scholarly journals BolA Is a Transcriptional Switch That Turns Off Motility and Turns On Biofilm Development

mBio ◽  
2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Clémentine Dressaire ◽  
Ricardo Neves Moreira ◽  
Susana Barahona ◽  
António Pedro Alves de Matos ◽  
Cecília Maria Arraiano
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Extracellular Polysaccharides ◽  
Bacterial Cells ◽  
Content Type ◽  
Bacterial Transcription ◽  
A Genome ◽  
Exact Function ◽  
Transcriptional Switch ◽  
Biofilm Development

ABSTRACTBacteria are extremely versatile organisms that rapidly adapt to changing environments. When bacterial cells switch from planktonic growth to biofilm, flagellum formation is turned off and the production of fimbriae and extracellular polysaccharides is switched on. BolA is present in most Gram-negative bacteria, and homologues can be found from proteobacteria to eukaryotes. Here, we show that BolA is a new bacterial transcription factor that modulates the switch from a planktonic to a sessile lifestyle. It negatively modulates flagellar biosynthesis and swimming capacity inEscherichia coli. Furthermore, BolA overexpression favors biofilm formation, involving the production of fimbria-like adhesins and curli. Our results also demonstrate that BolA is a protein with high affinity to DNA and is able to regulate many genes on a genome-wide scale. Moreover, we show that the most significant targets of this protein involve a complex network of genes encoding proteins related to biofilm development. Herein, we propose that BolA is a motile/adhesive transcriptional switch, specifically involved in the transition between the planktonic and the attachment stage of biofilm formation.IMPORTANCEEscherichia colicells possess several mechanisms to cope with stresses. BolA has been described as a protein important for survival in late stages of bacterial growth and under harsh environmental conditions. BolA-like proteins are widely conserved from prokaryotes to eukaryotes. Although their exact function is not fully established at the molecular level, they seem to be involved in cell proliferation or cell cycle regulation. Here, we unraveled the role of BolA in biofilm development and bacterial motility. Our work suggests that BolA actively contributes to the decision of bacteria to arrest flagellar production and initiate the attachment to form structured communities, such as biofilms. The molecular studies of different lifestyles coupled with the comprehension of the BolA functions may be an important step for future perspectives, with health care and biotechnology applications.

PBP4 and PBP5 are involved in regulating exopolysaccharide synthesis during Escherichia coli biofilm formation

Microbiology ◽  
2021 ◽  
Vol 167 (3) ◽  
Author(s):  
Sathi Mallick ◽  
Shanti Kiran ◽  
Tapas Kumar Maiti ◽  
Anindya S. Ghosh
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Type Species ◽  
Pentose Phosphate ◽  
Bacterial Cells ◽  
Surface Adhesion ◽  
Content Type ◽  
Penicillin Binding Proteins ◽  
E Coli ◽  
Link Type

Escherichia coli low-molecular-mass (LMM) Penicillin-binding proteins (PBPs) help in hydrolysing the peptidoglycan fragments from their cell wall and recycling them back into the growing peptidoglycan matrix, in addition to their reported involvement in biofilm formation. Biofilms are external slime layers of extra-polymeric substances that sessile bacterial cells secrete to form a habitable niche for themselves. Here, we hypothesize the involvement of Escherichia coli LMM PBPs in regulating the nature of exopolysaccharides (EPS) prevailing in its extra-polymeric substances during biofilm formation. Therefore, this study includes the assessment of physiological characteristics of E. coli CS109 LMM PBP deletion mutants to address biofilm formation abilities, viability and surface adhesion. Finally, EPS from parent CS109 and its ΔPBP4 and ΔPBP5 mutants were purified and analysed for sugars present. Deletions of LMM PBP reduced biofilm formation, bacterial adhesion and their viability in biofilms. Deletions also diminished EPS production by ΔPBP4 and ΔPBP5 mutants, purification of which suggested an increased overall negative charge compared with their parent. Also, EPS analyses from both mutants revealed the appearance of an unusual sugar, xylose, that was absent in CS109. Accordingly, the reason for reduced biofilm formation in LMM PBP mutants may be speculated as the subsequent production of xylitol and a hindrance in the standard flow of the pentose phosphate pathway.

