Development of Nano-ZnO Coated Food Packaging Film and its Inhibitory Effect on Escherichia coli In Vitro and in Actual Tests

2010 ◽  
Vol 152-153 ◽  
pp. 489-492 ◽  
Author(s):  
Wei Li Li ◽  
Xi Hong Li ◽  
Pei Pei Zhang ◽  
Ya Ge Xing
Keyword(s):  
Escherichia Coli ◽  
Food Packaging ◽  
Inhibitory Effect ◽  
Test Results ◽  
Nano Zno ◽  
E Coli ◽  
Ph Values ◽  
Coated Film ◽  
Actual Test

In this study, we investigated antibacterial activity of zinc oxide (ZnO) nanoparticles coated on polyvinyl chloride (PVC) films against Escherichia. coli both in vitro and in actual test. Results showed that the nano-ZnO coated films displayed excellent inhibition effects on the growth of E. coli and the nano-ZnO particular was contributed to the bactericidal ability. The more amounts of the ZnO particulars the film coated, the greater inhibitory effect it exhibited. The disinfection efficiency with ZnO film is relatively constant at pH values in the range of 4.5 to 8.0. In the actual test, the number of E. coli cells from cut apple stored in a ZnO-coated bag in the dark decreased from 8.72 to 6.3 log CFU/ml after 1 day, while that of an same bag irradiated with light decreased from 8.72 to 3.5 log CFU/ml after 2 days of storage. The results reveal that nano-ZnO coated film has a good promise to make antimicrobial packaging again E. coli and reduce the risks of microbial growth on fresh-cut produce.

Lactobacillus inhibitor production against Escherichia coli and coaggregation ability with uropathogens

1988 ◽  
Vol 34 (3) ◽  
pp. 344-351 ◽  
Author(s):  
Gregor Reid ◽  
Jacqueline A. McGroarty ◽  
Rosanne Angotti ◽  
Roger L. Cook
Keyword(s):  
Escherichia Coli ◽  
Defense Mechanism ◽  
Inhibitory Effect ◽  
Second Phase ◽  
Vitro Assay ◽  
E Coli ◽  
Host Defense Mechanism ◽  
Important Host ◽  
Two Phases

Previous investigations have shown that certain strains of lactobacilli can competitively exclude uropathogens from attaching to uroepithelial cells and from causing urinary tract infection in animals. The finding of an inhibitory effect produced by Lactobacillus casei ssp. rhamnosus GR-1 against the growth of uropathogens was investigated further using two Escherichia coli indicator strains Hu 734 and ATCC 25922. There were two phases to the inhibitor studies. The first one using an agar sandwich technique showed that the inhibitor activity was heat stable and inhibitory to the E. coli. The second phase showed that MRS broth provided optimum lactobacilli growth and inhibitor production. In addition, the inhibition was present under conditions buffering for acid and pH. The data indicated that the inhibitory effect was not due to bacteriophages or hydrogen peroxide. Strain GR-1 was found to coaggregate with E. coli ATCC 25922 in urine, a phenomenon that has not previously been reported for urogenital bacteria. An in vitro assay system was developed to study the coaggregation of various lactobacilli and uropathogens. The results demonstrated that highest coaggregation scores occurred after 4 h incubation at 37 °C with lactobacilli and two type-1 fimbriated E. coli strains. Of the nine lactobacilli strains tested, each was found to coaggregate with 2 or more of the 13 uropathogens. The dominance of inhibitor-producing lactobacilli on the urogenital epithelium and the ability of these organisms to interact closely with uropathogens would constitute an important host defense mechanism against infection.

scholarly journals Role of F1C Fimbriae, Flagella, and Secreted Bacterial Components in the Inhibitory Effect of Probiotic Escherichia coli Nissle 1917 on Atypical Enteropathogenic E. coli Infection

