Filamentation and spatiotemporal distribution of extracellular polymeric substances: role on X.fastidiosa single cell adhesion and biofilm formation (Conference Presentation)

ABSTRACT Extracellular DNA (eDNA) is a biofilm component that contributes to the formation and structural stability of biofilms. Streptococcus mutans, a major cariogenic bacterium, induces eDNA-dependent biofilm formation under specific conditions. Since cell death can result in the release and accumulation of DNA, the dead cells in biofilms are a source of eDNA. However, it remains unknown how eDNA is released from dead cells and is localized within S. mutans biofilms. We focused on cell death induced by the extracellular signaling peptide called competence-stimulating peptide (CSP). We demonstrate that nucleic acid release into the extracellular environment occurs in a subpopulation of dead cells. eDNA production induced by CSP was highly dependent on the lytF gene, which encodes an autolysin. Although lytF expression was induced bimodally by CSP, lytF-expressing cells further divided into surviving cells and eDNA-producing dead cells. Moreover, we found that lytF-expressing cells were abundant near the bottom of the biofilm, even when all cells in the biofilm received the CSP signal. Dead cells and eDNA were also abundantly present near the bottom of the biofilm. The number of lytF-expressing cells in biofilms was significantly higher than that in planktonic cultures, which suggests that adhesion to the substratum surface is important for the induction of lytF expression. The deletion of lytF resulted in reduced adherence to a polystyrene surface. These results suggest that lytF expression and eDNA production induced near the bottom of the biofilm contribute to a firmly attached and structurally stable biofilm. IMPORTANCE Bacterial communities encased by self-produced extracellular polymeric substances (EPSs), known as biofilms, have a wide influence on human health and environmental problems. The importance of biofilm research has increased, as biofilms are the preferred bacterial lifestyle in nature. Furthermore, in recent years it has been noted that the contribution of phenotypic heterogeneity within biofilms requires analysis at the single-cell or subpopulation level to understand bacterial life strategies. In Streptococcus mutans, a cariogenic bacterium, extracellular DNA (eDNA) contributes to biofilm formation. However, it remains unclear how and where the cells produce eDNA within the biofilm. We focused on LytF, an autolysin that is induced by extracellular peptide signals. We used single-cell level imaging techniques to analyze lytF expression in the biofilm population. Here, we show that S. mutans generates eDNA by inducing lytF expression near the bottom of the biofilm, thereby enhancing biofilm adhesion and structural stability.

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Process Description of an Unconventional Biofilm Formation by Bacterial Cells Autoagglutinating Through Sticky, Long, and Peritrichate Nanofibers

10.26434/chemrxiv.10001924.v1 ◽

2019 ◽

Author(s):

Yoshihide Furuichi ◽

Shogo Yoshimoto ◽

Tomohiro Inaba ◽

Nobuhiko Nomura ◽

Katsutoshi Hori

Keyword(s):

Formation Process ◽

Biofilm Formation ◽

Extracellular Polymeric Substances ◽

Waste Treatment ◽

Large Cell ◽

Dlvo Theory ◽

Bacterial Cells ◽

Chemical Production ◽

Discontinuous Surface ◽

Cell Cell

Biofilms are used in environmental biotechnologies including waste treatment and environmentally friendly chemical production. Understanding the mechanisms of biofilm formation is essential to control microbial behavior and improve environmental biotechnologies. Acinetobacter sp. Tol 5 autoagglutinate through the interaction of the long, peritrichate nanofiber protein AtaA, a trimeric autotransporter adhesin. Using AtaA, without cell growth or the production of extracellular polymeric substances, Tol 5 cells quickly form an unconventional biofilm. In this study, we investigated the formation process of this unconventional biofilm, which started with cell–cell interactions, proceeded to cell clumping, and led to the formation of large cell aggregates. The cell–cell interaction was described by DLVO theory based on a new concept, which considers two independent interactions between two cell bodies and between two AtaA fiber tips forming a virtual discontinuous surface. If cell bodies cannot collide owing to an energy barrier at low ionic strengths but approach within the interactive distance of AtaA fibers, cells can agglutinate through their contact. Cell clumping proceeds following the cluster–cluster aggregation model, and an unconventional biofilm containing void spaces and a fractal nature develops. Understanding its formation process would extend the utilization of various types of biofilms, enhancing environmental biotechnologies.

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Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

Current Pharmaceutical Biotechnology ◽

10.2174/1389201020666191112155905 ◽

2020 ◽

Vol 21 (4) ◽

pp. 270-286 ◽

Cited By ~ 2

Author(s):

Fazlurrahman Khan ◽

Dung T.N. Pham ◽

Sandra F. Oloketuyi ◽

Young-Mog Kim

Keyword(s):

Biofilm Formation ◽

Pathogenic Bacteria ◽

Extracellular Polymeric Substances ◽

Quorum Quenching ◽

Resistance Mechanisms ◽

Bacterial Biofilm ◽

Bacterial Cells ◽

High Concentration ◽

Biofilm Inhibition ◽

Abiotic Surfaces

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.

