scholarly journals An orphan cbb3-type cytochrome oxidase subunit supports Pseudomonas aeruginosa biofilm growth and virulence

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Jeanyoung Jo ◽  
Krista L Cortez ◽  
William Cole Cornell ◽  
Alexa Price-Whelan ◽  
Lars EP Dietrich
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cytochrome C ◽  
Opportunistic Pathogen ◽  
Bacterial Pathogenesis ◽  
Cytochrome Oxidase Subunit ◽  
Biofilm Growth ◽  
Unique Role ◽  
High Affinity ◽  
Biofilm Model ◽  
Biofilm Development

Hypoxia is a common challenge faced by bacteria during associations with hosts due in part to the formation of densely packed communities (biofilms). cbb3-type cytochrome c oxidases, which catalyze the terminal step in respiration and have a high affinity for oxygen, have been linked to bacterial pathogenesis. The pseudomonads are unusual in that they often contain multiple full and partial (i.e. ‘orphan’) operons for cbb3-type oxidases and oxidase subunits. Here, we describe a unique role for the orphan catalytic subunit CcoN4 in colony biofilm development and respiration in the opportunistic pathogen Pseudomonas aeruginosa PA14. We also show that CcoN4 contributes to the reduction of phenazines, antibiotics that support redox balancing for cells in biofilms, and to virulence in a Caenorhabditis elegans model of infection. These results highlight the relevance of the colony biofilm model to pathogenicity and underscore the potential of cbb3-type oxidases as therapeutic targets.

scholarly journals An orphancbb3-type cytochrome oxidase subunit supportsPseudomonas aeruginosabiofilm growth and virulence

2017 ◽  
Author(s):  
Jeanyoung Jo ◽  
Krista L. Cortez ◽  
William C. Cornell ◽  
Alexa Price-Whelan ◽  
Lars E.P. Dietrich
Keyword(s):  
Caenorhabditis Elegans ◽  
Cytochrome Oxidase ◽  
Opportunistic Pathogen ◽  
Bacterial Pathogenesis ◽  
Catalytic Subunit ◽  
Cytochrome Oxidase Subunit ◽  
Unique Role ◽  
High Affinity ◽  
Biofilm Model ◽  
Biofilm Development

ABSTRACTHypoxia is a common challenge faced by bacteria during associations with hosts due in part to the formation of densely packed communities (biofilms).cbb3-type cytochromecoxidases, which catalyze the terminal step in respiration and have a high affinity for oxygen, have been linked to bacterial pathogenesis. The pseudomonads are unusual in that they often contain multiple full and partial (i.e., “orphan”) operons forcbb3-type oxidases and oxidase subunits. Here, we describe a unique role for the orphan catalytic subunit CcoN4 in colony biofilm development and respiration in the opportunistic pathogenP. aeruginosaPA14. We also show that CcoN4 contributes to the reduction of phenazines, antibiotics that support redox balancing for cells in biofilms, and to virulence in aCaenorhabditis elegansmodel of infection. These results highlight the relevance of the colony biofilm model to pathogenicity and underscore the potential ofcbb3-type oxidases as therapeutic targets.

Recombinant R2-pyocin cream is effective in treating Pseudomonas aeruginosa-infected wounds

2021 ◽  
Author(s):  
Abdulaziz Alqahtani ◽  
London Mena ◽  
Dean Scholl ◽  
Cassandra Kruczek ◽  
Jane A. Colmer-Hamood ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Chronic Wounds ◽  
Opportunistic Pathogen ◽  
Biofilm Model ◽  
Major Species ◽  
Infected Wounds ◽  
New Antibiotics ◽  
Biofilm Development ◽  
Antibiofilm Agents

<i>Pseudomonas aeruginosa</i>, a Gram-negative opportunistic pathogen, is one of the major species isolated from infected chronic wounds. The multidrug resistance exhibited by <i>P. aeruginosa</i> plus its ability to form biofilms that are difficult to eradicate, along with rising cost of producing new antibiotics, has necessitated the search for alternatives to standard antibiotics. Pyocins are antimicrobial compounds produced by P. aeruginosa to protect itself from competitors. We synthesized and purified recombinant <i>P. aeruginosa</i> R2 pyocin and used it in aqueous solution (rR2P) or formulated in polyethylene glycol (rR2PC) to treat P. aeruginosa-infected wounds. Clinical strains of <i>P. aeruginosa</i> were found to be sensitive (completely), partially sensitive, or resistant to rR2P. In the in vitro biofilm model, rR2P inhibited biofilm development by rR2P-sensitive isolates; while rR2PC eliminated partial biofilms formed by these strains in the in vitro wound biofilm model. In the murine model of excision wound, and at 24 h post infection, rR2PC application significantly reduced the bioburden of clinical isolate BPI86. Application of rR2PC containing two glycoside hydrolase antibiofilm agents eliminated BPI86 from the infected wound. These results suggest that the topical application of rR2PC is an effective therapy to treat wounds infected with R2P-senstive P. aeruginosa strains.

