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1.
J Microbiol Biotechnol ; 29(7): 1043-1052, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31353877

RESUMO

Active lipase-producing bacterium Burkholderia gladioli Bps-1 was rapidly isolated using a modified trypan blue and tetracycline, ampicillin (TB-TA) plate. The electro-phoretically pure enzyme was obtained by purification using ethanol precipitation, ion-exchange chromatography, and gel filtration chromatography. The molecular weight was 34.6 kDa and the specific activity was determined to be 443.9 U/mg. The purified lipase showed the highest activity after hydrolysis with p-NPC16 at a pH of 8.5 and 50°C, and the Km, kcat, and kcat/Km values were 1.05, 292.95 s-1 and 279 s-1mM-1, respectively. The lipase was highly stable at 7.5 ≤ pH ≤ 10.0. K+ and Na+ exerted activation effects on the lipase which had favorable tolerance to short-chain alcohols with its residual enzyme activity being 110% after being maintained in 30% ethanol for 1 h. The results demonstrated that the lipase produced by the strain B. gladioli Bps-1 has high enzyme activity and is an alkaline lipase. The lipase has promising chemical properties for a range of applications in the food-processing and detergent industries, and has particularly high potential for use in the manufacture of biodiesel.


Assuntos
Burkholderia gladioli/enzimologia , Burkholderia gladioli/isolamento & purificação , Lipase/metabolismo , Biocatálise , Biocombustíveis , Burkholderia gladioli/crescimento & desenvolvimento , Burkholderia gladioli/metabolismo , Meios de Cultura , Detergentes , Estabilidade Enzimática , Etanol/metabolismo , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Lipase/química , Lipase/isolamento & purificação , Peso Molecular , Especificidade por Substrato , Temperatura
2.
Commun Biol ; 2: 131, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30993215

RESUMO

The emergence and spread of antimicrobial resistance highlights the urgent need for new antibiotics. Organoarsenicals have been used as antimicrobials since Paul Ehrlich's salvarsan. Recently a soil bacterium was shown to produce the organoarsenical arsinothricin. We demonstrate that arsinothricin, a non-proteinogenic analog of glutamate that inhibits glutamine synthetase, is an effective broad-spectrum antibiotic against both Gram-positive and Gram-negative bacteria, suggesting that bacteria have evolved the ability to utilize the pervasive environmental toxic metalloid arsenic to produce a potent antimicrobial. With every new antibiotic, resistance inevitably arises. The arsN1 gene, widely distributed in bacterial arsenic resistance (ars) operons, selectively confers resistance to arsinothricin by acetylation of the α-amino group. Crystal structures of ArsN1 N-acetyltransferase, with or without arsinothricin, shed light on the mechanism of its substrate selectivity. These findings have the potential for development of a new class of organoarsenical antimicrobials and ArsN1 inhibitors.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Arsenicais/química , Arsenicais/farmacologia , Burkholderia gladioli/metabolismo , Ácido Glutâmico/análogos & derivados , Acetilação , Antibacterianos/isolamento & purificação , Arsenicais/isolamento & purificação , Burkholderia gladioli/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Genes Bacterianos/genética , Glutamato-Amônia Ligase/análise , Humanos , Testes de Sensibilidade Microbiana , Mycobacterium bovis/efeitos dos fármacos , Óperon , Células THP-1
3.
Nat Prod Rep ; 35(12): 1236-1240, 2018 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-30474086

RESUMO

A personal selection of 32 recent papers is presented covering various aspects of current developments in bioorganic chemistry and novel natural products such as kadsuraol A from Kadsura longipedunculata.


Assuntos
Produtos Biológicos/química , Produtos Biológicos/metabolismo , Produtos Biológicos/síntese química , Burkholderia gladioli/química , Burkholderia gladioli/genética , Burkholderia gladioli/metabolismo , Compostos Heterocíclicos de 4 ou mais Anéis/química , Estrutura Molecular
4.
Artigo em Inglês | MEDLINE | ID: mdl-29164069

