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Sample records for ps aeruginosa pa

  1. Pseudomonas aeruginosa PA14 pathogenesis in Caenorhabditis elegans.

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    Kirienko, Natalia V; Cezairliyan, Brent O; Ausubel, Frederick M; Powell, Jennifer R

    2014-01-01

    The nematode Caenorhabditis elegans is a simple model host for studying the interaction between bacterial pathogens such as Pseudomonas aeruginosa and the metazoan innate immune system. Powerful genetic and molecular tools in both C. elegans and P. aeruginosa facilitate the identification and analysis of bacterial virulence factors as well as host defense factors. Here we describe three different assays that use the C. elegans-P. aeruginosa strain PA14 host-pathogen system. Fast Killing is a toxin-mediated death that depends on a diffusible toxin produced by PA14 but not on live bacteria. Slow Killing is due to an active infection in which bacteria colonize the C. elegans intestinal lumen. Liquid Killing is designed for high-throughput screening of chemical libraries for anti-infective compounds. Each assay has unique features and, interestingly, the PA14 virulence factors involved in killing are different in each assay.

  2. PA3297 Counteracts Antimicrobial Effects of Azithromycin in Pseudomonas aeruginosa

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    Hao eTan

    2016-03-01

    Full Text Available Pseudomonas aeruginosa causes acute and chronic infections in human. Its increasing resistance to antibiotics requires alternative treatments that are more effective than available strategies. Among the alternatives is the unconventional usage of conventional antibiotics, of which the macrolide antibiotic azithromycin (AZM provides a paradigmatic example. AZM therapy is associated with a small but consistent improvement in respiratory function of cystic fibrosis (CF patients suffering from chronic P. aeruginosa infection. Besides immunomodulating activities, AZM represses bacterial genes involved in virulence, quorum sensing, biofilm formation, and motility, all of which are due to stalling of ribosome and depletion of cellular tRNA pool. However, how P. aeruginosa responds to and counteracts the effects of AZM remain elusive. Here we found that deficiency of PA3297, a gene encoding a DEAH-box helicase, intensified AZM-mediated bacterial killing, suppression of pyocyanin production and swarming motility, and hypersusceptibility to hydrogen peroxide. We demonstrated that expression of PA3297 is induced by the interaction between AZM and ribosome. Importantly, mutation of PA3297 resulted in elevated levels of unprocessed 23S-5S rRNA in the presence of AZM, which might lead to increased susceptibility to AZM-mediated effects. Our results revealed one of the bacterial responses in counteracting the detrimental effects of AZM.

  3. Crystal structure of the flavoenzyme PA4991 from Pseudomonas aeruginosa

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    Jacewicz, Agata; Schnell, Robert; Lindqvist, Ylva; Schneider, Gunter, E-mail: gunter.schneider@ki.se [Karolinska Institutet, S-171 77 Stockholm (Sweden)

    2016-01-22

    PA4991 is a FAD-dependent oxidoreductase from the pathogen P. aeruginosa that is essential for virulence and survival in the infected host. The structure of this enzyme, determined to 2.4 Å resolution, reveals that PA4991 belongs to the GR{sub 2} family of flavoenzymes. The locus PA4991 in Pseudomonas aeruginosa encodes an open reading frame that has been identified as essential for the virulence and/or survival of this pathogenic organism in the infected host. Here, it is shown that this gene encodes a monomeric FAD-binding protein of molecular mass 42.2 kDa. The structure of PA4991 was determined by a combination of molecular replacement using a search model generated with Rosetta and phase improvement by a low-occupancy heavy-metal derivative. PA4991 belongs to the GR{sub 2} family of FAD-dependent oxidoreductases, comprising an FAD-binding domain typical of the glutathione reductase family and a second domain dominated by an eight-stranded mixed β-sheet. Most of the protein–FAD interactions are via the FAD-binding domain, but the isoalloxazine ring is located at the domain interface and interacts with residues from both domains. A comparison with the structurally related glycine oxidase and glycerol-3-phosphate dehydrogenase shows that in spite of very low amino-acid sequence identity (<18%) several active-site residues involved in substrate binding in these enzymes are conserved in PA4991. However, enzymatic assays show that PA4991 does not display amino-acid oxidase or glycerol-3-phosphate dehydrogenase activities, suggesting that it requires different substrates for activity.

  4. Pa0148 from Pseudomonas aeruginosa Catalyzes the Deamination of Adenine

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    A Goble; Z Zhang; J Sauder; S Burley; S Swaminathan; F Raushel

    2011-12-31

    Four proteins from NCBI cog1816, previously annotated as adenosine deaminases, have been subjected to structural and functional characterization. Pa0148 (Pseudomonas aeruginosa PAO1), AAur1117 (Arthrobacter aurescens TC1), Sgx9403e, and Sgx9403g have been purified and their substrate profiles determined. Adenosine is not a substrate for any of these enzymes. All of these proteins will deaminate adenine to produce hypoxanthine with k{sub cat}/K{sub m} values that exceed 10{sup 5} M{sup -1} s{sup -1}. These enzymes will also accept 6-chloropurine, 6-methoxypurine, N-6-methyladenine, and 2,6-diaminopurine as alternate substrates. X-ray structures of Pa0148 and AAur1117 have been determined and reveal nearly identical distorted ({beta}/{alpha}){sub 8} barrels with a single zinc ion that is characteristic of members of the amidohydrolase superfamily. Structures of Pa0148 with adenine, 6-chloropurine, and hypoxanthine were also determined, thereby permitting identification of the residues responsible for coordinating the substrate and product.

  5. PA0148 from Pseudomonas aeruginosa Catalyzes the Deamination of Adenine

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    Goble, A.M.; Swaminathan, S.; Zhang, Z.; Sauder, J. M.; Burley, S. K.; Raushel, F. M.

    2011-08-02

    Four proteins from NCBI cog1816, previously annotated as adenosine deaminases, have been subjected to structural and functional characterization. Pa0148 (Pseudomonas aeruginosa PAO1), AAur1117 (Arthrobacter aurescens TC1), Sgx9403e, and Sgx9403g have been purified and their substrate profiles determined. Adenosine is not a substrate for any of these enzymes. All of these proteins will deaminate adenine to produce hypoxanthine with k{sub cat}/K{sub m} values that exceed 10{sup 5} M{sup -1} s{sup -1}. These enzymes will also accept 6-chloropurine, 6-methoxypurine, N-6-methyladenine, and 2,6-diaminopurine as alternate substrates. X-ray structures of Pa0148 and AAur1117 have been determined and reveal nearly identical distorted ({beta}/{alpha}){sub 8} barrels with a single zinc ion that is characteristic of members of the amidohydrolase superfamily. Structures of Pa0148 with adenine, 6-chloropurine, and hypoxanthine were also determined, thereby permitting identification of the residues responsible for coordinating the substrate and product.

  6. Ginger Extract Inhibits Biofilm Formation by Pseudomonas aeruginosa PA14

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    Kim, Han-Shin; Park, Hee-Deung

    2013-01-01

    Bacterial biofilm formation can cause serious problems in clinical and industrial settings, which drives the development or screening of biofilm inhibitors. Some biofilm inhibitors have been screened from natural products or modified from natural compounds. Ginger has been used as a medicinal herb to treat infectious diseases for thousands of years, which leads to the hypothesis that it may contain chemicals inhibiting biofilm formation. To test this hypothesis, we evaluated ginger’s ability to inhibit Pseudomonas aeruginosa PA14 biofilm formation. A static biofilm assay demonstrated that biofilm development was reduced by 39–56% when ginger extract was added to the culture. In addition, various phenotypes were altered after ginger addition of PA14. Ginger extract decreased production of extracellular polymeric substances. This finding was confirmed by chemical analysis and confocal laser scanning microscopy. Furthermore, ginger extract formed noticeably less rugose colonies on agar plates containing Congo red and facilitated swarming motility on soft agar plates. The inhibition of biofilm formation and the altered phenotypes appear to be linked to a reduced level of a second messenger, bis-(3′-5′)-cyclic dimeric guanosine monophosphate. Importantly, ginger extract inhibited biofilm formation in both Gram-positive and Gram-negative bacteria. Also, surface biofilm cells formed with ginger extract detached more easily with surfactant than did those without ginger extract. Taken together, these findings provide a foundation for the possible discovery of a broad spectrum biofilm inhibitor. PMID:24086697

  7. A Novel Antimicrobial Endolysin, LysPA26, againstPseudomonas aeruginosa.

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    Guo, Mingquan; Feng, Chunyan; Ren, Jie; Zhuang, Xuran; Zhang, Yan; Zhu, Yongzhang; Dong, Ke; He, Ping; Guo, Xiaokui; Qin, Jinhong

    2017-01-01

    The global increase in multidrug resistant (MDR) bacteria has led to phage therapy being refocused upon. A novel endolysin, LysPA26, containing a lysozyme-like domain, was screened against Pseudomonas aeruginosa in this study. It had activity against MDR P. aeruginosa without pretreatment with an outer-membrane permeabilizer. LysPA26 could kill up to 4 log units P. aeruginosa in 30 min. In addition, temperature and pH effect assays revealed that LysPA26 had good stability over a broad range of pH and temperatures. Moreover, LysPA26 could kill other Gram-negative bacteria, such as Klebsiella pneumonia, Acinetobacter baumannii and Escherichia coli , but not Gram-positive bacteria. Furthermore, LysPA26 could eliminate P. aeruginosa in biofilm formation. Our current results show that LysPA26 is a new and promising antimicrobial agent for the combat of Gram-negative pathogens.

  8. Chemical Analysis of Cellular and Extracellular Carbohydrates of a Biofilm-Forming Strain Pseudomonas aeruginosa PA14

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    Coulon, Charlène; Vinogradov, Evgeny; Filloux, Alain; Sadovskaya, Irina

    2010-01-01

    Background Pseudomonas aeruginosa is a Gram-negative bacterium and an opportunistic pathogen, which causes persisting life-threatening infections in cystic fibrosis (CF) patients. Biofilm mode of growth facilitates its survival in a variety of environments. Most P. aeruginosa isolates, including the non-mucoid laboratory strain PA14, are able to form a thick pellicle, which results in a surface-associated biofilm at the air-liquid (A–L) interface in standing liquid cultures. Exopolysaccharides (EPS) are considered as key components in the formation of this biofilm pellicle. In the non-mucoid P. aeruginosa strain PA14, the “scaffolding” polysaccharides of the biofilm matrix, and the molecules responsible for the structural integrity of rigid A–L biofilm have not been identified. Moreover, the role of LPS in this process is unclear, and the chemical structure of the LPS O-antigen of PA14 has not yet been elucidated. Principal Findings In the present work we carried out a systematic analysis of cellular and extracellular (EC) carbohydrates of P. aeruginosa PA14. We also elucidated the chemical structure of the LPS O-antigen by chemical methods and 2-D NMR spectroscopy. Our results showed that it is composed of linear trisaccharide repeating units, identical to those described for P. aeruginosa Lanýi type O:2a,c (Lanýi-Bergman O-serogroup 10a, 10c; IATS serotype 19) and having the following structure: -4)-α-L-GalNAcA-(1–3)-α-D-QuiNAc-(1–3)- α-L-Rha-(1-. Furthermore, an EC O-antigen polysaccharide (EC O-PS) and the glycerol-phosphorylated cyclic β-(1,3)-glucans were identified in the culture supernatant of PA14, grown statically in minimal medium. Finally, the extracellular matrix of the thick biofilm formed at the A-L interface contained, in addition to eDNA, important quantities (at least ∼20% of dry weight) of LPS-like material. Conclusions We characterized the chemical structure of the LPS O-antigen and showed that the O-antigen polysaccharide is

  9. Chemical analysis of cellular and extracellular carbohydrates of a biofilm-forming strain Pseudomonas aeruginosa PA14.

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    Charlène Coulon

    Full Text Available BACKGROUND: Pseudomonas aeruginosa is a gram-negative bacterium and an opportunistic pathogen, which causes persisting life-threatening infections in cystic fibrosis (CF patients. Biofilm mode of growth facilitates its survival in a variety of environments. Most P. aeruginosa isolates, including the non-mucoid laboratory strain PA14, are able to form a thick pellicle, which results in a surface-associated biofilm at the air-liquid (A-L interface in standing liquid cultures. Exopolysaccharides (EPS are considered as key components in the formation of this biofilm pellicle. In the non-mucoid P. aeruginosa strain PA14, the "scaffolding" polysaccharides of the biofilm matrix, and the molecules responsible for the structural integrity of rigid A-L biofilm have not been identified. Moreover, the role of LPS in this process is unclear, and the chemical structure of the LPS O-antigen of PA14 has not yet been elucidated. PRINCIPAL FINDINGS: In the present work we carried out a systematic analysis of cellular and extracellular (EC carbohydrates of P. aeruginosa PA14. We also elucidated the chemical structure of the LPS O-antigen by chemical methods and 2-D NMR spectroscopy. Our results showed that it is composed of linear trisaccharide repeating units, identical to those described for P. aeruginosa Lanýi type O:2a,c (Lanýi-Bergman O-serogroup 10a, 10c; IATS serotype 19 and having the following structure: -4-α-L-GalNAcA-(1-3-α-D-QuiNAc-(1-3- α-L-Rha-(1-. Furthermore, an EC O-antigen polysaccharide (EC O-PS and the glycerol-phosphorylated cyclic β-(1,3-glucans were identified in the culture supernatant of PA14, grown statically in minimal medium. Finally, the extracellular matrix of the thick biofilm formed at the A-L interface contained, in addition to eDNA, important quantities (at least ∼20% of dry weight of LPS-like material. CONCLUSIONS: We characterized the chemical structure of the LPS O-antigen and showed that the O-antigen polysaccharide is

  10. Isolation and Characterization of a Virulent Bacteriophage φPA-HF17 of Pseudomonas aeruginosa

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    Fang Han

    2014-09-01

    Full Text Available Pseudomonas aeruginosa, an important causative agent of nosocomial infection, is found throughout the hospital environment in moist reservoirs, and multidrug-resistant strains of P. aeruginosa have been increasingly reported worldwide. Bacteriophages are often considered potential therapeutic candidates in treating infectious diseases. In this study, a novel virulent bacteriophage φPA-HF17, specific infecting clinical isolates of P. aeruginosa, was isolated and characterized from environmental sewage. Transmission electron microscopy showed that phage φPA-HF17 had an icosahedral head with a very short tail, and exhibited characteristics typical of a podovirus. Restriction analysis indicated that phage φPA-HF17 was a double-stranded DNA virus, which might be digested by some restriction endonucleases. Phage φPA-HF17 was highly infectious with a rapid adsorption (>90% adsorbed in 4 min. In a one-step growth experiment, phage φPA-HF17 was shown having a latent period of 10 minute, with corresponding burst sizes of 200 PFU/cell. Furthermore, when φPA-HF17 alone was incubated at different pHs and different temperatures, the phage was stable over a wide pH range (4 to 10 and at extreme temperature (50°C. These results suggest that φPA-HF17 may be candidate therapeutic phage to control P. aeruginosa infection.

  11. Molecular cloning and characterization of the alkaline ceramidase from Pseudomonas aeruginosa PA01

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    Nieuwenhuizen, W.F.; Leeuwen, S. van; Jack, R.W.; Egmond, M.R.; Götz, F.

    2003-01-01

    Ceramidase (CDase) hydrolyzes the amide bond in ceramides to yield free fatty acid and sphingosine. From a 3-L Pseudomonas aeruginosa PA01 culture, 70 μg of extracellular alkaline, Ca2+-dependent CDase, was purified to homogeneity, the N-terminal sequence was determined, and the CDase gene was

  12. Dataset of proteomics analysis of aging C. elegans exposed to Pseudomonas aeruginosa strain PA01

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    Christina D. King

    2017-04-01

    Full Text Available Here, we present the proteomics dataset of young and middle-aged Caenorhabditis elegans (C. elegans exposed to Pseudomonas aeruginosa (P. aeruginosa strain PA01, which is related to the article "Proteomic Identification of Virulence-Related Factors in Young and Aging C. elegans infected with Pseudomonas aeruginosa" (C. D. King et. al, in-revisions. This dataset was generated to better understand the effects of aging on molecular mechanisms involved in host response to pathogen exposure. Protein from C. elegans of different age and exposure to P. aeruginosa PA01 or control E. coli OP50 were extracted and tryptically digested. Peptides were labeled with the reagents tandem mass tag (TMT6-plex, separated, and detected by using offline strong-cation exchange and online liquid chromatography – mass spectrometry (SCX – LC – MS/MS & MS3. A separate mixture of peptides were labeled on N-terminal amines and lysines with dimethylation. Dimethylated peptides were analyzed using LC – MS/MS and a portion of the results were used to verify fold-change direction for TMT6-plex experiments. Raw data can be found online at www.CHORUSproject.org, a cloud-based data repository (see specifications table for details.

  13. Pyocyanin alters redox homeostasis and carbon flux through central metabolic pathways in Pseudomonas aeruginosa PA14.

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    Price-Whelan, Alexa; Dietrich, Lars E P; Newman, Dianne K

    2007-09-01

    The opportunistic pathogen Pseudomonas aeruginosa produces colorful, redox-active antibiotics called phenazines. Excretion of pyocyanin, the best-studied natural phenazine, is responsible for the bluish tint of sputum and pus associated with P. aeruginosa infections in humans. Although the toxicity of pyocyanin for other bacteria, as well as its role in eukaryotic infection, has been studied extensively, the physiological relevance of pyocyanin metabolism for the producing organism is not well understood. Pyocyanin reduction by P. aeruginosa PA14 is readily observed in standing liquid cultures that have consumed all of the oxygen in the medium. We investigated the physiological consequences of pyocyanin reduction by assaying intracellular concentrations of NADH and NAD+ in the wild-type strain and a mutant defective in phenazine production. We found that the mutant accumulated more NADH in stationary phase than the wild type. This increased accumulation correlated with a decrease in oxygen availability and was relieved by the addition of nitrate. Pyocyanin addition to a phenazine-null mutant also decreased intracellular NADH levels, suggesting that pyocyanin reduction facilitates redox balancing in the absence of other electron acceptors. Analysis of extracellular organic acids revealed that pyocyanin stimulated stationary-phase pyruvate excretion in P. aeruginosa PA14, indicating that pyocyanin may also influence the intracellular redox state by decreasing carbon flux through central metabolic pathways.

  14. Formation of monomer residues in PS, PC, PA-6 and PVC upon γ-irradiation

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    Young Park, Gun; Yong Cho, Seung; Hoon Jeon, Dae; Shin Kwak, In; Ho Lee, Kwang; Park, H. J.

    2006-09-01

    Food packaging polymers, polystyrene (PS), polycarbonate (PC), polyamide-6 (PA-6), and polyvinylchloride (PVC), were irradiated with dose in the range 5-200 kGy. The quantities of corresponding monomer residues (styrene monomer, bisphenol-A, ɛ-caprolactam, vinyl chloride) released from target materials were analyzed using a SIM mode of GC/MSD. Styrene monomer in PS showed a slight increase from 740 to 777 ppm at 5-30 kGy and then decreased as the dose increased from 30 to 200 kGy. Bisphenol-A in PC was dose independent at the low doses, 5, 10 and 30 kGy, but its level increased from 173 to 473 ppm at 30 kGy and thereafter remained unchanged through 200 kGy. ɛ-Caprolactam in PA-6 was also dose independent, in the range of 5-200 kGy, but its level (122-164 ppm) was found to be higher than those (71 ppm) of non-irradiated sample. As for PVC, the quantity of vinyl chloride tended to increase from 8 to 18 ppm at 5-200 kGy.

  15. Formation of monomer residues in PS, PC, PA-6 and PVC upon {gamma}-irradiation

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    Young Park, Gun [Graduate School of Biotechnology, Korea University, 1.5-Ka, Anam-Dong, Seongbuk-Ku, Seoul 136-701 (Korea, Republic of); Yong Cho, Seung [Functional Food Research Center, College of Life Sciences, Korea University, 1.5-Ka, Anam-Dong, Seongbuk-Ku, Seoul 136-701 (Korea, Republic of); Hoon Jeon, Dae [Graduate School of Biotechnology, Korea University, 1.5-Ka, Anam-Dong, Seongbuk-Ku, Seoul 136-701 (Korea, Republic of); Food Packaging Division, Korea Food and Drug Administration (KFDA), 5 Nokbun-Dong, Eunpyung-Ku, Seoul 122-704 (Korea, Republic of); Shin Kwak, In [Food Packaging Division, Korea Food and Drug Administration (KFDA), 5 Nokbun-Dong, Eunpyung-Ku, Seoul 122-704 (Korea, Republic of); Ho Lee, Kwang [Food Packaging Division, Korea Food and Drug Administration (KFDA), 5 Nokbun-Dong, Eunpyung-Ku, Seoul 122-704 (Korea, Republic of); Park, H.J. [Graduate School of Biotechnology, Korea University, 1.5-Ka, Anam-Dong, Seongbuk-Ku, Seoul 136-701 (Korea, Republic of) and Department of Packaging Science, Clemson University, Clemson, South Carolina 29634-0370 (United States)]. E-mail: hjpark@korea.ac.kr

    2006-09-15

    Food packaging polymers, polystyrene (PS), polycarbonate (PC), polyamide-6 (PA-6), and polyvinylchloride (PVC), were irradiated with dose in the range 5-200 kGy. The quantities of corresponding monomer residues (styrene monomer, bisphenol-A, {epsilon}-caprolactam, vinyl chloride) released from target materials were analyzed using a SIM mode of GC/MSD. Styrene monomer in PS showed a slight increase from 740 to 777 ppm at 5-30 kGy and then decreased as the dose increased from 30 to 200 kGy. Bisphenol-A in PC was dose independent at the low doses, 5, 10 and 30 kGy, but its level increased from 173 to 473 ppm at 30 kGy and thereafter remained unchanged through 200 kGy. {epsilon}-Caprolactam in PA-6 was also dose independent, in the range of 5-200 kGy, but its level (122-164 ppm) was found to be higher than those (71 ppm) of non-irradiated sample. As for PVC, the quantity of vinyl chloride tended to increase from 8 to 18 ppm at 5-200 kGy.

  16. PA0305 of Pseudomonas aeruginosa is a quorum quenching acylhomoserine lactone acylase belonging to the Ntn hydrolase superfamily

    NARCIS (Netherlands)

    Wahjudi, Mariana; Papaioannou, Evelina; Hendrawati, Oktavia; van Assen, Aart H. G.; van Merkerk, Ronald; Cool, Robbert H.; Poelarends, Gerrit J.; Quax, Wim

    The Pseudomonas aeruginosa PAO1 genome has at least two genes, pvdQ and quiP, encoding acylhomoserine lactone (AHL) acylases. Two additional genes, pa 1893 and pa0305, have been predicted to encode penicillin acylase proteins, but have not been characterized. Initial studies on a pa0305 transposon

  17. Gene PA2449 is essential for glycine metabolism and pyocyanin biosynthesis in Pseudomonas aeruginosa PAO1.

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    Lundgren, Benjamin R; Thornton, William; Dornan, Mark H; Villegas-Peñaranda, Luis Roberto; Boddy, Christopher N; Nomura, Christopher T

    2013-05-01

    Many pseudomonads produce redox active compounds called phenazines that function in a variety of biological processes. Phenazines are well known for their toxicity against non-phenazine-producing organisms, which allows them to serve as crucial biocontrol agents and virulence factors during infection. As for other secondary metabolites, conditions of nutritional stress or limitation stimulate the production of phenazines, but little is known of the molecular details underlying this phenomenon. Using a combination of microarray and metabolite analyses, we demonstrate that the assimilation of glycine as a carbon source and the biosynthesis of pyocyanin in Pseudomonas aeruginosa PAO1 are both dependent on the PA2449 gene. The inactivation of the PA2449 gene was found to influence the transcription of a core set of genes encoding a glycine cleavage system, serine hydroxymethyltransferase, and serine dehydratase. PA2449 also affected the transcription of several genes that are integral in cell signaling and pyocyanin biosynthesis in P. aeruginosa PAO1. This study sheds light on the unexpected relationship between the utilization of an unfavorable carbon source and the production of pyocyanin. PA2449 is conserved among pseudomonads and might be universally involved in the assimilation of glycine among this metabolically diverse group of bacteria.

  18. Genomic and proteomic analyses of the terminally redundant genome of the Pseudomonas aeruginosa phage PaP1: establishment of genus PaP1-like phages.

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    Shuguang Lu

    Full Text Available We isolated and characterized a new Pseudomonas aeruginosa myovirus named PaP1. The morphology of this phage was visualized by electron microscopy and its genome sequence and ends were determined. Finally, genomic and proteomic analyses were performed. PaP1 has an icosahedral head with an apex diameter of 68-70 nm and a contractile tail with a length of 138-140 nm. The PaP1 genome is a linear dsDNA molecule containing 91,715 base pairs (bp with a G+C content of 49.36% and 12 tRNA genes. A strategy to identify the genome ends of PaP1 was designed. The genome has a 1190 bp terminal redundancy. PaP1 has 157 open reading frames (ORFs. Of these, 143 proteins are homologs of known proteins, but only 38 could be functionally identified. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and high-performance liquid chromatography-mass spectrometry allowed identification of 12 ORFs as structural protein coding genes within the PaP1 genome. Comparative genomic analysis indicated that the Pseudomonas aeruginosa phage PaP1, JG004, PAK_P1 and vB_PaeM_C2-10_Ab1 share great similarity. Besides their similar biological characteristics, the phages contain 123 core genes and have very close phylogenetic relationships, which distinguish them from other known phage genera. We therefore propose that these four phages be classified as PaP1-like phages, a new phage genus of Myoviridae that infects Pseudomonas aeruginosa.

  19. Spontaneous quorum sensing mutation modulates electroactivity of Pseudomonas aeruginosa PA14.

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    Berger, Carola; Rosenbaum, Miriam A

    2017-10-01

    Pseudomonas aeruginosa is able to interact with the anode of a bioelectrochemical system through redox active phenazines. Earlier studies showed that this interaction is strain and carbon source dependent. With a spontaneously formed ΔlasR mutant of P. aeruginosa PA14 and the wildtype, we investigated the connection between the complex quorum sensing network and current production. Depending on the carbon source, phenazine production and subsequently current generation are effected differently in these two populations. In glucose-fed cultures, the lack of the LasR regulator led to a shift in phenazine concentration, relative composition, and time profiles. In contrast, with the common fermentation product 2,3-butanediol as carbon substrate, no phenazine production was detected for the ΔlasR mutant. For the wildtype, this carbon source is known to induce phenazine synthesis and elevated current production. This work supports the earlier hypothesis of a signaling link between 2,3-butanediol and the quorum-sensing regulatory system and extends this hypothesis to predict a lasR-dependent interaction. The wildtype and mutant population were also evaluated in direct competition, showing strong initial dominance of the wildtype but a higher survival rate of the ΔlasR mutant in later stages of growth. We found no evidence for strong social interactions between these two subpopulations. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Facultative control of matrix production optimizes competitive fitness in Pseudomonas aeruginosa PA14 biofilm models.

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    Madsen, Jonas S; Lin, Yu-Cheng; Squyres, Georgia R; Price-Whelan, Alexa; de Santiago Torio, Ana; Song, Angela; Cornell, William C; Sørensen, Søren J; Xavier, Joao B; Dietrich, Lars E P

    2015-12-01

    As biofilms grow, resident cells inevitably face the challenge of resource limitation. In the opportunistic pathogen Pseudomonas aeruginosa PA14, electron acceptor availability affects matrix production and, as a result, biofilm morphogenesis. The secreted matrix polysaccharide Pel is required for pellicle formation and for colony wrinkling, two activities that promote access to O2. We examined the exploitability and evolvability of Pel production at the air-liquid interface (during pellicle formation) and on solid surfaces (during colony formation). Although Pel contributes to the developmental response to electron acceptor limitation in both biofilm formation regimes, we found variation in the exploitability of its production and necessity for competitive fitness between the two systems. The wild type showed a competitive advantage against a non-Pel-producing mutant in pellicles but no advantage in colonies. Adaptation to the pellicle environment selected for mutants with a competitive advantage against the wild type in pellicles but also caused a severe disadvantage in colonies, even in wrinkled colony centers. Evolution in the colony center produced divergent phenotypes, while adaptation to the colony edge produced mutants with clear competitive advantages against the wild type in this O2-replete niche. In general, the structurally heterogeneous colony environment promoted more diversification than the more homogeneous pellicle. These results suggest that the role of Pel in community structure formation in response to electron acceptor limitation is unique to specific biofilm models and that the facultative control of Pel production is required for PA14 to maintain optimum benefit in different types of communities. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  1. Production of biosurfactants from Pseudomonas aeruginosa PA 1 isolated in oil environments

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    L.M. Santa Anna

    2002-04-01

    Full Text Available The potential production of rhamnolipid-type biosurfactants is assessed based on the development of a fermentative process with a strain of Pseudomonas aeruginosa PA1, which was isolated from oil production wastewater in the Northeast of Brazil. These production of molecules using different carbon (n-hexadecane, paraffinic oil, glycerol and babassu oil and nitrogen sources (NaNO3, (NH42SO4 and CH4N2O was studied. The best results were obtained when using glycerol as substrate. A C/N ratio of 60/1 and use of sodium nitrate as nitrogen source resulted in higher production of the rhamnolipid, expressed by rhamnose (3.16 g/L and by the yield in relation to biomass (Yp/x = 0.70 g/g. Additionally, physical-chemical characteristics of the spent broth with and without cells were studied, providing a low critical micelle concentration of 19 mg/L and toxicity values of 13 and 13.8 mg/L using two test organisms, the micro crustacean Daphnia similis and the bacterium Vibrio fisheri (Microtox, respectively.

  2. Rhamnolipid but not motility is associated with the initiation of biofilm seeding dispersal of Pseudomonas aeruginosa strain PA17.

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    Wang, Jingjing; Yu, Bing; Tian, Deying; Ni, Ming

    2013-03-01

    Seeding dispersal is an active detachment exhibit in aging Pseudomonas aeruginosa biofilm. Yet, effect factors of this process in the biofilm of clinical isolated mucoid P. aeruginosa strain remain to be better characterized. In our previous work, one mucoid P. earuginosa strain PA17 was isolated from a patient with recurrent pulmonary infection. In this study, confocal scanning laser microscope combined with LIVE/DEAD viability staining revealed that PA17 biofilm exhibited earlier seeding dispersal than non-mucoid PAO1. We further compared the motility and the expression of motility-associated gene during biofilm development between PA17 and PAO1. PA17 was found to be impaired in all three kinds of motility compared to PAO1. Moreover, we investigated the expression of rhamnolipid-associated genes in PA17 and PAO1 biofilm. The expression of these genes was in accordance with the process of seeding dispersal. Our results indicated that rhamnolipid but not motility is associated with the initiation of seeding dispersal of PA17 biofilm.

  3. Fast biodegradation of toxic bisphenol a by Pseudomonas aeruginosa NR.22 (Ps.NR.22) isolated from Malaysian local lake

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    Him, Nik Raikhan Nik; Zainuddin, Mohammad Fiqri; Basha, Anuar Zain Anuar

    2017-12-01

    The paper focused on microbial degradation of Bisphenol A (BPA) as a safe and fast method to reduce BPA contamination in water. BPA is found in waste water, sea water and home water pipeline and it is nondegradable pollutant. Biodegradation is suggested to be practical solution for large volume of BPA. Biodegradation plays an important role and the effect of low concentration significantly decreased the degradation rate. Pseudomonas aeruginosa NR.22 (Ps.NR.22) which has been isolated from a lake at Seksyen 2, Shah Alam, was used. In Malaysia, Ps.NR.22 isolation agar is used for the BPA degradation process. It was stained with Gram negative-rod shaped bacteria that confirmed to carry a 16S rRNA gene. BPA as a sole carbon has been tested at various concentrations. The research showed that BPA was degraded at 10, 20, 30, 40 and 50 ppm and the bacteria growth rate was excellent in 20 ppm BPA. Degradation of BPA was carried out for 9 hours to 18 hours and the maximum degradation was recorded at 9 hours. The value of the highest peak of growth at 540 nm was 2.0617 using 20 ppm BPA. This novel Pseudomonas aeruginosa NR.22 has great potential to be used in waste water treatment.

  4. Pyocyanin Alters Redox Homeostasis and Carbon Flux through Central Metabolic Pathways in Pseudomonas aeruginosa PA14▿ †

    Science.gov (United States)

    Price-Whelan, Alexa; Dietrich, Lars E. P.; Newman, Dianne K.

    2007-01-01

    The opportunistic pathogen Pseudomonas aeruginosa produces colorful, redox-active antibiotics called phenazines. Excretion of pyocyanin, the best-studied natural phenazine, is responsible for the bluish tint of sputum and pus associated with P. aeruginosa infections in humans. Although the toxicity of pyocyanin for other bacteria, as well as its role in eukaryotic infection, has been studied extensively, the physiological relevance of pyocyanin metabolism for the producing organism is not well understood. Pyocyanin reduction by P. aeruginosa PA14 is readily observed in standing liquid cultures that have consumed all of the oxygen in the medium. We investigated the physiological consequences of pyocyanin reduction by assaying intracellular concentrations of NADH and NAD+ in the wild-type strain and a mutant defective in phenazine production. We found that the mutant accumulated more NADH in stationary phase than the wild type. This increased accumulation correlated with a decrease in oxygen availability and was relieved by the addition of nitrate. Pyocyanin addition to a phenazine-null mutant also decreased intracellular NADH levels, suggesting that pyocyanin reduction facilitates redox balancing in the absence of other electron acceptors. Analysis of extracellular organic acids revealed that pyocyanin stimulated stationary-phase pyruvate excretion in P. aeruginosa PA14, indicating that pyocyanin may also influence the intracellular redox state by decreasing carbon flux through central metabolic pathways. PMID:17526704

  5. Structural insights into the UbiD protein family from the crystal structure of PA0254 from Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Agata Jacewicz

    Full Text Available The 3-polyprenyl-4-hydroxybenzoate decarboxylase (UbiD catalyzes the conversion of 3-polyprenyl-4-hydroxybenzoate to 2-polyprenylphenol in the biosynthesis of ubiquinone. Pseudomonas aeruginosa contains two genes (PA0254 and PA5237 that are related in sequence to putative UbiD enzymes. A bioinformatics analysis suggests that the UbiD sequence family can be divided into two subclasses, with PA5237 and PA0254 belonging to different branches of this family. The three-dimensional structure of PA0254 has been determined using single wavelength anomalous diffraction and molecular replacement in two different crystal forms to resolutions of 1.95 and 2.3 Å, respectively. The subunit of PA0254 consists of three domains, an N-terminal α/β domain, a split β-barrel with a similar fold of a family of flavin reductases and a C-terminal α/β domain with a topology characteristic for the UbiD protein family. The middle domain contains a metal binding site adjacent to a large open cleft that may represent the active site. The two protein ligands binding a magnesium ion, His188 and Glu229, invariant in the PA0254 subclass, are also conserved in a corresponding metal site found in one of the FMN binding proteins from the split β-barrel fold family. PA0254 forms, in contrast to the hexameric UbiD from E. coli and P. aeruginosa, a homo-dimer. Insertion of four residues in a loop region in the PA0254 type enzymes results in structural differences that are incompatible with hexamer assembly.

  6. DdaR (PA1196) Regulates Expression of Dimethylarginine Dimethylaminohydrolase for the Metabolism of Methylarginines in Pseudomonas aeruginosa PAO1.

    Science.gov (United States)

    Lundgren, Benjamin R; Bailey, Frank J; Moley, Gabriella; Nomura, Christopher T

    2017-04-15

    Dimethylarginine dimethylaminohydrolases (DDAHs) catalyze the hydrolysis of methylarginines to yield l-citrulline and methylamines as products. DDAHs and their central roles in methylarginine metabolism have been characterized for eukaryotic cells. While DDAHs are known to exist in some bacteria, including Streptomyces coelicolor and Pseudomonas aeruginosa, the physiological importance and genetic regulation of bacterial DDAHs remain poorly understood. To provide some insight into bacterial methylarginine metabolism, this study focused on identifying the key elements or factors regulating DDAH expression in P. aeruginosa PAO1. First, results revealed that P. aeruginosa can utilize NG ,NG -dimethyl-l-arginine (ADMA) as a sole source of nitrogen but not carbon. Second, expression of the ddaH gene was observed to be induced in the presence of methylarginines, including NG -monomethyl-l-arginine (l-NMMA) and ADMA. Third, induction of the ddaH gene was shown to be achieved through a mechanism consisting of the putative enhancer-binding protein PA1196 and the alternative sigma factor RpoN. Both PA1196 and RpoN were essential for the expression of the ddaH gene in response to methylarginines. On the basis of the results of this study, PA1196 was given the name DdaR, for dimethylarginine dimethylaminohydrolase regulator. Interestingly, DdaR and its target ddaH gene are conserved only among P. aeruginosa strains, suggesting that this particular Pseudomonas species has evolved to utilize methylarginines from its environment.IMPORTANCE Methylated arginine residues are common constituents of eukaryotic proteins. During proteolysis, methylarginines are released in their free forms and become accessible nutrients for bacteria to utilize as growth substrates. In order to have a clearer and better understanding of this process, we explored methylarginine utilization in the metabolically versatile bacterium Pseudomonas aeruginosa PAO1. Our results show that the transcriptional

  7. Pseudomonas aeruginosa PA1006, which plays a role in molybdenum homeostasis, is required for nitrate utilization, biofilm formation, and virulence.

    Directory of Open Access Journals (Sweden)

    Melanie J Filiatrault

    Full Text Available Pseudomonas aeruginosa (Pae is a clinically important opportunistic pathogen. Herein, we demonstrate that the PA1006 protein is critical for all nitrate reductase activities, growth as a biofilm in a continuous flow system, as well as virulence in mouse burn and rat lung model systems. Microarray analysis revealed that ΔPA1006 cells displayed extensive alterations in gene expression including nitrate-responsive, quorum sensing (including PQS production, and iron-regulated genes, as well as molybdenum cofactor and Fe-S cluster biosynthesis factors, members of the TCA cycle, and Type VI Secretion System components. Phenotype Microarray™ profiles of ΔPA1006 aerobic cultures using Biolog plates also revealed a reduced ability to utilize a number of TCA cycle intermediates as well as a failure to utilize xanthine as a sole source of nitrogen. As a whole, these data indicate that the loss of PA1006 confers extensive changes in Pae metabolism. Based upon homology of PA1006 to the E. coli YhhP protein and data from the accompanying study, loss of PA1006 persulfuration and/or molybdenum homeostasis are likely the cause of extensive metabolic alterations that impact biofilm development and virulence in the ΔPA1006 mutant.

  8. Modification of Pseudomonas aeruginosa Pa5196 Type IV Pilins at Multiple Sites with d-Araf by a Novel GT-C Family Arabinosyltransferase, TfpW▿

    OpenAIRE

    Kus, Julianne V.; Kelly, John; Tessier, Luc; Harvey, Hanjeong; Cvitkovitch, Dennis G.; Burrows, Lori L.

    2008-01-01

    Pseudomonas aeruginosa Pa5196 produces type IV pilins modified with unusual α1,5-linked d-arabinofuranose (α1,5-d-Araf) glycans, identical to those in the lipoarabinomannan and arabinogalactan cell wall polymers from Mycobacterium spp. In this work, we identify a second strain of P. aeruginosa, PA7, capable of expressing arabinosylated pilins and use a combination of site-directed mutagenesis, electrospray ionization mass spectrometry (MS), and electron transfer dissociation MS to identify th...

  9. Post-transcriptional regulation of gene PA5507 controls PQS concentration in Pseudomonas aeruginosa

    OpenAIRE

    Tipton, Kyle A.; Coleman, James P.; Pesci, Everett C.

    2015-01-01

    Pseudomonas aeruginosa can sense and respond to a myriad of environmental signals and utilizes a system of small molecules to communicate through intercellular signaling. The small molecule 2-heptyl-3-hydroxy-4-quinolone (Pseudomonas Quinolone Signal [PQS]) is one of these signals and its synthesis is important for virulence. Previously, we identified an RpiR-type transcriptional regulator, QapR, that positively affects PQS production by repressing the qapR operon. An in-frame deletion of thi...

  10. Characterization of the Direct Interaction between Hybrid Sensor Kinases PA1611 and RetS That Controls Biofilm Formation and the Type III Secretion System in Pseudomonas aeruginosa.

    Science.gov (United States)

    Bhagirath, Anjali Y; Pydi, Sai P; Li, Yanqi; Lin, Chen; Kong, Weina; Chelikani, Prashen; Duan, Kangmin

    2017-02-10

    One of the leading causes of morbidity and mortality in cystic fibrosis (CF) patients is pulmonary infection with Pseudomonas aeruginosa, and the pathophysiology of pulmonary infection in CF is affected by the lifestyle of this micro-organism. RetS-GacS/A-RsmA is a key regulatory pathway in P. aeruginosa that determines the bacterium's lifestyle choice. Previously, we identified PA1611, a hybrid sensor kinase, as a new player in this pathway that interacts with RetS and influences biofilm formation and type III secretion system. In this study, we explored the structural and mechanistic basis of the interaction between PA1611 and RetS. We identified the amino acid residues critical for PA1611-RetS interactions by molecular modeling. These residues were then targeted for site-directed mutagenesis. Amino acid substitutions were carried out at seven key positions in PA1611 and at six corresponding key positions in RetS. The influence of such substitutions in PA1611 on the interaction was analyzed by bacterial two-hybrid assays. We carried out functional analysis of these mutants in P. aeruginosa for their effect on specific phenotypes. Two residues, F269 and E276, located within the histidine kinase A and histidine kinase-like ATPase domains of PA1611 were found to play crucial roles in the PA1611-RetS interaction and had profound effects on phenotypes. Corresponding mutations in RetS demonstrated similar results. We further confirmed that these mutations in PA1611 function through the GacS/GacA-RsmY/Z signaling pathway. Collectively, our findings provide a noncognate sensor kinase direct interaction model for a signaling pathway, key for lifestyle selection in P. aeruginosa, and targeting such interaction may serve as a novel way of controlling infections with P. aeruginosa.

  11. Quorum sensing systems differentially regulate the production of phenazine-1-carboxylic acid in the rhizobacterium Pseudomonas aeruginosa PA1201.

    Science.gov (United States)

    Sun, Shuang; Zhou, Lian; Jin, Kaiming; Jiang, Haixia; He, Ya-Wen

    2016-07-26

    Pseudomonas aeruginosa strain PA1201 is a newly identified rhizobacterium that produces high levels of the secondary metabolite phenazine-1-carboxylic acid (PCA), the newly registered biopesticide Shenqinmycin. PCA production in liquid batch cultures utilizing a specialized PCA-promoting medium (PPM) typically occurs after the period of most rapid growth, and production is regulated in a quorum sensing (QS)-dependent manner. PA1201 contains two PCA biosynthetic gene clusters phz1 and phz2; both clusters contribute to PCA production, with phz2 making a greater contribution. PA1201 also contains a complete set of genes for four QS systems (LasI/LasR, RhlI/RhlR, PQS/MvfR, and IQS). By using several methods including gene deletion, the construction of promoter-lacZ fusion reporter strains, and RNA-Seq analysis, this study investigated the effects of the four QS systems on bacterial growth, QS signal production, the expression of phz1 and phz2, and PCA production. The possible mechanisms for the strain- and condition-dependent expression of phz1 and phz2 were discussed, and a schematic model was proposed. These findings provide a basis for further genetic engineering of the QS systems to improve PCA production.

  12. A Mig-14-like protein (PA5003) affects antimicrobial peptide recognition in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jochumsen, Nicholas; Liu, Yang; Molin, Søren

    2011-01-01

    The evolution of antibiotic resistance in pathogenic bacteria is a growing global health problem which is gradually making the treatment of infectious diseases less efficient. Antimicrobial peptides are small charged molecules found in organisms from the complete phylogenetic spectrum. The peptides...... are attractive candidates for novel drug development due to their activity against bacteria that are resistant to conventional antibiotics, and reports of peptide resistance are rare in the clinical setting. Paradoxically, many clinically relevant bacteria have mechanisms that can recognize and respond...... to the presence of cationic antimicrobial peptides (CAMPs) in the environment by changing the properties of the microbial surface thereby increasing the tolerance of the microbes towards the peptides. In Pseudomonas aeruginosa an essential component of this inducible tolerance mechanism is the lipopolysaccharide...

  13. The YebC family protein PA0964 negatively regulates the Pseudomonas aeruginosa quinolone signal system and pyocyanin production.

    Science.gov (United States)

    Liang, Haihua; Li, Lingling; Dong, Zhaolin; Surette, Michael G; Duan, Kangmin

    2008-09-01

    Bacterial pathogenicity is often manifested by the expression of various cell-associated and secreted virulence factors, such as exoenzymes, protease, and toxins. In Pseudomonas aeruginosa, the expression of virulence genes is coordinately controlled by the global regulatory quorum-sensing systems, which includes the las and rhl systems as well as the Pseudomonas quinolone signal (PQS) system. Phenazine compounds are among the virulence factors under the control of both the rhl and PQS systems. In this study, regulation of the phzA1B1C1D1E1 (phzA1) operon, which is involved in phenazine synthesis, was investigated. In an initial study of inducing conditions, we observed that phzA1 was induced by subinhibitory concentrations of tetracycline. Screening of 13,000 mutants revealed 32 genes that altered phzA1 expression in the presence of subinhibitory tetracycline concentrations. Among them, the gene PA0964, designated pmpR (pqsR-mediated PQS regulator), has been identified as a novel regulator of the PQS system. It belongs to a large group of widespread conserved hypothetical proteins with unknown function, the YebC protein family (Pfam family DUF28). It negatively regulates the quorum-sensing response regulator pqsR of the PQS system by binding at its promoter region. Alongside phzA1 expression and phenazine and pyocyanin production, a set of virulence factors genes controlled by both rhl and the PQS were shown to be modulated by PmpR. Swarming motility and biofilm formation were also significantly affected. The results added another layer of regulation in the rather complex quorum-sensing systems in P. aeruginosa and demonstrated a clear functional clue for the YebC family proteins.

  14. Simultaneous bioremediation and biodetection of mercury ion through surface display of carboxylesterase E2 from Pseudomonas aeruginosa PA1.

    Science.gov (United States)

    Yin, Kun; Lv, Min; Wang, Qiaoning; Wu, Yixuan; Liao, Chunyang; Zhang, Weiwei; Chen, Lingxin

    2016-10-15

    Mercury is a toxic heavy metal and presents significant threats to organisms and natural ecosystems. Recently, the mercury remediation as well as its detection by environmental-friendly biotechnology has received increasing attention. In this study, carboxylesterase E2 from mercury-resistant strain Pseudomonas aeruginosa PA1 has been successfully displayed on the outer membrane of Escherichia coli Top10 bacteria to simultaneously adsorb and detect mercury ion (Hg(2+)). The transmission electron microscopy analysis shows that Hg(2+) can be absorbed by carboxylesterase E2 and accumulated on the outer membrane of surface-displayed E. coli bacteria. The adsorption of Hg(2+) followed a physicochemical, equilibrated and saturatable mechanism, which well fits the traditional Langmuir adsorption model. The surface-displayed system can be regenerated through regulating pH values. As its activity can be inhibited by Hg(2+), carboxylesterase E2 has been used to detect the concentration of Hg(2+) in water samples. The developed surface display system will be of great potential in the simultaneous bioremediation and biodetection of environmental mercury pollution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Engineering of PA-IIL lectin from Pseudomonas aeruginosa – Unravelling the role of the specificity loop for sugar preference

    Directory of Open Access Journals (Sweden)

    Imberty Anne

    2007-06-01

    Full Text Available Abstract Background Lectins are proteins of non-immune origin capable of binding saccharide structures with high specificity and affinity. Considering the high encoding capacity of oligosaccharides, this makes lectins important for adhesion and recognition. The present study is devoted to the PA-IIL lectin from Pseudomonas aeruginosa, an opportunistic human pathogen capable of causing lethal complications in cystic fibrosis patients. The lectin may play an important role in the process of virulence, recognizing specific saccharide structures and subsequently allowing the bacteria to adhere to the host cells. It displays high values of affinity towards monosaccharides, especially fucose – a feature caused by unusual binding mode, where two calcium ions participate in the interaction with saccharide. Investigating and understanding the nature of lectin-saccharide interactions holds a great potential of use in the field of drug design, namely the targeting and delivery of active compounds to the proper site of action. Results In vitro site-directed mutagenesis of the PA-IIL lectin yielded three single point mutants that were investigated both structurally (by X-ray crystallography and functionally (by isothermal titration calorimetry. The mutated amino acids (22–23–24 triad belong to the so-called specificity binding loop responsible for the monosaccharide specificity of the lectin. The mutation of the amino acids resulted in changes to the thermodynamic behaviour of the mutants and subsequently in their relative preference towards monosaccharides. Correlation of the measured data with X-ray structures provided the molecular basis for rationalizing the affinity changes. The mutations either prevent certain interactions to be formed or allow formation of new interactions – both of afore mentioned have strong effects on the saccharide preferences. Conclusion Mutagenesis of amino acids forming the specificity binding loop allowed

  16. Pseudomonas aeruginosa Exopolysaccharide Psl Promotes Resistance to the Biofilm Inhibitor Polysorbate 80

    OpenAIRE

    Zegans, Michael E.; Wozniak, Daniel; Griffin, Edward; Toutain-Kidd, Christine M.; Hammond, John H.; Garfoot, Andrew; Lam, Joseph S.

    2012-01-01

    Polysorbate 80 (PS80) is a nonionic surfactant and detergent that inhibits biofilm formation by Pseudomonas aeruginosa at concentrations as low as 0.001% and is well tolerated in human tissues. However, certain clinical and laboratory strains (PAO1) of P. aeruginosa are able to form biofilms in the presence of PS80. To better understand this resistance, we performed transposon mutagenesis with a PS80-resistant clinical isolate, PA738. This revealed that mutation of algC rendered PA738 sensiti...

  17. Pseudomonas aeruginosa LysR PA4203 regulator NmoR acts as a repressor of the PA4202 nmoA gene, encoding a nitronate monooxygenase

    DEFF Research Database (Denmark)

    Vercammen, Ken; Wei, Qing; Charlier, Daniel

    2015-01-01

    The PA4203 gene encodes a LysR regulator and lies between the ppgL gene (PA4204), which encodes a periplasmic gluconolactonase, and, in the opposite orientation, the PA4202 (nmoA) gene, coding for a nitronate monooxygenase, and ddlA (PA4201), encoding a d-alanine alanine ligase. The intergenic...... gene, encoding a quinone oxidoreductase, was the most highly upregulated gene in the nmoR deletion mutant, independently of MexT. Finally, deletion of the nmoA gene resulted in an increased sensitivity of the cells to 3-nitropropionic acid (3-NPA), confirming the role of the nitronate monooxygenase...

  18. [Isolation, identification and characterization of rice rhizobacterium Pseudomonas aeruginosa PA1201 producing high level of biopesticide "Shenqinmycin" and phenazine-1-carboxamide].

    Science.gov (United States)

    Zhou, Lian; Jiang, Haixia; Jin, Kaiming; Sun, Shuang; Zhang, Wei; Zhang, Xuehong; He, Ya-Wen

    2015-04-04

    To identify bacterial strains with the inhibitory activity to rice pathogens, and to evaluate their potentials for the development of new biopesticides. Rice rhizosphere Pseudomonas strains were isolated using 1-aminocyclopropane-1-carboxylic acid as the sole carbon source. Strain PA1201 was further identified through morphological analysis, biochemical characterization, 16S rDNA sequence analysis and phospholipid fatty acid profiling. Qualitative and quantitative analysis of the production of the green pesticide Shenqinmycin as well as phenazine-1-carboxamide produced by PA1201 was done by HPLC. Cytotoxicity of PA1201 was evaluated using human alveolar epithelial cell line A549 and Drosophila melanogaster as hosts. Strain PA1201 inhibited Rhizotonia solani Kuhn and Xanthomonas oryzae pv. oryzae, the causal agents of rice sheath blight and bacterial blight, respectively. It was further identified as Pseudomonas aeruginosa PA1201, which produces shenqinmycin and phenazine-1-carboxamide. The fermentation titer of shenqinmycin and phenazine-1-carboxamide in the PPM medium was 81.7 mg/L and 18. 1 mg/L, respectively. In the medium supplemented with soybean meal and corn steep liquor, the level of shenqinmycin and phenazine-1-carboxamide reached 926. 9 mg/L and 489. 5 mg/L. PA1201 also produced high level of extracellular protease and was toxic to human cell line and fruit fly. Strain PA1201 could be engineered for higher yield of Shenqinmycin or for a new biopesticide.

  19. Proteomic profiling of Pseudomonas aeruginosa AES-1R, PAO1 and PA14 reveals potential virulence determinants associated with a transmissible cystic fibrosis-associated strain.

    Science.gov (United States)

    Hare, Nathan J; Solis, Nestor; Harmer, Christopher; Marzook, N Bishara; Rose, Barbara; Harbour, Colin; Crossett, Ben; Manos, Jim; Cordwell, Stuart J

    2012-01-22

    Pseudomonas aeruginosa is an opportunistic pathogen that is the major cause of morbidity and mortality in patients with cystic fibrosis (CF). While most CF patients are thought to acquire P. aeruginosa from the environment, person-person transmissible strains have been identified in CF clinics worldwide. The molecular basis for transmissibility and colonization of the CF lung remains poorly understood. A dual proteomics approach consisting of gel-based and gel-free comparisons were undertaken to analyse protein profiles in a transmissible, early (acute) isolate of the Australian epidemic strain 1 (AES-1R), the virulent burns/wound isolate PA14, and the poorly virulent, laboratory-associated strain PAO1. Over 1700 P. aeruginosa proteins were confidently identified. AES-1R protein profiles revealed elevated abundance of proteins associated with virulence and siderophore biosynthesis and acquisition, antibiotic resistance and lipopolysaccharide and fatty acid biosynthesis. The most abundant protein in AES-1R was confirmed as a previously hypothetical protein with sequence similarity to carbohydrate-binding proteins and database search revealed this gene is only found in the CF-associated strain PA2192. The link with CF infection may suggest that transmissible strains have acquired an ability to rapidly interact with host mucosal glycoproteins. Our data suggest that AES-1R expresses higher levels of proteins, such as those involved in antibiotic resistance, iron acquisition and virulence that may provide a competitive advantage during early infection in the CF lung. Identification of novel proteins associated with transmissibility and acute infection may aid in deciphering new strategies for intervention to limit P. aeruginosa infections in CF patients.

  20. A Pseudomonas aeruginosa EF-hand protein, EfhP (PA4107, modulates stress responses and virulence at high calcium concentration.

    Directory of Open Access Journals (Sweden)

    Svetlana A Sarkisova

    Full Text Available Pseudomonas aeruginosa is a facultative human pathogen, and a major cause of nosocomial infections and severe chronic infections in endocarditis and in cystic fibrosis (CF patients. Calcium (Ca2+ accumulates in pulmonary fluids of CF patients, and plays a role in the hyperinflammatory response to bacterial infection. Earlier we showed that P. aeruginosa responds to increased Ca2+ levels, primarily through the increased production of secreted virulence factors. Here we describe the role of putative Ca2+-binding protein, with an EF-hand domain, PA4107 (EfhP, in this response. Deletion mutations of efhP were generated in P. aeruginosa strain PAO1 and CF pulmonary isolate, strain FRD1. The lack of EfhP abolished the ability of P. aeruginosa PAO1 to maintain intracellular Ca2+ homeostasis. Quantitative high-resolution 2D-PAGE showed that the efhP deletion also affected the proteomes of both strains during growth with added Ca2+. The greatest proteome effects occurred when the pulmonary isolate was cultured in biofilms. Among the proteins that were significantly less abundant or absent in the mutant strains were proteins involved in iron acquisition, biosynthesis of pyocyanin, proteases, and stress response proteins. In support, the phenotypic responses of FRD1 ΔefhP showed that the mutant strain lost its ability to produce pyocyanin, developed less biofilm, and had decreased resistance to oxidative stress (H2O2 when cultured at high [Ca2+]. Furthermore, the mutant strain was unable to produce alginate when grown at high [Ca2+] and no iron. The effect of the ΔefhP mutations on virulence was determined in a lettuce model of infection. Growth of wild-type P. aeruginosa strains at high [Ca2+] causes an increased area of disease. In contrast, the lack of efhP prevented this Ca2+-induced increase in the diseased zone. The results indicate that EfhP is important for Ca2+ homeostasis and virulence of P. aeruginosa when it encounters host environments with

  1. Pseudomonas aeruginosa exopolysaccharide Psl promotes resistance to the biofilm inhibitor polysorbate 80.

    Science.gov (United States)

    Zegans, Michael E; Wozniak, Daniel; Griffin, Edward; Toutain-Kidd, Christine M; Hammond, John H; Garfoot, Andrew; Lam, Joseph S

    2012-08-01

    Polysorbate 80 (PS80) is a nonionic surfactant and detergent that inhibits biofilm formation by Pseudomonas aeruginosa at concentrations as low as 0.001% and is well tolerated in human tissues. However, certain clinical and laboratory strains (PAO1) of P. aeruginosa are able to form biofilms in the presence of PS80. To better understand this resistance, we performed transposon mutagenesis with a PS80-resistant clinical isolate, PA738. This revealed that mutation of algC rendered PA738 sensitive to PS80 biofilm inhibition. AlgC contributes to the biosynthesis of the exopolysaccharides Psl and alginate, as well as lipopolysaccharide and rhamnolipid. Analysis of mutations downstream of AlgC in these biosynthetic pathways established that disruption of the psl operon was sufficient to render the PA738 and PAO1 strains sensitive to PS80-mediated biofilm inhibition. Increased levels of Psl production in the presence of arabinose in a strain with an arabinose-inducible psl promoter were correlated with increased biofilm formation in PS80. In P. aeruginosa strains MJK8 and ZK2870, known to produce both Pel and Psl, disruption of genes in the psl but not the pel operon conferred susceptibility to PS80-mediated biofilm inhibition. The laboratory strain PA14 does not produce Psl and does not form biofilms in PS80. However, when PA14 was transformed with a cosmid containing the psl operon, it formed biofilms in the presence of PS80. Taken together, these data suggest that production of the exopolysaccharide Psl by P. aeruginosa promotes resistance to the biofilm inhibitor PS80.

  2. Inhibition of co-colonizing cystic fibrosis-associated pathogens by Pseudomonas aeruginosa and Burkholderia multivorans.

    Science.gov (United States)

    Costello, Anne; Reen, F Jerry; O'Gara, Fergal; Callaghan, Máire; McClean, Siobhán

    2014-07-01

    Cystic fibrosis (CF) is a recessive genetic disease characterized by chronic respiratory infections and inflammation causing permanent lung damage. Recurrent infections are caused by Gram-negative antibiotic-resistant bacterial pathogens such as Pseudomonas aeruginosa, Burkholderia cepacia complex (Bcc) and the emerging pathogen genus Pandoraea. In this study, the interactions between co-colonizing CF pathogens were investigated. Both Pandoraea and Bcc elicited potent pro-inflammatory responses that were significantly greater than Ps. aeruginosa. The original aim was to examine whether combinations of pro-inflammatory pathogens would further exacerbate inflammation. In contrast, when these pathogens were colonized in the presence of Ps. aeruginosa the pro-inflammatory response was significantly decreased. Real-time PCR quantification of bacterial DNA from mixed cultures indicated that Ps. aeruginosa significantly inhibited the growth of Burkholderia multivorans, Burkholderia cenocepacia, Pandoraea pulmonicola and Pandoraea apista, which may be a factor in its dominance as a colonizer of CF patients. Ps. aeruginosa cell-free supernatant also suppressed growth of these pathogens, indicating that inhibition was innate rather than a response to the presence of a competitor. Screening of a Ps. aeruginosa mutant library highlighted a role for quorum sensing and pyoverdine biosynthesis genes in the inhibition of B. cenocepacia. Pyoverdine was confirmed to contribute to the inhibition of B. cenocepacia strain J2315. B. multivorans was the only species that could significantly inhibit Ps. aeruginosa growth. B. multivorans also inhibited B. cenocepacia and Pa. apista. In conclusion, both Ps. aeruginosa and B. multivorans are capable of suppressing growth and virulence of co-colonizing CF pathogens. © 2014 The Authors.

  3. The ABC of Biofilm Drug Tolerance: the MerR-Like Regulator BrlR Is an Activator of ABC Transport Systems, with PA1874-77 Contributing to the Tolerance of Pseudomonas aeruginosa Biofilms to Tobramycin.

    Science.gov (United States)

    Poudyal, Bandita; Sauer, Karin

    2018-02-01

    A hallmark of biofilms is their tolerance to killing by antimicrobial agents. In Pseudomonas aeruginosa, biofilm drug tolerance requires the c-di-GMP-responsive MerR transcriptional regulator BrlR. However, the mechanism by which BrlR mediates biofilm drug tolerance has not been elucidated. Here, we demonstrate that BrlR activates the expression of at least 7 ABC transport systems, including the PA1874-PA1875-PA1876-PA1877 (PA1874-77) operon, with chromatin immunoprecipitation and DNA binding assays confirming BrlR binding to the promoter region of PA1874-77. Insertional inactivation of the 7 ABC transport systems rendered P. aeruginosa PAO1 biofilms susceptible to tobramycin or norfloxacin. Susceptibility was linked to drug accumulation, with BrlR contributing to norfloxacin accumulation in a manner dependent on multidrug efflux pumps and the PA1874-77 ABC transport system. Inactivation of the respective ABC transport system, furthermore, eliminated the recalcitrance of biofilms to killing by tobramycin but not norfloxacin, indicating that drug accumulation is not linked to biofilm drug tolerance. Our findings indicate for the first time that BrlR, a MerR-type transcriptional activator, activates genes encoding several ABC transport systems, in addition to multiple multidrug efflux pump genes. Moreover, our data confirm a BrlR target contributing to drug tolerance, likely countering the prevailing dogma that biofilm tolerance arises from a multiplicity of factors. Copyright © 2018 American Society for Microbiology.

  4. Characterization of the multiple molecular mechanisms underlying RsaL control of phenazine-1-carboxylic acid biosynthesis in the rhizosphere bacterium Pseudomonas aeruginosa PA1201.

    Science.gov (United States)

    Sun, Shuang; Chen, Bo; Jin, Zi-Jing; Zhou, Lian; Fang, Yun-Ling; Thawai, Chitti; Rampioni, Giordano; He, Ya-Wen

    2017-06-01

    Phenazines are important secondary metabolites that have been found to affect a broad spectrum of organisms. Two almost identical gene clusters phz1 and phz2 are responsible for phenazines biosynthesis in the rhizobacterium Pseudomonas aeruginosa PA1201. Here, we show that the transcriptional regulator RsaL is a potent repressor of phenazine-1-carboxylic acid (PCA) biosynthesis. RsaL negatively regulates phz1 expression and positively regulates phz2 expression via multiple mechanisms. First, RsaL binds to a 25-bp DNA region within the phz1 promoter to directly repress phz1 expression. Second, RsaL indirectly regulates the expression of both phz clusters by decreasing the activity of the las and pqs quorum sensing (QS) systems, and by promoting the rhl QS system. Finally, RsaL represses phz1 expression through the downstream transcriptional regulator CdpR. RsaL directly binds to the promoter region of cdpR to positively regulate its expression, and subsequently CdpR regulates phz1 expression in a negative manner. We also show that RsaL represents a new mechanism for the turnover of the QS signal molecule N-3-oxododecanoyl-homoserine lactone (3-oxo-C12-HSL). Overall, this study elucidates RsaL control of phenazines biosynthesis and indicates that a PA1201 strain harboring deletions in both the rsaL and cdpR genes could be used to improve the industrial production of PCA. © 2017 John Wiley & Sons Ltd.

  5. Glycosylation of Pseudomonas aeruginosa Strain Pa5196 Type IV Pilins with Mycobacterium-Like α-1,5-Linked d-Araf Oligosaccharides▿

    OpenAIRE

    Voisin, Sébastien; Kus, Julianne V.; Houliston, Scott; St-Michael, Frank; Watson, Dave; Cvitkovitch, Dennis G.; Kelly, John; Brisson, Jean-Robert; Burrows, Lori L.

    2006-01-01

    Pseudomonas aeruginosa is a gram-negative bacterium that uses polar type IV pili for adherence to various materials and for rapid colonization of surfaces via twitching motility. Within the P. aeruginosa species, five distinct alleles encoding variants of the structural subunit PilA varying in amino acid sequence, length, and presence of posttranslational modifications have been identified. In this work, a combination of mass spectrometry and nuclear magnetic resonance spectroscopy was used t...

  6. Genome-Wide Survey of Pseudomonas aeruginosa PA14 Reveals a Role for the Glyoxylate Pathway and Extracellular Proteases in the Utilization of Mucin.

    Science.gov (United States)

    Flynn, Jeffrey M; Phan, Chi; Hunter, Ryan C

    2017-08-01

    Chronic airway infections by the opportunistic pathogen Pseudomonas aeruginosa are a major cause of mortality in cystic fibrosis (CF) patients. Although this bacterium has been extensively studied for its virulence determinants, biofilm growth, and immune evasion mechanisms, comparatively little is known about the nutrient sources that sustain its growth in vivo Respiratory mucins represent a potentially abundant bioavailable nutrient source, although we have recently shown that canonical pathogens inefficiently use these host glycoproteins as a growth substrate. However, given that P. aeruginosa, particularly in its biofilm mode of growth, is thought to grow slowly in vivo, the inefficient use of mucin glycoproteins may be relevant to its persistence within the CF airways. To this end, we used whole-genome fitness analysis, combining transposon mutagenesis with high-throughput sequencing, to identify genetic determinants required for P. aeruginosa growth using intact purified mucins as a sole carbon source. Our analysis reveals a biphasic growth phenotype, during which the glyoxylate pathway and amino acid biosynthetic machinery are required for mucin utilization. Secondary analyses confirmed the simultaneous liberation and consumption of acetate during mucin degradation and revealed a central role for the extracellular proteases LasB and AprA. Together, these studies describe a molecular basis for mucin-based nutrient acquisition by P. aeruginosa and reveal a host-pathogen dynamic that may contribute to its persistence within the CF airways. Copyright © 2017 American Society for Microbiology.

  7. High affinity fucose binding of Pseudomonas aeruginosa lectin PA-IIL: 1.0 Å resolution crystal structure of the complex combined with thermodynamics and computational chemistry approaches

    Czech Academy of Sciences Publication Activity Database

    Mitchell, E.P.; Sabin, Ch.; Šnajdrová, L.; Pokorná, M.; Perret, S.; Gautier, C.; Hofr, Ctirad; Gilboa-Garber, N.; Koča, J.; Wimmerová, M.; Imberty, A.

    2005-01-01

    Roč. 58, č. 3 (2005), s. 735-746 ISSN 0887-3585 R&D Projects: GA ČR(CZ) GP202/01/D110 Grant - others:GA MŠk(CZ) LN00A016 Program:LN Institutional research plan: CEZ:AV0Z50040507 Keywords : Pseudomonas aeruginosa * lectin * fucose Subject RIV: BO - Biophysics Impact factor: 4.684, year: 2005

  8. Comparison of the antimicrobial adhesion potential of human body fluid glycoconjugates using fucose-binding lectin (PA-IIL) of Pseudomonas aeruginosa and Ulex europaeus lectin (UEA-I).

    Science.gov (United States)

    Lerrer, Batia; Lesman-Movshovich, Efrat; Gilboa-Garber, Nechama

    2005-09-01

    Pseudomonas aeruginosa produces a fucose-binding lectin (PA-IIL) which strongly binds to human cells. This lectin was shown to be highly sensitive to inhibition by fucose-bearing human milk glycoproteins. Since the glycans of these glycoproteins mimic human cell receptors, they may function as decoys in blocking lectin-dependent pathogen adhesion to the host cells. Human saliva and seminal fluid also contain such compounds, and body fluids of individuals who are "secretors" express additional fucosylated (alpha 1,2) residues. The latter are selectively detected by Ulex europaeus lectin UEA-I. The aim of the present research was to compare the PA-IIL and UEA-I interactions with human salivas and seminal fluids of "secretors" and "nonsecretors" with those obtained with the respective milks. Using hemagglutination inhibition and Western blot analyses, we showed that PA-IIL interactions with the saliva and seminal fluid glycoproteins were somewhat weaker than those obtained with the milk and that "nonsecretor" body fluids were not less efficient than those of "secretors" in PA-IIL blocking. UEA-I, which interacted only with the "secretors" glycoproteins, was most sensitive to those of the seminal fluids.

  9. The galactophilic lectin (PA-IL, gene LecA) from Pseudomonas aeruginosa. Its binding requirements and the localization of lectin receptors in various mouse tissues

    DEFF Research Database (Denmark)

    Kirkeby, Svend; Hansen, Axel K; d'Apice, Anthony

    2006-01-01

    . It is concluded that the carbohydrate recognizing site of the lectin can have a binding requirement of only one saccharide. Lectin histochemistry was performed on sections from wild type mice and from knock-out mice, which lack function of the alpha.1,3-galactosyltransferase gene. All assays with the P....... aeruginosa lectin were compared with the results obtained using an isolectin from the legume shrub Griffonia simplicifolia: the GSI-134 isolectin, which is highly specific for glycans terminating in Ga1 alpha 1-R. In the wild-type mice, lectin histochemistry showed a strong capillary reaction in heart...... was observed, it seems that, in the mouse, the Pseudomonas lectin adheres to the Gal alpha l-3Ga4 beta 1-G1cNAc carbohydrate on endothelial cells in most organs and tissues. Finally, lectin staining of the basement membrane of the acini in the exocrine pancreas suggests the presence of Ga1 alpha 1-3Gal...

  10. Surfactants and the attachment of Pseudomonas aeruginosa to ...

    African Journals Online (AJOL)

    2-phenylidole (DAPI) staining, scanning electron microscopy (SEM) and spectrophotometry for their efficacy in preventing adhesion and removing Ps. Aeruginosa attached to 3CR12 stainless steel coupons and glass. All the surfactants tested ...

  11. extracts of senna siamea (lam) on pseudomonas aeruginosa

    African Journals Online (AJOL)

    DR. AMINU

    2009-05-30

    May 30, 2009 ... convulsion in children (Alli – Smith, 2009). In an attempt to rationally identify which pathogen to screen, Pseudomonas aeruginosa was epidemiologically identified as the hardiest bacterium that constitutes problems to researchers and clinicians. As literature showed, the hardy nature of Ps aeruginosa is ...

  12. P. aeruginosa colonization at ICU admission as a risk factor for developing P. aeruginosa ICU pneumonia

    NARCIS (Netherlands)

    Paling, FP; Wolkewitz, Martin; Depuydt, Pieter; de Bus, Liesbet; Sifakis, Frangiscos; Bonten, Marc J M; Kluytmans, Jan A J W

    2017-01-01

    OBJECTIVE: To determine the incidence of P. aeruginosa (PA) ICU pneumonia and its independent association with PA colonization at ICU admission. METHODS: This was a post-hoc analysis of a prospectively collected cohort study. Adult ICU patients with a length of stay of ≥48 h were included and

  13. Iron-Regulated Expression of Alginate Production, Mucoid Phenotype, and Biofilm Formation by Pseudomonas aeruginosa

    Science.gov (United States)

    Wiens, Jacinta R.; Vasil, Adriana I.; Schurr, Michael J.; Vasil, Michael L.

