Detection of Escherichia coli Enterotoxins by Using Mouse Adrenal Cell and Suckling Mouse Assays: Collaborative Study

1984 ◽  
Vol 67 (5) ◽  
pp. 946-949
Author(s):  
Joseph Lovett ◽  
James T Peeler ◽  
◽  
B K Boutin ◽  
J S Cholensky ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Collaborative Study ◽  
Culture Broth ◽  
The Other ◽  
Casamino Acid ◽  
Suckling Mouse ◽  
Adrenal Cell ◽  
E Coli ◽  
Heat Stable

Abstract The ability of 10 Escherichia coli strains to produce heat-stable enterotoxin (ST) and heat-labile enterotoxin (LT) was determined by 8 analysts in a collaborative study. The suckling mouse model and the mouse adrenal cell line (Y-l) tests were used to detect ST and LT, respectively. Cultures for assay were grown 24 h in casamino acid-yeast extracttrace salts broth at 37°C in a shaker incubator at 250 rpm. Cell-free culture broth prepared by centrifugation and filtration was divided into 2 portions: One was heated for 30 min and used both for ST assay and as a heated control for LT assay; the other was used unheated for LT assay. Results were expressed as positive for ST, positive for LT, positive for ST and LT, or negative for both ST and LT; percent of correct estimates was calculated for each culture for each analyst. At the 95% confidence interval, the overall correct results were 96.3 ± 2.9 and 95.0 ± 3.4% for ST and LT, respectively. The test performances thus were satisfactory for detecting ST and LT produced in vitro by E. coli. The method has been adopted official first action.

scholarly journals In Vitro Activity of Newer and Conventional Antimicrobial Agents, Including Fosfomycin and Colistin, against Selected Gram-Negative Bacilli in Kuwait

Pathogens ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 75 ◽  
Author(s):  
Wadha Alfouzan ◽  
Rita Dhar ◽  
David Nicolau
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agents ◽  
The Other ◽  
In Vitro Activity ◽  
Limited Data ◽  
Gram Negative ◽  
E Coli ◽  
Microbroth Dilution

Limited data are available on susceptibilities of these organisms to some of the recently made accessible antimicrobial agents. The in vitro activities of newer antibiotics, such as, ceftolozane/tazobactam (C/T) and ceftazidime/avibactam (CZA) along with some “older” antibiotics, for example fosfomycin (FOS) and colistin (CL) were determined against selected strains (resistant to ≥ 3 antimicrobial agents) of Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Minimum inhibitory concentrations (MIC) were determined by Clinical and Laboratory Standards Institute microbroth dilution. 133 isolates: 46 E. coli, 39 K. pneumoniae, and 48 P. aeruginosa were tested. Results showed that E. coli isolates with MIC50/90, 0.5/1 μ g / mL for CL; 4/32 μ g / mL for FOS; 0.25/32 μ g / mL for C/T; 0.25/8 μ g / mL for CZA, exhibited susceptibility rates of 95.7%, 97.8%, 76.1%, and 89.1%, respectively. On the other hand, K. pneumoniae strains with MIC50/90, 0.5/1 μ g / mL for CL; 256/512 μ g / mL for FOS; 2/128 μ g / mL for C/T; 0.5/128 μ g / mL for CZA showed susceptibility rates of 92.3%, 7.7%, 51.3%, and 64.1%, respectively. P. aeruginosa isolates with MIC50/90, 1/1 μ g / mL for CL; 128/128 μ g / mL for C/T; 32/64 μ g / mL for CZA presented susceptibility rates of 97.9%, 33.3%, and 39.6%, respectively. Higher MICs were demonstrated against most of the antibiotics. However, CL retained efficacy at low MICs against most of the isolates tested.

scholarly journals Enterotoxigenic enteric bacteria in foods and outbreaks of food-borne diseases in Sweden

1979 ◽  
Vol 83 (1) ◽  
pp. 33-40 ◽  
Author(s):  
M.-L. Danielsson ◽  
R. Möllby ◽  
H. Brag ◽  
N. Hansson ◽  
P. Jonsson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Food Poisoning ◽  
Enteric Bacteria ◽  
Watery Diarrhoea ◽  
Suckling Mouse ◽  
Gram Negative ◽  
E Coli ◽  
Heat Stable ◽  
Food Borne ◽  
Micro Organisms

SUMMARYAll of 86 foods routinely examined for potentially pathogenic enteric bacteria were found to harbour one or more coliform species. None of the strains isolated produced heat-labile enterotoxin (LT) or showed invasive properties. The suckling mouse test indicated that one strain ofEscherichia coliproduced heat-stable enterotoxin (ST). Twelve incidents of suspected food poisoning were also investigated. In two of them the foods examined contained LT-producing strains ofE. coliand in two there were LT-producing strains ofKlebsiella pneumoniae. The counts of viable enterotoxigenic micro-organisms in these foods were 3000–30 000E. coli/g and 50 000 to 1 millionK. pneumoniae/g. The dominant symptom in all the incidents was watery diarrhoea. These seem to be the first reported cases of foodborne enterotoxigenic enteric bacteria in Europe. Though enterotoxigenicE. coliand related gram-negative enterotoxin-producing species are rare in correctly handled food in Sweden, these micro-organisms should be searched for when outbreaks of food poisoning are investigated.

