Indole can act as an extracellular signal to regulate biofilm formation of Escherichia coli and other indole-producing bacteria

2003 ◽  
Vol 49 (7) ◽  
pp. 443-449 ◽  
Author(s):  
P Di Martino ◽  
R Fursy ◽  
L Bret ◽  
B Sundararaju ◽  
R S Phillips
Keyword(s):  
Escherichia Coli ◽  
Mutant Strain ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Klebsiella Oxytoca ◽  
Laboratory Strain ◽  
Luria Bertani ◽  
Dependent Manner ◽  
E Coli ◽  
Signalling Molecule

We demonstrated previously that genetic inactivation of tryptophanase is responsible for a dramatic decrease in biofilm formation in the laboratory strain Escherichia coli S17-1. In the present study, we tested whether the biochemical inhibition of tryptophanase, with the competitive inhibitor oxindolyl-L-alanine, could affect polystyrene colonization by E. coli and other indole-producing bacteria. Oxindolyl-L-alanine inhibits, in a dose-dependent manner, indole production and biofilm formation by strain S17-1 grown in Luria–Bertani (LB) medium. Supplementation with indole at physiologically relevant concentrations restores biofilm formation by strain S17-1 in the presence of oxindolyl-L-alanine and by mutant strain E. coli 3714 (S17-1 tnaA::Tn5) in LB medium. Oxindolyl-L-alanine also inhibits the adherence of S17-1 cells to polystyrene for a 3-h incubation time, but mutant strain 3714 cells are unaffected. At 0.5 mg/mL, oxindolyl-L-alanine exhibits inhibitory activity against biofilm formation in LB medium and in synthetic urine for several clinical isolates of E. coli, Klebsiella oxytoca, Citrobacter koseri, Providencia stuartii, and Morganella morganii but has no affect on indole-negative Klebsiella pneumoniae strains. In conclusion, these data suggest that indole, produced by the action of tryptophanase, is involved in polystyrene colonization by several indole-producing bacterial species. Indole may act as a signalling molecule to regulate the expression of adhesion and biofilm-promoting factors.Key words: Escherichia coli, biofilm, indole, tryptophanase, signalling molecule.

scholarly journals Evidence for Transfer of CMY-2 AmpC β-Lactamase Plasmids between Escherichia coli andSalmonella Isolates from Food Animals and Humans

2001 ◽  
Vol 45 (10) ◽  
pp. 2716-2722 ◽  
Author(s):  
P. L. Winokur ◽  
D. L. Vonstein ◽  
L. J. Hoffman ◽  
E. K. Uhlenhopp ◽  
G. V. Doern
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Bacterial Species ◽  
Laboratory Strain ◽  
Epidemiological Studies ◽  
Geographic Region ◽  
Chromosomal Dna ◽  
E Coli ◽  
Clonal Relatedness ◽  
Food Animals

ABSTRACT Escherichia coli is an important pathogen that shows increasing antimicrobial resistance in isolates from both animals and humans. Our laboratory recently described Salmonellaisolates from food animals and humans that expressed an identical plasmid-mediated, AmpC-like β-lactamase, CMY-2. In the present study, 59 of 377 E. coli isolates from cattle and swine (15.6%) and 6 of 1,017 (0.6%) isolates of human E. coli from the same geographic region were resistant to both cephamycins and extended-spectrum cephalosporins. AnampC gene could be amplified with CMY-2 primers in 94.8% of animal and 33% of human isolates. Molecular epidemiological studies of chromosomal DNA revealed little clonal relatedness among the animal and human E. coli isolates harboring the CMY-2 gene. The ampC genes from 10 animal and human E. coli isolates were sequenced, and all carried an identical CMY-2 gene. Additionally, all were able to transfer a plasmid containing the CMY-2 gene to a laboratory strain of E. coli. CMY-2 plasmids demonstrated two different plasmid patterns that each showed strong similarities to previously describedSalmonella CMY-2 plasmids. Additionally, Southern blot analyses using a CMY-2 probe demonstrated conserved fragments among many of the CMY-2 plasmids identified in Salmonella andE. coli isolates from food animals and humans. These data demonstrate that common plasmids have been transferred between animal-associated Salmonella and E. coli, and identical CMY-2 genes carried by similar plasmids have been identified in humans, suggesting that the CMY-2 plasmid has undergone transfer between different bacterial species and may have been transmitted between food animals and humans.

