2603. Biofilm Formation as a Predictive Marker of Prognosis for Escherichia coli Sepsis

Abstract Background Escherichia coli is the Gram-negative organism most commonly associated with bloodstream infections and death due to sepsis. Timely administration of appropriate antibiotic(s) plays a significant role in improving patient outcomes. E. coli expresses virulence factors (VFs) such as biofilm formation and motility phenotypes which play a role in bacterial attachment and dissemination by enabling immune system evasion and host migration. The role of these VFs in bacteremia prognosis is not well characterized. Our study aims to evaluate the clinical characteristics and outcomes of E. coli bacteremia patients specifically in relation to biofilm forming isolates. Methods 91 E. coli bacteremia clinical isolates were consecutively collected from patients between 2013 to 2015. Virulence factor phenotypes were determined by in vitro biofilm formation, motility, and milk hydrolysis. Clinical patient data associated with the isolates were abstracted from the electronic medical records database and blinded from research team throughout characterization. Descriptive statistics were used for clinical variables and analyzed in a dichotomized fashion based on biofilm formation. The chi-square or Fisher exact test were used for categorical data and the Mann–Whitney U or Student T-test for continuous variables as appropriate. Results Of the 91 isolates, 41 had a biofilm-forming phenotype. Of the 87 isolates tested for milk hydrolysis and motility a positive finding was seen in 61 (70%) and 67(77%) isolates, respectively. In the multivariate model, patients with E.coli bacteremia from biofilm producing isolates were at increased risk of death or going into hospice during that hospitalization. ([OR],9.8; 95% CI, 1.1,88.7, P = 0.041) Conclusion Patients with biofilm-forming E. coli bacteremia had worse clinical outcomes than their non-biofilm forming counterparts suggesting that this phenotype leads to a more pathogenic organism. A prospective study to confirm this finding is needed as is the design of rapid diagnostics to promptly identify this phenotype in septic patients. Disclosures All authors: No reported disclosures.

Download Full-text

Novel Roles for the AIDA Adhesin from Diarrheagenic Escherichia coli: Cell Aggregation and Biofilm Formation

Journal of Bacteriology ◽

10.1128/jb.186.23.8058-8065.2004 ◽

2004 ◽

Vol 186 (23) ◽

pp. 8058-8065 ◽

Cited By ~ 128

Author(s):

Orla Sherlock ◽

Mark A. Schembri ◽

Andreas Reisner ◽

Per Klemm

Keyword(s):

Escherichia Coli ◽

Biofilm Formation ◽

Mammalian Cells ◽

Gastrointestinal Disease ◽

Cell Aggregation ◽

Bacterial Attachment ◽

E Coli ◽

Abiotic Surfaces ◽

Broad Variety ◽

Self Association

ABSTRACT Diarrhea-causing Escherichia coli strains are responsible for numerous cases of gastrointestinal disease and constitute a serious health problem throughout the world. The ability to recognize and attach to host intestinal surfaces is an essential step in the pathogenesis of such strains. AIDA is a potent bacterial adhesin associated with some diarrheagenic E. coli strains. AIDA mediates bacterial attachment to a broad variety of human and other mammalian cells. It is a surface-displayed autotransporter protein and belongs to the selected group of bacterial glycoproteins; only the glycosylated form binds to mammalian cells. Here, we show that AIDA possesses self-association characteristics and can mediate autoaggregation of E. coli cells. We demonstrate that intercellular AIDA-AIDA interaction is responsible for bacterial autoaggregation. Interestingly, AIDA-expressing cells can interact with antigen 43 (Ag43)-expressing cells, which is indicative of an intercellular AIDA-Ag43 interaction. Additionally, AIDA expression dramatically enhances biofilm formation by E. coli on abiotic surfaces in flow chambers.

