 99.1% similarity to the closest related type strain, Burkholderia zhejiangensis OP-1(T), and 97.6% similarity to Burkholderia glathei ATCC 29195(T). However, the DNA-DNA relatedness between strain R27(T) and B. zhejiangensis CCTCC AB 2010354(T) and B. glathei ATCC 29195(T) was 10.2 and 14.9%, respectively. Based on 16S rRNA and rpoB gene sequence similarities and phenotypic and chemotaxonomic data, strain R27(T) is considered to represent a novel species of the genus Burkholderia, for which the name Burkholderia grimmiae sp. nov. is proposed. The type strain is R27(T) (=CGMCC 1.11013(T) =DSM 25160(T)). PMID:23087167

  3. Burkholderia cenocepacia sp. nov.—a new twist to an old story

    Microsoft Academic Search

    Peter Vandamme; Barry Holmes; Tom Coenye; Johan Goris; Eshwar Mahenthiralingam; John J. LiPuma; John R. W. Govan

    2003-01-01

    DNA–DNA hybridisation experiments between isolates representing Burkholderia cepacia genomovar III recA lineages IIIA and IIIB reinforced the classification of both phylogenetic subgroups as a single genospecies, distinct from B. cepacia (genomovar I). A formal classification of B. cepacia genomovar III encompassing the recA lineages IIIA and IIIB, and the new recA lineages IIIC and IIID, as B. cenocepacia sp. nov., with LMG 16656 as the

  4. N-Acylhomoserine-lactone-mediated communication between Pseudomonas aeruginosa and Burkholderia cepacia in mixed biofilms

    Microsoft Academic Search

    Kathrin Riedel; Morten Hentzer; Otto Geisenberger; Birgit Huber; Anette Steidle; Hong Wu; Niels Høiby; Michael Givskov; Søren Molin; Leo Eberl

    Pseudomonas aeruginosa and Burkholderia cepacia are capable of forming mixed biofilms in the lungs of cystic fibrosis patients. Both bacteria employ quorum-sensing systems, which rely on N-acylhomoserine lactone (AHL) signal molecules, to co-ordinate expression of virulence factors with the formation of biofilms. As both bacteria utilize the same class of signal molecules the authors investigated whether communication between the species

  5. Toluene 2-monooxygenase-dependent growth of Burkholderia cepacia G4/PR1 on diethyl ether

    SciTech Connect

    Hur, H.G.; Newman, L.M.; Wackett, L.P.; Sadowsky, M.J. [Univ. of Minnesota, St. Paul, MN (United States)

    1997-04-01

    There is considerable interest in the biodegradation of solvents and fuel additives such as diethyl ether and tert-butyl methyl either. The present study investigated if toluene 2-monooxygenase would allow Burkholderia cepacia G4/PR1 to grow on either compounds via novel metabolic pathways. In addition, the role of enzyme induction in allowing growth on compounds not resembling toluene or phenol was studied. 29 refs., 2 figs., 2 tabs.

  6. Quorum Sensing in Burkholderia cepacia: Identification of the LuxRI Homologs CepRI

    Microsoft Academic Search

    SHAWN LEWENZA; BARBARA CONWAY; E. P. GREENBERG; PAMELA A. SOKOL

    1999-01-01

    Burkholderia cepacia has emerged as an important pathogen in patients with cystic fibrosis. Many gram- negative pathogens regulate the production of extracellular virulence factors by a cell density-dependent mech- anism termed quorum sensing, which involves production of diffusible N-acylated homoserine lactone signal molecules, called autoinducers. Transposon insertion mutants of B. cepacia K56-2 which hyperproduced sidero- phores on chrome azurol S

  7. Comparative Assessment of Genotyping Methods for Epidemiologic Study of Burkholderia cepacia Genomovar III

    Microsoft Academic Search

    Tom Coenye; Theodore Spilker; Alissa Martin; John J. LiPuma

    2002-01-01

    We analyzed a collection of 97 well-characterized Burkholderia cepacia genomovar III isolates to evaluate multiple genomic typing systems, including pulsed-field gel electrophoresis (PFGE), BOX-PCR fingerprinting and random amplified polymorphic DNA (RAPD) typing. The typeability, reproducibility, and discriminatory power of these techniques were evaluated, and the results were compared to each other and to data obtained in previous studies by using

  8. Gentamicin Delivery to Burkholderia cepacia Group IIIa Strains via Membrane Vesicles from Pseudomonas aeruginosa PAO1

    Microsoft Academic Search

    Nick D. Allan; Terry J. Beveridge

    2003-01-01

    When Pseudomonas aeruginosa PAO1 is treated with gentamicin, it releases membrane vesicles containing gentamicin (g-MVs) and peptidoglycan hydrolase, which makes the MVs bactericidal. We evaluate the ability of g-MVs to deliver gentamicin past the intrinsic permeability barrier of group IIIa Burkholderia cepacia and show that strain CEP0248 with low resistance to gentamicin is killed but the highly resistant strain C5424

  9. Genetic Diversity ofBurkholderia solanacearum(Synonym Pseudomonas solanacearum) Race 3 in Kenya

    Microsoft Academic Search

    JULIAN J. SMITH; LISA C. OFFORD; MARK HOLDERNESS; ANDGERARD S. SADDLER

    1995-01-01

    Genetic diversity among isolates of the bacterial plant pathogen Burkholderia solanacearum (synonym Pseudomonas solanacearum) race 3 biovar II of Kenya was determined by PCR with repetitive sequences (ERIC and BOX repetitive primer sets) and pulsed-field gel electrophoresis of genomic DNA digested by rare-cutting restriction endonucleases (RC-PFGE). The study comprised 46 isolates collected during 1992 from the major potato-growing regions of

  10. Burkholderia insulsa sp. nov., a facultatively chemolithotrophic bacterium isolated from an arsenic-rich shallow marine hydrothermal system.

    PubMed

    Rusch, Antje; Islam, Shaer; Savalia, Pratixa; Amend, Jan P

    2015-01-01

    Enrichment cultures inoculated with hydrothermally influenced nearshore sediment from Papua New Guinea led to the isolation of an arsenic-tolerant, acidophilic, facultatively aerobic bacterial strain designated PNG-April(T). Cells of this strain were Gram-stain-negative, rod-shaped, motile and did not form spores. Strain PNG-April(T) grew at temperatures between 4 °C and 40 °C (optimum 30-37 °C), at pH 3.5 to 8.3 (optimum pH 5-6) and in the presence of up to 2.7% NaCl (optimum 0-1.0%). Both arsenate and arsenite were tolerated up to concentrations of at least 0.5 mM. Metabolism in strain PNG-April(T) was strictly respiratory. Heterotrophic growth occurred with O2 or nitrate as electron acceptors, and aerobic lithoautotrophic growth was observed with thiosulfate or nitrite as electron donors. The novel isolate was capable of N2-fixation. The respiratory quinones were Q-8 and Q-7. Phylogenetically, strain PNG-April(T) belongs to the genus Burkholderia and shares the highest 16S rRNA gene sequence similarity with the type strains of Burkholderia fungorum (99.8%), Burkholderia phytofirmans (98.8%), Burkholderia caledonica (98.4%) and Burkholderia sediminicola (98.4%). Differences from these related species in several physiological characteristics (lipid composition, carbohydrate utilization, enzyme profiles) and DNA-DNA hybridization suggested the isolate represents a novel species of the genus Burkholderia, for which we propose the name Burkholderia insulsa sp. nov. The type strain is PNG-April(T) (?=?DSM 28142(T)?=?LMG 28183(T)). PMID:25323596

  11. Identification of Specific and Universal Virulence Factors in Burkholderia cenocepacia Strains by Using Multiple Infection Hosts? †

    PubMed Central

    Uehlinger, Susanne; Schwager, Stephan; Bernier, Steve P.; Riedel, Kathrin; Nguyen, David T.; Sokol, Pamela A.; Eberl, Leo

    2009-01-01

    Over the past few decades, strains of the Burkholderia cepacia complex have emerged as important pathogens for patients suffering from cystic fibrosis. Identification of virulence factors and assessment of the pathogenic potential of Burkholderia strains have increased the need for appropriate infection models. In previous studies, different infection hosts, including mammals, nematodes, insects, and plants, have been used. At present, however, the extent to which the virulence factors required to infect different hosts overlap is not known. The aim of this study was to analyze the roles of various virulence factors of two closely related Burkholderia cenocepacia strains, H111 and the epidemic strain K56-2, in a multihost pathogenesis system using four different model organisms, namely, Caenorhabditis elegans, Galleria mellonella, the alfalfa plant, and mice or rats. We demonstrate that most of the identified virulence factors are specific for one of the infection models, and only three factors were found to be essential for full pathogenicity in several hosts: mutants defective in (i) quorum sensing, (ii) siderophore production, and (iii) lipopolysaccharide biosynthesis were attenuated in at least three of the infection models and thus may represent promising targets for the development of novel anti-infectives. PMID:19528212

  12. Phenotypic Methods for Determining Genomovar Status of the Burkholderia cepacia Complex

    PubMed Central

    Henry, Deborah A.; Mahenthiralingam, Eshwar; Vandamme, Peter; Coenye, Tom; Speert, David P.

    2001-01-01

    Recent taxonomic advances have demonstrated that Burkholderia cepacia is a cluster of at least seven closely related genomic species (or genomovars) collectively referred to as the B. cepacia complex, all of which may cause infections among cystic fibrosis patients and other vulnerable individuals. Thus, it is important for clinical microbiologists to be able to differentiate genomovars. Prior to this study, 361 B. cepacia complex isolates and 51 isolates easily confused with B. cepacia complex previously had been identified using a polyphasic approach, and in this study, a comparison of phenotypic and biochemical tests was carried out. It was determined that Burkholderia multivorans and Burkholderia stabilis could reliably be separated from other members of the B. cepacia complex by phenotypic methods. A combination of phenotypic and molecular tests such as recA PCR and 16S rRNA RFLP are recommended for differentiation among the genomovars of the B. cepacia complex. A biochemical reaction scheme for the identification of B. gladioli, Pandoraea species, and Ralstonia pickettii and the differentiation of these species from the B. cepacia complex is also presented. PMID:11230429

  13. MtvR Is a Global Small Noncoding Regulatory RNA in Burkholderia cenocepacia

    PubMed Central

    Ramos, Christian G.; Grilo, André M.; da Costa, Paulo J. P.; Feliciano, Joana R.

    2013-01-01

    Burkholderia cenocepacia J2315 is a highly epidemic and transmissible clinical isolate of the Burkholderia cepacia complex (Bcc), a group of bacteria causing life-threatening respiratory infections among cystic fibrosis patients. This work describes the functional analysis of the 136-nucleotide (nt)-long MtvR small noncoding RNA (sRNA) from the Bcc member B. cenocepacia J2315, with homologues restricted to the genus Burkholderia. Bioinformatic target predictions revealed a total of 309 mRNAs to be putative MtvR targets. The mRNA levels corresponding to 17 of 19 selected genes were found to be affected when MtvR was either overexpressed or silenced. Analysis of the interaction between MtvR and the hfq mRNA, one of its targets, showed that the sRNA binds exclusively to the 5? untranslated region (UTR) of the hfq mRNA. This interaction resulted in decreased protein synthesis, suggesting a negative regulatory effect of MtvR on the RNA chaperone Hfq. Bacterial strains with MtvR silenced or overexpressed exhibited pleiotropic phenotypes related to growth and survival after several stresses, swimming and swarming motilities, biofilm formation, resistance to antibiotics, and ability to colonize and kill the nematode Caenorhabditis elegans. Together, the results indicate that the MtvR sRNA is a major posttranscriptional regulator in B. cenocepacia. PMID:23729649

  14. Identification of a Burkholderia mallei polysaccharide gene cluster by subtractive hybridization and demonstration that the encoded capsule is an essential virulence determinant

    Microsoft Academic Search

    David DeShazer; David M. Waag; David L. Fritz; Donald E. Woods

    2001-01-01

    Little is known about the virulence factors of Burkholderia mallei, the etiologic agent of glanders. We employed subtractive hybridization to identify genetic determinants present in B. mallei but not inBurkholderia thailandensis , a non-pathogenic soil microbe. Three subtractive hybridization products were mapped to a genetic locus encoding proteins involved in the biosynthesis, export and translocation of a capsular polysaccharide. We

  15. Expression of the bviIR and cepIR Quorum-Sensing Systems of Burkholderia vietnamiensis

    Microsoft Academic Search

    Rebecca J. Malott; Pamela A. Sokol

    2007-01-01

    Burkholderia vietnamiensis has both the cepIR quorum-sensing system that is widely distributed among the Burkholderia cepacia complex (BCC) and the bviIR system. Comparison of the expression of cepI, cepR, bviI, and bviR-luxCDABE fusions in B. vietnamiensis G4 and the G4 cepR and bviR mutants determined that the expression of bviI requires both a functional cognate regulator, BviR, and functional CepR.

  16. Purine biosynthesis-deficient Burkholderia mutants are incapable of symbiotic accommodation in the stinkbug

    PubMed Central

    Kim, Jiyeun Kate; Jang, Ho Am; Won, Yeo Jin; Kikuchi, Yoshitomo; Heum Han, Sang; Kim, Chan-Hee; Nikoh, Naruo; Fukatsu, Takema; Lee, Bok Luel

    2014-01-01

    The Riptortus–Burkholderia symbiotic system represents a promising experimental model to study the molecular mechanisms involved in insect–bacterium symbiosis due to the availability of genetically manipulated Burkholderia symbiont. Using transposon mutagenesis screening, we found a symbiosis-deficient mutant that was able to colonize the host insect but failed to induce normal development of host's symbiotic organ. The disrupted gene was identified as purL involved in purine biosynthesis. In vitro growth impairment of the purL mutant and its growth dependency on adenine and adenosine confirmed the functional disruption of the purine synthesis gene. The purL mutant also showed defects in biofilm formation, and this defect was not rescued by supplementation of purine derivatives. When inoculated to host insects, the purL mutant was initially able to colonize the symbiotic organ but failed to attain a normal infection density. The low level of infection density of the purL mutant attenuated the development of the host's symbiotic organ at early instar stages and reduced the host's fitness throughout the nymphal stages. Another symbiont mutant-deficient in a purine biosynthesis gene, purM, showed phenotypes similar to those of the purL mutant both in vitro and in vivo, confirming that the purL phenotypes are due to disrupted purine biosynthesis. These results demonstrate that the purine biosynthesis genes of the Burkholderia symbiont are critical for the successful accommodation of symbiont within the host, thereby facilitating the development of the host's symbiotic organ and enhancing the host's fitness values. PMID:24088627

  17. Versatility of the Burkholderia cepacia Complex for the Biosynthesis of Exopolysaccharides: A Comparative Structural Investigation

    PubMed Central

    Silipo, Alba; Lanzetta, Rosa; Liut, Gianfranco; Rizzo, Roberto; Cescutti, Paola

    2014-01-01

    The Burkholderia cepacia Complex assembles at least eighteen closely related species that are ubiquitous in nature. Some isolates show beneficial potential for biocontrol, bioremediation and plant growth promotion. On the contrary, other strains are pathogens for plants and immunocompromised individuals, like cystic fibrosis patients. In these subjects, they can cause respiratory tract infections sometimes characterised by fatal outcome. Most of the Burkholderia cepacia Complex species are mucoid when grown on a mannitol rich medium and they also form biofilms, two related characteristics, since polysaccharides are important component of biofilm matrices. Moreover, polysaccharides contribute to bacterial survival in a hostile environment by inhibiting both neutrophils chemotaxis and antimicrobial peptides activity, and by scavenging reactive oxygen species. The ability of these microorganisms to produce exopolysaccharides with different structures is testified by numerous articles in the literature. However, little is known about the type of polysaccharides produced in biofilms and their relationship with those obtained in non-biofilm conditions. The aim of this study was to define the type of exopolysaccharides produced by nine species of the Burkholderia cepacia Complex. Two isolates were then selected to compare the polysaccharides produced on agar plates with those formed in biofilms developed on cellulose membranes. The investigation was conducted using NMR spectroscopy, high performance size exclusion chromatography, and gas chromatography coupled to mass spectrometry. The results showed that the Complex is capable of producing a variety of exopolysaccharides, most often in mixture, and that the most common exopolysaccharide is always cepacian. In addition, two novel polysaccharide structures were determined: one composed of mannose and rhamnose and another containing galactose and glucuronic acid. Comparison of exopolysaccharides obtained from cultures on agar plates with those extracted from biofilms on cellulose membranes showed important differences, thus suggesting that extrapolating data from non-biofilm conditions might not always be applicable. PMID:24722641

  18. Assimilation of homotaurine-nitrogen by Burkholderia sp. and excretion of sulfopropanoate.

    PubMed

    Mayer, Jutta; Denger, Karin; Kaspar, Katrin; Hollemeyer, Klaus; Smits, Theo H M; Huhn, Thomas; Cook, Alasdair M

    2008-02-01

    Homotaurine (3-aminopropanesulfonate), free or derivatized, is in widespread pharmaceutical and laboratory use. Studies with enrichment cultures indicated that the compound is degradable as a sole source of carbon or as a sole source of nitrogen for bacterial growth. A pure culture of Burkholderia sp. was isolated which assimilated the amino group from homotaurine in a glucose-salts medium, and which released an organosulfonate, 3-sulfopropanoate, into the medium stoichiometrically. The deamination involved an inducible 2-oxoglutarate-dependent aminotransferase to yield glutamate, and 3-sulfopropanal. Release of the amino group was attributed to the measured NADP-coupled glutamate dehydrogenase. PMID:18081842

  19. Investigating early stages of biocorrosion with XPS: AISI 304 stainless steel exposed to Burkholderia species

    NASA Astrophysics Data System (ADS)

    Johansson, Leena-Sisko; Saastamoinen, Tuomas

    1999-04-01

    We have investigated the interactions of an exopolymer-producing bacteria, Burkholderia sp. with polished AISI 304 stainless steel substrates using X-ray photoelectron spectroscopy (XPS). Steel coupons were exposed to the pure bacteria culture in a specially designed flowcell for 6 h during which the experiment was monitored in situ with an optical microscope. XPS results verified the formation of biofilm containing extracellular polymer on all the samples exposed to bacteria. Sputter results indicated that some ions needed for metabolic processes were trapped within the biofilm. Changes in the relative Fe concentration and Fe 2p peak shape indicated that also iron had accumulated into the biofilm.

  20. The chlorobenzoate dioxygenase genes of Burkholderia sp. strain NK8 involved in the catabolism of chlorobenzoates

    Microsoft Academic Search

    Perigio B. Francisco Jr; Naoto Ogawa; Katsuhisa Suzuki; Kiyotaka Miyashita

    Burkholderia sp. NK8 grows abundantly on 3-chlorobenzoate (3CB), 4-chlorobenzoate (4CB) and benzoate. The genes encoding the oxidation of (chloro)benzoates (cbeABCD) and catechol (catA, catBC), the LysR-type regulatory gene cbeR and the gene cbeE with unknown function, all of which form a single cluster in NK8, were cloned and analysed. The protein sequence of chlorobenzoate 1,2-dioxygenase (CbeABC) is 50-65% identical to

  1. APPLICATION OF BURKHOLDERIA CEPACIA AND TRICHODERMA VIRENS , ALONE AND IN COMBINATIONS, AGAINST MELOIDOGYNE INCOGNITA ON BELL PEPPER

    Microsoft Academic Search

    Susan L. F. Meyer; Daniel P. Roberts; David J. Chitwood; Lynn K. Carta; Robert D. Lumsden; Weili Mao

    2001-01-01

    Meyer, S. L. F, D. P. Roberts, D. J. Chitwood, L. K. Carta, R. D. Lumsden, and W. Mao. 2001. Applica- tion of Burkholderia cepacia and Trichoderma virens , alone and in combinations, against Meloidogyne in- cognita on bell pepper. Nematropica 31:75-86. Bell pepper ( Capsicum annuum L.) seeds and seedlings were treated with three potentially benefi- cial microbes, applied

  2. Experimental Bacteriophage Therapy Increases Survival of Galleria mellonella Larvae Infected with Clinically Relevant Strains of the Burkholderia cepacia Complex

    Microsoft Academic Search

    Kimberley D. Seed; Jonathan J. Dennis

    2009-01-01

    The Burkholderia cepacia complex (BCC) is a group of bacterial pathogens that are highly antibiotic resistant and associated with debilitating respiratory infections. Although bacteriophages of the BCC have been isolated and characterized, no studies have yet examined phage therapy against the BCC in vivo. In a caterpillar infection model, we show that BCC phage therapy is an alternative treatment possibility

  3. A RAPD-derived STS marker is linked to a bacterial wilt ( Burkholderia caryophylli ) resistance gene in carnation

    Microsoft Academic Search

    Takashi Onozaki; Natsu Tanikawa; Mitsuyasu Taneya; Kiyofumi Kudo; Takuya Funayama; Hiroshi Ikeda; Michio Shibata

    2004-01-01

    Bacterial wilt caused by Burkholderia caryophylli is one of the most important and damaging diseases of carnations (Dianthus caryophyllus) in Japan. We aimed to identify random amplified polymorphic DNA (RAPD) markers associated with the genes controlling bacterial wilt resistance in a resistance-segregating population of 134 progeny plants derived from a cross between ‘Carnation Nou No. 1’ (a carnation breeding line

  4. Degradation of chlorobenzenes at nanomolar concentrations by Burkholderia sp. strain PS14 in liquid cultures and in soil

    SciTech Connect

    Rapp, P.; Timmis, K.N. [GBF-National Research Centre for Biotechnology, Braunschweig (Germany). Div. of Microbiology

    1999-06-01

    The utilization of 1,2,4,5-tetrachloro-, 1,2,4-trichloro-, the three isomeric dichlorobenzenes and fructose as the sole carbon and energy sources of nanomolar concentrations was studied in batch experiments with Burkholderia sp. strain PS14. In liquid culture, all chlorobenzenes were metabolized within 1 h from their initial concentration of 500 nM to below their detection limits of 0.5 nM for 1,2,4,5-tetrachloro- and 1,2,4-trichlorobenzene and 7.5 nM for the three dichlorobenzene isomers, with 63% mineralization during this time. In soil microcosms, Burkholderia sp. strain PS14 metabolized tetrachlorobenzene present at 64.8 ppb and trichlorobenzene present at 54.4 ppb over a 72-h incubation period to below the detection limits of 0.108 and 0.09 ppb, respectively, with approximately 80% mineralization. A high sorptive capacity of Burkholderia sp. strain PS14 for 1,2,4,5-tetrachlorobenzene was found at very low cell density. The results demonstrate that Burkholderia sp. strain PS14 exhibits a very high affinity for chlorobenzenes at nanomolar concentrations.

  5. Architecture of Burkholderia cepacia complex ?70 gene family: evidence of alternative primary and clade-specific factors, and genomic instability

    Microsoft Academic Search

    Aymeric Menard; Paulina Estrada de los Santos; Arnault Graindorge; Benoit Cournoyer

    2007-01-01

    BACKGROUND: The Burkholderia cepacia complex (Bcc) groups bacterial species with beneficial properties that can improve crop yields or remediate polluted sites but can also lead to dramatic human clinical outcomes among cystic fibrosis (CF) or immuno-compromised individuals. Genome-wide regulatory processes of gene expression could explain parts of this bacterial duality. Transcriptional ?70 factors are components of these processes. They allow

  6. Comparative Genome Sequence Analysis Reveals the Extent of Diversity and Conservation for Glycan-Associated Proteins in Burkholderia spp.