scholarly journals Role ofrpoSin Escherichia coli O157:H7 Strain H32 Biofilm Development and Survival

2012 ◽  
Vol 78 (23) ◽  
pp. 8331-8339 ◽  
Author(s):  
Jessica R. Sheldon ◽  
Mi-Sung Yim ◽  
Jessica H. Saliba ◽  
Wai-Hong Chung ◽  
Kwok-Yin Wong ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lake Water ◽  
Biofilm Formation ◽  
Survival Rates ◽  
Confocal Scanning Laser Microscopy ◽  
Wild Type ◽  
Minimal Growth ◽  
Content Type ◽  
Biofilm Development

ABSTRACTThe protein RpoS is responsible for mediating cell survival during the stationary phase by conferring cell resistance to various stressors and has been linked to biofilm formation. In this study, the role of therpoSgene inEscherichia coliO157:H7 biofilm formation and survival in water was investigated. Confocal scanning laser microscopy of biofilms established on coverslips revealed a nutrient-dependent role ofrpoSin biofilm formation, where the biofilm biomass volume of therpoSmutant was 2.4- to 7.5-fold the size of itsrpoS+wild-type counterpart in minimal growth medium. The enhanced biofilm formation of therpoSmutant did not, however, translate to increased survival in sterile double-distilled water (ddH2O), filter-sterilized lake water, or unfiltered lake water. TherpoSmutant had an overall reduction of 3.10 and 5.30 log10in sterile ddH2O and filter-sterilized lake water, respectively, while only minor reductions of 0.53 and 0.61 log10in viable counts were observed for the wild-type form in the two media over a 13-day period, respectively. However, the survival rates of the detached biofilm-derivedrpoS+andrpoSmutant cells were comparable. Under the competitive stress conditions of unfiltered lake water, the advantage conferred by the presence ofrpoSwas lost, and both the wild-type and knockout forms displayed similar declines in viable counts. These results suggest thatrpoSdoes have an influence on both biofilm formation and survival ofE. coliO157:H7 and that the advantage conferred byrpoSis contingent on the environmental conditions.

scholarly journals Effect of Micro- and Nanoscale Topography on the Adhesion of Bacterial Cells to Solid Surfaces

2013 ◽  
Vol 79 (8) ◽  
pp. 2703-2712 ◽  
Author(s):  
Lillian C. Hsu ◽  
Jean Fang ◽  
Diana A. Borca-Tasciuc ◽  
Randy W. Worobo ◽  
Carmen I. Moraru
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Bacterial Attachment ◽  
Listeria Innocua ◽  
Solid Surfaces ◽  
Bacterial Cells ◽  
Content Type ◽  
Nanoscale Topography ◽  
Key Microorganisms ◽  
Financial Losses

ABSTRACTAttachment and biofilm formation by bacterial pathogens on surfaces in natural, industrial, and hospital settings lead to infections and illnesses and even death. Minimizing bacterial attachment to surfaces using controlled topography could reduce the spreading of pathogens and, thus, the incidence of illnesses and subsequent human and financial losses. In this context, the attachment of key microorganisms, includingEscherichia coli,Listeria innocua, andPseudomonas fluorescens, to silica and alumina surfaces with micron and nanoscale topography was investigated. The results suggest that orientation of the attached cells occurs preferentially such as to maximize their contact area with the surface. Moreover, the bacterial cells exhibited different morphologies, including different number and size of cellular appendages, depending on the topographical details of the surface to which they attached. This suggests that bacteria may utilize different mechanisms of attachment in response to surface topography. These results are important for the design of novel microbe-repellant materials.

scholarly journals Inhibition of Staphylococcus epidermidis Biofilm by Trimethylsilane Plasma Coating

2012 ◽  
Vol 56 (11) ◽  
pp. 5923-5937 ◽  
Author(s):  
Yibao Ma ◽  
Meng Chen ◽  
John E. Jones ◽  
Andrew C. Ritts ◽  
Qingsong Yu ◽  
...  
Keyword(s):  
Antibiotic Treatment ◽  
Medical Devices ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Plasma Coating ◽  
Bacterial Cells ◽  
Implantable Medical Devices ◽  
Content Type ◽  
Coated Surfaces ◽  
Biofilm Development