Escherichia coli tol and rcs genes participate in the complex network affecting curli synthesis

Microbiology ◽  
2005 ◽  
Vol 151 (7) ◽  
pp. 2487-2497 ◽  
Author(s):  
Anne Vianney ◽  
Grégory Jubelin ◽  
Sophie Renault ◽  
Corine Dorel ◽  
Philippe Lejeune ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Membrane Integrity ◽  
Regulatory Proteins ◽  
Gram Negative Bacteria ◽  
Dependent Manner ◽  
Dominant Effect ◽  
Gram Negative ◽  
E Coli

Curli are necessary for the adherence of Escherichia coli to surfaces, and to each other, during biofilm formation, and the csgBA and csgDEFG operons are both required for their synthesis. A recent survey of gene expression in Pseudomonas aeruginosa biofilms has identified tolA as a gene activated in biofilms. The tol genes play a fundamental role in maintaining the outer-membrane integrity of Gram-negative bacteria. RcsC, the sensor of the RcsBCD phosphorelay, is involved, together with RcsA, in colanic acid capsule synthesis, and also modulates the expression of tolQRA and csgDEFG. In addition, the RcsBCD phosphorelay is activated in tol mutants or when Tol proteins are overexpressed. These results led the authors to investigate the role of the tol genes in biofilm formation in laboratory and clinical isolates of E. coli. It was shown that the adherence of cells was lowered in the tol mutants. This could be the result of a drastic decrease in the expression of the csgBA operon, even though the expression of csgDEFG was slightly increased under such conditions. It was also shown that the Rcs system negatively controls the expression of the two csg operons in an RcsA-dependent manner. In the tol mutants, activation of csgDEFG occurred via OmpR and was dominant upon repression by RcsB and RcsA, while these two regulatory proteins repressed csgBA through a dominant effect on the activator protein CsgD, thus affecting curli synthesis. The results demonstrate that the Rcs system, previously known to control the synthesis of the capsule and the flagella, is an additional component involved in the regulation of curli. Furthermore, it is shown that the defect in cell motility observed in the tol mutants depends on RcsB and RcsA.

scholarly journals IscR Controls Iron-Dependent Biofilm Formation in Escherichia coli by Regulating Type I Fimbria Expression

2008 ◽  
Vol 191 (4) ◽  
pp. 1248-1257 ◽  
Author(s):  
Yun Wu ◽  
F. Wayne Outten
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Developmental Process ◽  
Bacterial Species ◽  
Type I ◽  
Surface Attachment ◽  
Environmental Signals ◽  
Regulatory Pathways ◽  
E Coli ◽  
Type I Fimbriae

ABSTRACT Biofilm formation is a complex developmental process regulated by multiple environmental signals. In addition to other nutrients, the transition metal iron can also regulate biofilm formation. Iron-dependent regulation of biofilm formation varies by bacterial species, and the exact regulatory pathways that control iron-dependent biofilm formation are often unknown or only partially characterized. To address this gap in our knowledge, we examined the role of iron availability in regulating biofilm formation in Escherichia coli. The results indicate that biofilm formation is repressed under low-iron conditions in E. coli. Furthermore, a key iron regulator, IscR, controls biofilm formation in response to changes in cellular Fe-S homeostasis. IscR regulates the FimE recombinase to control expression of type I fimbriae in E. coli. We propose that iron-dependent regulation of FimE via IscR leads to decreased surface attachment and biofilm dispersal under iron-limiting conditions.

scholarly journals Identification of Type 3 Fimbriae in Uropathogenic Escherichia coli Reveals a Role in Biofilm Formation

2007 ◽  
Vol 190 (3) ◽  
pp. 1054-1063 ◽  
Author(s):  
Cheryl-Lynn Y. Ong ◽  
Glen C. Ulett ◽  
Amanda N. Mabbett ◽  
Scott A. Beatson ◽  
Richard I. Webb ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Klebsiella Oxytoca ◽  
The United States ◽  
Conjugative Plasmid ◽  
Biofilm Growth ◽  
Indwelling Catheters ◽  
E Coli ◽  
Type 3