    2014-01-01

    ABSTRACT Pseudomonas aeruginosa strains of non-cystic fibrosis (non-CF) origin do not produce significant amounts of extracellular alginate and are nonmucoid. In CF, such isolates can become mucoid through mutation of one of the genes (mucA, mucB, mucC, or mucD) that produce regulatory factors that sequester AlgU, required for increased expression of alginate genes. Mutation of the muc genes in the nonmucoid PAO1, PA14, PAKS-1, and Ps388 strains led to increased levels of extracellular alginate and an obvious mucoid phenotype, but only under iron-limiting growth conditions (≤5 µM), not under iron-replete conditions (≥10 µM). In contrast, >50% of P. aeruginosa isolates from chronic CF pulmonary infections expressed increased levels of alginate and mucoidy both under iron-limiting and iron-replete conditions (i.e., iron-constitutive phenotype). No single iron regulatory factor (e.g., Fur, PvdS) was associated with this loss of iron-regulated alginate expression and mucoidy in these CF isolates. However, the loss of only pyoverdine production, or its uptake, abrogated the ability of P. aeruginosa to produce a robust biofilm that represents the Psl-type of biofilm. In contrast, we show that mutation of the pyoverdine and pyochelin biosynthesis genes and the pyoverdine receptor (FpvA) lead to iron-constitutive expression of the key alginate biosynthesis gene, algD, and an explicitly mucoid phenotype in both iron-limiting and iron-replete conditions. These data indicate that alginate production and mucoidy, in contrast to other types of biofilms produced by P. aeruginosa, are substantially enhanced under iron limitation. These results also have compelling implications in relation to the use of iron chelators in the treatment of P. aeruginosa CF infections. PMID:24496793

  14. P. aeruginosa colonization at ICU admission as a risk factor for developing P. aeruginosa ICU pneumonia

    Directory of Open Access Journals (Sweden)

    Fleur P. Paling

    2017-04-01

    Full Text Available Abstract Objective To determine the incidence of P. aeruginosa (PA ICU pneumonia and its independent association with PA colonization at ICU admission. Methods This was a post-hoc analysis of a prospectively collected cohort study. Adult ICU patients with a length of stay of ≥48 h were included and assessed for microbiologically confirmed PA ICU pneumonia. Multivariate survival analysis was performed, including the covariates age, gender, PA colonization at ICU admission, ICU admission specialty and mechanical ventilation at ICU admission, while taking into account the effect of competing risks. Results We included 5093 patients, 2447 (48% were tested for colonization; of those 226 (9.2% were PA colonized at ICU admission. The incidence of PA ICU pneumonia was 1.34% (n = 68. PA colonization was an independent risk factor (subdistribution hazard ratio [SHR] 8.8; 95% confidence interval [CI] 4.9–15.7, as was mechanical ventilation (SHR 5.3, 95% CI 2.7–10.6. Conclusion In this study the incidence of P. aeruginosa ICU pneumonia was 1.34%. Hazard ratios for PA colonized patients compared to non-colonized to develop PA ICU pneumonia were 8.8. The high risk associated with P. aeruginosa colonization for subsequent infection may offer a target for future interventions.

  15. HD-GYP domain proteins regulate biofilm formation and virulence in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Ryan, Robert P.; Lucey, Jean; O'Donovan, Karen

    2009-01-01

    residues (YN-GYP). Here we have investigated the role of these proteins in biofilm formation, virulence factor synthesis and virulence of P. aeruginosa. Mutation of PA4108 and PA4781 led to an increase in the level of cyclic-di-GMP in P. aeruginosa, consistent with the predicted activity of the encoded......2572 had a negative influence on swarming that was cryptic and was revealed only after removal of an uncharacterized C-terminal domain. Mutation of PA4108, PA4781 and PA2572 had distinct effects on biofilm formation and architecture of P. aeruginosa. All three proteins contributed to virulence of P...

  16. Reconstruction of the metabolic network of Pseudomonas aeruginosa to interrogate virulence factor synthesis

    DEFF Research Database (Denmark)

    Bartell, Jennifer; Blazier, Anna S; Yen, Phillip

    2017-01-01

    to metabolism. We evaluate the complex interrelationships between growth and virulence-linked pathways using a genome-scale metabolic network reconstruction of Pseudomonas aeruginosa strain PA14 and an updated, expanded reconstruction of P. aeruginosa strain PAO1. The PA14 reconstruction accounts...

  17. Pseudomonas aeruginosa in Healthcare Settings

    Science.gov (United States)

    ... Sepsis Sharps Safety - CDC Transplant Safety Vaccine Safety Pseudomonas aeruginosa in Healthcare Settings Recommend on Facebook Tweet Share ... aeruginosa . Pseudomonas aeruginosa What types of infections does Pseudomonas aeruginosa cause? Serious Pseudomonas infections usually occur in people ...

  18. Last PS magnet refurbished

    CERN Document Server

    2009-01-01

    PS Magnet Refurbishment Programme Completed. The 51st and final refurbished magnet was transported to the PS on Tuesday 3 February. The repair and consolidation work on the PS started back in 2003 when two magnets and a busbar connection were found to be faulty during routine high-voltage tests. The cause of the fault was a combination of age and radiation on electrical insulation. After further investigation the decision was taken to overhaul half of the PS’s 100 magnets to reduce the risk of a similar fault. As from 20 February the PS ring will start a five-week test programme to be ready for operation at the end of March.

  19. Effective fiber for lactating dairy cows: a physically adjusted NDF (paNDF) system

    Science.gov (United States)

    Multiplying dietary NDF by particle size (PS) has been used as an estimate of physically effective fiber (peNDF). Our objectives were to: 1) compare the use of peNDF as dietary NDF × PS vs. use of individual NDF and PS descriptors in a physically adjusted NDF (paNDF) system when used with other fact...

  20. Inside the PS tunnel

    CERN Multimedia

    1974-01-01

    Pre-start work is going on at the end of the PS long shut-down. The photo shows secondary beams drawn from an internal target (bottom) towards South Hall, behind the shielding wall (top) (see also photo 7409012X).

  1. PS Control Room

    CERN Multimedia

    CERN PhotoLab

    1963-01-01

    The good old PS Control Room, all manual. For each parameter, a knob or a button to control it; for each, a light or meter or oscilloscope to monitor it; carefully written pages serve as the data bank; phones and intercom for communication. D.Dekkers is at the microphone, M.Valvini sits in front.

  2. PS auxiliary magnet

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    Units of the PS auxiliary magnet system. The picture shows how the new dipoles, used for vertical and horizontal high-energy beam manipulation, are split for installation and removal so that it is not necessary to break the accelerator vacuum. On the right, adjacent to the sector valve and the windings of the main magnet, is an octupole of the set.

  3. PS injection area

    CERN Multimedia

    1974-01-01

    Looking against the direction of protons in the main ring (left): the beam coming from the linac 1 either goes to the booster (on the right) or is deflected towards the PS to be directly injected into section 26 (facing the camera). Also shown the start of the TT2 line, ejected from straight section 16 to go towards the ISR passing over the beam line from the linac. (see Photo Archive 7409009)

  4. PS injection area

    CERN Multimedia

    1974-01-01

    To the right is the PS ring viewed along the direction of the protons. At the left the injection line coming from the 50 MeV Linac 1 (bottom) and going towards the 800 MeV booster, or deflected to the right to be injected directly into straight section 16. The drumlike element behind the (blue) dipole magnet is a 'debuncher' (a 200 MHz cavity). See photos 7409014X and 7409009.

  5. Intensive care unit-acquired pneumonia due to Pseudomonas aeruginosa with and without multidrug resistance.

    Science.gov (United States)

    Fernández-Barat, Laia; Ferrer, Miquel; De Rosa, Francesca; Gabarrús, Albert; Esperatti, Mariano; Terraneo, Silvia; Rinaudo, Mariano; Li Bassi, Gianluigi; Torres, Antoni

    2017-02-01

    Pseudomonas aeruginosa often presents multi-drug resistance (MDR) in intensive care unit (ICU)-acquired pneumonia (ICUAP), possibly resulting in inappropriate empiric treatment and worse outcomes. We aimed to identify patients with ICUAP at risk for these pathogens in order to improve treatment selection and outcomes. We prospectively assessed 222 consecutive immunocompetent ICUAP patients confirmed microbiologically. We determined the characteristics, risk factors, systemic inflammatory response and outcomes of P. aeruginosa pneumonia (Pa-ICUAP), compared to other aetiologies. We also compared patients with MDR vs. non-MDR Pa-ICUAP. Pseudomonas aeruginosa was the most frequent aetiology (64, 29%); 22 (34%) cases had MDR. Independent predictors for Pa-ICUAP were prior airway colonization by P. aeruginosa, previous antibiotic treatment, solid cancer and shock; alcohol abuse and pleural effusion were independently associated to lower risk for Pa-ICUAP. Chronic liver disease independently predicted MDR among Pa-ICUAP. The inflammatory biomarkers were similar between all groups. Patients with Pa-ICUAP had lower unadjusted 90-day survival (p = 0.049). However, the 90-day survival adjusted for confounding factors using a propensity score did not differ between all groups. Pseudomonas aeruginosa remains the most frequent aetiology of ICUAP, with high prevalence of MDR. These risk factors should be taken into account to avoid inappropriate empiric antibiotics for Pa-ICUAP. Pseudomonas aeruginosa, regardless multidrug resistance, was not associated with different propensity-adjusted survival. Copyright © 2016 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  6. Polysorbate 80 inhibition of Pseudomonas aeruginosa biofilm formation and its cleavage by the secreted lipase LipA.

    Science.gov (United States)

    Toutain-Kidd, Christine M; Kadivar, Samoneh C; Bramante, Carolyn T; Bobin, Stephen A; Zegans, Michael E

    2009-01-01

    Surface-associated bacterial communities known as biofilms are an important source of nosocomial infections. Microorganisms such as Pseudomonas aeruginosa can colonize the abiotic surfaces of medical implants, leading to chronic infections that are difficult to eradicate. Our study demonstrates that polysorbate 80 (PS80), a surfactant commonly added to food and medicines, is able to inhibit biofilm formation by P. aeruginosa on a variety of surfaces, including contact lenses. Many clinical isolates of P. aeruginosa, as well as gram-negative and gram-positive clinical isolates, were also inhibited in their ability to form biofilms in the presence of PS80. A P. aeruginosa mutant able to form biofilms in the presence of this surfactant was identified and characterized, and it was revealed that this mutant overexpresses a lipase, LipA. Surfactants such as PS80 can be cleaved by lipases, and we demonstrate that PS80 is cleaved by LipA at its ester bond. Finally, polyethoxylated(20) oleyl alcohol, a chemical with a structure that is similar to that of PS80 but that lacks the ester bond of PS80, can inhibit the biofilm formation of P. aeruginosa strains, including the mutant overexpressing LipA. Our results demonstrate that surfactants such as PS80 can inhibit bacterial biofilm formation on medically relevant materials at concentrations demonstrated to be safe in humans and suggest that the understanding of the mechanisms of bacterial resistance to such surfactants will be important in developing clinically effective derivatives.

  7. Polysorbate 80 Inhibition of Pseudomonas aeruginosa Biofilm Formation and Its Cleavage by the Secreted Lipase LipA▿

    Science.gov (United States)

    Toutain-Kidd, Christine M.; Kadivar, Samoneh C.; Bramante, Carolyn T.; Bobin, Stephen A.; Zegans, Michael E.

    2009-01-01

    Surface-associated bacterial communities known as biofilms are an important source of nosocomial infections. Microorganisms such as Pseudomonas aeruginosa can colonize the abiotic surfaces of medical implants, leading to chronic infections that are difficult to eradicate. Our study demonstrates that polysorbate 80 (PS80), a surfactant commonly added to food and medicines, is able to inhibit biofilm formation by P. aeruginosa on a variety of surfaces, including contact lenses. Many clinical isolates of P. aeruginosa, as well as gram-negative and gram-positive clinical isolates, were also inhibited in their ability to form biofilms in the presence of PS80. A P. aeruginosa mutant able to form biofilms in the presence of this surfactant was identified and characterized, and it was revealed that this mutant overexpresses a lipase, LipA. Surfactants such as PS80 can be cleaved by lipases, and we demonstrate that PS80 is cleaved by LipA at its ester bond. Finally, polyethoxylated(20) oleyl alcohol, a chemical with a structure that is similar to that of PS80 but that lacks the ester bond of PS80, can inhibit the biofilm formation of P. aeruginosa strains, including the mutant overexpressing LipA. Our results demonstrate that surfactants such as PS80 can inhibit bacterial biofilm formation on medically relevant materials at concentrations demonstrated to be safe in humans and suggest that the understanding of the mechanisms of bacterial resistance to such surfactants will be important in developing clinically effective derivatives. PMID:18955535

  8. Quorum quenching by an N-acyl-homoserine lactone acylase from Pseudomonas aeruginosa PAO1

    NARCIS (Netherlands)

    Sio, CF; Otten, LG; Cool, RH; Diggle, SP; Braun, PG; Daykin, M; Camara, M; Williams, P; Quax, WJ; Bos, R

    The virulence of the opportunistic human pathogen Pseudomonas aeruginosa PAO1 is controlled by an N-acyl-homoserine lactone (AHL)-dependent quorum-sensing system. During functional analysis of putative acylase genes in the P. aeruginosa PAO1 genome, the PA2385 gene was found to encode an acylase

  9. At PS170 (APPLE)

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    APPLE stands for Antiproton-Proton to Pair of LEptons (an acronym of the ancestor experiment PAPLEP), the PS170 experiment setup at LEAR to study e+e-pair production in antiproton-proton annihilation by Padova-(CEN) Saclay- Torino Collaboration. It consisted of a liquid hydrogen target surrounded by several layers of proportional chambers in the vertical field of a C-magnet (this photo), a gas Cerenkov counter, wire chambers, hodoscopes, and an electromagnetic calorimeter (see photo 8302539X, 8302540X). See also photo 8301539X for the setup assembly at an early stage.

  10. Pseudomonas Aeruginosa Toxins

    Science.gov (United States)

    1982-09-01

    Ill.,111. PROTEASES One characteristic of P. aeruginosa is its ability to liquefy gelatin or digest casein. This property has been known to...Recently the ,- isolation of enterotoxic P. aeruginosa strains which give positive ileal loop tests in piglets and rabbits have been reported by

  11. Elevated paracellular glucose flux across cystic fibrosis airway epithelial monolayers is an important factor for Pseudomonas aeruginosa growth.

    Science.gov (United States)

    Garnett, James P; Gray, Michael A; Tarran, Robert; Brodlie, Malcolm; Ward, Christopher; Baker, Emma H; Baines, Deborah L

    2013-01-01

    People with cystic fibrosis (CF) who develop related diabetes (CFRD) have accelerated pulmonary decline, increased infection with antibiotic-resistant Pseudomonas aeruginosa and increased pulmonary exacerbations. We have previously shown that glucose concentrations are elevated in airway surface liquid (ASL) of people with CF, particularly in those with CFRD. We therefore explored the hypotheses that glucose homeostasis is altered in CF airway epithelia and that elevation of glucose flux into ASL drives increased bacterial growth, with an effect over and above other cystic fibrosis transmembrane conductance regulator (CFTR)-related ASL abnormalities. The aim of this study was to compare the mechanisms governing airway glucose homeostasis in CF and non-CF primary human bronchial epithelial (HBE) monolayers, under normal conditions and in the presence of Ps. aeruginosa filtrate. HBE-bacterial co-cultures were performed in the presence of 5 mM or 15 mM basolateral glucose to investigate how changes in blood glucose, such as those seen in CFRD, affects luminal Ps. aeruginosa growth. Calu-3 cell monolayers were used to evaluate the potential importance of glucose on Ps. aeruginosa growth, in comparison to other hallmarks of the CF ASL, namely mucus hyperviscosity and impaired CFTR-dependent fluid secretions. We show that elevation of basolateral glucose promotes the apical growth of Ps. aeruginosa on CF airway epithelial monolayers more than non-CF monolayers. Ps. aeruginosa secretions elicited more glucose flux across CF airway epithelial monolayers compared to non-CF monolayers which we propose increases glucose availability in ASL for bacterial growth. In addition, elevating basolateral glucose increased Ps. aeruginosa growth over and above any CFTR-dependent effects and the presence or absence of mucus in Calu-3 airway epithelia-bacteria co-cultures. Together these studies highlight the importance of glucose as an additional factor in promoting Ps. aeruginosa growth

  12. Elevated paracellular glucose flux across cystic fibrosis airway epithelial monolayers is an important factor for Pseudomonas aeruginosa growth.

    Directory of Open Access Journals (Sweden)

    James P Garnett

    Full Text Available People with cystic fibrosis (CF who develop related diabetes (CFRD have accelerated pulmonary decline, increased infection with antibiotic-resistant Pseudomonas aeruginosa and increased pulmonary exacerbations. We have previously shown that glucose concentrations are elevated in airway surface liquid (ASL of people with CF, particularly in those with CFRD. We therefore explored the hypotheses that glucose homeostasis is altered in CF airway epithelia and that elevation of glucose flux into ASL drives increased bacterial growth, with an effect over and above other cystic fibrosis transmembrane conductance regulator (CFTR-related ASL abnormalities. The aim of this study was to compare the mechanisms governing airway glucose homeostasis in CF and non-CF primary human bronchial epithelial (HBE monolayers, under normal conditions and in the presence of Ps. aeruginosa filtrate. HBE-bacterial co-cultures were performed in the presence of 5 mM or 15 mM basolateral glucose to investigate how changes in blood glucose, such as those seen in CFRD, affects luminal Ps. aeruginosa growth. Calu-3 cell monolayers were used to evaluate the potential importance of glucose on Ps. aeruginosa growth, in comparison to other hallmarks of the CF ASL, namely mucus hyperviscosity and impaired CFTR-dependent fluid secretions. We show that elevation of basolateral glucose promotes the apical growth of Ps. aeruginosa on CF airway epithelial monolayers more than non-CF monolayers. Ps. aeruginosa secretions elicited more glucose flux across CF airway epithelial monolayers compared to non-CF monolayers which we propose increases glucose availability in ASL for bacterial growth. In addition, elevating basolateral glucose increased Ps. aeruginosa growth over and above any CFTR-dependent effects and the presence or absence of mucus in Calu-3 airway epithelia-bacteria co-cultures. Together these studies highlight the importance of glucose as an additional factor in promoting Ps

  13. Beyond iPS!

    Directory of Open Access Journals (Sweden)

    Editorial

    2012-01-01

    Full Text Available It’s undoubtedly a jubilant moment for scientists and clinicians working in the stem cell arena as Prof. Gurdon and Prof. Shinya Yamanaka have been chosen for the Nobel Prize in Physiology & Medicine this year. The mystery of cell biology is something unfathomable and probably the work of this duo as well as the other scientists, who have put their hands on in- vitro de-differentiation have opened our eyes to a new window or a new paradigm in cell biology. The iPS invention has brought a lot of hope in terms of potential direct benefits to treat several diseases, which have no definite options at the moment. But, we envisage that several spin-offs could come out of this invention and one very significant spin-off finding recently witnessed is the finding by Prof. Masaharu Seno and his team of researchers at the Okayama University, Japan (Chen L, et al. 2012, PLoS ONE 7(4:e33544.doi:10.1371/journal.pone.0033544. According to Prof. Seno, mouse iPS cells (miPS when cultured in the conditioned medium derived from cancer cell lines, differentiate into cancer stem cells (CSCs. While differentiating into CSCs, they do retain the potential to develop endothelial progenitor cells. Several questions arise here: 1.Are these miPS derived CSCs really pluripotent, even if the terminal differentiation destined to specific phenotypes? 2.Shouldn’t the Cancer Stem Cells be termed as cancer progenitor cells, as till date they are considered to be producing only cancer cells but not pluripotent to yield other types of normal tissues? The spin-offs could be infinite as the process of differentiation and de-differentiation happening due to trillions of signals and pathways, most still remaining not-so-well understood. A special mention should be made to Prof. Shinya Yamanaka as he has several sterling qualities to be a role-model for budding scientists. Apart from his passion for science, which made him shift his career from orthopedics to a cell biologist, his

  14. Characterization of a novel Zn²⁺-dependent intrinsic imipenemase from Pseudomonas aeruginosa.

    Science.gov (United States)

    Fajardo, Alicia; Hernando-Amado, Sara; Oliver, Antonio; Ball, Geneviève; Filloux, Alain; Martinez, Jose L

    2014-11-01

    Previous work showed that PA5542 inactivation increases Pseudomonas aeruginosa 59.20 susceptibility to carbapenems. The objective of the current study was to purify PA5542, to determine its role in carbapenem resistance and to analyse the kinetic constants of this putative new β-lactamase. PA5542 was cloned and expressed in Escherichia coli. The enzyme was purified by affinity as a GST fusion protein and, after that, cleaved to remove the GST tag. β-Lactamase activity was measured spectrophotometrically using imipenem as substrate. Susceptibility to antibiotics was determined by Etest. Zn(2+) was added when needed. The expression levels of PA5542, ampC, poxB, mexA and oprD were determined by real-time RT-PCR. Lack of PA5542 increases P. aeruginosa 59.20 susceptibility to carbapenems and its overexpression reduces E. coli susceptibility to these β-lactams. PA5542 is highly conserved in all sequenced P. aeruginosa strains. The clinical isolate 59.20 is resistant to imipenem (MIC >32 mg/L) and to meropenem (MIC 24 mg/L) and presents high-level expression of PA5542 in comparison with the wild-type strain PAO1. Spectrophotometric analyses showed that PA5542 is a Zn(2+)-dependent imipenemase. Analysis of the PA5542 sequence indicates that it does not belong to the classical categories of β-lactamases. PA5542 encodes a new Zn(2+)-dependent imipenemase. The presence of PA5542 in all sequenced P. aeruginosa genomes, maintaining the synteny and without adjacent gene-mobility elements, indicates that it belongs to the P. aeruginosa core genome. High PA5542 expression in 59.20 suggests it may contribute to the resistance to carbapenems of this P. aeruginosa clinical isolate. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  15. Identification of Genes Involved in Pseudomonas aeruginosa Biofilm-Specific Resistance to Antibiotics

    OpenAIRE

    Zhang, Li; Fritsch, Meredith; Hammond, Lisa; Landreville, Ryan; Slatculescu, Cristina; Colavita, Antonio; Mah, Thien-Fah

    2013-01-01

    Pseudomonas aeruginosa is a key opportunistic pathogen characterized by its biofilm formation ability and high-level multiple antibiotic resistance. By screening a library of random transposon insertion mutants with an increased biofilm-specifc antibiotic susceptibility, we previously identified 3 genes or operons of P. aeruginosa UCBPP-PA14 (ndvB, PA1875-1877 and tssC1) that do not affect biofilm formation but are involved in biofilm-specific antibiotic resistance. In this study, we demonstr...

  16. Human cysteine cathepsins are not reliable markers of infection by Pseudomonas aeruginosa in cystic fibrosis.

    Directory of Open Access Journals (Sweden)

    Clément Naudin

    Full Text Available Cysteine cathepsins have emerged as new players in inflammatory lung disorders. Their activities are dramatically increased in the sputum of cystic fibrosis (CF patients, suggesting that they are involved in the pathophysiology of CF. We have characterized the cathepsins in CF expectorations and evaluated their use as markers of colonization by Pseudomonas aeruginosa. The concentrations of active cathepsins B, H, K, L and S were the same in P. aeruginosa-positive (19 Ps+ and P. aeruginosa-negative (6 Ps- samples, unlike those of human neutrophil elastase. Also the cathepsin inhibitory potential and the cathepsins/cathepsin inhibitors imbalance remained unchanged and similar (∼2-fold in the Ps+ and Ps- groups (p<0.001, which correlated with the breakdown of their circulating cystatin-like inhibitors (kininogens. Procathepsins, which may be activated autocatalytically, are a potential proteolytic reservoir. Immunoblotting and active-site labeling identified the double-chain cathepsin B, the major cathepsin in CF sputum, as the main molecular form in both Ps+ and Ps- samples, despite the possible release of the ∼31 kDa single-chain form from procathepsin B by sputum elastase. Thus, the hydrolytic activity of cysteine cathepsins was not correlated with bacterial colonization, indicating that cathepsins, unlike human neutrophil elastase, are not suitable markers of P. aeruginosa infection.

  17. Human cysteine cathepsins are not reliable markers of infection by Pseudomonas aeruginosa in cystic fibrosis.

    Science.gov (United States)

    Naudin, Clément; Joulin-Giet, Alix; Couetdic, Gérard; Plésiat, Patrick; Szymanska, Aneta; Gorna, Emilia; Gauthier, Francis; Kasprzykowski, Franciszek; Lecaille, Fabien; Lalmanach, Gilles

    2011-01-01

    Cysteine cathepsins have emerged as new players in inflammatory lung disorders. Their activities are dramatically increased in the sputum of cystic fibrosis (CF) patients, suggesting that they are involved in the pathophysiology of CF. We have characterized the cathepsins in CF expectorations and evaluated their use as markers of colonization by Pseudomonas aeruginosa. The concentrations of active cathepsins B, H, K, L and S were the same in P. aeruginosa-positive (19 Ps+) and P. aeruginosa-negative (6 Ps-) samples, unlike those of human neutrophil elastase. Also the cathepsin inhibitory potential and the cathepsins/cathepsin inhibitors imbalance remained unchanged and similar (∼2-fold) in the Ps+ and Ps- groups (p<0.001), which correlated with the breakdown of their circulating cystatin-like inhibitors (kininogens). Procathepsins, which may be activated autocatalytically, are a potential proteolytic reservoir. Immunoblotting and active-site labeling identified the double-chain cathepsin B, the major cathepsin in CF sputum, as the main molecular form in both Ps+ and Ps- samples, despite the possible release of the ∼31 kDa single-chain form from procathepsin B by sputum elastase. Thus, the hydrolytic activity of cysteine cathepsins was not correlated with bacterial colonization, indicating that cathepsins, unlike human neutrophil elastase, are not suitable markers of P. aeruginosa infection.

  18. Pyocyanin promotes extracellular DNA release in Pseudomonas aeruginosa.

    Science.gov (United States)

    Das, Theerthankar; Manefield, Mike

    2012-01-01

    Bacterial adhesion and biofilm formation are both dependent on the production of extracellular polymeric substances (EPS) mainly composed of polysaccharides, proteins, lipids, and extracellular DNA (eDNA). eDNA promotes biofilm establishment in a wide range of bacterial species. In Pseudomonas aeruginosa eDNA is major component of biofilms and is essential for biofilm formation and stability. In this study we report that production of pyocyanin in P. aeruginosa PAO1 and PA14 batch cultures is responsible for promotion of eDNA release. A phzSH mutant of P. aeruginosa PAO1 that overproduces pyocyanin displayed enhanced hydrogen peroxide (H(2)O(2)) generation, cell lysis, and eDNA release in comparison to its wildtype strain. A ΔphzA-G mutant of P. aeruginosa PA14 deficient in pyocyanin production generated negligible amounts of H(2)O(2) and released less eDNA in comparison to its wildtype counterpart. Exogenous addition of pyocyanin or incubation with H(2)O(2) was also shown to promote eDNA release in low pyocyanin producing (PAO1) and pyocynain deficient (PA14) strains. Based on these data and recent findings in the biofilm literature, we propose that the impact of pyocyanin on biofilm formation in P. aeruginosa occurs via eDNA release through H(2)O(2) mediated cell lysis.

  19. Pyocyanin promotes extracellular DNA release in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Theerthankar Das

    Full Text Available Bacterial adhesion and biofilm formation are both dependent on the production of extracellular polymeric substances (EPS mainly composed of polysaccharides, proteins, lipids, and extracellular DNA (eDNA. eDNA promotes biofilm establishment in a wide range of bacterial species. In Pseudomonas aeruginosa eDNA is major component of biofilms and is essential for biofilm formation and stability. In this study we report that production of pyocyanin in P. aeruginosa PAO1 and PA14 batch cultures is responsible for promotion of eDNA release. A phzSH mutant of P. aeruginosa PAO1 that overproduces pyocyanin displayed enhanced hydrogen peroxide (H(2O(2 generation, cell lysis, and eDNA release in comparison to its wildtype strain. A ΔphzA-G mutant of P. aeruginosa PA14 deficient in pyocyanin production generated negligible amounts of H(2O(2 and released less eDNA in comparison to its wildtype counterpart. Exogenous addition of pyocyanin or incubation with H(2O(2 was also shown to promote eDNA release in low pyocyanin producing (PAO1 and pyocynain deficient (PA14 strains. Based on these data and recent findings in the biofilm literature, we propose that the impact of pyocyanin on biofilm formation in P. aeruginosa occurs via eDNA release through H(2O(2 mediated cell lysis.

  20. Cloning and expression of Pseudomonas aeruginosa flagellin in Escherichia coli.

    OpenAIRE

    Kelly-Wintenberg, K; Montie, T. C.

    1989-01-01

    The flagellin gene was isolated from a Pseudomonas aeruginosa PAO1 genomic bank by conjugation into a PA103 Fla- strain. Flagellin DNA was transferred from motile recipient PA103 Fla+ cells by transformation into Escherichia coli. We show that transformed E. coli expresses flagellin protein. Export of flagellin to the E. coli cell surface was suggested by positive colony blots of unlysed cells and by isolation of flagellin protein from E. coli supernatants.

  1. PaTux

    DEFF Research Database (Denmark)

    Abou-Zleikha, Mohamed; Shaker, Noor

    2014-01-01

    We present a demonstration of PaTux, an authoring tool for designing levels in SuperTux game through combining patterns. PaTux allows game designers to specify the design of their levels using patterns extracted from training level samples. The Non-negative Matrix Factorisation (NMF) method...

  2. Isolation and characterization of gallium resistant Pseudomonas aeruginosa mutants

    NARCIS (Netherlands)

    García-Contreras, R; Lira-Silva, E; Jasso-Chávez, R; Hernández-González, I.L.; Maeda, T.; Hashimoto, T.; Boogerd, F.C.; Sheng, L; Wood, TK; Moreno-Sánchez, R

    2013-01-01

    Pseudomonas aeruginosa PA14 cells resistant to the novel antimicrobial gallium nitrate (Ga) were developed using transposon mutagenesis and by selecting spontaneous mutants. The mutants showing the highest growth in the presence of Ga were selected for further characterization. These mutants showed

  3. Pseudomonas aeruginosa septicemia

    OpenAIRE

    Bocanegra C., Manuel; Departamento de Pediatría, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú; Kiyan T., Manuel; Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú; Hinostroza Ñ., Fidel; Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú; Velarde Z., Nicolás; Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú; Bazán A., Augusto; Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú

    2014-01-01

    Experiments in burned mice were conditioned so that, with adequate numbers of living germs Pseudonoma aeruginosa or their toxins, as high as 80 mortalities occur to 100%, after 72 hours of the burn produced and inoculum. These animals and were treated with standard gamma globulin horse (6%), immunized against Pseudonoma aeruginosa, "antiserum" and dilute the hundredth human gamma globulin to 16%, dilute the hundredth equally. The degree of protectiveness conferred by these two types of gamma...

  4. The effect of alginate lyase on the gentamicin resistance of Pseudomonas aeruginosa in mucoid biofilms.

    Science.gov (United States)

    Germoni, L A P; Bremer, P J; Lamont, I L

    2016-07-01

    Pseudomonas aeruginosa can secrete large amounts of alginate during chronic infections and this has been associated with high resistance to antibiotics. The major aim of this study was to investigate whether degradation of extracellular alginate by alginate lyase would increase the sensitivity of Ps. aeruginosa to gentamicin, an aminoglycoside antibiotic. Degradation of alginate from Ps. aeruginosa was monitored using a spectrometric assay. Alginate lyase depolymerized alginate, but calcium and zinc cations at concentrations found in the cystic fibrosis lung reduced enzyme activity. Biofilms formed on agar were partially degraded by alginate lyase, but staining with crystal violet showed that the biomass of biofilms grown in liquid was not significantly affected by the enzyme. Viability testing showed that the sensitivity to gentamicin of biofilm bacteria and of bacteria released from biofilms was unaffected by alginate lyase. Our results show that at least under the conditions used here alginate lyase does not affect gentamicin resistance of Ps. aeruginosa. Our study indicates that alginate does not contribute to resistance to gentamicin and so does not provide support for the concept of treating patients with alginate lyase in order to increase the antibiotic sensitivity of Ps. aeruginosa. © 2016 The Society for Applied Microbiology.

  5. SPS and PS Experiments Committee

    CERN Multimedia

    CERN. Geneva

    2004-01-01

    OPEN SESSION: 09:00 Status report of NA58 / COMPASS: A. Magnon 09:40 Status report of PS212 / DIRAC: L. Tausher 10:10 PS212 / DIRAC Addendum: L. Nemenov CLOSED SESSION on Tuesday, 27 April 2004 after the open session, Main Building, 6th floor conference room

  6. Inhibitory effects of sanguinarine against the cyanobacterium Microcystis aeruginosa NIES-843 and possible mechanisms of action

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Jihai [College of Resources and Environment, Hunan Agricultural University, Changsha 410128 (China); Hunan Provincial Key Laboratory of Farmland Pollution Control and Agricultural Resources Use, Hunan Agricultural University, Changsha 410128 (China); Liu, Deming [State Key Laboratory Breeding Base of Crop Germplasm Innovation and Resource Utilization, Hunan Agricultural University, Changsha 410128 (China); Gong, Daoxin; Zeng, Qingru; Yan, Zhiyong [College of Resources and Environment, Hunan Agricultural University, Changsha 410128 (China); Gu, Ji-Dong, E-mail: jdgu@hku.hk [Hunan Provincial Key Laboratory of Farmland Pollution Control and Agricultural Resources Use, Hunan Agricultural University, Changsha 410128 (China); Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, The University of Hong Kong, Hong Kong SAR (China)

    2013-10-15

    Highlights: •Sanguinarine was found as a strong algicidal biologically derived substance. •Sanguinarine can induce oxidative stress in the cells of Microcystis aeruginosa. •Photosystem is a target of toxicity of sanguinarine on M. aeruginosa. •Sanguinarine can induce DNA damage and inhibit cell division. -- Abstract: Sanguinarine showed strong inhibitory effect against Microcystis aeruginosa, a typical water bloom-forming and microcystins-producing cyanobacterium. The EC50 of sanguinarine against the growth of M. aeruginosa NIES-843 was 34.54 ± 1.17 μg/L. Results of chlorophyll fluorescence transient analysis indicated that all the electron donating side, accepting side, and the reaction center of the Photosystem II (PS II) were the targets of sanguinarine against M. aeruginosa NIES-843. The elevation of reactive oxygen species (ROS) level in the cells of M. aeruginosa NIES-843 upon exposure indicated that sanguinarine induced oxidative stress in the active growing cells of M. aeruginosa NIES-843. Further results of gene expression analysis indicated that DNA damage and cell division inhibition were also involved in the inhibitory action mechanism of sanguinarine against M. aeruginosa NIES-843. The inhibitory characteristics of sanguinarine against M. aeruginosa suggest that the ecological- and public health-risks need to be evaluated before its application in cyanobacterial bloom control to avoid devastating events irreversibly.

  7. Novel drug targets in cell wall biosynthesis exploited by gene disruption in Pseudomonas aeruginosa.

    Science.gov (United States)

    Elamin, Ayssar A; Steinicke, Susanne; Oehlmann, Wulf; Braun, Yvonne; Wanas, Hanaa; Shuralev, Eduard A; Huck, Carmen; Maringer, Marko; Rohde, Manfred; Singh, Mahavir

    2017-01-01

    For clinicians, Pseudomonas aeruginosa is a nightmare pathogen that is one of the top three causes of opportunistic human infections. Therapy of P. aeruginosa infections is complicated due to its natural high intrinsic resistance to antibiotics. Active efflux and decreased uptake of drugs due to cell wall/membrane permeability appear to be important issues in the acquired antibiotic tolerance mechanisms. Bacterial cell wall biosynthesis enzymes have been shown to be essential for pathogenicity of Gram-negative bacteria. However, the role of these targets in virulence has not been identified in P. aeruginosa. Here, we report knockout (k.o) mutants of six cell wall biosynthesis targets (murA, PA4450; murD, PA4414; murF, PA4416; ppiB, PA1793; rmlA, PA5163; waaA, PA4988) in P. aeruginosa PAO1, and characterized these in order to find out whether these genes and their products contribute to pathogenicity and virulence of P. aeruginosa. Except waaA k.o, deletion of cell wall biosynthesis targets significantly reduced growth rate in minimal medium compared to the parent strain. The k.o mutants showed exciting changes in cell morphology and colonial architectures. Remarkably, ΔmurF cells became grossly enlarged. Moreover, the mutants were also attenuated in vivo in a mouse infection model except ΔmurF and ΔwaaA and proved to be more sensitive to macrophage-mediated killing than the wild-type strain. Interestingly, the deletion of the murA gene resulted in loss of virulence activity in mice, and the virulence was restored in a plant model by unknown mechanism. This study demonstrates that cell wall targets contribute significantly to intracellular survival, in vivo growth, and pathogenesis of P. aeruginosa. In conclusion, these findings establish a link between cell wall targets and virulence of P. aeruginosa and thus may lead to development of novel drugs for the treatment of P. aeruginosa infection.

  8. Characterization of the Pseudomonas aeruginosa metalloendopeptidase, Mep72, a member of the Vfr regulon.

    Science.gov (United States)

    Balyimez, Aysegul; Colmer-Hamood, Jane A; San Francisco, Michael; Hamood, Abdul N

    2013-11-27

    Pseudomonas aeruginosa Vfr (the virulence factor regulator) enhances P. aeruginosa virulence by positively regulating the expression of numerous virulence genes. A previous microarray analysis identified numerous genes positively regulated by Vfr in strain PAK, including the yet uncharacterized PA2782 and PA2783. In this study, we report the detailed characterization of PA2783 in the P. aeruginosa strain PAO1. RT-PCR analysis confirmed that PA2782-PA2783 constitute an operon. A mutation in vfr significantly reduced the expression of both genes. The predicted protein encoded by PA2783 contains a typical leader peptide at its amino terminus end as well as metalloendopeptidase and carbohydrate binding motifs at its amino terminus and carboxy terminus regions, respectively. An in-frame PA2783::phoA fusion encoded a hybrid protein that was exported to the periplasmic space of Escherichia coli and P. aeruginosa. In PAO1, the proteolytic activity of the PA2783-encoded protein was masked by other P. aeruginosa extracellular proteases but an E. coli strain carrying a PA2783 recombinant plasmid produced considerable proteolytic activity. The outer membrane fraction of an E. coli strain in which PA2783 was overexpressed contained specific endopeptidase activity. In the presence of cAMP, purified recombinant Vfr (rVfr) bound to a 98-bp fragment within the PA2782-PA2783 upstream region that carries a putative Vfr consensus sequence. Through a series of electrophoretic mobility shift assays, we localized rVfr binding to a 33-bp fragment that contains part of the Vfr consensus sequence and a 5-bp imperfect (3/5) inverted repeat at its 3' and 5' ends (TGGCG-N22-CGCTG). Deletion of either repeat eliminated Vfr binding. PA2782 and PA2783 constitute an operon whose transcription is positively regulated by Vfr. The expression of PA2783 throughout the growth cycle of P. aeruginosa follows a unique pattern. PA2783 codes for a secreted metalloendopeptidase, which we named Mep72. Mep72

  9. In vitro management of hospital Pseudomonas aeruginosa biofilm using indigenous T7-like lytic phage.

    Science.gov (United States)

    Ahiwale, Sangeeta; Tamboli, Nilofer; Thorat, Kiran; Kulkarni, Rajendra; Ackermann, Hans; Kapadnis, Balasaheb

    2011-02-01

    Pseudomonas aeruginosa, a human pathogen capable of forming biofilm and contaminating medical settings, is responsible for 65% mortality in the hospitals all over the world. This study was undertaken to isolate lytic phages against biofilm forming Ps. aeruginosa hospital isolates and to use them for in vitro management of biofilms in the microtiter plate. Multidrug resistant strains of Ps. aeruginosa were isolated from the hospital environment in and around Pimpri-Chinchwad, Maharashtra by standard microbiological methods. Lytic phages against these strains were isolated from the Pavana river water by double agar layer plaque assay method. A wide host range phage bacterial virus Ps. aeruginosa phage (BVPaP-3) was selected. Electron microscopy revealed that BVPaP-3 phage is a T7-like phage and is a relative of phage species gh-1. A phage at MOI-0.001 could prevent biofilm formation by Ps. aeruginosa hospital strain-6(HS6) on the pegs within 24 h. It could also disperse pre-formed biofilms of all hospital isolates (HS1-HS6) on the pegs within 24 h. Dispersion of biofilm was studied by monitoring log percent reduction in cfu and log percent increase in pfu of respective bacterium and phage on the peg as well as in the well. Scanning electron microscopy confirmed that phage BVPaP-3 indeed causes biofilm reduction and bacterial cell killing. Laboratory studies prove that BVPaP-3 is a highly efficient phage in preventing and dispersing biofilms of Ps. aeruginosa. Phage BVPaP-3 can be used as biological disinfectant to control biofilm problem in medical devices.

  10. Pseudomonas aeruginosa Biofilms

    DEFF Research Database (Denmark)

    Alhede, Maria; Bjarnsholt, Thomas; Givskov, Michael

    2014-01-01

    The opportunistic gram-negative bacterium Pseudomonas aeruginosa is implicated in many chronic infections and is readily isolated from chronic wounds, medical devices, and the lungs of cystic fibrosis patients. P. aeruginosa is believed to persist in the host organism due to its capacity to form...... biofilms, which protect the aggregated, biopolymer-embedded bacteria from the detrimental actions of antibiotic treatments and host immunity. A key component in the protection against innate immunity is rhamnolipid, which is a quorum sensing (QS)-regulated virulence factor. QS is a cell-to-cell signaling...

  11. Detection of Pseudomonas aeruginosa in sputum headspace through volatile organic compound analysis

    Directory of Open Access Journals (Sweden)

    Goeminne Pieter C

    2012-10-01

    Full Text Available Abstract Introduction Chronic pulmonary infection is the hallmark of Cystic Fibrosis lung disease. Searching for faster and easier screening may lead to faster diagnosis and treatment of Pseudomonas aeruginosa (P. aeruginosa. Our aim was to analyze and build a model to predict the presence of P. aeruginosa in sputa. Methods Sputa from 28 bronchiectatic patients were used for bacterial culturing and analysis of volatile compounds by gas chromatography–mass spectrometry. Data analysis and model building were done by Partial Least Squares Regression Discriminant analysis (PLS-DA. Two analysis were performed: one comparing P. aeruginosa positive with negative cultures at study visit (PA model and one comparing chronic colonization according to the Leeds criteria with P. aeruginosa negative patients (PACC model. Results The PA model prediction of P. aeruginosa presence was rather poor, with a high number of false positives and false negatives. On the other hand, the PACC model was stable and explained chronic P. aeruginosa presence for 95% with 4 PLS-DA factors, with a sensitivity of 100%, a positive predictive value of 86% and a negative predictive value of 100%. Conclusion Our study shows the potential for building a prediction model for the presence of chronic P. aeruginosa based on volatiles from sputum.

  12. Avaliação da qualidade de vida e do sofrimento psíquico de pacientes com diferentes dermatoses em um centro de referência em dermatologia no sul do país Evaluation of the quality of life and psychological distress of patients with different dermatoses in a dermatology referral center in southern Brazil

    Directory of Open Access Journals (Sweden)

    Maria Laura Taborda

    2010-02-01

    Full Text Available FUNDAMENTOS: Algumas dermatoses repercutem, pela sua aparência, na vida pessoal, profissional e social dos pacientes. Faz-se necessária a valorização desse tema visando-se à avaliação global desses indivíduos, para o estabelecimento de uma abordagem terapêutica mais eficaz. OBJETIVOS: Avaliar a qualidade de vida e a frequência de sofrimento psíquico nos pacientes em um centro de Dermatologia. MÉTODOS: Estudo transversal. Após consulta, aplicou-se o Índice de Qualidade de Vida para Dermatologia (DLQI e o Self-Reported Questionnaire (SRQ-20. RESULTADOS: Foram entrevistados 1.000 pacientes. Não houve efeito da dermatose sobre a qualidade de vida em 21,5% deles; 34,2% apresentaram "pouco efeito", 21,6%, "efeito moderado", 19,3%, "grande efeito" e 3,4%, efeito extremo sobre a qualidade de vida. A correlação entre sofrimento psíquico e dermatoses não mostrou associação estatística significativa. Comparando-se os dois questionários, houve associação significante entre presença de sofrimento psíquico e pior qualidade de vida (pBACKGROUND: Some dermatoses affect the personal, professional and social lives of patients as a result of their unsightliness. It is important to pay appropriate attention in the overall evaluation of these individuals in order to implement a more effective therapeutic approach. OBJECTIVES: To evaluate the quality of life and the incidence of psychological distress in patients receiving care at a dermatology clinic. METHODS: A cross-sectional study. Following consultation, the Dermatology Life Quality Index (DLQI and the Self Report Questionnaire (SRQ-20 were applied. RESULTS: One thousand patients were interviewed, 77.2% of whom were women. Most patients were in the 4160 year age-group. Dermatoses had no effect at all on the quality of life of 21.5% of patients, a small effect in 34.2% of cases, a moderate effect in 21.6%, a very large effect in 19.3% and an extremely large effect in 3.4% of patients

  13. Molecular Control of Innate Immune Response to Pseudomonas aeruginosa Infection by Intestinal let-7 in Caenorhabditis elegans

    Science.gov (United States)

    Wang, Daoyong; Wang, Dayong

    2017-01-01

    The microRNA (miRNA) let-7 is an important miRNA identified in Caenorhabditis elegans and has been shown to be involved in the control of innate immunity. The underlying molecular mechanisms for let-7 regulation of innate immunity remain largely unclear. In this study, we investigated the molecular basis for intestinal let-7 in the regulation of innate immunity. Infection with Pseudomonas aeruginosa PA14 decreased let-7::GFP expression. Intestine- or neuron-specific activity of let-7 was required for its function in the regulation of innate immunity. During the control of innate immune response to P. aeruginosa PA14 infection, SDZ-24 was identified as a direct target for intestinal let-7. SDZ-24 was found to be predominantly expressed in the intestine, and P. aeruginosa PA14 infection increased SDZ-24::GFP expression. Intestinal let-7 regulated innate immune response to P. aeruginosa PA14 infection by suppressing both the expression and the function of SDZ-24. Knockout or RNA interference knockdown of sdz-24 dampened the resistance of let-7 mutant to P. aeruginosa PA14 infection. Intestinal overexpression of sdz-24 lacking 3’-UTR inhibited the susceptibility of nematodes overexpressing intestinal let-7 to P. aeruginosa PA14 infection. In contrast, we could observed the effects of intestinal let-7 on innate immunity in P. aeruginosa PA14 infected transgenic strain overexpressing sdz-24 containing 3’-UTR. In the intestine, certain SDZ-24-mediated signaling cascades were formed for nematodes against the P. aeruginosa PA14 infection. Our results highlight the crucial role of intestinal miRNAs in the regulation of the innate immune response to pathogenic infection. PMID:28095464

  14. Global analysis of disulfide bond proteins in Pseudomonas aeruginosa exposed to hydrogen peroxide and gamma rays.

    Science.gov (United States)

    An, Byung Chull; Lee, Seung Sik; Lee, Eun Mi; Wi, Seung Gon; Park, Woojun; Chung, Byung Yeoup

    2010-05-01

    To isolate and characterise the oxidative stress-responsible disulfide bond proteins (DSBP) from Pseudomonas aeruginosa, under hydrogen peroxide (H(2)O(2)) and gamma ray-induced stress conditions. Oxidative stress in P. aeruginosa was induced by H(2)O(2) or (60)Co gamma-rays. DSBP of P. aeruginosa were isolated by using a thiol affinity purification method and liquid chromatography-mass spectrometry (LC-MS/MS). Induction of DSBP and their transcriptional levels were analysed by Western blot and quantitative-polymerase chain reaction (q-PCR), respectively. We isolated and identified 40 DSBP in P. aeruginosa. A comparison of DSBP patterns under different stress conditions, including exposure to 0.5 mM H(2)O(2) and 30 Gy of gamma rays, was carried out. We selected 13 DSBP based on their increased intensity under oxidative stress and investigated their expression levels using q-PCR. Of these 13 proteins, P. aeruginosa (PA) 0126 and PA0277 transcriptional levels were strongly induced (4- to 9-fold) by gamma ray. A corresponding induction in the translational levels of PA0126 was confirmed by Western blot analysis. PA0126 was identified is a hypothetical protein with 206 amino acids and contained three cysteine residues. A shift in molecular weight of PA0126 under oxidised/reduced state indicated its homo-oligomeric structure under non-reducing condition. PA0126, a hypothetical protein with disulfide bonds was identified as a key responder to oxidative stress along with other known DSBP of P. aeruginosa. We determined that all DSBP underwent a redox cycling. Furthermore, our results give deeper insight into the relationship between oxidative stress and DSBP in P. aeruginosa.

  15. Polysorbate 80 Inhibition of Pseudomonas aeruginosa Biofilm Formation and Its Cleavage by the Secreted Lipase LipA▿

    OpenAIRE

    Toutain-Kidd, Christine M.; Kadivar, Samoneh C.; Bramante, Carolyn T.; Bobin, Stephen A.; Zegans, Michael E.

    2008-01-01

    Surface-associated bacterial communities known as biofilms are an important source of nosocomial infections. Microorganisms such as Pseudomonas aeruginosa can colonize the abiotic surfaces of medical implants, leading to chronic infections that are difficult to eradicate. Our study demonstrates that polysorbate 80 (PS80), a surfactant commonly added to food and medicines, is able to inhibit biofilm formation by P. aeruginosa on a variety of surfaces, including contact lenses. Many clinical is...

  16. Characterization of antimicrobial resistance of Pseudomonas aeruginosa isolated from canine infections.

    Science.gov (United States)

    Lin, D; Foley, S L; Qi, Y; Han, J; Ji, C; Li, R; Wu, C; Shen, J; Wang, Y

    2012-07-01

      To determine the prevalence of Pseudomonas aeruginosa among dogs with suspected soft tissue infections and to characterize these isolates.   Swabs were taken from infected soft tissues of 402 dogs. Pseudomonas aeruginosa strains were confirmed phenotypically and tested for susceptibility to 11 antimicrobial agents and genotyped by SpeI pulsed-field gel electrophoresis (PFGE). The genetic basis of fluoroquinolone (FQ) resistance and the presence of integrons were also characterized. A total of 27 (6·7%) dogs tested positive for Ps. aeruginosa. Fourteen different SpeI patterns were observed in 25 typeable strains. Among the β-lactams, three isolates presented resistance to ticarcillin and carbenicillin, while only one isolate exhibited resistance to ceftazidime. Among the aminoglycosides (AGs), three strains showed resistance to amikacin, and four strains exhibited resistance to gentamicin and tobramycin. Four strains with mutations that led to the substitution of Thr at position 83 with Ile in GyrA and the exchange of Ser at position 87 with Leu in ParC displayed resistance to all tested FQs. These strains also carried class 1 integrons and showed resistance to between 6 and 10 antimicrobials. These integrons included four different gene cassettes (aacA4-aadA1, bla(OXA-31) -aadA2, aadA1-arr-3-catB3 and cmlA5-cmlA-aadA1).   A small proportion of infected dogs treated in two animal hospitals in Beijing, China carried Ps. aeruginosa isolates. Low levels of resistance to anti-pseudomonal agents were observed in these strains.   This study is the first report on the antimicrobial resistance profiles of Ps. aeruginosa isolated from infected canine origin in China. Additionally, this is the first report of the oxacillin resistance gene bla(OXA-31) in a canine Ps. aeruginosa isolate. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  17. An orphan chemotaxis sensor regulates virulence and antibiotic tolerance in the human pathogen Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Heather Pearl McLaughlin

    Full Text Available The synthesis of virulence factors by pathogenic bacteria is highly regulated and occurs in response to diverse environmental cues. An array of two component systems (TCSs serves to link perception of different cues to specific changes in gene expression and/or bacterial behaviour. Those TCSs that regulate functions associated with virulence represent attractive targets for interference in anti-infective strategies for disease control. We have previously identified PA2572 as a putative response regulator required for full virulence of Pseudomonas aeruginosa, the opportunistic human pathogen, to Galleria mellonella (Wax moth larvae. Here we have investigated the involvement of candidate sensors for signal transduction involving PA2572. Mutation of PA2573, encoding a probable methyl-accepting chemotaxis protein, gave rise to alterations in motility, virulence, and antibiotic resistance, functions which are also controlled by PA2572. Comparative transcriptome profiling of mutants revealed that PA2572 and PA2573 regulate expression of a common set of 49 genes that are involved in a range of biological functions including virulence and antibiotic resistance. Bacterial two-hybrid analysis indicated a REC-dependent interaction between PA2572 and PA2573 proteins. Finally expression of PA2572 in the PA2573 mutant background restored virulence to G. mellonella towards wild-type levels. The findings indicate a role for the orphan chemotaxis sensor PA2573 in the regulation of virulence and antibiotic tolerance in P. aeruginosa and indicate that these effects are exerted in part through signal transduction involving PA2572.

  18. Characterization of the indole-3-glycerol phosphate synthase from Pseudomonas aeruginosa PAO1.

    Science.gov (United States)

    Gerth, Monica L; Nigon, Laura V; Patrick, Wayne M

    2012-06-01

    Pseudomonas aeruginosa is an opportunistic pathogen that causes chronic infections in the lungs of individuals with cystic fibrosis. It is intrinsically resistant to many antibiotics, and resistance is emerging rapidly to those drugs that currently remain efficacious. Therefore, there is a pressing need to identify new anti-pseudomonal drug targets. To this end, we have characterized the P. aeruginosa indole-3-glycerol phosphate synthase (PaIGPS). PaIGPS catalyzes the fifth reaction in the synthesis of tryptophan from chorismate--a reaction that is absent in mammals. PaIGPS was expressed heterologously in Escherichia coli, and purified with high yields. The purified enzyme is active over a broad pH range and has the highest turnover number of any characterized IGPS (k (cat) = 11.1 ± 0.1 s(-1)). These properties are likely to make PaIGPS useful in coupled assays for other enzymes in tryptophan biosynthesis. We have also shown that deleting the gene for PaIGPS reduces the fitness of P. aeruginosa strain PAO1 in synthetic cystic fibrosis sputum (relative fitness, W = 0.89 ± 0.02, P = 0.001). This suggests that de novo tryptophan biosynthesis may play a role in the establishment and maintenance of P. aeruginosa infections, and therefore that PaIGPS is a potential target for the development of new anti-pseudomonal drugs.

  19. The PS locomotive runs again

    CERN Multimedia

    2001-01-01

    Over forty years ago, the PS train entered service to steer the magnets of the accelerator into place... ... a service that was resumed last Tuesday. Left to right: Raymond Brown (CERN), Claude Tholomier (D.B.S.), Marcel Genolin (CERN), Gérard Saumade (D.B.S.), Ingo Ruehl (CERN), Olivier Carlier (D.B.S.), Patrick Poisot (D.B.S.), Christian Recour (D.B.S.). It is more than ten years since people at CERN heard the rumbling of the old PS train's steel wheels. Last Tuesday, the locomotive came back into service to be tested. It is nothing like the monstrous steel engines still running on conventional railways -just a small electric battery-driven vehicle employed on installing the magnets for the PS accelerator more than 40 years ago. To do so, it used the tracks that run round the accelerator. In fact, it is the grandfather of the LEP monorail. After PS was commissioned in 1959, the little train was used more and more rarely. This is because magnets never break down, or hardly ever! In fact, the loc...

  20. The PS Booster hits 40

    CERN Multimedia

    Joannah Caborn Wengler

    2012-01-01

    Many accelerators’ "round" birthdays are being celebrated at CERN these days – the PS turned 50 in 2009, the SPS was 35 in 2011, and this year it's the turn of the PS Booster to mark its 40th anniversary. Originally designed to accelerate 1013 protons to 800 MeV, it has far exceeded its initial design performance over the years.   The PS Booster in the 1970s. Imagine the scene: a group of accelerator physicists staring expectantly at a monitor, when suddenly a shout of joy goes up as a signal flickers across the screen. Does that sound familiar? Well, turn the clock back 40 years (longer hair, wider trouser legs) and you have the situation at the PS Booster on 26 May 1972. On that day, beam was injected into the Booster for the first time. “It was a real buzz,” says Heribert Koziol, then Chairman of the Running-in Committee. “We were very happy – and also a little relieved – when the beam finally...

  1. Population Structure of Pseudomonas aeruginosa

    National Research Council Canada - National Science Library

    Lutz Wiehlmann; Gerd Wagner; Nina Cramer; Benny Siebert; Peter Gudowius; Gracia Morales; Thilo Köhler; Christian van Delden; Christian Weinel; Peter Slickers; Burkhard Tümmler

    2007-01-01

    The metabolically versatile Gram-negative bacterium Pseudomonas aeruginosa inhabits terrestrial, aquatic, animal-, human-, and plant-host-associated environments and is an important causative agent...

  2. Characterization and interstrain transfer of prophage pp3 of Pseudomonas aeruginosa.

    Science.gov (United States)

    Li, Gang; Lu, Shuguang; Shen, Mengyu; Le, Shuai; Shen, Wei; Tan, Yinling; Wang, Jing; Zhao, Xia; Zhao, Yan; Gong, Yali; Yang, Yuhui; Zhu, Hongbin; Hu, Fuquan; Li, Ming

    2017-01-01

    Prophages are major contributors to horizontal gene transfer and drive the evolution and diversification of bacteria. Here, we describe the characterization of a prophage element designated pp3 in the clinical Pseudomonas aeruginosa isolate PA1. pp3 spontaneously excises from the PA1 genome and circularizes at a very high frequency of 25%. pp3 is likely to be a defective prophage due to its inability to form plaques on P. aeruginosa indicator strains, and no phage particles could be detected in PA1 supernatants. The pp3-encoded integrase is essential for excision by mediating site-specific recombination at the 26-bp attachment sequence. Using a filter mating experiment, we demonstrated that pp3 can transfer into P. aeruginosa recipient strains that do not possess this element naturally. Upon transfer, pp3 integrates into the same attachment site as in PA1 and maintains the ability to excise and circularize. Furthermore, pp3 significantly promotes biofilm formation in the recipient. Sequence alignment reveals that the 26-bp attachment site recognized by pp3 is conserved in all P. aeruginosa strains sequenced to date, making it possible that pp3 could be extensively disseminated in P. aeruginosa. This work improves our understanding of the ways in which prophages influence bacterial behavior and evolution.

  3. A new transcriptional repressor of the pseudomonas aeruginosa quorum sensing receptor gene lasR.

    Directory of Open Access Journals (Sweden)

    Francesca Longo

    Full Text Available Pseudomonas aeruginosa pathogenic potential is controlled via multiple regulatory pathways, including three quorum sensing (QS systems. LasR is a key QS signal receptor since it acts as a global transcriptional regulator required for optimal expression of main virulence factors. P. aeruginosa modulates the QS response by integrating this cell density-dependent circuit to environmental and metabolic cues. Hence, QS also controls the adaptation to challenging environmental niches, such as infection sites. However, little is known about the molecular mechanisms connecting QS and other signalling pathways. In this work, DNA-affinity chromatography was used to identify new lasR transcriptional regulators. This approach led to the identification and functional characterization of the TetR-like transcriptional repressor PA3699. This protein was purified and shown to directly bind to the lasR promoter region in vitro. The induction of PA3699 expression in P. aeruginosa PAO1 cultures repressed lasR promoter activity and the production of LasR-dependent virulence factors, such as elastase, pyocyanin, and proteases. These findings suggest a role for PA3699 in P. aeruginosa pathogenicity. P. aeruginosa genome encodes at least 38 TetR-family proteins, and PA3699 is the eighth member of this group functionally characterized so far and the first one shown to bind the lasR promoter in vitro.

  4. Pseudomonas aeruginosa d-Arabinofuranose Biosynthetic Pathway and Its Role in Type IV Pilus Assembly*

    OpenAIRE

    Harvey, Hanjeong; Kus, Julianne V.; Tessier, Luc; Kelly, John; Burrows, Lori L.

    2011-01-01

    Pseudomonas aeruginosa strains PA7 and Pa5196 glycosylate their type IVa pilins with α1,5-linked d-arabinofuranose (d-Araf), a rare sugar configuration identical to that found in cell wall polymers of the Corynebacterineae. Despite this chemical identity, the pathway for biosynthesis of α1,5-d-Araf in Gram-negative bacteria is unknown. Bioinformatics analyses pointed to a cluster of seven P. aeruginosa genes, including homologues of the Mycobacterium tuberculosis genes Rv3806c, Rv3790, and Rv...

  5. Development of New Therapeutics Targeting Biofilm Formation by the Opportunistic Pulmonary Pathogens Pseudomonas aeruginosa and Aspergillus Fumigatus

    Science.gov (United States)

    2017-10-01

    aeurginosa (PA) and fungus Aspergillus fumigatus (AF) are common causes of pulmonary disease in immunocompromised patients. During infection, both...The bacteria Pseudomonas aeruginosa (PA) and fungus Aspergillus fumigatus (AF) are common causes of pulmonary disease in immunocompromised patients...to Project: Ms. Smith has performed work in the area of combined error -control and constrained coding. Funding Support: The Ford

  6. Silver against Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Kirketerp-Møller, K.; Kristiansen, S.

    2007-01-01

    bacteria in both the planktonic and biofilm modes of growth. The action of silver on mature in vitro biofilms of Pseudomonas aeruginosa, a primary pathogen of chronic infected wounds, was investigated. The results show that silver is very effective against mature biofilms of P. aeruginosa...

  7. Dexamethasone and N-acetyl-cysteine attenuate Pseudomonas aeruginosa-induced mucus expression in human airways.

    Science.gov (United States)

    Sprenger, Lisa; Goldmann, Torsten; Vollmer, Ekkehard; Steffen, Armin; Wollenberg, Barbara; Zabel, Peter; Hauber, Hans-Peter

    2011-04-01

    Infection with Pseudomonas aeruginosa (PA) induces mucus hypersecretion in airways. Therapeutic options to attenuate excessive mucus expression are sparse. To investigate the effect of steroids and N-acetyl-cysteine (NAC) on PA-induced mucus expression. Calu-3 cells and explanted human mucosa from the upper airways were stimulated with either PA, lipopolysaccharide from alginate producing PA (smooth, sPA-LPS) or non-alginate producing PA (rough, rPA-LPS). Dexamethasone (DEX) and NAC were added in different concentrations. Expression of mucin (MUC5AC) gene and mucin protein expression was quantified using PAS (periodic acids Schiff) staining and real time PCR. PA, sPA-LPS or rPA-LPS significantly induced mucin protein and MUC5AC gene expression in Calu-3 cells and explanted mucosal tissue (P NAC significantly decreased PA-, sPA-LPS- and rPA-LPS-induced mucin protein expression both in vitro and ex vivo (P 0.05). Our data show that both an anti-inflammatory drug (DEX) and an anti-oxidative agent (NAC) can attenuate PA-induced mucus expression in human airways. These results support the use of steroids and NAC in clinical practice to treat PA-induced mucus hypersecretion. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Diverse effects of Galleria mellonella infection with entomopathogenic and clinical strains of Pseudomonas aeruginosa.

    Science.gov (United States)

    Andrejko, Mariola; Zdybicka-Barabas, Agnieszka; Cytryńska, Małgorzata

    2014-01-01

    In numerous studies, the greater wax moth Galleria mellonella has been exploited as an alternative model host for investigating virulence factors of different pathogenic bacteria. In the present paper, we provide evidence that G. mellonella constitutes a useful and convenient model for analysis of the pathogenicity of Pseudomonas aeruginosa clinical strains. In this in vivo study on the G. mellonella–P. aeruginosa interaction, a bidirectional analysis comprising evaluation of humoral immune response of the bacteria-infected larvae and determination of P. aeruginosa proteinases synthesized during the infection was performed. The effects of G. mellonella infection by two clinical strains (PA C124/9 and PA 02/18) and one entomopathogenic strain (ATCC 27853) cultured in a rich LB and minimal M9 medium, known to induce synthesis of different sets of extracellular proteinases, were evaluated. Both clinical isolates were able to establish infection in G. mellonella caterpillars after intrahemocelic injection. However, although the final effect of the larvae infection by each P. aeruginosa strain was their death within ca. 48 h, considerable strain and medium-dependent differences in the immune response of the insects were detected. The results indicated that G. mellonella larvae distinguished between the three P. aeruginosa strains, which was well reflected by the diverse humoral immune response. The significant differences concerned, among others, the level of phenoloxidase, lysozyme, and antibacterial activity in the hemolymph of the infected insects. An analysis of proteinases performed using specific activity tests, zymography and immunoblotting, revealed that elastase B and alkaline protease were synthesized by each P. aeruginosa strain during the infection. In contrast, a high level of elastase A activity was detected only in the larvae infected by the P. aeruginosa ATCC 27853 strain. It can be postulated that the three P. aeruginosa strains exploit different

  9. The outer membrane protein OprQ and adherence of Pseudomonas aeruginosa to human fibronectin.

    Science.gov (United States)

    Arhin, Abraham; Boucher, Cliff

    2010-05-01

    Outer membrane proteins of the Gram-negative organism Pseudomonas aeruginosa play a significant role in membrane permeability, antibiotic resistance, nutrient uptake, and virulence in the infection site. In this study, we show that the P. aeruginosa outer membrane protein OprQ, a member of the OprD superfamily, is involved in the binding of human fibronectin (Fn). Some members of the OprD subfamily have been reported to be important in the uptake of nutrients from the environment. Comparison of wild-type and mutant strains of P. aeruginosa revealed that inactivation of the oprQ gene does not reduce the growth rate. Although it does not appear to be involved in nutrient uptake, an increased doubling time was reproducibly observed with the loss of OprQ in P. aeruginosa. Utilizing an oprQ-xylE transcriptional fusion, we determined that the PA2760 gene, encoding OprQ, was upregulated under conditions of decreased iron and magnesium. This upregulation appears to occur in early exponential phase. Insertional inactivation of PA2760 in the P. aeruginosa wild-type background did not produce a significant increase in resistance to any antibiotic tested, a phenotype that is typical of OprD family members. Interestingly, the in trans expression of OprQ in the DeltaoprQ PAO1 mutant resulted in increased sensitivity to certain antibiotics. These findings suggest that OprQ is under dual regulation with other P. aeruginosa genes. Intact P. aeruginosa cells are capable of binding human Fn. We found that loss of OprQ resulted in a reduction of binding to plasmatic Fn in vitro. Finally, we present a discussion of the possible role of the P. aeruginosa outer membrane protein OprQ in adhesion to epithelial cells, thereby increasing colonization and subsequently enhancing lung destruction by P. aeruginosa.

  10. Pseudomonas aeruginosa vesicles associate with and are internalized by human lung epithelial cells

    Directory of Open Access Journals (Sweden)

    Kuehn Meta J

    2009-02-01

    Full Text Available Abstract Background Pseudomonas aeruginosa is the major pathogen associated with chronic and ultimately fatal lung infections in patients with cystic fibrosis (CF. To investigate how P. aeruginosa-derived vesicles may contribute to lung disease, we explored their ability to associate with human lung cells. Results Purified vesicles associated with lung cells and were internalized in a time- and dose-dependent manner. Vesicles from a CF isolate exhibited a 3- to 4-fold greater association with lung cells than vesicles from the lab strain PAO1. Vesicle internalization was temperature-dependent and was inhibited by hypertonic sucrose and cyclodextrins. Surface-bound vesicles rarely colocalized with clathrin. Internalized vesicles colocalized with the endoplasmic reticulum (ER marker, TRAPα, as well as with ER-localized pools of cholera toxin and transferrin. CF isolates of P. aeruginosa abundantly secrete PaAP (PA2939, an aminopeptidase that associates with the surface of vesicles. Vesicles from a PaAP knockout strain exhibited a 40% decrease in cell association. Likewise, vesicles from PAO1 overexpressing PaAP displayed a significant increase in cell association. Conclusion These data reveal that PaAP promotes the association of vesicles with lung cells. Taken together, these results suggest that P. aeruginosa vesicles can interact with and be internalized by lung epithelial cells and contribute to the inflammatory response during infection.

  11. 76 FR 29176 - Airworthiness Directives; Piper Aircraft, Inc. PA-23, PA-31, and PA-42 Airplanes

    Science.gov (United States)

    2011-05-20

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Piper Aircraft, Inc...) that applies to Piper Aircraft, Inc. PA-23, PA-31, and PA-42 airplanes. The existing AD currently... Federal holidays. For service information identified in this AD, contact Piper Aircraft, Inc., 2926 Piper...

  12. Raloxifene attenuates Pseudomonas aeruginosa pyocyanin production and virulence.

    Science.gov (United States)

    Ho Sui, Shannan J; Lo, Raymond; Fernandes, Aalton R; Caulfield, Mackenzie D G; Lerman, Joshua A; Xie, Lei; Bourne, Philip E; Baillie, David L; Brinkman, Fiona S L

    2012-09-01

    There has been growing interest in disrupting bacterial virulence mechanisms as a form of infectious disease control through the use of 'anti-infective' drugs. Pseudomonas aeruginosa is an opportunistic pathogen noted for its intrinsic antibiotic resistance that causes serious infections requiring new therapeutic options. In this study, an analysis of the P. aeruginosa PAO1 deduced proteome was performed to identify pathogen-associated proteins. A computational screening approach was then used to discover drug repurposing opportunities, i.e. identifying approved drugs that bind and potentially disrupt the pathogen-associated protein targets. The selective oestrogen receptor modulator raloxifene, a drug currently used in the prevention of osteoporosis and/or invasive breast cancer in post-menopausal women, was predicted from this screen to bind P. aeruginosa PhzB2. PhzB2 is involved in production of the blue pigment pyocyanin produced via the phenazine biosynthesis pathway. Pyocyanin is toxic to eukaryotic cells and has been shown to play a role in infection in a mouse model, making it an attractive target for anti-infective drug discovery. Raloxifene was found to strongly attenuate P. aeruginosa virulence in a Caenorhabditis elegans model of infection. Treatment of P. aeruginosa wild-type strains PAO1 and PA14 with raloxifene resulted in a dose-dependent reduction in pyocyanin production in vitro; pyocyanin production and virulence were also reduced for a phzB2 insertion mutant. These results suggest that raloxifene may be suitable for further development as a therapeutic for P. aeruginosa infection and that such already approved drugs may be computationally screened and potentially repurposed as novel anti-infective/anti-virulence agents. Copyright © 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  13. Characterization of antibiotic and disinfectant susceptibility profiles among Pseudomonas aeruginosa veterinary isolates recovered during 1994-2003.

    Science.gov (United States)

    Beier, R C; Foley, S L; Davidson, M K; White, D G; McDermott, P F; Bodeis-Jones, S; Zhao, S; Andrews, K; Crippen, T L; Sheffield, C L; Poole, T L; Anderson, R C; Nisbet, D J

    2015-02-01

    To evaluate susceptibility of Pseudomonas aeruginosa veterinary isolates to antibiotics and disinfectants. Pseudomonas aeruginosa isolates collected from dogs (n = 155) and other animals (n = 20) from sixteen states during 1994-2003 were tested for susceptibility. Most isolates were resistant to twenty-one antimicrobials tested, and the highest prevalence of resistance was to β-lactams (93.8%) and sulphonamides (93.5%). Fluoroquinolone resistance did not increase from 1994 to 2003. Ciprofloxacin and enrofloxacin had a 5 and 16% prevalence of resistance, respectively, while sarafloxacin and nalidixic acid had a prevalence of resistance of 97 and 98%, respectively. Strains were pan-resistant to triclosan and chlorhexidine, were highly resistant to benzalkonium chloride and demonstrated high susceptibility to other disinfectants. Didecyldimethylammonium chloride was the most active ammonium chloride. Inducible resistance was observed to cetyl ammonium halides, chlorhexidine and benzyl ammonium chlorides, which formulate disinfectants used in veterinary clinics and dairies. Organic acid inhibition was associated with the dissociated acid species. Dissociated organic acids appear able to inhibit Ps. aeruginosa, and rates of fluoroquinolone resistance merit sustained companion animal isolate surveillance. This is the first report of Ps. aeruginosa susceptibility to 24 disinfectants and illustrates the high resistance of Ps. aeruginosa to both antibiotics and disinfectants. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  14. Differences in prevalence and treatment of Pseudomonas aeruginosa in cystic fibrosis centres in Denmark, Norway and Sweden

    DEFF Research Database (Denmark)

    Knudsen, Per Kristian; Olesen, Hanne V; Hoiby, Niels

    2009-01-01

    BACKGROUND: Chronic Pseudomonas aeruginosa (PA) infection causes increased morbidity and mortality in cystic fibrosis (CF). This study aimed to answer the following questions: Does the prevalence of chronic infection with PA differ between the CF centres in Scandinavia? Which differences exist......) (p=0.037). The pulmonary function was similar. CONCLUSIONS: It is possible to maintain a very low prevalence of chronic PA infection in CF patients

  15. Expression of antisense small RNAs in response to stress in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Gómez Lozano, María; Marvig, Rasmus Lykke; Tulstrup, Monica Vera-Lise

    2014-01-01

    regulatory functions. Results: In this study we used RNA-seq to identify 232 antisense RNAs (asRNAs) in the opportunistic pathogen Pseudomonas aeruginosa grown under 13 different conditions. The conditions studied include exponential and stationary growth as well as osmotic, oxidative and antibiotic stress...... their expression under osmotic, oxidative and antibiotic stress, suggesting that asRNAs may play regulatory roles during these conditions. We also made a comparison between the asRNAs detected in this study in P. aeruginosa PAO1 with the asRNAs detected in two previous studies in P. aeruginosa PA14, and found...... that the extent of overlap between the studies is very limited. Conclusions: RNA-seq experiments are revealing hundreds of novel transcripts in all bacterial genomes investigated. The comparison between independent studies that used RNA-seq to detect novel asRNAs in P. aeruginosa shows that the overlap between...

