scholarly journals Functional Conservation of the Polysaccharide Biosynthetic Protein WbpM and Its Homologues in Pseudomonas aeruginosa and Other Medically Significant Bacteria

2000 ◽  
Vol 68 (2) ◽  
pp. 931-936 ◽  
Author(s):  
Lori L. Burrows ◽  
Robert V. Urbanic ◽  
Joseph S. Lam
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Functional Conservation ◽  
Homologous Genes ◽  
Knockout Mutants ◽  
Bacterial Exopolysaccharide ◽  
Exopolysaccharide Biosynthesis ◽  
H Pylori ◽  
O Antigens ◽  
Number Of Bacteria

ABSTRACT WbpM is a highly conserved protein involved in synthesis of the O antigens of Pseudomonas aeruginosa. Homologues of this protein have been identified in a large number of bacteria, and they can be divided into two subfamilies: subfamily 1, including WbpM, contains large proteins (∼600 amino acids), while subfamily 2, typified by HP0840 (FlaA1) of Helicobacter pylori, contains smaller proteins (∼350 amino acids) homologous to the C termini of proteins in subfamily 1. Analysis of knockout mutants ofwbpM in P. aeruginosa serotypes O3, O10, O15, and O17 showed that although all 20 serotypes of P. aeruginosa possess wbpM, it is not universally required for O-antigen biosynthesis. Homologous genes fromBordetella pertussis (wlbL),Staphylococcus aureus (cap8D), and H. pylori (flaA1) complemented a P. aeruginosa O5 wbpM mutant to various degrees. These conserved proteins may represent interesting targets for the design of inhibitors of bacterial exopolysaccharide biosynthesis.

scholarly journals The amino acid sequence of cytochromes c-551 from three species of Pseudomonas

1973 ◽  
Vol 131 (3) ◽  
pp. 485-498 ◽  
Author(s):  
R. P. Ambler ◽  
Margaret Wynn
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Cytochrome C ◽  
Amino Acid Sequence ◽  
Amino Acid Sequences ◽  
Mitochondrial Cytochrome ◽  
Cytochromes C ◽  
Lending Library ◽  
Single Peptide

The amino acid sequences of the cytochromes c-551 from three species of Pseudomonas have been determined. Each resembles the protein from Pseudomonas strain P6009 (now known to be Pseudomonas aeruginosa, not Pseudomonas fluorescens) in containing 82 amino acids in a single peptide chain, with a haem group covalently attached to cysteine residues 12 and 15. In all four sequences 43 residues are identical. Although by bacteriological criteria the organisms are closely related, the differences between pairs of sequences range from 22% to 39%. These values should be compared with the differences in the sequence of mitochondrial cytochrome c between mammals and amphibians (about 18%) or between mammals and insects (about 33%). Detailed evidence for the amino acid sequences of the proteins has been deposited as Supplementary Publication SUP 50015 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973), 131, 5.

scholarly journals Amino Acid-Mediated Induction of the Basic Amino Acid-Specific Outer Membrane Porin OprD from Pseudomonas aeruginosa

1999 ◽  
Vol 181 (17) ◽  
pp. 5426-5432 ◽  
Author(s):  
Martina M. Ochs ◽  
Chung-Dar Lu ◽  
Robert E. W. Hancock ◽  
Ahmed T. Abdelal
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Regulatory Protein ◽  
Basic Amino Acid ◽  
Sole Source ◽  
Activation Mechanism ◽  
Beta Lactam ◽  
Mobility Shift ◽  
Carbon And Nitrogen

ABSTRACT Pseudomonas aeruginosa can utilize arginine and other amino acids as both carbon and nitrogen sources. Earlier studies have shown that the specific porin OprD facilitates the diffusion of basic amino acids as well as the structurally analogous beta-lactam antibiotic imipenem. The studies reported here showed that the expression of OprD was strongly induced when arginine, histidine, glutamate, or alanine served as the sole source of carbon. The addition of succinate exerted a negative effect on induction ofoprD, likely due to catabolite repression. The arginine-mediated induction was dependent on the regulatory protein ArgR, and binding of purified ArgR to its operator upstream of theoprD gene was demonstrated by gel mobility shift and DNase assays. The expression of OprD induced by glutamate as the carbon source, however, was independent of ArgR, indicating the presence of more than a single activation mechanism. In addition, it was observed that the levels of OprD responded strongly to glutamate and alanine as the sole sources of nitrogen. Thus, that the expression ofoprD is linked to both carbon and nitrogen metabolism ofPseudomonas aeruginosa.