Foodborne Illness Caused by Escherichia coli: A Review

1982 ◽  
Vol 45 (11) ◽  
pp. 1051-1067 ◽  
Author(s):  
JEFFREY L. KORNACKI ◽  
ELMER H. MARTH
Keyword(s):  
Escherichia Coli ◽  
Intestinal Flora ◽  
Meat Products ◽  
Immunological Methods ◽  
Common Source ◽  
Invasive Infection ◽  
E Coli ◽  
Heat Stable ◽  
Diagnostic Microbiology

Enteropathogenic Escherichia coli (EEC) can be defined as any strain of E. coli that has the potential to cause diarrheal illness. Four major categories of EEC exist. Classical enteropathogenic E. coli (EPEC) commonly refers to serogroups of E. coli historically associated with outbreaks of diarrhea in young children and infants. Facultatively enteropathogenic E. coli (FEEC) are non-EPEC serogroups associated with sporadic diarrhea, and include many serogroups associated with the normal intestinal flora. Enterotoxigenic E. coli (ETEC) is commonly isolated from outbreaks of traveler's diarrhea, and includes those strains which produce a heat-stable enterotoxin (ST) only, a heat-labile enterotoxin (LT) only and those which produce both ST and LT. These organisms adhere to and colonize the epithelial cell surfaces of the proximal small intestine. This colonization is mediated by specific types of fimbriae which are host-specific. Toxigenicity is plasmid-related. Enteroinvasive E. coli (EIEC) exert their pathogenic effect through an invasive infection of the gastrointestinal tract. Many techniques currently exist to determine the presence of enterotoxins produced by a particular strain of E. coli. These include bioassay, tissue culture and in vitro immunological techniques. Of the newer in vitro immunological methods, the staphylococcal coagglutination technique to detect LT seems to have potential for routine use in diagnostic microbiology laboratories. Since large numbers (106 – 109) of EEC are necessary for diarrhea, an unsanitary environment is needed for transmission of illness. Presence of EEC varies geographically; however, E. coli diarrhea is not likely to occur in the more hygenic areas of the world, except in occasional common-source outbreaks where the organism has time to replicate in food or water. The following foods have been implicated in documented E. coli diarrheal outbreaks worldwide: meat and meat products, fish, poultry, milk and dairy products, vegetables, baked products, rice formulations, coffee substitutes and water.

scholarly journals Distinct stress responses to pyocyanin by planktonic and sessile Staphylococcus aureus UFPEDA 02 and Escherichia coli UFPEDA 224 / Respostas distintas ao estresse causado pela piocianina em células planctônicas e sésseis de Staphylococcus aureus UFPEDA 02 e Escherichia coli UFPEDA 224

2021 ◽  
Vol 7 (10) ◽  
pp. 98074-98088
Author(s):  
Bianca Teixeira Morais De Oliveira ◽  
Kaíque Yago Gervazio De Lima ◽  
Ray Ravilly Alves Arruda ◽  
Ulrich Vasconcelos
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Stress Responses ◽  
Cell Concentration ◽  
The Other ◽  
Planktonic Cells ◽  
E Coli ◽  
Highly Sensitive ◽  
A Cell

Antimicrobial activity of pyocyanin against competing organisms of Pseudomonas aeruginosa is related to the oxidative stress that the compound promotes in susceptible cells. The objective of this work was to produce, extract and verify the activity of pyocyanin in planktonic and sessile forms from clinical strains, Staphylococcus aureus UFPEDA 02 and Escherichia coli UFPEDA 224. About 600 µg/mL of pyocyanin were obtained. The planktonic cells were highly sensitive. The MIC determined for S. aureus UFPEDA 02 and E. coli UFPEDA 224 were 18.75 and 37.5 µg/mL, respectively. The pyocyanin demonstrated biocidal effect against S. aureus UFPEDA 02. On the other hand, pyocyanin was not active in either sessile strain. The presence of the pigment allowed a greater adherence of the strains, forming more robust biofilms compared to the control. S. aureus UFPEDA 02 and E. coli UFPEDA 224 presented moderate and high hydrophobicity, respectively. Glass and dolomite surfaces were tested in the in vitro biofilm test. Both strains formed the biofilm better on the dolomite surface, obtaining a cell concentration (MPN/cm2) in the order of 3 log units after 48h of incubation.