  16. Pseudomonas aeruginosa biofilm infections

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim

    2014-01-01

    Bacteria in natural, industrial and clinical settings predominantly live in biofilms, i.e., sessile structured microbial communities encased in self-produced extracellular matrix material. One of the most important characteristics of microbial biofilms is that the resident bacteria display...... a remarkable increased tolerance toward antimicrobial attack. Biofilms formed by opportunistic pathogenic bacteria are involved in devastating persistent medical device-associated infections, and chronic infections in individuals who are immune-compromised or otherwise impaired in the host defense. Because...... the use of conventional antimicrobial compounds in many cases cannot eradicate biofilms, there is an urgent need to develop alternative measures to combat biofilm infections. The present review is focussed on the important opportunistic pathogen and biofilm model organism Pseudomonas aeruginosa. Initially...

  17. EDH 'Millionaire' in PS Division

    CERN Document Server

    2001-01-01

    Christmas cheer! Left to right: Gerard Lobeau receives a bottle of Champagne from Derek Mathieson and Jurgen De Jonghe in recognition of EDH's millionth document. At 14:33 on Monday 3 December a technician in PS division, Gerard Lobeau, unwittingly became part of an important event in the life of CERN's Electronic Document Handling system (EDH). While ordering some pieces of aluminum for one of the PS's 10Mhz RF cavities, he created EDH document number 1,000,000. To celebrate the event Derek Mathieson (EDH Project Leader) and Jurgen De Jonghe (Original EDH Project Leader) presented Mr Lobeau with a bottle of champagne. As with 93% of material requests, Mr Lobeau's order was delivered within 24 hours. 'I usually never win anything' said Mr Lobeau as he accepted his prize, 'I initially though there may have been a problem with EDH when the document number had so many zeros in it, and was then surprised to get a phone call from you a few minutes later.' The EDH team had been monitoring the EDH document number ...

  18. What Makes Pseudomonas Aeruginosa Persist in the Lungs of CF Patients?

    DEFF Research Database (Denmark)

    Johansen, H.; Madsen Sommer, Lea Mette; Marvig, Rasmus Lykke

    2015-01-01

    The most important problem for cystic fibrosis (CF) patients is the airway infections responsible for the gradually decreasing lung function as the infections persist. We have investigated properties that may be involved in persistence of P. aeruginosa (PA) in the lungs of young CF children...

  19. Controlled trial of inhaled budesonide in patients with cystic fibrosis and chronic bronchopulmonary Psuedomonas aeruginosa infection

    DEFF Research Database (Denmark)

    Bisgaard, H; Pedersen, S S; Nielsen, K G

    1997-01-01

    The efficacy and safety of anti-inflammatory treatment with inhaled glucocorticosteroids in patients with cystic fibrosis (CF) and complicating chronic Pseudomonas aeruginosa (P.a.) lung infection was studied in a placebo-controlled, parallel, double-blind single center trial. Active treatment co...

  20. Friend or foe: genetic and functional characterization of plant endophytic Pseudomonas aeruginosa

    NARCIS (Netherlands)

    Kumar, A.; Munder, A.; Aravind, R.; Eapen, S.J.; Tümmler, B.; Raaijmakers, J.M.

    2013-01-01

    Endophytic Pseudomonas aeruginosa strain BP35 was originally isolated from black pepper grown in the rain forest in Kerala, India. Strain PaBP35 was shown to provide significant protection to black pepper against infections by Phytophthora capsici and Radopholus similis. For registration and

  1. Prediction of vaccine candidates against Pseudomonas aeruginosa: An integrated genomics and proteomics approach.

    Science.gov (United States)

    Rashid, Muhammad Ibrahim; Naz, Anam; Ali, Amjad; Andleeb, Saadia

    2017-07-01

    Pseudomonas aeruginosa is among top critical nosocomial infectious agents due to its persistent infections and tendency for acquiring drug resistance mechanisms. To date, there is no vaccine available for this pathogen. We attempted to exploit the genomic and proteomic information of P. aeruginosa though reverse-vaccinology approaches to unveil the prospective vaccine candidates. P. aeruginosa strain PAO1 genome was subjected to sequential prioritization approach following genomic, proteomics and structural analyses. Among, the predicted vaccine candidates: surface components of antibiotic efflux pumps (Q9HY88, PA2837), chaperone-usher pathway components (CupC2, CupB3), penicillin binding protein of bacterial cell wall (PBP1a/mrcA), extracellular component of Type 3 secretory system (PscC) and three uncharacterized secretory proteins (PA0629, PA2822, PA0978) were identified as potential candidates qualifying all the set criteria. These proteins were then analyzed for potential immunogenic surface exposed epitopes. These predicted epitopes may provide a basis for development of a reliable subunit vaccine against P. aeruginosa. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Two Isoforms of Clp Peptidase in Pseudomonas aeruginosa Control Distinct Aspects of Cellular Physiology

    OpenAIRE

    Hall, Branwen M.; Breidenstein, Elena B. M.; de la Fuente-Núñez, César; Reffuveille, Fany; Mawla, Gina D.; Hancock, Robert E. W.; Baker, Tania A.

    2017-01-01

    Caseinolytic peptidases (ClpPs) regulate diverse aspects of cellular physiology in bacteria. Some species have multiple ClpPs, including the opportunistic pathogen Pseudomonas aeruginosa, in which there is an archetypical isoform, ClpP1, and a second isoform, ClpP2, about which little is known. Here, we use phenotypic assays to investigate the biological roles of ClpP1 and ClpP2 and biochemical assays to characterize purified ClpP1, ClpP2, ClpX, and ClpA. Interestingly, ClpP1 and ClpP2 have d...

  3. Rapid detection of Pseudomonas aeruginosa biomarkers in biological fluids using surface-enhanced Raman scattering

    Science.gov (United States)

    Wu, Xiaomeng; Chen, Jing; Zhao, Yiping; Zughaier, Susu M.

    2014-05-01

    Pseudomonas aeruginosa (PA) is an opportunistic pathogen that causes major infection not only in Cystic Fibrosis patients but also in chronic obstructive pulmonary disease and in critically ill patients in intensive care units. Successful antibiotic treatment of the infection relies on accurate and rapid identification of the infectious agents. Conventional microbiological detection methods usually take more than 3 days to obtain accurate results. We have developed a rapid diagnostic technique based on surface-enhanced Raman scattering to directly identify PA from biological fluids. P. aeruginosa strains, PAO1 and PA14, are cultured in lysogeny broth, and the SERS spectra of the broth show the signature Raman peaks from pyocyanin and pyoverdine, two major biomarkers that P. aeruginosa secretes during its growth, as well as lipopolysaccharides. This provides the evidence that the presence of these biomarkers can be used to indicate P. aeruginosa infection. A total of 22 clinical exhaled breath condensates (EBC) samples were obtained from subjects with CF disease and from non-CF healthy donors. SERS spectra of these EBC samples were obtained and further analyzed by both principle component analysis and partial least square-discriminant analysis (PLS-DA). PLS-DA can discriminate the samples with P. aeruginosa infection and the ones without P. aeruginosa infection at 99.3% sensitivity and 99.6% specificity. In addition, this technique can also discriminate samples from subject with CF disease and healthy donor with 97.5% sensitivity and 100% specificity. These results demonstrate the potential of using SERS of EBC samples as a rapid diagnostic tool to detect PA infection.

  4. A Novel Insight into Dehydroleucodine Mediated Attenuation of Pseudomonas aeruginosa Virulence Mechanism

    Directory of Open Access Journals (Sweden)

    S. Mustafi

    2015-01-01

    Full Text Available Increasing resistance of Pseudomonas aeruginosa (P. aeruginosa to conventional treatments demands the search for novel therapeutic strategies. In this study, the antimicrobial activity of dehydroleucodine (DhL, a sesquiterpene lactone obtained from Artemisia (A. douglasiana, was screened against several pathogenic virulence effectors of P. aeruginosa. In vitro, minimum inhibitory concentration of DhL was determined against P. aeruginosa strains PAO1, PA103, PA14, and multidrug resistant clinical strain, CDN118. Results showed that DhL was active against each strain where PAO1 and PA103 showed higher susceptibility (MIC 0.48 mg/mL as compared to PA14 (MIC 0.96 mg/mL and CDN118 (MIC 0.98 mg/mL. Also, when PAO1 strain was grown in the presence of DhL (MIC50, 0.12 mg/mL, a delay in the generation time was noticed along with significant inhibition of secretory protease and elastase activities, interruption in biofilm attachment phase in a stationary culture, and a significant decline in Type III effector ExoS. At MIC50, DhL treatment increased the sensitivity of P. aeruginosa towards potent antibiotics. Furthermore, treatment of P. aeruginosa with DhL prevented toxin-induced apoptosis in macrophages. These observations suggest that DhL activity was at the bacterial transcriptional level. Hence, antimicrobial activity of DhL may serve as leads in the development of new anti-Pseudomonas pharmaceuticals.

  5. Chronic Pseudomonas aeruginosa cervical osteomyelitis

    Directory of Open Access Journals (Sweden)

    Sujeet Kumar Meher

    2016-01-01

    Full Text Available Pseudomonas aeruginosa is a rare cause of osteomyelitis of the cervical spine and is usually seen in the background of intravenous drug use and immunocompromised state. Very few cases of osteomyelitis of the cervical spine caused by pseudomonas aeruginosa have been reported in otherwise healthy patients. This is a case presentation of a young female, who in the absence of known risk factors for cervical osteomyelitis presented with progressively worsening neurological signs and symptoms.

  6. Hydrolysis of cefazolin by enzymes produced by Pseudomonas aeruginosa after exposure to ceftazidime in vitro

    Directory of Open Access Journals (Sweden)

    Papaioannidou Paraskevi

    2009-01-01

    Full Text Available Background/Aim. Sometimes resistance of Pseudomonas aeruginosa (Ps. aeruginosa is developed during antibiotic treatment, in spite of the initial susceptibility in vitro. The aim of this study was to use an in vitro model for the study of the development of resistant strains of Ps. aeruginosa after a short exposure to ceftazidime, and to study the hydrolysing capacity of β-lactamases produced by the resistant strains. Methods. Among 563 clinical strains of Ps. aeruginosa, 37 multisensitive strains were collected for the study. After being identified, strains with simultaneous sensitivity to 5 expanded spectrum cephalosporins were chosen. For each strain, the minimal inhibitory concentration (MIC of the 5 expanded spectrum cephalosporins was determined, and the production of extended spectrum β-lactamases (ESBL was excluded by the double-disc synergy diffusion test. Strains non producing ESBL were cultivated in concentrations of ceftazidime equal to MIC×2 and MIC×4. After 24 hours of culture, the development of resistant strains was estimated and the cephalosporinase activity of the produced β-lactamases was determined by their ability to hydrolyse cefazolin. Hydrolysis of cefazolin was studied by measuring the change of its absorbance on 272 nm using a Shimadzu 160A spectrophotometer. The hydrolyzing capacity of the enzymes was expressed as the percentage of the antibiotic, which was hydrolysed in 10 sec. Results. A total of 60% and 50% of strains developed resistant strains after exposure to ceftazidime in concentration MIC×2 and MIC×4, respectively. The hydrolyzing capacity of the original strains was 15-36% while the hydrolyzing capacity of the resistant strains was 10-73%. Totally 64% of the resistant strains expressed higher hydrolyzing capacity than the original strains. Conclusion. Regardless of the susceptibility test results, Ps. aeruginosa presented a high tendency to develop resistant strains after a short exposure to

  7. Trehalose biosynthesis promotes Pseudomonas aeruginosa pathogenicity in plants.

    Science.gov (United States)

    Djonović, Slavica; Urbach, Jonathan M; Drenkard, Eliana; Bush, Jenifer; Feinbaum, Rhonda; Ausubel, Jonathan L; Traficante, David; Risech, Martina; Kocks, Christine; Fischbach, Michael A; Priebe, Gregory P; Ausubel, Frederick M

    2013-03-01

    Pseudomonas aeruginosa strain PA14 is a multi-host pathogen that infects plants, nematodes, insects, and vertebrates. Many PA14 factors are required for virulence in more than one of these hosts. Noting that plants have a fundamentally different cellular architecture from animals, we sought to identify PA14 factors that are specifically required for plant pathogenesis. We show that synthesis by PA14 of the disaccharide trehalose is required for pathogenesis in Arabidopsis, but not in nematodes, insects, or mice. In-frame deletion of two closely-linked predicted trehalose biosynthetic operons, treYZ and treS, decreased growth in Arabidopsis leaves about 50 fold. Exogenously co-inoculated trehalose, ammonium, or nitrate, but not glucose, sulfate, or phosphate suppressed the phenotype of the double ΔtreYZΔtreS mutant. Exogenous trehalose or ammonium nitrate does not suppress the growth defect of the double ΔtreYZΔtreS mutant by suppressing the plant defense response. Trehalose also does not function intracellularly in P. aeruginosa to ameliorate a variety of stresses, but most likely functions extracellularly, because wild-type PA14 rescued the in vivo growth defect of the ΔtreYZΔtreS in trans. Surprisingly, the growth defect of the double ΔtreYZΔtreS double mutant was suppressed by various Arabidopsis cell wall mutants that affect xyloglucan synthesis, including an xxt1xxt2 double mutant that completely lacks xyloglucan, even though xyloglucan mutants are not more susceptible to pathogens and respond like wild-type plants to immune elicitors. An explanation of our data is that trehalose functions to promote the acquisition of nitrogen-containing nutrients in a process that involves the xyloglucan component of the plant cell wall, thereby allowing P. aeruginosa to replicate in the intercellular spaces in a leaf. This work shows how P. aeruginosa, a multi-host opportunistic pathogen, has repurposed a highly conserved "house-keeping" anabolic pathway (trehalose

  8. Trehalose biosynthesis promotes Pseudomonas aeruginosa pathogenicity in plants.

    Directory of Open Access Journals (Sweden)

    Slavica Djonović

    2013-03-01

    Full Text Available Pseudomonas aeruginosa strain PA14 is a multi-host pathogen that infects plants, nematodes, insects, and vertebrates. Many PA14 factors are required for virulence in more than one of these hosts. Noting that plants have a fundamentally different cellular architecture from animals, we sought to identify PA14 factors that are specifically required for plant pathogenesis. We show that synthesis by PA14 of the disaccharide trehalose is required for pathogenesis in Arabidopsis, but not in nematodes, insects, or mice. In-frame deletion of two closely-linked predicted trehalose biosynthetic operons, treYZ and treS, decreased growth in Arabidopsis leaves about 50 fold. Exogenously co-inoculated trehalose, ammonium, or nitrate, but not glucose, sulfate, or phosphate suppressed the phenotype of the double ΔtreYZΔtreS mutant. Exogenous trehalose or ammonium nitrate does not suppress the growth defect of the double ΔtreYZΔtreS mutant by suppressing the plant defense response. Trehalose also does not function intracellularly in P. aeruginosa to ameliorate a variety of stresses, but most likely functions extracellularly, because wild-type PA14 rescued the in vivo growth defect of the ΔtreYZΔtreS in trans. Surprisingly, the growth defect of the double ΔtreYZΔtreS double mutant was suppressed by various Arabidopsis cell wall mutants that affect xyloglucan synthesis, including an xxt1xxt2 double mutant that completely lacks xyloglucan, even though xyloglucan mutants are not more susceptible to pathogens and respond like wild-type plants to immune elicitors. An explanation of our data is that trehalose functions to promote the acquisition of nitrogen-containing nutrients in a process that involves the xyloglucan component of the plant cell wall, thereby allowing P. aeruginosa to replicate in the intercellular spaces in a leaf. This work shows how P. aeruginosa, a multi-host opportunistic pathogen, has repurposed a highly conserved "house-keeping" anabolic

  9. Phosphatidylserine externalization and procoagulant activation of erythrocytes induced by Pseudomonas aeruginosa virulence factor pyocyanin.

    Science.gov (United States)

    Qadri, Syed M; Donkor, David A; Bhakta, Varsha; Eltringham-Smith, Louise J; Dwivedi, Dhruva J; Moore, Jane C; Pepler, Laura; Ivetic, Nikola; Nazi, Ishac; Fox-Robichaud, Alison E; Liaw, Patricia C; Sheffield, William P

    2016-04-01

    The opportunistic pathogen Pseudomonas aeruginosa causes a wide range of infections in multiple hosts by releasing an arsenal of virulence factors such as pyocyanin. Despite numerous reports on the pleiotropic cellular targets of pyocyanin toxicity in vivo, its impact on erythrocytes remains elusive. Erythrocytes undergo an apoptosis-like cell death called eryptosis which is characterized by cell shrinkage and phosphatidylserine (PS) externalization; this process confers a procoagulant phenotype on erythrocytes as well as fosters their phagocytosis and subsequent clearance from the circulation. Herein, we demonstrate that P. aeruginosa pyocyanin-elicited PS exposure and cell shrinkage in erythrocyte while preserving the membrane integrity. Mechanistically, exposure of erythrocytes to pyocyanin showed increased cytosolic Ca(2+) activity as well as Ca(2+) -dependent proteolytic processing of μ-calpain. Pyocyanin further up-regulated erythrocyte ceramide abundance and triggered the production of reactive oxygen species. Pyocyanin-induced increased PS externalization in erythrocytes translated into enhanced prothrombin activation and fibrin generation in plasma. As judged by carboxyfluorescein succinimidyl-ester labelling, pyocyanin-treated erythrocytes were cleared faster from the murine circulation as compared to untreated erythrocytes. Furthermore, erythrocytes incubated in plasma from patients with P. aeruginosa sepsis showed increased PS exposure as compared to erythrocytes incubated in plasma from healthy donors. In conclusion, the present study discloses the eryptosis-inducing effect of the virulence factor pyocyanin, thereby shedding light on a potentially important mechanism in the systemic complications of P. aeruginosa infection. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  10. Friend or foe: genetic and functional characterization of plant endophytic Pseudomonas aeruginosa.

    Science.gov (United States)

    Kumar, A; Munder, A; Aravind, R; Eapen, S J; Tümmler, B; Raaijmakers, J M

    2013-03-01

    Endophytic Pseudomonas aeruginosa strain BP35 was originally isolated from black pepper grown in the rain forest in Kerala, India. Strain PaBP35 was shown to provide significant protection to black pepper against infections by Phytophthora capsici and Radopholus similis. For registration and implementation in disease management programmes, several traits of PaBP35 were investigated including its endophytic behaviour, biocontrol activity, phylogeny and toxicity to mammals. The results showed that PaBP35 efficiently colonized black pepper shoots and displayed a typical spatiotemporal pattern in its endophytic movement with concomitant suppression of Phytophthora rot. Confocal laser scanning microscopy revealed high populations of PaBP35::gfp2 inside tomato plantlets, supporting its endophytic behaviour in other plant species. Polyphasic approaches to genotype PaBP35, including BOX-PCR, recN sequence analysis, multilocus sequence typing and comparative genome hybridization analysis, revealed its uniqueness among P. aeruginosa strains representing clinical habitats. However, like other P. aeruginosa strains, PaBP35 exhibited resistance to antibiotics, grew at 25-41°C and produced rhamnolipids and phenazines. PaBP35 displayed strong type II secretion effectors-mediated cytotoxicity on mammalian A549 cells. Coupled with pathogenicity in a murine airway infection model, we conclude that this plant endophytic strain is as virulent as clinical P. aeruginosa strains. Safety issues related to the selection of plant endophytic bacteria for crop protection are discussed. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  11. High-level amikacin resistance in Pseudomonas aeruginosa associated with a 3'-phosphotransferase with high affinity for amikacin.

    Science.gov (United States)

    Torres, C; Perlin, M H; Baquero, F; Lerner, D L; Lerner, S A

    2000-08-01

    This work describes the characterization of the phosphotransferase enzymatic activity responsible for amikacin resistance in two clinical Pseudomona aeruginosa strains, isolated from a hospital that used amikacin as first-line aminoglycoside. Amikacin-resistant P. aeruginosa PA40 and PA43 (MIC: 128 mg/l) were shown to have APH activity with a substrate profile similar to that of APH(3')-VI. The enzyme from P. aeruginosa PA40 was purified to > 70% homogeneity. The Km of amikacin for this enzyme was 1.4 microM, the Vmax/Km ratio for amikacin was higher than for the other aminoglycosides tested and PCR and DNA sequencing ruled out the presence of aph(3')-IIps. Amikacin resistance in this strain was, therefore, associated with APH(3')-VI and the high affinity of this enzyme for amikacin could explain the high-level resistance that we observed.

  12. Pseudomonas aeruginosa mucoid strain 8830 binds glycans containing the sialyl-Lewis x epitope.

    Science.gov (United States)

    Xia, Baoyun; Sachdev, Goverdhan P; Cummings, Richard D

    2007-01-01

    Pseudomonas aeruginosa infection of patients with cystic fibrosis (CF) is a leading cause of their morbidity and mortality. Pathogenesis is initiated in part by molecular interactions of P. aeruginosa with carbohydrate residues in airway mucins that accumulate in the lungs of patients with this disease. To explore the nature of the glycans recognized by a stable, mucoid, alginate-producing strain P. aeruginosa 8830 we generated a genetically modified Pa8830 expressing green fluorescent protein (Pa3380-GFP). We tested its binding to a panel of glycolipids and neoglycolipids in which selected glycans were covalently attached to dipalmitoyl phosphatidylethanolamine and analyzed on silica gel surfaces. Among all glycans tested, Pa8830-GFP bound best to sialyl-Le(x)-containing glycan NeuAc(alpha2-3)Gal(beta1-4)[Fuc(alpha1-3)]GlcNAc-R and bound weakly to H-type blood group Fucalpha1-2Galbeta1-4GlcNAc-R, sialyl-lactose, and Le(x), and exhibited little binding toward non-fucosylated derivatives. Interestingly, while Pa8830-GFP bound to the glycosphingolipid asialoGM1, it did not appear to bind to a wide variety of other glycosphingolipids including GM1, GM2, asialoGM2, and sulfatide. These results indicate that P. aeruginosa 8830 has preferential binding to sialyl-Le(x)-containing glycans and has weak recognition of related fucose- and sialic acid-containing glycans. The finding that Pa8830 binds sialyl-Le(x)-containing glycans, which occur at increased levels in mucins from CF patients, is consistent with studies of other strains of P. aeruginosa and further suggests that such glycans on CF mucins contribute to disease pathogenesis.

  13. Identification of genes involved in Pseudomonas aeruginosa biofilm-specific resistance to antibiotics.

    Directory of Open Access Journals (Sweden)

    Li Zhang

    Full Text Available Pseudomonas aeruginosa is a key opportunistic pathogen characterized by its biofilm formation ability and high-level multiple antibiotic resistance. By screening a library of random transposon insertion mutants with an increased biofilm-specifc antibiotic susceptibility, we previously identified 3 genes or operons of P. aeruginosa UCBPP-PA14 (ndvB, PA1875-1877 and tssC1 that do not affect biofilm formation but are involved in biofilm-specific antibiotic resistance. In this study, we demonstrate that PA0756-0757 (encoding a putative two-component regulatory system, PA2070 and PA5033 (encoding hypothetical proteins of unknown function display increased expression in biofilm cells and also have a role in biofilm-specific antibiotic resistance. Furthermore, deletion of each of PA0756, PA2070 and PA5033 resulted in a significant reduction of lethality in Caenorhabditis elegans, indicating a role for these genes in both biofilm-specific antibiotic resistance and persistence in vivo. Together, these data suggest that these genes are potential targets for antimicrobial agents.

  14. Detection and enumeration of Pseudomonas aeruginosa in soil and manure assessed by an ecfX qPCR assay.

    Science.gov (United States)

    Colinon, C; Deredjian, A; Hien, E; Brothier, E; Bouziri, L; Cournoyer, B; Hartman, A; Henry, S; Jolivet, C; Ranjard, L; Nazaret, S

    2013-06-01

    To develop a qPCR approach for the detection of Pseudomonas aeruginosa in soil and manure and explore its efficacy and limitations compared with that of a classical culture-dependent approach. A Ps. aeruginosa ecfX qPCR assay was developed. This assay was optimized for soils of contrasting physico-chemical properties and evidenced a three-log dynamic range of detection [5 × 10(4)  - 5 × 10(6) cells (g drywt soil)(-1) ] in inoculated microcosms. Sensitivity was determined to be around 5 × 10(4)  cells (g drywt soil)(-1) . In parallel, the minimum detection limit was estimated in the range of 10-100 CFU (g drywt soil)(-1) using a culture-dependent approach based on the use of a selective medium (cetrimide agar base medium supplemented with nalidixic acid), coupled to ecfX gene amplification to confirm isolate identity. These soil samples led to the growth of abundant non-Ps. aeruginosa colonies mainly belonging to other Pseudomonas species but also some beta-Proteobacteria. These bacteria strongly impacted the detection threshold of this approach. Efficacy of these approaches was compared for Ps. aeruginosa enumeration among manure and agricultural soil samples from various sites in France, Tunisia and Burkina Faso. The developed qPCR assay enabled a specific detection of Ps. aeruginosa in soil and manure samples. The culture-based approach was usually found more sensitive than the qPCR assay. However, abundance of non-Ps. aeruginosa species among the indigenous communities able to grow on the selective medium affected the sensitivity of this latter approach. This study describes the first specific and sensitive qPCR assay for the detection and enumeration of Ps. aeruginosa in soil and manure and shows its complementarity with a culture-based approach. © 2013 The Society for Applied Microbiology.

  15. PaR-PaR laboratory automation platform.

    Science.gov (United States)

    Linshiz, Gregory; Stawski, Nina; Poust, Sean; Bi, Changhao; Keasling, Jay D; Hillson, Nathan J

    2013-05-17

    Labor-intensive multistep biological tasks, such as the construction and cloning of DNA molecules, are prime candidates for laboratory automation. Flexible and biology-friendly operation of robotic equipment is key to its successful integration in biological laboratories, and the efforts required to operate a robot must be much smaller than the alternative manual lab work. To achieve these goals, a simple high-level biology-friendly robot programming language is needed. We have developed and experimentally validated such a language: Programming a Robot (PaR-PaR). The syntax and compiler for the language are based on computer science principles and a deep understanding of biological workflows. PaR-PaR allows researchers to use liquid-handling robots effectively, enabling experiments that would not have been considered previously. After minimal training, a biologist can independently write complicated protocols for a robot within an hour. Adoption of PaR-PaR as a standard cross-platform language would enable hand-written or software-generated robotic protocols to be shared across laboratories.

  16. Identification of Pseudomonas aeruginosa phenazines that kill Caenorhabditis elegans.

    Science.gov (United States)

    Cezairliyan, Brent; Vinayavekhin, Nawaporn; Grenfell-Lee, Daniel; Yuen, Grace J; Saghatelian, Alan; Ausubel, Frederick M

    2013-01-01

    Pathogenic microbes employ a variety of methods to overcome host defenses, including the production and dispersal of molecules that are toxic to their hosts. Pseudomonas aeruginosa, a Gram-negative bacterium, is a pathogen of a diverse variety of hosts including mammals and the nematode Caenorhabditis elegans. In this study, we identify three small molecules in the phenazine class that are produced by P. aeruginosa strain PA14 that are toxic to C. elegans. We demonstrate that 1-hydroxyphenazine, phenazine-1-carboxylic acid, and pyocyanin are capable of killing nematodes in a matter of hours. 1-hydroxyphenazine is toxic over a wide pH range, whereas the toxicities of phenazine-1-carboxylic acid and pyocyanin are pH-dependent at non-overlapping pH ranges. We found that acidification of the growth medium by PA14 activates the toxicity of phenazine-1-carboxylic acid, which is the primary toxic agent towards C. elegans in our assay. Pyocyanin is not toxic under acidic conditions and 1-hydroxyphenazine is produced at concentrations too low to kill C. elegans. These results suggest a role for phenazine-1-carboxylic acid in mammalian pathogenesis because PA14 mutants deficient in phenazine production have been shown to be defective in pathogenesis in mice. More generally, these data demonstrate how diversity within a class of metabolites could affect bacterial toxicity in different environmental niches.

  17. Identification of Pseudomonas aeruginosa phenazines that kill Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Brent Cezairliyan

    2013-01-01

    Full Text Available Pathogenic microbes employ a variety of methods to overcome host defenses, including the production and dispersal of molecules that are toxic to their hosts. Pseudomonas aeruginosa, a Gram-negative bacterium, is a pathogen of a diverse variety of hosts including mammals and the nematode Caenorhabditis elegans. In this study, we identify three small molecules in the phenazine class that are produced by P. aeruginosa strain PA14 that are toxic to C. elegans. We demonstrate that 1-hydroxyphenazine, phenazine-1-carboxylic acid, and pyocyanin are capable of killing nematodes in a matter of hours. 1-hydroxyphenazine is toxic over a wide pH range, whereas the toxicities of phenazine-1-carboxylic acid and pyocyanin are pH-dependent at non-overlapping pH ranges. We found that acidification of the growth medium by PA14 activates the toxicity of phenazine-1-carboxylic acid, which is the primary toxic agent towards C. elegans in our assay. Pyocyanin is not toxic under acidic conditions and 1-hydroxyphenazine is produced at concentrations too low to kill C. elegans. These results suggest a role for phenazine-1-carboxylic acid in mammalian pathogenesis because PA14 mutants deficient in phenazine production have been shown to be defective in pathogenesis in mice. More generally, these data demonstrate how diversity within a class of metabolites could affect bacterial toxicity in different environmental niches.

  18. Identification of Pseudomonas aeruginosa Phenazines that Kill Caenorhabditis elegans

    Science.gov (United States)

    Cezairliyan, Brent; Vinayavekhin, Nawaporn; Grenfell-Lee, Daniel; Yuen, Grace J.; Saghatelian, Alan; Ausubel, Frederick M.

    2013-01-01

    Pathogenic microbes employ a variety of methods to overcome host defenses, including the production and dispersal of molecules that are toxic to their hosts. Pseudomonas aeruginosa, a Gram-negative bacterium, is a pathogen of a diverse variety of hosts including mammals and the nematode Caenorhabditis elegans. In this study, we identify three small molecules in the phenazine class that are produced by P. aeruginosa strain PA14 that are toxic to C. elegans. We demonstrate that 1-hydroxyphenazine, phenazine-1-carboxylic acid, and pyocyanin are capable of killing nematodes in a matter of hours. 1-hydroxyphenazine is toxic over a wide pH range, whereas the toxicities of phenazine-1-carboxylic acid and pyocyanin are pH-dependent at non-overlapping pH ranges. We found that acidification of the growth medium by PA14 activates the toxicity of phenazine-1-carboxylic acid, which is the primary toxic agent towards C. elegans in our assay. Pyocyanin is not toxic under acidic conditions and 1-hydroxyphenazine is produced at concentrations too low to kill C. elegans. These results suggest a role for phenazine-1-carboxylic acid in mammalian pathogenesis because PA14 mutants deficient in phenazine production have been shown to be defective in pathogenesis in mice. More generally, these data demonstrate how diversity within a class of metabolites could affect bacterial toxicity in different environmental niches. PMID:23300454

  19. Challenges with current inhaled treatments for chronic Pseudomonas aeruginosa infection in patients with cystic fibrosis.

    LENUS (Irish Health Repository)

    Greally, Peter

    2012-06-01

    Pseudomonas aeruginosa (Pa) is the predominant pathogen infecting the airways of patients with cystic fibrosis (CF). Initial colonization is usually transient and associated with non-mucoid strains, which can be eradicated if identified early. This strategy can prevent, or at least delay, chronic Pa infection, which eventually develops in the majority of patients by their late teens or early adulthood. This article discusses the management and latest treatment developments of Pa lung infection in patients with CF, with a focus on nebulized antibiotic therapy.

  20. Utility of in vivo transcription profiling for identifying Pseudomonas aeruginosa genes needed for gastrointestinal colonization and dissemination

    DEFF Research Database (Denmark)

    Koh, Andrew Y; Mikkelsen, Per J; Smith, Roger S

    2010-01-01

    these mutants and WT P. aeruginosa PA14. To evaluate T3SS factors, we tested GI colonization and neutropenia-induced dissemination of both deletional (PAO1 and PAK) and insertional (PA14) mutants in four genes in the P. aeruginosa T3SS, exoS or exoU, exoT, and popB. There were no significant differences in GI......, increased transcription of genes during in vivo murine GI colonization is not predictive of an essential role for the gene product in either colonization or overall survival following induction of neutropenia....

  1. Ps-atom scattering at low energies

    CERN Document Server

    Fabrikant, I I

    2015-01-01

    A pseudopotential for positronium-atom interaction, based on electron-atom and positron-atom phase shifts, is constructed, and the phase shifts for Ps-Kr and Ps-Ar scattering are calculated. This approach allows us to extend the Ps-atom cross sections, obtained previously in the impulse approximation [Phys. Rev. Lett. 112, 243201 (2014)], to energies below the Ps ionization threshold. Although experimental data are not available in this low-energy region, our results describe well the tendency of the measured cross sections to drop with decreasing velocity at $v<1$ a.u. Our results show that the effect of the Ps-atom van der Waals interaction is weak compared to the polarization interaction in electron-atom and positron-atom scattering. As a result, the Ps scattering length for both Ar and Kr is positive, and the Ramsauer-Townsend minimum is not observed for Ps scattering from these targets. This makes Ps scattering quite different from electron scattering in the low-energy region, in contrast to the inter...

  2. Enhanced personal protection at the PS

    CERN Multimedia

    Samuel Morier Genoud

    2013-01-01

    Pictures 03, 06, 07 08 : Pierre Ninin, deputy group leader of GS-ASE and responsible for the installation of the new PS complex safety system, in front of a new access control system.Pictures 10, 12 ,13 : View of Building 271, the future control centre of the new PS complex safety system.

  3. PS, SL and LHC Auditoria change names

    CERN Document Server

    2003-01-01

    Following the replacement of the PS, SL and LHC Divisions by the AB and AT Divisions, the Auditoria are also changing their names. PS Auditorium is renamed AB Meyrin SL Auditorium is renamed AB Prévessin LHC Auditorium is renamed AT

  4. ExoU contributes to late killing of Pseudomonas aeruginosa - infected endothelial cells ExoU contribui para a morte tardia de células endoteliais infectadas por Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Alessandra Mattos Saliba

    2003-11-01

    Full Text Available To ascertain the role of ExoU in late P. aeruginosa cytotoxicity, endothelial cells (EC were exposed to wild type PA103, PA103deltaexoU and PA103::exsA for 1h and to gentamicin in culture medium. After 24h, the viability of PA103-infected cells (33.7 ± 14.3% was significantly lower than the viability of PA103deltaexoU- (77.7 ± 6.3% or PA103::exsA- (79.5 ± 23.3% infected EC. P. aeruginosa cytotoxicity did not depend on the bacterial ability to interact with EC because the percentage of cells with associated PA103 (35.9 ± 15.8% was similar to the percentage in PA103deltaexoU- (34.2 ± 16.0% and lower than the percentage in PA103::exsA-infected cultures (82.9 ± 18.9%. Cell treatment with cytochalasin D reduced the PA103 internalization by EC but did not interfere with its ability to kill host cells.Para determinar o papel de ExoU na citotoxicidade tardia de P. aeruginosa, células endoteliais (CE foram expostas às cepas PA103, PA103deltaxoU e PA103::exsA por 1h e à gentamicina em meio de cultura. Após 24h, a viabilidade das CE infectadas com PA103 (33.7 ± 14.3% foi inferior à de CE infectadas com PA103deltaexoU (77.7 ± 6.3% e PA103::exsA (79.5 ± 23.3%. A citotoxicidade não dependeu da capacidade de interagir com as CE porque o percentual de células com bactérias associadas em culturas expostas a PA103 foi semelhante ao percentual em culturas expostas a PA103deltaexoU e inferior em culturas expostas a PA103::exsA. O tratamento das CE com citocalasina D reduziu a internalização de PA103, mas não interferiu em sua citotoxicidade.

  5. Characterization of the core and accessory genomes of Pseudomonas aeruginosa using bioinformatic tools Spine and AGEnt.

    Science.gov (United States)

    Ozer, Egon A; Allen, Jonathan P; Hauser, Alan R

    2014-08-29

    Pseudomonas aeruginosa is an important opportunistic pathogen responsible for many infections in hospitalized and immunocompromised patients. Previous reports estimated that approximately 10% of its 6.6 Mbp genome varies from strain to strain and is therefore referred to as "accessory genome". Elements within the accessory genome of P. aeruginosa have been associated with differences in virulence and antibiotic resistance. As whole genome sequencing of bacterial strains becomes more widespread and cost-effective, methods to quickly and reliably identify accessory genomic elements in newly sequenced P. aeruginosa genomes will be needed. We developed a bioinformatic method for identifying the accessory genome of P. aeruginosa. First, the core genome was determined based on sequence conserved among the completed genomes of twelve reference strains using Spine, a software program developed for this purpose. The core genome was 5.84 Mbp in size and contained 5,316 coding sequences. We then developed an in silico genome subtraction program named AGEnt to filter out core genomic sequences from P. aeruginosa whole genomes to identify accessory genomic sequences of these reference strains. This analysis determined that the accessory genome of P. aeruginosa ranged from 6.9-18.0% of the total genome, was enriched for genes associated with mobile elements, and was comprised of a majority of genes with unknown or unclear function. Using these genomes, we showed that AGEnt performed well compared to other publically available programs designed to detect accessory genomic elements. We then demonstrated the utility of the AGEnt program by applying it to the draft genomes of two previously unsequenced P. aeruginosa strains, PA99 and PA103. The P. aeruginosa genome is rich in accessory genetic material. The AGEnt program accurately identified the accessory genomes of newly sequenced P. aeruginosa strains, even when draft genomes were used. As P. aeruginosa genomes become available

  6. Experimental investigation on tribological behaviours of PA6, PA6 ...

    Indian Academy of Sciences (India)

    The test specimens were prepared in an injection-moulding machine by varying the weight proportions of Al 2 O 3 and graphite particles blended with PA6. The tribological properties of the composites were observed by using pin-on-disc wear test rig under dry slidingconditions. The worn surfaces of the composites were ...

  7. Gallium induces the production of virulence factors in Pseudomonas aeruginosa.

    Science.gov (United States)

    García-Contreras, Rodolfo; Pérez-Eretza, Berenice; Lira-Silva, Elizabeth; Jasso-Chávez, Ricardo; Coria-Jiménez, Rafael; Rangel-Vega, Adrián; Maeda, Toshinari; Wood, Thomas K

    2014-02-01

    The novel antimicrobial gallium is a nonredox iron III analogue with bacteriostatic and bactericidal properties, effective for the treatment of Pseudomonas aeruginosa in vitro and in vivo in mouse and rabbit infection models. It interferes with iron metabolism, transport, and presumably its homeostasis. As gallium exerts its antimicrobial effects by competing with iron, we hypothesized that it ultimately will lead cells to an iron deficiency status. As iron deficiency promotes the expression of virulence factors in vitro and promotes the pathogenicity of P. aeruginosa in animal models, it is anticipated that treatment with gallium will also promote the production of virulence factors. To test this hypothesis, the reference strain PA14 and two clinical isolates from patients with cystic fibrosis were exposed to gallium, and their production of pyocyanin, rhamnolipids, elastase, alkaline protease, alginate, pyoverdine, and biofilm was determined. Gallium treatment induced the production of all the virulence factors tested in the three strains except for pyoverdine. In addition, as the Ga-induced virulence factors are quorum sensing controlled, co-administration of Ga and the quorum quencher brominated furanone C-30 was assayed, and it was found that C-30 alleviated growth inhibition from gallium. Hence, adding both C-30 and gallium may be more effective in the treatment of P. aeruginosa infections. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  8. Proteomic Response of Pseudomonas aeruginosa PAO1 Adhering to Solid Surfaces

    Directory of Open Access Journals (Sweden)

    Morgan Guilbaud

    2017-08-01

    Full Text Available Pseudomonas aeruginosa is a pathogenic micro-organism responsible for many hospital-acquired infections. It is able to adhere to solid surfaces and develop an immobilized community or so-called biofilm. Many studies have been focusing on the use of specific materials to prevent the formation of these biofilms, but the reactivity of the bacteria in contact to surfaces remains unknown. The aim of this study was to evaluate the impact of the abiotic surface on the physiology of adherent bacteria. Three different materials, stainless steel (SS, glass (G, and polystyrene (PS that were relevant to industrial or medical environments were characterized at the physicochemical level in terms of their hydrophobicity and roughness. We showed that SS was moderately hydrophilic and rough, potentially containing crevices, G was hydrophilic and smooth while PS was hydrophobic and smooth. We further showed that P. aeruginosa cells were more likely able to adhere to SS and G rather than PS surfaces under our experimental conditions. The physiological response of P. aeruginosa when adhering to each of these materials was then evaluated by global proteomic analysis. The abundance of 70 proteins was shown to differ between the materials suggesting that their abundance was modified as a function of the material to which bacteria adhered. Our data lead to enabling the identification of abundance patterns that appeared to be specific to a given surface. Taken together, our data showed that P. aeruginosa is capable of sensing and responding to a surface probably via specific programmes to adapt its physiological response accordingly.

  9. Use of bacteriophage endolysin EL188 and outer membrane permeabilizers against Pseudomonas aeruginosa.

    Science.gov (United States)

    Briers, Y; Walmagh, M; Lavigne, R

    2011-03-01

    To select and evaluate an appropriate outer membrane (OM) permeabilizer to use in combination with the highly muralytic bacteriophage endolysin EL188 to inactivate (multi-resistant) Pseudomonas aeruginosa. We tested the combination of endolysin EL188 and several OM permeabilizing compounds on three selected Ps. aeruginosa strains with varying antibiotic resistance. We analysed OM permeabilization using the hydrophobic probe N-phenylnaphtylamine and a recombinant fusion protein of a peptidoglycan binding domain and green fluorescent protein on the one hand and cell lysis assays on the other hand. Antibacterial assays showed that incubation of 10(6) Ps. aeruginosa cells ml(-1) in presence of 10 mmol l(-1) ethylene diamine tetraacetic acid disodium salt dihydrate (EDTA) and 50 μg ml(-1) endolysin EL188 led to a strain-dependent inactivation between 3·01 ± 0·17 and 4·27 ± 0·11 log units in 30 min. Increasing the EL188 concentration to 250 μg ml(-1) further increased the inactivation of the most antibiotic resistant strain Br667 (4·07 ± 0·09 log units). Ethylene diamine tetraacetic acid disodium salt dihydrate was selected as the most suitable component to combine with EL188 in order to reduce Ps. aeruginosa with up to 4 log units in a time interval of 30 min. This in vitro study demonstrates that the application range of bacteriophage encoded endolysins as 'enzybiotics' must not be limited to gram-positive pathogens. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  10. On the crystallization behavior of syndiotactic-b-atactic polystyrene stereodiblock copolymers, atactic/syndiotactic polystyrene blends, and aPS/sPS blends modified with sPS-b-aPS

    Energy Technology Data Exchange (ETDEWEB)

    Annunziata, Liana, E-mail: liana.annunziatta@univ-rennes1.fr [Organométalliques et Catalyse, UMR 6226 Sciences Chimiques CNRS, Université de Rennes 1, Campus de Beaulieu, F-35042 Rennes Cedex (France); Monasse, Bernard, E-mail: bernard.monasse@mines-paristech.fr [Mines-ParisTech, CEMEF, Centre de Mise en Forme des Matériaux, UMR CNRS 7635, Sophia Antipolis (France); Rizzo, Paola; Guerra, Gaetano [Dipartimento di Chimica e Biologia, Università degli studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano, SA (Italy); Duc, Michel [Total Petrochemicals Research Feluy, Zone Industrielle Feluy C, B-7181 Seneffe (Belgium); Carpentier, Jean-François, E-mail: jean-francois.carpentier@univ-rennes1.fr [Organométalliques et Catalyse, UMR 6226 Sciences Chimiques CNRS, Université de Rennes 1, Campus de Beaulieu, F-35042 Rennes Cedex (France)

    2013-09-16

    Crystallization and morphological features of syndiotactic-b-atactic polystyrene stereodiblock copolymers (sPS-b-aPS), atactic/syndiotactic polystyrene blends (aPS/sPS), and aPS/sPS blends modified with sPS-b-aPS, with different compositions in aPS and sPS, have been investigated using differential scanning calorimetry (DSC), polarized light optical microscopy (POM) and wide angle X-ray diffraction (WAXRD) techniques. For comparative purposes, the properties of parent pristine sPS samples were also studied. WAXRD analyses revealed for all the samples, independently from their composition (aPS/sPS ratio) and structure (blends, block copolymers, blends modified with block copolymers), the same polymorphic β form of sPS. The molecular weight of aPS and sPS showed opposite effects on the crystallization of 50:50 aPS/sPS blends: the lower the molecular weight of aPS, the slower the crystallization while the lower the molecular weight of sPS, the faster the crystallization. DSC studies performed under both isothermal and non-isothermal conditions, independently confirmed by POM studies, led to a clear trend for the crystallization rate at a given sPS/aPS ratio (ca. 50:50 and 20:80): sPS homopolymers > sPS-b-aPS block copolymers ∼sPS/aPS blends modified with sPS-b-aPS copolymers > sPS/aPS blends. Interestingly, sPS-b-aPS block copolymers not only crystallized faster than blends, but also affected positively the crystallization behavior of blends. At 50:50 sPS/aPS ratio, blends (Blend-2), block copolymers (Cop-1) and blends modified with block copolymers (Blend-2-mod) crystallized via spherulitic crystalline growth controlled by an interfacial process. In all cases, an instantaneous nucleation was observed. The density of nuclei in block copolymers (160,000−190,000 nuclei mm{sup −3}) was always higher than that in blends and modified blends (30,000−60,000 nuclei mm{sup −3}), even for quite different sPS/aPS ratio. At 20:80 sPS/aPS ratio, the block copolymers

  11. The emergence of multidrug-resistant Pseudomonas aeruginosa in cystic fibrosis patients on inhaled antibiotics

    Directory of Open Access Journals (Sweden)

    Atqah AbdulWahab

    2017-01-01

    Full Text Available Introduction: Multidrug-resistant Pseudomonas aeruginosa (MDR-PA is an important and growing issue in the care of patients with cystic fibrosis (CF, and a major cause of morbidity and mortality. Objective: The objective of the study was to describe the frequency of MDR-PA recovered from the lower respiratory samples of pediatric and adult CF patients, and its antibiotic resistance pattern to commonly used antimicrobial agents including β-lactams, aminoglycosides, and fluoroquinolones. Materials and Methods: The lower respiratory isolates of P. aeruginosa were obtained from inpatients and outpatients CF clinics from a tertiary care teaching hospital for the period from October 2014 to September 2015. The identification and antimicrobial susceptibility for all the isolates were performed by using the BD Phoenix™ and E-test in compliance with Clinical and Laboratory Standards Institute (CLSI guidelines. Results: A total of 61 P. aeruginosa samples were isolated from thirty CF patients from twenty families. Twelve sputum samples were positive for MDR-PA (seven nonmucoid and five mucoid isolates from five CF patients (five families with moderate-to-very severe lung disease given MDR-PA frequency of 19.7%. The median age of the study group was 20 (range 10–30 years. Three CF patients were on chronic inhaled tobramycin and two on nebulized colistin. The antimicrobial patterns of isolates MDR-PA showed the highest rate of resistance toward each gentamycin, amikacin, and cefepime (100%, followed by 91.7% to ciprofloxacin, 75% to tobramycin, 58.3% to meropenem, and 50% to piperacillin-tazobactam. None of the isolates were resistant to colistin during the study period. Conclusion: The study results emphasize that the emergence of a significant problem in the clinical isolates of P. aeruginosa in CF patients that dictate appropriate attention to the antibiotic management after proper surveillance.

  12. Feng shui pa-kua / Ann Tenno

    Index Scriptorium Estoniae

    Tenno, Ann, 1952-

    2003-01-01

    Pa-kua sümbol, kolmikmärkide Varane Taevane Järjestus - yin pa-kua ja Hilisem Taevane Järjestus - yang pa-kua. Inimeste kodude - majade ja aedade kujundamiseks kasutatakse Hilisema Taevase Järjestuse pa-kua'd. Pa-kua kolmikmärgid yang pa-kua järjestuses, soovitusi aia kujundamiseks. 8 ill

  13. Dermal wound transcriptomic responses to Infection with Pseudomonas aeruginosa versus Klebsiella pneumoniae in a rabbit ear wound model

    OpenAIRE

    Leung, Kai P.; D’Arpa, Peter; Seth, Akhil K; Geringer, Matthew R.; Jett, Marti; Xu, Wei; Hong, Seok J; Galiano, Robert D.; Chen, Tsute; Mustoe, Thomas A.

    2014-01-01

    Background Bacterial infections of wounds impair healing and worsen scarring. We hypothesized that transcriptome analysis of wounds infected with Klebsiella pneumoniae (K.p.) or Pseudomonas aeruginosa (P.a.) would indicate host-responses associated with the worse healing of P.a.- than K.p.-infected wounds. Methods Wounds created on post-operative day (POD) 0 were infected during the inflammatory phase of healing on POD3 and were harvested on POD4 for microarray and transcriptome analysis. Oth...

  14. Ps 22 in Gospels’ interpretation of Passion

    Directory of Open Access Journals (Sweden)

    Sylwester Jędrzejewski

    2012-09-01

    Full Text Available Ps 22 is a piece of artistically high poetry, clear images and metaphors, historical and prophetic references. The conviction of biblical scholars that the New Testament writers has recognized in Ps 22 prophetic witness of passion, accompanies the Church from its beginnings. The words of Jesus on the cross, taken from Ps 22: 2, have a character of lamentable re-symbolization of the prayer of Israel. These words establish a theological answer in the form of suitable credo as well. Dramatic question “why?” is connected with a proclamation and identification “My God”. The personal experience of oppression and death is included by Jesus in the history of his nation and in the experience of God. Ps 22 in the Gospels’ passion context becomes a proclamation form of prayer and a very personal, expressed in such dramatic circumstances confession of the faith.

  15. Excited levels of Pa-233; Niveles excitados del Pa-233

    Energy Technology Data Exchange (ETDEWEB)

    Vara Cuadrado, J. M.

    1969-07-01

    A study of Pa-233 excited levels from the alpha decay of Np-237 and from beta decay of Th-233 has been performed. The alpha decay spectrum was measured with a semiconductor spectrometer of 18 keV effective resolution (FWHM). Over 13 new lines were identified. The gamma ray spectra of Np-237 and Th-233 were obtained with a Ge-Li detector low and medium range energy lines, and with Si-Li detector for the low energy region. A continuous purification method of Np-237 from its comparatively short-lived daughter Pa-233 was applied. A high number of new lines were identified in both spectra. The gamma-gamma coincidence spectra were obtained with INa(T{sub 1}) detectors. (Author) 54 refs.

  16. Yasp for LEIR to PS injection

    CERN Document Server

    Kain, V; Bartosik, H; Huschauer, A; Jacquet, D; Nicosia, D; Pasinelli, S; Wenninger, J

    2017-01-01

    The steering program YASP was introduced in the LEIRinjection as well as the extraction lines in 2016 to correctthe trajectories with well-known model based correctionalgorithms such as MICADO or SVD. In addition a YASPconfiguration was prepared to correct the extraction linetogether with the first turn of the PS. In this way the injectionoscillations can be corrected while keeping the trajectoryreasonable in the PS injection line.

  17. PS overcomes two serious magnet failures

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Two magnets and a bus bar connection in the PS were found to be faulty during high-voltage tests at the end of the accelerator shutdown. A five-week repair schedule was quickly devised. A team of mechanics, technicians and engineers worked at full speed to replace the faulty magnets, succeeding in limiting the delay of the accelerators' spring start-up to two weeks. Here we see the PS magnet string awaiting the replacement no. 6 magnet.

  18. Key role of an ADP - ribose - dependent transcriptional regulator of NAD metabolism for fitness and virulence of Pseudomonas aeruginosa.

    Science.gov (United States)

    Okon, Elza; Dethlefsen, Sarah; Pelnikevich, Anna; Barneveld, Andrea van; Munder, Antje; Tümmler, Burkhard

    2017-01-01

    NAD is an essential co-factor of redox reactions and metabolic conversions of NAD-dependent enzymes. NAD biosynthesis in the opportunistic pathogen Pseudomonas aeruginosa has yet not been experimentally explored. The in silico search for orthologs in the P. aeruginosa PAO1 genome identified the operon pncA - pncB1-nadE (PA4918-PA4920) to encode the nicotinamidase, nicotinate phosporibosyltransferase and Nad synthase of salvage pathway I. The functional role of the preceding genes PA4917 and PA4916 was resolved by the characterization of recombinant protein. PA4917 turned out to encode the nicotinate mononucleotide adenylyltransferase NadD2 and PA4916 was determined to encode the transcriptional repressor NrtR that binds to an intergenic sequence between nadD2 and pncA. Complex formation between the catalytically inactive Nudix protein NrtR and its DNA binding site was suppressed by the antirepressor ADP-ribose. NrtR plasposon mutagenesis abrogated virulence of P. aeruginosa TBCF10839 in a murine acute airway infection model and constrained its metabolite profile. When grown together with other isogenic plasposon mutants, the nrtR knock-out was most compromised in competitive fitness to persist in nutrient-rich medium in vitro or murine airways in vivo. This example demonstrates how tightly metabolism and virulence can be intertwined by key elements of metabolic control. Copyright © 2016 Elsevier GmbH. All rights reserved.

  19. Activity of Bacteriophages in Removing Biofilms of Pseudomonas aeruginosa Isolates from Chronic Rhinosinusitis Patients

    Directory of Open Access Journals (Sweden)

    Stephanie A. Fong

    2017-09-01

    Full Text Available Introduction:Pseudomonas aeruginosa infections are prevalent amongst chronic rhinosinusitis (CRS sufferers. Many P. aeruginosa strains form biofilms, leading to treatment failure. Lytic bacteriophages (phages are viruses that infect, replicate within, and lyse bacteria, causing bacterial death.Aim: To assess the activity of a phage cocktail in eradicating biofilms of ex vivo P.aeruginosa isolates from CRS patients.Methods: P. aeruginosa isolates from CRS patients with and without cystic fibrosis (CF across three continents were multi-locus sequence typed and tested for antibiotic resistance. Biofilms grown in vitro were treated with a cocktail of four phages (CT-PA. Biofilm biomass was measured after 24 and 48 h, using a crystal violet assay. Phage titrations were performed to confirm replication of the phages. A linear mixed effects model was applied to assess the effects of treatment, time, CF status, and multidrug resistance on the biomass of the biofilm.Results: The isolates included 44 strain types. CT-PA treatment significantly reduced biofilm biomass at both 24 and 48 h post-treatment (p < 0.0001, regardless of CF status or antibiotic resistance. Biomass was decreased by a median of 76% at 48 h. Decrease in biofilm was accompanied by a rise in phage titres for all except one strain.Conclusion: A single dose of phages is able to significantly reduce biofilms formed in vitro by a range of P.aeruginosa isolates from CRS patients. This represents an exciting potential and novel targeted treatment for P. aeruginosa biofilm infections and multidrug resistant bacteria.

  20. Pseudomonas aeruginosa biofilm aggravates skin inflammatory response in BALB/c mice in a novel chronic wound model

    DEFF Research Database (Denmark)

    Trøstrup, Hannah; Thomsen, Kim; Christophersen, Lars J

    2013-01-01

    model in C3H/HeN and BALB/c mice. The chronic wound was established by an injection of seaweed alginate-embedded P. aeruginosa PAO1 beneath a third-degree thermal lesion providing full thickness skin necrosis, as in human chronic wounds. Cultures revealed growth of PA, and both alginate with or without...

  1. Synergistic Activities of an Efflux Pump Inhibitor and Iron Chelators against Pseudomonas aeruginosa Growth and Biofilm Formation

    DEFF Research Database (Denmark)

    Liu, Yang; Yang, Liang; Molin, Søren

    2010-01-01

    The efflux pump inhibitor phenyl-arginine-beta-naphthylamide (PA beta N) was paired with iron chelators 2,2'-dipyridyl, acetohydroxamic acid, and EDTA to assess synergistic activities against Pseudomonas aeruginosa growth and biofilm formation. All of the tested iron chelators synergistically...

  2. The Oxidative Stress Agent Hypochlorite Stimulates c-di-GMP Synthesis and Biofilm Formation in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Nikola Strempel

    2017-11-01

    Full Text Available The opportunistic human pathogen Pseudomonas aeruginosa is able to survive under a variety of often harmful environmental conditions due to a multitude of intrinsic and adaptive resistance mechanisms, including biofilm formation as one important survival strategy. Here, we investigated the adaptation of P. aeruginosa PAO1 to hypochlorite (HClO, a phagocyte-derived host defense compound and frequently used disinfectant. In static biofilm assays, we observed a significant enhancement in initial cell attachment in the presence of sublethal HClO concentrations. Subsequent LC-MS analyses revealed a strong increase in cyclic-di-GMP (c-di-GMP levels suggesting a key role of this second messenger in HClO-induced biofilm development. Using DNA microarrays, we identified a 26-fold upregulation of ORF PA3177 coding for a putative diguanylate cyclase (DGC, which catalyzes the synthesis of the second messenger c-di-GMP – an important regulator of bacterial motility, sessility and persistence. This DGC PA3177 was further characterized in more detail demonstrating its impact on P. aeruginosa motility and biofilm formation. In addition, cell culture assays attested a role for PA3177 in the response of P. aeruginosa to human phagocytes. Using a subset of different mutants, we were able to show that both Pel and Psl exopolysaccharides are effectors in the PA3177-dependent c-di-GMP network.

  3. Tetrahydrodipicolinate N-succinyltransferase and dihydrodipicolinate synthase from Pseudomonas aeruginosa: structure analysis and gene deletion.

    Directory of Open Access Journals (Sweden)

    Robert Schnell

    Full Text Available The diaminopimelic acid pathway of lysine biosynthesis has been suggested to provide attractive targets for the development of novel antibacterial drugs. Here we report the characterization of two enzymes from this pathway in the human pathogen Pseudomonas aeruginosa, utilizing structural biology, biochemistry and genetics. We show that tetrahydrodipicolinate N-succinyltransferase (DapD from P. aeruginosa is specific for the L-stereoisomer of the amino substrate L-2-aminopimelate, and its D-enantiomer acts as a weak inhibitor. The crystal structures of this enzyme with L-2-aminopimelate and D-2-aminopimelate, respectively, reveal that both compounds bind at the same site of the enzyme. Comparison of the binding interactions of these ligands in the enzyme active site suggests misalignment of the amino group of D-2-aminopimelate for nucleophilic attack on the succinate moiety of the co-substrate succinyl-CoA as the structural basis of specificity and inhibition. P. aeruginosa mutants where the dapA gene had been deleted were viable and able to grow in a mouse lung infection model, suggesting that DapA is not an optimal target for drug development against this organism. Structure-based sequence alignments, based on the DapA crystal structure determined to 1.6 Å resolution revealed the presence of two homologues, PA0223 and PA4188, in P. aeruginosa that could substitute for DapA in the P. aeruginosa PAO1ΔdapA mutant. In vitro experiments using recombinant PA0223 protein could however not detect any DapA activity.

  4. Identification of essential genes of Pseudomonas aeruginosa for its growth in airway mucus.

    Science.gov (United States)

    Alrahman, Mohammed Abd; Yoon, Sang Sun

    2017-01-01

    Pseudomonas aeruginosa has been identified as an important causative agent of airway infection, mainly in cystic fibrosis. This disease is characterized by defective mucociliary clearance induced in part by mucus hyper-production. Mucin is a major component of airway mucus and is heavily O-glycosylated, with a protein backbone. Airway infection is known to be established with bacterial adhesion to mucin. However, the genes involved in mucin degradation or utilization remain elusive. In this study, we sought to provide a genetic basis of P. aeruginosa airway growth by identifying those genes. First, using RNASeq analyses, we compared genome-wide expression profiles of PAO1, a prototype P. aeruginosa laboratory strain, grown in M9-mucin (M9M) and M9-glucose (M9G) media. Additionally, a PAO1 transposon (Tn) insertion mutants library was screened for mutants defective in growth in M9M medium. One mutant with a Tn insertion in the xcpU gene (PA3100) was determined to exhibit faulty growth in M9M medium. This gene contributes to the type II secretion system, suggesting that P. aeruginosa uses this secretion system to produce a number of proteins to break down and assimilate the mucin molecule. Furthermore, we screened the PAO1 genome for genes with protease activity. Of 13 mutants, one with mutation in PA3247 gene exhibited defective growth in M9M, suggesting that the PA3247-encoded protease plays a role in mucin utilization. Further mechanistic dissection of this particular process will reveal new drug targets, the inhibition of which could control recalcitrant P. aeruginosa infections.

  5. Pyocyanin facilitates extracellular DNA binding to Pseudomonas aeruginosa influencing cell surface properties and aggregation.

    Science.gov (United States)

    Das, Theerthankar; Kutty, Samuel K; Kumar, Naresh; Manefield, Mike

    2013-01-01

    Pyocyanin is an electrochemically active metabolite produced by the human pathogen Pseudomonas aeruginosa. It is a recognized virulence factor and is involved in a variety of significant biological activities including gene expression, maintaining fitness of bacterial cells and biofilm formation. It is also recognized as an electron shuttle for bacterial respiration and as an antibacterial and antifungal agent. eDNA has also been demonstrated to be a major component in establishing P. aeruginosa biofilms. In this study we discovered that production of pyocyanin influences the binding of eDNA to P. aeruginosa PA14 cells, mediated through intercalation of pyocyanin with eDNA. P. aeruginosa cell surface properties including cell size (hydrodynamic diameter), hydrophobicity and attractive surface energies were influenced by eDNA in the presence of pyocyanin, affecting physico-chemical interactions and promoting aggregation. A ΔphzA-G PA14 mutant, deficient in pyocynain production, could not bind with eDNA resulting in a reduction in hydrodynamic diameter, a decrease in hydrophobicity, repulsive physico-chemical interactions and reduction in aggregation in comparison to the wildtype strain. Removal of eDNA by DNase I treatment on the PA14 wildtype strain resulted in significant reduction in aggregation, cell surface hydrophobicity and size and an increase in repulsive physico-chemical interactions, similar to the level of the ΔphzA-G mutant. The cell surface properties of the ΔphzA-G mutant were not affected by DNase I treatment. Based on these findings we propose that pyocyanin intercalation with eDNA promotes cell-to-cell interactions in P. aeruginosa cells by influencing their cell surface properties and physico-chemical interactions.

  6. Pyocyanin facilitates extracellular DNA binding to Pseudomonas aeruginosa influencing cell surface properties and aggregation.

    Directory of Open Access Journals (Sweden)

    Theerthankar Das

    Full Text Available Pyocyanin is an electrochemically active metabolite produced by the human pathogen Pseudomonas aeruginosa. It is a recognized virulence factor and is involved in a variety of significant biological activities including gene expression, maintaining fitness of bacterial cells and biofilm formation. It is also recognized as an electron shuttle for bacterial respiration and as an antibacterial and antifungal agent. eDNA has also been demonstrated to be a major component in establishing P. aeruginosa biofilms. In this study we discovered that production of pyocyanin influences the binding of eDNA to P. aeruginosa PA14 cells, mediated through intercalation of pyocyanin with eDNA. P. aeruginosa cell surface properties including cell size (hydrodynamic diameter, hydrophobicity and attractive surface energies were influenced by eDNA in the presence of pyocyanin, affecting physico-chemical interactions and promoting aggregation. A ΔphzA-G PA14 mutant, deficient in pyocynain production, could not bind with eDNA resulting in a reduction in hydrodynamic diameter, a decrease in hydrophobicity, repulsive physico-chemical interactions and reduction in aggregation in comparison to the wildtype strain. Removal of eDNA by DNase I treatment on the PA14 wildtype strain resulted in significant reduction in aggregation, cell surface hydrophobicity and size and an increase in repulsive physico-chemical interactions, similar to the level of the ΔphzA-G mutant. The cell surface properties of the ΔphzA-G mutant were not affected by DNase I treatment. Based on these findings we propose that pyocyanin intercalation with eDNA promotes cell-to-cell interactions in P. aeruginosa cells by influencing their cell surface properties and physico-chemical interactions.

  7. Complete sequence of two KPC-harbouring plasmids from Pseudomonas aeruginosa.

    Science.gov (United States)

    Naas, Thierry; Bonnin, Rémy A; Cuzon, Gaëlle; Villegas, Maria-Virginia; Nordmann, Patrice

    2013-08-01

    KPC-producing Pseudomonas aeruginosa are increasingly isolated in the Americas and in the Caribbean islands. Here, we determined the whole-plasmid sequence of two plasmids carrying the blaKPC-2 gene from multidrug-resistant P. aeruginosa clinical isolates from Colombia. The two plasmids, pCOL-1 and pPA-2, were transferred to Escherichia coli recipient strain TOP10 and completely sequenced using high-throughput pyrosequencing for pCOL-1 and classical Sanger sequencing for pPA-2. Both plasmids could be transferred to E. coli by transformation and displayed no other resistance marker besides KPC. Plasmid pCOL-1 was 31 529 bp in size, contained 31 open reading frames (ORFs) and belonged to the IncP-6 replicon group. It exhibited genes involved in replication, mobilization and partitioning, but none involved in conjugation. Plasmid pPA-2 was 7995 bp in size and contained seven ORFs. It exhibited a replicase gene of IncU, but was lacking genes involved in mobilization, partitioning and conjugation. Only 2072 bp matched Tn4401, including the blaKPC-2 gene, part of ISKpn6 and a 73 bp segment located upstream of the blaKPC-2 gene, containing the P1 promoter. Sequence identity was interrupted by a Tn3 transposon, itself interrupted by an IS26 element inserted within the β-lactamase blaTEM-1 gene. Here we present the genetic features of the very first plasmids carrying the blaKPC-2 gene from P. aeruginosa. The emergence of the blaKPC-2 gene on unrelated plasmids, differing in size and in incompatibility group, and harbouring different genetic structures containing the blaKPC-2 genes in P. aeruginosa isolates suggests that this resistance trait may follow a dissemination scheme in P. aeruginosa similar to that seen in Enterobacteriaceae.

  8. Low energy o-Ps-o-Ps elastic scattering using a simple model

    Energy Technology Data Exchange (ETDEWEB)

    Himanshu, Sharma [Veer Kunwar Singh Univ., Dept. of Physics, Bihar (India); Kiran, Kumari [R N College, P. G. Dept. of Physics, Bihar (India); Sumana, Chakraborty [Indian Association for the Cultivation of Science, Dept. of Theoretical Physics (India)

    2009-06-15

    A simple model is employed to investigate o-Ps-o-Ps (positronium-positronium) scattering at low energies. This model contains the effect of exchange explicitly and a model long range potential in the framework of static-exchange model. These two physical features are of key importance in Ps-Ps (atom-atom) scattering system. S-wave triplet-triplet and singlet-singlet scattering lengths and corresponding phase shifts up to the incident momentum k = 0.5 a.u. are in excellent agreement with those yielded by most elaborate and theoretically sound predictions. (authors)

  9. Inhibition of Pseudomonas aeruginosa by Peptide-Conjugated Phosphorodiamidate Morpholino Oligomers.

    Science.gov (United States)

    Howard, James J; Sturge, Carolyn R; Moustafa, Dina A; Daly, Seth M; Marshall-Batty, Kimberly R; Felder, Christina F; Zamora, Danniel; Yabe-Gill, Marium; Labandeira-Rey, Maria; Bailey, Stacey M; Wong, Michael; Goldberg, Joanna B; Geller, Bruce L; Greenberg, David E

    2017-04-01

    Pseudomonas aeruginosa is a highly virulent, multidrug-resistant pathogen that causes significant morbidity and mortality in hospitalized patients and is particularly devastating in patients with cystic fibrosis. Increasing antibiotic resistance coupled with decreasing numbers of antibiotics in the developmental pipeline demands novel antibacterial approaches. Here, we tested peptide-conjugated phosphorodiamidate morpholino oligomers (PPMOs), which inhibit translation of complementary mRNA from specific, essential genes in P. aeruginosa PPMOs targeted to acpP, lpxC, and rpsJ, inhibited P. aeruginosa growth in many clinical strains and activity of PPMOs could be enhanced 2- to 8-fold by the addition of polymyxin B nonapeptide at subinhibitory concentrations. The PPMO targeting acpP was also effective at preventing P. aeruginosa PAO1 biofilm formation and at reducing existing biofilms. Importantly, treatment with various combinations of a PPMO and a traditional antibiotic demonstrated synergistic growth inhibition, the most effective of which was the PPMO targeting rpsJ with tobramycin. Furthermore, treatment of P. aeruginosa PA103-infected mice with PPMOs targeting acpP, lpxC, or rpsJ significantly reduced the bacterial burden in the lungs at 24 h by almost 3 logs. Altogether, this study demonstrates that PPMOs targeting the essential genes acpP, lpxC, or rpsJ in P. aeruginosa are highly effective at inhibiting growth in vitro and in vivo These data suggest that PPMOs alone or in combination with antibiotics represent a novel approach to addressing the problems associated with rapidly increasing antibiotic resistance in P. aeruginosa. Copyright © 2017 American Society for Microbiology.