scholarly journals Microarray Analysis of Pseudomonas aeruginosa Quorum-Sensing Regulons: Effects of Growth Phase and Environment

2003 ◽  
Vol 185 (7) ◽  
pp. 2080-2095 ◽  
Author(s):  
Victoria E. Wagner ◽  
Daniel Bushnell ◽  
Luciano Passador ◽  
Andrew I. Brooks ◽  
Barbara H. Iglewski
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Expression Patterns ◽  
Antibiotic Sensitivity ◽  
Opportunistic Pathogen ◽  
Homoserine Lactone ◽  
Medium Composition ◽  
Logarithmic Phase ◽  
Significant Differential Expression ◽  
Biofilm Development

ABSTRACT Bacterial communication via quorum sensing (QS) has been reported to be important in the production of virulence factors, antibiotic sensitivity, and biofilm development. Two QS systems, known as the las and rhl systems, have been identified previously in the opportunistic pathogen Pseudomonas aeruginosa. High-density oligonucleotide microarrays for the P. aeruginosa PAO1 genome were used to investigate global gene expression patterns modulated by QS regulons. In the initial experiments we focused on identifying las and/or rhl QS-regulated genes using a QS signal generation-deficient mutant (PAO-JP2) that was cultured with and without added exogenous autoinducers [N-(3-oxododecanoyl) homoserine lactone and N-butyryl homoserine lactone]. Conservatively, 616 genes showed statistically significant differential expression (P ≤ 0.05) in response to the exogenous autoinducers and were classified as QS regulated. A total of 244 genes were identified as being QS regulated at the mid-logarithmic phase, and 450 genes were identified as being QS regulated at the early stationary phase. Most of the previously reported QS-promoted genes were confirmed, and a large number of additional QS-promoted genes were identified. Importantly, 222 genes were identified as being QS repressed. Environmental factors, such as medium composition and oxygen availability, eliminated detection of transcripts of many genes that were identified as being QS regulated.

scholarly journals Pseudomonas aeruginosa Displays Multiple Phenotypes during Development as a Biofilm

2002 ◽  
Vol 184 (4) ◽  
pp. 1140-1154 ◽  
Author(s):  
Karin Sauer ◽  
Anne K. Camper ◽  
Garth D. Ehrlich ◽  
J. William Costerton ◽  
David G. Davies
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Protein Identification ◽  
Electrophoretic Analysis ◽  
Cell Protein ◽  
Biofilm Growth ◽  
Alginate Production ◽  
Multiple Phenotypes ◽  
Reporter Gene Analysis ◽  
Biofilm Development

ABSTRACT Complementary approaches were employed to characterize transitional episodes in Pseudomonas aeruginosa biofilm development using direct observation and whole-cell protein analysis. Microscopy and in situ reporter gene analysis were used to directly observe changes in biofilm physiology and to act as signposts to standardize protein collection for two-dimensional electrophoretic analysis and protein identification in chemostat and continuous-culture biofilm-grown populations. Using these approaches, we characterized five stages of biofilm development: (i) reversible attachment, (ii) irreversible attachment, (iii) maturation-1, (iv) maturation-2, and (v) dispersion. Biofilm cells were shown to change regulation of motility, alginate production, and quorum sensing during the process of development. The average difference in detectable protein regulation between each of the five stages of development was 35% (approximately 525 proteins). When planktonic cells were compared with maturation-2 stage biofilm cells, more than 800 proteins were shown to have a sixfold or greater change in expression level (over 50% of the proteome). This difference was higher than when planktonic P. aeruginosa were compared with planktonic cultures of Pseudomonas putida. Las quorum sensing was shown to play no role in early biofilm development but was important in later stages. Biofilm cells in the dispersion stage were more similar to planktonic bacteria than to maturation-2 stage bacteria. These results demonstrate that P. aeruginosa displays multiple phenotypes during biofilm development and that knowledge of stage-specific physiology may be important in detecting and controlling biofilm growth.