    PubMed Central

    Ong, Hui San; Mohamed, Rahmah; Firdaus-Raih, Mohd

    2012-01-01

    Members of the Burkholderia family occupy diverse ecological niches. In pathogenic family members, glycan-associated proteins are often linked to functions that include virulence, protein conformation maintenance, surface recognition, cell adhesion, and immune system evasion. Comparative analysis of available Burkholderia genomes has revealed a core set of 178 glycan-associated proteins shared by all Burkholderia of which 68 are homologous to known essential genes. The genome sequence comparisons revealed insights into species-specific gene acquisitions through gene transfers, identified an S-layer protein, and proposed that significantly reactive surface proteins are associated to sugar moieties as a potential means to circumvent host defense mechanisms. The comparative analysis using a curated database of search queries enabled us to gain insights into the extent of conservation and diversity, as well as the possible virulence-associated roles of glycan-associated proteins in members of the Burkholderia spp. The curated list of glycan-associated proteins used can also be directed to screen other genomes for glycan-associated homologs. PMID:22991502

  7. Polyhydroxyalkanoate biosynthesis and simultaneous remotion of organic inhibitors from sugarcane bagasse hydrolysate by Burkholderia sp.

    PubMed

    Lopes, Mateus Schreiner Garcez; Gomez, José Gregório Cabrera; Taciro, Marilda Keico; Mendonça, Thatiane Teixeira; Silva, Luiziana Ferreira

    2014-09-01

    Burkholderia sp. F24, originally isolated from soil, was capable of growth on xylose and removed organic inhibitors present in a hemicellulosic hydrolysate and simultaneously produced poly-3-hydroxybutyrate (P3HB). Using non-detoxified hydrolysate, Burkholderia sp. F24 reached a cell dry weight (CDW) of 6.8 g L(-1), containing 48 % of P3HB and exhibited a volumetric productivity (PP3HB) of 0.10 g L(-1) h(-1). Poly-3-hydroxybutyrate-co-3-hydroxyvalerate copolymers (P3HB-co-3HV) were produced using xylose and levulinic acid (LA) as carbon sources. In shake flask cultures, the 3HV content in the copolymer increased from 9 to 43 mol% by adding LA from 1.0 to 5.0 g L(-1). In high cell density cultivation using concentrated hemicellulosic hydrolysate F24 reached 25.04 g L(-1) of CDW containing 49 % of P3HB and PP3HB of 0.28 g L(-1 )h(-1). Based on these findings, second-generation ethanol and bioplastics from sugarcane bagasse is proposed. PMID:25059637

  8. Virulence and Cellular Interactions of Burkholderia multivorans in Chronic Granulomatous Disease?

    PubMed Central

    Zelazny, Adrian M.; Ding, Li; Elloumi, Houda Z.; Brinster, Lauren R.; Benedetti, Fran; Czapiga, Meggan; Ulrich, Ricky L.; Ballentine, Samuel J.; Goldberg, Joanna B.; Sampaio, Elizabeth P.; Holland, Steven M.

    2009-01-01

    Chronic granulomatous disease (CGD) patients are susceptible to life-threatening infections by the Burkholderia cepacia complex. We used leukocytes from CGD and healthy donors and compared cell association, invasion, and cytokine induction by Burkholderia multivorans strains. A CGD isolate, CGD1, showed higher cell association than that of an environmental isolate, Env1, which correlated with cell entry. All B. multivorans strains associated significantly more with cells from CGD patients than with those from healthy donors. Similar findings were observed with another CGD pathogen, Serratia marcescens, but not with Escherichia coli. In a mouse model of CGD, strain CGD1 was virulent while Env1 was avirulent. B. multivorans organisms were found in the spleens of CGD1-infected mice at levels that were 1,000 times higher than those found in Env1-infected mice, which was coincident with higher levels of the proinflammatory cytokine interleukin-1?. Taken together, these results may shed light on the unique susceptibility of CGD patients to specific pathogens. PMID:19635825

  9. Gut symbiotic bacteria of the genus Burkholderia in the broad-headed bugs Riptortus clavatus and Leptocorisa chinensis (Heteroptera: Alydidae).

    PubMed

    Kikuchi, Yoshitomo; Meng, Xian-Ying; Fukatsu, Takema

    2005-07-01

    The Japanese common broad-headed bugs Riptortus clavatus and Leptocorisa chinensis possess a number of crypts in the posterior region of the midgut, whose lumen contains a copious amount of bacterial cells. We characterized the gut symbiotic bacteria by using molecular phylogenetic analysis, light and electron microscopy, in situ hybridization, and PCR-based detection techniques. Restriction fragment length polymorphism analysis of 16S rRNA gene clones suggested that a single bacterium dominated the microbiota in the crypts of the both bug species. The predominant 16S rRNA gene sequences obtained from different individuals and species of the bugs were not identical but were very similar to each other. Homology searches in the DNA databases revealed that the sequences showed the highest levels of similarity (96% to 99%) to the sequences of Burkholderia spp. belonging to the beta subdivision of the class Proteobacteria. In situ hybridization with specific oligonucleotide probes confirmed the localization of the Burkholderia symbiont in the lumen of the midgut crypts. Electron microscopy showed that the lumen of the crypts was filled with rod-shaped bacteria of a single morphotype. Molecular phylogenetic analysis demonstrated that the Burkholderia symbionts of the bugs formed a well-defined monophyletic group, although the group also contained several environmental Burkholderia strains. The phylogenetic relationship of the Burkholderia symbionts did not reflect the relationship of the host bug species at all. The sequences from R. clavatus and the sequences from L. chinensis did not form clades but were intermingled in the phylogeny, suggesting that horizontal transmission of the symbiont might have occasionally occurred between populations and species of the bugs. PMID:16000818

  10. Proof that Burkholderia Strains Form Effective Symbioses with Legumes: a Study of Novel Mimosa-Nodulating Strains from South America

    PubMed Central

    Chen, Wen-Ming; de Faria, Sergio M.; Straliotto, Rosângela; Pitard, Rosa M.; Simões-Araùjo, Jean L.; Chou, Jui-Hsing; Chou, Yi-Ju; Barrios, Edmundo; Prescott, Alan R.; Elliott, Geoffrey N.; Sprent, Janet I.; Young, J. Peter W.; James, Euan K.

    2005-01-01

    Twenty Mimosa-nodulating bacterial strains from Brazil and Venezuela, together with eight reference Mimosa-nodulating rhizobial strains and two other ?-rhizobial strains, were examined by amplified rRNA gene restriction analysis. They fell into 16 patterns and formed a single cluster together with the known ?-rhizobia, Burkholderia caribensis, Burkholderia phymatum, and Burkholderia tuberum. The 16S rRNA gene sequences of 15 of the 20 strains were determined, and all were shown to belong to the genus Burkholderia; four distinct clusters could be discerned, with strains isolated from the same host species usually clustering very closely. Five of the strains (MAP3-5, Br3407, Br3454, Br3461, and Br3469) were selected for further studies of the symbiosis-related genes nodA, the NodD-dependent regulatory consensus sequences (nod box), and nifH. The nodA and nifH sequences were very close to each other and to those of B. phymatum STM815, B. caribensis TJ182, and Cupriavidus taiwanensis LMG19424 but were relatively distant from those of B. tuberum STM678. In addition to nodulating their original hosts, all five strains could also nodulate other Mimosa spp., and all produced nodules on Mimosa pudica that had nitrogenase (acetylene reduction) activities and structures typical of effective N2-fixing symbioses. Finally, both wild-type and green fluorescent protein-expressing transconjugant strains of Br3461 and MAP3-5 produced N2-fixing nodules on their original hosts, Mimosa bimucronata (Br3461) and Mimosa pigra (MAP3-5), and hence this confirms strongly that Burkholderia strains can form effective symbioses with legumes. PMID:16269788

  11. Biodegradation of 3-Nitrotyrosine by Burkholderia sp. Strain JS165 and Variovorax paradoxus JS171

    PubMed Central

    Nishino, Shirley F.; Spain, Jim C.

    2006-01-01

    The cascade of reactive nitrogen species generated from nitric oxide causes modification of proteins, lipids, and nucleic acids in a wide range of organisms. 3-Nitrotyrosine is one of the most common products of the action of reactive nitrogen species on proteins. Although a great deal is known about the formation of 3-nitrotyrosine, the subsequent metabolism of this compound is a mystery. Variovorax paradoxus JS171 and Burkholderia sp. strain JS165 were isolated from soil slurries when 3-nitrotyrosine was provided as the sole carbon, nitrogen, and energy source. During growth on 3-nitrotyrosine stoichiometric amounts of nitrite were released along with approximately one-half of the theoretically available ammonia. The catabolic pathway involving oxidative denitration is distinct from the pathway for tyrosine metabolism. The facile isolation and the specific, regulated pathway for 3-nitrotyrosine degradation in natural ecosystems suggest that there is a significant flux of 3-nitrotyrosine in such environments. PMID:16461647

  12. Two quorum sensing systems control biofilm formation and virulence in members of the Burkholderia cepacia complex.

    PubMed

    Suppiger, Angela; Schmid, Nadine; Aguilar, Claudio; Pessi, Gabriella; Eberl, Leo

    2013-07-01

    The Burkholderia cepacia complex (Bcc) consists of 17 closely related species that are problematic opportunistic bacterial pathogens for cystic fibrosis patients and immunocompromised individuals. These bacteria are capable of utilizing two different chemical languages: N-acyl homoserine lactones (AHLs) and cis-2-unsaturated fatty acids. Here we summarize the current knowledge of the underlying molecular architectures of these communication systems, showing how they are interlinked and discussing how they regulate overlapping as well as specific sets of genes. A particular focus is laid on the role of these signaling systems in the formation of biofilms, which are believed to be highly important for chronic infections. We review genes that have been implicated in the sessile lifestyle of this group of bacteria. The new emerging role of the intracellular second messenger cyclic dimeric guanosine monophosphate (c-di-GMP) as a downstream regulator of the fatty acid signaling cascade and as a key factor in biofilm formation is also discussed. PMID:23799665

  13. [Advances in virulence determinants in Burkholderia cepacia complex--a review].

    PubMed

    Tang, Qinghua; Zhu, Hui; Qin, Weiquan

    2014-05-01

    Most members of the Burkholderia cepacia complex (Bcc) are important human opportunistic pathogens. Although progress has been achieved on the taxonomy and molecular identification of these bacteria, the molecular mechanisms of Bcc pathogenicity remain unclear and little development is made for new therapeutic agents. As Bcc is resistant to many common clinically-relevant antibiotics, revealing its virulence determinants is therefore very important to develop novel antibiotics or alternative anti-infective therapies. In this review, we summarize current advances in principal virulence determinants, limitations and genetic tools for studies of pathogenesis of Bcc. We primarily focus on key pathogenicity factors, including innate resistance to antibiotics, protein secretion system, and quorum-sensing systems. PMID:25199247

  14. Biodiesel production from Jatropha oil catalyzed by immobilized Burkholderia cepacia lipase on modified attapulgite.

    PubMed

    You, Qinghong; Yin, Xiulian; Zhao, Yuping; Zhang, Yan

    2013-11-01

    Lipase from Burkholderia cepacia was immobilized on modified attapulgite by cross-linking reaction for biodiesel production with jatropha oil as feedstock. Effects of various factors on biodiesel production were studied by single-factor experiment. Results indicated that the best conditions for biodiesel preparation were: 10 g jatropha oil, 2.4 g methanol (molar ratio of oil to methanol is 1:6.6) being added at 3h intervals, 7 wt% water, 10 wt% immobilized lipase, temperature 35°C, and time 24h. Under these conditions, the maximum biodiesel yield reached 94%. The immobilized lipase retained 95% of its relative activity during the ten repeated batch reactions. The half-life time of the immobilized lipase is 731 h. Kinetics was studied and the Vmax of the immobilized lipases were 6.823 mmol L(-1). This immobilized lipase catalyzed process has potential industrial use for biodiesel production to replace chemical-catalyzed method. PMID:24055964

  15. Microbial pathogenesis in cystic fibrosis: mucoid Pseudomonas aeruginosa and Burkholderia cepacia.

    PubMed Central

    Govan, J R; Deretic, V

    1996-01-01

    Respiratory infections with Pseudomonas aeruginosa and Burkholderia cepacia play a major role in the pathogenesis of cystic fibrosis (CF). This review summarizes the latest advances in understanding host-pathogen interactions in CF with an emphasis on the role and control of conversion to mucoidy in P. aeruginosa, a phenomenon epitomizing the adaptation of this opportunistic pathogen to the chronic chourse of infection in CF, and on the innate resistance to antibiotics of B. cepacia, person-to-person spread, and sometimes rapidly fatal disease caused by this organism. While understanding the mechanism of conversion to mucoidy in P. aeruginosa has progressed to the point where this phenomenon has evolved into a model system for studying bacterial stress response in microbial pathogenesis, the more recent challenge with B. cepacia, which has emerged as a potent bona fide CF pathogen, is discussed in the context of clinical issues, taxonomy, transmission, and potential modes of pathogenicity. PMID:8840786

  16. A putative porin gene of Burkholderia sp. NK8 involved in chemotaxis toward ?-ketoadipate.

    PubMed

    Yamamoto-Tamura, Kimiko; Kawagishi, Ikuro; Ogawa, Naoto; Fujii, Takeshi

    2015-06-01

    Burkholderia sp. NK8 can utilize 3-chlorobenzoate (3CB) as a sole source of carbon because it has a megaplasmid (pNK8) that carries the gene cluster (tfdT-CDEF) encoding chlorocatechol-degrading enzymes. The expression of tfdT-CDEF is induced by 3CB. In this study, we found that NK8 cells were attracted to 3CB and its degradation products, 3- and 4-chlorocatechol, and ?-ketoadipate. Capillary assays revealed that a pNK8-eliminated strain (NK82) was defective in chemotaxis toward ?-ketoadipate. The introduction of a plasmid carrying a putative outer membrane porin gene, which we name ompNK8, into strain NK82 restored chemotaxis toward ?-ketoadipate. RT-PCR analyses demonstrated that the transcription of the ompNK8 gene was enhanced in the presence of 3CB. PMID:25649919

  17. Burkholderia cepacia Complex: Emerging Multihost Pathogens Equipped with a Wide Range of Virulence Factors and Determinants

    PubMed Central

    Sousa, Sílvia A.; Ramos, Christian G.; Leitão, Jorge H.

    2011-01-01

    The Burkholderia cepacia complex (Bcc) comprises at least 17 closely-related species of the ?-proteobacteria subdivision, widely distributed in natural and man-made inhabitats. Bcc bacteria are endowed with an extraordinary metabolic diversity and emerged in the 1980s as life-threatening and difficult-to-treat pathogens among patients suffering from cystic fibrosis. More recently, these bacteria became recognized as a threat to hospitalized patients suffering from other diseases, in particular oncological patients. In the present paper, we review these and other traits of Bcc bacteria, as well as some of the strategies used to identify and validate the virulence factors and determinants used by these bacteria. The identification and characterization of these virulence factors is expected to lead to the design of novel therapeutic strategies to fight the infections caused by these emergent multidrug resistant human pathogens. PMID:20811541

  18. Characterization of the Burkholderia thailandensis SOS Response by Using Whole-Transcriptome Shotgun Sequencing

    PubMed Central

    Ulrich, Ricky L.; DeShazer, David; Kenny, Tara A.; Ulrich, Melanie P.; Moravusova, Anna; Opperman, Timothy; Bavari, Sina; Bowlin, Terry L.; Moir, Donald T.

    2013-01-01

    The bacterial SOS response is a well-characterized regulatory network encoded by most prokaryotic bacterial species and is involved in DNA repair. In addition to nucleic acid repair, the SOS response is involved in pathogenicity, stress-induced mutagenesis, and the emergence and dissemination of antibiotic resistance. Using high-throughput sequencing technology (SOLiD RNA-Seq), we analyzed the Burkholderia thailandensis global SOS response to the fluoroquinolone antibiotic, ciprofloxacin (CIP), and the DNA-damaging chemical, mitomycin C (MMC). We demonstrate that a B. thailandensis recA mutant (RU0643) is ?4-fold more sensitive to CIP in contrast to the parental strain B. thailandensis DW503. Our RNA-Seq results show that CIP and MMC treatment (P < 0.01) resulted in the differential expression of 344 genes in B. thailandensis and 210 genes in RU0643. Several genes associated with the SOS response were induced and include lexA, uvrA, dnaE, dinB, recX, and recA. At the genome-wide level, we found an overall decrease in gene expression, especially for genes involved in amino acid and carbohydrate transport and metabolism, following both CIP and MMC exposure. Interestingly, we observed the upregulation of several genes involved in bacterial motility and enhanced transcription of a B. thailandensis genomic island encoding a Siphoviridae bacteriophage designated ?E264. Using B. thailandensis plaque assays and PCR with B. mallei ATCC 23344 as the host, we demonstrate that CIP and MMC exposure in B. thailandensis DW503 induces the transcription and translation of viable bacteriophage in a RecA-dependent manner. This is the first report of the SOS response in Burkholderia spp. to DNA-damaging agents. We have identified both common and unique adaptive responses of B. thailandensis to chemical stress and DNA damage. PMID:23872555

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

    PubMed Central

    Memiševi?, Vesna; Zavaljevski, Nela; Pieper, Rembert; Rajagopala, Seesandra V.; Kwon, Keehwan; Townsend, Katherine; Yu, Chenggang; Yu, Xueping; DeShazer, David; Reifman, Jaques; Wallqvist, Anders

    2013-01-01

    Burkholderia mallei is an infectious intracellular pathogen whose virulence and resistance to antibiotics makes it a potential bioterrorism agent. Given its genetic origin as a commensal soil organism, it is equipped with an extensive and varied set of adapted mechanisms to cope with and modulate host-cell environments. One essential virulence mechanism constitutes the specialized secretion systems that are designed to penetrate host-cell membranes and insert pathogen proteins directly into the host cell's cytosol. However, the secretion systems' proteins and, in particular, their host targets are largely uncharacterized. Here, we used a combined in silico, in vitro, and in vivo approach to identify B. mallei proteins required for pathogenicity. We used bioinformatics tools, including orthology detection and ab initio predictions of secretion system proteins, as well as published experimental Burkholderia data to initially select a small number of proteins as putative virulence factors. We then used yeast two-hybrid assays against normalized whole human and whole murine proteome libraries to detect and identify interactions among each of these bacterial proteins and host proteins. Analysis of such interactions provided both verification of known virulence factors and identification of three new putative virulence proteins. We successfully created insertion mutants for each of these three proteins using the virulent B. mallei ATCC 23344 strain. We exposed BALB/c mice to mutant strains and the wild-type strain in an aerosol challenge model using lethal B. mallei doses. In each set of experiments, mice exposed to mutant strains survived for the 21-day duration of the experiment, whereas mice exposed to the wild-type strain rapidly died. Given their in vivo role in pathogenicity, and based on the yeast two-hybrid interaction data, these results point to the importance of these pathogen proteins in modulating host ubiquitination pathways, phagosomal escape, and actin-cytoskeleton rearrangement processes. PMID:23800426

  20. Unusual multiple production of N-acylhomoserine lactones a by Burkholderia sp. strain C10B isolated from dentine caries.

    PubMed

    Goh, Share Yuan; Tan, Wen-Si; Khan, Saad Ahmed; Chew, Hooi Pin; Abu Kasim, Noor Hayaty; Yin, Wai-Fong; Chan, Kok-Gan

    2014-01-01

    Bacteria realize the ability to communicate by production of quorum sensing (QS) molecules called autoinducers, which regulate the physiological activities in their ecological niches. The oral cavity could be a potential area for the presence of QS bacteria. In this study, we report the isolation of a QS bacterial isolate C10B from dentine caries. Preliminary screening using Chromobacterium violaceum CV026 biosensor showed that isolate C10B was able to produce N-acylhomoserine lactones (AHLs). This bacterium was further identified as a member of Burkholderia, an opportunistic pathogen. The isolated Burkholderia sp. was confirmed to produce N-hexanoyl-L-homoserine lactone (C6-HSL), N-octanoyl-L-homoserine lactone (C8-HSL), N-decanoyl-L-homoserine lactone (C10-HSL) and N-dodecanoyl-L-homoserine lactone (C12-HSL). PMID:24854358

  1. Exploring the metabolic network of the epidemic pathogen Burkholderia cenocepacia J2315 via genome-scale reconstruction

    Microsoft Academic Search

    Kechi Fang; Hansheng Zhao; Changyue Sun; Carolyn M C Lam; Suhua Chang; Kunlin Zhang; Gurudutta Panda; Miguel Godinho; Vítor A P Martins dos Santos; Jing Wang

    2011-01-01

    Background  \\u000a Burkholderia cenocepacia is a threatening nosocomial epidemic pathogen in patients with cystic fibrosis (CF) or a compromised immune system. Its high\\u000a level of antibiotic resistance is an increasing concern in treatments against its infection. Strain B. cenocepacia J2315 is the most infectious isolate from CF patients. There is a strong demand to reconstruct a genome-scale metabolic network\\u000a of B.

  2. Burkholderia xenovorans LB400 harbors a multi-replicon, 9.73-Mbp genome shaped for versatility

    PubMed Central

    Chain, Patrick S. G.; Denef, Vincent J.; Konstantinidis, Konstantinos T.; Vergez, Lisa M.; Agulló, Loreine; Reyes, Valeria Latorre; Hauser, Loren; Córdova, Macarena; Gómez, Luis; González, Myriam; Land, Miriam; Lao, Victoria; Larimer, Frank; LiPuma, John J.; Mahenthiralingam, Eshwar; Malfatti, Stephanie A.; Marx, Christopher J.; Parnell, J. Jacob; Ramette, Alban; Richardson, Paul; Seeger, Michael; Smith, Daryl; Spilker, Theodore; Sul, Woo Jun; Tsoi, Tamara V.; Ulrich, Luke E.; Zhulin, Igor B.; Tiedje, James M.

    2006-01-01

    Burkholderia xenovorans LB400 (LB400), a well studied, effective polychlorinated biphenyl-degrader, has one of the two largest known bacterial genomes and is the first nonpathogenic Burkholderia isolate sequenced. From an evolutionary perspective, we find significant differences in functional specialization between the three replicons of LB400, as well as a more relaxed selective pressure for genes located on the two smaller vs. the largest replicon. High genomic plasticity, diversity, and specialization within the Burkholderia genus are exemplified by the conservation of only 44% of the genes between LB400 and Burkholderia cepacia complex strain 383. Even among four B. xenovorans strains, genome size varies from 7.4 to 9.73 Mbp. The latter is largely explained by our findings that >20% of the LB400 sequence was recently acquired by means of lateral gene transfer. Although a range of genetic factors associated with in vivo survival and intercellular interactions are present, these genetic factors are likely related to niche breadth rather than determinants of pathogenicity. The presence of at least eleven “central aromatic” and twenty “peripheral aromatic” pathways in LB400, among the highest in any sequenced bacterial genome, supports this hypothesis. Finally, in addition to the experimentally observed redundancy in benzoate degradation and formaldehyde oxidation pathways, the fact that 17.6% of proteins have a better LB400 paralog than an ortholog in a different genome highlights the importance of gene duplication and repeated acquirement, which, coupled with their divergence, raises questions regarding the role of paralogs and potential functional redundancies in large-genome microbes. PMID:17030797

  3. Comparison of Culture and PCR for Detection of Burkholderia cepacia in Sputum Samples of Patients with Cystic Fibrosis

    Microsoft Academic Search

    PAUL W. WHITBY; HANI L. N. DICK; PRESTON W. CAMPBELL; D. ELIZABETH TULLIS; ANNE MATLOW; TERRENCE L. STULL

    1998-01-01

    We investigated the utility of PCR to detect Burkholderia cepacia directly in sputum samples at two cystic fibrosis (CF) centers serving children and adults. Following liquefaction of the sputa by using N-acetyl-L- cysteine, DNA was isolated and analyzed by PCRs with three different primer pairs directed toward bacterial rRNA loci. Two primer pairs were putatively specific for B. cepacia. The

  4. In Vitro Activities of a Novel Nanoemulsion against Burkholderia and Other Multidrug-Resistant Cystic Fibrosis-Associated Bacterial Species

    Microsoft Academic Search

    John J. LiPuma; Sivaprakash Rathinavelu; Bridget K. Foster; Jordan C. Keoleian; Paul E. Makidon; Linda M. Kalikin; James R. Baker

    2009-01-01

    Respiratory tract infection, most often involving opportunistic bacterial species with broad-spectrum anti- biotic resistance, is the primary cause of death in persons with cystic fibrosis (CF). Species within the Burkholderia cepacia complex are especially problematic in this patient population. We investigated a novel surfactant-stabilized oil-in-water nanoemulsion (NB-401) for activity against 150 bacterial isolates recovered primarily from CF respiratory tract specimens.