  10. Tracking Down Antibiotic-Resistant Pseudomonas aeruginosa Isolates in a Wastewater Network

    Science.gov (United States)

    Slekovec, Céline; Plantin, Julie; Cholley, Pascal; Thouverez, Michelle; Talon, Daniel; Bertrand, Xavier; Hocquet, Didier

    2012-01-01

    The Pseudomonas aeruginosa-containing wastewater released by hospitals is treated by wastewater treatment plants (WWTPs), generating sludge, which is used as a fertilizer, and effluent, which is discharged into rivers. We evaluated the risk of dissemination of antibiotic-resistant P. aeruginosa (AR-PA) from the hospital to the environment via the wastewater network. Over a 10-week period, we sampled weekly 11 points (hospital and urban wastewater, untreated and treated water, sludge) of the wastewater network and the river upstream and downstream of the WWTP of a city in eastern France. We quantified the P. aeruginosa load by colony counting. We determined the susceptibility to 16 antibiotics of 225 isolates, which we sorted into three categories (wild-type, antibiotic-resistant and multidrug-resistant). Extended-spectrum β-lactamases (ESBLs) and metallo-β-lactamases (MBLs) were identified by gene sequencing. All non-wild-type isolates (n = 56) and a similar number of wild-type isolates (n = 54) were genotyped by pulsed-field gel electrophoresis and multilocus sequence typing. Almost all the samples (105/110, 95.5%) contained P. aeruginosa, with high loads in hospital wastewater and sludge (≥3×106 CFU/l or/kg). Most of the multidrug-resistant isolates belonged to ST235, CC111 and ST395. They were found in hospital wastewater and some produced ESBLs such as PER-1 and MBLs such as IMP-29. The WWTP greatly reduced P. aeruginosa counts in effluent, but the P. aeruginosa load in the river was nonetheless higher downstream than upstream from the WWTP. We conclude that the antibiotic-resistant P. aeruginosa released by hospitals is found in the water downstream from the WWTP and in sludge, constituting a potential risk of environmental contamination. PMID:23284623

  11. Characterization of chromosomal mediated cadmium resistance in Pseudomonas aeruginosa strain BC15.

    Science.gov (United States)

    Raja, Chellaiah Edward; Selvam, Govindan Sadasivam

    2012-04-01

    Cadmium (Cd) has been used extensively in metal plating, mining, paints and plastic generation etc. In this study, Cd resistance (cadR) gene was characterized from the environmental isolate Pseudomonas aeruginosa BC15. The cadR sequences showed high homology with P. aeruginosa FLH033011 (100%), P. aeruginosa PAO1 (99%), and P. aeruginosa UCBPP-PA14 (98%) respectively. Homology modeling of cadR was carried out by using swiss-prot server. Crystal structures of E. coli CueR for Cu (1q05) and ZntR (1q08) for Zn have been used as a template. The sequence identity of P. aeruginosa cadR shares 34% for CueR and 43% for ZntR. Fold recognition of P. aeruginosa cadR was created by using PHYRE web server. Transcriptional regulator CueR (1q06a) from E. coli was chosen as the template. CadR has 31% identity and the estimated precision was 100%. The cadR gene was cloned in pET30b and transformed into E. coli BL21. The molecular weight protein of cadR was estimated to be 25 kDa by SDS-PAGE. The recombinant E. coli cadR efficiently grow in the Cd supplemented LB medium and agar plate. The order of the resistance of E. coli cadR was Mn > Pb > Cu > Cd > Ni > Zn. These findings can lead to the use of P. aeruginosa BC15 for the remediation of Cd and other heavy metals present in the polluted environment. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Antibiotic-resistant Pseudomonas aeruginosa infection in patients with bronchiectasis: prevalence, risk factors and prognostic implications

    Directory of Open Access Journals (Sweden)

    Gao YH

    2018-01-01

    Full Text Available Yong-hua Gao,1,* Wei-jie Guan,2,* Ya-nan Zhu,3 Rong-chang Chen,2 Guo-jun Zhang1 1Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 2State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 3Department of Emergency Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, People’s Republic of China *These authors contributed equally to this work Background and aims: Pseudomonas aeruginosa (PA is the most common pathogen in bronchiectasis and frequently develops resistance to multiple classes of antibiotics, but little is known about the clinical impacts of PA-resistant (PA-R isolates on bronchiectasis. We, therefore, investigated the prevalence, risk factors and prognostic implications of PA-R isolates in hospitalized bronchiectasis patients.Patients and methods: Between June 2011 and July 2016, data from adult bronchiectasis patients isolated with PA at the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed. PA was classified as PA-R in case antibiogram demonstrated resistance on at least one occasion.Results: Seven hundred forty-seven bronchiectasis patients were assessed. Of these, 147 (19.7% had PA isolate in the sputum or bronchoscopic culture. PA-R and PA-sensitive accounted for 88 (59.9% and 59 (31.1% patients, respectively. In multivariate model, factors associated with PA-R isolate in bronchiectasis included prior exposure to antibiotics (odds ratio [OR] =6.18, three or more exacerbations in the previous year (OR =2.81, higher modified Medical Research Council dyspnea scores (OR =1.93 and greater radiologic severity (OR =1.15. During follow-up (median: 26 months; interquartile range: 6–59 months, 36 patients died, of whom 24 (66

  13. Pseudomonas aeruginosa eliminates natural killer cells via phagocytosis-induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Jin Woong Chung

    2009-08-01

    Full Text Available Pseudomonas aeruginosa (PA is an opportunistic pathogen that causes the relapse of illness in immunocompromised patients, leading to prolonged hospitalization, increased medical expense, and death. In this report, we show that PA invades natural killer (NK cells and induces phagocytosis-induced cell death (PICD of lymphocytes. In vivo tumor metastasis was augmented by PA infection, with a significant reduction in NK cell number. Adoptive transfer of NK cells mitigated PA-induced metastasis. Internalization of PA into NK cells was observed by transmission electron microscopy. In addition, PA invaded NK cells via phosphoinositide 3-kinase (PI3K activation, and the phagocytic event led to caspase 9-dependent apoptosis of NK cells. PA-mediated NK cell apoptosis was dependent on activation of mitogen-activated protein (MAP kinase and the generation of reactive oxygen species (ROS. These data suggest that the phagocytosis of PA by NK cells is a critical event that affects the relapse of diseases in immunocompromised patients, such as those with cancer, and provides important insights into the interactions between PA and NK cells.

  14. Facultative control of matrix production optimizes competitive fitness in Pseudomonas aeruginosa PA14 biofilm models

    DEFF Research Database (Denmark)

    Madsen, Jonas Stenløkke; Lin, Yu Cheng; Squyres, Georgia R.

    2015-01-01

    response to electron acceptor limitation in both biofilm formation regimes, we found variation in the exploitability of its production and necessity for competitive fitness between the two systems. The wild type showed a competitive advantage against a non-Pel-producing mutant in pellicles but no advantage...... in colonies. Adaptation to the pellicle environment selected for mutants with a competitive advantage against the wild type in pellicles but also caused a severe disadvantage in colonies, even in wrinkled colony centers. Evolution in the colony center produced divergent phenotypes, while adaptation...... to the colony edge produced mutants with clear competitive advantages against the wild type in this O2-replete niche. In general, the structurally heterogeneous colony environment promoted more diversification than the more homogeneous pellicle. These results suggest that the role of Pel in community structure...

  15. A Marine Actinomycete Rescues Caenorhabditis elegans from Pseudomonas aeruginosa Infection through Restitution of Lysozyme 7

    Directory of Open Access Journals (Sweden)

    Siti N. Fatin

    2017-11-01

    Full Text Available The resistance of Pseudomonas aeruginosa to conventional antimicrobial treatment is a major scourge in healthcare. Therefore, it is crucial that novel potent anti-infectives are discovered. The aim of the present study is to screen marine actinomycetes for chemical entities capable of overcoming P. aeruginosa infection through mechanisms involving anti-virulence or host immunity activities. A total of 18 actinomycetes isolates were sampled from marine sediment of Songsong Island, Kedah, Malaysia. Upon confirming that the methanolic crude extract of these isolates do not display direct bactericidal activities, they were tested for capacity to rescue Caenorhabditis elegans infected with P. aeruginosa strain PA14. A hexane partition of the extract from one isolate, designated as Streptomyces sp. CCB-PSK207, could promote the survival of PA14 infected worms by more than 60%. Partial 16S sequence analysis on this isolate showed identity of 99.79% with Streptomyces sundarbansensis. This partition did not impair feeding behavior of C. elegans worms. Tested on PA14, the partition also did not affect bacterial growth or its ability to colonize host gut. The production of biofilm, protease, and pyocyanin in PA14 were uninterrupted, although there was an increase in elastase production. In lys-7::GFP worms, this partition was shown to induce the expression of lysozyme 7, an important innate immunity defense molecule that was repressed during PA14 infection. GC-MS analysis of the bioactive fraction of Streptomyces sp. CCB-PSK207 revealed the presence of methyl esters of branched saturated fatty acids. In conclusion, this is the first report of a marine actinomycete producing metabolites capable of rescuing C. elegans from PA14 through a lys-7 mediated activity.

  16. LS1 Report: PS beams are back!

    CERN Multimedia

    Katarina Anthony & Anaïs Schaeffer

    2014-01-01

    For the first time in over 15 months, there are beams back in the PS. Making their first tour of the accelerator today, 20 June, their injection marks the end of weeks of cold checkouts and hardware commissioning in the PS.   The CERN Control Centre (CCC) is back in business: people gather to restart the LHC injectors, today the PS. Since hardware commissioning was wrapped up on 23 May, the Operations Group (BE-OP) has been conducting cold checkouts on the PS. This involves switching on all of the machine's systems, verifying that they respond to commands by OP and ensuring they are calibrated to beam timings. "These verifications were done, in part, during the hardware commissioning dry runs," says Rende Steerenberg, PS section leader. "But the cold checkouts are on a much larger scale, as we act as if there is beam in the whole machine. We placed a full load on the controls system, cooling, networks, etc. in order to setup the accelerator in the most realis...

  17. The Mla pathway is critical for Pseudomonas aeruginosa resistance to outer membrane permeabilization and host innate immune clearance.

    Science.gov (United States)

    Munguia, Jason; LaRock, Doris L; Tsunemoto, Hannah; Olson, Joshua; Cornax, Ingrid; Pogliano, Joseph; Nizet, Victor

    2017-10-01

    Pseudomonas aeruginosa is an important opportunistic pathogen that has become a serious problem due to increased rates of antibiotic resistance. Due to this along with a dearth in novel antibiotic development, especially against Gram-negative pathogens, new therapeutic strategies are needed to prevent a post-antibiotic era. Here, we describe the importance of the vacJ/Mla pathway in resisting bactericidal actions of the host innate immune response. P. aeruginosa tn5 transposon mutants in genes from the VacJ/Mla pathway showed increased susceptibility to killing by the host cathelicidin antimicrobial peptide, LL-37, when compared to the wild-type parent strain. The P. aeruginosa vacJ - mutant demonstrated increased membrane permeability upon damage as well as sensitivity to killing in the presence of the detergent sodium dodecyl sulfate and the divalent cation chelator EDTA. When exposed to human whole blood and serum complement, the vacJ - mutant was killed more rapidly when compared to the wild-type parent strain and complemented mutant. Finally, in an in vivo mouse lung infection model, infection with the vacJ - mutant resulted in reduced mortality, lower bacterial burden, and reduced lung damage when compared to the wild-type strain. This study highlights the potential in therapeutically targeting the VacJ/Mla pathway in sensitizing P. aeruginosa to killing by the host innate immune response. • The Mla pathway regulates outer membrane dynamics in human pathogen Pseudomonas aeruginosa (PA). • Disruption of Mla pathway gene vacJ sensitizes PA to host cathelicidin antimicrobial peptide LL-37. • Loss of vacJ expression renders PA more sensitive to human whole blood and serum killing. • Loss of vacJ expression reduces PA survival and virulence in a murine lung infection model. • The Mla pathway merits exploration as a pharmacologic target to sensitize PA to host innate immunity.

  18. Structural Characterization of Novel Pseudomonas aeruginosa Type IV Pilins

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Y.; Jackson, S; Aidoo, F; Junop, M; Burrows, L

    2010-01-01

    Pseudomonas aeruginosa type IV pili, composed of PilA subunits, are used for attachment and twitching motility on surfaces. P. aeruginosa strains express one of five phylogenetically distinct PilA proteins, four of which are associated with accessory proteins that are involved either in pilin posttranslational modification or in modulation of pilus retraction dynamics. Full understanding of pilin diversity is crucial for the development of a broadly protective pilus-based vaccine. Here, we report the 1.6-{angstrom} X-ray crystal structure of an N-terminally truncated form of the novel PilA from strain Pa110594 (group V), which represents the first non-group II pilin structure solved. Although it maintains the typical T4a pilin fold, with a long N-terminal {alpha}-helix and four-stranded antiparallel {beta}-sheet connected to the C-terminus by a disulfide-bonded loop, the presence of an extra helix in the {alpha}{beta}-loop and a disulfide-bonded loop with helical character gives the structure T4b pilin characteristics. Despite the presence of T4b features, the structure of PilA from strain Pa110594 is most similar to the Neisseria gonorrhoeae pilin and is also predicted to assemble into a fiber similar to the GC pilus, based on our comparative pilus modeling. Interactions between surface-exposed areas of the pilin are suggested to contribute to pilus fiber stability. The non-synonymous sequence changes between group III and V pilins are clustered in the same surface-exposed areas, possibly having an effect on accessory protein interactions. However, based on our high-confidence model of group III PilA{sub PA14}, compensatory changes allow for maintenance of a similar shape.

  19. Pyocyanin production by Pseudomonas aeruginosa confers resistance to ionic silver.

    Science.gov (United States)

    Muller, Michael; Merrett, Neil D

    2014-09-01

    Silver in its ionic form (Ag+), but not the bulk metal (Ag0), is toxic to microbial life forms and has been used for many years in the treatment of wound infections. The prevalence of bacterial resistance to silver is considered low due to the nonspecific nature of its toxicity. However, the recent increased use of silver as an antimicrobial agent for medical, consumer, and industrial products has raised concern that widespread silver resistance may emerge. Pseudomonas aeruginosa is a common pathogen that produces pyocyanin, a redox toxin and a reductant for molecular oxygen and ferric (Fe3+) ions. The objective of this study was to determine whether pyocyanin reduces Ag+ to Ag0, which may contribute to silver resistance due to lower bioavailability of the cation. Using surface plasmon resonance spectroscopy and scanning electron microscopy, pyocyanin was confirmed to be a reductant for Ag+, forming Ag0 nanoparticles and reducing the bioavailability of free Ag+ by >95% within minutes. Similarly, a pyocyanin-producing strain of P. aeruginosa (PA14) reduced Ag+ but not a pyocyanin-deficient (ΔphzM) strain of the bacterium. Challenge of each strain with Ag+ (as AgNO3) gave MICs of 20 and 5 μg/ml for the PA14 and ΔphzM strains, respectively. Removal of pyocyanin from the medium strain PA14 was grown in or its addition to the medium that ΔphzM mutant was grown in gave MICs of 5 and 20 μg/ml, respectively. Clinical isolates demonstrated similar pyocyanin-dependent resistance to Ag+. We conclude that pseudomonal silver resistance exists independently of previously recognized intracellular mechanisms and may be more prevalent than previously considered. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  20. Pseudomonas aeruginosa colonization enhances ventilator-associated pneumonia-induced lung injury.

    Science.gov (United States)

    Tsay, Tzyy-Bin; Jiang, Yu-Zhen; Hsu, Ching-Mei; Chen, Lee-Wei

    2016-08-09

    Pseudomonas aeruginosa (PA) is the single-most common pathogen of ventilator-associated pneumonia (VAP). Large quantities of PA in the trachea of ventilated patients are associated with an increased risk of death. However, the role of PA colonization in PA VAP-induced lung injury remains elusive. This study examined the effect and mechanism of PA colonization in VAP-induced lung injury. C57BL/6 wild-type (WT) and c-Jun N-terminal kinase knockout (JNK1(-/-)) mice received mechanical ventilation for 3 h at 2 days after receiving nasal instillation of PA (1 × 10(6) colony forming unit) or normal saline. Intranasal instillation of PA or mechanical ventilation induced the expression of interleukin-6 (IL-6) in the lungs. Phospho-JNK protein expression in the lungs was significantly increased in mice receiving mechanical ventilation after PA instillation as compared with those receiving ventilation alone. Mechanical ventilation after PA instillation significantly increased the expression of tumor necrosis factor-α (TNF-α), IL-1β, and macrophage inflammatory protein-2 (MIP-2) proteins; neutrophil sequestration; and TNF-α, IL-1β, and IL-6 levels in the lungs of WT mice, but not in JNK1(-/-) mice. PA colonization plays an important role in PA VAP-induced lung injury through the induction of JNK1-mediated inflammation. PA-induced VAP causes lung injury through JNK signaling pathway in the lungs. JNK inhibition in ICU patients with higher percentages of PA colonization may reduce VAP-induced lung injury and mortality.

  1. Photodynamic therapy for the eradication of biofilms formed by catheter associated Pseudomonas aeruginosa strains

    Directory of Open Access Journals (Sweden)

    Viviana Teresa Orlandi

    2011-06-01

    Full Text Available Pseudomonas aeruginosa has emerged as a major opportunistic pathogen causing catheter-associated urinary tract infections (CA-UTIs associated with high mortality and morbidity. In this study 18 P. aeruginosa isolates from urine of catheterized patients were evaluated for in vitro biofilm formation.All the tested strains showed the ability to form biofilm more thicker than those formed by a cohort of 29 blood culture strains belonging to the same species. Photodynamic antimicrobial chemotherapy (PACT is a novel antimicrobial treatment that exploits a photosensitizer (PS and visible light to induce lethal oxidative damages in bacterial cells and could be used as local antimicrobial approach in CA-UTIs. Here we tested the susceptibility of planktonic and sessile cultures of P. aeruginosa strains, the model strain PAO1 and CA-UTI isolates, to photodynamic inactivation with a di cationic porphyrinic photosensitizer, the 5, 15-di (N-benzyl-4-pyridynium-porphyrin di chloride.Although Pseudomonas aeruginosa is regarded as a difficult target for antimicrobial chemotherapy, satisfactory bactericidal activities on both planktonic and biofilm cultures were observed.

  2. Cyclic Di-GMP Signaling Contributes to Pseudomonas aeruginosa-Mediated Catheter-Associated Urinary Tract Infection.

    Science.gov (United States)

    Cole, Stephanie J; Lee, Vincent T

    2015-07-20

    Bis-(3'-5') cyclic dimeric GMP (c-di-GMP) controls the lifestyle transition between the sessile and motile states in many Gram-negative bacteria, including the opportunistic human pathogen Pseudomonas aeruginosa. Under laboratory conditions, high concentrations of c-di-GMP decrease motility and promote biofilm formation, while low concentrations of c-di-GMP promote motility and decease biofilm formation. Here we sought to determine the contribution of c-di-GMP signaling to biofilm formation during P. aeruginosa-mediated catheter-associated urinary tract infection (CAUTI). Using a murine CAUTI model, a decrease in CFU was detected in the bladders and kidneys of mice infected with strains overexpressing the phosphodiesterases (PDEs) encoded by PA3947 and PA2133 compared to those infected with wild-type P. aeruginosa. Conversely, overexpression of the diguanylate cyclases (DGCs) encoded by PA3702 and PA1107 increased the number of bacteria in bladder and significantly increased dissemination of bacteria to the kidneys compared to wild-type infection. To determine which of the DGCs and PDEs contribute to c-di-GMP signaling during infection, a panel of PA14 in-frame deletion mutants lacking DGCs and PDEs were tested in the CAUTI model. Results from these infections revealed five mutants, three containing GGDEF domains (ΔPA14_26970, ΔPA14_72420, and ΔsiaD) and two containing dual GGDEF-EAL domains (ΔmorA and ΔPA14_07500), with decreased colonization of the bladder and dissemination to the kidneys. These results indicate that c-di-GMP signaling influences P. aeruginosa-mediated biofilms during CAUTI. Biofilm-based infections are an important cause of nosocomial infections, since they resist the immune response and traditional antibiotic treatment. Cyclic di-GMP (c-di-GMP) is a second messenger that promotes biofilm formation in many Gram-negative pathogens, including Pseudomonas aeruginosa. Here we determined the contribution of c-di-GMP signaling to catheter

  3. Estudo da função do gene kerV de Pseudomonas aeruginosa

    OpenAIRE

    Diogo de Abreu Meireles

    2011-01-01

    P. aeruginosa PA14 é uma linhagem isolada de queimadura que apresenta vários fatores de patogenicidade comuns no quadro de infecção de hospedeiros filogeneticamente distintos (plantas, mamíferos ou invertebrados). O gene kerV foi revelado numa busca por mutantes atenuados em virulência em uma biblioteca de mutantes por transposons da linhagem PA14 (Rahme et al., 1997). A caracterização da linhagem D12, mutante em kerV, confirmou sua virulência atenuada (Apidianakis et al., 2005 e An et al., 2...

  4. Nosocomial outbreak of extensively drug-resistant Pseudomonas aeruginosa associated with aromatherapy.

    Science.gov (United States)

    Mayr, Astrid; Hinterberger, Guido; Lorenz, Ingo H; Kreidl, Peter; Mutschlechner, Wolfgang; Lass-Flörl, Cornelia

    2017-04-01

    An increase of extensively drug-resistant Pseudomonas aeruginosa (XDR-PA) in various clinical specimens among intensive care unit patients (n = 7) initiated an outbreak investigation consisting of patient data analyses, control of adherence to infection control guidelines, microbiologic surveys, and molecular-based studies. XDR-PA was detected in a jointly used aroma-oil nursing bottle for aromatherapy. We implemented the restriction of oil sharing among patients. Hence, the outbreak was controlled successfully. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  5. Genome-Wide Identification of Pseudomonas aeruginosa Virulence-Related Genes Using a Caenorhabditis elegans Infection Model

    Science.gov (United States)

    Feinbaum, Rhonda L.; Urbach, Jonathan M.; Liberati, Nicole T.; Djonovic, Slavica; Adonizio, Allison; Carvunis, Anne-Ruxandra; Ausubel, Frederick M.

    2012-01-01

    Pseudomonas aeruginosa strain PA14 is an opportunistic human pathogen capable of infecting a wide range of organisms including the nematode Caenorhabditis elegans. We used a non-redundant transposon mutant library consisting of 5,850 clones corresponding to 75% of the total and approximately 80% of the non-essential PA14 ORFs to carry out a genome-wide screen for attenuation of PA14 virulence in C. elegans. We defined a functionally diverse 180 mutant set (representing 170 unique genes) necessary for normal levels of virulence that included both known and novel virulence factors. Seven previously uncharacterized virulence genes (ABC transporters PchH and PchI, aminopeptidase PepP, ATPase/molecular chaperone ClpA, cold shock domain protein PA0456, putative enoyl-CoA hydratase/isomerase PA0745, and putative transcriptional regulator PA14_27700) were characterized with respect to pigment production and motility and all but one of these mutants exhibited pleiotropic defects in addition to their avirulent phenotype. We examined the collection of genes required for normal levels of PA14 virulence with respect to occurrence in P. aeruginosa strain-specific genomic regions, location on putative and known genomic islands, and phylogenetic distribution across prokaryotes. Genes predominantly contributing to virulence in C. elegans showed neither a bias for strain-specific regions of the P. aeruginosa genome nor for putatively horizontally transferred genomic islands. Instead, within the collection of virulence-related PA14 genes, there was an overrepresentation of genes with a broad phylogenetic distribution that also occur with high frequency in many prokaryotic clades, suggesting that in aggregate the genes required for PA14 virulence in C. elegans are biased towards evolutionarily conserved genes. PMID:22911607

  6. Genome-wide identification of Pseudomonas aeruginosa virulence-related genes using a Caenorhabditis elegans infection model.

    Science.gov (United States)

    Feinbaum, Rhonda L; Urbach, Jonathan M; Liberati, Nicole T; Djonovic, Slavica; Adonizio, Allison; Carvunis, Anne-Ruxandra; Ausubel, Frederick M

    2012-01-01

    Pseudomonas aeruginosa strain PA14 is an opportunistic human pathogen capable of infecting a wide range of organisms including the nematode Caenorhabditis elegans. We used a non-redundant transposon mutant library consisting of 5,850 clones corresponding to 75% of the total and approximately 80% of the non-essential PA14 ORFs to carry out a genome-wide screen for attenuation of PA14 virulence in C. elegans. We defined a functionally diverse 180 mutant set (representing 170 unique genes) necessary for normal levels of virulence that included both known and novel virulence factors. Seven previously uncharacterized virulence genes (ABC transporters PchH and PchI, aminopeptidase PepP, ATPase/molecular chaperone ClpA, cold shock domain protein PA0456, putative enoyl-CoA hydratase/isomerase PA0745, and putative transcriptional regulator PA14_27700) were characterized with respect to pigment production and motility and all but one of these mutants exhibited pleiotropic defects in addition to their avirulent phenotype. We examined the collection of genes required for normal levels of PA14 virulence with respect to occurrence in P. aeruginosa strain-specific genomic regions, location on putative and known genomic islands, and phylogenetic distribution across prokaryotes. Genes predominantly contributing to virulence in C. elegans showed neither a bias for strain-specific regions of the P. aeruginosa genome nor for putatively horizontally transferred genomic islands. Instead, within the collection of virulence-related PA14 genes, there was an overrepresentation of genes with a broad phylogenetic distribution that also occur with high frequency in many prokaryotic clades, suggesting that in aggregate the genes required for PA14 virulence in C. elegans are biased towards evolutionarily conserved genes.

  7. Nosocomial infections with metallo-beta-lactamase-producing Pseudomonas aeruginosa: molecular epidemiology, risk factors, clinical features and outcomes.

    Science.gov (United States)

    Lucena, A; Dalla Costa, L M; Nogueira, K S; Matos, A P; Gales, A C; Paganini, M C; Castro, M E S; Raboni, S M

    2014-08-01

    Metallo-β-lactamases (MBLs) have emerged as one of the most important bacterial resistance mechanisms because of their ability to hydrolyse virtually all β-lactam agents. MBL-producing Pseudomonas aeruginosa (MBL-PA) are an important cause of nosocomial infections, particularly in intensive care units (ICUs), where they are associated with serious infections and present a significant clinical risk. To assess the molecular epidemiology, risk factors and outcomes of nosocomial infections caused by MBL-PA in a teaching hospital in Southern Brazil. From January 2001 to December 2008, 142 carbapenem-resistant P. aeruginosa strains were isolated from distinct clinical samples from hospitalized patients. These isolates were screened for MBLs, and underwent polymerase chain reaction, sequencing and pulsed-field gel electrophoresis (PFGE). Patients infected with carbapenem-resistant MBL-PA were considered as cases, and patients infected with non-MBL-PA were considered as controls. Eighty-four of 142 patients with positive carbapenem-resistant P. aeruginosa cultures met the criteria of the Centers for Disease Control and Prevention for infection. Fifty-eight patients were infected with MBL-PA (69%) and 26 patients were infected with non-MBL-PA (31%). Multi-variate analysis revealed that ICU stay [P = 0.003, odds ratio (OR) 4.01, 95% confidence interval (CI) 1.15-14.01] and urinary tract infection (P = 0.001, OR 9.67, 95% CI 1.72-54.48) were important risk factors for MBL-PA infection. Patients infected with MBL-PA showed faster onset of infection (P = 0.002) and faster progression to death (P = 0.04). These results showed the severity of MBL-PA infections, and demonstrated the urgent need for strategies to improve infection control measures to prevent an increase in these nosocomial infections. Copyright © 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  8. Genome-wide identification of Pseudomonas aeruginosa virulence-related genes using a Caenorhabditis elegans infection model.

    Directory of Open Access Journals (Sweden)

    Rhonda L Feinbaum

    Full Text Available Pseudomonas aeruginosa strain PA14 is an opportunistic human pathogen capable of infecting a wide range of organisms including the nematode Caenorhabditis elegans. We used a non-redundant transposon mutant library consisting of 5,850 clones corresponding to 75% of the total and approximately 80% of the non-essential PA14 ORFs to carry out a genome-wide screen for attenuation of PA14 virulence in C. elegans. We defined a functionally diverse 180 mutant set (representing 170 unique genes necessary for normal levels of virulence that included both known and novel virulence factors. Seven previously uncharacterized virulence genes (ABC transporters PchH and PchI, aminopeptidase PepP, ATPase/molecular chaperone ClpA, cold shock domain protein PA0456, putative enoyl-CoA hydratase/isomerase PA0745, and putative transcriptional regulator PA14_27700 were characterized with respect to pigment production and motility and all but one of these mutants exhibited pleiotropic defects in addition to their avirulent phenotype. We examined the collection of genes required for normal levels of PA14 virulence with respect to occurrence in P. aeruginosa strain-specific genomic regions, location on putative and known genomic islands, and phylogenetic distribution across prokaryotes. Genes predominantly contributing to virulence in C. elegans showed neither a bias for strain-specific regions of the P. aeruginosa genome nor for putatively horizontally transferred genomic islands. Instead, within the collection of virulence-related PA14 genes, there was an overrepresentation of genes with a broad phylogenetic distribution that also occur with high frequency in many prokaryotic clades, suggesting that in aggregate the genes required for PA14 virulence in C. elegans are biased towards evolutionarily conserved genes.

  9. mir-67 regulates P. aeruginosa avoidance behavior in C. elegans.

    Science.gov (United States)

    Ma, Yi-Cheng; Zhang, Lu; Dai, Li-Li; Khan, Rahat Ullah; Zou, Cheng-Gang

    2017-12-09

    Pathogen avoidance behaviors are found throughout the animal kingdom and are important for animal's survival in nature. As a free-living nematode, C. elegans is exposed to a variety of microorganisms, including toxic or pathogenic bacteria, in soil. C. elegans can develop efficient avoidance responses to pathogenic bacteria to minimize the infection risk. However, the role of microRNAs (miRNAs) in pathogen avoidance in C. elegans remains unclear. In this report, we showed that the miRNA mir-67 was involved in a behavioral avoidance response to P. aeruginosa PA14. Exposure to P. aeruginosa PA14 induced the expression of mir-67 in worms. mir-67(n4899) mutants exhibited a reduced ability to avoid P. aeruginosa PA14. By combining quantitative proteomic analysis with miRNA target prediction algorithms, we identified SAX-7/L1CAM, which is transmembrane cell adhesion receptor molecule, as the target of mir-67. Silencing of sax-7 by RNAi on mir-67 mutants rescued avoidance behavioral. Our data demonstrate that the mir-67-SAX-7 pathway modulate the behavioral avoidance response to pathogens, thus providing a new perspective in the role of miRNAs in host-microbe interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Solution structure of protein synthesis initiation factor 1 from Pseudomonas aeruginosa.

    Science.gov (United States)

    Hu, Yanmei; Bernal, Alejandra; Bullard, James M; Zhang, Yonghong

    2016-12-01

    Pseudomonas aeruginosa is an opportunistic bacterial pathogen and a primary cause of nosocomial infection in humans. The rate of antibiotic resistance in P. aeruginosa is increasing worldwide leading to an unmet need for discovery of new chemical compounds distinctly different from present antimicrobials. Protein synthesis is an essential metabolic process and a validated target for the development of new antibiotics. Initiation factor 1 from P. aeruginosa (Pa-IF1) is the smallest of the three initiation factors that act to establish the 30S initiation complex during initiation of protein biosynthesis. Here we report the characterization and solution NMR structure of Pa-IF1. Pa-IF1 consists of a five-stranded β-sheet with an unusual extended β-strand at the C-terminus and one short α-helix arranged in the sequential order β1-β2-β3-α1-β4-β5. The structure adopts a typical β-barrel fold and contains an oligomer-binding motif. A cluster of basic residues (K39, R41, K42, K64, R66, R70, and R72) located on the surface of strands β4 and β5 near the short α-helix may compose the binding interface with the 30S subunit. © 2016 The Protein Society.

  11. Anaerobic survival of Pseudomonas aeruginosa by pyruvate fermentation requires an Usp-type stress protein

    DEFF Research Database (Denmark)

    Schreiber, K; Boes, N; Escbach, M

    2006-01-01

    activity was detected in the deeper layers of a P. aeruginosa biofilm using a PPA3309-gfp (green fluorescent protein gene) fusion and confocal laser-scanning microscopy. This is the first description of an Anr-dependent, anaerobically induced, and functional Usp-like protein in bacteria....... the induced synthesis of three enzymes involved in arginine fermentation, ArcA, ArcB, and ArcC, and the outer membrane protein OprL. Moreover, formation of two proteins of unknown function, PA3309 and PA4352, increased by factors of 72- and 22-fold, respectively. Both belong to the group of universal stress...... proteins (Usp). Long-term survival of a PA3309 knockout mutant by pyruvate fermentation was found drastically reduced. The oxygen-sensing regulator Anr controls expression of the PPA3309-lacZ reporter gene fusion after a shift to anaerobic conditions and further pyruvate fermentation. PA3309 expression...

  12. PS overcomes two serious magnet failures

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Two magnets and a bus bar connection in the PS were found to be faulty during high-voltage tests at the end of the accelerator shutdown. A five-week repair schedule was quickly devised. A team of mechanics, technicians and engineers worked at full speed to replace the faulty magnets, succeeding in limiting the delay of the accelerators' spring start-up to two weeks. These pictures show one of the magnets (no. 19) on the PS locomotive brought back into service for the removal and replacement operations.

  13. In vivo photodynamic inactivation of Psuedomonas aeruginosa in burned skin in rats

    Science.gov (United States)

    Hirao, Akihiro; Sato, Shunichi; Terakawa, Mitsuhiro; Saitoh, Daizoh; Shinomiya, Nariyoshi; Ashida, Hiroshi; Obara, Minoru

    2010-02-01

    Control of infection in wounds is critically important to avoid transition to sepsis; however, recent rise of drug-resistant bacteria makes it difficult. Thus, antimicrobial photodynamic therapy (APDT) has recently received considerable attention. In this study, we examined methylene blue (MB)-mediated photodynamic inactivation of Psuedomonas aeruginosa in rat burned skin. Two days after infection, the wound surface was contacted with a MB solution at different concentrations, and thereafter the wound was irradiated with cw 665-nm light at a constant power density of 250 mW/cm2 for different time durations. We obtained a two orders of magnitude decrease in the number of bacteria by PDT with a 2-h contact of 0.5-mM MB solution and a illumination of 480 J/cm2, demonstrating the efficacy of PDT against infection with Ps. aeruginosa in burns.

  14. Effects of electrolysis by low-amperage electric current on the chlorophyll fluorescence characteristics of Microcystis aeruginosa.

    Science.gov (United States)

    Lin, Li; Feng, Cong; Li, Qingyun; Wu, Min; Zhao, Liangyuan

    2015-10-01

    Effects of electrolysis by low-amperage electric current on the chlorophyll fluorescence characteristics of Microcystis aeruginosa were investigated in order to reveal the mechanisms of electrolytic inhibition of algae. Threshold of current density was found under a certain initial no. of algae cell. When current density was equal to or higher than the threshold (fixed electrolysis time), growth of algae was inhibited completely and the algae lost the ability to survive. Effect of algal solution volume on algal inhibition was insignificant. Thresholds of current density were 8, 10, 14, 20, and 22 mA cm(-2) at 2.5 × 10(7), 5 × 10(7), 1 × 10(8), 2.5 × 10(8), and 5 × 10(8) cells mL(-1) initial no. of algae cell, respectively. Correlativity between threshold of current and initial no. of algae cells was established for scale-up and determining operating conditions. Changes of chlorophyll fluorescence parameters demonstrated that photosystem (PS) II of algae was damaged by electrolysis but still maintained relatively high activity when algal solution was treated by current densities lower than the threshold. The activity of algae recovered completely after 6 days of cultivation. On the contrary, when current density was higher than the threshold, connection of phycobilisome (PBS) and PS II core complexes was destroyed, PS II system of algae was damaged irreversibly, and algae could not survive thoroughly. The inactivation of M. aeruginosa by electrolysis can be attributed to irreversible separation of PBS from PS II core complexes and the damage of PS II of M. aeruginosa.

  15. Pseudomonas aeruginosa RhlR is required to neutralize the cellular immune response in a Drosophila melanogaster oral infection model

    Science.gov (United States)

    Limmer, Stefanie; Haller, Samantha; Drenkard, Eliana; Lee, Janice; Yu, Shen; Kocks, Christine; Ausubel, Frederick M.; Ferrandon, Dominique

    2011-01-01

    An in-depth mechanistic understanding of microbial infection necessitates a molecular dissection of host–pathogen relationships. Both Drosophila melanogaster and Pseudomonas aeruginosa have been intensively studied. Here, we analyze the infection of D. melanogaster by P. aeruginosa by using mutants in both host and pathogen. We show that orally ingested P. aeruginosa crosses the intestinal barrier and then proliferates in the hemolymph, thereby causing the infected flies to die of bacteremia. Host defenses against ingested P. aeruginosa included an immune deficiency (IMD) response in the intestinal epithelium, systemic Toll and IMD pathway responses, and a cellular immune response controlling bacteria in the hemocoel. Although the observed cellular and intestinal immune responses appeared to act throughout the course of the infection, there was a late onset of the systemic IMD and Toll responses. In this oral infection model, P. aeruginosa PA14 did not require its type III secretion system or other well-studied virulence factors such as the two-component response regulator GacA or the protease AprA for virulence. In contrast, the quorum-sensing transcription factor RhlR, but surprisingly not LasR, played a key role in counteracting the cellular immune response against PA14, possibly at an early stage when only a few bacteria are present in the hemocoel. These results illustrate the power of studying infection from the dual perspective of host and pathogen by revealing that RhlR plays a more complex role during pathogenesis than previously appreciated. PMID:21987808

  16. Activity of AMP2041 against human and animal multidrug resistant Pseudomonas aeruginosa clinical isolates.

    Science.gov (United States)

    Cabassi, Clotilde Silvia; Sala, Andrea; Santospirito, Davide; Alborali, Giovanni Loris; Carretto, Edoardo; Ghibaudo, Giovanni; Taddei, Simone

    2017-03-23

    Antimicrobial resistance is a growing threat to public health. Pseudomonas aeruginosa is a relevant pathogen causing human and animal infections, frequently displaying high levels of resistance to commonly used antimicrobials. The increasing difficulty to develop new effective antibiotics have discouraged investment in this area and only a few new antibiotics are currently under development. An approach to overcome antibiotic resistance could be based on antimicrobial peptides since they offer advantages over currently used microbicides. The antimicrobial activity of the synthetic peptide AMP2041 was evaluated against 49 P. aeruginosa clinical strains with high levels of antimicrobial resistance, isolated from humans (n = 19) and animals (n = 30). In vitro activity was evaluated by a microdilution assay for lethal dose 90% (LD90), while the activity over time was performed by time-kill assay with 12.5 µg/ml of AMP2014. Evidences for a direct membrane damage were investigated on P. aeruginosa ATCC 27853 reference strain, on animal isolate PA-VET 38 and on human isolate PA-H 24 by propidium iodide and on P. aeruginosa ATCC 27853 by scanning electron microscopy. AMP2041 showed a dose-dependent activity, with a mean (SEM) LD90 of 1.69 and 3.3 µg/ml for animal and human strains, respectively. AMP2041 showed microbicidal activity on P. aeruginosa isolates from a patient with cystic fibrosis (CF) and resistance increased from first infection isolate (LD90 = 0.3 μg/ml) to the mucoid phenotype (LD90 = 10.4 μg/ml). The time-kill assay showed a time-dependent bactericidal effect of AMP2041 and LD90 was reached within 20 min for all the strains. The stain-dead assay showed an increasing of membrane permeabilization and SEM analysis revealed holes, dents and bursts throughout bacterial cell wall after 30 min of incubation with AMP2041. The obtained results assessed for the first time the good antimicrobial activity of AMP2041 on P. aeruginosa strains of

  17. Colony to colorimetry in 6 h: ELISA detection of a surface-expressed Pseudomonas aeruginosa virulence factor using immobilized bacteria.

    Science.gov (United States)

    Adawi, Azmi; Neville, Lewis F

    2012-09-01

    A rapid ELISA employing intact Pseudomonas aeruginosa (PA) is described that allows discrimination between strains harboring flagellin type a or b. All 52 PA strains known to harbor flagellin type b were positive in this ELISA when screened with a fully human monoclonal antibody (LST-007) targeting flagellin type b. Completion of this assay in only 6 h, from picking a single bacterial colony to a colorimetric product, could easily be adapted to a clinical laboratory setting and permit the appropriate choice of therapeutic monoclonal antibody versus its homologous flagellin target in PA-infected patients. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Biosynthesis of pyocyanin pigment by Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    M.Z. El-Fouly

    2015-01-01

    Full Text Available Sixty-three isolates belonging to the genus Pseudomonas were isolated from different environmental sources including; soil, water and clinical specimens. Twenty out of them were identified as Pseudomonas aeruginosa and individually screened for pyocyanin production. P. aeruginosa R1; isolated from rice-cultivated soil and P. aeruginosa U3 selected from clinical specimen (Urinary tract infection were the highest pyocyanin producers; pyocyanin production reached 9.3 and 5.9 μg/ml, respectively on synthetic glucose supplemented nutrient medium (GSNB. The identification of both selected strains (P. aeruginosa R1 and P. aeruginosa U3 was confirmed by 16S rRNA, the similarity with other strains available in database was 97% (with P. aeruginosa FPVC 14 and 94% (with P. aeruginosa 13.A, respectively. P. aeruginosa R1 and P. aeruginosa U3 are accessed at gene bank with accession numbers KM924432 and KM603511, in the same order. Pyocyanin was extracted by standard methods, purified by column chromatography and characterized by UV-Vis absorption, mass spectrometry and nuclear magnetic resonance. The antimicrobial activity of purified pyocyanin against multi-drug resistant microbes was investigated; the efficiency of pyocyanin was more obvious in Gram +ve bacteria than Gram−ve bacteria and yeast. To reduce the cost of pyocyanin production, a new conventional medium based on cotton seed meal supplemented with peptone was designed. The pyocyanin production of both selected strains P. aeruginosa R1 and P. aeruginosa U3 using the new medium is increased by 30.1% and 17.2%, respectively in comparison with synthetic GSNB medium, while the cost of production process is reduced by 56.7%.

  19. Major Transcriptome Changes Accompany the Growth of Pseudomonas aeruginosa in Blood from Patients with Severe Thermal Injuries.

    Directory of Open Access Journals (Sweden)

    Cassandra Kruczek

    Full Text Available Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen that causes serious infections in immunocompromised hosts including severely burned patients. After multiplying within the burn wound, P. aeruginosa translocate into the bloodstream causing bacterial sepsis frequently leading to organ dysfunction and septic shock. Although the pathogenesis of P. aeruginosa infection of thermally-injured wounds has been extensively analyzed, little is known regarding the ability of P. aeruginosa to adapt and survive within the blood of severely burned patients during systemic infection. To identify such adaptations, transcriptome analyses (RNA-seq were conducted on P. aeruginosa strain PA14 that was grown in whole blood from a healthy volunteer or three severely burned patients. Compared with growth in blood from healthy volunteers, growth of PA14 in the blood from severely burned patients significantly altered the expression of 2596 genes, with expression of 1060 genes enhanced, while that of 1536 genes was reduced. Genes whose expression was significantly reduced included genes related to quorum sensing, quorum sensing-controlled virulence factors and transport of heme, phosphate, and phosphonate. Genes whose expression was significantly enhanced were related to the type III secretion system, the pyochelin iron-acquisition system, flagellum synthesis, and pyocyanin production. We confirmed changes in expression of many of these genes using qRT-PCR. Although severe burns altered the levels of different blood components in each patient, the growth of PA14 in their blood produced similar changes in the expression of each gene. These results suggest that, in response to changes in the blood of severely burned patients and as part of its survival strategy, P. aeruginosa enhances the expression of certain virulence genes and reduces the expression of others.

  20. Positron Annihilation in the Bipositronium Ps2

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, David H.; Frolov, Alexei M.

    2005-07-01

    The electron-positron-pair annihilation in the bipositronium PS2 is considered. In particular, the two-, three-, one- and zero-photon annihilation rates are determined to high accuracy. The corresponding analytical expressions are also presented. Also, a large number of bound state properties have been determined for this system.

  1. The 4 Ps as a Guiding Perspective

    Science.gov (United States)

    Kalsbeek, David H.

    2013-01-01

    A 4 Ps perspective addresses immediate needs: to help institutions gain traction in their retention strategies by framing and reframing the challenges and the possible responses, by challenging some of the traditional mental models about retention that can distract or dilute those strategies, and by offering focus and coherence to institutional…

  2. 10th Anniversary P.S.

    CERN Multimedia

    Adams,J

    1969-01-01

    John Adams parle de la préhistoire du P.S. avec présentation des dias. Le DG B.Gregory prend la parole. Les organisateurs présentent sous la direction du "Prof.Ocktette"(?) un sketch très humoristique (p.e.existence de Quark etc.....)

  3. Back to work for the PS

    CERN Multimedia

    2006-01-01

    On 22 June, the PS's rotating machine started turning again for the first time since its enforced shutdown one month ago (see Bulletin No. 23-24/2006) - and the PS was back in operation the very next day! A team from Siemens worked their socks off, 6 days a week for one month (including public holidays), to repair the electrical power supply in collaboration with the AB/PO Group's Main Power Converters (MPC) Section. The generator's faulty rotor was dismantled and replaced by the renovated spare rotor. The multitude of electrical and mechanical connections together with the sheer weight of the rotor (80 tonnes) made this an extremely complex job. The AB/PO Group used the shutdown to test a back-up solution for the PS power supply. The accelerator was directly wired up to the 18 kV electrical network via a 13 MVA transformer, installed at the end of the 1970s but never used. This solution succeeded in bringing the PS back into operation but at limited energy and frequency. Just 14 GeV could be achieved, whic...

  4. AHP 45: REVIEW: SMUG PA

    Directory of Open Access Journals (Sweden)

    Konchok Gelek དཀོན་མཆོག་དགེ་ལེགས། (Dkon mchog dge legs, Gengqiu Gelai 更求格来

    2017-03-01

    Full Text Available Tshe ring don grub was born in 1961 in Sog rdzong (Henan Mongolian Autonomous County of Rma lho (Huangnan Tibetan Autonomous Prefecture, Mtsho sngon (Qinghai Province. Though he is classified as Mongolian, his mother tongue is A mdo Tibetan. Smug pa is his second novel, the first being Mes po 'Ancestor', which was published in 2001. He also authored Rlung dmar 'ur 'ur 'The Red Wind Screams' (2009. Fog begins with the protagonist, Seng ge, disappointed by a publisher's rejection of his novel, Tears of the Wild Yak. Seng ge, once a teacher at Rtse Area Nationality Middle School, shares with his colleagues, Red-Eyed Scholar (nickname and Bde mchog, an interest in Tibetan literature and reading.

  5. Safety and Immunogenicity Testing of a Pilot Polysaccharide Vaccine Preparation to Pseudomonas aeruginosa.

    Science.gov (United States)

    1985-02-15

    aeruginosa the sera of 15 of 22 kelsen 1261, Ullmann and Schmulling (271, and patients contained at least one precipitin for LPS Southern et al. (28...froml I - [SI had a I han iarinan,. t rat ion of tilie ’IS I did noi t siicces’..fills rilc io redti :ed corntent of mannose coiiipred with IDS s...mncic i tat c pai ition oft (T[he Itlianilos Cotnt in I’S froit 1)-11. -IBI could han -depleted1 high- molecula r-iws eicht PS frim eoite Ul:-151) be

  6. Producción equina en Argentina afectada por Pseudomonas aeruginosa : Abortos, infecciones genitales y portadores

    OpenAIRE

    Monteverde, José J.

    1980-01-01

    El microorganismo patogénico Ps. aeruginosa, también designado como "Bacilo del pus azul" , Bacillus pyocyaneous, Bacterium aeruginosum, Pseudomonas pyocyaneous, Bacterium pyocyaneum, Pseudomonas pyocyanea, es conocido desde el año 1882 como responsable de cuadros patológicos en el hombre y los animales, estando ampliamente difundido en la naturaleza. En esta comunicación se presenta información que puede interesar a quienes actúan en el campo de la patología de la raza Sangre Pura ...

  7. Chronic lung infection by Pseudomonas aeruginosa biofilm is cured by L-Methionine in combination with antibiotic therapy.

    Science.gov (United States)

    Gnanadhas, Divya Prakash; Elango, Monalisha; Datey, Akshay; Chakravortty, Dipshikha

    2015-11-02

    Bacterial biofilms are associated with 80-90% of infections. Within the biofilm, bacteria are refractile to antibiotics, requiring concentrations >1,000 times the minimum inhibitory concentration. Proteins, carbohydrates and DNA are the major components of biofilm matrix. Pseudomonas aeruginosa (PA) biofilms, which are majorly associated with chronic lung infection, contain extracellular DNA (eDNA) as a major component. Herein, we report for the first time that L-Methionine (L-Met) at 0.5 μM inhibits Pseudomonas aeruginosa (PA) biofilm formation and disassembles established PA biofilm by inducing DNase expression. Four DNase genes (sbcB, endA, eddB and recJ) were highly up-regulated upon L-Met treatment along with increased DNase activity in the culture supernatant. Since eDNA plays a major role in establishing and maintaining the PA biofilm, DNase activity is effective in disrupting the biofilm. Upon treatment with L-Met, the otherwise recalcitrant PA biofilm now shows susceptibility to ciprofloxacin. This was reflected in vivo, in the murine chronic PA lung infection model. Mice treated with L-Met responded better to antibiotic treatment, leading to enhanced survival as compared to mice treated with ciprofloxacin alone. These results clearly demonstrate that L-Met can be used along with antibiotic as an effective therapeutic against chronic PA biofilm infection.

  8. Linguistic Research with PaQU

    NARCIS (Netherlands)

    Odijk, J.E.J.M.

    2015-01-01

    In this paper I illustrate the use of the PaQu (Parse and Query) application for carrying out linguistic research. The major findings of this paper are: (1) PaQu is very useful for aiding researchers in effcient manual verification of hypotheses; (2) PaQu can even be used for automatic verification

  9. Catheter-associated urinary tract infection by Pseudomonas aeruginosa is mediated by exopolysaccharide-independent biofilms.

    Science.gov (United States)

    Cole, Stephanie J; Records, Angela R; Orr, Mona W; Linden, Sara B; Lee, Vincent T

    2014-05-01

    Pseudomonas aeruginosa is an opportunistic human pathogen that is especially adept at forming surface-associated biofilms. P. aeruginosa causes catheter-associated urinary tract infections (CAUTIs) through biofilm formation on the surface of indwelling catheters. P. aeruginosa encodes three extracellular polysaccharides, PEL, PSL, and alginate, and utilizes the PEL and PSL polysaccharides to form biofilms in vitro; however, the requirement of these polysaccharides during in vivo infections is not well understood. Here we show in a murine model of CAUTI that PAO1, a strain harboring pel, psl, and alg genes, and PA14, a strain harboring pel and alg genes, form biofilms on the implanted catheters. To determine the requirement of exopolysaccharide during in vivo biofilm infections, we tested isogenic mutants lacking the pel, psl, and alg operons and showed that PA14 mutants lacking these operons can successfully form biofilms on catheters in the CAUTI model. To determine the host factor(s) that induces the ΔpelD mutant to form biofilm, we tested mouse, human, and artificial urine and show that urine can induce biofilm formation by the PA14 ΔpelD mutant. By testing the major constituents of urine, we show that urea can induce a pel-, psl-, and alg-independent biofilm. These pel-, psl-, and alg-independent biofilms are mediated by the release of extracellular DNA. Treatment of biofilms formed in urea with DNase I reduced the biofilm, indicating that extracellular DNA supports biofilm formation. Our results indicate that the opportunistic pathogen P. aeruginosa utilizes a distinct program to form biofilms that are independent of exopolysaccharides during CAUTI.

  10. Preventing Pseudomonas aeruginosa and Chromobacterium violaceum infections by anti-adhesion-active components of edible seeds

    Science.gov (United States)

    2012-01-01

    Background Pseudomonas aeruginosa adhesion to animal/human cells for infection establishment involves adhesive proteins, including its galactose- and fucose-binding lectins PA-IL (LecA) and PA-IIL (LecB). The lectin binding to the target-cell receptors may be blocked by compatible glycans that compete with those of the receptors, functioning as anti-adhesion glycodecoys. The anti-adhesion treatment is of the utmost importance for abrogating devastating antibiotic-resistant P. aeruginosa infections in immunodeficient and cystic fibrosis (CF) patients. This strategy functions in nature in protecting embryos and neonates. We have shown that PA-IL, PA-IIL, and also CV-IIL (a PA-IIL homolog produced in the related pathogen Chromobacterium violaceum) are highly useful for revealing natural glycodecoys that surround embryos in diverse avian eggs and are supplied to neonates in milks and royal jelly. In the present study, these lectins were used as probes to search for seed embryo-protecting glycodecoys. Methods The lectin-blocking glycodecoy activities were shown by the hemagglutination-inhibition test. Lectin-binding glycoproteins were detected by Western blotting with peroxidase-labeled lectins. Results The present work reports the finding - by using PA-IL, PA-IIL, and CV-IIL - of rich glycodecoy activities of low ( 10 kDa) compounds (including glycoproteins) in extracts of cashew, cocoa, coffee, pumpkin, and tomato seeds, resembling those of avian egg whites, mammal milks, and royal jelly. Conclusions Edible seed extracts possess lectin-blocking glycodecoys that might protect their embryos from infections and also might be useful for hampering human and animal infections. PMID:22336073

  11. Preventing Pseudomonas aeruginosa and Chromobacterium violaceum infections by anti-adhesion-active components of edible seeds

    Directory of Open Access Journals (Sweden)

    Rachmaninov Ofra

    2012-02-01

    Full Text Available Abstract Background Pseudomonas aeruginosa adhesion to animal/human cells for infection establishment involves adhesive proteins, including its galactose- and fucose-binding lectins PA-IL (LecA and PA-IIL (LecB. The lectin binding to the target-cell receptors may be blocked by compatible glycans that compete with those of the receptors, functioning as anti-adhesion glycodecoys. The anti-adhesion treatment is of the utmost importance for abrogating devastating antibiotic-resistant P. aeruginosa infections in immunodeficient and cystic fibrosis (CF patients. This strategy functions in nature in protecting embryos and neonates. We have shown that PA-IL, PA-IIL, and also CV-IIL (a PA-IIL homolog produced in the related pathogen Chromobacterium violaceum are highly useful for revealing natural glycodecoys that surround embryos in diverse avian eggs and are supplied to neonates in milks and royal jelly. In the present study, these lectins were used as probes to search for seed embryo-protecting glycodecoys. Methods The lectin-blocking glycodecoy activities were shown by the hemagglutination-inhibition test. Lectin-binding glycoproteins were detected by Western blotting with peroxidase-labeled lectins. Results The present work reports the finding - by using PA-IL, PA-IIL, and CV-IIL - of rich glycodecoy activities of low ( 10 kDa compounds (including glycoproteins in extracts of cashew, cocoa, coffee, pumpkin, and tomato seeds, resembling those of avian egg whites, mammal milks, and royal jelly. Conclusions Edible seed extracts possess lectin-blocking glycodecoys that might protect their embryos from infections and also might be useful for hampering human and animal infections.

  12. 3-Amino-4-aminoximidofurazan derivatives: small molecules possessing antimicrobial and antibiofilm activity against Staphylococcus aureus and Pseudomonas aeruginosa.

    Science.gov (United States)

    Das, M C; Paul, S; Gupta, P; Tribedi, P; Sarkar, S; Manna, D; Bhattacharjee, S

    2016-04-01

    The therapeutic treatment of microbial infections involving biofilm becomes quite challenging because of its increasing antibiotic resistance capacities. Towards this direction, in the present study we have evaluated the antibiofilm property of synthesized 3-amino-4-aminoximidofurazan compounds having polyamine skeleton. These derivatives were synthesized by incorporating furazan and biguanide moieties. Different 3-amino-4-aminoximidofurazan derivatives (PI1-4) were synthesized via protic acid catalysis and subsequently characterized by (1) H NMR and (13) C NMR spectra, recorded at 400 and 100 MHz respectively. We have tested the antimicrobial and antibiofilm activities of these synthetic derivatives (PI1-4) against both Staphylococcus aureus and Pseudomonas aeruginosa. The compounds so tested were also compared with standard antibiotics namely Tobramycin (Ps. aeruginosa) and Azithromycin (Staph. aureus) which were used as a positive control in all experimental sets. All these compounds (PI1-4) exhibited moderate to significant antimicrobial activities against both micro-organisms wherein compound PI3 showed maximum activity. Biofilm inhibition of both micro-organisms was then evaluated by crystal violet and safranin staining, estimation of biofilm total protein and microscopy methods using sub-MIC dose of these compounds. Results showed that all compounds executed anti biofilm activity against both Staph. aureus and Ps. aeruginosa wherein compound PI3 exhibited maximum activity. In relation with microbial biofilm inhibition, we have observed reduction in bacterial motility, proteolytic activity and secreted exo-polysaccharide (EPS) from both Staph. aureus and Ps. aeruginosa when they were grown in presence of these compounds. While addressing the issue of toxicity on host, we have observed that these molecules exhibited minimum level of R.B.C degradation. These findings establish the antibacterial and anti biofilm properties of 3-amino-4-aminoximidofurazan

  13. The mobA gene is required for assimilatory and respiratory nitrate reduction but not xanthine dehydrogenase activity in Pseudomonas aeruginosa.

    Science.gov (United States)

    Noriega, Chris; Hassett, Daniel J; Rowe, John J

    2005-12-01

    The requirement for the mobA gene in key assimilatory and respiratory nitrogen metabolism of Pseudomonas aeruginosa PAO1 was investigated by mutational analysis of PA3030 (mobA; MoCo guanylating enzyme), PA1779 (nasA; assimilatory nitrate reductase), and PA3875 (narG; respiratory nitrate reductase). The mobA mutant was deficient in both assimilatory and respiratory nitrate reductase activities, whereas xanthine dehydrogenase activity remained unaffected. Thus, P. aeruginosa requires both the molybdopterin (MPT) and molybdopterin guanine dinucleotide (MGD) forms of the molybdenum cofactor for a complete spectrum of nitrogen metabolism, and one form cannot substitute for the other. Regulation studies using a Phi(PA3030-lacZGm) reporter strain suggest that expression of mobA is not influenced by the type of nitrogen source or by anaerobiosis, whereas assimilatory nitrate reductase activity was detected only in the presence of nitrate.

  14. Azithromycin Modulates 3',5'-cyclic Diguanylic Acid Signaling in Pseudomonas aeruginosa.

    Science.gov (United States)

    Kimura, Soichiro; Mori, Nobuaki; Kai, Toshihiro; Ishii, Yoshikazu; Yamaguchi, Keizo; Tateda, Kazuhiro

    2017-08-01

    Macrolides have been reported to exert a variety of effects on both host immunomodulation and repression of bacterial pathogenicity. In this study, we report that the 3',5'-cyclic diguanylic acid (c-di-GMP) signaling system, which regulates virulence in Pseudomonas aeruginosa, is affected by the macrolide azithromycin. Using DNA microarray analysis, we selected a gene encoding PA2567 related to c-di-GMP metabolism that was significantly affected by azithromycin treatment. Expression of the PA2567 gene was significantly repressed by azithromycin in a time- and dose-dependent manner, whereas no difference in PA2567 gene expression was observed in the absence of azithromycin. In-frame deletion of the PA2567 gene affected both virulence factors and the quorum-sensing system, and significantly decreased total bacteria in a mouse pneumonia model compared to the wild-type strain (P < 0.05). These results suggest that macrolides possess the ability to modulate c-di-GMP intracellular signaling in P. aeruginosa. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  15. PS overcomes two serious magnet failures

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Two magnets (no.'s 6 and 19)and a bus bar connection in the PS were found to be faulty during high-voltage tests at the end of the accelerator shutdown. A five-week repair schedule was quickly devised. A team of mechanics, technicians and engineers worked at full speed to replace the faulty magnets, succeeding in limiting the delay of the accelerators' spring start-up to two weeks. Pictured here are members of the PS team with the replacement no. 6 magnet. From left to right: In the back row, Frédéric Roussel (Transport DBS), Yves Bernard (Transport DBS), Luc Moreno (Cegelec), Thierry Battimanza (Transport DBS), Raymond Brown (AB/ABP), Thomas Zickler (AT/MEL); at the front, Steven Southern (AT/VAC), Thierry Gaidon (Brun & Sorensen), Philippe Vidales (Cegelec), Daniel Aubert (Cegelec), Jerome Cachet (Transport DBS), Jose Manual Gomes de Faria (AT/MEL), Eric Page (AT/VAC).

  16. PS overcomes two serious magnet failures

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Two magnets and a bus bar connection in the PS were found to be faulty during high-voltage tests at the end of the accelerator shutdown. A five-week repair schedule was quickly devised. A team of mechanics, technicians and engineers worked at full speed to replace the faulty magnets, succeeding in limiting the delay of the accelerators´ spring start-up to two weeks. Here we see one of the replacement magnets (no. 19) being prepared.

  17. The PS overcomes two serious magnet failures

    CERN Multimedia

    2003-01-01

    Two magnets and a bus bar connection in the PS were found to be faulty during high-voltage tests at the end of the accelerator shutdown. A five-week repair schedule was quickly devised. A team of mechanics, technicians and engineers worked at full speed to replace the faulty magnets, succeeding in limiting the delay of the accelerators' spring start-up to two weeks.

  18. Motor-Generator Set, PS Main Supply

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    This is the "new" motor-generator set. It replaced the previous, original, one which had served from the PS start-up in 1959. Ordered in 1965, installed in 1967, it was brought into operation at the beginning of 1968. Regularly serviced and fitted with modern regulation and controls, it still serves at the time of writing (2006) and promises to serve for several more years, as a very much alive museum-piece. See also 6803016 and 0201010.

  19. Measuring target for the PS Booster

    CERN Multimedia

    1971-01-01

    The measuring target for the PS Booster (originally 800 MeV, now 1.4 GeV). It measures the size of the beam by destroying all particles with amplitudes greater than the size of the fork, the position and width of which are adjustable. The plunging time is only 20 ms and the acceleration at the tip of the fork reaches 90 g. The servo-controlled linear motor is shown detached from the mechanism. See also 7602008.

  20. Memories of the PS and of LEP

    CERN Document Server

    Steinberger, Jack

    2012-01-01

    The CERN PS, which started in 1959, and the Brookhaven AGS in 1960, represented an advance by a factor of more than five in the energy of proton accelerators, from the 5 GeV of the Berkeley Bevatron to about 30 GeV. These accelerators made possible the large progress in our understanding of particles and their interactions over the next two decades, culminating in the electroweak and QCD gauge theories.

  1. PS overcomes two serious magnet failures

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Two magnets and a bus bar connection in the PS were found to be faulty during high-voltage tests at the end of the accelerator shutdown. A five-week repair schedule was quickly devised. A team of mechanics, technicians and engineers worked at full speed to replace the faulty magnets, succeeding in limiting the delay of the accelerators' spring start-up to two weeks. Here we see one of the replacement magnets (no. 6) being prepared.

  2. Enhanced personal protection system for the PS

    CERN Multimedia

    Caroline Duc

    2013-01-01

    During the first long shutdown (LS1) a new safety system will be installed in the primary beam areas of the PS complex in order to bring the standard of personnel radiation protection at the PS into line with that of the LHC.   Pierre Ninin, deputy group leader of GS-ASE and responsible for the installation of the new PS complex safety system, in front of a new access control system. The LHC access control systems are state-of-the-art, whereas those of the injection chain accelerators were running the risk of becoming obsolete. For the past two years a project to upgrade the access and safety systems of the first links in the LHC accelerator chain has been underway to bring them into compliance with nuclear safety standards. These systems provide the personnel with automatic protection by limiting access to hazardous areas and by ensuring that nobody is present in the areas when the accelerator is in operation. By the end of 2013, the project teams will ha...

  3. Stratified growth in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Werner, E.; Roe, F.; Bugnicourt, A.

    2004-01-01

    In this study, stratified patterns of protein synthesis and growth were demonstrated in Pseudomonas aeruginosa biofilms. Spatial patterns of protein synthetic activity inside biofilms were characterized by the use of two green fluorescent protein (GFP) reporter gene constructs. One construct...... of oxygen limitation in the biofilm. Oxygen microelectrode measurements showed that oxygen only penetrated approximately 50 mum into the biofilm. P. aeruginosa was incapable of anaerobic growth in the medium used for this investigation. These results show that while mature P. aeruginosa biofilms contain...

  4. Aspergillus triggers phenazine production in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib

    Aspergillus species. Methods: A suspension of fungal spores was streaked onto WATM agar plates. After 24 hours incubation at 37 °C, a P. aeruginosa overnight culture was streaked out perpendicular to the fungal streak. The plates were incubated at 37 °C for five days, examined and plugs were extracted...... for HPLC-DAD and HPLC-DAD-MS analysis. Results: P. aeruginosa PAO1 suppressed growth of A. fumigatus, A. niger, A. flavus, A. oryzae, A. terreus and Emericella nidulans. HPLC and HPLC-DAD-MS results showed an increase in phenazine-1-carboxylic acid and phenazine-1-carboxamide production by P. aeruginosa...

  5. Suppression of Aspergillus by Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib

    culture plates. After 24 hours incubation at 37 °C, a P. aeruginosa overnight culture diluted to 108 CFU/ml was streaked out perpendicular to the fungal streak. The plates were incubated at 37 °C for 5 days, examined and plugs were extracted for HPLC and LC-DAD-MS analysis. Results: P. aeruginosa PAO1...... suppressed growth of A. fumigatus, A. niger, A. flavus, A. oryzae, A. terreus and E. nidulans. HPLC and LC-DAD-MS results showed an increase in phenazine-1-carboxylic acid and phenazine-1-carboxamide production by P. aeruginosa in the contact area of Aspergillus. Different quinolones were also identified...

  6. A Pseudomonas aeruginosa toxin that hijacks the host ubiquitin proteolytic system.

    Directory of Open Access Journals (Sweden)

    Jennifer M Bomberger

    2011-03-01

    Full Text Available Pseudomonas aeruginosa (P. aeruginosa is an opportunistic pathogen chronically infecting the lungs of patients with chronic obstructive pulmonary disease (COPD, pneumonia, cystic fibrosis (CF, and bronchiectasis. Cif (PA2934, a bacterial toxin secreted in outer membrane vesicles (OMV by P. aeruginosa, reduces CFTR-mediated chloride secretion by human airway epithelial cells, a key driving force for mucociliary clearance. The aim of this study was to investigate the mechanism whereby Cif reduces CFTR-mediated chloride secretion. Cif redirected endocytosed CFTR from recycling endosomes to lysosomes by stabilizing an inhibitory effect of G3BP1 on the deubiquitinating enzyme (DUB, USP10, thereby reducing USP10-mediated deubiquitination of CFTR and increasing the degradation of CFTR in lysosomes. This is the first example of a bacterial toxin that regulates the activity of a host DUB. These data suggest that the ability of P. aeruginosa to chronically infect the lungs of patients with COPD, pneumonia, CF, and bronchiectasis is due in part to the secretion of OMV containing Cif, which inhibits CFTR-mediated chloride secretion and thereby reduces the mucociliary clearance of pathogens.

  7. Elucidating the Pseudomonas aeruginosa fatty acid degradation pathway: identification of additional fatty acyl-CoA synthetase homologues.

    Directory of Open Access Journals (Sweden)

    Jan Zarzycki-Siek

    Full Text Available The fatty acid (FA degradation pathway of Pseudomonas aeruginosa, an opportunistic pathogen, was recently shown to be involved in nutrient acquisition during BALB/c mouse lung infection model. The source of FA in the lung is believed to be phosphatidylcholine, the major component of lung surfactant. Previous research indicated that P. aeruginosa has more than two fatty acyl-CoA synthetase genes (fadD; PA3299 and PA3300, which are responsible for activation of FAs using ATP and coenzyme A. Through a bioinformatics approach, 11 candidate genes were identified by their homology to the Escherichia coli FadD in the present study. Four new homologues of fadD (PA1617, PA2893, PA3860, and PA3924 were functionally confirmed by their ability to complement the E. coli fadD mutant on FA-containing media. Growth phenotypes of 17 combinatorial fadD mutants on different FAs, as sole carbon sources, indicated that the four new fadD homologues are involved in FA degradation, bringing the total number of P. aeruginosa fadD genes to six. Of the four new homologues, fadD4 (PA1617 contributed the most to the degradation of different chain length FAs. Growth patterns of various fadD mutants on plant-based perfumery substances, citronellic and geranic acids, as sole carbon and energy sources indicated that fadD4 is also involved in the degradation of these plant-derived compounds. A decrease in fitness of the sextuple fadD mutant, relative to the ΔfadD1D2 mutant, was only observed during BALB/c mouse lung infection at 24 h.

  8. Interspecies signalling via the Stenotrophomonas maltophilia diffusible signal factor influences biofilm formation and polymyxin tolerance in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Ryan, R.P.; Fouhy, Y.; Garcia, B.F.

    2008-01-01

    Interspecies signalling through the action of diffusible signal molecules can influence the behaviour of organisms growing in polymicrobial communities. Stenotrophomonas maltophilia and Pseudomonas aeruginosa occur ubiquitously in the environment and can be found together in diverse niches...... including the rhizosphere of plants and the cystic fibrosis lung. In mixed species biofilms, S. maltophilia substantially influenced the architecture of P. aeruginosa structures, which developed as extended filaments. This effect depended upon the synthesis of the diffusible signal factor (DSF) by S...... or addition of DSF to P. aeruginosa led to increased levels of a number of proteins with roles in bacterial stress tolerance, including those implicated in resistance to cationic antimicrobial peptides. This effect was associated with increased tolerance to polymyxins. Homologues of PA1396 occur in a number...

  9. Pseudomonas aeruginosa ATCC 9027 is a non-virulent strain suitable for mono-rhamnolipids production.

    Science.gov (United States)

    Grosso-Becerra, María-Victoria; González-Valdez, Abigail; Granados-Martínez, María-Jessica; Morales, Estefanía; Servín-González, Luis; Méndez, José-Luis; Delgado, Gabriela; Morales-Espinosa, Rosario; Ponce-Soto, Gabriel-Yaxal; Cocotl-Yañez, Miguel; Soberón-Chávez, Gloria

    2016-12-01

    Rhamnolipids produced by Pseudomonas aeruginosa are biosurfactants with a high biotechnological potential, but their extensive commercialization is limited by the potential virulence of P. aeruginosa and by restrictions in producing these surfactants in heterologous hosts. In this work, we report the characterization of P. aeruginosa strain ATCC 9027 in terms of its genome-sequence, virulence, antibiotic resistance, and its ability to produce mono-rhamnolipids when carrying plasmids with different cloned genes from the type strain PAO1. The genes that were expressed from the plasmids are those coding for enzymes involved in the synthesis of this biosurfactant (rhlA and rhlB), as well as the gene that codes for the RhlR transcriptional regulator. We confirm that strain ATCC 9027 forms part of the PA7 clade, but contrary to strain PA7, it is sensitive to antibiotics and is completely avirulent in a mouse model. We also report that strain ATCC 9027 mono-rhamnolipid synthesis is limited by the expression of the rhlAB-R operon. Thus, this strain carrying the rhlAB-R operon produces similar rhamnolipids levels as PAO1 strain. We determined that strain ATCC 9027 with rhlAB-R operon was not virulent to mice. These results show that strain ATCC 9027, expressing PAO1 rhlAB-R operon, has a high biotechnological potential for industrial mono-rhamnolipid production.

  10. The (7,7) optics at CERN PS

    CERN Document Server

    Serluca, M; Efthymiopoulos, I; Sperati, F; Sterbini, G; Tecker, F; Zisopoulos, P

    2017-01-01

    The PS lattice is composed by one hundred combinedfunction magnets, which set the bare tune of the machineto (Qh,Qv) = (6.25, 6.28). Low energy quadrupoles areused at injection to move the tune in a limited working pointarea. In particular the vertical tune is moved below 6.25 toavoid the structural resonance 8Qv= 50 coupled with spacecharge, which leads to strong losses. In view of the highdemands in terms of beam brightness for LIU and HL-LHCprojects, the interest of exploring different integer tune work-ing area started during last years. During 2016, for the firsttime, it has been possible to explore the (7,7) tune workingarea at injection using the auxiliary circuits of the combinedfunction magnets. A finite-element magnetic model, underdevelopment, has been used to predict the required currentsin order to get the desired optical parameters. In this pa-per we present the results and issues encountered duringthe Machine Development (MD) studies about the injectionin the (7,7) area along with optics and be...

  11. Molecular characterization and properties of (R)-specific enoyl-CoA hydratases from Pseudomonas aeruginosa: metabolic tools for synthesis of polyhydroxyalkanoates via fatty acid beta-oxidation.

    Science.gov (United States)

    Tsuge, Takeharu; Taguchi, Kazunori; Seiichi, Taguchi; Doi, Yoshiharu

    2003-01-15

    The use of (R)-specific enoyl-coenzyme A (CoA) hydratase (PhaJ) provides a powerful tool for polyhydroxyalkanoate (PHA) synthesis from fatty acids or plant oils in recombinant bacteria. PhaJ provides monomer units for PHA synthesis from the fatty acid ss-oxidation cycle. Previously, two phaJ genes (phaJ1(Pa) and phaJ2(Pa)) were identified in Pseudomonas aeruginosa. This report identifies two new phaJ genes (phaJ3(Pa) and phaJ4(Pa)) in P. aeruginosa through a genomic database search. The abilities of the four PhaJ(Pa) proteins and the (R)-3-hydroxyacyl-acyl carrier protein [(R)-3HA-ACP] dehydrases, FabA(Pa) and FabZ(Pa), to supply monomers from enoyl-CoA substrates for PHA synthesis were determined. The presence of either PhaJ1(Pa) or PhaJ4(Pa) in recombinant Escherichia coli led to the high levels of PHA accumulation (as high as 36-41 wt.% in dry cells) consisting of mainly short- (C4-C6) and medium-chain-length (C6-C10) 3HA units, respectively. Furthermore, detailed characterizations of PhaJ1(Pa) and PhaJ4(Pa) were performed using purified samples. Kinetic analysis revealed that only PhaJ4(Pa) exhibits almost constant maximum reaction rates (V(max)) irrespective of the chain length of the substrates. The assay for stereospecific hydration revealed that, unlike PhaJ1(Pa), PhaJ4(Pa) has relatively low (R)-specificity. These hydratases may be very useful as monomer-suppliers for the synthesis of designed PHAs in recombinant bacteria.

