scholarly journals Hyperbiofilm phenotype of Pseudomonas aeruginosa defective for the PlcB and PlcN secreted phospholipases

2017 ◽  
Vol 63 (9) ◽  
pp. 780-787 ◽  
Author(s):  
Shawn Lewenza ◽  
Laetitia Charron-Mazenod ◽  
Shirin Afroj ◽  
Erik van Tilburg Bernardes
Keyword(s):  
Biofilm Formation ◽  
Membrane Vesicles ◽  
Membrane Lipid ◽  
Secretion System ◽  
Outer Membrane Vesicles ◽  
Extracellular Dna ◽  
Type Ii Secretion ◽  
Chronic Infections ◽  
Type Ii Secretion System ◽  
Biofilm Matrix

Biofilms are dense communities of bacteria enmeshed in a protective extracellular matrix composed mainly of exopolysaccharides, extracellular DNA, proteins, and outer membrane vesicles (OMVs). Given the role of biofilms in antibiotic-tolerant and chronic infections, novel strategies are needed to block, disperse, or degrade biofilms. Enzymes that degrade the biofilm matrix are a promising new therapy. We screened mutants in many of the enzymes secreted by the type II secretion system (T2SS) and determined that the T2SS, and specifically phospholipases, play a role in biofilm formation. Mutations in the xcp secretion system and in the plcB and plcN phospholipases all resulted in hyperbiofilm phenotypes. PlcB has activity against many phospholipids, including the common bacterial membrane lipid phosphatidylethanolamine, and may degrade cell membrane debris or OMVs in the biofilm matrix. Exogenous phospholipase was shown to reduce aggregation and biofilm formation, suggesting its potential role as a novel enzymatic treatment to dissolve biofilms.

scholarly journals Pushing beyond the Envelope: the Potential Roles of OprF inPseudomonas aeruginosaBiofilm Formation and Pathogenicity

2019 ◽  
Vol 201 (18) ◽  
Author(s):  
Erin K. Cassin ◽  
Boo Shan Tseng
Keyword(s):  
Extracellular Matrix ◽  
Outer Membrane ◽  
Biofilm Formation ◽  
Matrix Protein ◽  
Cell Envelope ◽  
Outer Membrane Vesicles ◽  
Extracellular Dna ◽  
Future Research ◽  
Content Type ◽  
Biofilm Matrix

ABSTRACTThe ability ofPseudomonas aeruginosato form biofilms, which are communities of cells encased in a self-produced extracellular matrix, protects the cells from antibiotics and the host immune response. While some biofilm matrix components, such as exopolysaccharides and extracellular DNA, are relatively well characterized, the extracellular matrix proteins remain understudied. Multiple proteomic analyses of theP. aeruginosasoluble biofilm matrix and outer membrane vesicles, which are a component of the matrix, have identified OprF as an abundant matrix protein. To date, the few reports on the effects ofoprFmutations on biofilm formation are conflicting, and little is known about the potential role of OprF in the biofilm matrix. The majority of OprF studies focus on the protein as a cell-associated porin. As a component of the outer membrane, OprF assumes dual conformations and is involved in solute transport, as well as cell envelope integrity. Here, we review the current literature on OprF inP. aeruginosa, discussing how the structure and function of the cell-associated and matrix-associated protein may affect biofilm formation and pathogenesis in order to inform future research on this understudied matrix protein.

Extracellular DNA and Outer Membrane Vesicles contribute to P. fluorescens SBW25 air-liquid interface biofilms.

2020 ◽  
Author(s):  
Olena Moshynets ◽  
Airat Kayumov ◽  
Olga Iungin ◽  
Svitlana Rymar ◽  
Ianina Pokholenko ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Extracellular Dna ◽  
Exogenous Dna ◽  
Rhizosphere Bacterium ◽  
Cellulose Matrix ◽  
Dnase Treatment ◽  
Biofilm Development ◽  
Biofilm Matrix

<p>Outer membrane vesicles (OMVs) and extracellular DNA (eDNA) are important for biofilm formation for many bacteria. OMVs are a perfect transport system to deliver biofilm-related components including eDNA beyond the boundaries of cells, and eDNA itself is an important structural component of biofilms as well as enabling horizontal gene transfer and local adaptation. Both OMVs and eDNA are found in the biofilms produced by the opportunistic human pathogen P. aeruginosa and the plant pathogen P. syringae, but as yet, they have not been reported in the cellulose matrix-based biofilms produced by the related model rhizosphere bacterium Pseudomonas fluorescens SBW25.</p> <p>In this work we have gone back to re-assess the complexity of SBW25 biofilms by looking for evidence of OMVs and eDNA associated with biofilm–formation. OMVs were first imaged by SEM and LC-MC analysis used to identify 51 biofilm matrix-associated proteins of which 12 were also identified in biofilm OMVs. Interestingly, only 5 proteins were identified in both biofilm matrix and OMV samples, but not in planktonic OMVs, suggesting that these may be biofilm-specific components.  </p> <p>We also observed eDNA by CLSM in both the weak and poorly-attached Viscous Mass (VM) and robust and well-attached Wrinkly Spreader (WS) air-liquid (A-L) interface biofilms produced by wild-type SBW25 and the Wrinkly Spreader mutant. The eDNA fraction could be precipitated from biofilm cell-free supernatant samples which demonstrated that WS biofilms had two-fold–higher levels than VM biofilms. DNAse treatment effected the development of both types of biofilm and reduced the strength and attachment levels when added to mature VM and WS biofilms. Testing with exogenous DNA suggests that high molecular weight (HMW) DNA is involved in both strength and attachment, perhaps by surface conditioning and interactions with the primary cellulose matrix common to both biofilms. HMW eDNA could be isolated directly from biofilm supernatants whereas two different HMW size fractions could be isolated from OMVs, presumably, from the outer OMV surface because DNAse treatment led to a substantially reduced DNA signal. This suggest that eDNA persistence and degradation in SBW25 biofilms is complex and eDNA fractions may play different roles in biofilm development, protection and adaptation.</p>

scholarly journals The Type II Secretion System Delivers Matrix Proteins for Biofilm Formation by Vibrio cholerae