  5. Intracellular survival and saprophytic growth of isolates from the Burkholderia cepacia complex in free-living amoebae

    Microsoft Academic Search

    Cristina L. Marolda; Barbel HaurOder; Michael A. John; R. Michel; M. A. Valvano

    1999-01-01

    Members of the taxonomically diverse Burkholderia cepacia complex have become a major health risk for patients with cystic fibrosis (CF). Although patient-to-patient transmission of B. cepacia strains has been well- documented, very little is known about possible vehicles of transmission and reservoirs for these micro-organisms. In this work, it is shown that strains of the B. cepacia complex can survive

  6. Development of a Species-Specific fur Gene-Based Method for Identification of the Burkholderia cepacia Complex

    Microsoft Academic Search

    Karlene H. Lynch; Jonathan J. Dennis

    Burkholderia is an important bacterial genus with a complex taxonomy that contains species of both ecological and pathogenic importance, including nine closely related species collectively termed the Burkhold- eria cepacia complex (BCC). Unfortunately, 16S rRNA gene analysis has proven to be not sensitive enough to discriminate between species of the BCC. Alternative species identification strategies such as recA-based PCR followed

  7. Development of a Species-Specific fur Gene-Based Method for Identification of the Burkholderia cepacia Complex

    Microsoft Academic Search

    Karlene H. Lynch; Jonathan J. Dennis

    2008-01-01

    Burkholderia is an important bacterial genus with a complex taxonomy that contains species of both ecological and pathogenic importance, including nine closely related species collectively termed the Burkhold- eria cepacia complex (BCC). Unfortunately, 16S rRNA gene analysis has proven to be not sensitive enough to discriminate between species of the BCC. Alternative species identification strategies such as recA-based PCR followed

  8. Degradation of dimethyl carboxylic phthalate ester by Burkholderia cepacia DA2 isolated from marine sediment of South China Sea

    Microsoft Academic Search

    Yali Wang; Bo Yin; Yiguo Hong; Yan Yan; Ji-Dong Gu

    2008-01-01

    Burkholderia cepacia DA2, isolated from marine sediment of the South China Sea, is capable of utilizing dimethyl phthalate (DMP) as the sole source\\u000a of carbon and energy. During the transformation of DMP in batch culture, its corresponding degradation intermediates were\\u000a identified as monomethyl phthalate (MMP) and phthalate acid (PA) sequentially over the time of incubation. The biodegradation\\u000a biochemical pathway of

  9. Mobilization, Cloning, and Sequence Determination of a Plasmid-Encoded Polygalacturonase from a Phytopathogenic Burkholderia ( Pseudomonas ) cepacia

    Microsoft Academic Search

    Carlos F. Gonzalez; Elizabeth A. Pettit; Victoria A. Valadez; Ellen M. Provin

    1997-01-01

    Phytopathogenic strains of Burkholderia cepacia (synonym Pseudomonas cepacia) produce endopolygalacturonase, whereas strains of clinical and soil origin do not. Growth of a phytopathogenic strain (ATCC25416) at elevated tem- peratures resulted in nonpectolytic derivatives that were either cured of a resident plasmid or contained a plasmid of reduced mass. The resident 200-kb plasmid (pPEC320) in strain ATCC25416 was tagged with Tn5-Mob.

  10. Endophytic Colonization of Vitis vinifera L. by Plant Growth-Promoting Bacterium Burkholderia sp. Strain PsJN

    Microsoft Academic Search

    Stephane Compant; Birgit Reiter; Angela Sessitsch; Jerzy Nowak; Christophe Clement; E. Ait Barka

    2005-01-01

    Patterns of colonization of Vitis vinifera L. cv. Chardonnay plantlets by a plant growth-promoting bacterium, Burkholderia sp. strain PsJN, were studied under gnotobiotic conditions. Wild-type strain PsJN and genetically engineered derivatives of this strain tagged with gfp (PsJN::gfp2x) or gusA (PsJN::gusA11) genes were used to enumerate and visualize tissue colonization. The rhizospheres of 4- to 5-week-old plantlets with five developed

  11. 60 FR 7630 - Recombinant DNA Research: Proposed Actions Under the Guidelines

    Federal Register 2010, 2011, 2012, 2013, 2014

    1995-02-08

    ...lamblia Heterophyes spp. Hymenolepis spp. including H. diminuta, H. nana Isospora spp. Leishmania spp. including L. braziliensis...melitensis (USDA restricted), B. suis Burkholderia (Pseudomonas) mallei, B. pseudomallei (see Appendix B-VI- F)...

  12. 60 FR 27206 - Recombinant DNA Research: Proposed Actions Under the Guidelines

    Federal Register 2010, 2011, 2012, 2013, 2014

    1995-05-22

    ...lamblia Heterophyes spp. Hymenolepis spp. including H. diminuta, H. nana Isospora spp. Leishmania spp. including L. braziliensis...melitensis (USDA restricted), B. suis Burkholderia (Pseudomonas) mallei, B. pseudomallei (see Appendix B-VI- F)...

  13. Outbreak of bacteremia due to Burkholderia contaminans linked to intravenous fentanyl from an institutional compounding pharmacy.

    PubMed

    Moehring, Rebekah W; Lewis, Sarah S; Isaacs, Pamela J; Schell, Wiley A; Thomann, Wayne R; Althaus, Mary M; Hazen, Kevin C; Dicks, Kristen V; Lipuma, John J; Chen, Luke F; Sexton, Daniel J

    2014-04-01

    IMPORTANCE Many health care facilities compound medications on site to fulfill local demands when customized formulations are needed, national supply is critically low, or costs for manufactured pharmaceuticals are excessive. Small, institutional compounding facilities may perform the same high-risk procedures as large distributors of compounded medications. OBJECTIVES To investigate an outbreak related to contamination of compounded sterile preparations and to determine processes to prevent future outbreaks. DESIGN, SETTING, AND PARTICIPANTS We performed an outbreak investigation of inpatients at Duke University Hospital from August 31 through September 6, 2012. The investigation included a case-control study, compounding facility inspection and environmental sampling, observation of a mock compounding demonstration, and microbiologic and molecular testing of sequestered medication. EXPOSURES Intravenous fentanyl prepared by an institutional compounding pharmacy. MAIN OUTCOMES AND MEASURES Microbiologic and molecular evidence of contamination of a compounded sterile preparation and failure of routine sterility testing. RESULTS Blood cultures of 7 patients during a 7-day period at Duke University Hospital yielded pan-susceptible Burkholderia cepacia complex bacteria. The risk factor common to all patients was receipt of continuous fentanyl infusion prepared by our institutional compounding pharmacy (odds ratio, 11.22; 95% CI, 2.09-?; P?=?.01). The outbreak was terminated after sequestration of compounded fentanyl. An intensive evaluation of the compounding facility, its practice, and its procedures was completed. Investigators evaluated the clean room, collected targeted microbiologic samples within the compounding pharmacy environment, and observed a mock demonstration of compounding practice. The B cepacia complex was found in the anteroom sink drain and pH probe calibration fluid from the compounding clean room. Multiple microbiologic analyses of sequestered fentanyl initially failed. Ultimately, a batched, vacuum-assisted filtration method produced B cepacia complex from a single lot. Molecular analyses using repetitive element polymerase chain reaction and pulsed-field gel electrophoresis confirmed a clonal Burkholderia contaminans strain from patients, fentanyl, and environmental samples. CONCLUSIONS AND RELEVANCE An outbreak of B contaminans bacteremia was linked to contamination of locally compounded intravenous fentanyl. Health care facilities that house institutional compounding facilities must be vigilant in efforts to prevent, recognize, and terminate medication-related outbreaks. PMID:24493147

  14. Genomic analysis and relatedness of P2-like phages of the Burkholderia cepacia complex

    PubMed Central

    2010-01-01

    Background The Burkholderia cepacia complex (BCC) is comprised of at least seventeen Gram-negative species that cause infections in cystic fibrosis patients. Because BCC bacteria are broadly antibiotic resistant, phage therapy is currently being investigated as a possible alternative treatment for these infections. The purpose of our study was to sequence and characterize three novel BCC-specific phages: KS5 (vB_BceM-KS5 or vB_BmuZ-ATCC 17616), KS14 (vB_BceM-KS14) and KL3 (vB_BamM-KL3 or vB_BceZ-CEP511). Results KS5, KS14 and KL3 are myoviruses with the A1 morphotype. The genomes of these phages are between 32317 and 40555 base pairs in length and are predicted to encode between 44 and 52 proteins. These phages have over 50% of their proteins in common with enterobacteria phage P2 and so can be classified as members of the Peduovirinae subfamily and the "P2-like viruses" genus. The BCC phage proteins similar to those encoded by P2 are predominantly structural components involved in virion morphogenesis. As prophages, KS5 and KL3 integrate into an AMP nucleosidase gene and a threonine tRNA gene, respectively. Unlike other P2-like viruses, the KS14 prophage is maintained as a plasmid. The P2 E+E' translational frameshift site is conserved among these three phages and so they are predicted to use frameshifting for expression of two of their tail proteins. The lysBC genes of KS14 and KL3 are similar to those of P2, but in KS5 the organization of these genes suggests that they may have been acquired via horizontal transfer from a phage similar to ?. KS5 contains two sequence elements that are unique among these three phages: an ISBmu2-like insertion sequence and a reverse transcriptase gene. KL3 encodes an EcoRII-C endonuclease/methylase pair and Vsr endonuclease that are predicted to function during the lytic cycle to cleave non-self DNA, protect the phage genome and repair methylation-induced mutations. Conclusions KS5, KS14 and KL3 are the first BCC-specific phages to be identified as P2-like. As KS14 has previously been shown to be active against Burkholderia cenocepacia in vivo, genomic characterization of these phages is a crucial first step in the development of these and similar phages for clinical use against the BCC. PMID:20973964

  15. Molecular detection of Burkholderia cepacia in toiletry, cosmetic, and pharmaceutical raw materials and finished products.

    PubMed

    Jimenez, L; Smalls, S; Jimenez, L; Smalls, S

    2000-01-01

    A polymerase chain reaction (PCR) assay was developed and compared with standard methods for rapid detection of Burkholderia cepacia, a major industrial contaminant, in cosmetic and pharmaceutical raw materials and finished products. Artificially contaminated samples were incubated for 24 h in trypticase soy broth containing 4% Tween 20 and 0.5% soy lecithin. DNA was extracted from each sample using a proteinase K-tris-EDTA-Tween 20 treatment at 35 degrees C. The extracted DNA was added to Ready-To-Go PCR beads and specific DNA primers for B. cepacia. The B. cepacia DNA primers coded for a 209-base pair (bp) fragment of the 16S rRNA ribosomal gene. No DNA amplification was observed in samples that were not spiked with B. cepacia. However, all contaminated samples showed the specific 209-bp fragment for B. cepacia. There was a 100% correlation between standard methods and the PCR assay. Standard microbiological methods required 5-6 days for isolation and identification of spiked microorganisms, whereas PCR detection and identification was completed in 27 h. PCR detection of B. cepacia allows for rapid quality evaluation of cosmetic and pharmaceutical raw materials and finished products. PMID:10995122

  16. A new species of Burkholderia isolated from sugarcane roots promotes plant growth

    PubMed Central

    Paungfoo-Lonhienne, Chanyarat; Lonhienne, Thierry G A; Yeoh, Yun Kit; Webb, Richard I; Lakshmanan, Prakash; Chan, Cheong Xin; Lim, Phaik-Eem; Ragan, Mark A; Schmidt, Susanne; Hugenholtz, Philip

    2014-01-01

    Sugarcane is a globally important food, biofuel and biomaterials crop. High nitrogen (N) fertilizer rates aimed at increasing yield often result in environmental damage because of excess and inefficient application. Inoculation with diazotrophic bacteria is an attractive option for reducing N fertilizer needs. However, the efficacy of bacterial inoculants is variable, and their effective formulation remains a knowledge frontier. Here, we take a new approach to investigating diazotrophic bacteria associated with roots using culture-independent microbial community profiling of a commercial sugarcane variety (Q208A) in a field setting. We first identified bacteria that were markedly enriched in the rhizosphere to guide isolation and then tested putative diazotrophs for the ability to colonize axenic sugarcane plantlets (Q208A) and promote growth in suboptimal N supply. One isolate readily colonized roots, fixed N2 and stimulated growth of plantlets, and was classified as a new species, Burkholderia australis sp. nov. Draft genome sequencing of the isolate confirmed the presence of nitrogen fixation. We propose that culture-independent identification and isolation of bacteria that are enriched in rhizosphere and roots, followed by systematic testing and confirming their growth-promoting capacity, is a necessary step towards designing effective microbial inoculants. PMID:24350979

  17. Divergence and Mosaicism among Virulent Soil Phages of the Burkholderia cepacia Complex‡

    PubMed Central

    Summer, Elizabeth J.; Gonzalez, Carlos F.; Bomer, Morgan; Carlile, Thomas; Embry, Addie; Kucherka, Amalie M.; Lee, Jonte; Mebane, Leslie; Morrison, William C.; Mark, Louise; King, Maria D.; LiPuma, John J.; Vidaver, Anne K.; Young, Ry

    2006-01-01

    We have determined the genomic sequences of four virulent myophages, Bcep1, Bcep43, BcepB1A, and Bcep781, whose hosts are soil isolates of the Burkholderia cepacia complex. Despite temporal and spatial separations between initial isolations, three of the phages (Bcep1, Bcep43, and Bcep781, designated the Bcep781 group) exhibit 87% to 99% sequence identity to one another and most coding region differences are due to synonymous nucleotide substitutions, a hallmark of neutral genetic drift. Phage BcepB1A has a very different genome organization but is clearly a mosaic with respect to many of the genes of the Bcep781 group, as is a defective prophage element in Photorhabdus luminescens. Functions were assigned to 27 out of 71 predicted genes of Bcep1 despite extreme sequence divergence. Using a lambda repressor fusion technique, 10 Bcep781-encoded proteins were identified for their ability to support homotypic interactions. While head and tail morphogenesis genes have retained canonical gene order despite extreme sequence divergence, genes involved in DNA metabolism and host lysis are not organized as in other phages. This unusual genome arrangement may contribute to the ability of the Bcep781-like phages to maintain a unified genomic type. However, the Bcep781 group phages can also engage in lateral gene transfer events with otherwise unrelated phages, a process that contributes to the broader-scale genomic mosaicism prevalent among the tailed phages. PMID:16352842

  18. A Pipeline for Screening Small Molecules with Growth Inhibitory Activity against Burkholderia cenocepacia

    PubMed Central

    Selin, Carrie; Stietz, Maria S.; Blanchard, Jan E.; Hall, Dennis G.; Brown, Eric D.; Cardona, Silvia T.

    2015-01-01

    Infections with the bacteria Burkholderia cepacia complex (Bcc) are very difficult to eradicate in cystic fibrosis patients due the intrinsic resistance of Bcc to most available antibiotics and the emergence of multiple antibiotic resistant strains during antibiotic treatment. In this work, we used a whole-cell based assay to screen a diverse collection of small molecules for growth inhibitors of a relevant strain of Bcc, B. cenocepacia K56-2. The primary screen used bacterial growth in 96-well plate format and identified 206 primary actives among 30,259 compounds. From 100 compounds with no previous record of antibacterial activity secondary screening and data mining selected a total of Bce bioactives that were further analyzed. An experimental pipeline, evaluating in vitro antibacterial and antibiofilm activity, toxicity and in vivo antibacterial activity using C. elegans was used for prioritizing compounds with better chances to be further investigated as potential Bcc antibacterial drugs. This high throughput screen, along with the in vitro and in vivo analysis highlights the utility of this experimental method to quickly identify bioactives as a starting point of antibacterial drug discovery. PMID:26053039

  19. Enhanced Susceptibility to Pulmonary Infection with Burkholderia cepacia in Cftr?/? Mice

    PubMed Central

    Sajjan, Uma; Thanassoulis, George; Cherapanov, Vera; Lu, Annie; Sjolin, Carola; Steer, Brent; Wu, Yi Jun; Rotstein, Ori D.; Kent, Geraldine; McKerlie, Colin; Forstner, Janet; Downey, Gregory P.

    2001-01-01

    Progressive pulmonary infection is the dominant clinical feature of cystic fibrosis (CF), but the molecular basis for this susceptibility remains incompletely understood. To study this problem, we developed a model of chronic pneumonia by repeated instillation of a clinical isolate of Burkholderia cepacia (genomovar III, ET12 strain), an opportunistic gram-negative bacterium, from a case of CF into the lungs of Cftr m1unc?/? (Cftr?/?) and congenic Cftr+/+ controls. Nine days after the last instillation, the CF transmembrane regulator knockout mice showed persistence of viable bacteria with chronic severe bronchopneumonia while wild-type mice remained healthy. The histopathological changes in the lungs of the susceptible Cftr?/? mice were characterized by infiltration of a mixed inflammatory-cell population into the peribronchiolar and perivascular spaces, Clara cell hyperplasia, mucus hypersecretion in airways, and exudation into alveolar airspaces by a mixed population of macrophages and neutrophils. An increased proportion of neutrophils was observed in bronchoalveolar lavage fluid from the Cftr?/? mice, which, despite an increased bacterial load, demonstrated minimal evidence of activation. Alveolar macrophages from Cftr?/? mice also demonstrated suboptimal activation. These observations suggest that the pulmonary host defenses are compromised in lungs from animals with CF, as manifested by increased susceptibility to bacterial infection and lung injury. This murine model of chronic pneumonia thus reflects, in part, the situation in human patients and may help elucidate the mechanisms leading to defective host defense in CF. PMID:11447196

  20. Enhanced Polychlorinated Biphenyl Removal in a Switchgrass Rhizosphere by Bioaugmentation with Burkholderia xenovorans LB400.

    PubMed

    Liang, Yi; Meggo, Richard; Hu, Dingfei; Schnoor, Jerald L; Mattes, Timothy E

    2014-10-01

    Phytoremediation makes use of plants and associated microorganisms to clean up soils and sediments contaminated with inorganic and organic pollutants. In this study, switchgrass (Panicum virgatum) was used to test for its efficiency in improving the removal of three specific polychlorinated biphenyl (PCB) congeners (PCB 52, 77 and 153) in soil microcosms. The congeners were chosen for their ubiquity, toxicity, and recalcitrance. After 24 weeks of incubation, loss of 39.9 ± 0.41% of total PCB molar mass was observed in switchgrass treated soil, significantly higher than in unplanted soil (29.5 ± 3.4%) (p<0.05). The improved PCB removal in switchgrass treated soils could be explained by phytoextraction processes and enhanced microbial activity in the rhizosphere. Bioaugmentation with Burkholderia xenovorans LB400 was performed to further enhance aerobic PCB degradation. The presence of LB400 was associated with improved degradation of PCB 52, but not PCB 77 or PCB 153. Increased abundances of bphA (a functional gene that codes for a subunit of PCB-degrading biphenyl dioxygenase in bacteria) and its transcript were observed after bioaugmentation. The highest total PCB removal was observed in switchgrass treated soil with LB400 bioaugmentation (47.3 ± 1.22 %), and the presence of switchgrass facilitated LB400 survival in the soil. Overall, our results suggest the combined use of phytoremediation and bioaugmentation could be an efficient and sustainable strategy to eliminate recalcitrant PCB congeners and remediate PCB-contaminated soil. PMID:25246731

  1. In vitro activities of antimicrobial agents, alone and in combinations, against Burkholderia cepacia isolated from blood.

    PubMed

    Lu, D C; Chang, S C; Chen, Y C; Luh, K T; Hsieh, W C

    1997-08-01

    Burkholderia cepacia is a widespread, environmental gram-negative bacillus that is associated with nosocomial infections. This bacterium is considered to be an important pathogen in immunocompromised patients and is inherently resistant to multiple antimicrobial agents. To compare the activity of different antimicrobial agents and the potential of combinations against invasive strains of B. cepacia, we collected 36 isolates of B. cepacia from blood cultures and checked their susceptibilities to 13 antimicrobials by broth microdilution method. Most strains tested were susceptible to minocycline (94.4%), ceftazidime (86.1%), ciprofloxacin (83.3%), and trimethoprim-sulfamethoxazole (83.3%). All strains were resistant to aminoglycosides, and only some strains were susceptible to imipenem (16.7%), aztreonam (19.4%), moxalactam (25.0%), piperacillin (25.0%), and carbenicillin (47.2%). The effects of combinations of ceftazidime with amikacin, ceftazidime with ciprofloxacin, and ciprofloxacin with amikacin were assayed by checkerboard titration method. Synergistic effect was found in 28 out of 36 tested strains (77.8%), when ceftazidime was combined with amikacin, in 25 out of 36 strains (69.4%) when ceftazidime was combined with ciprofloxacin, and in only 8 out of 36 strains (22.2%) when ciprofloxacin was combined with amikacin. PMID:9327247

  2. Plant-Influenced Gene Expression in the Rice Endophyte Burkholderia kururiensis M130.

    PubMed

    Coutinho, Bruna G; Licastro, Danilo; Mendonça-Previato, Lucia; Cámara, Miguel; Venturi, Vittorio

    2015-01-01

    Burkholderia kururiensis M130 is one of the few rice endophytic diazotrophic bacteria identified thus far which is able to enhance growth of rice. To date, very little is known of how strain M130 and other endophytes enter and colonize plants. Here, we identified genes of strain M130 that are differentially regulated in the presence of rice plant extract. A genetic screening of a promoter probe transposon mutant genome bank and RNAseq analysis were performed. The screening of 10,100 insertions of the genomic transposon reporter library resulted in the isolation of 61 insertions displaying differential expression in response to rice macerate. The RNAseq results validated this screen and indicated that this endophytic bacterium undergoes major changes in the presence of plant extract regulating 27.7% of its open reading frames. A large number of differentially expressed genes encode membrane transporters and secretion systems, indicating that the exchange of molecules is an important aspect of bacterial endophytic growth. Genes related to motility, chemotaxis, and adhesion were also overrepresented, further suggesting plant-bacteria interaction. This work highlights the potential close signaling taking place between plants and bacteria and helps us to begin to understand the adaptation of an endophyte in planta. PMID:25494355

  3. Kinetics of enzymatic transesterification and thermal deactivation using immobilized Burkholderia lipase as catalyst.

    PubMed

    Tran, Dang-Thuan; Chang, Jo-Shu

    2014-03-01

    The most effective way of enzymatic synthesis of biodiesel is through lipase-catalyzed transesterification, while its performance and economic feasibility should still be improved. In this study, lipase produced by an isolated Burkholderia sp. was immobilized on microsize Celite materials functionally modified with long alkyl groups. The specific activity of the immobilized lipase was 1,154 U/g. The methanolysis of olive oil catalyzed by the immobilized lipase obeyed Ping Pong Bi Bi model with an estimated V max, K m,TG, K m,M and K i,M value of 0.61 mol/(L min), 7.93 mol/L, 1.01 mol/L, and 0.24 mol/L, respectively. The activation energy of the enzymatic reaction is estimated as 15.51 kJ/mol. The immobilized lipase exhibits high thermal stability with thermal deactivation energy of 83 kJ/mol and a long half-life. The enthalpy, Gibb's free energy, and entropy of the immobilized lipase were in the range of 80.02-80.35 kJ/mol, 88.35-90.13 kJ/mol, and -28.22 to -25.11 J/(mol K), respectively. PMID:23880737

  4. Exploring the Anti-Burkholderia cepacia Complex Activity of Essential Oils: A Preliminary Analysis

    PubMed Central

    Lo Nostro, Antonella; Calonico, Carmela; Perrin, Elena; Chiellini, Carolina; Fondi, Marco; Mengoni, Alessio; Vannacci, Alfredo; Bilia, Anna Rita; Gori, Luigi

    2014-01-01

    In this work we have checked the ability of the essential oils extracted from six different medicinal plants (Eugenia caryophyllata, Origanum vulgare, Rosmarinus officinalis, Lavandula officinalis, Melaleuca alternifolia, and Thymus vulgaris) to inhibit the growth of 18 bacterial type strains belonging to the 18 known species of the Burkholderia cepacia complex (Bcc). These bacteria are opportunistic human pathogens that can cause severe infection in immunocompromised patients, especially those affected by cystic fibrosis (CF), and are often resistant to multiple antibiotics. The analysis of the aromatograms produced by the six oils revealed that, in spite of their different chemical composition, all of them were able to contrast the growth of Bcc members. However, three of them (i.e., Eugenia caryophyllata, Origanum vulgare, and Thymus vulgaris) were particularly active versus the Bcc strains, including those exhibiting a high degree or resistance to ciprofloxacin, one of the most used antibiotics to treat Bcc infections. These three oils are also active toward both environmental and clinical strains (isolated from CF patients), suggesting that they might be used in the future to fight B. cepacia complex infections. PMID:24701243

  5. Purification, biochemical characterization, and genetic cloning of the phytase produced by Burkholderia sp. strain a13.