  12. Psühhodramaatikud annavad Pärnus eksami

    Index Scriptorium Estoniae

    2008-01-01

    29. maist kuni 1. juunini kestab Pärnus psühhodraama konverents "Geeniuste kohtumine", kus rahvusvahelise koolituse läbinud annavad eksami. Ruuda Palmquist on psühhodraama kui teadusharu rajajaid Eestis. Pärnus on kohal Rootsi Moreno Instituudi juhataja, psühhodraama lavastaja Marc Treadwell

  13. Transcriptomic and Metabolomic Analysis Revealed Multifaceted Effects of Phage Protein Gp70.1 on Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Xia Zhao

    2016-09-01

    Full Text Available The impact of phage infection on the host cell is severe. In order to take over the cellular machinery, some phage proteins were produced to shut off the host biosynthesis early in the phage infection. The discovery and identification of these phage-derived inhibitors have a significant prospect of application in antibacterial treatment. This work presented a phage protein, gp70.1, with nonspecific inhibitory effects on Pseudomonas aeruginosa (P. aeruginosa and Escherichia coli (E. coli. Gp70.1 was encoded by early gene – orf 70.1 from P. aeruginosa phage PaP3. The P. aeruginosa with a plasmid encoding gp70.1 showed with delayed growth and had the appearance of a small colony. The combination of multifaceted analysis including microarray-based transcriptomic analysis, RT-qPCR, nuclear magnetic resonance (NMR spectroscopy-based metabolomics and phenotype experiments were performed to investigate the effects of gp70.1 on P. aeruginosa. A total of 178 genes of P. aeruginosa mainly involved in extracellular function and metabolism were differentially expressed in the presence of gp70.1 at 3 examined time points. Furthermore, our results indicated that gp70.1 had an extensive impact on the extracellular phenotype of P. aeruginosa, such as motility, pyocyanin, extracellular protease, polysaccharide, and cellulase. For the metabolism of P. aeruginosa, the main effect of gp70.1 was the reduction of amino acid consumption. Finally, the RNA polymerase sigma factor RpoS was identified as a potential cellular target of gp70.1. Gp70.1 was the first bacterial inhibitor identified from Pseudomonas aeruginosa phage PaP3. It was also the first phage protein that interacted with the global regulator RpoS of bacteria. Our results indicated the potential value of gp70.1 in antibacterial applications. This study preliminarily revealed the biological function of gp70.1 and provided a reference for the study of other phage genes sharing similarities with orf70.1.

  14. Dynamics of Pseudomonas aeruginosa Genome Evolution

    National Research Council Canada - National Science Library

    Kalai Mathee; Giri Narasimhan; Camilo Valdes; Xiaoyun Qiu; Jody M. Matewish; Michael Koehrsen; Antonis Rokas; Chandri N. Yandava; Reinhard Engels; Erliang Zeng; Raquel Olavarietta; Melissa Doud; Roger S. Smith; Philip Montgomery; Jared R. White; Paul A. Godfrey; Chinnappa Kodira; Bruce Birren; James E. Galagan; Stephen Lory

    2008-01-01

    One of the hallmarks of the Gram-negative bacterium Pseudomonas aeruginosa is its ability to thrive in diverse environments that includes humans with a variety of debilitating diseases or immune deficiencies...

  15. Pseudomonas aeruginosa: resistance to the max

    National Research Council Canada - National Science Library

    Poole, Keith

    2011-01-01

    Pseudomonas aeruginosa is intrinsically resistant to a variety of antimicrobials and can develop resistance during anti-pseudomonal chemotherapy both of which compromise treatment of infections caused by this organism...

  16. Antibiotic Conditioned Growth Medium of Pseudomonas Aeruginosa

    Science.gov (United States)

    Benathen, Isaiah A.; Cazeau, Barbara; Joseph, Njeri

    2004-01-01

    A simple method to study the consequences of bacterial antibiosis after interspecific competition between microorganisms is presented. Common microorganisms are used as the test organisms and Pseudomonas aeruginosa are used as the source of the inhibitor agents.

  17. Pseudomonas aeruginosa (Family Pseudomonadaceae) is an ...

    African Journals Online (AJOL)

    Pseudomonas aeruginosa (Family Pseudomonadaceae) is an obligate aerobic, motile, gram negative bacillus.which is able to grow and survive in almost any environment and resistant to temperature extremes. It is involved in the etiology of several diseases i.

  18. Molecular cloning, characterisation and ligand-bound structure of an azoreductase from Pseudomonas aeruginosa.

    Science.gov (United States)

    Wang, Chan-Ju; Hagemeier, Christoph; Rahman, Nawreen; Lowe, Edward; Noble, Martin; Coughtrie, Michael; Sim, Edith; Westwood, Isaac

    2007-11-09

    The gene PA0785 from Pseudomonas aeruginosa strain PAO1, which is annotated as a probable acyl carrier protein phosphodiesterase (acpD), has been cloned and heterologously overexpressed in Escherichia coli. The purified recombinant enzyme exhibits activity corresponding to that of azoreductase but not acpD. Each recombinant protein molecule has an estimated molecular mass of 23,050 Da and one non-covalently bound FMN as co-factor. This enzyme, now identified as azoreductase 1 from Pseudomonas aeruginosa (paAzoR1), is a flavodoxin-like protein with an apparent molecular mass of 110 kDa as determined by gel-filtration chromatography, indicating that the protein is likely to be tetrameric in solution. The three-dimensional structure of paAzoR1, in complex with the substrate methyl red, was solved at a resolution of 2.18 A by X-ray crystallography. The protein exists as a dimer of dimers in the crystal lattice, with two spatially separated active sites per dimer, and the active site of paAzoR1 was shown to be a well-conserved hydrophobic pocket formed between two monomers. The paAzoR1 enzyme is able to reduce different classes of azo dyes and activate several azo pro-drugs used in the treatment of inflammatory bowel disease (IBD). During azo reduction, FMN serves as a redox centre in the electron-transferring system by mediating the electron transfer from NAD(P)H to the azo substrate. The spectral properties of paAzoR1 demonstrate the hydrophobic interaction between FMN and the active site in the protein. The structure of the ligand-bound protein also highlights the pi-stacking interactions between FMN and the azo substrate.

  19. tPA-binding RNA Aptamers

    DEFF Research Database (Denmark)

    Bjerregaard, Nils

    2015-01-01

    The serine protease Tissue-type Plasminogen Activator (tPA) is the principal initiator of fibrinolysis in mammalian physiology. Recombinant tPA is employed in the pharmacological resolution of vessel occlusions caused by pathological thrombosis, the originating cause of cerebral ischaemic strokes......-density lipoprotein receptor Related Protein-1 (LRP-1). Here, we describe the selection and characterisation of structured RNA ligands (“RNA aptamers”) to tPA, K18 and K32. Both aptamers were truncated to minimal 32-nucleotide constructs (v2) with improved or unchanged activities, and were shown to bind tPA with low...

  20. Taguchi approach significantly increases bioremediation process efficiency: a case study with Hg (II) removal by Pseudomonas aeruginosa.

    Science.gov (United States)

    Tupe, S G; Rajwade, J M; Paknikar, K M

    2007-07-01

    Optimization of process parameters for mercury removal by an Hg (II)-reducing Pseudomonas aeruginosa strain. A strain of Ps. aeruginosa was found to reduce 10 mg l(-1) Hg (II) to Hg0 with 70% efficiency in 24 h. To optimize process performance, a statistical tool--Taguchi design of experiments (DOE)--was used to carry out 18 well-defined experiments (L18 Orthogonal array) with eight variable parameters (viz. agitation, temperature, pH, carbon source, medium volume: flask volume ratio and concentrations of Hg (II), ammonium sulfate and yeast extract). When data obtained were analyzed using specialized software for Taguchi design, Qualitek-4 (Nutek Inc., MI, USA), Hg (II) reduction efficiency was predicted to be 95% in 24 h under the optimized process parameters (also suggested by the software). In the validation experiment, Hg (II) removal of 99.29% in 24 h was indeed obtained. Using Taguchi DOE, Hg (II) reduction (and hence its removal) using Ps. aeruginosa could be improved by 29.3%. Taguchi approach could be employed as an efficient and time-saving strategy for parameter optimization in bioremediation processes.

  1. Psychometric properties of the French translation of the reduced KOOS and HOOS (KOOS-PS and HOOS-PS)

    DEFF Research Database (Denmark)

    Ornetti, P; Perruccio, A V; Roos, E M

    2009-01-01

    OBJECTIVE: To evaluate the psychometric properties of the French KOOS physical function (KOOS-PS) and HOOS physical function (HOOS-PS), specifically its feasibility, reliability, construct validity, and responsiveness. METHODS: Consecutive outpatients consulting for primary knee or hip osteoarthr......OBJECTIVE: To evaluate the psychometric properties of the French KOOS physical function (KOOS-PS) and HOOS physical function (HOOS-PS), specifically its feasibility, reliability, construct validity, and responsiveness. METHODS: Consecutive outpatients consulting for primary knee or hip...

  2. Evolving science enhanced with iPS

    Directory of Open Access Journals (Sweden)

    Editor

    2007-11-01

    Full Text Available Dear friends, Greetings from all in the team. With the stage set for online submissions and the review-response-revision-resubmission process standardized, we have come with the first regular issue and from now there will be quarterly issues of the journal. Since the starting of the JSRM in a short span there have been a lot of developments, which we would rather say as "evolutions" keeping in mind, the recent iPS! This evolution we would like you to see from a background of the various developments in the art and science of medicine throughout in the past three centuries. We have come across the era of investigative tools such as bamboo made laryngoscopes to era of vaccines and antibiotics followed by the era of revolutionary non-invasive procedures and recently the nano technology based drugs and now the iPS! Macro to Micro, but still more to go. All through the influence of the society, religions, philosophies have been playing a very important role in every step the science of biology moves ahead. Starting with the contraception, assisted reproduction then the gene modified plants....and now the embryonic stem cells! With the advent of the iPS, though the issues of oncogenes, teratoma yet to be ruled out, we have found there is a way which can bypass the ES cells! Hats off to those scientists who have burnt their midnight oil to have found this way out! The lesson we learn is to explore things with an open mind and continue to proceed further without spending much time fingers crossed. Yours sincerely,The Editorial team.

  3. Position pickup of the PS Booster

    CERN Multimedia

    CERN PhotoLab

    1975-01-01

    The beam position around the 4 rings of the PS Booster (originally 800 MeV, now 1.4 GeV), is measured with electrostatic pickups (PU). They consist of a ceramic cylinder forming part of the vacuum chamber, and, in order to save space, they are located inside the multipole lenses. The inside of the ceramic is coated with a metallic layer, into which the form of the electrodes was cut by computer-controlled micro-sandblasting. Each PU has a pair of horizontal and a pair of vertical electrodes, as well as a separate intensity-sensing circular electrode.

  4. Space charge studies in the PS

    CERN Document Server

    Asvesta, F; Damerau, H; Huschauer, A; Papaphilippou, Y; Serluca, M; Sterbini, G; Zisopoulos, P

    2017-01-01

    In this paper the results of Machine Development (MD)studies conducted at the CERN Proton Sychrotron (PS) arepresented. The main focus was the investigation of newworking points in an effort to characterize and potentiallyimprove the brightness for LHC-type beams in view of theLHC Injectors Upgrade (LIU). Various working points werecompared in terms of losses and emittance evolution. Sincespace charge and the resonances it excites are the main causefor emittance blow-up and losses, tunes close to excitedresonances were carefully studied. Mitigation techniques,such as bunch flattening using a double harmonic RF system,were also tested.

  5. Gene expression in Pseudomonas aeruginosa swarming motility

    Directory of Open Access Journals (Sweden)

    Déziel Eric

    2010-10-01

    Full Text Available Abstract Background The bacterium Pseudomonas aeruginosa is capable of three types of motilities: swimming, twitching and swarming. The latter is characterized by a fast and coordinated group movement over a semi-solid surface resulting from intercellular interactions and morphological differentiation. A striking feature of swarming motility is the complex fractal-like patterns displayed by migrating bacteria while they move away from their inoculation point. This type of group behaviour is still poorly understood and its characterization provides important information on bacterial structured communities such as biofilms. Using GeneChip® Affymetrix microarrays, we obtained the transcriptomic profiles of both bacterial populations located at the tip of migrating tendrils and swarm center of swarming colonies and compared these profiles to that of a bacterial control population grown on the same media but solidified to not allow swarming motility. Results Microarray raw data were corrected for background noise with the RMA algorithm and quantile normalized. Differentially expressed genes between the three conditions were selected using a threshold of 1.5 log2-fold, which gave a total of 378 selected genes (6.3% of the predicted open reading frames of strain PA14. Major shifts in gene expression patterns are observed in each growth conditions, highlighting the presence of distinct bacterial subpopulations within a swarming colony (tendril tips vs. swarm center. Unexpectedly, microarrays expression data reveal that a minority of genes are up-regulated in tendril tip populations. Among them, we found energy metabolism, ribosomal protein and transport of small molecules related genes. On the other hand, many well-known virulence factors genes were globally repressed in tendril tip cells. Swarm center cells are distinct and appear to be under oxidative and copper stress responses. Conclusions Results reported in this study show that, as opposed to

  6. Antimicrobial photodynamic effect of phenothiazinic photosensitizers in formulations with ethanol on Pseudomonas aeruginosa biofilms.

    Science.gov (United States)

    Prochnow, Emilia Pithan; Martins, Maritieli Righi; Campagnolo, Cibele Bruno; Santos, Roberto Christ; Villetti, Marcos Antonio; Kantorski, Karla Zanini

    2016-03-01

    Methylene blue (MB) and toluidine blue (TB) are recognized as safe photosensitizers (Ps) for use in humans. The clinical effectiveness of the antimicrobial photodynamic therapy with MB and TB needs to be optimized, and ethanol can increase their antimicrobial effect. Formulations of MB and TB containing ethanol were evaluated for their ability to produce singlet oxygen and their antibacterial effect on Pseudomonas aeruginosa biofilms. Photoactivated formulations were prepared by diluting the Ps (250 μM) in buffered water (pH 5.6, sodium acetate/acetic acid), 10% ethanol (buffer: ethanol, 90:10), or 20% ethanol (buffer: ethanol, 80:20). Biofilms also were exposed to the buffer, 10% ethanol, or 20% ethanol without photoactivation. Untreated biofilm was considered the control group. The production of singlet oxygen in the formulations was measured based on the photo-oxidation of 1,3-diphenylisobenzofuran. The photo-oxidation and CFU (log10) data were evaluated by two-way ANOVA and post-hoc Tukey's tests. In all the formulations, compared to TB, MB showed higher production of singlet oxygen. In the absence of photoactivation, neither the buffer nor the 10% ethanol solution showed any antimicrobial effect, while the 20% ethanol solution significantly reduced bacterial viability (P=0.009). With photoactivation, only the formulations containing MB and both 10% and 20% ethanol solutions significantly reduced the viability of P. aeruginosa biofilms when compared with the control. MB formulations containing ethanol enhanced the antimicrobial effect of the photodynamic therapy against P. aeruginosa biofilms in vitro. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Characterization of clinical extensively drug-resistant Pseudomonas aeruginosa in the Hunan province of China.

    Science.gov (United States)

    Li, Jun; Zou, Mingxiang; Dou, Qingya; Hu, Yongmei; Wang, Haichen; Yan, Qun; Liu, Wen' En

    2016-05-23

    Pseudomonas aeruginosa strains that are classed as extensively drug resistant (XDR-PA) are resistant to all antibiotics except for one or two classes and are frequently the cause of hard-to-treat infections worldwide. Our study aimed to characterize clinical XDR-PA isolates recovered during 2011-2012 at nine hospitals in the Hunan province of China. Thirty-seven non-repetitive XDR-PA strains from 37 patients were investigated for genes encoding antimicrobial resistance determinants, efflux pumps, outer membrane proteins, and movable genetic elements using polymerase chain reaction (PCR). The expression of genes encoding the efflux pump component MexA and the outer membrane protein OprD was measured using real-time PCR. In addition, clonal relatedness of these XDR-PA isolates was analyzed by pulsed-field gel electrophoresis (PFGE). Various genes encoding antimicrobial resistance determinants were found in all isolates. In particular, the bla TEM-1, bla CARB, armA, bla IMP-4, bla VIM-2, and rmtB, were found in 100, 37.8, 22, 22, 19 and 5 % of the isolates, respectively. Remarkably, two isolates coharbored bla IMP-4, bla VIM-2, and armA. In all 37 antibiotic-resistant strains, the relative expression of oprD was decreased while mexA was increased compared to the expression of these genes in antibiotic-susceptible P. aeruginosa strains. All of the XDR-PA isolates harbored class I integrons as well as multiple other mobile genetic elements, such as tnpU, tnp513, tnpA (Tn21), and merA. A high genotypic diversity among the strains was detected by PFGE. Multiple antibiotic-resistance mechanisms contributed to the drug resistance of the XDR-PA isolates investigated in this study. Thus, the XDR-PA isolates in this area were not clonally related. Instead, multiple types of movable genetic elements were coharbored within each XDR-PA isolate, which may have aided the rapid development of these XDR-PA strains. This is the first report of XDR-PA strains that coharbor bla IMP-4

  8. Structure and characterization of a NAD(P)H-dependent carbonyl reductase from Pseudomonas aeruginosa PAO1.

    Science.gov (United States)

    Li, Shanshan; Teng, Xiaozhen; Su, Li; Mao, Guannan; Xu, Yueyang; Li, Tingting; Liu, Riuhua; Zhang, Qionglin; Wang, Yingying; Bartlam, Mark

    2017-06-01

    To investigate the function of the pa4079 gene from the opportunistic pathogen Pseudomonas aeruginosa PAO1, we determined its crystal structure and confirmed it to be a NAD(P)-dependent short-chain dehydrogenase/reductase. Structural similarity and activity for a broad range of substrates indicate that PA4079 functions as a carbonyl reductase. Comparison of apo- and holo-PA4079 shows that NADP stabilizes the active site specificity loop, and small molecule binding induces rotation of the Tyr183 side chain by approximately 90° out of the active site. Quantitative real-time PCR results show that pa4079 maintains high expression levels during antibiotic exposure. This work provides a starting point for understanding substrate recognition and selectivity by PA4079, as well as its possible reduction of antimicrobial drugs. Structural data are available in the Protein Data Bank (PDB) under the following accession numbers: apo PA4079 (condition I), 5WQM; apo PA4079 (condition II), 5WQN; PA4079 + NADP (condition I), 5WQO; PA4079 + NADP (condition II), 5WQP. © 2017 Federation of European Biochemical Societies.

  9. PAN/PS elctrospun fibers for oil spill cleanup

    Science.gov (United States)

    Ying, Qiao; Lili, Zhao; Haixiang, Sun; Peng, Li

    2014-08-01

    A high-capacity oil sorbent was fabricated by electrospinning using PS/PAN blend. Morphology, contact angle and oil adsorption of PAN/PS fiber and PP nonwoven fabric were studied. It was found that the PAN/PS fiber had a smaller diameter than PP, and the maximum sorption capacities of the PAN/PS sorbent for pump oil, peanut oil, diesel, and gasoline were 194.85, 131.7, 66.75, and 43.38 g/g, which were far higher than those of PP. The sorbent PS/PAN fiber showed a contact angle of water144.32° and diesel oil 0°. The sorption kinetics of PAN/PS and PP sorbent were also investigated. Compared with the commercial PP fabric, the PAN/PS fiber seems to have the ability to be used in oil-spill cleanup application.

  10. Chemotherapy and quality of life in NSCLC PS 2 patients

    DEFF Research Database (Denmark)

    Helbekkmo, Nina; Strøm, Hans H; Sundstrøm, Stein H

    2009-01-01

    INTRODUCTION: Nearly 40% of patients with advanced NSCLC are in performance status (PS) 2. These patients have a shorter life expectancy than PS 0/1 patients and they are underrepresented in clinical trials. Data on how platinum-based combination chemotherapy affects Health Related Quality of Life...... (HRQOL) of patients with PS 2 are scarce and the treatment of this important group of patients is controversial. METHODS: A national multicenter phase III study on platinum based chemotherapy to 432 advanced NSCLC patients included 123 patients with PS 2. To explore the treatment impact on HRQOL......: Whereas the demographic data at baseline were well balanced between the groups, the PS 2 patients had significantly worse function and more severe symptoms than the PS 0/1 patients. In response to combination chemotherapy, the PS 2 patients had a more profound improvement of global QOL, cognitive function...

  11. 49 CFR 372.211 - Pittsburgh, PA.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Pittsburgh, PA. 372.211 Section 372.211... ZONES, AND TERMINAL AREAS Commercial Zones § 372.211 Pittsburgh, PA. The zone adjacent to, and commercially a part of Pittsburgh within which transportation by motor vehicle in interstate or foreign...

  12. The PS Booster Fast Wire Scanner

    CERN Document Server

    Burger, S; Priestnall, K; Raich, U

    2003-01-01

    The very tight emittance budget for LHC type beams makes precise emittance measurements in the injector complex a necessity. The PS machine uses 2 fast wire scanners per transverse plane for emittance measurement of the circulating beams. In order to ease comparison the same type of wire scanners have been newly installed in the upstream machine, the PS Booster, where each of the 4 rings is equipped with 2 wire scanners measuring the horizontal and vertical profiles. Those wire scanners use new and more modern control and readout electronics featuring dedicated intelligent motor movement controllers, which relieves the very stringent real time constraints due to the very high speed of 20m/s. In order to be able to measure primary beams at the very low injection energy of the Booster (50MeV) secondary emission currents from the wire can be measured as well as secondary particle flows at higher primary particle energies during and after acceleration. The solution adopted for the control of the devices is descri...

  13. Sofrimento psíquico e trabalho

    Directory of Open Access Journals (Sweden)

    Sarah Rosa Salles Vieira

    2014-03-01

    Full Text Available O presente artigo aprofunda questões clínico-téoricas relacionadas especificamente ao trabalho docente e ao sofrimento psíquico a ele relacionado a partir da observação clínica e vivência grupal nos atendimentos terapêuticos ocupacionais realizados no Hospital do Servidor Público Estadual de São Paulo "Francisco Morato de Oliveira" (HSPE-FMO. Partindo dos estudos acerca da Psicopatologia do Trabalho de Christophe Dejours, do trabalho docente e do relato de um caso clínico, caracteriza a problemática do sofrimento no trabalho, os sistemas de defesa contra este sofrimento, a ameaça à subjetividade do próprio trabalhador, as representações e conflitos vivenciados no trabalho docente, bem como a relação aditiva estabelecida como uma estratégia inconsciente de sobrevivência psíquica.

  14. ExoU-induced vascular hyperpermeability and platelet activation in the course of experimental Pseudomonas aeruginosa pneumosepsis.

    Science.gov (United States)

    Machado, Gloria-Beatriz S; de Assis, Maria-Cristina; Leão, Robson; Saliba, Alessandra M; Silva, Mauricio C A; Suassuna, Jose H; de Oliveira, Albanita V; Plotkowski, Maria-Cristina

    2010-03-01

    To address the question whether ExoU, a Pseudomonas aeruginosa cytotoxin with phospholipase A2 activity, can induce hemostatic abnormalities during the course of pneumosepsis, mice were instilled i.t. with the ExoU-producing PA103 P. aeruginosa or with a mutant obtained by deletion of the exoU gene. Control animals were instilled with sterile vehicle. To assess the role of ExoU in animal survival, mice were evaluated for 72 h. In all the other experiments, animals were studied at 24 h after infection. PA103-infected mice showed significantly higher mortality rate, lower blood leukocyte concentration, and higher platelet concentration and hematocrit than animals infected with the bacterial mutant, as well as evidences of increased vascular permeability and plasma leakage, which were confirmed by our finding of higher protein concentration in bronchoalveolar lavage fluids and by the Evans blue dye assay. Platelets from PA103-infected mice demonstrated features of activation, assessed by the flow cytometric detection of higher percentage of P-selectin expression and of platelet-derived microparticles as well as by the enzyme immunoassay detection of increased thromboxane A2 concentration in animal plasma. Histopathology of lung and kidney sections from PA103-infected mice exhibited evidences of thrombus formation that were not detected in sections of animals from the other groups. Our results demonstrate the ability of ExoU to induce vascular hyperpermeability, platelet activation, and thrombus formation during P. aeruginosa pneumosepsis, and we speculate that this ability may contribute to the reported poor outcome of patients with severe infection by ExoU-producing P. aeruginosa.

  15. KAJIAN INDUCED PLURIPOTENT STEMCELL (iPS (HARAPAN DAN TANTANGAN

    Directory of Open Access Journals (Sweden)

    Masagus Zainuri

    2014-05-01

    Full Text Available AbstractInduced Pluripotent Stemcell (iPS are adult cells which the genetic information in the nucleus of those cells being reprogrammed (reprogram by inserting exogenous pluripotential genes. The exogenous gene transduction is using vectors, such as lentivirus, retrovirus, or adenovirus, which suppressed the gene expression of the original cells, so they will express the transduced exogenous gene. Viral vectors are then used to reprogramming and producing iPS clones that are pluripotent. iPS derived from adult cells of patient with certain diseases will be used as a tool to study the mechanisms of those specific diseases and the effects of selected drugs against the diseases. Several previous studies have shown that iPS clones developed from specific genetic disease have its original genotype and retain the character of the response to the drug that similar as the original adult cells. Opportunities for the utilization of autologous iPS cell therapy in the future is wide open as expected iPS transplant will not be rejected when transplanted back to the patient. Behind all its potential, iPS production is still facing some problems to be applicable clinically. The use of viruses as vectors may cause problems due to virus gene sequences may be integrated into the genome of the DNA donor cell, thereby causing mutations of the iPS clones. Several subsequent studies have succeeded in replacing the use of viruses as vectors, but the level of efficiency obtained is still very low. Another problem that arises is that epigenetic changes may occur in iPS cultures. Many advanced research related to iPS may be developed in Indonesia and is necessary to improve the production efficiency of iPS and solve iPS clones epigenetic changes problems in the future.Keywords: iPS, pluripotency, transduction, transfection.AbstrakInduced Pluripotent Stemcell (iPS adalah sel somatic dewasa yang informasi genetika dalam inti selnyadiprogram ulang (reprogram dengan cara

  16. Reconstruction of the metabolic network of Pseudomonas aeruginosa to interrogate virulence factor synthesis

    Science.gov (United States)

    Bartell, Jennifer A.; Blazier, Anna S.; Yen, Phillip; Thøgersen, Juliane C.; Jelsbak, Lars; Goldberg, Joanna B.; Papin, Jason A.

    2017-03-01

    Virulence-linked pathways in opportunistic pathogens are putative therapeutic targets that may be associated with less potential for resistance than targets in growth-essential pathways. However, efficacy of virulence-linked targets may be affected by the contribution of virulence-related genes to metabolism. We evaluate the complex interrelationships between growth and virulence-linked pathways using a genome-scale metabolic network reconstruction of Pseudomonas aeruginosa strain PA14 and an updated, expanded reconstruction of P. aeruginosa strain PAO1. The PA14 reconstruction accounts for the activity of 112 virulence-linked genes and virulence factor synthesis pathways that produce 17 unique compounds. We integrate eight published genome-scale mutant screens to validate gene essentiality predictions in rich media, contextualize intra-screen discrepancies and evaluate virulence-linked gene distribution across essentiality datasets. Computational screening further elucidates interconnectivity between inhibition of virulence factor synthesis and growth. Successful validation of selected gene perturbations using PA14 transposon mutants demonstrates the utility of model-driven screening of therapeutic targets.

  17. Comparison of molecular species of various transphosphatidylated phosphatidylserine (PS) with bovine cortex PS by mass spectrometry

    NARCIS (Netherlands)

    Chen, S.; Li, K.W.

    2008-01-01

    The exogenous introduction of a molecular species mixture of bovine cortex phosphatidylserine (BC-PS) has been claimed to improve memory function in subjects suffering from age-associated memory impairment and dementia. However, it has been also reported that oral administration of another molecular

  18. Cholesterol oxidase with high catalytic activity from Pseudomonas aeruginosa: Screening, molecular genetic analysis, expression and characterization.

    Science.gov (United States)

    Doukyu, Noriyuki; Nihei, Shyou

    2015-07-01

    An extracellular cholesterol oxidase producer, Pseudomonas aeruginosa strain PA157, was isolated by a screening method to detect 6β-hydroperoxycholest-4-en-3-one-forming cholesterol oxidase. On the basis of a putative cholesterol oxidase gene sequence in the genome sequence data of P. aeruginosa strain PAO1, the cholesterol oxidase gene from strain PA157 was cloned. The mature form of the enzyme was overexpressed in Escherichia coli cells. The overexpressed enzyme formed inclusion bodies in recombinant E. coli cells grown at 20 °C and 30 °C. A soluble and active PA157 enzyme was obtained when the recombinant cells were grown at 10 °C. The purified enzyme was stable at pH 5.5 to 10 and was most active at pH 7.5-8.0, showing optimal activity at pH 7.0 and 70 °C. The enzyme retained about 90% of its activity after incubation for 30 min at 70 °C. The enzyme oxidized 3β-hydroxysteroids such as cholesterol, β-cholestanol, and β-sitosterol at high rates. The Km value and Vmax value for the cholesterol were 92.6 μM and 15.9 μmol/min/mg of protein, respectively. The Vmax value of the enzyme was higher than those of commercially available cholesterol oxidases. This is the first report to characterize a cholesterol oxidase from P. aeruginosa. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  19. Strain-dependent induction of neutrophil histamine production and cell death by Pseudomonas aeruginosa

    Science.gov (United States)

    Xu, Xiang; Zhang, Hong; Song, Yuanlin; Lynch, Susan V.; Lowell, Clifford A.; Wiener-Kronish, Jeanine P.; Caughey, George H.

    2012-01-01

    Airway diseases often feature persistent neutrophilic inflammation and infection. In cystic fibrosis bronchitis, for example, Pseudomonas aeruginosa is isolated frequently. Previously, this laboratory revealed that neutrophils become major sources of histamine in mice with tracheobronchitis caused by the wall-less bacterium Mycoplasma pulmonis. To test the hypothesis that more-broadly pathogenic P. aeruginosa (which expresses cell wall-associated LPS and novel toxins) has similar effects, we incubated naïve mouse neutrophils with two strains of P. aeruginosa. Strain PAO1 greatly increased neutrophil histamine content and secretion, whereas strain PA103 depressed histamine production by killing neutrophils. The histamine-stimulating capacity of PAO1, but not PA103-mediated toxicity, persisted in heat-killed organisms. In PAO1-infected mice, lung and neutrophil histamine content increased. However, PAO1 did not alter production by mast cells (classical histamine reservoirs), which also resisted PA103 toxicity. To explore mechanisms of neutrophil-selective induction, we measured changes in mRNA encoding histidine decarboxylase (rate-limiting for histamine synthesis), probed involvement of endotoxin-TLR pathways in Myd88-deficient neutrophils, and examined contributions of pyocyanin and exotoxins. Results revealed that PAO1 increased histamine production by up-regulating histidine decarboxylase mRNA via pathways largely independent of TLR, pyocyanin, and type III secretion system exotoxins. PAO1 also increased histidine decarboxylase mRNA in neutrophils purified from infected lung. Stimulation required direct contact with neutrophils and was blocked by phagocytosis inhibitor cytochalasin D. In summary, Pseudomonas-augmented histamine production by neutrophils is strain-dependent in vitro and likely mediated by up-regulation of histidine decarboxylase. These findings raise the possibility that Pseudomonas-stimulated neutrophils can enhance airway inflammation by

  20. Dissection of the cis-2-decenoic acid signaling network in Pseudomonas aeruginosa using microarray technique

    Directory of Open Access Journals (Sweden)

    Azadeh eRahmani-Badi

    2015-04-01

    Full Text Available Many bacterial pathogens use quorum-sensing (QS signaling to regulate the expression of factors contributing to virulence and persistence. Bacteria produce signals of different chemical classes. The signal molecule, known as diffusible signal factor (DSF, is a cis-unsaturated fatty acid that was first described in the plant pathogen Xanthomonas campestris. Previous works have shown that human pathogen, Pseudomonas aeruginosa, also synthesizes a structurally related molecule, characterized as cis-2-decenoic acid (C10: Δ2, CDA that induces biofilm dispersal by multiple types of bacteria. Furthermore, CDA has been shown to be involved in inter-kingdom signaling that modulates fungal behavior. Therefore, an understanding of its signaling mechanism could suggest strategies for interference, with consequences for disease control. To identify the components of CDA signaling pathway in this pathogen, a comparative transcritpome analysis was conducted, in the presence and absence of CDA. A protein-protein interaction (PPI network for differentially expressed (DE genes with known function was then constructed by STRING and Cytoscape. In addition, the effects of CDA in combination with antimicrobial agents on the biofilm surface area and bacteria viability were evaluated using fluorescence microscopy and digital image analysis. Microarray analysis identified 666 differentially expressed genes in the presence of CDA and gene ontology (GO analysis revealed that in P. aeruginosa, CDA mediates dispersion of biofilms through signaling pathways, including enhanced motility, virulence as well as persistence at different temperatures. PPI data suggested that a cluster of five genes (PA4978, PA4979, PA4980, PA4982, PA4983 is involved in the CDA synthesis and perception. Combined treatments using both CDA and antimicrobial agents showed that following exposure of the biofilms to CDA, remaining cells on the surface were easily removed and killed by antimicrobials.

  1. PS main supply: motor-generator set.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    In picture 04 the motor is on the right in the background and the main view is of the generator. The peak power in each PS cycle drawn from the generator, up to 96 MW, is taken from the rotational kinetic energy of the rotor (a heavy-weight of 80 tons), which makes the rotational speed drop by only a few percent. The motor replenishes the average power of 2 to 4 MW. Photo 05: The motor-generator set is serviced every year and, in particular, bearings and slip-rings are carefully checked. To the left is the motor with its slip-rings visible. It has been detached from the axle and moved to the side, so that the rotor can be removed from the huge generator, looming at the right.

  2. Antimicrobial potentials of Helicteres isora silver nanoparticles against extensively drug-resistant (XDR) clinical isolates of Pseudomonas aeruginosa.

    Science.gov (United States)

    Mapara, Nikunj; Sharma, Mansi; Shriram, Varsha; Bharadwaj, Renu; Mohite, K C; Kumar, Vinay

    2015-12-01

    Pseudomonas aeruginosa is a leading opportunistic pathogen and its expanding drug resistance is a growing menace to public health. Its ubiquitous nature and multiple resistance mechanisms make it a difficult target for antimicrobial chemotherapy and require a fresh approach for developing new antimicrobial agents against it. The broad-spectrum antibacterial effects of silver nanoparticles (SNPs) make them an excellent candidate for use in the medical field. However, attempts made to check their potency against extensively drug-resistant (XDR) microbes are meager. This study describes the biosynthesis and biostabilization of SNPs by Helicteres isora aqueous fruit extract and their characterization by ultraviolet-visible spectroscopy, transmission electron microscopy, dynamic light scattering, X-ray diffraction, and Fourier transform infrared spectroscopy. Majority of SNPs synthesized were of 8--20-nm size. SNPs exhibited dose-dependent antibacterial activities against four XDR P. aeruginosa (XDR-PA) clinical isolates as revealed by growth curves, with a minimum inhibitory concentration of 300 μg/ml. The SNPs exhibited antimicrobial activity against all strains, with maximum zone of inhibition (16.4 mm) in XRD-PA-2 at 1000 μg/ml. Amongst four strains, their susceptibilities to SNPs were in the following order: XDR-PA-2 > XDR-PA-4 > XDR-PA-3 > XDR-PA-1. The exposure of bacterial cells to 300 μg/ml SNPs resulted into a substantial leakage of reducing sugars and proteins, inactivation of respiratory chain dehydrogenases, and eventual cell death. SNPs also induced lipid peroxidation, a possible underlying factor to membrane porosity. The effects were more pronounced in XDR-PA-2 which may be correlated with its higher susceptibility to SNPs. These results are indicative of SNP-induced turbulence of membranous permeability as an important causal factor in XDR-PA growth inhibition and death.

  3. Pseudomonas aeruginosa Dose-Response and Bathing Water Infection

    Science.gov (United States)

    Pseudomonas aeruginosa is the most commonly identified opportunistic pathogen associated with pool acquired bather disease. To better understand why this microorganism poses this protracted problem we recently appraised P. aeruginosa pool risk management. Much is known about the ...

  4. Alginate overproduction affects Pseudomonas aeruginosa biofilm structure and function

    DEFF Research Database (Denmark)

    Hentzer, Morten; Teitzel, G.M.; Balzer, G.J.

    2001-01-01

    During the course of chronic cystic fibrosis (CF) infections, Pseudomonas aeruginosa undergoes a conversion to a mucoid phenotype, which is characterized by overproduction of the exopolysaccharide alginate. Chronic P. aeruginosa infections involve surface-attached, highly antibiotic-resistant com...

  5. Pseudomonas aeruginosa pyocyanin modulates mucin glycosylation with sialyl-Lewis(x) to increase binding to airway epithelial cells.

    Science.gov (United States)

    Jeffries, Jayme L; Jia, Jing; Choi, Woosuk; Choe, Shawn; Miao, Jinfeng; Xu, Ying; Powell, Rebecca; Lin, Jingjun; Kuang, Zhizhou; Gaskins, H Rex; Lau, Gee W

    2016-07-01

    Cystic fibrosis (CF) patients battle life-long pulmonary infections with the respiratory pathogen Pseudomonas aeruginosa (PA). An overabundance of mucus in CF airways provides a favorable niche for PA growth. When compared with that of non-CF individuals, mucus of CF airways is enriched in sialyl-Lewis(x), a preferred binding receptor for PA. Notably, the levels of sialyl-Lewis(x) directly correlate with infection severity in CF patients. However, the mechanism by which PA causes increased sialylation remains uncharacterized. In this study, we examined the ability of PA virulence factors to modulate sialyl-Lewis(x) modification in airway mucins. We found pyocyanin (PCN) to be a potent inducer of sialyl-Lewis(x) in both mouse airways and in primary and immortalized CF and non-CF human airway epithelial cells. PCN increased the expression of C2/4GnT and ST3Gal-IV, two of the glycosyltransferases responsible for the stepwise biosynthesis of sialyl-Lewis(x), through a tumor necrosis factor (TNF)-α-mediated phosphoinositol-specific phospholipase C (PI-PLC)-dependent pathway. Furthermore, PA bound more efficiently to airway epithelial cells pre-exposed to PCN in a flagellar cap-dependent manner. Importantly, antibodies against sialyl-Lewis(x) and anti-TNF-α attenuated PA binding. These results indicate that PA secretes PCN to induce a favorable environment for chronic colonization of CF lungs by increasing the glycosylation of airway mucins with sialyl-Lewis(x).

  6. Vaccines for preventing infection with Pseudomonas aeruginosa in cystic fibrosis

    DEFF Research Database (Denmark)

    Johansen, Helle Krogh; Gøtzsche, Peter C

    2013-01-01

    Chronic pulmonary infection in cystic fibrosis results in progressive lung damage. Once colonisation of the lungs with Pseudomonas aeruginosa occurs, it is almost impossible to eradicate. Vaccines, aimed at reducing infection with Pseudomonas aeruginosa, have been developed.......Chronic pulmonary infection in cystic fibrosis results in progressive lung damage. Once colonisation of the lungs with Pseudomonas aeruginosa occurs, it is almost impossible to eradicate. Vaccines, aimed at reducing infection with Pseudomonas aeruginosa, have been developed....

  7. Complement activation by Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Jensen, E T; Kharazmi, A; Garred, P

    1993-01-01

    In chronic infections, such as the bronchopulmonary Pseudomonas aeruginosa infection in cystic fibrosis (CF) patients, bacteria persist despite an intact host immune defense and frequent antibiotic treatment. An important reason for the persistence of the bacteria is their capacity for the biofilm...... mode of growth. In this study we investigated the role of biofilms in activation of complement, a major contributor to the inflammatory process. Complement activation by P. aeruginosa was examined in a complement consumption assay, production of C3 and factor B conversion products assessed by crossed...... immuno-electrophoresis, C5a generation tested by a PMN chemotactic assay, and terminal complement complex formation measured by ELISA. Two of the four assays showed that P. aeruginosa grown in biofilm activated complement less than planktonic bacteria, and all assays showed that activation by intact...

  8. Cooperative production of siderophores by Pseudomonas aeruginosa.

    Science.gov (United States)

    Harrison, Freya; Buckling, Angus

    2009-01-01

    The production of iron-scavenging siderophores by the opportunistic animal pathogen Pseudomonas aeruginosa is a textbook example of public goods cooperation. This trait provides an excellent model system with which to study cooperation. Further, the links between siderophore production and P. aeruginosa virulence allow us to investigate how pathogen ecology, social behaviour and pathology might be connected. We present here the results of basic research on the evolution and ecology of siderophore cooperation in this species. In particular, we explore the effects of population and community structure, iron regime and genomic mutation rate on the relative success of siderophore cooperators and cheats. We also present preliminary data on the links between siderophore production and another clinically-relevant social trait, biofilm formation. It is our hope that more realistic laboratory studies of siderophore cooperation in P. aeruginosa will eventually cast light on the roles played by social traits in long-term microbial infections.

  9. The MSHA strain of Pseudomonas aeruginosa activated TLR pathway and enhanced HIV-1 DNA vaccine immunoreactivity.

    Directory of Open Access Journals (Sweden)

    Jue Hou

    Full Text Available The mannose-sensitive hemagglutination pilus strain of Pseudomonas aeruginosa (PA-MSHA has been shown to trigger naïve immune responses through the activation of monocytes, macrophages, natural killer cells (NK cells and antigen presenting cells (APCs. Based on the hypothesis that PA-MSHA activates natural immunity through the Toll-like receptor (TLR pathway, we scanned several critical TLR pathway molecules in mouse splenocytes using high-throughput real-time QRT-PCR and co-stimulatory molecule in bone marrow-derived dendritic cells (BMDCs following in vitro stimulation by PA-MSHA. PA-MSHA enabled activation of the TLR pathway mediated by NF-κB and JNK signaling in splenocytes, and the co-stimulatory molecule CD86 was up-regulated in BMDCs. We then assessed the adjuvant effect of PA-MSHA for HIV-1 DNA vaccines. In comparison to DNA inoculation alone, co-inoculation with low dosage of PA-MSHA enhanced specific immunoreactivity against HIV-1 Env in both cellular and humoral responses, and promoted antibody avidity maturation. However, high doses of adjuvant resulted in an immunosuppressive effect; a two- or three-inoculation regimen yielded low antibody responses and the two-inoculation regimen exhibited only a slight cellular immunity response. To our knowledge, this is the first report demonstrating the utility of PA-MSHA as an adjuvant to a DNA vaccine. Further research is needed to investigate the exact mechanisms through which PA-MSHA achieves its adjuvant effects on innate immune responses, especially on dendritic cells.

  10. Airway epithelial cell tolerance to Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Verghese Margrith W

    2005-04-01

    Full Text Available Abstract Background The respiratory tract epithelium is a critical environmental interface that regulates inflammation. In chronic infectious airway diseases, pathogens may permanently colonize normally sterile luminal environments. Host-pathogen interactions determine the intensity of inflammation and thus, rates of tissue injury. Although many cells become refractory to stimulation by pathogen products, it is unknown whether the airway epithelium becomes either tolerant or hypersensitive in the setting of chronic infection. Our goals were to characterize the response of well-differentiated primary human tracheobronchial epithelial cells to Pseudomonas aeruginosa, to understand whether repeated exposure induced tolerance and, if so, to explore the mechanism(s. Methods The apical surface of well-differentiated primary human tracheobronchial epithelial cell cultures was repetitively challenged with Pseudomonas aeruginosa culture filtrates or the bacterial media control. Toxicity, cytokine production, signal transduction events and specific effects of dominant negative forms of signaling molecules were examined. Additional experiments included using IL-1β and TNFα as challenge agents, and performing comparative studies with a novel airway epithelial cell line. Results An initial challenge of the apical surface of polarized human airway epithelial cells with Pseudomonas aeruginosa culture filtrates induced phosphorylation of IRAK1, JNK, p38, and ERK, caused degradation of IκBα, generation of NF-κB and AP-1 transcription factor activity, and resulted in IL-8 secretion, consistent with activation of the Toll-like receptor signal transduction pathway. These responses were strongly attenuated following a second Pseudomonas aeruginosa, or IL-1β, but not TNFα, challenge. Tolerance was associated with decreased IRAK1 protein content and kinase activity and dominant negative IRAK1 inhibited Pseudomonas aeruginosa -stimulated NF-κB transcriptional

  11. PS: A nonprocedural language with data types and modules

    Science.gov (United States)

    Gokhale, M. B.

    1986-01-01

    The Problem Specification (PS) nonprocedural language is a very high level language for algorithm specification. PS is suitable for nonprogrammers, who can specify a problem using mathematically-oriented equations; for expert programmers, who can prototype different versions of a software system for evaluation; and for those who wish to use specifications for portions (if not all) of a program. PS has data types and modules similar to Modula-2. The compiler generates C code. PS is first shown by example, and then efficiency issues in scheduling and code generation are discussed.

  12. Distinct iPS Cells Show Different Cardiac Differentiation Efficiency.

    Science.gov (United States)

    Ohno, Yohei; Yuasa, Shinsuke; Egashira, Toru; Seki, Tomohisa; Hashimoto, Hisayuki; Tohyama, Shugo; Saito, Yuki; Kunitomi, Akira; Shimoji, Kenichiro; Onizuka, Takeshi; Kageyama, Toshimi; Yae, Kojiro; Tanaka, Tomofumi; Kaneda, Ruri; Hattori, Fumiyuki; Murata, Mitsushige; Kimura, Kensuke; Fukuda, Keiichi

    2013-01-01

    Patient-specific induced pluripotent stem (iPS) cells can be generated by introducing transcription factors that are highly expressed in embryonic stem (ES) cells into somatic cells. This opens up new possibilities for cell transplantation-based regenerative medicine by overcoming the ethical issues and immunological problems associated with ES cells. Despite the development of various methods for the generation of iPS cells that have resulted in increased efficiency, safety, and general versatility, it remains unknown which types of iPS cells are suitable for clinical use. Therefore, the aims of the present study were to assess (1) the differentiation potential, time course, and efficiency of different types of iPS cell lines to differentiate into cardiomyocytes in vitro and (2) the properties of the iPS cell-derived cardiomyocytes. We found that high-quality iPS cells exhibited better cardiomyocyte differentiation in terms of the time course and efficiency of differentiation than low-quality iPS cells, which hardly ever differentiated into cardiomyocytes. Because of the different properties of the various iPS cell lines such as cardiac differentiation efficiency and potential safety hazards, newly established iPS cell lines must be characterized prior to their use in cardiac regenerative medicine.

  13. Two isoforms of Clp peptidase in Pseudomonas aeruginosa control distinct aspects of cellular physiology.

    Science.gov (United States)

    Hall, Branwen M; Breidenstein, Elena B M; de la Fuente-Núñez, César; Reffuveille, Fany; Mawla, Gina D; Hancock, Robert E W; Baker, Tania A

    2016-11-14

    Caseinolytic peptidases (ClpPs) regulate diverse aspects of cellular physiology in bacteria. Some species have multiple ClpPs including opportunistic pathogen Pseudomonas aeruginosa in which there is an archetypical isoform, ClpP1, and a second isoform, ClpP2, about which little is known. Here we use phenotypic assays to investigate biological roles of ClpP1 and ClpP2 and biochemical assays to characterize purified ClpP1, ClpP2, ClpX and ClpA. Interestingly ClpP1 and ClpP2 have distinct intracellular roles for motility, pigment production, iron scavenging and biofilm formation. Of particular interest ClpP2, but not ClpP1, is required for microcolony organization, where multicellular, organized structures first form on the pathway to biofilm production. We found that purified ClpP1, with ClpX or ClpA was enzymatically active, yet to our surprise ClpP2 was inactive and not fully assembled in vitro; attempts to assist ClpP2 assembly and activation by mixing with the other Clp components failed to turn on ClpP2, as did solution conditions that have helped activate other ClpPs in vitro We postulate that the active form of ClpP2 has yet to be discovered and present several potential models to explain its activation as well as the unique role ClpP2 plays in development of the clinically important biofilms in P. aeruginosa IMPORTANCE: Pseudomonas aeruginosa is responsible for severe infections of immunocompromised patients. Our work demonstrates that two different isoforms of Clp peptidase, ClpP1 and ClpP2, control distinct aspects of cellular physiology for this organism. In particular, we identify ClpP2 as necessary for microcolony organization. Pure, active forms of ClpP1 and either ClpX, or ClpA were characterized as assembled and active, ClpP2 was incompletely assembled and inactive. By establishing both the unique biological roles of ClpP1 and ClpP2 and their initial biochemical assemblies, we set the stage for important future work on the structure, function and

  14. Pseudomonas aeruginosa Reduces VX-809 Stimulated F508del-CFTR Chloride Secretion by Airway Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Bruce A Stanton

    Full Text Available P. aeruginosa is an opportunistic pathogen that chronically infects the lungs of 85% of adult patients with Cystic Fibrosis (CF. Previously, we demonstrated that P. aeruginosa reduced wt-CFTR Cl secretion by airway epithelial cells. Recently, a new investigational drug VX-809 has been shown to increase F508del-CFTR Cl secretion in human bronchial epithelial (HBE cells, and, in combination with VX-770, to increase FEV1 (forced expiratory volume in 1 second by an average of 3-5% in CF patients homozygous for the F508del-CFTR mutation. We propose that P. aeruginosa infection of CF lungs reduces VX-809 + VX-770- stimulated F508del-CFTR Cl secretion, and thereby reduces the clinical efficacy of VX-809 + VX-770.F508del-CFBE cells and primary cultures of CF-HBE cells (F508del/F508del were exposed to VX-809 alone or a combination of VX-809 + VX-770 for 48 hours and the effect of P. aeruginosa on F508del-CFTR Cl secretion was measured in Ussing chambers. The effect of VX-809 on F508del-CFTR abundance was measured by cell surface biotinylation and western blot analysis. PAO1, PA14, PAK and 6 clinical isolates of P. aeruginosa (3 mucoid and 3 non-mucoid significantly reduced drug stimulated F508del-CFTR Cl secretion, and plasma membrane F508del-CFTR.The observation that P. aeruginosa reduces VX-809 and VX-809 + VX-770 stimulated F508del CFTR Cl secretion may explain, in part, why VX-809 + VX-770 has modest efficacy in clinical trials.

  15. LEADIR-PS: providing unprecedented SMR safety and economics

    Energy Technology Data Exchange (ETDEWEB)

    Hart, R.S., E-mail: N2i2@xplornet.ca [Northern Nuclear Industries Incorporated, Cambridge, ON (Canada)

    2015-07-01

    Northern Nuclear Industries Incorporated (N{sup 2} I{sup 2}) is developing Small Modular Reactors (SMRs) called LEADIR-PS, an acronym for LEAD-cooled Integral Reactor-Passively Safe. LEADIR-PS integrates proven technologies including TRISO fuel, Pebble Bed core and graphite moderator, with molten lead coolant in an integral pool type reactor configuration to achieve unprecedented safety and economics. Plants under development are LEADIR-PS30, producing 30 MWth, LEADIR-PS100 producing 100 MWth and LEADIR-PS300 producing 300 MWth that are focused on serving the energy demands of areas with a small electrical grid and/or process heat applications. A plant consisting of six LEADIR-PS300 reactor modules serving a common turbine-generator, called the LEADIR-PS Six-Pack, is focused on serving areas with higher energy demands and a robust electricity grid. The Gen{sup +} I LEADIR-PS plants are inherently/passively safe. There is no potential for a Loss Of Coolant Accident, a reactivity transient without shutdown, a loss of heat sink, or hydrogen generation. No active systems or operator actions are required to assure safety. The unprecedented safety of LEADIR-PS reactors avoids large exclusion radius and demanding evacuation plan requirements. LEADIR-PS, with steam conditions of 370 {sup o}C and 12 MPa can serve over 85% of the world's non-transportation process heat demands. In Canada, the electricity and process heat demands, ranging from those of remote communities and the oil sands to densely populated areas can be served by LEADIR-PS. (author)

  16. Redundant phenazine operons in Pseudomonas aeruginosa exhibit environment-dependent expression and differential roles in pathogenicity.

    Science.gov (United States)

    Recinos, David A; Sekedat, Matthew D; Hernandez, Adriana; Cohen, Taylor Sitarik; Sakhtah, Hassan; Prince, Alice S; Price-Whelan, Alexa; Dietrich, Lars E P

    2012-11-20

    Evolutionary biologists have postulated that several fitness advantages may be conferred by the maintenance of duplicate genes, including environmental adaptation resulting from differential regulation. We examined the expression and physiological contributions of two redundant operons in the adaptable bacterium Pseudomonas aeruginosa PA14. These operons, phzA1-G1 (phz1) and phzA2-G2 (phz2), encode nearly identical sets of proteins that catalyze the synthesis of phenazine-1-carboxylic acid, the precursor for several phenazine derivatives. Phenazines perform diverse roles in P. aeruginosa physiology and act as virulence factors during opportunistic infections of plant and animal hosts. Although reports have indicated that phz1 is regulated by the Pseudomonas quinolone signal, factors controlling phz2 expression have not been identified, and the relative contributions of these redundant operons to phenazine biosynthesis have not been evaluated. We found that in liquid cultures, phz1 was expressed at higher levels than phz2, although phz2 showed a greater contribution to phenazine production. In colony biofilms, phz2 was expressed at high levels, whereas phz1 expression was not detectable, and phz2 was responsible for virtually all phenazine production. Analysis of mutants defective in quinolone signal synthesis revealed a critical role for 4-hydroxy-2-heptylquinoline in phz2 induction. Finally, deletion of phz2, but not of phz1, decreased lung colonization in a murine model of infection. These results suggest that differential regulation of the redundant phz operons allows P. aeruginosa to adapt to diverse environments.

  17. Pseudomonas aeruginosa. Vacunas: un reto a la investigación

    Directory of Open Access Journals (Sweden)

    Sara C. Esnard

    2004-04-01

    Full Text Available Pseudomonas aeruginosa, patógeno gramnegativo versátil y oportunista debido a su gran adaptabilidad fisiológica, potencial metabólico y mecanismos de virulencia, es causa frecuente a escala mundial de severas o letales infecciones en pacientes hospitalizados. El empeño por lograr terapias alternativas para prevenir o combatir las infecciones producidas por P. aeruginosa ha ocupado a investigadores de todo el mundo desde la segunda mitad del pasado siglo y actualmente se continúan reportando trabajos que respaldan los ensayos de candidatos vacunales, fundamentalmente a partir de antígenos proteicos, mayoritariamente basados en la construcción de vacunas recombinantes. En este artículo se presenta una revisión de trabajos publicados sobre las investigaciones desarrolladas en diferentes países, con el objetivo de obtener candidatos vacunales para la prevención o tratamiento de las infecciones causadas por Pseudomonas aeruginosa, a partir de la década de los años 50 del siglo XX hasta el 2003.

  18. The HARP detector at the CERN PS

    CERN Document Server

    Catanesi, M G; Radicioni, E; Simone, S; Edgecock, R; Ellis, M; Robbins, S; Soler, F J P; Gößling, C; Mass, M; Bunyatov, S; Chukanov, A; Klimov, O; Krasin, I; Krasnoperov, A; Kustov, D; Popov, B; Serdiouk, V; Tereshchenko, V; Carassiti, V; Di Capua, E; Evangelisti, F; Vidal-Sitjes, G; Artamonov, A; Arce, P; Brocard, R; Decreuse, G; Friend, B; Giani, S; Gilardoni, S; Gorbunov, p; Grant, A; Grossheim, A; Gruber, P; Ivanchenko, V; Legrand, J C; Kayis-Topaksu,A; Panman, P; Papadopoulos, I; Pasternak, J; Chernyaev, E; Tsukerman, I; van der Vlugt, R; Veenhof, R; Wiebusch, C; Zucchelli, P; Blondel, A; Borghi, S; Campanelli, M; Cervera-Villanueva, A; Morone, M C; Prior, G; Schroeter, R; Kato, I; Gastaldi, Ugo; Mills, G B; Graulich, J S; Grégoire, G; Bonesini, M; Chignoli, F; Ferri, F; Paleari, F; Kirsanov, M; Postoev, V; Bagulya A; Grichine, V; Polukhina, N; Palladino, V; Coney, L; Schmitz, D; Barr, G; De Santo, A; Pattison, C; Zuber, K; Barichello, G; Bobisut, F; Gibin, D; Guglielmi, A; Laveder, M; Menegolli, A; Mezzetto M; Pepato, Adriano; Dumarchez, J; Troquereau, S; Vannucci, F; Dore, U; Iaciofano, A; Lobello, M; Marinilli, F; Orestano, D; Panayotov, D; Pasquali, M; Pastore, F; Tonazzo, A; Tortora, L; Booth, C; Buttar, C; Hodgson, P; Howlett, L; Nicholson, R; Bogomilovw, M; Burin, K; Chizhov, M; Kolev, D; Petev, P; Rusinov, I; Tsenov, R; Piperov, S; Temnikov, P; Apollonio, M; Chimenti, P; Giannini, G; Santin, G; Burguet-Castell, J; Gómez-Cadenas, J J; Novella, P; Sorel, M; Tornero, A

    2007-01-01

    HARP is a high-statistics, large solid angle experiment to measure hadron production using proton and pion beams with momenta between 1.5 and 15 GeV/c impinging on many different solid and liquid targets from low to high Z. The experiment, located in the T9 beam of the CERN PS, took data in 2001 and 2002. For the measurement of momenta of produced particles and for the identification of particle types, the experiment includes a large-angle spectrometer, based on a Time Projection Chamber and a system of Resistive Plate Chambers, and a forward spectrometer equipped with a set of large drift chambers, a threshold Cherenkov detector, a time-of-flight wall and an electromagnetic calorimeter. The large angle system uses a solenoidal magnet, while the forward spectrometer is based on a dipole magnet. Redundancy in particle identification has been sought, to enable the cross-calibration of efficiencies and to obtain a few percent overall accuracy in the cross-section measurements. Detector construction, operation an...

  19. Antibiotics Susceptibility Pattern of Pseudomonas aeruginosa ...

    African Journals Online (AJOL)

    ABSTRACT: This work investigated the prevalence and antibiotics sensitivity of Pseudomonas aeruginosa isolated from wounds of patients attending Ahmadu Bello University Teaching Hospital (ABUTH), Zaria-Nigeria. One hundred Isolates were characterized and identified from the specimens using standard ...

  20. Characterization of drug resistant Pseudomonas aeruginosa and ...

    African Journals Online (AJOL)

    Despite the fact that they remain asymptomatic in many cases, they nevertheless play significant roles in the epidemiology of these pathogens through their dissemination to the public, sometimes through the food chain. Four multidrug resistant Gram negative pathogens including: 2 Pseudomonas aeruginosa and 2 Proteus ...

  1. Standardized chemical synthesis of Pseudomonas aeruginosa pyocyanin

    Directory of Open Access Journals (Sweden)

    Rajkumar Cheluvappa

    2014-01-01

    As we have extracted pyocyanin both from P. aeruginosa cultures, and via chemical synthesis; we know the procedural and product-quality differences. We endorse the relative ease, safety, and convenience of using the chemical synthesis described here. Crucially, our “naturally endotoxin-free” pyocyanin can be extracted easily without using infectious bacteria.

  2. Interleaving of beam lines inside the PS tunnel

    CERN Multimedia

    1983-01-01

    View against the direction of the proton beams. The PS ring (section 26) is on the left. The injection tunnel for LEAR leaving from here has increased the trafic in this already busy area where the two Linacs and the transfer tunnel leading to the SPS, ISR and AA join the PS ring (cf. photo 7802260, 7802261, Annual Report 1981, p. 89, fig. 12).

  3. Modulation of enzymatic PS synthesis by liposome membrane composition.

    Science.gov (United States)

    Pinsolle, Alexandre; Roy, Philippe; Cansell, Maud

    2014-03-01

    Phosphatidylserine (PS) is a phospholipid known to exert important physiological roles in humans. However, this phospholipid (PL) is poorly available as a natural source and hardly produced by the chemical route. In this work, PS was obtained by transphosphatidylation using phospholipase D (PLD) and PL self-assembled into liposomes as the substrates. The aim was to better understand how the liposome membrane composition could modulate PS yield. Three lecithins were used as PL substrates, one originated from a marine source providing a high amount of n-3 polyunsaturated fatty acids, and two issued from soya differing in their phosphatidylcholine (PC) content. Different parameters such as Ca(2+) content, enzyme and L-serine concentrations modulated PS synthesis. The presence of Ca(2+) increased PS conversion yield. The alcohol acceptor (L-serine) concentration positively acted on PL conversion, by governing the equilibrium between transphosphatidylation and hydrolysis. Beside these specific reaction conditions, it was demonstrated that the membrane composition of the liposomes modulated PS synthesis. A direct correlation between PS accumulation and the amount of cholesterol or α-tocopherol incorporated into the soya lecithins was observed. This result was interpreted in terms of "head" spacers promoting PLD transphosphatidylation. On the whole, this work provided key parameters for the formulation of liposomes using enzymatic PLD technology, to produce lecithins enriched in different proportions of PS and esterified with various types of fatty acids depending on the initial lecithin source. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Spectroscopic Classification of PS16chs with SOAR/Goodman

    Science.gov (United States)

    Miller, J. A.; Hounsell, R. A.; Pan, Y.-C.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-05-01

    We report the classification of PS16chs from spectroscopic observation with the Goodman spectrograph on the SOAR telescope. The observation was made on 2016 May 08 UT. We classify PS16chs as a SN Ia near maximum light at z = 0.19.

  5. Motor-Generator powering the PS (Proton Synchrotron) main magnets

    CERN Multimedia

    1983-01-01

    This motor-generator,30 MW peak, 1500 r.p.m.,pulsed power supply for the PS main magnet replaced in 1968 the initial 3000 r.p.m. motor-generator-flywheel set which had served from the PS start-up in 1959 until end 1967. See also photo 8302337 and its abstract.

  6. Transfer line TT70 (electrons from PS to SPS)

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    As injectors for LEP, PS and SPS had to be converted to the acceleration of electrons and positrons. So far, only positively charged particles had been transferred from the PS to the SPS, for the negatively charged electrons a new transfer line, TT70, had to be built. Due to the difference in level of the two machines, the transfer line slopes and tilts.

  7. Psühhodraama - spontaansuse kool / Taimi Elenurm

    Index Scriptorium Estoniae

    Elenurm, Taimi

    2010-01-01

    Viinis ja New Yorgis tegutsenud psühhiaatri Jakob Levy Moreno loodud psühhodraamast, mis võimaldab rollimängu kaudu näha ennast läbi teiste silmade, aga ka vabaneda pingetest andes võimaluse käituda teisiti kui tavaelus

  8. [Effect on keratocyte-mediated collagen degradation by Pseudomonas aeruginosa].

    Science.gov (United States)

    Hao, J; Lu, Y; Jia, H; Liu, J; Xu, J; Zhang, R

    2000-01-01

    To study the pathogenesis of cornea melting (ulceration) by pseudomona (P) aeruginosa for instruction of clinical treatment. Type I collagen gels with or without suspended keratocytes were incubated for 24 hours under medium containing sterile P. aeruginosa culture broth. Native collagen fibrils were removed from the media by ultrafiltration. The ultrafiltrates were then hydrolyzed, and the amount of hydroxyproline was measured spectrophotometrically. The effect of a synthetic matrix metalloproteinase (MMP) inhibitor, Galardin, on collagen degradation was also examined. P. aeruginosa broth induced type I collagen gel degradation directly. In the presence of keratocytes, degradation by P. aeruginosa broth was enhanced. Galardin significantly reduced the amount of collagen degraded by P. aeruginosa culture broth, no matter keratocytes were present or not. P. aeruginosa culture broth directly degrades type I collagen and also increases keratocyte-mediated collagen degradation. The result is helpful to the clinical treatment of cornea melting caused by P. aeruginosa, and the mechanism should be further studied.

  9. Pseudomonas aeruginosa increases MUC1 expression in macrophages through the TLR4-p38 pathway.

    Science.gov (United States)

    Kato, Kosuke; Hanss, Alec D; Zemskova, Marina A; Morgan, Nicole E; Kim, Marianne; Knox, Kenneth S; Lin, Yong; Lillehoj, Erik P; Kim, Kwang Chul

    2017-10-14

    Alveolar macrophages (AMs) play a critical role in the clearance of Pseudomonas aeruginosa (Pa) from the airways. However, hyper-activation of macrophages can impair bacterial clearance and contribute to morbidity and mortality. MUC1 mucin is a membrane-tethered, high molecular mass glycoprotein expressed on the apical surface of mucosal epithelial cells and some hematopoietic cells, including macrophages, where it counter-regulates inflammation. We recently reported that Pa up-regulates the expression of MUC1 in primary human AMs and THP-1 macrophages, and that increased MUC1 expression in these cells prevents hyper-activation of macrophages that appears to be important for host defense against severe pathology of Pa lung infection. The aims of this study were to elucidate the mechanism by which Pa increases MUC1 expression in macrophages. The results showed that: (a) Pa stimulation of THP-1 macrophages increased MUC1 expression both at transcriptional and protein levels in a dose-dependent manner; (b) Both Pa- and LPS-induced MUC1 expression in THP-1 cells were significantly diminished by an inhibitory peptide of TLR4; and (c) LPS-stimulated MUC1 expression was diminished at both the mRNA and protein levels by an inhibitor of the p38 mitogen-activated protein kinase, but not by inhibitors of ERK1/2, JNK, or IKK. We conclude that Pa-stimulated MUC1 expression in THP-1 macrophages is regulated mainly through the TLR4-p38 signaling pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Biofilm Filtrates of Pseudomonas aeruginosa Strains Isolated from Cystic Fibrosis Patients Inhibit Preformed Aspergillus fumigatus Biofilms via Apoptosis.

    Science.gov (United States)

    Shirazi, Fazal; Ferreira, Jose A G; Stevens, David A; Clemons, Karl V; Kontoyiannis, Dimitrios P

    2016-01-01

    Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af) colonize cystic fibrosis (CF) patient airways. Pa culture filtrates inhibit Af biofilms, and Pa non-CF, mucoid (Muc-CF) and nonmucoid CF (NMuc-CF) isolates form an ascending inhibitory hierarchy. We hypothesized this activity is mediated through apoptosis induction. One Af and three Pa (non-CF, Muc-CF, NMuc-CF) reference isolates were studied. Af biofilm was formed in 96 well plates for 16 h ± Pa biofilm filtrates. After 24 h, apoptosis was characterized by viability dye DiBAc, reactive oxygen species (ROS) generation, mitochondrial membrane depolarization, DNA fragmentation and metacaspase activity. Muc-CF and NMuc-CF filtrates inhibited and damaged Af biofilm (pbiofilms (3.7- fold) compared to treatment with filtrates from Muc-CF- (2.5- fold) or non-CF Pa (1.7- fold). Depolarization of mitochondrial potential was greater upon exposure to NMuc-CF (2.4-fold) compared to Muc-CF (1.8-fold) or non-CF (1.25-fold) (pbiofilm, compared to control, mediated by metacaspase activation. In conclusion, filtrates from CF-Pa isolates were more inhibitory against Af biofilms than from non-CF. The apoptotic effect involves mitochondrial membrane damage associated with metacaspase activation.

  11. Valoración de salud oral en una población de disminuidos psíquicos de la provincia de Sevilla.

    OpenAIRE

    Vigo Martínez, Manuel Francisco

    1993-01-01

    Falta palabras clave La atención odontológica de los pacientes minusválidos psíquicos adultos ha sido frecuentemente subestimada. Como consecuencia de esta situación se constata la escasez de estudios valorativos en nuestro país y mucho más acusados en Andalucía, donde son prácticamente inexistentes. Por todo ello, hemos realizado el presente estudio de la valoración de la salud oral y las necesidades de tratamiento en una población de minusválidos psíquicos, referidos a tres centros asist...

  12. Successful online learning – the five Ps

    Directory of Open Access Journals (Sweden)

    Jim FLOOD

    2004-04-01

    Full Text Available Successful online learning – the five Ps Jim FLOOD E-learning Consultant-UK jimflood@btinternet.com Key learning points • An important aspect of design for online learning is visual ergonomics. • Learning theories offer poor predictive power in terms of how learners work and learn. • Success at learning is closely related to emotional engagement–and learning designers tend to ignore this aspect. • Online learning poses a challenging experience for learners–and they need support to cope with it. • A key goal to achieve Praxis – being able to put learning into practice. Many of you will be familiar with the three (or more Ps of marketing and even if not, as trainers or teachers you are likely to have used mnemonics as an aid to retention and recall. Mnemonics are especially useful when you need to get the key points to ‘stick’ in the minds of your audience. With this in mind I offer you the 5 Ps of online learning: Presentation, Pedagogy, Promotion, Preparation and Props. What I offer is not new; in fact much of it results from the eleven years of online teaching and learning at The Open University, the £22 million it has spent on research and evaluation 1, and the worldwide community that have been sharing experience in recent years. You can therefore consider these 5 Ps to be a convenient re-packing of the information and experience that can be found in abundance on the Internet. Presentation Good graphic design appeals to the subtle process by which the brain processes information and, as a result, we decide if we like the ‘look and feel’ of a visual environment. Part of liking this ‘look and feel’ is the way the text and pictorial layout can appear inviting and encouraging–a vital aspect of any online learning environment. Another aspect of presentation is how the text reads in terms of engaging the learner and introducing the story to be told–as well as being written in clear and concise English When browsing through books

  13. Comparison of the systemic inflammatory response syndrome between monomicrobial and polymicrobial Pseudomonas aeruginosa nosocomial bloodstream infections

    Directory of Open Access Journals (Sweden)

    Wenzel Richard P

    2005-10-01

    Full Text Available Abstract Background Some studies of nosocomial bloodstream infection (nBSI have demonstrated a higher mortality for polymicrobial bacteremia when compared to monomicrobial nBSI. The purpose of this study was to compare differences in systemic inflammatory response and mortality between monomicrobial and polymicrobial nBSI with Pseudomonas aeruginosa. Methods We performed a historical cohort study on 98 adults with P. aeruginosa (Pa nBSI. SIRS scores were determined 2 days prior to the first positive blood culture through 14 days afterwards. Monomicrobial (n = 77 and polymicrobial BSIs (n = 21 were compared. Results 78.6% of BSIs were caused by monomicrobial P. aeruginosa infection (MPa and 21.4% by polymicrobial P. aeruginosa infection (PPa. Median APACHE II score on the day of BSI was 22 for MPa and 23 for PPa BSIs. Septic shock occurred in 33.3% of PPa and in 39.0% of MPa (p = 0.64. Progression to septic shock was associated with death more frequently in PPa (OR 38.5, CI95 2.9–508.5 than MPa (OR 4.5, CI95 1.7–12.1. Maximal SIR (severe sepsis, septic shock or death was seen on day 0 for PPa BSI vs. day 1 for MPa. No significant difference was noted in the incidence of organ failure, 7-day or overall mortality between the two groups. Univariate analysis revealed that APACHE II score ≥20 at BSI onset, Charlson weighted comorbidity index ≥3, burn injury and respiratory, cardiovascular, renal and hematologic failure were associated with death, while age, malignant disease, diabetes mellitus, hepatic failure, gastrointestinal complications, inappropriate antimicrobial therapy, infection with imipenem resistant P. aeruginosa and polymicrobial nBSI were not. Multivariate analysis revealed that hematologic failure (p Conclusion In this historical cohort study of nBSI with P. aeruginosa, the incidence of septic shock and organ failure was high in both groups. Additionally, patients with PPa BSI were not more acutely ill, as judged by APACHE II

  14. Telomere reprogramming and maintenance in porcine iPS cells.

    Directory of Open Access Journals (Sweden)

    Guangzhen Ji

    Full Text Available Telomere reprogramming and silencing of exogenous genes have been demonstrated in mouse and human induced pluripotent stem cells (iPS cells. Pigs have the potential to provide xenotransplant for humans, and to model and test human diseases. We investigated the telomere length and maintenance in porcine iPS cells generated and cultured under various conditions. Telomere lengths vary among different porcine iPS cell lines, some with telomere elongation and maintenance, and others telomere shortening. Porcine iPS cells with sufficient telomere length maintenance show the ability to differentiate in vivo by teratoma formation test. IPS cells with short or dysfunctional telomeres exhibit reduced ability to form teratomas. Moreover, insufficient telomerase and incomplete telomere reprogramming and/or maintenance link to sustained activation of exogenous genes in porcine iPS cells. In contrast, porcine iPS cells with reduced expression of exogenous genes or partial exogene silencing exhibit insufficient activation of endogenous pluripotent genes and telomerase genes, accompanied by telomere shortening with increasing passages. Moreover, telomere doublets, telomere sister chromatid exchanges and t-circles that presumably are involved in telomere lengthening by recombination also are found in porcine iPS cells. These data suggest that both telomerase-dependent and telomerase-independent mechanisms are involved in telomere reprogramming during induction and passages of porcine iPS cells, but these are insufficient, resulting in increased telomere damage and shortening, and chromosomal instability. Active exogenes might compensate for insufficient activation of endogenous genes and incomplete telomere reprogramming and maintenance of porcine iPS cells. Further understanding of telomere reprogramming and maintenance may help improve the quality of porcine iPS cells.