An FTIR study of Pseudomonas aeruginosa PAO1 biofilm growth and dispersion. An improved ATR method for studying biofilms: the C–H stretch spectral region

Biofilms ◽  
2004 ◽  
Vol 1 (3) ◽  
pp. 157-163 ◽  
Author(s):  
J. Pink ◽  
T. Smith-Palmer ◽  
T. J. Beveridge ◽  
D. A. Pink
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Subsequent Development ◽  
Growth Period ◽  
Flow Cell ◽  
Biofilm Growth ◽  
Chemical Difference ◽  
Qualitative And Quantitative ◽  
Quantitative Changes ◽  
Biofilm Development ◽  
First Time

Pseudomonas aeruginosa PAO1 was grown on 40° ZnSe and 40° AMTIR® (Amorphous Material Transmitting Infrared Radiation, Ge33As12Se55) internal reflection elements in a thermostatted flow cell. Information about the chemistry of the biofilm development was obtained using Fourier transform infrared spectroscopy. The weakly absorbing C–H stretching region of the infrared spectrum was measured for the first time and revealed qualitative and quantitative changes not evident in the amide region studied by previous investigators. There is a chemical difference between the early growth period and subsequent development of the biofilm.

scholarly journals Anti-Virulence Activity of the Cell-Free Supernatant of the Antarctic Bacterium Psychrobacter sp. TAE2020 against Pseudomonas aeruginosa Clinical Isolates from Cystic Fibrosis Patients

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 944
Author(s):  
Rosanna Papa ◽  
Gianluca Vrenna ◽  
Caterina D’Angelo ◽  
Angela Casillo ◽  
Michela Relucenti ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Opportunistic Pathogen ◽  
Sem Analysis ◽  
Protease Production ◽  
Polar Regions ◽  
Biofilm Growth ◽  
Antarctic Bacterium ◽  
Airway Infections

Pseudomonas aeruginosa is an opportunistic pathogen often involved in airway infections of cystic fibrosis (CF) patients. Its pathogenicity is related to several virulence factors, such as biofilm formation, motility and production of toxins and proteases. The expression of these virulence factors is controlled by quorum sensing (QS). Thus, QS inhibition is considered a novel strategy for the development of antipathogenic compounds acting on specific bacterial virulence programs without affecting bacterial vitality. In this context, cold-adapted marine bacteria living in polar regions represent an untapped reservoir of biodiversity endowed with an interesting chemical repertoire. In this paper, we investigated the biological activity of a supernatant derived from a novel Antarctic bacterium (SN_TAE2020) against specific virulence factors produced by P. aeruginosa strains isolated from FC patients. Our results clearly show a reduction in pyocyanin and protease production in the presence of SN_TAE2020. Finally, SN_TAE2020 was also able to strongly affect swarming and swimming motility for almost all tested strains. Furthermore, the effect of SN_TAE2020 was investigated on biofilm growth and texture, captured by SEM analysis. In consideration of the novel results obtained on clinical strains, polar bacteria might represent potential candidates for the discovery of new compounds limiting P. aeruginosa virulence in CF patients.

scholarly journals Neutron crystallography reveals novel mechanisms used by Pseudomonas aeruginosa for host-cell binding

2021 ◽  
Author(s):  
Lukas Gajdos ◽  
Matthew P Blakeley ◽  
Michael Haertlein ◽  
V Trevor Forsyth ◽  
Juliette M Devos ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Calcium Ions ◽  
Bacterial Infections ◽  
Opportunistic Pathogen ◽  
Host Cells ◽  
Carbohydrate Binding ◽  
Hydrogen Atoms ◽  
High Affinity ◽  
Structural Details ◽  
Neutron Crystallography

The opportunistic pathogen Pseudomonas aeruginosa, a major cause of nosocomial infections, uses carbohydrate-binding proteins (lectins) as part of its binding to host cells. The fucose-binding lectin, LecB, displays a unique carbohydrate-binding site that incorporates two closely located calcium ions bridging between the ligand and protein, providing specificity and unusually high affinity. Here, we investigate the mechanisms involved in binding based on neutron crystallography studies of a fully deuterated LecB/fucose/calcium complex. The neutron structure, which includes the positions of all the hydrogen atoms, reveals that the high affinity of binding may be related to the occurrence of a low barrier hydrogen bond induced by the proximity of the two calcium ions, the presence of coordination rings between the sugar, calcium and LecB, and the dynamic behaviour of bridging water molecules at room temperature. These key structural details may assist in the design of anti-adhesive compounds to combat multi-resistance bacterial infections.