    PubMed

    Graminho, Eduardo Rezende; Takaya, Naoki; Nakamura, Akira; Hoshino, Takayuki

    2015-01-01

    A phytase-producing bacterium, Burkholderia sp. a13 (JCM 30421), was isolated from Lake Kasumigaura by enrichment cultivation using minimum medium containing phytic acid as the sole phosphorus source. The phytase production by strain a13 was induced by the presence of phytic acid and repressed by the addition of glucose. The purified enzyme had a molecular weight of 44 kDa and a phytase activity of 174 ?mol min(-1) mg(-1). The enzyme showed broad substrate specificity, but the highest activity was observed with phytic acid. The enzyme activity was strongly inhibited by Cu(2+), Zn(2+), Hg(2+), and iodoacetic acid, indicating the requirement of a thiol group for the activity. Genetic cloning reveals that the mature portion of this enzyme consists of 428 amino acids with a calculated molecular weight of 46 kDa. The amino acid sequence showed the highest similarity to the phytase produced by Hafnia alvei with 48% identity; it also contained histidine acid phosphatase (HAP) motifs (RHGXRXP and HD), indicating the classification of this enzyme in the HAP phytase family. We have successfully expressed the cloned gene in Escherichia coli from its putative initiation codon, showing that the gene actually encodes the phytase. PMID:25833676

  6. Proteomic analysis of quorum sensing-dependent proteins in Burkholderia glumae.

    PubMed

    Goo, Eunhye; Kang, Yongsung; Kim, Hongsup; Hwang, Ingyu

    2010-06-01

    Burkholderia glumae, the causal agent of bacterial rice grain rot, utilizes quorum sensing (QS) systems that rely on N-octanoyl homoserine lactone (synthesized by TofI) and its cognate receptor TofR to activate toxoflavin biosynthesis genes and an IclR-type transcriptional regulator gene, qsmR. Since QS is essential for B. glumae pathogenicity, we analyzed the QS-dependent proteome by 2-dimensional gel electrophoresis. A total of 79 proteins, including previously known QS-dependent proteins, were differentially expressed between the wild-type BGR1 and the tofI mutant BGS2 strains. Among this set, 59 proteins were found in the extracellular fraction, and 20 were cytoplasmic. Thirty-four proteins, including lipase and proteases, were secreted through the type II secretion system (T2SS). Real-time RT-PCR analysis showed that the corresponding genes of the 49 extracellular and 13 intracellular proteins are regulated by QS at the transcriptional level. The T2SS, encoded by 12 general secretion pathway (gsp) genes with 3 independent transcriptional units, was controlled by QS. beta-Glucuronidase activity analysis of gsp::Tn3-gusA gene fusions and electrophoretic mobility shift assays revealed that the expression of gsp genes is directly regulated by QsmR. T2SS-defective mutants exhibited reduced virulence, indicating that the T2SS-dependent extracellular proteins play important roles in B. glumae virulence. PMID:20408571

  7. Diversities in Virulence, Antifungal Activity, Pigmentation and DNA Fingerprint among Strains of Burkholderia glumae

    PubMed Central

    Karki, Hari S.; Shrestha, Bishnu K.; Han, Jae Woo; Groth, Donald E.; Barphagha, Inderjit K.; Rush, Milton C.; Melanson, Rebecca A.; Kim, Beom Seok; Ham, Jong Hyun

    2012-01-01

    Burkholderia glumae is the primary causal agent of bacterial panicle blight of rice. In this study, 11 naturally avirulent and nine virulent strains of B. glumae native to the southern United States were characterized in terms of virulence in rice and onion, toxofalvin production, antifungal activity, pigmentation and genomic structure. Virulence of B. glumae strains on rice panicles was highly correlated to virulence on onion bulb scales, suggesting that onion bulb can be a convenient alternative host system to efficiently determine the virulence of B. glumae strains. Production of toxoflavin, the phytotoxin that functions as a major virulence factor, was closely associated with the virulence phenotypes of B. glumae strains in rice. Some strains of B. glumae showed various levels of antifungal activity against Rhizoctonia solani, the causal agent of sheath blight, and pigmentation phenotypes on casamino acid-peptone-glucose (CPG) agar plates regardless of their virulence traits. Purple and yellow-green pigments were partially purified from a pigmenting strain of B. glumae, 411gr-6, and the purple pigment fraction showed a strong antifungal activity against Collectotrichum orbiculare. Genetic variations were detected among the B. glumae strains from DNA fingerprinting analyses by repetitive element sequence-based PCR (rep-PCR) for BOX-A1R-based repetitive extragenic palindromic (BOX) or enterobacterial repetitive intergenic consensus (ERIC) sequences of bacteria; and close genetic relatedness among virulent but pigment-deficient strains were revealed by clustering analyses of DNA fingerprints from BOX-and ERIC-PCR. PMID:23028972

  8. A novel rhamno-mannan exopolysaccharide isolated from biofilms of Burkholderia multivorans C1576.

    PubMed

    Dolfi, Stefania; Sveronis, Aris; Silipo, Alba; Rizzo, Roberto; Cescutti, Paola

    2015-06-26

    Burkholderia multivorans C1576 is a Gram negative opportunistic pathogen causing serious lung infection in cystic fibrosis patients. Considering that bacteria naturally form biofilms, and exopolysaccharides are recognized as important factors for biofilm architecture set-up, B. multivorans was grown both in biofilm and in non-biofilm mode on two different media in order to compare the exopolysaccharides biosynthesized in these different experimental conditions. The exopolysaccharides produced were purified and their structure was determined resorting mainly to NMR spectroscopy, ESI mass spectrometry and gas chromatography coupled to mass spectrometry. The experimental data showed that both in biofilm and non-biofilm mode B. multivorans C1576 produced a novel exopolysaccharide having the following structure: About 50% of the 2-linked rhamnose residues are substituted on C-3 with a methyl ether group. The high percentage of deoxysugar Rha units, coupled with OMe substitutions, suggest a possible role for polymer domains with marked hydrophobic characteristics able to create exopolysaccharide junction zones favouring the stability of the biofilm matrix. PMID:25974852

  9. Investigation into the susceptibility of Burkholderia cepacia complex isolates to photodynamic antimicrobial chemotherapy (PACT)

    NASA Astrophysics Data System (ADS)

    Cassidy, C. M.; Watters, A. L.; Donnelly, R. F.; Tunney, M. M.

    2009-06-01

    The main cause of morbidity and mortality in cystic fibrosis (CF) sufferers is progressive pulmonary damage caused by recurrent and often unremitting respiratory tract infection. Causative organisms include Pseudomonas aeruginosa and Haemophilus influenzae, but in recent years the Burkholderia cepacia complex has come to the fore. This group of highly drug-resistant Gram-negative bacteria are associated with a rapid decline in lung function and the often fatal cepacia syndrome, with treatment limited to patient segregation and marginally effective antibacterial regimens. Thus, development of an effective treatment is of the upmost importance. PACT, a non-target specific therapy, has proven successful in killing both Gram-positive and Gram-negative bacteria. In this study, planktonic cultures of six strains of the B. cepacia complex were irradiated (635 nm, 200 J cm-2,10 minutes irradiation) following 30 seconds incubation with methylene blue (MB) or meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate (TMP). Rates of kill of > 99 % were achieved with MB- and TMP-PACT. A MB concentration of 50 ?g ml-1 and TMP concentration of 500 ?g ml-1 were associated with highest percentage kills for each photosensitizer. PACT is an attractive option for treatment of B.cepacia complex infection. Further study, involving biofilm culture susceptibility, delivery of light to the target and in vivo testing will be necessary before it PACT becomes a viable treatment option for CF patients who are colonised or infected with B. cepacia complex.

  10. Antisense Phosphorodiamidate Morpholino Oligomers Targeted to an Essential Gene Inhibit Burkholderia cepacia complex

    PubMed Central

    Greenberg, David E.; Marshall-Batty, Kimberly R.; Brinster, Lauren R.; Zarember, Kol A.; Shaw, Pamela A.; Mellbye, Brett L.; Iversen, Patrick L.; Holland, Steven M.; Geller, Bruce L.

    2010-01-01

    Background: Members of the Burkholderia cepacia complex (Bcc) cause significant morbidity and mortality in patients with chronic granulomatous disease (CGD) and cystic fibrosis (CF). Many Bcc strains are antibiotic resistant requiring the exploration of novel antimicrobial approaches including antisense technologies, such as phosphorodiamidate morpholino oligomers (PMOs). Methods: Peptide-conjugated PMOs (PPMOs) were developed to target the acpP gene, encoding an acyl carrier protein thought to be essential for growth. Their antimicrobial activities were tested against different strains of Bcc in vitro and in infection models. Results: PPMOs targeting acpP were bactericidal against clinical isolates of Bcc (> 4 log reduction), whereas a PPMO with a scrambled base sequence (Scr) had no effect on growth. Human neutrophils (PMN) were infected with B. multivorans, and treated with AcpP PPMO. AcpP PPMO augmented killing compared to PMN alone ± Scr PPMO. CGD mice infected with B. multivorans were treated with AcpP PPMO, Scr PPMO or water at 0, 3 and 6 hours post-infection. Compared to water treated controls, the AcpP PPMO treated mice showed a ~80% reduction in the risk of dying by day 30 and relatively little pathology. Conclusions: AcpP PPMO is active against Bcc infections in vitro and in vivo. PMID:20438352

  11. Biodegradation of Mono-Hydroxylated PCBs by Burkholderia xenovorans LB400

    PubMed Central

    Tehrani, Rouzbeh; Lyv, Monica M.; Kaveh, Rashid; Schnoor, Jerald L.; Aken, Benoit Van

    2013-01-01

    Three hydroxylated derivatives of PCBs, including 2?-hydroxy-4-chlorobiphenyl (2?-OH-4-CB), 3?-hydroxy-4-chlorobiphenyl (3?-OH-4-CB), and 4?-hydroxy-4-chlorobiphenyl (4?-OH-4-CB), were transformed by the PCB degrader, Burkholderia xenovorans LB400. When the bacterium was growing on biphenyl (biphenyl pathway-inducing conditions), all three hydroxylated isomers were significantly transformed. On the contrary, only 2?-OH-4-CB was transformed by the bacterium growing on succinate (conditions non-inductive of the biphenyl pathway). Gene expression analyses showed a strong induction of key genes of the biphenyl pathway (bph) when cells were grown on biphenyl, which is consistent with the transformation of the three isomers by biphenyl-grown cells. When cells were grown on succinate, only exposure to 2?-OH-4-CB resulted in expression of biphenyl pathway genes, which suggests that this isomer was capable of inducing the biphenyl pathway. These results provide the first evidence that bacteria are able to metabolize PCB derivatives hydroxylated on the non-chlorinated ring. PMID:22918793

  12. Burkholderia cenocepacia Lipopolysaccharide Modification and Flagellin Glycosylation Affect Virulence but Not Innate Immune Recognition in Plants

    PubMed Central

    Khodai-Kalaki, Maryam; Andrade, Angel; Fathy Mohamed, Yasmine

    2015-01-01

    ABSTRACT Burkholderia cenocepacia causes opportunistic infections in plants, insects, animals, and humans, suggesting that “virulence” depends on the host and its innate susceptibility to infection. We hypothesized that modifications in key bacterial molecules recognized by the innate immune system modulate host responses to B. cenocepacia. Indeed, modification of lipopolysaccharide (LPS) with 4-amino-4-deoxy-l-arabinose and flagellin glycosylation attenuates B. cenocepacia infection in Arabidopsis thaliana and Galleria mellonella insect larvae. However, B. cenocepacia LPS and flagellin triggered rapid bursts of nitric oxide and reactive oxygen species in A. thaliana leading to activation of the PR-1 defense gene. These responses were drastically reduced in plants with fls2 (flagellin FLS2 host receptor kinase), Atnoa1 (nitric oxide-associated protein 1), and dnd1-1 (reduced production of nitric oxide) null mutations. Together, our results indicate that LPS modification and flagellin glycosylation do not affect recognition by plant receptors but are required for bacteria to establish overt infection. PMID:26045541

  13. Biodiversity of a Burkholderia cepacia population isolated from the maize rhizosphere at different plant growth stages.

    PubMed Central

    Di Cello, F; Bevivino, A; Chiarini, L; Fani, R; Paffetti, D; Tabacchioni, S; Dalmastri, C

    1997-01-01

    A Burkholderia cepacia population naturally occurring in the rhizosphere of Zea mays was investigated in order to assess the degree of root association and microbial biodiversity at five stages of plant growth. The bacterial strains isolated on semiselective PCAT medium were mostly assigned to the species B. cepacia by an analysis of the restriction patterns produced by amplified DNA coding for 16S rRNA (16S rDNA) (ARDRA) with the enzyme AluI. Partial 16S rDNA nucleotide sequences of some randomly chosen isolates confirmed the ARDRA results. Throughout the study, B. cepacia was strictly associated with maize roots, ranging from 0.6 to 3.6% of the total cultivable microflora. Biodiversity among 83 B. cepacia isolates was analyzed by the random amplified polymorphic DNA (RAPD) technique with two 10-mer primers. An analysis of RAPD patterns by the analysis of molecular variance method revealed a high level of intraspecific genetic diversity in this B. cepacia population. Moreover, the genetic diversity was related to divergences among maize root samplings, with microbial genetic variability markedly higher in the first stages of plant growth; in other words, the biodiversity of this rhizosphere bacterial population decreased over time. PMID:9361434

  14. Sorption versus Biomineralization of Pb(II) within Burkholderia cepacia Biofilms

    SciTech Connect

    Templeton, Alexis S.; Trainor, T. P.; Spormann, Alfred M.; Newville, Mathew; Sutton , Steven R.; Dohnalkova, Alice; Gorby, Yuri A.; Brown, Gordon E.

    2003-01-15

    X-ray spectroscopy measurements have been combined with macroscopic uptake data and transmission electron microscopy (TEM) results to show that Pb(II) uptake by Burkholderia cepacia is due to simultaneous sorption and biomineralization processes. X-ray microprobe mapping of B. cepacia biofilms formed on -Al2O3 surfaces shows that Pb(II) is distributed heterogeneously throughout the biofilms because of the formation of Pb "hot spots". EXAFS data and TEM observations show that the enhanced Pb accumulation is due to the formation of nanoscale crystals of pyromorphite (Pb5(PO4)3(OH)) adjacent to the outer-membrane of a fraction of the total population of B. cepacia cells. In contrast, B. cepacia cell suspensions or biofilms that were heat-killed or pretreated with X-rays do not form pyromorphite, which suggests that metabolic activity is required. Precipitation of pyromorphite occurs over several orders of magnitude in [H+] and [Pb] and accounts for approximately 90% of the total Pb uptake below pH 4.5 but only 45-60% at near-neutral pH because of the formation of additional Pb(II) adsorption complexes. Structural fits of Pb LIII EXAFS data collected for heat-treated cells at near-neutral pH suggest that Pb(II) forms inner-sphere adsorption complexes with carboxyl functional groups in the biofilms.

  15. Involvement of toxin-antitoxin modules in Burkholderia cenocepacia biofilm persistence.

    PubMed

    Van Acker, Heleen; Sass, Andrea; Dhondt, Inne; Nelis, Hans J; Coenye, Tom

    2014-08-01

    Biofilms are involved in the recalcitrance of infections due to the presence of persister cells. Although the molecular basis of persistence is still largely unknown, toxin-antitoxin modules (TA) are thought to play a role in this process. In this study, we investigated whether TA modules contribute to persistence toward antibiotics in Burkholderia cenocepacia J2315. Sixteen pairs of genes were identified based on their apparent similarity to TA modules. Overexpression of the putative toxins had various effects on growth, persistence, and biofilm formation. Toxins, whose overexpression resulted in growth inhibition, often increased the number of surviving persisters; in contrast, overexpression of putative toxins showing no effects on growth had no positive influence on the number of surviving persisters. Furthermore, the expression of the TA modules was compared between treated and untreated sessile and planktonic wild-type cultures. For 10 toxin-encoding genes, the expression was higher in untreated sessile cells than in untreated planktonic cells. Nine toxin-encoding genes were upregulated after treatment with tobramycin, but none after treatment with ciprofloxacin. These results indicate that most, but not all TA modules contribute to persistence in B. cenocepacia J2315 and that this contribution depends on the mode of growth and the antibiotic used. PMID:24719230

  16. Mesaconase Activity of Class I Fumarase Contributes to Mesaconate Utilization by Burkholderia xenovorans.

    PubMed

    Kronen, Miriam; Sasikaran, Jahminy; Berg, Ivan A

    2015-08-15

    Pseudomonas aeruginosa, Yersinia pestis, and many other bacteria are able to utilize the C5-dicarboxylic acid itaconate (methylenesuccinate). Itaconate degradation starts with its activation to itaconyl coenzyme A (itaconyl-CoA), which is further hydrated to (S)-citramalyl-CoA, and citramalyl-CoA is finally cleaved into acetyl-CoA and pyruvate. The xenobiotic-degrading betaproteobacterium Burkholderia xenovorans possesses a P. aeruginosa-like itaconate degradation gene cluster and is able to grow on itaconate and its isomer mesaconate (methylfumarate). Although itaconate degradation proceeds in B. xenovorans in the same way as in P. aeruginosa, the pathway of mesaconate utilization is not known. Here, we show that mesaconate is metabolized through its hydration to (S)-citramalate. The latter compound is then metabolized to acetyl-CoA and pyruvate with the participation of two enzymes of the itaconate degradation pathway, a promiscuous itaconate-CoA transferase able to activate (S)-citramalate in addition to itaconate and (S)-citramalyl-CoA lyase. The first reaction of the pathway, the mesaconate hydratase (mesaconase) reaction, is catalyzed by a class I fumarase. As this enzyme (Bxe_A3136) has similar efficiencies (kcat/Km) for both fumarate and mesaconate hydration, we conclude that B. xenovorans class I fumarase is in fact a promiscuous fumarase/mesaconase. This promiscuity is physiologically relevant, as it allows the growth of this bacterium on mesaconate as a sole carbon and energy source. PMID:26070669

  17. Lung transplantation for cystic fibrosis patients with Burkholderia cepacia complex. Survival linked to genomovar type.

    PubMed

    Aris, R M; Routh, J C; LiPuma, J J; Heath, D G; Gilligan, P H

    2001-12-01

    The number of cystic fibrosis (CF) patients undergoing lung transplant has risen over the past decade, because of a clear-cut survival benefit. However, patients with Burkholderia cepacia complex are often excluded from transplantation because of increased mortality. To determine the influence of B. cepacia complex genomovar type on transplant outcome, we undertook a retrospective study in 121 CF patients transplanted at UNC. Twenty-one and three patients, respectively, were infected pre- or postoperatively with B. cepacia complex. All posttransplant acquisitions were successfully treated. However, excess mortality occurred over the first 6 postoperative months in those infected preoperatively with B. cepacia complex compared with those not infected (33% versus 12%, p = 0.01). The 1-, 3-, and 5-yr survival were significantly lower in the B. cepacia complex cohort. Of the patients infected preoperatively, genomovar III patients were at the highest risk of B. cepacia complex-related mortality (5 of 12 versus 0 of 8, one isolate not typed; p = 0.035). Each of the B. cepacia complex-related deaths was caused by a unique genotype as determined by pulsed-field gel electrophoresis. All isolates were negative for the cable pilin gene. These results warrant a multicenter analysis of B. cepacia complex-infected patients with genomovar-typing to confirm that genomovar III patients are at highest risk for post-transplant complications. PMID:11739142

  18. Burkholderia cenocepacia J2315 escapes to the cytosol and actively subverts autophagy in human macrophages

    PubMed Central

    Al-Khodor, Souhaila; Marshall-Batty, Kimberly; Nair, Vinod; Ding, Li; Greenberg, David E.; Fraser, Iain D.C.