ABSTRACT Catheter-associated urinary tract infection (CAUTI) is the most common nosocomial infection in the United States. Uropathogenic Escherichia coli (UPEC), the most common cause of CAUTI, can form biofilms on indwelling catheters. Here, we identify and characterize novel factors that affect biofilm formation by UPEC strains that cause CAUTI. Sixty-five CAUTI UPEC isolates were characterized for phenotypic markers of urovirulence, including agglutination and biofilm formation. One isolate, E. coli MS2027, was uniquely proficient at biofilm growth despite the absence of adhesins known to promote this phenotype. Mini-Tn5 mutagenesis of E. coli MS2027 identified several mutants with altered biofilm growth. Mutants containing insertions in genes involved in O antigen synthesis (rmlC and manB) and capsule synthesis (kpsM) possessed enhanced biofilm phenotypes. Three independent mutants deficient in biofilm growth contained an insertion in a gene locus homologous to the type 3 chaperone-usher class fimbrial genes of Klebsiella pneumoniae. These type 3 fimbrial genes (mrkABCDF), which were located on a conjugative plasmid, were cloned from E. coli MS2027 and could complement the biofilm-deficient transconjugants when reintroduced on a plasmid. Primers targeting the mrkB chaperone-encoding gene revealed its presence in CAUTI strains of Citrobacter koseri, Citrobacter freundii, Klebsiella pneumoniae, and Klebsiella oxytoca. All of these mrkB-positive strains caused type 3 fimbria-specific agglutination of tannic acid-treated red blood cells. This is the first description of type 3 fimbriae in E. coli, C. koseri, and C. freundii. Our data suggest that type 3 fimbriae may contribute to biofilm formation by different gram-negative nosocomial pathogens.

scholarly journals Comparative Structure-Function Analysis of Mannose-Specific FimH Adhesins from Klebsiella pneumoniae and Escherichia coli

2009 ◽  
Vol 191 (21) ◽  
pp. 6592-6601 ◽  
Author(s):  
Steen G. Stahlhut ◽  
Veronika Tchesnokova ◽  
Carsten Struve ◽  
Scott J. Weissman ◽  
Sujay Chattopadhyay ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Function Analysis ◽  
Bacterial Species ◽  
Host Cells ◽  
Structural Basis ◽  
Adaptive Mutation ◽  
Single Mutation ◽  
Dependent Manner ◽  
E Coli

ABSTRACT FimH, the adhesive subunit of type 1 fimbriae expressed by many enterobacteria, mediates mannose-sensitive binding to target host cells. At the same time, fine receptor-structural specificities of FimH from different species can be substantially different, affecting bacterial tissue tropism and, as a result, the role of the particular fimbriae in pathogenesis. In this study, we compared functional properties of the FimH proteins from Escherichia coli and Klebsiella pneumoniae, which are both 279 amino acids in length but differ by some ∼15% of residues. We show that K. pneumoniae FimH is unable to mediate adhesion in a monomannose-specific manner via terminally exposed Manα(1-2) residues in N-linked oligosaccharides, which are the structural basis of the tropism of E. coli FimH for uroepithelial cells. However, K. pneumoniae FimH can bind to the terminally exposed Manα(1-3)Manβ(1-4)GlcNAcβ1 trisaccharide, though only in a shear-dependent manner, wherein the binding is marginal at low shear force but enhanced sevenfold under increased shear. A single mutation in the K. pneumoniae FimH, S62A, converts the mode of binding from shear dependent to shear independent. This mutation has occurred naturally in the course of endemic circulation of a nosocomial uropathogenic clone and is identical to a pathogenicity-adaptive mutation found in highly virulent uropathogenic strains of E. coli, in which it also eliminates the dependence of E. coli binding on shear. The shear-dependent binding properties of the K. pneumoniae and E. coli FimH proteins are mediated via an allosteric catch bond mechanism. Thus, despite differences in FimH structure and fine receptor specificity, the shear-dependent nature of FimH-mediated adhesion is highly conserved between bacterial species, supporting its remarkable physiological significance.

scholarly journals Chemotaxis towards autoinducer 2 mediates autoaggregation in Escherichia coli

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Leanid Laganenka ◽  
Remy Colin ◽  
Victor Sourjik
Keyword(s):  
Escherichia Coli ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Physiological Role ◽  
Growth Conditions ◽  
Signal Molecules ◽  
E Coli ◽  
Autoinducer 2 ◽  
Cell Densities

Abstract Bacteria communicate by producing and sensing extracellular signal molecules called autoinducers. Such intercellular signalling, known as quorum sensing, allows bacteria to coordinate and synchronize behavioural responses at high cell densities. Autoinducer 2 (AI-2) is the only known quorum-sensing molecule produced by Escherichia coli but its physiological role remains elusive, although it is known to regulate biofilm formation and virulence in other bacterial species. Here we show that chemotaxis towards self-produced AI-2 can mediate collective behaviour—autoaggregation—of E. coli. Autoaggregation requires motility and is strongly enhanced by chemotaxis to AI-2 at physiological cell densities. These effects are observed regardless whether cell–cell interactions under particular growth conditions are mediated by the major E. coli adhesin (antigen 43) or by curli fibres. Furthermore, AI-2-dependent autoaggregation enhances bacterial stress resistance and promotes biofilm formation.

