Decrypting the matrix: how interspecies interactions influence matrix in multispecies biofilm?

2020 ◽  
Author(s):  
Cristina Amador ◽  
Henriette L. Røder ◽  
Ute Kuhlicke ◽  
Thomas Neu ◽  
Mette Burmølle
Keyword(s):  
Single Species ◽  
Matrix Composition ◽  
Emergent Properties ◽  
Interspecies Interactions ◽  
Matrix Encoding ◽  
The Matrix ◽  
Static Conditions ◽  
Encoding Genes ◽  
Multispecies Biofilms ◽  
Biofilm Matrix

<p>The biofilm matrix contributes to the establishment of microbial cells on very diverse surfaces, stabilizing biofilms and providing cells with protection against multiple hostile conditions. Moreover, the biofilm matrix can also retain nutrients, enzymes or quorum sensing molecules, favoring the establishment of social interactions among biofilm cells. Functional bacterial amyloids are part of the biofilm structural components of various species, and they were previously proven to bind QS molecules and strengthen the matrix. Multiple studies have been conducted to characterize matrix determinants and their regulation in single species biofilms, while these remain scarcely understood in multispecies biofilms. We have previously isolated and characterized a soil-derived consortium composed of Xanthomonas retroflexus, Stenotrophomonas rhizophila, Microbacterium oxydans and Paenibacillus amylolyticus showing enhanced biofilm biomass and differential gene/protein expression specific of the four-species biofilm.</p> <p>This study aimed at exploring the effect of interspecies interactions on biofilm matrix production in the four-species biofilm. We hypothesize that interspecies interactions may result in differential expression of matrix-encoding genes responsible for biofilm emergent properties.</p> <p>We searched for matrix determinant homologues in X.retroflexus and combined different techniques for characterizing the matrix identity and expression in mono-, dual- and multispecies biofilms.</p> <p>The fap amyloid operon, described in Pseudomonas as a biofilm-scaffold contributing element, was deleted in X. retroflexus, replaced in the four-species model and compared to the parental community for biofilm structure and adhesion capability. The fap mutant displayed poor substrate colonization in flow cells in both mono- and multispecies biofilms with relative filamentous structure compared to the parental strain/ consortium. However, adhesion did not significantly change under static conditions. To characterize matrix composition, we tested 78 different lectins in multispecies biofilms and identified five that bound to our samples. Interestingly, some matrix glycoconjugates were only produced in the consortium.</p> <p>Our data suggest that loss of matrix components, such as the Fap amyloid, and the presence of other species, influences synergistic biofilm properties in the four-species consortium. Ongoing approaches involving localized expression of matrix-encoding genes and matrix proteomes will aid in identifying the mechanisms underlying emergent properties in the four-species biofilm.</p> <p> </p>

scholarly journals Escherichia coli and Salmonella Enteritidis dual-species biofilms: interspecies interactions and antibiofilm efficacy of phages

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Catarina Milho ◽  
Maria Daniela Silva ◽  
Diana Alves ◽  
Hugo Oliveira ◽  
Clara Sousa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Salmonella Enteritidis ◽  
Spatial Organization ◽  
Growth Parameters ◽  
Single Species ◽  
Matrix Composition ◽  
Interspecies Interactions ◽  
Host Interactions ◽  
Phage Growth

AbstractEscherichia coli and Salmonella Enteritidis are foodborne pathogens forming challenging biofilms that contribute to their virulence, antimicrobial resistance, and survival on surfaces. Interspecies interactions occur between species in mixed biofilms promoting different outcomes to each species. Here we describe the interactions between E. coli and S. Enteritidis strains, and their control using specific phages. Single-species biofilms presented more cells compared to dual-species biofilms. The spatial organization of strains, observed by confocal microscopy, revealed similar arrangements in both single- and dual-species biofilms. The EPS matrix composition, assessed by Fourier-transform infrared spectroscopy, disclosed that the spectra extracted from the different dual-species biofilms can either be a combination of both species EPS matrix components or that the EPS matrix of one species predominates. Phages damaged more the single-species biofilms than the mixed biofilms, showing also that the killing efficacy was greatly dependent on the phage growth characteristics, bacterial growth parameters, and bacterial spatial distribution in biofilms. This combination of methodologies provides new knowledge of species-species and phage-host interactions in biofilms of these two major foodborne pathogens.