Download Full-text

The TibA Adhesin/Invasin from Enterotoxigenic Escherichia coli Is Self Recognizing and Induces Bacterial Aggregation and Biofilm Formation

Infection and Immunity ◽

10.1128/iai.73.4.1954-1963.2005 ◽

2005 ◽

Vol 73 (4) ◽

pp. 1954-1963 ◽

Cited By ~ 93

Author(s):

Orla Sherlock ◽

Rebecca Munk Vejborg ◽

Per Klemm

Keyword(s):

Escherichia Coli ◽

Biofilm Formation ◽

Mammalian Cells ◽

Gastrointestinal Disease ◽

Bacterial Attachment ◽

Enterotoxigenic Escherichia Coli ◽

E Coli ◽

Abiotic Surfaces ◽

Self Association ◽

Exclusive Group

ABSTRACT Escherichia coli strains are responsible for many cases of gastrointestinal disease and represent a serious health problem worldwide. An essential step in the pathogenesis of such strains involves recognition and attachment to host intestinal surfaces. TibA is a potent bacterial adhesin associated with a number of enterotoxigenic E. coli strains and mediates bacterial attachment to a variety of human cells; additionally, it promotes invasion of such cells. This adhesin is a surface-displayed autotransporter protein and belongs to the exclusive group of bacterial glycoproteins; only the glycosylated form confers binding to and invasion of mammalian cells. Here we characterized TibA and showed that it possesses self-association characteristics and can mediate autoaggregation of E. coli cells. We demonstrated that intercellular TibA-TibA interaction is responsible for bacterial autoaggregation. Also, TibA expression significantly enhances biofilm formation by E. coli on abiotic surfaces.

Download Full-text

Genotypic and phenotypic characteristics associated with biofilm formation in Escherichia coli and Salmonella spp. isolated from ulam in Terengganu

Food Research ◽

10.26656/fr.2017.4(1).240 ◽

2019 ◽

Vol 4 (1) ◽

pp. 91-101

Author(s):

Anis, A. Bahri ◽

Wan Zawiah Wan Abdullah ◽

Mohd Nizam Lani ◽

W. Salleh ◽

Rozila Alias

Keyword(s):

Escherichia Coli ◽

Disease Transmission ◽

Congo Red ◽

Biofilm Formation ◽

Initial Step ◽

Bacterial Attachment ◽

Salmonella Spp ◽

Pellicle Formation ◽

E Coli ◽

Fresh Vegetables

Nowadays, the foodborne outbreaks associated with fresh produces, including ulam, are increasing worldwide. The biofilm formation or bacterial attachment to plant surface is the initial step towards the contamination in fresh produce. The biofilm phenotype of bacteria grown on congo red agar is termed as red, dry and rough (rdar) morphotype. The binding of congo red dye with both biological proteins and inert surfaces is due to the presence of curli fimbriae and cellulose as the main extracellular components. The objective of this study was to determine the rdar morphotypes, biofilm ability and the role of csgA gene of Escherichia coli and Salmonella spp. isolated from ulam or Malaysian herbs. A total of 29 isolates, including 23 E. coli and 6 Salmonella spp. were analyzed for their ability to produce biofilm by colony morphology test, microtiter plate biofilm assay and qualitative biofilm test (pellicle formation). The presence of the csgA gene of E. coli was identified by PCR, which demonstrated the potential gene that able to produce curli fimbriae. Results revealed that 16 (69.6%) E. coli isolates were categorized as strong biofilm producers, 2 (8.7%) as moderate biofilm producers, 3 (13%) as weak biofilm producers, whereas 2 (8.7%) as negative biofilm producers (did not produce biofilm). While 4 (66.7%) Salmonella spp. isolates were identified as strong biofilm producers, 1 (16.7%) as moderate biofilm producers and 1 (16.7%) as negative biofilm producers. Majority of the E. coli strains (69.6%) were identified as strong biofilm producers and able to express rdar morphotypes. The ability of the of E. coli and Salmonella spp. isolates to form biofilm reveals the ability of these isolates to persist on the fresh vegetables and become hosts for the disease transmission to humans or/and animals.

Download Full-text

Conditional Function of Autoaggregative Protein Cah and Common cah Mutations in Shiga Toxin-Producing Escherichia coli

Applied and Environmental Microbiology ◽

10.1128/aem.01739-17 ◽

2017 ◽

Vol 84 (1) ◽

Cited By ~ 3

Author(s):

Michelle Qiu Carter ◽

Maria T. Brandl ◽

Indira T. Kudva ◽

Robab Katani ◽

Matthew R. Moreau ◽

...