2014 ◽  
Vol 196 (24) ◽  
pp. 4245-4252 ◽  
Author(s):  
T. L. Johnson ◽  
J. C. Fong ◽  
C. Rule ◽  
A. Rogers ◽  
F. H. Yildiz ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Secretion System ◽  
Matrix Proteins ◽  
Type Ii Secretion ◽  
Type Ii ◽  
Type Ii Secretion System

scholarly journals The Type II Secretion System and Its Ubiquitous Lipoprotein Substrate, SslE, Are Required for Biofilm Formation and Virulence of Enteropathogenic Escherichia coli

2012 ◽  
Vol 80 (6) ◽  
pp. 2042-2052 ◽  
Author(s):  
Deborah L. Baldi ◽  
Ellen E. Higginson ◽  
Dianna M. Hocking ◽  
Judyta Praszkier ◽  
Rosalia Cavaliere ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Secretion System ◽  
Type Ii Secretion ◽  
Type Ii ◽  
Content Type ◽  
Type Ii Secretion System ◽  
Heat Labile ◽  
Outer Membrane Lipoprotein ◽  
Biofilm Development

ABSTRACTEnteropathogenicEscherichia coli(EPEC) is a major cause of diarrhea in infants in developing countries. We have identified a functional type II secretion system (T2SS) in EPEC that is homologous to the pathway responsible for the secretion of heat-labile enterotoxin by enterotoxigenicE. coli. The wild-type EPEC T2SS was able to secrete a heat-labile enterotoxin reporter, but an isogenic T2SS mutant could not. We showed that the major substrate of the T2SS in EPEC is SslE, an outer membrane lipoprotein (formerly known as YghJ), and that a functional T2SS is essential for biofilm formation by EPEC. T2SS and SslE mutants were arrested at the microcolony stage of biofilm formation, suggesting that the T2SS is involved in the development of mature biofilms and that SslE is a dominant effector of biofilm development. Moreover, the T2SS was required for virulence, as infection of rabbits with a rabbit-specific EPEC strain carrying a mutation in either the T2SS or SslE resulted in significantly reduced intestinal colonization and milder disease.

scholarly journals Solution Structure of Homology Region (HR) Domain of Type II Secretion System

2012 ◽  
Vol 287 (12) ◽  
pp. 9072-9080 ◽  
Author(s):  
Shuang Gu ◽  
Geoff Kelly ◽  
Xiaohui Wang ◽  
Tom Frenkiel ◽  
Vladimir E. Shevchik ◽  
...  
Keyword(s):  
Solution Structure ◽  
Secretion System ◽  
Type Ii Secretion ◽  
Type Ii ◽  
Homology Region ◽  
Type Ii Secretion System

scholarly journals Vesicle-associatedPseudomonas aeruginosaleucine aminopeptidase modulates bacterial biofilms grown on host cellular substrates

2019 ◽  
Author(s):  
Caitlin N. Esoda ◽  
Meta J. Kuehn
Keyword(s):  
Biofilm Formation ◽  
Chronic Wounds ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Bacterial Biofilm ◽  
Lung Epithelial ◽  
Coculture Model ◽  
Chronic Colonization ◽  
Bacterial Outer Membrane ◽  
Future Work

AbstractPseudomonas aeruginosa, known as one of the leading causes of morbidity and mortality in cystic fibrosis (CF) patients, secretes a variety of virulence-associated proteases. These enzymes have been shown to contribute significantly toP. aeruginosapathogenesis and biofilm formation in the chronic colonization of CF patient lungs, as well as playing a role in infections of the cornea, burn wounds and chronic wounds. Our lab has previously characterized a secretedP. aeruginosapeptidase, PaAP, that is highly expressed in chronic CF isolates. This leucine aminopeptidase is not only secreted solubly, it also associates with bacterial outer membrane vesicles (OMVs), structures known for their contribution to virulence mechanisms in a variety of Gram-negative species and one of the major components of the biofilm matrix. With this in mind, we hypothesized that PaAP may play a role inP. aeruginosabiofilm formation. Using a lung epithelial cell/bacterial biofilm coculture model, we show that PaAP deletion in a clinicalP. aeruginosabackground leads to increased early biofilm formation. We additionally found that only native vesicle-bound PaAP, as opposed to its soluble forms, could reconstitute the original PaAP-mediated inhibition phenotype, and that the PaAP-containing vesicles could disperse preformed biofilm microcolonies ofKlebsiella pneumoniae, another lung pathogen. These data provide the basis for future work into the mechanism behind PaAP-OMV mediated bacterial microcolony dispersal and the application of these findings to clinical anti-biofilm research.

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