RESUMO

Burkholderia is a genus within the ß-Proteobacteriaceae that contains at least 90 validly named species which can be found in a diverse range of environments. A number of pathogenic species occur within the genus. These include Burkholderia cenocepacia and Burkholderia multivorans, opportunistic pathogens that can infect the lungs of patients with cystic fibrosis, and are members of the Burkholderia cepacia complex (Bcc). Burkholderia pseudomallei is also an opportunistic pathogen, but in contrast to Bcc species it causes the tropical human disease melioidosis, while its close relative Burkholderia mallei is the causative agent of glanders in horses. For these pathogens to survive within a host and cause disease they must be able to acquire iron. This chemical element is essential for nearly all living organisms due to its important role in many enzymes and metabolic processes. In the mammalian host, the amount of accessible free iron is negligible due to the low solubility of the metal ion in its higher oxidation state and the tight binding of this element by host proteins such as ferritin and lactoferrin. As with other pathogenic bacteria, Burkholderia species have evolved an array of iron acquisition mechanisms with which to capture iron from the host environment. These mechanisms include the production and utilization of siderophores and the possession of a haem uptake system. Here, we summarize the known mechanisms of iron acquisition in pathogenic Burkholderia species and discuss the evidence for their importance in the context of virulence and the establishment of infection in the host. We have also carried out an extensive bioinformatic analysis to identify which siderophores are produced by each Burkholderia species that is pathogenic to humans.


Assuntos
Infecções por Burkholderia/metabolismo , Infecções por Burkholderia/microbiologia , Burkholderia/metabolismo , Burkholderia/patogenicidade , Ferro/metabolismo , Virulência , Animais , Burkholderia/classificação , Burkholderia/genética , Burkholderia gladioli/metabolismo , Burkholderia gladioli/patogenicidade , Burkholderia mallei/metabolismo , Burkholderia mallei/patogenicidade , Burkholderia pseudomallei/metabolismo , Burkholderia pseudomallei/patogenicidade , Biologia Computacional , Fibrose Cística/microbiologia , Ferritinas/metabolismo , Mormo , Heme/metabolismo , Cavalos , Humanos , Lactoferrina/metabolismo , Pulmão/microbiologia , Melioidose/microbiologia , Sideróforos/metabolismo
5.
Nat Commun ; 8: 15172, 2017 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-28452358

RESUMO

Pathogenic and mutualistic bacteria associated with eukaryotic hosts often lack distinctive genomic features, suggesting regular transitions between these lifestyles. Here we present evidence supporting a dynamic transition from plant pathogenicity to insect-defensive mutualism in symbiotic Burkholderia gladioli bacteria. In a group of herbivorous beetles, these symbionts protect the vulnerable egg stage against detrimental microbes. The production of a blend of antibiotics by B. gladioli, including toxoflavin, caryoynencin and two new antimicrobial compounds, the macrolide lagriene and the isothiocyanate sinapigladioside, likely mediate this defensive role. In addition to vertical transmission, these insect symbionts can be exchanged via the host plant and retain the ability to initiate systemic plant infection at the expense of the plant's fitness. Our findings provide a paradigm for the transition between pathogenic and mutualistic lifestyles and shed light on the evolution and chemical ecology of this defensive mutualism.


Assuntos
Antibacterianos/metabolismo , Antifúngicos/metabolismo , Burkholderia gladioli/crescimento & desenvolvimento , Besouros/microbiologia , Fungos/crescimento & desenvolvimento , Soja/microbiologia , Simbiose/fisiologia , Animais , Burkholderia gladioli/genética , Burkholderia gladioli/metabolismo , Fungos/genética , Fungos/metabolismo , Hibridização in Situ Fluorescente , Pirimidinonas/metabolismo , Triazinas/metabolismo
6.
J Med Toxicol ; 13(2): 173-179, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28105575

RESUMO

INTRODUCTION: Bongkrekic acid (BA) has a unique mechanism of toxicity among the mitochondrial toxins: it inhibits adenine nucleotide translocase (ANT) rather than the electron transport chain. Bongkrekic acid is produced by the bacterium Burkholderia gladioli pathovar cocovenenans (B. cocovenenans) which has been implicated in outbreaks of food-borne illness involving coconut- and corn-based products in Indonesia and China. Our objective was to summarize what is known about the epidemiology, exposure sources, toxicokinetics, pathophysiology, clinical presentation, and diagnosis and treatment of human BA poisoning. METHODS: We searched MEDLINE (1946 to present), EMBASE (1947 to present), SCOPUS, The Indonesia Publication Index ( http://id.portalgaruda.org/ ), ToxNet, book chapters, Google searches, Pro-MED alerts, and references from previously published journal articles. We identified a total of 109 references which were reviewed. Of those, 29 (26 %) had relevant information and were included. Bongkrekic acid is a heat-stable, highly unsaturated tricarboxylic fatty acid with a molecular weight of 486 kDa. Outbreaks have been reported from Indonesia, China, and more recently in Mozambique. Very little is known about the toxicokinetics of BA. Bongkrekic acid produces its toxic effects by inhibiting mitochondrial (ANT). ANT can also alter cellular apoptosis. Signs and symptoms in humans are similar to the clinical findings from other mitochondrial poisons, but they vary in severity and time course. Management of patients is symptomatic and supportive. CONCLUSIONS: Bongkrekic acid is a mitochondrial ANT toxin and is reported primarily in outbreaks of food-borne poisoning involving coconut and corn. It should be considered in outbreaks of food-borne illness when signs and symptoms manifest involving the liver, brain, and kidneys and when coconut- or corn-based foods are implicated.