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Calcium Binding ◽

Biofilm Formation ◽

Bacterial Attachment ◽

Ecological Niches ◽

Loss Of Function ◽

Host Colonization ◽

Content Type ◽

E Coli

ABSTRACTCah is a calcium-binding autotransporter protein involved in autoaggregation and biofilm formation. Althoughcahis widespread in Shiga toxin-producingEscherichia coli(STEC), we detected mutations incahat a frequency of 31.3% in this pathogen. In STEC O157:H7 supershedder strain SS17, a large deletion results in a smaller coding sequence, encoding a protein lacking the C-terminal 71 amino acids compared with Cah in STEC O157:H7 strain EDL933. We examined the function of Cah in biofilm formation and host colonization to better understand the selective pressures forcahmutations. EDL933-Cah played a conditional role in biofilm formationin vitro: it enhancedE. coliDH5α biofilm formation on glass surfaces under agitated culture conditions that prevented autoaggregation but inhibited biofilm formation under hydrostatic conditions that facilitated autoaggregation. This function appeared to be strain dependent since Cah-mediated biofilm formation was diminished when an EDL933cahgene was expressed in SS17. Deletion ofcahin EDL933 enhanced bacterial attachment to spinach leaves and altered the adherence pattern of EDL933 to bovine recto-anal junction squamous epithelial (RSE) cells. In contrast, intransexpression of EDL933cahin SS17 increased its attachment to leaf surfaces, and in DH5α, it enhanced its adherence to RSE cells. Hence, the ecological function of Cah appears to be modulated by environmental conditions and other bacterial strain-specific properties. Considering the prevalence ofcahin STEC and its role in attachment and biofilm formation,cahmutations might be selected in ecological niches in which inactivation of Cah would result in an increased fitness in STEC during colonization of plants or animal hosts.IMPORTANCEShiga toxin-producingEscherichia coli(STEC) harbors genes encoding diverse adhesins, and many of these are known to play an important role in bacterial attachment and host colonization. We demonstrated here that the autotransporter protein Cah confers onE. coliDH5α cells a strong autoaggregative phenotype that is inversely correlated with its ability to form biofilms and plays a strain-specific role in plant and animal colonization by STEC. Althoughcahis widespread in the STEC population, we detected a mutation rate of 31.3% incah, which is similar to that reported forrpoSandfimH. The formation of cell aggregates due to increased bacterium-to-bacterium interactions may be disadvantageous to bacterial populations under conditions that favor a planktonic state in STEC. Therefore, a loss-of-function mutation incahis likely a selective trait in STEC when autoaggregative properties become detrimental to bacterial cells and may contribute to the adaptability of STEC to fluctuating environments.

Download Full-text

The Effect of Mianserin on Lifespan of Caenorhabditis elegans is Abolished by Glucose

Current Aging Science ◽

10.2174/1874609813999210104203614 ◽

2021 ◽

Vol 13 ◽

Author(s):

Abdullah Almotayri ◽

Jency Thomas ◽

Mihiri Munasinghe ◽

Markandeya Jois

Keyword(s):

Caenorhabditis Elegans ◽

Scaffolding Protein ◽

Lifespan Extension ◽

Wild Type ◽

E Coli ◽

C Elegans ◽

Risk Of Death ◽

Increased Risk ◽

Antidepressant Use ◽

Extension Effect

Background: The antidepressant mianserin has been shown to extend the lifespan of Caenorhabditis elegans (C. elegans), a well-established model organism used in aging research. The extension of lifespan in C. elegans was shown to be dependent on increased expression of the scaffolding protein (ANK3/unc-44). In contrast, antidepressant use in humans is associated with an increased risk of death. The C. elegans in the laboratory are fed Escherichia coli (E. coli), a diet high in protein and low in carbohydrate, whereas a typical human diet is high in carbohydrates. We hypothesized that dietary carbohydrates might mitigate the lifespan-extension effect of mianserin. Objective: To investigate the effect of glucose added to the diet of C. elegans on the lifespan-extension effect of mianserin. Methods: Wild-type Bristol N2 and ANK3/unc-44 inactivating mutants were cultured on agar plates containing nematode growth medium and fed E. coli. Treatment groups included (C) control, (M50) 50 μM mianserin, (G) 73 mM glucose, and (M50G) 50 μM mianserin and 73 mM glucose. Lifespan was determined by monitoring the worms until they died. Statistical analysis was performed using the Kaplan-Meier version of the log-rank test. Results: Mianserin treatment resulted in a 12% increase in lifespan (P<0.05) of wild-type Bristol N2 worms but reduced lifespan by 6% in ANK3/unc-44 mutants, consistent with previous research. The addition of glucose to the diet reduced the lifespan of both strains of worms and abolished the lifespan-extension by mianserin. Conclusion: The addition of glucose to the diet of C. elegans abolishes the lifespan-extension effects of mianserin.