2014 ◽  
Vol 82 (5) ◽  
pp. 1801-1812 ◽  
Author(s):  
Sylvia Kleta ◽  
Marcel Nordhoff ◽  
Karsten Tedin ◽  
Lothar H. Wieler ◽  
Rafal Kolenda ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Mechanisms ◽  
Inhibitory Effect ◽  
Host Cells ◽  
Single Infection ◽  
Content Type ◽  
E Coli ◽  
Initial Adhesion

ABSTRACTEnteropathogenicEscherichia coli(EPEC) is recognized as an important intestinal pathogen that frequently causes acute and persistent diarrhea in humans and animals. The use of probiotic bacteria to prevent diarrhea is gaining increasing interest. The probioticE. colistrain Nissle 1917 (EcN) is known to be effective in the treatment of several gastrointestinal disorders. While bothin vitroandin vivostudies have described strong inhibitory effects of EcN on enteropathogenic bacteria, including pathogenicE. coli, the underlying molecular mechanisms remain largely unknown. In this study, we examined the inhibitory effect of EcN on infections of porcine intestinal epithelial cells with atypical enteropathogenicE. coli(aEPEC) with respect to single infection steps, including adhesion, microcolony formation, and the attaching and effacing phenotype. We show that EcN drastically reduced the infection efficiencies of aEPEC by inhibiting bacterial adhesion and growth of microcolonies, but not the attaching and effacing of adherent bacteria. The inhibitory effect correlated with EcN adhesion capacities and was predominantly mediated by F1C fimbriae, but also by H1 flagella, which served as bridges between EcN cells. Furthermore, EcN seemed to interfere with the initial adhesion of aEPEC to host cells by secretion of inhibitory components. These components do not appear to be specific to EcN, but we propose that the strong adhesion capacities enable EcN to secrete sufficient local concentrations of the inhibitory factors. The results of this study are consistent with a mode of action whereby EcN inhibits secretion of virulence-associated proteins of EPEC, but not their expression.

In Vitro Inactivation of Escherichia coli O157:H7 in Bovine Rumen Fluid by Caprylic Acid

2004 ◽  
Vol 67 (5) ◽  
pp. 884-888 ◽  
Author(s):  
THIRUNAVUKKARASU ANNAMALAI ◽  
MANOJ KUMAR MOHAN NAIR ◽  
PATRICK MAREK ◽  
PRADEEP VASUDEVAN ◽  
DAVID SCHREIBER ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Caprylic Acid ◽  
Rumen Fluid ◽  
Bacterial Load ◽  
Anaerobic Bacteria ◽  
Inhibitory Effect ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Bovine Rumen

The antibacterial effect of caprylic acid (35 and 50 mM) on Escherichia coli O157:H7 and total anaerobic bacteria at 39° C in rumen fluid (pH 5.6 and 6.8) from 12 beef cattle was investigated. The treatments containing caprylic acid at both pHs significantly reduced (P < 0.05) the population of E. coli O157:H7 compared with that in the control samples. At pH 5.6, both levels of caprylic acid killed E. coli O157:H7 rapidly, reducing the pathogen population to undetectable levels at 1 min of incubation (a more than 6.0-log CFU/ml reduction). In buffered rumen fluid at pH 6.8, 50 mM caprylic acid reduced the E. coli O157:H7 population to undetectable levels at 1 min of incubation, whereas 35 mM caprylic acid reduced the pathogen by approximately 3.0 and 5.0 log CFU/ml at 8 and 24 h of incubation, respectively. At both pHs, caprylic acid had a significantly lesser (P < 0.05) and minimal inhibitory effect on the population of total anaerobic bacteria in rumen compared with that on E. coli O157:H7. At 24 h of incubation, caprylic acid (35 and 50 mM) reduced the population of total anaerobic bacteria by approximately 2.0 log CFU/ml at pH 5.6, whereas at pH 6.8, caprylic acid (35 mM) did not have any significant (P > 0.05) inhibitory effect on total bacterial load. Results of this study revealed that caprylic acid was effective in inactivating E. coli O157:H7 in bovine rumen fluid, thereby justifying its potential as a preslaughter dietary supplement for reducing pathogen carriage in cattle.