    2013-01-01

    SUMMARY Selective autophagy functions to specifically degrade cellular cargo tagged by ubiquitination, including bacteria. Strains of the Burkholderia cepacia complex (Bcc) are opportunistic pathogens that cause life-threatening infections in patients with cystic fibrosis (CF) and chronic granulomatous disease (CGD). While there is evidence that defective macrophage autophagy in a mouse model of CF can influence B. cenocepacia susceptibility, there have been no comprehensive studies on how this bacterium is sensed and targeted by the host autophagy response in human macrophages. Here, we describe the intracellular life cycle of B. cenocepacia J2315 and its interaction with the autophagy pathway in human cells. Electron and confocal microscopy analysis demonstrates that the invading bacteria interact transiently with the endocytic pathway before escaping to the cytosol. This escape triggers the selective autophagy pathway, and the recruitment of ubiquitin, the ubiquitin-binding adaptors p62 and NDP52 and the autophagosome membrane-associated protein LC3B, to the bacterial vicinity. However, despite recruitment of these key autophagy pathway effectors, B. cenocepacia blocks autophagosome completion and replicates in the host cytosol. We find that a pre-infection increase in cellular autophagy flux can significantly inhibit B. cenocepacia replication and that lower autophagy flux in macrophages from immunocompromised CGD patients could contribute to increased B. cenocepacia susceptibility, identifying autophagy manipulation as a potential therapeutic approach to reduce bacterial burden in B. cenocepacia infections. PMID:24119232

  19. Exploring the Anti-Burkholderia cepacia Complex Activity of Essential Oils: A Preliminary Analysis.

    PubMed

    Maida, Isabel; Lo Nostro, Antonella; Pesavento, Giovanna; Barnabei, Martina; Calonico, Carmela; Perrin, Elena; Chiellini, Carolina; Fondi, Marco; Mengoni, Alessio; Maggini, Valentina; Vannacci, Alfredo; Gallo, Eugenia; Bilia, Anna Rita; Flamini, Guido; Gori, Luigi; Firenzuoli, Fabio; Fani, Renato

    2014-01-01

    In this work we have checked the ability of the essential oils extracted from six different medicinal plants (Eugenia caryophyllata, Origanum vulgare, Rosmarinus officinalis, Lavandula officinalis, Melaleuca alternifolia, and Thymus vulgaris) to inhibit the growth of 18 bacterial type strains belonging to the 18 known species of the Burkholderia cepacia complex (Bcc). These bacteria are opportunistic human pathogens that can cause severe infection in immunocompromised patients, especially those affected by cystic fibrosis (CF), and are often resistant to multiple antibiotics. The analysis of the aromatograms produced by the six oils revealed that, in spite of their different chemical composition, all of them were able to contrast the growth of Bcc members. However, three of them (i.e., Eugenia caryophyllata, Origanum vulgare, and Thymus vulgaris) were particularly active versus the Bcc strains, including those exhibiting a high degree or resistance to ciprofloxacin, one of the most used antibiotics to treat Bcc infections. These three oils are also active toward both environmental and clinical strains (isolated from CF patients), suggesting that they might be used in the future to fight B. cepacia complex infections. PMID:24701243

  20. Susceptibility of opportunistic Burkholderia glumae to copper surfaces following wet or dry surface contact.

    PubMed

    Cui, Zhouqi; Ibrahim, Muhammad; Yang, Chunlan; Fang, Yuan; Annam, Hussain; Li, Bin; Wang, Yanli; Xie, Guan-Lin; Sun, Guochang

    2014-01-01

    Burkholderia glumae has been proposed to have a potential risk to vulnerable communities. In this work, we investigated the antibacterial activity and mechanism of copper surfaces against multi-drug resistant B. glumae from both patients and rice plants. The susceptibility of B. glumae to copper surfaces was noted by a significant decline in viable bacterial counts, relative to the slight reduction of stainless steel and polyvinylchloride, both of which were used as control surfaces. The mode of action of bacterial killing was determined by examing the mutagenicity, DNA damage, copper ions accumulation, and membrane damage in bacterial cells. The results indicated that the cells exposed to copper surfaces did not cause severe DNA lesions or increase the mutation frequencies, but resulted in a loss of cell membrane integrity within minutes. Furthermore, bacterial cells exposed to copper surfaces accumulated significantly higher amounts of copper compared to control surfaces. Overall, this study showed that metallic copper had strong antibacterial effect against B. glumae by causing DNA and membrane damage, cellular accumulation of copper, and cell death following DNA degradation, which could be utilized to reduce the risk of bacterial contamination and infection. PMID:25010469

  1. Characterization of BCAM0224, a Multifunctional Trimeric Autotransporter from the Human Pathogen Burkholderia cenocepacia

    PubMed Central

    Mil-Homens, Dalila; Leça, Maria Inês; Fernandes, Fábio; Pinto, Sandra N.

    2014-01-01

    Members of the trimeric autotransporter adhesin (TAA) family play a crucial role in adhesion of Gram-negative pathogens to host cells. Moreover, these proteins are multifunctional virulence factors involved in several other biological traits, including invasion into host cells and evasion of the host immune system. In cystic fibrosis epidemic Burkholderia cenocepacia strain J2315, we identified a unique TAA (BCAM0224)-encoding gene, previously described as being implicated in virulence. Here, we characterized this multifunctional protein, trying to establish its role in B. cenocepacia pathogenicity. We show that BCAM0224 occurs on the bacterial surface and adopts a trimeric conformation. Furthermore, we demonstrated that BCAM0224 is needed for earlier stages of biofilm formation and is required for swarming motility. In addition, BCAM0224 plays an important role in evasion of the human innate immune system, providing resistance against the bactericidal activity of serum via the complement classical pathway. Finally, BCAM0224 mediates bacterial adhesion to and invasion of cultured human bronchial epithelial cells. Together, these data reveal the high versatility of the BCAM0224 protein as a virulence factor in the pathogenic bacterium B. cenocepacia. PMID:24659767

  2. Localization of Burkholderia cepacia complex bacteria in cystic fibrosis lungs and interactions with Pseudomonas aeruginosa in hypoxic mucus.

    PubMed

    Schwab, Ute; Abdullah, Lubna H; Perlmutt, Olivia S; Albert, Daniel; Davis, C William; Arnold, Roland R; Yankaskas, James R; Gilligan, Peter; Neubauer, Heiner; Randell, Scott H; Boucher, Richard C

    2014-11-01

    The localization of Burkholderia cepacia complex (Bcc) bacteria in cystic fibrosis (CF) lungs, alone or during coinfection with Pseudomonas aeruginosa, is poorly understood. We performed immunohistochemistry for Bcc and P. aeruginosa bacteria on 21 coinfected or singly infected CF lungs obtained at transplantation or autopsy. Parallel in vitro experiments examined the growth of two Bcc species, Burkholderia cenocepacia and Burkholderia multivorans, in environments similar to those occupied by P. aeruginosa in the CF lung. Bcc bacteria were predominantly identified in the CF lung as single cells or small clusters within phagocytes and mucus but not as "biofilm-like structures." In contrast, P. aeruginosa was identified in biofilm-like masses, but densities appeared to be reduced during coinfection with Bcc bacteria. Based on chemical analyses of CF and non-CF respiratory secretions, a test medium was defined to study Bcc growth and interactions with P. aeruginosa in an environment mimicking the CF lung. When test medium was supplemented with alternative electron acceptors under anaerobic conditions, B. cenocepacia and B. multivorans used fermentation rather than anaerobic respiration to gain energy, consistent with the identification of fermentation products by high-performance liquid chromatography (HPLC). Both Bcc species also expressed mucinases that produced carbon sources from mucins for growth. In the presence of P. aeruginosa in vitro, both Bcc species grew anaerobically but not aerobically. We propose that Bcc bacteria (i) invade a P. aeruginosa-infected CF lung when the airway lumen is anaerobic, (ii) inhibit P. aeruginosa biofilm-like growth, and (iii) expand the host bacterial niche from mucus to also include macrophages. PMID:25156735

  3. Bacterial Cell Wall Synthesis Gene uppP Is Required for Burkholderia Colonization of the Stinkbug Gut

    PubMed Central

    Kim, Jiyeun Kate; Lee, Ho Jin; Kikuchi, Yoshitomo; Kitagawa, Wataru; Nikoh, Naruo

    2013-01-01

    To establish a host-bacterium symbiotic association, a number of factors involved in symbiosis must operate in a coordinated manner. In insects, bacterial factors for symbiosis have been poorly characterized at the molecular and biochemical levels, since many symbionts have not yet been cultured or are as yet genetically intractable. Recently, the symbiotic association between a stinkbug, Riptortus pedestris, and its beneficial gut bacterium, Burkholderia sp., has emerged as a promising experimental model system, providing opportunities to study insect symbiosis using genetically manipulated symbiotic bacteria. Here, in search of bacterial symbiotic factors, we targeted cell wall components of the Burkholderia symbiont by disruption of uppP gene, which encodes undecaprenyl pyrophosphate phosphatase involved in biosynthesis of various bacterial cell wall components. Under culture conditions, the ?uppP mutant showed higher susceptibility to lysozyme than the wild-type strain, indicating impaired integrity of peptidoglycan of the mutant. When administered to the host insect, the ?uppP mutant failed to establish normal symbiotic association: the bacterial cells reached to the symbiotic midgut but neither proliferated nor persisted there. Transformation of the ?uppP mutant with uppP-encoding plasmid complemented these phenotypic defects: lysozyme susceptibility in vitro was restored, and normal infection and proliferation in the midgut symbiotic organ were observed in vivo. The ?uppP mutant also exhibited susceptibility to hypotonic, hypertonic, and centrifugal stresses. These results suggest that peptidoglycan cell wall integrity is a stress resistance factor relevant to the successful colonization of the stinkbug midgut by Burkholderia symbiont. PMID:23747704

  4. Localization of Burkholderia cepacia Complex Bacteria in Cystic Fibrosis Lungs and Interactions with Pseudomonas aeruginosa in Hypoxic Mucus

    PubMed Central

    Abdullah, Lubna H.; Perlmutt, Olivia S.; Albert, Daniel; Davis, C. William; Arnold, Roland R.; Yankaskas, James R.; Gilligan, Peter; Neubauer, Heiner; Randell, Scott H.; Boucher, Richard C.

    2014-01-01

    The localization of Burkholderia cepacia complex (Bcc) bacteria in cystic fibrosis (CF) lungs, alone or during coinfection with Pseudomonas aeruginosa, is poorly understood. We performed immunohistochemistry for Bcc and P. aeruginosa bacteria on 21 coinfected or singly infected CF lungs obtained at transplantation or autopsy. Parallel in vitro experiments examined the growth of two Bcc species, Burkholderia cenocepacia and Burkholderia multivorans, in environments similar to those occupied by P. aeruginosa in the CF lung. Bcc bacteria were predominantly identified in the CF lung as single cells or small clusters within phagocytes and mucus but not as “biofilm-like structures.” In contrast, P. aeruginosa was identified in biofilm-like masses, but densities appeared to be reduced during coinfection with Bcc bacteria. Based on chemical analyses of CF and non-CF respiratory secretions, a test medium was defined to study Bcc growth and interactions with P. aeruginosa in an environment mimicking the CF lung. When test medium was supplemented with alternative electron acceptors under anaerobic conditions, B. cenocepacia and B. multivorans used fermentation rather than anaerobic respiration to gain energy, consistent with the identification of fermentation products by high-performance liquid chromatography (HPLC). Both Bcc species also expressed mucinases that produced carbon sources from mucins for growth. In the presence of P. aeruginosa in vitro, both Bcc species grew anaerobically but not aerobically. We propose that Bcc bacteria (i) invade a P. aeruginosa-infected CF lung when the airway lumen is anaerobic, (ii) inhibit P. aeruginosa biofilm-like growth, and (iii) expand the host bacterial niche from mucus to also include macrophages. PMID:25156735

  5. Characterization of a chromosomally encoded 2,4-dichlorophenoxyacetic acid/alpha-ketoglutarate dioxygenase from Burkholderia sp. strain RASC.

    PubMed Central

    Suwa, Y; Wright, A D; Fukimori, F; Nummy, K A; Hausinger, R P; Holben, W E; Forney, L J

    1996-01-01

    The findings of previous studies indicate that the genes required for metabolism of the pesticide 2,4-dichlorophenoxyacetic acid (2,4-D) are typically encoded on broad-host-range plasmids. However, characterization of plasmid-cured strains of Burkholderia sp. strain RASC, as well as mutants obtained by transposon mutagenesis, suggested that the 2,4-D catabolic genes were located on the chromosome of this strain. Mutants of Burkholderia strain RASC unable to degrade 2,4-D (2,4-D- strains) were obtained by insertional inactivation with Tn5. One such mutant (d1) was shown to have Tn5 inserted in tfdARASC, which encodes 2,4-D/alpha-ketoglutarate dioxygenase. This is the first reported example of a chromosomally encoded tfdA. The tfdARASC gene was cloned from a library of wild-type Burkholderia strain RASC DNA and shown to express 2,4-D/alpha-ketoglutarate dioxygenase activity in Escherichia coli. The DNA sequence of the gene was determined and shown to be similar, although not identical, to those of isofunctional genes from other bacteria. Moreover, the gene product (TfdARASC) was purified and shown to be similar in molecular weight, amino-terminal sequence, and reaction mechanism to the canonical TfdA of Alcaligenes eutrophus JMP134. The data presented here indicate that tfdA genes can be found on the chromosome of some bacterial species and suggest that these catabolic genes are rather mobile and may be transferred by means other than conjugation. PMID:8779585

  6. In vitro efficacy of high-dose tobramycin against Burkholderia cepacia complex and Stenotrophomonas maltophilia isolates from cystic fibrosis patients.

    PubMed

    Ratjen, Anina; Yau, Yvonne; Wettlaufer, Jillian; Matukas, Larissa; Zlosnik, James E A; Speert, David P; LiPuma, John J; Tullis, Elizabeth; Waters, Valerie

    2015-01-01

    Burkholderia cepacia complex and Stenotrophomonas maltophilia infections are associated with poor clinical outcomes in persons with cystic fibrosis (CF). The MIC50 based on planktonic growth and the biofilm concentration at which 50% of the isolates tested are inhibited (BIC50) of tobramycin were measured for 180 B. cepacia complex and 101 S. maltophilia CF isolates and were 100 ?g/ml for both species. New inhalation devices that deliver high tobramycin levels to the lung may be able to exceed these MICs. PMID:25348526

  7. Degradation of toluene and trichlorethylene by Burkholderia cepacia G4 in growth-limited fed-batch culture

    SciTech Connect

    Mars, A.E.; Houwing, J.; Dolfing, J.; Janssen, D.B. [Univ. of Groningen (Netherlands)

    1996-03-01

    Trichloroethyene(TCE), widely used as a solvent and a degreasing agent, is a toxic environmental contaminant with possible carcinogenic properties. No microorganisms which can grow on this compound are known but comatebolic conversion of TCE by oxygenases has been described. Burkholderia (Pseudomonas) cepacia G4 can aerobically degrade TCE when grown on Toluene or other aromatic compounds as carbon and energy sources. In this paper, the TCE degradation capacity of B. cepacia G4 in a growth limited fed-batch culture with toluene as the primary substrate is described. 34 refs., 4 figs., 3 tabs.

  8. Draft genomes of three Antarctic Psychrobacter strains producing antimicrobial compounds against Burkholderia cepacia complex, opportunistic human pathogens.

    PubMed

    Fondi, Marco; Orlandini, Valerio; Perrin, Elena; Maida, Isabel; Bosi, Emanuele; Papaleo, Maria Cristiana; Michaud, Luigi; Lo Giudice, Angelina; de Pascale, Donatella; Tutino, Maria Luisa; Liò, Pietro; Fani, Renato

    2014-02-01

    Herein we present the draft genomes of three Psychrobacter strains isolated from Antarctic sponges and able to inhibit the growth of bacteria belonging to the Burkholderia cepacia complex, responsible for infections of the respiratory system in patients affected by Cystic Fibrosis. The comparative analysis of the annotated genomes of these Psychrobacter strains highlighted their differences in terms of overall genomic content (e.g. shared gene sets) and allowed the identification of gene clusters hypothetically involved in the biosynthesis of antimicrobial compounds. PMID:24401162

  9. Burkholderia cepacia respiratory tract acquisition: epidemiology and molecular characterization of a large nosocomial outbreak.

    PubMed Central

    Pegues, C. F.; Pegues, D. A.; Ford, D. S.; Hibberd, P. L.; Carson, L. A.; Raine, C. M.; Hooper, D. C.

    1996-01-01

    In 1994 we investigated a large outbreak of Burkholderia (formerly Pseudomonas) cepacia respiratory tract acquisition. A case patient was defined as any patient with at least one sputum culture from which B. cepacia was isolated from 1 January to 31 December 1994. Seventy cases were identified. Most (40 [61%]) occurred between 1 February and 31 March 1994; of these, 35 (86%) were mechanically ventilated patients, 30 of whom were in an intensive-care unit (ICU) when B. cepacia was first isolated. Compared with control patients who were mechanically ventilated in an ICU, these 30 case-patients were significantly more likely to have been ventilated for 2 or more days (30/30 v. 15/30; P < 0.001) or to have been intubated more than once (12/30 v. 2/30; OR = 9.3, 95% CI 1.6-68.8; P = 0.002) before the first isolation of B. cepacia. By multivariate analysis, the 35 mechanically ventilated case-patients were significantly more likely to have received a nebulized medication (OR = 11.9, 95% CI = 1.6-553.1; P < 0.001) and a cephalosporin antimicrobial (OR = 11.9, 95% CI = 1.6-553.1) in the 10 days before the first isolation of B. cepacia, compared with B. cepacia-negative control-patients matched by date and duration of most recent mechanical ventilation. Although B. cepacia was not cultured from medications or the hospital environment, all outbreak strains tested had an identical DNA restriction endonuclease digestion pattern by pulsed-field gel electrophoresis. Review of respiratory therapy procedures revealed opportunities for contamination of nebulizer reservoirs. This investigation suggests that careful adherence to standard procedures for administration of nebulized medications is essential to prevent nosocomial respiratory infections. Images Fig. 3 PMID:8666075

  10. Involvement of outer membrane proteins and peroxide-sensor genes in Burkholderia cepacia resistance to isothiazolone.

    PubMed

    Zhou, Gang; Shi, Qing-shan; Ouyang, You-sheng; Chen, Yi-ben

    2014-04-01

    Isothiazolones are used as preservatives in various modern industrial products. Although microorganisms that exhibit resistance towards these biocides have been identified, the underlying resistance mechanisms are still unclear. Therefore, we investigated the resistance properties of the following Burkholderia cepacia strains to Kathon (a representative of isothiazolones): a wild-type (WT) strain; a laboratory resistance strain (BC-IR) induced from WT; and an isolated strain (BC-327) screened from industrial contamination samples. The bacterial cell structure was disrupted by 50 ?g ml?¹ Kathon treatment. BC-IR and BC-327 did not display resistance in the presence of 1 ml L?¹ Tween 80, 1 ml L?¹ Triton X-100, 0.1 % sodium dodecyl sulfate or 1 mmol L?¹ EDTA-2Na. Additionally, BC-IR and BC-327 exhibited lower relative conductivity from 10 to 180 min. The types as well as the levels of outer-membrane proteins (OMPs) were altered among WT, BC-IR and BC-327. Finally, the two Kathon-resistance strains BC-IR and BC-327 presented higher resistance capacity to H?O?. We measured the levels of peroxide-sensor genes and observed that the transcriptional activator oxyR, superoxide dismutase sod1, sod2, catalase cat1 and cat3 were all up-regulated under oxidative conditions for all strains. Taken together, OMPs and peroxide-sensor genes in B. cepacia contributed to isothiazolone resistance; However, the laboratory strain BC-IR exhibited a different resistance mechanism and properties compared to the isolated strain BC-327. PMID:24197783

  11. Characterization of ergothionase from Burkholderia sp. HME13 and its application to enzymatic quantification of ergothioneine.

    PubMed

    Muramatsu, Hisashi; Matsuo, Hidenori; Okada, Naoki; Ueda, Momoko; Yamamoto, Hiroaki; Kato, Shin-ichiro; Nagata, Shinji

    2013-06-01

    We identified ergothionase, which catalyzes conversion of ergothioneine to thiolurocanic acid and trimethylamine, in a newly isolated ergothioneine-utilizing strain, Burkholderia sp. HME13. The enzyme was purified and its N-terminal amino acid sequence was determined. Based on the amino acid sequence, the gene encoding the enzyme was cloned and expressed in Escherichia coli. The recombinant enzyme was purified to homogeneity and characterized. The enzyme consisted of four identical 55-kDa subunits. The enzyme showed maximum activity at pH 8.0 and 65 °C and was stable between pH 7.0 and pH 10.0 and up to 60 °C. The enzyme acted on ergothioneine (K m: 19 ?M, V max: 270 ?mol/min/mg), but not D-histidine, L-histidine, D-tyrosine, L-tyrosine, D-phenylalanine, or L-phenylalanine. The enzyme was activated by BaCl2 and strongly inhibited by CuSO4, ZnSO4, and HgCl2. The amino acid sequence of ergothionase showed 23 % similarity to histidine ammonia-lyase (HAL) from Pseudomonas putida and 17 % similarity to phenylalanine ammonia-lyase (PAL) from parsley. However, the tripeptide sequence, Ala-Ser-Gly, which is important for catalysis in both HAL and PAL, was not conserved in ergothionase. The application of ergothionase for the quantification of ergothioneine contained in practical food and blood samples was investigated by performing a recovery test. Satisfactory recovery data (98.7-104 %) were obtained when ergothioneine was added to extract of tamogitake and hemolysis blood. PMID:23053092

  12. Survey of Bartonella spp. in U.S. bed bugs detects Burkholderia multivorans but not Bartonella.

    PubMed

    Saenz, Virna L; Maggi, Ricardo G; Breitschwerdt, Edward B; Kim, Jung; Vargo, Edward L; Schal, Coby

    2013-01-01

    Bed bugs (Cimex lectularius L.) have resurged in the United States and globally. Bed bugs are hematophagous ectoparasites of humans and other animals, including domestic pets, chickens, and bats, and their blood feeding habits contribute to their potential as disease vectors. Several species of Bartonella are re-emergent bacterial pathogens that also affect humans, domestic pets, bats and a number of other wildlife species. Because reports of both bed bugs and Bartonella have been increasing in the U.S., and because their host ranges can overlap, we investigated whether the resurgences of these medically important pathogens and their potential vector might be linked, by screening for Bartonella spp. in bed bugs collected from geographic areas where these pathogens are prevalent and from bed bugs that have been in culture in the laboratory for several years. We screened a total of 331 bed bugs: 316 bed bugs from 36 unique collections in 29 geographic locations in 13 states, 10 bed bugs from two colonies maintained in the laboratory for 3 yr, and 5 bed bugs from a colony that has been in culture since before the recent resurgence of bed bugs. Bartonella spp. DNA was screened using a polymerase chain reaction assay targeting the 16S-23S rRNA intergenic transcribed spacer region. Bartonella DNA was not amplified from any bed bug, but five bed bugs from four different apartments of an elderly housing building in North Carolina contained DNA sequences that corresponded to Burkholderia multivorans, an important pathogen in nosocomial infections that was not previously linked to an arthropod vector. PMID:24040015

  13. Factors Influencing Acquisition of Burkholderia cepacia Complex Organisms in Patients with Cystic Fibrosis

    PubMed Central

    Butler, Claire A.; Paynter, Stuart; Ware, Robert S.; Kidd, Timothy J.; Wainwright, Claire E.; Bell, Scott C.