scholarly journals Anti-Biofilm Effect of Octenidine and Polyhexanide on Uropathogenic Biofilm-Producing Bacteria

2021 ◽  
pp. 1-7
Author(s):  
Maria Loose ◽  
Kurt G. Naber ◽  
Larry Purcell ◽  
Manfred P. Wirth ◽  
Florian M.E. Wagenlehner
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
E Coli ◽  
Mueller Hinton ◽  
High Dilutions ◽  
Artificial Urine ◽  
Tract Infections ◽  
Mueller Hinton Broth

<b><i>Background:</i></b> A catheter allowing a release of antibacterial substances such as antiseptics into the bladder could be a new way of preventing biofilm formation and subsequent catheter-associated urinary tract infections. <b><i>Methods:</i></b> Minimal inhibitory and bactericidal concentration (MIC/MBC) determinations in cation-adjusted Mueller-Hinton broth and artificial urine were performed for 4 antiseptics against 3 uropathogenic biofilm producers, <i>Escherichia coli</i>, <i>Pseudomonas aeruginosa</i>, and <i>Proteus mirabilis</i>. Furthermore, effects of octenidine and polyhexanide against catheter biofilm formation were determined by quantification of biofilm-producing bacteria. <b><i>Results:</i></b> Sodium hypochlorite showed MIC/MBC values between 200 and 800 mg/L for all strains tested. Triclosan was efficient against <i>E. coli</i> and <i>P. mirabilis</i> (MIC ≤2.98 mg/L) but ineffective against <i>P. aeruginosa</i>. Octenidine and polyhexanide showed antibacterial activity against all 3 species tested (MIC 1.95–7.8 and 3.9–31.25 mg/L). Both octenidine and polyhexanide were able to prevent biofilm formation on catheter segments in a concentration dependent manner. Furthermore, adding 250 mg/L of each biocide disrupted biofilms formed by <i>E. coli</i> and <i>P. mirabilis</i>, whereas even 500 mg/L was not sufficient to completely destroy <i>P. aeruginosa</i> biofilms. <b><i>Conclusion:</i></b> Octenidine- and polyhexanide-containing antiseptics showed a broad effect against typical uropathogenic biofilm producers even in high dilutions. This study provides a basis for further investigation of the potential of octenidine and polyhexanide as prophylaxis or treatment of catheter biofilms.

scholarly journals Effect of Temperature, pH and Plasmids on In Vitro Biofilm Formation in Escherichia coli

Acta Naturae ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 129-132 ◽  
Author(s):  
A. Mathlouthi ◽  
E. Pennacchietti ◽  
D. De Biase
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Acid Resistance ◽  
Transcriptional Regulators ◽  
Growth Conditions ◽  
Luria Bertani ◽  
Effect Of Temperature ◽  
E Coli ◽  
Static Conditions

Acid resistance (AR) in Escherichia coli is an important trait that protects this microorganism from the deleterious effect of low-pH environments. Reports on biofilm formation in E. coli K12 showed that the genes participating in AR were differentially expressed. Herein, we investigated the relationship between AR genes, in particular those coding for specific transcriptional regulators, and their biofilm-forming ability at the phenotypic level. The latter was measured in 96-well plates by staining the bacteria attached to the well, following 24-hour growth under static conditions, with crystal violet. The growth conditions were as follows: Luria Bertani (LB) medium at neutral and acidic pH, at 37C or 25C. We observed that the three major transcriptional regulators of the AR genes (gadX, gadE, gadW) only marginally affected biofilm formation in E. coli. However, a striking and novel finding was the different abilities of all the tested E. coli strains to form a biofilm depending on the temperature and pH of the medium: LB, pH 7.4, strongly supported biofilm formation at 25C, with biofilm being hardly detectable at 37C. On the contrary, LB, pH 5.5, best supported biofilm formation at 37C. Moreover, we observed that when E. coli carried a plasmid, the presence of the plasmid itself affected the ability to develop a biofilm, typically by increasing its formation. This phenomenon varies from plasmid to plasmid, depends on growth conditions, and, to the best of our knowledge, remains largely uninvestigated.

scholarly journals The relationship between biofilm formation, genes of virulence and iron metabolism in Escherichia coli

2018 ◽  
Author(s):  
Lívia Handrová ◽  
Anna Čuvalová ◽  
Vladimír Kmeť
Keyword(s):  
Escherichia Coli ◽  
Iron Metabolism ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Opportunistic Infections ◽  
Bacterial Species ◽  
Pcr Amplification ◽  
Bacterial Strains ◽  
E Coli ◽  
Wide Range