ABSTRACTBiofilm formation on implantable medical devices is a major impediment to the treatment of nosocomial infections and promotes local progressive tissue destruction.Staphylococcus epidermidisinfections are the leading cause of biofilm formation on indwelling devices. Bacteria in biofilms are highly resistant to antibiotic treatment, which in combination with the increasing prevalence of antibiotic resistance among human pathogens further complicates treatment of biofilm-related device infections. We have developed a novel plasma coating technology. Trimethylsilane (TMS) was used as a monomer to coat the surfaces of 316L stainless steel and grade 5 titanium alloy, which are widely used in implantable medical devices. The results of biofilm assays demonstrated that this TMS coating markedly decreasedS. epidermidisbiofilm formation by inhibiting the attachment of bacterial cells to the TMS-coated surfaces during the early phase of biofilm development. We also discovered that bacterial cells on the TMS-coated surfaces were more susceptible to antibiotic treatment than their counterparts in biofilms on uncoated surfaces. These findings suggested that TMS coating could result in a surface that is resistant to biofilm development and also in a bacterial community that is more sensitive to antibiotic therapy than typical biofilms.

scholarly journals The Nitrite Transporter Facilitates Biofilm Formation via Suppression of Nitrite Reductase and Is a New Antibiofilm Target in Pseudomonas aeruginosa

mBio ◽  
2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Ji-Su Park ◽  
Ha-Young Choi ◽  
Won-Gon Kim
Keyword(s):  
Nitric Oxide ◽  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Nitrite Reductase ◽  
Biofilm Formation ◽  
No Production ◽  
Content Type ◽  
A Genome ◽  
Biofilm Dispersal ◽  
Gmp Production

ABSTRACT Biofilm-forming bacteria, including the Gram-negative Pseudomonas aeruginosa, cause multiple types of chronic infections and are responsible for serious health burdens in humans, animals, and plants. Nitric oxide (NO) has been shown to induce biofilm dispersal via triggering a reduction in cyclic-di-GMP levels in a variety of bacteria. However, how NO, at homeostatic levels, also facilitates biofilm formation is unknown. Here, we found that complestatin, a structural analog of vancomycin isolated from Streptomyces, inhibits P. aeruginosa biofilm formation by upregulating NO production via nitrite reductase (NIR) induction and c-di-GMP degradation via phosphodiesterase (PDE) stimulation. The complestatin protein target was identified as a nitrite transporter from a genome-wide screen using the Keio Escherichia coli knockout library and confirmed using nitrite transporter knockout and overexpression strains. We demonstrated that the nitrite transporter stimulated biofilm formation by controlled NO production via appropriate NIR suppression and subsequent diguanylate cyclase (DGC) activation, not PDE activity, and c-di-GMP production in E. coli and P. aeruginosa. Thus, this study provides a mechanism for NO-mediated biofilm formation, which was previously not understood. IMPORTANCE Bacterial biofilms play roles in infections and avoidance of host defense mechanisms of medically important pathogens and increase the antibiotic resistance of the bacteria. Nitric oxide (NO) is reported to be involved in both biofilm formation and dispersal, which are conflicting processes. The mechanism by which NO regulates biofilm dispersal is relatively understood, but there are no reports about how NO is involved in biofilm formation. Here, by investigating the mechanism by which complestatin inhibits biofilm formation, we describe a novel mechanism for governing biofilm formation in Escherichia coli and Pseudomonas aeruginosa. Nitrite transporter is required for biofilm formation via regulation of NO levels and subsequent c-di-GMP production. Additionally, the nitrite transporter contributes more to P. aeruginosa virulence than quorum sensing. Thus, this study identifies nitrite transporters as new antibiofilm targets for future practical and therapeutic agent development.

scholarly journals Evidence for Escherichia coli Diguanylate Cyclase DgcZ Interlinking Surface Sensing and Adhesion via Multiple Regulatory Routes

2016 ◽  
Vol 198 (18) ◽  
pp. 2524-2535 ◽  
Author(s):  
Egidio Lacanna ◽  
Colette Bigosch ◽  
Volkhard Kaever ◽  
Alex Boehm ◽  
Anke Becker
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Primary Role ◽  
Bacterial Cells ◽  
Diguanylate Cyclase ◽  
Surface Attachment ◽  
Content Type ◽  
Surface Sensing

