scholarly journals Correlation Between in vitro Biofilm Formation and Virulence Properties of Extra-Intestinal Pathogenic Escherichia Coli (Expec)

2014 ◽  
Vol 14 (4) ◽  
pp. 261-270 ◽  
Author(s):  
Md. Fakruddin ◽  
Khanjada Shahnewaj Bin Mannan ◽  
Reaz Mohammad Mazumdar
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Virulence Properties

Correlation between virulence factors and in vitro biofilm formation by Escherichia coli strains

2008 ◽  
Vol 45 (2) ◽  
pp. 86-91 ◽  
Author(s):  
Plínio Naves ◽  
Gema del Prado ◽  
Lorena Huelves ◽  
Matilde Gracia ◽  
Vicente Ruiz ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Biofilm Formation

scholarly journals Novel regulators of the csgD gene encoding the master regulator of biofilm formation in Escherichia coli K-12

Microbiology ◽  
2020 ◽  
Vol 166 (9) ◽  
pp. 880-890 ◽  
Author(s):  
Hiroshi Ogasawara ◽  
Toshiyuki Ishizuka ◽  
Shuhei Hotta ◽  
Michiko Aoki ◽  
Tomohiro Shimada ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Cell Aggregation ◽  
Master Regulator ◽  
Gene Encoding ◽  
Content Type ◽  
Promoter Probe ◽  
K 12 ◽  
Specific Environmental Condition

Under stressful conditions, Escherichia coli forms biofilm for survival by sensing a variety of environmental conditions. CsgD, the master regulator of biofilm formation, controls cell aggregation by directly regulating the synthesis of Curli fimbriae. In agreement of its regulatory role, as many as 14 transcription factors (TFs) have so far been identified to participate in regulation of the csgD promoter, each monitoring a specific environmental condition or factor. In order to identify the whole set of TFs involved in this typical multi-factor promoter, we performed in this study ‘promoter-specific transcription-factor’ (PS-TF) screening in vitro using a set of 198 purified TFs (145 TFs with known functions and 53 hitherto uncharacterized TFs). A total of 48 TFs with strong binding to the csgD promoter probe were identified, including 35 known TFs and 13 uncharacterized TFs, referred to as Y-TFs. As an attempt to search for novel regulators, in this study we first analysed a total of seven Y-TFs, including YbiH, YdcI, YhjC, YiaJ, YiaU, YjgJ and YjiR. After analysis of curli fimbriae formation, LacZ-reporter assay, Northern-blot analysis and biofilm formation assay, we identified at least two novel regulators, repressor YiaJ (renamed PlaR) and activator YhjC (renamed RcdB), of the csgD promoter.

scholarly journals Association between Biofilm-Production and Antibiotic Resistance in Uropathogenic Escherichia coli (UPEC): An In Vitro Study

Diseases ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 17 ◽  
Author(s):  
Payam Behzadi ◽  
Edit Urbán ◽  
Márió Gajdács
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
In Vitro Study ◽  
Point Of View ◽  
Diffusion Method ◽  
Medical Attention ◽  
Disk Diffusion Method ◽  
Biofilm Production ◽  
Tract Infections

Urinary tract infections (UTIs) are among the most common infections requiring medical attention worldwide. The production of biofilms is an important step in UTIs, not only from a mechanistic point of view, but this may also confer additional resistance, distinct from other aspects of multidrug resistance (MDR). A total of two hundred and fifty (n = 250) Escherichia coli isolates, originating from clean-catch urine samples, were included in this study. The isolates were classified into five groups: wild-type, ciprofloxacin-resistant, fosfomycin-resistant, trimethoprim-sulfamethoxazole-resistant and extended spectrum β-lactamase (ESBL)-producing strains. The bacterial specimens were cultured using eosine methylene blue agar and the colony morphology of isolates were recorded. Antimicrobial susceptibility testing was performed using the Kirby–Bauer disk diffusion method and E-tests. Biofilm-formation of the isolates was carried out with the crystal violet tube-adherence method. n = 76 isolates (30.4%) produced large colonies (>3 mm), mucoid variant colonies were produced in n = 135 cases (54.0%), and n = 119 (47.6%) were positive for biofilm formation. The agreement (i.e., predictive value) of mucoid variant colonies in regard to biofilm production in the tube-adherence assay was 0.881 overall. Significant variation was seen in the case of the group of ESBL-producers in the ratio of biofilm-producing isolates. The relationship between biofilm-production and other resistance determinants has been extensively studied. However, no definite conclusion can be reached from the currently available data.