scholarly journals In Vitro Antimicrobial Activity of Various Cefoperazone/Sulbactam Products

Antibiotics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 77
Author(s):  
Ming-Jen Sheu ◽  
Chi-Chung Chen ◽  
Ying-Chen Lu ◽  
Bo-An Su ◽  
Chun-Cheng Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
The Other ◽  
In Vitro Activity ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Multidrug Resistant Organisms

This study aims to assess the in vitro activity of different samples of cefoperazone/sulbactam (CFP/SUL) against multidrug-resistant organisms (MDROs). Clinical isolates of extended-spectrum β-lactamase (ESBL)-Escherichia coli, ESBL-Klebsiella pneumoniae, carbapenem-resistant Acinetobacter baumannii (CR-AB), and carbapenem-resistant Pseudomonas aeruginosa (CR-PA) were collected. The minimum inhibitory concentration (MIC) and time-killing methods were used to assess and compare the in vitro activities of different samples of cefoperazone/sulbactam (CFP/SUL) against these MDROs. For ESBL-E. coli, ESBL-K. pneumoniae, and CR-PA, product C had smaller variations than product A and B (p < 0.05). For CR-AB, product B had the largest variation compared to the other two products (p < 0.05). In the time-killing studies, significant differences among the products when used at 16/16 µg/mL were noted for ESBL-E. coli, ESBL-K. pneumoniae, and CR-AB isolates. In conclusion, this study demonstrated the significantly different activity of different products of CFP/SUL against MDROs.

Of Bacteria and Men: Toxicity of 30 MEIC Chemicals to Bacteria and Humans

1993 ◽  
Vol 21 (2) ◽  
pp. 233-238 ◽  
Author(s):  
Gustaw Kerszman
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Blood Concentration ◽  
In Vitro Cytotoxicity ◽  
Human Cells ◽  
The Other ◽  
Minimal Inhibitory Concentrations ◽  
E Coli ◽  
Lethal Blood

The toxicity of chemicals (numbers 11–30 from the multicenter evaluation of in vitro cytotoxicity [MEIC] programme) to Escherichia coli and Bacillus subtilis was examined. Malathion was not detectably toxic to bacteria. Theophylline was toxic to E. coli but not to B. subtilis. All of the other chemicals were toxic to both bacteria, with minimal inhibitory concentrations (MIC) ranging from 10-5M to 1.3M. The sensitivities of both organisms to the chemicals were quite similar. A highly significant correlation could be established for the first 30 MEIC chemicals between MIC in bacteria and acute lethal blood concentration in humans. A significant correlation was also established for sets of MEIC chemicals between MIC in bacteria and the relevant endpoint concentrations in various tests employing human cells.

scholarly journals Pooling Method for Screening Large Numbers of Escherichia coli for Production of Heat-Stable Enterotoxin, and Its Application in Field Studies

1979 ◽  
Vol 9 (4) ◽  
pp. 541-543
Author(s):  
Patricia A. Byers ◽  
Herbert L. DuPont
Keyword(s):  
Escherichia Coli ◽  
Field Studies ◽  
Suckling Mouse ◽  
E Coli ◽  
Heat Stable ◽  
Large Numbers

A modified suckling mouse assay was developed for use in field studies whereby five E. coli isolates could be tested as a pool for heat-stable enterotoxin.

Substituted 4-Formyl-2H-chromen-2-ones: Their Reaction with N-(2,3,4,6-Tetra-Oacetyl- β-D-galactopyranosyl)thiosemicarbazide, Antibacterial and Antifungal Activity of Their Thiosemicarbazone Products

2020 ◽  
Vol 24 (19) ◽  
pp. 2272-2282
Author(s):  
Vu Ngoc Toan ◽  
Nguyen Minh Tri ◽  
Nguyen Dinh Thanh
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Selenium Dioxide ◽  
Antibacterial And Antifungal Activity ◽  
E Coli ◽  
Antibacterial And Antifungal Activities ◽  
Alkyl Ethers ◽  
Antibacterial And Antifungal

