Kojic acid and tea polyphenols inactivate Escherichia coli O157:H7 in vitro and on salmon fillets by inflicting damage on cell membrane and binding to genomic DNA

2021 ◽  
Author(s):  
Ruifei Wang ◽  
Meimei Fang ◽  
Xinyi Hu ◽  
Yigang Yu ◽  
Xinglong Xiao
Keyword(s):  
Escherichia Coli ◽  
Cell Membrane ◽  
Genomic Dna ◽  
Kojic Acid ◽  
Tea Polyphenols ◽  
Escherichia Coli O157

Ability ofEscherichia coliO157:H7 isolates to colonize the intestinal tract of conventional adult CD1 mice is transient

2001 ◽  
Vol 47 (1) ◽  
pp. 91-95 ◽  
Author(s):  
J Wayne Conlan ◽  
Sonia L Bardy ◽  
Rhonda KuoLee ◽  
Ann Webb ◽  
Malcolm B Perry
Keyword(s):  
Escherichia Coli ◽  
Mouse Model ◽  
Intestinal Tract ◽  
Vaccine Development ◽  
Escherichia Coli O157 ◽  
Intestinal Colonization ◽  
E Coli ◽  
Cd1 Mice ◽  
A Current

In an attempt to improve upon a current mouse model of intestinal colonization by Escherichia coli O157:H7 used in this laboratory for vaccine development, nine clinical isolates of the pathogen were screened for their ability to persist in the intestinal tract of conventional adult CD-1 mice. None of the test isolates of E. coli O157:H7 were capable of colonizing these mice for a period of more than two weeks. Most of the isolates appeared to be benign for the experimental host, but one isolate was lethal. This virulence correlated with the ability of the latter isolate to produce large quantities of Shiga-like toxin 2 in vitro.

Effect of Tannins on the In Vitro Growth of Escherichia coli O157:H7 and In Vivo Growth of Generic Escherichia coli Excreted from Steers

2007 ◽  
Vol 70 (3) ◽  
pp. 543-550 ◽  
Author(s):  
BYENG R. MIN ◽  
WILLIAM E. PINCHAK ◽  
ROBIN C. ANDERSON ◽  
TODD R. CALLAWAY
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Bacterial Growth ◽  
Escherichia Coli O157 ◽  
Tannin Extract ◽  
Bacterial Growth Rate ◽  
Linear Effect ◽  
E Coli

The effect of commercially available chestnut and mimosa tannins in vitro (experiment 1) or in vivo (experiment 2) on the growth or recovery of Escherichia coli O157:H7 or generic fecal E. coli was evaluated. In experiment 1, the mean growth rate of E. coli O157:H7, determined via the measurement of optical density at 600 nm during anaerobic culture in tryptic soy broth at 37°C, was reduced (P < 0.05) with as little as 400 μg of either tannin extract per ml of culture fluid. The addition of 200, 400, 600, 800, and 1,200 μg of tannins per ml significantly (P < 0.01) reduced the specific bacterial growth rate when compared with the nontannin control. The specific growth rate decreased with increasing dose levels up to 800 μg of tannins per ml. Bacterial growth inhibition effects in chestnut tannins were less pronounced than in mimosa tannins. Chestnut tannin extract addition ranged from 0 to 1,200 μg/ml, and a linear effect (P < 0.05) was observed in cultures incubated for 6 h against the recovery of viable cells, determined via the plating of each strain onto MacConkey agar, of E. coli O157:H7 strains 933 and 86-24, but not against strain 6058. Similar tests with mimosa tannin extract showed a linear effect (P < 0.05) against the recovery of E. coli O157:H7 strain 933 only. The bactericidal effect observed in cultures incubated for 24 h with the tannin preparations was similar, although it was less than that observed from cultures incubated for 6 h. When chestnut tannins (15 g of tannins per day) were infused intraruminally to steers fed a Bermuda grass hay diet in experiment 2, fecal E. coli shedding was lower on days 3 (P < 0.03), 12 (P = 0.08), and 15 (P < 0.001) when compared with animals that were fed a similar diet without tannin supplementation. It was concluded that dietary levels and sources of tannins potentially reduce the shedding of E. coli from the gastrointestinal tract.

scholarly journals Use of In Vivo-Induced Antigen Technology for Identification of Escherichia coli O157:H7 Proteins Expressed during Human Infection

2005 ◽  
Vol 73 (5) ◽  
pp. 2665-2679 ◽  
Author(s):  
Manohar John ◽  
Indira T. Kudva ◽  
Robert W. Griffin ◽  
Allen W. Dodson ◽  
Bethany McManus ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Vaccine Development ◽  
Human Infection ◽  
Escherichia Coli O157 ◽  
Standard Laboratory ◽  
E Coli ◽  
Phase Culture ◽  
Stool Specimens

ABSTRACT Using in vivo-induced antigen technology (IVIAT), a modified immunoscreening technique that circumvents the need for animal models, we directly identified immunogenic Escherichia coli O157:H7 (O157) proteins expressed either specifically during human infection but not during growth under standard laboratory conditions or at significantly higher levels in vivo than in vitro. IVIAT identified 223 O157 proteins expressed during human infection, several of which were unique to this study. These in vivo-induced (ivi) proteins, encoded by ivi genes, mapped to the backbone, O islands (OIs), and pO157. Lack of in vitro expression of O157-specific ivi proteins was confirmed by proteomic analysis of a mid-exponential-phase culture of E. coli O157 grown in LB broth. Because ivi proteins are expressed in response to specific cues during infection and might help pathogens adapt to and counter hostile in vivo environments, those identified in this study are potential targets for drug and vaccine development. Also, such proteins may be exploited as markers of O157 infection in stool specimens.

scholarly journals Lowering S-Adenosylmethionine Levels inEscherichia coli Modulates C-to-T Transition Mutations

2001 ◽  
Vol 183 (3) ◽  
pp. 921-927 ◽  
Author(s):  
Georgina Macintyre ◽  
C. Victoria Atwood ◽  
Claire G. Cupples
Keyword(s):  
Escherichia Coli ◽  
Dna Methylation ◽  
Genomic Dna ◽  
Synthetase Activity ◽  
Inescherichia Coli ◽  
Genome Methylation ◽  
Sam Synthetase ◽  
Methyl Cytosine

ABSTRACT Deoxycytosine methylase (Dcm) enzyme activity causes mutagenesis in vitro either directly by enzyme-induced deamination of cytosine to uracil in the absence of the methyl donor,S-adenosylmethionine (SAM), or indirectly through spontaneous deamination of [5-methyl]cytosine to thymine. Using a Lac reversion assay, we investigated the contribution of the first mechanism to Dcm mutagenesis in vivo by lowering the levels of SAM.Escherichia coli SAM levels were lowered by reducing SAM synthetase activity via the introduction of a metK84 allele or by hydrolyzing SAM using the bacteriophage T3 SAM hydrolase. ThemetK84 strains exhibited increased C-to-T mutagenesis. Expression of the T3 SAM hydrolase gene, under the control of the arabinose-inducible PBAD promoter, effectively reduced Dcm-mediated genomic DNA methylation. However, increased mutagenesis was not observed until extremely high arabinose concentrations were used, and genome methylation at Dcm sites was negligible.

Recombinant anti-EspA antibodies block Escherichia coli O157:H7-induced attaching and effacing lesions in vitro

2006 ◽  
Vol 8 (2) ◽  
pp. 426-433 ◽  
Author(s):  
Roberto M. La Ragione ◽  
Shila Patel ◽  
Ben Maddison ◽  
Martin J. Woodward ◽  
Angus Best ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157
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