scholarly journals Inhibition of Glucosyltransferase Activity and Glucan Production as an Antibiofilm Mechanism of Lemongrass Essential Oil against Escherichia coli O157:H7

Antibiotics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 102 ◽  
Author(s):  
Luis A. Ortega-Ramirez ◽  
M. Melissa Gutiérrez-Pacheco ◽  
Irasema Vargas-Arispuro ◽  
Gustavo A. González-Aguilar ◽  
Miguel A. Martínez-Téllez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Essential Oil ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Inhibitory Effect ◽  
Escherichia Coli O157 ◽  
Cymbopogon Citratus ◽  
Docking Analysis ◽  
E Coli ◽  
Lemongrass Essential Oil

The resistance of Escherichia coli O157:H7 to disinfection is associated with its ability to form biofilms, mainly constituted by glucans produced by glucosyltransferases. Citral and geraniol, terpenes found in the essential oil of Cymbopogon citratus (EO), have proven antibacterial activity against planktonic E. coli; however, no information was found about their efficacy and mode of action against E. coli biofilms. Therefore, the inhibitory effect of C. citratus EO, citral, and geraniol on glucans production and glucosyltransferase activity as anti-biofilm mechanism against E. coli was evaluated. EO, citral, and geraniol inhibited the planktonic growth of E. coli (minimal inhibitory concentration or MIC= 2.2, 1.0, and 3.0 mg/mL, respectively) and the bacterial adhesion (2.0, 2.0, and 4.0 mg/mL, respectively) on stainless steel. All compounds decreased the glucans production; citral and geraniol acted as uncompetitive inhibitors of glucosyltransferase activity (The half maximal inhibitory concentrations or IC50 were 8.5 and 6.5 µM, respectively). The evidence collected by docking analysis indicated that both terpenes could interact with the helix finger of the glucosyltransferase responsible for the polymer production. In conclusion, C. citratus EO, citral, and geraniol inhibited glucosyltransferase activity, glucans production, and the consequent biofilm formation of E. coli O157:H7.

Growth Inhibition of Escherichia coli O157:H7 and Listeria monocytogenes by Carvacrol and Eugenol Encapsulated in Surfactant Micelles

2005 ◽  
Vol 68 (12) ◽  
pp. 2559-2566 ◽  
Author(s):  
SYLVIA GAYSINSKY ◽  
P. MICHAEL DAVIDSON ◽  
BARRY D. BRUCE ◽  
JOCHEN WEISS
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Essential Oil ◽  
Growth Inhibition ◽  
Surfactant Concentration ◽  
Escherichia Coli O157 ◽  
Surfactant Micelles ◽  
E Coli ◽  
Oil Components

Growth inhibition of four strains of Escherichia coli O157:H7 (H1730, F4546, 932, and E0019) and Listeria monocytogenes (Scott A, 101, 108, and 310) by essential oil components (carvacrol and eugenol) solubilized in nonionic surfactant micelles (Surfynol 465 and 485W) was investigated. Concentrations of encapsulated essential oil components ranged from 0.02 to 1.25% depending on compound, surfactant type, and surfactant concentration (0.5 to 5%). Eugenol encapsulated in Surfynol 485W micelles was most efficient in inhibiting growth of the pathogens; 1% Surfynol 485W and 0.15% eugenol was sufficient to inhibit growth of all strains of E. coli O157:H7 and three of four strains of L. monocytogenes (Scott A, 310, and 108). The fourth strain, L. monocytogenes 101, was inhibited by 2.5% Surfynol and 0.225% eugenol. One percent Surfynol 485W in combination with 0.025% carvacrol was effective in inhibiting three of four strains of E. coli O157:H7. Strain H1730 was the most resistant strain, requiring 0.3% carvacrol and 5% surfactant for complete inhibition. Growth inhibition of L. monocytogenes by combinations of carvacrol and Surfynol 465 ranged between 0.15 and 0.35% and 1 and 3.75%, respectively. Generally, the antimicrobial activity of Surfynol 465 in combination with eugenol was higher than that for the combination with carvacrol. The potent activity was attributed to increased solubility of essential oil components in the aqueous phase due to the presence of surfactants and improved interactions of antimicrobials with microorganisms.