ABSTRACTDgcZ is the main cyclic dimeric GMP (c-di-GMP)-producing diguanylate cyclase (DGC) controlling biosynthesis of the exopolysaccharide poly-β-1,6-N-acetylglucosamine (poly-GlcNAc or PGA), which is essential for surface attachment ofEscherichia coli. Although the complex regulation of DgcZ has previously been investigated, its primary role and the physiological conditions under which the protein is active are not fully understood. Transcription ofdgcZis regulated by the two-component system CpxAR activated by the lipoprotein NlpE in response to surface sensing. Here, we show that the negative effect of acpxRmutation and the positive effect ofnlpEoverexpression on biofilm formation both depend on DgcZ. Coimmunoprecipitation data suggest several potential interaction partners of DgcZ. Interaction with FrdB, a subunit of the fumarate reductase complex (FRD) involved in anaerobic respiration and in control of flagellum assembly, was further supported by a bacterial-two-hybrid assay. Furthermore, the FRD complex was required for the increase in DgcZ-mediated biofilm formation upon induction of oxidative stress by addition of paraquat. A DgcZ-mVENUS fusion protein was found to localize at one bacterial cell pole in response to alkaline pH and carbon starvation. Based on our data and previous knowledge, an integrative role of DgcZ in regulation of surface attachment is proposed. We speculate that both DgcZ-stimulated PGA biosynthesis and interaction of DgcZ with the FRD complex contribute to impeding bacterial escape from the surface.IMPORTANCEBacterial cells can grow by clonal expansion to surface-associated biofilms that are ubiquitous in the environment but also constitute a pervasive problem related to bacterial infections. Cyclic dimeric GMP (c-di-GMP) is a widespread bacterial second messenger involved in regulation of motility and biofilm formation, and plays a primary role in bacterial surface attachment.E. colipossesses a plethora of c-di-GMP-producing diguanylate cyclases, including DgcZ. Our study expands the knowledge on the role of DgcZ in regulation of surface attachment and suggests that it interconnects surface sensing and adhesion via multiple routes.

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 Escherichia coli Biofilms Have an Organized and Complex Extracellular Matrix Structure

mBio ◽  
2013 ◽  
Vol 4 (5) ◽  
Author(s):  
Chia Hung ◽  
Yizhou Zhou ◽  
Jerome S. Pinkner ◽  
Karen W. Dodson ◽  
Jan R. Crowley ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Extracellular Matrix ◽  
Biofilm Formation ◽  
Developmental Stages ◽  
Three Dimensional ◽  
Bacterial Biofilms ◽  
Content Type ◽  
Abiotic Surfaces ◽  
Biochemical Analyses ◽  
Biofilm Development

ABSTRACTBacterial biofilms are ubiquitous in nature, and their resilience is derived in part from a complex extracellular matrix that can be tailored to meet environmental demands. Although common developmental stages leading to biofilm formation have been described, how the extracellular components are organized to allow three-dimensional biofilm development is not well understood. Here we show that uropathogenicEscherichia coli(UPEC) strains produce a biofilm with a highly ordered and complex extracellular matrix (ECM). We used electron microscopy (EM) techniques to image floating biofilms (pellicles) formed by UPEC. EM revealed intricately constructed substructures within the ECM that encase individual, spatially segregated bacteria with a distinctive morphology. Mutational and biochemical analyses of these biofilms confirmed curli as a major matrix component and revealed important roles for cellulose, flagella, and type 1 pili in pellicle integrity and ECM infrastructure. Collectively, the findings of this study elucidated that UPEC pellicles have a highly organized ultrastructure that varies spatially across the multicellular community.IMPORTANCEBacteria can form biofilms in diverse niches, including abiotic surfaces, living cells, and at the air-liquid interface of liquid media. Encasing these cellular communities is a self-produced extracellular matrix (ECM) that can be composed of proteins, polysaccharides, and nucleic acids. The ECM protects biofilm bacteria from environmental insults and also makes the dissolution of biofilms very challenging. As a result, formation of biofilms within humans (during infection) or on industrial material (such as water pipes) has detrimental and costly effects. In order to combat bacterial biofilms, a better understanding of components required for biofilm formation and the ECM is required. This study defined the ECM composition and architecture of floating pellicle biofilms formed byEscherichia coli.