  15. Telomere reprogramming and maintenance in porcine iPS cells.

    Science.gov (United States)

    Ji, Guangzhen; Ruan, Weimin; Liu, Kai; Wang, Fang; Sakellariou, Despoina; Chen, Jijun; Yang, Yang; Okuka, Maja; Han, Jianyong; Liu, Zhonghua; Lai, Liangxue; Gagos, Sarantis; Xiao, Lei; Deng, Hongkui; Li, Ning; Liu, Lin

    2013-01-01

    Telomere reprogramming and silencing of exogenous genes have been demonstrated in mouse and human induced pluripotent stem cells (iPS cells). Pigs have the potential to provide xenotransplant for humans, and to model and test human diseases. We investigated the telomere length and maintenance in porcine iPS cells generated and cultured under various conditions. Telomere lengths vary among different porcine iPS cell lines, some with telomere elongation and maintenance, and others telomere shortening. Porcine iPS cells with sufficient telomere length maintenance show the ability to differentiate in vivo by teratoma formation test. IPS cells with short or dysfunctional telomeres exhibit reduced ability to form teratomas. Moreover, insufficient telomerase and incomplete telomere reprogramming and/or maintenance link to sustained activation of exogenous genes in porcine iPS cells. In contrast, porcine iPS cells with reduced expression of exogenous genes or partial exogene silencing exhibit insufficient activation of endogenous pluripotent genes and telomerase genes, accompanied by telomere shortening with increasing passages. Moreover, telomere doublets, telomere sister chromatid exchanges and t-circles that presumably are involved in telomere lengthening by recombination also are found in porcine iPS cells. These data suggest that both telomerase-dependent and telomerase-independent mechanisms are involved in telomere reprogramming during induction and passages of porcine iPS cells, but these are insufficient, resulting in increased telomere damage and shortening, and chromosomal instability. Active exogenes might compensate for insufficient activation of endogenous genes and incomplete telomere reprogramming and maintenance of porcine iPS cells. Further understanding of telomere reprogramming and maintenance may help improve the quality of porcine iPS cells.

  16. High-Sensitivity Monoclonal Antibodies Specific for Homoserine Lactones Protect Mice from Lethal Pseudomonas aeruginosa Infections

    Science.gov (United States)

    Downham, Christina; Broadbent, Ian; Charlton, Keith; Porter, Andrew J.

    2014-01-01

    A number of bacteria, including pathogens like Pseudomonas aeruginosa, utilize homoserine lactones (HSLs) as quorum sensing (QS) signaling compounds and engage in cell-to-cell communication to coordinate their behavior. Blocking this bacterial communication may be an attractive strategy for infection control as QS takes a central role in P. aeruginosa biology. In this study, immunomodulation of HSL molecules by monoclonal antibodies (MAbs) was used as a novel approach to prevent P. aeruginosa infections and as tools to detect HSLs in bodily fluids as a possible first clue to an undiagnosed Gram-negative infection. Using sheep immunization and recombinant antibody technology, a panel of sheep-mouse chimeric MAbs were generated which recognized HSL compounds with high sensitivity (nanomolar range) and cross-reactivity. These MAbs retained their nanomolar sensitivity in complex matrices and were able to recognize HSLs in P. aeruginosa cultures grown in the presence of urine. In a nematode slow-killing assay, HSL MAbs significantly increased the survival of worms fed on the antibiotic-resistant strain PA058. The therapeutic benefit of these MAbs was further studied using a mouse model of Pseudomonas infection in which groups of mice treated with HSL-2 and HSL-4 MAbs survived, 7 days after pathogen challenge, in significantly greater numbers (83 and 67%, respectively) compared with the control groups. This body of work has provided early proof-of-concept data to demonstrate the potential of HSL-specific, monoclonal antibodies as theranostic clinical leads suitable for the diagnosis, prevention, and treatment of life-threatening bacterial infections. PMID:24185854

  17. Fitness of isogenic colony morphology variants of Pseudomonas aeruginosa in murine airway infection.

    Directory of Open Access Journals (Sweden)

    Elza Rakhimova

    Full Text Available Chronic lung infections with Pseudomonas aeruginosa are associated with the diversification of the persisting clone into niche specialists and morphotypes, a phenomenon called 'dissociative behaviour'. To explore the potential of P. aeruginosa to change its morphotype by single step loss-of-function mutagenesis, a signature-tagged mini-Tn5 plasposon library of the cystic fibrosis airway isolate TBCF10839 was screened for colony morphology variants under nine different conditions in vitro. Transposon insertion into 1% of the genome changed colony morphology into eight discernable morphotypes. Half of the 55 targets encode features of primary or secondary metabolism whereby quinolone production was frequently affected. In the other half the transposon had inserted into genes of the functional categories transport, regulation or motility/chemotaxis. To mimic dissociative behaviour of isogenic strains in lungs, pools of 25 colony morphology variants were tested for competitive fitness in an acute murine airway infection model. Six of the 55 mutants either grew better or worse in vivo than in vitro, respectively. Metabolic proficiency of the colony morphology variant was a key determinant for survival in murine airways. The most common morphotype of self-destructive autolysis did unexpectedly not impair fitness. Transposon insertions into homologous genes of strain PAO1 did not reproduce the TBCF10839 mutant morphotypes for 16 of 19 examined loci pointing to an important role of the genetic background on colony morphology. Depending on the chosen P. aeruginosa strain, functional genome scans will explore other areas of the evolutionary landscape. Based on our discordant findings of mutant phenotypes in P. aeruginosa strains PAO1, PA14 and TBCF10839, we conclude that the current focus on few reference strains may miss modes of niche adaptation and dissociative behaviour that are relevant for the microevolution of complex traits in the wild.

  18. Pseudomonas aeruginosa AES-1 exhibits increased virulence gene expression during chronic infection of cystic fibrosis lung.

    Science.gov (United States)

    Naughton, Sharna; Parker, Dane; Seemann, Torsten; Thomas, Torsten; Turnbull, Lynne; Rose, Barbara; Bye, Peter; Cordwell, Stuart; Whitchurch, Cynthia; Manos, Jim

    2011-01-01

    Pseudomonas aeruginosa, the leading cause of morbidity and mortality in people with cystic fibrosis (CF), adapts for survival in the CF lung through both mutation and gene expression changes. Frequent clonal strains such as the Australian Epidemic Strain-1 (AES-1), have increased ability to establish infection in the CF lung and to superimpose and replace infrequent clonal strains. Little is known about the factors underpinning these properties. Analysis has been hampered by lack of expression array templates containing CF-strain specific genes. We sequenced the genome of an acute infection AES-1 isolate from a CF infant (AES-1R) and constructed a non-redundant micro-array (PANarray) comprising AES-1R and seven other sequenced P. aeruginosa genomes. The unclosed AES-1R genome comprised 6.254Mbp and contained 6957 putative genes, including 338 not found in the other seven genomes. The PANarray contained 12,543 gene probe spots; comprising 12,147 P. aeruginosa gene probes, 326 quality-control probes and 70 probes for non-P. aeruginosa genes, including phage and plant genes. We grew AES-1R and its isogenic pair AES-1M, taken from the same patient 10.5 years later and not eradicated in the intervening period, in our validated artificial sputum medium (ASMDM) and used the PANarray to compare gene expression of both in duplicate. 675 genes were differentially expressed between the isogenic pairs, including upregulation of alginate, biofilm, persistence genes and virulence-related genes such as dihydroorotase, uridylate kinase and cardiolipin synthase, in AES-1M. Non-PAO1 genes upregulated in AES-1M included pathogenesis-related (PAGI-5) genes present in strains PACS2 and PA7, and numerous phage genes. Elucidation of these genes' roles could lead to targeted treatment strategies for chronically infected CF patients.

  19. Characterization of molecular mechanisms controlling fabAB transcription in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Herbert P Schweizer

    Full Text Available BACKGROUND: The FabAB pathway is one of the unsaturated fatty acid (UFA synthesis pathways for Pseudomonas aeruginosa. It was previously noted that this operon was upregulated in biofilms and repressed by exogenous UFAs. Deletion of a 30 nt fabA upstream sequence, which is conserved in P. aeruginosa, P. putida, and P. syringae, led to a significant decrease in fabA transcription, suggesting positive regulation by an unknown positive regulatory mechanism. METHODS/PRINCIPAL FINDINGS: Here, genetic and biochemical approaches were employed to identify a potential fabAB activator. Deletion of candidate genes such as PA1611 or PA1627 was performed to determine if any of these gene products act as a fabAB activator. However, none of these genes were involved in the regulation of fabAB transcription. Use of mariner-based random mutagenesis to screen for fabA activator(s showed that several genes encoding unknown functions, rpoN and DesA may be involved in fabA regulation, but probably via indirect mechanisms. Biochemical attempts performed did fail to isolate an activator of fabAB operon. CONCLUSION/SIGNIFICANCE: The data suggest that fabA expression might not be regulated by protein-binding, but by a distinct mechanism such as a regulatory RNA-based mechanism.

  20. Polyamines induce resistance to cationic peptide, aminoglycoside, and quinolone antibiotics in Pseudomonas aeruginosa PAO1.

    Science.gov (United States)

    Kwon, Dong H; Lu, Chung-Dar

    2006-05-01

    Pseudomonas aeruginosa, a gram-negative bacterium of human pathogens, is noted for its environmental versatility, enormous metabolic capacity, and resistance to antibiotics. Overexpression of the outer membrane protein OprH and increased resistance to polycationic peptide antibiotics (e.g., polymyxin B) mediated by the PhoPQ two-component system on induction of a putative lipopolysaccharide (LPS) modification operon (PA3552-PA3559) have been reported as part of the adaptive responses to magnesium limitation in P. aeruginosa. Induction of the oprH-phoPQ operon and the LPS modification operon by exogenous spermidine was revealed from GeneChip analysis during studies of polyamine metabolism and was confirmed by the lacZ fusions of affected promoters. From the results of MIC measurements, it was found that addition of spermidine or other polyamines to the growth medium increased the MIC values of multiple antibiotics, including polycationic antibiotics, aminoglycosides, quinolones, and fluorescent dyes. MIC values of these compounds in the transposon insertion mutants of oprH, phoP, phoQ, and pmrB were also determined in the presence and absence of spermidine. The results showed that the spermidine effect on cationic peptide antibiotic and quinolone resistance was diminished in the phoP mutant only. The spermidine effect on antibiotics was not influenced by magnesium concentrations, as demonstrated by MICs and oprH::lacZ fusion studies in the presence of 20 muM or 2 mM magnesium. Furthermore, in spermidine uptake mutants, MICs of cationic peptide antibiotics and fluorescent dyes, but not of aminoglycosides and quinolones, were increased by spermidine. These results suggested the presence of a complicated molecular mechanism for polyamine-mediated resistance to multiple antibiotics in P. aeruginosa.

  1. The LasB Elastase of Pseudomonas aeruginosa Acts in Concert with Alkaline Protease AprA To Prevent Flagellin-Mediated Immune Recognition.

    Science.gov (United States)

    Casilag, Fiordiligie; Lorenz, Anne; Krueger, Jonas; Klawonn, Frank; Weiss, Siegfried; Häussler, Susanne

    2015-10-26

    The opportunistic pathogen Pseudomonas aeruginosa is capable of establishing severe and persistent infections in various eukaryotic hosts. It encodes a wide array of virulence factors and employs several strategies to evade immune detection. In the present study, we screened the Harvard Medical School transposon mutant library of P. aeruginosa PA14 for bacterial factors that modulate interleukin-8 responses in A549 human airway epithelial cells. We found that in addition to the previously identified alkaline protease AprA, the elastase LasB is capable of degrading exogenous flagellin under calcium-replete conditions and prevents flagellin-mediated immune recognition. Our results indicate that the production of two proteases with anti-flagellin activity provides a failsafe mechanism for P. aeruginosa to ensure the maintenance of protease-dependent immune-modulating functions. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  2. Identification of MupP as a New Peptidoglycan Recycling Factor and Antibiotic Resistance Determinant in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Coralie Fumeaux

    2017-03-01

    Full Text Available Peptidoglycan (PG is an essential cross-linked polymer that surrounds most bacterial cells to prevent osmotic rupture of the cytoplasmic membrane. Its synthesis relies on penicillin-binding proteins, the targets of beta-lactam antibiotics. Many Gram-negative bacteria, including the opportunistic pathogen Pseudomonas aeruginosa, are resistant to beta-lactams because of a chromosomally encoded beta-lactamase called AmpC. In P. aeruginosa, expression of the ampC gene is tightly regulated and its induction is linked to cell wall stress. We reasoned that a reporter gene fusion to the ampC promoter would allow us to identify mutants defective in maintaining cell wall homeostasis and thereby uncover new factors involved in the process. A library of transposon-mutagenized P. aeruginosa was therefore screened for mutants with elevated ampC promoter activity. As an indication that the screen was working as expected, mutants with transposons disrupting the dacB gene were isolated. Defects in DacB have previously been implicated in ampC induction and clinical resistance to beta-lactam antibiotics. The screen also uncovered murU and PA3172 mutants that, upon further characterization, displayed nearly identical drug resistance and sensitivity profiles. We present genetic evidence that PA3172, renamed mupP, encodes the missing phosphatase predicted to function in the MurU PG recycling pathway that is widely distributed among Gram-negative bacteria.

  3. Regulation of Initial Attachment of P. aeruginosa

    Science.gov (United States)

    2010-12-08

    PA2300 chiC chitinase v - v - PA4217 phzS flavin-containing monooxygenase probable FAD-dependent monooxygenase v - - - PA1800 tig trigger...test whether inactivation of regulatory proteins involved in biofilm development also play a role in virulence by using two distinct in vivo plant ...avirulent as determined using the Arabidopsis thaliana infection model ( plant death was used as indicator of virulence). While more than 44% of

  4. Physical activity (PA) and the disablement process

    DEFF Research Database (Denmark)

    Schultz-Larsen, Kirsten; Rahmanfard, Naghmeh; Holst, Claus

    2012-01-01

    Few studies have explored the associations of reported PA (RPA) with the processes underlying the development of disability. The present study was performed to explore RPA among older persons and its association with onset of functional dependence and mortality. Among a probability sample of 1782...

  5. Seepage Model for PA Including Dift Collapse

    Energy Technology Data Exchange (ETDEWEB)

    G. Li; C. Tsang

    2000-12-20

    The purpose of this Analysis/Model Report (AMR) is to document the predictions and analysis performed using the Seepage Model for Performance Assessment (PA) and the Disturbed Drift Seepage Submodel for both the Topopah Spring middle nonlithophysal and lower lithophysal lithostratigraphic units at Yucca Mountain. These results will be used by PA to develop the probability distribution of water seepage into waste-emplacement drifts at Yucca Mountain, Nevada, as part of the evaluation of the long term performance of the potential repository. This AMR is in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' (CRWMS M&O 2000 [153447]). This purpose is accomplished by performing numerical simulations with stochastic representations of hydrological properties, using the Seepage Model for PA, and evaluating the effects of an alternative drift geometry representing a partially collapsed drift using the Disturbed Drift Seepage Submodel. Seepage of water into waste-emplacement drifts is considered one of the principal factors having the greatest impact of long-term safety of the repository system (CRWMS M&O 2000 [153225], Table 4-1). This AMR supports the analysis and simulation that are used by PA to develop the probability distribution of water seepage into drift, and is therefore a model of primary (Level 1) importance (AP-3.15Q, ''Managing Technical Product Inputs''). The intended purpose of the Seepage Model for PA is to support: (1) PA; (2) Abstraction of Drift-Scale Seepage; and (3) Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR). Seepage into drifts is evaluated by applying numerical models with stochastic representations of hydrological properties and performing flow simulations with multiple realizations of the permeability field around the drift. The Seepage Model for PA uses the distribution of permeabilities derived from air injection testing in

  6. Shallow PS-logging by high frequency wave; Koshuha wo mochiita senbu PS kenso

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, A.; Miyazawa, M.; Azuma, H. [OYO Corp., Tokyo (Japan)

    1996-05-01

    This paper describes the following matters on down-hole PS logging in shallow subsurface. Determining an elastic wave velocity structure in shallow subsurface with high accuracy by using down-hole PS logging requires reduction of errors in reading travel time. Therefore, a high-frequency vibration source was fabricated with an objective to raise frequencies of waves used for the measurement. Measurements were made on two holes, A and B, at a measurement interval of 0.5 m, whereas at the hole A a measurement was performed simultaneously by using a normal type (low-frequency) vibration source. A spectral analysis on the waveform record revealed that the frequencies with each vibration source were 127 Hz and 27 Hz for the hole A, 115 Hz for the hole B, and the S/N ratio was all the same for both holes. When the high-frequency vibration source was used, the velocity was determined at accuracy of 5% over the whole length of the shallow section. When the low-frequency vibration source was used, sections with the velocity determining error greater than 5% were found, and it was not possible to derive the velocity structure in the shallow subsurface in fine segments. 3 refs., 8 figs., 2 tabs.

  7. N-acetylcysteine inhibit biofilms produced by Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Liu Youning

    2010-05-01

    Full Text Available Abstract Background Pseudomonas aeruginosa is a common pathogen in chronic respiratory tract infections. It typically makes a biofilm, which makes treatment of these infections difficult. In this study, we investigated the inhibitory effects of N-acetylcysteine (NAC on biofilms produced by P. aeruginosa. Results We found that minimum inhibitory concentrations (MICs of NAC for most isolates of P. aeruginosa were 10 to 40 mg/ml, the combination of NAC and ciprofloxacin (CIP demonstrated either synergy (50% or no interaction (50% against the P. aeruginosa strains. NAC at 0.5 mg/ml could detach mature P. aeruginosa biofilms. Disruption was proportional to NAC concentrations, and biofilms were completely disrupted at 10 mg/ml NAC. Analysis using COMSTAT software also showed that PAO1 biofilm biomass decreased and its heterogeneity increased as NAC concentration increased. NAC and ciprofloxacin showed significant killing of P. aeruginosa in biofilms at 2.5 mg/ml and > 2 MIC, respectively (p p P. aeruginosa also decreased by 27.64% and 44.59% at NAC concentrations of 0.5 mg/ml and 1 mg/ml. Conclusions NAC has anti-bacterial properties against P. aeruginosa and may detach P. aeruginosa biofilms. Use of NAC may be a new strategy for the treatment of biofilm-associated chronic respiratory infections due to P. aeruginosa, although it would be appropriate to conduct clinical studies to confirm this.

  8. Relative resistance index (RRI) - a scoring system for antibiotic resistance in Pseudomonas aeruginosa.

    Science.gov (United States)

    Ewing, J; McCaughan, J; Moore, J; Fairley, D; Sutherland, B; Reid, A; Downey, D

    2017-10-01

    There is a need to measure antibiotic resistance of Pseudomonas aeruginosa (PA) in cystic fibrosis (CF), either qualitatively or quantitatively, to inform patient management. The aim of this study was to develop a simple method by which resistance can be quantified by calculating a relative resistance index (RRI), and to assess correlation of RRIs with clinical variables. In our model, RRIs were calculated based on resistance to aztreonam, ceftazidime, ciprofloxacin, colistin, meropenem, tazocin, temicillin and tobramycin. Eighty-five adults with CF and chronic PA colonisation were identified. For each, all PA cultures were allocated a score of 0 for susceptible, 0.5 for intermediate resistance or 1 for resistance for each antibiotic listed above, and the RRI calculated by dividing the sum of these by the number of antibiotics, giving a maximum score of 1. The mean RRIs for all cultures were correlated with key clinical variables monitored in CF patients (including age, FEV1, IV antibiotic days and BMI). RRIs for non-mucoid PA exhibited moderate positive correlation with total number of IV days (r = 0.405; p resistance.

  9. Overview of the Moral Status of iPS Cells.

    Science.gov (United States)

    Martinho, Andreia Martins

    2016-07-01

    The production of induced pluripotent stem (iPS) cells in 2006 by Takahashi and Yamanaka was a major breakthrough in stem cell research. IPS cells technology holds great promise for cell therapy, disease modelling, and drug testing, but it poses ethical questions concerning the moral status of somatic cells, which can re-gain pluripotency (iPS cells). This article provides an overview of the arguments that substantiate the debate on the moral assessment of iPS cells: potentiality argument; relational properties/standard view; and genetic basis for moral status.

  10. Transcriptomic Analyses Elucidate Adaptive Differences of Closely Related Strains of Pseudomonas aeruginosa in Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gunasekera, Thusitha S.; Bowen, Loryn L.; Zhou, Carol E.; Howard-Byerly, Susan C.; Foley, William S.; Striebich, Richard C.; Dugan, Larry C.; Ruiz, Oscar N.; Stams, Alfons J. M.

    2017-03-17

    Pseudomonas aeruginosacan utilize hydrocarbons, but different strains have various degrees of adaptation despite their highly conserved genome.P. aeruginosaATCC 33988 is highly adapted to hydrocarbons, whileP. aeruginosastrain PAO1, a human pathogen, is less adapted and degrades jet fuel at a lower rate than does ATCC 33988. We investigated fuel-specific transcriptomic differences between these strains in order to ascertain the underlying mechanisms utilized by the adapted strain to proliferate in fuel. During growth in fuel, the genes related to alkane degradation, heat shock response, membrane proteins, efflux pumps, and several novel genes were upregulated in ATCC 33988. Overexpression ofalkgenes in PAO1 provided some improvement in growth, but it was not as robust as that of ATCC 33988, suggesting the role of other genes in adaptation. Expression of the function unknown gene PA5359 from ATCC 33988 in PAO1 increased the growth in fuel. Bioinformatic analysis revealed that PA5359 is a predicted lipoprotein with a conserved Yx(FWY)xxD motif, which is shared among bacterial adhesins. Overexpression of the putative resistance-nodulation-division (RND) efflux pump PA3521 to PA3523 increased the growth of the ATCC 33988 strain, suggesting a possible role in fuel tolerance. Interestingly, the PAO1 strain cannot utilizen-C8andn-C10. The expression of green fluorescent protein (GFP) under the control ofalkBpromoters confirmed thatalkgene promoter polymorphism affects the expression ofalkgenes. Promoter fusion assays further confirmed that the regulation ofalkgenes was different in the two strains. Protein sequence analysis

  11. Transcriptomic Analyses Elucidate Adaptive Differences of Closely Related Strains of Pseudomonas aeruginosa in Fuel.

    Science.gov (United States)

    Gunasekera, Thusitha S; Bowen, Loryn L; Zhou, Carol E; Howard-Byerly, Susan C; Foley, William S; Striebich, Richard C; Dugan, Larry C; Ruiz, Oscar N

    2017-05-15

    Pseudomonas aeruginosa can utilize hydrocarbons, but different strains have various degrees of adaptation despite their highly conserved genome. P. aeruginosa ATCC 33988 is highly adapted to hydrocarbons, while P. aeruginosa strain PAO1, a human pathogen, is less adapted and degrades jet fuel at a lower rate than does ATCC 33988. We investigated fuel-specific transcriptomic differences between these strains in order to ascertain the underlying mechanisms utilized by the adapted strain to proliferate in fuel. During growth in fuel, the genes related to alkane degradation, heat shock response, membrane proteins, efflux pumps, and several novel genes were upregulated in ATCC 33988. Overexpression of alk genes in PAO1 provided some improvement in growth, but it was not as robust as that of ATCC 33988, suggesting the role of other genes in adaptation. Expression of the function unknown gene PA5359 from ATCC 33988 in PAO1 increased the growth in fuel. Bioinformatic analysis revealed that PA5359 is a predicted lipoprotein with a conserved Yx(FWY)xxD motif, which is shared among bacterial adhesins. Overexpression of the putative resistance-nodulation-division (RND) efflux pump PA3521 to PA3523 increased the growth of the ATCC 33988 strain, suggesting a possible role in fuel tolerance. Interestingly, the PAO1 strain cannot utilize n -C 8 and n -C 10 The expression of green fluorescent protein (GFP) under the control of alkB promoters confirmed that alk gene promoter polymorphism affects the expression of alk genes. Promoter fusion assays further confirmed that the regulation of alk genes was different in the two strains. Protein sequence analysis showed low amino acid differences for many of the upregulated genes, further supporting transcriptional control as the main mechanism for enhanced adaptation. IMPORTANCE These results support that specific signal transduction, gene regulation, and coordination of multiple biological responses are required to improve the survival

  12. Risk assessment of Pseudomonas aeruginosa in water.

    Science.gov (United States)

    Mena, Kristina D; Gerba, Charles P

    2009-01-01

    P. aeruginosa is part of a large group of free-living bacteria that are ubiquitous in the environment. This organism is often found in natural waters such as lakes and rivers in concentrations of 10/100 mL to >1,000/100 mL. However, it is not often found in drinking water. Usually it is found in 2% of samples, or less, and at concentrations up to 2,300 mL(-1) (Allen and Geldreich 1975) or more often at 3-4 CFU/mL. Its occurrence in drinking water is probably related more to its ability to colonize biofilms in plumbing fixtures (i.e., faucets, showerheads, etc.) than its presence in the distribution system or treated drinking water. P. aeruginosa can survive in deionized or distilled water (van der Jooij et al. 1982; Warburton et al. 1994). Hence, it may be found in low nutrient or oligotrophic environments, as well as in high nutrient environments such as in sewage and in the human body. P. aeruginosa can cause a wide range of infections, and is a leading cause of illness in immunocompromised individuals. In particular, it can be a serious pathogen in hospitals (Dembry et al. 1998). It can cause endocarditis, osteomyelitis, pneumonia, urinary tract infections, gastrointestinal infections, and meningitis, and is a leading cause of septicemia. P. aeruginosa is also a major cause of folliculitis and ear infections acquired by exposure to recreational waters containing the bacterium. In addition, it has been recognized as a serious cause of keratitis, especially in patients wearing contact lenses. P. aeruginosa is also a major pathogen in burn and cystic fibrosis (CF) patients and causes a high mortality rate in both populations (MOlina et al. 1991; Pollack 1995). P. aeruginosa is frequently found in whirlpools and hot tubs, sometimes in 94-100% of those tested at concenrations of ozone, or iodine. One author, however, did find it to be slightly more resistant to UV disinfection than most other bacteria (Wolfe 1990). Although much has been written about biofilms in the

  13. Cell death in Pseudomonas aeruginosa biofilm development

    DEFF Research Database (Denmark)

    Webb, J.S.; Thompson, L.S.; James, S.

    2003-01-01

    Bacteria growing in biofilms often develop multicellular, three-dimensional structures known as microcolonies. Complex differentiation within biofilms of Pseudomonas aeruginosa occurs, leading to the creation of voids inside microcolonies and to the dispersal of cells from within these voids....... However, key developmental processes regulating these events are poorly understood. A normal component of multicellular development is cell death. Here we report that a repeatable pattern of cell death and lysis occurs in biofilms of P. aeruginosa during the normal course of development. Cell death...... occurred with temporal and spatial organization within biofilms, inside microcolonies, when the biofilms were allowed to develop in continuous-culture flow cells. A subpopulation of viable cells was always observed in these regions. During the onset of biofilm killing and during biofilm development...

  14. Pseudomonas aeruginosa endophthalmitis masquerading as chronic uveitis

    Directory of Open Access Journals (Sweden)

    Kalpana Badami Nagaraj

    2013-01-01

    Full Text Available A 65-year-old male presented with decreased vision in the left eye of 15-day duration after having undergone an uneventful cataract surgery 10 months back. He had been previously treated with systemic steroids for recurrent uveitis postoperatively on three occasions in the same eye. B-scan ultrasonography showed multiple clumplike echoes suggestive of vitreous inflammation. Aqueous tap revealed Pseudomonas aeruginosa sensitive to ciprofloxacin. The patient was treated with intravitreal ciprofloxacin and vancomycin along with systemic ciprofloxacin with good clinical response. Even a virulent organism such as P.aeruginosa can present as a chronic uveitis, which, if missed, can lead to a delay in accurate diagnosis and appropriate management.

  15. Pseudomonas aeruginosa biofilms in cystic fibrosis

    DEFF Research Database (Denmark)

    Høiby, Niels; Ciofu, Oana; Bjarnsholt, Thomas

    2010-01-01

    of mutations, slow growth and adaptation of the bacteria to the conditions in the lungs, and to antibiotic therapy. Low bacterial metabolic activity and increase of doubling times of the bacterial cells in CF lungs are responsible for some of the tolerance to antibiotics. Conventional resistance mechanisms......, such as chromosomal ß-lactamase, upregulated efflux pumps, and mutations of antibiotic target molecules in the bacteria, also contribute to the survival of P. aeruginosa biofilms. Biofilms can be prevented by early aggressive antibiotic prophylaxis or therapy, and they can be treated by chronic suppressive therapy.......The persistence of chronic Pseudomonas aeruginosa lung infections in cystic fibrosis (CF) patients is due to biofilm-growing mucoid (alginate-producing) strains. A biofilm is a structured consortium of bacteria, embedded in a self-produced polymer matrix consisting of polysaccharide, protein...

  16. Technical Insights for Saltstone PA Maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Flach, G.; Sarkar, S.; Mahadevan, S.; Kosson, D.

    2011-07-20

    The Cementitious Barriers Partnership (CBP) is a collaborative program sponsored by the US DOE Office of Waste Processing. The objective of the CBP is to develop a set of computational tools to improve understanding and prediction of the long-term structural, hydraulic, and chemical performance of cementitious barriers and waste forms used in nuclear applications. CBP tools are expected to better characterize and reduce the uncertainties of current methodologies for assessing cementitious barrier performance and increase the consistency and transparency of the assessment process, as the five-year program progresses. In September 2009, entering its second year of funded effort, the CBP sought opportunities to provide near-term tangible support to DOE Performance Assessments (PAs). The Savannah River Saltstone Disposal Facility (SDF) was selected for the initial PA support effort because (1) cementitious waste forms and barriers play a prominent role in the performance of the facility, (2) certain important long-term behaviors of cementitious materials composing the facility are uncertain, (3) review of the SDF PA by external stakeholders is ongoing, and (4) the DOE contractor responsible for the SDF PA is open to receiving technical assistance from the CBP. A review of the current (SRR Closure & Waste Disposal Authority 2009) and prior Saltstone PAs (e.g., Cook et al. 2005) suggested five potential opportunities for improving predictions. The candidate topics considered were (1) concrete degradation from external sulfate attack, (2) impact of atmospheric exposure to concrete and grout before closure, such as accelerated slag and Tc-99 oxidation, (3) mechanistic prediction of geochemical conditions, (4) concrete degradation from rebar corrosion due to carbonation, and (5) early age cracking from drying and/or thermal shrinkage. The candidate topics were down-selected considering the feasibility of addressing each issue within approximately six months, and

  17. The immune system vs. Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Jensen, Peter Østrup; Givskov, Michael; Bjarnsholt, Thomas

    2010-01-01

    Ilya Metchnikoff and Paul Ehrlich were awarded the Nobel price in 1908. Since then, numerous studies have unraveled a multitude of mechanistically different immune responses to intruding microorganisms. However, in the vast majority of these studies, the underlying infectious agents have appeared...... the present review on the immune system vs. biofilm bacteria is focused on Pseudomonas aeruginosa (mainly because this is the most thoroughly studied), many of the same mechanisms are also seen with biofilm infections generated by other microorganisms....

  18. Therapy of Pseudomonas aeruginosa infections with tobramycin.

    Science.gov (United States)

    Blair, D C; Fekety, F R; Bruce, B; Silva, J; Archer, G

    1975-07-01

    The efficacy of tobramycin in doses of 2.7 to 5.6 mg/kg per day in 29 courses of therapy in 25 hospitalized patients with serious Pseudomonas aeruginosa infections was studied. Eighty-three percent of the P. aeruginosa strains showed zones of inhibition of 16 mm or more around a 10-mug tobramycin disk in the Bauer-Kirby disk method. Tobramycin minimal inhibitory concentration ranged from <0.05 to 1.5 mug/ml (microtiter twofold dilution method); for gentamicin they ranged from 0.05 to 6.2 mug/ml; corresponding geometric means were 0.19 and 0.49 mug/ml. Therapy was given for a median of 10 days (mean 19, range 1 to 83). The clinically satisfactory response rate for the 29 courses of therapy was 52%: critically ill, 44%; seriously ill, 50%; moderately ill, 80%. The response rates for various sites of infection were bone and cartilage, 100%; urinary tract infection, 56%; wound, 50%; respiratory tract, 67%; septicemia, 40%; abscess, 0%; burns, 44%. No adverse reactions were seen. Serum concentration (mug/ml +/- standard deviation) of tobramycin determined by an agar-well plate method, were 4.81 +/- 2.17 (1 h); 3.24 +/- 1.43 (2 h); 2.35 +/- 1.30 (4 h); and 1.40 +/- 1.09 (8 h). Tobramycin appears to be as effacacious as gentamicin in the treatment of serious P. aeruginosa infections and has a theoretical advantage of lower minimal inhibitory concentration for P. aeruginosa. The data suggest that, for life-threatening infections, dosages of tobramycin may need to be increased over those used in this study.

  19. Nosocomial outbreak of Pseudomonas aeruginosa endophthalmitis.

    Science.gov (United States)

    Mateos, I; Valencia, R; Torres, M J; Cantos, A; Conde, M; Aznar, J

    2006-11-01

    We describe an outbreak of nosocomial endophthalmitis due to a common source, which was determined to be trypan blue solution prepared in the hospital's pharmacy service. We assume that viable bacteria probably gained access to the trypan blue stock solution during cooling after autoclaving. The temporal cluster of Pseudomonas aeruginosa endophthalmitis was readily perceived on the basis of clinical and microbiological findings, and an exogenous source of contamination was unequivocally identified by means of DNA fingerprinting.

  20. The Study of Synergistic Effects of n.butanolic Cyclamen coum Extract and Ciprofloxacin on inhibition of Pseudomonas aeruginosa biofilm formation

    Directory of Open Access Journals (Sweden)

    ahya abdi ali

    2015-02-01

    Full Text Available   Introduction : Infections caused by Pseudomonas aeruginosa biofilm are the major causes of death in patients with cystic fibrosis (CF. Some studies revealed that biofilms are resistant to several antibiotics because of their impermeable structures. In order to re-sensitize bacteria to different antibiotics, biofilm formation should be inhibited. In this research, evaluation of antibiofilm activity of n-butanolic Cyclamen coum extract as a medici­nal plant from Myrsinaceae family, in combination with ciprofloxacin was carried out.   Materials and method s: The biofilm formation ability by P. aeruginosa PAO1 and one clinically isolated P. aeruginosa (PA214 was confirmed by microtiter plate method. Extraction of the tubers of Cyclamen coum was done by fractionation method . The antibiofilm and antibacterial properties of n-butanolic C. coum extract (which includes saponin compounds alone and in combination with ciprofloxacin by using microdilution and crystal violet methods were examined. The cytotoxicity effect of the n-butanolic extract on HT-29 cells was assayed by MTT (3- (4,5-dimethylthiazol-2-yl -2,5-diphenyl-tetrazolium bromide test.   Results : The biofilm formation ability by P. aeruginosa strains was quantitatively confirmed. Saponin content of the n-butanolic C.coum extract was 156 µg/mL. The extract revealed antibacterial activity against the growth of planktonic P. aeruginosa strains. The combination of n-butanolic C.coum extract and ciprofloxacin significantly inhibited P.aeruginosa biofilm formation (ΣFBIC = 0.5. The n-butanolic C.coum extract showed insignificant cytotoxic effect against HT-29 human cancer cell line after 48 hours and 72 hours incubation .   Discussion and conclusion : It can be concluded that n-butanolic C.coum extract in combination with ciprofloxacin significantly revealed antibiofilm activity against P. aeruginosa biofilm however, further clinical investigations are required.

  1. Effects of ginseng on Pseudomonas aeruginosa motility and biofilm formation

    DEFF Research Database (Denmark)

    Wu, Hong; Lee, Baoleri; Yang, Liang

    2011-01-01

    Biofilm-associated chronic Pseudomonas aeruginosa lung infections in patients with cystic fibrosis are virtually impossible to eradicate with antibiotics because biofilm-growing bacteria are highly tolerant to antibiotics and host defense mechanisms. Previously, we found that ginseng treatments...... protected animal models from developing chronic lung infection by P. aeruginosa. In the present study, the effects of ginseng on the formation of P. aeruginosa biofilms were further investigated in vitro and in vivo. Ginseng aqueous extract at concentrations of 0.5-2.0% did not inhibit the growth of P....... aeruginosa, but significantly prevented P. aeruginosa from forming biofilm. Exposure to 0.5% ginseng aqueous extract for 24 h destroyed most 7-day-old mature biofilms formed by both mucoid and nonmucoid P. aeruginosa strains. Ginseng treatment enhanced swimming and twitching motility, but reduced swarming...

  2. Antivirulence activity of azithromycin in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Francesco eImperi

    2014-04-01

    Full Text Available Antibiotics represent our bulwark to combat bacterial infections, but the spread of antibiotic resistance compromises their clinical efficacy. Alternatives to conventional antibiotics are urgently needed in order to complement the existing antibacterial arsenal. The macrolide antibiotic azithromycin (AZM provides a paradigmatic example of an unconventional antibacterial drug. Besides its growth-inhibiting activity, AZM displays potent anti-inflammatory properties, as well as antivirulence activity on some intrinsically resistant bacteria, such as Pseudomonas aeruginosa. In this bacterium, the antivirulence activity of AZM mainly relies on its ability to interact with the ribosome, resulting in direct and/or indirect repression of specific subsets of genes involved in virulence, quorum sensing, biofilm formation and intrinsic antibiotic resistance. Both clinical experience and clinical trials have shown the efficacy of AZM in the treatment of chronic pulmonary infections caused by P. aeruginosa. The aim of this review is to combine results from laboratory studies with evidence from clinical trials in order to unify the information on the in vivo mode of action of AZM in P. aeruginosa infection.

  3. PS buildings : reinforced concrete structure for shielding "bridge" pillar

    CERN Multimedia

    CERN PhotoLab

    1956-01-01

    The PS ring traverses the region between the experimental halls South and North (buildings Nos 150 and 151) under massive bridge-shaped concrete beams. This pillar stands at the S-W end of the structure.

  4. New safety training for access to the PS complex areas

    CERN Multimedia

    2012-01-01

    Since 10/08/2012, a new course dedicated to the specific radiological risks in the accelerators of the PS complex has been available on SIR (https://sir.cern.ch/). This course complements the general classroom-based Radiation Safety training. Successful completion of the course will be obligatory and verified by the access system as from 01/11/2012 for access to the following accelerator areas: LINAC2, BOOSTER, PS and TT2. Information and reminder e-mails will be sent to all persons currently authorized to access the accelerators of the PS complex. For questions please contact the HSE unit and in particular, the Radiation Protection Group (+41227672504 or safety-rp-ps-complex@cern.ch).

  5. Detection of host-derived sphingosine by Pseudomonas aeruginosa is important for survival in the murine lung.

    Directory of Open Access Journals (Sweden)

    Annette E LaBauve

    2014-01-01

    Full Text Available Pseudomonas aeruginosa is a common environmental bacterium that is also a significant opportunistic pathogen, particularly of the human lung. We must understand how P. aeruginosa responds to the lung environment in order to identify the regulatory changes that bacteria use to establish and maintain infections. The P. aeruginosa response to pulmonary surfactant was used as a model to identify transcripts likely induced during lung infection. The most highly induced transcript in pulmonary surfactant, PA5325 (sphA, is regulated by an AraC-family transcription factor, PA5324 (SphR. We found that sphA was specifically induced by sphingosine in an SphR-dependent manner, and also via metabolism of sphingomyelin, ceramide, or sphingoshine-1-phosphate to sphingosine. These sphingolipids not only play a structural role in lipid membranes, but some are also intracellular and intercellular signaling molecules important in normal eukaryotic cell functions as well as orchestrating immune responses. The members of the SphR transcriptome were identified by microarray analyses, and DNA binding assays showed specific interaction of these promoters with SphR, which enabled us to determine the consensus SphR binding site. SphR binding to DNA was modified by sphingosine and we used labeled sphingosine to demonstrate direct binding of sphingosine by SphR. Deletion of sphR resulted in reduced bacterial survival during mouse lung infection. In vitro experiments show that deletion of sphR increases sensitivity to the antimicrobial effects of sphingosine which could, in part, explain the in vivo phenotype. This is the first identification of a sphingosine-responsive transcription factor in bacteria. We predict that SphR transcriptional regulation may be important in response to many sites of infection in eukaryotes and the presence of homologous transcription factors in other pathogens suggests that sphingosine detection is not limited to P. aeruginosa.

  6. A first glycoside hydrolase family 50 endo-β-1,3-d-glucanase from Pseudomonas aeruginosa.

    Science.gov (United States)

    Yi, Ping; Yan, Qiaojuan; Jiang, Zhengqiang; Wang, Ling

    2018-01-01

    A novel β-1,3-glucanase gene (PaBglu50A) from Pseudomonas aeruginosa CAU 342A was cloned and expressed in Escherichia coli. The deduced amino acid sequence of PaBglu50A showed the highest identity of 34% with the β-agarase belonging to glycoside hydrolase (GH) family 50. The purified PaBglu50A had maximal activity at pH 5.5 and 45°C, respectively. It was stable in the range of pH 4.0-8.0 and at temperatures below 40°C. The Km and Vmax of PaBglu50A for curdlan and laminarin were 94.4mgml-1 and 23.4μmolmin-1mg-1, 3.65mgml-1 and 8.89μmolmin-1mg-1, respectively. All characterized members of GH family 50 were only active towards agarose so far. However, the recombinant protein PaBglu50A did not display activity towards agarose but showed activity towards water-insoluble curdlan and laminarin. The hydrolysis products for curdlan supported this protein to be an endo-β-1,3-glucanase, making a significant difference from the reported enzymes of GH family 50. These results suggested that PaBglu50A is the first endo-type β-1,3-glucanase (EC 3.2.1.39) in GH family 50. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Evaluation of 233Pa decay data.

    Science.gov (United States)

    Xiaolong, Huang; Ping, Liu; Baosong, Wang

    2005-05-01

    An evaluation of the complete scheme and data for (233)Pa decay, including results of the recent measurements, is presented. Several data evaluation procedures were used in the analysis of the half-life data. The half-life has been determined to be 26.971+/-0.013 days. All the gamma-ray emission probabilities ever published have been examined, and the gamma-ray emission probability for the reference 312-keV gamma line is recommended as 38.35+/-0.28%. The calculated internal conversion coefficients and their uncertainties have been used to obtain the complete decay intensity balance. Other decay characteristics have been calculated using the ENSDF analysis program. Finally, a new (233)Pa decay scheme has been built.

  8. o marca país

    Directory of Open Access Journals (Sweden)

    Sandra I. Fuentes Martínez

    2007-01-01

    Full Text Available De manera creciente en las últimas décadas, la gestión de marca se ha convertido en uno de los temas obligados para los gobiernos y las organizaciones privadas y públicas de las ciudades y de los países. Este nuevo frente de gestión cobra gran importancia, ya que gracias a su planificación se puede evidenciar logros importantes en el fortalecimiento de la competitividad y la imagen de las ciudades y de los países. Por este motivo, el objetivo de esta ponencia es retomar el concepto de marca integral a partir de la propuesta de un sistema comunicacional de gestión, donde se desarrollan 3 subsistemas: Entorno de gestión, estructura de marca, construcción de vínculos.

  9. Pseudomonas aeruginosa Virulence Analyzed in a Dictyostelium discoideum Host System

    OpenAIRE

    Cosson, Pierre; Zulianello, Laurence; Join-Lambert, Olivier; Faurisson, François; Gebbie, Leigh; Benghezal, Mohammed; Van Delden, Christian; Kocjancic Curty, Lasta; Köhler, Thilo

    2002-01-01

    Pseudomonas aeruginosa is an important opportunistic pathogen that produces a variety of cell-associated and secreted virulence factors. P. aeruginosa infections are difficult to treat effectively because of the rapid emergence of antibiotic-resistant strains. In this study, we analyzed whether the amoeba Dictyostelium discoideum can be used as a simple model system to analyze the virulence of P. aeruginosa strains. The virulent wild-type strain PAO1 was shown to inhibit growth of D. discoide...

  10. Recent advances in understanding Pseudomonas aeruginosa as a pathogen

    Science.gov (United States)

    Klockgether, Jens; Tümmler, Burkhard

    2017-01-01

    The versatile and ubiquitous Pseudomonas aeruginosa is an opportunistic pathogen causing acute and chronic infections in predisposed human subjects. Here we review recent progress in understanding P. aeruginosa population biology and virulence, its cyclic di-GMP-mediated switches of lifestyle, and its interaction with the mammalian host as well as the role of the type III and type VI secretion systems in P. aeruginosa infection. PMID:28794863

  11. Synthesis of ZnO thin films by 40 ps rate at 532 nm laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Ristoscu, C.; Socol, G.; Mihailescu, I.N. [National Institute for Lasers, Plasma and Radiations Physics, Lasers Department, 409 Atomistilor, P.O. Box MG-54, Magurele, Ilfov (Romania); Socol, M. [National Institute for Materials Physics, P.O. Box MG-7, Magurele, Ilfov (Romania); Jafer, R.; Al-Hadeethi, Y.; Batani, D. [Universita degli Studi di Milano-Bicocca, Dipartimento di Fisica ' ' G. Occhialini' ' , Milano (Italy)

    2011-09-15

    The synthesis by pulsed laser deposition of ZnO thin films with a Nd:YAG laser system delivering pulses of 40 ps rate at 532 nm is reported. The laser beam irradiated the target placed inside a vacuum chamber evacuated down to 1.33 x 10{sup -1} Pa. The incident laser fluence was of 28 J/cm{sup 2} in a spot of 0.1 mm{sup 2}. The ablated material was collected onto double face polished (111) Si or quartz wafers placed parallel at a separation distance of 7 mm. The AFM, SEM, UV-Vis, FT-IR and absorption ellipsometry results indicated that we obtained pure ZnO films with a rather uniform surface, having an average roughness of 37 nm. We observed by SEM that particulates are present on ZnO film surface or embedded into bulk. Their density and dimension were intermediary between particulates observed on similar structures deposited with fs or ns laser pulses. We noticed that the density of the particulates is increasing while their average size is decreasing when passing from ns to ps and fs laser pulses. The average transmission in the UV-Vis spectral region was found to be higher than 85%. (orig.)

  12. Study of Value Co-Creation in CoPS

    OpenAIRE

    Mingli Zhang; Jianhua Ye

    2013-01-01

    Value co-creation is associated with specific investment in the context of CoPS. The feature of CoPS decides that the study of co-creation cannot execute without regarding asset specificity. This study considers that value co-creation will be associated with specific value, which is outcome of relationship value and asset specificity. Supplier and customer have a close relation, which conducts to specific investment and then it turns to obstacle for competitors. Trust, commitment and satisfac...

  13. Motor-generator set of the PS main supply

    CERN Multimedia

    Photographic Service; CERN PhotoLab

    1968-01-01

    Already in 1964, the PS improvement programme included a new main magnet supply with more power for the longer cycles needed for slow extraction at the full energy of 26 GeV. This motor-generator set was installed in 1967 and took up service at the beginning of 1968. Regularly serviced and fitted with modern electronic regulation, it pulses the PS to this day.

  14. The Libera as a PS orbit measurement system building block

    CERN Document Server

    Belleman, J M; CERN. Geneva. AB Department

    2005-01-01

    During the year 2004, extensive tests using a Libera data processor have been made in order to study its suitability as a building block for a complete PS trajectory and orbit measurement system. The Libera consists of four fast 12-bits ADCs, a Virtex II Pro FPGA and a large memory. This note presents some of the results of the analysis of acquisitions made on a position pick-up in the CERN PS.

  15. DiPS: A Unifying Approach for developing System Software

    OpenAIRE

    Michiels, Sam; Matthijs, Frank; Walravens, Dirk; Verbaeten, Pierre

    2002-01-01

    In this paper we unify three essential features for flexible system software: a component oriented approach, self-adaptation and separation of concerns.We propose DiPS (Distrinet Protocol Stack), a component framework, which offers components, an anonymous interaction model and connectors to handle non-functional aspects such as concurrency. DiPS has effectively been used in industrial protocol stacks and device drivers.

  16. The Widespread Multidrug-Resistant Serotype O12 Pseudomonas aeruginosa Clone Emerged through Concomitant Horizontal Transfer of Serotype Antigen and Antibiotic Resistance Gene Clusters.

    Science.gov (United States)

    Thrane, Sandra Wingaard; Taylor, Véronique L; Freschi, Luca; Kukavica-Ibrulj, Irena; Boyle, Brian; Laroche, Jérôme; Pirnay, Jean-Paul; Lévesque, Roger C; Lam, Joseph S; Jelsbak, Lars

    2015-09-22

    The O-specific antigen (OSA) in Pseudomonas aeruginosa lipopolysaccharide is highly varied by sugar identity, side chains, and bond between O-repeats. These differences classified P. aeruginosa into 20 distinct serotypes. In the past few decades, O12 has emerged as the predominant serotype in clinical settings and outbreaks. These serotype O12 isolates exhibit high levels of resistance to various classes of antibiotics. Here, we explore how the P. aeruginosa OSA biosynthesis gene clusters evolve in the population by investigating the association between the phylogenetic relationships among 83 P. aeruginosa strains and their serotypes. While most serotypes were closely linked to the core genome phylogeny, we observed horizontal exchange of OSA biosynthesis genes among phylogenetically distinct P. aeruginosa strains. Specifically, we identified a "serotype island" ranging from 62 kb to 185 kb containing the P. aeruginosa O12 OSA gene cluster, an antibiotic resistance determinant (gyrA(C248T)), and other genes that have been transferred between P. aeruginosa strains with distinct core genome architectures. We showed that these genes were likely acquired from an O12 serotype strain that is closely related to P. aeruginosa PA7. Acquisition and recombination of the "serotype island" resulted in displacement of the native OSA gene cluster and expression of the O12 serotype in the recipients. Serotype switching by recombination has apparently occurred multiple times involving bacteria of various genomic backgrounds. In conclusion, serotype switching in combination with acquisition of an antibiotic resistance determinant most likely contributed to the dissemination of the O12 serotype in clinical settings. Infection rates in hospital settings by multidrug-resistant (MDR) Pseudomonas aeruginosa clones have increased during the past decades, and serotype O12 is predominant among these epidemic strains. It is not known why the MDR phenotype is associated with serotype

  17. The new heart of the PS is beating strongly

    CERN Document Server

    Corinne Pralavorio

    2011-01-01

    The PS has resumed operation with a brand new electrical power system called POPS; this enormous system comprising power electronics and capacitors is crucial because if it broke down practically no particles would be able to circulate at CERN. As soon as it started, POPS passed all the tests with flying colours and is now pulsing at full power.   The new PS power system is made up of 6 containers, each with 60 tonnes of capacitors and 8 power converters. The date 11/02/11 will always be remembered with affection by the engineers in the Electrical Power Converters Group. At 11:11 in the morning (no joke), the first beams powered by the new system began to circulate in the PS. The cutely-named POPS (POwer for PS) took over from the old rotating machine that had been working since 1968. From now on it will be POPS that supplies the PS main magnets with the electrical pulses needed to accelerate the beams for the LHC and all CERN's other facilities. The system is crucial as the PS is one of the lyn...

  18. The PS will soon be back in operation

    CERN Multimedia

    2006-01-01

    The PS's power supply system is undergoing repairs for the accelerator to restart on 26 June. The AB Department's Power Converter Group is working flat out with Siemens to return the PS's power supply system to working order. A problem appeared on the insulation of the power cables of the rotor of the rotating machine (photo) which supplies power to the PS magnets. To prevent more significant damage to the rotating machine, the AB Department, with the approval of the CERN Management, decided to shut down the PS which had started running on 15 May. Everything is being done to restart the accelerator on 26 June. The PS's rotating machine comprises a motor coupled to a generator. The generator's rotor acts like a flywheel, supplying high-power pulses of 40 to 50 megawatts to the PS magnets. The 6 megawatt motor drives the installation at 1000 revolutions per minute and compensates only for variations in speed. It is an essential interface since it would be hard to imagine connecting such an electrical charge, p...

  19. Identification of MupP as a New Peptidoglycan Recycling Factor and Antibiotic Resistance Determinant in Pseudomonas aeruginosa.

    Science.gov (United States)

    Fumeaux, Coralie; Bernhardt, Thomas G

    2017-03-28

    Peptidoglycan (PG) is an essential cross-linked polymer that surrounds most bacterial cells to prevent osmotic rupture of the cytoplasmic membrane. Its synthesis relies on penicillin-binding proteins, the targets of beta-lactam antibiotics. Many Gram-negative bacteria, including the opportunistic pathogen Pseudomonas aeruginosa, are resistant to beta-lactams because of a chromosomally encoded beta-lactamase called AmpC. In P. aeruginosa, expression of the ampC gene is tightly regulated and its induction is linked to cell wall stress. We reasoned that a reporter gene fusion to the ampC promoter would allow us to identify mutants defective in maintaining cell wall homeostasis and thereby uncover new factors involved in the process. A library of transposon-mutagenized P. aeruginosa was therefore screened for mutants with elevated ampC promoter activity. As an indication that the screen was working as expected, mutants with transposons disrupting the dacB gene were isolated. Defects in DacB have previously been implicated in ampC induction and clinical resistance to beta-lactam antibiotics. The screen also uncovered murU and PA3172 mutants that, upon further characterization, displayed nearly identical drug resistance and sensitivity profiles. We present genetic evidence that PA3172, renamed mupP, encodes the missing phosphatase predicted to function in the MurU PG recycling pathway that is widely distributed among Gram-negative bacteria.IMPORTANCE The cell wall biogenesis pathway is the target of many of our best antibiotics, including penicillin and related beta-lactam drugs. Resistance to these therapies is on the rise, particularly among Gram-negative species like Pseudomonas aeruginosa, a problematic opportunistic pathogen. To better understand how these organisms resist cell wall-targeting antibiotics, we screened for P. aeruginosa mutants defective in maintaining cell wall homeostasis. The screen identified a new factor, called MupP, involved in the recycling

  20. Apparatus to measure the vapor pressure of slowly decomposing compounds from 1 Pa to 105 Pa

    OpenAIRE

    Berg, Robert F.

    2015-01-01

    This article describes an apparatus and method for measuring vapor pressures in the range from 1 Pa to 105 Pa. Its three distinctive elements are : (1) the static pressure measurements were made with only a small temperature difference between the vapor and the condensed phase, (2) the sample was degassed in situ, and (3) the temperature range extended up to 200 °C. The apparatus was designed to measure metal-organic precursors, which often are toxic, pyrophoric, or unstable. Vapor pressures ...

  1. iPS-Cinderella Story in Cell Biology

    Directory of Open Access Journals (Sweden)

    Editorial

    2010-01-01

    Full Text Available As we step through the frontiers of modern Science, we are all witnesses to the Cinderella story repeating itself in the form of the iPS. The process of re-programming adult somatic cells to derive Induced Pluripotent stem cells (iPS with the wand of transcription factors and then differentiating them back to adult somatic cells resembles the transformation of Cinderella from a Cinder girl to princess and back to a Cinder girl after the ball; but the iPS-Cinderella is the most fascinating thing ever in cell biology!From the day iPS first made its headlines when it was first produced by Shinya Yamanaka at Kyoto University in Japan, Stem Cell scientists all over the world are re- doing their experiments so far done using other sources like embryonic and adult Stem cells with the iPS cells exploring their potential to the fullest. A Stem Cell science news page without this magic word of iPS is difficult to imagine these days and Scientists have been successful in growing most of the adult Cell types from iPS cells.iPS cells was the key to solve the problems of Immune rejection and Immunosupression required when using other allogeneic Stem cell types which had baffled scientists previously. But the issues raised by scientists about the use of viruses and Oncogenes in producing iPS cells were made groundless when scientists in February 2008 published the discovery of a technique that could remove oncogenes after the induction of pluripotency and now it is possible to induce pluripotency using plasmid transfection, piggyback transposon system and piggyback transposon system combined with a non viral vector system. The word of the day is pIPS which are protein-induced Pluripotent stem cells which are iPS cells that were generated without any genetic alteration of the adult cell. This research by the group of Sheng Ding in La Jolla, California made public in April 2009 showed that the generation of poly-arginine anchors was sufficient to induce

  2. Simulation of a wide area survey for NEOs with Pan-STARRS PS1 & PS2 Telescopes

    Science.gov (United States)

    Chambers, Kenneth C.; Lilly (Schunova), Eva; Dukes, Martin Todd; Wainscoat, Richard J.

    2017-10-01

    We have performed a new survey simulation for a wide area survey with PS1 & PS2 as part of our quest to optimize the discovery rate of Near Earth Objects with the full Pan-STARRS system. The survey is intended to be as unbiased and as complete as possible given the available sky visibility and the anticipated performance of the PS1 and PS2 telescopes working together. The simulation includes a complete model of both telescopes, camera and slew overhead, sky visibility, moon phase, galactic plane exclusion, and weather. The performance of the resulting survey strategy is then evaluated using the method of Lilly et. al. 2017. This uses the Greenstreet et al. 2012 model with 50 million NEOs with absolute magnitudes 13 < H < 29 and the Moving Object Processing System (MOPS, Denneau et al. 2013) for linkages. The results are compared with other possible strategies.

  3. Contribution of the platelet activating factor signaling pathway to cerebral microcirculatory dysfunction during experimental sepsis by ExoU producing Pseudomonas aeruginosa.

    Science.gov (United States)

    Plotkowski, Maria Cristina; Estato, Vanessa; Santos, Sabrina Alves; da Silva, Mauricio Costa Alves; Miranda, Aline Silva; de Miranda, Pedro Elias; Pinho, Vanessa; Tibiriça, Eduardo; Morandi, Verônica; Teixeira, Mauro Martins; Vianna, Albanita; Saliba, Alessandra Mattos

    2015-10-01

    Intravital microscopy was used to assess the involvement of ExoU, a Pseudomonas aeruginosa cytotoxin with phospholipase A2 activity, in dysfunction of cerebral microcirculation during experimental pneumosepsis. Cortical vessels from mice intratracheally infected with low density of the ExoU-producing PA103 P. aeruginosa strain exhibited increased leukocyte rolling and adhesion to venule endothelium, decreased capillar density and impaired arteriolar response to vasoactive acetylcholine. These phenomena were mediated by the platelet activating factor receptor (PAFR) pathway because they were reversed in mice treated with a PAFR antagonist prior to infection. Brains from PA103-infected animals exhibited a perivascular inflammatory infiltration that was not detected in animals infected with an exoU deficient mutant or in mice treated with the PAFR antagonist and infected with the wild type bacteria. No effect on brain capillary density was detected in mice infected with the PAO1 P. aeruginosa strain, which do not produce ExoU. Finally, after PA103 infection, mice with a targeted deletion of the PAFR gene exhibited higher brain capillary density and lower leukocyte adhesion to venule endothelium, as well as lower increase of systemic inflammatory cytokines, when compared to wild-type mice. Altogether, our results establish a role for PAFR in mediating ExoU-induced cerebral microvascular failure in a murine model of sepsis. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. The PAPI-1 pathogenicity island-encoded small RNA PesA influences Pseudomonas aeruginosa virulence and modulates pyocin S3 production.

    Science.gov (United States)

    Ferrara, Silvia; Falcone, Marilena; Macchi, Raffaella; Bragonzi, Alessandra; Girelli, Daniela; Cariani, Lisa; Cigana, Cristina; Bertoni, Giovanni

    2017-01-01

    Small non-coding RNAs (sRNAs) are post-transcriptional regulators of gene expression that have been recognized as key contributors to bacterial virulence and pathogenic mechanisms. In this study, we characterized the sRNA PesA of the opportunistic human pathogen Pseudomonas aeruginosa. We show that PesA, which is transcribed within the pathogenicity island PAPI-1 of P. aeruginosa strain PA14, contributes to P. aeruginosa PA14 virulence. In fact, pesA gene deletion resulted in a less pathogenic strain, showing higher survival of cystic fibrosis human bronchial epithelial cells after infection. Moreover, we show that PesA influences positively the expression of pyocin S3 whose genetic locus comprises two structural genes, pyoS3A and pyoS3I, encoding the killing S3A and the immunity S3I proteins, respectively. Interestingly, the deletion of pesA gene results in increased sensitivity to UV irradiation and to the fluoroquinolone antibiotic ciprofloxacin. The degree of UV sensitivity displayed by the PA14 strain lacking PesA is comparable to that of a strain deleted for pyoS3A-I. These results suggest an involvement of pyocin S3 in DNA damage repair and a regulatory role of PesA on this function.

  5. Profiling the microRNA Expression in Human iPS and iPS-derived Retinal Pigment Epithelium.

    Science.gov (United States)

    Wang, Heuy-Ching; Greene, Whitney A; Kaini, Ramesh R; Shen-Gunther, Jane; Chen, Hung-I H; Cai, Hong; Wang, Yufeng

    2014-01-01

    The purpose of this study is to characterize the microRNA (miRNA) expression profiles of induced pluripotent stem (iPS) cells and retinal pigment epithelium (RPE) derived from induced pluripotent stem cells (iPS-RPE). MiRNAs have been demonstrated to play critical roles in both maintaining pluripotency and facilitating differentiation. Gene expression networks accountable for maintenance and induction of pluripotency are linked and share components with those networks implicated in oncogenesis. Therefore, we hypothesize that miRNA expression profiling will distinguish iPS cells from their iPS-RPE progeny. To identify and analyze differentially expressed miRNAs, RPE was derived from iPS using a spontaneous differentiation method. MiRNA microarray analysis identified 155 probes that were statistically differentially expressed between iPS and iPS-RPE cells. Up-regulated miRNAs including miR-181c and miR-129-5p may play a role in promoting differentiation, while down-regulated miRNAs such as miR-367, miR-18b, and miR-20b are implicated in cell proliferation. Subsequent miRNA-target and network analysis revealed that these miRNAs are involved in cellular development, cell cycle progression, cell death, and survival. A systematic interrogation of temporal and spatial expression of iPS-RPE miRNAs and their associated target mRNAs will provide new insights into the molecular mechanisms of carcinogenesis, eye differentiation and development.

  6. Endovascular therapy after intravenous t-PA versus t-PA alone for stroke.

    Science.gov (United States)

    Broderick, Joseph P; Palesch, Yuko Y; Demchuk, Andrew M; Yeatts, Sharon D; Khatri, Pooja; Hill, Michael D; Jauch, Edward C; Jovin, Tudor G; Yan, Bernard; Silver, Frank L; von Kummer, Rüdiger; Molina, Carlos A; Demaerschalk, Bart M; Budzik, Ronald; Clark, Wayne M; Zaidat, Osama O; Malisch, Tim W; Goyal, Mayank; Schonewille, Wouter J; Mazighi, Mikael; Engelter, Stefan T; Anderson, Craig; Spilker, Judith; Carrozzella, Janice; Ryckborst, Karla J; Janis, L Scott; Martin, Renée H; Foster, Lydia D; Tomsick, Thomas A

    2013-03-07

    Endovascular therapy is increasingly used after the administration of intravenous tissue plasminogen activator (t-PA) for patients with moderate-to-severe acute ischemic stroke, but whether a combined approach is more effective than intravenous t-PA alone is uncertain. We randomly assigned eligible patients who had received intravenous t-PA within 3 hours after symptom onset to receive additional endovascular therapy or intravenous t-PA alone, in a 2:1 ratio. The primary outcome measure was a modified Rankin scale score of 2 or less (indicating functional independence) at 90 days (scores range from 0 to 6, with higher scores indicating greater disability). The study was stopped early because of futility after 656 participants had undergone randomization (434 patients to endovascular therapy and 222 to intravenous t-PA alone). The proportion of participants with a modified Rankin score of 2 or less at 90 days did not differ significantly according to treatment (40.8% with endovascular therapy and 38.7% with intravenous t-PA; absolute adjusted difference, 1.5 percentage points; 95% confidence interval [CI], -6.1 to 9.1, with adjustment for the National Institutes of Health Stroke Scale [NIHSS] score [8-19, indicating moderately severe stroke, or ≥20, indicating severe stroke]), nor were there significant differences for the predefined subgroups of patients with an NIHSS score of 20 or higher (6.8 percentage points; 95% CI, -4.4 to 18.1) and those with a score of 19 or lower (-1.0 percentage point; 95% CI, -10.8 to 8.8). Findings in the endovascular-therapy and intravenous t-PA groups were similar for mortality at 90 days (19.1% and 21.6%, respectively; P=0.52) and the proportion of patients with symptomatic intracerebral hemorrhage within 30 hours after initiation of t-PA (6.2% and 5.9%, respectively; P=0.83). The trial showed similar safety outcomes and no significant difference in functional independence with endovascular therapy after intravenous t-PA, as

  7. Kinetic characterization of tissue-type plasminogen activator (t-PA) and t-PA deletion mutants

    NARCIS (Netherlands)

    de Vries, C. [=Carlie J. M.; Veerman, H.; Nesheim, M. E.; Pannekoek, H.

    1991-01-01

    The binding of t-PA to fibrin is mediated both by its "finger" (F) and its "kringle 2" (K2) domain. In addition, these domains are involved in the stimulation of t-PA activity by fibrin. We analyzed the kinetic characteristics of Glu-plasminogen activation by t-PA and a set of t-PA deletion mutants

  8. Pseudomonas aeruginosa-associated Diarrheal Diseases in Children.

    Science.gov (United States)

    Chuang, Chih-Hsien; Janapatla, Rajendra Prasad; Wang, Yi-Hsin; Chang, Hsin-Ju; Huang, Yhu-Chering; Lin, Tzou-Yien; Chiu, Cheng-Hsun

    2017-12-01

    The gastrointestinal tract is not the common infection site of Pseudomonas aeruginosa. The role of P. aeruginosa as a causative agent for diarrhea in children without preexisting disease is controversial. From 2003 to 2012, we reviewed the records of 259 diarrheal patients less than 5 years of age whose stool culture grew P. aeruginosa. Virulence phenotypes of bacterial isolates were determined in vitro, including cytotoxicity, penetration and adherence to epithelial cells. The presence of P. aeruginosa in children with diarrhea less than 5 years old is 0.91%. P. aeruginosa-associated diarrheal diseases were classified into 4 groups: Shanghai fever (enteric infection and sepsis) (5%), P. aeruginosa enterocolitis (15%), P. aeruginosa-related diarrhea (19%) and antibiotic-associated diarrhea (43%). The remaining patients had coinfection with other pathogens (18%). Shanghai fever was the most severe enteric disease with invasive infection and complications. The clinical features of P. aeruginosa enterocolitis were prolonged fever with bloody or mucoid diarrhea mimicking bacterial enterocolitis. The clinical features of P. aeruginosa-related diarrhea and antibiotic-associated diarrhea were similar to viral or toxin-mediated diarrhea. Compared with other P. aeruginosa-associated diarrheal diseases, patients with Shanghai fever were younger, usually infants, and the characteristic laboratory findings included leukopenia, thrombocytopenia, high C-reactive protein, hyponatremia and hyperglycemia. Except for Shanghai fever, antibiotic treatment is not recommended. Isolates from Shanghai fever were more cytotoxic and adherent than isolates from uncomplicated diarrheal patients. P. aeruginosa could be an enteric pathogen even in healthy children. Young age and highly virulent bacterial strains were risk factors for Shanghai fever.

  9. Plasminogen activation independent of uPA and tPA maintains wound healing in gene-deficient mice

    DEFF Research Database (Denmark)

    Lund, Leif R; Green, Kirsty A; Stoop, Allart A

    2006-01-01

    Simultaneous ablation of the two known activators of plasminogen (Plg), urokinase-type (uPA) and the tissue-type (tPA), results in a substantial delay in skin wound healing. However, wound closure and epidermal re-epithelialization are significantly less impaired in uPA;tPA double-deficient mice...... than in Plg-deficient mice. Skin wounds in uPA;tPA-deficient mice treated with the broad-spectrum matrix metalloproteinase (MMP) inhibitor galardin (N-[(2R)-2-(hydroxamido-carbonylmethyl)-4-methylpentanoyl]-L-tryptophan methylamide) eventually heal, whereas skin wounds in galardin-treated Plg......-deficient mice do not heal. Furthermore, plasmin is biochemically detectable in wound extracts from uPA;tPA double-deficient mice. In vivo administration of a plasma kallikrein (pKal)-selective form of the serine protease inhibitor ecotin exacerbates the healing impairment of uPA;tPA double-deficient wounds...

  10. Efficacy of cinnamon bark oil and cinnamaldehyde on anti-multidrug resistant Pseudomonas aeruginosa and the synergistic effects in combination with other antimicrobial agents.

    Science.gov (United States)

    Utchariyakiat, Itsaraporn; Surassmo, Suvimol; Jaturanpinyo, Montree; Khuntayaporn, Piyatip; Chomnawang, Mullika Traidej

    2016-06-01

    The emergence of drug resistant pathogens becomes a crucial problem for infectious diseases worldwide. Among these bacteria, Pseudomonas aeruginosa is one of which highly resists to many currently used drugs and becomes a major concern in public health. Up till now, the search for potential antimicrobial agents has been still a challenge for researchers. Broth microdilution assay was used to determine minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of the essential oils and antibiotics against P. aeruginosa. Inhibition activity of the essential oils under vapor condition was examined to obtain the minimum inhibitory dose (MID). Time-kill assay included in this study was performed according to CLSI guideline. Bioautographic assay was used to detect active components of the essential oil. Synergistic effect with currently used antibiotics was further examined by checkerboard assay. In this study, a variety of essential oils were examined for anti-multidrug resistant P. aeruginosa (MDR-PA) activity, of which cinnamon bark oil showed the strongest antimicrobial activity against all clinical-isolated MDR-PA strains with MIC of 0.0562-0.225 % v/v and MBC of 0.1125-1.8 % v/v. Bioautographic results demonstrated that the active compounds of cinnamon bark oil were cinnamaldehyde and eugenol which showed strong inhibitory effect against P. aeruginosa. Interestingly, cinnamaldehyde, a major constituent of cinnamon bark oil, possessed stronger antimicrobial effect to P. aeruginosa than eugenol. Under gaseous condition, cinnamon bark oil and cinnamaldehyde showed antibacterial activity against MDR-PA strains with MID of 0.5-1 mg/L. Moreover, combination of cinnamon bark oil or cinnamaldehyde with currently used antibiotics was further studied by checkerboard assay to examine synergistic interactions on clinically isolated MDR-PA strains. Cinnamon bark oil and cinnamaldehyde combined with colistin demonstrated synergistic rates at 16

  11. Molecular cloning of two (R)-specific enoyl-CoA hydratase genes from Pseudomonas aeruginosa and their use for polyhydroxyalkanoate synthesis.