Staphylococcus aureus biofilm matrix under bone environment influence

2020 ◽  
Author(s):  
Fabien Lamret ◽  
Jennifer Varin-Simon ◽  
Sophie Gangloff ◽  
Fany Reffuveille
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Matrix Composition ◽  
Magnesium Concentration ◽  
Bone Microenvironment ◽  
Low Oxygen ◽  
The Matrix ◽  
Main Components ◽  
Biofilm Matrix

<p>Bone and joint infections linked to implanted materials are mostly due to Staphylococcus aureus. Deciphering the biofilm structure appears to be a promising strategy to develop antibiofilm molecules in order to curb infection occurrence and the bacterial recurrence. Indeed, the characterization of biofilm architecture and physiology could help to find new therapeutic targets through notable quantification of the matrix main components. Our hypothesis is that the very complex and interconnected bone microenvironment influences the bacterial adhesion and biofilm maturation and so its composition.</p> <p>To identify the main factors influencing biofilm formation in the bone microenvironment, we determined biofilm biomass and the number of live adhered bacteria in a static model, completed with microscopy approaches to support our results. Different factors of bone microenvironment were tested: starvation, low oxygen rate, excess of magnesium, and presence of bone cell products. Our first results showed that MSSA or MRSA strains did not have the same behaviors under the tested conditions. However, for both types of strains, excess of magnesium combined to paucity of amino acids and oxygen increased the most the proportion of adhered Staphylococcus aureus (a 6 to 43 fold-increase, p = < 0.01). But biofilm biomass quantification and bacterial adhesion results showed divergent profiles leading us to think that matrix could be involved in such contrasts. Scanning electron microscopy highlighted several structures of matrix produced by these bacteria: well-known slime aspect, but also fibrous appearance, and no matrix production was revealed under some conditions. Indeed, all strains produced few matrix when cultured with control medium and oxygenated condition. Only CIP 53.154 strain built a strong slime-like matrix in response to oxygen depletion. However, both MSSA CIP 53.154 and SH1000 strains developed fibrous structures under anaerobic conditions associated with amino acid starvation, high magnesium concentration with or without glucose. MRSA USA300 strain did not seem to produce a matrix under our conditions, which is supported by the literature. Further investigations of the biofilm matrix are needed to conclude on the matrix nature, which surrounds bacteria under our conditions.</p> <p>The bone microenvironment is complex but our results show that the parameters that mimicked this specific environment influenced the bacterial adhesion and probably the biofilm matrix composition of several strains of Staphylococcus aureus. Further investigations will help to understand how the different factors influence biofilm formation through quantification of the matrix main components by fluorescence microscopy and enzyme digestion. Our final aim is to develop an in vitro model mimicking this specific microenvironment in order to screen different antimicrobial molecules, which could target the biofilm matrix.</p>

scholarly journals Conserved Role for Biofilm Matrix Polysaccharides in Candida auris Drug Resistance

mSphere ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
E. G. Dominguez ◽  
R. Zarnowski ◽  
H. L. Choy ◽  
M. Zhao ◽  
H. Sanchez ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Biofilm Formation ◽  
Resistance Mechanism ◽  
Matrix Composition ◽  
Candida Auris ◽  
Biofilm Growth ◽  
Content Type ◽  
The Matrix ◽  
And Function ◽  
Biofilm Matrix

ABSTRACT Candida auris has emerged as an outbreak pathogen associated with high mortality. Biofilm formation and linked drug resistance are common among Candida species. Drug sequestration by the biofilm matrix accounts for much of the antifungal tolerance. In this study, we examine the biofilm matrix composition and function for a diverse set of C. auris isolates. We show that matrix sequesters nearly 70% of the available triazole antifungal. Like the biofilms formed by other Candida spp., we find that the matrix of C. auris is rich in mannan-glucan polysaccharides and demonstrate that their hydrolysis reduces drug tolerance. This biofilm matrix resistance mechanism appears conserved among Candida species, including C. auris. IMPORTANCE Candida auris is an emerging fungal threat linked to poor patient outcomes. The factors responsible for this apparent increase in pathogenicity remain largely unknown. Biofilm formation has been suggested as an important factor for persistence of this organism in patients and the environment. Our findings reveal one mechanism utilized by C. auris to evade the effect of triazole antifungal therapy during biofilm growth. The conservation of the protective biofilm matrix among Candida spp. suggests that is a promising pan-fungal Candida biofilm drug target.

scholarly journals Enzymes Catalyzing the TCA- and Urea Cycle Influence the Matrix Composition of Biofilms Formed by Methicillin-Resistant Staphylococcus aureus USA300