scholarly journals Rcs Phosphorelay Activation in Cardiolipin-DeficientEscherichia coliReduces Biofilm Formation

2019 ◽  
Vol 201 (9) ◽  
Author(s):  
Julia F. Nepper ◽  
Yin C. Lin ◽  
Douglas B. Weibel
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Lipid Membrane ◽  
Protein Translocation ◽  
Membrane Composition ◽  
Anionic Phospholipid ◽  
Content Type ◽  
Envelope Stress ◽  
Biofilm Development

ABSTRACTBiofilm formation is a complex process that requires a number of transcriptional, proteomic, and physiological changes to enable bacterial survival. The lipid membrane presents a barrier to communication between the machinery within bacteria and the physical and chemical features of their extracellular environment, and yet little is known about how the membrane influences biofilm development. We found that depleting the anionic phospholipid cardiolipin reduces biofilm formation inEscherichia colicells by as much as 50%. The absence of cardiolipin activates the regulation of colanic acid synthesis (Rcs) envelope stress response, which represses the production of flagella, disrupts initial biofilm attachment, and reduces biofilm growth. We demonstrate that a reduction in the concentration of cardiolipin impairs translocation of proteins across the inner membrane, which we hypothesize activates the Rcs pathway through the outer membrane lipoprotein RcsF. Our study demonstrates a molecular connection between the composition of membrane phospholipids and biofilm formation inE. coliand suggests that altering lipid biosynthesis may be a viable approach for altering biofilm formation and possibly other multicellular phenotypes related to bacterial adaptation and survival.IMPORTANCEThere is a growing interest in the role of lipid membrane composition in the physiology and adaptation of bacteria. We demonstrate that a reduction in the anionic phospholipid cardiolipin impairs biofilm formation inEscherichia colicells. Depleting cardiolipin reduced protein translocation across the inner membrane and activated the Rcs envelope stress response. Consequently, cardiolipin depletion produced cells lacking assembled flagella, which impacted their ability to attach to surfaces and seed the earliest stage in biofilm formation. This study provides empirical evidence for the role of anionic phospholipid homeostasis in protein translocation and its effect on biofilm development and highlights modulation of the membrane composition as a potential method of altering bacterial phenotypes related to adaptation and survival.

scholarly journals The Role of Exopolysaccharides in Oral Biofilms

2019 ◽  
Vol 98 (7) ◽  
pp. 739-745 ◽  
Author(s):  
C. Cugini ◽  
M. Shanmugam ◽  
N. Landge ◽  
N. Ramasubbu
Keyword(s):  
Biofilm Formation ◽  
Bacterial Colonization ◽  
Super Resolution ◽  
Extracellular Proteins ◽  
Extracellular Polysaccharides ◽  
Oral Biofilms ◽  
The Matrix ◽  
Oral Microbes ◽  
Biofilm Development

The oral cavity contains a rich consortium of exopolysaccharide-producing microbes. These extracellular polysaccharides comprise a major component of the oral biofilm. Together with extracellular proteins, DNA, and lipids, they form the biofilm matrix, which contributes to bacterial colonization, biofilm formation and maintenance, and pathogenesis. While a number of oral microbes have been studied in detail with regard to biofilm formation and pathogenesis, the exopolysaccharides have been well characterized for only select organisms, namely Streptococcus mutans and Aggregatibacter actinomycetemcomitans. Studies on the exopolysaccharides of other oral organisms, however, are in their infancy. In this review, we present the current research on exopolysaccharides of oral microbes regarding their biosynthesis, regulation, contributions to biofilm formation and stability of the matrix, and immune evasion. In addition, insight into the role of exopolysaccharides in biofilms is highlighted through the evaluation of emerging techniques such as pH probing of biofilm colonies, solid-state nuclear magnetic resonance for macromolecular interactions within biofilms, and super-resolution microscopy analysis of biofilm development. Finally, exopolysaccharide as a potential nutrient source for species within a biofilm is discussed.

Sign in / Sign up

Export Citation Format

Share Document