Assuntos
Ácido Bongcréquico/envenenamento , Infecções por Burkholderia/microbiologia , Burkholderia gladioli/metabolismo , Cocos/microbiologia , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Mitocôndrias/enzimologia , Translocases Mitocondriais de ADP e ATP/antagonistas & inibidores , Zea mays/microbiologia , Animais , Ácido Bongcréquico/farmacocinética , Infecções por Burkholderia/enzimologia , Infecções por Burkholderia/epidemiologia , Infecções por Burkholderia/terapia , Burkholderia gladioli/patogenicidade , Doenças Transmitidas por Alimentos/enzimologia , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/terapia , Mitocôndrias/patologia , Translocases Mitocondriais de ADP e ATP/metabolismo , Resultado do Tratamento
7.
Mol Plant Pathol ; 17(1): 65-76, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25845410

RESUMO

Burkholderia gladioli is a causal agent of bacterial panicle blight and sheath/grain browning in rice in many countries. Many strains produce the yellow pigment toxoflavin, which is highly toxic to plants, fungi, animals and microorganisms. Although there have been several studies on the toxoflavin biosynthesis system of B. glumae, it is still unclear how B. gladioli activates toxoflavin biosynthesis. In this study, we explored the genomic organization of the toxoflavin system of B. gladioli and its biological functions using comparative genomic analysis between toxoflavin-producing strains (B. glumae BGR1 and B. gladioli BSR3) and a strain not producing toxoflavin (B. gladioli KACC11889). The latter exhibits normal physiological characteristics similar to other B. gladioli strains. Burkholderia gladioli KACC11889 possesses all the genes involved in toxoflavin biosynthesis, but lacks the quorum-sensing (QS) system that functions as an on/off switch for toxoflavin biosynthesis. These data suggest that B. gladioli has evolved to use the QS signalling cascade of toxoflavin production (TofI/TofR of QS → ToxJ or ToxR → tox operons) similar to that in B. glumae. However, some strains may have evolved to eliminate toxoflavin production through deletion of the QS genes. In addition, we demonstrate that the toxoflavin biosynthetic system enhances the virulence of B. gladioli. These findings provide another line of evidence supporting the differential regulation of the toxoflavin system in Burkholderia strains.


Assuntos
Burkholderia gladioli/metabolismo , Burkholderia gladioli/patogenicidade , Pirimidinonas/metabolismo , Triazinas/metabolismo , Vias Biossintéticas/genética , Burkholderia gladioli/genética , Genes Bacterianos , Teste de Complementação Genética , Movimento , Cebolas/microbiologia , Óperon/genética , Reprodutibilidade dos Testes , Virulência/genética
8.
Fungal Biol ; 119(7): 605-14, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26058536

RESUMO

The interactions between aflatoxin-producing fungi and bacteria have opened up a new avenue for identifying biological agents suitable for controlling aflatoxin contamination. In this study, we analysed the interactions between A. flavus and the bacterium Burkholderia gladioli M3 that coexist in rice that is naturally contaminated with A. flavus. Our results showed that a cell-free culture filtrate (CCF) and the metabolite bongkrekic acid of the M3 strain potently suppressed the mycelial growth and spore production, and then affected the production of aflatoxin of A. flavus. Bongkrekic acid secreted by the M3 strain exhibited higher antifungal activity than did analogues. The CCF of the M3 strain and its metabolite bongkrekic acid can inhibit the growth of A. flavus, but the metabolites of A. flavus, aflatoxins, exerted no inhibitory effect on the growth of the M3 strain. Furthermore, we determined that the M3 cells could use the dead mycelia of A. flavus as energy sources for reproduction, while A. flavus could not grow in a solution containing dead M3 cells. In summary, these results indicated that B. gladioli has a competitive advantage in survival when it coexists with its fungal partner A. flavus.