2018 ◽  
Vol 6 (4) ◽  
pp. 113 ◽  
Author(s):  
Sarah De Backer ◽  
Julia Sabirova ◽  
Ines De Pauw ◽  
Henri De Greve ◽  
Jean-Pierre Hernalsteens ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Urea Cycle ◽  
Citrate Synthase ◽  
Fumarate Hydratase ◽  
Tca Cycle ◽  
Matrix Composition ◽  
Methicillin Resistant ◽  
The Tca Cycle ◽  
The Matrix ◽  
Biofilm Matrix

In methicillin-sensitive Staphylococcus aureus (MSSA), the tricarboxylic acid (TCA) cycle is known to negatively regulate production of the major biofilm-matrix exopolysaccharide, PIA/PNAG. However, methicillin-resistant S. aureus (MRSA) produce a primarily proteinaceous biofilm matrix, and contribution of the TCA-cycle therein remains unclear. Utilizing USA300-JE2 Tn-mutants (NARSA) in genes encoding TCA- and urea cycle enzymes for transduction into a prolific biofilm-forming USA300 strain (UAS391-Erys), we studied the contribution of the TCA- and urea cycle and of proteins, eDNA and PIA/PNAG, to the matrix. Genes targeted in the urea cycle encoded argininosuccinate lyase and arginase (argH::Tn and rocF::Tn), and in the TCA-cycle encoded succinyl-CoA synthetase, succinate dehydrogenase, aconitase, isocitrate dehydrogenase, fumarate hydratase class II, and citrate synthase II (sucC::Tn, sdhA/B::Tn, acnA::Tn, icd::Tn, fumC::Tn and gltA::Tn). Biofilm formation was significantly decreased under no flow and flow conditions by argH::Tn, fumC::Tn, and sdhA/B::Tn (range OD492 0.374−0.667; integrated densities 2.065−4.875) compared to UAS391-EryS (OD492 0.814; integrated density 10.676) (p ≤ 0.008). Cellular and matrix stains, enzymatic treatment (Proteinase K, DNase I), and reverse-transcriptase PCR-based gene-expression analysis of fibronectin-binding proteins (fnbA/B) and the staphylococcal accessory regulator (sarA) on pre-formed UAS391-Erys and Tn-mutant biofilms showed: (i) < 1% PIA/PNAG in the proteinaceous/eDNA matrix; (ii) increased proteins under no flow and flow in the matrix of Tn mutant biofilms (on average 50 and 51 (±11)%) compared to UAS391-Erys (on average 22 and 25 (±4)%) (p < 0.001); and (iii) down- and up-regulation of fnbA/B and sarA, respectively, in Tn-mutants compared to UAS391-EryS (0.62-, 0.57-, and 2.23-fold on average). In conclusion, we show that the biofilm matrix of MRSA-USA300 and the corresponding Tn mutants is PIA/PNAG-independent and are mainly composed of proteins and eDNA. The primary impact of TCA-cycle inactivation was on the protein component of the biofilm matrix of MRSA-USA300.

scholarly journals We Are One: Multispecies Metabolism of a Biofilm Consortium and Their Treatment Strategies

2021 ◽  
Vol 12 ◽  
Author(s):  
Ruchika Vinod Joshi ◽  
Cindy Gunawan ◽  
Riti Mann
Keyword(s):  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Treatment Options ◽  
Cell Communication ◽  
Treatment Strategies ◽  
Single Species ◽  
Interspecies Interactions ◽  
Metabolic Substrates ◽  
Multispecies Biofilm ◽  
Multispecies Biofilms

The ecological and medical significance of bacterial biofilms have been well recognized. Biofilms are harder to control than their planktonic free-living counterparts and quite recently, the focus of the study has shifted to the multispecies consortia, which represent the vast majority of real-case infection scenarios. Studies have begun to explore the complex interspecies interactions within these biofilms. However, only little attention is currently given to the role of cellular metabolites in the cell-to-cell communication. The concentration gradients of metabolic substrates and products affect the spatial growth of bacteria in multispecies biofilm. This, if looked into more deeply, can lead to identification of potential therapies targeting the specific metabolites and hence the coordinated protection in the bacterial community. Herein, we review the interspecies communications, including their metabolic cross-talking, in multispecies biofilm, to signify the importance of such interactions on the initial formation and subsequent growth of these biofilms. Multispecies biofilms with their species heterogeneity are more resilient to antimicrobial agents than their single species biofilm counterparts and this characteristic is of particular interest when dealing with pathogenic bacteria. In this Review, we also discuss the treatment options available, to include current and emerging avenues to combat pathogenic multispecies biofilms in the clinical, environmental, as well as industrial settings.