    2013-01-01

    Burkholderia cepacia complex organisms are important transmissible pathogens found in cystic fibrosis (CF) patients. In recent years, the rates of cross-infection of epidemic strains have declined due to effective infection control efforts. However, cases of sporadic B. cepacia complex infection continue to occur in some centers. The acquisition pathways and clinical outcomes of sporadic B. cepacia complex infection are unclear. We sought to determine the patient clinical characteristics, outcomes, incidence, and genotypic relatedness for all cases of B. cepacia complex infection at two CF centers. We also sought to study the external conditions that influence the acquisition of infection. From 2001 to 2011, 67 individual organisms were cultured from the respiratory samples of 64 patients. Sixty-five percent of the patients were adults, in whom chronic infections were more common (68%) (P = 0.006). The incidence of B. cepacia complex infection increased by a mean of 12% (95% confidence interval [CI], 3 to 23%) per year. The rates of transplantation and death were similar in the incident cases who developed chronic infection compared to those in patients with chronic Pseudomonas aeruginosa infection. Multilocus sequence typing revealed 50 individual strains from 65 isolates. Overall, 85% of the patients were infected with unique strains, suggesting sporadic acquisition of infection. The yearly incidence of nonepidemic B. cepacia complex infection was positively correlated with the amount of rainfall in the two sites examined: subtropical Brisbane (r = 0.65, P = 0.031) and tropical Townsville (r = 0.82, P = 0.002). This study demonstrates that despite strict cohort segregation, new cases of unrelated B. cepacia complex infection continue to occur. These data also support an environmental origin of infection and suggest that climate conditions may be associated with the acquisition of B. cepacia complex infections. PMID:24048536

  14. Burkholderia cenocepacia ShvR-Regulated Genes That Influence Colony Morphology, Biofilm Formation, and Virulence ?

    PubMed Central

    Subramoni, Sujatha; Nguyen, David T.; Sokol, Pamela A.

    2011-01-01

    Burkholderia cenocepacia is an opportunistic pathogen that primarily infects cystic fibrosis (CF) patients. Previously, we reported that ShvR, a LysR regulator, influences colony morphology, virulence, and biofilm formation and regulates the expression of an adjacent 24-kb genomic region encoding 24 genes. In this study, we report the functional characterization of selected genes in this region. A Tn5 mutant with shiny colony morphology was identified with a polar mutation in BCAS0208, predicted to encode an acyl-coenzyme A dehydrogenase. Mutagenesis of BCAS0208 and complementation analyses revealed that BCAS0208 is required for rough colony morphology, biofilm formation, and virulence on alfalfa seedlings. It was not possible to complement with BCAS0208 containing a mutation in the catalytic site. BCAS0201, encoding a putative flavin adenine dinucleotide (FAD)-dependent oxidoreductase, and BCAS0207, encoding a putative citrate synthase, do not influence colony morphology but are required for optimum levels of biofilm formation and virulence. Both BCAS0208 and BCAS0201 contribute to pellicle formation, although individual mutations in each of these genes had no appreciable effect on pellicle formation. A mutant with a polar insertion in BCAS0208 was significantly less virulent in a rat model of chronic lung infection as well as in the alfalfa model. Genes in this region were shown to influence utilization of branched-chain fatty acids, tricarboxylic acid cycle substrates, l-arabinose, and branched-chain amino acids. Together, our data show that the ShvR-regulated genes BCAS0208 to BCAS0201 are required for the rough colony morphotype, biofilm and pellicle formation, and virulence in B. cenocepacia. PMID:21690240

  15. A Large Gene Cluster in Burkholderia xenovorans Encoding Abietane Diterpenoid Catabolism? †

    PubMed Central

    Smith, Daryl J.; Park, Joonhong; Tiedje, James M.; Mohn, William W.

    2007-01-01

    Abietane diterpenoids are defense compounds synthesized by trees that are abundant in natural environments and occur as significant pollutants from pulp and paper production. Burkholderia xenovorans LB400 has diverse catabolic capabilities and represents an important group of heterotrophic bacteria in soil environments. The genome sequence of LB400 revealed homologs of the dit genes of Pseudomonas abietaniphila BKME-9, which encode abietane diterpenoid degradation. LB400 grew on abietic acid (AbA), dehydroabietic acid (DhA), palustric acid (PaA), and 7-oxo-DhA. A Xeotron microarray set, with probes for 8450 of the estimated 9000 LB400 genes, was used to compare the transcriptomes of LB400 growing on DhA versus on succinate. On DhA, 97 genes were upregulated, 43 of which were within an 80-kb cluster located on the 1.47-Mbp megaplasmid of LB400. Upregulated genes in this cluster encode a permease, a ring-hydroxylating dioxygenase system (DitA), a ring-cleavage dioxygenase (DitC), a P450 monooxygenase (DitQ), and enzymes catalyzing beta-oxidation-type reactions. Disruption of the ditA1 gene, encoding the alpha-subunit of DitA, abolished growth on these abietanes. Analyses of the metabolism of abietanes by cell suspensions of wild-type LB400 and the ditA1 mutant indicate a convergent pathway, with 7-oxo-DhA as a common intermediate for ring hydroxylation by DitA. Also, 7-oxo-PaA was identified as a metabolite of both AbA and PaA. Sequence analysis indicates that genes encoding this pathway have been horizontally transferred among Betaproteobacteria and Gammaproteobacteria. PMID:17586638

  16. Tom, a new aromatic degradative plasmid from Burkholderia (Pseudomonas) cepacia G4

    SciTech Connect

    Shields, M.S.; Reagin, J.J.; Campbell, R. [Univ. of West Florida, Pensacola, FL (United States)] [and others

    1995-04-01

    Burkholderia (Pseudomonas) cepacia PR1{sub 23} has been shown to constitutively express a toluene catabolic pathway distinguished by a unique toluene ortho-monooxygenase (Tom). This strain has also been shown to contain two extrachromosomal elements of <70 and> 100 kb. A derivative strain cured of the largest plasmid, PR1{sub 23} Cure, was unable to grow on phenol or toluene as the sole source of carbon and energy, which requires expression of the Tom pathway. Transfer of the larger plasmid from strain G4 J(the parent strain inducible for Tom) enabled PR1{sub 23} Cure to grow on toluene or phenol via inducible Tom pathway expression. Conjugal transfer of TOM{sub 23c} from PR1{sub 23} to an antibiotic-resistant derivative of PR1{sub 23} Cure enabled the transconjugant to grow with either phenol or toluene as the sole source of carbon and energy through constitutive expression of the Tom pathway. A cloned 11.2-kb EcoRI restriction fragment of Tom{sub 23c} resulted in the expression of both Tom and catechol 2,3-dioxygenase in Escherichia coli, as evidenced by its ability to oxidize trichloroethylene, toluene, m-cresol, o-cresol, phenol, and catechol. The largest resident plasmid of PR1 was identified as the source of these genes by DNA hybridization. These results indicate that the genes which encode Tom and catechol 2,3-dioxygenase are located on TOM, an approximately 108-kb degradative plasmid of B. cepacia G4. 35 refs., 3 figs., 3 tabs.

  17. Survival and susceptibility of Burkholderia cepacia complex in chlorhexidine gluconate and benzalkonium chloride.

    PubMed

    Kim, Jeong Myeong; Ahn, Youngbeom; LiPuma, John J; Hussong, David; Cerniglia, Carl E

    2015-06-01

    The Burkholderia cepacia complex (BCC) includes opportunistic pathogenic bacteria that have occasionally been recovered from various pharmaceutical products, including antiseptics and disinfectants. Plausible reasons for the contamination include intrinsic sources, such as inadequate process controls, especially for water or equipment used during product manufacture, or extrinsic sources, such as improper handling and dilution or distribution in contaminated containers. Because the survival of BCC in antiseptics is a concern to the public health and pharmaceutical industry, we determined minimum inhibitory concentrations (MICs) of 36 BCC strains against the antiseptics, following exposure to chlorhexidine gluconate (CHX) and benzalkonium chloride (BZK) solutions (1-500 µg/ml for each chemical). Susceptibility to CHX and BZK varied across the BCC strains and was recorded as mean 90.3 and 111.1 µg/ml, respectively, at initial inoculation, which was significantly higher than the 46.4 and 61.1 µg/ml levels measured for BCC incubated in water for 40 days. After determining antiseptic MICs of individual BCC strains, BCC recovery was measured on Tryptic Soy Agar (TSA), Reasoner's Second Agar (R2A) and diluted preparations of these media under their sub-MICs. The survival of BCC was monitored for 14 days (336 h) in sub-MICs diluted to less than their antiseptic susceptible concentration value. Diluted TSA and R2A media exhibited greater efficiency of recovery for most BCC strains from the CHX and BZK solutions than full strength TSA or R2A. For BCC survival in antiseptic solutions, the cell number of BCC decreased rapidly within the first 20 min in both antiseptics, but after this, recovery remained constant in CHX and increased in BZK over the 14 day incubation period. The results indicate that BCC in water can remain viable with low susceptibility to antiseptics for 14 days, which suggests the necessity for improved detection methods and control measures to monitor BCC contamination in pharmaceutical products. PMID:25794566

  18. Quorum sensing in Burkholderia cepacia: identification of the LuxRI homologs CepRI.

    PubMed

    Lewenza, S; Conway, B; Greenberg, E P; Sokol, P A

    1999-02-01

    Burkholderia cepacia has emerged as an important pathogen in patients with cystic fibrosis. Many gram-negative pathogens regulate the production of extracellular virulence factors by a cell density-dependent mechanism termed quorum sensing, which involves production of diffusible N-acylated homoserine lactone signal molecules, called autoinducers. Transposon insertion mutants of B. cepacia K56-2 which hyperproduced siderophores on chrome azurol S agar were identified. One mutant, K56-R2, contained an insertion in a luxR homolog that was designated cepR. The flanking DNA region was used to clone the wild-type copy of cepR. Sequence analysis revealed the presence of cepI, a luxI homolog, located 727 bp upstream and divergently transcribed from cepR. A lux box-like sequence was identified upstream of cepI. CepR was 36% identical to Pseudomonas aeruginosa RhlR and 67% identical to SolR of Ralstonia solanacearum. CepI was 38% identical to RhlI and 64% identical to SolI. K56-R2 demonstrated a 67% increase in the production of the siderophore ornibactin, was protease negative on dialyzed brain heart infusion milk agar, and produced 45% less lipase activity in comparison to the parental strain. Complementation of a cepR mutation restored parental levels of ornibactin and protease but not lipase. An N-acylhomoserine lactone was purified from culture fluids and identified as N-octanoylhomoserine lactone. K56-I2, a cepI mutant, was created and shown not to produce N-octanoylhomoserine lactone. K56-I2 hyperproduced ornibactin and did not produce protease. These data suggest both a positive and negative role for cepIR in the regulation of extracellular virulence factor production by B. cepacia. PMID:9922236

  19. Inactivation of [Fe-S] Metalloproteins Mediates Nitric Oxide-Dependent Killing of Burkholderia mallei

    PubMed Central

    Jones-Carson, Jessica; Laughlin, James; Hamad, Mohammed A.; Stewart, Amanda L.; Voskuil, Martin I.; Vázquez-Torres, Andrés

    2008-01-01

    Background Much remains to be known about the mechanisms by which O2-dependent host defenses mediate broad antimicrobial activity. Methodology/Principal Findings We show herein that reactive nitrogen species (RNS) generated by inducible nitric oxide (NO) synthase (iNOS) account for the anti-Burkholderia mallei activity of IFN?-primed macrophages. Inducible NOS-mediated intracellular killing may represent direct bactericidal activity, because B. mallei showed an exquisite sensitivity to NO generated chemically. Exposure of B. mallei to sublethal concentrations of NO upregulated transcription of [Fe-S] cluster repair genes, while damaging the enzymatic activity of the [Fe-S] protein aconitase. To test whether [Fe-S] clusters are critical targets for RNS-dependent killing of B. mallei, a mutation was constructed in the NO-induced, [Fe-S] cluster repair regulator iscR. Not only was the iscR mutant hypersusceptible to iNOS-mediated killing, but its aconitase pool was readily oxidized by NO donors as compared to wild-type controls. Although killed by authentic H2O2, which also oxidizes [Fe-S] clusters, B. mallei appear to be resilient to NADPH oxidase-mediated cytotoxicity. The poor respiratory burst elicited by this bacterium likely explains why the NADPH oxidase is nonessential to the killing of B. mallei while it is still confined within phagosomes. Conclusions/Significance Collectively, these findings have revealed a disparate role for NADPH oxidase and iNOS in the innate macrophage response against the strict aerobe B. mallei. To the best of our knowledge, this is the first instance in which disruption of [Fe-S] clusters is demonstrated as cause of the bactericidal activity of NO congeners. PMID:18398486

  20. TOM, a new aromatic degradative plasmid from Burkholderia (Pseudomonas) cepacia G4.

    PubMed Central

    Shields, M S; Reagin, M J; Gerger, R R; Campbell, R; Somerville, C

    1995-01-01

    Burkholderia (Pseudomonas) cepacia PR1(23) has been shown to constitutively express to toluene catabolic pathway distinguished by a unique toluene ortho-monooxygenase (Tom). This strain has also been shown to contain two extrachromosomal elements of < 70 and > 100 kb. A derivative strain cured of the largest plasmid, PR1(23) Cure, was unable to grow on phenol or toluene as the sole source of carbon and energy, which requires expression of the Tom pathway. Transfer of the larger plasmid from strain G4 (the parent strain inducible for Tom) enabled PR1(23) Cure to grow on toluene or phenol via inducible Tom pathway expression. Conjugal transfer of TOM23c from PR1(23) to an antibiotic-resistant derivative of PR1(23) Cure enabled the transconjugant to grow with either phenol or toluene as the sole source of carbon and energy through constitutive expression of the Tom pathway. A cloned 11.2-kb EcoRI restriction fragment of TOM23c resulted in the expression of both Tom and catechol 2,3-dioxygenase in Escherichia coli, as evidenced by its ability to oxidize trichloroethylene, toluene, m-cresol, o-cresol, phenol, and catechol. The largest resident plasmid of PR1 was identified as the source of these genes by DNA hybridization. These results indicate that the genes which encode Tom and catechol 2,3-dioxygenase are located on TOM, an approximately 108-kb degradative plasmid of B. cepacia G4. PMID:7538275

  1. Key Role for Efflux in the Preservative Susceptibility and Adaptive Resistance of Burkholderia cepacia Complex Bacteria

    PubMed Central

    Rushton, Laura; Sass, Andrea; Baldwin, Adam; Dowson, Christopher G.; Donoghue, Denise

    2013-01-01

    Bacteria from the Burkholderia cepacia complex (Bcc) are encountered as industrial contaminants, and little is known about the species involved or their mechanisms of preservative resistance. Multilocus sequence typing (MLST) revealed that multiple Bcc species may cause contamination, with B. lata (n = 17) and B. cenocepacia (n = 11) dominant within the collection examined. At the strain level, 11 of the 31 industrial sequence types identified had also been recovered from either natural environments or clinical infections. Minimal inhibitory (MIC) and minimum bactericidal (MBC) preservative concentrations varied across 83 selected Bcc strains, with industrial strains demonstrating increased tolerance for dimethylol dimethyl hydantoin (DMDMH). Benzisothiazolinone (BIT), DMDMH, methylisothiazolinone (MIT), a blend of 3:1 methylisothiazolinone-chloromethylisothiazolinone (M-CMIT), methyl paraben (MP), and phenoxyethanol (PH), were all effective anti-Bcc preservatives; benzethonium chloride (BC) and sodium benzoate (SB) were least effective. Since B. lata was the dominant industrial Bcc species, the type strain, 383T (LMG 22485T), was used to study preservative tolerance. Strain 383 developed stable preservative tolerance for M-CMIT, MIT, BIT, and BC, which resulted in preservative cross-resistance and altered antibiotic susceptibility, motility, and biofilm formation. Transcriptomic analysis of the B. lata 383 M-CMIT-adapted strain demonstrated that efflux played a key role in its M-CMIT tolerance and elevated fluoroquinolone resistance. The role of efflux was corroborated using the inhibitor l-Phe-Arg-?-napthylamide, which reduced the MICs of M-CMIT and ciprofloxacin. In summary, intrinsic preservative tolerance and stable adaptive changes, such as enhanced efflux, play a role in the ability of Bcc bacteria to cause industrial contamination. PMID:23587949

  2. Key role for efflux in the preservative susceptibility and adaptive resistance of Burkholderia cepacia complex bacteria.

    PubMed

    Rushton, Laura; Sass, Andrea; Baldwin, Adam; Dowson, Christopher G; Donoghue, Denise; Mahenthiralingam, Eshwar

    2013-07-01

    Bacteria from the Burkholderia cepacia complex (Bcc) are encountered as industrial contaminants, and little is known about the species involved or their mechanisms of preservative resistance. Multilocus sequence typing (MLST) revealed that multiple Bcc species may cause contamination, with B. lata (n = 17) and B. cenocepacia (n = 11) dominant within the collection examined. At the strain level, 11 of the 31 industrial sequence types identified had also been recovered from either natural environments or clinical infections. Minimal inhibitory (MIC) and minimum bactericidal (MBC) preservative concentrations varied across 83 selected Bcc strains, with industrial strains demonstrating increased tolerance for dimethylol dimethyl hydantoin (DMDMH). Benzisothiazolinone (BIT), DMDMH, methylisothiazolinone (MIT), a blend of 3:1 methylisothiazolinone-chloromethylisothiazolinone (M-CMIT), methyl paraben (MP), and phenoxyethanol (PH), were all effective anti-Bcc preservatives; benzethonium chloride (BC) and sodium benzoate (SB) were least effective. Since B. lata was the dominant industrial Bcc species, the type strain, 383(T) (LMG 22485(T)), was used to study preservative tolerance. Strain 383 developed stable preservative tolerance for M-CMIT, MIT, BIT, and BC, which resulted in preservative cross-resistance and altered antibiotic susceptibility, motility, and biofilm formation. Transcriptomic analysis of the B. lata 383 M-CMIT-adapted strain demonstrated that efflux played a key role in its M-CMIT tolerance and elevated fluoroquinolone resistance. The role of efflux was corroborated using the inhibitor l-Phe-Arg-?-napthylamide, which reduced the MICs of M-CMIT and ciprofloxacin. In summary, intrinsic preservative tolerance and stable adaptive changes, such as enhanced efflux, play a role in the ability of Bcc bacteria to cause industrial contamination. PMID:23587949

  3. Draft Genome Sequence of Burkholderia sp. Strain MP-1, a Methyl Parathion (MP)-Degrading Bacterium from MP-Contaminated Soil

    PubMed Central

    Liu, Xu-Yun; Luo, Xiao-Jing; Li, Chun-Xiu; Lai, Qi-Liang

    2014-01-01

    Burkholderia sp. strain MP-1 was isolated from pesticide-contaminated soil. Herein, we report the draft genome sequence of strain MP-1, which contains 168 contigs of 8,611,053 bp, with a G+C content of 62.55% and 7,631 protein-coding genes. PMID:24855293

  4. Gene expression changes linked to antimicrobial resistance, oxidative stress, iron depletion and retained motility are observed when Burkholderia cenocepacia grows in cystic fibrosis sputum

    Microsoft Academic Search

    Pavel Drevinek; Matthew T. G. Holden; Zhaoping Ge; Andrew M. Jones; Ian Ketchell; Ryan T. Gill; Eshwar Mahenthiralingam

    2008-01-01

    BACKGROUND: Bacteria from the Burkholderia cepacia complex (Bcc) are the only group of cystic fibrosis (CF) respiratory pathogens that may cause death by an invasive infection known as cepacia syndrome. Their large genome (> 7000 genes) and multiple pathways encoding the same putative functions make virulence factor identification difficult in these bacteria. METHODS: A novel microarray was designed to the

  5. Distribution of Genes Encoding Putative Transmissibility Factors among Epidemic and Nonepidemic Strains of Burkholderia cepacia from Cystic Fibrosis Patients in the United Kingdom

    Microsoft Academic Search

    FIONA E. CLODE; MARY E. KAUFMANN; HENRY MALNICK; TYRONE L. PITT

    2000-01-01

    In the last 15 years, Burkholderia cepacia has emerged as a significant pathogen in cystic fibrosis (CF) patients, mainly due to the severity of infection observed in a subset of patients and the fear of transmission of the organism to noncolonized patients. Although patients who deteriorate rapidly cannot be predicted by microbiological characteristics, three genetic markers have been described for

  6. Differentiation of Burkholderia Species by PCR-Restriction Fragment Length Polymorphism Analysis of the 16S rRNA Gene and Application to Cystic Fibrosis Isolates

    Microsoft Academic Search

    CHRISTINE SEGONDS; THIERRY HEULIN; NICOLE MARTY; GERARD CHABANON

    1999-01-01

    Burkholderia cepacia, which is an important pathogen in cystic fibrosis (CF) owing to the potential severity of the infections and the high transmissibility of some clones, has been recently shown to be a complex of five genomic groups, i.e., genomovars I, II (B. multivorans), III, and IV and B. vietnamiensis. B. gladioli is also in- volved, though rarely, in CF.

  7. Coping with Polychlorinated Biphenyl (PCB) Toxicity: Physiological and Genome-Wide Responses of Burkholderia xenovorans LB400 to PCB-Mediated Stress

    Microsoft Academic Search

    J. Jacob Parnell; Vincent Denef; Tamara Tsoi; Syed Hashsham; John Quensen; James M. Tiedje

    2006-01-01

    The biodegradation of polychlorinated biphenyls (PCBs) relies on the ability of aerobic microorganisms such as Burkholderia xenovorans sp. LB400 to tolerate two potential modes of toxicity presented by PCB degradation: passive toxicity, as hydrophobic PCBs potentially disrupt membrane and protein function, and degradation-dependent toxicity from intermediates of incomplete degradation. We monitored the physiological characteristics and genome- wide expression patterns of

  8. Colonization of Morus alba L. by the plant-growth-promoting and antagonistic bacterium Burkholderia cepacia strain Lu10-1

    Microsoft Academic Search

    Xianling Ji; Guobing Lu; Yingping Gai; Huijv Gao; Baoyun Lu; Lingrang Kong; Zhimei Mu

    2010-01-01

    BACKGROUND: Anthracnose, caused by Colletotrichum dematium, is a serious threat to the production and quality of mulberry leaves in susceptible varieties. Control of the disease has been a major problem in mulberry cultivation. Some strains of Burkholderia cepacia were reported to be useful antagonists of plant pests and could increase the yields of several crop plants. Although B. cepacia Lu10-1

  9. Intracellular bacteria find the right motion.

    PubMed

    Gouin, Edith; Torres, Juan-Jose Quereda; Cossart, Pascale

    2015-04-01

    Benanti et al. report that Burkholderia pseudomallei and Burkholderia mallei bacteria express proteins that mimic Ena/Vasp family proteins to polymerize actin, thereby inducing actin-based motility. Thus, bacteria can use the various cellular actin polymerization mechanisms for intra- and inter-cellular dissemination. PMID:25860603

  10. Distribution of Cepacian Biosynthesis Genes among Environmental and Clinical Burkholderia Strains and Role of Cepacian Exopolysaccharide in Resistance to Stress Conditions?

    PubMed Central

    Ferreira, Ana S.; Leitão, Jorge H.; Silva, Inês N.; Pinheiro, Pedro F.; Sousa, Sílvia A.; Ramos, Christian G.; Moreira, Leonilde M.