scholarly journals Role ofepaQ, a Previously UncharacterizedEnterococcus faecalisGene, in Biofilm Development and Antimicrobial Resistance

2019 ◽  
Vol 201 (18) ◽  
Author(s):  
Michelle L. Korir ◽  
Jennifer L. Dale ◽  
Gary M. Dunny
Keyword(s):  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Cell Surface Hydrophobicity ◽  
Opportunistic Pathogen ◽  
Surface Hydrophobicity ◽  
Biofilm Growth ◽  
Content Type ◽  
Biofilm Architecture ◽  
High Level ◽  
Biofilm Development

ABSTRACTEnterococcus faecalisis a commensal of the human gastrointestinal tract; it is also an opportunistic pathogen and one of the leading causes of hospital-acquired infections.E. faecalisproduces biofilms that are highly resistant to antibiotics, and it has been previously reported that certain genes of theepaoperon contribute to biofilm-associated antibiotic resistance. Despite several studies examining theepaoperon, many gene products of this operon remain annotated as hypothetical proteins. Here, we further explore theepaoperon; we identifiedepaQ, currently annotated as encoding a hypothetical membrane protein, as being important for biofilm formation in the presence of the antibiotic daptomycin. Mutants with disruptions ofepaQwere more susceptible to daptomycin relative to the wild type, suggesting its importance in biofilm-associated antibiotic resistance. Furthermore, the ΔepaQmutant exhibited an altered biofilm architectural arrangement and formed small aggregates in liquid cultures. Our cumulative data show thatepamutations result in altered polysaccharide content, increased cell surface hydrophobicity, and decreased membrane potential. Surprisingly, severalepamutations significantly increased resistance to the antibiotic ceftriaxone, indicating that the way in which theepaoperon impacts antibiotic resistance is antibiotic dependent. These results further define the key role ofepain antibiotic resistance in biofilms and in biofilm architecture.IMPORTANCEE. faecalisis a common cause of nosocomial infection, has a high level of antibiotic resistance, and forms robust biofilms. Biofilm formation is associated with increased antibiotic resistance. Therefore, a thorough understanding of biofilm-associated antibiotic resistance is important for combating resistance. Several genes from theepaoperon have previously been implicated in biofilm-associated antibiotic resistance, pathogenesis, and competitive fitness in the GI tract, but most genes in this locus remain uncharacterized. Here, we examineepaQ,which has not been characterized functionally. We show that the ΔepaQmutant exhibits reduced biofilm formation in the presence of daptomycin, altered biofilm architecture, and increased resistance to ceftriaxone, further expanding our understanding of the contribution of this operon to intrinsic enterococcal antibiotic resistance and biofilm growth.

scholarly journals Parallel evolutionary paths to produce more than one Pseudomonas aeruginosa biofilm phenotype

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Janne G. Thöming ◽  
Jürgen Tomasch ◽  
Matthias Preusse ◽  
Michal Koska ◽  
Nora Grahl ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Parallel Evolution ◽  
Opportunistic Pathogen ◽  
Clinical Isolates ◽  
Transcriptional Responses ◽  
Regulatory Pathways ◽  
Extracellular Matrix Components ◽  
The Individual ◽  
Biofilm Development ◽  
General Response

AbstractStudying parallel evolution of similar traits in independent within-species lineages provides an opportunity to address evolutionary predictability of molecular changes underlying adaptation. In this study, we monitored biofilm forming capabilities, motility, and virulence phenotypes of a plethora of phylogenetically diverse clinical isolates of the opportunistic pathogen Pseudomonas aeruginosa. We also recorded biofilm-specific and planktonic transcriptional responses. We found that P. aeruginosa isolates could be stratified based on the production of distinct organismal traits. Three major biofilm phenotypes, which shared motility and virulence phenotypes, were produced repeatedly in several isolates, indicating that the phenotypes evolved via parallel or convergent evolution. Of note, while we found a restricted general response to the biofilm environment, the individual groups of biofilm phenotypes reproduced biofilm transcriptional profiles that included the expression of well-known biofilm features, such as surface adhesive structures and extracellular matrix components. Our results provide insights into distinct ways to make a biofilm and indicate that genetic adaptations can modulate multiple pathways for biofilm development that are followed by several independent clinical isolates. Uncovering core regulatory pathways that drive biofilm-associated growth and tolerance towards environmental stressors promises to give clues to host and environmental interactions and could provide useful targets for new clinical interventions.

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