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Biofilm Formation in Xanthomonas arboricola pv. pruni: Structure and Development

Agronomy ◽

10.3390/agronomy11030546 ◽

2021 ◽

Vol 11 (3) ◽

pp. 546

Author(s):

Pilar Sabuquillo ◽

Jaime Cubero

Keyword(s):

Biofilm Formation ◽

Extracellular Polymeric Substances ◽

Environmental Changes ◽

Nutrient Content ◽

Infection Process ◽

Bacterial Attachment ◽

Key Factors ◽

Cell Structures ◽

Microscopy Techniques

Xanthomonasarboricola pv. pruni (Xap) causes bacterial spot of stone fruit and almond, an important plant disease with a high economic impact. Biofilm formation is one of the mechanisms that microbial communities use to adapt to environmental changes and to survive and colonize plants. Herein, biofilm formation by Xap was analyzed on abiotic and biotic surfaces using different microscopy techniques which allowed characterization of the different biofilm stages compared to the planktonic condition. All Xap strains assayed were able to form real biofilms creating organized structures comprised by viable cells. Xap in biofilms differentiated from free-living bacteria forming complex matrix-encased multicellular structures which become surrounded by a network of extracellular polymeric substances (EPS). Moreover, nutrient content of the environment and bacterial growth have been shown as key factors for biofilm formation and its development. Besides, this is the first work where different cell structures involved in bacterial attachment and aggregation have been identified during Xap biofilm progression. Our findings provide insights regarding different aspects of the biofilm formation of Xap which improve our understanding of the bacterial infection process occurred in Prunus spp and that may help in future disease control approaches.

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Eap1p, an Adhesin That Mediates Candida albicans Biofilm Formation In Vitro and In Vivo

Eukaryotic Cell ◽

10.1128/ec.00049-07 ◽

2007 ◽

Vol 6 (6) ◽

pp. 931-939 ◽

Cited By ~ 96

Author(s):

Fang Li ◽

Michael J. Svarovsky ◽

Amy J. Karlsson ◽

Joel P. Wagner ◽

Karen Marchillo ◽

...

Keyword(s):

Candida Albicans ◽

Cell Adhesion ◽

Biofilm Formation ◽

Fungal Infections ◽

Gene Dosage ◽

Venous Catheter ◽

Flow Chamber ◽

Dependent Manner

ABSTRACT Candida albicans is the leading cause of systemic fungal infections in immunocompromised humans. The ability to form biofilms on surfaces in the host or on implanted medical devices enhances C. albicans virulence, leading to antimicrobial resistance and providing a reservoir for infection. Biofilm formation is a complex multicellular process consisting of cell adhesion, cell growth, morphogenic switching between yeast form and filamentous states, and quorum sensing. Here we describe the role of the C. albicans EAP1 gene, which encodes a glycosylphosphatidylinositol-anchored, glucan-cross-linked cell wall protein, in adhesion and biofilm formation in vitro and in vivo. Deleting EAP1 reduced cell adhesion to polystyrene and epithelial cells in a gene dosage-dependent manner. Furthermore, EAP1 expression was required for C. albicans biofilm formation in an in vitro parallel plate flow chamber model and in an in vivo rat central venous catheter model. EAP1 expression was upregulated in biofilm-associated cells in vitro and in vivo. Our results illustrate an association between Eap1p-mediated adhesion and biofilm formation in vitro and in vivo.

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Transcriptome Analysis Reveals the Genes Involved in Bifidobacterium Longum FGSZY16M3 Biofilm Formation

Microorganisms ◽

10.3390/microorganisms9020385 ◽

2021 ◽

Vol 9 (2) ◽

pp. 385 ◽

Cited By ~ 1

Author(s):

Zongmin Liu ◽

Lingzhi Li ◽

Qianwen Wang ◽

Faizan Ahmed Sadiq ◽

Yuankun Lee ◽

...

Keyword(s):

Network Analysis ◽

Biofilm Formation ◽

Extracellular Polymeric Substances ◽

Molecular Mechanisms ◽

Early Stage ◽

Bifidobacterium Longum ◽

Regulation Of Gene Expression ◽

Interaction Network ◽

Structural Development ◽

Sequencing Analysis

Biofilm formation has evolved as an adaptive strategy for bacteria to cope with harsh environmental conditions. Currently, little is known about the molecular mechanisms of biofilm formation in bifidobacteria. A time series transcriptome sequencing analysis of both biofilm and planktonic cells of Bifidobacterium longum FGSZY16M3 was performed to identify candidate genes involved in biofilm formation. Protein–protein interaction network analysis of 1296 differentially expressed genes during biofilm formation yielded 15 clusters of highly interconnected nodes, indicating that genes related to the SOS response (dnaK, groS, guaB, ruvA, recA, radA, recN, recF, pstA, and sufD) associated with the early stage of biofilm formation. Genes involved in extracellular polymeric substances were upregulated (epsH, epsK, efp, frr, pheT, rfbA, rfbJ, rfbP, rpmF, secY and yidC) in the stage of biofilm maturation. To further investigate the genes related to biofilm formation, weighted gene co-expression network analysis (WGCNA) was performed with 2032 transcript genes, leading to the identification of nine WGCNA modules and 133 genes associated with response to stress, regulation of gene expression, quorum sensing, and two-component system. These results indicate that biofilm formation in B. longum is a multifactorial process, involving stress response, structural development, and regulatory processes.