Assuntos
Aflatoxinas/metabolismo , Aspergillus flavus/metabolismo , Burkholderia gladioli/metabolismo , Oryza/microbiologia , Aspergillus flavus/crescimento & desenvolvimento , Ácido Bongcréquico/metabolismo , Burkholderia gladioli/química , Burkholderia gladioli/crescimento & desenvolvimento
9.
Artigo em Inglês | MEDLINE | ID: mdl-25463198

RESUMO

(2S, 3R)-methyl-2-benzamidomethyl-3-hydroxybutyrate (MBHB) is a key intermediate in the synthesis of 4-aceoxyazetidinone, a building block for the production of penems and carbapenems. More attentions have been paid to screen biocatalysts achieving asymmetric preparation of (2S, 3R)-MBHB. In this study, an improved chiral high-performance liquid chromatographic (HPLC) method was developed for the stereoselective determination of 2-benzamidomethyl-3-oxobutanoate (BMOB) and MBHB, and further employed into the biotransformation of BMOB. Chiral separation was achieved within 12 min on Chiralpak AY-H column, which was faster and more suitable for screening biocatalysts exhibited reduction activity and (2S, 3R)-stereospecificity toward BMOB than on other columns. Ultimately, a new strain, Burkholderia gladioli ZJB-12126 capable of reducing BMOB to (2S, 3R)-MBHB was successfully isolated based on this newly constructed HPLC method. Samples were prepared by liquid-liquid extraction system using ethyl acetate as the extractor solvent. The extraction recoveries of BMOB and MBHB isomers ranged from 91.6 to 94.1% with relative standard deviation (RSD) below 10%. Linear calibration curves were obtained in the concentration range of 50-5000 µg/mL for both BMOB and MBHB isomers, respectively. Intra-day and inter-day precisions and accuracy were below 15% for all isomers evaluated by RSDs and relative errors (REs), respectively. This novel method was demonstrated to be suitable for assessing the biotransformation process of BMOB.


Assuntos
Burkholderia gladioli/metabolismo , Butiratos/química , Cromatografia Líquida de Alta Pressão/métodos , Biotransformação , Burkholderia gladioli/química , Butiratos/metabolismo , Estereoisomerismo
10.
Mycoses ; 57 Suppl 3: 48-55, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25250879

RESUMO

Fungi-bacteria interactions can impact the course of fungal infection and biotechnological use. The mucoralean fungus Rhizopus microsporus, traditionally used in food fermentations (tempe and sufu), is frequently accompanied by Burkholderia gladioli pv. cocovenenans. When producing tempe bongkrek, the bacterial contamination can lead to lethal food-related intoxications caused by the respiratory toxin bongkrekic acid. To unveil the metabolic potential of the fungus-associated bacterium, we sequenced its genome, assigned secondary metabolite biosynthesis gene clusters and monitored the metabolic profile under various growth conditions. In addition to the bongkrekic acid biosynthesis gene cluster we found gene clusters coding for the biosynthesis of toxoflavin and a complex polyketide. The orphan polyketide synthase gene cluster was activated under conditions that emulate tempe production, which enabled isolation and structure elucidation of four members of the enacyloxin family of antibiotics, out of which one is new. Moreover, we found that the fungus positively influences the growth of the bacteria and dramatically increases bongkrekic acid production in stationary culture, which inhibits the growth of the fungus. These results showcase the context-dependent formation of antifungal and antibacterial agents at the fungal-bacterial interface, which may also serve as a model for scenarios observed in mixed infections.