Rosemary and Tea Tree Essential Oils Exert Antibiofilm Activities In Vitro against Staphylococcus aureus and Escherichia coli

2020 ◽  
Vol 83 (7) ◽  
pp. 1261-1267
Author(s):  
TING LIU ◽  
JINGFAN WANG ◽  
XIAOMAN GONG ◽  
XIAOXIA WU ◽  
LIU LIU ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Essential Oil ◽  
Biofilm Formation ◽  
Gas Chromatography Mass Spectrometry ◽  
Tea Tree ◽  
E Coli ◽  
Microdilution Method ◽  
Broth Microdilution Method

ABSTRACT The purpose of the present study was to determine the bioactive compounds in rosemary essential oil (REO) and tea tree essential oil (TEO) and to investigate their antibacterial and antibiofilm activities against Staphylococcus aureus and Escherichia coli in vitro. The MIC and MBC assays were performed to assess the antibacterial activity of these two EOs against S. aureus and E. coli with the broth microdilution method. A crystal violet assay was used to ascertain the effects of EOs on the biofilm formation of the test strains, and a tetrazolium bromide (MTT) assay was used to measure the level of inactivation of mature biofilms by EOs. Gas chromatography–mass spectrometry revealed 15 compounds in REO and 27 compounds in TEO, representing 97.78 and 98.13% of the total EO, respectively. Eucalyptol and α-pinene were found in high concentrations in REO, and the two major compounds in TEO were 4-terpineol and terpinolene. The MICs of REO for the two S. aureus and E. coli test strains were both 0.5 mg/mL, and the MICs of TEO for the two strains were both 0.25 mg/mL. Therefore, these EOs can significantly inhibit the formation of biofilms and induced morphological biofilm changes, as verified by scanning electron microscopy. Both EOs had destructive effects on the mature biofilm of the two test strains. TEO was more inhibitory than REO for biofilm formation by the two test strains. HIGHLIGHTS

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.

Inhibition of Growth of Escherichia coli O157:H7 in Fresh Radish (Raphanus sativus L.) Sprout Production by Calcinated Calcium

1999 ◽  
Vol 62 (2) ◽  
pp. 128-132 ◽  
Author(s):  
M. L. BARI ◽  
H. KUSUNOKI ◽  
H. FURUKAWA ◽  
H. IKEDA ◽  
K. ISSHIKI ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Raphanus Sativus ◽  
Inhibitory Effect ◽  
Seed Extract ◽  
Escherichia Coli O157 ◽  
Experimental Conditions ◽  
E Coli ◽  
Inhibition Of Growth ◽  
Raphanus Sativus L ◽  
Radish Sprouts

The inhibitory effect of calcinated calcium on the growth of Escherichia coli O157:H7 during fresh radish (Raphanus sativus L.) sprout production was studied. It was revealed that the addition of 0.4% (wt/vol) calcinated calcium into radish sprouting medium which was artificially contaminated with E. coli O157:H7 (3.0 to 3.2 log CFU/ml) completely inhibited the growth or inactivated the microorganism. When radish seed extract was used instead of radish sprout production, the same extent of growth inhibition or inactivation was observed with much lower amounts (0.07%) of calcinated calcium under similar experimental conditions. The findings suggested that calcinated calcium may be useful to control E. coli O157:H7 contamination during the production of radish sprouts.

Enhanced Inhibition of Escherichia coli O157:H7 by Lysozyme and Chelators

2003 ◽  
Vol 66 (10) ◽  
pp. 1783-1789 ◽  
Author(s):  
J. S. BOLAND ◽  
P. M. DAVIDSON ◽  
J. WEISS
Keyword(s):  
Escherichia Coli ◽  
Inhibitory Activity ◽  
Chelating Agents ◽  
Inhibitory Effect ◽  
Escherichia Coli O157 ◽  
Inhibitory Effects ◽  
Antimicrobial Spectrum ◽  
E Coli ◽  
Dilution Assay ◽  
Microbroth Dilution

This study examined the effects of three chelating agents (EDTA, disodium pyrophosphate [DSPP], and pentasodium tripolyphosphate [PSTPP]) on the inhibition of the growth of Escherichia coli O157:H7 by lysozyme. The objective of this study was to identify replacement chelators that exhibit synergistic properties similar to those of EDTA. The inhibitory effects of EDTA at 300 to 1,500 μg/ml and of DSPP and PSTPP at 3,000 to 15,000 μg/ml in combination with lysozyme at 200 to 600 μg/ml for up to 48 h at pHs of 6.0, 7.0, and 8.0 on four strains of E. coli O157:H7 was studied with the use of a microbroth dilution assay. The addition of EDTA enhanced lysozyme's inhibitory effect on strains of E. coli O157:H7. EDTA at ≥300 μg/ml combined with lysozyme at 200 to 600 μg/ml was sufficient to inhibit the growth of the strains at pHs of 6.0 and 8.0. At pH 7.0, lysozyme at 200 to 600 μg/ml and EDTA concentrations of ≥1,000 μg/ml were effective in inhibiting three of the four strains. DSPP at pH 6.0 was inhibitory at ≥10,000 μg/ml when combined with lysozyme at 200 to 300 μg/ml. In contrast, PSTPP increased the inhibitory activity of lysozyme more effectively at pH 8.0. Lysozyme at 200 to 600 μg/ml was effective against two strains of E. coli O157:H7 when used in conjunction with PSTPP at ≥5,000 μg/ml. The remaining strains were inhibited by PSTPP at ≥10,000 μg/ml. Our results indicate that inhibition occurred with each lysozyme-chelator combination, but the concentrations of phosphates required to increase the antimicrobial spectrum of lysozyme against E. coli O157:H7 were higher than the EDTA concentrations required to achieve the same effect.

