scholarly journals Detection of Escherichia coli and Coliforms in Spring Water Using a Rapid Method. Comparison of LB-BGLB and Two Chromogenic Substrate Medium Methods for Escherichia coli and Coliform Detection in Spring Water.

1998 ◽  
Vol 15 (3/4) ◽  
pp. 153-160
Author(s):  
Yuichi FUCHI ◽  
Tadashi MIYAZAKI ◽  
Kikuyo OGATA ◽  
Kikuo HOASHI ◽  
Yoshihiro MAKINO
Keyword(s):  
Escherichia Coli ◽  
Rapid Method ◽  
Method Comparison ◽  
Spring Water ◽  
Chromogenic Substrate ◽  
Substrate Medium

scholarly journals A High-Throughput Approach To Identify Compounds That Impair Envelope Integrity in Escherichia coli

2016 ◽  
Vol 60 (10) ◽  
pp. 5995-6002 ◽  
Author(s):  
Kristin R. Baker ◽  
Bimal Jana ◽  
Henrik Franzyk ◽  
Luca Guardabassi
Keyword(s):  
Escherichia Coli ◽  
High Throughput ◽  
High Throughput Screening ◽  
Gram Negative Bacteria ◽  
Chromogenic Substrate ◽  
Intrinsic Resistance ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Screening Platform

ABSTRACTThe envelope of Gram-negative bacteria constitutes an impenetrable barrier to numerous classes of antimicrobials. This intrinsic resistance, coupled with acquired multidrug resistance, has drastically limited the treatment options against Gram-negative pathogens. The aim of the present study was to develop and validate an assay for identifying compounds that increase envelope permeability, thereby conferring antimicrobial susceptibility by weakening of the cell envelope barrier in Gram-negative bacteria. A high-throughput whole-cell screening platform was developed to measureEscherichia colienvelope permeability to a β-galactosidase chromogenic substrate. The signal produced by cytoplasmic β-galactosidase-dependent cleavage of the chromogenic substrate was used to determine the degree of envelope permeabilization. The assay was optimized by using known envelope-permeabilizing compounds andE. coligene deletion mutants with impaired envelope integrity. As a proof of concept, a compound library comprising 36 peptides and 45 peptidomimetics was screened, leading to identification of two peptides that substantially increased envelope permeability. Compound 79 reduced significantly (from 8- to 125-fold) the MICs of erythromycin, fusidic acid, novobiocin and rifampin and displayed synergy (fractional inhibitory concentration index, <0.2) with these antibiotics by checkerboard assays in two genetically distinctE. colistrains, including the high-risk multidrug-resistant, CTX-M-15-producing sequence type 131 clone. Notably, in the presence of 0.25 μM of this peptide, both strains were susceptible to rifampin according to the resistance breakpoints (R> 0.5 μg/ml) for Gram-positive bacterial pathogens. The high-throughput screening platform developed in this study can be applied to accelerate the discovery of antimicrobial helper drug candidates and targets that enhance the delivery of existing antibiotics by impairing envelope integrity in Gram-negative bacteria.

scholarly journals Rapid Method for Cloning a Ca2+ -Dependent Metalloprotease From a Gram-Positive Bacterium in Escherichia coli

BioTechniques ◽  
1997 ◽  
Vol 22 (1) ◽  
pp. 58-60 ◽  
Author(s):  
Alain Kohl ◽  
Klaus-D. Wittchen ◽  
Friedhelm Meinhardt
Keyword(s):  
Escherichia Coli ◽  
Rapid Method ◽  
Positive Bacterium ◽  
Gram Positive

scholarly journals Rapid method of luxS and pfs gene inactivation in enterotoxigenic Escherichia coli and the effect on biofilm formation

2015 ◽  
Vol 13 (1) ◽  
pp. 257-264 ◽  
Author(s):  
XIAOXU WANG ◽  
SHIYU LI ◽  
XIAORAN LU ◽  
PAN HU ◽  
HAIYAN CHEN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rapid Method ◽  
Biofilm Formation ◽  
Gene Inactivation ◽  
Enterotoxigenic Escherichia Coli

scholarly journals Studies on a Rapid Method for Detecting Shiga Toxin-Producing Escherichia coli (STEC) in Food Using the QUALIBAXTM Q7 System

2014 ◽  
Vol 31 (4) ◽  
pp. 194-203
Author(s):  
Tetsuya MORI ◽  
Masumi HATA ◽  
Akimasa WATANABE ◽  
Yoshito IWADE ◽  
Shintaro WADA ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rapid Method ◽  
Shiga Toxin

scholarly journals A Rapid Method to Quantify Fungicide Sensitivity in the Brown Rot Pathogen Monilinia fructicola

Plant Disease ◽  
2009 ◽  
Vol 93 (4) ◽  
pp. 328-331 ◽  
Author(s):  
Kerik D. Cox ◽  
Kacie Quello ◽  
Ryan J. Deford ◽  
Janna L. Beckerman
Keyword(s):  
Rapid Method ◽  
Fungicide Resistance ◽  
Mycelial Growth ◽  
Brown Rot ◽  
Spore Density ◽  
Monilinia Fructicola ◽  
Chromogenic Substrate ◽  
Alamar Blue ◽  
Resistance Screening ◽  
Fungicide Sensitivity

Management of brown rot of stone fruit relies upon the application of effective fungicides that may be compromised by the development of fungicide resistance. We evaluated fungicide resistance in the brown rot pathogen, Monilinia fructicola, using Alamar blue (AB) dye, or resazurin, a chromogenic substrate that can be used as an indicator of respiration, in a 96-well microtiter format. We compared the AB method to traditional mycelial growth assays for resistance screening using 10 isolates of M. fructicola that represented a range of sensitivities to fenbuconazole. Using traditional mycelial growth assays, isolate sensitivity ranged from 17.7 to 115.3% growth on medium amended with fenbuconazole at 0.03 μg/ml relative to that on nonamended medium. Concordant results between both assays were obtained (R2 = 0.9943, P < 0.0001), but the AB method provided results within 24 h, as opposed to the 3- to 5-day period required for mycelial growth assays. We found that sensitive isolates reduced AB less than resistant isolates in the presence of fungicide. Spore density influenced the reduction of AB by M. fructicola; spectrophotometric discrimination of fungicide sensitivity was best achieved at a density of 105 spores/ml.

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