Assuntos
Antibacterianos/biossíntese , Antifúngicos/metabolismo , Burkholderia gladioli/metabolismo , Policetídeos/farmacologia , Rhizopus/metabolismo , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Ácido Bongcréquico/biossíntese , Burkholderia gladioli/genética , Técnicas de Cocultura , Biologia Computacional , Família Multigênica , Policetídeos/metabolismo , Rhizopus/genética , Análise de Sequência de DNA
11.
Int J Mol Sci ; 13(12): 16291-302, 2012 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-23208371

RESUMO

The trend to search novel microbial natural biocides has recently been increasing in order to avoid the environmental pollution from use of synthetic pesticides. Among these novel natural biocides are the bioactive secondary metabolites of Burkholderia gladioli pv. agaricicola (Bga). The aim of this study is to determine antifungal activity of Bga strains against some phytopathogenic fungi. The fungicidal tests were carried out using cultures and cell-free culture filtrates against Botrytis cinerea, Aspergillus flavus, Aspergillus niger, Penicillium digitatum, Penicillium expansum, Sclerotinia sclerotiorum and Phytophthora cactorum. Results demonstrated that all tested strains exert antifungal activity against all studied fungi by producing diffusible metabolites which are correlated with their ability to produce extracellular hydrolytic enzymes. All strains significantly reduced the growth of studied fungi and the bacterial cells were more bioactive than bacterial filtrates. All tested Bulkholderia strains produced volatile organic compounds (VOCs), which inhibited the fungal growth and reduced the growth rate of Fusarium oxysporum and Rhizoctonia solani. GC/MS analysis of VOCs emitted by strain Bga 11096 indicated the presence of a compound that was identified as 1-methyl-4-(1-methylethenyl)-cyclohexene, a liquid hydrocarbon classified as cyclic terpene. This compound could be responsible for the antifungal activity, which is also in agreement with the work of other authors.


Assuntos
Antibiose , Antifúngicos , Burkholderia gladioli/fisiologia , Fungos/patogenicidade , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Ascomicetos/crescimento & desenvolvimento , Aspergillus/crescimento & desenvolvimento , Botrytis/crescimento & desenvolvimento , Burkholderia gladioli/metabolismo , Fungos/crescimento & desenvolvimento , Fusarium/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Penicillium/crescimento & desenvolvimento , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/farmacologia
12.
Chem Biol ; 19(9): 1164-74, 2012 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-22999884

RESUMO

Bongkrekic acid (BA), an infamous respiratory toxin of the pathogenic bacterium Burkholderia gladioli, causes lethal intoxications when tempe bongkrek is produced with contaminated Rhizopus oligosporus cultures. Genome sequencing of B. gladioli pathovar cocovenenans unveiled the genetic basis for BA biosynthesis, and pointed to a homologous bon gene cluster in a B. gladioli strain from an infected rice plant. For functional genetics in B. gladioli λ Red recombination was established. Dissection of the modular type I polyketide synthase (a trans-AT PKS) provided insights into complex polyketide assembly. Isoprenoid-like ß-branching events and a six-electron oxidation of a methyl group to a carboxylic acid give rise to the unique branched tricarboxylic fatty acid. The role of the cytochrome P450 monooxygenase, BonL, was proven by structural elucidation of deoxybongkrekic acid from a mutant.


Assuntos
Ácido Bongcréquico/biossíntese , Burkholderia gladioli/metabolismo , Ácido Bongcréquico/química , Conformação Molecular
13.
Indian J Med Res ; 135(5): 666-71, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22771597

RESUMO

BACKGROUND & OBJECTIVES: Drug resistant microbes are a serious challenge to human health. During the search for novel antibiotics/inhibitors from the agricultural soil, a bacterial colony was found to inhibit the growth of clinical isolates including Staphylococcus (resistant to amikacin, ciprofloxacin, clindamycin, clinafloxacin, erythromycin, gentamicin and methicillin) and Candida (resistant to fluconazole and itraconazole). The culture was identified as Burkholderia gladioli and produced at least five different antimicrobial compounds which were highly stable at high temperature (121 o C) and in the broad pH range (3.0-11.0). We report here the antimicrobial activity of B. gladioli against drug resistant bacterial pathogens. METHODS: The bacterial culture was identified using morphological, biochemical and 16S rRNA gene sequencing techniques. The antimicrobial activity of the identified organism against a range of microbial pathogens was checked by Kirby-Bauer's disc diffusion method. The antimicrobial compounds in the cell free supernatant were chloroform-extracted and separated by thin layer chromatography (TLC). RESULTS: B. gladioli OR1 exhibited broad spectrum antimicrobial activity against drug resistant clinical isolates belonging to various genera of bacteria (Staphylococcus, Enterobacter, Enterococcus, Acinetobacter and Citrobacter) and a fungus (Candida). Based on TLC profile and bioautography studies, the chloroform extract of B. gladioli OR1 consisted of at least three anti-staphylococcal and two anti-Candida metabolites. The antimicrobial activity was heat stable (121 o C/20 min) as well as pH stable (3.0-11.0). INTERPRETATION & CONCLUSIONS: The bacterial soil isolate, B. gladioli OR1 possessed the ability to kill various drug resistant bacteria and a fungus. This organism produced many antimicrobial metabolites which might have the potential to be used as antibiotics in future.