scholarly journals Biofilm Formation by Escherichia coli O157:H7 on Stainless Steel: Effect of Exopolysaccharide and Curli Production on Its Resistance to Chlorine

2005 ◽  
Vol 71 (1) ◽  
pp. 247-254 ◽  
Author(s):  
Jee-Hoon Ryu ◽  
Larry R. Beuchat
Keyword(s):  
Escherichia Coli ◽  
Stainless Steel ◽  
Biofilm Formation ◽  
Escherichia Coli O157 ◽  
Strain Atcc ◽  
Planktonic Cells ◽  
E Coli ◽  
Biofilm Production ◽  
Resistant Population ◽  
Population Sizes

ABSTRACT The resistance of Escherichia coli O157:H7 strains ATCC 43895-, 43895-EPS (an exopolysaccharide [EPS]-overproducing mutant), and ATCC 43895+ (a curli-producing mutant) to chlorine, a sanitizer commonly used in the food industry, was studied. Planktonic cells of strains 43895-EPS and/or ATCC 43895+ grown under conditions supporting EPS and curli production, respectively, showed the highest resistance to chlorine, indicating that EPS and curli afford protection. Planktonic cells (ca. 9 log10 CFU/ml) of all strains, however, were killed within 10 min by treatment with 50 μg of chlorine/ml. Significantly lower numbers of strain 43895-EPS, compared to those of strain ATCC 43895-, attached to stainless steel coupons, but the growth rate of strain 43895-EPS on coupons was not significantly different from that of strain ATCC 43895-, indicating that EPS production did not affect cell growth during biofilm formation. Curli production did not affect the initial attachment of cells to coupons but did enhance biofilm production. The resistance of E. coli O157:H7 to chlorine increased significantly as cells formed biofilm on coupons; strain ATCC 43895+ was the most resistant. Population sizes of strains ATCC 43895+ and ATCC 43895- in biofilm formed at 12�C were not significantly different, but cells of strain ATCC 43895+ showed significantly higher resistance than did cells of strain ATCC 43895-. These observations support the hypothesis that the production of EPS and curli increase the resistance of E. coli O157:H7 to chlorine.

scholarly journals Anti-biofilm Potential of Elletaria cardamomum Essential Oil Against Escherichia coli O157:H7 and Salmonella Typhimurium JSG 1748

2021 ◽  
Vol 12 ◽  
Author(s):  
Abdullah ◽  
Ali Asghar ◽  
Ammar Algburi ◽  
Qingrong Huang ◽  
Talha Ahmad ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Essential Oil ◽  
Foodborne Pathogens ◽  
Biofilm Formation ◽  
Mutagenic Activity ◽  
Escherichia Coli O157 ◽  
Safe Alternative ◽  
Mutagenicity Assay ◽  
Green Cardamom ◽  
Alternative Antimicrobials

Foodborne pathogens, microbial recurrent infections, and antibiotic resistance have driven researchers to explore natural compounds as safe alternative antimicrobials. In this study, the chemical profile, antimicrobial, and mutagenic activities of the Elletaria cardamomum essential oil were investigated. GC-MS analysis identified the major bioactive components as α-terpinyl acetate, 1,8-cineole, linalool acetate, and sabinene, at concentrations of 34.95, 25.30, 8.13, and 5.48% respectively, of the essential oil’s content. Regarding antimicrobial activity, the minimum inhibitory concentration of green cardamom essential oil was 1% against Escherichia coli O157:H7 and Pseudomonas aeruginosa ATCC 14213. Green cardamom essential oil, when used at concentrations of 0.015, 0.031, 0.062, and 0.125% (v/v) prevented biofilm formation of Escherichia coli O157:H7 by 64.29, 65.98, 70.41, and 85.59%, respectively. Furthermore, these concentrations inhibited 6.13, 45.50, 49.45, and 100%, respectively, of the Salmonella Typhimurium JSG 1748 biofilm. A mutagenicity assay confirmed that green cardamom essential oil has no demonstrable mutagenic activity against the tested strains. The study’s findings suggest that green cardamom derived bioactive compounds are safe organic antimicrobials, effective in controlling biofilm formation by Gram-negative pathogens. Moreover, such compounds could possibly be used in the food industry (e.g., bakery, dairy, meat, and other food products) as a safe alternative to chemical preservatives (antimicrobials) to enhance shelf life by improving the antimicrobial status while at the same time imparting a pleasant and appealing aroma for consumers.

