A Complex Transcription Network Controls the Early Stages of Biofilm Development by Escherichia coli

Amyloids are highly aggregated proteinaceous fibers historically associated with neurodegenerative conditions including Alzheimers, Parkinsons, and prion-based encephalopathies. Polymerization of amyloidogenic proteins into ordered fibers can be accelerated by preformed amyloid aggregates derived from the same protein in a process called seeding. Seeding of disease-associated amyloids and prions is highly specific and cross-seeding is usually limited or prevented. Here we describe the first study on the cross-seeding potential of bacterial functional amyloids. Curli are produced on the surface of many Gram-negative bacteria where they facilitate surface attachment and biofilm development. Curli fibers are composed of the major subunit CsgA and the nucleator CsgB, which templates CsgA into fibers. Our results showed that curli subunit homologs from Escherichia coli, Salmonella typhimurium LT2, and Citrobacter koseri were able to cross-seed in vitro. The polymerization of Escherichia coli CsgA was also accelerated by fibers derived from a distant homolog in Shewanella oneidensis that shares less than 30% identity in primary sequence. Cross-seeding of curli proteins was also observed in mixed colony biofilms with E. coli and S. typhimurium. CsgA was secreted from E. coli csgB− mutants assembled into fibers on adjacent S. typhimurium that presented CsgB on its surfaces. Similarly, CsgA was secreted by S. typhimurium csgB− mutants formed curli on CsgB-presenting E. coli. This interspecies curli assembly enhanced bacterial attachment to agar surfaces and supported pellicle biofilm formation. Collectively, this work suggests that the seeding specificity among curli homologs is relaxed and that heterogeneous curli fibers can facilitate multispecies biofilm development.

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Metabolic block at early stages of the glycolytic pathway activates the Rcs phosphorelay system via increased synthesis of dTDP-glucose in Escherichia coli

Molecular Microbiology ◽

10.1046/j.1365-2958.2003.03888.x ◽

2003 ◽

Vol 51 (4) ◽

pp. 1117-1128 ◽

Cited By ~ 22

Author(s):

Waleed El-Kazzaz ◽

Teppei Morita ◽

Hideaki Tagami ◽

Toshifumi Inada ◽

Hiroji Aiba

Keyword(s):

Escherichia Coli ◽

Glycolytic Pathway ◽

Early Stages ◽

Metabolic Block

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Sequence of Colonization Determines the Composition of Mixed Biofilms by Escherichia coli O157:H7 and O111:H8 Strains†

Journal of Food Protection ◽

10.4315/0362-028x.jfp-15-009 ◽

2015 ◽

Vol 78 (8) ◽

pp. 1554-1559 ◽

Cited By ~ 7

Author(s):

RONG WANG ◽

NORASAK KALCHAYANAND ◽

JAMES L. BONO

Keyword(s):

Escherichia Coli ◽

Foodborne Pathogens ◽

Early Stage ◽

Critical Role ◽

The United States ◽

Food Samples ◽

E Coli ◽

Cell Percentage ◽

Composition And Structure ◽

Biofilm Development

Bacterial biofilms are one of the potential sources of cross-contamination in food processing environments. Shiga toxin–producing Escherichia coli (STEC) O157:H7 and O111:H8 are important foodborne pathogens capable of forming biofilms, and the coexistence of these two STEC serotypes has been detected in various food samples and in multiple commercial meat plants throughout the United States. Here, we investigated how the coexistence of these two STEC serotypes and their sequence of colonization could affect bacterial growth competition and mixed biofilm development. Our data showed that E. coli O157:H7 strains were able to maintain a higher cell percentage in mixed biofilms with the co-inoculated O111:H8 companion strains, even though the results of planktonic growth competition were strain dependent. On solid surfaces with preexisting biofilms, the sequence of colonization played a critical role in determining the composition of the mixed biofilms because early stage precolonization significantly affected the competition results between the E. coli O157:H7 and O111:H8 strains. The precolonizer of either serotype was able to outgrow the other serotype in both planktonic and biofilm phases. The competitive interactions among the various STEC serotypes would determine the composition and structure of the mixed biofilms as well as their potential risks to food safety and public health, which is largely influenced by the dominant strains in the mixtures. Thus, the analysis of mixed biofilms under various conditions would be of importance to determine the nature of mixed biofilms composed of multiple microorganisms and to help implement the most effective disinfection operations accordingly.