Assuntos
Anti-Infecciosos/metabolismo , Burkholderia gladioli/metabolismo , Microbiologia do Solo , Anti-Infecciosos/administração & dosagem , Burkholderia gladioli/genética , Burkholderia gladioli/isolamento & purificação , Candida/efeitos dos fármacos , Candida/patogenicidade , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Bacteriana , Temperatura Alta , Humanos , Testes de Sensibilidade Microbiana , RNA Ribossômico 16S/genética , Staphylococcus/efeitos dos fármacos , Staphylococcus/patogenicidade
14.
Org Biomol Chem ; 8(7): 1520-2, 2010 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-20237660

RESUMO

Biosynthetic studies with (13)C-labelled acetates and methionine revealed that the infamous, food-related toxin bongkrekic acid from Burkholderia gladioli is a polyketide with acetate-derived beta-branches and a carboxylate terminus derived from the methyl group of an acetate.


Assuntos
Toxinas Bacterianas/química , Toxinas Bacterianas/metabolismo , Ácido Bongcréquico/química , Ácido Bongcréquico/metabolismo , Burkholderia gladioli/metabolismo , Translocases Mitocondriais de ADP e ATP/antagonistas & inibidores , Mitocôndrias/enzimologia , Estrutura Molecular
15.
J Clin Microbiol ; 47(5): 1510-6, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19297595

RESUMO

Burkholderia gladioli, primarily known as a plant pathogen, is involved in human infections, especially in patients with cystic fibrosis (CF). In the present study, the first respiratory isolates recovered from 14 French patients with CF and 4 French patients without CF, identified by 16S rRNA gene analysis, were tested for growth on B. cepacia selective media, for identification by commercial systems, and for their antimicrobial susceptibilities, and were compared by pulsed-field gel electrophoresis (PFGE). Patients' data were collected. All 18 isolates grew on oxidation-fermentation-polymyxin B-bacitracin-lactose medium and Pseudomonas cepacia agar, but only 13 grew on Burkholderia cepacia selective agar. API 20NE strips did not differentiate B. gladioli from B. cepacia, whereas Vitek 2 GN cards correctly identified 15 isolates. All isolates were susceptible to piperacillin, imipenem, aminoglycosides, and ciprofloxacin and were far less resistant to ticarcillin than B. cepacia complex organisms. Fifteen PFGE types were observed among the 18 isolates, but shared types were not identified among epidemiologically related patients. The microbiological follow-up of CF patients showed that colonization was persistent in 3 of 13 documented cases; B. gladioli was isolated from posttransplantation cultures of blood from 1 patient. Among the patients without CF, B. gladioli was associated with intubation (three cases) or bronchiectasis (one case). In summary, the inclusion of B. gladioli in the databases of commercial identification systems should improve the diagnostic capabilities of those systems. In CF patients, this organism is more frequently involved in transient infections than in chronic infections, but it may be responsible for complications posttransplantation; patient-to-patient transmission has not been demonstrated to date. Lastly, B. gladioli appears to be naturally susceptible to aminoglycosides and ciprofloxacin, although resistant isolates may emerge in the course of chronic infections.


Assuntos
Infecções por Burkholderia/microbiologia , Burkholderia gladioli/classificação , Burkholderia gladioli/isolamento & purificação , Adolescente , Adulto , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Burkholderia gladioli/efeitos dos fármacos , Burkholderia gladioli/metabolismo , Criança , Pré-Escolar , Análise por Conglomerados , Fibrose Cística/complicações , Impressões Digitais de DNA , DNA Bacteriano/genética , DNA Ribossômico/genética , Eletroforese em Gel de Campo Pulsado , Feminino , França , Genótipo , Humanos , Masculino , Testes de Sensibilidade Microbiana , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Adulto Jovem
16.
J Microbiol Biotechnol ; 18(6): 1095-100, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18600053

RESUMO

The role of exopolysaccharides (EPSs) from a plant growth-promoting rhizobacterium, Burkholderia gladioli IN26, on elicitation of induced systemic resistance was investigated. A purified EPS induced expression of PR- 1a::GUS on tobacco and elicited induced resistance against Colletotrichum orbiculare on cucumber. The maximum level of disease protection was noted when seeds were soaked in 200 ppm of the EPS. Our results indicate that EPS from specific rhizobacteria can elicit induced resistance and suggest that bacterial EPS might be a useful elicitor of resistance under field conditions.