Escherichia coli is known as one of the bacterial species with the widest adaptability to variety of niches either within organisms or outside in environment. Most strains of E. coli are of low virulence and associated with opportunistic infections, whereas others are highly virulent. The success of E. coli in colonising such a wide range of hosts and environments is basically due to a noticeable ductility in exploiting the available resources. It is becoming increasingly clear that biofilms have an enormous impact on medicine because since 65% of animal and human bacterial infections involve biofilms. In present study, we isolated strains of E. coli from animals. 19 interesting isolates were selected and tested by PCR amplification to virulence – iutA, cvaC, iss, tsh, papC, kps, iha and iron metabolism genes – sitA, feoB, irp2, fyuA, iroN, ireA. The ability of biofilm formation was assessed in a quantitative assay using a microtiter-plate test. Bacterial strains were grown on BHI. We divided isolates of E. coli into four classes: very weak (63.0%), weak (10.5%), moderate (10.5%) and strong (16.0%) biofilm producers. Representation genes of virulence were highly in isolates from very weak biofilm producers – from 7 genes were 6 highly; only papC (P fimbrial adhesin) was low. Genes of iron metabolism were different. Genes – sitA, fyuA, ireA in strong isolates producing biofilm and feoB, irp2, iroN in weak producers were most represented. The results show possible relation between presence virulence factor and low biofilm formation.

scholarly journals Response of Escherichia coli minimal ter operon to UVC and auto-aggregation: pilot study

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11197
Author(s):  
Lenka Jánošíková ◽  
Lenka Pálková ◽  
Dušan Šalát ◽  
Andrej Klepanec ◽  
Katarina Soltys
Keyword(s):  
Escherichia Coli ◽  
Environmental Stress ◽  
Biofilm Formation ◽  
Large Fraction ◽  
Bacterial Species ◽  
Whole Genome Sequence ◽  
Lower Sensitivity ◽  
Aggregation Assay ◽  
E Coli

Aim The study of minimal ter operon as a determinant of tellurium resistance (TeR) is important for the purpose of confirming the relationship of these genes to the pathogenicity of microorganisms. The ter operon is widespread among bacterial species and pathogens, implicated also in phage inhibition, oxidative stress and colicin resistance. So far, there is no experimental evidence for the role of the Escherichia coli (E. coli) minimal ter operon in ultraviolet C (UVC) resistance, biofilm formation and auto-aggregation. To identify connection with UVC resistance of the minimal ter operon, matched pairs of Ter-positive and -negative E. coli cells were stressed and differences in survival and whole genome sequence analysis were performed. This study was aimed also to identify differences in phenotype of cells induced by environmental stress. Methods In the current study, a minimal ter operon(terBCDEΔF) originating from the uropathogenic strain E. coli KL53 was used. Clonogenic assay was the method of choice to determine cell reproductive death after treatment with UVC irradiation at certain time intervals. Bacterial suspensions were irradiated with 254 nm UVC-light (germicidal lamp in biological safety cabinet) in vitro. UVC irradiance output was 2.5 mW/cm2 (calculated at the UVC device aperture) and plate-lamp distance of 60 cm. DNA damage analysis was performed using shotgun sequencing on Illumina MiSeq platform. Biofilm formation was measured by a crystal violet retention assay. Auto-aggregation assay was performed according to the Ghane, Babaeekhou & Ketabi (2020). Results A large fraction of Ter-positive E. coli cells survived treatment with 120-s UVC light (300 mJ/cm2) compared to matched Ter-negative cells; ∼5-fold higher resistance of Ter-positive cells to UVC dose (p = 0.0007). Moreover, UVC surviving Ter-positive cells showed smaller mutation rate as Ter-negative cells. The study demonstrated that a 1200-s exposure to UVC (3,000 mJ/cm2) was sufficient for 100% inhibition of growth for all the Ter-positive and -negative E. coli cells. The Ter-positive strain exhibited of 26% higher auto-aggregation activities and was able to inhibit biofilm formation over than Ter- negative strain (**** P < 0.0001). Conclusion Our study shows that Ter-positive cells display lower sensitivity to UVC radiation, corresponding to a presence in minimal ter operon. In addition, our study suggests that also auto-aggregation ability is related to minimal ter operon. The role of the minimal ter operon (terBCDEΔF) in resistance behavior of E. coli under environmental stress is evident.

Sign in / Sign up

Export Citation Format

Share Document