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3 results on '"PA7 clade"'

1. The outlier Pseudomonas aeruginosa strain ATCC 9027 harbors a defective LasR quorum-sensing transcriptional regulator.

Author

García-Reyes, Selene, Soto-Aceves, Martín P, Cocotl-Yañez, Miguel, González-Valdez, Abigail, Servín-González, Luis, and Chávez, Gloria Soberón

Subjects
*QUORUM sensing, *PSEUDOMONAS aeruginosa, *PSEUDOMONAS aeruginosa infections, *GLUTAMIC acid, *ASPARTIC acid, *AMINO acids
Abstract

Pseudomonas aeruginosa infections represent an important health problem that has been recognized by the World Health Organization as a research priority. A complex regulatory network called the quorum sensing (QS) regulates several P. aeruginosa virulence-related traits, including production of elastase, rhamnolipids and pyocyanin. The avirulent P. aeruginosa strain ATCC 9027 belongs to clade 3, which is the more distant phylogroup in relationship to the other four clades of this species. This strain does not produce QS-regulated virulence factors such as elastase and rhamnolipids when cultured in rich LB medium. We report here that ATCC 9027 harbors a defective LasR protein, presumably due to the presence of an aspartic acid in position 196 instead of a glutamic acid which is the amino acid present in this position in functional LasR proteins of the type strains PAO1 (clade 1) and PA7 (also belonging to clade 3), among others. In addition, we report that ATCC 9027 and PA7 strains present differences compared to the PAO1 strain in lasB which encodes elastase, and in the rhlR regulatory sequences that modify las- boxes, and that these mutations have a little effect in the expression of these genes by a functional LasR transcriptional regulator. [ABSTRACT FROM AUTHOR]

Published
2020
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2. Genomic rearrangements and functional diversification of lecA and lecB lectin-coding regions impacting the efficacy of glycomimetics directed against pseudomonas aeruginosa

Author

Rachel Tabaroni, Amine M. Boukerb, Anne Imberty, Loris Commin, Annabelle Varrot, Benoit Cournoyer, Aude Decor, Sébastien Vidal, Anne Doléans-Jordheim, Samuel Buff, Audric Rousset, Sébastien Ribun, Ecologie microbienne ( EM ), Centre National de la Recherche Scientifique ( CNRS ) -Ecole Nationale Vétérinaire de Lyon ( ENVL ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique ( INRA ) -VetAgro Sup ( VAS ), Centre de recherches sur les macromolécules végétales ( CERMAV ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Chimie et Biochimie Moléculaires et Supramoléculaires ( ICBMS ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique ( CNRS ), Interactions Cellules Environnement ( UR ICE ), VetAgro Sup ( VAS ), Chimie Organique 2-Glycochimie ( CO2GLYCO ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Vétérinaire de Lyon (ENVL)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique (INRA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Chimie Organique 2-Glycochimie (CO2GLYCO), Institut de Chimie et Biochimie Moléculaires et Supramoléculaires (ICBMS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS), Interactions Cellules Environnement - UR (ICE), VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Ecole Nationale Vétérinaire de Lyon (ENVL), Centre de Recherches sur les Macromolécules Végétales (CERMAV ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Supérieure Chimie Physique Électronique de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Supérieure Chimie Physique Électronique de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Anses project 'pyo-eau' of the 'Programme Environnement-Sante-Travail' (French Ministers in charge of ecological and environmental issues) 2011/1/137, CNRS, Universite Lyon 1, VetAgro Sup, Cluster 'Infectiology' of the Rhone-Alpes region, Labex IMU (Intelligence des Mondes Urbains) (France), French Fond Unique Interministeriel, FUI anti-pyo, Labex ARCANE ANR-11-LABX-0003-01, COST Action CM-1102, Conseil Regional Rhone-Alpes, and GDR Pseudomonas

Subjects
0301 basic medicine, Microbiology (medical), glycan array, 030106 microbiology, lcsh:QR1-502, cytométrie de flux, Fucose binding, glycoclusters, Biology, medicine.disease_cause, PA7 clade, Microbiology, lcsh:Microbiology, pseudomonas aeruginosa, 03 medical and health sciences, chemistry.chemical_compound, [ SDV.BBM.BC ] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], [ CHIM.ORGA ] Chemical Sciences/Organic chemistry, Genomic island, medicine, élément soluble, region of genomic plasticity (RGP), [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], crystallography, Prophage, Original Research, chemistry.chemical_classification, soluble lectins, PA7 glade, flow cytometry, Pseudomonas aeruginosa, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Lectin, réarrangement génomique, Phenotype, Amino acid, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], Crystallography, 030104 developmental biology, efficacité, chemistry, Biochemistry, Galactose, biology.protein, lectine
Abstract