    2010-01-01

    The genus Burkholderia includes strains pathogenic to animals and plants, bioremediators, or plant growth promoters. Genome sequence analyses of representative Burkholderia cepacia complex (Bcc) and non-Bcc strains for the presence of the bce-I gene cluster, directing the biosynthesis of the exopolysaccharide (EPS) cepacian, further extended this previously described cluster by another 9 genes. The genes in the bce-II cluster were named bceM to bceU and encode products putatively involved in nucleotide sugar precursor biosynthesis and repeat unit assembly, modification, and translocation across the cytoplasmic membrane. Disruption of the B. cepacia IST408 bceQ and bceR genes, encoding a putative repeat unit flippase and a glycosyltransferase, respectively, resulted in the abolishment of cepacian biosynthesis. A mutation in the bceS gene, encoding a putative acyltransferase, did not affect EPS production yield significantly but decreased its acetylation content by approximately 20%. Quantitative real-time reverse transcription-PCR experiments confirmed the induction of genes in the bce-I and bce-II clusters in a Burkholderia multivorans EPS producer clinical isolate in comparison to the level for its isogenic EPS-defective strain. Fourier Transform infrared spectroscopy analysis confirmed that the exopolysaccharide produced by 10 Burkholderia isolates tested was cepacian. The ability of Burkholderia strains to withstand desiccation and metal ion stress was higher when bacteria were incubated in the presence of 2.5 g/liter of cepacian, suggesting that this EPS plays a role in the survival of these bacteria by contributing to their ability to thrive in different environments. PMID:19948863

  11. Mutational analysis and biochemical characterization of the Burkholderia thailandensis DW503 quorum-sensing network.

    PubMed

    Ulrich, Ricky L; Hines, Harry B; Parthasarathy, N; Jeddeloh, Jeffrey A

    2004-07-01

    Numerous gram-negative bacteria communicate and regulate gene expression through a cell density-responsive mechanism termed quorum sensing (QS), which involves the synthesis and perception of diffusible N-acyl-homoserine lactones (AHL). In this study we genetically and physiologically characterized the Burkholderia thailandensis DW503 QS network. In silico analysis of the B. thailandensis genome revealed the presence of at least three AHL synthases (AHS) and five transcriptional regulators belonging to the LuxIR family of proteins. Mass spectrometry demonstrated that wild-type B. thailandensis synthesizes N-hexanoyl-homoserine lactone (C6-HSL), N-octanoyl-homoserine lactone (C8-HSL), and N-decanoyl-homoserine lactone (C10-HSL). Mutation of the btaI1 (luxI) AHS gene prevented accumulation of C8-HSL in culture supernatants, enhanced beta-hemolysis of sheep erythrocytes, increased lipase production, and altered colony morphology on swarming and twitching motility plates. Disruption of the btaI3 (luxI) AHS prevented biosynthesis of C6-HSL and increased lipase production and beta-hemolysis, whereas mutagenesis of the btaI2 (luxI) allele eliminated C10-HSL accumulation and reduced lipase production. Complementation of the btaI1 and btaI3 mutants fully restored the synthesis of C8-HSL and C6-HSL to parental levels. In contrast, mutagenesis of the btaR1, btaR3, btaR4, and btaR5 (luxR) transcriptional regulators had no effect on AHL accumulation, enhanced lipase production, and resulted in extensive beta-hemolysis on sheep blood agar plates. Furthermore, interruption of the btaI1, btaR1, and btaR3 genes altered colony morphology on twitching and swarming motility plates and induced pigmentation. Additionally, phenotypic microarray analysis indicated that QS in B. thailandensis both positively and negatively affects the metabolism of numerous substrates, including citric acid, formic acid, glucose 6-phosphate, capric acid, gamma-hydroxybutyric acid, and d-arabinose. These results demonstrate that mutagenesis of the B. thailandensis QS system affects various cellular processes, including lipase production, swarming and twitching motility, beta-hemolysis of sheep erythrocytes, and carbon metabolism and/or transport. PMID:15205437

  12. Cable Pili and the Associated 22 Kda Adhesin Contribute to Burkholderia Cenocepacia Persistence In Vivo

    PubMed Central

    Goldberg, Joanna B.; Ganesan, Shyamala; Comstock, Adam T.; Zhao, Ying; Sajjan, Uma S.

    2011-01-01

    Background Infection by Burkholderia cenocepacia in cystic fibrosis (CF) patients is associated with poor clinical prognosis. Previously, we demonstrated that one of the highly transmissible strains, BC7, expresses cable pili and the associated 22 kDa adhesin, both of which contribute to BC7 binding to airway epithelial cells. However, the contribution of these factors to induce inflammation and bacterial persistence in vivo is not known. Methodology/Principal Findings Wild-type BC7 stimulated higher IL-8 responses than the BC7 cbl and BC7 adhA mutants in both CF and normal bronchial epithelial cells. To determine the role of cable pili and the associated adhesin, we characterized a mouse model of B. cenocepacia, where BC7 are suspended in Pseudomonas aeruginosa alginate. C57BL/6 mice were infected intratracheally with wild-type BC7 suspended in either alginate or PBS and were monitored for lung bacterial load and inflammation. Mice infected with BC7 suspended in PBS completely cleared the bacteria by 3 days and resolved the inflammation. In contrast, mice infected with BC7 suspended in alginate showed persistence of bacteria and moderate lung inflammation up to 5 days post-infection. Using this model, mice infected with the BC7 cbl and BC7 adhA mutants showed lower bacterial loads and mild inflammation compared to mice infected with wild-type BC7. Complementation of the BC7 cblS mutation in trans restored the capacity of this strain to persist in vivo. Immunolocalization of bacteria revealed wild-type BC7 in both airway lumen and alveoli, while the BC7 cbl and BC7 adhA mutants were found mainly in airway lumen and peribronchiolar region. Conclusions and Significance B. cenocepacia suspended in alginate can be used to determine the capacity of bacteria to persist and cause lung inflammation in normal mice. Both cable pili and adhesin contribute to BC7-stimulated IL-8 response in vitro, and BC7 persistence and resultant inflammation in vivo. PMID:21811611

  13. Speciation of Pb(II) Sorbed by Burkholderia Cepacia/Goethite Composites

    SciTech Connect

    Templeton, Alexis S.; Spormann, Alfred M.; Brown, Gordon E.

    2003-04-08

    Bacterial-mineral composites are important in the retention of heavy metals such as Pb due to their large sorption capacity under a wide range of environmental conditions. However, the partitioning of heavy metals between components in such composites is not probed directly. Using Burkholderia cepaciabiofilms coated with goethite (RFeOOH) particles, the partitioning of Pb(II) between the biological and iron-(oxyhydr)oxide surfaces has been measured using an X-ray spectroscopic approach. EXAFS spectra were fit to quantitatively determine the fraction of Pb(II) associated with each component as a function of pH and [Pb]. At pH <5.5, at least 50% of the total sorbed Pb(II) is associated with the biofilm component, whereas the total uptake within the composite is dominated by goethite (>70% Pb/goethite) above pH 6. Direct comparison can be made between the amount of Pb(II) bound to each component in the composite vs separate binary systems (i.e., Pb/biofilm or Pb/goethite). At high pH, Pb(II) uptake on the biofilm is dramatically decreased due to competition with the goethite surface. In contrast, Pb uptake on goethite is significantly enhanced at low pH (2-fold increase at pH 5) compared to systems with no complexing ligands. The mode of Pb(II)-binding to the goethite component changes from low to high [Pb]. Structural fitting of the EXAFS spectra collected from 10-5.6 to 10-3.6 M [Pb]eq at pH 6 shows that the Pb-goethite surface complexes at low [Pb] are dominated by inner-sphere bidentate, binuclear complexes bridging two adjacent singly coordinated surface oxygens, giving rise to Pb-Fe distances of 3.9 ? At high [Pb], the dominant Pb(II) inner-sphere complexes on the goethite surface shift to bidentate edge-sharing complexes with Pb-Fe distances of 3.3 ?

  14. Selenium speciation and partitioning within Burkholderia cepacia biofilms formed on ?-Al 2O 3 surfaces

    NASA Astrophysics Data System (ADS)

    Templeton, Alexis S.; Trainor, Thomas P.; Spormann, Alfred M.; Brown, Gordon E.

    2003-10-01

    The distribution and speciation of Se within aerobic Burkholderia cepacia biofilms formed on ?-Al 2O 3 (1-102) surfaces have been examined using grazing-angle X-ray spectroscopic techniques. We present quantitative information on the partitioning of 10 -6 M to 10 -3 M selenate and selenite between the biofilms and underlying alumina surfaces derived from long-period X-ray standing wave (XSW) data. Changes in the Se partitioning behavior over time are correlated with microbially induced reduction of Se(VI) and Se(IV) to Se(0), as observed from X-ray absorption near edge structure (XANES) spectroscopy. Selenite preferentially binds to the alumina surfaces, particularly at low [Se], and is increasingly partitioned into the biofilms at higher [Se]. When B. cepacia is metabolically active, B. cepacia rapidly reduces a fraction of the SeO 32- to red elemental Se(0). In contrast, selenate is preferentially partitioned into the B. cepacia biofilms at all [Se] tested due to a lower affinity for binding to the alumina surface. Rapid reduction of SeO 42- by B. cepacia to Se(IV) and Se(0) subsequently results in a vertical segregation of Se species at the B. cepacia/?-Al 2O 3 interface. Elemental Se(0) accumulates within the biofilm with Se(VI), whereas Se(IV) intermediates preferentially sorb to the alumina surface. B. cepacia/?-Al 2O 3 samples incubated with SeO 42- and SeO 32- when the bacteria were metabolically active result in a significant reduction in the mobility of Se vs. X-ray treated biofilms. Remobilization experiments show that a large fraction of the insoluble Se(0) produced within the biofilm is retained during exchange with Se-free solutions. In addition, Se(IV) intermediates generated during Se(VI) reduction are preferentially bound to the alumina surface and do not fully desorb. In contrast, Se(VI) is rapidly and extensively remobilized.

  15. The new group of non-pathogenic plant-associated nitrogen-fixing Burkholderia spp. shares a conserved quorum-sensing system, which is tightly regulated by the RsaL repressor

    Microsoft Academic Search

    Z. R. Suarez-Moreno; J. Caballero-Mellado; V. Venturi

    2008-01-01

    A novel group of nitrogen-fixing plant-associated Burkholderia species has emerged in the last few years. The purpose of this investigation was to determine if these species possess an N- acylhomoserine lactone (AHL) quorum-sensing (QS) cell-cell signalling system, and whether it is important for nitrogen fixation and other phenotypic features in Burkholderia kururiensis. It was determined that B. kururiensis, and other

  16. Production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) by Burkholderia sacchari using wheat straw hydrolysates and gamma-butyrolactone.

    PubMed

    Cesário, M Teresa; Raposo, Rodrigo S; M D de Almeida, M Catarina; van Keulen, Frederik; Ferreira, Bruno S; Telo, João P; R da Fonseca, M Manuela

    2014-11-01

    Burkholderia sacchari DSM 17165 is able to grow and produce poly(3-hydroxybutyrate) both on hexoses and pentoses. In a previous study, wheat straw lignocellulosic hydrolysates (WSH) containing high C6 and C5 sugar concentrations were shown to be excellent carbon sources for P(3HB) production. Using a similar feeding strategy developed for P(3HB) production based on WSH, fed-batch cultures were developed aiming at the production of the copolymer P(3HB-co-4HB) (poly(3-hydroxybutyrate-co-4-hydroxybutyrate)) by B. sacchari. The ability of this strain to synthesize P(3HB-co-4HB) was first shown in shake flasks using gamma-butyrolactone (GBL) as precursor of the 4HB units. Fed-batch cultures using glucose as carbon source (control) and GBL were developed to achieve high copolymer productivities and 4HB incorporations. The attained P(3HB-co-4HB) productivity and 4HB molar% were 0.7g/(Lh) and 4.7molar%, respectively. The 4HB incorporation was improved to 6.3 and 11.8molar% by addition of 2g/L propionic and acetic acid, respectively. When WSH were used as carbon source under the same feeding conditions, the values achieved were 0.5g/(Lh) and 5.0molar%, respectively. Burkholderia sacchari, a strain able to produce biopolymers based on xylose-rich lignocellulosic hydrolysates, is for the first time reported to produce P(3HB-co-4HB) using gamma butyrolactone as precursor. PMID:24811901

  17. Biogenic magnetic nanoparticles from Burkholderia sp. YN01 exhibiting intrinsic peroxidase-like activity and their applications.

    PubMed

    Pan, Yu; Li, Na; Mu, Jianshuai; Zhou, Runhong; Xu, Yan; Cui, Daizong; Wang, Yan; Zhao, Min

    2015-01-01

    A novel bacterial strain containing biogenic magnetic nanoparticles (BMNPs) was isolated from the sediments of Songhua River in Harbin, China, and was identified as Burkholderia sp. YN01. Extracted BMNPs from YN01 were characterized as pure face-centered cubic Fe3O4 with an average size of 80 nm through transmission electron microscope (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The hysteresis parameters of the BMNP samples such as Bc and Bcr and ratios Mrs/Ms were deduced as 35.6 mT, 43.2 mT, and 0.47, respectively, indicating that the BMNPs exhibit a ferromagnetic behavior. This is the first report concerning on biogenic Fe3O4 NPs produced in Burkholderia genus. Significantly, the BMNPs were proved to possess intrinsic peroxidase-like activity that could catalyze the oxidation of peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2. Kinetic analysis indicates that the catalytic behavior is in accord with typical Michaelis-Menten kinetics and follows ping-pong mechanism. The catalytic constants (K cat) were 6.5?×?10(4) s(-1) and 0.78?×?10(4) s(-1) with H2O2 and TMB as substrate, respectively, which was higher than that of horseradish peroxidase (HRP). Electron spin resonance (ESR) spectroscopy experiments showed that the BMNPs could catalyze H2O2 to produce hydroxyl radicals. The origin of peroxidase-like activity is also associated with their ability to transfer electron between electrode and H2O2 according to an electrochemical study. As a novel peroxidase mimetic, the BMNPs were employed to offer a simple, sensitive, and selective colorimetric method for H2O2 and glucose determination, and the BMNPs could efficiently catalyze the degradation of phenol and Congo red dye. PMID:25030455

  18. Effects of the inoculation of Burkholderia vietnamensis and related endophytic diazotrophic bacteria on grain yield of rice.

    PubMed

    Govindarajan, Munusamy; Balandreau, Jacques; Kwon, Soon-Wo; Weon, Hang-Yeon; Lakshminarasimhan, Cunthipuram

    2008-01-01

    During a survey of endophytic diazotrophic bacteria associated with different rice varieties in Tamilnadu, some "endophytes" were obtained. Thirteen bacterial isolates from surface-sterilized roots and shoots were obtained in pure culture, which produced indole acetic acid (IAA) and reduced acetylene to ethylene. Polymerase chain reaction (PCR) amplification confirmed the presence of nif-H gene in all the isolates. Morphological, biochemical, and molecular characteristics indicated that all of them belonged to the genus Burkholderia One of them, MGK3, was consistently more active in reducing acetylene, and 16S rDNA sequences of isolate MGK3 confirmed its identification as Burkholderia vietnamiensis. Colonization of rice root was confirmed by strain MGK3 marked with gusA gene. The inoculated roots showed a blue color, which was most intense at the points of lateral root emergence and at the root tip. Transverse sections of roots, 15 days after inoculation, revealed beta-glucuronidase (GUS) activity within many of the cortical intercellular spaces next to the stele and within the aerenchyma. Nitrogen fixation was quantified by using (15)N isotope dilution method with two different cultivars grown in pot and field experiments. Higher nitrogen fixation was observed in variety Ponni than in ADT-43, where nearly 42% (field) and 40% (pot) of the nitrogen was derived from the atmosphere (% Ndfa). Isolate MGK3 was used to inoculate rice seedlings in a comparison with four other diazotrophs, viz., Gluconacetobacter diazotrophicus LMG7603, Herbaspirillum seropedicae LMG6513, Azospirillum lipoferum 4B LMG4348, and B. vietnamiensis LMG10929. They were used to conduct two pot and four field inoculation experiments. MGK3 alone, and combined with other diazotrophs, performed best under both pot and field conditions: combined inoculation produced yield increases between 9.5 and 23.6%, while MGK3 alone increased yield by 5.6 to 12.16% over the uninoculated control treatment. PMID:17406771

  19. Endophytic colonization of Vitis vinifera L. by plant growth-promoting bacterium Burkholderia sp. strain PsJN.

    PubMed

    Compant, Stéphane; Reiter, Birgit; Sessitsch, Angela; Nowak, Jerzy; Clément, Christophe; Ait Barka, Essaïd

    2005-04-01

    Patterns of colonization of Vitis vinifera L. cv. Chardonnay plantlets by a plant growth-promoting bacterium, Burkholderia sp. strain PsJN, were studied under gnotobiotic conditions. Wild-type strain PsJN and genetically engineered derivatives of this strain tagged with gfp (PsJN::gfp2x) or gusA (PsJN::gusA11) genes were used to enumerate and visualize tissue colonization. The rhizospheres of 4- to 5-week-old plantlets with five developed leaves were inoculated with bacterial suspensions. Epiphytic and endophytic colonization patterns were then monitored by dilution plating assays and microscopic observation of organ sections. Bacteria were chronologically detected first on root surfaces, then in root internal tissues, and finally in the fifth internode and the tissues of the fifth leaf. Analysis of the PsJN colonization patterns showed that this strain colonizes grapevine root surfaces, as well as cell walls and the whole surface of some rhizodermal cells. Cells were also abundant at lateral root emergence sites and root tips. Furthermore, cell wall-degrading endoglucanase and endopolygalacturonase secreted by PsJN explained how the bacterium gains entry into root internal tissues. Host defense reactions were observed in the exodermis and in several cortical cell layers. Bacteria were not observed on stem and leaf surfaces but were found in xylem vessels of the fifth internode and the fifth leaf of plantlets. Moreover, bacteria were more abundant in the fifth leaf than in the fifth internode and were found in substomatal chambers. Thus, it seems that Burkholderia sp. strain PsJN induces a local host defense reaction and systemically spreads to aerial parts through the transpiration stream. PMID:15811990

  20. Biofilm-grown Burkholderia cepacia complex cells survive antibiotic treatment by avoiding production of reactive oxygen species.

    PubMed

    Van Acker, Heleen; Sass, Andrea; Bazzini, Silvia; De Roy, Karen; Udine, Claudia; Messiaen, Thomas; Riccardi, Giovanna; Boon, Nico; Nelis, Hans J; Mahenthiralingam, Eshwar; Coenye, Tom

    2013-01-01

    The presence of persister cells has been proposed as a factor in biofilm resilience. In the present study we investigated whether persister cells are present in Burkholderia cepacia complex (Bcc) biofilms, what the molecular basis of antimicrobial tolerance in Bcc persisters is, and how persisters can be eradicated from Bcc biofilms. After treatment of Bcc biofilms with high concentrations of various antibiotics often a small subpopulation survived. To investigate the molecular mechanism of tolerance in this subpopulation, Burkholderia cenocepacia biofilms were treated with 1024 µg/ml of tobramycin. Using ROS-specific staining and flow cytometry, we showed that tobramycin increased ROS production in treated sessile cells. However, approximately 0.1% of all sessile cells survived the treatment. A transcriptome analysis showed that several genes from the tricarboxylic acid cycle and genes involved in the electron transport chain were downregulated. In contrast, genes from the glyoxylate shunt were upregulated. These data indicate that protection against ROS is important for the survival of persisters. To confirm this, we determined the number of persisters in biofilms formed by catalase mutants. The persister fraction in ?katA and ?katB biofilms was significantly reduced, confirming the role of ROS detoxification in persister survival. Pretreatment of B. cenocepacia biofilms with itaconate, an inhibitor of isocitrate lyase (ICL), the first enzyme in the glyoxylate shunt, reduced the persister fraction approx. 10-fold when the biofilms were subsequently treated with tobramycin. In conclusion, most Bcc biofilms contain a significant fraction of persisters that survive treatment with high doses of tobramycin. The surviving persister cells downregulate the TCA cycle to avoid production of ROS and at the same time activate an alternative pathway, the glyoxylate shunt. This pathway may present a novel target for combination therapy. PMID:23516582

  1. Culture-Based and Non-Growth-Dependent Detection of the Burkholderia cepacia Complex in Soil Environments

    PubMed Central

    Miller, Suzanne C. M.; LiPuma, John J.; Parke, Jennifer L.

    2002-01-01

    Burkholderia cepacia complex (Bcc) bacteria reside in soil, plant rhizospheres, and water, but their prevalence and distribution in outdoor environments is not clear. We sampled a variety of soil and rhizosphere environments with which people may have contact: playgrounds, athletic fields, parks, hiking trails, residential yards, and gardens. A total of 91 sites was sampled in three large U.S. cities. In the first phase of the study, putative Bcc isolates were recovered on Burkholderia cepacia selective agar and trypan blue tetracycline medium and subsequently examined for biochemical reactivity and growth at 32 and 22°C. Isolates were further examined by PCR assays targeting Bcc-specific ribosomal DNA and recA gene sequences. Among the 1,013 bacterial isolates examined, 68 were identified as Bcc; 14 (15%) of 91 sampled sites yielded Bcc isolates. In the second phase, DNA was extracted directly from soil samples and examined with PCR assays targeting Bcc 16S rRNA gene sequences. Either 82 or 93% of the soil samples were positive for at least one Bcc genomovar, depending on the PCR assay system used. Cloning and sequencing were performed to check the specificity of the PCR assays. Sequence analysis of the 463-bp 16S rRNA inserts from eight clones indicated that all were from members of the Bcc. The four soil samples from which these clones were generated did not yield isolates identified as Bcc. Based on PCR detection, Bcc appears to be prevalent in soil from urban and suburban environments. Culture-based recovery of Bcc may underestimate environmental populations. PMID:12147469

  2. Regulation of Hfq mRNA and Protein Levels in Escherichia coli and Pseudomonas aeruginosa by the Burkholderia cenocepacia MtvR sRNA

    PubMed Central

    Ramos, Christian G.; Grilo, André M.; Sousa, Sílvia A.; Feliciano, Joana R.; da Costa, Paulo J. P.; Leitão, Jorge H.

    2014-01-01

    Small non-coding RNAs (sRNAs) are important players of gene expression regulation in bacterial pathogens. MtvR is a 136-nucleotide long sRNA previously identified in the human pathogen Burkholderia cenocepacia J2315 and with homologues restricted to bacteria of the Burkholderia cepacia complex. In this work we have investigated the effects of expressing MtvR in Escherichia coli and Pseudomonas aeruginosa. Results are presented showing that MtvR negatively regulates the hfq mRNA levels in both bacterial species. In the case of E. coli, this negative regulation is shown to involve binding of MtvR to the 5?-UTR region of the hfqEc mRNA. Results presented also show that expression of MtvR in E. coli and P. aeruginosa originates multiple phenotypes, including reduced resistance to selected stresses, biofilm formation ability, and increased susceptibility to various antibiotics. PMID:24901988

  3. Insecticide-degrading Burkholderia symbionts of the stinkbug naturally occupy various environments of sugarcane fields in a Southeast island of Japan.