    Science.gov (United States)

    Tsuge, T; Fukui, T; Matsusaki, H; Taguchi, S; Kobayashi, G; Ishizaki, A; Doi, Y

    2000-03-15

    Two Pseudomonas aeruginosa genes, termed phaJ1(Pa) and phaJ2(Pa), homologous to the Aeromonas caviae (R)-specific enoyl-CoA hydratase gene (phaJ(Ac)) were cloned using a PCR technique to investigate the monomer-supplying ability for polyhydroxyalkanoate (PHA) synthesis from beta-oxidation cycle. Two expression plasmids for phaJ1(Pa) and phaJ2(Pa) were constructed and introduced into Escherichia coli DH5alpha strain. The recombinants harboring phaJ1(Pa) or phaJ2(Pa) showed high (R)-specific enoyl-CoA hydratase activity with different substrate specificities, that is, specific for short chain-length enoyl-CoA or medium chain-length enoyl-CoA, respectively. In addition, co-expression of these two hydratase genes with PHA synthase gene in E. coli LS5218 resulted in the accumulation of PHA up to 14-29 wt% of cell dry weight from dodecanoate as a sole carbon source. It has been suggested that phaJ1(Pa) and phaJ2(Pa) products have the monomer-supplying ability for PHA synthesis from beta-oxidation cycle.

  12. Effect of bacterial components of mixed culture supernatants of planktonic and biofilm Pseudomonas aeruginosa with commensal Escherichia coli on the neutrophil response in vitro.

    Science.gov (United States)

    Maslennikova, Irina L; Kuznetsova, Marina V; Nekrasova, Irina V; Shirshev, Sergei V

    2017-11-30

    Pseudomonas aeruginosa (PA) responsible for acute and chronic infections often forms a well-organized bacterial population with different microbial species including commensal strains of Escherichia coli. Bacterial extracellular components of mixed culture can modulate the influence of bacteria on the neutrophil functions. The objective of this study was to compare the effect of pyocyanin, pyoverdine, LPS, exopolysaccharide of single species and mixed culture supernatants of PA strains and E. coli K12 on microbicidal, secretory activity of human neutrophils in vitro. Bacterial components of E. coli K12 in mixed supernatants with 'biofilm' PA strains (PA ATCC, PA BALG) enhanced short-term microbicidal mechanisms and inhibited neutrophil secretion delayed in time. The influence of 'planktonic' PA (PA 9-3) exometabolites in mixed culture is almost mimicked by E. coli K12 effect on functional neutrophil changes. This investigation may help to understand some of the mechanisms of neutrophil response to mixed infections of different PA with other bacteria species. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Step-By-Step In Vitro Mutagenesis: Lessons From Fucose-Binding Lectin PA-IIL.

    Science.gov (United States)

    Mrázková, Jana; Malinovská, Lenka; Wimmerová, Michaela

    2017-01-01

    Site-directed mutagenesis is a powerful technique which is used to understand the basis of interactions between proteins and their binding partners, as well as to modify these interactions. Methods of rational design that are based on detailed knowledge of the structure of a protein of interest are often used for preliminary investigations of the possible outcomes which can result from the practical application of site-directed mutagenesis. Also, random mutagenesis can be used in tandem with site-directed mutagenesis for an examination of amino acid "hotspots."Lectins are sugar-binding proteins which, among other functions, mediate the recognition of host cells by a pathogen and its adhesion to the host cell surface. Hence, lectins and their binding properties are studied and engineered using site-directed mutagenesis.In this chapter, we describe a site-directed mutagenesis method used for investigating the sugar binding pattern of the PA-IIL lectin from the pathogenic bacterium Pseudomonas aeruginosa. Moreover, procedures for the production and purification of PA-IIL mutants are described, and several basic methods for characterizing the mutants are discussed.

  14. Chromosomal organization and segregation in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Isabelle Vallet-Gely

    2013-05-01

    Full Text Available The study of chromosomal organization and segregation in a handful of bacteria has revealed surprising variety in the mechanisms mediating such fundamental processes. In this study, we further emphasized this diversity by revealing an original organization of the Pseudomonas aeruginosa chromosome. We analyzed the localization of 20 chromosomal markers and several components of the replication machinery in this important opportunistic γ-proteobacteria pathogen. This technique allowed us to show that the 6.3 Mb unique circular chromosome of P. aeruginosa is globally oriented from the old pole of the cell to the division plane/new pole along the oriC-dif axis. The replication machinery is positioned at mid-cell, and the chromosomal loci from oriC to dif are moved sequentially to mid-cell prior to replication. The two chromosomal copies are subsequently segregated at their final subcellular destination in the two halves of the cell. We identified two regions in which markers localize at similar positions, suggesting a bias in the distribution of chromosomal regions in the cell. The first region encompasses 1.4 Mb surrounding oriC, where loci are positioned around the 0.2/0.8 relative cell length upon segregation. The second region contains at least 800 kb surrounding dif, where loci show an extensive colocalization step following replication. We also showed that disrupting the ParABS system is very detrimental in P. aeruginosa. Possible mechanisms responsible for the coordinated chromosomal segregation process and for the presence of large distinctive regions are discussed.

  15. Characterization of crosslinked polystyrene(PS) beads in SBR matrix

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Yoon-Jong; Choe, Soonja [Inha Univ. (Korea, Republic of)

    1995-12-01

    Monodisperse sized crosslinked polystyrene(PS) beads were prepared by a reaction of semibatch emulsion polymerization with styrene monomer, divinylbenzene(DVB) crosslinking agent and potassium persulfate(K{sub 2}S{sub 2}O{sub 9}) initiator in the absence of emulsifier. The glass transition temperature(T{sub g}) and the mean diameter of the beads were increased from 100{degrees}C to 135{degrees}C and from 402 nm to 532 nm, respectively, for an incorporation of 2 to 10 mol% DVB. Crosslinking density was also linearly increased with DVB content. SEM microphotographs of SBR composite filled with various contents of PS beads revealed that PS beads are relatively well dispersed without changing the spherical shape of the beads in all range of compositions. In stress-strain analysis, elongation at break and tensile strength of SBR composite were increased with the bead content. Applicability of the PS beads as a filler in SBR matrix is tested by plotting Mooney-Rivlin or Guth-Smallwood equations. However, mechanical properties of the composite with the beads were not so excellent as those of the composite with carbon black. Crosslinked PS beads are still tentative as a white color reinforcing filler on SBR matrix.

  16. The PS complex produces the nominal LHC beam

    CERN Document Server

    Benedikt, Michael; Borburgh, J; Cappi, R; Chanel, M; Chohan, V; Cyvoct, G; Garoby, R; Grier, D G; Gruber, J; Hancock, S; Hill, C E; Jensen, E; Krusche, A; Lindroos, M; Métral, Elias; Métral, G; Metzmacher, K D; Olsfors, J; Pedersen, F; Raich, U; Riunaud, J P; Royer, J P; Sassowsky, M; Schindl, Karlheinz; Schönauer, Horst Otto; Thivent, M; Ullrich, H M; Völker, F V; Vretenar, Maurizio; Barnes, M; Blackmore, E W; Cifarelli, F; Clark, G; Jones, F; Koscielniak, Shane Rupert; Mammarella, F; Mitra, A; Poirier, R; Reiniger, K W; Ries, T C

    2000-01-01

    The LHC [1] will be supplied, via the SPS, with protons from the pre-injector chain comprising Linac2, PS Booster (PSB) and PS. These accelerators have under-gone a major upgrading programme [2] during the last five years so as to meet the stringent requirements of the LHC. These imply that many high-intensity bunches of small emittance and tight spacing (25 ns) be available at the PS extraction energy (25 GeV). The upgrading project involved an increase of Linac2 current, new RF systems in the PSB and the PS, raising the PSB energy from 1 to 1.4 GeV, two-batch filling of the PS and the installation of high-resolution beam profile measurement devices. With the project entering its final phase and most of the newly installed hardware now being operational, the emphasis switches to producing the nominal LHC beam and tackling the associated beam physics problems. While a beam with transverse characteristics better than nominal has been obtained, the longitudinal density still needs to be increased. An alternativ...

  17. Pressure Monitoring Using Hybrid fs/ps Rotational CARS

    Science.gov (United States)

    Kearney, Sean P.; Danehy, Paul M.

    2015-01-01

    We investigate the feasibility of gas-phase pressure measurements at kHz-rates using fs/ps rotational CARS. Femtosecond pump and Stokes pulses impulsively prepare a rotational Raman coherence, which is then probed by a high-energy 6-ps pulse introduced at a time delay from the Raman preparation. Rotational CARS spectra were recorded in N2 contained in a room-temperature gas cell for pressures from 0.1 to 3 atm and probe delays ranging from 10-330 ps. Using published self-broadened collisional linewidth data for N2, both the spectrally integrated coherence decay rate and the spectrally resolved decay were investigated as means for detecting pressure. Shot-averaged and single-laser-shot spectra were interrogated for pressure and the accuracy and precision as a function of probe delay and cell pressure are discussed. Single-shot measurement accuracies were within 0.1 to 6.5% when compared to a transducer values, while the precision was generally between 1% and 6% of measured pressure for probe delays of 200 ps or more, and better than 2% as the delay approached 300 ps. A byproduct of the pressure measurement is an independent but simultaneous measurement of the gas temperature.

  18. Isolation and characterization of gallium resistant Pseudomonas aeruginosa mutants.

    Science.gov (United States)

    García-Contreras, Rodolfo; Lira-Silva, Elizabeth; Jasso-Chávez, Ricardo; Hernández-González, Ismael L; Maeda, Toshinari; Hashimoto, Takahiro; Boogerd, Fred C; Sheng, Lili; Wood, Thomas K; Moreno-Sánchez, Rafael

    2013-12-01

    Pseudomonas aeruginosa PA14 cells resistant to the novel antimicrobial gallium nitrate (Ga) were developed using transposon mutagenesis and by selecting spontaneous mutants. The mutants showing the highest growth in the presence of Ga were selected for further characterization. These mutants showed 4- to 12-fold higher Ga minimal inhibitory growth concentrations and a greater than 8-fold increase in the minimum biofilm eliminating Ga concentration. Both types of mutants produced Ga resistant biofilms whereas the formation of wild-type biofilms was strongly inhibited by Ga. The gene interrupted in the transposon mutant was hitA, which encodes a periplasmic iron binding protein that delivers Fe³⁺ to the HitB iron permease; complementation of the mutant with the hitA gene restored the Ga sensitivity. This hitA mutant showed a 14-fold decrease in Ga internalization versus the wild-type strain, indicating that the HitAB system is also involved in the Ga uptake. Ga uptake in the spontaneous mutant was also lower, although no mutations were found in the hitAB genes. Instead, this mutant harbored 64 non-silent mutations in several genes including those of the phenazine pyocyanin biosynthesis. The spontaneous mutant produced 2-fold higher pyocyanin basal levels than the wild-type; the addition of this phenazine to wild-type cultures protected them from the Ga bacteriostatic effect. The present data indicate that mutations affecting Ga transport and probably pyocyanin biosynthesis enable cells to develop resistance to Ga. Copyright © 2013 Elsevier GmbH. All rights reserved.

  19. Ap-PCR typing of carbapenem sensitive Pseudomonas aeruginosa ...

    African Journals Online (AJOL)

    In this study the antibiotic susceptibility of 51 P. aeruginosa strains isolated from clinical samples were detected by the disc diffusion test. The susceptibility of P. aeruginosa strains were found as respectively 55% amicacin, 43% aztreonam, 75% netilmycin, 68% sefepim, 73% ceftazidim, 76% ciproflaxacin, 37% gentamicin, ...

  20. Infections with Pseudomonas aeruginosa in Charcot arthropathy of the foot.

    Science.gov (United States)

    Illgner, Ulrich; Uekoetter, Andreas; Runge, Sabrina; Wetz, Hans Henning

    2013-02-01

    Patients with Charcot arthropathy present a high risk for ulcers with secondary bone infection. Infections with Pseudomonas aeruginosa represent a severe threat to the patients. We hypothesized that infections with P aeruginosa result in a longer stay in hospital and more operations than infections with other bacteria. All patients who underwent surgery for Charcot arthropathy of the feet between 1996 and 2006 (n = 205) in our clinic were included. The duration of hospitalization and number of surgeries for infections due to methicillin-resistant Staphylococcus aureus (MRSA) versus P aeruginosa were compared to infections with other bacteria. All patients were scanned for MRSA and were isolated when tested positive and treated according to a defined algorithm. Seventy-nine intraoperative samples exhibited bacterial growth: 12 cases of MRSA, 14 cases of P aeruginosa, and 53 case of other bacteria. Patients with deep infections due to P aeruginosa stayed significantly longer in the hospital (52 vs 35 days, P < .041) and needed significantly more surgery (1.71 vs 1.28 surgeries, P < .027). There was no significant difference between patients with MRSA infections and those without MRSA or P aeruginosa. Infections with P aeruginosa resulted in more surgeries and a longer stay in the hospital. Early debridement is the basic treatment. A specific algorithm for isolation and operative and antibiotic treatment for P aeruginosa infections is proposed similar to an algorithm for MRSA that has been shown to be successful. Level IV, retrospective case Series.

  1. Pseudomonas aeruginosa: an uncommon cause of diabetic foot infection.

    Science.gov (United States)

    Young, Heather; Knepper, Bryan; Hernandez, Whitney; Shor, Asaf; Bruntz, Merribeth; Berg, Chrystal; Price, Connie S

    2015-03-01

    Pseudomonas aeruginosa has traditionally been considered a common pathogen in diabetic foot infection (DFI), yet the 2012 Infectious Diseases Society of America guideline for DFI states that "empiric therapy directed at P aeruginosa is usually unnecessary." The objective of this study was to evaluate the frequency of P aeruginosa isolated from bone or tissue cultures from patients with DFI. This study is a cross-sectional survey of diabetic patients presenting with a foot infection to an urban county hospital between July 1, 2012, and December 31, 2013. All of the patients had at least one debridement procedure during which tissue or bone cultures from operative or bedside debridements were obtained. The χ(2) test and the t test of means were used to determine relationships between variables and the frequency of P aeruginosa in culture. The median number of bacteria isolated from DFI was two. Streptococcus spp and Staphylococcus aureus were the most commonly isolated organisms; P aeruginosa was isolated in only five of 112 patients (4.5%). The presence of P aeruginosa was not associated with the patient's age, glycosylated hemoglobin level, tobacco abuse, the presence of osteomyelitis, a prescription for antibiotic drugs in the preceding 3 months, or the type of operative procedure. Pseudomonas aeruginosa was an infrequent isolate from DFI in this urban, underserved diabetic population. The presence of P aeruginosa was not associated with any measured risk factors. By introducing a clinical practice guideline, we hope to discourage frontline providers from using routine antipseudomonal antibiotic drugs for DFI.

  2. Pseudomonas aeruginosa burn wound infection in a dedicated ...

    African Journals Online (AJOL)

    Background. Pseudomonas aeruginosa infection is a major cause of morbidity in burns patients. There is a paucity of publications dealing with this infection in the paediatric population. We describe the incidence, microbiology and impact of P. aeruginosa infection in a dedicated paediatric burns unit. Methods.

  3. Inhibition of Microcystis aeruginosa and microcystin- LR with one ...

    African Journals Online (AJOL)

    Yomi

    The discovery of algicidal bacteria has brought renewed attention in the treatment of the harmful algae blooms (HABs). In this study ... eutrophic lake and its inhibition effects on M. aeruginosa and microcystin-LR released by M. aeruginosa was studied. ... People have found that bacteria and virus may play important roles in ...

  4. 33 original article infections a pseudomonas aeruginosa dans un ...

    African Journals Online (AJOL)

    boaz

    institution of effective resistance surveillance and infection control measures. . Keywords: Pseudomonas aeruginosa, National Hospital Abuja, Susceptibility. INFECTIONS A PSEUDOMONAS AERUGINOSA DANS UN HOPITAL TERTIAIRE. AU NIGERIA. *Iregbu KC, Eze SO,. Département de Microbiologie Médicale and ...

  5. Multi-drug resistant Pseudomonas aeruginosa keratitis and its effective treatment with topical colistimethate

    Directory of Open Access Journals (Sweden)

    Samrat Chatterjee

    2016-01-01

    Full Text Available The purpose was to evaluate the clinical outcome in multi-drug resistant Pseudomonas aeruginosa (MDR-PA bacterial keratitis and report the successful use of an alternative antibiotic, topical colistimethate in some of them. The medical records of 12 culture-proven MDR-PA keratitis patients, all exhibiting in vitro resistance by Kirby–Bauer disc diffusion method to ≥ three classes of routinely used topical antibiotics were reviewed. Eight patients were treated with 0.3% ciprofloxacin or ofloxacin, 1 patient with 5% imipenem/cilastatin and 3 patients with 1.6% colistimethate. The outcomes in 8 eyes treated with only fluoroquinolones were evisceration in 4 eyes, therapeutic corneal graft in 1 eye, phthisis bulbi in 1 eye, and no improvement in 2 eyes. The eye treated with imipenem/cilastin required a therapeutic corneal graft. All the three eyes treated with 1.6% colistimethate healed. Colistimethate may prove to be an effective alternative antibiotic in the treatment of MDR-PA keratitis.

  6. Chemotaxis and Binding of Pseudomonas aeruginosa to Scratch-Wounded Human Cystic Fibrosis Airway Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Christian Schwarzer

    Full Text Available Confocal imaging was used to characterize interactions of Pseudomonas aeruginosa (PA, expressing GFP or labeled with Syto 11 with CF airway epithelial cells (CFBE41o-, grown as confluent monolayers with unknown polarity on coverglasses in control conditions and following scratch wounding. Epithelia and PAO1-GFP or PAK-GFP (2 MOI were incubated with Ringer containing typical extracellular salts, pH and glucose and propidium iodide (PI, to identify dead cells. PAO1 and PAK swam randomly over and did not bind to nonwounded CFBE41o- cells. PA migrated rapidly (began within 20 sec, maximum by 5 mins and massively (10-80 fold increase, termed "swarming", but transiently (random swimming after 15 mins, to wounds, particularly near cells that took up PI. Some PA remained immobilized on cells near the wound. PA swam randomly over intact CFBE41o- monolayers and wounded monolayers that had been incubated with medium for 1 hr. Expression of CFTR and altered pH of the media did not affect PA interactions with CFBE41o- wounds. In contrast, PAO1 swarming and immobilization along wounds was abolished in PAO1 (PAO1ΔcheYZABW, no expression of chemotaxis regulatory components cheY, cheZ, cheA, cheB and cheW and greatly reduced in PAO1 that did not express amino acid receptors pctA, B and C (PAO1ΔpctABC and in PAO1 incubated in Ringer containing a high concentration of mixed amino acids. Non-piliated PAKΔpilA swarmed normally towards wounded areas but bound infrequently to CFBE41o- cells. In contrast, both swarming and binding of PA to CFBE41o- cells near wounds were prevented in non-flagellated PAKΔfliC. Data are consistent with the idea that (i PA use amino acid sensor-driven chemotaxis and flagella-driven swimming to swarm to CF airway epithelial cells near wounds and (ii PA use pili to bind to epithelial cells near wounds.

  7. Chronic Pseudomonas aeruginosa lung infection in normal and athymic rats

    DEFF Research Database (Denmark)

    Johansen, H K; Espersen, F; Pedersen, S S

    1993-01-01

    We have compared a chronic lung infection with Pseudomonas aeruginosa embedded in alginate beads in normal and athymic rats with an acute infection with free live P. aeruginosa bacteria. The following parameters were observed and described: mortality, macroscopic and microscopic pathologic changes......, and antibody responses. The rats challenged with P. aeruginosa alginate beads experienced a generally more severe lung pathology and the antibody responses were more homogeneous with less dispersion as compared to the rats having free live P. aeruginosa bacteria. In general, manifestations were more severe...... in the athymic rats compared to the normal rats. It is, however, notable that the athymic rats developed similar microscopic lung manifestations as the normal rats when given a large number of P. aeruginosa in the beads, with dense accumulation of neutrophil granulocytes and microcolonies comparable...

  8. Electron Enhancement Of Photodynamic Action (EE-PA)

    Science.gov (United States)

    Swartz, M. R.; Clark, G. A.

    1989-03-01

    A new method is described which enhances classical photodynamic action (PA) by adding electricity. Rather than producing singlet oxygen, the electrical enhancement of photodynamic action (EE-PA) drives the photochemical reactions towards the creation of superoxide, and other, oxygen radicals. The benefits of EE-PA over PA are illustrated by reviewing results from four groups of experiments where this process was used either to inactivate Herpes viruses, gliosarcomas, bacteria, or to enable charge transfer to oxidized hemoglobin. The experiments have suggested several advantages of EE-PA over traditional photodynamic action (PA).

  9. Effects of environmental enrichment and physical activity on neurogenesis in transgenic PS1/APP mice.

    Science.gov (United States)

    Catlow, Briony J; Rowe, Amanda R; Clearwater, Courtney R; Mamcarz, Maggie; Arendash, Gary W; Sanchez-Ramos, Juan

    2009-02-23

    Rodents exposed to environmental enrichment show many differences, including improved cognitive performance, when compared to those living in standard (impoverished) housing. The purpose of the present study was to determine if a selective increase in neurogenesis occurred in cognitively-protected Tg mice raised in an enriched environment compared to those reared in physical activity housing. At weaning, double Tg APP+PS1 mice were placed into one of three environments: complete environmental enrichment (CE), enhanced physical activity (PA), or individual, impoverished housing (IMP). At 9-10 months of age, Tg mice were injected with BrdU (100 mg/kg BID) followed by euthanasia either 24 h or 2 weeks after the last injection. Unbiased estimates of BrdU positive cells in the hippocampal subgranular zone revealed a significant increase in cellular proliferation in Tg mice raised in CE or PA compared to Tg mice reared in IMP housing. However, counts of BrdU birth-dated cells 2 weeks after labeling showed no difference among the three groups, indicating decreased survival of cells in those groups (CE and PA) with higher cellular proliferation rates in the neurogenic niche. Counts of calretinin-expressing cells, a marker of immature neurons, also indicated no difference among the three groups of mice. In view of our prior study showing that enhanced cognitive activity (but not enhanced physical activity) protects Tg mice against cognitive impairment, the present results indicate that increased generation and survival of new neurons in the hippocampal dentate gyrus is not involved with the cognitively-protective effects of complete CE in Alzheimer's transgenic mice.

  10. 3D-QSAR, Molecular Docking and Molecular Dynamics Simulation of Pseudomonas aeruginosa LpxC Inhibitors.

    Science.gov (United States)

    Zuo, Ke; Liang, Li; Du, Wenyi; Sun, Xin; Liu, Wei; Gou, Xiaojun; Wan, Hua; Hu, Jianping

    2017-05-06

    As an important target for the development of novel antibiotics, UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase (LpxC) has been widely studied. Pyridone methylsulfone hydroxamate (PMH) compounds can effectively inhibit the catalytic activity of LpxC. In this work, the three-dimensional quantitative structure-activity relationships of PMH inhibitors were explored and models with good predictive ability were established using comparative molecular field analysis and comparative molecular similarity index analysis methods. The effect of PMH inhibitors' electrostatic potential on the inhibitory ability of Pseudomonas aeruginosa LpxC (PaLpxC) is revealed at the molecular level via molecular electrostatic potential analyses. Then, two molecular dynamics simulations for the PaLpxC and PaLpxC-inhibitor systems were also performed respectively to investigate the key residues of PaLpxC hydrolase binding to water molecules. The results indicate that orderly alternative water molecules can form stable hydrogen bonds with M62, E77, T190, and H264 in the catalytic center, and tetracoordinate to zinc ion along with H78, H237, and D241. It was found that the conformational transition space of PaLpxC changes after association with PMH inhibitors through free energy landscape and cluster analyses. Finally, a possible inhibitory mechanism of PMH inhibitors was proposed, based on our molecular simulation. This paper will provide a theoretical basis for the molecular design of LpxC-targeting antibiotics.

  11. Final Results on the CERN PS Electrostatic Septa Consolidation Program

    CERN Document Server

    Borburgh, Jan; Bobbio, Piero; Carlier, Etienne; Hourican, Michael; Masson, Thierry; Müller, Tania; Prost, Antoine; Crescenti, Massimo

    2003-01-01

    The CERN PS electrostatic septum consolidation program is coming to completion after almost 4 years of development. The program was started to fulfil the increased requirements on vacuum performance and the need to reduce the time necessary for maintenance interventions. The new design of septum 31, used for the so-called 'continuous transfer' 5-turn extraction, and the related construction issues will be presented together with the operational experience gained during the PS 2002 run. In addition, the experience of two years of operation with the new generation septum 23, used for a resonant slow extraction, will be briefly discussed. The continued development undertaken since its installation in the PS ring in 2001 will also be described.

  12. A&T Sector Note on the PS transverse feedback

    CERN Document Server

    Coly, Marcel; Blas, Alfred; Sterbini, Guido; CERN. Geneva. ATS Department

    2017-01-01

    In a particle accelerator, several contributions can degrade the beam quality and particularly the beam transverse emittance. In this document we will describe a system used in the CERN Proton Synchrotron (PS) to cope with the injection steering errors and the transverse instabilities: the PS transverse feedback (PS TFB). As time progresses, this system is also being used for other purpose, to increase in a controlled way the beam transverse emittance and to excite the beam for the Multi-Turn-Extraction (MTE). In 2016, it has been successfully used on some operational beams to damp injection oscillations. This allowed to test the reliability of the system for its operational deployment. A piquet service is available in case of problem.

  13. SAFETY: STRICTER CONTROLS IN CONTROLLED AREAS IN THE PS

    CERN Document Server

    G. Daems

    2001-01-01

    The PS accelerators will soon stop for several months. Work will take place in controlled areas in the PS and will involve many people who are not always aware of the risks associated with the work sites. To guarentee the safety of these workers, the following two measures will be applied: everyone working in a controlled zone - Linacs, PSB, and PS machines tunnels, and transfer lines - must wear, visibly, his CERN access card and his film badge. the CERN access card and the film badge will only be issued after following a basic safety course. Regular checks will be carried out during the shutdown. Anyone without these two items on their person will be obliged to leave the area immediately.

  14. Electrophysical properties of PMN-PT-PS-PFN:Li ceramics

    Directory of Open Access Journals (Sweden)

    R. Skulski

    2013-01-01

    Full Text Available We present the technology of obtaining and the electrophysical properties of a multicomponent material 0.61PMN-0.20PT-0.09PS-0.1PFN:Li (PMN-PT-PS-PFN:Li. The addition of PFN into PMN-PT decreases the temperature of final sintering which is very important during technological process (addition of Li decreases electric conductivity of PFN. Addition of PS i.e., PbSnO3 (which is unstable in ceramic form permits to shift the temperature of the maximum of dielectric permittivity. One-step method of obtaining ceramic samples from oxides and carbonates has been used. XRD, microstructure, scanning calorimetry measurements and the main dielectric, ferroelectric and electromechanical properties have been investigated for the obtained samples.

  15. Apparatus to measure the vapor pressure of slowly decomposing compounds from 1 Pa to 105 Pa

    Science.gov (United States)

    Berg, Robert F.

    2016-01-01

    This article describes an apparatus and method for measuring vapor pressures in the range from 1 Pa to 105 Pa. Its three distinctive elements are : (1) the static pressure measurements were made with only a small temperature difference between the vapor and the condensed phase, (2) the sample was degassed in situ, and (3) the temperature range extended up to 200 °C. The apparatus was designed to measure metal-organic precursors, which often are toxic, pyrophoric, or unstable. Vapor pressures are presented for naphthalene, ferrocene, diethyl phthalate, and TEMAH (tetrakisethylmethylaminohafnium). Also presented are data for the temperature-dependent decomposition rate of TEMAH. PMID:27274567

  16. Effect of interfaces on the melting of PEO confined in triblock PS-b-PEO-b-PS copolymers.

    Science.gov (United States)

    Beaudoin, E; Phan, T N T; Robinet, M; Denoyel, R; Davidson, P; Bertin, D; Bouchet, R

    2013-08-27

    Block copolymers form nanostructures that have interesting physical properties because they combine, for a single compound, the complementary features brought by each block. However, in order to fully exploit these properties, the physical state of each kind of domain must be precisely controlled. In this work, triblock PS-b-PEO-b-PS copolymers consisting of a central poly(ethylene oxide) (PEO) block covalently bonded to polystyrene (PS) blocks were synthesized by Atom Transfer Radical Polymerization. Their morphology was investigated by X-ray scattering and TEM experiments whereas their thermodynamic behavior was characterized by DSC. A strong decrease of both the melting temperature and the degree of crystallinity of PEO, due to its confinement between the PS domains, was observed and analyzed with a modified Gibbs-Thomson equation, following the approaches used for fluids confined in porous media. The existence of an amorphous bound layer, a few nanometers thick, at the PEO/PS interface, that does not undergo any phase transition in the temperature range investigated, accounts for both the melting temperature depression and the decrease of crystallinity upon confinement. This interfacial layer may significantly affect the mechanical and transport properties of these block copolymers that find applications as solid polymer electrolytes in batteries for example. Moreover, the value obtained for the solid PEO/liquid PEO surface tension is lower than those previously published but is thermodynamically consistent with the surface tensions of polymers at the solid/vapor and liquid/vapor interfaces.

  17. Oligoribonuclease is required for the type III secretion system and pathogenesis of Pseudomonas aeruginosa.

    Science.gov (United States)

    Chen, Gukui; Zhao, Qiang; Zhu, Feng; Chen, Ronghao; Jin, Yongxin; Liu, Chang; Pan, Xiaolei; Jin, Shouguang; Wu, Weihui; Cheng, Zhihui

    2016-01-01

    Oligoribonuclease (Orn) is a 3' to 5' exonuclease that degrades nanoRNAs, which can serve as primers for transcription initiation at a significant fraction of promoters. One of Orn's substrates, pGpG inhibits the enzymatic activity of EAL-domain containing phosphodiesterases (PDEs), thereby increasing intracellular cyclic-di-GMP (c-di-GMP) level. Here, we found that an orn mutant of Pseudomonas aeruginosa displayed reduced cytotoxicity, which was mainly due to deficient type III secretion system (T3SS). Given the importance of T3SS in pathogenicity, we examined the bacterial virulence in a mouse acute pneumonia model and found that the Δorn mutant was highly attenuated compared to the wild type PA14 strain. Overexpression of an EAL domain-containing PDE reduced the c-di-GMP level as well as biofilm formation in the Δorn mutant. However, no effect was observed on the expression of T3SS genes, suggesting that increased c-di-GMP level is not the solely cause of defective T3SS in the Δorn mutant. Overall, our results demonstrated an essential role of Orn in the expression of T3SS as well as pathogenesis of P. aeruginosa. Copyright © 2016 Elsevier GmbH. All rights reserved.

  18. Inauguration of POPS: the new power system of the PS

    CERN Multimedia

    Maximilien Brice

    2010-01-01

    Pictures 03 and 04 : The team from the Electrical Power Converters Group (TE/EPC) is joined by the Director of Accelerators, the heads of the BE, TE and FI departments, CERN managers and Converteam representatives in a group portrait in front of three of the containers that house the capacitor banks of the PS's new power supply system, POPS. Pictures 01, 06 and 07 : Magid-Michel Saikaly, energy and infrastructure director at Converteam, receives a prize from Steve Myers, Director of Accelerators at CERN, for the development and fabrication of the new electrical power system for the PS, called POPS.

  19. The Septa for LEIR Extraction and PS Injection

    CERN Document Server

    Borburgh, J; Masson, T; Prost, A

    2006-01-01

    The Low Energy Ion Ring (LEIR) is part of the CERN LHC injector chain for ions. The LEIR extraction uses a pulsed magnetic septum, clamped around a metallic vacuum chamber. Apart from separating the ultra high vacuum in the LEIR ring from the less good vacuum in the transfer line to the PS this chamber also serves as magnetic screen and retains the septum conductor in place. The PS ion injection septum consists of a pulsed laminated magnet under vacuum, featuring a single-turn water cooled coil and a remote positioning system. The design, the construction and the commissioning of both septa are described.

  20. Biotransformation of myrcene by Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Hashemi Elham

    2011-05-01

    Full Text Available Abstract Background Dihydrolinalool and terpineol are sources of fragrances that provide a unique volatile terpenoid alcohol of low toxicity and thus are widely used in the perfumery industry, in folk medicine, and in aromatherapy. They are important chemical constituents of the essential oil of many plants. Previous studies have concerned the biotransformation of limonene by Pseudomonas putida. The objective of this research was to study biotransformation of myrcene by Pseudomonas aeruginosa. The culture preparation was done using such variables as different microbial methods and incubation periods to obtain maximum cells of P. aeruginosa for myrcene biotransformation. Results It was found that myrcene was converted to dihydrolinalool and 2,6-dimethyloctane in high percentages. The biotransformation products were identified by Fourier-transform infrared spectroscopy (FT-IR, ultraviolet (UV analysis, gas chromatography (GC, and gas chromatography-mass spectroscopy (GC-MS. Comparison of the different incubation times showed that 3 days was more effective, the major products being 2,6-dimethyloctane (90.0% and α-terpineol (7.7% and comprising 97.7%. In contrast, the main compounds derived for an incubation time of 1.5 days were dihydrolinalool (79.5% and 2,6-dimethyloctane (9.3%, with a total yield of 88.8%.

  1. Evidence that a novel quaternary compound and its organic N-chloramine derivative do not select for resistant mutants of Pseudomonas aeruginosa.

    Science.gov (United States)

    De Silva, M; Ning, C; Ghanbar, S; Zhanel, G; Logsetty, S; Liu, S; Kumar, A

    2015-09-01

    Pseudomonas aeruginosa is well known for causing hospital-acquired infections that are often difficult to treat because of its high intrinsic and acquired resistance to antibiotics. Resistance-nodulation-division (RND) efflux pumps are the major contributors to the intrinsic multidrug resistance (MDR) in this organism. Various biocides used in hospital settings have been shown to select for RND-pump-overexpressing mutants of P. aeruginosa that show cross-resistance to clinically relevant antibiotics. Therefore, finding biocides that do not select for multidrug-resistant mutants is important in controlling the spread of bacteria such as P. aeruginosa. To evaluate the potential of a novel quaternary ammonium compound and its N-chloramine derivative in selecting for MDR mutants of P. aeruginosa. P. aeruginosa PA01 was cultured in the presence of increasing concentrations of the quaternary ammonium compound and its N-chloramine derivative respectively, and one mutant each selected. Susceptibility of the mutants to both compounds as well as antibiotics was tested. Susceptibility of P. aeruginosa strains with deletions in RND pumps was also tested for both compounds to determine whether they are a substrate of these pumps. Expression of mexB, mexD, and mexY genes in the mutants was analysed using quantitative reverse transcriptase-polymerase chain reaction to determine whether the compounds can select for pump-overexpressing mutants. We show that whereas both compounds can be pumped by the MexCD-OprJ pump, they neither select for mutants that overexpress RND pumps nor for mutants that display cross-resistance to antibiotics. These compounds are promising candidates to be used as disinfectants in hospital settings. Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  2. Pyocyanin effects on respiratory epithelium: relevance in Pseudomonas aeruginosa airway infections.

    Science.gov (United States)

    Rada, Balázs; Leto, Thomas L

    2013-02-01

    Pseudomonas aeruginosa (PA) uses several virulence factors to establish chronic respiratory infections in bronchiectasis, chronic obstructive pulmonary disease, and cystic fibrosis (CF) patients. One of its toxins, pyocyanin (PYO), is a redox-active pigment that is required for full virulence in animal models and has been detected in patients' airway secretions. PYO promotes virulence by interfering with several cellular functions in host cells including electron transport, cellular respiration, energy metabolism, gene expression, and innate immune mechanisms. This review summarizes recent advances in PYO biology with special attention to current views on its role in human airway infections and on its interactions with the first line of our airway defense, the respiratory epithelium. Published by Elsevier Ltd.

  3. Epigenetic control of virulence gene expression in Pseudomonas aeruginosa by a LysR-type transcription regulator.

    Directory of Open Access Journals (Sweden)

    Keith H Turner

    2009-12-01

    Full Text Available Phenotypic variation within an isogenic bacterial population is thought to ensure the survival of a subset of cells in adverse conditions. The opportunistic pathogen Pseudomonas aeruginosa variably expresses several phenotypes, including antibiotic resistance, biofilm formation, and the production of CupA fimbriae. Here we describe a previously unidentified bistable switch in P. aeruginosa. This switch controls the expression of a diverse set of genes, including aprA, which encodes the secreted virulence factor alkaline protease. We present evidence that bistable expression of PA2432, herein named bexR (bistable expression regulator, which encodes a LysR-type transcription regulator, controls this switch. In particular, using DNA microarrays, quantitative RT-PCR analysis, chromatin immunoprecipitation, and reporter gene fusions, we identify genes directly under the control of BexR and show that these genes are bistably expressed. Furthermore, we show that bexR is itself bistably expressed and positively autoregulated. Finally, using single-cell analyses of a GFP reporter fusion, we present evidence that positive autoregulation of bexR is necessary for bistable expression of the BexR regulon. Our findings suggest that a positive feedback loop involving a LysR-type transcription regulator serves as the basis for an epigenetic switch that controls virulence gene expression in P. aeruginosa.

  4. The OMERACT psoriatic arthritis magnetic resonance imaging scoring system (PsAMRIS): definitions of key pathologies, suggested MRI sequences, and preliminary scoring system for PsA Hands

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; McQueen, Fiona; Wiell, Charlotte

    2009-01-01

    This article describes a preliminary OMERACT psoriatic arthritis magnetic resonance image scoring system (PsAMRIS) for evaluation of inflammatory and destructive changes in PsA hands, which was developed by the international OMERACT MRI in inflammatory arthritis group. MRI definitions of important...... pathologies in peripheral PsA and suggestions concerning appropriate MRI sequences for use in PsA hands are also provided....

  5. PaDe - The particle detection program

    Science.gov (United States)

    Ott, T.; Drolshagen, E.; Koschny, D.; Poppe, B.

    2016-01-01

    This paper introduces the Particle Detection program PaDe. Its aim is to analyze dust particles in the coma of the Jupiter-family comet 67P/Churyumov-Gerasimenko which were recorded by the two OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) cameras onboard the ESA spacecraft Rosetta, see e.g. Keller et al. (2007). In addition to working with the Rosetta data, the code was modified to work with images from meteors. It was tested with data recorded by the ICCs (Intensified CCD Cameras) of the CILBO-System (Canary Island Long-Baseline Observatory) on the Canary Islands; compare Koschny et al. (2013). This paper presents a new method for the position determination of the observed meteors. The PaDe program was written in Python 3.4. Its original intent is to find the trails of dust particles in space from the OSIRIS images. For that it determines the positions where the trail starts and ends. They were found using a fit following the so-called error function (Andrews, 1998) for the two edges of the profiles. The positions where the intensities fall to the half maximum were found to be the beginning and end of the particle. In the case of meteors, this method can be applied to find the leading edge of the meteor. The proposed method has the potential to increase the accuracy of the position determination of meteors dramatically. Other than the standard method of finding the photometric center, our method is not influenced by any trails or wakes behind the meteor. This paper presents first results of this ongoing work.

  6. Stent-retriever thrombectomy after intravenous t-PA vs. t-PA alone in stroke

    DEFF Research Database (Denmark)

    Saver, Jeffrey L; Goyal, Mayank; Bonafe, Alain

    2015-01-01

    BACKGROUND: Among patients with acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, less than 40% regain functional independence when treated with intravenous tissue plasminogen activator (t-PA) alone. Thrombectomy with the use of a stent retriever, in addit...

  7. Inhibition of Aspergillus fumigatus and Its Biofilm by Pseudomonas aeruginosa Is Dependent on the Source, Phenotype and Growth Conditions of the Bacterium.

    Directory of Open Access Journals (Sweden)

    Jose A G Ferreira

    Full Text Available Aspergillus fumigatus (Af and Pseudomonas aeruginosa (Pa are leading fungal and bacterial pathogens, respectively, in many clinical situations. Relevant to this, their interface and co-existence has been studied. In some experiments in vitro, Pa products have been defined that are inhibitory to Af. In some clinical situations, both can be biofilm producers, and biofilm could alter their physiology and affect their interaction. That may be most relevant to airways in cystic fibrosis (CF, where both are often prominent residents. We have studied clinical Pa isolates from several sources for their effects on Af, including testing involving their biofilms. We show that the described inhibition of Af is related to the source and phenotype of the Pa isolate. Pa cells inhibited the growth and formation of Af biofilm from conidia, with CF isolates more inhibitory than non-CF isolates, and non-mucoid CF isolates most inhibitory. Inhibition did not require live Pa contact, as culture filtrates were also inhibitory, and again non-mucoid>mucoid CF>non-CF. Preformed Af biofilm was more resistant to Pa, and inhibition that occurred could be reproduced with filtrates. Inhibition of Af biofilm appears also dependent on bacterial growth conditions; filtrates from Pa grown as biofilm were more inhibitory than from Pa grown planktonically. The differences in Pa shown from these different sources are consistent with the extensive evolutionary Pa changes that have been described in association with chronic residence in CF airways, and may reflect adaptive changes to life in a polymicrobial environment.

  8. Pseudomonas aeruginosa MifS-MifR Two-Component System Is Specific for α-Ketoglutarate Utilization.

    Directory of Open Access Journals (Sweden)

    Gorakh Tatke

    Full Text Available Pseudomonas aeruginosa is a Gram-negative, metabolically versatile opportunistic pathogen that elaborates a multitude of virulence factors, and is extraordinarily resistant to a gamut of clinically significant antibiotics. This ability, in part, is mediated by two-component regulatory systems (TCS that play a crucial role in modulating virulence mechanisms and metabolism. MifS (PA5512 and MifR (PA5511 form one such TCS implicated in biofilm formation. MifS is a sensor kinase whereas MifR belongs to the NtrC superfamily of transcriptional regulators that interact with RpoN (σ54. In this study we demonstrate that the mifS and mifR genes form a two-gene operon. The close proximity of mifSR operon to poxB (PA5514 encoding a ß-lactamase hinted at the role of MifSR TCS in regulating antibiotic resistance. To better understand this TCS, clean in-frame deletions were made in P. aeruginosa PAO1 creating PAO∆mifS, PAO∆mifR and PAO∆mifSR. The loss of mifSR had no effect on the antibiotic resistance profile. Phenotypic microarray (BioLOG analyses of PAO∆mifS and PAO∆mifR revealed that these mutants were unable to utilize C5-dicarboxylate α-ketoglutarate (α-KG, a key tricarboxylic acid cycle intermediate. This finding was confirmed using growth analyses, and the defect can be rescued by mifR or mifSR expressed in trans. These mifSR mutants were able to utilize all the other TCA cycle intermediates (citrate, succinate, fumarate, oxaloacetate or malate and sugars (glucose or sucrose except α-KG as the sole carbon source. We confirmed that the mifSR mutants have functional dehydrogenase complex suggesting a possible defect in α-KG transport. The inability of the mutants to utilize α-KG was rescued by expressing PA5530, encoding C5-dicarboxylate transporter, under a regulatable promoter. In addition, we demonstrate that besides MifSR and PA5530, α-KG utilization requires functional RpoN. These data clearly suggests that P. aeruginosa MifSR TCS

  9. Regulation of endothelial cell t-PA synthesis and release

    NARCIS (Netherlands)

    Kooistra, T.; Schrauwen, Y.; Arts, J.; Emeis, J.J.

    1994-01-01

    The fibrinolytic activity of blood is to a large extent determined by the plasma level of tissue-type plasminogen activator (t-PA). Changes in the plasma level of t-PA are mainly achieved by the endothelium by two mechanisms: (a) a rapid, short-term release of t-PA, which occurs within minutes

  10. Gene ercA, encoding a putative iron-containing alcohol dehydrogenase, is involved in regulation of ethanol utilization in Pseudomonas aeruginosa.

    Science.gov (United States)

    Hempel, Niels; Görisch, Helmut; Mern, Demissew S

    2013-09-01

    Several two-component regulatory systems are known to be involved in the signal transduction pathway of the ethanol oxidation system in Pseudomonas aeruginosa ATCC 17933. These sensor kinases and response regulators are organized in a hierarchical manner. In addition, a cytoplasmic putative iron-containing alcohol dehydrogenase (Fe-ADH) encoded by ercA (PA1991) has been identified to play an essential role in this regulatory network. The gene ercA (PA1991) is located next to ercS, which encodes a sensor kinase. Inactivation of ercA (PA1991) by insertion of a kanamycin resistance cassette created mutant NH1. NH1 showed poor growth on various alcohols. On ethanol, NH1 grew only with an extremely extended lag phase. During the induction period on ethanol, transcription of structural genes exa and pqqABCDEH, encoding components of initial ethanol oxidation in P. aeruginosa, was drastically reduced in NH1, which indicates the regulatory function of ercA (PA1991). However, transcription in the extremely delayed logarithmic growth phase was comparable to that in the wild type. To date, the involvement of an Fe-ADH in signal transduction processes has not been reported.

  11. Mast cells protect against Pseudomonas aeruginosa-induced lung injury.

    Science.gov (United States)

    Junkins, Robert D; Carrigan, Svetlana O; Wu, Zhengli; Stadnyk, Andrew W; Cowley, Elizabeth; Issekutz, Thomas; Berman, Jason; Lin, Tong-Jun

    2014-08-01

    Pseudomonas aeruginosa, an opportunistic pathogen, is the leading cause of morbidity and mortality in immune-compromised individuals. Maintaining the integrity of the respiratory epithelium is critical for an effective host response to P. aeruginosa. Given the close spatial relationship between mast cells and the respiratory epithelium, and the importance of tightly regulated epithelial permeability during lung infections, we examined whether mast cells influence airway epithelial integrity during P. aeruginosa lung infection in a mouse model. We found that mast cell-deficient Kit(W-sh)/Kit(W-sh) mice displayed greatly increased epithelial permeability, bacterial dissemination, and neutrophil accumulation compared with wild-type animals after P. aeruginosa infection; these defects were corrected on reconstitution with mast cells. An in vitro Transwell co-culture model further demonstrated that a secreted mast cell factor decreased epithelial cell apoptosis and tumor necrosis factor production after P. aeruginosa infection. Together, our data demonstrate a previously unrecognized role for mast cells in the maintenance of epithelial integrity during P. aeruginosa infection, through a mechanism that likely involves prevention of epithelial apoptosis and tumor necrosis factor production. Our understanding of mechanisms of the host response to P. aeruginosa will open new avenues for the development of successful preventative and treatment strategies. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  12. Pseudomonas aeruginosa in premise plumbing of large buildings.

    Science.gov (United States)

    Bédard, Emilie; Prévost, Michèle; Déziel, Eric

    2016-12-01

    Pseudomonas aeruginosa is an opportunistic bacterial pathogen that is widely occurring in the environment and is recognized for its capacity to form or join biofilms. The present review consolidates current knowledge on P. aeruginosa ecology and its implication in healthcare facilities premise plumbing. The adaptability of P. aeruginosa and its capacity to integrate the biofilm from the faucet and the drain highlight the role premise plumbing devices can play in promoting growth and persistence. A meta-analysis of P. aeruginosa prevalence in faucets (manual and electronic) and drains reveals the large variation in device positivity reported and suggest the high variability in the sampling approach and context as the main reason for this variation. The effects of the operating conditions that prevail within water distribution systems (disinfection, temperature, and hydraulic regime) on the persistence of P. aeruginosa are summarized. As a result from the review, recommendations for proactive control measures of water contamination by P. aeruginosa are presented. A better understanding of the ecology of P. aeruginosa and key influencing factors in premise plumbing are essential to identify culprit areas and implement effective control measures. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  13. Interactions between Neutrophils and Pseudomonas aeruginosa in Cystic Fibrosis

    Science.gov (United States)

    Rada, Balázs

    2017-01-01

    Cystic fibrosis (CF) affects 70,000 patients worldwide. Morbidity and mortality in CF is largely caused by lung complications due to the triad of impaired mucociliary clearance, microbial infections and chronic inflammation. Cystic fibrosis airway inflammation is mediated by robust infiltration of polymorphonuclear neutrophil granulocytes (PMNs, neutrophils). Neutrophils are not capable of clearing lung infections and contribute to tissue damage by releasing their dangerous cargo. Pseudomonas aeruginosa is an opportunistic pathogen causing infections in immunocompromised individuals. P. aeruginosa is a main respiratory pathogen in CF infecting most patients. Although PMNs are key to attack and clear P. aeruginosa in immunocompetent individuals, PMNs fail to do so in CF. Understanding why neutrophils cannot clear P. aeruginosa in CF is essential to design novel therapies. This review provides an overview of the antimicrobial mechanisms by which PMNs attack and eliminate P. aeruginosa. It also summarizes current advances in our understanding of why PMNs are incapable of clearing P. aeruginosa and how this bacterium adapts to and resists PMN-mediated killing in the airways of CF patients chronically infected with P. aeruginosa. PMID:28282951

  14. Dynorphin activates quorum sensing quinolone signaling in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Olga Zaborina

    2007-03-01

    Full Text Available There is now substantial evidence that compounds released during host stress directly activate the virulence of certain opportunistic pathogens. Here, we considered that endogenous opioids might function as such compounds, given that they are among the first signals to be released at multiple tissue sites during host stress. We tested the ability of various opioid compounds to enhance the virulence of Pseudomonas aeruginosa using pyocyanin production as a biological readout, and demonstrated enhanced virulence when P. aeruginosa was exposed to synthetic (U-50,488 and endogenous (dynorphin kappa-agonists. Using various mutants and reporter strains of P. aeruginosa, we identified involvement of key elements of the quorum sensing circuitry such as the global transcriptional regulator MvfR and the quorum sensing-related quinolone signaling molecules PQS, HHQ, and HQNO that respond to kappa-opioids. The in vivo significance of kappa-opioid signaling of P. aeruginosa was demonstrated in mice by showing that dynorphin is released from the intestinal mucosa following ischemia/reperfusion injury, activates quinolone signaling in P. aeruginosa, and enhances the virulence of P. aeruginosa against Lactobacillus spp. and Caenorhabditis elegans. Taken together, these data demonstrate that P. aeruginosa can intercept opioid compounds released during host stress and integrate them into core elements of quorum sensing circuitry leading to enhanced virulence.

  15. Optimization of protease production by an actinomycete Strain, PS ...

    African Journals Online (AJOL)

    Actinomycetes were isolated from the sediment samples of an estuarine shrimp pond located along the south east coast of India. During the investigation, a total of 28 strains of actinomycetes were isolated and examined for their protease activity. Among them, one strain PS-18A which was tentatively identified as ...

  16. Seismic receiver function interpretation: Ps splitting or anisotropic underplating?

    Science.gov (United States)

    Liu, Zhen; Park, Jeffrey

    2017-03-01

    Crustal anisotropy is crucial to understanding the evolutionary history of Earth's lithosphere. Shear wave splitting of Moho P-to-S converted phases in receiver functions (RFs) have been often used to study crustal anisotropy. Harmonic variation of Moho Ps phases in delay times are used to infer splitting parameters of averaged anisotropy in the crust. However, crustal anisotropy may distribute at various levels within the crust due to complex deformational processes. Layered anisotropy requires careful investigation of the distribution of anisotropy before interpreting Moho Ps splitting. In this study, we show results from stations ARU in Russia, KIP in the Hawaiian Islands and LSA in Tibetan Plateau, where layered anisotropy is constrained well by intracrust Ps conversions at high frequencies using a harmonic-decomposition technique. Anisotropic velocity models are inferred by forward-modeling decomposed RF waveforms. We suggest that the harmonic variation of Moho Ps phases should always be investigated to check for anisotropic layering using RFs with frequency content above 1 Hz, rather than simply reporting averaged anisotropy of the whole crust.

  17. Optimization of protease production by an actinomycete Strain, PS ...

    African Journals Online (AJOL)

    STORAGESEVER

    Isolation Agar Medium in duplicate Petri plates. To minimize ... on the Petri plates were counted from 5th day onwards, up to 28th .... After the dialysis, the volume was measured and analyzed for proteins and stored in deep freezer. Taxonomic investigation. The genus level identification was made for the strain PS-18A using ...

  18. Framing Retention for Institutional Improvement: A 4 Ps Framework

    Science.gov (United States)

    Kalsbeek, David H.

    2013-01-01

    A 4 Ps framework for student retention strategy is a construct for reframing the retention discussion in a way that enables institutional improvement by challenging some conventional wisdom and prevailing perspectives that have characterized retention strategy for years. It opens new possibilities for action and improvement by suggesting that…

  19. Multipole stack for the 4 rings of the PS Booster

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    The PS Booster (originally 800 MeV, now 1.4 GeV) saw first beam in 1972, routine operation began in 1973. The strive for ever higher intensities required the addition of multipoles. Manufacture of 8 stacks of multipoles was launched in 1974, for installation in 1976. For details, see 7511120X.

  20. The Swelling Behaviour of Polystyrene (PS)/ Polyvinylacetate (Pvac ...

    African Journals Online (AJOL)

    The effect of the variation of the type of solvent responsible for the differences in the swelling kinetics of Polystyrene (PS) and Polyvinyl acetate (PVAc) blends was studied. The results showed that the nature of solvent control or affects the degree of swelling. Also, 1-V characteristics at temperature range of 323-363K shows ...

  1. Boiling treatment of ABS and PS plastics for flotation separation.

    Science.gov (United States)

    Wang, Chong-qing; Wang, Hui; Wu, Bao-xin; Liu, Qun

    2014-07-01

    A new physical method, namely boiling treatment, was developed to aid flotation separation of acrylonitrile-butadiene-styrene (ABS) and polystyrene (PS) plastics. Boiling treatment was shown to be effective in producing a hydrophilic surface on ABS plastic. Fourier Transform Infrared analysis was conducted to investigate the mechanism of boiling treatment of ABS. Surface rearrangement of polymer may be responsible for surface change of boiling treated ABS, and the selective influence of boiling treatment on the floatability of boiling treated plastics may be attributed to the difference in the molecular mobility of polymer chains. The effects of flotation time, frother concentration and particle size on flotation behavior of simple plastic were investigated. Based on flotation behavior of simple plastic, flotation separation of boiling treatment ABS and PS with different particle sizes was achieved efficiently. The purity of ABS and PS was up to 99.78% and 95.80%, respectively; the recovery of ABS and PS was up to 95.81% and 99.82%, respectively. Boiling treatment promotes the industrial application of plastics flotation and facilitates plastic recycling. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Effective antibiotics in combination against extreme drug-resistant Pseudomonas aeruginosa with decreased susceptibility to polymyxin B.

    Directory of Open Access Journals (Sweden)

    Tze-Peng Lim

    Full Text Available OBJECTIVE: Extreme drug-resistant Pseudomonas aeruginosa (XDR-PA with decreased susceptibility to polymyxin B (PB has emerged in Singapore, causing infections in immunocompromised hosts. Combination therapy may be the only viable therapeutic option until new antibiotics become available. The objective of this study is to assess the in vitro activity of various antibiotics against local XDR-PA isolates. METHODS: PA isolates from all public hospitals in Singapore were systematically collected between 2006 and 2007. MICs were determined according to CLSI guidelines. All XDR-PA isolates identified were genotyped using a PCR-based method. Time-kill studies (TKS were performed with approximately 10(5 CFU/ml at baseline using clinically achievable unbound concentrations of amikacin (A, levofloxacin (L, meropenem (M, rifampicin (R and PB alone and in combination. Bactericidal activity (primary endpoint was defined as a ≥3 log(10 CFU/ml decrease in the colony count from the initial inoculum at 24 hours. RESULTS: 22 clinical XDR-PA isolates with PB MIC 2-16 µg/ml were collected. From clonal typing, 5 clonal groups were identified and nine isolates exhibited clonal diversity. In TKS, meropenem plus PB, amikacin plus meropenem, amikacin plus rifampicin, amikacin plus PB exhibited bactericidal activity in 8/22, 3/22, 1/22 and 6/22 isolates at 24 hours respectively. Against the remaining ten isolates where none of the dual-drug combination achieved bactericidal activity against, only the triple-antibiotic combinations of ARP and AMP achieved bactericidal activity against 7/10 and 6/10 isolates respectively. CONCLUSION: Bactericidal activity with sustained killing effect of ≥99.9% is critical for eradicating XDR-PA infections, especially in immunocompromised hosts. These findings underscore the difficulty of developing combination therapeutic options against XDR-PA, demonstrating that at least 3 antibiotics are required in combination and that efficacy is

  3. Structural and Molecular Mechanism of CdpR Involved in Quorum-Sensing and Bacterial Virulence in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Jingru Zhao

    2016-04-01

    Full Text Available Although quorum-sensing (QS systems are important regulators of virulence gene expression in the opportunistic human pathogen Pseudomonas aeruginosa, their detailed regulatory mechanisms have not been fully characterized. Here, we show that deletion of PA2588 resulted in increased production of pyocyanin and biofilm, as well as enhanced pathogenicity in a mouse model. To gain insights into the function of PA2588, we performed a ChIP-seq assay and identified 28 targets of PA2588, including the intergenic region between PA2588 and pqsH, which encodes the key synthase of Pseudomonas quinolone signal (PQS. Though the C-terminal domain was similar to DNA-binding regions of other AraC family members, structural studies revealed that PA2588 has a novel fold at the N-terminal region (NTR, and its C-terminal HTH (helix-turn-helix domain is also unique in DNA recognition. We also demonstrated that the adaptor protein ClpS, an essential regulator of ATP-dependent protease ClpAP, directly interacted with PA2588 before delivering CdpR to ClpAP for degradation. We named PA2588 as CdpR (ClpAP-degradation and pathogenicity Regulator. Moreover, deletion of clpP or clpS/clpA promotes bacterial survival in a mouse model of acute pneumonia infection. Taken together, this study uncovered that CdpR is an important QS regulator, which can interact with the ClpAS-P system to regulate the expression of virulence factors and pathogenicity.

  4. SuhB is a novel ribosome associated protein that regulates expression of MexXY by modulating ribosome stalling in Pseudomonas aeruginosa.

    Science.gov (United States)

    Shi, Jing; Jin, Yongxin; Bian, Ting; Li, Kewei; Sun, Ziyu; Cheng, Zhihui; Jin, Shouguang; Wu, Weihui

    2015-10-01

    Translation elongation is modulated by various ribosome-binding proteins. Environmental stresses, such as starvation and antibiotics, can cause stalling of bacterial ribosomes, which may alter gene expression through a transcription or translation attenuation mechanism. In Pseudomonas aeruginosa, the expression of MexXY multidrug efflux system, which plays a significant role in resistance against aminoglycoside antibiotics, is controlled by a translation surveillance mechanism. Stalling of ribosome at the PA5471 leader peptide (PA5471.1) mRNA leads to transcription of PA5471, which subsequently up-regulates the expression of MexXY. In this study, we found that mutation in a suhB gene leads to decreased susceptibility to aminoglycosides. Transcriptomic analysis revealed an up-regulation of MexXY and PA5471, which were demonstrated to be responsible for the decreased susceptibility of the suhB mutant. We further demonstrated that PA5471.1 is essential for the up-regulation of PA5471 in the suhB mutant. Co-immunoprecipitation assay revealed an interaction between SuhB and ribosome, suggesting a role of SuhB in translation. Indeed, higher amount of PA5471.1 mRNA was found to associate with ribosome isolated from the suhB mutant, indicating increased ribosome stalling. Therefore, this study identified SuhB as a novel ribosome associated protein that is involved in modulating ribosome activity. © 2015 John Wiley & Sons Ltd.

  5. Effect of dietary monosaccharides on Pseudomonas aeruginosa virulence.

    Science.gov (United States)

    Nelson, Ryan K; Poroyko, Valeriy; Morowitz, Michael J; Liu, Don; Alverdy, John C

    2013-02-01

    Pseudomonas aeruginosa is an opportunistic, gram-negative pathogen associated with many hospital-acquired infections and disease states. In particular, P. aeruginosa has been identified as a crucial factor in the pathogenesis of neonatal necrotizing enterocolitis (NEC). This condition presents more frequently in infants fed a formula-based diet, which may be a result of the specific monosaccharide content of this diet. We hypothesized that P. aeruginosa would express virulence genes differentially when exposed to monosaccharides present in formula versus those in human milk. Using the results of a metabolomics study on infant diets and their resulting fecal samples, we identified several monosaccharides that distinguished milk from formula diets. Of these compounds, four were found to be metabolized by P. aeruginosa. We subsequently grew P. aeruginosa in tryptic soy broth (TSB) supplemented with these four monosaccharides and used quantitative reverse transcriptase-polymerase chain reaction to measure the expression of 59 major P. aeruginosa virulence genes. The results were standardized to an external control of P. aeruginosa grown in TSB alone. P. aeruginosa did not respond differentially to the monosaccharides after 6 h of growth. However, after 24 h, the organism grown in arabinose (present in formula), xylose (present in human milk), and galactose (present in both formula and feces from milk-fed infants) displayed a significant increase in the expression of virulence genes in all categories. In contrast, P. aeruginosa grown in mannose (present in the feces of milk-fed infants) displayed a significant decrease in virulence gene expression. These results demonstrate the importance of nutrient content on the relative expression of virulence genes in pathogens that colonize commonly the gut of infants. Understanding the effect of current dietary formulas on virulence gene expression in various gut-colonizing pathogens may present a new approach to elucidating the

  6. Type VI Secretion System in Pseudomonas aeruginosa

    Science.gov (United States)

    Hachani, Abderrahman; Lossi, Nadine S.; Hamilton, Alexander; Jones, Cerith; Bleves, Sophie; Albesa-Jové, David; Filloux, Alain

    2011-01-01

    Pseudomonas aeruginosa is a Gram-negative bacterium causing chronic infections in cystic fibrosis patients. Such infections are associated with an active type VI secretion system (T6SS), which consists of about 15 conserved components, including the AAA+ ATPase, ClpV. The T6SS secretes two categories of proteins, VgrG and Hcp. Hcp is structurally similar to a phage tail tube component, whereas VgrG proteins show similarity to the puncturing device at the tip of the phage tube. In P. aeruginosa, three T6SSs are known. The expression of H1-T6SS genes is controlled by the RetS sensor. Here, 10 vgrG genes were identified in the PAO1 genome, among which three are co-regulated with H1-T6SS, namely vgrG1a/b/c. Whereas VgrG1a and VgrG1c were secreted in a ClpV1-dependent manner, secretion of VgrG1b was ClpV1-independent. We show that VgrG1a and VgrG1c form multimers, which confirmed the VgrG model predicting trimers similar to the tail spike. We demonstrate that Hcp1 secretion requires either VgrG1a or VgrG1c, which may act independently to puncture the bacterial envelope and give Hcp1 access to the surface. VgrG1b is not required for Hcp1 secretion. Thus, VgrG1b does not require H1-T6SS for secretion nor does H1-T6SS require VgrG1b for its function. Finally, we show that VgrG proteins are required for secretion of a genuine H1-T6SS substrate, Tse3. Our results demonstrate that VgrG proteins are not only secreted components but are essential for secretion of other T6SS substrates. Overall, we emphasize variability in behavior of three P. aeruginosa VgrGs, suggesting that, although very similar, distinct VgrGs achieve specific functions. PMID:21325275

  7. psRNATarget: a plant small RNA target analysis server.

    Science.gov (United States)

    Dai, Xinbin; Zhao, Patrick Xuechun

    2011-07-01

    Plant endogenous non-coding short small RNAs (20-24 nt), including microRNAs (miRNAs) and a subset of small interfering RNAs (ta-siRNAs), play important role in gene expression regulatory networks (GRNs). For example, many transcription factors and development-related genes have been reported as targets of these regulatory small RNAs. Although a number of miRNA target prediction algorithms and programs have been developed, most of them were designed for animal miRNAs which are significantly different from plant miRNAs in the target recognition process. These differences demand the development of separate plant miRNA (and ta-siRNA) target analysis tool(s). We present psRNATarget, a plant small RNA target analysis server, which features two important analysis functions: (i) reverse complementary matching between small RNA and target transcript using a proven scoring schema, and (ii) target-site accessibility evaluation by calculating unpaired energy (UPE) required to 'open' secondary structure around small RNA's target site on mRNA. The psRNATarget incorporates recent discoveries in plant miRNA target recognition, e.g. it distinguishes translational and post-transcriptional inhibition, and it reports the number of small RNA/target site pairs that may affect small RNA binding activity to target transcript. The psRNATarget server is designed for high-throughput analysis of next-generation data with an efficient distributed computing back-end pipeline that runs on a Linux cluster. The server front-end integrates three simplified user-friendly interfaces to accept user-submitted or preloaded small RNAs and transcript sequences; and outputs a comprehensive list of small RNA/target pairs along with the online tools for batch downloading, key word searching and results sorting. The psRNATarget server is freely available at http://plantgrn.noble.org/psRNATarget/.

  8. Secretome of transmissible Pseudomonas aeruginosa AES-1R grown in a cystic fibrosis lung-like environment.

    Science.gov (United States)

    Scott, Nichollas E; Hare, Nathan J; White, Melanie Y; Manos, Jim; Cordwell, Stuart J

    2013-12-06

    Pseudomonas aeruginosa is the predominant cause of mortality in patients with cystic fibrosis (CF). We examined the secretome of an acute, transmissible CF P. aeruginosa (Australian epidemic strain 1-R; AES-1R) compared with laboratory-adapted PAO1. Culture supernatant proteins from rich (LB) and minimal (M9) media were compared using 2-DE and 2DLC-MS/MS, which revealed elevated abundance of PasP protease and absence of AprA protease in AES-1R. CF lung-like artificial sputum medium (ASMDM) contains serum and mucin that generally preclude proteomics of secreted proteins. ASMDM culture supernatants were subjected to 2DLC-MS/MS, which allowed the identification of 57 P. aeruginosa proteins, and qualitative spectral counting was used to estimate relative abundance. AES-1R-specific AES_7139 and PasP were more abundant in AES-1R ASMDM culture supernatants, while AprA could only be identified in PAO1. Relative quantitation was performed using selected reaction monitoring. Significantly elevated levels of PasP, LasB, chitin-binding protein (CbpD), and PA4495 were identified in AES-1R ASMDM supernatants. Quantitative PCR showed elevated pasP in AES-1R during early (18 h) ASMDM growth, while no evidence of aprA expression could be observed. Genomic screening of CF isolates revealed aes_7139 was present in all AES-1 and one pair of sequential nonepidemic isolates. Secreted proteins may be crucial in aiding CF-associated P. aeruginosa to establish infection and for adaptation to the CF lung.

  9. Development of potent inhibitors of pyocyanin production in Pseudomonas aeruginosa.

    Science.gov (United States)

    Miller, Laura C; O'Loughlin, Colleen T; Zhang, Zinan; Siryaporn, Albert; Silpe, Justin E; Bassler, Bonnie L; Semmelhack, Martin F

    2015-02-12

    The development of new approaches for the treatment of antimicrobial-resistant infections is an urgent public health priority. The Pseudomonas aeruginosa pathogen, in particular, is a leading source of infection in hospital settings, with few available treatment options. In the context of an effort to develop antivirulence strategies to combat bacterial infection, we identified a series of highly effective small molecules that inhibit the production of pyocyanin, a redox-active virulence factor produced by P. aeruginosa. Interestingly, these new antagonists appear to suppress P. aeruginosa virulence factor production through a pathway that is independent of LasR and RhlR.

  10. Comparison of transcriptomes of wild-type and isothiazolone-resistant Pseudomonas aeruginosa by using RNA-seq.

    Science.gov (United States)

    Zhou, Gang; Shi, Qing-Shan; Huang, Xiao-Mo; Xie, Xiao-Bao

    2016-06-01

    Isothiazolone biocides (such as Kathon) are widely used in a variety of industrial and domestic applications. However, the mechanisms through which bacteria develop resistance to these biocides are not completely clear. A better understanding of these mechanisms can contribute to optimal use of these biocides. In this study, transcription profiles of a Kathon-resistant strain of Pseudomonas aeruginosa (Pa-R) and the wild-type strain were determined using RNA sequencing (RNA-Seq) with the Illumina HiSeq 2000 platform. RNA-Seq generated 18,657,896 sequence reads aligned to 7093 genes. In all, 1550 differently expressed genes (DEGs, log2 ratio ≥1, false discovery rate (FDR) ≤0.001) were identified, of which 482 were up-regulated and 1068 were down-regulated. Most Kathon-induced genes were involved in metabolic and cellular processes. DEGs significantly enriched nitrogen metabolism and oxidative phosphorylation pathways. In addition, Pa-R showed cross-resistance to triclosan and ciprofloxacin and showed repressed pyocyanin production. These results may improve our understanding of the resistance mechanisms of P. aeruginosa against isothiazolones, and provide insight into the development of more efficient isothiazolones.

  11. Studies on EB radiation effect on PA610

    Energy Technology Data Exchange (ETDEWEB)

    Yang Kebin; Zhang Huaming; Li Xiurong; Xiong Ruilin [Sichuan Forever Group Co. Ltd., China Academy of Engineering Physics, Miangany (China)

    2000-03-01

    Radiation effect of PA610 with polyfunctional monomer trially isocyanurate (TAIC) was studied, the results show that crosslinking effect of EB radiation on PA610 is obvious. After the PA610 samples were radiated by EB with dosage 75KGY, the physical characters of PA610 materials were greatly improved, especially their tensile strength being increased about 18% and their impact strength about 50%, but their water and oil absorption were decreased. So, EB radiation can enhance PA610 materials physical strength, resistance to solvents and water and increase their thermal-deformation temperature. (author)

  12. Pseudomonas aeruginosa extracellular products inhibit staphylococcal growth, and disrupt established biofilms produced by Staphylococcus epidermidis

    DEFF Research Database (Denmark)

    Qin, Zhiqiang; Yang, Liang; Qu, Di

    2009-01-01

    in overnight cultures had no effect on established P. aeruginosa biofilms and planktonic growth. These findings reveal that P. aeruginosa extracellular products are important microbial competition factors that overcome competition with S. epidermidis, and the results may provide clues for the development...... and planktonic cultures were challenged with P. aeruginosa supernatant cultures overnight. Results indicated that quorum-sensing-controlled factors from P. aeruginosa supernatant inhibited S. epidermidis growth in planktonic cultures. We also found that P. aeruginosa extracellular products, mainly...

  13. Sent packing: protein engineering generates a new crystal form of Pseudomonas aeruginosa DsbA1 with increased catalytic surface accessibility

    Energy Technology Data Exchange (ETDEWEB)

    McMahon, Roisin M., E-mail: r.mcmahon1@uq.edu.au; Coinçon, Mathieu; Tay, Stephanie; Heras, Begoña [University of Queensland, 306 Carmody Road, Brisbane, Queensland 4072 (Australia); Morton, Craig J. [Biota Holdings Limited, Unit 10, 585 Blackburn Road, Notting Hill, Victoria 3168 (Australia); Scanlon, Martin J. [Monash University, 381 Royal Parade, Parkville, Victoria 3052 (Australia); Martin, Jennifer L. [University of Queensland, 306 Carmody Road, Brisbane, Queensland 4072 (Australia)

    2015-11-26

    The crystal structure of a P. aeruginosa DsbA1 variant is more suitable for fragment-based lead discovery efforts to identify inhibitors of this antimicrobial drug target. In the reported structures the active site of the protein can simultaneously bind multiple ligands introduced in the crystallization solution or via soaking. Pseudomonas aeruginosa is an opportunistic human pathogen for which new antimicrobial drug options are urgently sought. P. aeruginosa disulfide-bond protein A1 (PaDsbA1) plays a pivotal role in catalyzing the oxidative folding of multiple virulence proteins and as such holds great promise as a drug target. As part of a fragment-based lead discovery approach to PaDsbA1 inhibitor development, the identification of a crystal form of PaDsbA1 that was more suitable for fragment-soaking experiments was sought. A previously identified crystallization condition for this protein was unsuitable, as in this crystal form of PaDsbA1 the active-site surface loops are engaged in the crystal packing, occluding access to the target site. A single residue involved in crystal-packing interactions was substituted with an amino acid commonly found at this position in closely related enzymes, and this variant was successfully used to generate a new crystal form of PaDsbA1 in which the active-site surface is more accessible for soaking experiments. The PaDsbA1 variant displays identical redox character and in vitro activity to wild-type PaDsbA1 and is structurally highly similar. Two crystal structures of the PaDsbA1 variant were determined in complex with small molecules bound to the protein active site. These small molecules (MES, glycerol and ethylene glycol) were derived from the crystallization or cryoprotectant solutions and provide a proof of principle that the reported crystal form will be amenable to co-crystallization and soaking with small molecules designed to target the protein active-site surface.