scholarly journals Methods to extract the exopolymeric matrix from biofilms: a comparative study

1999 ◽  
Vol 39 (7) ◽  
pp. 243-250 ◽  
Author(s):  
Joana Azeredo ◽  
Valentina Lazarova ◽  
Rosário Oliveira
Keyword(s):  
Organic Carbon ◽  
Comparative Study ◽  
Mixed Culture ◽  
Pure Culture ◽  
Cell Walls ◽  
Extraction Method ◽  
Extraction Methods ◽  
Suitable Method ◽  
The Matrix ◽  
Biofilm Matrix

To study the composition of a biofilm a previous extraction method is required to separate cells from the matrix. There are several methods reported in the literature; however they are not efficient or promote leakage of intracellular material. In this work several extraction methods were assayed in mixed culture and pure culture biofilms and their efficiency was evaluated by the amount of organic carbon, proteins and intracellular material extracted. The results showed that the extraction with glutaraldehyde 3% (w/v) was the most suitable method, extracting great amounts of organic carbon without promoting cell lysis or permeabilization. Glutaraldehyde is a bifunctional reagent that binds to cell walls avoiding their permeabilization and the biofilm matrix is solubilized in the solution.

Precipitation of highly luminescent phases from PECVD Si suboxides

2004 ◽  
Vol 832 ◽  
Author(s):  
M. Perálvarez ◽  
M. López ◽  
B. Garrido ◽  
J.R. Morante ◽  
J. Barreto ◽  
...  
Keyword(s):  
Refractive Index ◽  
Phase Separation ◽  
Ion Implantation ◽  
Composition Profile ◽  
Matrix Composition ◽  
Light Sources ◽  
The Matrix ◽  
Detailed Composition ◽  
Preparation Route

ABSTRACTSi nanoclusters (Si-nc) embedded in SiO2 present outstanding luminescent emission in the visible and are the material of choice for the realization of efficient light sources integrated with Si technology. PECVD is an attractive preparation route but there is still the need to understand how Si excess and matrix composition affect the precipitation of Si-nc and their photoluminescence (PL) efficiency. The SiOx PECVD layers studied here have a Si excess up to 50% and a thickness between 50 and 100 nm. The phase separation, precipitation and growth of the Si-nc have been achieved by annealing at 1250 °C. For reference, the same study has been performed in Si-nc/SiO2 materials synthesized by ion implantation and annealing. Refractive index and thickness measured by ellipsometry show a densification of the layers after the H release during annealing. A detailed composition profile has been determined by XPS and FTIR analyses and shows almost complete phase separation except for the interfaces, where a depletion of Si-nc is found. EFTEM demonstrates that isolated Si-nc are formed for Si excess up to 25% while for higher Si excess a continuous Si phase is observed. The PL efficiency in PECVD samples is maximized for a Si excess of 17% which is the same Si excess than that for the most emitting implanted samples. No dependence of PL efficiency has been found on the presence of Nitrogen in the matrix (up to the 10%).

scholarly journals EIGENVECTOR LOCALIZATION AS A TOOL TO STUDY SMALL COMMUNITIES IN ONLINE SOCIAL NETWORKS

2010 ◽  
Vol 13 (06) ◽  
pp. 699-723 ◽  
Author(s):  
FRANTIŠEK SLANINA ◽  
ZDENĚK KONOPÁSEK
Keyword(s):  
Online Social Networks ◽  
Large Network ◽  
Bipartite Networks ◽  
Small Communities ◽  
Complementary Approach ◽  
Matrix Encoding ◽  
The Matrix ◽  
Network Modules ◽  
Principal Tool ◽  
Eigenvector Localization

We present and discuss a mathematical procedure for identification of small "communities" or segments within large bipartite networks. The procedure is based on spectral analysis of the matrix encoding network structure. The principal tool here is localization of eigenvectors of the matrix, by means of which the relevant network segments become visible. We exemplified our approach by analyzing the data related to product reviewing on Amazon.com. We found several segments, a kind of hybrid communities of densely interlinked reviewers and products, which we were able to meaningfully interpret in terms of the type and thematic categorization of reviewed items. The method provides a complementary approach to other ways of community detection, typically aiming at identification of large network modules.

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