Protective effects of indigenous Escherichia coli against a pathogenic E. coli challenge strain in pigs

2017 ◽  
Vol 8 (5) ◽  
pp. 779-783 ◽  
Author(s):  
W. Vahjen ◽  
T. Cuisiniere ◽  
J. Zentek
Keyword(s):  
Escherichia Coli ◽  
Inhibitory Activity ◽  
Inhibitory Effect ◽  
Coli Strain ◽  
Protective Effects ◽  
Macconkey Agar ◽  
Challenge Strain ◽  
E Coli ◽  
Pathogenic Factors

To investigate the inhibitory effect of indigenous enterobacteria on pathogenic Escherichia coli, a challenge trial with postweaning pigs was conducted. A pathogenic E. coli strain was administered to all animals and their health was closely monitored thereafter. Faecal samples were taken from three healthy and three diarrhoeic animals. Samples were cultivated on MacConkey agar and isolates were subcultured. A soft agar overlay assay was used to determine the inhibitory activity of the isolates. A total of 1,173 enterobacterial isolates were screened for their ability to inhibit the E. coli challenge strain. Colony forming units of enterobacteria on MacConkey agar were not different between healthy and diarrhoeic animals in the original samples. Furthermore, numbers of isolates per animal were also not significantly different between healthy (482 isolates) and diarrhoeic animals (691 isolates). A total of 43 isolates (3.7%) with inhibitory activity against the pathogenic E. coli challenge strain were detected. All inhibitory isolates were identified as E. coli via MALDI-TOF. The isolates belonged to the phylotypes A, C and E. Many isolates (67.4%) were commensal E. coli without relevant porcine pathogenic factors, but toxin- and fimbrial genes (stx2e, fae, estIb, elt1a, fas, fan) were detected in 14 inhibitory isolates. Healthy animals showed significantly (P=0.003) more inhibitory isolates (36 of 482 isolates; 7.5%) than diseased animals (7 of 691 isolates; 1.0%). There were no significant correlations regarding phylotype or pathogenic factors between healthy and diseased animals. This study has shown that a small proportion of indigenous E. coli is able to inhibit in vitro growth of a pathogenic E. coli strain in pigs. Furthermore, healthy animals possess significantly more inhibitory E. coli strains than diarrhoeic animals. The inhibition of pathogenic E. coli by specific indigenous E. coli strains may be an underlying principle for the containment of pathogenic E. coli in pigs.

Inhibitory effect of Zanthoxylum bungeanum essential oil (ZBEO) on Escherichia coli and intestinal dysfunction

2017 ◽  
Vol 8 (4) ◽  
pp. 1569-1576 ◽  
Author(s):  
Lei Hong ◽  
Wu Jing ◽  
Wang Qing ◽  
Su Anxiang ◽  
Xue Mei ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Essential Oil ◽  
Inhibitory Effect ◽  
Intestinal Health ◽  
Inhibitory Effects ◽  
E Coli ◽  
Zanthoxylum Bungeanum

The inhibitory effects of Zanthoxylum bungeanum essential oil (ZBEO) on Escherichia coli (E. coli) in vitro and in vivo were investigated, as well as its function of improvement of intestinal health.

scholarly journals Biotic and Abiotic Factors Influencing In Vitro Growth of Escherichia coli O157:H7 in Ruminant Digestive Contents

2006 ◽  
Vol 72 (6) ◽  
pp. 4136-4142 ◽  
Author(s):  
Fr�d�rique Chaucheyras-Durand ◽  
Jordan Madic ◽  
Florent Doudin ◽  
Christine Martin
Keyword(s):  
Escherichia Coli ◽  
Pathogenic Bacteria ◽  
Rumen Fluid ◽  
Abiotic Factors ◽  
Probiotic Strain ◽  
Inhibitory Effect ◽  
Main Site ◽  
E Coli ◽  
Biotic And Abiotic Factors