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.

Role of Nutrient Limitation in the Competition between Pseudomonas fluorescens and Escherichia coli O157:H7

2007 ◽  
Vol 70 (7) ◽  
pp. 1739-1743 ◽  
Author(s):  
R. C. MCKELLAR
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Fluorescens ◽  
Nutrient Limitation ◽  
Foodborne Pathogens ◽  
Raw Milk ◽  
Inhibitory Effect ◽  
Nutrient Broth ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Spoilage Microflora

Competition between spoilage microorganisms and foodborne pathogens provides a potentially simple approach to limiting the growth of pathogens. A strain of Pseudomonas fluorescens isolated from raw milk repressed growth of Escherichia coli O157:H7 at 22°C in nutrient broth once the maximum population density of the pseudomonad had been reached (9.6 log CFU ml−1). The presence of iron in the growth medium and the parallel inhibitory effect of a siderophore-deficient mutant of P. fluorescens precluded iron limitation as the mechanism of action. Medium depleted by prior growth of P. fluorescens prevented the growth of E. coli, and this effect was reversed by the replenishment of the nutrient broth, its component fractions, or the addition of soy peptones but not peptones derived from milk protein. This is the first report of competition between spoilage microflora and foodborne pathogens in which the mechanism was clearly shown to be nutrient limitation. These results suggest possible improvements in biocontrol systems to prevent pathogen growth on foods.

Attachment and Biofilm Formation by Escherichia coli O157:H7 on Stainless Steel as Influenced by Exopolysaccharide Production, Nutrient Availability, and Temperature

2004 ◽  
Vol 67 (10) ◽  
pp. 2123-2131 ◽  
Author(s):  
JEE-HOON RYU ◽  
HOIKYUNG KIM ◽  
LARRY R. BEUCHAT
Keyword(s):  
Escherichia Coli ◽  
Stainless Steel ◽  
Nutrient Availability ◽  
Biofilm Formation ◽  
Escherichia Coli O157 ◽  
Strain Atcc ◽  
Wild Type ◽  
E Coli ◽  
Nutrient Environment ◽  
Phosphate Buffered Saline

The influence of exopolysaccharide (EPS) production, nutrient availability, and temperature on attachment and biofilm formation by Escherichia coli O157:H7 strains ATCC 43895 (wild type) and 43895-EPS (extensive EPS-producing mutant) on stainless steel coupons (SSCs) was investigated. Cells grown on heated lettuce juice agar and modified tryptic soy agar were suspended in phosphate-buffered saline (PBS). SSCs were immersed in the cell suspension (109 CFU/ml) at 4°C for 24 h. Biofilm formation by cells attached to SSCs as affected by immersing in 10% tryptic soy broth (TSB), lettuce juice broth (LJB), and minimal salts broth (MSB) at 12 and 22°C was studied. A significantly lower number of strain 43895-EPS cells, compared to strain ATCC 43895 cells, attached to SSCs during a 24-h incubation (4°C) period in PBS suspension. Neither strain formed a biofilm on SSCs subsequently immersed in 10% TSB or LJB, but both strains formed biofilms in MSB. Populations of attached cells and planktonic cells of strain ATCC 43895 gradually decreased during incubation for 6 days in LJB at 22°C, but populations of strain 43895-EPS remained constant for 6 days at 22°C, indicating that the EPS-producing mutant, compared to the wild-type strain, has a higher tolerance to the low-nutrient environment presented by LJB. It is concluded that EPS production by E. coli O157:H7 inhibits attachment to SSCs and that reduced nutrient availability enhances biofilm formation. Biofilms formed under conditions favorable for EPS production may protect E. coli O157:H7 against sanitizers used to decontaminate lettuce and produce processing environments. Studies are under way to test this hypothesis.

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