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Archaeal biofilms: widespread and complex

Biochemical Society Transactions ◽

10.1042/bst20120304 ◽

2013 ◽

Vol 41 (1) ◽

pp. 393-398 ◽

Cited By ~ 52

Author(s):

Sabrina Fröls

Keyword(s):

Biofilm Formation ◽

Extracellular Polymeric Substances ◽

Bacterial Species ◽

Surface Adhesion ◽

Form Complex ◽

Abiotic Surfaces ◽

Archaeal Species ◽

Physical And Chemical ◽

Insight Into ◽

Mixed Communities

Biofilms or multicellular structures become accepted as the dominant microbial lifestyle in Nature, but in the past they were only studied extensively in bacteria. Investigations on archaeal monospecies cultures have shown that many archaeal species are able to adhere on biotic and abiotic surfaces and form complex biofilm structures. Biofilm-forming archaea were identified in a broad range of extreme and moderate environments. Natural biofilms observed are mostly mixed communities composed of archaeal and bacterial species of various abundances. The physiological functions of the archaea identified in such mixed communities suggest a significant impact on the biochemical cycles maintaining the flow and recycling of the nutrients on earth. Therefore it is of high interest to investigate the characteristics and mechanisms underlying the archaeal biofilm formation. In the present review, I summarize and discuss the present investigations of biofilm-forming archaeal species, i.e. their diverse biofilm architectures in monospecies or mixed communities, the identified EPSs (extracellular polymeric substances), archaeal structures mediating surface adhesion or cell–cell connections, and the response to physical and chemical stressors implying that archaeal biofilm formation is an adaptive reaction to changing environmental conditions. A first insight into the molecular differentiation of cells within archaeal biofilms is given.

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Evolutionary Perspectives on the Moonlighting Functions of Bacterial Factors That Support Actin-Based Motility

mBio ◽

10.1128/mbio.01520-19 ◽

2019 ◽

Vol 10 (4) ◽

Cited By ~ 1

Author(s):

Volkan K. Köseoğlu ◽

Hervé Agaisse

Keyword(s):

Cell Adhesion ◽

Host Cell ◽

Biofilm Formation ◽

Actin Polymerization ◽

Current Knowledge ◽

Bacterial Pathogens ◽

Actin Nucleation ◽

Bacterial Aggregation ◽

Moonlighting Functions ◽

Evolutionary Perspectives

ABSTRACT Various bacterial pathogens display an intracellular lifestyle and spread from cell to cell through actin-based motility (ABM). ABM requires actin polymerization at the bacterial pole and is mediated by the expression of bacterial factors that hijack the host cell actin nucleation machinery or exhibit intrinsic actin nucleation properties. It is increasingly recognized that bacterial ABM factors, in addition to having a crucial task during the intracellular phase of infection, display “moonlighting” adhesin functions, such as bacterial aggregation, biofilm formation, and host cell adhesion/invasion. Here, we review our current knowledge of ABM factors and their additional functions, and we propose that intracellular ABM functions have evolved from ancestral, extracellular adhesin functions.

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Controlled spatial organization of bacterial clusters reveals cell filamentation is vital for Xylella fastidiosa biofilm formation

10.1101/2021.01.08.425936 ◽

2021 ◽

Author(s):

Silambarasan Anbumani ◽

Aldeliane M. da Silva ◽

Eduarda R. Fischer ◽

Mariana de Souza e Silva ◽

Antonio A.G. von Zuben ◽

...

Keyword(s):

Cell Adhesion ◽

Quorum Sensing ◽

Biofilm Formation ◽

Spatial Organization ◽

Xylella Fastidiosa ◽

Cell Formation ◽

Formation Mechanisms ◽

Cell Morphogenesis ◽

Cell Clusters ◽

Filamentous Cell

The morphological plasticity of bacteria to form filamentous cells commonly represents an adaptive strategy induced by stresses. In contrast, for diverse pathogens filamentous cells have been observed during biofilm formation, with function yet to be elucidated. To identify prior hypothesized quorum sensing as trigger of such cell morphogenesis, spatially controlled cell adhesion is pivotal. Here, we demonstrate highly-selective cell adhesion of the biofilm-forming phytopathogen Xylella fastidiosa to gold-patterned SiO2 substrates with well-defined geometries and dimensions. The consequent control of both cell density and distances between cell clusters using these patterns provided evidence of quorum sensing governing filamentous cell formation. While cell morphogenesis is induced by cell cluster density, filamentous cell growth is oriented towards neighboring cell clusters and distance-dependent; large interconnected cell clusters create the early biofilm structural framework. Together, our findings and investigative platform could facilitate therapeutic developments targeting biofilm formation mechanisms of X. fastidiosa and other pathogens.

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