ABSTRACT The gastrointestinal tract (GIT) of ruminants is the main reservoir of enterohemorrhagic Escherichia coli, which is responsible for food-borne infections in humans that can lead to severe kidney disease. Characterization of biotic and abiotic factors that influence the carriage of these pathogens by the ruminant would help in the development of ecological strategies to reduce their survival in the GIT and to decrease the risk of contamination of animal products. We found that growth of E. coli O157:H7 in rumen fluid was inhibited by the autochthonous microflora. Growth was also reduced when rumen fluid came from sheep fed a mixed diet composed of 50% wheat and 50% hay, as opposed to a 100% hay diet. In fecal suspensions, E. coli O157:H7 growth was not suppressed by the autochthonous flora. However, a probiotic strain of Lactobacillus acidophilus inhibited E. coli O157:H7 growth in fecal suspensions. The inhibitory effect was dose dependent. These lactic acid bacteria could be a relevant tool for controlling O157:H7 development in the terminal part of the ruminant GIT, which has been shown to be the main site of colonization by these pathogenic bacteria.

scholarly journals Inhibitory Effect of Heterologous Ribosome Recycling Factor on Growth of Escherichia coli

2000 ◽  
Vol 182 (21) ◽  
pp. 6154-6160 ◽  
Author(s):  
Kenji Atarashi ◽  
Akira Kaji
Keyword(s):  
Escherichia Coli ◽  
Helicobacter Pylori ◽  
Thermotoga Maritima ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Ribosome Recycling Factor ◽  
E Coli ◽  
Genes Encoding ◽  
Dose Dependent

ABSTRACT Ribosome recycling factor (RRF) of Thermotoga maritimawas expressed in Escherichia coli from the cloned T. maritima RRF gene and purified. Expression of T. maritima RRF inhibited growth of the E. coli host in a dose-dependent manner, an effect counteracted by the overexpression of E. coli RRF. T. maritima RRF also inhibited the E. coli RRF reaction in vitro. Genes encoding RRFs fromStreptococcus pneumoniae and Helicobacter pylori have been cloned, and they also impair growth of E. coli, although the inhibitory effect of these RRFs was less pronounced than that of T. maritima RRF. The amino acid sequence at positions 57 to 62, 74 to 78, 118 to 122, 154 to 160, and 172 to 176 in T. maritima RRF differed totally from that ofE. coli RRF. This suggests that these regions are important for the inhibitory effect of heterologous RRF. We further suggest that bending and stretching of the RRF molecule at the hinge between two domains may be critical for RRF activity and therefore responsible forT. maritima RRF inhibition of the E. coli RRF reaction.

scholarly journals Impact of Different Parameters upon the Production of Virulence Factors in Escherichia coli Strains Isolated from Marine Water

2020 ◽  
Vol 10 (6) ◽  
pp. 7049-7060
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Inhibitory Effect ◽  
Environmental Stressors ◽  
The Black Sea ◽  
Anaerobic Incubation ◽  
E Coli ◽  
Ph Values ◽  
Black Sea Coast ◽  
Aerobic And Anaerobic

This study aimed to look into the expression of 10 virulence factors (VF) in 100 Escherichia coli strains harvested from the Black Sea Coast. E. coli strains were grown under different conditions, simulating various environmental stressors. The VF production [esculinase, amylase, pore-forming enzymes (hemolysin - spot and CAMP-like hemolysis; lipase; lecithinase)], lysine-decarboxylase, proteases (caseinase, gelatinase) and DNase was investigated at variable temperatures (4°C, 22°C, 37°C, 44°C and 56°C), NaCl (from 0 to 10%) and glucose concentrations (1.5% and 3%), different pH values (5.0, 7.2 and 9.6) and also in aerobic or anaerobic incubation conditions. The investigation of E. coli strains unraveled their ability to grow at 22°C, 37°C, 44°C, regardless of the salinity, pH, and glucose concentration, both in aerobic and anaerobic incubation conditions. The VF were better expressed at 37°C, followed by 22°C, especially siderophores, amylase, and caseinase production. The expression of different VF was variable at a certain salinity, i.e., at 0% NaCl, only amylase and siderophores production was observed. At 2% and 3%, the amylase was better expressed. The best expression of siderophores and caseinase was at 6% NaCl. At higher salinity, the expression of VF started to decrease. The amylase and caseinase were better expressed at pH 9.6 and siderophores at pH 7.2. Higher glucose concentrations (3%) proved to have an inhibitory effect on amylase expression and caseinase. The aerobic/anaerobic incubation conditions exhibited no significant differences in the VF expression. In conclusion, these outcomes reveal the ability of enterobacterial aquatic strains to survive in the presence of different stressors and maintain the expression of potential VF expression even in extreme environmental conditions.