Assuntos
Burkholderia gladioli/metabolismo , Colletotrichum/patogenicidade , Cucumis sativus/efeitos dos fármacos , Doenças das Plantas/microbiologia , Polissacarídeos Bacterianos/farmacologia , Cucumis sativus/microbiologia , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Polissacarídeos Bacterianos/isolamento & purificação , Sementes/microbiologia , Tabaco/genética , Tabaco/metabolismo
17.
Appl Environ Microbiol ; 72(5): 3558-65, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16672503

RESUMO

Cavity disease in white button mushrooms is caused by Burkholderia gladioli pv. agaricicola. We describe the isolation and characterization of six mutants of the strain BG164R that no longer cause this disease on mushrooms. The mutations were mapped to genes of the general secretory pathway (GSP). This is the first report of the association of the type II secretion pathway with a disease in mushrooms. Phenotypes of the six avirulent mutants were the following: an inability to degrade mushroom tissue, a highly reduced capacity to secrete chitinase and protease, and a reduced number of flagella. Using these mutants, we also made the novel observation that the factors causing mushroom tissue degradation, thereby leading to the expression of cavity disease, can be separated from mycelium inhibition because avirulent mutants continued to inhibit the growth of actively growing mushroom mycelia. The GSP locus of B. gladioli was subsequently cloned and mapped and compared to the same locus in closely related species, establishing that the genetic organization of the gsp operon of B. gladioli pv. agaricicola is consistent with that of other species of the genus. We also identify the most common indigenous bacterial population present in the mushroom fruit bodies from a New Zealand farm, one of which, Ewingella americana, was found to be an apparent antagonist of B. gladioli pv. agaricicola. While other investigators have reported enhanced disease symptoms due to interactions between endogenous and disease-causing bacteria in other mushroom diseases, to the best of our knowledge this is the first report of an antagonistic effect.


Assuntos
Agaricus , Antibiose , Proteínas de Bactérias/metabolismo , Burkholderia gladioli/patogenicidade , Enterobacteriaceae/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Proteínas de Bactérias/genética , Burkholderia gladioli/genética , Burkholderia gladioli/crescimento & desenvolvimento , Burkholderia gladioli/metabolismo , Enterobacteriaceae/genética , Mutação , Virulência , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
18.
Microbiol Immunol ; 47(12): 915-25, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14695441

RESUMO

Burkholderia cocovenenans produces a lethal toxin (Bongkrekic acid) that leads to high fatality in food poisoning cases. However, B. cocovenenans was combined in Burkholderia gladioli in 1999. B. gladioli was originally described as a phytopathogenic bacteria that sometimes causes pneumonia in humans and that acts as an opportunistic pathogen. We thought that it was clinically dangerous to describe these two species without considering their pathogenicities. From our data of 16S rRNA sequence analysis, DNA-DNA hybridization, and fatty acid analysis, we could confirm that B. cocovenenans and B. gladioli should be categorized as a single species. However the species really weaved lethal toxin-producing strains with non-lethal strains. To emphasize that B. gladioli contains two different pathogens, we describe a new pathovar, B. gladioli pathovar cocovenenans, for the lethal toxin-producing strains. We provide characteristics that differentiate this lethal toxin-producing pathovar from other phytopathogenic pathovars within B. gladioli, together with an emended description of B. gladioli.


Assuntos
Ácido Bongcréquico/biossíntese , Burkholderia gladioli/classificação , Burkholderia gladioli/patogenicidade , Doenças Transmitidas por Alimentos/microbiologia , Animais , Toxinas Bacterianas/biossíntese , Toxinas Bacterianas/envenenamento , Técnicas de Tipagem Bacteriana , Composição de Bases , Ácido Bongcréquico/envenenamento , Burkholderia gladioli/genética , Burkholderia gladioli/metabolismo , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , DNA Ribossômico/química , DNA Ribossômico/isolamento & purificação , Ácidos Graxos/análise , Camundongos , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Fenótipo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
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