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Periodicity of Cell Attachment Patterns during Escherichia coli Biofilm Development

Journal of Bacteriology ◽

10.1128/jb.185.18.5632-5638.2003 ◽

2003 ◽

Vol 185 (18) ◽

pp. 5632-5638 ◽

Cited By ~ 24

Author(s):

Konstantin Agladze ◽

Debra Jackson ◽

Tony Romeo

Keyword(s):

Escherichia Coli ◽

Laminar Flow ◽

Biofilm Formation ◽

Cell Attachment ◽

Bacterial Biofilms ◽

Flow Conditions ◽

Biofilm Development ◽

Complex Architecture ◽

Activator Inhibitor ◽

Laminar Flow Conditions

ABSTRACT The complex architecture of bacterial biofilms inevitably raises the question of their design. Microstructure of developing Escherichia coli biofilms was analyzed under static and laminar flow conditions. Cell attachment during early biofilm formation exhibited periodic density patterns that persisted during development. Several models for the origination of biofilm microstructure are considered, including an activator-inhibitor or Turing model.

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Respiratory Heterogeneity Shapes Biofilm Formation and Host Colonization in Uropathogenic Escherichia coli

mBio ◽

10.1128/mbio.02400-18 ◽

2019 ◽

Vol 10 (2) ◽

Cited By ~ 11

Author(s):

Connor J. Beebout ◽

Allison R. Eberly ◽

Sabrina H. Werby ◽

Seth A. Reasoner ◽

John R. Brannon ◽

...

Keyword(s):

Escherichia Coli ◽

Extracellular Matrix ◽

Bacterial Communities ◽

Spatial Organization ◽

Bet Hedging ◽

Content Type ◽

Dna Organization ◽

Quinol Oxidases ◽

Biofilm Development ◽

Biofilm Community

ABSTRACT Biofilms are multicellular bacterial communities encased in a self-secreted extracellular matrix comprised of polysaccharides, proteinaceous fibers, and DNA. Organization of these components lends spatial organization to the biofilm community such that biofilm residents can benefit from the production of common goods while being protected from exogenous insults. Spatial organization is driven by the presence of chemical gradients, such as oxygen. Here we show that two quinol oxidases found in Escherichia coli and other bacteria organize along the biofilm oxygen gradient and that this spatially coordinated expression controls architectural integrity. Cytochrome bd, a high-affinity quinol oxidase required for aerobic respiration under hypoxic conditions, is the most abundantly expressed respiratory complex in the biofilm community. Depletion of the cytochrome bd-expressing subpopulation compromises biofilm complexity by reducing the abundance of secreted extracellular matrix as well as increasing cellular sensitivity to exogenous stresses. Interrogation of the distribution of quinol oxidases in the planktonic state revealed that ∼15% of the population expresses cytochrome bd at atmospheric oxygen concentration, and this population dominates during acute urinary tract infection. These data point toward a bet-hedging mechanism in which heterogeneous expression of respiratory complexes ensures respiratory plasticity of E. coli across diverse host niches. IMPORTANCE Biofilms are multicellular bacterial communities encased in a self-secreted extracellular matrix comprised of polysaccharides, proteinaceous fibers, and DNA. Organization of these components lends spatial organization in the biofilm community. Here we demonstrate that oxygen gradients in uropathogenic Escherichia coli (UPEC) biofilms lead to spatially distinct expression programs for quinol oxidases—components of the terminal electron transport chain. Our studies reveal that the cytochrome bd-expressing subpopulation is critical for biofilm development and matrix production. In addition, we show that quinol oxidases are heterogeneously expressed in planktonic populations and that this respiratory heterogeneity provides a fitness advantage during infection. These studies define the contributions of quinol oxidases to biofilm physiology and suggest the presence of respiratory bet-hedging behavior in UPEC.