Several 6- and 7-alkoxy-2-oxo-2H-chromene-4-carbaldehydes were prepared from corresponding alkyl ethers of 6- and 7-hydroxy-4-methyl-2-oxo-2H-chromen-2-ones by oxidation using selenium dioxide. 6- and 7-Alkoxy-4-methyl-2H-chromenes were obtained with yields of 57-85%. Corresponding 4-carbaldehyde derivatives were prepared with yields of 41-67%. Thiosemicarbazones of these aldehydes with D-galactose moiety were synthesized by reaction of these aldehydes with N-(2,3,4,6-tetra-O-acetyl-β-Dgalactopyranosyl) thiosemicarbazide with yields of 62-74%. These thiosemicarbazones were screened for their antibacterial and antifungal activities in vitro against bacteria, such as Staphylococcus aureus, Escherichia coli, and fungi, such as Aspergillus niger, Candida albicans. Several compounds exhibited strong inhibitory activity with MIC values of 0.78- 1.56 μM, including 8a (against S. aureus, E. coli, and C. albicans), 8d (against E. coli and A. niger), 9a (against S. aureus), and 9c (against S. aureus and C. albicans).

scholarly journals In vitro activity of antimicrobial peptide CDP-B11 alone and in combination with colistin against colistin-resistant and multidrug-resistant Escherichia coli

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kaitlin S. Witherell ◽  
Jason Price ◽  
Ashok D. Bandaranayake ◽  
James Olson ◽  
Douglas R. Call
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Peptide ◽  
Membrane Integrity ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
E Coli ◽  
Minimal Media

AbstractMultidrug-resistant bacteria are a growing global concern, and with increasingly prevalent resistance to last line antibiotics such as colistin, it is imperative that alternative treatment options are identified. Herein we investigated the mechanism of action of a novel antimicrobial peptide (CDP-B11) and its effectiveness against multidrug-resistant bacteria including Escherichia coli #0346, which harbors multiple antibiotic-resistance genes, including mobilized colistin resistance gene (mcr-1). Bacterial membrane potential and membrane integrity assays, measured by flow cytometry, were used to test membrane disruption. Bacterial growth inhibition assays and time to kill assays measured the effectiveness of CDP-B11 alone and in combination with colistin against E. coli #0346 and other bacteria. Hemolysis assays were used to quantify the hemolytic effects of CDP-B11 alone and in combination with colistin. Findings show CDP-B11 disrupts the outer membrane of E. coli #0346. CDP-B11 with colistin inhibits the growth of E. coli #0346 at ≥ 10× lower colistin concentrations compared to colistin alone in Mueller–Hinton media and M9 media. Growth is significantly inhibited in other clinically relevant strains, such as Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae. In rich media and minimal media, the drug combination kills bacteria at a lower colistin concentration (1.25 μg/mL) compared to colistin alone (2.5 μg/mL). In minimal media, the combination is bactericidal with killing accelerated by up to 2 h compared to colistin alone. Importantly, no significant red blood hemolysis is evident for CDP-B11 alone or in combination with colistin. The characteristics of CDP-B11 presented here indicate that it can be used as a potential monotherapy or as combination therapy with colistin for the treatment of multidrug-resistant infections, including colistin-resistant infections.

scholarly journals Lysyl-tRNA synthetase from Escherichia coli K12. Chromatographic heterogeneity and the lysU-gene product

1987 ◽  
Vol 248 (1) ◽  
pp. 43-51 ◽  
Author(s):  
J Charlier ◽  
R Sanchez
Keyword(s):  
Escherichia Coli ◽  
Gene Product ◽  
Activity Ratio ◽  
Deae Cellulose ◽  
Trna Synthetase ◽  
Trna Synthetases ◽  
E Coli ◽  
Aminoacyl Trna Synthetases

In contrast with most aminoacyl-tRNA synthetases, the lysyl-tRNA synthetase of Escherichia coli is coded for by two genes, the normal lysS gene and the inducible lysU gene. During its purification from E. coli K12, lysyl-tRNA synthetase was monitored by its aminoacylation and adenosine(5′)tetraphospho(5′)adenosine (Ap4A) synthesis activities. Ap4A synthesis was measured by a new assay using DEAE-cellulose filters. The heterogeneity of lysyl-tRNA synthetase (LysRS) was revealed on hydroxyapatite; we focused on the first peak, LysRS1, because of its higher Ap4A/lysyl-tRNA activity ratio at that stage. Additional differences between LysRS1 and LysRS2 (major peak on hydroxyapatite) were collected. LysRS1 was eluted from phosphocellulose in the presence of the substrates, whereas LysRS2 was not. Phosphocellulose chromatography was used to show the increase of LysRS1 in cells submitted to heat shock. Also, the Mg2+ optimum in the Ap4A-synthesis reaction is much higher for LysRS1. LysRS1 showed a higher thermostability, which was specifically enhanced by Zn2+. These results in vivo and in vitro strongly suggest that LysRS1 is the heat-inducible lysU-gene product.

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