    PubMed

    Tago, Kanako; Okubo, Takashi; Itoh, Hideomi; Kikuchi, Yoshitomo; Hori, Tomoyuki; Sato, Yuya; Nagayama, Atsushi; Hayashi, Kentaro; Ikeda, Seishi; Hayatsu, Masahito

    2015-01-01

    The stinkbug Cavelerius saccharivorus, which harbors Burkholderia species capable of degrading the organophosphorus insecticide, fenitrothion, has been identified on a Japanese island in farmers' sugarcane fields that have been exposed to fenitrothion. A clearer understanding of the ecology of the symbiotic fenitrothion degraders of Burkholderia species in a free-living environment is vital for advancing our knowledge on the establishment of degrader-stinkbug symbiosis. In the present study, we analyzed the composition and abundance of degraders in sugarcane fields on the island. Degraders were recovered from field samples without an enrichment culture procedure. Degrader densities in the furrow soil in fields varied due to differences in insecticide treatment histories. Over 99% of the 659 isolated degraders belonged to the genus Burkholderia. The strains related to the stinkbug symbiotic group predominated among the degraders, indicating a selection for this group in response to fenitrothion. Degraders were also isolated from sugarcane stems, leaves, and rhizosphere in fields that were continuously exposed to fenitrothion. Their density was lower in the plant sections than in the rhizosphere. A phylogenetic analysis of 16S rRNA gene sequences demonstrated that most of the degraders from the plants and rhizosphere clustered with the stinkbug symbiotic group, and some were identical to the midgut symbionts of C. saccharivorus collected from the same field. Our results confirmed that plants and the rhizosphere constituted environmental reservoirs for stinkbug symbiotic degraders. To the best of our knowledge, this is the first study to investigate the composition and abundance of the symbiotic fenitrothion degraders of Burkholderia species in farmers' fields. PMID:25736865

  4. Evaluation of shelf life and rock phosphate solubilization of Burkholderia sp. in nutrient-amended clay, rice bran and rock phosphate-based granular formulation

    Microsoft Academic Search

    R. Anandham; Kwan Ho Choi; P. Indira Gandhi; Woo Jong Yim; Soo Jae Park; Kyoung A Kim; M. Madhaiyan; Tong Min Sa

    2007-01-01

    Five phosphate-solubilizing bacteria (PSB) used in this study were isolated based on their ability to solubilize tricalcium\\u000a phosphate (TCP) in Pikovskaya’s medium. Among the tested bacterial strains Burkholderia sp. strain CBPB-HIM showed the highest solubilization (363 ?g of soluble P ml?1) activity at 48 h of incubation. Further, this strain has been selected to assess its shelf life in nutrient-amended and\\u000a -unamended clay,

  5. Synergistic Activities of Macrolide Antibiotics against Pseudomonas aeruginosa, Burkholderia cepacia, Stenotrophomonas maltophilia, and Alcaligenes xylosoxidans Isolated from Patients with Cystic Fibrosis

    Microsoft Academic Search

    Lisa Saiman; Yunhua Chen; Pablo San Gabriel; Charles Knirsch

    2002-01-01

    Azithromycin and clarithromycin were paired with other antibiotics to test synergistic activity against 300 multidrug-resistant pathogens isolated from cystic fibrosis (CF) patients. Clarithromycin-tobramycin was most active against Pseudomonas aeruginosa and inhibited 58% of strains. Azithromycin-trimethoprim-sulfa- methoxazole, azithromycin-ceftazidime, and azithromycin-doxycycline or azithromycin-trimethoprim-sulfame- thoxazole inhibited 40, 20, and 22% of Stenotrophomonas maltophilia, Burkholderia cepacia complex, and Ach- romobacter (Alcaligenes) xylosoxidans strains, respectively.

  6. Cell-free culture medium of Burkholderia cepacia improves seed germination and seedling growth in maize ( Zea mays ) and rice ( Oryza sativa )

    Microsoft Academic Search

    Annia Hernández-Rodríguez; Mayra Heydrich-Pérez; Billo Diallo; Mondher El Jaziri; Olivier M. Vandeputte

    2010-01-01

    The saprophytic bacterium Burkholderia\\u000a cepacia has been shown to play an active role as plant growth promoting bacteria (PGPB). In this study, the ability of cell-free\\u000a culture medium (CFCM) of B. cepacia to improve early developmental stages of plants has been assessed on two agronomically important crops, maize (Zea\\u000a mays) and rice (Oryza\\u000a sativa). Treating maize and rice seeds for

  7. Insecticide-Degrading Burkholderia Symbionts of the Stinkbug Naturally Occupy Various Environments of Sugarcane Fields in a Southeast Island of Japan

    PubMed Central

    Tago, Kanako; Okubo, Takashi; Itoh, Hideomi; Kikuchi, Yoshitomo; Hori, Tomoyuki; Sato, Yuya; Nagayama, Atsushi; Hayashi, Kentaro; Ikeda, Seishi; Hayatsu, Masahito

    2015-01-01

    The stinkbug Cavelerius saccharivorus, which harbors Burkholderia species capable of degrading the organophosphorus insecticide, fenitrothion, has been identified on a Japanese island in farmers’ sugarcane fields that have been exposed to fenitrothion. A clearer understanding of the ecology of the symbiotic fenitrothion degraders of Burkholderia species in a free-living environment is vital for advancing our knowledge on the establishment of degrader-stinkbug symbiosis. In the present study, we analyzed the composition and abundance of degraders in sugarcane fields on the island. Degraders were recovered from field samples without an enrichment culture procedure. Degrader densities in the furrow soil in fields varied due to differences in insecticide treatment histories. Over 99% of the 659 isolated degraders belonged to the genus Burkholderia. The strains related to the stinkbug symbiotic group predominated among the degraders, indicating a selection for this group in response to fenitrothion. Degraders were also isolated from sugarcane stems, leaves, and rhizosphere in fields that were continuously exposed to fenitrothion. Their density was lower in the plant sections than in the rhizosphere. A phylogenetic analysis of 16S rRNA gene sequences demonstrated that most of the degraders from the plants and rhizosphere clustered with the stinkbug symbiotic group, and some were identical to the midgut symbionts of C. saccharivorus collected from the same field. Our results confirmed that plants and the rhizosphere constituted environmental reservoirs for stinkbug symbiotic degraders. To the best of our knowledge, this is the first study to investigate the composition and abundance of the symbiotic fenitrothion degraders of Burkholderia species in farmers’ fields. PMID:25736865

  8. Inoculation of Burkholderia cepacia, Pseudomonas fluorescens and Enterobacter sp. on Sorghum bicolor: Root colonization and plant growth promotion of dual strain inocula

    Microsoft Academic Search

    Luigi Chiarini; Annamaria Bevivino; Silvia Tabacchioni; Claudia Dalmastri

    1998-01-01

    Burkholderia cepacia strain PHP7 was tested for its ability to colonize roots and to promote the growth of Sorghum bicolor alone or in combination with Enterobacter sp. strain BB23T4d or Pseudomonas fluorescnes strain A23T3c. All three strains were able to colonize the root system of sorghum but only B. cepacia and P. fluorescens promoted plant growth in single strain inoculation

  9. Role of Ornibactin Biosynthesis in the Virulence of Burkholderia cepacia: Characterization of pvdA, the Gene Encoding L-Ornithine N5Oxygenase

    Microsoft Academic Search

    P. A. SOKOL; P. DARLING; D. E. WOODS; E. MAHENTHIRALINGAM; C. Koom

    1999-01-01

    Burkholderia cepacia is a frequent cause of respiratory infections in cystic fibrosis patients. B. cepacia has been shown to produce at least four siderophores which may play a role in the virulence of this organism. To characterize genes involved in the synthesis of siderophores, Tn5-OT182 mutants were isolated in strain K56-2, which produces two siderophores, salicylic acid (SA) and ornibactins.

  10. Species-Specific Oligonucleotides for Enumeration of Pseudomonas putida F1, Burkholderia sp. Strain JS150, and Bacillus subtilis ATCC 7003 in Biodegradation Experiments

    Microsoft Academic Search

    NANCY M. DUTEAU; JULIA D. ROGERS; CHRISTIAN T. BARTHOLOMAY; KENNETH F. REARDON

    1998-01-01

    Species-specific sequences were identified within the V4 variable region of 16S rRNA of two bacterial species capable of aromatic hydrocarbon metabolism, Pseudomonas putida F1 and Burkholderia sp. strain JS150, and a third, Bacillus subtilis ATCC 7003, that can function as a secondary degrader. Fluorescent in situ hybridi- zation (FISH) with species-specific oligonucleotides was used for direct counting of these species

  11. Stereoselective lipases from Burkholderia sp., cloning and their application to preparation of methyl ( R)- N-(2,6-dimethylphenyl)alaninate, a key intermediate for ( R)-Metalaxyl

    Microsoft Academic Search

    Oh-Jin Park; Sang-Hyun Lee

    2005-01-01

    Two microbial strains (referred to as MC 16-3 and 99-2-1) that produce extracellular lipases were isolated from soil samples and identified as Burkholderia species. The lipases were partially purified by isopropyl alcohol precipitation and gave molecular weight of 33kDa. The lipases were characterized in terms of stereoselectivity with racemic methoxyethyl (R,S)-N-(2,6-dimethylphenyl)alaninate and the genes encoding the proteins have been identified

  12. Architecture of Burkholderia cepacia complex ?70 gene family: evidence of alternative primary and clade-specific factors, and genomic instability

    PubMed Central

    Menard, Aymeric; de los Santos, Paulina Estrada; Graindorge, Arnault; Cournoyer, Benoit

    2007-01-01

    Background The Burkholderia cepacia complex (Bcc) groups bacterial species with beneficial properties that can improve crop yields or remediate polluted sites but can also lead to dramatic human clinical outcomes among cystic fibrosis (CF) or immuno-compromised individuals. Genome-wide regulatory processes of gene expression could explain parts of this bacterial duality. Transcriptional ?70 factors are components of these processes. They allow the reversible binding of the DNA-dependent RNA polymerase to form the holoenzyme that will lead to mRNA synthesis from a DNA promoter region. Bcc genome-wide analyses were performed to investigate the major evolutionary trends taking place in the ?70 family of these bacteria. Results Twenty ?70 paralogous genes were detected in the Burkholderia cenocepacia strain J2315 (Bcen-J2315) genome, of which 14 were of the ECF (extracytoplasmic function) group. Non-ECF paralogs were related to primary (rpoD), alternative primary, stationary phase (rpoS), flagellin biosynthesis (fliA), and heat shock (rpoH) factors. The number of ?70 genetic determinants among this genome was of 2,86 per Mb. This number is lower than the one of Pseudomonas aeruginosa, a species found in similar habitats including CF lungs. These two bacterial groups showed strikingly different ?70 family architectures, with only three ECF paralogs in common (fecI-like, pvdS and algU). Bcen-J2315 ?70 paralogs showed clade-specific distributions. Some paralogs appeared limited to the ET12 epidemic clone (ecfA2), particular Bcc species (sigI), the Burkholderia genus (ecfJ, ecfF, and sigJ), certain proteobacterial groups (ecfA1, ecfC, ecfD, ecfE, ecfG, ecfL, ecfM and rpoS), or were broadly distributed in the eubacteria (ecfI, ecfK, ecfH, ecfB, and rpoD-, rpoH-, fliA-like genes). Genomic instability of this gene family was driven by chromosomal inversion (ecfA2), recent duplication events (ecfA and RpoD), localized (ecfG) and large scale deletions (sigI, sigJ, ecfC, ecfH, and ecfK), and a phage integration event (ecfE). Conclusion The Bcc ?70 gene family was found to be under strong selective pressures that could lead to acquisition/deletion, and duplication events modifying its architecture. Comparative analysis of Bcc and Pseudomonas aeruginosa ?70 gene families revealed distinct evolutionary strategies, with the Bcc having selected several alternative primary factors, something not recorded among P. aeruginosa and only previously reported to occur among the actinobacteria. PMID:17784948

  13. The Burkholderia bcpAIOB Genes Define Unique Classes of Two-Partner Secretion and Contact Dependent Growth Inhibition Systems

    PubMed Central

    Anderson, Melissa S.; Garcia, Erin C.; Cotter, Peggy A.

    2012-01-01

    Microbes have evolved many strategies to adapt to changes in environmental conditions and population structures, including cooperation and competition. One apparently competitive mechanism is contact dependent growth inhibition (CDI). Identified in Escherichia coli, CDI is mediated by Two–Partner Secretion (TPS) pathway proteins, CdiA and CdiB. Upon cell contact, the toxic C-terminus of the TpsA family member CdiA, called the CdiA-CT, inhibits the growth of CDI? bacteria. CDI+ bacteria are protected from autoinhibition by an immunity protein, CdiI. Bioinformatic analyses indicate that CDI systems are widespread amongst ?, ?, and ? proteobacteria and that the CdiA-CTs and CdiI proteins are highly variable. CdiI proteins protect against CDI in an allele-specific manner. Here we identify predicted CDI system-encoding loci in species of Burkholderia, Ralstonia and Cupriavidus, named bcpAIOB, that are distinguished from previously-described CDI systems by gene order and the presence of a small ORF, bcpO, located 5? to the gene encoding the TpsB family member. A requirement for bcpO in function of BcpA (the TpsA family member) was demonstrated, indicating that bcpAIOB define a novel class of TPS system. Using fluorescence microscopy and flow cytometry, we show that these genes are expressed in a probabilistic manner during culture of Burkholderia thailandensis in liquid medium. The bcpAIOB genes and extracellular DNA were required for autoaggregation and adherence to an abiotic surface, suggesting that CDI is required for biofilm formation, an activity not previously attributed to CDI. By contrast to what has been observed in E. coli, the B. thailandensis bcpAIOB genes only mediated interbacterial competition on a solid surface. Competition occurred in a defined spatiotemporal manner and was abrogated by allele-specific immunity. Our data indicate that the bcpAIOB genes encode distinct classes of CDI and TPS systems that appear to function in sociomicrobiological community development. PMID:22912595

  14. 3-Hydroxyphenylacetic Acid Induces the Burkholderia cenocepacia Phenylacetic Acid Degradation Pathway – Toward Understanding the Contribution of Aromatic Catabolism to Pathogenesis

    PubMed Central

    Imolorhe, Ijeme A.; Cardona, Silvia T.

    2011-01-01

    The phenylacetic acid (PA) degradative pathway is the central pathway by which various aromatic compounds (e.g., styrene) are degraded. Upper pathways for different aromatic compounds converge at common intermediate phenylacetyl-CoA (PA-CoA), which is then metabolized to succinyl-CoA and acetyl-CoA. We previously made a link in Burkholderia cenocepacia between PA degradation and virulence by showing that insertional mutagenesis of paaA and paaE genes, that encode part of a multicomponent oxidase of PA-CoA, results in PA-conditional growth and an attenuated killing phenotype in the Caenorhabditis elegans model of infection. However, insertional mutagenesis of paaK1, which encodes a phenylacetate-CoA ligase, did not result in a PA-conditional growth probably due to the presence of a putative paralog gene paaK2. Recently published crystallographic and enzyme kinetics data comparing the two PaaK ligases showed that PaaK1 is more active than PaaK2 and that the larger binding pocket of PaaK1 can accommodate hydroxylated PA derived molecules such as 3-hydroxyphenylacetic (3-OHPA) acid and 4-hydroxyphenylacetic acid (4-OHPA). The higher activity and broader substrate specificity suggested a more active role in pathogenesis. In this work, we aimed to determine the relevance of PaaK1 activity to the killing ability of B. cenocepacia to C. elegans. Using reporter activity assays, we demonstrate that 3-OHPA activated PA degradation gene promoters of Burkholderia cenocepacia K56-2 in a paaK1-dependent manner, while 4-OHPA had no effect. We compared the pathogenicity of a paaK1 deletion mutant with that of the wild type in C. elegans and observed no differences in the killing ability of the strains. Taken together, these studies suggest that 3-OHPA, but not 4-OHPA, can induce the PA pathway and that this induction is dependent on the paaK1 gene. However, the more active PaaK1 does not play a distinct role in pathogenesis of B. cenocepacia as previously suggested. PMID:22919580

  15. Pathways of reductive degradation of crystal violet in wastewater using free-strain Burkholderia vietnamiensis C09V.

    PubMed

    Gan, Li; Cheng, Ying; Palanisami, Thavamani; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

    2014-09-01

    A new strain isolated from activated sludge and identified as Burkholderia vietnamiensis C09V was used to biodegrade crystal violet (CV) from aqueous solution. To understand the degradation pathways of CV, batch experiments showed that the degradation using B. vietnamiensis C09V significantly depended on conditions such as pH, initial dye concentration and media components, carbon and nitrogen sources. Acceleration in the biodegradation of CV was observed in presence of metal ions such as Cd and Mn. More than 98.86C of CV (30 mg l(-1)) was degraded within 42 h at pH 5 and 30 °C. The biodegradation kinetics of CV corresponded to the pseudo first-order rate model with a rate constant of 0.046 h(-1). UV-visible and Fourier transform infrared spectroscopy (FTIR) were used to identify degradation metabolites. Which further confirmed by LC-MS analysis, indicating that CV was biodegraded to N,N-dimethylaminophenol and Michler's ketone prior to these intermediates being further degraded. Finally, the ability of B. vietnamiensis C09V to remove CV in wastewater was demonstrated. PMID:24862483

  16. The Burkholderia cenocepacia sensor kinase hybrid AtsR is a global regulator modulating quorum-sensing signalling.

    PubMed

    Aubert, Daniel F; O'Grady, Eoin P; Hamad, Mohamad A; Sokol, Pamela A; Valvano, Miguel A

    2013-02-01

    Burkholderia cenocepacia is commonly found in the environment and also as an important opportunistic pathogen infecting patients with cystic fibrosis. Successful infection by this bacterium requires coordinated expression of virulence factors, which is achieved through different quorum sensing (QS) regulatory systems. Biofilm formation and Type 6 secretion system (T6SS) expression in B. cenocepacia K56-2 are positively regulated by QS and negatively regulated by the sensor kinase hybrid AtsR. This study reveals that in addition to affecting biofilm and T6SS activity, the deletion of atsR in B. cenocepacia leads to overproduction of other QS-regulated virulence determinants including proteases and swarming motility. Expression of the QS genes, cepIR and cciIR, was upregulated in the ?atsR mutant and resulted in early and increased N-acylhomoserine lactone (AHL) production, suggesting that AtsR plays a role in controlling the timing and fine-tuning of virulence gene expression by modulating QS signalling. Furthermore, a ?atsR?cepI?cciI mutant could partially upregulate the same virulence determinants indicating that AtsR also modulates the expression of virulence genes by a second mechanism, independently of any AHL production. Together, our results strongly suggest that AtsR is a global virulence regulator in B. cenocepacia. PMID:22830644

  17. Biocontrol of Late Blight (Phytophthora capsici) Disease and Growth Promotion of Pepper by Burkholderia cepacia MPC-7

    PubMed Central

    Sopheareth, Mao; Chan, Sarun; Naing, Kyaw Wai; Lee, Yong Seong; Hyun, Hae Nam; Kim, Young Cheol; Kim, Kil Yong

    2013-01-01

    A chitinolytic bacterial strain having strong antifungal activity was isolated and identified as Burkholderia cepacia MPC-7 based on 16S rRNA gene analysis. MPC-7 solubilized insoluble phosphorous in hydroxyapatite agar media. It produced gluconic acid and 2-ketogluconic acid related to the decrease in pH of broth culture. The antagonist produced benzoic acid (BA) and phenylacetic acid (PA). The authentic compounds, BA and PA, showed a broad spectrum of antimicrobial activity against yeast, several bacterial and fungal pathogens in vitro. To demonstrate the biocontrol efficiency of MPC-7 on late blight disease caused by Phytophthora capsici, pepper plants in pot trials were treated with modified medium only (M), M plus zoospore inoculation (MP), MPC-7 cultured broth (B) and B plus zoospore inoculation (BP). With the sudden increase in root mortality, plants in MP wilted as early as five days after pathogen inoculation. However, plant in BP did not show any symptom of wilting until five days. Root mortality in BP was markedly reduced for as much as 50%. Plants in B had higher dry weight, P concentration in root, and larger leaf area compared to those in M and MP. These results suggested that B. cepacia MPC-7 should be considered as a candidate for the biological fertilizer as well as antimicrobial agent for pepper plants. PMID:25288930

  18. Burkholderia phytofirmans PsJN primes Vitis vinifera L. and confers a better tolerance to low nonfreezing temperatures.

    PubMed

    Theocharis, Andreas; Bordiec, Sophie; Fernandez, Olivier; Paquis, Sandra; Dhondt-Cordelier, Sandrine; Baillieul, Fabienne; Clément, Christophe; Barka, Essaïd Ait

    2012-02-01

    Several endophytic bacteria reportedly induce resistance to biotic stress and abiotic stress tolerance in several plant species. Burkholderia phytofirmans PsJN is a plant-growth-promoting rhizobacterium (PGPR) that is able to colonize grapevine tissues and induce resistance to gray mold. Further, PsJN induces physiological changes that increase grapevine tolerance to low nonfreezing temperatures. To better understand how bacteria induced the observed phenomena, stress-related gene expression and metabolite accumulation were monitored in 6-week-old Chardonnay grapevine plantlets after exposure to low nonfreezing temperatures. Under normal conditions (26°C), plantlet bacterization had no significant effect on the monitored parameters. By contrast, at 4°C, both stress-related gene transcripts and metabolite levels increased earlier and faster, and reached higher levels in PsJN-bacterized plantlets than in nonbacterized counterparts, in accordance with priming phenomena. The recorded changes may be correlated with the tolerance to cold stress conferred by the presence of PsJN. This is the first time that PGPR-induced priming has been shown to protect plants against low-temperature stress. Moreover, 1 week after cold exposure, levels of stress-related metabolites had declined more in PsJN-bacterized plants, suggesting that the endophyte is involved in the cold acclimation process via the scavenging system. PMID:21942451

  19. Induction of Biofilm Formation in the Betaproteobacterium Burkholderia unamae CK43B Exposed to Exogenous Indole and Gallic Acid

    PubMed Central

    Kim, Dongyeop; Sitepu, Irnayuli R.

    2013-01-01

    Burkholderia unamae CK43B, a member of the Betaproteobacteria that was isolated from the rhizosphere of a Shorea balangeran sapling in a tropical peat swamp forest, produces neither indole nor extracellular polymeric substances associated with biofilm formation. When cultured in a modified Winogradsky's medium supplemented with up to 1.7 mM indole, B. unamae CK43B maintains its planktonic state by cell swelling and effectively degrades exogenous indole. However, in medium supplemented with 1.7 mM exogenous indole and 1.0 mM gallic acid, B. unamae CK43B produced extracellular polymeric substances and formed a biofilm. The concentration indicated above of gallic acid alone had no effect on either the growth or the differentiation of B. unamae CK43B cells above a certain concentration threshold, whereas it inhibited indole degradation by B. unamae CK43B to 3-hydroxyindoxyl. In addition, coculture of B. unamae CK43B with indole-producing Escherichia coli in nutrient-rich Luria-Bertani medium supplemented with 1.0 mM gallic acid led to the formation of mixed cell aggregates. The viability and active growth of B. unamae CK43B cells in a coculture system with Escherichia coli were evidenced by fluorescence in situ hybridization. Our data thus suggest that indole facilitates intergenus communication between indole-producing gammaproteobacteria and some indole-degrading bacteria, particularly in gallic acid-rich environments. PMID:23747701

  20. Cloning and expression of Vitreoscilla hemoglobin gene in Burkholderia sp. strain DNT for enhancement of 2,4-dinitrotoluene degradation

    SciTech Connect

    Patel, S.M.; Stark, B.C.; Hwang, K.W.; Dikshit, K.L.; Webster, D.A.

    2000-02-01

    The gene (vgb) encoding the hemoglobin (VHb) of Vitreoscilla sp. was cloned into a broad host range vector and stably transformed into Burkholderia (formerly Pseudomonas) sp. strain DNT, which is able to degrade and metabolize 1,4-dinitrotoluene (DNT). Vgb was stably maintained and expressed in functional form in this recombinant strain (YV1). When growth of YV1, in both tryptic soy broth and minimal salts broth containing DNT and yeast extract, was compared with that of the untransformed strain, YV1 grew significantly better on a cell mass basis (A{sub 600}) and reached slightly higher maximum viable cell numbers. YV1 also had roughly twice the respiration as strain DNT on a cell mass basis, and in DNT-containing medium, YV1 degraded DNT faster than the untransformed strain. YV1 cells pregrown in medium containing DNT plus succinate showed the fastest degradation: 100% of the initial 200 ppm DNT was removed from the medium within 3 days.