  14. Targeting quorum sensing in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Jakobsen, Tim Holm; Bjarnsholt, Thomas; Jensen, Peter Østrup

    2013-01-01

    Bacterial resistance to conventional antibiotics combined with an increasing acknowledgement of the role of biofilms in chronic infections has led to a growing interest in new antimicrobial strategies that target the biofilm mode of growth. In the aggregated biofilm mode, cell-to-cell communication...... systems involved in the process known as quorum sensing regulate coordinated expression of virulence with immune shielding mechanisms and antibiotic resistance. For two decades, the potential of interference with quorum sensing by small chemical compounds has been investigated with the aim of developing...... alternative antibacterial strategies. Here, we review state of the art research of quorum sensing inhibitors against the opportunistic human pathogen Pseudomonas aeruginosa, which is found in a number of biofilm-associated infections and identified as the predominant organism infecting the lungs of cystic...

  15. The role of a conserved membrane proximal cysteine in altering αPS2CβPS integrin diffusion

    Science.gov (United States)

    Syed, Aleem; Arora, Neha; Bunch, Thomas A.; Smith, Emily A.

    2016-12-01

    Cysteine residues (Cys) in the membrane proximal region are common post-translational modification (PTM) sites in transmembrane proteins. Herein, the effects of a highly conserved membrane proximal α-subunit Cys1368 on the diffusion properties of αPS2CβPS integrins are reported. Sequence alignment shows that this cysteine is palmitoylated in human α3 and α6 integrin subunits. Replacing Cys1368 in wild-type integrins with valine (Val1368) putatively blocks a PTM site and alters integrins’ ligand binding and diffusion characteristics. Both fluorescence recovery after photobleaching (FRAP) and single particle tracking (SPT) diffusion measurements show Val1368 integrins are more mobile compared to wild-type integrins. Approximately 33% and 8% more Val1368 integrins are mobile as measured by FRAP and SPT, respectively. The mobile Val1368 integrins also exhibit less time-dependent diffusion, as measured by FRAP. Tandem mass spectrometry data suggest that Cys1368 contains a redox or palmitoylation PTM in αPS2CβPS integrins. This membrane proximal Cys may play an important role in the diffusion of other alpha subunits that contain this conserved residue.

  16. Ambroxol interferes with Pseudomonas aeruginosa quorum sensing.

    Science.gov (United States)

    Lu, Qi; Yu, Jialin; Yang, Xiqiang; Wang, Jiarong; Wang, Lijia; Lin, Yayin; Lin, Lihua

    2010-09-01

    The mucolytic agent ambroxol has been reported to interfere with the formation of Pseudomonas aeruginosa-derived biofilms in addition to reducing alginate production by undefined mechanisms. Since quorum sensing is a key regulator of virulence and biofilm formation, we examined the effects of ambroxol on P. aeruginosa PAO1 wild-type bacterial clearance rates, adhesion profiles and biofilm formation compared with the quorum sensing-deficient, double-mutant strains DeltalasR DeltarhlR and DeltalasI DeltarhlI. Data presented in this report demonstrated that ambroxol treatment reduced survival rates of the double-mutant strains compared with the wild-type strain in a dose-dependent manner even though the double-mutants had increased adhesion in the presence of ambroxol compared with the wild-type strain. The PAO1 wild-type strain produced a significantly thicker biofilm (21.64+/-0.57 microm) compared with the biofilms produced by the DeltalasR DeltarhlR (7.36+/-0.2 microm) and DeltalasI DeltarhlI (6.62+/-0.31 microm) isolates. Ambroxol treatment reduced biofilm thickness, increased areal porosity, and decreased the average diffusion distance and textual entropy of wild-type and double-mutant strains. However, compared with the double-mutant strains, the changes observed for the wild-type strain were more clearly defined. Finally, ambroxol exhibited significant antagonistic quorum-sensing properties, suggesting that it could be adapted for use clinically in the treatment of cystic fibrosis and to reduce biofilm formation and in the colonisation of indwelling devices. Copyright (c) 2010 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  17. 76 FR 36395 - Airworthiness Directives; Piper Aircraft, Inc. Models PA-24, PA-24-250, and PA-24-260 Airplanes

    Science.gov (United States)

    2011-06-22

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Piper Aircraft, Inc... proposed AD, contact Piper Aircraft, Inc., 2926 Piper Drive, Vero Beach, Florida 32960; telephone: (772... September 15, 2004. This SAIB alerted owners and operators of Piper Aircraft, Inc. (Piper) Models PA-23, PA...

  18. Role of tyrosine 131 in the active site of paAzoR1, an azoreductase with specificity for the inflammatory bowel disease prodrug balsalazide.

    Science.gov (United States)

    Wang, Chan-Ju; Laurieri, Nicola; Abuhammad, Areej; Lowe, Edward; Westwood, Isaac; Ryan, Ali; Sim, Edith

    2010-01-01

    Azoreductase 1 from Pseudomonas aeruginosa strain PAO1 (paAzoR1) catalyses the activation of the prodrug balsalazide and reduces the azo dye methyl red using reduced nicotinamide adenine dinucleotide cofactor as an electron donor. To investigate the mechanism of the enzyme, a Y131F mutation was introduced and the enzymic properties of the mutant were compared with those of the wild-type enzyme. The crystallographic structure of the mutant with methyl red bound was solved at 2.1 A resolution and compared with the wild-type structure. Tyr131 is important in the architecture of the active site but is not essential for enzymic activity.

  19. [Retinal Cell Therapy Using iPS Cells].

    Science.gov (United States)

    Takahashi, Masayo

    2016-03-01

    Progress in basic research, starting with the work on neural stem cells in the middle 1990's to embryonic stem (ES) cells and induced pluripotent stem (iPS) cells at present, will lead the cell therapy (regenerative medicine) of various organs, including the central nervous system to a big medical field in the future. The author's group transplanted iPS cell-derived retinal pigment epithelial (RPE) cell sheets to the eye of a patient with exudative age-related macular degeneration (AMD) in 2014 as a clinical research. Replacement of the RPE with the patient's own iPS cell-derived young healthy cell sheet will be one new radical treatment of AMD that is caused by cellular senescence of RPE cells. Since it was the first clinical study using iPS cell-derived cells, the primary endpoint was safety judged by the outcome one year after surgery. The safety of the cell sheet has been confirmed by repeated tumorigenisity tests using immunodeficient mice, as well as purity of the cells, karyotype and genetic analysis. It is, however, also necessary to prove the safety by clinical studies. Following this start, a good strategy considering cost and benefit is needed to make regenerative medicine a standard treatment in the future. Scientifically, the best choice is the autologous RPE cell sheet, but autologous cell are expensive and sheet transplantation involves a risky part of surgical procedure. We should consider human leukocyte antigen (HLA) matched allogeneic transplantation using the HLA 6 loci homozyous iPS cell stock that Prof. Yamanaka of Kyoto University is working on. As the required forms of donor cells will be different depending on types and stages of the target diseases, regenerative medicine will be accomplished in a totally different manner from the present small molecule drugs. Proof of concept (POC) of photoreceptor transplantation in mouse is close to being accomplished using iPS cell-derived photoreceptor cells. The shortest possible course for treatment

  20. A transmissão psíquica geracional

    Directory of Open Access Journals (Sweden)

    Vinícius Oliveira dos Santos

    Full Text Available O artigo seguinte refere-se a um estudo sobre como ocorre a transmissão psíquica entre as gerações e qual sua importância na constituição psíquica do sujeito. É também objetivo deste artigo explicar o que são as transmissões intergeracional e transgeracional. Para buscar respostas para essas questões, fez-se uma pesquisa bibliográfica sobre a transmissão psíquica, pelo viés psicanalítico, principalmente a partir da teoria lacaniana e com conceitos oriundos da linguística saussuriana. Será a partir de uma determinada ordem simbólica, constituída pela linguagem que precede o sujeito, nomeado por Lacan como o Outro, que a transmissão psíquica entre gerações ganhará o seu caráter unívoco, sempre se tendo em mente a importância fundamental do recalcamento e de seus efeitos, bem como do retorno do recalcado nas diferentes gerações. A transmissão psíquica é necessária e concomitante à constituição do sujeito, e ocorre através da linguagem, dos significantes que irão determinar uma ordem simbólica para o ser que nasce através dos diferentes discursos que perpassam as gerações nas figuras dos pais desse novo ser. Essa ordem simbólica continuará a se fazer presente nesse novo sujeito pelo restante de sua existência. Este artigo busca dar nova luz ao aspecto da transmissão psíquica transgeracional, diferenciando-se da recalque s abordagens psicanalíticas contemporâneas por ser uma leitura lacaniana. Serão usados dois exemplos: um de como a transmissão aparece na cultura, outro, na subjetividade do sujeito através da arte.

  1. Characterization of Pseudomonas aeruginosa PB112 (JN996498 ...

    African Journals Online (AJOL)

    Characterization of Pseudomonas aeruginosa PB112 (JN996498) isolated from infected Labeo bata (Hamilton) by 16S rRNA gene sequence analysis and fatty acid methyl ester (FAME) analysis. Somerita Panda, PK Bandyopadhyay, SN Chatterjee ...

  2. The Enzymes of the Ammonia Assimilation in Pseudomonas aeruginosa

    NARCIS (Netherlands)

    Janssen, Dick B.; Camp, Huub J.M. op den; Leenen, Pieter J.M.; Drift, Chris van der

    1980-01-01

    Glutamine synthetase from Pseudomonas aeruginosa is regulated by repression/derepression of enzyme synthesis and by adenylylation/deadenylylation control. High levels of deadenylylated biosynthetically active glutamine synthetase were observed in cultures growing with limiting amounts of nitrogen

  3. Resistance patterns of Pseudomonas aeruginosa isolated from HIV ...

    African Journals Online (AJOL)

    negative bacilli in patients with impaired host defences emphasizes the need for information on the antibiotic susceptibility of the organisms that infects such patients. Pseudomonas aeruginosa are becoming increasingly resistant to ...

  4. Caenorhabditis elegans reveals novel Pseudomonas aeruginosa virulence mechanism

    NARCIS (Netherlands)

    Utari, Putri Dwi; Quax, Wim J.

    The susceptibility of Caenorhabditis elegans to different virulent phenotypes of Pseudomonas aeruginosa makes the worms an excellent model for studying host-pathogen interactions. Including the recently described liquid killing, five different killing assays are now available offering superb

  5. Sequencing and characterization of Pseudomonas aeruginosa phage JG004

    National Research Council Canada - National Science Library

    Garbe, Julia; Bunk, Boyke; Rohde, Manfred; Schobert, Max

    2011-01-01

    .... Pseudomonas aeruginosa. For an effective use of bacteriophages as antimicrobial agents, it is important to understand phage biology but also genes of the bacterial host essential for phage infection...

  6. Infectious conjunctivitis caused by Pseudomonas aeruginosa isolated from a bathroom

    National Research Council Canada - National Science Library

    Eguchi, Hiroshi; Miyamoto, Tatsuro; Kuwahara, Tomomi; Mitamura, Sayaka; Mitamura, Yoshinori

    2013-01-01

    .... The purpose of this report is to describe a case of suture-related conjunctivitis caused by Pseudomonas aeruginosa for which we identified the transmission route using pulsed-field gel electrophoresis (PFGE...

  7. Characterization of Glutamine-Requiring Mutants of Pseudomonas aeruginosa

    NARCIS (Netherlands)

    Janssen, Dick B.; Joosten, Han M.L.J.; Herst, Patricia M.; Drift, Chris van der

    1982-01-01

    Revertants were isolated from a glutamine-requiring mutant of Pseudomonas aeruginosa PAO. One strain showed thermosensitive glutamine requirement and formed thermolabile glutamine synthetase, suggesting the presence of a mutation in the structural gene for glutamine synthetase. The mutation

  8. Isolation of chlorhexidine-resistant Pseudomonas aeruginosa from clinical lesions.

    OpenAIRE

    Nakahara, H; Kozukue, H

    1982-01-01

    The chlorhexidine resistance of 317 strains of Pseudomonas aeruginosa isolated from hospital patients was determined. The distribution pattern of their susceptibility to chlorhexidine clearly revealed two peaks, and the frequency of resistance to chlorhexidine was 84.2%.

  9. Autophagy enhances bacterial clearance during P. aeruginosa lung infection

    National Research Council Canada - National Science Library

    Junkins, Robert D; Shen, Ann; Rosen, Kirill; McCormick, Craig; Lin, Tong-Jun

    2013-01-01

    .... aeruginosa is primarily considered an extacellular pathogen, recent reports have demonstrated that throughout the course of infection the bacterium acquires the ability to enter and reside within host cells...

  10. Hyperbaric oxygen sensitizes anoxic Pseudomonas aeruginosa biofilm to ciprofloxacin

    DEFF Research Database (Denmark)

    Kolpen, Mette; Lerche, Christian J; Kragh, Kasper Nørskov

    2017-01-01

    Chronic Pseudomonas aeruginosa lung infection is characterized by the presence of endobronchial antibiotic-tolerant biofilm subject to strong oxygen (O2) depletion due to the activity of surrounding polymorphonuclear leukocytes. The exact mechanisms affecting the antibiotic susceptibility of biof...

  11. Acquisition and Role of Molybdate in Pseudomonas aeruginosa

    Science.gov (United States)

    Pederick, Victoria G.; Eijkelkamp, Bart A.; Ween, Miranda P.; Begg, Stephanie L.; Paton, James C.

    2014-01-01

    In microaerophilic or anaerobic environments, Pseudomonas aeruginosa utilizes nitrate reduction for energy production, a process dependent on the availability of the oxyanionic form of molybdenum, molybdate (MoO42−). Here, we show that molybdate acquisition in P. aeruginosa occurs via a high-affinity ATP-binding cassette permease (ModABC). ModA is a cluster D-III solute binding protein capable of interacting with molybdate or tungstate oxyanions. Deletion of the modA gene reduces cellular molybdate concentrations and results in inhibition of anaerobic growth and nitrate reduction. Further, we show that conditions that permit nitrate reduction also cause inhibition of biofilm formation and an alteration in fatty acid composition of P. aeruginosa. Collectively, these data highlight the importance of molybdate for anaerobic growth of P. aeruginosa and reveal novel consequences of nitrate reduction on biofilm formation and cell membrane composition. PMID:25172858

  12. Pseudomonas aeruginosa diversity in distinct paediatric patient groups

    DEFF Research Database (Denmark)

    Tramper-Stranders, G.A.; Ent, C.K. van der; Wolfs, T.F.

    2008-01-01

    -CF patients and whether clonality of isolates occurs in other patient groups. The aim of this study was to investigate P. aeruginosa diversity and the occurrence of clones within five distinct paediatric patient groups susceptible to P. aeruginosa infection. P. aeruginosa isolates were cultured from 157...... patients (CF first infection (CF-1 group) (29); CF chronic infection (CF-chronic group) (27); urinary tract infection (34); chronic suppurative otitis media (43); and intensive-care hospitalization/immunodeficiency (24)). All 202 phenotypically different isolates were tested for antimicrobial resistance...... and further typed by pulsed-field gel electrophoresis. Simpson's diversity index was calculated for the five groups. CF-chronic patients carried the highest number of distinct P. aeruginosa phenotypes and genotypes per culture. Isolates from the CF-chronic group were significantly less diverse than those from...

  13. Vaccines for preventing infection with Pseudomonas aeruginosa in cystic fibrosis

    DEFF Research Database (Denmark)

    Johansen, H.K.; Gøtzsche, Peter C.; Johansen, Helle Krogh

    2008-01-01

    BACKGROUND: Chronic pulmonary infection in cystic fibrosis results in progressive lung damage. Once colonisation of the lungs with Pseudomonas aeruginosa occurs, it is almost impossible to eradicate. Vaccines, aimed at reducing infection with Pseudomonas aeruginosa, have been developed. OBJECTIVES......: To assess the effectiveness of vaccination against Pseudomonas aeruginosa in cystic fibrosis. SEARCH STRATEGY: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register using the terms vaccines AND pseudomonas (last search May 2008) and PubMed using the terms vaccin* AND cystic...... fibrosis (last search May 2008). SELECTION CRITERIA: Randomised trials (published or unpublished) comparing Pseudomonas aeruginosa vaccines (oral, parenteral or intranasal) with control vaccines or no intervention in cystic fibrosis. DATA COLLECTION AND ANALYSIS: The authors independently selected trials...

  14. Pseudomonas aeruginosa Bloodstream Infection: Importance of Appropriate Initial Antimicrobial Treatment

    OpenAIRE

    Micek, Scott T; Lloyd, Ann E.; David J. Ritchie; Reichley, Richard M.; Fraser, Victoria J.; Kollef, Marin H

    2005-01-01

    Pseudomonas aeruginosa bloodstream infection is a serious infection with significant patient mortality and health-care costs. Nevertheless, the relationship between initial appropriate antimicrobial treatment and clinical outcomes is not well established. This study was a retrospective cohort analysis employing automated patient medical records and the pharmacy database at Barnes-Jewish Hospital. Three hundred five patients with P. aeruginosa bloodstream infection were identified over a 6-yea...

  15. Biodegradasi Petroleum dan Hidrokarbon Eikosana oleh Isolat Bakteri Pseudomonas aeruginosa

    OpenAIRE

    Faiqah Umar

    2015-01-01

    Biodegradation of petroleum and hydrocarbon eicosane by Pseudomonas aeruginosa isolate. Hydrocarbon are important environmental contaminants in soil and water. These compounds have a potential risk to human health, as many of them are carsinogenic and toxic to marine organisms such as diatome, gasthrophode, mussel, and fish. The purpose of this research was to know the ability of Pseudomonas aeruginosa to degradate the hydrocarbon (petroleum Hundill and eicosane) substrate. Growing test used ...

  16. Pyochelin Potentiates the Inhibitory Activity of Gallium on Pseudomonas aeruginosa

    Science.gov (United States)

    Frangipani, Emanuela; Bonchi, Carlo; Minandri, Fabrizia; Imperi, Francesco

    2014-01-01

    Gallium (Ga) is an iron mimetic that has successfully been repurposed for antibacterial chemotherapy. To improve the antibacterial potency of Ga on Pseudomonas aeruginosa, the effect of complexation with a variety of siderophores and synthetic chelators was tested. Ga complexed with the pyochelin siderophore (at a 1:2 ratio) was more efficient than Ga(NO3)3 in inhibiting P. aeruginosa growth, and its activity was dependent on increased Ga entrance into the cell through the pyochelin translocon. PMID:24957826

  17. Transfer line from the PSB to the PS (recombination)

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    After sequential ejection of 5 bunches from each of the 4 rings of the Booster (originally 800 MeV, now 1.4 GeV), the 4 batches are brought to the same vertical level, so as to form a string of 20 bunches, filling the circumference of the PS. This vertical "recombination" is performed in the transfer line, using vertical bending magnets, septa and kickers. Here we see the section where the beam from ring 4 (the top one) is brought down to the level of ring 3, and the beam from ring 1 up to the level of ring 2. Further downstream (to the right, outside this picture), level 2 is brought up to level 3, identical to that of the PS. After this original recombination scheme, other ways of combining the 4 beams, vertically and/or longitudinally, were developed and used in operation.

  18. O Trabalho Psíquico da Intersubjetividade

    Directory of Open Access Journals (Sweden)

    Maria Inês Assumpção Fernandes

    2003-01-01

    Full Text Available O presente trabalho procura refletir sobre o trabalho psíquico da intersubjetividade nos grupos. Trata-se de pensá-lo na relação com a ruptura de investimentos durante o processo de Transformação x Criação, em primeiro lugar. A partir desse ponto, discutiremos a relação entre Transformação, Trabalho e Dispositivo. Neste caso pensamos nas possibilidades de intervenção, refletindo sobre a intervenção inpidual e a intervenção grupal. A questão da Transmissão Psíquica entre gerações será focalizada, fundamentalmente, no que se refere aos tempos lógicos do recalque.

  19. Images of Christ's Saving Work in Ps.-Epiphanius' Homilies

    Directory of Open Access Journals (Sweden)

    H. F. Stander

    1997-12-01

    Full Text Available Images of Christ's Saving Work in Ps.-Epiphanius' Homilies. One cannot really speak of a systematic theology on the subject of atone-ment in the patristic writers. Frances Young once said that 'it is in fact impossible to categorize neatly the thought of the major patristic writers on the subject of atonement'. She adds that one cannot do justice to the range of motifs and images that are found in describing the saving and atoning work of Christ if we merely dismember 'systematic theologies' to illustrate common soteriological themes. One can only appreciate patristic views of atonement if one begins by recognizing the multifaceted unity of imagery that pervades the literature. This then is the goal of this article: to discuss the rich images which Ps: -Epiphanius uses to describe the atoning work of Christ.

  20. Magnetoelectric MnPS3 as a candidate for ferrotoroidicity

    Science.gov (United States)

    Ressouche, E.; Loire, M.; Simonet, V.; Ballou, R.; Stunault, A.; Wildes, A.

    2010-09-01

    We have revisited the magnetic structure of manganese phosphorus trisulfide MnPS3 using neutron diffraction and polarimetry. MnPS3 undergoes a transition toward a collinear antiferromagnetic order at 78 K. The resulting magnetic point-group breaks both the time reversal and the space inversion thus allowing a linear magnetoelectric coupling. Neutron polarimetry was subsequently used to prove that this coupling provides a way to manipulate the antiferromagnetic domains simply by cooling the sample under crossed magnetic and electrical fields, in agreement with the nondiagonal form of the magnetoelectric tensor. In addition, this tensor has, in principle, an antisymmetric part that results in a toroidic moment and provides with a pure ferrotoroidic compound.

  1. PS Dreyer: Bakens op die pad van die wetenskap

    Directory of Open Access Journals (Sweden)

    A. J. Antonites

    1986-01-01

    Full Text Available PS Dreyer: Beacons on the path of science Professor PS Dreyer is an academic who has shown insight and vision into several problems of the human sciences since 1951. He has identified problems, but also contributed solutions to them. In this respect his philosophy on causality and freedom is of utmost importance. The same applies to his investigations into the relationship history-Christianity as well as the unity of sciences and how the concepts scientific, unscientic and nonscientific are related to one another. His contribution to the understanding of Greek philosophy should be of significance for time to come. Two milestones could be distinguished: Dreyer's particular solution to the problem of the criterion on truth, viz meaningfulness and his notion of the knowledge of values in ethics by valuation in contradistinction to knowledge through feeling, reason and will.

  2. Images of Christ's Saving Work in Ps.-Epiphanius' Homilies

    Directory of Open Access Journals (Sweden)

    H. F. Stander

    1997-01-01

    Full Text Available Images of Christ's Saving Work in Ps.-Epiphanius' Homilies. One cannot really speak of a systematic theology on the subject of atone-ment in the patristic writers. Frances Young once said that 'it is in fact impossible to categorize neatly the thought of the major patristic writers on the subject of atonement'. She adds that one cannot do justice to the range of motifs and images that are found in describing the saving and atoning work of Christ if we merely dismember 'systematic theologies' to illustrate common soteriological themes. One can only appreciate patristic views of atonement if one begins by recognizing the multifaceted unity of imagery that pervades the literature. This then is the goal of this article: to discuss the rich images which Ps: -Epiphanius uses to describe the atoning work of Christ.

  3. Longitudinal coupled-bunch instability studies in the PS

    CERN Document Server

    Damerau, H

    2017-01-01

    The main longitudinal limitation for LHC-type beams inthe PS are coupled-bunch instabilities. A dedicated proto-typefeedbacksystemusingaFinemetcavityasalongitudinalkicker has been installed. Extensive tests with beam havebeen performed to explore the intensity reach with this feed-back. The maximum intensity with nominal longitudinalemittance at PS extraction has been measured, as well as theemittance required to keep the beam longitudinally stableat the design intensity for the High-Luminosity LHC (HL-LHC). A higher-harmonic cavity is a complementary op-tion to extend the intensity reach beyond the capabilities ofthe coupled-bunch feedback. Preliminary machine develop-ment (MD) studies operating one20MHzor one40MHzRF system as a higher harmonic at the flat-top indicate thebeneficial effect on longitudinal beam stability

  4. Impact of Silver Nanoparticle Transformation on Pseudomonas aeruginosa GFP Biofilm

    Science.gov (United States)

    Adegboye, Temitope Azeezat

    Silver nanoparticles (Ag NP) undergo transformations when released into the environment and often the transformed nanoparticles exhibit different behavior from the pristine analog. It is important to understand the influence of Ag NP transformation (particularly sulfidation) on its potential impacts in order to determine the effects of environmental transformation on biofilms. The goal of our study was to investigate interactions of polyvinylpyrrolidone-capped (PVP) pristine and transformed Ag NP (30 - 50 nm particle size) with bacterial biofilm to assess their impacts on biofilm communities. In this study, Pseudomonas aeruginosa GFP (ATCCRTM 10145GFP(TM)) biofilms were subjected to similar concentrations of pristine- Ag NP and transformed- Ag2S NP under environmentally relevant conditions. Residual concentrations of dissolved silver and NP after exposure to biofilms were evaluated by ICP-AES (Inductively Coupled Plasma Atomic Emission Spectroscopy) analysis. The morphological properties of Pseudomonas aeruginosa GFP (P. aeruginosa) biofilms after exposure to both forms of silver nanoparticles were characterized by cell viability studies (using microplate reader and live/dead assay) and scanning electron microscopy (SEM). We also analyzed the distribution and size of investigated silver nanoparticles within P.aeruginosa biofilms using SEM coupled with EDS. Here, we report that transformed silver nanoparticle (Ag2S NP) exhibit reduced biofilm inactivation effects against P. aeruginosa biofilms compared to its pristine form (Ag NP). This result could be explained by a lower uptake of Ag2S nanoparticle by P. aeruginosa biofilms demonstrated by ICP-AES and SEM/EDS analysis.

  5. A dynamic and intricate regulatory network determines Pseudomonas aeruginosa virulence

    Science.gov (United States)

    Balasubramanian, Deepak; Schneper, Lisa; Kumari, Hansi; Mathee, Kalai

    2013-01-01

    Pseudomonas aeruginosa is a metabolically versatile bacterium that is found in a wide range of biotic and abiotic habitats. It is a major human opportunistic pathogen causing numerous acute and chronic infections. The critical traits contributing to the pathogenic potential of P. aeruginosa are the production of a myriad of virulence factors, formation of biofilms and antibiotic resistance. Expression of these traits is under stringent regulation, and it responds to largely unidentified environmental signals. This review is focused on providing a global picture of virulence gene regulation in P. aeruginosa. In addition to key regulatory pathways that control the transition from acute to chronic infection phenotypes, some regulators have been identified that modulate multiple virulence mechanisms. Despite of a propensity for chaotic behaviour, no chaotic motifs were readily observed in the P. aeruginosa virulence regulatory network. Having a ‘birds-eye’ view of the regulatory cascades provides the forum opportunities to pose questions, formulate hypotheses and evaluate theories in elucidating P. aeruginosa pathogenesis. Understanding the mechanisms involved in making P. aeruginosa a successful pathogen is essential in helping devise control strategies. PMID:23143271

  6. Mechanisms of phagocytosis and host clearance of Pseudomonas aeruginosa

    Science.gov (United States)

    Lovewell, Rustin R.; Patankar, Yash R.

    2014-01-01

    Pseudomonas aeruginosa is an opportunistic bacterial pathogen responsible for a high incidence of acute and chronic pulmonary infection. These infections are particularly prevalent in patients with chronic obstructive pulmonary disease and cystic fibrosis: much of the morbidity and pathophysiology associated with these diseases is due to a hypersusceptibility to bacterial infection. Innate immunity, primarily through inflammatory cytokine production, cellular recruitment, and phagocytic clearance by neutrophils and macrophages, is the key to endogenous control of P. aeruginosa infection. In this review, we highlight recent advances toward understanding the innate immune response to P. aeruginosa, with a focus on the role of phagocytes in control of P. aeruginosa infection. Specifically, we summarize the cellular and molecular mechanisms of phagocytic recognition and uptake of P. aeruginosa, and how current animal models of P. aeruginosa infection reflect clinical observations in the context of phagocytic clearance of the bacteria. Several notable phenotypic changes to the bacteria are consistently observed during chronic pulmonary infections, including changes to mucoidy and flagellar motility, that likely enable or reflect their ability to persist. These traits are likewise examined in the context of how the bacteria avoid phagocytic clearance, inflammation, and sterilizing immunity. PMID:24464809

  7. Macrolides protect against Pseudomonas aeruginosa infection via inhibition of inflammasomes.

    Science.gov (United States)

    Fan, Li-Chao; Lin, Jie-Lu; Yang, Jia-Wei; Mao, Bei; Lu, Hai-Wen; Ge, Bao-Xue; Choi, Augustine M K; Xu, Jin-Fu

    2017-10-01

    Macrolides antibiotics have been effectively used in many chronic diseases, especially with Pseudomonas aeruginosa (P. aeruginosa) infection. The mechanisms underlying the therapeutic effects of macrolides in these diseases remain poorly understood. We established a mouse model of chronic lung infection using P. aeruginosa agar-beads, with azithromycin treatment or placebo. Lung injury, bacterial clearance, and inflammasome-related proteins were measured. In vitro, the inflammasomes activation induced by flagellin or ATP were assessed in LPS-primed macrophages with or without macrolides treatment. Plasma IL-18 levels were determined from patients who were diagnosed with bronchiectasis isolated with or without P. aeruginosa and treated with azithromycin for 3-5 days. Azithromycin treatment enhanced bacterial clearance and attenuated lung injury in mice chronically infected with P. aeruginosa, which resulted from the inhibition of caspase-1-dependent IL-1β and IL-18 secretion. In vitro, azithromycin and erythromycin inhibited NLRC4 and NLRP3 inflammasomes activation. Plasma IL-18 levels were higher in bronchiectasis patients with P. aeruginosa isolation compared with healthy controls. Azithromycin administration markedly decreased IL-18 secretion in bronchiectasis patients. The results of this study reveal that azithromycin and erythromycin exert a novel anti-inflammatory effect by attenuating inflammasomes activation, which suggests potential treatment options for inflammasome-related diseases. Copyright © 2017 the American Physiological Society.

  8. Interspecies Interaction between Pseudomonas aeruginosa and Other Microorganisms

    Science.gov (United States)

    Tashiro, Yosuke; Yawata, Yutaka; Toyofuku, Masanori; Uchiyama, Hiroo; Nomura, Nobuhiko

    2013-01-01

    Microbes interact with each other in multicellular communities and this interaction enables certain microorganisms to survive in various environments. Pseudomonas aeruginosa is a highly adaptable bacterium that ubiquitously inhabits diverse environments including soil, marine habitats, plants and animals. Behind this adaptivity, P. aeruginosa has abilities not only to outcompete others but also to communicate with each other to develop a multispecies community. In this review, we focus on how P. aeruginosa interacts with other microorganisms. P. aeruginosa secretes antimicrobial chemicals to compete and signal molecules to cooperate with other organisms. In other cases, it directly conveys antimicrobial enzymes to other bacteria using the Type VI secretion system (T6SS) or membrane vesicles (MVs). Quorum sensing is a central regulatory system used to exert their ability including antimicrobial effects and cooperation with other microbes. At least three quorum sensing systems are found in P. aeruginosa, Las, Rhl and Pseudomonas quinolone signal (PQS) systems. These quorum-sensing systems control the synthesis of extracellular antimicrobial chemicals as well as interaction with other organisms via T6SS or MVs. In addition, we explain the potential of microbial interaction analysis using several micro devices, which would bring fresh sensitivity to the study of interspecies interaction between P. aeruginosa and other organisms. PMID:23363620

  9. Probenecid reduces infection and inflammation in acute Pseudomonas aeruginosa pneumonia.

    Science.gov (United States)

    Wonnenberg, Bodo; Tschernig, Thomas; Voss, Meike; Bischoff, Markus; Meier, Carola; Schirmer, Stephan H; Langer, Frank; Bals, Robert; Beisswenger, Christoph

    2014-07-01

    The activation of inflammasome signaling mediates pathology of acute Pseudomonas aeruginosa pneumonia. This suggests that the inflammasome might represent a target to limit the pathological consequences of acute P. aeruginosa lung infection. Pannexin-1 (Px1) channels mediate the activation of caspase-1 and release of IL-1β induced by P2X7 receptor activation. The approved drug probenecid is an inhibitor of Px1 and ATP release. In this study, we demonstrate that probenecid reduces infection and inflammation in acute P. aeruginosa pneumonia. Treatment of mice prior to infection with P. aeruginosa resulted in an enhanced clearance of P. aeruginosa and reduced levels of inflammatory mediators, such as IL-1β. In addition, probenecid inhibited the release of inflammatory mediators in murine alveolar macrophages and human U937 cell-derived macrophages upon bacterial infection but not in human bronchial epithelial cells. Thus, Px1 blockade via probenecid treatment may be a therapeutic option in P. aeruginosa pneumonia by improving bacterial clearance and reducing negative consequences of inflammation. Copyright © 2014 Elsevier GmbH. All rights reserved.

  10. Vaccines for preventing infection with Pseudomonas aeruginosa in cystic fibrosis

    DEFF Research Database (Denmark)

    Johansen, Helle Krogh; Gøtzsche, Peter C

    2015-01-01

    BACKGROUND: Chronic pulmonary infection in cystic fibrosis results in progressive lung damage. Once colonisation of the lungs with Pseudomonas aeruginosa occurs, it is almost impossible to eradicate. Vaccines, aimed at reducing infection with Pseudomonas aeruginosa, have been developed. This is a......BACKGROUND: Chronic pulmonary infection in cystic fibrosis results in progressive lung damage. Once colonisation of the lungs with Pseudomonas aeruginosa occurs, it is almost impossible to eradicate. Vaccines, aimed at reducing infection with Pseudomonas aeruginosa, have been developed....... This is an update of a previously published review. OBJECTIVES: To assess the effectiveness of vaccination against Pseudomonas aeruginosa in cystic fibrosis. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register using the terms vaccines AND pseudomonas (last search 30...... March 2015). We previously searched PubMed using the terms vaccin* AND cystic fibrosis (last search 30 May 2013). SELECTION CRITERIA: Randomised trials (published or unpublished) comparing Pseudomonas aeruginosa vaccines (oral, parenteral or intranasal) with control vaccines or no intervention in cystic...

  11. [Analysis of drug resistance of Pseudomonas aeruginosa and use of antibiotics in burn wards during 6 years].

    Science.gov (United States)

    Dou, Yi; Zhang, Qin

    2014-02-01

    To study the distribution characteristics of pathogens, the drug resistance of Pseudomonas aeruginosa (PA), and the use of antibiotics against Gram negative bacilli (GNB) in burn wards, so as to provide a guide for future treatment. A total of 2 758 strains of pathogens were isolated from specimens of wound excretion, venous catheter attachment, blood, stool, urine, and sputum from 7 441 patients hospitalized in our burn wards from January 2007 to December 2012. After being identified by API strips and automatic microorganism identification and drug sensitivity analyzer, drug resistance of all the pathogens to 13 antibiotics commonly used in clinic, including amikacin, cefoperazone/sulbactam, ceftazidime, etc., was tested by K-B paper disk diffusion method. The defined daily doses per 1 000 patient-day of 5 antibiotics including amikacin, cefoperazone/sulbactam, ceftazidime, imipenem, and ciprofloxacin each year was set as use intensity. The WHONET 5.6 software was used to analyze the distribution of pathogens and the drug resistance of PA to 13 antibiotics. The SPSS 19.0 software was used to analyze the relation between changes in drug-resistant rates of PA to 13 antibiotics and year, the relation between the proportion of PA in all the pathogens and the use intensity of 5 antibiotics commonly used against GNB, and the relation between the use intensity of ciprofloxacin and the change in drug-resistant rates of PA to amikacin, cefoperazone/sulbactam, and imipenem with Pearson correlation analysis. (1) In 6 years, Staphylococcus aureus ranked the first with the highest proportion (31%, 865/2 758). The proportion of PA increased to tie in with Acinetobacter baumannii (both accounting for 17%, 458/2 758), both taking the second place. (2) Drug-resistant rates of PA to amikacin, gentamicin, aztreonam, piperacillin, cefoperazone, cefepime, piperacillin/tazobactam, cefoperazone/sulbactam, imipenem, and meropenem were significantly increased and positively correlated

  12. 3,4-Dihydroxyphenylacetate 2,3-dioxygenase from Pseudomonas aeruginosa: An Fe(II-containing enzyme with fast turnover.

    Directory of Open Access Journals (Sweden)

    Soraya Pornsuwan

    Full Text Available 3,4-dihydroxyphenylacetate (DHPA dioxygenase (DHPAO from Pseudomonas aeruginosa (PaDHPAO was overexpressed in Escherichia coli and purified to homogeneity. As the enzyme lost activity over time, a protocol to reactivate and conserve PaDHPAO activity has been developed. Addition of Fe(II, DTT and ascorbic acid or ROS scavenging enzymes (catalase or superoxide dismutase was required to preserve enzyme stability. Metal content and activity analyses indicated that PaDHPAO uses Fe(II as a metal cofactor. NMR analysis of the reaction product indicated that PaDHPAO catalyzes the 2,3-extradiol ring-cleavage of DHPA to form 5-carboxymethyl-2-hydroxymuconate semialdehyde (CHMS which has a molar absorptivity of 32.23 mM-1cm-1 at 380 nm and pH 7.5. Steady-state kinetics under air-saturated conditions at 25°C and pH 7.5 showed a Km for DHPA of 58 ± 8 μM and a kcat of 64 s-1, indicating that the turnover of PaDHPAO is relatively fast compared to other DHPAOs. The pH-rate profile of the PaDHPAO reaction shows a bell-shaped plot that exhibits a maximum activity at pH 7.5 with two pKa values of 6.5 ± 0.1 and 8.9 ± 0.1. Study of the effect of temperature on PaDHPAO activity indicated that the enzyme activity increases as temperature increases up to 55°C. The Arrhenius plot of ln(k'cat versus the reciprocal of the absolute temperature shows two correlations with a transition temperature at 35°C. Two activation energy values (Ea above and below the transition temperature were calculated as 42 and 14 kJ/mol, respectively. The data imply that the rate determining steps of the PaDHPAO reaction at temperatures above and below 35°C may be different. Sequence similarity network analysis indicated that PaDHPAO belongs to the enzyme clusters that are largely unexplored. As PaDHPAO has a high turnover number compared to most of the enzymes previously reported, understanding its biochemical and biophysical properties should be useful for future applications in

  13. Functional characterization of calcineurin homologs PsCNA1/PsCNB1 in Puccinia striiformis f. sp. tritici using a host-induced RNAi system.

    Directory of Open Access Journals (Sweden)

    Hong Zhang

    Full Text Available Calcineurin plays a key role in morphogenesis, pathogenesis and drug resistance in most fungi. However, the function of calcineurin genes in Puccinia striiformis f. sp. tritici (Pst is unclear. We identified and characterized the calcineurin genes PsCNA1 and PsCNB1 in Pst. Phylogenetic analyses indicate that PsCNA1 and PsCNB1 form a calcium/calmodulin regulated protein phosphatase belonging to the calcineurin heterodimers composed of subunits A and B. Quantitative RT-PCR analyses revealed that both PsCNA1 and PsCNB1 expression reached their maximum in the stage of haustorium formation, which is one day after inoculation. Using barely stripe mosaic virus (BSMV as a transient expression vector in wheat, the expression of PsCNA1 and PsCNB1 in Pst was suppressed, leading to slower extension of fungal hyphae and reduced production of urediospores. The immune-suppressive drugs cyclosporin A and FK506 markedly reduced the germination rates of urediospores, and when germination did occur, more than two germtubes were produced. These results suggest that the calcineurin signaling pathway participates in stripe rust morphogenetic differentiation, especially the formation of haustoria during the early stage of infection and during the production of urediospores. Therefore PsCNA1 and PsCNB1 can be considered important pathogenicity genes involved in the wheat-Pst interaction.

  14. Consolidation of the 45-Year Old PS Main Magnet System

    CERN Document Server

    Zickler, Thomas; Kalbreier, Wilhelm; Mess, Karl Hubert; Newborough, Antony

    2006-01-01

    After a major coil insulation breakdown on two of the 47-year-old CERN PS main magnets in 2003, an extensive magnet consolidation program has been launched. This article reviews the analysis of the magnet state be-fore the repair and the applied major improvements. An overview is given of the production of the new compo-nents, the actual refurbishment and the commissioning of the main magnet system after 18 months shutdown.

  15. Specification of the Beam Position Measurement in the PS Machine

    CERN Document Server

    Bravin, Enrico; Chanel, M; Ludwig, M; Métral, Elias; Métral, G; Potier, J P; Raich, U; Scrivens, R; Steerenberg, R; CERN. Geneva. AB Department

    2003-01-01

    This specification, drawn up by the instrumentation specification board 2, describes the requirements concerning orbit and trajectory measurements in the PS machine. The orbit measurement and the trajectory measurement are both indispensable in order to be able to guarantee the correct beam quality for beams like LHC, the future Grand Sasso beam, the nTOF beam and surely the combined operation of the nTOF beam and the East Area beam.

  16. Science spin: iPS cell research in the news.

    Science.gov (United States)

    Caulfield, T; Rachul, C

    2011-05-01

    Big scientific developments have always been spun to meet particular social agendas. We have seen it in the context of global warming, nuclear power, and genetically modified organisms. But few stories illustrate the phenomenon of spin as well as the reaction, and concomitant media coverage, that surrounded the November 2007 announcement regarding the reprogramming of skin cells to produce cells with qualities comparable to those of human embryonic stem cells (hESCs) known as induced pluripotent stem (iPS) cells.

  17. Physics at the AD/PS/SPS (1/4)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Lecture 1: The CERN injector complex and beams for non-LHC physics. The various machines and beam lines in the CERN injector complex are presented, from the linacs to the SPS. Special emphasis is given to the beam lines at the PS and SPS machines: AD, North and East Areas, nTOF and CNGS and HiRadMad as well as the ion beams. A short outlook is given to possible future upgrades and projects.

  18. Ps18.pdf | sep2002 | jess | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; jess; sep2002; Ps18.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Associates – 2017. Posted on 17 July 2017. Click here to see the list · 28th Mid Year Meeting. Posted on 26 May ...

  19. Cross-regulation by CrcZ RNA controls anoxic biofilm formation in Pseudomonas aeruginosa

    Science.gov (United States)

    Pusic, Petra; Tata, Muralidhar; Wolfinger, Michael T.; Sonnleitner, Elisabeth; Häussler, Susanne; Bläsi, Udo

    2016-12-01

    Pseudomonas aeruginosa (PA) can thrive in anaerobic biofilms in the lungs of cystic fibrosis (CF) patients. Here, we show that CrcZ is the most abundant PA14 RNA bound to the global regulator Hfq in anoxic biofilms grown in cystic fibrosis sputum medium. Hfq was crucial for anoxic biofilm formation. This observation complied with an RNAseq based transcriptome analysis and follow up studies that implicated Hfq in regulation of a central step preceding denitrification. CrcZ is known to act as a decoy that sequesters Hfq during relief of carbon catabolite repression, which in turn alleviates Hfq-mediated translational repression of catabolic genes. We therefore inferred that CrcZ indirectly impacts on biofilm formation by competing for Hfq. This hypothesis was supported by the findings that over-production of CrcZ mirrored the biofilm phenotype of the hfq deletion mutant, and that deletion of the crcZ gene augmented biofilm formation. To our knowledge, this is the first example where competition for Hfq by CrcZ cross-regulates an Hfq-dependent physiological process unrelated to carbon metabolism.

  20. Conformational differences between the Pfr and Pr states in Pseudomonas aeruginosa bacteriophytochrome

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaojing; Kuk, Jane; Moffat, Keith; (UC)

    2009-09-16

    Phytochromes are red-light photoreceptors that regulate light responses in plants, fungi, and bacteria by means of reversible photoconversion between red (Pr) and far-red (Pfr) light-absorbing states. Here, we report the crystal structure of the Q188L mutant of Pseudomonas aeruginosa bacteriophytochrome (PaBphP) photosensory core module, which exhibits altered photoconversion behavior and different crystal packing from wild type. We observe two distinct chromophore conformations in the Q188L crystal structure that we identify with the Pfr and Pr states. The Pr/Pfr compositions, varying from crystal to crystal, seem to correlate with light conditions under which the Q188L crystals are cryoprotected. We also compare all known Pr and Pfr structures. Using site-directed mutagenesis, we identify residues that are involved in stabilizing the 15Ea (Pfr) and 15Za (Pr) configurations of the biliverdin chromophore. Specifically, Ser-261 appears to be essential to form a stable Pr state in PaBphP, possibly by means of its interaction with the propionate group of ring C. We propose a 'flip-and-rotate' model that summarizes the major conformational differences between the Pr and Pfr states of the chromophore and its binding pocket.

  1. New Electron Cloud Detectors for the PS Main Magnets

    CERN Document Server

    Yin Vallgren, Ch; Gilardoni, S; Taborelli, M; Neupert, H; Ferreira Somoza, J

    2014-01-01

    Electron cloud (EC) has already been observed during normal operation of the PS, therefore it is necessary to study its in fluence on any beam instability for the future LHC Injector Upgrade (LIU). Two new electron cloud detectors have been discussed, developed and installed during the Long Shutdown (LS1) in one of the PS main magnets. The first measurement method is based on current measurement by using a shielded button-type pick-up. Due to the geometry and space limitation in the PS magnet, the button-type pick-up made of a 96%Al2O3 block coated with a thin layer of solvent-based Ag painting, placed 30 degrees to the bottom part of the vacuum chamber was installed in the horizontal direction where the only opening of the magnet coil is. The other newly developed measurement method is based on detection of photons emitted by the electrons from the electron cloud impinging on the vacuum chamber walls. The emitted photons are reected to a quartz window. A MCP-PMT (Micro-Channel Plate Photomultiplier Tube) wit...

  2. LS1 Report: PS Booster prepares for beam

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    With Linac2 already up and running, the countdown to beam in the LHC has begun! The next in line is the PS Booster, which will close up shop to engineers early next week. The injector will be handed over to the Operations Group who are tasked with getting it ready for active duty.   Taken as we approach the end of LS1 activities, this image shows where protons will soon be injected from Linac2 into the four PS Booster rings. Over the coming two months, the Operations Group will be putting the Booster's new elements through their paces. "Because of the wide range of upgrades and repairs carried out in the Booster, we have a very full schedule of tests planned for the machine," says Bettina Mikulec, PS Booster Engineer in Charge. "We will begin with cold checks; these are a wide range of tests carried out without beam, including system tests with power on/off and with varying settings, as well as verification of the controls system and timings." Amon...

  3. A novel mouse model of conditional IRAK-M deficiency in myeloid cells: application in lung Pseudomonas aeruginosa infection.

    Science.gov (United States)

    Jiang, Di; Matsuda, Jennifer; Berman, Reena; Schaefer, Niccolette; Stevenson, Connor; Gross, James; Zhang, Bicheng; Sanchez, Amelia; Li, Liwu; Chu, Hong Wei

    2017-02-01

    Myeloid cells such as macrophages are critical to innate defense against infection. IL-1 receptor-associated kinase M (IRAK-M) is a negative regulator of TLR signaling during bacterial infection, but the role of myeloid cell IRAK-M in bacterial infection is unclear. Our goal was to generate a novel conditional knockout mouse model to define the role of myeloid cell IRAK-M during bacterial infection. Myeloid cell-specific IRAK-M knockout mice were generated by crossing IRAK-M floxed mice with LysM-Cre knock-in mice. The resulting LysM-Cre+/IRAK-Mfl/wt and control (LysM-Cre-/IRAK-Mfl/wt) mice were intranasally infected with Pseudomonas aeruginosa (PA). IRAK-M deletion, inflammation, myeloperoxidase (MPO) activity and PA load were measured in leukocytes, bronchoalveolar lavage (BAL) fluid and lungs. PA killing assay with BAL fluid was performed to determine mechanisms of IRAK-M-mediated host defense. IRAK-M mRNA and protein levels in alveolar and lung macrophages were significantly reduced in LysM-Cre+/IRAK-Mfl/wt mice compared with control mice. Following PA infection, LysM-Cre+/IRAK-Mfl/wt mice have enhanced lung neutrophilic inflammation, including MPO activity, but reduced PA load. The increased lung MPO activity in LysM-Cre+/IRAK-Mfl/wt mouse BAL fluid reduced PA load. Generation of IRAK-M conditional knockout mice will enable investigators to determine precisely the function of IRAK-M in myeloid cells and other types of cells during infection and inflammation.

  4. Paraoxonase 2 is down-regulated by the Pseudomonas aeruginosa quorumsensing signal N-(3-oxododecanoyl)-L-homoserine lactone and attenuates oxidative stress induced by pyocyanin.

    Science.gov (United States)

    Horke, Sven; Witte, Ines; Altenhöfer, Sebastian; Wilgenbus, Petra; Goldeck, Marion; Förstermann, Ulrich; Xiao, Junhui; Kramer, Gerald L; Haines, Donovan C; Chowdhary, Puneet K; Haley, Robert W; Teiber, John F

    2010-01-27

    Two virulence factors produced by Pseudomonas aeruginosa are pyocyanin and N-(3-oxododecanoyl)-L-homoserine lactone (3OC12). Pyocyanin damages host cells by generating ROS (reactive oxygen species). 3OC12 is a quorum-sensing signalling molecule which regulates bacterial gene expression and modulates host immune responses. PON2 (paraoxonase-2) is an esterase that inactivates 3OC12 and potentially attenuates Ps. aeruginosa virulence. Because increased intracellular Ca2+ initiates the degradation of PON2 mRNA and protein and 3OC12 causes increases in cytosolic Ca2+, we hypothesized that 3OC12 would also down-regulate PON2. 3OC12 and the Ca2+ ionophore A23187 caused a rapid cytosolic Ca2+ influx and down-regulated PON2 mRNA, protein and hydrolytic activity in A549 and EA.hy 926 cells. The decrease in PON2 hydrolytic activity was much more extensive and rapid than decreases in protein, suggesting a rapid post-translational mechanism which blocks PON2's hydrolytic activity. The Ca2+ chelator BAPTA/AM [1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid tetrakis(acetoxymethyl ester)] diminished the ability of 3OC12 to decrease PON2, demonstrating that the effects are mediated by Ca2+. PON2 also has antioxidative properties and we show that it protects cells from pyocyanin-induced oxidative stress. Knockdown of PON2 by transfecting cells with siRNA (small interfering RNA) rendered them more sensitive to, whereas overexpression of PON2 protected cells from, pyocyanin-induced ROS formation. Additionally, 3OC12 potentiated pyocyanin-induced ROS formation, presumably by inactivating PON2. These findings support a key role for PON2 in the defence against Ps. aeruginosa virulence, but also reveal a mechanism by which the bacterium may subvert the protection afforded by PON2.

  5. Genetics of Persister Formation in Pseudomonas aeruginosa

    Science.gov (United States)

    2012-12-14

    infectious diseases ” (2012) American Society for Microbiology San Francisco, CA “Antibiotic Tolerance & Microbial Persistence” (2012) Lyme Disease ...Dormant Persisters: Mechanisms of Formation and Role in Disease ” (2009). American Society For Microbiology. Philadelphia, PA. “Death and Survival in...1983). "hipA, a newly recognized gene of Escherichia coli K-12 that affects frequency of persistence after inhibition of murein synthesis." J

  6. Determination of agmatine using isotope dilution UPLC-tandem mass spectrometry: application to the characterization of the arginine decarboxylase pathway in Pseudomonas aeruginosa.

    Science.gov (United States)

    Dalluge, Joseph J; McCurtain, Jennifer L; Gilbertsen, Adam J; Kalstabakken, Kyle A; Williams, Bryan J

    2015-07-01

    A method has been developed for the direct determination of agmatine in bacterial culture supernatants using isotope dilution ultra performance liquid chromatography (UPLC)-tandem mass spectrometry (UPLC-MS/MS). Agmatine determination in bacterial supernatants is comprised of spiking culture or isolate supernatants with a fixed concentration of uniformly labeled (13)C5,(15)N4-agmatine (synthesized by decarboxylation of uniformly labeled (13)C6,(15)N4-arginine using arginine decarboxylase from Pseudomonas aeruginosa) as an internal standard, followed by derivatization with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBDF) to improve the reversed-phase chromatographic retention characteristics of agmatine, as well as the selectivity and sensitivity of UPLC-MS/MS detection of this amine in complex biologically derived mixtures. Intrasample precisions for measurement of agmatine in culture supernatants average 4.1% (relative standard deviation). Calibration curves are linear over the range 5 nM to 10 μM, and the detection limit is estimated at 1.5 nM. To demonstrate the utility of the method, agmatine levels in supernatants of overnight cultures of wild-type (UCBPP-PA14), as well as arginine decarboxylase and agmatine deiminase mutant strains of P. aeruginosa strain UCBPP-PA14 were measured. This method verified that the mutant strains are lacking the specific metabolic capabilities to produce and metabolize agmatine. In addition, measurement of agmatine in supernatants of a panel of clinical isolates from patients with cystic fibrosis revealed that three of the P. aeruginosa isolates hyper-secreted agmatine into the supernatant, hypothesized to be a result of a mutation in the aguA gene. Because agmatine has potential inflammatory activities in the lung, this phenotype may be a virulence factor for P. aeruginosa in the lung environment of cystic fibrosis patients.

  7. Tripartite Motif 8 (TRIM8) Positively Regulates Pro-inflammatory Responses in Pseudomonas aeruginosa-Induced Keratitis Through Promoting K63-Linked Polyubiquitination of TAK1 Protein.

    Science.gov (United States)

    Guo, Litao; Dong, Weili; Fu, Xiaoxiao; Lin, Jing; Dong, Zhijun; Tan, Xiaobo; Zhang, Tiemin

    2017-04-01

    Pseudomonas aeruginosa (PA)-induced keratitis is a rapidly progressive ocular infectious disease that often leads to inflammatory epithelial edema, stromal infiltration, tissue destruction, corneal ulceration, and vision loss. In this study, we investigate the role of tripartite motif 8 (TRIM8) in regulating the inflammatory process of PA-induced keratitis. The expression of TRIM8 was increased in mouse corneas and in vitro-cultured macrophages after PA infection. Knockdown of the expression of TRIM8 significantly inhibited the activation of NF-κB signaling and decreased the production of pro-inflammatory cytokines both in vivo and in vitro after infected with PA. Furthermore, we investigated the potential mechanism and we found after PA infection that TRIM8 could promote K63-linked polyubiquitination of transforming growth factor β-activated kinase 1 (TAK1), leading to the activation of TAK1 and enhanced inflammatory responses. Taken together, we demonstrated that TRIM8 has pro-inflammatory effect on PA-induced keratitis and suggest TRIM8 as a potential therapeutic target for keratitis.

  8. In vitro and in vivo properties of a fully human IgG1 monoclonal antibody that combats multidrug resistant Pseudomonas aeruginosa

    Science.gov (United States)

    ADAWI, AZMI; BISIGNANO, CARLO; GENOVESE, TIZIANA; FILOCAMO, ANGELA; KHOURI-ASSI, CAMELLIA; NEVILLE, ANAT; FEUERSTEIN, GIORA Z.; CUZZOCREA, SALVATORE; NEVILLE, LEWIS F.

    2012-01-01

    The development of an anti-bacterial drug in the form of a monoclonal antibody (mAb) targeting an exposed virulence factor, represents an innovative therapeutic strategy. Consequently, a fully human IgG1 mAb (LST-007) targeting Pseudomonas aeruginosa (PA) flagellin type b was recombinantly expressed and characterized in vitro and in an infection model driven by a multidrug resistant (MDR) PA strain. LST-007 demonstrated a highly specific binding towards whole PA bacteria harboring flagellin type b and its recombinant counterpart, with a KD of 7.4×10−10 M. In bioactivity assays, LST-007 or titers of Cmax sera derived from pharmacokinetic studies, markedly attenuated PA motility in an equipotent manner. In vivo, parenteral LST-007 (20 mg/kg) given as a single or double-dosing paradigm post-infection, afforded survival (up to 75% at Day 7) in a lethal model of pneumonia driven by the intratracheal (i.t.) instillation of an LD80 of the MDR PA isolate. This protective effect was markedly superior to that of imipenem (30% survival at Day 7) and totally devoid with an irrelevant, human isotype mAb. These data lay credence that LST-007 may be a valuable adjunct to the limited list of anti-bacterials that can tackle MDR PA strains, thereby warranting its continued development for eventual clinical evaluation. PMID:22735858

  9. Kultuur isiksuse psühholoogiat ei mõjuta / Tiit Kändler

    Index Scriptorium Estoniae

    Kändler, Tiit, 1948-

    2010-01-01

    Psühholoogia uuemate andmete kohaselt ei sõltu indiviidi seadumus kultuurist, soost, vanusest, haridusest. Eesti psühholoogide Jüri Alliku ja Ann Realo osalusel ajakirjas "Journal Personality and Social Psychology" ilmunud artiklist

  10. Kultuur isiksuse psühholoogiat ei mõjuta / Tiit Kändler

    Index Scriptorium Estoniae

    Kändler, Tiit, 1948-

    2005-01-01

    Psühholoogia uuemate andmete kohaselt ei sõltu indiviidi seadumus kultuurist, soost, vanusest, haridusest. Eesti psühholoogide Jüri Alliku ja Anu Realo osalusel ajakirjas "Journal Personality and Social Psychology" ilmunud artiklist

  11. Comparative, validity and responsiveness of the HOOS-PS and KOOS-PS to the WOMAC physical function subscale in total joint replacement for osteoarthritis

    DEFF Research Database (Denmark)

    Davis, A M; Perruccio, A V; Canizares, M

    2009-01-01

    OBJECTIVE: To evaluate the internal consistency of the Hip disability and Osteoarthritis Outcome Score-Physical Function Short-form (HOOS-PS) and the Knee injury and Osteoarthritis Outcome Score-Physical Function Short-form (KOOS-PS) in total hip replacement (THR) and total knee (TKR) replacement....... Construct validity and responsiveness were compared to the Western Ontario McMaster Universities' Osteoarthritis Index (WOMAC) Likert 3.0 physical function (PF) subscale and the PF excluding the items in the short measures (PF-exclusions). METHODS: Participants completed the full HOOS or KOOS, measures...... of fatigue, anxiety, depression and the Chronic Pain Grade (CPG) pre-surgery and the HOOS or KOOS 6 months post-surgery. Internal consistency for the HOOS-PS and KOOS-PS was calculated using Cronbach's alpha. For construct validity, it was hypothesized that correlations between the HOOS-PS or KOOS-PS and PF...

  12. C-di-GMP hydrolysis by Pseudomonas aeruginosa HD-GYP phosphodiesterases: analysis of the reaction mechanism and novel roles for pGpG.

    Directory of Open Access Journals (Sweden)

    Valentina Stelitano

    Full Text Available In biofilms, the bacterial community optimizes the strategies to sense the environment and to communicate from cell to cell. A key player in the development of a bacterial biofilm is the second messenger c-di-GMP, whose intracellular levels are modulated by the opposite activity of diguanylate cyclases and phosphodiesterases. Given the huge impact of bacterial biofilms on human health, understanding the molecular details of c-di-GMP metabolism represents a critical step in the development of novel therapeutic approaches against biofilms. In this study, we present a detailed biochemical characterization of two c-di-GMP phosphodiesterases of the HD-GYP subtype from the human pathogen Pseudomonas aeruginosa, namely PA4781 and PA4108. Upstream of the catalytic HD-GYP domain, PA4781 contains a REC domain typical of two-component systems, while PA4108 contains an uncharacterized domain of unknown function. Our findings shed light on the activity and catalytic mechanism of these phosphodiesterases. We show that both enzymes hydrolyse c-di-GMP in a two-step reaction via the linear intermediate pGpG and that they produce GMP in vitro at a surprisingly low rate. In addition, our data indicate that the non-phosphorylated REC domain of PA4781 prevents accessibility of c-di-GMP to the active site. Both PA4108 and phosphorylated PA4781 are also capable to use pGpG as an alternative substrate and to hydrolyse it into GMP; the affinity of PA4781 for pGpG is one order of magnitude higher than that for c-di-GMP. These results suggest that these enzymes may not work (primarily as genuine phosphodiesterases. Moreover, the unexpected affinity of PA4781 for pGpG may indicate that pGpG could also act as a signal molecule in its own right, thus further widening the c-di-GMP-related signalling scenario.

  13. Perception of first respiratory infection with Pseudomonas aeruginosa by people with cystic fibrosis and those close to them: an online qualitative study.

    Science.gov (United States)

    Palser, Sally C; Rayner, Oliver C; Leighton, Paul A; Smyth, Alan R

    2016-12-28

    People with cystic fibrosis (CF) are susceptible to respiratory infection with Pseudomonas aeruginosa (PA), which may become chronic if initial eradication fails. Environmental acquisition and person-to-person transmission can occur. Respiratory PA infection is associated with increased mortality and more hospitalisations. This may cause patients and families anxiety and lead them to adopt preventive measures which may be ineffectual and intrusive. It is not possible to hold a conventional focus group to explore these issues because people with CF cannot meet together due to the risk of cross-infection. To explore the perceptions of first respiratory infection with PA in people with CF and those close to them. We designed an online survey, to maximise accessibility and avoid the risk of cross-infection. This established the respondent's relationship with CF, asked 3 open questions about perceptions of PA and a final question about the prioritisation of research. Responses were analysed using a structured, iterative process. We identified keywords, analysed these incontext and derived key themes. Promotion through social media allowed respondents from any country to participate. People with CF and those close to them. Responses were received from 393 people, including 266 parents and 97 people with CF. The key themes were the emotional burden of PA (fear in particular); the burden of treatment PA entails and the need for accurate knowledge about PA. Lack of knowledge and the health beliefs of individuals may promote fear of infection and inappropriate avoidance measures. Uncertainty about the implications of PA infection and the treatment required may cause anxiety. Healthcare professionals should provide clear information about how PA might be acquired and the treatment necessary, making clear the limitations of current understanding and acknowledging health beliefs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted

  14. Analüütilised voolud psühholoogias ja nende rakendamine pedagoogikas / Aleksander Elango

    Index Scriptorium Estoniae

    Elango, Aleksander, 1902-2004

    2001-01-01

    Analüütise psühholoogia kolm koolkonda - S.Freudì koolkond e. päris-psühhoanalüüs, A.Adlerì koolkond e. individuaalpsühholoogia ja C.G.Jungì psühhoanalüüsi ja individuaalpsühholoogia sünteesi luua püüdev koolkond. Analüütise psühholoogia koolkondade ja pedagoogika suhetest

  15. Bioadsorption characteristics of Pseudomonas aeruginosa PAOI

    Directory of Open Access Journals (Sweden)

    Kőnig-Péter Anikó

    2014-01-01

    Full Text Available Biosorption of Cd(II and Pb(II ions from aqueous solution using lyophilized Pseudomonas aeruginosa (PAOI cells were observed under various experimental conditions. The effect of pH, initial metal concentration, equilibration time and temperature on bioadsorption was investigated. The optimum pH value for Pb(II adsorption was found to be 5.0, and for Cd(II 5.0 − 6.0. The Pb(II and Cd(II bioadsorption equilibrium were analyzed by using Freundlich and Langmuir model using nonlinear least-squares estimation. The experimental maximum uptake capacity of Pb(II and Cd(II was estimated to be 164 mg g-1 and 113 mg g-1, respectively. For biosorption kinetic study the pseudo second-order kinetic model was applied at various temperatures. The temperature had no significant effect on Pb(II bioadsorption. In case of Cd(II bioadsorption the adsorbed amount decreased with increasing temperature.

  16. File list: His.PSC.05.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.05.AllAg.iPS_cells hg19 Histone Pluripotent stem cell iPS cells SRX317576,S...077,SRX317607 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.PSC.05.AllAg.iPS_cells.bed ...

  17. File list: His.PSC.50.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.50.AllAg.iPS_cells mm9 Histone Pluripotent stem cell iPS cells SRX977417,SR...RX127376,SRX146530,SRX146522,SRX146547,SRX333561,SRX035985,SRX1090869 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.PSC.50.AllAg.iPS_cells.bed ...

  18. File list: ALL.PSC.50.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.PSC.50.AllAg.iPS_cells hg19 All antigens Pluripotent stem cell iPS cells SRX088...16,SRX189400,SRX189399 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.PSC.50.AllAg.iPS_cells.bed ...

  19. File list: His.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.10.AllAg.iPS_cells hg19 Histone Pluripotent stem cell iPS cells SRX110016,S...315,SRX381309 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.PSC.10.AllAg.iPS_cells.bed ...

  20. File list: ALL.PSC.20.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.PSC.20.AllAg.iPS_cells hg19 All antigens Pluripotent stem cell iPS cells SRX088...27,SRX189400,SRX189399 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.PSC.20.AllAg.iPS_cells.bed ...

  1. File list: His.PSC.50.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.50.AllAg.iPS_cells hg19 Histone Pluripotent stem cell iPS cells SRX110015,S...079,SRX317585 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.PSC.50.AllAg.iPS_cells.bed ...

  2. File list: Pol.PSC.20.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.PSC.20.AllAg.iPS_cells mm9 RNA polymerase Pluripotent stem cell iPS cells SRX97...7435,SRX977434,SRX027462 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.PSC.20.AllAg.iPS_cells.bed ...

  3. File list: ALL.PSC.05.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.PSC.05.AllAg.iPS_cells hg19 All antigens Pluripotent stem cell iPS cells SRX753...00,SRX189399,SRX317607 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.PSC.05.AllAg.iPS_cells.bed ...

  4. File list: Pol.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.PSC.10.AllAg.iPS_cells mm9 RNA polymerase Pluripotent stem cell iPS cells SRX97...7435,SRX977434,SRX027462 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.PSC.10.AllAg.iPS_cells.bed ...

  5. File list: ALL.PSC.05.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.PSC.05.AllAg.iPS_cells mm9 All antigens Pluripotent stem cell iPS cells SRX9774...30,SRX146524,SRX146522,SRX146547 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.PSC.05.AllAg.iPS_cells.bed ...

  6. File list: Oth.PSC.50.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.PSC.50.AllAg.iPS_cells mm9 TFs and others Pluripotent stem cell iPS cells SRX97...RX146524 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.PSC.50.AllAg.iPS_cells.bed ...

  7. File list: Pol.PSC.50.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.PSC.50.AllAg.iPS_cells mm9 RNA polymerase Pluripotent stem cell iPS cells SRX97...7435,SRX977434,SRX027462 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.PSC.50.AllAg.iPS_cells.bed ...

  8. File list: DNS.PSC.20.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.PSC.20.AllAg.iPS_cells hg19 DNase-seq Pluripotent stem cell iPS cells SRX040379...,SRX040378,SRX135563,SRX040377,SRX040376,SRX189427,SRX189400,SRX189399 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.PSC.20.AllAg.iPS_cells.bed ...

  9. File list: DNS.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.PSC.10.AllAg.iPS_cells hg19 DNase-seq Pluripotent stem cell iPS cells SRX040379...,SRX040378,SRX040377,SRX040376,SRX135563,SRX189427,SRX189400,SRX189399 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.PSC.10.AllAg.iPS_cells.bed ...

  10. File list: Pol.PSC.05.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.PSC.05.AllAg.iPS_cells mm9 RNA polymerase Pluripotent stem cell iPS cells SRX97...7435,SRX027462,SRX977434 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.PSC.05.AllAg.iPS_cells.bed ...

  11. File list: ALL.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.PSC.10.AllAg.iPS_cells hg19 All antigens Pluripotent stem cell iPS cells SRX753...09,SRX189400,SRX189399 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.PSC.10.AllAg.iPS_cells.bed ...

  12. File list: His.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.10.AllAg.iPS_cells mm9 Histone Pluripotent stem cell iPS cells SRX977417,SR...RX127372,SRX1090869,SRX127376,SRX035977,SRX146530,SRX146547,SRX146522 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.PSC.10.AllAg.iPS_cells.bed ...

  13. File list: Oth.PSC.20.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.PSC.20.AllAg.iPS_cells mm9 TFs and others Pluripotent stem cell iPS cells SRX97...RX146524 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.PSC.20.AllAg.iPS_cells.bed ...

  14. File list: DNS.PSC.05.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.PSC.05.AllAg.iPS_cells hg19 DNase-seq Pluripotent stem cell iPS cells SRX040379...,SRX040378,SRX040377,SRX040376,SRX135563,SRX189427,SRX189400,SRX189399 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.PSC.05.AllAg.iPS_cells.bed ...

  15. File list: His.PSC.20.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.20.AllAg.iPS_cells mm9 Histone Pluripotent stem cell iPS cells SRX127389,SR...RX127372,SRX127373,SRX1090869,SRX127376,SRX146530,SRX146522,SRX146547 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.PSC.20.AllAg.iPS_cells.bed ...

  16. Genomic imprinting is variably lost during reprogramming of mouse iPS cells.

    Science.gov (United States)

    Takikawa, Sachiko; Ray, Chelsea; Wang, Xin; Shamis, Yulia; Wu, Tien-Yuan; Li, Xiajun

    2013-09-01

    Derivation of induced pluripotent stem (iPS) cells is mainly an epigenetic reprogramming process. It is still quite controversial how genomic imprinting is reprogrammed in iPS cells. Thus, we derived multiple iPS clones from genetically identical mouse somatic cells. We found that parentally inherited imprint was variably lost among these iPS clones. Concurrent with the loss of DNA methylation imprint at the corresponding Snrpn and Peg3 imprinted regions, parental origin-specific expression of the Snrpn and Zim1 imprinted genes was also lost in these iPS clones. This loss of parental genomic imprinting in iPS cells was likely caused by the reprogramming process during iPS cell derivation because extended culture of iPS cells did not lead to significant increase in the loss of genomic imprinting. Intriguingly, one to several paternal chromosomes appeared to have acquired de novo methylation at the Snrpn and Zac1 imprinted regions in a high percentage of iPS clones. These results might have some implications for future therapeutic applications of iPS cells. Since DNA methylation imprint can be completely erased in some iPS clones at multiple imprinted regions, iPS cell reprogramming may also be employed to dissect the underlying mechanisms of erasure, reacquisition and maintenance of genomic imprinting in mammals. Copyright © 2013. Published by Elsevier B.V.

  17. File list: Oth.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.PSC.10.AllAg.iPS_cells mm9 TFs and others Pluripotent stem cell iPS cells SRX65...RX146524 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.PSC.10.AllAg.iPS_cells.bed ...

  18. File list: His.PSC.05.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.05.AllAg.iPS_cells mm9 Histone Pluripotent stem cell iPS cells SRX977417,SR...RX127374,SRX127373,SRX1090869,SRX333561,SRX146530,SRX146522,SRX146547 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.PSC.05.AllAg.iPS_cells.bed ...

  19. File list: ALL.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.PSC.10.AllAg.iPS_cells mm9 All antigens Pluripotent stem cell iPS cells SRX9774...30,SRX146524,SRX146547,SRX146522 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.PSC.10.AllAg.iPS_cells.bed ...

  20. File list: ALL.PSC.50.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.PSC.50.AllAg.iPS_cells mm9 All antigens Pluripotent stem cell iPS cells SRX9773...1,SRX035985,SRX1090869 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.PSC.50.AllAg.iPS_cells.bed ...