scholarly journals Effects of Ethyl and Benzyl Analogues of Spermine on Escherichia coli Peptidyltransferase Activity, Polyamine Transport, and Cellular Growth

1999 ◽  
Vol 181 (13) ◽  
pp. 3904-3911 ◽  
Author(s):  
Panagiotis Karahalios ◽  
Ioannis Amarantos ◽  
Petros Mamos ◽  
Dionysios Papaioannou ◽  
Dimitrios L. Kalpaxis
Keyword(s):  
Escherichia Coli ◽  
Bond Formation ◽  
Peptide Bond ◽  
Inhibitory Effect ◽  
Cellular Growth ◽  
Uptake System ◽  
Peptide Bond Formation ◽  
E Coli ◽  
Polyamine Transport

ABSTRACT Various ethyl and benzyl spermine analogues, including the anticancer agentN 1,N 12-bis(ethyl)spermine, were studied for their ability to affect the growth of culturedEscherichia coli cells, to inhibit [3H]putrescine and [3H]spermine uptake into cells, and to modulate the peptidyltransferase activity (EC 2. 3. 2. 12). Relative to other cell lines, growth of E. coli was uniquely insensitive to these analogues. Nevertheless, these analogues conferred similar modulation of in vitro protein synthesis and inhibition of [3H]putrescine and [3H]spermine uptake, as is seen in other cell types. Thus, both ethyl and benzyl analogues of spermine not only promote the formation and stabilization of the initiator ribosomal ternary complex, but they also have a sparing effect on the Mg2+requirements. Also, in a complete cell-free protein-synthesizing system, these analogues at low concentrations stimulated peptide bond formation, whereas at higher concentrations, they inhibited the reaction. The ranking order for stimulation of peptide-bond formation by the analogues wasN 4,N 9-dibenzylspermine >N 4,N 9-bis(ethyl)spermine ≅ N 1-ethylspermine >N 1,N 12-bis(ethyl)spermine, whereas the order of analogue potency regarding the inhibitory effect was inverted, with inhibition constant values of 10, 3.1, 1.5, and 0.98 μM, respectively. Although the above analogues failed to interact with the putrescine-specific uptake system, they exhibited high affinity for the polyamine uptake system encoded by thepotABCD operon. Despite this fact, none of the analogues could be internalized by the polyamine transport system, and therefore they could not influence the intracellular polyamine pools and growth of E. coli cells.

scholarly journals In vitro growth of uropathogenic Escherichia coli isolated from a snow leopard treated with homeopathic and isopathic remedies: a pilot study

2021 ◽  
Vol 8 (27) ◽  
pp. 41-44
Author(s):  
Ana Paula Kawakami ◽  
Lika Osugui ◽  
Amarylis Toledo César ◽  
Silvia Waisse Priven ◽  
Vania Maria de Carvalho ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Inhibitory Effect ◽  
Uropathogenic Escherichia Coli ◽  
Snow Leopard ◽  
In Vitro Growth ◽  
E Coli ◽  
Significant Inhibitory Effect