Rosemary and Tea Tree Essential Oils Exert Antibiofilm Activities In Vitro against Staphylococcus aureus and Escherichia coli

2020 ◽  
Vol 83 (7) ◽  
pp. 1261-1267
Author(s):  
TING LIU ◽  
JINGFAN WANG ◽  
XIAOMAN GONG ◽  
XIAOXIA WU ◽  
LIU LIU ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Essential Oil ◽  
Biofilm Formation ◽  
Gas Chromatography Mass Spectrometry ◽  
Tea Tree ◽  
E Coli ◽  
Microdilution Method ◽  
Broth Microdilution Method

ABSTRACT The purpose of the present study was to determine the bioactive compounds in rosemary essential oil (REO) and tea tree essential oil (TEO) and to investigate their antibacterial and antibiofilm activities against Staphylococcus aureus and Escherichia coli in vitro. The MIC and MBC assays were performed to assess the antibacterial activity of these two EOs against S. aureus and E. coli with the broth microdilution method. A crystal violet assay was used to ascertain the effects of EOs on the biofilm formation of the test strains, and a tetrazolium bromide (MTT) assay was used to measure the level of inactivation of mature biofilms by EOs. Gas chromatography–mass spectrometry revealed 15 compounds in REO and 27 compounds in TEO, representing 97.78 and 98.13% of the total EO, respectively. Eucalyptol and α-pinene were found in high concentrations in REO, and the two major compounds in TEO were 4-terpineol and terpinolene. The MICs of REO for the two S. aureus and E. coli test strains were both 0.5 mg/mL, and the MICs of TEO for the two strains were both 0.25 mg/mL. Therefore, these EOs can significantly inhibit the formation of biofilms and induced morphological biofilm changes, as verified by scanning electron microscopy. Both EOs had destructive effects on the mature biofilm of the two test strains. TEO was more inhibitory than REO for biofilm formation by the two test strains. HIGHLIGHTS

Chlorpromazine-impregnated catheters as a potential strategy to control biofilm-associated urinary tract infections

2019 ◽  
Vol 14 (12) ◽  
pp. 1023-1034 ◽  
Author(s):  
José JC Sidrim ◽  
Bruno R Amando ◽  
Francisco IF Gomes ◽  
Marilia SMG do Amaral ◽  
Paulo CP de Sousa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Klebsiella Pneumoniae ◽  
Urinary Tract Infections ◽  
Proteus Mirabilis ◽  
Biofilm Formation ◽  
Antibiofilm Activity ◽  
Potential Strategy ◽  
Tract Infections

Aim: This study proposes the impregnation of Foley catheters with chlorpromazine (CPZ) to control biofilm formation by Escherichia coli, Proteus mirabilis and Klebsiella pneumoniae. Materials & methods: The minimum inhibitory concentrations (MICs) for CPZ and the effect of CPZ on biofilm formation were assessed. Afterward, biofilm formation and the effect of ciprofloxacin and meropenem (at MIC) on mature biofilms grown on CPZ-impregnated catheters were evaluated. Results: CPZ MIC range was 39.06–625 mg/l. CPZ significantly reduced (p < 0.05) biofilm formation in vitro and on impregnated catheters. In addition, CPZ-impregnation potentiated the antibiofilm activity of ciprofloxacin and meropenem. Conclusion: These findings bring perspectives for the use of CPZ as an adjuvant for preventing and treating catheter-associated urinary tract infections.