Barrier and Antibacterial Properties of 2-Octyl Cyanoacrylate-Derived Wound Treatment Films

2003 ◽  
Vol 7 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Patricia M. Mertz ◽  
Stephen C. Davis ◽  
Alejandro L. Cazzaniga ◽  
Anna Drosou ◽  
William H. Eaglstein
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Contamination ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Bacterial Invasion ◽  
Wound Treatment ◽  
Antimicrobial Study ◽  
And Control ◽  
Number Of Bacteria

Background: Besides enhancing healing, an ideal dressing should prevent invasion of pathogens and control the number of bacteria already present in the wounds. Objective: To evaluate the barrier and antimicrobial properties of a cyanoacrylate-based bandage (LAB) against Staphylococcus aureus or Pseudomonas aeruginosa on partial thickness wounds in swines. Methods: Barrier study: Bacteria were inoculated over test materials (LAB, standard bandage, air-exposed) that were placed over wounds. The bacteria from wounds were quantitated at 24, 48, and 72 hours postinoculation. Antimicrobial study: Wounds inoculated with bacteria were covered with LAB, standard bandage, or hydrocolloid bandage or left air-exposed. The bacteria recovered from wounds were quantitated at 24 and 72 hours after treatment. Results: Barrier study: No bacteria were recovered from LAB-treated wounds. Antimicrobial study: LAB reduced the number of inoculated bacteria in comparison to all other groups. Conclusion: LAB is effective in protecting wounds from external bacterial invasion and reducing bacterial contamination.

STUDIES ON THE BIOSYNTHESIS OF PYOCYANINE

1962 ◽  
Vol 8 (1) ◽  
pp. 49-56 ◽  
Author(s):  
J. M. Ingram ◽  
A. C. Blackwood
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Oxalic Acid ◽  
Dicarboxylic Acid ◽  
Sodium Formate ◽  
Complete Medium ◽  
Tetracarboxylic Acid ◽  
Dipotassium Salt

The biosynthesis of pyocyanine, the blue phenazine pigment produced by Pseudomonas aeruginosa, was studied by the addition of radioactive substrates to a culture growing on a complete medium. The distribution of labelled carbon from radioactive substrates in the pyocyanine was examined by degrading the pigment to 1-hydroxyphenazine, quinoxaline dicarboxylic acid, quinoxaline, and pyrazine tetracarboxylic acid dipotassium salt, and thus 7 of the 13 carbons were assayed separately or in pairs.Glycerol-1,3-C14 is the principal donor of radioactivity to the pyocyanine carbon, but not all the carbon atoms tested were labeled. Alanine-U-C14 contributed carbon to pyocyanine also, but not to all carbons, and at a much lower level of efficiency than glycerol. However, with leucine-U-C14, all carbon atoms tested were labeled to a slight extent. These amino acids, when labeled specifically, and glutamate-U-C14, oxalic acid-C14, and sodium formate-C14 did not contribute significantly to pyocyanine carbon.The distribution of radioactivity from glycerol in the pyocyanine molecule suggests the pigment is formed from glycerol or a product closely related to it by the condensation of two carbon units or the condensation of four and two carbon units.

Regulation of Exopolysaccharide Biosynthesis in Pseudomonas aeruginosa

2016 ◽  
pp. 171-189
Author(s):  
Yuta Okkotsu ◽  
Christopher L. Pritchett ◽  
Michael J. Schurr
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Exopolysaccharide Biosynthesis

scholarly journals Negative Regulation of the Pseudomonas aeruginosa Outer Membrane Porin OprD Selective for Imipenem and Basic Amino Acids

1999 ◽  
Vol 43 (5) ◽  
pp. 1085-1090 ◽  
Author(s):  
Martina M. Ochs ◽  
Matthew P. McCusker ◽  
Manjeet Bains ◽  
Robert E. W. Hancock
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Clinical Effectiveness ◽  
Multiple Antibiotic Resistance ◽  
Outer Membranes ◽  
Basic Amino Acids ◽  
Outer Membrane Porin ◽  
Strong Homology ◽  
Imipenem Resistance