Download Full-text

Label-free quantitative proteomic analysis of the inhibition effect of Lactobacillus rhamnosus GG on Escherichia coli biofilm formation in co-culture

Proteome Science ◽

10.1186/s12953-021-00172-0 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Huiyi Song ◽

Ni Lou ◽

Jianjun Liu ◽

Hong Xiang ◽

Dong Shang

Keyword(s):

Escherichia Coli ◽

Proteomic Analysis ◽

Biofilm Formation ◽

Lactobacillus Rhamnosus ◽

Differentially Expressed ◽

Differentially Expressed Proteins ◽

Label Free ◽

Quantitative Proteomic Analysis ◽

E Coli ◽

Protein Ubiquitination

Abstract Background Escherichia coli (E. coli) is the principal pathogen that causes biofilm formation. Biofilms are associated with infectious diseases and antibiotic resistance. This study employed proteomic analysis to identify differentially expressed proteins after coculture of E. coli with Lactobacillus rhamnosus GG (LGG) microcapsules. Methods To explore the relevant protein abundance changes after E. coli and LGG coculture, label-free quantitative proteomic analysis and qRT-PCR were applied to E. coli and LGG microcapsule groups before and after coculture, respectively. Results The proteomic analysis characterised a total of 1655 proteins in E. coli K12MG1655 and 1431 proteins in the LGG. After coculture treatment, there were 262 differentially expressed proteins in E. coli and 291 in LGG. Gene ontology analysis showed that the differentially expressed proteins were mainly related to cellular metabolism, the stress response, transcription and the cell membrane. A protein interaction network and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis indicated that the differentiated proteins were mainly involved in the protein ubiquitination pathway and mitochondrial dysfunction. Conclusions These findings indicated that LGG microcapsules may inhibit E. coli biofilm formation by disrupting metabolic processes, particularly in relation to energy metabolism and stimulus responses, both of which are critical for the growth of LGG. Together, these findings increase our understanding of the interactions between bacteria under coculture conditions.

Download Full-text

Promiscuous Cross-seeding between Bacterial Amyloids Promotes Interspecies Biofilms

Journal of Biological Chemistry ◽

10.1074/jbc.m112.383737 ◽

2012 ◽

Vol 287 (42) ◽

pp. 35092-35103 ◽

Cited By ~ 61

Author(s):

Yizhou Zhou ◽

Daniel Smith ◽

Bryan J. Leong ◽

Kristoffer Brännström ◽

Fredrik Almqvist ◽

...

Keyword(s):

Escherichia Coli ◽

Shewanella Oneidensis ◽

Bacterial Attachment ◽

Surface Attachment ◽

E Coli ◽

Amyloid Aggregates ◽

Functional Amyloids ◽

Biofilm Development ◽

Distant Homolog

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.

Download Full-text

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

Microbiology ◽

10.1099/mic.0.001031 ◽

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.

Download Full-text

Escherichia coli Harboring a Natural IncF Conjugative F Plasmid Develops Complex Mature Biofilms by Stimulating Synthesis of Colanic Acid and Curli

Journal of Bacteriology ◽

10.1128/jb.00823-08 ◽

2008 ◽

Vol 190 (22) ◽

pp. 7479-7490 ◽

Cited By ~ 58

Author(s):

Thithiwat May ◽

Satoshi Okabe

Keyword(s):