scholarly journals Regulation of type 1 fimbriae synthesis and biofilm formation by the transcriptional regulator LrhA of Escherichia coli

Microbiology ◽  
2005 ◽  
Vol 151 (10) ◽  
pp. 3287-3298 ◽  
Author(s):  
Caroline Blumer ◽  
Alexandra Kleefeld ◽  
Daniela Lehnen ◽  
Margit Heintz ◽  
Ulrich Dobrindt ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Invertible Element ◽  
Transcriptional Regulator ◽  
Host Cells ◽  
Yeast Cells ◽  
Type 1 Fimbriae ◽  
Biofilm Development

Type 1 fimbriae of Escherichia coli facilitate attachment to the host mucosa and promote biofilm formation on abiotic surfaces. The transcriptional regulator LrhA, which is known as a repressor of flagellar, motility and chemotaxis genes, regulates biofilm formation and expression of type 1 fimbriae. Whole-genome expression profiling revealed that inactivation of lrhA results in an increased expression of structural components of type 1 fimbriae. In vitro, LrhA bound to the promoter regions of the two fim recombinases (FimB and FimE) that catalyse the inversion of the fimA promoter, and to the invertible element itself. Translational lacZ fusions with these genes and quantification of fimE transcript levels by real-time PCR showed that LrhA influences type 1 fimbrial phase variation, primarily via activation of FimE, which is required for the ON-to-OFF transition of the fim switch. Enhanced type 1 fimbrial expression as a result of lrhA disruption was confirmed by mannose-sensitive agglutination of yeast cells. Biofilm formation was stimulated by lrhA inactivation and completely suppressed upon LrhA overproduction. The effects of LrhA on biofilm formation were exerted via the changed levels of surface molecules, most probably both flagella and type 1 fimbriae. Together, the data show a role for LrhA as a repressor of type 1 fimbrial expression, and thus as a regulator of the initial stages of biofilm development and, presumably, bacterial adherence to epithelial host cells also.

scholarly journals Inhibition of curli assembly and Escherichia coli biofilm formation by the human systemic amyloid precursor transthyretin

2017 ◽  
Vol 114 (46) ◽  
pp. 12184-12189 ◽  
Author(s):  
Neha Jain ◽  
Jörgen Ådén ◽  
Kanna Nagamatsu ◽  
Margery L. Evans ◽  
Xinyi Li ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Amyloid Β ◽  
Amyloid Formation ◽  
Amyloid Fibers ◽  
Amyloidogenic Protein ◽  
Aβ Aggregation ◽  
Antibiotic Efficacy

During biofilm formation, Escherichia coli and other Enterobacteriaceae produce an extracellular matrix consisting of curli amyloid fibers and cellulose. The precursor of curli fibers is the amyloidogenic protein CsgA. The human systemic amyloid precursor protein transthyretin (TTR) is known to inhibit amyloid-β (Aβ) aggregation in vitro and suppress the Alzheimer’s-like phenotypes in a transgenic mouse model of Aβ deposition. We hypothesized that TTR might have broad antiamyloid activity because the biophysical properties of amyloids are largely conserved across species and kingdoms. Here, we report that both human WT tetrameric TTR (WT-TTR) and its engineered nontetramer-forming monomer (M-TTR, F87M/L110M) inhibit CsgA amyloid formation in vitro, with M-TTR being the more efficient inhibitor. Preincubation of WT-TTR with small molecules that occupy the T4 binding site eliminated the inhibitory capacity of the tetramer; however, they did not significantly compromise the ability of M-TTR to inhibit CsgA amyloidogenesis. TTR also inhibited amyloid-dependent biofilm formation in two different bacterial species with no apparent bactericidal or bacteriostatic effects. These discoveries suggest that TTR is an effective antibiofilm agent that could potentiate antibiotic efficacy in infections associated with significant biofilm formation.

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