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Rosmarinic Acid Interaction with Planktonic and Biofilm Staphylococcus aureus

Natural Product Communications ◽

10.1177/1934578x1300801223 ◽

2013 ◽

Vol 8 (12) ◽

pp. 1934578X1300801 ◽

Cited By ~ 5

Author(s):

Lívia Slobodníková ◽

Silvia Fialová ◽

Helena Hupková ◽

Daniel Grančai

Keyword(s):

Staphylococcus Aureus ◽

Rosmarinic Acid ◽

Antibacterial Activities ◽

Microtiter Plate ◽

Dependent Manner ◽

Early Stages ◽

Microtiter Plates ◽

Sole Agent ◽

The Subject ◽

Biofilm Development

The subject of study was the evaluation of antibacterial activities of rosmarinic acid (RA) on clinical Staphylococcus aureus strains obtained from catheter-related infections. Minimal inhibitory (MIC) and minimal bactericidal concentrations (MBC) of RA were tested by broth microdilution assay. Biofilm-eradication activity was detected on 24-hour biofilm in microtiter plates using a regrowth technique; activity on biofilm formation was measured by a microtiter plate method after RA application to bacterial samples after 0, 1, 3 and 6 hours of biofilm development. RA had antimicrobial activity on all tested strains in concentrations from 625 to 1250 μg.mL−1 (MICs equal to MBCs). No biofilm-eradication activity on 24-hour biofilm was observed in the tested range of concentrations (from 156 to 5000 μg.mL−1). Subinhibitory RA concentrations suppressed the biofilm production, when applied at early stages of its development. Concentrations lower than subinhibitory stimulated the biofilm mass production in a concentration- and time-dependent manner. Considering our results, RA could be a candidate for a topical antimicrobial agent with killing activity on planktonic forms of bacteria and suppressing activity in the early stages of biofilm development, but probably not for the therapy of catheter-related infections as a sole agent.

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Regulatory Circuitry of the CsrA/CsrB and BarA/UvrY Systems of Escherichia coli

Journal of Bacteriology ◽

10.1128/jb.184.18.5130-5140.2002 ◽

2002 ◽

Vol 184 (18) ◽

pp. 5130-5140 ◽

Cited By ~ 197

Author(s):

Kazushi Suzuki ◽

Xin Wang ◽

Thomas Weilbacher ◽

Anna-Karin Pernestig ◽

Öjar Melefors ◽

...

Keyword(s):

Escherichia Coli ◽

Biofilm Formation ◽

Rna Binding ◽

Ectopic Expression ◽

Central Carbon Metabolism ◽

Two Component Signal Transduction ◽

Carbon Storage Regulator ◽

Flagellum Biosynthesis ◽

Biofilm Development ◽

Autoregulatory Mechanism

ABSTRACT The global regulator CsrA (carbon storage regulator) is an RNA binding protein that coordinates central carbon metabolism, activates flagellum biosynthesis and motility, and represses biofilm formation in Escherichia coli. CsrA activity is antagonized by the untranslated RNA CsrB, to which it binds and forms a globular ribonucleoprotein complex. CsrA indirectly activates csrB transcription, in an apparent autoregulatory mechanism. In the present study, we elucidate the intermediate regulatory circuitry of this system. Mutations affecting the BarA/UvrY two-component signal transduction system decreased csrB transcription but did not affect csrA′-′lacZ expression. The uvrY defect was severalfold more severe than that of barA. Both csrA and uvrY were required for optimal barA expression. The latter observation suggests an autoregulatory loop for UvrY. Ectopic expression of uvrY suppressed the csrB-lacZ expression defects caused by uvrY, csrA, or barA mutations; csrA suppressed csrA or barA defects; and barA complemented only the barA mutation. Purified UvrY protein stimulated csrB-lacZ expression approximately sixfold in S-30 transcription-translation reactions, revealing a direct effect of UvrY on csrB transcription. Disruption of sdiA, which encodes a LuxR homologue, decreased the expression of uvrY′-′lacZ and csrB-lacZ fusions but did not affect csrA′-′lacZ. The BarA/UvrY system activated biofilm formation. Ectopic expression of uvrY stimulated biofilm formation by a csrB-null mutant, indicative of a CsrB-independent role for UvrY in biofilm development. Collectively, these results demonstrate that uvrY resides downstream from csrA in a signaling pathway for csrB and that CsrA stimulates UvrY-dependent activation of csrB expression by BarA-dependent and -independent mechanisms.

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