Specific Lux Biosensors of Escherichia coli Containing pRecA::lux, pColD::lux, and pDinI::lux Plasmids for Detection of Genotoxic Agents

2020 ◽  
Vol 56 (6) ◽  
pp. 666-673
Author(s):  
S. K. Abilev ◽  
V. Y. Kotova ◽  
S. V. Smirnova ◽  
T. N. Shapiro ◽  
G. B. Zavilgelsky
Keyword(s):  
Escherichia Coli ◽  
Genotoxic Agents ◽  
Lux Biosensors

scholarly journals Selective Advantage of Resistant Strains at Trace Levels of Antibiotics: a Simple and Ultrasensitive Color Test for Detection of Antibiotics and Genotoxic Agents

2011 ◽  
Vol 55 (3) ◽  
pp. 1204-1210 ◽  
Author(s):  
Anne Liu ◽  
Amie Fong ◽  
Elinne Becket ◽  
Jessica Yuan ◽  
Cindy Tamae ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Human Microbiome ◽  
Selective Advantage ◽  
Color Test ◽  
Minimum Concentration ◽  
Wide Range ◽  
Genotoxic Agents ◽  
Bacterial Mutants ◽  
Increased Sensitivity ◽  
Resistant Mutants

ABSTRACTMany studies have examined the evolution of bacterial mutants that are resistant to specific antibiotics, and many of these focus on concentrations at and above the MIC. Here we ask for the minimum concentration at which existing resistant mutants can outgrow sensitive wild-type strains in competition experiments at antibiotic levels significantly below the MIC, and we define a minimum selective concentration (MSC) inEscherichia colifor two antibiotics, which is near 1/5 of the MIC for ciprofloxacin and 1/20 of the MIC for tetracycline. Because of the prevalence of resistant mutants already in the human microbiome, allowable levels of antibiotics to which we are exposed should be below the MSC. Since this concentration often corresponds to low or trace levels of antibiotics, it is helpful to have simple tests to detect such trace levels. We describe a simple ultrasensitive test for detecting the presence of antibiotics and genotoxic agents. The test is based on the use of chromogenic proteins as color markers and the use of single and multiple mutants ofEscherichia colithat have greatly increased sensitivity to either a wide range of antibiotics or specific antibiotics, antibiotic families, and genotoxic agents. This test can detect ciprofloxacin at 1/75 of the MIC.

scholarly journals Determination of hypersensitivity to genotoxic agents among Escherichia coli single gene knockout mutants

DNA Repair ◽  
2010 ◽  
Vol 9 (9) ◽  
pp. 949-957 ◽  
Author(s):  
Elinne Becket ◽  
Frank Chen ◽  
Cindy Tamae ◽  
Jeffrey H. Miller
Keyword(s):  
Escherichia Coli ◽  
Gene Knockout ◽  
Single Gene ◽  
Knockout Mutants ◽  
Genotoxic Agents

The Escherichia coli K-12 SOS chromotest agar spot test for simple, rapid detection of genotoxic agents

1986 ◽  
Vol 171 (2-3) ◽  
pp. 83-90 ◽  
Author(s):  
Stephen W. Mamber ◽  
Wanda G. Okasinski ◽  
Cheryl D. Pinter ◽  
Josefino B. Tunac
Keyword(s):  
Escherichia Coli ◽  
Rapid Detection ◽  
Spot Test ◽  
Sos Chromotest ◽  
Genotoxic Agents ◽  
K 12

Induction of the SOS response of Escherichia coli in repair-defective strains by several genotoxic agents

2020 ◽  
Vol 854-855 ◽  
pp. 503196
Author(s):  
Jorge Serment-Guerrero ◽  
Viridiana Dominguez-Monroy ◽  
Jenny Davila-Becerril ◽  
Enrique Morales-Avila ◽  
Jorge Luis Fuentes-Lorenzo
Keyword(s):  
Escherichia Coli ◽  
Sos Response ◽  
Genotoxic Agents

Reactive oxygen and nitrogen species’ effect on lux-biosensors based on Escherichia coli and Salmonella typhimurium

2016 ◽  
Vol 52 (3) ◽  
pp. 269-276 ◽  
Author(s):  
D. N. Karimova ◽  
I. V. Manukhov ◽  
E. Yu. Gnuchikh ◽  
I. F. Karimov ◽  
D. G. Deryabin
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Reactive Oxygen ◽  
Nitrogen Species ◽  
Lux Biosensors ◽  
Species Effect