ABSTRACT Pseudomonas aeruginosa OprD is a specific porin which facilitates the uptake of basic amino acids and imipenem, a carbapenem antibiotic. Resistance to imipenem due to the loss of OprD is an important mechanism for the loss of clinical effectiveness. To investigate the negative regulatory mechanisms influencingoprD expression, a gene upstream of the coregulatedmexEF-oprN efflux operon, designated mexT, was cloned. The predicted 304-amino-acid mature MexT protein showed strong homology to LysR-type regulators. When overexpressed it induced the expression of the mexEF-oprN efflux operon while decreasing the level of expression of OprD. The use of anoprD::xylE transcriptional fusion indicated that it acted by repressing the transcription ofoprD. Salicylate, a weak aromatic acid known to reduce porin expression and induce low levels of multiple antibiotic resistance in Escherichia coli, was able to induce imipenem resistance and reduce the expression of OprD but not multiple antibiotic resistance or OprN expression in P. aeruginosa. This was also demonstrated to occur at the level of transcription. Acetyl salicylate and benzoate, but not catechol, were also able to reduce the levels of OprD in the P. aeruginosa outer membranes. These OprD-suppressing compounds increased imipenem resistance even in a mexT-overexpressing andnfxC mutant backgrounds, suggesting that such resistance is independent of the MexT repressor and that oprD is influenced by more than a single mechanism of repression.

scholarly journals d-Amino Acids Enhance the Activity of Antimicrobials against Biofilms of Clinical Wound Isolates of Staphylococcus aureus and Pseudomonas aeruginosa

2014 ◽  
Vol 58 (8) ◽  
pp. 4353-4361 ◽  
Author(s):  
Carlos J. Sanchez ◽  
Kevin S. Akers ◽  
Desiree R. Romano ◽  
Ronald L. Woodbury ◽  
Sharanda K. Hardy ◽  
...  
Keyword(s):  
Amino Acids ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Clinical Isolates ◽  
Chronic Infections ◽  
Content Type ◽  
Log Reduction ◽  
Viable Bacteria ◽  
Biofilm Bacteria

ABSTRACTWithin wounds, microorganisms predominantly exist as biofilms. Biofilms are associated with chronic infections and represent a tremendous clinical challenge. As antibiotics are often ineffective against biofilms, use of dispersal agents as adjunctive, topical therapies for the treatment of wound infections involving biofilms has gained interest. We evaluatedin vitrothe dispersive activity ofd-amino acids (d-AAs) on biofilms from clinical wound isolates ofStaphylococcus aureusandPseudomonas aeruginosa; moreover, we determined whether combinations ofd-AAs and antibiotics (clindamycin, cefazolin, oxacillin, rifampin, and vancomycin forS. aureusand amikacin, colistin, ciprofloxacin, imipenem, and ceftazidime forP. aeruginosa) enhance activity against biofilms.d-Met,d-Phe, andd-Trp at concentrations of ≥5 mM effectively dispersed preformed biofilms ofS. aureusandP. aeruginosaclinical isolates, an effect that was enhanced when they were combined as an equimolar mixture (d-Met/d-Phe/d-Trp). When combined withd-AAs, the activity of rifampin was significantly enhanced against biofilms of clinical isolates ofS. aureus, as indicated by a reduction in the minimum biofilm inhibitory concentration (MBIC) (from 32 to 8 μg/ml) and a >2-log reduction of viable biofilm bacteria compared to treatment with antibiotic alone. The addition ofd-AAs was also observed to enhance the activity of colistin and ciprofloxacin against biofilms ofP. aeruginosa, reducing the observed MBIC and the number of viable bacteria by >2 logs and 1 log at 64 and 32 μg/ml in contrast to antibiotics alone. These findings indicate that the biofilm dispersal activity ofd-AAs may represent an effective strategy, in combination with antimicrobials, to release bacteria from biofilms, subsequently enhancing antimicrobial activity.

S17.7 Glycopolymers from synthetic fragments (amides of ?-d-galacturonic acid with amino acids) ofprotens O-antigens

1993 ◽  
Vol 10 (4) ◽  
pp. 325-325
Author(s):  
L. O. Kononov ◽  
A. Ya. Chernyak ◽  
N. K. Kochetkov ◽  
N. D. Zelinsky
Keyword(s):  
Amino Acids ◽  
Galacturonic Acid ◽  
O Antigens
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