International audience; LecA and LecB tetrameric lectins take part in oligosaccharide-mediated adhesion-processes of Pseudomonas aeruginosa. Glycomimetics have been designed to block these interactions. The great versatility of P. aeruginosa suggests that the range of application of these glycomimetics could be restricted to genotypes with particular lectin types. The likelihood of having genomic and genetic changes impacting LecA and LecB interactions with glycomimetics such as galactosylated and fucosylated calix[4]arene was investigated over a collection of strains from the main clades of P. aeruginosa. Lectin types were defined, and their ligand specificities were inferred. These analyses showed a loss of lecA among the PA7 clade. Genomic changes impacting lec loci were thus assessed using strains of this clade, and by making comparisons with the PAO1 genome. The lecA regions were found challenged by phage attacks and PAGI-2 (genomic island) integrations. A prophage was linked to the loss of lecA. The lecB regions were found less impacted by such rearrangements but greater lecB than lecA genetic divergences were recorded. Sixteen combinations of LecA and LecB types were observed. Amino acid variations were mapped on PAO1 crystal structures. Most significant changes were observed on LecBPA7, and found close to the fucose binding site. Glycan array analyses were performed with purified LecBPA7. LecBPA7 was found less specific for fucosylated oligosaccharides than LecBPAO1, with a preference for H type 2 rather than type 1, and Lewis(a) rather than Lewis(x). Comparison of the crystal structures of LecBPA7 and LecBPAO1 in complex with Lewis(a) showed these changes in specificity to have resulted from a modification of the water network between the lectin, galactose and GlcNAc residues. Incidence of these modifications on the interactions with calix[4]arene glycomimetics at the cell level was investigated. An aggregation test was used to establish the efficacy of these ligands. Great variations in the responses were observed. Glycomimetics directed against LecB yielded the highest numbers of aggregates for strains from all clades. The use of a PAO1ΔlecB strain confirmed a role of LecB in this aggregation phenotype. Fucosylated calix[4]arene showed the greatest potential for a use in the prevention of P. aeruginosa infections.

Published
2016

3. Genomic Rearrangements and Functional Diversification of lecA and lecB Lectin-Coding Regions Impacting the Efficacy of Glycomimetics Directed against Pseudomonas aeruginosa.

Author

Boukerb AM, Decor A, Ribun S, Tabaroni R, Rousset A, Commin L, Buff S, Doléans-Jordheim A, Vidal S, Varrot A, Imberty A, and Cournoyer B

Abstract

LecA and LecB tetrameric lectins take part in oligosaccharide-mediated adhesion-processes of Pseudomonas aeruginosa. Glycomimetics have been designed to block these interactions. The great versatility of P. aeruginosa suggests that the range of application of these glycomimetics could be restricted to genotypes with particular lectin types. The likelihood of having genomic and genetic changes impacting LecA and LecB interactions with glycomimetics such as galactosylated and fucosylated calix[4]arene was investigated over a collection of strains from the main clades of P. aeruginosa. Lectin types were defined, and their ligand specificities were inferred. These analyses showed a loss of lecA among the PA7 clade. Genomic changes impacting lec loci were thus assessed using strains of this clade, and by making comparisons with the PAO1 genome. The lecA regions were found challenged by phage attacks and PAGI-2 (genomic island) integrations. A prophage was linked to the loss of lecA. The lecB regions were found less impacted by such rearrangements but greater lecB than lecA genetic divergences were recorded. Sixteen combinations of LecA and LecB types were observed. Amino acid variations were mapped on PAO1 crystal structures. Most significant changes were observed on LecBPA7, and found close to the fucose binding site. Glycan array analyses were performed with purified LecBPA7. LecBPA7 was found less specific for fucosylated oligosaccharides than LecBPAO1, with a preference for H type 2 rather than type 1, and Lewis(a) rather than Lewis(x). Comparison of the crystal structures of LecBPA7 and LecBPAO1 in complex with Lewis(a) showed these changes in specificity to have resulted from a modification of the water network between the lectin, galactose and GlcNAc residues. Incidence of these modifications on the interactions with calix[4]arene glycomimetics at the cell level was investigated. An aggregation test was used to establish the efficacy of these ligands. Great variations in the responses were observed. Glycomimetics directed against LecB yielded the highest numbers of aggregates for strains from all clades. The use of a PAO1ΔlecB strain confirmed a role of LecB in this aggregation phenotype. Fucosylated calix[4]arene showed the greatest potential for a use in the prevention of P. aeruginosa infections.

Published
2016
Full Text
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