Protective properties of five newly synthesized cyclic compounds against sodium azide and N-methyl-N′-nitro-N-nitrosoguanidine genotoxicity

2011 ◽  
Vol 28 (7) ◽  
pp. 605-613 ◽  
Author(s):  
Kadir Turhan ◽  
S Arda Ozturkcan ◽  
Zuhal Turgut ◽  
Mehmet Karadayi ◽  
Medine Gulluce
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Sodium Azide ◽  
Antimutagenic Activity ◽  
Bacterial Strains ◽  
Mutagenic Potential ◽  
Protective Properties ◽  
Genotoxic Agents ◽  
Cyclic Compounds ◽  
Chemical Prevention

The current study aims to determine the antimutagenic potential of five newly synthesized cyclic compounds against the genotoxic agents sodium azide (NaN3) and N-methyl- N′-nitro- N-nitrosoguanidine (MNNG). The mutant bacterial tester strains were NaN3-sensitive Salmonella typhimurium TA1535 and MNNG-sensitive Escherichia coli WP2 uvrA. According to the results, all the test compounds showed significant antimutagenic activity. The inhibition rates ranged from 26.05% (Compound 4—1 µg/plate) to 68.54% (Compound 5—0.01 µg/plate) for NaN3 and from 32.44% (Compound 3—1 µg/plate) to 60.77% (Compound 5—1 µg/plate) for MNNG genotoxicity. Moreover, the mutagenic potential of the test compounds was investigated using the same strains. The results showed that all the test compounds do not have mutagenic potential on the bacterial strains at the tested concentrations. Thus, the findings of the present study give valuable information about chemical prevention from NaN3 and MNNG genotoxicity.

Structural organization of escherichia coli ribosomes as determined by immuno electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 166-167 ◽  
Author(s):  
G. Stöffler ◽  
R.W. Bald ◽  
J. Dieckhoff ◽  
H. Eckhard ◽  
R. Lührmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Ribosomal Subunit ◽  
Spatial Arrangement ◽  
Small Subunit ◽  
Antibody Binding ◽  
Immuno Electron Microscopy

A central step towards an understanding of the structure and function of the Escherichia coli ribosome, a large multicomponent assembly, is the elucidation of the spatial arrangement of its 54 proteins and its three rRNA molecules. The structural organization of ribosomal components has been investigated by a number of experimental approaches. Specific antibodies directed against each of the 54 ribosomal proteins of Escherichia coli have been performed to examine antibody-subunit complexes by electron microscopy. The position of the bound antibody, specific for a particular protein, can be determined; it indicates the location of the corresponding protein on the ribosomal surface.The three-dimensional distribution of each of the 21 small subunit proteins on the ribosomal surface has been determined by immuno electron microscopy: the 21 proteins have been found exposed with altogether 43 antibody binding sites. Each one of 12 proteins showed antibody binding at remote positions on the subunit surface, indicating highly extended conformations of the proteins concerned within the 30S ribosomal subunit; the remaining proteins are, however, not necessarily globular in shape (Fig. 1).

Sites of Adsorption of the Bacteriophages T3 and T5 on the Wall of Escherichia Coli B.

1967 ◽  
Vol 25 ◽  
pp. 96-97
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Electron Microscope ◽  
Uranyl Acetate ◽  
E Coli ◽  
Receptor Sites ◽  
Rigid Cell Wall ◽  
Host Cell Surface ◽  
Bacterial Viruses ◽  
Escherichia Coli B

Bacterial viruses adsorb specifically to receptors on the host cell surface. Although the chemical composition of some of the cell wall receptors for bacteriophages of the T-series has been described and the number of receptor sites has been estimated to be 150 to 300 per E. coli cell, the localization of the sites on the bacterial wall has been unknown.When logarithmically growing cells of E. coli are transferred into a medium containing 20% sucrose, the cells plasmolize: the protoplast shrinks and becomes separated from the somewhat rigid cell wall. When these cells are fixed in 8% Formaldehyde, post-fixed in OsO4/uranyl acetate, embedded in Vestopal W, then cut in an ultramicrotome and observed with the electron microscope, the separation of protoplast and wall becomes clearly visible, (Fig. 1, 2). At a number of locations however, the protoplasmic membrane adheres to the wall even under the considerable pull of the shrinking protoplast. Thus numerous connecting bridges are maintained between protoplast and cell wall. Estimations of the total number of such wall/membrane associations yield a number of about 300 per cell.

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