This paper reports the results of incubation of a strain of uropathogenic Escherichia coli (UPEC) isolated from a snow leopard - which had died of septicemia secondary to necro-hemorrhagic cystitis - with homeopathic and isopathic remedies. Methods: UPEC was isolated from heart blood and previously typified for virulence factors; it was incubated with homeopathic remedies Cantharis vesicatoria (urinary tract infection affinity), Mercurius solubilis (from symptoms analysis) and nosode prepared from the actual strain, all in dilution 12cH. Results: 2 patterns of bacterial growth were observed, associated to the quality of nutrients in the culture medium; in rich-nutrient medium, nosode of E. coli 12cH had a significant inhibitory effect; in poor-nutrient medium, Merc 12cH exerted significant inhibitory effect. Conclusion: results suggest that the previous conditions of prokaryote systems may influence the in vitro response to homeopathic and isopathic remedies. Keywords: urinary tract infection; Felines; Uropathogenic Escherichia coli; Homeopathy; Isopathy.  Estudo do crescimento (in vitro) de Escherichia coli uropatogénica isolada a partir de um leopardo das neves e tratada com medicamentos homeopáticos e isopáticos: estudo piloto. ResumoEste artigo relata os resultados da incubação de uma linhagem de Escherichia coli uropatogénica (UPEC) isolada a partir de um leopardo das neves, que morreu de septicemia secundária a cistite necrótica-hemorrágica. A UPEC foi tratada com preparados homeopáticos e isopáticos. Métodos: UPEC foi isolada de sangue cardíaco e previamente tipificada para fatores de viruléncia; foi incubada com o medicamento homeopático Cantharis vesicatoria (afinidade com infecção do trato urinário), Mercurius solubilis (a partir da análise de sintomas) e nosódio preparado a partir da mesma linhagem de bactérias, todas em 12 cH. Resultados: 2 padrões de crescimento bacteriano foram observados, associados à qualidade dos nutrientes do meio de cultura; em meios ricos em nutrientes, nosódio de E. coli 12 cH teve um significativo efeito inibitório; em meio pobre de nutrientes, Merc 12 cH exerceu efeito inibitório significativo. Conclusão: os resultados sugerem que as condições prévias do sistema procarioto estudado podem influenciar as respostas proliferativas in vitro para preparados homeopáticos e isopáticos. Palavras-chave: infecção do trato urinário, felinos, Escherichia coli uropatogénica; homeopatia, isopatia.  Crecimiento in vitro de Escherichia coli uropatogenica, aisladas de un leopardo de la nieve, tratadas con remedios homeopáticos y isopáticos: un estudio preliminar ResumenEste trabajo presenta los resultados de la incubación de una cepa de Escherichia coli uropatogenica (UPEC) aislada de un leopardo de la nieve, que había muerto de septicemia secundaria a la necro-hemorrágica cistitis, con remedios homeopáticos y isopáticos. Métodos: Se aisló UPEC de la sangre del corazón y caracterizado por factores de virulencia, y se incubó con los remedios homeopáticos Cantharis vesicatoria (afinidad con la infección del tracto urinario), Mercurius solubilis (a partir de la análisis de los síntomas) y nosódio preparado a partir de la cepa, todos em la dilución 12cH. Resultados: 2 patrones de crecimiento de las bacterias se han observado, asociado a la calidad de los nutrientes en el medio de cultivo. En medio rico en nutrientes, nosódios de E. coli 12cH tuvo un importante efecto inhibitorio; en médios pobres en nutrientes, Merc 12cH haz ejercido importante efecto inhibitorio. Conclusión: los resultados sugieren que las condiciones anteriores de los sistemas procariotos pueden influir en la respuesta in vitro a los remedios homeopáticos y isopáticos. Palabras-clave: Infección del tracto urinario; Felinos; Escherichia coli Uropatogenica ; Homeopatía; Isopatía  Correspondence author: Leoni Villano Bonamin, [email protected] How to cite this article: Kawakami AP; Osugui L; César AT; Priven SW; Carvalho VM; Bonamin LV. In vitro growth of uropathogenic Escherichia coli isolated from a snow leopard treated with homeopathic and isopathic remedies: a pilot study. Int J High Dilution Res [online]. 2009 [cited YYYY Month dd]; 8 (27): 41-44. Available from: http://journal.giri-society.org/index.php/ijhdr/article/view/341/394.  

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