Escherichia Coli ◽

Biofilm Formation ◽

Three Dimensional ◽

F Plasmid ◽

Form Complex ◽

Global Regulators ◽

E Coli ◽

Colanic Acid ◽

Regulatory Systems ◽

Initial Deposition

ABSTRACT It has been shown that Escherichia coli harboring the derepressed IncFI and IncFII conjugative F plasmids form complex mature biofilms by using their F-pilus connections, whereas a plasmid-free strain forms only patchy biofilms. Therefore, in this study we investigated the contribution of a natural IncF conjugative F plasmid to the formation of E. coli biofilms. Unlike the presence of a derepressed F plasmid, the presence of a natural IncF F plasmid promoted biofilm formation by generating the cell-to-cell mating F pili between pairs of F+ cells (approximately two to four pili per cell) and by stimulating the formation of colanic acid and curli meshwork. Formation of colanic acid and curli was required after the initial deposition of F-pilus connections to generate a three-dimensional mushroom-type biofilm. In addition, we demonstrated that the conjugative factor of F plasmid, rather than a pilus synthesis function, was involved in curli production during biofilm formation, which promoted cell-surface interactions. Curli played an important role in the maturation process. Microarray experiments were performed to identify the genes involved in curli biosynthesis and regulation. The results suggested that a natural F plasmid was more likely an external activator that indirectly promoted curli production via bacterial regulatory systems (the EnvZ/OmpR two-component regulators and the RpoS and HN-S global regulators). These data provided new insights into the role of a natural F plasmid during the development of E. coli biofilms.

Download Full-text

More than Enzymes That Make or Break Cyclic Di-GMP—Local Signaling in the Interactome of GGDEF/EAL Domain Proteins of Escherichia coli

mBio ◽

10.1128/mbio.01639-17 ◽

2017 ◽

Vol 8 (5) ◽

Cited By ~ 60

Author(s):

Olga Sarenko ◽

Gisela Klauck ◽

Franziska M. Wilke ◽

Vanessa Pfiffer ◽

Anja M. Richter ◽

...

Keyword(s):

Escherichia Coli ◽

Biofilm Formation ◽

Second Messenger ◽

Bacterial Biofilm ◽

Interaction Patterns ◽

Systematic Analysis ◽

E Coli ◽

Diguanylate Cyclases ◽

Hub Proteins ◽

Effector Target

ABSTRACT The bacterial second messenger bis-(3′-5′)-cyclic diguanosine monophosphate (c-di-GMP) ubiquitously promotes bacterial biofilm formation. Intracellular pools of c-di-GMP seem to be dynamically negotiated by diguanylate cyclases (DGCs, with GGDEF domains) and specific phosphodiesterases (PDEs, with EAL or HD-GYP domains). Most bacterial species possess multiple DGCs and PDEs, often with surprisingly distinct and specific output functions. One explanation for such specificity is “local” c-di-GMP signaling, which is believed to involve direct interactions between specific DGC/PDE pairs and c-di-GMP-binding effector/target systems. Here we present a systematic analysis of direct protein interactions among all 29 GGDEF/EAL domain proteins of Escherichia coli . Since the effects of interactions depend on coexpression and stoichiometries, cellular levels of all GGDEF/EAL domain proteins were also quantified and found to vary dynamically along the growth cycle. Instead of detecting specific pairs of interacting DGCs and PDEs, we discovered a tightly interconnected protein network of a specific subset or “supermodule” of DGCs and PDEs with a coregulated core of five hyperconnected hub proteins. These include the DGC/PDE proteins representing the c-di-GMP switch that turns on biofilm matrix production in E. coli . Mutants lacking these core hub proteins show drastic biofilm-related phenotypes but no changes in cellular c-di-GMP levels. Overall, our results provide the basis for a novel model of local c-di-GMP signaling in which a single strongly expressed master PDE, PdeH, dynamically eradicates global effects of several DGCs by strongly draining the global c-di-GMP pool and thereby restricting these DGCs to serving as local c-di-GMP sources that activate specific colocalized effector/target systems. IMPORTANCE c-di-GMP signaling in bacteria is believed to occur via changes in cellular c-di-GMP levels controlled by antagonistic and potentially interacting pairs of diguanylate cyclases (DGCs) and c-di-GMP phosphodiesterases (PDEs). Our systematic analysis of protein-protein interaction patterns of all 29 GGDEF/EAL domain proteins of E. coli , together with our measurements of cellular c-di-GMP levels, challenges both aspects of this current concept. Knocking out distinct DGCs and PDEs has drastic effects on E. coli biofilm formation without changing the cellular c-di-GMP level. In addition, rather than generally coming in interacting DGC/PDE pairs, a subset of DGCs and PDEs operates as central interaction hubs in a larger "supermodule," with other DGCs and PDEs behaving as “lonely players” without contacts to other c-di-GMP-related enzymes. On the basis of these data, we propose a novel concept of “local” c-di-GMP signaling in bacteria with multiple enzymes that make or break the second messenger c-di-GMP.

Download Full-text